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Note: This page contains sample records for the topic "variable compression ratio" 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.


1

Envera Variable Compression Ratio Engine  

DOE Green Energy (OSTI)

Aggressive engine downsizing, variable compression ratio and use of the Atkinson cycle are being combined to improve fuel economy by up to 40 percent relative to port fuel injected gasoline engines, while maintaining full engine power. Approach Engine downsizing is viewed by US and foreign automobile manufacturers as one of the best options for improving fuel economy. While this strategy has already demonstrated a degree of success, downsizing and fuel economy gains are currently limited. With new variable compression ratio technology however, the degree of engine downsizing and fuel economy improvement can be greatly increased. A small variable compression ratio (VCR) engine has the potential to return significantly higher vehicle fuel economy while also providing high power. Affordability and potential for near term commercialization are key attributes of the Envera VCR engine. VCR Technology To meet torque and power requirements, a smaller engine needs to do more work per stroke. This is typically accomplished by boosting the incoming charge with either a turbo or supercharger so that more energy is present in the cylinder per stroke to do the work. With current production engines the degree of engine boosting (which correlates to downsizing) is limited by detonation (combustion knock) at high boost levels. Additionally, the turbo or supercharger needs to be responsive and efficient while providing the needed boost. VCR technology eliminates the limitation of engine knock at high load levels by reducing compression ratio to {approx}9:1 (or whatever level is appropriate) when high boost pressures are needed. By reducing the compression ratio during high load demand periods there is increased volume in the cylinder at top dead center (TDC) which allows more charge (or energy) to be present in the cylinder without increasing the peak pressure. Cylinder pressure is thus kept below the level at which the engine would begin to knock. When loads on the engine are low the compression ratio can be raised (to as much as 18:1) providing high engine efficiency. It is important to recognize that for a well designed VCR engine cylinder pressure does not need to be higher than found in current production turbocharged engines. As such, there is no need for a stronger crankcase, bearings and other load bearing parts within the VCR engine. The Envera VCR mechanism uses an eccentric carrier approach to adjust engine compression ratio. The crankshaft main bearings are mounted in this eccentric carrier or 'crankshaft cradle' and pivoting the eccentric carrier 30 degrees adjusts compression ratio from 9:1 to 18:1. The eccentric carrier is made up of a casting that provides rigid support for the main bearings, and removable upper bearing caps. Oil feed to the main bearings transits through the bearing cap fastener sockets. The eccentric carrier design was chosen for its low cost and rigid support of the main bearings. A control shaft and connecting links are used to pivot the eccentric carrier. The control shaft mechanism features compression ratio lock-up at minimum and maximum compression ratio settings. The control shaft method of pivoting the eccentric carrier was selected due to its lock-up capability. The control shaft can be rotated by a hydraulic actuator or an electric motor. The engine shown in Figures 3 and 4 has a hydraulic actuator that was developed under the current program. In-line 4-cylinder engines are significantly less expensive than V engines because an entire cylinder head can be eliminated. The cost savings from eliminating cylinders and an entire cylinder head will notably offset the added cost of the VCR and supercharging. Replacing V6 and V8 engines with in-line VCR 4-cylinder engines will provide high fuel economy at low cost. Numerous enabling technologies exist which have the potential to increase engine efficiency. The greatest efficiency gains are realized when the right combination of advanced and new technologies are packaged together to provide the greatest gains at the least cost. Aggressive engine downsiz

Charles Mendler

2011-03-15T23:59:59.000Z

2

Available Technologies: Compression Ratio Dehumidification  

The Compression Ratio Dehumidification technology will address a growing concern since energy efficiency standards became broadly adopted nationwide.

3

The Use of Fuel Chemistry and Property Variations to Evaluate the Robustness of Variable Compression Ratio as a Control Method for Gasoline HCCI  

Science Conference Proceedings (OSTI)

On a gasoline engine platform, homogeneous charge compression ignition (HCCI) holds the promise of improved fuel economy and greatly reduced engine-out NOx emissions, without an increase in particulate matter emissions. In this investigation, a variable compression ratio (CR) engine equipped with a throttle and intake air heating was used to test the robustness of these control parameters to accommodate a series of fuels blended from reference gasoline, straight run refinery naptha, and ethanol. Higher compression ratios allowed for operation with higher octane fuels, but operation could not be achieved with the reference gasoline, even at the highest compression ratio. Compression ratio and intake heat could be used separately or together to modulate combustion. A lambda of 2 provided optimum fuel efficiency, even though some throttling was necessary to achieve this condition. Ethanol did not appear to assist combustion, although only two ethanol-containing fuels were evaluated. The increased pumping work from throttling was minimal compared to the efficiency increases that were the result of lower unburned hydrocarbon (HC) and carbon monoxide (CO) emissions. Low temperature heat release was present for all the fuels, but could be suppressed with a higher intake air temperature. Results will be used to design future fuels and combustion studies with this research platform.

Szybist, James P [ORNL; Bunting, Bruce G [ORNL

2007-01-01T23:59:59.000Z

4

Variable ratio regenerative braking device  

DOE Patents (OSTI)

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

Hoppie, Lyle O. (Birmingham, MI)

1981-12-15T23:59:59.000Z

5

Investigation of Knock limited Compression Ratio of Ethanol Gasoline Blends  

DOE Green Energy (OSTI)

Ethanol offers significant potential for increasing the compression ratio of SI engines resulting from its high octane number and high latent heat of vaporization. A study was conducted to determine the knock limited compression ratio of ethanol gasoline blends to identify the potential for improved operating efficiency. To operate an SI engine in a flex fuel vehicle requires operating strategies that allow operation on a broad range of fuels from gasoline to E85. Since gasoline or low ethanol blend operation is inherently limited by knock at high loads, strategies must be identified which allow operation on these fuels with minimal fuel economy or power density tradeoffs. A single cylinder direct injection spark ignited engine with fully variable hydraulic valve actuation (HVA) is operated at WOT conditions to determine the knock limited compression ratio (CR) of ethanol fuel blends. The geometric compression ratio is varied by changing pistons, producing CR from 9.2 to 13.66. The effective CR is varied using an electro-hydraulic valvetrain that changed the effective trapped displacement using both Early Intake Valve Closing (EIVC) and Late Intake Valve Closing (LIVC). The EIVC and LIVC strategies result in effective CR being reduced while maintaining the geometric expansion ratio. It was found that at substantially similar engine conditions, increasing the ethanol content of the fuel results in higher engine efficiency and higher engine power. These can be partially attributed to a charge cooling effect and a higher heating valve of a stoichiometric mixture for ethanol blends (per unit mass of air). Additional thermodynamic effects on and a mole multiplier are also explored. It was also found that high CR can increase the efficiency of ethanol fuel blends, and as a result, the fuel economy penalty associated with the lower energy content of E85 can be reduced by about a third. Such operation necessitates that the engine be operated in a de-rated manner for gasoline, which is knock-prone at these high CR, in order to maintain compatibility. By using EIVC and LIVC strategies, good efficiency is maintained with gasoline, but power is reduced by about 34%.

Szybist, James P [ORNL; Youngquist, Adam D [ORNL; Wagner, Robert M [ORNL; Moore, Wayne [Delphi; Foster, Matthew [Delphi; Confer, Keith [Delphi

2010-01-01T23:59:59.000Z

6

AFIS data compression: an example of how domain specific compression algorithms can produce very high compression ratios  

Science Conference Proceedings (OSTI)

This article describes the development and implementation of a data compression algorithm designed specifically for fingerprints, referred to as GBP compression. The algorithm is herein discussed. Data Compression algorithms can be designed for general ... Keywords: AFIS, automated fingerprint identification systems, compatibility, compression, data compression, data encryption, data integrity, double compression, fingerprinting, graphics, image compression, image quality, limits of compression, portability, retrofitting, serial compression, software engineering

Givon Zirkind

2007-11-01T23:59:59.000Z

7

Effects of operating conditions, compression ratio, and gasoline reformate on SI engine knock limits  

E-Print Network (OSTI)

A set of experiments was performed to investigate the effects of air-fuel ratio, inlet boost pressure, hydrogen rich fuel reformate, and compression ratio on engine knock behavior. For each condition the effect of spark ...

Gerty, Michael D

2005-01-01T23:59:59.000Z

8

Low Bandwidth Video Compression with Variable Dimension Vector Quantization  

E-Print Network (OSTI)

Lambert,R. Fryer,R.J. Cockshott,W.P. Mcgregor,D.R. Proceedings of the First Advanced Digital Video Compression Engineering Conference (Cambridge, UK)

Lambert, R.; Fryer, R.J.; Cockshott, W.P.

9

Influence of Transport Variables on Isospin Transport Ratios  

E-Print Network (OSTI)

The symmetry energy in the nuclear equation of state affects many aspects of nuclear astrophysics, nuclear structure, and nuclear reactions. Recent constraints from heavy ion collisions, including isospin diffusion observables, have started to put constraints on the symmetry energy below nuclear saturation density, but these constraints depend on the employed transport model and input physics other than the symmetry energy. To understand these dependencies, we study the influence of the symmetry energy, isoscaler mean field compressibility and momentum dependence, in-medium nucleon-nucleon cross sections, and light cluster production on isospin diffusion within the pBUU transport code. In addition to the symmetry energy, several uncertain issues strongly affect isospin diffusion, most notably the cross sections and cluster production. In addition, there is a difference in the calculated isospin transport ratios, depending upon whether they are computed using the isospin asymmetry of either the residue or of all forward moving fragments. Measurements that compare the isospin transport ratios of these two quantities would help place constraints on the input physics, such as the density dependence of the symmetry energy.

D. D. S. Coupland; W. G. Lynch; M. B. Tsang; P. Danielewicz; Yingxun Zhang

2011-07-19T23:59:59.000Z

10

Fast Selection of Spectral Variables with B-Spline Compression  

E-Print Network (OSTI)

The large number of spectral variables in most data sets encountered in spectral chemometrics often renders the prediction of a dependent variable uneasy. The number of variables hopefully can be reduced, by using either projection techniques or selection methods; the latter allow for the interpretation of the selected variables. Since the optimal approach of testing all possible subsets of variables with the prediction model is intractable, an incremental selection approach using a nonparametric statistics is a good option, as it avoids the computationally intensive use of the model itself. It has two drawbacks however: the number of groups of variables to test is still huge, and colinearities can make the results unstable. To overcome these limitations, this paper presents a method to select groups of spectral variables. It consists in a forward-backward procedure applied to the coefficients of a B-Spline representation of the spectra. The criterion used in the forward-backward procedure is the mutual infor...

Rossi, Fabrice; Wertz, Vincent; Meurens, Marc; Verleysen, Michel

2007-01-01T23:59:59.000Z

11

Research of Speed Ratio Matching Strategies of Hydro-Mechanical Continuously Variable Transmission System for Tractor  

Science Conference Proceedings (OSTI)

To realize the optimal power and best fuel economy performance of engine, the speed ratio matching strategies of tractor with hydro-mechanical continuously variable transmission (HMCVT) system are studied. The engine output torque model and fuel consumption ... Keywords: Tractor, Hydro-mechanical continuously variable transmission, Speed ratio, Matching strategies

Liyou Xu; Zhili Zhou; Fuyi Cao; Mingzhu Zhang

2009-10-01T23:59:59.000Z

12

High density packings of equal circles in rectangles with variable aspect ratio  

Science Conference Proceedings (OSTI)

Arranging a fixed number n of equal non-overlapping circles in a rectangle with variable aspect ratio is a non-standard packing problem. It arises if one has to decide how a certain number of circular items should be packed into a rectangular box when ... Keywords: Circle packing, Container design, Hexagonal grid, Rectangular container, Variable aspect ratio

E. Specht

2013-01-01T23:59:59.000Z

13

The effect of crack growth stability induced by residual compressive stresses on strength variability  

Science Conference Proceedings (OSTI)

Rising {ital T}- (or {ital R}-) curve behavior is increasingly being used in order to improve the mechanical reliability of ceramic materials. In this study, the possibility of inducing such behavior using residual compressive stresses is analyzed. The {ital T}-curves obtained for certain residual stress profiles induce crack stability when the stress minima (compressive stress maxima) lie away from the surface of the sample. The consequences of this stabilization on the strength characteristics are a significant reduction in the strength variability and strength insensitivity to the initial flaw size. In addition to these desirable features, considerable strengthening is also obtained. Hence, suitably engineered compressive stress profiles are shown to be a novel and alternative means of enhancing mechanical reliability.

Tandon, R.; Green, D.J. (Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States))

1992-03-01T23:59:59.000Z

14

Influence of variables on the consolidation and unconfined compressive strength of crushed salt: Technical report  

SciTech Connect

Eight hydrostatic compression creep tests were performed on crushed salt specimens fabricated from Avery Island dome salt. Following the creep test, each specimen was tested in unconfined compression. The experiments were performed to assess the influence of the following four variables on the consolidation and unconfined strength of crushed salt: grain size distribution, temperature, time, and moisture content. The experiment design comprised a half-fraction factorial matrix at two levels. The levels of each variable investigated were grain size distribution, uniform-graded and well-graded (coefficient of uniformity of 1 and 8); temperature 25/sup 0/C and 100/sup 0/C; time, 3.5 x 10/sup 3/s and 950 x 10/sup 3/s (approximately 60 minutes and 11 days, respectively); and moisture content, dry and wet (85% relative humidity for 24 hours). The hydrostatic creep stress was 10 MPa. The unconfined compression tests were performed at an axial strain rate of 1 x 10/sup -5/s/sup -1/. Results show that the variables time and moisture content have the greatest influence on creep consolidation, while grain size distribution and, to a somewhat lesser degree, temperature have the greatest influence on total consolidation. Time and moisture content and the confounded two-factor interactions between either grain size distribution and time or temperature and moisture content have the greatest influence on unconfined strength. 7 refs., 7 figs., 11 tabs.

Pfeifle, T.W.; Senseny, P.E.; Mellegard, K.D.

1987-01-01T23:59:59.000Z

15

An Interactive Nesting Algorithm for Stretched Grids and Variable Nesting Ratios  

Science Conference Proceedings (OSTI)

An existing two-way interactive grid-nesting technique is generalized to accommodate stretched grids and a spatially variable grid-nesting ratio. The new scheme applies the same reversibility constraint and possesses the same scalar and momentum ...

Robert L. Walko; Craig J. Tremback; Roger A. Pielke; William R. Cotton

1995-04-01T23:59:59.000Z

16

Dynamic Cost-Loss Ratio Decision-making Model with an Autocorrelated Climate Variable  

Science Conference Proceedings (OSTI)

A dynamic decision-making problem is considered involving the use of information about the autocorrelation of a climate variable. Specifically, an infinite horizon, discounted version of the dynamic cost-loss ratio model is treated, in which only ...

Richard W. Katz

1993-01-01T23:59:59.000Z

17

Sensitivity of 5-cm Wavelength Polarimetric Radar Variables to Raindrop Axial Ratio and Drop Size Distribution  

Science Conference Proceedings (OSTI)

The sensitivity of polarimetric variables at a 5-cm wavelength to raindrop size and axial ratio is examined using T-matrix modeling of the scattering process for gamma raindrop size distributions fitted to tropical rainfall collected at Darwin, ...

T. D. Keenan; L. D. Carey; D. S. Zrni?; P. T. May

2001-03-01T23:59:59.000Z

18

The combined effects on fluid flow during compression of piston bowl shape and offset, and swirl ratio  

SciTech Connect

Computational results are presented of air flow during the compression stroke of three engines with differently shaped piston bowls. The three dimensional computer code uses orthogonal curvilinear coordinate systems to body fit the engine shapes. A parametric variation of bowl offset position and swirl ratio is performed to assess their effects on the mean flow and the turbulence parameters. The bowl shape and swirl ratio are found to be most influential. Bowl offset is less important except when combined with swirl in which case significant effects are made on the mean flow and to a lesser extent on the turbulence.

Watkins, A.P.; Dessipris, S.; Khaleghi, H.

1987-01-01T23:59:59.000Z

19

Dual to ratio-cumproduct estimator using known parameters of auxiliary variables  

E-Print Network (OSTI)

This paper deals with the dual to ratio-cum-product estimator for population mean using known parameters of auxiliary variables. In this paper, dual to ratio-cum-product estimator of Singh and Tailor (2005) has been suggested. The Bias and mean squared error expressions have also been obtained up to the first degree of approximation. Suggested estimator has been compared theoretically as well as empirically.

Rajesh Tailor; Ritesh Tailor; Rajesh Parmar; Manish Kumar

2012-01-01T23:59:59.000Z

20

Temporal variability of uranium concentrations and 234 activity ratios in the Mississippi river and its tributaries  

E-Print Network (OSTI)

Department of Geology and Geophysics, Texas A&M University, College Station, TX 77845, United States c-basins exert the greatest control on Lower Mississippi River uranium concentration and isotope signatures; Uranium isotope ratios; Temporal variability; Tributary sources; Global riverine uranium flux 1

Note: This page contains sample records for the topic "variable compression ratio" 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

Thermodynamic modeling of performance of a Miller cycle with engine speed and variable specific heat ratio of working fluid  

Science Conference Proceedings (OSTI)

The performance of an air standard Miller cycle is analyzed using finite-time thermodynamics. The results show that if the compression ratio is less than certain value, the increase of the value of the specific heat ratio will make the power output bigger. ... Keywords: Finite-time processes, Friction, Heat resistance, Internal irreversibility, Miller heat-engine

Rahim Ebrahimi

2011-09-01T23:59:59.000Z

22

Control system and method for a power delivery system having a continuously variable ratio transmission  

DOE Patents (OSTI)

A control system and method for a power delivery system, such as in an automotive vehicle, having an engine coupled to a continuously variable ratio transmission (CVT). Totally independent control of engine and transmission enable the engine to precisely follow a desired operating characteristic, such as the ideal operating line for minimum fuel consumption. CVT ratio is controlled as a function of commanded power or torque and measured load, while engine fuel requirements (e.g., throttle position) are strictly a function of measured engine speed. Fuel requirements are therefore precisely adjusted in accordance with the ideal characteristic for any load placed on the engine. 4 figs.

Frank, A.A.

1984-07-10T23:59:59.000Z

23

Control system and method for a power delivery system having a continuously variable ratio transmission  

DOE Patents (OSTI)

A control system and method for a power delivery system, such as in an automotive vehicle, having an engine coupled to a continuously variable ratio transmission (CVT). Totally independent control of engine and transmission enable the engine to precisely follow a desired operating characteristic, such as the ideal operating line for minimum fuel consumption. CVT ratio is controlled as a function of commanded power or torque and measured load, while engine fuel requirements (e.g., throttle position) are strictly a function of measured engine speed. Fuel requirements are therefore precisely adjusted in accordance with the ideal characteristic for any load placed on the engine.

Frank, Andrew A. (1034 Hillside Ave., Madison, WI 53705)

1984-01-01T23:59:59.000Z

24

Design and development of a continuously variable ratio transmission for automotive vehicles. Final report  

DOE Green Energy (OSTI)

Work accomplished between July 1974 and October 1978 in a program directed toward the design and development of a continuously variable ratio transmission (CVT) for an automotive vehicle is reported. The following major accomplishments were achieved: the laboratory and mathematical projections establishing the viability of the program and the predicted attainment of the primary goal of fuel economy were verified; the proposed Concept Demonstration prototype hydromechanical transmission (HMT) was completed from design to operation; the HMT was thoroughly tested in the laboratory and on the road and its in-vehicle performance was verified by independent testing laboratories; and design of a second generation Pre-Production HMT has proceeded to the point of confirming the practicality of the automotive HMT size and weight; most of the necessary information has been generated which could permit its production cost/competitiveness to be evaluated. (LCL)

None

1978-09-30T23:59:59.000Z

25

Analysis of a variable speed vapor compression system using artificial neural networks  

Science Conference Proceedings (OSTI)

An artificial neural network (ANN) is a mathematical model that is inspired by the operation of biological neural networks. However, this is typically considered a computational model. An ANN can easily adapt to multiple situations and extract information ... Keywords: Artificial neural network, Energetic performance, Hidden neurons, Mapping configuration, Simulated annealing, Vapor compression system

J. M. Belman-Flores; S. E. Ledesma; M. G. Garcia; J. Ruiz; J. L. RodríGuez-MuñOz

2013-09-01T23:59:59.000Z

26

Variability of the proton-to-electron mass ratio on cosmological scales  

E-Print Network (OSTI)

So far the only seemingly significant indication of a cosmological variation exists for the proton-to-electron mass ratio as stated by Reinhold et al. (2006). The measured indication of variation is based on the combined analysis of H2 absorption systems in the spectra of Q0405-443 and Q0347-383 at z=2.595 and z=3.025, respectively. The high resolution data of the latter is reanalyzed in this work to examine the influence of different fitting procedures and further potential nonconformities. This analysis cannot reproduce the significance achieved by the previous detection.

Martin Wendt; Dieter Reimers

2008-02-08T23:59:59.000Z

27

Design and development of a continuously variable ratio transmission for an automotive vehicle. Phase IV. Quarterly progress report  

DOE Green Energy (OSTI)

Progress in the design and development of a continuously variable ratio transmission for an automotive vehicle is reported. The Major automotive hydromechanical transmission development problem continues to be the reduction of hydrostatic noise and the project plan, therefore, concentrated on the new hydrostatic module. The potential for achieving acceptably low noise levels in the second generation hydromechanical transmission is to be assessed by comparing the noise levels of the hydrostatic modules for the first and second generation transmissions. A set of twelve test points was selected comprising of road load steady state and wide-open-throttle acceleration at 10, 20, 30, 40, 50 and 60 mph. The module operating conditions for the two transmissions at each of these twelve points were calculated. Baseline noise data was measured on the first generation module. The results are given testing of co-axial hydrostatic module for second generation hydromechanical transmission will be emphasized. (LCL)

None

1978-05-31T23:59:59.000Z

28

High-Pressure Micellar Solutions of Symmetric and Asymmetric Styrene?Diene Diblocks in Compressible Near Critical Solvents: Micellization Pressures and Cloud Pressures Respond but Micellar Cloud Pressures Insensitive to Copolymer Molecular Weight, Concentration, and Block Ratio Changes  

Science Conference Proceedings (OSTI)

Micellar solutions of polystyrene-block-polybutadiene and polystyrene-block-polyisoprene in propane are found to exhibit significantly lower cloud pressures than the corresponding hypothetical nonmicellar solutions. Such a cloud-pressure reduction indicates the extent to which micelle formation enhances the apparent diblock solubility in near-critical and hence compressible propane. Concentration-dependent pressure-temperature points beyond which no micelles can be formed, referred to as the micellization end points, are found to depend on the block type, size, and ratio. The cloud-pressure reduction and the micellization end point measured for styrene-diene diblocks in propane should be characteristic of all amphiphilic diblock copolymer solutions that form micelles in compressible solvents.

Winoto, Winoto [University of Wyoming, Laramie; Tan, Sugata [University of Wyoming, Laramie; Shen, Youqin [University of Wyoming, Laramie; Radosz, Maciej [University of Wyoming, Laramie; Hong, Kunlun [ORNL; Mays, Jimmy [ORNL

2009-01-01T23:59:59.000Z

29

Variability of SO=4, Total Sulfate, NO?3, and Total Nitrate Scavenging Ratios for the Frontal Boundary Study  

Science Conference Proceedings (OSTI)

Precipitation and air concentration data collected during a U.S. Department of Energy–sponsored Frontal Boundary Study (FBS) were used to calculate scavenging ratios. The precipitation data were collected on a 100 km × 100 km surface grid ...

W. E. Davis; J. M. Thorp; R. N. Lee

1997-06-01T23:59:59.000Z

30

Snow-to-Liquid Ratio Variability and Prediction at a High-Elevation Site in Utah’s Wasatch Mountains  

Science Conference Proceedings (OSTI)

Contemporary snowfall forecasting is a three-step process involving a quantitative precipitation forecast (QPF), determination of precipitation type, and application of a snow-to-liquid ratio (SLR). The final step is often performed using ...

Trevor I. Alcott; W. James Steenburgh

2010-02-01T23:59:59.000Z

31

Steam compression with inner evaporative spray cooling: a case study  

Science Conference Proceedings (OSTI)

An adiabatic dry saturated steam compression process with inner evaporative spray cooling in screw compressors for steam heat pump systems is studied. Thermodynamic model and simulation of this variable-mass compression process are devised. Differential ... Keywords: inner evaporative spray cooling, screw compressors, simulation, steam compression, steam heat pumps, thermodynamic modelling, variable-mass compression, water injection

Jian Qui; Zhaolin Gu; Guoguang Cai

2004-12-01T23:59:59.000Z

32

Preventing numerical errors generated by interface-capturing schemes in compressible multi-material flows  

Science Conference Proceedings (OSTI)

In the present work, errors generated in computations of compressible multi-material flows using shock-capturing schemes are examined, specifically pressure oscillations (when the specific heats ratio is variable), but also temperature spikes and species ... Keywords: High-order accurate schemes, Interface capturing, Material discontinuities, Multi-material flows, Multifluid algorithms, Shock capturing, WENO

Eric Johnsen; Frank Ham

2012-07-01T23:59:59.000Z

33

Compressed Sensing in Astronomy  

E-Print Network (OSTI)

Recent advances in signal processing have focused on the use of sparse representations in various applications. A new field of interest based on sparsity has recently emerged: compressed sensing. This theory is a new sampling framework that provides an alternative to the well-known Shannon sampling theory. In this paper we investigate how compressed sensing (CS) can provide new insights into astronomical data compression and more generally how it paves the way for new conceptions in astronomical remote sensing. We first give a brief overview of the compressed sensing theory which provides very simple coding process with low computational cost, thus favoring its use for real-time applications often found on board space mission. We introduce a practical and effective recovery algorithm for decoding compressed data. In astronomy, physical prior information is often crucial for devising effective signal processing methods. We particularly point out that a CS-based compression scheme is flexible enough to account for such information. In this context, compressed sensing is a new framework in which data acquisition and data processing are merged. We show also that CS provides a new fantastic way to handle multiple observations of the same field view, allowing us to recover information at very low signal-to-noise ratio, which is impossible with standard compression methods. This CS data fusion concept could lead to an elegant and effective way to solve the problem ESA is faced with, for the transmission to the earth of the data collected by PACS, one of the instruments on board the Herschel spacecraft which will be launched in 2008.

J. Bobin; J-L Starck; R. Ottensamer

2008-02-01T23:59:59.000Z

34

Tension-Compression Testing  

Science Conference Proceedings (OSTI)

Tension-Compression Testing. ... version of the tension-compression test, to enable ... loading around draw-beads, where calibration tests must include ...

2013-04-10T23:59:59.000Z

35

Evolutionary lossless compression with GP-zip  

E-Print Network (OSTI)

In recent research we proposed GP-zip, a system which uses evolution to find optimal ways to combine standard compression algorithms for the purpose of maximally losslessly compressing files and archives. The system divides files into blocks of predefined length. It then uses a linear, fixed-length representation where each primitive indicates what compression algorithm to use for a specific data block. GP-zip worked well with heterogonous data sets, providing significant improvements in compression ratio compared to some of the best standard compression algorithms. In this paper we propose a substantial improvement, called GP-zip*, which uses a new representation and intelligent crossover and mutation operators such that blocks of different sizes can be evolved. Like GP-zip, GP-zip * finds what the best compression technique to use for each block is. The compression algorithms available in the primitive set of GP-zip* are: Arithmetic coding (AC), Lempel-Ziv-Welch (LZW), Unbounded Prediction by Partial Matching (PPMD), Run Length Encoding (RLE), and Boolean Minimization. In addition, two transformation techniques are available: the Burrows-Wheeler Transformation (BWT) and Move to Front (MTF). Results show that GP-zip* provides improvements in compression ratio ranging from a fraction to several tens of percent over its predecessor.

Ahmad Kattan; Riccardo Poli

2008-01-01T23:59:59.000Z

36

Mechanical Compression Heat Pumps  

E-Print Network (OSTI)

Mechanical compression heat pumping is not new in industrial applications. In fact, industry history suggests that the theoretical concept was developed before 1825. Heat pump manufacturers gained the support of consultants and end-users when the energy crisis hit this country in 1973. That interest, today, has been dampened because there is a current abundance of the basic sources of industrial energy (namely oil and natural gas). Meanwhile, Mycom used the window of the current opportunities to develop, design and test compressors built to meet the needs of the mechanically demanding industrial heat pump applications which often require high compression ratios and temperatures in excess of 200 degrees F. This paper will review the theoretical foundation for heat pumps and present the mechanical and thermal requirements of the compressors which constitute the heart and soul of the system. It will also provide a quick survey of the available types of compressors for heat pumping and some of the industrial processes where simultaneous heating and cooling proceed along parallel demand paths. The case history will examine the system flexibility and the economic advantages realized in a barley malting process.

Apaloo, T. L.; Kawamura, K.; Matsuda, J.

1986-06-01T23:59:59.000Z

37

High-Compression-Ratio; Atkinson-Cycle Engine Using Low-Pressure Direct Injection and Pneumatic-Electronic Valve Actuation Enabled by Ionization Current and Foward-Backward Mass Air Flow Sensor Feedback  

DOE Green Energy (OSTI)

This report describes the work completed over a two and one half year effort sponsored by the US Department of Energy. The goal was to demonstrate the technology needed to produce a highly efficient engine enabled by several technologies which were to be developed in the course of the work. The technologies included: (1) A low-pressure direct injection system; (2) A mass air flow sensor which would measure the net airflow into the engine on a per cycle basis; (3) A feedback control system enabled by measuring ionization current signals from the spark plug gap; and (4) An infinitely variable cam actuation system based on a pneumatic-hydraulic valve actuation These developments were supplemented by the use of advanced large eddy simulations as well as evaluations of fuel air mixing using the KIVA and WAVE models. The simulations were accompanied by experimental verification when possible. In this effort a solid base has been established for continued development of the advanced engine concepts originally proposed. Due to problems with the valve actuation system a complete demonstration of the engine concept originally proposed was not possible. Some of the highlights that were accomplished during this effort are: (1) A forward-backward mass air flow sensor has been developed and a patent application for the device has been submitted. We are optimistic that this technology will have a particular application in variable valve timing direct injection systems for IC engines. (2) The biggest effort on this project has involved the development of the pneumatic-hydraulic valve actuation system. This system was originally purchased from Cargine, a Swedish supplier and is in the development stage. To date we have not been able to use the actuators to control the exhaust valves, although the actuators have been successfully employed to control the intake valves. The reason for this is the additional complication associated with variable back pressure on the exhaust valves when they are opened. As a result of this effort, we have devised a new design and have filed for a patent on a method of control which is believed to overcome this problem. The engine we have been working with originally had a single camshaft which controlled both the intake and exhaust valves. Single cycle lift and timing control was demonstrated with this system. (3) Large eddy simulations and KIVA based simulations were used in conjunction with flow visualizations in an optical engine to study fuel air mixing. During this effort we have devised a metric for quantifying fuel distribution and it is described in several of our papers. (4) A control system has been developed to enable us to test the benefits of the various technologies. This system used is based on Opal-RT hardware and is being used in a current DOE sponsored program.

Harold Schock; Farhad Jaberi; Ahmed Naguib; Guoming Zhu; David Hung

2007-12-31T23:59:59.000Z

38

Conducting fiber compression tester  

DOE Patents (OSTI)

The invention measures the resistance across a conductive fiber attached to a substrate place under a compressive load to determine the amount of compression needed to cause the fiber to fail. 3 figs.

DeTeresa, S.J.

1989-12-07T23:59:59.000Z

39

Carbon Dioxide Compression  

Science Conference Proceedings (OSTI)

Page 1. © C opyright 2009 Carbon Dioxide Compression DOE – EPRI – NIST ... Greenhouse gas sequestration Page 5. 5 © C opyright 2009 ...

2013-04-22T23:59:59.000Z

40

RATIO COMPUTER  

DOE Patents (OSTI)

An electronic computer circuit is described for producing an output voltage proportional to the product or quotient of tbe voltages of a pair of input signals. ln essence, the disclosed invention provides a computer having two channels adapted to receive separate input signals and each having amplifiers with like fixed amplification factors and like negatlve feedback amplifiers. One of the channels receives a constant signal for comparison purposes, whereby a difference signal is produced to control the amplification factors of the variable feedback amplifiers. The output of the other channel is thereby proportional to the product or quotient of input signals depending upon the relation of input to fixed signals in the first mentioned channel.

Post, R.F.

1958-11-11T23:59:59.000Z

Note: This page contains sample records for the topic "variable compression ratio" 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

Predicting the fidelity of JPEG2000 compressed CT images using DICOM header information  

Science Conference Proceedings (OSTI)

Purpose: To propose multiple logistic regression (MLR) and artificial neural network (ANN) models constructed using digital imaging and communications in medicine (DICOM) header information in predicting the fidelity of Joint Photographic Experts Group (JPEG) 2000 compressed abdomen computed tomography (CT) images. Methods: Our institutional review board approved this study and waived informed patient consent. Using a JPEG2000 algorithm, 360 abdomen CT images were compressed reversibly (n = 48, as negative control) or irreversibly (n = 312) to one of different compression ratios (CRs) ranging from 4:1 to 10:1. Five radiologists independently determined whether the original and compressed images were distinguishable or indistinguishable. The 312 irreversibly compressed images were divided randomly into training (n = 156) and testing (n = 156) sets. The MLR and ANN models were constructed regarding the DICOM header information as independent variables and the pooled radiologists' responses as dependent variable. As independent variables, we selected the CR (DICOM tag number: 0028, 2112), effective tube current-time product (0018, 9332), section thickness (0018, 0050), and field of view (0018, 0090) among the DICOM tags. Using the training set, an optimal subset of independent variables was determined by backward stepwise selection in a four-fold cross-validation scheme. The MLR and ANN models were constructed with the determined independent variables using the training set. The models were then evaluated on the testing set by using receiver-operating-characteristic (ROC) analysis regarding the radiologists' pooled responses as the reference standard and by measuring Spearman rank correlation between the model prediction and the number of radiologists who rated the two images as distinguishable. Results: The CR and section thickness were determined as the optimal independent variables. The areas under the ROC curve for the MLR and ANN predictions were 0.91 (95% CI; 0.86, 0.95) and 0.92 (0.87, 0.96), respectively. The correlation coefficients of the MLR and ANN predictions with the number of radiologists who responded as distinguishable were 0.76 (0.69, 0.82, p < 0.001) and 0.78 (0.71, 0.83, p < 0.001), respectively. Conclusions: The MLR and ANN models constructed using the DICOM header information offer promise in predicting the fidelity of JPEG2000 compressed abdomen CT images.

Kim, Kil Joong; Kim, Bohyoung; Lee, Hyunna; Choi, Hosik; Jeon, Jong-June; Ahn, Jeong-Hwan; Lee, Kyoung Ho [Department of Radiation Applied Life Science, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul, 110-744 (Korea, Republic of); School of Computer Science and Engineering, Seoul National University, 599 Kwanak-Ro, Kwanak-Gu, Seoul, 151-742 (Korea, Republic of); Department of Informational Statistics, Hoseo University, 165, Sechul-ri, Baebang-myeon, Asan-si, Chungcheongnam-do, 336-795 (Korea, Republic of); Department of Statistics, Seoul National University, 599 Kwanak-Ro, Kwanak-Gu, Seoul, 151-742 (Korea, Republic of); Korean Intellectual Property Office, Government Complex-Daejeon, 139 Seonsa-ro, Seo-gu, Daejeon, 302-701 (Korea, Republic of); Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Institute of Radiation Medicine, and Seoul National University Medical Research Center, 300 Gumi-dong, Bundang-gu, Seongnam-si, Gyeonggi-do, 463-707 (Korea, Republic of)

2011-12-15T23:59:59.000Z

42

NETL: CO2 Compression  

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

CO2 Compression CO2 Compression The CO2 captured from a power plant will need to be compressed from near atmospheric pressure to a pressure between 1,500 and 2,200 psi in order to be transported via pipeline and then injected into an underground sequestration site. Read More! CO2 Compression The compression of CO2 represents a potentially large auxiliary power load on the overall power plant system. For example, in an August 2007 study conducted for DOE/NETL, CO2 compression was accomplished using a six-stage centrifugal compressor with interstage cooling that required an auxiliary load of approximately 7.5 percent of the gross power output of a subcritical pressure, coal-fired power plant. As a result, DOE/NETL is sponsoring R&D to develop novel methods that can significantly decrease the

43

Compressed Air Storage with Humidification: An Economic Evaluation  

Science Conference Proceedings (OSTI)

Compressed Air Storage with Humidification (CASH) plants utilize air saturation to greatly improve the energy ratio. This EPRI study examines whether the CASH Power Plant can provide electric power at the lowest cost for cycling operation.

1999-03-08T23:59:59.000Z

44

Modeling Compressed Turbulence  

Science Conference Proceedings (OSTI)

From ICE to ICF, the effect of mean compression or expansion is important for predicting the state of the turbulence. When developing combustion models, we would like to know the mix state of the reacting species. This involves density and concentration fluctuations. To date, research has focused on the effect of compression on the turbulent kinetic energy. The current work provides constraints to help development and calibration for models of species mixing effects in compressed turbulence. The Cambon, et al., re-scaling has been extended to buoyancy driven turbulence, including the fluctuating density, concentration, and temperature equations. The new scalings give us helpful constraints for developing and validating RANS turbulence models.

Israel, Daniel M. [Los Alamos National Laboratory

2012-07-13T23:59:59.000Z

45

Context based medical image compression for ultrasound images with contextual set partitioning in hierarchical trees algorithm  

Science Conference Proceedings (OSTI)

The basic goal of medical image compression is to reduce the bit rate and enhance the compression efficiency for the transmission and storage of the medical imagery while maintaining an acceptable diagnostic image quality. Because of the storage, transmission ... Keywords: CR (compression ratio), CoC (correlation coefficient), EBCOT (embedded block coding with optimized truncation), JPEG2K (JPEG 2000), MSE (mean square error), PSNR (peak signal to noise ratio)

M. A. Ansari; R. S. Anand

2009-07-01T23:59:59.000Z

46

Active RF Pulse Compression Using An Electrically Controlled Semiconductor Switch  

SciTech Connect

First we review the theory of active pulse compression systems using resonant delay lines. Then we describe the design of an electrically controlled semiconductor active switch. The switch comprises an active window and an overmoded waveguide three-port network. The active window is based on a four-inch silicon wafer which has 960 PIN diodes. These are spatially combined in an overmoded waveguide. We describe the philosophy and design methodology for the three-port network and the active window. We then present the results of using this device to compress 11.4 GHz RF signals with high compression ratios. We show how the system can be used with amplifier like sources, in which one can change the phase of the source by manipulating the input to the source. We also show how the active switch can be used to compress a pulse from an oscillator like sources, which is not possible with passive pulse compression systems.

Guo, Jiquan; Tantawi, Sami; /SLAC

2007-01-10T23:59:59.000Z

47

Compressed Gas Cylinder Policy  

E-Print Network (OSTI)

, storage, and usage of compressed gas cylinders. 2.0 POLICY Colorado School of Mines ("Mines" or "the, storage, and usage requirements outlined below. This policy is applicable school-wide including all, or electrical circuits. Flammable gas cylinders must be stored in the building's gas cylinder storage cage until

48

Functional compression : theory and application  

E-Print Network (OSTI)

We consider the problem of functional compression. The objective is to separately compress possibly correlated discrete sources such that an arbitrary deterministic function of those sources can be computed given the ...

Doshi, Vishal D. (Vishal Devendra)

2008-01-01T23:59:59.000Z

49

Compressed Air System Maintenance Guide  

Science Conference Proceedings (OSTI)

The "Compressed Air System Maintenance Guide" provides fossil plant personnel with information on the operation and maintenance of the compressed air system. The contents of this guide will assist personnel in improving performance of the compressed air system, reducing maintenance costs, and increasing air system reliability.

2002-11-27T23:59:59.000Z

50

Improving Floating Point Compression  

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

Improving Improving Floating Point Compression through Binary Masks Leonardo A. Bautista Gomez Argonne National Laboratory Franck Cappello Argonne National Laboratory Abstract-Modern scientific technology such as particle accel- erators, telescopes and supercomputers are producing extremely large amounts of data. That scientific data needs to be processed using systems with high computational capabilities such as supercomputers. Given that the scientific data is increasing in size at an exponential rate, storing and accessing the data is becoming expensive in both, time and space. Most of this scientific data is stored using floating point representation. Scientific applications executed in supercomputers spend a large amount of CPU cycles reading and writing floating point values, making data compression techniques an interesting way to increase computing efficiency.

51

Electrochemical Hydrogen Compression (EHC)  

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

Electrochemical Hydrogen Compression (EHC) Pinakin Patel and Ludwig Lipp Presentation at DOE Hydrogen Compression, Storage and Dispensing Workshop at ANL Argonne, IL March 20, 2013 2 * Experience with all fuel cells - MCFC, SOFC, PEM, PAFC, etc. * Excellent progress in commercialization of MCFC technology (>300 MW installed + backlog, >50 MW per year production rate, 11 MW single site unit in Korea, >1.5 billion kWh produced) * Unique internal reforming technology for high efficiency fuel cells FCE Overview $- $2,000 $4,000 $6,000 $8,000 $10,000 2003 2007 2011 mid-term Product cost per kW 3 H 2 Peak and Back- up Power Fuel Cell Cars DFC ® Power Plant (Electricity + Hydrogen) Solid State Hydrogen Separator (EHS) Solid State Hydrogen

52

Real gas effects for compressible nozzle flows  

SciTech Connect

Numerical simulation of compressible nozzle flows of real gas with or without the addition of heat is presented. A generalized real gas method, using an upwind scheme and curvilinear coordinates, is applied to solve the unsteady compressible Euler equations in axisymmetric form. The present method is an extension of a previous 2D method, which was developed to solve the problem for a gas having the general equation of state in the form p=p ([rho], i). In the present work the method is generalized for an arbitrary P-V-T equation of state introducing an iterative procedure for the determination of the temperature from the specific internal energy and the flow variables. The solution procedure is applied for the study of real gas effects in an axisymmetric nozzle flow.

Drikakis, D.; Tsangaris, S. (National Technical Univ. of Athens, (Greece). Dept. of Mechanical Engineering)

1993-03-01T23:59:59.000Z

53

Compressed Air 101: Getting Compressed Air to Work  

E-Print Network (OSTI)

"Air compressors are a significant industrial energy user. Based on a survey (conducted by Oregon State University and the Bonneville Power Administration) of energy audit reports from 125 plants, air compressors account for roughly 10% of total plant energy use. Furthermore, air compression is inefficient with up to 95% of compressor power dissipated as heat. Thus even minor improvements in system operation, control strategies, and efficiency can yield large energy savings and significant non-energy or productivity benefits from reliable compressed air. Compressed air is often called the ""fourth utility"" in industrial facilities after electricity, natural gas, and water. It provides motive power for machinery, cooling, materials handling, and hand tools. It is a safe, flexible, and powerful resource, but one that is seldom run for low operating costs or best productivity. Learning the basics of compressed air systems represents the beginning of both reducing energy costs and enjoying the productive benefits of reliable compressed air. Compressed air management systems, including a system approach to managing demand, stabilizing pressure, reducing leaks and compressor controls, can allow the industrial end user to save 20% - 50% of their air compressor electricity usage. The monitoring capabilities of compressed air management systems provide a useful tool through power, pressure and flow trending to maintain both the energy savings and increased system reliability. More efficiently managed compressed air systems are less costly to maintain and have less impact on the environment. The most important issues of industrial compressed air in relation to energy efficiency and management are: 1. Compressed air is an essential industrial utility; 2. Compressing air is a fundamentally inefficient energy transformation process; 3. Optimal operation of compressed air systems in industrial plants is seldom a priority and adequate management infonnation is rare, resulting in negative impacts on production and even less efficiency."

Burke, J. J.; Bessey, E. G.

2003-05-01T23:59:59.000Z

54

Photon compression in cylinders  

DOE Green Energy (OSTI)

It has been shown theoretically that intense microwave radiation is absorbed non-classically by a newly enunciated mechanism when interacting with hydrogen plasma. Fields > 1 Mg, lambda > 1 mm are within this regime. The predicted absorption, approximately P/sub rf/v/sub theta/sup e/, has not yet been experimentally confirmed. The applications of such a coupling are many. If microwave bursts approximately > 5 x 10/sup 14/ watts, 5 ns can be generated, the net generation of power from pellet fusion as well as various military applications becomes feasible. The purpose, then, for considering gas-gun photon compression is to obtain the above experimental capability by converting the gas kinetic energy directly into microwave form. Energies of >10/sup 5/ joules cm/sup -2/ and powers of >10/sup 13/ watts cm/sup -2/ are potentially available for photon interaction experiments using presently available technology. The following topics are discussed: microwave modes in a finite cylinder, injection, compression, switchout operation, and system performance parameter scaling.

Ensley, D.L.

1977-01-12T23:59:59.000Z

55

Shock compression of precompressed deuterium  

DOE Green Energy (OSTI)

Here we report quasi-isentropic dynamic compression and thermodynamic characterization of solid, precompressed deuterium over an ultrafast time scale (< 100 ps) and a microscopic length scale (< 1 {micro}m). We further report a fast transition in shock wave compressed solid deuterium that is consistent with the ramp to shock transition, with a time scale of less than 10 ps. These results suggest that high-density dynamic compression of hydrogen may be possible on microscopic length scales.

Armstrong, M R; Crowhurst, J C; Zaug, J M; Bastea, S; Goncharov, A F; Militzer, B

2011-07-31T23:59:59.000Z

56

A novel compound regularization and fast algorithm for compressive sensing deconvolution  

Science Conference Proceedings (OSTI)

Compressive Sensing Deconvolution (CS-Deconvolution) is a new challenge problem encountered in a wide variety of image processing fields. Since CS is more efficient for sparse signals, in our scheme, the input image is firstly sparse represented by curvelet ... Keywords: Compound regularization, Compressive sensing, Deconvolution from incomplete measurements, Variable splitting

Liang Xiao, Jun Shao, Lili Huang, Zhihui Wei

2013-11-01T23:59:59.000Z

57

Heat release effects on decaying homogeneous compressible turbulence  

E-Print Network (OSTI)

High Mach-number compressible flows with heat release are inherently more complicated than incompressible flows due to, among other reasons, the activation of the thermal energy mode. Such flow fields can experience significant fluctuations in density, temperature, viscosity, conductivity and specific heat, which affect velocity and pressure fluctuations. Furthermore, the flow field cannot be assumed to be dilatation-free in high Mach numbers and even in low Mach-number flows involving combustion, or in boundary layers on heated walls. The main issue in these high-speed and highly-compressible flows is the effect of thermal gradients and fluctuations on turbulence. The thermal field has various routes through which it affects flow structures of compressible turbulence. First, it has direct influence through pressure, which affects turbulence via pressure-strain correlation. The indirect effects of thermal fields on compressible turbulence are through the changes in flow properties. The high temperature gradients alter the transport coefficient and compressibility of the flow. The objective of this work is to answer the following questions: How do temperature fluctuations change the compressible flow structure and energetics? How does compressibility in the flow affect the non-linear pressure redistribution process? What is the main effect of spatial transport-coefficient variation? We perform direct numerical simulations (DNS) to answer the above questions. The investigations are categorized into four parts: 1) Turbulent energy cascade and kinetic-internal energy interactions under the influence of temperature fluctuations; 2) Return-to-isotropy of anisotropic turbulence under the influence of large temperature fluctuations; 3) The effect of turbulent Mach number and dilatation level on small-scale (velocity-gradient) dynamics; 4) The effect of variable transport-coefficients (viscosity and diffusivity) on cascade and dissipation processes of turbulence. The findings lead to a better understanding of temperature fluctuation effects on non-linear processes in compressible turbulence. This improved understanding is expected to provide direction for improving second-order closure models of compressible turbulence.

Lee, Kurn Chul

2008-05-01T23:59:59.000Z

58

Compressed String Dictionaries  

E-Print Network (OSTI)

The problem of storing a set of strings --- a string dictionary --- in compact form appears naturally in many cases. While classically it has represented a small part of the whole data to be processed (e.g., for Natural Language processing or for indexing text collections), more recent applications in Web engines, Web mining, RDF graphs, Internet routing, Bioinformatics, and many others, make use of very large string dictionaries, whose size is a significant fraction of the whole data. Thus novel approaches to compress them efficiently are necessary. In this paper we experimentally compare time and space performance of some existing alternatives, as well as new ones we propose. We show that space reductions of up to 20% of the original size of the strings is possible while supporting fast dictionary searches.

Brisaboa, Nieves R; Martínez-Prieto, Miguel A; Navarro, Gonzalo

2011-01-01T23:59:59.000Z

59

New Regenerative Cycle for Vapor Compression Refrigeration  

SciTech Connect

The main objective of this project is to confirm on a well-instrumented prototype the theoretically derived claims of higher efficiency and coefficient of performance for geothermal heat pumps based on a new regenerative thermodynamic cycle as comparing to existing technology. In order to demonstrate the improved performance of the prototype, it will be compared to published parameters of commercially available geothermal heat pumps manufactured by US and foreign companies. Other objectives are to optimize the design parameters and to determine the economic viability of the new technology. Background (as stated in the proposal): The proposed technology closely relates to EERE mission by improving energy efficiency, bringing clean, reliable and affordable heating and cooling to the residential and commercial buildings and reducing greenhouse gases emission. It can provide the same amount of heating and cooling with considerably less use of electrical energy and consequently has a potential of reducing our nations dependence on foreign oil. The theoretical basis for the proposed thermodynamic cycle was previously developed and was originally called a dynamic equilibrium method. This theory considers the dynamic equations of state of the working fluid and proposes the methods for modification of T-S trajectories of adiabatic transformation by changing dynamic properties of gas, such as flow rate, speed and acceleration. The substance of this proposal is a thermodynamic cycle characterized by the regenerative use of the potential energy of two-phase flow expansion, which in traditional systems is lost in expansion valves. The essential new features of the process are: (1) The application of two-step throttling of the working fluid and two-step compression of its vapor phase. (2) Use of a compressor as the initial step compression and a jet device as a second step, where throttling and compression are combined. (3) Controlled ratio of a working fluid at the first and second step of compression. In the proposed system, the compressor compresses the vapor only to 50-60% of the final pressure, while the additional compression is provided by a jet device using internal potential energy of the working fluid flow. Therefore, the amount of mechanical energy required by a compressor is significantly reduced, resulting in the increase of efficiency (either COP or EER). The novelty of the cycle is in the equipment and in the way the multi-staging is accomplished. The anticipated result will be a new refrigeration system that requires less energy to accomplish a cooling task. The application of this technology will be for more efficient designs of: (1) Industrial chillers, (2) Refrigeration plants, (3) Heat pumps, (4) Gas Liquefaction plants, (5) Cryogenic systems.

Mark J. Bergander

2005-08-29T23:59:59.000Z

60

Data Compression with Prime Numbers  

E-Print Network (OSTI)

A compression algorithm is presented that uses the set of prime numbers. Sequences of numbers are correlated with the prime numbers, and labeled with the integers. The algorithm can be iterated on data sets, generating factors of doubles on the compression.

Gordon Chalmers

2005-11-16T23:59:59.000Z

Note: This page contains sample records for the topic "variable compression ratio" 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

Signal compression by subband coding  

Science Conference Proceedings (OSTI)

This is a survey/tutorial paper on data compression using the technique of subband coding. This is widely used in practice, for example, in the MPEG audio coder. A subband coder has two main components: a filter bank that decomposes the source into components, ... Keywords: Compression, Filter banks, Subband coding

Bruce Francis; Soura Dasgupta

1999-12-01T23:59:59.000Z

62

Streaming Compression of Hexahedral Meshes  

Science Conference Proceedings (OSTI)

We describe a method for streaming compression of hexahedral meshes. Given an interleaved stream of vertices and hexahedral our coder incrementally compresses the mesh in the presented order. Our coder is extremely memory efficient when the input stream documents when vertices are referenced for the last time (i.e. when it contains topological finalization tags). Our coder then continuously releases and reuses data structures that no longer contribute to compressing the remainder of the stream. This means in practice that our coder has only a small fraction of the whole mesh in memory at any time. We can therefore compress very large meshes - even meshes that do not file in memory. Compared to traditional, non-streaming approaches that load the entire mesh and globally reorder it during compression, our algorithm trades a less compact compressed representation for significant gains in speed, memory, and I/O efficiency. For example, on the 456k hexahedra 'blade' mesh, our coder is twice as fast and uses 88 times less memory (only 3.1 MB) with the compressed file increasing about 3% in size. We also present the first scheme for predictive compression of properties associated with hexahedral cells.

Isenburg, M; Courbet, C

2010-02-03T23:59:59.000Z

63

Transformer Ratio Enhancement Experiment  

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

TRANSFORMER RATIO ENHANCEMENT EXPERIMENT A. Kanareykin, Euclid Concepts LLC, Solon, OH 44139, USA W. Gai, J. G. Power. ANL, Argonne, IL, 60439, USA E. Nenasheva, Ceramics Ltd., St....

64

Dictionary Design for Text Image Compression with JBIG2  

E-Print Network (OSTI)

The JBIG2 standard for lossy and lossless bi-level image coding is a very flexible encoding strategy based on pattern matching techniques. This paper addresses the problem of compressing text images with JBIG2. For text image compression, JBIG2 allows two encoding strategies: SPM and PM&S. We compare in detail the lossless and lossy coding performance using the SPM-based and PM&S-based JBIG2, including their coding efficiency, reconstructed image quality and system complexity. For the SPM-based JBIG2, we discuss the bit rate trade-off associated with symbol dictionary design. We propose two symbol dictionary design techniques: the class-based and tree-based techniques. Experiments show that the SPM-based JBIG2 is a more efficient lossless system, leading to 8% higher compression ratios on average. It also provides better control over the reconstructed image quality in lossy compression. However, SPM's advantages come at the price of higher encoder complexity. The proposed class-based and tree-based symbol dictionary designs outperform simpler dictionary formation techniques by 8% for lossless and 16-18% for lossy compression. Keywords Bi-level image coding, text image compression, JBIG2, soft pattern matching, symbol dictionary. 1 1

Yan Ye; Pamela Cosman

2001-01-01T23:59:59.000Z

65

Advances in compressible turbulent mixing  

Science Conference Proceedings (OSTI)

This volume includes some recent additions to original material prepared for the Princeton International Workshop on the Physics of Compressible Turbulent Mixing, held in 1988. Workshop participants were asked to emphasize the physics of the compressible mixing process rather than measurement techniques or computational methods. Actual experimental results and their meaning were given precedence over discussions of new diagnostic developments. Theoretical interpretations and understanding were stressed rather than the exposition of new analytical model developments or advances in numerical procedures. By design, compressibility influences on turbulent mixing were discussed--almost exclusively--from the perspective of supersonic flow field studies. The papers are arranged in three topical categories: Foundations, Vortical Domination, and Strongly Coupled Compressibility. The Foundations category is a collection of seminal studies that connect current study in compressible turbulent mixing with compressible, high-speed turbulent flow research that almost vanished about two decades ago. A number of contributions are included on flow instability initiation, evolution, and transition between the states of unstable flow onset through those descriptive of fully developed turbulence. The Vortical Domination category includes theoretical and experimental studies of coherent structures, vortex pairing, vortex-dynamics-influenced pressure focusing. In the Strongly Coupled Compressibility category the organizers included the high-speed turbulent flow investigations in which the interaction of shock waves could be considered an important source for production of new turbulence or for the enhancement of pre-existing turbulence. Individual papers are processed separately.

Dannevik, W.P.; Buckingham, A.C.; Leith, C.E. [eds.

1992-01-01T23:59:59.000Z

66

Fuel Cell Technologies Office: Hydrogen Compression, Storage...  

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

Hydrogen Compression, Storage, and Dispensing Cost Reduction Workshop to someone by E-mail Share Fuel Cell Technologies Office: Hydrogen Compression, Storage, and Dispensing Cost...

67

ARM - Measurement - Isotope ratio  

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

govMeasurementsIsotope ratio govMeasurementsIsotope ratio ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Isotope ratio Ratio of stable isotope concentrations. Categories Atmospheric Carbon, Atmospheric State Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments FLASK : Flask Samplers for Carbon Cycle Gases and Isotopes Field Campaign Instruments FLASK : Flask Samplers for Carbon Cycle Gases and Isotopes Datastreams FLASK : Flask Samplers for Carbon Cycle Gases and Isotopes

68

General Compression | Open Energy Information  

Open Energy Info (EERE)

Compression Compression Jump to: navigation, search Name General Compression Place Newton, Massachusetts Zip 2458 Product Massachusetts-based developer of compressed air energy storage systems. Coordinates 43.996685°, -87.803724° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":43.996685,"lon":-87.803724,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

69

Hydrogen Delivery Liquefaction and Compression  

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

to Praxair Hydrogen Liquefaction Hydrogen Compression 3 Praxair at a Glance The largest industrial gas company in North and South America Only U.S. Hydrogen Supplier in All Sizes...

70

High compression rate text summarization  

E-Print Network (OSTI)

This thesis focuses on methods for condensing large documents into highly concise summaries, achieving compression rates on par with human writers. While the need for such summaries in the current age of information overload ...

Branavan, Satchuthananthavale Rasiah Kuhan

2008-01-01T23:59:59.000Z

71

Normalized Compression Distance of Multiples  

E-Print Network (OSTI)

Normalized compression distance (NCD) is a parameter-free similarity measure based on compression. The NCD between pairs of objects is not sufficient for all applications. We propose an NCD of finite multisets (multiples) of objacts that is metric and is better for many applications. Previously, attempts to obtain such an NCD failed. We use the theoretical notion of Kolmogorov complexity that for practical purposes is approximated from above by the length of the compressed version of the file involved, using a real-world compression program. We applied the new NCD for multiples to retinal progenitor cell questions that were earlier treated with the pairwise NCD. Here we get significantly better results. We also applied the NCD for multiples to synthetic time sequence data. The preliminary results are as good as nearest neighbor Euclidean classifier.

Cohen, Andrew R

2012-01-01T23:59:59.000Z

72

Carbon Dioxide Compression and Transportation  

Science Conference Proceedings (OSTI)

This report summarizes the state of the art regarding carbon dioxide CO2 compression and transportation in the United States and Canada. The primary focus of the report was on CO2 compression because it is a significant cost and energy penalty in carbon capture and storage CCS. The secondary focus of the report was to document the state of the art of CO2 pipeline transportation in the United States and Canada.

2008-12-23T23:59:59.000Z

73

Orthobaric Density: A Thermodynamic Variable for Ocean Circulation Studies  

Science Conference Proceedings (OSTI)

A new density variable, empirically corrected for pressure, is constructed. This is done by first fitting compressibility (or sound speed) computed from global ocean datasets to an empirical function of pressure and in situ density (or specific ...

Roland A. de Szoeke; Scott R. Springer; David M. Oxilia

2000-11-01T23:59:59.000Z

74

Linear phase compressive filter  

DOE Patents (OSTI)

A phase linear filter for soliton suppression is in the form of a laddered series of stages of non-commensurate low pass filters with each low pass filter having a series coupled inductance (L) and a reverse biased, voltage dependent varactor diode, to ground which acts as a variable capacitance (C). L and C values are set to levels which correspond to a linear or conventional phase linear filter. Inductance is mapped directly from that of an equivalent nonlinear transmission line and capacitance is mapped from the linear case using a large signal equivalent of a nonlinear transmission line.

McEwan, Thomas E. (Livermore, CA)

1995-01-01T23:59:59.000Z

75

Gas turbine power plant with supersonic shock compression ramps  

SciTech Connect

A gas turbine engine. The engine is based on the use of a gas turbine driven rotor having a compression ramp traveling at a local supersonic inlet velocity (based on the combination of inlet gas velocity and tangential speed of the ramp) which compresses inlet gas against a stationary sidewall. The supersonic compressor efficiently achieves high compression ratios while utilizing a compact, stabilized gasdynamic flow path. Operated at supersonic speeds, the inlet stabilizes an oblique/normal shock system in the gasdynamic flow path formed between the rim of the rotor, the strakes, and a stationary external housing. Part load efficiency is enhanced by use of a lean pre-mix system, a pre-swirl compressor, and a bypass stream to bleed a portion of the gas after passing through the pre-swirl compressor to the combustion gas outlet. Use of a stationary low NOx combustor provides excellent emissions results.

Lawlor, Shawn P. (Bellevue, WA); Novaresi, Mark A. (San Diego, CA); Cornelius, Charles C. (Kirkland, WA)

2008-10-14T23:59:59.000Z

76

An approach for modeling the valve train system to control the homogeneous combustion in a compression ignition engine  

Science Conference Proceedings (OSTI)

This paper presents an approach for modeling the valve train system to obtain a homogeneous charge compression ignition (HCCI) engine from a gasoline engine. The HCCI engines use different indirect strategies to control the start of the combustion. The ... Keywords: exhaust gas recirculation, homogeneous charge compression ignition, variable valve timing

Radu Cosgarea; Corneliu Cofaru; Mihai Aleonte; Maria Luminita Scutaru; Liviu Jelenschi; Gabriel Sandu

2011-04-01T23:59:59.000Z

77

Variable Screw Compressor, Variable Screw Compressor Suppliers ...  

U.S. Energy Information Administration (EIA)

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

78

Slope preserving lossy terrain compression  

Science Conference Proceedings (OSTI)

Accurate terrain representation with appropriate preservation of important terrain characteristics, especially slope steepness, is becoming more crucial and fundamental as the geographical models are becoming more complex. Based on our earlier success ... Keywords: GIS, PDE solver, terrain elevation data set compression, terrain modeling

Zhongyi Xie; W. Randolph Franklin; Daniel M. Tracy

2010-11-01T23:59:59.000Z

79

Environmental monitoring via compressive sensing  

Science Conference Proceedings (OSTI)

Environmental monitoring aims to describe the state of the environment. It identifies environmental issues to show us how well our environmental objectives are being met. Traditional large-scale sensor networks for environmental monitoring suffers from ... Keywords: compressive sensing, environmental monitoring, information management, sensor networks

Shulin Yan; Chao Wu; Wei Dai; Moustafa Ghanem; Yike Guo

2012-08-01T23:59:59.000Z

80

Apparatus for measuring tensile and compressive properties of solid materials at cryogenic temperatures  

DOE Patents (OSTI)

An apparatus for evaluating the tensile and compressive properties of material samples at very low or cryogenic temperatures employs a stationary frame and a dewar mounted below the frame. A pair of coaxial cylindrical tubes extend downward towards the bottom of the dewar. A compressive or tensile load is generated hydraulically and is transmitted by the inner tube to the material sample. The material sample is located near the bottom of the dewar in a liquid refrigerant bath. The apparatus employs a displacement measuring device, such as a linear variable differential transformer, to measure the deformation of the material sample relative to the amount of compressive or tensile force applied to the sample.

Gonczy, John D. (Oaklawn, IL); Markley, Finley W. (St. Charles, IL); McCaw, William R. (Burr Ridge, IL); Niemann, Ralph C. (Downers Grove, IL)

1992-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "variable compression ratio" 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

Fact Sheet: Isothermal Compressed Air Energy Storage (October...  

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

Isothermal Compressed Air Energy Storage (October 2012) Fact Sheet: Isothermal Compressed Air Energy Storage (October 2012) SustainX will demonstrate an isothermal compressed air...

82

Used Fuel Disposition Campaign Phase I Ring Compression Testing...  

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

Phase I Ring Compression Testing of High Burnup Cladding Used Fuel Disposition Campaign Phase I Ring Compression Testing of High Burnup Cladding The purpose of ring compression...

83

Stream programming for image and video compression  

E-Print Network (OSTI)

Video playback devices rely on compression algorithms to minimize storage, transmission bandwidth, and overall cost. Compression techniques have high realtime and sustained throughput requirements, and the end of CPU clock ...

Drake, Matthew Henry

2006-01-01T23:59:59.000Z

84

Hydrostatic Adjustment in Nonhydrostatic, Compressible Mesoscale Models  

Science Conference Proceedings (OSTI)

The ability of various numerical techniques used in compressible, nonhydrostatic models to handlehydrostatic adjustment is intercompared. The exact solution of a linearized model of an isothermal, compressible, nonrotating atmosphere is compared ...

Dean G. Duffy

1997-12-01T23:59:59.000Z

85

Technical Assessment: Cryo-Compressed Hydrogen Storage  

E-Print Network (OSTI)

Technical Assessment: Cryo-Compressed Hydrogen Storage for Vehicular Applications October 30, 2006* U.S. Department of Energy Hydrogen Program *Revised June, 2008 #12;Table of Contents Introduction .....................................................................................................................................................................8 APPENDIX A: Review of Cryo-Compressed Hydrogen Storage Systems

86

Flux compression generators as plasma compression power sources  

SciTech Connect

A survey is made of applications where explosive-driven magnetic flux compression generators have been or can be used to directly power devices that produce dense plasmas. Representative examples are discussed that are specific to the theta pinch, the plasma gun, the dense plasma focus and the Z pinch. These examples are used to illustrate the high energy and power capabilities of explosive generators. An application employing a rocket-borne, generator-powered plasma gun emphasizes the size and weight potential of flux compression power supplies. Recent results from a local effort to drive a dense plasma focus are provided. Imploding liners ae discussed in the context of both the theta and Z pinches.

Fowler, C.M.; Caird, R.S.; Erickson, D.J.; Freeman, B.L.; Thomson, D.B.; Garn, W.B.

1979-01-01T23:59:59.000Z

87

ADVANCED RECIPROCATING COMPRESSION TECHNOLOGY (ARCT)  

SciTech Connect

The U.S. natural gas pipeline industry is facing the twin challenges of increased flexibility and capacity expansion. To meet these challenges, the industry requires improved choices in gas compression to address new construction and enhancement of the currently installed infrastructure. The current fleet of installed reciprocating compression is primarily slow-speed integral machines. Most new reciprocating compression is and will be large, high-speed separable units. The major challenges with the fleet of slow-speed integral machines are: limited flexibility and a large range in performance. In an attempt to increase flexibility, many operators are choosing to single-act cylinders, which are causing reduced reliability and integrity. While the best performing units in the fleet exhibit thermal efficiencies between 90% and 92%, the low performers are running down to 50% with the mean at about 80%. The major cause for this large disparity is due to installation losses in the pulsation control system. In the better performers, the losses are about evenly split between installation losses and valve losses. The major challenges for high-speed machines are: cylinder nozzle pulsations, mechanical vibrations due to cylinder stretch, short valve life, and low thermal performance. To shift nozzle pulsation to higher orders, nozzles are shortened, and to dampen the amplitudes, orifices are added. The shortened nozzles result in mechanical coupling with the cylinder, thereby, causing increased vibration due to the cylinder stretch mode. Valve life is even shorter than for slow speeds and can be on the order of a few months. The thermal efficiency is 10% to 15% lower than slow-speed equipment with the best performance in the 75% to 80% range. The goal of this advanced reciprocating compression program is to develop the technology for both high speed and low speed compression that will expand unit flexibility, increase thermal efficiency, and increase reliability and integrity. Retrofit technologies that address the challenges of slow-speed integral compression are: (1) optimum turndown using a combination of speed and clearance with single-acting operation as a last resort; (2) if single-acting is required, implement infinite length nozzles to address nozzle pulsation and tunable side branch absorbers for 1x lateral pulsations; and (3) advanced valves, either the semi-active plate valve or the passive rotary valve, to extend valve life to three years with half the pressure drop. This next generation of slow-speed compression should attain 95% efficiency, a three-year valve life, and expanded turndown. New equipment technologies that address the challenges of large-horsepower, high-speed compression are: (1) optimum turndown with unit speed; (2) tapered nozzles to effectively reduce nozzle pulsation with half the pressure drop and minimization of mechanical cylinder stretch induced vibrations; (3) tunable side branch absorber or higher-order filter bottle to address lateral piping pulsations over the entire extended speed range with minimal pressure drop; and (4) semi-active plate valves or passive rotary valves to extend valve life with half the pressure drop. This next generation of large-horsepower, high-speed compression should attain 90% efficiency, a two-year valve life, 50% turndown, and less than 0.75 IPS vibration. This program has generated proof-of-concept technologies with the potential to meet these ambitious goals. Full development of these identified technologies is underway. The GMRC has committed to pursue the most promising enabling technologies for their industry.

Danny M. Deffenbaugh; Klaus Brun; Ralph E. Harris; J. Pete Harrell; Robert J. Mckee; J. Jeffrey Moore; Steven J. Svedeman; Anthony J. Smalley; Eugene L. Broerman; Robert A Hart; Marybeth G. Nored; Ryan S. Gernentz; Shane P. Siebenaler

2005-12-01T23:59:59.000Z

88

Measuring Devices: Compressed Natural Gas Retail Motor ...  

Science Conference Proceedings (OSTI)

Compressed Natural Gas Retail Motor-Fuel Dispensers. ... Hydrogen Measuring Devices; Liquefied Petroleum Gas Liquid-Measuring Devices; ...

2010-10-05T23:59:59.000Z

89

Tunable Compression of Wind Tunnel Data  

Science Conference Proceedings (OSTI)

Tunable Compression of Wind Tunnel Data. Summary: Measurements of pressures exerted by wind on buildings, as are ...

2010-09-12T23:59:59.000Z

90

Compression and Hydration Effects of PFSA Membranes  

E-Print Network (OSTI)

compression requires a testing system that is more sophisticated than the conventional methods (such as weight balance or vapor

Kusoglu, Ahmet

2013-01-01T23:59:59.000Z

91

Performance Variability  

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

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

92

Compressed air energy storage system  

DOE Patents (OSTI)

An internal combustion reciprocating engine is operable as a compressor during slack demand periods utilizing excess power from a power grid to charge air into an air storage reservoir and as an expander during peak demand periods to feed power into the power grid utilizing air obtained from the air storage reservoir together with combustible fuel. Preferably the internal combustion reciprocating engine is operated at high pressure and a low pressure turbine and compressor are also employed for air compression and power generation.

Ahrens, Frederick W. (Naperville, IL); Kartsounes, George T. (Naperville, IL)

1981-01-01T23:59:59.000Z

93

Bit-Optimal Lempel-Ziv compression  

E-Print Network (OSTI)

One of the most famous and investigated lossless data-compression scheme is the one introduced by Lempel and Ziv about 40 years ago. This compression scheme is known as "dictionary-based compression" and consists of squeezing an input string by replacing some of its substrings with (shorter) codewords which are actually pointers to a dictionary of phrases built as the string is processed. Surprisingly enough, although many fundamental results are nowadays known about upper bounds on the speed and effectiveness of this compression process and references therein), ``we are not aware of any parsing scheme that achieves optimality when the LZ77-dictionary is in use under any constraint on the codewords other than being of equal length'' [N. Rajpoot and C. Sahinalp. Handbook of Lossless Data Compression, chapter Dictionary-based data compression. Academic Press, 2002. pag. 159]. Here optimality means to achieve the minimum number of bits in compressing each individual input string, without any assumption on its ge...

Ferragina, Paolo; Venturini, Rossano

2008-01-01T23:59:59.000Z

94

SPECTRUM analysis of multispectral imagery in conjunction with wavelet/KLT data compression  

SciTech Connect

The data analysis program, SPECTRUM, is used for fusion, visualization, and classification of multi-spectral imagery. The raw data used in this study is Landsat Thematic Mapper (TM) 7-channel imagery, with 8 bits of dynamic range per channel. To facilitate data transmission and storage, a compression algorithm is proposed based on spatial wavelet transform coding and KLT decomposition of interchannel spectral vectors, followed by adaptive optimal multiband scalar quantization. The performance of SPECTRUM clustering and visualization is evaluated on compressed multispectral data. 8-bit visualizations of 56-bit data show little visible distortion at 50:1 compression and graceful degradation at higher compression ratios. Two TM images were processed in this experiment: a 1024 x 1024-pixel scene of the region surrounding the Chernobyl power plant, taken a few months before the reactor malfunction, and a 2048 x 2048 image of Moscow and surrounding countryside.

Bradley, J.N.; Brislawn, C.M.

1993-12-01T23:59:59.000Z

95

Effect of Compressibility on the Annihilation Process  

E-Print Network (OSTI)

Annihilation processes, where the reacting particles are influenced by some external advective field, are one of the simplest examples of nonlinear statistical systems. This type of processes can be observed in miscellaneous chemical, biological or physical systems. In low space dimensions usual description by means of kinetic rate equation is not sufficient and the effect of density fluctuations must be taken into ac- count. Using perturbative renormalization group we study the influ- ence of random velocity field on the kinetics of single-species annihila- tion reaction at and below its critical dimension $d_c = 2$. The advecting velocity field is modelled by the self-similar in space Gaussian variable finite correlated in time (Antonov-Kraichnan model). Effect of the compressibility of velocity field is taken into account and the model is analyzed near its critical dimension by means of three-parameter expansion in $\\epsilon$, $\\Delta$ and $\\eta$. Here $\\epsilon$ is the deviation from the Kolmogorov scaling, $\\Delta$ is the deviation from the (critical) space dimension 2 and {\\eta} is the deviation from the parabolic dispersion law. Depending on the value of these exponents and the value of compressiblity parameter {\\alpha}, the studied model can exhibit various asymptotic (long-time) regimes corresponding to the infrared (IR) fixed points of the renormalization group. The possible regimes are summarized and the decay rates for the mean particle number are calculated in the leading order of the perturbation theory.

Michal Hnati?; Juha Honkonen; Tomáš Lu?ivjanský

2013-02-01T23:59:59.000Z

96

Industrial Compressed Air System Energy Efficiency Guidebook.  

DOE Green Energy (OSTI)

Energy efficient design, operation and maintenance of compressed air systems in industrial plants can provide substantial reductions in electric power and other operational costs. This guidebook will help identify cost effective, energy efficiency opportunities in compressed air system design, re-design, operation and maintenance. The guidebook provides: (1) a broad overview of industrial compressed air systems, (2) methods for estimating compressed air consumption and projected air savings, (3) a description of applicable, generic energy conservation measures, and, (4) a review of some compressed air system demonstration projects that have taken place over the last two years. The primary audience for this guidebook includes plant maintenance supervisors, plant engineers, plant managers and others interested in energy management of industrial compressed air systems.

United States. Bonneville Power Administration.

1993-12-01T23:59:59.000Z

97

220-MW compressed air storage  

Science Conference Proceedings (OSTI)

SOYLAND Power Cooperative, Inc., a Decatur, Illinois based co-op, could get reasonably priced baseload power from neighboring utilities, had a plant of its own planned for the near future as well as a share in another, but peaking power, generated by oil and gas, to meet surges in demand, was very costly. The co-op's solution, first in the U.S., is a 220-megawatt compressed air energy storage system (CAES), which the electric utility industry is watching with great interest. CAES splits the two basic stages of a conventional gas turbine, making the most of baseload power while using the least peaking or intermediate fuel. During off-peak periods, inexpensive baseload electricity from coal or nuclear power plants runs a combination motor-generator in motor mode which, in turn, operates a compressor. The compressed air is cooled and pumped into an underground storage reservoir hundreds of thousands of cubic yards in volume and about two thousand feet (about 610 m) below the surface. There the air remains, at pressures up to about 60 atm (6.1 MPa), until peaking or intermediate power is required. Then, the air is released into a combustor at a controlled rate, heated by oil or gas, and expanded through a turbine. The turbine drives the motor-generator in a generator mode, thereby supplying peaking or intermediate power to the grid.

Lihach, N.

1983-01-01T23:59:59.000Z

98

Compressed sensing for multidimensional electronic spectroscopy experiments  

E-Print Network (OSTI)

Compressed sensing is a processing method that significantly reduces the number of measurements needed to accurately resolve signals in many fields of science and engineering. We develop a two-dimensional (2D) variant of compressed sensing for multidimensional electronic spectroscopy and apply it to experimental data. For the model system of atomic rubidium vapor, we find that compressed sensing provides significantly better resolution of 2D spectra than a conventional discrete Fourier transform from the same experimental data. We believe that by combining powerful resolution with ease of use, compressed sensing can be a powerful tool for the analysis and interpretation of ultrafast spectroscopy data.

J. N. Sanders; S. Mostame; S. K. Saikin; X. Andrade; J. R. Widom; A. H. Marcus; A. Aspuru-Guzik

2012-07-16T23:59:59.000Z

99

Compressed Air Energy Storage Act (Kansas)  

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

This act lays out regulations for the local authorities related to site selection, design, operation and monitoring for underground storage of compressed air.

100

Fuel Cell Technologies Office: Hydrogen Compression, Storage...  

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

of Energy's (DOE's) Argonne National Laboratory (ANL) held a Hydrogen Compression, Storage, and Dispensing Cost Reduction Workshop on March 20-21, 2013, in Argonne, Illinois....

Note: This page contains sample records for the topic "variable compression ratio" 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

Advanced Manufacturing Office: Compressed Air Systems  

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

training and other resources Training Calendar Events Calendar Tools Tools to Assess Your Energy System AIRMaster+ Tool Scorecards and Simple Calculators Compressed Air Scorecard...

102

Optimization of Storage vs. Compression Capacity  

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

Storage Volume vs. Compression Capacity Amgad Elgowainy Argonne National Laboratory Presentation at CSD Workshop Argonne National Laboratory March 21, 2013 0 5 10 15 20 25 0 100...

103

Novel Concepts for the Compression of Large Volumes of Carbon Dioxide  

SciTech Connect

In the effort to reduce the release of CO{sub 2} greenhouse gases to the atmosphere, sequestration of CO{sub 2} from Integrated Gasification Combined Cycle (IGCC) and Oxy-Fuel power plants is being pursued. This approach, however, requires significant compression power to boost the pressure to typical pipeline levels. The penalty can be as high as 8% to 12% on a typical IGCC plant. The goal of this research is to reduce this penalty through novel compression concepts and integration with existing IGCC processes. The primary objective of the study of novel CO{sub 2} compression concepts is to boost the pressure of CO{sub 2} to pipeline pressures with the minimal amount of energy required. Fundamental thermodynamics were studied to explore pressure rise in both liquid and gaseous states. For gaseous compression, the project investigated novel methods to compress CO{sub 2} while removing the heat of compression internal to the compressor. The high-pressure ratio due to the delivery pressure of the CO{sub 2} for enhanced oil recovery results in significant heat of compression. Since less energy is required to boost the pressure of a cooler gas stream, both upstream and interstage cooling is desirable. While isothermal compression has been utilized in some services, it has not been optimized for the IGCC environment. This project determined the optimum compressor configuration and developed technology concepts for internal heat removal. Other compression options using liquefied CO{sub 2} and cryogenic pumping were explored as well. Preliminary analysis indicates up to a 35% reduction in power is possible with the new concepts being considered.

J. Jeffrey Moore; Marybeth G. Nored; Ryan S. Gernentz; Klaus Brun

2007-09-30T23:59:59.000Z

104

Determination of Friction Coefficient in Unconfined Compression of Brain Tissue  

E-Print Network (OSTI)

Unconfined compression tests are more convenient to perform on cylindrical samples of brain tissue than tensile tests in order to estimate mechanical properties of the brain tissue because they allow for homogeneous deformations. The reliability of these tests depends significantly on the amount of friction generated at the specimen/platen interface. Thus, there is a crucial need to find an approximate value of the friction coefficient in order to predict a possible overestimation of stresses during unconfined compression tests. In this study, a combined experimental-computational approach was adopted to estimate the dynamic friction coefficient mu of porcine brain matter against metal platens in compressive tests. Cylindrical samples of porcine brain tissue were tested up to 30% strain at variable strain rates, both under bonded and lubricated conditions in the same controlled environment. It was established that mu was equal to 0.09 +/- 0.03, 0.18 +/- 0.04, 0.18 +/- 0.04 and 0.20 +/- 0.02 at strain rates of...

Rashid, Badar; Gilchrist, Michael; 10.1016/j.jmbbm.2012.05.001

2013-01-01T23:59:59.000Z

105

Variable selection and ranking for analyzing automobile traffic accident data  

Science Conference Proceedings (OSTI)

Variable ranking and feature selection are important concepts in data mining and machine learning. This paper introduces a new variable ranking technique named Sum Max Gain Ratio (SMGR). The new technique is evaluated within the domain of traffic accident ... Keywords: decision tree, traffic accident data, variable and feature selection, variable ranking

Huanjing Wang; Allen Parrish; Randy K. Smith; Susan Vrbsky

2005-03-01T23:59:59.000Z

106

The role of compressibility in energy release by magnetic reconnection  

SciTech Connect

Using resistive compressible magnetohydrodynamics, we investigate the energy release and transfer by magnetic reconnection in finite (closed or periodic) systems. The emphasis is on the magnitude of energy released and transferred to plasma heating in configurations that range from highly compressible to incompressible, based on the magnitude of the background {beta} (ratio of plasma pressure over magnetic pressure) and of a guide field in two-dimensional reconnection. As expected, the system becomes more incompressible, and the role of compressional heating diminishes, with increasing {beta} or increasing guide field. Nevertheless, compressional heating may dominate over Joule heating for values of the guide field of 2 or 3 (in relation to the reconnecting magnetic field component) and {beta} of 5-10. This result stems from the strong localization of the dissipation near the reconnection site, which is modeled based on particle simulation results. Imposing uniform resistivity, corresponding to a Lundquist number of 10{sup 3} to 10{sup 4}, leads to significantly larger Ohmic heating. Increasing incompressibility greatly reduces the magnetic flux transfer and the amount of energy released, from {approx}10% of the energy associated with the reconnecting field component, for zero guide field and low {beta}, to {approx}0.2%-0.4% for large values of the guide field B{sub y0}>5 or large {beta}. The results demonstrate the importance of taking into account plasma compressibility and localization of dissipation in investigations of heating by turbulent reconnection, possibly relevant for solar wind or coronal heating.

Birn, J.; Borovsky, J. E. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Hesse, M. [NASA/Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)

2012-08-15T23:59:59.000Z

107

A Space-Charge-Neutralizing Plasma for Beam Drift Compression  

SciTech Connect

Simultaneous radial focusing and longitudinal compression of intense ion beams are being studied to heat matter to the warm dense matter, or strongly coupled plasma regime. Higher compression ratios can be achieved if the beam compression takes place in a plasma-filled drift region in which the space-charge forces of the ion beam are neutralized. Recently, a system of four cathodic arc plasma sources has been fabricated and the axial plasma density has been measured. A movable plasma probe array has been developed to measure the radial and axial plasma distribution inside and outside of a {approx} 10 cm long final focus solenoid (FFS). Measured data show that the plasma forms a thin column of diameter {approx} 5 mm along the solenoid axis when the FFS is powered with an 8T field. Measured plasma density of {ge} 1 x 10{sup 13} cm{sup -3} meets the challenge of n{sub p}/Zn{sub b} > 1, where n{sub p} and n{sub b} are the plasma and ion beam density, respectively, and Z is the mean ion charge state of the plasma ions.

Roy, P.K.; Seidl, P.A.; Anders, A.; Bieniosek, F.M.; Coleman, J.E.; Gilson, E.P.; Greenway, W.; Grote, D.P.; Jung, J.Y.; Leitner, M.; Lidia, S.M.; Logan, B.G.; Sefkow, A.B.; Waldron, W.L.; Welch, D.R.

2008-08-01T23:59:59.000Z

108

Compressed Beamforming in Ultrasound Imaging  

E-Print Network (OSTI)

Emerging sonography techniques often require increasing the number of transducer elements involved in the imaging process. Consequently, larger amounts of data must be acquired and processed. The significant growth in the amounts of data affects both machinery size and power consumption. Within the classical sampling framework, state of the art systems reduce processing rates by exploiting the bandpass bandwidth of the detected signals. It has been recently shown, that a much more significant sample-rate reduction may be obtained, by treating ultrasound signals within the Finite Rate of Innovation framework. These ideas follow the spirit of Xampling, which combines classic methods from sampling theory with recent developments in Compressed Sensing. Applying such low-rate sampling schemes to individual transducer elements, which detect energy reflected from biological tissues, is limited by the noisy nature of the signals. This often results in erroneous parameter extraction, bringing forward the need to enhan...

Wagner, Noam; Feuer, Arie; Friedman, Zvi

2012-01-01T23:59:59.000Z

109

Compressed Air Audits using AIRMaster  

E-Print Network (OSTI)

Air compressors are a significant industrial energy user and therefore a prime target for industrial energy audits. The project goal was to develop a software tool, AIRMaster, and supporting methodology for performing compressed air system audits. Seven field audits were conducted to refine the software and methodology as well as assess the savings potential of six common Operation and Maintenance measures. Audit results yielded significant savings with short payback periods. Total estimated savings for the project were 4,056,000 kWh or 49.2% of annual compressor energy for a cost savings of $152,000. Total implementation costs were $94,700 for a project payback period of 0.6 years. Capital benefits of delaying or avoiding the cost of a new compressor might double the energy benefits if a new compressor is being considered. The methodology proved to be a simple and effective audit tool.

Wheeler, G. M.; McGill, R. D.; Bessey, E. G.; Vischer, K.

1997-04-01T23:59:59.000Z

110

Compression molding of aerogel microspheres  

DOE Patents (OSTI)

An aerogel composite material produced by compression molding of aerogel microspheres (powders) mixed together with a small percentage of polymer binder to form monolithic shapes in a cost-effective manner. The aerogel composites are formed by mixing aerogel microspheres with a polymer binder, placing the mixture in a mold and heating under pressure, which results in a composite with a density of 50-800 kg/m.sup.3 (0.05-0.80 g/cc). The thermal conductivity of the thus formed aerogel composite is below that of air, but higher than the thermal conductivity of monolithic aerogels. The resulting aerogel composites are attractive for applications such as thermal insulation since fabrication thereof does not require large and expensive processing equipment. In addition to thermal insulation, the aerogel composites may be utilized for filtration, ICF target, double layer capacitors, and capacitive deionization.

Pekala, Richard W. (Pleasant Hill, CA); Hrubesh, Lawrence W. (Pleasanton, CA)

1998-03-24T23:59:59.000Z

111

Compression molding of aerogel microspheres  

DOE Patents (OSTI)

An aerogel composite material produced by compression molding of aerogel microspheres (powders) mixed together with a small percentage of polymer binder to form monolithic shapes in a cost-effective manner is disclosed. The aerogel composites are formed by mixing aerogel microspheres with a polymer binder, placing the mixture in a mold and heating under pressure, which results in a composite with a density of 50--800 kg/m{sup 3} (0.05--0.80 g/cc). The thermal conductivity of the thus formed aerogel composite is below that of air, but higher than the thermal conductivity of monolithic aerogels. The resulting aerogel composites are attractive for applications such as thermal insulation since fabrication thereof does not require large and expensive processing equipment. In addition to thermal insulation, the aerogel composites may be utilized for filtration, ICF target, double layer capacitors, and capacitive deionization. 4 figs.

Pekala, R.W.; Hrubesh, L.W.

1998-03-24T23:59:59.000Z

112

Alternative Fuels Data Center: Compressed Natural Gas (CNG) Deregulation  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Compressed Natural Gas Compressed Natural Gas (CNG) Deregulation to someone by E-mail Share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Deregulation on Facebook Tweet about Alternative Fuels Data Center: Compressed Natural Gas (CNG) Deregulation on Twitter Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Deregulation on Google Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Deregulation on Delicious Rank Alternative Fuels Data Center: Compressed Natural Gas (CNG) Deregulation on Digg Find More places to share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Deregulation on AddThis.com... More in this section... Federal State Advanced Search All Laws & Incentives Sorted by Type Compressed Natural Gas (CNG) Deregulation

113

Alternative Fuels Data Center: Compressed Natural Gas (CNG) Deregulation  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Compressed Natural Gas Compressed Natural Gas (CNG) Deregulation to someone by E-mail Share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Deregulation on Facebook Tweet about Alternative Fuels Data Center: Compressed Natural Gas (CNG) Deregulation on Twitter Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Deregulation on Google Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Deregulation on Delicious Rank Alternative Fuels Data Center: Compressed Natural Gas (CNG) Deregulation on Digg Find More places to share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Deregulation on AddThis.com... More in this section... Federal State Advanced Search All Laws & Incentives Sorted by Type Compressed Natural Gas (CNG) Deregulation

114

Alternative Fuels Data Center: Compressed Natural Gas Fueling Stations  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Compressed Natural Gas Compressed Natural Gas Fueling Stations to someone by E-mail Share Alternative Fuels Data Center: Compressed Natural Gas Fueling Stations on Facebook Tweet about Alternative Fuels Data Center: Compressed Natural Gas Fueling Stations on Twitter Bookmark Alternative Fuels Data Center: Compressed Natural Gas Fueling Stations on Google Bookmark Alternative Fuels Data Center: Compressed Natural Gas Fueling Stations on Delicious Rank Alternative Fuels Data Center: Compressed Natural Gas Fueling Stations on Digg Find More places to share Alternative Fuels Data Center: Compressed Natural Gas Fueling Stations on AddThis.com... More in this section... Natural Gas Basics Benefits & Considerations Stations Locations Infrastructure Development Compressed Natural Gas Stations

115

Alternative Fuels Data Center: Compressed Natural Gas (CNG) Deregulation  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Compressed Natural Gas Compressed Natural Gas (CNG) Deregulation to someone by E-mail Share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Deregulation on Facebook Tweet about Alternative Fuels Data Center: Compressed Natural Gas (CNG) Deregulation on Twitter Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Deregulation on Google Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Deregulation on Delicious Rank Alternative Fuels Data Center: Compressed Natural Gas (CNG) Deregulation on Digg Find More places to share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Deregulation on AddThis.com... More in this section... Federal State Advanced Search All Laws & Incentives Sorted by Type Compressed Natural Gas (CNG) Deregulation

116

High dynamic range texture compression for graphics hardware  

Science Conference Proceedings (OSTI)

In this paper, we break new ground by presenting algorithms for fixed-rate compression of high dynamic range textures at low bit rates. First, the S3TC low dynamic range texture compression scheme is extended in order to enable compression of HDR data. ... Keywords: graphics hardware, high dynamic range images, image compression, texture compression

Jacob Munkberg; Petrik Clarberg; Jon Hasselgren; Tomas Akenine-Möller

2006-07-01T23:59:59.000Z

117

Compression techniques for fast external sorting  

Science Conference Proceedings (OSTI)

External sorting of large files of records involves use of disk space to store temporary files, processing time for sorting, and transfer time between CPU, cache, memory, and disk. Compression can reduce disk and transfer costs, and, in the case of external ... Keywords: External sorting, Query evaluation, Semi-static compression, Sorting

John Yiannis; Justin Zobel

2007-04-01T23:59:59.000Z

118

A compressible flow model with capillary effects  

Science Conference Proceedings (OSTI)

A quasi-conservative formulation for compressible flows with interfaces including both capillary and viscous effects is developed. The model involves: (i) acoustic and convective transport; (ii) surface tension effects introduced as an extension of the ... Keywords: break-up, coalescence, compressibility, conservative formulation, interface capturing, mixture thermodynamics, surface tension, two-phase flows, viscosity

Guillaume Perigaud; Richard Saurel

2005-10-01T23:59:59.000Z

119

Discriminative sentence compression with conditional random fields  

Science Conference Proceedings (OSTI)

The paper focuses on a particular approach to automatic sentence compression which makes use of a discriminative sequence classifier known as Conditional Random Fields (CRF). We devise several features for CRF that allow it to incorporate information ... Keywords: Conditional random fields, Machine learning, Natural language syntax, RSS, Sentence compression, Sequence alignment

Tadashi Nomoto

2007-11-01T23:59:59.000Z

120

Secure Compressed Reading in Smart Grids  

E-Print Network (OSTI)

Smart Grids measure energy usage in real-time and tailor supply and delivery accordingly, in order to improve power transmission and distribution. For the grids to operate effectively, it is critical to collect readings from massively-installed smart meters to control centers in an efficient and secure manner. In this paper, we propose a secure compressed reading scheme to address this critical issue. We observe that our collected real-world meter data express strong temporal correlations, indicating they are sparse in certain domains. We adopt Compressed Sensing technique to exploit this sparsity and design an efficient meter data transmission scheme. Our scheme achieves substantial efficiency offered by compressed sensing, without the need to know beforehand in which domain the meter data are sparse. This is in contrast to traditional compressed-sensing based scheme where such sparse-domain information is required a priori. We then design specific dependable scheme to work with our compressed sensing based ...

Cai, Sheng; Chen, Minghua; Yan, Jianxin; Jaggi, Sidharth

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "variable compression ratio" 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

EA-1752: Pacific Gas & Electric, Compressed Air Energy Storage Compression  

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

52: Pacific Gas & Electric, Compressed Air Energy Storage 52: Pacific Gas & Electric, Compressed Air Energy Storage Compression Testing Phase and Temporary Site Facilities, Kings Island, San Joaquin County, California EA-1752: Pacific Gas & Electric, Compressed Air Energy Storage Compression Testing Phase and Temporary Site Facilities, Kings Island, San Joaquin County, California Summary DOE prepared an EA to evaluate the potential environmental impacts of providing a financial assistance grant under the American Recovery and Reinvestment Act of 2009 for the construction of an advanced compressed air energy storage plant in San Francisco, California. Public Comment Opportunities Draft EA: Comment Period Ended 12/31/13. DOE will consider late submissions to the extent practicable. Comments should be marked "PG&E Compressed Air Energy Storage Draft EA

122

Modeling of homogeneous charge compression ignition (HCCI) of methane  

DOE Green Energy (OSTI)

The operation of piston engines on a compression ignition cycle using a lean, homogeneous charge has many potential attractive features. These include the potential for extremely low NO{sub x} and particulate emissions while maintaining high thermal efficiency and not requiring the expensive high pressure injection system of the typical modem diesel engine. Using the HCT chemical kinetics code to simulate autoignition of methane-air mixtures, we have explored the ignition timing, burn duration, NO{sub x} production, indicated efficiency and power output of an engine with a compression ratio of 15:1 at 1200 and 2400 rpm. HCT was modified to include the effects of heat transfer. This study used a single control volume reaction zone that varies as a function of crank angle. The ignition process is controlled by varying the intake equivalence ratio and varying the residual gas trapping (RGT). RGT is internal exhaust gas recirculation which recycles both heat and combustion product species. It is accomplished by varying the timing of the exhaust valve closure. Inlet manifold temperature was held constant at 330 Kelvins. Results show that there is a narrow range of operational conditions that show promise of achieving the control necessary to vary power output while keeping indicated efficiency above 50% and NO{sub x} levels below 100 ppm.

Smith, J.R.; Aceves, S.M.; Westbrook, C.; Pitz, W.

1997-05-01T23:59:59.000Z

123

Neural network control of air-to-fuel ratio in a bi-fuel engine  

Science Conference Proceedings (OSTI)

In this paper, a neural network-based control system is proposed for fine control of the intake air/fuel ratio in a bi-fuel engine. This control system is an add-on module for an existing vehicle manufacturer's electronic control units (ECUs). Typically ... Keywords: Artificial neural networks, bi-fuel engines, compressed natural gas (CNG), fuel injection control

G. Gnanam; S. R. Habibi; R. T. Burton; M. T. Sulatisky

2006-09-01T23:59:59.000Z

124

High ratio recirculating gas compressor  

DOE Patents (OSTI)

A high ratio positive displacement recirculating rotary compressor is disclosed. The compressor includes an integral heat exchanger and recirculation conduits for returning cooled, high pressure discharge gas to the compressor housing to reducing heating of the compressor and enable higher pressure ratios to be sustained. The compressor features a recirculation system which results in continuous and uninterrupted flow of recirculation gas to the compressor with no direct leakage to either the discharge port or the intake port of the compressor, resulting in a capability of higher sustained pressure ratios without overheating of the compressor.

Weinbrecht, John F. (601 Oakwood Pl., NE., Albuquerque, NM 87123)

1989-01-01T23:59:59.000Z

125

High ratio recirculating gas compressor  

DOE Patents (OSTI)

A high ratio positive displacement recirculating rotary compressor is disclosed. The compressor includes an integral heat exchanger and recirculation conduits for returning cooled, high pressure discharge gas to the compressor housing to reducing heating of the compressor and enable higher pressure ratios to be sustained. The compressor features a recirculation system which results in continuous and uninterrupted flow of recirculation gas to the compressor with no direct leakage to either the discharge port or the intake port of the compressor, resulting in a capability of higher sustained pressure ratios without overheating of the compressor. 10 figs.

Weinbrecht, J.F.

1989-08-22T23:59:59.000Z

126

Alternative Fuels Data Center: Compressed Natural Gas (CNG) Vehicle  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Compressed Natural Gas Compressed Natural Gas (CNG) Vehicle Aftermarket Conversion Requirements to someone by E-mail Share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Vehicle Aftermarket Conversion Requirements on Facebook Tweet about Alternative Fuels Data Center: Compressed Natural Gas (CNG) Vehicle Aftermarket Conversion Requirements on Twitter Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Vehicle Aftermarket Conversion Requirements on Google Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Vehicle Aftermarket Conversion Requirements on Delicious Rank Alternative Fuels Data Center: Compressed Natural Gas (CNG) Vehicle Aftermarket Conversion Requirements on Digg Find More places to share Alternative Fuels Data Center: Compressed

127

Alternative Fuels Data Center: Compressed Natural Gas (CNG) Vehicle Rebate  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Compressed Natural Gas Compressed Natural Gas (CNG) Vehicle Rebate - Metropolitan Utilities District to someone by E-mail Share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Vehicle Rebate - Metropolitan Utilities District on Facebook Tweet about Alternative Fuels Data Center: Compressed Natural Gas (CNG) Vehicle Rebate - Metropolitan Utilities District on Twitter Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Vehicle Rebate - Metropolitan Utilities District on Google Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Vehicle Rebate - Metropolitan Utilities District on Delicious Rank Alternative Fuels Data Center: Compressed Natural Gas (CNG) Vehicle Rebate - Metropolitan Utilities District on Digg Find More places to share Alternative Fuels Data Center: Compressed

128

Alternative Fuels Data Center: Compressed Natural Gas (CNG) Fueling  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Compressed Natural Gas Compressed Natural Gas (CNG) Fueling Infrastructure Development to someone by E-mail Share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Fueling Infrastructure Development on Facebook Tweet about Alternative Fuels Data Center: Compressed Natural Gas (CNG) Fueling Infrastructure Development on Twitter Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Fueling Infrastructure Development on Google Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Fueling Infrastructure Development on Delicious Rank Alternative Fuels Data Center: Compressed Natural Gas (CNG) Fueling Infrastructure Development on Digg Find More places to share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Fueling Infrastructure Development on AddThis.com...

129

Alternative Fuels Data Center: Compressed Natural Gas (CNG) Fueling  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Compressed Natural Gas Compressed Natural Gas (CNG) Fueling Infrastructure Inspection to someone by E-mail Share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Fueling Infrastructure Inspection on Facebook Tweet about Alternative Fuels Data Center: Compressed Natural Gas (CNG) Fueling Infrastructure Inspection on Twitter Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Fueling Infrastructure Inspection on Google Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Fueling Infrastructure Inspection on Delicious Rank Alternative Fuels Data Center: Compressed Natural Gas (CNG) Fueling Infrastructure Inspection on Digg Find More places to share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Fueling Infrastructure Inspection on AddThis.com...

130

EA-1752: Pacific Gas & Electric, Compressed Air Energy Storage...  

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

752: Pacific Gas & Electric, Compressed Air Energy Storage Compression Testing Phase and Temporary Site Facilities, Kings Island, San Joaquin County, California EA-1752: Pacific...

131

Microsoft Word - inactive 40915_Ramgen_Shock Wave Compression...  

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

to decouple compression, combustion and propulsion, and reduce the scale of the engine to 400kW. Subsequently, this decoupling led to recognition that the compression aspect...

132

Understanding the Effects of Compression and Constraint on Water...  

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

Understanding the Effects of Compression and Constraint on Water Uptake of Fuel-Cell Membranes Title Understanding the Effects of Compression and Constraint on Water Uptake of...

133

State Energy Program Helping Arkansans Convert to Compressed...  

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

State Energy Program Helping Arkansans Convert to Compressed Natural Gas State Energy Program Helping Arkansans Convert to Compressed Natural Gas January 25, 2012 - 4:30pm Addthis...

134

COMPRESSIVE STRESS SYSTEM FOR A GAS TURBINE ENGINE - Energy ...  

The present application provides a compressive stress system for a gas turbine engine. The compressive stress system may include a first bucket ...

135

An efficient compression scheme for bitmap indices  

Science Conference Proceedings (OSTI)

When using an out-of-core indexing method to answer a query, it is generally assumed that the I/O cost dominates the overall query response time. Because of this, most research on indexing methods concentrate on reducing the sizes of indices. For bitmap indices, compression has been used for this purpose. However, in most cases, operations on these compressed bitmaps, mostly bitwise logical operations such as AND, OR, and NOT, spend more time in CPU than in I/O. To speedup these operations, a number of specialized bitmap compression schemes have been developed; the best known of which is the byte-aligned bitmap code (BBC). They are usually faster in performing logical operations than the general purpose compression schemes, but, the time spent in CPU still dominates the total query response time. To reduce the query response time, we designed a CPU-friendly scheme named the word-aligned hybrid (WAH) code. In this paper, we prove that the sizes of WAH compressed bitmap indices are about two words per row for large range of attributes. This size is smaller than typical sizes of commonly used indices, such as a B-tree. Therefore, WAH compressed indices are not only appropriate for low cardinality attributes but also for high cardinality attributes.In the worst case, the time to operate on compressed bitmaps is proportional to the total size of the bitmaps involved. The total size of the bitmaps required to answer a query on one attribute is proportional to the number of hits. These indicate that WAH compressed bitmap indices are optimal. To verify their effectiveness, we generated bitmap indices for four different datasets and measured the response time of many range queries. Tests confirm that sizes of compressed bitmap indices are indeed smaller than B-tree indices, and query processing with WAH compressed indices is much faster than with BBC compressed indices, projection indices and B-tree indices. In addition, we also verified that the average query response time is proportional to the index size. This indicates that the compressed bitmap indices are efficient for very large datasets.

Wu, Kesheng; Otoo, Ekow J.; Shoshani, Arie

2004-04-13T23:59:59.000Z

136

ARM - Measurement - Backscatter depolarization ratio  

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

govMeasurementsBackscatter depolarization ratio govMeasurementsBackscatter depolarization ratio ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Backscatter depolarization ratio The ratio of cross polarized to co-polarized elastic backscatter. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments HSRL : High Spectral Resolution Lidar RL : Raman Lidar Field Campaign Instruments HSRL : High Spectral Resolution Lidar MIRAI : JAMSTEC Research Vessel Mirai MPL-AIR : Micropulse Lidar- Airborne

137

EA-1752: Pacific Gas & Electric, Compressed Air Energy Storage Compression  

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

752: Pacific Gas & Electric, Compressed Air Energy Storage 752: Pacific Gas & Electric, Compressed Air Energy Storage Compression Testing Phase and Temporary Site Facilities, Kings Island, San Joaquin County, California EA-1752: Pacific Gas & Electric, Compressed Air Energy Storage Compression Testing Phase and Temporary Site Facilities, Kings Island, San Joaquin County, California Summary DOE prepared an EA to evaluate the potential environmental impacts of providing a financial assistance grant under the American Recovery and Reinvestment Act of 2009 for the construction of an advanced compressed air energy storage plant in San Francisco, California. Public Comment Opportunities Draft EA: Comment Period Ends 12/31/13. DOE will consider late submissions to the extent practicable. A notice of availability will be published in The Record (Stockton) and the

138

Method for compression of binary data  

DOE Patents (OSTI)

The disclosed method for compression of a series of data bytes, based on LZSS-based compression methods, provides faster decompression of the stored data. The method involves the creation of a flag bit buffer in a random access memory device for temporary storage of flag bits generated during normal LZSS-based compression. The flag bit buffer stores the flag bits separately from their corresponding pointers and uncompressed data bytes until all input data has been read. Then, the flag bits are appended to the compressed output stream of data. Decompression can be performed much faster because bit manipulation is only required when reading the flag bits and not when reading uncompressed data bytes and pointers. Uncompressed data is read using byte length instructions and pointers are read using word instructions, thus reducing the time required for decompression.

Berlin, Gary J. (Beech Island, SC)

1996-01-01T23:59:59.000Z

139

Increased demand spurs gas compression industry  

Science Conference Proceedings (OSTI)

The increasing demand for natural gas in the last five years has led to dynamic development in the gas compression industry as producers and transmission companies expand operations to supply gas. To handle the increase, for example, transmission companies have been steadily adding new lines to the pipeline infrastructure--3,437 miles in 1995 and an estimated 4,088 miles in 1997. New compression for pipelines has also increased from 212,637 horsepower added in 1989 to an estimated 311,685 horsepower to be added in 1997. Four key trends which influence the gas compression business have developed since the mid 1980s: first, a steady resurgence of demand for natural gas each year; second, a phenomenal number of mergers and buyouts among gas compression companies; third, an alarming drop in average daily gas production per well since 1972; and fourth, high drilling activity in the Gulf of Mexico.

Honea, M. [Weatherford Enterra, Inc., Houston, TX (United States)

1997-10-01T23:59:59.000Z

140

Free energy and shock compression of diamond  

Science Conference Proceedings (OSTI)

The new approach has been developed to calculate the free energy in quasiharmonic approximation for homogeneous condensed matter. Common result has been demonstrated on an example of solid and liquid diamond at high pressures and temperatures of shock compression.

A. M. Molodets; M. A. Molodets; S. S. Nabatov

1998-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "variable compression ratio" 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

Seneca Compressed Air Energy Storage (CAES) Project  

DOE Green Energy (OSTI)

This document provides specifications for the process air compressor for a compressed air storage project, requests a budgetary quote, and provides supporting information, including compressor data, site specific data, water analysis, and Seneca CAES value drivers.

None

2012-11-30T23:59:59.000Z

142

Method for compression of binary data  

DOE Patents (OSTI)

The disclosed method for compression of a series of data bytes, based on LZSS-based compression methods, provides faster decompression of the stored data. The method involves the creation of a flag bit buffer in a random access memory device for temporary storage of flag bits generated during normal LZSS-based compression. The flag bit buffer stores the flag bits separately from their corresponding pointers and uncompressed data bytes until all input data has been read. Then, the flag bits are appended to the compressed output stream of data. Decompression can be performed much faster because bit manipulation is only required when reading the flag bits and not when reading uncompressed data bytes and pointers. Uncompressed data is read using byte length instructions and pointers are read using word instructions, thus reducing the time required for decompression.

Berlin, G.J.

1994-12-31T23:59:59.000Z

143

Pulse compression and prepulse suppression apparatus  

DOE Patents (OSTI)

A pulse compression and prepulse suppression apparatus (10) for time compressing the output of a laser (14). A pump pulse (46) is separated from a seed pulse (48) by a first polarized beam splitter (20) according to the orientation of a half wave plate (18). The seed pulse (48) is directed into an SBS oscillator (44) by two plane mirrors (22, 26) and a corner mirror (24), the corner mirror (24) being movable to adjust timing. The pump pulse (46) is directed into an SBS amplifier 34 wherein SBS occurs. The seed pulse (48), having been propagated from the SBS oscillator (44), is then directed through the SBS amplifier (34) wherein it sweeps the energy of the pump pulse (46) out of the SBS amplifier (34) and is simultaneously compressed, and the time compressed pump pulse (46) is emitted as a pulse output (52). A second polarized beam splitter (38) directs any undepleted pump pulse 58 away from the SBS oscillator (44).

Dane, C.B.; Hackel, L.A.; George, E.V.; Miller, J.L.; Krupke, W.F.

1993-11-09T23:59:59.000Z

144

Method for compression of binary data  

DOE Patents (OSTI)

The disclosed method for compression of a series of data bytes, based on LZSS-based compression methods, provides faster decompression of the stored data. The method involves the creation of a flag bit buffer in a random access memory device for temporary storage of flag bits generated during normal LZSS-based compression. The flag bit buffer stores the flag bits separately from their corresponding pointers and uncompressed data bytes until all input data has been read. Then, the flag bits are appended to the compressed output stream of data. Decompression can be performed much faster because bit manipulation is only required when reading the flag bits and not when reading uncompressed data bytes and pointers. Uncompressed data is read using byte length instructions and pointers are read using word instructions, thus reducing the time required for decompression. 5 figs.

Berlin, G.J.

1996-03-26T23:59:59.000Z

145

Effects of Sequence Partitioning on Compression Rate  

E-Print Network (OSTI)

In the paper, a theoretical work is done for investigating effects of splitting data sequence into packs of data set. We proved that a partitioning of data sequence is possible to find such that the entropy rate at each subsequence is lower than entropy rate of the source. Effects of sequence partitioning on overall compression rate are argued on the bases of partitioning statistics, and then, an optimization problem for an optimal partition is defined to improve overall compression rate of a sequence.

Alagoz, B Baykant

2010-01-01T23:59:59.000Z

146

Market Analysis for Natural Gas Compression Technologies  

Science Conference Proceedings (OSTI)

The natural gas compression market offers huge growth potential for the electric utility industry. As utilities search for ways to expand electricity sales, a combination of economic, environmental, and regulatory factors are further encouraging the use of electric motors in a market that has long been dominated by gas-driven systems. This report provides information and strategies that can help utilities capture a larger share of the gas compression market.

1997-03-21T23:59:59.000Z

147

Parametric internal waves in a compressible fluid  

E-Print Network (OSTI)

We describe the effect of vibration on a confined volume of fluid which is density stratified due to its compressibility. We show that internal gravity-acoustic waves can be parametrically destabilized by the vibration. The resulting instability is similar to the classic Faraday instability of surface waves, albeit modified by the compressible nature of the fluid. It may be possible to observe experimentally near a gas-liquid critical point.

Kausik S. Das; Stephen W. Morris; A. Bhattacharyay

2007-10-11T23:59:59.000Z

148

Parametric internal waves in a compressible fluid  

E-Print Network (OSTI)

We describe the effect of vibration on a confined volume of fluid which is density stratified due to its compressibility. We show that internal gravity-acoustic waves can be parametrically destabilized by the vibration. The resulting instability is similar to the classic Faraday instability of surface waves, albeit modified by the compressible nature of the fluid. It may be possible to observe experimentally near a gas-liquid critical point.

Das, Kausik S; Bhattacharyay, A

2007-01-01T23:59:59.000Z

149

Lossless compression of instrumentation data. Final report  

Science Conference Proceedings (OSTI)

This is our final report on Sandia National Laboratories Laboratory- Directed Research and Development (LDRD) project 3517.070. Its purpose has been to investigate lossless compression of digital waveform and image data, particularly the types of instrumentation data generated and processed at Sandia Labs. The three-year project period ran from October 1992 through September 1995. This report begins with a descriptive overview of data compression, with and without loss, followed by a summary of the activities on the Sandia project, including research at several universities and the development of waveform compression software. Persons who participated in the project are also listed. The next part of the report contains a general discussion of the principles of lossless compression. Two basic compression stages, decorrelation and entropy coding, are described and discussed. An example of seismic data compression is included. Finally, there is a bibliography of published research. Taken together, the published papers contain the details of most of the work and accomplishments on the project. This final report is primarily an overview, without the technical details and results found in the publications listed in the bibliography.

Stearns, S.D.

1995-11-01T23:59:59.000Z

150

Time-compression: systems concerns, usage, and benefits  

Science Conference Proceedings (OSTI)

With the proliferation of online multimedia content and the popularity of multimedia streaming systems, it is increasingly useful to be able to skim and browse multimedia quickly. A key technique that enables quick browsing of multimedia is time-compression. ... Keywords: compression granularity, compression rate, latency, multimedia, time-compression, video browsing

Nosa Omoigui; Liwei He; Anoop Gupta; Jonathan Grudin; Elizabeth Sanocki

1999-05-01T23:59:59.000Z

151

Alternative Fuels Data Center: Reduced Compressed Natural Gas (CNG) Fueling  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Reduced Compressed Reduced Compressed Natural Gas (CNG) Fueling Infrastructure Lease - AGL to someone by E-mail Share Alternative Fuels Data Center: Reduced Compressed Natural Gas (CNG) Fueling Infrastructure Lease - AGL on Facebook Tweet about Alternative Fuels Data Center: Reduced Compressed Natural Gas (CNG) Fueling Infrastructure Lease - AGL on Twitter Bookmark Alternative Fuels Data Center: Reduced Compressed Natural Gas (CNG) Fueling Infrastructure Lease - AGL on Google Bookmark Alternative Fuels Data Center: Reduced Compressed Natural Gas (CNG) Fueling Infrastructure Lease - AGL on Delicious Rank Alternative Fuels Data Center: Reduced Compressed Natural Gas (CNG) Fueling Infrastructure Lease - AGL on Digg Find More places to share Alternative Fuels Data Center: Reduced

152

Valuation Ratios and the Long-Run Stock Market Outlook: An Update  

E-Print Network (OSTI)

The use of price--earnings ratios and dividend-price ratios as forecasting variables for the stock market is examined using aggregate annual US data 1871 to 2000 and aggregate quarterly data for twelve countries since 1970. Various simple efficient-markets models of financial markets imply that these ratios should be useful in forecasting future dividend growth, future earnings growth, or future productivity growth. We conclude that, overall, the ratios do poorly in forecasting any of these.

John Campbell; John Y. Campbell; Robert Shiller; Robert J. Shiller

2001-01-01T23:59:59.000Z

153

Dynamic Time Expansion and Compression Using Nonlinear Waveguides  

DOE Patents (OSTI)

Dynamic time expansion or compression of a small amplitude input signal generated with an initial scale is performed using a nonlinear waveguide. A nonlinear waveguide having a variable refractive index is connected to a bias voltage source having a bias signal amplitude that is large relative to the input signal to vary the reflective index and concomitant speed of propagation of the nonlinear waveguide and an electrical circuit for applying the small amplitude signal and the large amplitude bias signal simultaneously to the nonlinear waveguide. The large amplitude bias signal with the input signal alters the speed of propagation of the small-amplitude signal with time in the nonlinear waveguide to expand or contract the initial time scale of the small-amplitude input signal.

Findikoglu, Alp T.; Hahn, Sangkoo F.; Jia, Quanxi

2004-06-22T23:59:59.000Z

154

Dynamic time expansion and compression using nonlinear waveguides  

DOE Patents (OSTI)

Dynamic time expansion or compression of a small-amplitude input signal generated with an initial scale is performed using a nonlinear waveguide. A nonlinear waveguide having a variable refractive index is connected to a bias voltage source having a bias signal amplitude that is large relative to the input signal to vary the reflective index and concomitant speed of propagation of the nonlinear waveguide and an electrical circuit for applying the small-amplitude signal and the large amplitude bias signal simultaneously to the nonlinear waveguide. The large amplitude bias signal with the input signal alters the speed of propagation of the small-amplitude signal with time in the nonlinear waveguide to expand or contract the initial time scale of the small-amplitude input signal.

Findikoglu, Alp T. (Los Alamos, NM); Hahn, Sangkoo F. (Los Alamos, NM); Jia, Quanxi (Los Alamos, NM)

2004-06-22T23:59:59.000Z

155

Stresses resulting from compression of bulk cotton lint fibers  

E-Print Network (OSTI)

The modulus of elasticity, Poisson's ratio and shear modulus of bulk cotton lint fibers were determined. The cotton lint was compressed in an MTS machine to a predetermined density, and the resilient forces induced by the cotton lint after being compressed were measured. Finite element analysis was used to model force on cotton bale ties, and determine the magnitude of the resilient forces on the bale ties. The nodal forces on the bale tie material were evaluated for three different bale tie materials to determine if bale tie breakage would occur. Young's modulus of bulk lint cotton was found to be 9 MPa and the Poisson's ratio was 0. 1, while 12 MPa was recorded for the shear modulus. The FEA analysis showed that round steel ties, at six ties per bale were loaded at 5.9 % of their tensile yield strength, and at 5.4 % for eight ties per bale. Plastic ties were loaded at 11.9 % of their tensile yield strength at six ties per bale, and at 10.8 % at eight ties per bale. The flat steel ties were loaded at 10.7 % of their tensile yield strength at six ties per bale, and at 9.4 % at eight ties per bale. Depth adjustment on the basis of the sample depth to the actual depth resulted in plastic ties being loaded to 84 % of their tensile yield strength at six ties per bale. Round steel ties were loaded to 62% and the flat steel ties were loaded to 66% at six ties per bale.

Chimbombi, Ezekiel Maswe

1998-01-01T23:59:59.000Z

156

Low-Fuel Compressed Air Energy Storage System Development and Preliminary Evaluation  

Science Conference Proceedings (OSTI)

Compressed air energy storage (CAES) is a valuable solution for mitigating the current challenges of renewable power variability, facilitating future higher renewable penetration levels, enhancing grid reliability and improving the utilization of transmission and existing generation assets. Fuel-based CAES systems are subject to future natural gas price volatility and potential carbon dioxide (CO2) emission charges. Low-Fuel CAES (LFCAES) is a potential near-term technology that captures and stores heat ...

2010-12-17T23:59:59.000Z

157

Reference Design Description and Cost Evaluation for Compressed Air Energy Storage Systems  

Science Conference Proceedings (OSTI)

Compressed-air energy storage (CAES) is a valuable solution for mitigating the current challenges of renewable-power variability, facilitating higher renewable penetration levels, enhancing grid reliability, and improving the utilization of transmission and generation assets. However, capital costs play a critical role in evaluating the overall CAES value proposition, at least relative to direct-market revenues (energy and ancillary services). Although the first U.S. CAES plant in Alabama was built at co...

2011-12-21T23:59:59.000Z

158

compressed natural gas | OpenEI  

Open Energy Info (EERE)

compressed natural gas compressed natural gas Dataset Summary Description Alternative fueling stations are located throughout the United States and their availability continues to grow. The Alternative Fuels Data Center (AFDC) maintains a website where you can find alternative fuels stations near you or on a route, obtain counts of alternative fuels stations by state, Source Alternative Fuels Data Center Date Released December 13th, 2010 (3 years ago) Date Updated December 13th, 2010 (3 years ago) Keywords alt fuel alternative fuels alternative fuels stations biodiesel CNG compressed natural gas E85 Electricity ethanol hydrogen liquefied natural gas LNG liquefied petroleum gas LPG propane station locations Data text/csv icon alt_fuel_stations_apr_4_2012.csv (csv, 2.3 MiB) Quality Metrics

159

Energy Efficiency in Compressed Air Systems  

E-Print Network (OSTI)

Energy use in compressed air systems accounts for typically 10% of the total industrial electricity consumption. It also accounts for close to 99% of the CO2 footprint of an air compressor and approximately 80% of the life cycle costs of a compressor, over its lifetime. Considering these facts, it is sometimes surprising to see the lack of attention to compressed air systems in industry. This paper attempts to create awareness as to how a great deal of energy can be saved through a conscious process of selection and use of compressed air systems, bringing substantial benefits in economics and the environment. It also attempts to highlight the relative importance of energy savings over the costs of investments made in energy saving features and processes.

Hingorani, A.; Pavlov, A.

2010-01-01T23:59:59.000Z

160

Dictionary Approaches To Image Compression And Reconstruction  

E-Print Network (OSTI)

This paper proposes using a collection of parameterized waveforms, known as a dictionary, for the purpose of medical image compression. These waveforms, denoted as f g , are discrete time signals, where g represents the dictionary index. A dictionary with a collection of these waveforms is typically complete or overcomplete. Given such a dictionary, the goal is to obtain a representation image based on the dictionary. We examine the effectiveness of applying Basis Pursuit (BP), Best Orthogonal Basis (BOB), Matching Pursuits (MP), and the Method of Frames (MOF) methods for the compression of digitized radiological images with a wavelet-packet dictionary. The performance of these algorithms is studied for medical images with and without additive noise. Keywords: Image coding and compression, Medical Image Processing, Signal Reconstruction, Wavelets Prepared through collaborative participation in the Advanced Telecommunications/Information Distribution Research Program (ATIRP) Consortiu...

Nigel A. Ziyad; Erwin T. Gilmore; Mohamed F. Chouikha

1998-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "variable compression ratio" 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

Alternative Fuels Data Center: Compressed Natural Gas (CNG) Tax  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Compressed Natural Gas Compressed Natural Gas (CNG) Tax to someone by E-mail Share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Tax on Facebook Tweet about Alternative Fuels Data Center: Compressed Natural Gas (CNG) Tax on Twitter Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Tax on Google Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Tax on Delicious Rank Alternative Fuels Data Center: Compressed Natural Gas (CNG) Tax on Digg Find More places to share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Tax on AddThis.com... More in this section... Federal State Advanced Search All Laws & Incentives Sorted by Type Compressed Natural Gas (CNG) Tax CNG is taxed at a rate of $0.10 per gallon when used as a motor fuel. CNG

162

Alternative Fuels Data Center: State Compressed Natural Gas (CNG) Study  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Compressed Compressed Natural Gas (CNG) Study to someone by E-mail Share Alternative Fuels Data Center: State Compressed Natural Gas (CNG) Study on Facebook Tweet about Alternative Fuels Data Center: State Compressed Natural Gas (CNG) Study on Twitter Bookmark Alternative Fuels Data Center: State Compressed Natural Gas (CNG) Study on Google Bookmark Alternative Fuels Data Center: State Compressed Natural Gas (CNG) Study on Delicious Rank Alternative Fuels Data Center: State Compressed Natural Gas (CNG) Study on Digg Find More places to share Alternative Fuels Data Center: State Compressed Natural Gas (CNG) Study on AddThis.com... More in this section... Federal State Advanced Search All Laws & Incentives Sorted by Type State Compressed Natural Gas (CNG) Study At the direction of the Alaska Legislature, the Department of

163

Alternative Fuels Data Center: Compressed Natural Gas (CNG) Project Loans  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Compressed Natural Gas Compressed Natural Gas (CNG) Project Loans to someone by E-mail Share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Project Loans on Facebook Tweet about Alternative Fuels Data Center: Compressed Natural Gas (CNG) Project Loans on Twitter Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Project Loans on Google Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Project Loans on Delicious Rank Alternative Fuels Data Center: Compressed Natural Gas (CNG) Project Loans on Digg Find More places to share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Project Loans on AddThis.com... More in this section... Federal State Advanced Search All Laws & Incentives Sorted by Type Compressed Natural Gas (CNG) Project Loans

164

General Compression Looks at Energy Storage from a Different Angle |  

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

General Compression Looks at Energy Storage from a Different Angle General Compression Looks at Energy Storage from a Different Angle General Compression Looks at Energy Storage from a Different Angle February 3, 2011 - 3:36pm Addthis Image of the General Compression CAES system | courtesy of General Compression, Inc. Image of the General Compression CAES system | courtesy of General Compression, Inc. April Saylor April Saylor Former Digital Outreach Strategist, Office of Public Affairs Earlier this week, we told you about a new company that's developing battery technology that will allow energy storage for multiple hours on the power grid. General Compression is another innovative company that's developing a different way to store electricity by using compressed air energy storage, or CAES. The technology uses cheap power to pump air into

165

Alternative Fuels Data Center: Compressed Natural Gas (CNG) Permit  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Compressed Natural Gas Compressed Natural Gas (CNG) Permit to someone by E-mail Share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Permit on Facebook Tweet about Alternative Fuels Data Center: Compressed Natural Gas (CNG) Permit on Twitter Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Permit on Google Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Permit on Delicious Rank Alternative Fuels Data Center: Compressed Natural Gas (CNG) Permit on Digg Find More places to share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Permit on AddThis.com... More in this section... Federal State Advanced Search All Laws & Incentives Sorted by Type Compressed Natural Gas (CNG) Permit Anyone dispensing CNG for use in vehicles must obtain a permit from the

166

General Compression Looks at Energy Storage from a Different Angle |  

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

General Compression Looks at Energy Storage from a Different Angle General Compression Looks at Energy Storage from a Different Angle General Compression Looks at Energy Storage from a Different Angle February 3, 2011 - 3:36pm Addthis Image of the General Compression CAES system | courtesy of General Compression, Inc. Image of the General Compression CAES system | courtesy of General Compression, Inc. April Saylor April Saylor Former Digital Outreach Strategist, Office of Public Affairs Earlier this week, we told you about a new company that's developing battery technology that will allow energy storage for multiple hours on the power grid. General Compression is another innovative company that's developing a different way to store electricity by using compressed air energy storage, or CAES. The technology uses cheap power to pump air into

167

Alternative Fuels Data Center: Compressed Natural Gas (CNG) Dealer Permit  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Compressed Natural Gas Compressed Natural Gas (CNG) Dealer Permit to someone by E-mail Share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Dealer Permit on Facebook Tweet about Alternative Fuels Data Center: Compressed Natural Gas (CNG) Dealer Permit on Twitter Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Dealer Permit on Google Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Dealer Permit on Delicious Rank Alternative Fuels Data Center: Compressed Natural Gas (CNG) Dealer Permit on Digg Find More places to share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Dealer Permit on AddThis.com... More in this section... Federal State Advanced Search All Laws & Incentives Sorted by Type Compressed Natural Gas (CNG) Dealer Permit

168

Argonne TTRDC - Engines - Home - combustion, compression ignition,  

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

* Combustion Visualization * Combustion Visualization * Compression-Ignition * Emissions Control * Fuel Injection and Sprays * Idling * Multi-Dimensional Modeling * Particulate Matter * Spark Ignition Green Racing GREET Hybrid Electric Vehicles Hydrogen & Fuel Cells Materials Modeling, Simulation & Software Plug-In Hybrid Electric Vehicles PSAT Smart Grid Student Competitions Technology Analysis Transportation Research and Analysis Computing Center Working With Argonne Contact TTRDC Engines Omnivorous engine tested by Thomas Wallner Thomas Wallner tests the omnivorous engine, a type of spark-ignition engine. Argonne's engine research is contributing to advances in technology that will impact the use of conventional and alternative fuels and the design of advanced technology vehicles. Compression Ignition

169

Techniques for optically compressing light intensity ranges  

DOE Patents (OSTI)

A pin hole camera assembly for use in viewing an object having a relatively large light intensity range, for example a crucible containing molten uranium in an atomic vapor laser isotope separator (AVLIS) system is disclosed herein. The assembly includes means for optically compressing the light intensity range appearing at its input sufficient to make it receivable and decipherable by a standard video camera. A number of different means for compressing the intensity range are disclosed. These include the use of photogray glass, the use of a pair of interference filters, and the utilization of a new liquid crystal notch filter in combination with an interference filter.

Rushford, Michael C. (Livermore, CA)

1989-01-01T23:59:59.000Z

170

Techniques for optically compressing light intensity ranges  

DOE Patents (OSTI)

A pin hole camera assembly for use in viewing an object having a relatively large light intensity range, for example a crucible containing molten uranium in an atomic vapor laser isotope separator (AVLIS) system is disclosed herein. The assembly includes means for optically compressing the light intensity range appearing at its input sufficient to make it receivable and decipherable by a standard video camera. A number of different means for compressing the intensity range are disclosed. These include the use of photogray glass, the use of a pair of interference filters, and the utilization of a new liquid crystal notch filter in combination with an interference filter. 18 figs.

Rushford, M.C.

1989-03-28T23:59:59.000Z

171

Wage Compression and Self-Employment  

E-Print Network (OSTI)

[Draft version, incomplete] Self-employment and entrepreneurship are important phenomena for questions ranging from the labour market options and behaviour of individuals to the overall growth dynamics of the economy. Here, we focus on how self-employment may arise in response to an important institutional feature of some economies: Wage compression resulting from institutional wage setting. We solve for the pattern of worker unemployment, wage employment, and entrepreneurship as a function of worker ability in a model that allows the workers to switch to self-employment after a period of wage employment during which the workers learn and become more productive. Wage compression can result in workers becoming self-employed in equilibrium for “carrrot ” and “stick ” reasons. Low-skilled workers may not be offered formal wage employment because the institutionallyset wage may be above their productivity. High-skilled workers may choose entrepreneurship over wage employment because the compressed wage would pay them less than their productivity. For some parameterisations, workers with intermediate skills may prefer to learn during a period of wage employment before switching, but are forced into selfemployment at time zero because firms calculate that the worker will 1 switch too early for the firm to make a profit. While our focus is primarily on the positive economics of wage compression, we also note the inefficiencies induced by the firm and worker responses to these constraints. 1

Nikolaj Malchow-møller; James R. Markusen; Jan Rose Skaksen

2004-01-01T23:59:59.000Z

172

Compressing tags to find interesting media groups  

Science Conference Proceedings (OSTI)

On photo sharing websites like Flickr and Zooomr, users are offered the possibility to assign tags to their uploaded pictures. Using these tags to find interesting groups of semantically related pictures in the result set of a given query is a problem ... Keywords: compression, tags

Matthijs van Leeuwen; Francesco Bonchi; Börkur Sigurbjörnsson; Arno Siebes

2009-11-01T23:59:59.000Z

173

Heat pump employing optimal refrigerant compressor for low pressure ratio applications  

DOE Patents (OSTI)

What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler for circulating the fluid in heat exchange relationship with a refrigerant fluid; two refrigerant heat exchangers; one for effecting the heat exchange with the fluid and a second refrigerant-heat exchange fluid heat exchanger for effecting a low pressure ratio of compression of the refrigerant; a rotary compressor for compressing the refrigerant with low power consumption at the low pressure ratio; at least one throttling valve connecting at the inlet side of heat exchanger in which liquid refrigerant is vaporized; a refrigerant circuit serially connecting the above elements; refrigerant in the circuit; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant.

Ecker, Amir L. (Dallas, TX)

1982-01-01T23:59:59.000Z

174

A strain gage?variable area flowmeter  

Science Conference Proceedings (OSTI)

This article presents a unique hybrid flowmeter that combines the turndown ratio/low resistance benefits of a variable area differential pressure flowmeter with the low component simplicity of a target flowmeter. The design attaches a single element strain gage to the flexural membrane suspended in a fluid flow passage

D. W. Guillaume; D. DeVries

1990-01-01T23:59:59.000Z

175

Alternative Fuel Vehicles: The Case of Compressed Natural Gas (CNG) Vehicles in California Households  

E-Print Network (OSTI)

VEHICLES: THE CASE OF COMPRESSED NATURAL GAS (CNG) VEHICLESyou first learn about compressed natural gas (CNG) vehicles?VEHICLES: THE CASE OF COMPRESSED NATURAL GAS (CNG) VEHICLES

Abbanat, Brian A.

2001-01-01T23:59:59.000Z

176

Improving Energy Efficiency of Compressed Air System Based on System Audit  

E-Print Network (OSTI)

50 compressed air system energy audits completed by Shanghai50 compressed air system energy audits completed by Shanghaiof compressed air energy audits conducted by the Shanghai

Shanghai, Hongbo Qin; McKane, Aimee

2008-01-01T23:59:59.000Z

177

Alternative Fuels Data Center: Compressed Natural Gas School Buses Grant  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Compressed Natural Gas Compressed Natural Gas School Buses Grant and Loan Pilot Program to someone by E-mail Share Alternative Fuels Data Center: Compressed Natural Gas School Buses Grant and Loan Pilot Program on Facebook Tweet about Alternative Fuels Data Center: Compressed Natural Gas School Buses Grant and Loan Pilot Program on Twitter Bookmark Alternative Fuels Data Center: Compressed Natural Gas School Buses Grant and Loan Pilot Program on Google Bookmark Alternative Fuels Data Center: Compressed Natural Gas School Buses Grant and Loan Pilot Program on Delicious Rank Alternative Fuels Data Center: Compressed Natural Gas School Buses Grant and Loan Pilot Program on Digg Find More places to share Alternative Fuels Data Center: Compressed Natural Gas School Buses Grant and Loan Pilot Program on AddThis.com...

178

Alternative Fuels Data Center: Propane and Compressed Natural Gas (CNG)  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Propane and Compressed Propane and Compressed Natural Gas (CNG) Device Fee to someone by E-mail Share Alternative Fuels Data Center: Propane and Compressed Natural Gas (CNG) Device Fee on Facebook Tweet about Alternative Fuels Data Center: Propane and Compressed Natural Gas (CNG) Device Fee on Twitter Bookmark Alternative Fuels Data Center: Propane and Compressed Natural Gas (CNG) Device Fee on Google Bookmark Alternative Fuels Data Center: Propane and Compressed Natural Gas (CNG) Device Fee on Delicious Rank Alternative Fuels Data Center: Propane and Compressed Natural Gas (CNG) Device Fee on Digg Find More places to share Alternative Fuels Data Center: Propane and Compressed Natural Gas (CNG) Device Fee on AddThis.com... More in this section... Federal State Advanced Search All Laws & Incentives Sorted by Type

179

Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Compressed Natural Gas Compressed Natural Gas (CNG) and Propane Regulatory Authority to someone by E-mail Share Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Regulatory Authority on Facebook Tweet about Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Regulatory Authority on Twitter Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Regulatory Authority on Google Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Regulatory Authority on Delicious Rank Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Regulatory Authority on Digg Find More places to share Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Regulatory Authority on AddThis.com...

180

Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Electricity  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Compressed Natural Gas Compressed Natural Gas (CNG) and Electricity Tax Exemption for Transit Use to someone by E-mail Share Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Electricity Tax Exemption for Transit Use on Facebook Tweet about Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Electricity Tax Exemption for Transit Use on Twitter Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Electricity Tax Exemption for Transit Use on Google Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Electricity Tax Exemption for Transit Use on Delicious Rank Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Electricity Tax Exemption for Transit Use on Digg Find More places to share Alternative Fuels Data Center: Compressed

Note: This page contains sample records for the topic "variable compression ratio" 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

Fuel Cell Technologies Office: Compressed Natural Gas and Hydrogen Fuels  

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

Compressed Natural Gas Compressed Natural Gas and Hydrogen Fuels Workshop to someone by E-mail Share Fuel Cell Technologies Office: Compressed Natural Gas and Hydrogen Fuels Workshop on Facebook Tweet about Fuel Cell Technologies Office: Compressed Natural Gas and Hydrogen Fuels Workshop on Twitter Bookmark Fuel Cell Technologies Office: Compressed Natural Gas and Hydrogen Fuels Workshop on Google Bookmark Fuel Cell Technologies Office: Compressed Natural Gas and Hydrogen Fuels Workshop on Delicious Rank Fuel Cell Technologies Office: Compressed Natural Gas and Hydrogen Fuels Workshop on Digg Find More places to share Fuel Cell Technologies Office: Compressed Natural Gas and Hydrogen Fuels Workshop on AddThis.com... Publications Program Publications Technical Publications Educational Publications

182

Alternative Fuels Data Center: Compressed Natural Gas (CNG) Vehicle  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Compressed Natural Gas Compressed Natural Gas (CNG) Vehicle Conversion Loans - Allegiance Credit Union to someone by E-mail Share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Vehicle Conversion Loans - Allegiance Credit Union on Facebook Tweet about Alternative Fuels Data Center: Compressed Natural Gas (CNG) Vehicle Conversion Loans - Allegiance Credit Union on Twitter Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Vehicle Conversion Loans - Allegiance Credit Union on Google Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Vehicle Conversion Loans - Allegiance Credit Union on Delicious Rank Alternative Fuels Data Center: Compressed Natural Gas (CNG) Vehicle Conversion Loans - Allegiance Credit Union on Digg Find More places to share Alternative Fuels Data Center: Compressed

183

Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Compressed Natural Gas Compressed Natural Gas (CNG) and Propane Deregulation to someone by E-mail Share Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Deregulation on Facebook Tweet about Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Deregulation on Twitter Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Deregulation on Google Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Deregulation on Delicious Rank Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Deregulation on Digg Find More places to share Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Deregulation on AddThis.com... More in this section... Federal State Advanced Search

184

Fuel Cell Technologies Office: R&D Strategies for Compressed...  

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

R&D Strategies for Compressed, Cryo-Compressed and Cryo-Sorbent Hydrogen Storage Technologies Workshops to someone by E-mail Share Fuel Cell Technologies Office: R&D Strategies for...

185

CO? compression for capture-enabled power systems  

E-Print Network (OSTI)

The objective of this thesis is to evaluate a new carbon dioxide compression technology - shock compression - applied specifically to capture-enabled power plants. Global warming has increased public interest in carbon ...

Suri, Rajat

2009-01-01T23:59:59.000Z

186

Compression and query execution within column oriented databases  

E-Print Network (OSTI)

Compression is a known technique used by many database management systems ("DBMS") to increase performance[4, 5, 14]. However, not much research has been done in how compression can be used within column oriented architectures. ...

Ferreira, Miguel C. (Miguel Cacela Rosa Lopes Ferreira)

2005-01-01T23:59:59.000Z

187

Design upgrade for 2.670 compressed air robot  

E-Print Network (OSTI)

2.670 is an introductory Mechanical Engineering course that introduces students to the fundamentals of machine tool and computer tool use through the fabrication of a robot that is powered by compressed air. The compressed ...

James, Jeremy P., S.B. Massachusetts Institute of Technology

2009-01-01T23:59:59.000Z

188

NETL: IEP – CO2 Compression - Novel Concepts for the Compression of Large  

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

Novel Concepts for the Compression of Large Volumes of Carbon Dioxide Novel Concepts for the Compression of Large Volumes of Carbon Dioxide Project No.: FC26-05NT42650 The Southwest Research Institute (SwRI) will design an efficient and cost-effective compression system to reduce the overall cost of carbon dioxide (CO2) capture and storage for coal-based power plants. SwRI will develop two novel concepts that have the potential to reduce CO2 compression power requirements by 35 percent compared to conventional compressor designs. The first concept is a semi-isothermal compression process where the CO2 is continually cooled using an internal cooling jacket rather than using conventional interstage cooling. This concept can potentially reduce power requirements because less energy is required to boost the pressure of a cool gas. The second concept involves the use of refrigeration to liquefy the CO2 so that its pressure can be increased using a pump, rather than a compressor. The primary power requirements are the initial compression required to boost the CO2 to approximately 250 pounds per square inch absolute and the refrigeration power required to liquefy the gaseous CO2. Once the CO2 is liquefied, the pumping power to boost the pressure to pipeline supply pressure is minimal. Prototype testing of each concept will be conducted.

189

Weather-Corrected Performance Ratio  

Science Conference Proceedings (OSTI)

Photovoltaic (PV) system performance depends on both the quality of the system and the weather. One simple way to communicate the system performance is to use the performance ratio (PR): the ratio of the electricity generated to the electricity that would have been generated if the plant consistently converted sunlight to electricity at the level expected from the DC nameplate rating. The annual system yield for flat-plate PV systems is estimated by the product of the annual insolation in the plane of the array, the nameplate rating of the system, and the PR, which provides an attractive way to estimate expected annual system yield. Unfortunately, the PR is, again, a function of both the PV system efficiency and the weather. If the PR is measured during the winter or during the summer, substantially different values may be obtained, making this metric insufficient to use as the basis for a performance guarantee when precise confidence intervals are required. This technical report defines a way to modify the PR calculation to neutralize biases that may be introduced by variations in the weather, while still reporting a PR that reflects the annual PR at that site given the project design and the project weather file. This resulting weather-corrected PR gives more consistent results throughout the year, enabling its use as a metric for performance guarantees while still retaining the familiarity this metric brings to the industry and the value of its use in predicting actual annual system yield. A testing protocol is also presented to illustrate the use of this new metric with the intent of providing a reference starting point for contractual content.

Dierauf, T.; Growitz, A.; Kurtz, S.; Cruz, J. L. B.; Riley, E.; Hansen, C.

2013-04-01T23:59:59.000Z

190

Summary of Compression Testing of U-10Mo  

SciTech Connect

The mechanical properties of depleted uranium plus 10 weight percent molybdenum alloy have been evaluated by high temperature compression testing.

Nyberg, Eric A.; Joshi, Vineet V.; Lavender, Curt A.; Burkes, Douglas

2012-10-31T23:59:59.000Z

191

Exploring benefits of non-linear time compression  

Science Conference Proceedings (OSTI)

In comparison to text, audio-video content is much more challenging to browse. Time-compression has been suggested as a key technology that can support browsing-time compression speeds up the playback of audio-video content without causing the ... Keywords: digital library, multimedia browsing, time compression, user evaluation

Liwei He; Anoop Gupta

2001-10-01T23:59:59.000Z

192

The Choice of Variable for Atmospheric Moisture Analysis  

Science Conference Proceedings (OSTI)

The implications of using different control variables for the analysis of moisture observations in a global atmospheric data assimilation system are investigated. A moisture analysis based on either mixing ratio or specific humidity is prone to ...

Dick P. Dee; Arlindo M. da Silva

2003-01-01T23:59:59.000Z

193

On the ratio X/Y for some elliptically symmetric distributions  

Science Conference Proceedings (OSTI)

The distributions of the ratio X/Y are derived when (X,Y) has the elliptically symmetric Pearson-type II distribution, elliptically symmetric Pearson-type VII distribution and the elliptically symmetric Kotz-type distribution. Keywords: 33C90, 62E99, Elliptically symmetric distributions, Ratios of random variables

Saralees Nadarajah

2006-02-01T23:59:59.000Z

194

Compressive Object Tracking using Entangled Photons  

E-Print Network (OSTI)

We present a compressive sensing protocol that tracks a moving object by removing static components from a scene. The implementation is carried out on a ghost imaging scheme to minimize both the number of photons and the number of measurements required to form a quantum image of the tracked object. This procedure tracks an object at low light levels with fewer than 3% of the measurements required for a raster scan, permitting us to more effectively use the information content in each photon.

Omar S. Magaña-Loaiza; Gregory A. Howland; Mehul Malik; John C. Howell; Robert W. Boyd

2013-06-10T23:59:59.000Z

195

Compression of ground-motion data  

Science Conference Proceedings (OSTI)

Ground motion data has been recorded for many years at Nevada Test Site and is now stored on thousands of digital tapes. The recording format is very inefficient in terms of space on tape. This report outlines a method to compress the data onto a few hundred tapes while maintaining the accuracy of the recording and allowing restoration of any file to the original format for future use. For future digitizing a more efficient format is described and suggested.

Long, J.W.

1981-04-01T23:59:59.000Z

196

Compressed Air Storage for Electric Power Generation  

Science Conference Proceedings (OSTI)

This Technical Report focuses on the use of underground storage of natural gas as a means of leveling the load between supply and demand. The book presents a view of the way compressed air storage can reduce costs when constructing new facilities for generating peak load electricity. The primary emphasis given concerns underground storage of air in underground porous media, the vehicle utilized on a large scale for over 25 years by the natural gas industry.

1990-06-01T23:59:59.000Z

197

Beta wavelet based ECG signal compression using lossless encoding with modified thresholding  

Science Conference Proceedings (OSTI)

In this paper, an ECG compression method based on beta wavelet using lossless encoding technique is presented. Wavelet based compression techniques minimize the compression distortion, while run-length encoding (RLE) further increases the compression ...

Ranjeet Kumar; A. Kumar; Rajesh K. Pandey

2013-01-01T23:59:59.000Z

198

Compressed Baryonic Matter: from Nuclei to Pulsars  

E-Print Network (OSTI)

Our world is wonderful because of the negligible baryonic part although unknown dark matter and dark energy dominate the Universe. Those nuclei in the daily life are forbidden to fuse by compression due to the Coulomb repulse, nevertheless, it is usually unexpected in extraterrestrial extreme-environments: the gravity in a core of massive evolved star is so strong that all the other forces (including the Coulomb one) could be neglected. Compressed baryonic matter is then produced after supernova, manifesting itself as pulsar-like stars observed. The study of this compressed baryonic matter can not only be meaningful in fundamental physics (e.g., the elementary color interaction at low-energy scale, testing gravity theories, detecting nano-Hertz background gravitational waves), but has also profound implications in engineering applications (including time standard and navigation), and additionally, is focused by Chinese advanced telescopes, either terrestrial or in space. Historically, in 1930s, L. Landau speculated that dense matter at supra-nuclear density in stellar cores could be considered as gigantic nuclei (the prototype of standard model of neutron star), however, we address that the residual compact object of supernova could be of condensed matter of quark clusters. The idea that pulsars are quark-cluster stars was not ruled out during the last decade, and we are expecting to test further by future powerful facilities. (in Chinese)

Renxin Xu

2013-10-12T23:59:59.000Z

199

Alternative Fuels Data Center: Public Access to State Compressed Natural  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Public Access to State Public Access to State Compressed Natural Gas (CNG) Fueling Stations to someone by E-mail Share Alternative Fuels Data Center: Public Access to State Compressed Natural Gas (CNG) Fueling Stations on Facebook Tweet about Alternative Fuels Data Center: Public Access to State Compressed Natural Gas (CNG) Fueling Stations on Twitter Bookmark Alternative Fuels Data Center: Public Access to State Compressed Natural Gas (CNG) Fueling Stations on Google Bookmark Alternative Fuels Data Center: Public Access to State Compressed Natural Gas (CNG) Fueling Stations on Delicious Rank Alternative Fuels Data Center: Public Access to State Compressed Natural Gas (CNG) Fueling Stations on Digg Find More places to share Alternative Fuels Data Center: Public Access to State Compressed Natural Gas (CNG) Fueling Stations on

200

Alternative Fuels Data Center: Deregulation of Compressed Natural Gas (CNG)  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Deregulation of Deregulation of Compressed Natural Gas (CNG) as a Motor Fuel to someone by E-mail Share Alternative Fuels Data Center: Deregulation of Compressed Natural Gas (CNG) as a Motor Fuel on Facebook Tweet about Alternative Fuels Data Center: Deregulation of Compressed Natural Gas (CNG) as a Motor Fuel on Twitter Bookmark Alternative Fuels Data Center: Deregulation of Compressed Natural Gas (CNG) as a Motor Fuel on Google Bookmark Alternative Fuels Data Center: Deregulation of Compressed Natural Gas (CNG) as a Motor Fuel on Delicious Rank Alternative Fuels Data Center: Deregulation of Compressed Natural Gas (CNG) as a Motor Fuel on Digg Find More places to share Alternative Fuels Data Center: Deregulation of Compressed Natural Gas (CNG) as a Motor Fuel on AddThis.com...

Note: This page contains sample records for the topic "variable compression ratio" 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

Alternative Fuels Data Center: Deregulation of Compressed Natural Gas (CNG)  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Deregulation of Deregulation of Compressed Natural Gas (CNG) as a Motor Fuel to someone by E-mail Share Alternative Fuels Data Center: Deregulation of Compressed Natural Gas (CNG) as a Motor Fuel on Facebook Tweet about Alternative Fuels Data Center: Deregulation of Compressed Natural Gas (CNG) as a Motor Fuel on Twitter Bookmark Alternative Fuels Data Center: Deregulation of Compressed Natural Gas (CNG) as a Motor Fuel on Google Bookmark Alternative Fuels Data Center: Deregulation of Compressed Natural Gas (CNG) as a Motor Fuel on Delicious Rank Alternative Fuels Data Center: Deregulation of Compressed Natural Gas (CNG) as a Motor Fuel on Digg Find More places to share Alternative Fuels Data Center: Deregulation of Compressed Natural Gas (CNG) as a Motor Fuel on AddThis.com...

202

State Energy Program Helping Arkansans Convert to Compressed Natural Gas |  

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

State Energy Program Helping Arkansans Convert to Compressed State Energy Program Helping Arkansans Convert to Compressed Natural Gas State Energy Program Helping Arkansans Convert to Compressed Natural Gas January 25, 2012 - 4:30pm Addthis The Arkansas Energy Office recently launched a Compressed Natural Gas Conversion Rebate Program, which provides incentives for fleets and individuals to purchase and/or convert their Arkansas-licensed vehicles to compressed natural gas (CNG). | All Rights Reserved. The Arkansas Energy Office recently launched a Compressed Natural Gas Conversion Rebate Program, which provides incentives for fleets and individuals to purchase and/or convert their Arkansas-licensed vehicles to compressed natural gas (CNG). | All Rights Reserved. Grayson Bryant Project Officer -- State Energy Program

203

PDM performance Test Results and Preliminary Analysis: Incompressible and Compressible Fluids  

Science Conference Proceedings (OSTI)

Three, small diameter, Moineau, positive displacement (drilling) motors (PDMs) were dynamometer tested using water, air-water mist, air-water foam, and aerated water. The motors included (1) a 1.5-inch OD, single-lobe mud motor; (2) a 1.69-inch OD, 5:6 multi-lobe mud motor; and (3) a 1.75-inch OD, 5:6 multi-lobe air motor. This paper describes the test apparatus, procedures, data analysis, and results. Incompressible and compressible fluid performance are compared; linear performance, predicted by a positive displacement motor model, is identified where it occurs. Preliminary results and conclusions are (1) the performance of all three motors is accurately modeled using a two-variable, linear model for incompressible fluid and (2) the model was not successfully adapted to model compressible fluid performance.

Dreesen, D.S.; Gruenhagan, E.; Cohen, J.C.; Moran, D.W.

1999-02-01T23:59:59.000Z

204

VARIABLE TIME DELAY MEANS  

DOE Patents (OSTI)

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

Clemensen, R.E.

1959-11-01T23:59:59.000Z

205

Application of pulse compression signal processing techniques to electromagnetic acoustic transducers for noncontact thickness measurements and imaging  

Science Conference Proceedings (OSTI)

A pair of noncontact Electromagnetic Acoustic Transducers (EMATs) has been used for thickness measurements and imaging of metallic plates. This was performed using wide bandwidth EMATs and pulse-compression signal processing techniques, using chirp excitation. This gives a greatly improved signal-to-noise ratio for air-coupled experiments, increasing the speed of data acquisition. A numerical simulation of the technique has confirmed the performance. Experimental results indicate that it is possible to perform noncontact ultrasonic imaging and thickness gauging in a wide range of metal plates. An accuracy of up to 99% has been obtained for aluminum, brass, and copper samples. The resolution of the image obtained using the pulse compression approach was also improved compared to a transient pulse signal from conventional pulser(receiver). It is thus suggested that the combination of EMATs and pulse compression can lead to a wide range of online applications where fast time acquisition is required.

Ho, K.S.; Gan, T.H.; Billson, D.R.; Hutchins, D.A. [School of Engineering, University of Warwick, Coventry, CV4 7AL (United Kingdom)

2005-05-15T23:59:59.000Z

206

Experimental Verifi cation of Discretely Variable Compression Braking Control for Heavy Duty Vehicles: Final Report  

E-Print Network (OSTI)

Conference, 2002. [14] T.R. Fortescue, L.S. Kershenbaum, andscheme is proposed by Fortescue et al. [14] in which a time-

Vahidi, Ardalan; Stefanopoulou, Anna G.; Wang, Xiaoyong; Tsao, Tsu Chin

2004-01-01T23:59:59.000Z

207

Experimental Verification of Discretely Variable Compression Braking Control for Heavy Duty Vehicles  

E-Print Network (OSTI)

and Control, [11] T.R. Fortescue, L.S. Kershenbaum, and B.E.scheme is proposed by Fortescue et al. [11] in which a time-

Vahidi, Ardalan; Stefanopoulou, Anna G.; Farias, Phil; Tsao, Tsu Chin

2003-01-01T23:59:59.000Z

208

International magnetic pulse compression workshop: (Proceedings)  

SciTech Connect

A few individuals have tried to broaden the understanding of specific and salient pulsed-power topics. One such attempt is this documentation of a workshop on magnetic switching as it applies primarily to pulse compression (power transformation), affording a truly international perspective by its participants under the initiative and leadership of Hugh Kirbie and Mark Newton of the Lawrence Livermore National Laboratory (LLNL) and supported by other interested organizations. During the course of the Workshop at Granlibakken, a great deal of information was amassed and a keen insight into both the problems and opportunities as to the use of this switching approach was developed. The segmented workshop format proved ideal for identifying key aspects affecting optimum performance in a variety of applications. Individual groups of experts addressed network and system modeling, magnetic materials, power conditioning, core cooling and dielectrics, and finally circuits and application. At the end, they came together to consolidate their input and formulate the workshop's conclusions, identifying roadblocks or suggesting research projects, particularly as they apply to magnetic switching's trump card--its high-average-power-handling capability (at least on a burst-mode basis). The workshop was especially productive both in the quality and quantity of information transfer in an environment conducive to a free and open exchange of ideas. We will not delve into the organization proper of this meeting, rather we wish to commend to the interested reader this volume, which provides the definitive and most up-to-date compilation on the subject of magnetic pulse compression from underlying principles to current state of the art as well as the prognosis for the future of magnetic pulse compression as a consensus of the workshop's organizers and participants.

Kirbie, H.C.; Newton, M.A.; Siemens, P.D.

1991-04-01T23:59:59.000Z

209

Compressed Air Energy Storage Demonstration Newsletter  

Science Conference Proceedings (OSTI)

The Compressed Air Energy Storage (CAES) Demonstration Project includes the phased planning, engineering design, construction, demonstration, and performance monitoring of two CAES plants. One plant will be a system rated at 300 MWs for up to 10 hours with a below-ground reservoir for bulk energy air storage, and the other will be a system rated at 15 MWs for 2 hours with above-ground air vessel/piping. This is a critical technology demonstration project that is necessary to enable higher penetration of ...

2011-04-21T23:59:59.000Z

210

Low emissions compression ignited engine technology  

DOE Patents (OSTI)

A method and apparatus for operating a compression ignition engine having a cylinder wall, a piston, and a head defining a combustion chamber. The method and apparatus includes delivering fuel substantially uniformly into the combustion chamber, the fuel being dispersed throughout the combustion chamber and spaced from the cylinder wall, delivering an oxidant into the combustion chamber sufficient to support combustion at a first predetermined combustion duration, and delivering a diluent into the combustion chamber sufficient to change the first predetermined combustion duration to a second predetermined combustion duration different from the first predetermined combustion duration.

Coleman, Gerald N. (Dunlap, IL); Kilkenny, Jonathan P. (Peoria, IL); Fluga, Eric C. (Dunlap, IL); Duffy, Kevin P. (East Peoria, IL)

2007-04-03T23:59:59.000Z

211

Compressed Remote Sensing of Sparse Objects  

E-Print Network (OSTI)

The linear inverse source and scattering problems are studied from the perspective of compressed sensing, in particular the idea that sufficient incoherence and sparsity guarantee uniqueness of the solution. By introducing the sensor as well as target ensembles, the maximum number of recoverable targets is proved to be at least proportional to the number of measurement data modulo a log-square factor with overwhelming probability. Important contributions of the analysis include the discoveries of the threshold aperture, consistent with the classical Rayleigh criterion, and the decoherence effect induced by random antenna locations. The prediction of theorems are confirmed by numerical simulations.

Fannjiang, Albert; Strohmer, Thomas

2009-01-01T23:59:59.000Z

212

Shock Waves in Weakly Compressed Granular Media  

E-Print Network (OSTI)

We experimentally probe nonlinear wave propagation in weakly compressed granular media, and observe a crossover from quasi-linear sound waves at low impact, to shock waves at high impact. We show that this crossover grows with the confining pressure $P_0$, whereas the shock wave speed is independent of $P_0$ --- two hallmarks of granular shocks predicted recently. The shocks exhibit powerlaw attenuation, which we model with a logarithmic law implying that local dissipation is weak. We show that elastic and potential energy balance in the leading part of the shocks.

Siet van den Wildenberg; Rogier van Loo; Martin van Hecke

2013-04-23T23:59:59.000Z

213

Investigation of a rotary valving system with variable valve timing for internal combustion engines: Final technical report  

DOE Green Energy (OSTI)

The objective of the program was to provide a functional demonstration of the Hansen Rotary Valving System with Variable Valve timing (HRVS/VVT), capable of throttleless inlet charge control, as an alternative to conventional poppet-valves for use in spark ignited internal combustion engines. The goal of this new technology is to secure benefits in fuel economy, broadened torque band, vibration reduction, and overhaul accessibility. Additionally, use of the variable valve timing capability to vary the effective compression ratio is expected to improve multi-fuel tolerance and efficiency. Efforts directed at the design of HRVS components proved to be far more extensive than had been anticipated, ultimately requiring that proof-trial design/development work be performed. Although both time and funds were exhausted before optical or ion-probe types of in-cylinder investigation could be undertaken, a great deal of laboratory data was acquired during the course of the design/development work. This laboratory data is the basis for the information presented in this Final Report.

Cross, P.C.; Hansen, C.N.

1994-11-18T23:59:59.000Z

214

CASTRO: A NEW COMPRESSIBLE ASTROPHYSICAL SOLVER. III. MULTIGROUP RADIATION HYDRODYNAMICS  

SciTech Connect

We present a formulation for multigroup radiation hydrodynamics that is correct to order O(v/c) using the comoving-frame approach and the flux-limited diffusion approximation. We describe a numerical algorithm for solving the system, implemented in the compressible astrophysics code, CASTRO. CASTRO uses a Eulerian grid with block-structured adaptive mesh refinement based on a nested hierarchy of logically rectangular variable-sized grids with simultaneous refinement in both space and time. In our multigroup radiation solver, the system is split into three parts: one part that couples the radiation and fluid in a hyperbolic subsystem, another part that advects the radiation in frequency space, and a parabolic part that evolves radiation diffusion and source-sink terms. The hyperbolic subsystem and the frequency space advection are solved explicitly with high-order Godunov schemes, whereas the parabolic part is solved implicitly with a first-order backward Euler method. Our multigroup radiation solver works for both neutrino and photon radiation.

Zhang, W.; Almgren, A.; Bell, J. [Center for Computational Sciences and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Howell, L. [Center for Applied Scientific Computing, Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Burrows, A.; Dolence, J. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

2013-01-15T23:59:59.000Z

215

Reynolds and Favre-averaged rapid distortion theory for compressible, ideal-gas turbulence  

E-Print Network (OSTI)

Compressible ideal-gas turbulence subjected to homogeneous shear is investigated at the rapid distortion limit. Specific issues addressed are (i) the interaction between kinetic and internal energies and role of pressure-dilatation; (ii) the modifications to pressure-strain correlation and Reynolds stress anisotropy and (iii) the effect of the composition of velocity fluctuations (solenoidal vs. dilatational). Turbulence evolution is found to be strongly influenced by gradient Mach number, the initial solenoidal-to-dilatational ratio of the velocity field and the initial intensity of the thermodynamic fluctuations. The balance between the initial fluctuations in velocity and thermodynamic variables is also found to be very important. Any imbalance in the two fluctuating fields leads to high levels of pressure-dilatation and intense exchange. For a given initial condition, it is found that the interaction via the pressuredilatation term between the momentum and energy equations reaches a peak at an intermediate gradient Mach number. The energy exchange between internal and kinetic modes is negligible at very high or very low Mach number values due to lack of pressure dilatation. When present, the exchange exhibits oscillations even as the sum of the two energies evolves smoothly. The interaction between shear and solenoidal initial velocity field generates dilatational fluctuations; for some intermediate levels of shear Mach number dilatational fluctuations account for 20% of the total fluctuations. Similarly, the interaction between shear and initial dilatation produces solenoidal oscillations. Somewhat surprisingly, the generation of solenoidal fluctuations increases with gradient Mach number. Larger levels of pressure-strain correlation are seen with dilatational rather than solenoidal initial conditions. Anisotropies of solenoidal and dilatational components are investigated individually. The most interesting observation is that solenoidal and dilatational turbulence tend toward a one componential state but the energetic component is different in each case. As in incompressible shear flows, with solenoidal fluctuations, the streamwise (1,1) component of Reynolds stress is dominant. With dilatational fluctuations, the stream-normal (2,2) component is the strongest. Overall, the study yields valuable insight into the linear processes in high Mach number shear flows and identifies important closure modeling issues.

Lavin, Tucker Alan

2003-05-01T23:59:59.000Z

216

Consequences of Strong Compression in Tidal Disruption Events  

E-Print Network (OSTI)

The tidal disruption of a star by a supermassive black hole (SMBH) is a highly energetic event with consequences dependent on the degree to which the star plunges inside the SMBH's tidal sphere. We introduce a new analytic model for tidal disruption events (TDEs) to analyze the dependence of these events on beta, the ratio of the tidal radius to the orbital pericenter. We find, contrary to most previous work, that the spread in debris energy for a TDE is largely constant for all beta. This result has important consequences for optical transient searches targeting TDEs, which we discuss. We quantify leading-order general relativistic corrections to this spread in energy and find that they are small. We also examine the role of stellar spin, and find that a combination of spin-orbit misalignment, rapid rotation, and high beta may increase the spread in debris energy. Finally, we quantify for the first time the gravitational wave emission due to the strong compression of a star in a high-beta TDE. Although this signal is unlikely to be detectable for disruptions of main sequence stars, the tidal disruption of a white dwarf by an intermediate mass black hole can produce a strong signal visible to Advanced LIGO at tens of megaparsecs.

Nicholas Stone; Re'em Sari; Abraham Loeb

2012-10-11T23:59:59.000Z

217

Injection, compression and stability of intense ion-rings  

SciTech Connect

Recent advances in pulsed high power ion beam technology make possible the creation of intense ion-rings with strong self-magnetic fields by single pulse injection. Such ion rings have several uses in controlled fusion e.g., to produce a min parallel B parallel magnetic geometry with a mirror ratio much higher than is possible with external conductors. For even stronger ion rings a min parallel B parallel with closed lines of force (ASTRON type) can be created. For this purpose, since the ion energies required are much higher than are available from high power sources, magnetic compression can be utilized to increase the ion energy. The success of this scheme depends critically on the stability of the ion ring. The low frequency perturbations of the ring-plasma system is examined by means of a generalization of the energy principle which established sufficient conditions for stability. The high-frequency micro- instabilities and their nonlinear consequences are discussed in terms of conventional techniques. (auth)

Sudan, R.N.

1975-01-01T23:59:59.000Z

218

Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Dealer License to someone by E-mail Dealer License to someone by E-mail Share Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Dealer License on Facebook Tweet about Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Dealer License on Twitter Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Dealer License on Google Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Dealer License on Delicious Rank Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Dealer License on Digg Find More places to share Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Dealer License on AddThis.com... More in this section... Federal State Advanced Search All Laws & Incentives Sorted by Type

219

Fact Sheet: Isothermal Compressed Air Energy Storage (October 2012)  

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

SustainX SustainX American Recovery and Reinvestment Act (ARRA) Isothermal Compressed Air Energy Storage Demonstrating a modular, market-ready energy storage system that uses compressed air as a storage medium SustainX will demonstrate an isothermal compressed air energy storage (ICAES) system. Energy can be stored in compressed air, with minimal energy losses, and released when the air is later allowed to expand. Many traditional compressed air energy storage (CAES) projects store energy in underground geological formations such as salt caverns. However, in these systems, the air warms when it is compressed and cools when it is expanded. CAES systems generally use gas combustion turbines to reheat the cooled air before expansion. This process creates inefficiencies and emissions.

220

Fuel cell separator with compressible sealing flanges  

DOE Patents (OSTI)

A separator for separating adjacent fuel cells in a stack of such cells includes a flat, rectangular, gas-impermeable plate disposed between adjacent cells and having two opposite side margins thereof folded back over one side of the plate to form two first seal flanges and having the other side margins thereof folded back over the opposite side of the plate to form two second seal flanges, each of the seal flanges cooperating with the plate to define a channel in which is disposed a resiliently compressible stack of thin metal sheets. The two first seal flanges cooperate with the electrolyte matrix of one of the cells to form a gas-impermeable seal between an electrode of the one cell and one of two reactant gas manifolds. The second seal flanges cooperate with the electrolyte matrix of the other cell for forming a gas-impermeable seal between an electrode of the other cell and the other of the two reactant gas manifolds. The seal flanges cooperate with the associated compressible stacks of sheets for maintaining a spacing between the plate and the electrolyte matrices while accommodating variation of that spacing.

Mientek, A.P.

1984-03-30T23:59:59.000Z

Note: This page contains sample records for the topic "variable compression ratio" 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

Compression station key to Texas pipeline project  

SciTech Connect

This was probably the largest pipeline project in the US last year, and the largest in Texas in the last decade. The new compressor station is a key element in this project. TECO, its servicing dealer, and compression packager worked closely throughout the planning and installation stages of the project. To handle the amount of gas required, TECO selected the GEMINI F604-1 compressor, a four-throw, single-stage unit with a six-inch stroke manufactured by Weatherford Enterra Compression Co. (WECC) in Corpus Christi, TX. TECO also chose WECC to package the compressors. Responsibility for ongoing support of the units will be shared among TECO, the service dealer and the packager. TECO is sending people to be trained by WECC, and because the G3600 family of engines is still relatively new, both the Caterpillar dealer and WECC sent people for advanced training at Caterpillar facilities in Peoria, IL. As part of its service commitment to TECO, the servicing dealer drew up a detailed product support plan, encompassing these five concerns: Training, tooling; parts support; service support; and commissioning.

NONE

1996-10-01T23:59:59.000Z

222

A Quadratic Closure for Compressible Turbulence  

Science Conference Proceedings (OSTI)

We have investigated a one-point closure model for compressible turbulence based on third- and higher order cumulant discard for systems undergoing rapid deformation, such as might occur downstream of a shock or other discontinuity. In so doing, we find the lowest order contributions of turbulence to the mean flow, which lead to criteria for Adaptive Mesh Refinement. Rapid distortion theory (RDT) as originally applied by Herring closes the turbulence hierarchy of moment equations by discarding third order and higher cumulants. This is similar to the fourth-order cumulant discard hypothesis of Millionshchikov, except that the Millionshchikov hypothesis was taken to apply to incompressible homogeneous isotropic turbulence generally, whereas RDT is applied only to fluids undergoing a distortion that is 'rapid' in the sense that the interaction of the mean flow with the turbulence overwhelms the interaction of the turbulence with itself. It is also similar to Gaussian closure, in which both second and fourth-order cumulants are retained. Motivated by RDT, we develop a quadratic one-point closure for rapidly distorting compressible turbulence, without regard to homogeneity or isotropy, and make contact with two equation turbulence models, especially the K-{var_epsilon} and K-L models, and with linear instability growth. In the end, we arrive at criteria for Adaptive Mesh Refinement in Finite Volume simulations.

Futterman, J A

2008-09-16T23:59:59.000Z

223

University of Arizona Compressed Air Energy Storage  

SciTech Connect

Boiled down to its essentials, the grant’s purpose was to develop and demonstrate the viability of compressed air energy storage (CAES) for use in renewable energy development. While everyone agrees that energy storage is the key component to enable widespread adoption of renewable energy sources, the development of a viable scalable technology has been missing. The Department of Energy has focused on expanded battery research and improved forecasting, and the utilities have deployed renewable energy resources only to the extent of satisfying Renewable Portfolio Standards. The lack of dispatchability of solar and wind-based electricity generation has drastically increased the cost of operation with these components. It is now clear that energy storage coupled with accurate solar and wind forecasting make up the only combination that can succeed in dispatchable renewable energy resources. Conventional batteries scale linearly in size, so the price becomes a barrier for large systems. Flow batteries scale sub-linearly and promise to be useful if their performance can be shown to provide sufficient support for solar and wind-base electricity generation resources. Compressed air energy storage provides the most desirable answer in terms of scalability and performance in all areas except efficiency. With the support of the DOE, Tucson Electric Power and Science Foundation Arizona, the Arizona Research Institute for Solar Energy (AzRISE) at the University of Arizona has had the opportunity to investigate CAES as a potential energy storage resource.

Simmons, Joseph; Muralidharan, Krishna

2012-12-31T23:59:59.000Z

224

Ethanol production by vapor compression distillation  

DOE Green Energy (OSTI)

The goal of this project is to develop and demonstrate a one gallon per hour vapor compression distillation unit for fuel ethanol production that can be profitably manufactured and economically operated by individual family units. Vapor compression distillation is already an industrially accepted process and this project's goal is to demonstrate that it can be done economically on a small scale. Theoretically, the process is independent of absolute pressure. It is only necessary that the condenser be at higher pressure than the evaporator. By reducing the entire process to a pressure of approximately 0.1 atmosphere, the evaporation and condensation can occur at near ambient temperature. Even though this approach requires a vacuum pump, and thus will not represent the final cost effective design, it does not require preheaters, high temperature materials, or as much insulation as if it were to operate a near ambient pressure. Therefore, the operation of the ambient temperature unit constitutes the first phase of this project. Presently, the ambient temperature unit is fully assembled and has begun testing. So far it has successfully separated ethanol from a nine to one diluted input solution. However the production rate has been very low.

Ellis, G.S.

1981-01-01T23:59:59.000Z

225

Program on Technology Innovation: Adiabatic Compressed Air Energy Storage Systems for Renewable Energy Integration  

Science Conference Proceedings (OSTI)

This report summarizes the status and progress of the research, development, and demonstration (RD&D) work at the Electric Power Research Institute (EPRI) on adiabatic no-fuel compressed air energy storage (CAES) for wind integration. Bulk energy storage (BES) is necessary to provide grid damping in order to mitigate wind power variability. The objective of adiabatic no-fuel CAES RD&D is to combine the lowest-cost BES option (which is CAES) with carbon-free operation. The research focuses on system desig...

2010-11-08T23:59:59.000Z

226

Lossless compression using the adaptive discrete cosine transform  

Science Conference Proceedings (OSTI)

This paper describes a technique using the adaptive discrete cosine transform for lossless waveform data compression. The technique is a variation on a two-stage lossless method that was developed by one of the authors. The earlier work employed an adaptive ... Keywords: ADPCM scheme, adaptive differential pulse code modulation-type, adaptive discrete cosine transform, data compression, encoding, integer residual sequence, lossless successive difference operation, lossless waveform data compression, storage, transmission, two-stage lossless method

L. Gerhardt; M. Fargues; G. Coutu

1995-10-01T23:59:59.000Z

227

Inspection of Compression Connectors: Infrared Testing and Results  

Science Conference Proceedings (OSTI)

Conductor-connector systems are vital components to the safety and reliability of the bulk-power overhead electric transmission system. Although today’s electric system is 99.97% reliable, power outages and interruptions still occur, some of which are attributed to failures of compression connectors.When properly selected and installed, compression connectors are expected to last the design life of the transmission line. When not properly constructed, compression connectors place ...

2013-12-20T23:59:59.000Z

228

Compressibility and local instabilities of differentially rotating magnetized gas  

E-Print Network (OSTI)

We study the stability of compressible cylindrical differentially rotating flow in the presence of the magnetic field, and show that compressibility alters qualitatively the stability properties of flows. Apart from the well-known magnetorotational instability that can occur even in incompressible flow, there exist a new instability caused by compressibility. The necessary condition of the newly found instability can easily be satisfied in various flows in laboratory and astrophysical conditions and reads $B_{s} B_{\\phi} \\Omega' \

Bonanno, A; Bonanno, Alfio; Urpin, Vadim

2007-01-01T23:59:59.000Z

229

DOE Hydrogen Analysis Repository: Carbon Dioxide Compression, Transport,  

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

Carbon Dioxide Compression, Transport, and Storage Carbon Dioxide Compression, Transport, and Storage Project Summary Full Title: Techno-Economic Models for Carbon Dioxide Compression, Transport, and Storage & Correlations for Estimating Carbon Dioxide Density and Viscosity Project ID: 195 Principal Investigator: David McCollum Brief Description: This project addresses several components of carbon capture and storage (CCS) costs, provides technical models for determining the engineering and infrastructure requirements of CCS, and describes some correlations for estimating CO2 density and viscosity. Keywords: Pipeline, transportation, greenhouse gases (GHG), costs, technoeconomic analysis Purpose Estimate costs of carbon dioxide capture, compression, transport, storage, etc., and provide some technical models for determining the engineering and

230

ESS 2012 Peer Review - Modular Undersea Compressed Air Energy...  

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

solar.energy.govsunshotcsp.html ENERGY STORAGE SYSTEMS: Sept. 27, 2012 Modular Undersea Compressed Air Energy Storage (UCAES) System Bill Caruso www.BraytonEnergy.com Brayton...

231

NETL: News Release - Natural Gas Compression Technology Improves...  

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

2 Natural Gas Compression Technology Improves Transport and Efficiencies, Lowers Operating Costs Innovative Compressor Design Can Extend Productive Life of Stripper Wells,...

232

Saturable inductor and transformer structures for magnetic pulse compression  

DOE Patents (OSTI)

Saturable inductor and transformer for magnetic compression of an electronic pulse, using a continuous electrical conductor looped several times around a tightly packed core of saturable inductor material.

Birx, Daniel L. (Londonderry, NH); Reginato, Louis L. (Orinda, CA)

1990-01-01T23:59:59.000Z

233

Argonne TTRDC - Engines - Compression-Ignition - diesel, fuel...  

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

Compression Ignition Engines Clean Diesel Technologies for Greener Performance Mechanical engineer Alan Kastengren examines a diesel injection nozzle used in Argonne's X-ray spray...

234

Matrix-free Interior Point Method for Compressed Sensing Problems  

E-Print Network (OSTI)

Aug 27, 2012 ... Matrix-free Interior Point Method for Compressed Sensing Problems. Kimon Fountoulakis (K.Fountoulakis ***at*** sms.ed.ac.uk) Jacek Gondzio ...

235

National Ignition Facility (NIF): Under Pressure: Ramp-Compression...  

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

National Ignition Facility (NIF): Under Pressure: Ramp-Compression Smashes Record American Fusion News Category: National Ignition Facility Link: National Ignition Facility (NIF):...

236

Ultra-short pulse compression using photonic crystal fibre  

Science Conference Proceedings (OSTI)

ABSTRACT A short section of photonic crystal fibre has been used for ultra-short pulse compression. The unique optical prop- erties of this novel medium in ...

237

Energy Recovery During Expansion of Compressed Gas Using Power...  

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

Recovery During Expansion of Compressed Gas Using Power Plant Low-Quality Heat Sources Opportunity The Department of Energy's National Energy Technology Laboratory (NETL) is...

238

In-Plane Compressive Properties of Hybrid Dyneema®/Carbon ...  

Science Conference Proceedings (OSTI)

Presentation Title, In-Plane Compressive Properties of Hybrid Dyneema®/ Carbon Fiber Reinforced Polymer Matrix Composites. Author(s), Shahram Amini, John ...

239

Electron acceleration & laser pulse compression using a laser...  

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

acceleration & laser pulse compression using a laser-plasma accelerator Wednesday, August 14, 2013 - 3:00pm SLAC, Redtail Hawk Conference Room 108A Andreas Walker, Oxford...

240

List of Compressed air Incentives | Open Energy Information  

Open Energy Info (EERE)

Energy Efficiency Incentive Program (Texas) Local Grant Program Texas Commercial Ceiling Fan Central Air conditioners Chillers Comprehensive MeasuresWhole Building Compressed air...

Note: This page contains sample records for the topic "variable compression ratio" 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

Energy efficiency improvements in Chinese compressed air systems  

E-Print Network (OSTI)

air system assessments and energy audits based on a systemaudit. These compressed air system assessments may be conducted by compressor manufacturers/distributors or energy

McKane, Aimee; Li, Li; Li, Yuqi; Taranto, T.

2008-01-01T23:59:59.000Z

242

Compressive Properties of Low Relative Density Materials, Both ...  

Science Conference Proceedings (OSTI)

Abstract Scope, The compressive constitutive behavior of low relatively density materials bas been characterized for various materials. It has been seen that ...

243

Compression Behavior and Energy Absorption of Aluminum Alloys ...  

Science Conference Proceedings (OSTI)

Presentation Title, Compression Behavior and Energy Absorption of ... Abstract Scope, The usage of advanced high strength steels and Aluminum Alloys as ...

244

Optimization of Energy Saving Materials and Compressed Insulating ...  

Science Conference Proceedings (OSTI)

Sep 16, 2007 ... Optimization of Energy Saving Materials and Compressed Insulating Layers in the Automotive Chemical Converters by E. Litovsky, V. Issoupov, ...

245

Neuroadaptive speed assistance control of wind turbine with variable ratio gearbox (VRG)  

Science Conference Proceedings (OSTI)

Wind power as a renewable energy source is irregular in occurrence. It is interesting yet challenging to maximize the energy capture from wind. Most existing control methods for wind power generation are traditionally based on wind turbine with fixed ... Keywords: PMSM, neuroadaptive control, speed regulation, wind turbine

Xue-fei Wang; Yong-duan Song; Dan-yong Li; Kai Zhang; Shan Xue; Ming Qin

2012-07-01T23:59:59.000Z

246

Compressed Air Energy Storage: Proven US CAES Plant Cost Achievements and Potential Engineering, Design & Project Management Based C ost Reductions  

Science Conference Proceedings (OSTI)

Compressed Air Energy Storage (CAES) is a market ready technology that can play a valuable role in enhancing grid flexibility for variable generation integration. Relative to combustion turbines, CAES provides additional benefits and value streams, such as potential classification as a transmission asset, lower emissions, superior regulation service, reduction of wind spillage and in other ways improving wind plant economics. Although high cost estimates for CAES circulate in the industry, the first ...

2012-12-20T23:59:59.000Z

247

Estimated Global Hydrographic Variability  

Science Conference Proceedings (OSTI)

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

Gaël Forget; Carl Wunsch

2007-08-01T23:59:59.000Z

248

Understanding Biomass Feedstock Variability  

SciTech Connect

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

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

2013-01-01T23:59:59.000Z

249

Fuel-Free Compressed-Air Energy Storage: Fuel-Free, Ubiquitous Compressed-Air Energy Storage and Power Conditioning  

SciTech Connect

GRIDS Project: General Compression has developed a transformative, near-isothermal compressed air energy storage system (GCAES) that prevents air from heating up during compression and cooling down during expansion. When integrated with renewable generation, such as a wind farm, intermittent energy can be stored in compressed air in salt caverns or pressurized tanks. When electricity is needed, the process is reversed and the compressed air is expanded to produce electricity. Unlike conventional compressed air energy storage (CAES) projects, no gas is burned to convert the stored high-pressure air back into electricity. The result of this breakthrough is an ultra-efficient, fully shapeable, 100% renewable and carbon-free power product. The GCAES™ system can provide high quality electricity and ancillary services by effectively integrating renewables onto the grid at a cost that is competitive with gas, coal and nuclear generation.

None

2010-09-13T23:59:59.000Z

250

Abstract--The variability and non-dispatchable nature of wind and solar energy production presents  

E-Print Network (OSTI)

storage (for over several hours or for a day) are generally pumped hydro or compressed air energy storage1 Abstract--The variability and non-dispatchable nature of wind and solar energy production, energy storage can be a viable solution to balance energy production against its consumption. This paper

251

Modeling ramp compression experiments using large-scale molecular dynamics simulation.  

Science Conference Proceedings (OSTI)

Molecular dynamics simulation (MD) is an invaluable tool for studying problems sensitive to atomscale physics such as structural transitions, discontinuous interfaces, non-equilibrium dynamics, and elastic-plastic deformation. In order to apply this method to modeling of ramp-compression experiments, several challenges must be overcome: accuracy of interatomic potentials, length- and time-scales, and extraction of continuum quantities. We have completed a 3 year LDRD project with the goal of developing molecular dynamics simulation capabilities for modeling the response of materials to ramp compression. The techniques we have developed fall in to three categories (i) molecular dynamics methods (ii) interatomic potentials (iii) calculation of continuum variables. Highlights include the development of an accurate interatomic potential describing shock-melting of Beryllium, a scaling technique for modeling slow ramp compression experiments using fast ramp MD simulations, and a technique for extracting plastic strain from MD simulations. All of these methods have been implemented in Sandia's LAMMPS MD code, ensuring their widespread availability to dynamic materials research at Sandia and elsewhere.

Mattsson, Thomas Kjell Rene; Desjarlais, Michael Paul; Grest, Gary Stephen; Templeton, Jeremy Alan; Thompson, Aidan Patrick; Jones, Reese E.; Zimmerman, Jonathan A.; Baskes, Michael I. (University of California, San Diego); Winey, J. Michael (Washington State University); Gupta, Yogendra Mohan (Washington State University); Lane, J. Matthew D.; Ditmire, Todd (University of Texas at Austin); Quevedo, Hernan J. (University of Texas at Austin)

2011-10-01T23:59:59.000Z

252

X-ray Thomson scattering measurements from shock-compressed deuterium  

Science Conference Proceedings (OSTI)

X-ray Thomson scattering has recently been shown to be an effective method of diagnosing a variety of high energy density plasma conditions. We apply this powerful technique to the widely studied problem of shock-compressed liquid deuterium. The behavior of deuterium under extreme conditions has received considerable attention due to its central role in models of giant planets and the importance of the high-pressure insulator-metal transition. We have used spectrally resolved x-ray scattering from electron-plasma waves to perform microscopic observations of ionization during compression. In these experiments, a single shock was launched in cryogenic deuterium reaching compressions of 3x. The 2 keV Ly-{alpha} line in silicon was used as an x-ray source in a forward scattering geometry. In addition to elastic scattering from tightly bound electrons, this low probe energy accessed the collective plasmon oscillations of delocalized electrons. Inelastic scattering from the plasmons allowed accurate measurements of the free electron density through the spectral position of the resonance and provided an estimate of the temperature through its ratio with the elastic feature. Combined with velocity interferometry from the reflective shock front, this lead to a direct determination of the ionization state. We compare the measured ionization conditions with computational models. Additionally, we discuss the possibility of using this technique to determine electrical conductivity and to directly observe pressure-induced molecular dissociation along the Hugoniot.

Davis, P.; Doeppner, T.; Rygg, J. R.; Fortmann, C.; Unites, W.; Salmonson, J.; Collins, G. W.; Landen, O. L.; Falcone, R. W.; Glenzer, S. H. [University of California, Berkeley. Berkeley, CA, 94720 (United States); Lawrence Livermore National Laboratory. Livermore, CA 94551 (United States); University of California, Berkeley. Berkeley, CA, 94720 (United States)

2012-05-25T23:59:59.000Z

253

New Regenerative Cycle for Vapor Compression Refrigeration  

Office of Scientific and Technical Information (OSTI)

SCIENTIFIC REPORT SCIENTIFIC REPORT Title Page Project Title: New Regenerative Cycle for Vapor Compression Refrigeration DOE Award Number: DE-FG36-04GO14327 Document Title: Final Scientific Report Period Covered by Report: September 30, 2004 to September 30, 2005 Name and Address of Recipient Organization: Magnetic Development, Inc., 68 Winterhill Road, Madison, CT 06443, phone: 203-214-7247, fax: 203-421-7948, e-mail: mjb1000@aol.com Contact Information: Mark J. Bergander, Ph.D., P.E., Principal Investigator, phone: 203-214-7247, fax: 203-421-7948, e-mail: mjb1000@aol.com Project Objective (as stated in the proposal): The main objective of this project is to confirm on a well-instrumented prototype the theoretically derived claims of higher efficiency and coefficient

254

Seneca Compressed Air Energy Storage (CAES) Project  

SciTech Connect

This report provides a review and an analysis of potential environmental justice areas that could be affected by the New York State Electric & Gas (NYSEG) compress air energy storage (CAES) project and identifies existing environmental burden conditions on the area and evaluates additional burden of any significant adverse environmental impact. The review assesses the socioeconomic and demographic conditions of the area surrounding the proposed CAES facility in Schuyler County, New York. Schuyler County is one of 62 counties in New York. Schuyler County’s 2010 population of 18,343 makes it one of the least populated counties in the State (U.S. Census Bureau, 2010). This report was prepared for WorleyParsons by ERM and describes the study area investigated, methods and criteria used to evaluate this area, and the findings and conclusions from the evaluation.

None

2012-11-30T23:59:59.000Z

255

Combustion dynamics in steady compressible flows  

E-Print Network (OSTI)

We study the evolution of a reactive field advected by a one-dimensional compressible velocity field and subject to an ignition-type nonlinearity. In the limit of small molecular diffusivity the problem can be described by a spatially discretized system, and this allows for an efficient numerical simulation. If the initial field profile is supported in a region of size l < lc one has quenching, i.e., flame extinction, where lc is a characteristic length-scale depending on the system parameters (reacting time, molecular diffusivity and velocity field). We derive an expression for lc in terms of these parameters and relate our results to those obtained by other authors for different flow settings.

S. Berti; D. Vergni; A. Vulpiani

2008-07-03T23:59:59.000Z

256

SEED BANKS FOR MAGNETIC FLUX COMPRESSION GENERATORS  

DOE Green Energy (OSTI)

In recent years the Lawrence Livermore National Laboratory (LLNL) has been conducting experiments that require pulsed high currents to be delivered into inductive loads. The loads fall into two categories (1) pulsed high field magnets and (2) the input stage of Magnetic Flux Compression Generators (MFCG). Three capacitor banks of increasing energy storage and controls sophistication have been designed and constructed to drive these loads. One bank was developed for the magnet driving application (20kV {approx} 30kJ maximum stored energy.) Two banks where constructed as MFCG seed banks (12kV {approx} 43kJ and 26kV {approx} 450kJ). This paper will describe the design of each bank including switching, controls, circuit protection and safety.

Fulkerson, E S

2008-05-14T23:59:59.000Z

257

Hybrid Vapor Compression Adsorption System: Thermal Storage Using Hybrid Vapor Compression Adsorption System  

SciTech Connect

HEATS Project: UTRC is developing a new climate-control system for EVs that uses a hybrid vapor compression adsorption system with thermal energy storage. The targeted, closed system will use energy during the battery-charging step to recharge the thermal storage, and it will use minimal power to provide cooling or heating to the cabin during a drive cycle. The team will use a unique approach of absorbing a refrigerant on a metal salt, which will create a lightweight, high-energy-density refrigerant. This unique working pair can operate indefinitely as a traditional vapor compression heat pump using electrical energy, if desired. The project will deliver a hot-and-cold battery that provides comfort to the passengers using minimal power, substantially extending the driving range of EVs.

None

2012-01-04T23:59:59.000Z

258

Video transmission over a relay channel with a compress-forward code design  

E-Print Network (OSTI)

There is an increasing demand to support high data rate multimedia applications over the current day wireless networks which are highly prone to errors. Relay channels, by virtue of their spatial diversity, play a vital role in meeting this demand without much change to the current day systems. A compress-forward relaying scheme is one of the exciting prospects in this regard owing to its ability to always outperform direct transmission. With regards to video transmission, there is a serious need to ensure higher protection for the source bits that are more important and sensitive. The objective of this thesis is to develop a practical scheme for transmitting video data over a relay channel using a compress-forward relaying scheme and compare it to direct and multi-hop transmissions. We also develop a novel scheme whereby the relay channel can be used as a means to provide the required unequal error protection among the MPEG-2 bit stream. The area of compress-forward (CF) relaying has not been developed much to date, with most of the research directed towards the decode-forward scheme. The fact that compress-forward relaying always ensures better results than direct transmission is an added advantage. This has motivated us to employ CF relaying in our implementation. Video transmission and streaming applications are being increasingly sought after in the current generation wireless systems. The fact that video applications are bandwidth demanding and error prone, and the wireless systems are band-limited and unreliable, makes this a challenging task. CF relaying, by virtue of their path diversity, can be considered to be a new means for video transmission. To exploit the above advantages, we propose an implementation for video transmission over relay channels using a CF relaying scheme. Practical gains in peak signal-to-noise ratio (PSNR) have been observed for our implementation compared to the simple binary-input additive white Gaussian noise (BIAWGN) and two-hop transmission scenarios.

Polapragada, Chaitanya

2008-05-01T23:59:59.000Z

259

Model-based compression in wireless ad hoc networks  

Science Conference Proceedings (OSTI)

We present a technique for compression of shortest paths routing tables for wireless ad hoc networks. The main characteristic of such networks is that geographic location of nodes determines network topology. As opposed to encoding individual node locations, ... Keywords: compression, modeling, routing protocols, routing tables, sensor networks, trajectory

Milenko Drinic; Darko Kirovski; Miodrag Potkonjak

2003-11-01T23:59:59.000Z

260

Z-Pinch Driven Isentropic Compression for Inertial Fusion  

Science Conference Proceedings (OSTI)

The achievement of high gain with inertial fusion requires the compression of hydrogen isotopes to high density and temperatures. High densities can be achieved most efficiently by isentropic compression. This requires relatively slow pressure pulses on the order of 10-20 nanoseconds; however, the pressure profile must have the appropriate time. We present 1-D numerical simulations that indicate such a pressure profile can be generated by using pulsed power driven z pinches. Although high compression is calculated, the initial temperature is too low for ignition. Ignition could be achieved by heating a small portion of this compressed fuel with a short (-10 ps) high power laser pulse as previously described. Our 1-D calculations indicate that the existing Z-accelerator could provide the driving current (-20 MA) necessary to compress fuel to roughly 1500 times solid density. At this density the required laser energy is approximately 10 kJ. Multidimensional effects such as the Rayleigh-Taylor were not addressed in this brief numerical study. These effects will undoubtedly lower fuel compression for a given chive current. Therefore it is necessary to perform z-pinch driven compression experiments. Finally, we present preliminary experimental data from the Z-accelerator indicating that current can be efficiently delivered to appropriately small loads (- 5 mm radius) and that VISAR can be used measure high pressure during isentropic compression.

Asay, J.R.; Hall, C.A.; Holland, K.G.; Slutz, S.A.; Spielman, R.B.; Stygar, W.A.

1999-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "variable compression ratio" 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

Dynamic data compression in multi-hop wireless networks  

Science Conference Proceedings (OSTI)

Data compression can save energy and increase network capacity in wireless sensor networks. However, the decision of whether and when to compress data can depend upon platform hardware, topology, wireless channel conditions, and application data rates. ... Keywords: energy efficiency, stochatic network optimization

Abhishek B. Sharma; Leana Golubchik; Ramesh Govindan; Michael J. Neely

2009-06-01T23:59:59.000Z

262

Novel Approach for fast Compressed Hybrid color image Cryptosystem  

Science Conference Proceedings (OSTI)

In this Paper, the issues pertaining with efficient, fast, cost effective and secured image transmission are addressed in totality. The proposed model employs Compressed Hybrid Cryptosystem constitutes compression, encryption and secured session key ... Keywords: Cat map, Chaotic map, Curvelet transform, ECDLP, Elliptic Curve Cryptography, Standard map

Kamlesh Gupta; Sanjay Silakari

2012-07-01T23:59:59.000Z

263

Face recognition in JPEG and JPEG2000 compressed domain  

Science Conference Proceedings (OSTI)

In this paper we investigate the potential of performing face recognition in JPEG and JPEG2000 compressed domain. This is achieved by avoiding full decompression and using transform coefficients as input to face recognition algorithms. We propose a new ... Keywords: Compressed Domain, DCT, DWT, Face Recognition, JPEG, JPEG2000

Kresimir Delac; Mislav Grgic; Sonja Grgic

2009-07-01T23:59:59.000Z

264

Adaptive Header Compression for Wireless Networks Changli Jiao  

E-Print Network (OSTI)

Adaptive Header Compression for Wireless Networks Changli Jiao Department of Electrical without compression. From the standpoint of the communication medium, the channel usage will be improved at a lower speed if the gap between ACKs is too big. This will have two side results. First, the efficiency

Richard III, Golden G.

265

Iterative Dictionary Construction for Compression of Large DNA Data Sets  

Science Conference Proceedings (OSTI)

Genomic repositories increasingly include individual as well as reference sequences, which tend to share long identical and near-identical strings of nucleotides. However, the sequential processing used by most compression algorithms, and the volumes ... Keywords: Dictionary construction, compression, DNA, large data sets.

Shanika Kuruppu; Bryan Beresford-Smith; Thomas Conway; Justin Zobel

2012-01-01T23:59:59.000Z

266

The Development of the Electrically Controlled High Power RF Switch and Its Application to Active RF Pulse Compression Systems  

SciTech Connect

In the past decades, there has been increasing interest in pulsed high power RF sources for building high-gradient high-energy particle accelerators. Passive RF pulse compression systems have been used in many applications to match the available RF sources to the loads requiring higher RF power but a shorter pulse. Theoretically, an active RF pulse compression system has the advantage of higher efficiency and compactness over the passive system. However, the key component for such a system an element capable of switching hundreds of megawatts of RF power in a short time compared to the compressed pulse width is still an open problem. In this dissertation, we present a switch module composed of an active window based on the bulk effects in semiconductor, a circular waveguide three-port network and a movable short plane, with the capability to adjust the S-parameters before and after switching. The RF properties of the switch module were analyzed. We give the scaling laws of the multiple-element switch systems, which allow the expansion of the system to a higher power level. We present a novel overmoded design for the circular waveguide three-port network and the associated circular-to-rectangular mode-converter. We also detail the design and synthesis process of this novel mode-converter. We demonstrate an electrically controlled ultra-fast high power X-band RF active window built with PIN diodes on high resistivity silicon. The window is capable of handling multi-megawatt RF power and can switch in 2-300ns with a 1000A current driver. A low power active pulse compression experiment was carried out with the switch module and a 375ns resonant delay line, obtaining 8 times compression gain with a compression ratio of 20.

Guo, Jiquan; /SLAC

2009-03-20T23:59:59.000Z

267

Georeactor Variability and Integrity  

E-Print Network (OSTI)

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

J. Marvin Herndon

2005-10-04T23:59:59.000Z

268

Georeactor Variability and Integrity  

E-Print Network (OSTI)

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

Herndon, J M

2005-01-01T23:59:59.000Z

269

Compressed Air Energy Storage (CAES) | Open Energy Information  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Compressed Air Energy Storage (CAES) Jump to: navigation, search Contents 1 Introduction 2 Technology Description 3 Plants 4 References Introduction Compressed air energy storage (CAES) is a way to store energy that is generated at night and deliver the energy during the day to meet peak demand. This is performed by compressing air and storing it during periods of excess electricity and expanding the air through a turbine when electricity is needed. Technology Description Diabatic Diabatic compressed air energy storage is what the two existing compressed air energy storage facilities currently employ. This method is

270

Compressive Passive Millimeter-Wave Imager (Flash format)  

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

Compressive Passive Millimeter-Wave Imager > (Flash) Compressive Passive Millimeter-Wave Imager > (Flash) Multimedia Nuclear Systems Analysis Engineering Analysis Nonproliferation and National Security Detection & Diagnostic Systems Compressive Passive Millimeter-Wave Imager VIDEO TRANSCRIPT Remote Vital Sign Monitoring System Preventing the Worst (by CNN) Engineering Development & Applications Argonne's Nuclear Science & Technology Legacy Other Multimedia Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Detection & Diagnostic Systems - Multimedia Bookmark and Share Compressive Passive Millimeter-Wave Imager Argonne National Laboratory Read full story Argonne has developed a passive compressive sensing system that uses millimeter waves (MMWs) to rapidly image targets with high resolution and

271

High Transformer ratios in collinear wakefield accelerators.  

Science Conference Proceedings (OSTI)

Based on our previous experiment that successfully demonstrated wakefield transformer ratio enhancement in a 13.625 GHz dielectric-loaded collinear wakefield accelerator using the ramped bunch train technique, we present here a redesigned experimental scheme for even higher enhancement of the efficiency of this accelerator. Design of a collinear wakefield device with a transformer ratio R2, is presented. Using a ramped bunch train (RBT) rather than a single drive bunch, the enhanced transformer ratio (ETR) technique is able to increase the transformer ratio R above the ordinary limit of 2. To match the wavelength of the fundamental mode of the wakefield with the bunch length (sigmaz=2 mm) of the new Argonne wakefield accelerator (AWA) drive gun (where the experiment will be performed), a 26.625 GHz dielectric based accelerating structure is required. This transformer ratio enhancement technique based on our dielectric-loaded waveguide design will result in a compact, high efficiency accelerating structures for future wakefield accelerators.

Power, J. G.; Conde, M.; Yusof, Z.; Gai, W.; Jing, C.; Kanreykin, A.; Schoessow, P.; High Energy Physics; Euclid Techlabs, LLC

2008-01-01T23:59:59.000Z

272

Modeling of coupled thermodynamic and geomechanical performance of underground compressed air energy storage (CAES) in lined rock caverns  

E-Print Network (OSTI)

Williams, Compressed air energy storage: Theory, resources,for the compressed air energy storage technology by thefor compressed air energy storage power generation, Japan

Rutqvist, J.

2013-01-01T23:59:59.000Z

273

Modeling 18° Water Variability  

Science Conference Proceedings (OSTI)

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

Robert Marsh; Adrian L. New

1996-06-01T23:59:59.000Z

274

Integrated Hydrogen Production, Purification and Compression System  

DOE Green Energy (OSTI)

The project was started in April 2005 with the objective to meet the DOE target of delivered hydrogen of <$1.50/gge, which was later revised by DOE to $2-$3/gge range for hydrogen to be competitive with gasoline as a fuel for vehicles. For small, on-site hydrogen plants being evaluated at the time for refueling stations (the 'forecourt'), it was determined that capital cost is the main contributor to the high cost of delivered hydrogen. The concept of this project was to reduce the cost by combining unit operations for the entire generation, purification, and compression system (refer to Figure 1). To accomplish this, the Fluid Bed Membrane Reactor (FBMR) developed by MRT was used. The FBMR has hydrogen selective, palladium-alloy membrane modules immersed in the reformer vessel, thereby directly producing high purity hydrogen in a single step. The continuous removal of pure hydrogen from the reformer pushes the equilibrium 'forward', thereby maximizing the productivity with an associated reduction in the cost of product hydrogen. Additional gains were envisaged by the integration of the novel Metal Hydride Hydrogen Compressor (MHC) developed by Ergenics, which compresses hydrogen from 0.5 bar (7 psia) to 350 bar (5,076 psia) or higher in a single unit using thermal energy. Excess energy from the reformer provides up to 25% of the power used for driving the hydride compressor so that system integration improved efficiency. Hydrogen from the membrane reformer is of very high, fuel cell vehicle (FCV) quality (purity over 99.99%), eliminating the need for a separate purification step. The hydride compressor maintains hydrogen purity because it does not have dynamic seals or lubricating oil. The project team set out to integrate the membrane reformer developed by MRT and the hydride compression system developed by Ergenics in a single package. This was expected to result in lower cost and higher efficiency compared to conventional hydrogen production technologies. The overall objective was to develop an integrated system to directly produce high pressure, high-purity hydrogen from a single unit, which can meet the DOE cost H2 cost target of $2 - $3/gge when mass produced. The project was divided into two phases with the following tasks and corresponding milestones, targets and decision points. Phase 1 - Task 1 - Verify feasibility of the concept, perform a detailed techno-economic analysis, and develop a test plan; and Task 2: Build and experimentally test a Proof of Concept (POC) integrated membrane reformer/metal hydride compressor system. Phase 2 - Task 3: Build an Advanced Prototype (AP) system with modifications based on POC learning and demonstrate at a commercial site; and Task 4: Complete final product design for mass manufacturing units capable of achieving DOE 2010 H2 cost and performance targets.

Tamhankar, Satish; Gulamhusein, Ali; Boyd, Tony; DaCosta, David; Golben, Mark

2011-06-30T23:59:59.000Z

275

A fast and efficient method for compressing fMRI data sets  

Science Conference Proceedings (OSTI)

We present a new lossless compression method named FTTcoder, which compresses images and 3d sequences collected during a typical functional MRI experiment. The large data sets involved in this popular medical application necessitate novel compression ...

Fabian J. Theis; Toshihisa Tanaka

2005-09-01T23:59:59.000Z

276

Desalination Using Vapor-Compression Distillation  

E-Print Network (OSTI)

The ability to produce potable water economically is the primary purpose of seawater desalination research. Reverse osmosis (RO) and multi-stage flash (MSF) cost more than potable water produced from fresh water resources. As an alternative to RO and MSF, this research investigates a high-efficiency mechanical vapor-compression distillation system that employs an improved water flow arrangement. The incoming salt concentration was 0.15% salt for brackish water and 3.5% salt for seawater, whereas the outgoing salt concentration was 1.5% and 7%, respectively. Distillation was performed at 439 K (331oF) and 722 kPa (105 psia) for both brackish water feed and seawater feed. Water costs of the various conditions were calculated for brackish water and seawater feeds using optimum conditions considered as 25 and 20 stages, respectively. For brackish water at a temperature difference of 0.96 K (1.73oF), the energy requirement is 2.0 kWh/m3 (7.53 kWh/kgal). At this condition, the estimated water cost is $0.39/m3 ($1.48/kgal) achieved with 10,000,000 gal/day distillate, 30-year bond, 5% interest rate, and $0.05/kWh electricity. For seawater at a temperature difference of 0.44 K (0.80oF), the energy requirement is 3.97 kWh/m3 (15.0 kWh/kgal) and the estimated water cost is $0.61/m3 ($2.31/kgal). Greater efficiency of the vapor compression system is achieved by connecting multiple evaporators in series, rather than the traditional parallel arrangement. The efficiency results from the gradual increase of salinity in each stage of the series arrangement in comparison to parallel. Calculations using various temperature differences between boiling brine and condensing steam show the series arrangement has the greatest improvement at lower temperature differences. The following table shows the improvement of a series flow arrangement compared to parallel: ?T (K) Improvement (%)*1.111 2.222 3.333 15.21 10.80 8.37 * Incoming salt concentration: 3.5% Outgoing salt concentration: 7% Temperature: 450 K (350oF) Pressure: 928 kPa (120 psig) Stages: 4

Lubis, Mirna R.

2009-05-01T23:59:59.000Z

277

VARIABILITY OF KD VALUES IN CEMENTITIOUS MATERIALS AND SEDIMENTS  

Science Conference Proceedings (OSTI)

Measured distribution coefficients (K{sub d} values) for environmental contaminants provide input data for performance assessments (PA) that evaluate physical and chemical phenomena for release of radionuclides from wasteforms, degradation of engineered components and subsequent transport of radionuclides through environmental media. Research efforts at SRNL to study the effects of formulation and curing variability on the physiochemical properties of the saltstone wasteform produced at the Saltstone Disposal Facility (SDF) are ongoing and provide information for the PA and Saltstone Operations. Furthermore, the range and distribution of plutonium K{sub d} values in soils is not known. Knowledge of these parameters is needed to provide guidance for stochastic modeling in the PA. Under the current SRS liquid waste processing system, supernate from F & H Tank Farm tanks is processed to remove actinides and fission products, resulting in a low-curie Decontaminated Salt Solution (DSS). At the Saltstone Production Facility (SPF), DSS is mixed with premix, comprised of blast furnace slag (BFS), Class F fly ash (FA), and portland cement (OPC) to form a grout mixture. The fresh grout is subsequently placed in SDF vaults where it cures through hydration reactions to produce saltstone, a hardened monolithic waste form. Variation in saltstone composition and cure conditions of grout can affect the saltstone's physiochemical properties. Variations in properties may originate from variables in DSS, premix, and water to premix ratio, grout mixing, placing, and curing conditions including time and temperature (Harbour et al. 2007; Harbour et al. 2009). There are no previous studies reported in the literature regarding the range and distribution of K{sub d} values in cementitious materials. Presently, the Savannah River Site (SRS) estimate ranges and distributions of K{sub d} values based on measurements of K{sub d} values made in sandy SRS sediments (Kaplan 2010). The actual cementitious material K{sub d} values and solubility values differ from the sandy sediments. The K{sub d} value range and distribution currently used in the PA are estimated to range between 0.25*K{sub d} and 1.75*K{sub d}, where the minimum and maximum values of the ranges reflect the 95% confidence level for the mean K{sub d} value (Kaplan 2010). The objective of the research with cementitious materials was to measure the range and distribution of a monovalent (Cs) and I{sup -} (anion), divalent (Sr), and trivalent (Eu) ions for a variety of laboratory-prepared saltstone surrogate samples to establish a K{sub d} range other than that which is presently used in the PA. It has been observed in laboratory samples that cure temperature profiles can affect properties such as heat of hydration, permeability, porosity, compressive strength, and set time (Harbour et al. 2009). The intent was to identify a range and distribution that could be used by stochastic modelers for the PA. Furthermore, the intent was to replace the arbitrarily selected distributions based on geological sandy sediments and to base it on actual cementitious materials. The scope of this study did not include understanding saltstone sorption mechanisms responsible for increasing or decreasing sorption. Similar to the work with cementitious materials, the purpose of the Pu sediment K{sub d} dataset was not to attempt to understand through statistics how to better understand Pu sorption to sediments or to lower Pu K{sub d} variance. The sediment Pu K{sub d} data is included in this study because it is a key risk driver for the PAs on the SRS, and there is presently no direct studies of Pu variability in SRS soils. Instead the distribution of Pu sediment K{sub d} values was assumed to be similar to other cations, as presented by Kaplan (2010).

Almond, P.; Kaplan, D.; Shine, E.

2012-02-02T23:59:59.000Z

278

High Aspect Ratio Semiconductor Heterojunction Solar Cells  

E-Print Network (OSTI)

High Aspect Ratio Semiconductor Heterojunction Solar Cells Haoting Shen Prof. Redwing's Research and in-situ dopant for Si nanowires Y. Ke, X.J. Weng, J.M. Redwing, C.M. Eichfeld, T.R. Swisher, S

Yener, Aylin

279

Sulfate Washout Ratios in Winter Storms  

Science Conference Proceedings (OSTI)

Washout ratios for sulfate were computed from simultaneous measurements of sulfate in precipitation and in the air below cloud base. Stratification of the data according to predominant mode of precipitation growth (growth primarily by accretion ...

B. C. Scott

1981-06-01T23:59:59.000Z

280

Compression wave studies in Blair dolomite  

DOE Green Energy (OSTI)

Dynamic compression wave studies have been conducted on Blair dolomite in the stress range of 0-7.0 GPa. Impact techniques were used to generate stress impulse input functions, and diffuse surface laser interferometry provided the dynamic instrumentation. Experimental particle velocity profiles obtained by this method were coupled with the conservation laws of mass and momentum to determine the stress-strain and stress-modulus constitutive properties of the material. Comparison between dynamic and quasistatic uniaxial stress-strain curves uncovered significant differences. Energy dissipated in a complete load and unload cycle differed by almost an order of magnitude and the longitudinal moduli differed by as much as a factor of two. Blair dolomite was observed to yield under dynamic loading at 2.5 GPa. Below 2.5 GPa the loading waves had a finite risetime and exhibited steady propagation. A finite linear viscoelastic constitutive model satisfactorily predicted the observed wave propagation. We speculate that dynamic properties of preexisting cracks provides a physical mechanism for both the rate dependent steady wave behavior and the difference between dynamic and quasistatic response.

Grady, D.E.; Hollenbach, R.E.; Schuler, K.W.; Callender, J.F.

1976-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "variable compression ratio" 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

Plutonium isotope ratio variations in North America  

Science Conference Proceedings (OSTI)

Historically, approximately 12,000 TBq of plutonium was distributed throughout the global biosphere by thermo nuclear weapons testing. The resultant global plutonium fallout is a complex mixture whose {sup 240}Pu/{sup 239}Pu atom ratio is a function of the design and yield of the devices tested. The average {sup 240}Pu/{sup 239}Pu atom ratio in global fallout is 0.176 + 014. However, the {sup 240}Pu/{sup 239}Pu atom ratio at any location may differ significantly from 0.176. Plutonium has also been released by discharges and accidents associated with the commercial and weapons related nuclear industries. At many locations contributions from this plutonium significantly alters the {sup 240}Pu/{sup 239}Pu atom ratios from those observed in global fallout. We have measured the {sup 240}Pu/{sup 239}Pu atom ratios in environmental samples collected from many locations in North America. This presentation will summarize the analytical results from these measurements. Special emphasis will be placed on interpretation of the significance of the {sup 240}Pu/{sup 239}Pu atom ratios measured in environmental samples collected in the Arctic and in the western portions of the United States.

Steiner, Robert E [Los Alamos National Laboratory; La Mont, Stephen P [Los Alamos National Laboratory; Eisele, William F [Los Alamos National Laboratory; Fresquez, Philip R [Los Alamos National Laboratory; Mc Naughton, Michael [Los Alamos National Laboratory; Whicker, Jeffrey J [Los Alamos National Laboratory

2010-12-14T23:59:59.000Z

282

Logic Compression Of Dictionaries For Multilingual Spelling Checkers  

E-Print Network (OSTI)

To provide practical spelling checkers on micro-computers, good compression algorithms ,are essential. Curtcut techniques used to compress lexicons for indo-European languages provide efficient spelling checker. Applying mine methods to languages which have a different morpho- logical system (Arabic, Turkish,...) gives insufficicut resalts. To get better results, we apply other "logical" compression mechanisms based on the strnctare of the lan guage itself. Experiments with multilingual dictionaries show a significant reduction rate attributable to our logic colnpression Illone and even better resulls when using our method in conjunction with existing me0uxls.

Boubaker Meddeb Hamrouni

1994-01-01T23:59:59.000Z

283

Variable percentage sampler  

DOE Patents (OSTI)

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

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

1976-01-01T23:59:59.000Z

284

Variable laser attenuator  

DOE Patents (OSTI)

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

Foltyn, S.R.

1987-05-29T23:59:59.000Z

285

Variable laser attenuator  

SciTech Connect

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

Foltyn, Stephen R. (Los Alamos, NM)

1988-01-01T23:59:59.000Z

286

Solar-type Variables  

E-Print Network (OSTI)

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

Houdek, Gunter

2009-01-01T23:59:59.000Z

287

Errors in all variables  

SciTech Connect

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

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

2005-11-23T23:59:59.000Z

288

Lattice Boltzmann Method for Multiphase Flows with High Density and Viscosity Ratios  

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

Lattice Boltzmann Method for Multiphase Flows with High Density and Viscosity Ratios Lattice Boltzmann Method for Multiphase Flows with High Density and Viscosity Ratios Seckin Gokaltun, Dwayne McDaniel and David Roelant Florida International University, Miami, FL Background As a result of atomic weapons production, millions of gallons of radioactive waste was generated and stored in underground tanks at various U.S. Department of Energy sites. Department of Energy is currently in the process of transferring the waste from single shell tanks to double shell tanks. Various waste retrieval and processing methods are employed during the transfer of the waste. One such method, pulsed-air mixing, involves injection of discrete pulses of compressed air or inert gas at the bottom of the tank to produce large bubbles that rise due to buoyancy and mix the waste in the tank

289

Revisiting the Recommended Geometry for the Diametrally Compressed Ceramic C-Ring Specimen  

SciTech Connect

A study conducted several years ago found that a stated allowable width/thickness (b/t) ratio in ASTM C1323 (Standard Test Method for Ultimate Strength of Advanced Ceramics with Diametrally Compressed C-Ring Specimens at Ambient Temperature) could ultimately cause the prediction of a non-conservative probability of survival when the measured C-ring strength was scaled to a different size. Because of that problem, this study sought to reevaluate the stress state and geometry of the C-ring specimen and suggest changes to ASTM C1323 that would resolve that issue. Elasticity, mechanics of materials, and finite element solutions were revisited with the C ring geometry. To avoid the introduction of more than 2% error, it was determined that the C ring width/thickness (b/t) ratio should range between 1-3 and that its inner radius/outer radius (ri/ro) ratio should range between 0.50-0.95. ASTM C1323 presently allows for b/t to be as large as 4 so that ratio should be reduced to 3.

Jadaan, Osama M. [University of Wisconsin, Platteville; Wereszczak, Andrew A [ORNL

2009-04-01T23:59:59.000Z

290

Altering the volumetric expansion ratio of a Lysholm helical screw expander  

Science Conference Proceedings (OSTI)

This is an analysis of the effects of the volumetric expansion ratio on the operation of a Lysholm helical screw expander. Extensive testing of the University of California Lysholm engine with a 5.3 volumetric expansion ratio was performed. In this experiment, the expansion ratio has been reduced from 5.3 to 4.0. Tests were performed at a variety of speeds and qualities for a 5.0 pressure ratio and at a variety of speeds and pressure ratios for 99 percent quality. It was predicted that decreasing the volumetric expansion ratio would decrease the leakage fraction and thereby increase efficiency. This occurred as predicted. Isentropic efficiency increased 20 percent for 50 percent quality steam and 16 percent for 33 percent quality steam, all for an inlet pressure of 120 psia and a speed of 9000 rpm. A maximum efficiency of 47.2 percent was reached at 33 percent quality, 9000 rpm and a pressure ratio of 5.0. It was noted that the leakage rate did not appear to be a function of expansion ratio, as had been expected. Using this fact the previous empirical models of the engine were extended to include volumetric expansion ratio as a variable parameter.

Dunbar, M.K.

1984-01-01T23:59:59.000Z

291

Selective document image data compression technique  

DOE Patents (OSTI)

A method of storing information from filled-in form-documents comprises extracting the unique user information in the foreground from the document form information in the background. The contrast of the pixels is enhanced by a gamma correction on an image array, and then the color value of each of pixel is enhanced. The color pixels lying on edges of an image are converted to black and an adjacent pixel is converted to white. The distance between black pixels and other pixels in the array is determined, and a filled-edge array of pixels is created. User information is then converted to a two-color format by creating a first two-color image of the scanned image by converting all pixels darker than a threshold color value to black. All the pixels that are lighter than the threshold color value to white. Then a second two-color image of the filled-edge file is generated by converting all pixels darker than a second threshold value to black and all pixels lighter than the second threshold color value to white. The first two-color image and the second two-color image are then combined and filtered to smooth the edges of the image. The image may be compressed with a unique Huffman coding table for that image. The image file is also decimated to create a decimated-image file which can later be interpolated back to produce a reconstructed image file using a bilinear interpolation kernel.--(235 words)

Fu, Chi-Yung (29 Cameo Way, San Francisco, CA 94131); Petrich, Loren I. (1674 Cordoba St., #4, Livermore, CA 94550)

1998-01-01T23:59:59.000Z

292

Selective document image data compression technique  

DOE Patents (OSTI)

A method of storing information from filled-in form-documents comprises extracting the unique user information in the foreground from the document form information in the background. The contrast of the pixels is enhanced by a gamma correction on an image array, and then the color value of each of pixel is enhanced. The color pixels lying on edges of an image are converted to black and an adjacent pixel is converted to white. The distance between black pixels and other pixels in the array is determined, and a filled-edge array of pixels is created. User information is then converted to a two-color format by creating a first two-color image of the scanned image by converting all pixels darker than a threshold color value to black. All the pixels that are lighter than the threshold color value to white. Then a second two-color image of the filled-edge file is generated by converting all pixels darker than a second threshold value to black and all pixels lighter than the second threshold color value to white. The first two-color image and the second two-color image are then combined and filtered to smooth the edges of the image. The image may be compressed with a unique Huffman coding table for that image. The image file is also decimated to create a decimated-image file which can later be interpolated back to produce a reconstructed image file using a bilinear interpolation kernel. 10 figs.

Fu, C.Y.; Petrich, L.I.

1998-05-19T23:59:59.000Z

293

Compressed Hydrogen and PEM Fuel Cell System  

DOE Green Energy (OSTI)

PEMFC technology for transportation must be competitive with internal combustion engine powertrains in a number of key metrics, including performance, life, reliability, and cost. Demonstration of PEMFC cost competitiveness has its own challenges because the technology has not been applied to high volume automotive markets. The key stack materials including membranes, electrodes, bipolar plates, and gas diffusion layers have not been produced in automotive volumes to the exacting quality requirements that will be needed for high stack yields and to the evolving property specifications of high performance automotive stacks. Additionally, balance-of-plant components for air, water, and thermal management are being developed to meet the unique requirements of fuel cell systems. To address the question of whether fuel cells will be cost competitive in automotive markets, the DOE has funded this project to assess the high volume production cost of PEM fuel cell systems. In this report a historical perspective of our efforts in assessment of PEMFC cost for DOE is provided along with a more in-depth assessment of the cost of compressed hydrogen storage is provided. Additionally, the hydrogen storage costs were incorporated into a system cost update for 2004. Assessment of cost involves understanding not only material and production costs, but also critical performance metrics, i.e., stack power density and associated catalyst loadings that scale the system components. We will discuss the factors influencing the selection of the system specification (i.e., efficiency, reformate versus direct hydrogen, and power output) and how these have evolved over time. The reported costs reflect internal estimates and feedback from component developers and the car companies. Uncertainty in the cost projection was addressed through sensitivity analyses.

Eric J. Carlson

2004-10-20T23:59:59.000Z

294

Natural Gas Compression Technology Improves Transport and Efficiencies,  

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

Natural Gas Compression Technology Improves Transport and Natural Gas Compression Technology Improves Transport and Efficiencies, Lowers Operating Costs Natural Gas Compression Technology Improves Transport and Efficiencies, Lowers Operating Costs May 10, 2012 - 1:00pm Addthis Washington, DC - An award-winning compressor design that decreases the energy required to compress and transport natural gas, lowers operating costs, improves efficiencies and reduces the environmental footprint of well site operations has been developed by a Massachusetts-based company with support from the U.S. Department of Energy (DOE). OsComp Systems designed and tested the novel compressor design with funding from the DOE-supported Stripper Well Consortium, an industry-driven organization whose members include natural gas and petroleum producers,

295

MHK Technologies/Ocean Powered Compressed Air Stations | Open Energy  

Open Energy Info (EERE)

Powered Compressed Air Stations Powered Compressed Air Stations < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Ocean Powered Compressed Air Stations.png Technology Profile Primary Organization Wave Power Plant Inc Technology Resource Click here Wave Technology Type Click here Point Absorber - Submerged Technology Readiness Level Click here TRL 4 Proof of Concept Technology Description The Ocean Powered Compressed Air Station is a point absorber that uses an air pump to force air to a landbased generator The device only needs 4m water depth and electricity production fluctations through storing energy at a constant air pressure Technology Dimensions Device Testing Date Submitted 13:16.5 << Return to the MHK database homepage Retrieved from

296

Compressive Passive Millimeter-Wave Imager - Argonne National Laboratory  

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

Compressive Passive Millimeter-Wave Imager Compressive Passive Millimeter-Wave Imager Multimedia Nuclear Systems Analysis Engineering Analysis Nonproliferation and National Security Detection & Diagnostic Systems Compressive Passive Millimeter-Wave Imager VIDEO TRANSCRIPT Remote Vital Sign Monitoring System Preventing the Worst (by CNN) Engineering Development & Applications Argonne's Nuclear Science & Technology Legacy Other Multimedia Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Detection & Diagnostic Systems Multimedia Compressive Passive Millimeter-Wave Imager Video | Other sizes/formats available Other available versions of this video: Problems viewing the video in this page? Choose another format/size from the menu below; this video is available in Flash Video Flash, Quicktime video Quicktime or Windows Media video Windows Media format

297

Copper laser modulator driving assembly including a magnetic compression laser  

DOE Patents (OSTI)

A laser modulator (10) having a low voltage assembly (12) with a plurality of low voltage modules (14) with first stage magnetic compression circuits (20) and magnetic assist inductors (28) with a common core (91), such that timing of the first stage magnetic switches (30b) is thereby synchronized. A bipolar second stage of magnetic compression (42) is coupled to the low voltage modules (14) through a bipolar pulse transformer (36) and a third stage of magnetic compression (44) is directly coupled to the second stage of magnetic compression (42). The low voltage assembly (12) includes pressurized boxes (117) for improving voltage standoff between the primary winding assemblies (34) and secondary winding (40) contained therein.

Cook, Edward G. (Livermore, CA); Birx, Daniel L. (Oakley, CA); Ball, Don G. (Livermore, CA)

1994-01-01T23:59:59.000Z

298

Algorithms for transform selection in multiple-transform video compression  

E-Print Network (OSTI)

Selecting proper transforms for video compression has been based on the rate-distortion criterion. Transforms that appear reasonable are incorporated into a video coding system and their performance is evaluated. This ...

Cai, Xun, S.M. Massachusetts Institute of Technology

2012-01-01T23:59:59.000Z

299

Adaptive Cache Compression for High-Performance Processors  

Science Conference Proceedings (OSTI)

Modern processors use two or more levels ofcache memories to bridge the rising disparity betweenprocessor and memory speeds. Compression canimprove cache performance by increasing effectivecache capacity and eliminating misses. However,decompressing ...

Alaa R. Alameldeen; David A. Wood

2004-06-01T23:59:59.000Z

300

Transporting & Shipping Hazardous Materials at LBNL: Compressed Gases  

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

Compressed Gases Compressed Gases Self-Transport by Hand & Foot Self-Transport by Vehicle Ship by Common Carrier Conduct Field Work Return Cylinders Self-Transport by Hand & Foot Staff may personally move (self-transport) compressed gas cylinders by hand & foot between buildings and in connecting spaces (i.e., hallways, elevators, etc.) within buildings provided it can be done safely. The following safety precautions apply: Use standard cylinder dollies to transport compressed gas cylinders. While dollies are preferred, cylinders weighing 11 Kg (25 lbs) or less may be hand-carried. Never move a cylinder with a regulator connected to it. Cylinder valve-protection caps and valve-opening caps must be in place when moving cylinders. Lecture bottles and other cylinders that are

Note: This page contains sample records for the topic "variable compression ratio" 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

Analyses of Compressed Hydrogen On-Board Storage Systems  

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

Compressed Compressed Hydrogen On-Board Storage Systems © 2010 TIAX LLC Compressed and Cryo-Compressed Hydrogen Storage Workshop February 14, 2011 Jeff Rosenfeld Karen Law Jayanti Sinha TIAX LLC 35 Hartwell Ave Lexington, MA 02421-3102 Tel. 781-879-1708 Fax 781-879-1201 www.TIAXLLC.com Reference: D0268 Overview Project Objectives Project Objectives Description Overall Help guide DOE and developers toward promising R&D and commercialization pathways by evaluating the status of the various on-board hydrogen storage technologies on a consistent basis On-Board Storage System Assessment Evaluate or develop system-level designs for the on-board storage system to project bottom-up factory costs Off-Board Fuel Cycle Assessment Evaluate or develop designs and cost inputs for the fuel cycle to

302

Investing in Our Energy Future: The Story of General Compression |  

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

Our Energy Future: The Story of General Compression Our Energy Future: The Story of General Compression Investing in Our Energy Future: The Story of General Compression February 29, 2012 - 9:23am Addthis April Saylor April Saylor Former Digital Outreach Strategist, Office of Public Affairs What does government funding mean to a small clean energy startup? In the case of many ARPA-E awardees and small businesses across the country, it means being able to secure the private capital necessary to bring their innovations to life. Just ask David Marcus, founder of General Compression, a Massachusetts company founded in 2006 that received a $750,000 award from ARPA-E to develop a technology that has the ability to store renewable energy for use at any location on the electric grid. "Investors were interested in the

303

Axial Compression of a Hollow Cylinder Filled with a Foam  

Science Conference Proceedings (OSTI)

Presentation Title, Axial Compression of a Hollow Cylinder Filled with a Foam: A Porcupine ... Characterization of (Ti,Mg)N Thin Film Coatings Produced Via Physical Vapor Deposition ... Non-Toxic SPD Processed Ti Alloys for Orthopaedics.

304

Acceptance Test Report for 241-U compressed air system  

SciTech Connect

This Acceptance Test Report (ATR) documents the results of acceptance testing of a newly upgraded compressed air system at 241-U Farm. The system was installed and the test successfully performed under work package 2W-92-01027.

Freeman, R.D.

1994-10-20T23:59:59.000Z

305

Solvent Clustering around Pyrazine Ions in the High-Compressibility...  

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

Solvent Clustering around Pyrazine Ions in the High-Compressibility Region of Supercritical Ethane R. A. Holroyd, M. Nishikawa, and K. Itoh J. Phys. Chem. B 104, 11585-11590...

306

Wavelet-Compressed Representation of Deep Moist Convection  

Science Conference Proceedings (OSTI)

The capacity of wavelets to effectively represent atmospheric processes under compression is tested by a dataset generated by a cloud-resolving model simulation of deep convective events observed during the Tropical Ocean Global Atmosphere ...

Jun-Ichi Yano; Peter Bechtold; Jean-Luc Redelsperger; Francoise Guichard

2004-06-01T23:59:59.000Z

307

Unsteady flows of in homogeneous in compressible fluids  

SciTech Connect

In this paper, we study the unsteady motion of in homogeneous in compressible viscous fluids. We present the results corresponding to Stokes second problem and for the flow between two parallel plates where one is oscillating.

Massoudi, Mehrdad; Vaidya, Ashwin

2011-01-01T23:59:59.000Z

308

Probabilistic analysis of compression system stability using importance sampling  

E-Print Network (OSTI)

The probability of instability is computed via a new approach based on Importance Sampling and a dynamic compression system model. In contrast to ordinary Monte Carlo methods Importance Sampling offers reduced confidence ...

Kambouchev, Nayden Dimitrov, 1980-

2005-01-01T23:59:59.000Z

309

ESS 2012 Peer Review - Isothermal Compressed Air Energy Storage...  

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

materials or chemicals Proven mechanical systems using steel, water, and air SustainX Heat Transfer Technology (CompressionExpansion) 0 20 40 60 80 100 120 Lead Acid Lithium...

310

Business Case for Compressed Natural Gas in Municipal Fleets  

SciTech Connect

This report describes how NREL used the CNG Vehicle and Infrastructure Cash-Flow Evaluation (VICE) model to establish guidance for fleets making decisions about using compressed natural gas.

Johnson, C.

2010-06-01T23:59:59.000Z

311

Fuel effects in homogeneous charge compression ignition (HCCI) engines  

E-Print Network (OSTI)

Homogenous-charge, compression-ignition (HCCI) combustion is a new method of burning fuel in internal combustion (IC) engines. In an HCCI engine, the fuel and air are premixed prior to combustion, like in a spark-ignition ...

Angelos, John P. (John Phillip)

2009-01-01T23:59:59.000Z

312

Pseudomomentum Diagnostics for Two-Dimensional Stratified Compressible Flow  

Science Conference Proceedings (OSTI)

Expressions are derived for the local pseudomomentum density in two-dimensional compressible stratified flow and are compared with the expressions for pseudomomentum in two-dimensional Boussinesq and anelastic flow derived by Shepherd and by ...

Dale R. Durran

1995-11-01T23:59:59.000Z

313

Blowing Ratio Effects on Film Cooling Effectiveness  

E-Print Network (OSTI)

The research focuses on testing the film cooling effectiveness on a gas turbine blade suction side surface. The test is performed on a five bladed cascade with a blow down facility. Four different blowing ratios are used in this study, which are 0.5, 1.0, 1.6, and 2.0; mainstream flow conditions are maintained at exit Mach number of 0.7, 1.1 and 1.3. Nitrogen is injected as the coolant so that the oxygen concentration levels can be obtained for the test surface. Based on mass transfer analogy, film cooling effectiveness can be computed with pressure sensitive paint (PSP) technique. The effect of blowing ratio on film cooling effectiveness is presented for each testing condition. The spanwise averaged effectiveness for each case is also presented to compare the blowing ratio and mainstream effect on film cooling effectiveness. Results show that due to effects of shock, the optimum blowing ratio is 1.6 for exit Mach number of 1.1 and 1.3; however; without the effects of shock, the optimum blowing ratio is 1.0 for exit Mach number of 0.7.

Liu, Kuo-Chun

2009-08-01T23:59:59.000Z

314

Projectile-power-compressed magnetic-field pulse generator  

DOE Green Energy (OSTI)

Design considerations and experimental results are presented of a compressed magnetic field pulsed energy source. A 100-mm-diameter, gun-fired projectile of approx. 2MJ kinetic energy was the input energy source. An initial magnetic field was trapped and compressed by the projectile. With a shorted load, a magajoule in a nanohenry was the design goal, i.e., 50 percent energy transformation from kinetic to magnetic. Five percent conversion was the highest recorded before gauge failure.

Barlett, R.H.; Takemori, H.T.; Chase, J.B.

1983-03-17T23:59:59.000Z

315

Commissioning Results of the Upgraded Neutralized Drift Compression Experiment  

SciTech Connect

Recent changes to the NDCX beamline offer the promise of higher charge compressed bunches (>15nC), with correspondingly large intensities (>500kW/cm2), delivered to the target plane for ion-beam driven warm dense matter experiments. We report on commissioning results of the upgraded NDCX beamline that includes a new induction bunching module with approximately twice the volt-seconds and greater tuning flexibility, combined with a longer neutralized drift compression channel.

Lidia, S.M.; Roy, P.K.; Seidl, P.A.; Waldron, W.L.; Gilson, E.P.

2009-04-30T23:59:59.000Z

316

SCADA Protocol Anomaly Detection Utilizing Compression (SPADUC) 2013  

SciTech Connect

There is a significant need to protect the nation’s energy infrastructures from malicious actors using cyber methods. Supervisory, Control, and Data Acquisition (SCADA) systems may be vulnerable due to the insufficient security implemented during the design and deployment of these control systems. This is particularly true in older legacy SCADA systems that are still commonly in use. The purpose of INL’s research on the SCADA Protocol Anomaly Detection Utilizing Compression (SPADUC) project was to determine if and how data compression techniques could be used to identify and protect SCADA systems from cyber attacks. Initially, the concept was centered on how to train a compression algorithm to recognize normal control system traffic versus hostile network traffic. Because large portions of the TCP/IP message traffic (called packets) are repetitive, the concept of using compression techniques to differentiate “non-normal” traffic was proposed. In this manner, malicious SCADA traffic could be identified at the packet level prior to completing its payload. Previous research has shown that SCADA network traffic has traits desirable for compression analysis. This work investigated three different approaches to identify malicious SCADA network traffic using compression techniques. The preliminary analyses and results presented herein are clearly able to differentiate normal from malicious network traffic at the packet level at a very high confidence level for the conditions tested. Additionally, the master dictionary approach used in this research appears to initially provide a meaningful way to categorize and compare packets within a communication channel.

Gordon Rueff; Lyle Roybal; Denis Vollmer

2013-01-01T23:59:59.000Z

317

Compression effects on pressure loss in flexible HVAC ducts  

SciTech Connect

A study was conducted to evaluate the effect of compression on pressure drop in flexible, spiral wire helix core ducts used in residential and light commercial applications. Ducts of 6 inches, 8 inches and 10 inches (150, 200 and 250 mm) nominal diameters were tested under different compression configurations following ASHRAE Standard 120-1999--Methods of Testing to Determine Flow Resistance of HVAC Air Ducts and Fittings. The results showed that the available published references tend to underestimate the effects of compression. The study demonstrated that moderate compression in flexible ducts, typical of that often seen in field installations, could increase the pressure drop by a factor of four, while further compression could increase the pressure drop by factors close to ten. The results proved that the pressure drop correction factor for compressed ducts cannot be independent of the duct size, as suggested by ASHRAE Fundamentals, and therefore a new relationship was developed for better quantification of the pressure drop in flexible ducts. This study also suggests potential improvements to ASHRAE Standard 120-1999 and provides new data for duct design.

Abushakra, Bass; Walker, Iain S.; Sherman, Max H.

2002-07-01T23:59:59.000Z

318

Proposed generation and compression of a target plasma for MTF  

SciTech Connect

Magnetized target fusion (MTF), in which a magnetothermally insulated plasma is hydrodynamically compressed to fusion conditions, represents an approach to controlled fusion which avoids difficulties of both traditional inertial confinement and magnetic confinement approaches. The authors are proposing to demonstrate the feasibility of magnetized target fusion by: (1) creating a suitable magnetized target plasma, (2) performing preliminary liner compression experiments using existing pulsed power facilities and demonstrated liner performance. Once the target plasma and the means for its generation have been optimized, the authors plan to conduct preliminary liner compression experiments aimed at demonstrating the near-adiabatic compression of the target plasma desired for MTF. Relevant liner compression experiments have been performed at Los Alamos in the Scyllac Fast Liner Program and, more recently, in the Pegasus facility and the Procyon explosive pulsed power program. In a series of liner experiments they plan to map out the dependence of temperature and neutron production as functions of the initial plasma conditions and the liner compression achieved. With the above research program, they intend to demonstrate most of the key principles involved in magnetized target fusion, and develop the experimental and theoretical tools needed to design and execute fully integrated MTF ignition experiments.

Kirkpatrick, R.C.; Thurston, R.S.; Chrien, R.E. [and others

1995-09-01T23:59:59.000Z

319

Jets with Variable R  

E-Print Network (OSTI)

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

David Krohn; Jesse Thaler; Lian-Tao Wang

2009-03-02T23:59:59.000Z

320

Radioactive anomaly discrimination from spectral ratios  

DOE Patents (OSTI)

A method for discriminating a radioactive anomaly from naturally occurring radioactive materials includes detecting a first number of gamma photons having energies in a first range of energy values within a predetermined period of time and detecting a second number of gamma photons having energies in a second range of energy values within the predetermined period of time. The method further includes determining, in a controller, a ratio of the first number of gamma photons having energies in the first range and the second number of gamma photons having energies in the second range, and determining that a radioactive anomaly is present when the ratio exceeds a threshold value.

Maniscalco, James; Sjoden, Glenn; Chapman, Mac Clements

2013-08-20T23:59:59.000Z

Note: This page contains sample records for the topic "variable compression ratio" 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 Generalized Savage-Dickey Ratio  

E-Print Network (OSTI)

In this brief research note I present a generalized version of the Savage-Dickey Density Ratio for representation of the Bayes factor (or marginal likelihood ratio) of nested statistical models; the new version takes the form of a Radon-Nikodym derivative and is thus applicable to a wider family of probability spaces than the original (restricted to those admitting an ordinary Lebesgue density). A derivation is given following the measure-theoretic construction of Marin & Robert (2010), and the equivalent estimator is demonstrated in application to a distributional modeling problem.

Cameron, Ewan

2013-01-01T23:59:59.000Z

322

Solar Irradiance Variability  

E-Print Network (OSTI)

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

Solanki, Sami K

2012-01-01T23:59:59.000Z

323

Liquid piston gas compression James D. Van de Ven a,*, Perry Y. Li b,1  

E-Print Network (OSTI)

Liquid piston gas compression James D. Van de Ven a,*, Perry Y. Li b,1 a Worcester Polytechnic piston Gas compression Air compressor Compression efficiency a b s t r a c t A liquid piston concept is proposed to improve the efficiency of gas compression and expansion. Because a liquid can conform

Li, Perry Y.

324

Out-of-Core Progressive Lossless Compression and Selective Decompression of Large Triangle Meshes  

Science Conference Proceedings (OSTI)

In this paper we propose a novel {\\em out-of-core} technique for{\\em progressive} lossless compression and {\\em selective}decompression of 3D triangle meshes larger than main memory. Most existing compression methods, in order to optimize compression ... Keywords: Progressive Lossless Compression, Selective Decompression, Out-of-Core Techniques, Triangle Meshes

Zhiyan Du; Pavel Jaromersky; Yi-Jen Chiang; Nasir Memon

2009-03-01T23:59:59.000Z

325

Climate Variability, Fish, and Fisheries  

Science Conference Proceedings (OSTI)

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

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

2006-10-01T23:59:59.000Z

326

Colorado River Basin Hydroclimatic Variability  

Science Conference Proceedings (OSTI)

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

Kenneth Nowak; Martin Hoerling; Balaji Rajagopalan; Edith Zagona

2012-06-01T23:59:59.000Z

327

System using data compression and hashing adapted for use for multimedia encryption  

DOE Patents (OSTI)

A system and method is disclosed for multimedia encryption. Within the system of the present invention, a data compression module receives and compresses a media signal into a compressed data stream. A data acquisition module receives and selects a set of data from the compressed data stream. And, a hashing module receives and hashes the set of data into a keyword. The method of the present invention includes the steps of compressing a media signal into a compressed data stream; selecting a set of data from the compressed data stream; and hashing the set of data into a keyword.

Coffland, Douglas R. (Livermore, CA)

2011-07-12T23:59:59.000Z

328

Seneca Compressed Air Energy Storage (CAES) Project  

SciTech Connect

Compressed Air Energy Storage (CAES) is a hybrid energy storage and generation concept that has many potential benefits especially in a location with increasing percentages of intermittent wind energy generation. The objectives of the NYSEG Seneca CAES Project included: for Phase 1, development of a Front End Engineering Design for a 130MW to 210 MW utility-owned facility including capital costs; project financials based on the engineering design and forecasts of energy market revenues; design of the salt cavern to be used for air storage; draft environmental permit filings; and draft NYISO interconnection filing; for Phase 2, objectives included plant construction with a target in-service date of mid-2016; and for Phase 3, objectives included commercial demonstration, testing, and two-years of performance reporting. This Final Report is presented now at the end of Phase 1 because NYSEG has concluded that the economics of the project are not favorable for development in the current economic environment in New York State. The proposed site is located in NYSEG’s service territory in the Town of Reading, New York, at the southern end of Seneca Lake, in New York State’s Finger Lakes region. The landowner of the proposed site is Inergy, a company that owns the salt solution mining facility at this property. Inergy would have developed a new air storage cavern facility to be designed for NYSEG specifically for the Seneca CAES project. A large volume, natural gas storage facility owned and operated by Inergy is also located near this site and would have provided a source of high pressure pipeline quality natural gas for use in the CAES plant. The site has an electrical take-away capability of 210 MW via two NYSEG 115 kV circuits located approximately one half mile from the plant site. Cooling tower make-up water would have been supplied from Seneca Lake. NYSEG’s engineering consultant WorleyParsons Group thoroughly evaluated three CAES designs and concluded that any of the designs would perform acceptably. Their general scope of work included development of detailed project construction schedules, capital cost and cash flow estimates for both CAES cycles, and development of detailed operational data, including fuel and compression energy requirements, to support dispatch modeling for the CAES cycles. The Dispatch Modeling Consultant selected for this project was Customized Energy Solutions (CES). Their general scope of work included development of wholesale electric and gas market price forecasts and development of a dispatch model specific to CAES technologies. Parsons Brinkerhoff Energy Storage Services (PBESS) was retained to develop an air storage cavern and well system design for the CAES project. Their general scope of work included development of a cavern design, solution mining plan, and air production well design, cost, and schedule estimates for the project. Detailed Front End Engineering Design (FEED) during Phase 1 of the project determined that CAES plant capital equipment costs were much greater than the $125.6- million originally estimated by EPRI for the project. The initial air storage cavern Design Basis was increased from a single five million cubic foot capacity cavern to three, five million cubic foot caverns with associated air production wells and piping. The result of this change in storage cavern Design Basis increased project capital costs significantly. In addition, the development time required to complete the three cavern system was estimated at approximately six years. This meant that the CAES plant would initially go into service with only one third of the required storage capacity and would not achieve full capability until after approximately five years of commercial operation. The market price forecasting and dispatch modeling completed by CES indicated that the CAES technologies would operate at only 10 to 20% capacity factors and the resulting overall project economics were not favorable for further development. As a result of all of these factors, the Phase 1 FEED developed an installe

None

2012-11-30T23:59:59.000Z

329

Scalable analysis of variable software  

Science Conference Proceedings (OSTI)

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

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

2013-08-01T23:59:59.000Z

330

Variability within Modeling Language Definitions  

Science Conference Proceedings (OSTI)

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

María Victoria Cengarle; Hans Grönniger; Bernhard Rumpe

2009-10-01T23:59:59.000Z

331

Symmetrization Of Binary Random Variables  

E-Print Network (OSTI)

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

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

1999-01-01T23:59:59.000Z

332

Effective Compressibility of A Bubbly Slurry: II. Fitting Numerical Results to Field Data and Implications  

Science Conference Proceedings (OSTI)

The goal of this study is to fit model parameters to changes in waste level in response to barometric pressure changes in underground storage tanks at the Hanford Site. This waste compressibility is a measure of the quantity of gas, typically hydrogen and other flammable gases that can pose a safety hazard, retained in the waste. A one-dimensional biconical-pore-network model for compressibility of a bubbly slurry is presented in a companion paper. Fitting these results to actual waste level changes in the tanks implies that bubbles are long in the slurry layer and the ratio of pore-body radius to pore-throat radius is close to one; unfortunately, capillary effects can not be quantified unambiguously from the data without additional information on pore geometry. Therefore determining the quantity of gas in the tanks requires more than just slurry volume data. Similar ambiguity also exists with two other simple models: a capillary-tube model with contact angle hysteresis and spherical-p ore model.

Kam, Seung I. (PEMEX REFINACION); Gauglitz, Phillip A. (BATTELLE (PACIFIC NW LAB)); Rossen, William R. (UNKNOWN)

2000-12-01T23:59:59.000Z

333

Control and Optimization of Vapor Compression Cycles Using Recursive Least Squares Estimation  

E-Print Network (OSTI)

Vapor compression cycles are the primary method by which refrigeration and air-conditioning systems operate, and thus constitute a significant portion of commercial and residential building energy consumption. This thesis presents a data-driven approach to find the optimal operating conditions of a multi-evaporator system in order to minimize the energy consumption while meeting operational requirements such as constant cooling or constant evaporator outlet temperature. The experimental system used for controller evaluation is a custom built small-scale water chiller with three evaporators; each evaporator services a separate body of water, referred to as a cooling zone. The three evaporators are connected to a single condenser and variable speed compressor, and feature variable water flow and electronic expansion valves. The control problem lies in development of a control architecture that will minimize the energy consumed by the system without prior information about the system in the form of performance maps, or complex mathematical models. The control architecture explored in this thesis relies on the data collected by sensors alone to formulate a function for the power consumption of the system in terms of controlled variables, namely, condenser and evaporator pressures, using recursive least squares estimation. This cost function is then minimized to attain optimal set points for the pressures which are fed to local controllers.

Rani, Avinash

2012-08-01T23:59:59.000Z

334

Energy recovery during expansion of compressed gas using power plant low-quality heat sources  

SciTech Connect

A method of recovering energy from a cool compressed gas, compressed liquid, vapor, or supercritical fluid is disclosed which includes incrementally expanding the compressed gas, compressed liquid, vapor, or supercritical fluid through a plurality of expansion engines and heating the gas, vapor, compressed liquid, or supercritical fluid entering at least one of the expansion engines with a low quality heat source. Expansion engines such as turbines and multiple expansions with heating are disclosed.

Ochs, Thomas L. (Albany, OR); O' Connor, William K. (Lebanon, OR)

2006-03-07T23:59:59.000Z

335

Variability in properties of Salado Mass Concrete  

SciTech Connect

Salado Mass Concrete (SMC) has been developed for use as a seal component in the Waste Isolation Pilot Plant. This concrete is intended to be mixed from pre-bagged materials, have an initial slump of 10 in., and remain pumpable and placeable for two hours after mixing. It is a mass concrete because it will be placed in monoliths large enough that the heat generated during cement hydration has the potential to cause thermal expansion and subsequent cracking, a phenomenon to avoid in the seal system. This report describes effects on concrete properties of changes in ratio of water to cement, batch size, and variations in characteristics of different lots of individual components of the concrete. The research demonstrates that the concrete can be prepared from laboratory-batched or pre-bagged dry materials in batches from 1.5 ft{sup 3} to 5.0 yd{sup 3}, with no chemical admixtures other than the sodium chloride added to improve bonding with the host rock, at a water-to-cement ratio ranging from 0.36 to 0.42. All batches prepared according to established procedures had adequate workability for at least 1.5 hours, and achieved or exceeded the target compressive strength of 4500 psi at 180 days after casting. Portland cement and fly ash from different lots or sources did not have a measurable effect on concrete properties, but variations in a shrinkage-compensating cement used as a component of the concrete did appear to affect workability. A low initial temperature and the water-reducing and set-retarding functions of the salt are critical to meeting target properties.

Wakeley, L.D.; Harrington, P.T. [US Army Engineer Waterways Experiment Station, Vicksburg, MS (United States); Hansen, F.D. [Sandia National Labs., Albuquerque, NM (United States)

1995-08-01T23:59:59.000Z

336

An advanced vapor-compression desalination system  

E-Print Network (OSTI)

Currently, the two dominant desalination methods are reverse osmosis (RO) and multi-stage flash (MSF). RO requires large capital investment and maintenance, whereas MSF is too energy intensive. An innovative vapor-compression desalination system is developed in this study. A comprehensive mathematical model for the heat exchanger/evaporator is described. The literature indicates that extraordinarily high overall heat transfer coefficients for the evaporator are possible at selected operating conditions that employ dropwise condensation in the steam side and pool boiling in the liquid side. A smooth titanium surface is chosen to promote dropwise condensation and to resist corrosion. To maximize energy efficiency, a combined-cycle cogeneration scheme is employed composed of a gas turbine, a heat recovery boiler, and a steam turbine that drive a compressor. The combined-cycle power source is oversized relative to the needs of the compressor. The excess power is converted to electricity and sold to the open market. A three-effect evaporator is employed. It is fed with seawater, assumed to be 3.5% salt. Boiling brine (7% salt) is in the low pressure side of the heat exchanger and condensing steam is in the high-pressure side of the heat exchanger. The condensing steam flows at 1.52 m/s (5 ft/s), which maximizes the heat transfer coefficient. The plant is sized to produce 37,854 m3/d (10 mill gal/day) and is assumed to be financed with a 5%, 30-yr municipal bond. Two economic cases were emphasized: the United States and the Middle East. For the United States, the fuel costs $5/GJ ($5.27/mill Btu) with the latent heat exchanger at ( ) 1.11 K 2.00 F T � = ° . The required compressor energy is 14 MJ/m3 (14.7 kW h/thous gal). The capital cost for the U.S. is $884 d/m3 ($3,342/thous gal) and the delivered water selling price is $0.47/m3 ($1.79/thous/gal). For the Middle East, the fuel costs $0.5/GJ ($0.53/mill Btu) with the latent heat exchanger at K T 33 . 3 = � ( ) F 00 . 6 ° . The required compressor energy is 26 MJ/m3 (27.3 kW h/thous gal). ). The capital cost for the Middle East is $620 d/m3 ($2,344/thous gal), and the delivered water selling price is $0.25/m3 ($0.95/thous/gal). In all cases, the water selling price is attractive relative to competing technologies.

Lara Ruiz, Jorge Horacio Juan

2005-12-01T23:59:59.000Z

337

Ignition properties of n-butane and iso-butane in a rapid compression machine  

Science Conference Proceedings (OSTI)

Autoignition delay times of n-butane and iso-butane have been measured in a Rapid Compression Machine in the temperature range 660-1010 K, at pressures varying from 14 to 36 bar and at equivalence ratios {phi} = 1.0 and {phi} = 0.5. Both butane isomers exhibit a negative-temperature-coefficient (NTC) region and, at low temperatures, two-stage ignition. At temperatures below {proportional_to}900 K, the delay times for iso-butane are longer than those for the normal isomer, while above this temperature both butanes give essentially the same results. At temperatures above {proportional_to}720 K the delay times of the lean mixtures are twice those for stoichiometric compositions; at T butane using a comprehensive model for butane ignition, including both delay times in the two-stage region, with substantial differences being observed for iso-butane, particularly in the NTC region. (author)

Gersen, S.; Darmeveil, J.H. [Gasunie Engineering and Technology, P.O. Box 19, 9700 MA Groningen (Netherlands); Mokhov, A.V. [Laboratory for Fuel and Combustion Science, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands); Levinsky, H.B. [Gasunie Engineering and Technology, P.O. Box 19, 9700 MA Groningen (Netherlands); Laboratory for Fuel and Combustion Science, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands)

2010-02-15T23:59:59.000Z

338

Variability in electricity demand highlights potential roles ...  

U.S. Energy Information Administration (EIA)

These technologies convert electricity into another form of energy for storage: the potential energy in water pumped uphill to a reservoir and in compressed air, ...

339

Efficient Compression of CO2 and Pipeline Transport Considerations  

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

CONCEPTS FOR THE COMPRESSION OF CONCEPTS FOR THE COMPRESSION OF LARGE VOLUMES OF CARBON DIOXIDE - PHASE III Southwest Research Institute Team: J. Jeffrey Moore, Ph.D. Neal Evans Timothy Allison, Ph.D. Brian Moreland Klaus Brun, Ph.D. Dresser-Rand Team: Jorge Pacheco, Ph.D. Jason Kerth Michael Dollinger Project Funded by DOE NETL DOE PM: Travis Shultz 2 SOUTHWEST RESEARCH INSTITUTE 11 Divisions *Engine Emissions *Fuels & Lubricants *Automation *Aerospace Electronics *Space Science *Nuclear Waste *Applied Physics *Applied Power *Chemistry *Electronics *Mechanical Engineering * Rotating Machinery Group *1200 Acres *2 million Ft 2 *3200 Employees *1200 Engineers *170 Buildings Project Motivation * CO 2 capture has a significant compression penalty - as high as 8 to 12%.

340

Compressible Turbulence and Interactions with Shock Waves and Material  

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

Compressible Turbulence Compressible Turbulence and Interactions with Shock Waves and Material Interfaces Compressible Turbulence and Interactions with Shock Waves and Material Interfaces Lele.jpg Alternate Title: High-fidelity simulations of supersonic turbulent mixing and combustion Key Challenges: Direct numerical simulation (DNS) of isotropic turbulence interacting with a normal shock wave and turbulent multi-material mixing in the Richtmyer-Meshkov instability (RMI) Why it Matters: Shock/turbulence interaction is a fundamental phenomenon in fluid mechanics that occurs in a wide range of interesting problems in various disciplines, including supernova explosions, inertial confinement fusion, hypersonic flight and propulsion, and shock wave lithotripsy. Accomplishments: A novel solution-adaptive algorithm that applies different

Note: This page contains sample records for the topic "variable compression ratio" 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

Fuel Cell Technologies Office: Compressed Natural Gas and Hydrogen Fuels  

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

Compressed Natural Gas and Hydrogen Fuels Workshop Compressed Natural Gas and Hydrogen Fuels Workshop Fuel experts from China, India, and the United States shared lessons learned about deploying CNG- and hydrogen-fueled vehicles in public transit fleets and the consumer sector at the Compressed Natural Gas and Hydrogen Fuels: Lessons Learned for the Safe Deployment of Vehicles workshop. The U.S. Department of Energy (DOE) and the U.S. Department of Transportation (DOT) hosted the workshop on December 10-11, 2009. Here you'll find information about the workshop's focus, agenda and notes, and presentations. Some of the following documents are available as Adobe Acrobat PDFs. Download Adobe Reader. Focus of the Workshop The workshop aimed to: Compare fuel properties-including blends-industries, and applications (e.g., product specifications, tanks, reliability, safety procedures, risk mitigation, and dispensing)

342

Inexpensive Delivery of Compressed Hydrogen with Advanced Vessel Technology  

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

delivery of compressed hydrogen delivery of compressed hydrogen with advanced vessel technology Gene Berry Andrew Weisberg Salvador M. Aceves Lawrence Livermore National Laboratory (925) 422-0864 saceves@LLNL.GOV DOE and FreedomCar & Fuel Partnership Hydrogen Delivery and On-Board Storage Analysis Workshop Washington, DC January 25, 2006 LLNL is developing innovative concepts for efficient containment of hydrogen in light duty vehicles concepts may offer advantages for hydrogen delivery Conformable containers efficiently use available space in the vehicle. We are pursuing multiple approaches to conformability High Strength insulated pressure vessels extend LH 2 dormancy 10x, eliminate boiloff, and enable efficiencies of flexible refueling (compressed/cryogenic H 2 /(L)H 2 ) The PVT properties of H

343

Compressive strength of concrete and mortar containing fly ash  

DOE Patents (OSTI)

The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specifications required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs.

Liskowitz, John W. (Belle Mead, NJ); Wecharatana, Methi (Parsippany, NJ); Jaturapitakkul, Chai (Bangkok, TH); Cerkanowicz, deceased, Anthony E. (late of Livingston, NJ)

1997-01-01T23:59:59.000Z

344

Compressive strength of concrete and mortar containing fly ash  

DOE Patents (OSTI)

The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specification required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs. 33 figs.

Liskowitz, J.W.; Wecharatana, M.; Jaturapitakkul, C.; Cerkanowicz, A.E.

1998-12-29T23:59:59.000Z

345

Compressive strength of concrete and mortar containing fly ash  

DOE Patents (OSTI)

The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specification required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs.

Liskowitz, John W. (Belle Mead, NJ); Wecharatana, Methi (Parsippany, NJ); Jaturapitakkul, Chai (Bangkok, TH); Cerkanowicz, deceased, Anthony E. (late of Livingston, NJ)

1998-01-01T23:59:59.000Z

346

Compressive strength of concrete and mortar containing fly ash  

DOE Patents (OSTI)

The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specifications required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs. 33 figs.

Liskowitz, J.W.; Wecharatana, M.; Jaturapitakkul, C.; Cerkanowicz, A.E.

1997-04-29T23:59:59.000Z

347

Compressibility Consideration in the Boundary of a Strongly Collapsing Bubble  

E-Print Network (OSTI)

Equations of radial motion of a gas bubble in a compressible viscous liquid have been modified to account for compressibility at the bubble boundary. It has been done by deriving a new bubble boundary equation. This equation has a new term due to liquid compressibility. The influence of this term in the bubble dynamics has been numerically investigated using isothermal-adiabatic model for the gas bubble evolution. The results clearly indicate that at the end of the collapse the new term has very significant role and its consideration dramatically changes the bubble characteristics. The effect of this term is more prominent for the more intense collapses, so that its consideration scales up the maximum values of gas pressure and gas temperature. We have also reasoned that the new bubble behavior will be established even when the effects of mass (water vapor) exchange, chemical reactions, and gas dynamics inside the bubble are taken into account in the model.

Moshaii, A; Taeibi-Rahni, M; Moshaii, Ahmad; Sadighi-Bonabi, Rasool; Taeibi-Rahni, Mohammad

2003-01-01T23:59:59.000Z

348

Mica-based Composite Compressive Seals for SOFC  

DOE Green Energy (OSTI)

One of the critical challenges facing planar solid oxide fuel cell (SOFC) technology is the need for reliable sealing technology. Seals are required for long-term stability and integrity in the high temperature SOFC environment during normal and transient operations. Several different approaches for sealing SOFC stacks are under development, including glass or glass-ceramic seals, metallic brazes, and compressive seals. Compressive seals potentially offer a significant and unique advantage over the other approaches by providing a means of mechanically ''de-coupling'' adjacent stack components, thereby minimizing the need for closely matching the coefficients of thermal expansion (CTE) of the various SOFC stack components. In an attempt to help the SOFC industry overcome sealing challenges, PNNL is developing mica-based hybrid compressive seals which exhibit leak rates 2 to 3 orders of magnitude lower than obtained with simple mica gasket seals.

Chou, Y S.; Meinhardt, Kerry D.; Stevenson, Jeffry W.; Singh, Prabhakar

2004-07-07T23:59:59.000Z

349

Beam Compression in Heavy-Ion Induction Linacs  

SciTech Connect

The Heavy-Ion Fusion Sciences Virtual National Laboratory is pursuing an approach to target heating experiments in the Warm Dense Matter regime, using space-charge-dominated ion beams that are simultaneously longitudinally bunched and transversely focused. Longitudinal beam compression by large factors has been demonstrated in the LBNL Neutralized Drift Compression Experiment (NDCX) experiment with controlled ramps and forced neutralization. The achieved peak beam current and energy can be used in experiments to heat targets and create warm dense matter. Using an injected 30 mA K{sup +} ion beam with initial kinetic energy 0.3 MeV, axial compression leading to {approx}50x current amplification and simultaneous radial focusing to beam radii of a few mm have led to encouraging energy deposition approaching the intensities required for eV-range target heating experiments. We discuss experiments that are under development to reach the necessary higher beam intensities and the associated beam diagnostics.

Seidl, P.A.; Anders, A.; Bieniosek, F.M.; Barnard, J.J.; Calanog, J.; Chen, A.X.; Cohen, R.H.; Coleman, J.E.; Dorf, M.; Gilson, E.P.; Grote, D.P.; Jung, J.Y.; Leitner, M.; Lidia, S.M.; Logan, B.G.; Ni, P.; Roy, P.K.; Van den Bogert, K.; Waldron, W.L.; Welch, D.R.

2009-01-01T23:59:59.000Z

350

Variation of equivalence ratio and element ratios in low-pressure premixed flames of aliphatic fuels  

DOE Green Energy (OSTI)

In previously published work it was found that the element ratios (such as C/O, H/O, H/C) and the equivalence ratio all varied in the flame zone of a low-pressure premixed fuel-rich benzene/oxygen/argon laminar flat flame. These variations were seen from analyses of both the data and detailed kinetic modeling. In the present work, seven additional flames were analyzed in the same manner, including five flames with a single hydrocarbon fuel (methane, acetylene, ethylene, allene, and propene) and two flames with a mixture of fuels (acetylene/allene, hydrogen/allene). All the flames had argon as the diluent, with pressures between 20 and 37.5 Torr, equivalence ratios between 1.6 and 2.5, cold gas velocities between 42 and 126 cm/sec. All of these flames showed variations in the element ratios and equivalence ratios. Furthermore, these variations changed in a consistent pattern with respect to the molecular weight of the fuel. In the flame zone, the percent change in the H/O, C/O and equivalence ratios increased with increasing molecular weight of the fuel, except for the hydrogen/allene flame in which the C/O ratio first increases, then decreases in the flame zone. Also, unlike all the other hydrocarbon flames, the C/O ratio decreases below its inlet value for the methane flame. The H/O and equivalence ratios decrease below their inlet values for the hydrogen/allene flame. These results are explained in terms of differential diffusion effects between the products and the reactants, which increase as the fuel becomes increasingly heavier than the major carbon- and hydrogen-containing products.

C. J. Pope; J. A. Miller

2000-03-14T23:59:59.000Z

351

Alternative Fuels Data Center: Compressed Natural Gas (CNG) Tax and Permit  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Compressed Natural Gas Compressed Natural Gas (CNG) Tax and Permit to someone by E-mail Share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Tax and Permit on Facebook Tweet about Alternative Fuels Data Center: Compressed Natural Gas (CNG) Tax and Permit on Twitter Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Tax and Permit on Google Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) Tax and Permit on Delicious Rank Alternative Fuels Data Center: Compressed Natural Gas (CNG) Tax and Permit on Digg Find More places to share Alternative Fuels Data Center: Compressed Natural Gas (CNG) Tax and Permit on AddThis.com... More in this section... Federal State Advanced Search All Laws & Incentives Sorted by Type Compressed Natural Gas (CNG) Tax and Permit

352

Author manuscript, published in "SPARS'09- Signal Processing with Adaptive Sparse Structured Representations (2009)" 1 Compressed sensing based compression of SAR raw data  

E-Print Network (OSTI)

Abstract—Due to their noise-like features, SAR images are difficult to acquire with compressed sensing techniques. However, some parts of the images, typically associated to man-made structures, are compressible and we investigate two techniques exploiting that information to allow a compressive acquisition of the whole image. These techniques result in a significant enhancement of the image quality compared to classical compressed sensing. Moreover, compared to classical sampling and quantisation of the SAR raw data, they allow a significant reduction of bitrate with a limited increase of the distortion. However, their efficiency depends strongly on the presence of compressible parts in the image. I.

Gabriel Rilling; Mike Davies; Bernard Mulgrew

2009-01-01T23:59:59.000Z

353

Plasmons in strongly coupled shock-compressed matter  

Science Conference Proceedings (OSTI)

We present the first measurements of the plasmon dispersion and damping in laser shock-compressed solid matter. Petawatt laser produced K-{alpha} radiation scatters on boron targets compressed by a 10 ns-long 400 J laser pulse. In the vicinity of the Fermi momentum, the scattering spectra show dispersionless, collisionally damped plasmons, indicating a strongly coupled electron liquid. These observations agree with x-ray scattering calculations that include both the Born-Mermin approximation to account for electron-ion collisional damping and local field corrections reflecting electron-electron correlations.

Neumayer, P; Fortmann, C; Doppner, T; Davis, P; Falcone, R W; Kritcher, A L; Landen, O L; Lee, H J; Lee, R W; Niemann, C; Pape, S L; Glenzer, S H

2010-04-15T23:59:59.000Z

354

Compressed supersymmetry after 1/fb at the Large Hadron Collider  

E-Print Network (OSTI)

We study the reach of the Large Hadron Collider with 1/fb of data at sqrt{s} = 7 TeV for several classes of supersymmetric models with compressed mass spectra, using jets and missing transverse energy cuts like those employed by ATLAS for Summer 2011 data. In the limit of extreme compression, the best limits come from signal regions that do not require more than 2 or 3 jets and that remove backgrounds by requiring more missing energy rather than higher effective mass.

Thomas J. LeCompte; Stephen P. Martin

2011-11-29T23:59:59.000Z

355

Three-dimensional evaluation of the compression and recovery behavior in a flexible graphite sheet by synchrotron radiation microtomography  

SciTech Connect

The compression and unloading behavior of flexible graphite sheets was investigated using synchrotron radiation microtomography with 1 {mu}m voxel size. The recovery ratio of the flexible graphite sheet was measured accurately by in-situ observation. The three-dimensional strain distribution in the interior of the specimen was obtained using the microstructural tracking method. The inner strain distribution with micrometer scale indicated inhomogeneous deformation. The microstructural tracking analysis revealed that deformation units exist in the flexible graphite sheet. The units seem to deform, affecting the neighboring units with each other. The units had a similar size and shape with compacted exfoliated graphite worms that constitute the flexible graphite sheet. Microscopic deformations during compression and unloading are surely affected by the microstructure of the sheet. Highlights: Black-Right-Pointing-Pointer The compression and recovery behavior was investigated using microtomography. Black-Right-Pointing-Pointer The tracking analysis revealed that deformation units exist in the specimen. Black-Right-Pointing-Pointer Each unit deforms in relation to the neighboring unit.

Kobayashi, M., E-mail: m-kobayashi@me.tut.ac.jp [Department of Mechanical Engineering, Toyohashi University of Technology, Toyohashi, AICHI 441-8580 (Japan); Toda, H. [Department of Mechanical Engineering, Toyohashi University of Technology, Toyohashi, AICHI 441-8580 (Japan); Takeuchi, A.; Uesugi, K.; Suzuki, Y. [Japan Synchrotron Radiation Research Institute, Sayo-gun, HYOGO 679-5198 (Japan)

2012-07-15T23:59:59.000Z

356

VARIABLE TIME-INTERVAL GENERATOR  

DOE Patents (OSTI)

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

Gross, J.E.

1959-10-31T23:59:59.000Z

357

Isotopic ratio method for determining uranium contamination  

SciTech Connect

The presence of high concentrations of uranium in the subsurface can be attributed either to contamination from uranium processing activities or to naturally occurring uranium. A mathematical method has been employed to evaluate the isotope ratios from subsurface soils at the Rocky Flats Nuclear Weapons Plant (RFP) and demonstrates conclusively that the soil contains uranium from a natural source and has not been contaminated with enriched uranium resulting from RFP releases. This paper describes the method used in this determination which has widespread application in site characterizations and can be adapted to other radioisotopes used in manufacturing industries. The determination of radioisotope source can lead to a reduction of the remediation effort.

Miles, R.E.; Sieben, A.K.

1994-02-03T23:59:59.000Z

358

CO (Carbon Monoxide Mixing Ratio System) Handbook  

Science Conference Proceedings (OSTI)

The main function of the CO instrument is to provide continuous accurate measurements of carbon monoxide mixing ratio at the ARM SGP Central Facility (CF) 60-meter tower (36.607 °N, 97.489 °W, 314 meters above sea level). The essential feature of the control and data acquisition system is to record signals from a Thermo Electron 48C and periodically calibrate out zero and span drifts in the instrument using the combination of a CO scrubber and two concentrations of span gas (100 and 300 ppb CO in air). The system was deployed on May 25, 2005.

Biraud, S

2011-02-23T23:59:59.000Z

359

High aspect ratio, remote controlled pumping assembly  

DOE Patents (OSTI)

A miniature dual syringe-type pump assembly is described which has a high aspect ratio and which is remotely controlled, for use such as in a small diameter penetrometer cone or well packer used in water contamination applications. The pump assembly may be used to supply and remove a reagent to a water contamination sensor, for example, and includes a motor, gearhead and motor encoder assembly for turning a drive screw for an actuator which provides pushing on one syringe and pulling on the other syringe for injecting new reagent and withdrawing used reagent from an associated sensor. 4 figs.

Brown, S.B.; Milanovich, F.P.

1995-11-14T23:59:59.000Z

360

Implications of Fast Reactor Transuranic Conversion Ratio  

SciTech Connect

Theoretically, the transuranic conversion ratio (CR), i.e. the transuranic production divided by transuranic destruction, in a fast reactor can range from near zero to about 1.9, which is the average neutron yield from Pu239 minus 1. In practice, the possible range will be somewhat less. We have studied the implications of transuranic conversion ratio of 0.0 to 1.7 using the fresh and discharge fuel compositions calculated elsewhere. The corresponding fissile breeding ratio ranges from 0.2 to 1.6. The cases below CR=1 (“burners”) do not have blankets; the cases above CR=1 (“breeders”) have breeding blankets. The burnup was allowed to float while holding the maximum fluence to the cladding constant. We graph the fuel burnup and composition change. As a function of transuranic conversion ratio, we calculate and graph the heat, gamma, and neutron emission of fresh fuel; whether the material is “attractive” for direct weapon use using published criteria; the uranium utilization and rate of consumption of natural uranium; and the long-term radiotoxicity after fuel discharge. For context, other cases and analyses are included, primarily once-through light water reactor (LWR) uranium oxide fuel at 51 MWth-day/kg-iHM burnup (UOX-51). For CR<1, the heat, gamma, and neutron emission increase as material is recycled. The uranium utilization is at or below 1%, just as it is in thermal reactors as both types of reactors require continuing fissile support. For CR>1, heat, gamma, and neutron emission decrease with recycling. The uranium utilization exceeds 1%, especially as all the transuranic elements are recycled. exceeds 1%, especially as all the transuranic elements are recycled. At the system equilibrium, heat and gamma vary by somewhat over an order of magnitude as a function of CR. Isotopes that dominate heat and gamma emission are scattered throughout the actinide chain, so the modest impact of CR is unsurprising. Neutron emitters are preferentially found among the higher actinides, so the neutron emission varies much stronger with CR, about three orders of magnitude.

Steven J. Piet; Edward A. Hoffman; Samuel E. Bays

2010-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "variable compression ratio" from the National Library of EnergyBeta (NLEBeta).
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361

Energy Balance Bowen Ratio Station (EBBR) Handbook  

Science Conference Proceedings (OSTI)

The energy balance Bowen ratio (EBBR) system produces 30-minute estimates of the vertical fluxes of sensible and latent heat at the local surface. Flux estimates are calculated from observations of net radiation, soil surface heat flux, and the vertical gradients of temperature and relative humidity (RH). Meteorological data collected by the EBBR are used to calculate bulk aerodynamic fluxes, which are used in the Bulk Aerodynamic Technique (BA) EBBR value-added product (VAP) to replace sunrise and sunset spikes in the flux data. A unique aspect of the system is the automatic exchange mechanism (AEM), which helps to reduce errors from instrument offset drift.

Cook, DR

2011-02-23T23:59:59.000Z

362

Device for adapting continuously variable transmissions to infinitely variable transmissions with forward-neutral-reverse capabilities  

DOE Patents (OSTI)

An infinitely variable transmission is capable of operating between a maximum speed in one direction and a minimum speed in an opposite direction, including a zero output angular velocity, while being supplied with energy at a constant angular velocity. Input energy is divided between a first power path carrying an orbital set of elements and a second path that includes a variable speed adjustment mechanism. The second power path also connects with the orbital set of elements in such a way as to vary the rate of angular rotation thereof. The combined effects of power from the first and second power paths are combined and delivered to an output element by the orbital element set. The transmission can be designed to operate over a preselected ratio of forward to reverse output speeds.

Wilkes, Donald F. (Albuquerque, NM); Purvis, James W. (Albuquerque, NM); Miller, A. Keith (Albuquerque, NM)

1997-01-01T23:59:59.000Z

363

CDIAC Climate Data: Available Variables  

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

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

364

Hydraulic system for a ratio change transmission  

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

365

Measurement of the Branching Ratio for  

E-Print Network (OSTI)

We have measured the branching ratio B(\\Upsilon(1S) ! + \\Gamma ) using the CLEO II detector. A clean sample of tau pair events is identified via events containing two charged particles where exactly one of the particles is an identified electron. We find B(\\Upsilon(1S) ! + \\Gamma ) = (2:59 \\Sigma 0:12 +0:13 \\Gamma0:16 )%. The result is consistent with expectations from lepton universality. Permanent address: INP, Novosibirsk, Russia y Permanent address: University of Hawaii at Manoa 1 One of the interesting aspects of heavy quarkonia is that in the lower energy states the electromagnetic decays compete with the strong decays due to OZI suppression. In the b b system, the first three \\Upsilon resonances all lie below the threshold for strong decay into pairs of B mesons, and the measured leptonic decays are of the order of a few percent. For the \\Upsilon(1S), the world average of the branching ratio into tau pairs is (2:97 \\Sigma 0:35)% [1] based on two measureme...

Upsilon Gamma Cinabro; Ichep Ref; Gls Cleo Conf; M. Saulnier; G. Gollin

1994-01-01T23:59:59.000Z

366

Flexible Conversion Ratio Fast Reactor Systems Evaluation  

Science Conference Proceedings (OSTI)

Conceptual designs of lead-cooled and liquid salt-cooled fast flexible conversion ratio reactors were developed. Both concepts have cores reated at 2400 MWt placed in a large-pool-type vessel with dual-free level, which also contains four intermediate heat exchanges coupling a primary coolant to a compact and efficient supercritical CO2 Brayton cycle power conversion system. Decay heat is removed passively using an enhanced Reactor Vessel Auxiliary Cooling System and a Passive Secondary Auxiliary Cooling System. The most important findings were that (1) it is feasible to design the lead-cooled and salt-cooled reactor with the flexible conversion ratio (CR) in the range of CR=0 and CR=1 n a manner that achieves inherent reactor shutdown in unprotected accidents, (2) the salt-cooled reactor requires Lithium thermal Expansion Modules to overcme the inherent salt coolant's large positive coolant temperature reactivity coefficient, (3) the preferable salt for fast spectrum high power density cores is NaCl-Kcl-MgCl2 as opposed to fluoride salts due to its better themal-hydraulic and neutronic characteristics, and (4) both reactor, but attain power density 3 times smaller than that of the sodium-cooled reactor.

Neil Todreas; Pavel Hejzlar

2008-06-30T23:59:59.000Z

367

Aerosol organic carbon to black carbon ratios: Analysis of published...  

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

Aerosol organic carbon to black carbon ratios: Analysis of published data and implications for climate forcing Title Aerosol organic carbon to black carbon ratios: Analysis of...

368

Table E7.1. Consumption Ratios of Fuel, 1998  

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

1. Consumption Ratios of Fuel, 1998;" " Level: National and Regional Data; " " Row: Values of Shipments and Employment Sizes;" " Column: Energy-Consumption Ratios;" " Unit:...

369

Superradiant pulse compression using free-carrier plasma  

SciTech Connect

Free-carrier plasma can be used as an effective nonlinear medium for pulse compression. In the backward Raman amplifier geometry, the lower-frequency seed can extract most of the long pump energy through the mechanism of nonlinear superradiance. Filamentation is avoided due to strong dependence of the Raman instability growth rate on the wavenumber.

G. Shvets; N. J. Fisch; A. Pukhov; J. Meyer-ter-Vehn

2000-07-21T23:59:59.000Z

370

Nuclear Maintenance Applications Center: Compression Fitting Application Manual  

Science Conference Proceedings (OSTI)

The Nuclear Maintenance Applications Center: Compression Fitting Application Manual provides power plant maintenance personnel with current maintenance information on this type of component used in power plants, both fossil fuel and nuclear. This guide will assist plant maintenance personnel in improving the reliability of and reducing the maintenance costs for this equipment.

2008-12-22T23:59:59.000Z

371

Data sampling control, compression and query in sensor networks  

Science Conference Proceedings (OSTI)

Nodes in wireless sensor networks have very limited storage capacity, computing ability and battery power. Node failure and communication link disconnection occur frequently, which means weak services of the network layer. Sensed data is inaccurate which ... Keywords: data accuracy, data compression, data sampling, energy efficiency, power limitation, query, sampling frequency control, sensor networks

Jinbao Li; Jianzhong Li

2007-04-01T23:59:59.000Z

372

Fast compression of transportable Tcl agents Robert S. Gray  

E-Print Network (OSTI)

Fast compression of transportable Tcl agents Robert S. Gray Department of Computer Science implemented a transportable agent system that uses the Tool Command Language (Tcl) as the agent language. Each Tcl script can suspend its execution at an arbitrary point, transport itself to another machine

373

Joint watermarking and progressive geometric compression of 3D meshes  

Science Conference Proceedings (OSTI)

With the ever-increasing development of digital technologies and digital 3D models, the question of 3D mesh protection has becoming more and more important. One of the problems in digital watermarking is to decide how to embed in a 3D mesh as many bits ... Keywords: 3D compression, blind watermarking, dither modulation, semi-regular 3D meshes, wavelet transform

Ines Bouzidi; Azza Ouled Zaid; Meha Hachani; William Puech

2013-06-01T23:59:59.000Z

374

Economic and technical feasibility study of compressed air storage  

DOE Green Energy (OSTI)

The results of a study of the economic and technical feasibility of compressed air energy storage (CAES) are presented. The study, which concentrated primarily on the application of underground air storage with combustion turbines, consisted of two phases. In the first phase a general assessment of the technical alternatives, economic characteristics and the institutional constraints associated with underground storage of compressed air for utility peaking application was carried out. The goal of this assessment was to identify potential barrier problems and to define the incentive for the implementation of compressed air storage. In the second phase, the general conclusions of the assessment were tested by carrying out the conceptual design of a CAES plant at two specific sites, and a program of further work indicated by the assessment study was formulated. The conceptual design of a CAES plant employing storage in an aquifer and that of a plant employing storage in a conventionally excavated cavern employing a water leg to maintain constant pressure are shown. Recommendations for further work, as well as directions of future turbo-machinery development, are made. It is concluded that compressed air storage is technically feasible for off-peak energy storage, and, depending on site conditions, CAES plants may be favored over simple cycle turbine plants to meet peak demands. (LCL)

Not Available

1976-03-01T23:59:59.000Z

375

Mound Isotope Power Systems; AMTEC Integral Cell Wall Compression Test  

DOE Green Energy (OSTI)

An AMTEC (Alkali Metal Thermal-to-Electric Conversion) device is tested under a compression load at a rate of 0.0025 inches/minute. The integral cell wall is made of Haynes Alloy 25. The wall buckled at 724 pounds load.

None

1997-11-05T23:59:59.000Z

376

Economics of compressed air energy storage employing thermal energy storage  

DOE Green Energy (OSTI)

The approach taken in this study is to adopt system design and capital cost estimates from three independent CAES studies (eight total designs) and, by supplying a common set of fuel/energy costs and economic assumptions in conjunction with a common methodology, to arrive at a series of levelized energy costs over the system's lifetime. In addition, some analyses are provided to gauge the sensitivity of these levelized energy costs to fuel and compression energy costs and to system capacity factors. The systems chosen for comparison are of four generic types: conventional CAES, hybrid CAES, adiabatic CAES, and an advanced-design gas turbine (GT). In conventional CAES systems the heat of compression generated during the storage operation is rejected to the environment, and later, during the energy-generation phase, turbine fuel must be burned to reheat the compressed air. In the hybrid systems some of the heat of compression is stored and reapplied later during the generation phase, thereby reducing turbine fuel requirements. The adiabatic systems store adequate thermal energy to eliminate the need for turbine fuel entirely. The gas turbine is included within the report for comparison purposes; it is an advanced-design turbine, one that is expected to be available by 1985.

Schulte, S.C.; Reilly, R.W.

1979-11-01T23:59:59.000Z

377

Economics of compressed air energy storage employing thermal energy storage  

SciTech Connect

The approach taken in this study is to adopt system design and capital cost estimates from three independent CAES studies (eight total designs) and, by supplying a common set of fuel/energy costs and economic assumptions in conjunction with a common methodology, to arrive at a series of levelized energy costs over the system's lifetime. In addition, some analyses are provided to gauge the sensitivity of these levelized energy costs to fuel and compression energy costs and to system capacity factors. The systems chosen for comparison are of four generic types: conventional CAES, hybrid CAES, adiabatic CAES, and an advanced-design gas turbine (GT). In conventional CAES systems the heat of compression generated during the storage operation is rejected to the environment, and later, during the energy-generation phase, turbine fuel must be burned to reheat the compressed air. In the hybrid systems some of the heat of compression is stored and reapplied later during the generation phase, thereby reducing turbine fuel requirements. The adiabatic systems store adequate thermal energy to eliminate the need for turbine fuel entirely. The gas turbine is included within the report for comparison purposes; it is an advanced-design turbine, one that is expected to be available by 1985.

Schulte, S.C.; Reilly, R.W.

1979-11-01T23:59:59.000Z

378

Computational study of compressive loading of carbon nanotubes  

Science Conference Proceedings (OSTI)

A reduced-order general continuum method is used to examine the mechanical behavior of single-walled carbon nanotubes (CNTs) under compressive loading and unloading conditions. Quasi-static solutions are sought where the total energy of the system is ... Keywords: carbon nanotube, component, finite element method, mechanical properties

Yang Yang; William W. Liou

2010-03-01T23:59:59.000Z

379

Environmental concerns related to compressed air energy storage  

DOE Green Energy (OSTI)

The report describes the technologies of compressed air energy storage and some of the environmental concerns associated with siting, construction, operation and decommissioning of such a system. Also described is an ongoing research program, the goal of which is to evaluate methods to control the effects of these environmental factors.

Stottlemyre, J. A.; Craig, R. A.; Loscutoff, W. V.; Boehm, D. W.; Chang, G. C.

1978-01-01T23:59:59.000Z

380

Test Data Compression with Partial LFSR-Reseeding  

Science Conference Proceedings (OSTI)

The large amount of test data becomes a serious problem in SOC testing. In this paper, we propose a method to improve the LFSR reseeding based compression scheme. This method rearranges a given set of test data by merging and partitioning test cubes ...

Yu-Hsuan Fu; Sying-Jyan Wang

2005-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "variable compression ratio" 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

Prius: generic hybrid trace compression for wireless sensor networks  

Science Conference Proceedings (OSTI)

Several diagnostic tracing techniques (e.g., event, power, and control-flow tracing) have been proposed for run-time debugging and postmortem analysis of wireless sensor networks (WSNs). Traces generated by such techniques can become large, defying the ... Keywords: compression, sensor networks, tracing

Vinaitheerthan Sundaram; Patrick Eugster; Xiangyu Zhang

2012-11-01T23:59:59.000Z

382

The conservative cascade of kinetic energy in compressible turbulence  

E-Print Network (OSTI)

The physical nature of compressible turbulence is of fundamental importance in a variety of astrophysical settings. We present the first direct evidence that mean kinetic energy cascades conservatively beyond a transitional "conversion" scale-range despite not being an invariant of the compressible flow dynamics. We use high-resolution three-dimensional simulations of compressible hydrodynamic turbulence on $512^3$ and $1024^3$ grids. We probe regimes of forced steady-state isothermal flows and of unforced decaying ideal gas flows. The key quantity we measure is pressure dilatation cospectrum, $E^{PD}(k)$, where we provide the first numerical evidence that it decays at a rate faster than $k^{-1}$ as a function of wavenumber. This is sufficient to imply that mean pressure dilatation acts primarily at large-scales and that kinetic and internal energy budgets statistically decouple beyond a transitional scale-range. Our results suggest that an extension of Kolmogorov's inertial-range theory to compressible turbulence is possible.

Hussein Aluie; Shengtai Li; Hui Li

2011-07-28T23:59:59.000Z

383

The conservative cascade of kinetic energy in compressible turbulence  

E-Print Network (OSTI)

The physical nature of compressible turbulence is of fundamental importance in a variety of astrophysical settings. We present the first direct evidence that mean kinetic energy cascades conservatively beyond a transitional "conversion" scale-range despite not being an invariant of the compressible flow dynamics. We use high-resolution three-dimensional simulations of compressible hydrodynamic turbulence on $512^3$ and $1024^3$ grids. We probe regimes of forced steady-state isothermal flows and of unforced decaying ideal gas flows. The key quantity we measure is pressure dilatation cospectrum, $E^{PD}(k)$, where we provide the first numerical evidence that it decays at a rate faster than $k^{-1}$ as a function of wavenumber. This is sufficient to imply that mean pressure dilatation acts primarily at large-scales and that kinetic and internal energy budgets statistically decouple beyond a transitional scale-range. Our results suggest that an extension of Kolmogorov's inertial-range theory to compressible turbu...

Aluie, Hussein; Li, Hui

2011-01-01T23:59:59.000Z

384

Cloud-Level Penetrative Compressible Convection in the Venus Atmosphere  

Science Conference Proceedings (OSTI)

A two-dimensional, nonlinear, fully compressible model of a perfect gas is used to simulate cloud-level penetrative convection in the Venus atmosphere from 40 to 60 km altitude. Three cases with different amounts of solar heating are considered: ...

R. David Baker; Gerald Schubert; Philip W. Jones

1998-01-01T23:59:59.000Z

385

SP-59: Rheological Performance and Compressive Strength of ...  

Science Conference Proceedings (OSTI)

Stage III studies the 90 days compressive strengths (Sc) of mortar cubes at w/b= 0.35, ... SEM examinations show that Sc was controlled by densification of the ITZ . ... Properties in the Nickel-Titanium-Hafnium System for Shape-Memory Optimization · SP-45: Design of pH and Thermal Sensitive Hydrogels for Catheter Based ...

386

New Variable Stars in the Globular Cluster NGC 6584  

E-Print Network (OSTI)

Using the Southeastern Association for Research in Astronomy 0.6 meter telescope located at Cerro Tololo, we searched for variable stars in the southern globular cluster NGC 6584. We obtained images during 8 nights between 28 May and 6 July of 2011. After processing the images, we used the image subtraction package ISIS developed by Alard (2000)to search for the variable stars. We identified a total of 69 variable stars in our 10x10 arcmin^2 field, including 43 variables cataloged by Millis & Liller (1980) and 26 hereto unknown variables. In total, we classified 46 of the variables as type RRab, with a mean period of 0.56776 days, 15 as type RRc with a mean period of 0.30886 days, perhaps one lower amplitude type RRe, with a period of 0.26482 days, 4 eclipsing binaries, and 3 long period (P > 2 days) variable stars. As many as 15 of the RRab Lyrae stars exhibited the Blazhko Effect. Furthermore, the mean periods of the RR Lyrae types, the exhibited period/amplitude relationship, and the ratio of N_c/(N_ab...

Toddy, Joseph M; Darragh, Andrew N; Murphy, Brian W

2012-01-01T23:59:59.000Z

387

Lossless Data Compression with Error Detection using Cantor Set  

E-Print Network (OSTI)

In 2009, a lossless compression algorithm based on 1D chaotic maps known as Generalized Lur\\"{o}th Series (or GLS) has been proposed. This algorithm (GLS-coding) encodes the input message as a symbolic sequence on an appropriate 1D chaotic map (GLS) and the compressed file is obtained as the initial value by iterating backwards on the map. For ergodic sources, it was shown that GLS-coding achieves the best possible lossless compression (in the noiseless setting) bounded by Shannon entropy. However, in the presence of noise, even small errors in the compressed file leads to catastrophic decoding errors owing to sensitive dependence on initial values. In this paper, we first show that Repetition codes $\\mathcal{R}_n$ (every symbol is repeated $n$ times, where $n$ is a positive odd integer), the oldest and the most basic error correction and detection codes in literature, actually lie on a Cantor set with a fractal dimension of $\\frac{1}{n}$, which is also the rate of the code. Inspired by this, we incorporate error detection capability to GLS-coding by ensuring that the compressed file (initial value on the map) lies on a Cantor set of measure zero. Even a 1-bit error in the initial value will throw it outside the Cantor set which can be detected while decoding. The error detection performance (and also the rate of the code) can be controlled by the fractal dimension of the Cantor set and could be suitably adjusted depending on the noise level of the communication channel.

Nithin Nagaraj

2013-08-10T23:59:59.000Z

388

Electronic branching ratio of the. tau. lepton  

Science Conference Proceedings (OSTI)

Using data accumulated by the CLEO I detector operating at the Cornell Electron Storage Ring, we have measured the ratio {ital R}={Gamma}({tau}{r arrow}{ital e}{bar {nu}}{sub {ital e}}{nu}{sub {tau}})/{Gamma}{sub 1}, where {Gamma}{sub 1} is the {tau} decay rate to final states with one charged particle. We find {ital R}=0.2231{plus minus}0.0044{plus minus}0.0073 where the first error is statistical and the second is systematic. Together with the measured topological one-charged-particle branching fraction, this yields the branching fraction of the {tau} lepton to electrons, {ital B}{sub {ital e}}=0.192{plus minus}0.004{plus minus}0.006.

Ammar, R.; Baringer, P.; Coppage, D.; Davis, R.; Kelly, M.; Kwak, N.; Lam, H.; Ro, S.; Kubota, Y.; Lattery, M.; Nelson, J.K.; Perticone, D.; Poling, R.; Schrenk, S.; Wang, R.; Alam, M.S.; Kim, I.J.; Nemati, B.; Romero, V.; Sun, C.R.; Wang, P.; Zoeller, M.M.; Crawford, G.; Fulton, R.; Gan, K.K.; Kagan, H.; Kass, R.; Lee, J.; Malchow, R.; Morrow, F.; Sung, M.K.; Whitmore, J.; Wilson, P.; Butler, F.; Fu, X.; Kalbfleisch, G.; Lambrecht, M.; Skubic, P.; Snow, J.; Wang, P.; Bortoletto, D.; Brown, D.N.; Dominick, J.; McIlwain, R.L.; Miller, D.H.; Modesitt, M.; Shibata, E.I.; Schaffner, S.F.; Shipsey, I.P.J.; Battle, M.; Ernst, J.; Kroha, H.; Roberts, S.; Sparks, K.; Thorndike, E.H.; Wang, C.; Stroynowski, R.; Artuso, M.; Goldberg, M.; Haupt, T.; Horwitz, N.; Kennett, R.; Moneti, G.C.; Playfer, S.; Rozen, Y.; Rubin, P.; Skwarnicki, T.; Stone, S.; Thulasidas, M.; Yao, W.; Zhu, G.; Barnes, A.V.; Bartelt, J.; Csorna, S.E.; Jain, V.; Letson, T.; Mestayer, M.D.; Akerib, D.S.; Barish, B.; Chadha, M.; (CLEO Collaboration)

1992-06-01T23:59:59.000Z

389

Hybrid energy storage systems based on compressed air and supercapacitors with maximum efficiency point tracking  

E-Print Network (OSTI)

This paper presents a hybrid energy storage system based on Compressed Air Energy Storage (CAES), where the charging and discharging is done within maximum efficiency conditions. As the maximum efficiency conditions impose the level of converted power, an intermittent time-modulated operation mode is applied to the thermodynamic converter to obtain a variable converted power. A smoothly variable output power is achieved with the help of a supercapacitive auxiliary storage device used as a filter. The paper describes the concept of the system, the power-electronic interface circuits and especially the Maximum Efficiency Point Tracking (MEPT) algorithm and the strategy used to vary the output power. In addition, the paper will present the characteristics of a high efficiency storage device where the pure pneumatic machine is replaced by an oil-hydraulics and pneumatics converter, used under isothermal conditions. Practical results are also presented, recorded from a low-power pneumatic motor coupled to a small DC generator, as well as from a first prototype of the final hydraulic/pneumatic system.

Sylvain Lemofouet; Alfred Rufer

2005-01-01T23:59:59.000Z

390

Computer-assisted apparatus for measuring physical properties of meat during compression  

Science Conference Proceedings (OSTI)

Prototype apparatus was developed to measure the optical properties of meat during compression and the rheological properties of meat during thawing. Compression may be a source of error when meat quality is measured with an optical probe and the rheological ...

H. J. Swatland

1992-07-01T23:59:59.000Z

391

Thermally Induced Compression Waves and Gravity Waves Generated by Convective Storms  

Science Conference Proceedings (OSTI)

A three-dimensional, fully compressible cloud model is used to simulate a convective storm in order to investigate the properties of compression waves and gravity waves induced by latent heat release. Time series of the low-level pressure ...

Melville E. Nicholls; Roger A. Pielke Sr.

2000-10-01T23:59:59.000Z

392

Optical, electronic, and dynamical phenomena in the shock compression of condensed matter  

E-Print Network (OSTI)

Despite the study of shock wave compression of condensed matter for over 100 years, scant progress has been made in understanding the microscopic details. This thesis explores microscopic phenomena in shock compression of ...

Reed, Evan J. (Evan John), 1976-

2003-01-01T23:59:59.000Z

393

ASE/CAGI Meeting about Compressors and Compressed Air System Efficiency  

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

On April 25, 2013, several representatives of energy efficiency advocacy organizations met with staff and members of the Compressed Air and Gas Institute (CAGI) along with some compressed air...

394

Extension of the high load limit in the Homogeneous Charge Compression Ignition engine  

E-Print Network (OSTI)

The Homogeneous Charge Compression Ignition (HCCI) engine offers diesel-like efficiency with very low soot and NOx emissions. In a HCCI engine, a premixed charge of air, fuel and burned gas is compressed to achieve ...

Scaringe, Robert J. (Robert Joseph)

2009-01-01T23:59:59.000Z

395

Influences of atmospheric conditions and air mass on the ratio of ultraviolet to total solar radiation  

SciTech Connect

The technology to detoxify hazardous wastes using ultraviolet (UV) solar radiation is being investigated by the DOE/SERI Solar Thermal Technology Program. One of the elements of the technology evaluation is the assessment and characterization of UV solar radiation resources available for detoxification processes. This report describes the major atmospheric variables that determine the amount of UV solar radiation at the earth's surface, and how the ratio of UV-to-total solar radiation varies with atmospheric conditions. These ratios are calculated from broadband and spectral solar radiation measurements acquired at SERI, and obtained from the literature on modeled and measured UV solar radiation. The following sections discuss the atmospheric effects on UV solar radiation and provide UV-to-total solar radiation ratios from published studies, as well as measured values from SERI's data. A summary and conclusions are also given.

Riordan, C.J.; Hulstrom, R.L.; Myers, D.R.

1990-08-01T23:59:59.000Z

396

Energy Saving Technology of Thermal Regenerative Compressed Air Dryer by Regenerates Adsorbent with Residual Heat  

Science Conference Proceedings (OSTI)

According to the characteristic of the compressed air dryer located at the same place with the air compressor, for the large capacity thermal regenerative compressed air dryer that the absorbent is regenerated by an electric heater, this thesis puts ... Keywords: Compressed air dryer, Regeneration, Heater, Residual heat, Energy saving

Zhang Mingzhu; Zhou Zhili; Li Hongtao; Zhang Yongbo

2009-10-01T23:59:59.000Z

397

High-Throughput Compression of FASTQ Data with SeqDB  

Science Conference Proceedings (OSTI)

Compression has become a critical step in storing next-generation sequencing (NGS) data sets because of both the increasing size and decreasing costs of such data. Recent research into efficiently compressing sequence data has focused largely on improving ... Keywords: Throughput,Arrays,Bandwidth,Libraries,Bioinformatics,Instruction sets,Genomics,FASTQ,Compression,data storage,next-generation sequencing

Mark Howison

2013-01-01T23:59:59.000Z

398

COMPRESSED-AIR ENERGY STORAGE SYSTEMS FOR STAND-ALONE OFF-GRID PHOTOVOLTAIC MODULES  

E-Print Network (OSTI)

-storage materials, flywheels, pumped hydro (PH), superconducting magnetic energy storage (SMES) and compressed airCOMPRESSED-AIR ENERGY STORAGE SYSTEMS FOR STAND-ALONE OFF-GRID PHOTOVOLTAIC MODULES Dominique, USA ABSTRACT In this work, a low-cost, low-volume, low-maintenance, small-scale compressed-air energy

Deymier, Pierre

399

In-cylinder pressure and inter-cycle variability analysis for a compression ignition engine : Bayesian approaches.  

E-Print Network (OSTI)

??This thesis introduced Bayesian statistics as an analysis technique to isolate resonant frequency information in in-cylinder pressure signals taken from internal combustion engines. Applications of… (more)

Bodisco, Timothy Alexis

2013-01-01T23:59:59.000Z

400

On Sub-ENSO Variability  

Science Conference Proceedings (OSTI)

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

Noel S. Keenlyside; Mojib Latif; Anke Dürkop

2007-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "variable compression ratio" 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

Image Compression and Watermarking scheme using Scalar Quantization  

E-Print Network (OSTI)

This paper presents a new compression technique and image watermarking algorithm based on Contourlet Transform (CT). For image compression, an energy based quantization is used. Scalar quantization is explored for image watermarking. Double filter bank structure is used in CT. The Laplacian Pyramid (LP) is used to capture the point discontinuities, and then followed by a Directional Filter Bank (DFB) to link point discontinuities. The coefficients of down sampled low pass version of LP decomposed image are re-ordered in a pre-determined manner and prediction algorithm is used to reduce entropy (bits/pixel). In addition, the coefficients of CT are quantized based on the energy in the particular band. The superiority of proposed algorithm to JPEG is observed in terms of reduced blocking artifacts. The results are also compared with wavelet transform (WT). Superiority of CT to WT is observed when the image contains more contours. The watermark image is embedded in the low pass image of contourlet decomposition. ...

Swamy, Kilari Veera; Reddy, Y V Bhaskar; Kumar, S Srinivas; 10.5121/ijngn.2010.2104

2010-01-01T23:59:59.000Z

402

Business Case for Compressed Natural Gas in Municipal Fleets  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Technical Report Technical Report NREL/TP-7A2-47919 June 2010 Business Case for Compressed Natural Gas in Municipal Fleets Caley Johnson National Renewable Energy Laboratory 1617 Cole Boulevard, Golden, Colorado 80401-3393 303-275-3000 * www.nrel.gov NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Operated by the Alliance for Sustainable Energy, LLC Contract No. DE-AC36-08-GO28308 Technical Report NREL/TP-7A2-47919 June 2010 Business Case for Compressed Natural Gas in Municipal Fleets C Johnson aley Prepared under Task No. FC08.0032 NOTICE This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any

403

Geometrical Constraints on Plasma Couplers for Raman Compression  

SciTech Connect

Backward Raman compression in plasma is based on a 3-wave resonant interaction, which includes two- counter propagating laser pulses (pump and seed pulses) and an electron plasma wave (Langmuir wave). A high-density, roughly homogeneous, plasma mediates the energy transfer between the lasers by ensuring resonance with the plasma wave. However, in practice, a laser pulse entering or leaving plasma source encounters plasma at the edges of the homogeneous section that is far too tenuous to maintain resonance. When these tenuous plasma regions are extensive, such as for the wider plasma necessary for compression at higher powers, significant inverse bremsstrahlung and seed dispersion may occur. These deleterious effects may, however, be mitigated by chirping the seed and pump pulses.

Z. Toroker, V.M. Malkin, G.M. Fraiman, A.A. Balakin, and N.J. Fisch

2012-07-18T23:59:59.000Z

404

Shock Experiments on Pre-Compressed Fluid Helium  

Science Conference Proceedings (OSTI)

We summarize current methods and results for coupling laser-induced shocks into pre-compressed Helium contained in a diamond anvil cell (DAC). We are able to load helium, hydrogen, deuterium, and helium-hydrogen mixtures into a DAC and propagate a laser-generated shock into the pre-compressed sample. This technique has allowed us to measure the Hugoniot for helium at initial densities ranging from 1 to 3.5 times liquid density. We have developed and used a methodology whereby all of our measurements are referenced to crystalline quartz, which allows us to update our results as the properties of quartz are refined in the future. We also report the identification and elimination of severe electro-magnetic pulses (EMP) associated with plasma stagnation associated with ablation in a DAC.

Eggert, J. H.; Celliers, P. M.; Hicks, D. G.; Rygg, J. R.; Collins, G. W. [Lawrence Livermore National Laboratory, Livermore CA (United States); Brygoo, S.; Loubeyre, P. [Commissariat a l'Energie Atomique, Bruyeres-le-Chatel (France); McWilliams, R. S.; Spaulding, D.; Jeanloz, R. [University of California, Berkeley, CA (United States); Boehly, T. R. [University of Rochester, Rochester, NY (United States)

2009-09-10T23:59:59.000Z

405

Frequency shift measurement in shock-compressed materials  

DOE Patents (OSTI)

A method is disclosed for determining molecular vibrational frequencies in shock-compressed transparent materials. A single laser beam pulse is directed into a sample material while the material is shock-compressed from a direction opposite that of the incident laser beam. A Stokes beam produced by stimulated Raman scattering is emitted back along the path of the incident laser beam, that is, in the opposite direction to that of the incident laser beam. The Stokes beam is separated from the incident beam and its frequency measured. The difference in frequency between the Stokes beam and the incident beam is representative of the characteristic frequency of the Raman active mode of the sample. Both the incident beam and the Stokes beam pass perpendicularly through the stock front advancing through the sample, thereby minimizing adverse effects of refraction.

Moore, D.S.; Schmidt, S.C.

1984-02-21T23:59:59.000Z

406

Compression algorithm for discrete light-cone quantization  

E-Print Network (OSTI)

We adapt the compression algorithm of Weinstein, Auerbach, and Chandra from eigenvectors of spin lattice Hamiltonians to eigenvectors of light-front field-theoretic Hamiltonians. The latter are approximated by the standard discrete light-cone quantization technique, which provides a matrix representation of the Hamiltonian eigenvalue problem. The eigenvectors are represented as singular value decompositions of two-dimensional arrays, indexed by transverse and longitudinal momenta, and compressed by truncation of the decomposition. The Hamiltonian is represented by a rank-four tensor that is decomposed as a sum of contributions factorized into direct products of separate matrices for transverse and longitudinal interactions. The algorithm is applied to a model theory, to illustrate its use.

Xiao Pu; Sophia S. Chabysheva; John R. Hiller

2013-08-22T23:59:59.000Z

407

Environmental and regulatory aspects of compressed-air energy storage  

DOE Green Energy (OSTI)

The effects of fuel regulations, environmental protection laws, the National Environmental Policy Act, underground injection regulations, and state regulations on the development of compressed air storage systems and power plants are discussed. It is concluded that environmental regulatory concerns of conventional energy technologies are often different from those associated with new technologies such as compressed air energy storage (CAES). Confusion and uncertainty often results when the current environmental regulatory system is applied to new technologies. Evolution of the regulatory system must accompany and rapidly accommodate technological development if the benefits of such development are to be fully realized in a timely manner. Those responsible for technological development in the energy field must be aware of these disparities and conduct their efforts accordingly.

Beckwith, M.A.; Mathur, J.

1981-01-01T23:59:59.000Z

408

Frequency shift measurement in shock-compressed materials  

DOE Patents (OSTI)

A method for determining molecular vibrational frequencies in shock-compressed transparent materials. A single laser beam pulse is directed into a sample material while the material is shock-compressed from a direction opposite that of the incident laser beam. A Stokes beam produced by stimulated Raman scattering is emitted back along the path of the incident laser beam, that is, in the opposite direction to that of the incident laser beam. The Stokes beam is separated from the incident beam and its frequency measured. The difference in frequency between the Stokes beam and the incident beam is representative of the characteristic frequency of the Raman active mode of the sample. Both the incident beam and the Stokes beam pass perpendicularly through the shock front advancing through the sample, thereby minimizing adverse effects of refraction.

Moore, David S. (Los Alamos, NM); Schmidt, Stephen C. (Los Alamos, NM)

1985-01-01T23:59:59.000Z

409

Isentropic compression studies using the NHMFL single turn  

SciTech Connect

Magnetic isentropic compression experiments (ICE) provide the most accurate shock free compression data for materials at megabar stresses. Recent ICE experiments performed on the Sandia Z-machine (Asay, 1999) and at the Los Alamos High Explosive Pulsed Power facility (Tasker, 2006) are providing our nation with data on material properties in extreme dynamic high stress environments. The LANL National High Magnetic Field Laboratory (NHMFL) can offer a less complex ICE experiment at high stresses (up to {approx}1Mbar) with a high sample throughput and relatively low cost. This is not to say that the NHMFL technique will replace the other methods but rather complement them. For example, NHMFL-ICE is ideal for the development of advanced diagnostics, e.g., to detect phase changes. We will discuss the physics of the NHMFL-ICE experiments and present data from the first proof-of-principle experiments that were performed in September 2010.

Tasker, Douglas G [Los Alamos National Laboratory; Mielke, Charles [Los Alamos National Laboratory; Rodriguez, George [Los Alamos National Laboratory; Rickel, Dwight [Los Alamos National Laboratory

2010-10-19T23:59:59.000Z

410

Novel concept for pulse compression via structured spatial energy distribution  

E-Print Network (OSTI)

We present a novel concept for pulse compression scheme applicable at RF, microwave and possibly to optical frequencies based on structured energy distribution in cavities supporting degenerate band-edge (DBE) modes. For such modes a significant fraction of energy resides in a small fraction of the cavity length. Such energy concentration provides a basis for superior performance for applications in microwave pulse compression devices (MPC) when compared to conventional cavities. The novel design features: far larger loaded quality factor of the cavity and stored energy compared to conventional designs, energy feeding and extraction at the cavity center, substantial reduction of the cavity size by use of equivalent lumped circuits for low energy sections of the cavity, controlled pulse shaping via engineered extraction techniques. The presented concepts are general, in terms of equivalent transmission lines, and can be applied to a variety of realistic guiding structures.

Tamma, Venkata Ananth; Capolino, Filippo

2013-01-01T23:59:59.000Z

411

Compressed Air Energy Storage To Support Wind Integration  

Science Conference Proceedings (OSTI)

Wind generators produce much of their energy during off-peak time periods and their output has high power fluctuations which cause different types of unit commitment and dispatch problems. Compressed Air Energy Storage (CAES) plants with large amounts of bulk energy storage capability can shift large amounts off-peak energy from wind generators to more price advantageous on-peak time periods; and, CAES can smooth out the power fluctuations from wind generators so that grid operators can resolve ramping a...

2008-12-23T23:59:59.000Z

412

Structural transitions in laterally compressed two-dimensional Coulomb clusters  

Science Conference Proceedings (OSTI)

We model structural transitions of small-size Wigner crystals in laterally compressed two-dimensional traps. Ground and metastable configurations are calculated and their transformations are linked to conspicuous changes in the heat capacity of the system. We show that various types of structural transitions are reflected by characteristic features in the behavior of the heat capacity. For deeper understanding, results produced by the Monte Carlo numerical calculations are compared to predictions of simple one-dimensional models.

Rancova, O.; Anisimovas, E.; Varanavicius, T. [Department of Theoretical Physics, Vilnius University, Sauletekio 9, LT-10222 Vilnius (Lithuania)

2011-03-15T23:59:59.000Z

413

CLASSIFICATION OF THE MGR SITE COMPRESSED AIR SYSTEM  

SciTech Connect

The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) site compressed air system structures, systems and components (SSCs) performed by the MGR Safety Assurance Department. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMP 1998). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333P, ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998).

J.A. Ziegler

1999-08-31T23:59:59.000Z

414

Compressed Air Energy Storage (CAES) Demonstration Newsletter, April 2013  

Science Conference Proceedings (OSTI)

The Compressed Air Energy Storage (CAES) demonstration project includes the phased planning, engineering design, construction, demonstration and performance monitoring of two CAES plants. These plants are envisioned to be the following: 1) a system rated at 300 MWs for up to 10 hours with a below-ground reservoir for bulk energy air storage and 2) a system rated at 15 MWs for 2 hours with above-ground air vessel/piping.This is a critical technology demonstration project, necessary to ...

2013-04-25T23:59:59.000Z

415

Compressed Air Energy Storage Demonstration Newsletter, October 2013  

Science Conference Proceedings (OSTI)

The Compressed Air Energy Storage (CAES) demonstration project includes the phased planning, engineering design, construction, demonstration and performance monitoring of two CAES plants. These plants are envisioned to be the following: 1) a system rated at 300 MWs for up to 10 hours with a below-ground reservoir for bulk energy air storage and 2) a system rated at 15 MWs for 2 hours with above-ground air vessel/piping.This is a critical technology demonstration project, necessary to ...

2013-10-30T23:59:59.000Z

416

Compressed Air Energy Storage State-of-Science  

Science Conference Proceedings (OSTI)

Reliable and cost-effective bulk energy storage (BES) will become an important part of the electricity grid. In the form of compressed air energy storage (CAES), BES is a cost-effective option for applications requiring hundreds of megawatt-hours of energy storage. Experience in Alabama and Germany has shown that an optimized CAES plant design can further improve plant capital costs, economics, and performance. Advanced CAES technologies can defer expensive upgrades and capital purchases for transmission...

2009-10-27T23:59:59.000Z

417

Shock compression of water and solutions of ammonium nitrate  

E-Print Network (OSTI)

4.3 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 4.4 Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 5 Shock compression of water 95 5.1 Cell development... .pwcs.com.au/display/assets/download.php?id=498. W. B. Sudweeks. Physical and chemical properties of industrial slurry explo- sives. Industrial & Engineering Chemistry Product Research and Development, 24(3):432–436, 1985. N. Taylor. Hot spots in Ammonium Nitrate. PhD thesis, University of Cam...

Morley, Michael James

2011-07-12T23:59:59.000Z

418

Ris-R-1393(EN) Compression Strength of a Fibre  

E-Print Network (OSTI)

Data 11 2.2.4 Analysis Type and Load Steps 11 2.3 FEM-results 12 2.3.1 Load-Displacement Response) #12;Risø-R-1393(EN) 5 Contents 1 Introduction 7 2 FEM-simulation of the Full-scale Test 8 2.1 FEM-Software of geometrical nonlinear analysis simulat- ing fibre composite in compression. In this project the Finite Element

419

Compressed Air Energy Storage (CAES) Demonstration Newsletter, July 2013  

Science Conference Proceedings (OSTI)

The Compressed Air Energy Storage (CAES) demonstration project includes the phased planning, engineering design, construction, demonstration and performance monitoring of two CAES plants. These plants are envisioned to be the following: 1) a system rated at 300 MWs for up to 10 hours with a below-ground reservoir for bulk energy air storage and 2) a system rated at 15 MWs for 2 hours with above-ground air vessel/piping.This is a critical technology demonstration project, necessary to ...

2013-07-29T23:59:59.000Z

420

Sacramento Municipal Utility District (SMUD) Compressed Air Energy Storage Plant  

Science Conference Proceedings (OSTI)

This report provides a scoping and conceptual engineering analysis of the compressed air energy storage (CAES) technology and how it can be deployed within the Sacramento Municipal Utility District (SMUD) services territory, with specific focus on the use of one or more Solano County, California, depleted gas reservoirs, which are underneath the SMUD Solano Wind Farm near the city of Rio Vista, California. Results are presented on the geologic opportunities for building a CAES plant that uses sites near ...

2012-03-26T23:59:59.000Z

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


421

CONSERVATIVE CASCADE OF KINETIC ENERGY IN COMPRESSIBLE TURBULENCE  

SciTech Connect

The physical nature of compressible turbulence is of fundamental importance in a variety of astrophysical settings. We investigate the question: 'At what scales does the mechanism of pressure-dilatation operate?' and present the first direct evidence that mean kinetic energy cascades conservatively beyond a transitional 'conversion' scale range despite not being an invariant of the dynamics. We use high-resolution 1024{sup 3} subsonic and transonic simulations. The key quantity we measure is the pressure-dilatation cospectrum, E{sup PD}(k), where we show that it decays at a rate faster than k{sup -1} in wavenumber in at least the subsonic and transonic regimes. This is sufficient to imply that mean pressure-dilatation acts primarily at large scales and that kinetic and internal energy budgets statistically decouple beyond a transitional scale range. However, we observe that small-scale dynamics remains highly compressible locally in space and that the statistical decoupling in the energy budgets is unrelated to the existence of a subsonic scale range. Our results suggest that an extension of Kolmogorov's inertial-range theory to compressible turbulence is possible.

Aluie, Hussein; Li Shengtai; Li, Hui [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2012-06-01T23:59:59.000Z

422

Pulse code modulation data compression for automated test equipment  

SciTech Connect

Development of automated test equipment for an advanced telemetry system requires continuous monitoring of PCM data while exercising telemetry inputs. This requirements leads to a large amount of data that needs to be stored and later analyzed. For example, a data stream of 4 Mbits/s and a test time of thirty minutes would yield 900 Mbytes of raw data. With this raw data, information needs to be stored to correlate the raw data to the test stimulus. This leads to a total of 1.8 Gb of data to be stored and analyzed. There is no method to analyze this amount of data in a reasonable time. A data compression method is needed to reduce the amount of data collected to a reasonable amount. The solution to the problem was data reduction. Data reduction was accomplished by real time limit checking, time stamping, and smart software. Limit checking was accomplished by an eight state finite state machine and four compression algorithms. Time stamping was needed to correlate stimulus to the appropriate output for data reconstruction. The software was written in the C programming language with a DOS extender used to allow it to run in extended mode. A 94--98% compression in the amount of data gathered was accomplished using this method. 1 fig.

Navickas, T.A.; Jones, S.G.

1991-05-01T23:59:59.000Z

423

Active high-power RF switch and pulse compression system  

DOE Patents (OSTI)

A high-power RF switching device employs a semiconductor wafer positioned in the third port of a three-port RF device. A controllable source of directed energy, such as a suitable laser or electron beam, is aimed at the semiconductor material. When the source is turned on, the energy incident on the wafer induces an electron-hole plasma layer on the wafer, changing the wafer's dielectric constant, turning the third port into a termination for incident RF signals, and. causing all incident RF signals to be reflected from the surface of the wafer. The propagation constant of RF signals through port 3, therefore, can be changed by controlling the beam. By making the RF coupling to the third port as small as necessary, one can reduce the peak electric field on the unexcited silicon surface for any level of input power from port 1, thereby reducing risk of damaging the wafer by RF with high peak power. The switch is useful to the construction of an improved pulse compression system to boost the peak power of microwave tubes driving linear accelerators. In this application, the high-power RF switch is placed at the coupling iris between the charging waveguide and the resonant storage line of a pulse compression system. This optically controlled high power RF pulse compression system can handle hundreds of Megawatts of power at X-band.

Tantawi, Sami G. (San Mateo, CA); Ruth, Ronald D. (Woodside, CA); Zolotorev, Max (Mountain View, CA)

1998-01-01T23:59:59.000Z

424

Research and Development Strategies for Compressed & Cryo-Hydrogen Storage Systems - Workshop Summary Report  

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

and Development and Development Strategies for Compressed & Cryo-Hydrogen Storage Systems Workshop Summary Report Prepared by: Fuel Cell Technologies Program Compressed & Cryo-Hydrogen Storage Systems Workshops February 14-15, 2011 Crystal City, Virginia Compressed and Cryo-Hydrogen Storage Systems Workshop Summary Report 2 Research and Development Strategies for Compressed & Cryo- Hydrogen Storage Systems Summary: On February 14-15, 2011, the Systems Integration group of the National Renewable Energy Laboratory, in conjunction with the Hydrogen Storage team of the EERE Fuel Cell Technologies Program, hosted two days of workshops on compressed and cryo- hydrogen storage systems in Crystal City, VA. The overarching objective was to

425

TECHNOLOGIES TO ENHANCE THE OPERATION OF EXISTING NATURAL GAS COMPRESSION INFRASTRUCTURE  

SciTech Connect

This project has documented and demonstrated the feasibility of technologies and operational choices for companies who operate the large installed fleet of integral engine compressors in pipeline service. Continued operations of this fleet is required to meet the projected growth of the U.S. gas market. Applying project results will meet the goals of the DOE-NETL Natural Gas Infrastructure program to enhance integrity, extend life, improve efficiency, and increase capacity, while managing NOx emissions. These benefits will translate into lower cost, more reliable gas transmission, and options for increasing deliverability from the existing infrastructure on high demand days. The power cylinders on large bore slow-speed integral engine/compressors do not in general combust equally. Variations in cylinder pressure between power cylinders occur cycle-to-cycle. These variations affect both individual cylinder performance and unit average performance. The magnitude of the variations in power cylinder combustion is dependent on a variety of parameters, including air/fuel ratio. Large variations in cylinder performance and peak firing pressure can lead to detonation and misfires, both of which can be damaging to the unit. Reducing the variation in combustion pressure, and moving the high and low performing cylinders closer to the mean is the goal of engine balancing. The benefit of improving the state of the engine ''balance'' is a small reduction in heat rate and a significant reduction in both crankshaft strain and emissions. A new method invented during the course of this project is combustion pressure ratio (CPR) balancing. This method is more effective than current methods because it naturally accounts for differences in compression pressure, which results from cylinder-to-cylinder differences in the amount of air flowing through the inlet ports and trapped at port closure. It also helps avoid compensation for low compression pressure by the addition of excess fuel to achieve equalizing peak firing pressure, even if some of the compression pressure differences are attributed to differences in cylinder and piston geometry, clearance, and kinematics. The combination of high-pressure fuel injection and turbocharging should produce better mixing of fuel and air in lean mixtures. Test results documented modest improvements in heat rate and efficiency and significant improvements in emissions. The feasibility of a closed-loop control of waste-gate setting, which will maintain an equivalence ratio set point, has been demonstrated. This capability allows more direct tuning to enhance combustion stability, heat rate, or emissions. The project has documented the strong dependence of heat rate on load. The feasibility of directly measuring power and torque using the GMRC Rod Load Monitor (RLM) has been demonstrated. This capability helps to optimize heat rate while avoiding overload. The crankshaft Strain Data Capture Module (SDCM) has shown the sensitivity to changes in operating conditions and how they influence crankshaft bending strain. The results indicate that: balancing reduces the frequency of high-strain excursions, advanced timing directly increases crankshaft dynamic strain, reduced speed directly reduces strain, and high-pressure fuel injection reduces crankshaft strain slightly. The project demonstrated that when the timing is advanced, the heat rate is reduced, and when the timing is retarded, the heat rate is increased. One reason why timing is not advanced as much as it might be is the potential for detonation on hot days. A low-cost knock detector was demonstrated that allowed active control to use timing to allow the heat rate benefit to be realized safely. High flow resistance losses in the pulsation control systems installed on some compressors have been shown to hurt efficiency of both compressor and engine/compressor system. Improved pulsation control systems have the potential to recover almost 10% of available engine power. Integrity enhancements and reduced component failure probability will enhance aggregate

Anthony J. Smalley; Ralph E. Harris; Gary D. Bourn; Ford A. Phillips; Danny M. Deffenbaugh

2006-05-31T23:59:59.000Z

426

Benchmarking Variable Cost Performance in an Industrial Power Plant  

E-Print Network (OSTI)

One of the most perplexing problems for industrial power plants committed to improving competitiveness is measuring variable cost performance over time. Because variable costs like fuel and electricity represent the overwhelming majority of power plant expenses, it is imperative to develop and deploy a tool that can help plants benchmark operating performance. This paper introduces a benchmarking methodology designed to meet this need. The "Energy Conversion Index" (ECI) ratios the "value" of utilities exported from the power plant to the actual cost of the fuel and electricity required to produce them, generating a single number or "index." Variable cost performance is benchmarked by comparing the index from one period of time to the index of another comparable period of time. Savings (or costs) attributable to excellent (or poor) performance can easily be calculated by using the former period's index to project the current period's cost.

Kane, J. F.; Bailey, W. F.

1998-04-01T23:59:59.000Z

427

Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Tax  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

Tax to someone by E-mail Tax to someone by E-mail Share Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Tax on Facebook Tweet about Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Tax on Twitter Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Tax on Google Bookmark Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Tax on Delicious Rank Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Tax on Digg Find More places to share Alternative Fuels Data Center: Compressed Natural Gas (CNG) and Propane Tax on AddThis.com... More in this section... Federal State Advanced Search All Laws & Incentives Sorted by Type Compressed Natural Gas (CNG) and Propane Tax Retail sales for CNG and liquefied petroleum gas (propane) used to operate

428

Thermodynamic Modeling and Analysis of the Ratio of Heat to Power Based on a Conceptual CHP System  

E-Print Network (OSTI)

The CHP system not only produces electrical energy, but also produces thermal energy. An extensive analysis of the CHP market reveals that one of the most important engineering characteristics is flexibility. A variable heat-to-power ratio has compelling advantages over a fixed one and enables a power plant to achieve reliability and flexibility, which are very important characteristics for a CHP system. In this paper, a conceptual SOFC/GT CHP system is presented. The parameters' effect on the variable heat-to-power ratio is investigated. As SOFC reactors are still under development, a flexible simulation tool based on mass and energy balances coupled with appropriate expressions for the reaction kinetics, thermodynamic constants and material properties, is presented for adaptation to different cell geometries and operating conditions. Simulation results show that the SOFC/GT CHP system's advantage over the engine is that a low stack running temperature can achieve a low heat-to- power ratio.

Liu, Z.; Li, X.; Liu, Z.

2006-01-01T23:59:59.000Z

429

ENSEMBLE VARIABILITY OF NEAR-INFRARED-SELECTED ACTIVE GALACTIC NUCLEI  

Science Conference Proceedings (OSTI)

We present the properties of the ensemble variability V for nearly 5000 near-infrared active galactic nuclei (AGNs) selected from the catalog of Quasars and Active Galactic Nuclei (13th Edition) and the SDSS-DR7 quasar catalog. From three near-infrared point source catalogs, namely, Two Micron All Sky Survey (2MASS), Deep Near Infrared Survey (DENIS), and UKIDSS/LAS catalogs, we extract 2MASS-DENIS and 2MASS-UKIDSS counterparts for cataloged AGNs by cross-identification between catalogs. We further select variable AGNs based on an optimal criterion for selecting the variable sources. The sample objects are divided into subsets according to whether near-infrared light originates by optical emission or by near-infrared emission in the rest frame; and we examine the correlations of the ensemble variability with the rest-frame wavelength, redshift, luminosity, and rest-frame time lag. In addition, we also examine the correlations of variability amplitude with optical variability, radio intensity, and radio-to-optical flux ratio. The rest-frame optical variability of our samples shows negative correlations with luminosity and positive correlations with rest-frame time lag (i.e., the structure function, SF), and this result is consistent with previous analyses. However, no well-known negative correlation exists between the rest-frame wavelength and optical variability. This inconsistency might be due to a biased sampling of high-redshift AGNs. Near-infrared variability in the rest frame is anticorrelated with the rest-frame wavelength, which is consistent with previous suggestions. However, correlations of near-infrared variability with luminosity and rest-frame time lag are the opposite of these correlations of the optical variability; that is, the near-infrared variability is positively correlated with luminosity but negatively correlated with the rest-frame time lag. Because these trends are qualitatively consistent with the properties of radio-loud quasars reported by some previous studies, most of our sample objects are probably radio-loud quasars. Finally, we also discuss the negative correlations seen in the near-infrared SFs.

Kouzuma, S. [School of International Liberal Studies, Chukyo University, Toyota 470-0393 (Japan); Yamaoka, H., E-mail: skouzuma@lets.chukyo-u.ac.jp, E-mail: yamaoka@phys.kyushu-u.ac.jp [Department of Physics, Kyushu University, Fukuoka 812-8581 (Japan)

2012-03-01T23:59:59.000Z

430

Efficient Compression of CO2 and Pipeline Transport Considerations  

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

to simulate a slower speed. * Smooth wall with higher radius ratio - In order to increase heat exchanger effectiveness, surface area was increased by using a longer diffuser. *...

431

Ratio Statistics for Randomized Experiments in Precipitation Stimulation  

Science Conference Proceedings (OSTI)

A variety of ratio statistics has been used in the design and evaluation of weather modification experiments and their significance has usually been estimated by rerandomization. These ratios, and especially their logarithms, are asymptotically ...

K. Ruben Gabriel

1999-03-01T23:59:59.000Z

432

The CALIPSO Automated Aerosol Classification and Lidar Ratio Selection Algorithm  

Science Conference Proceedings (OSTI)

Descriptions are provided of the aerosol classification algorithms and the extinction-to-backscatter ratio (lidar ratio) selection schemes for the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) aerosol products. One ...

Ali H. Omar; David M. Winker; Mark A. Vaughan; Yongxiang Hu; Charles R. Trepte; Richard A. Ferrare; Kam-Pui Lee; Chris A. Hostetler; Chieko Kittaka; Raymond R. Rogers; Ralph E. Kuehn; Zhaoyan Liu

2009-10-01T23:59:59.000Z

433

Final Report on Isotope Ratio Techniques for Light Water Reactors  

SciTech Connect

The Isotope Ratio Method (IRM) is a technique for estimating the energy or plutonium production in a fission reactor by measuring isotope ratios in non-fuel reactor components. The isotope ratios in these components can then be directly related to the cumulative energy production with standard reactor modeling methods.

Gerlach, David C.; Gesh, Christopher J.; Hurley, David E.; Mitchell, Mark R.; Meriwether, George H.; Reid, Bruce D.

2009-07-01T23:59:59.000Z

434

Variable focal length deformable mirror  

DOE Patents (OSTI)

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

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

2007-06-12T23:59:59.000Z

435

Interannual Variability of the Global Radiation Budget  

Science Conference Proceedings (OSTI)

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

Seiji Kato

2009-09-01T23:59:59.000Z

436

A top-down approach for compressing data cubes under the simultaneous evaluation of multiple hierarchical range queries  

Science Conference Proceedings (OSTI)

A novel top-down compression technique for data cubes is introduced and experimentally assessed in this paper. This technique considers the previously unrecognized case in which multiple Hierarchical Range Queries (HRQ), a very useful class ... Keywords: Advanced OLAP, Compressing data cubes under simultaneous multiple OLAP queries, Multi-objective compression of data cubes, Multiple-query data cube compression techniques

Alfredo Cuzzocrea

2010-06-01T23:59:59.000Z

437

Effects of electrode compression on the performance of a solid polymer electrolyte fuel cell  

E-Print Network (OSTI)

The effects of electrode compression on the performance of a polymer electrolyte fuel cell (PEFC) were investigated. Preliminary testing showed that considerable compression of the carbon cloth electrodes was provided by the PEFC structure. Further, the level of electrode compression was identified as a design parameter having a possible effect on the properties of the electrodes as well as the performance of the PEFC system. Performance-affecting properties of the carbon cloth electrode material, such as electrical conductivity and porosity, were determined over a range of compression levels. Compression was found to have a significant effect on the electrical conductivity and porosity of the carbon cloth electrode material, justifying further testing to measure the effects of electrode compression on PEFC performance. A new PEFC structure was developed which provided uniform mechanical pressure distribution over the area of the electrodes and allowed determination of the level of electrode compression. Utilizing this structure, several fuel cell systems were operated under various levels of electrode compression, and their electrical power output was measured using a linear-sweep voltammetry technique. Fuel cells of two different sizes using two different cathodic reactants--pure oxygen and air--were tested. Results of these experiments were plotted in a manner to illustrate the effect of electrode compression on PEFC performance. Electrode compression was found to have a significant effect on the performance of the PEFC systems observed in this investigation. A level of electrode compression was found for each fuel cell configuration which provided optimal performance. It was concluded from the findings of this work that the performance of PEFC systems utilizing porous carbon cloth electrodes is significantly affected by the level of compression placed on the electrodes. It was further concluded that an electrode compression level exists for PEFC systems which provides optimal performance under a given set of operating conditions.

Del Campo, Christopher Scott

1997-01-01T23:59:59.000Z

438

Compressed Air Energy Storage Demonstration Newsletter, July 2011  

Science Conference Proceedings (OSTI)

The Compressed Air Energy Storage (CAES) demonstration project includes the phased planning, engineering design, construction, demonstration and performance monitoring of two CAES plants. These plants are envisioned to be the following: 1) a system rated at 300 MWs for up to 10 hours with a below-ground reservoir for bulk energy air storage and 2) a system rated at 15 MWs for 2 hours with above-ground air vessel/piping. This is a critical technology demonstration project, necessary to enable higher penet...

2011-07-31T23:59:59.000Z

439

Compressed Air Energy Storage Demonstration Newsletter, October 2011  

Science Conference Proceedings (OSTI)

The Compressed Air Energy Storage (CAES) demonstration project includes the phased planning, engineering design, construction, demonstration and performance monitoring of two CAES plants. These plants are envisioned to be the following: 1) a system rated at 300 MWs for up to 10 hours with a below-ground reservoir for bulk energy air storage and 2) a system rated at 15 MWs for 2 hours with above-ground air vessel/piping. This is a critical technology demonstration project, necessary to enable higher penet...

2011-10-24T23:59:59.000Z

440

Pdc - The Worldwide Leader in Hydrogen Refueling Station Compression  

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

Pdc - Pdc - The Worldwide Leader in Hydrogen Refueling Station Compression Over 185 Compressors in the Worlds 220+ Hydrogen Energy Facilities Diaphragm Compressor Technology: Benefits of Technology: - Highest duty cycle of all current technologies - Lowest power consumption of the technologies - Lowest cooling requirements Challenges: - High(er) capital cost amongst the technologies - Currently - If not run properly, susceptible to maintenance problems. - Compressor likes to "run often". Cost Constraints of All Technologies General Cost Issues Currently Facing Compressor Manufacturers: Low Volume. Take Away: Buy More, Save More. Lack of clear codes and standards for industry. Take Away: Standardize, Standardize, Standardize Cost Constraints of All Technologies

Note: This page contains sample records for the topic "variable compression ratio" 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

Quantum dynamics of a nano-rod under compression  

E-Print Network (OSTI)

A nano-rod under compression, which is capacitively coupled to a Cooper-pair box, can be modeled in terms of a quartic oscillator linearly interacting with a tunnelling pseudo-spin. We have integrated numerically the quantum dynamics of this system in the partial Wigner representation and calculated the pseudo-spin population difference. Depending on the coupling, we have verified that the quantum tunnelling of the oscillator can lead to a more effective reduction of the Rabi oscillation amplitude of the pseudo-spin. Such findings suggests an experimental set-up that might be able to discriminate between the quantum and the classical motion of a nano-rod.

Geoffrey M. Beck; Alessandro Sergi

2013-02-16T23:59:59.000Z

442

Compressed Air Energy Storage Demonstration Newsletter, January 2012  

Science Conference Proceedings (OSTI)

The Compressed Air Energy Storage (CAES) demonstration project includes the phased planning, engineering design, construction, demonstration and performance monitoring of two CAES plants. These plants are envisioned to be the following: 1) a system rated at 300 MWs for up to 10 hours with a below-ground reservoir for bulk energy air storage and 2) a system rated at 15 MWs for 2 hours with above-ground air vessel/piping. This is a critical technology demonstration project, necessary to enable higher penet...

2012-01-30T23:59:59.000Z

443

Pre-stressed/pre-compressed gas turbine nozzle  

SciTech Connect

A method of increasing low cycle fatigue life of a turbine nozzle comprising a plurality of stationary airfoils extending between radially inner and outer ring segments comprising a) providing at least one radial passage in each of the plurality of airfoils; b) installing a rod in the radial passage extending between the radially inner and outer ring segments and fixing one end of the rod to one of the inner and outer rings; and c) pre-loading the rod to compress the airfoil between the inner and outer ring segments.

Jang, Hoyle (Schenectady, NY); Itzel, Gary Michael (Clifton Park, NY); Yu, Yufeng Phillip (Guilderland, NY)

2002-01-01T23:59:59.000Z

444

Exhaust gas recirculation in a homogeneous charge compression ignition engine  

DOE Patents (OSTI)

A homogeneous charge compression ignition engine operates by injecting liquid fuel directly in a combustion chamber, and mixing the fuel with recirculated exhaust and fresh air through an auto ignition condition of the fuel. The engine includes at least one turbocharger for extracting energy from the engine exhaust and using that energy to boost intake pressure of recirculated exhaust gas and fresh air. Elevated proportions of exhaust gas recirculated to the engine are attained by throttling the fresh air inlet supply. These elevated exhaust gas recirculation rates allow the HCCI engine to be operated at higher speeds and loads rendering the HCCI engine a more viable alternative to a conventional diesel engine.

Duffy, Kevin P. (Metamora, IL); Kieser, Andrew J. (Morton, IL); Rodman, Anthony (Chillicothe, IL); Liechty, Michael P. (Chillicothe, IL); Hergart, Carl-Anders (Peoria, IL); Hardy, William L. (Peoria, IL)

2008-05-27T23:59:59.000Z

445

NONEQUILIBRIUM FLUCTUATIONS IN SHOCK COMPRESSION OF POLYCRYSTALLINE ALPHA-IRON  

Science Conference Proceedings (OSTI)

We report a numerical study of heterogeneous and nonequilibrium fluctuations in shock compression of {alpha}-iron at the grain level. A quasi-molecular code called DM2 is used to model the interactions of a plane shock wave with grain boundaries and crystal anisotropy over the pressure range of 5-45 GPa. Highly transient eddies that were reported earlier are again observed. We show new features through an elementary statistical analysis. They are (1) a characteristic decay constant for the non-equilibrium fluctuation on the order of 20ns, (2) a resonance phenomenon at an intermediate shock pressure, and (3) a more uniform shock structure for very high pressures.

Y. HORIE; K. YANO

2001-06-01T23:59:59.000Z

446

Design of a high-gain flux-compression generator  

SciTech Connect

The current gain of a high-gain, high-explosive helical magnetic-flux-compression generator (HEG) is limited both by nonuniformities in stator expansion and by armature-stator misalignment. We set out to achieve three goals: first, an output current of at least 2 MA with a current gain greater than 1000 to drive a 150- to 300-nH load; second, a generator with an acceptably small volume and length; and finally, generator output of a reliable magnitude. 5 refs., 6 figs.

Pincosy, P.A.; Abe, D.K.; Chase, J.B. (Lawrence Livermore National Lab., CA (USA))

1989-09-01T23:59:59.000Z

447

Compressed air energy storage technology program. Annual report for 1980  

DOE Green Energy (OSTI)

All of the major research funded under the Compressed Air Energy Storage Technology Program during the period March 1980 to March 1981 is described. This annual report is divided into two segments: Reservoir Stability Studies and Second-Generation Concepts Studies. The first represents research performed to establish stability criteria for CAES reservoirs while the second reports progress on research performed on second-generation CAES concepts. The report consists of project reports authored by research engineers and scientists from PNL and numerous subcontractors including universities, architect-engineering, and other private firms.

Kannberg, L.D.

1981-06-01T23:59:59.000Z

448

Effect of Impurities on Compression and Transportation of CO2  

Science Conference Proceedings (OSTI)

This technical update contains a summary and evaluation of the state of the art in equations of state (EOS) for mixtures of CO2 with co-constituents that are likely to be found in carbon capture and storage processes. The update provides background in EOS as well as information on current efforts to build EOS models for gas systems and for CCS applications. The ramifications of CO2 product purity and the effect of specific co-constituents of interest are considered as they impact compression and transpor...

2011-12-30T23:59:59.000Z

449

Operating Reserves and Variable Generation  

DOE Green Energy (OSTI)

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

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

2011-08-01T23:59:59.000Z

450

Multiple-Zone Variable Refrigerant Flow System Modeling and Equipment Performance Mapping  

Science Conference Proceedings (OSTI)

We developed a variable refrigerant flow (VRF) vapor compression system model, which has five indoor units, one outdoor unit and one water heater. The VRF system can run simultaneous space conditioning (cooling or heating) and water heating. The indoor units and outdoor unit use fin-&-tube coil heat exchangers, and the water heater uses a tube-in-tube heat exchanger. The fin-&-tube coil heat exchangers are modeled using a segment-by-segment approach and the tube-in-tube water heater is modeled using a phase-by-phase approach. The compressor used is a variable-speed rotary design. We calibrated our model against a manufacturer s product literature. Based on the vapor compression system model, we investigated the methodology for generating VRF equipment performance maps, which can be used for energy simulations in TRNSYS and EnergyPlus, etc. In the study, the major independent variables for mapping are identified and the deviations between the simplified performance map and the actual equipment system simulation are quantified.

Shen, Bo [ORNL; Rice, C Keith [ORNL

2012-01-01T23:59:59.000Z

451

A Gas-Kinetic Scheme For The Simulation Of Compressible Turbulent Flows  

E-Print Network (OSTI)

A gas-kinetic scheme for the continuum regime is applied to the simulation of turbu- lent compressible flow, by replacing the molecular relaxation time with a turbulent relaxation time in the BGK model. The turbulence dynamics is modelled on the basis of a standard, linear two-equation turbulence model. The hydrodynamic limit of the resulting turbulence model is linear in smooth flow and non-linear in the presence of stronger flow gradients. The non-linear correction terms in the numerical flux are weighed as a function of "rarefaction" - referred to turbulence dynamics and not to molecular dynamics, i.e. measured by the ratio of turbulence to mean flow scales of motion. Even though no assumptions on the nature of the turbulence have been made and a linear two-equation turbulence model is used, the turbulence gas-kinetic scheme seems able to correct the turbulent stress tensor in an effective way; on the basis of a number of turbulence modelling benchmark flow cases, characterized by strong shock - boundary l...

Righi, Marcello

2013-01-01T23:59:59.000Z

452

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

E-Print Network (OSTI)

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

453

Low-pressure-ratio regenerative exhaust-heated gas turbine  

SciTech Connect

A design study of coal-burning gas-turbine engines using the exhaust-heated cycle and state-of-the-art components has been completed. In addition, some initial experiments on a type of rotary ceramic-matrix regenerator that would be used to transfer heat from the products of coal combustion in the hot turbine exhaust to the cool compressed air have been conducted. Highly favorable results have been obtained on all aspects on which definite conclusions could be drawn.

Tampe, L.A.; Frenkel, R.G.; Kowalick, D.J.; Nahatis, H.M.; Silverstein, S.M.; Wilson, D.G.

1991-01-01T23:59:59.000Z

454

Self-compression by femtosecond pulse filamentation: Experiments versus numerical simulations  

SciTech Connect

We analyze pulse self-compression in femtosecond filaments, both experimentally and numerically. We experimentally demonstrate the compression of 45 fs pulses down to a duration of 7.4 fs at millijoule pulse energies. This sixfold compression in a self-generated filament does not require any means for dispersion compensation and is highly efficient. We compare our results to numerical simulations, providing a complete propagation model that accounts for full dispersion, pressure variations, Kerr nonlinearity and plasma generation in multiphoton and tunnel regimes. The equations are numerically integrated and allow for a quantitative comparison with the experiment. Our experiments and numerical simulations reveal a characteristic spectrotemporal structure of the self-compressed pulses, consisting of a compressible blue wing and an incompressible red pedestal. We explain the underlying mechanism that leads to this structure and examine the scalability of filament self-compression with respect to pulse energy and gas pressure.

Skupin, Stefan; Berge, Luc [Departement de Physique Theorique et Appliquee, CEA-DAM/Ile de France, B.P. 12, 91680 Bruyeres-le-Chatel (France); Stibenz, Gero; Sokollik, Thomas; Schnuerer, Matthias; Zhavoronkov, Nickolai; Steinmeyer, Guenter [Max-Born-Institut fuer Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Strasse 2a, 12489 Berlin (Germany); Lederer, Falk [Institute for Condensed Matter Theory and Solid State Optics, Friedrich-Schiller-Universitaet Jena, Max-Wien-Platz 1, 07743 Jena (Germany)

2006-11-15T23:59:59.000Z

455

Extrinsic Radio Variability of JVAS/CLASS Gravitational Lenses  

E-Print Network (OSTI)

We present flux-ratio curves of the fold and cusp (i.e. close multiple) images of six JVAS/CLASS gravitational lens systems. The data were obtained over a period of 8.5 months in 2001 with the Multi-Element Radio-Linked Interferometer Network (MERLIN) at 5-GHz with 50 mas resolution, as part of a MERLIN Key-Project. Even though the time delays between the fold and cusp images are small (<~1 day) compared to the time-scale of intrinsic source variability, all six lens systems show evidence that suggests the presence of extrinsic variability. In particular, the cusp images of B2045+265 -- regarded as the strongest case of the violation of the cusp relation (i.e. the sum of the magnifications of the three cusp images add to zero) -- show extrinsic variations in their flux-ratios up to ~40 percent peak-to-peak on time scales of several months. Its low Galactic latitude of b=-10 degree and a line-of-sight toward the Cygnus superbubble region suggest that Galactic scintillation is the most likely cause. The cusp images of B1422+231 at b=+69 degree do not show strong extrinsic variability. Galactic scintillation can therefore cause significant scatter in the cusp and fold relations of some radio lens systems (up to 10 percent rms), even though these relations remain violated when averaged over a <~1 year time baseline.

L. V. E. Koopmans; A. Biggs; R. D. Blandford; I. W. A. Browne; N. J. Jackson; S. Mao; P. N. Wilkinson; A. G. de Bruyn; J. Wambsganss

2003-02-11T23:59:59.000Z

456

Guiding of Laser Beams in Plasmas by Radiation Cascade Compression  

SciTech Connect

The near-resonant heatwave excitation of an electron plasma wave (EPW) can be employed for generating trains of few-fs electromagnetic pulses in rarefied plasmas. The EPW produces a co-moving index grating that induces a laser phase modulation at the beat frequency. Consequently, the cascade of sidebands red- and blue-shifted from the fundamental by integer multiples of the beat frequency is generated in the laser spectrum. When the beat frequency is lower than the electron plasma frequency, the phase chirp enables laser beatnote compression by the group velocity dispersion [S. Kalmykov and G. Shvets, Phys. Rev. E 73, 046403 (2006)]. In the 3D cylindrical geometry, the frequency-downshifted EPW not only modulates the laser frequency, but also causes the pulse to self-focus [P. Gibbon, Phys. Fluids B 2, 2196 (1990)]. After self-focusing, the multi-frequency laser beam inevitably diverges. Remarkably, the longitudinal beatnote compression can compensate the intensity drop due to diffraction. A train of high-intensity radiation spikes with continually evolving longitudinal profile can be self-guided over several Rayleigh lengths in homogeneous plasmas. High amplitude of the EPW is maintained over the entire propagation length. Numerical experiments on the electron acceleration in the cascade-driven (cascade-guided) EPW [using the code WAKE by P. Mora and T. M. Antonsen Jr., Phys. Plasmas 4, 217 (1997)] show that achieving GeV electron energy is possible under realistic experimental parameters.

Kalmykov, Serguei; Shvets, Gennady [Department of Physics, University of Texas at Austin, Austin, Texas 78712 (United States); Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States)

2006-11-27T23:59:59.000Z

457

Generation of Coherent X-Ray Radiation through Modulation Compression  

Science Conference Proceedings (OSTI)

In this paper, we propose a scheme to generate tunable coherent X-ray radiation for future light source applications. This scheme uses an energy chirped electron beam, a laser modulator, a laser chirper and two bunch compressors to generate a prebunched kilo-Ampere current electron beam from a few tens Ampere electron beam out of a linac. The initial modulation energy wavelength can be compressed by a factor of 1 + h{sub b}R{sub 56}{sup a} in phase space, where h{sub b} is the energy bunch length chirp introduced by the laser chirper, R{sub 56}{sup a} is the momentum compaction factor of the first bunch compressor. As an illustration, we present an example to generate more than 400 MW, 170 attoseconds pulse, 1 nm coherent X-ray radiation using a 60 A electron beam out of the linac and 200 nm laser seed. Both the final wavelength and the radiation pulse length in the proposed scheme are tunable by adjusting the compression factor and the laser parameters.

Qiang, Ji; /LBL, Berkeley; Wu, Juhao; /SLAC

2012-06-12T23:59:59.000Z

458

Massive-scale RDF Processing Using Compressed Bitmap Indexes  

SciTech Connect

The Resource Description Framework (RDF) is a popular data model for representing linked data sets arising from the web, as well as large scienti#12;c data repositories such as UniProt. RDF data intrinsically represents a labeled and directed multi-graph. SPARQL is a query language for RDF that expresses subgraph pattern-#12;nding queries on this implicit multigraph in a SQL- like syntax. SPARQL queries generate complex intermediate join queries; to compute these joins e#14;ciently, we propose a new strategy based on bitmap indexes. We store the RDF data in column-oriented structures as compressed bitmaps along with two dictionaries. This paper makes three new contributions. (i) We present an e#14;cient parallel strategy for parsing the raw RDF data, building dictionaries of unique entities, and creating compressed bitmap indexes of the data. (ii) We utilize the constructed bitmap indexes to e#14;ciently answer SPARQL queries, simplifying the join evaluations. (iii) To quantify the performance impact of using bitmap indexes, we compare our approach to the state-of-the-art triple-store RDF-3X. We #12;nd that our bitmap index-based approach to answering queries is up to an order of magnitude faster for a variety of SPARQL queries, on gigascale RDF data sets.

Madduri, Kamesh; Wu, Kesheng

2011-05-26T23:59:59.000Z

459

A Rapid Compression Machine Modelling Study of the Heptane Isomers  

DOE Green Energy (OSTI)

Previously we have reported on the combustion behavior of all nine isomers of heptane in a rapid compression machine (RCM) with stoichiometric fuel and ''air'' mixtures at a compressed gas pressure of 15 atm. The dependence of autoignition delay times on molecular structure was illustrated. Here, we report some additional experimental work that was performed in order to address unusual results regarding significant differences in the ignition delay times recorded at the same fuel and oxygen composition, but with different fractions of nitrogen and argon diluent gases. Moreover, we have begun to simulate these experiments with detailed chemical kinetic mechanisms. These mechanisms are based on previous studies of other alkane molecules, in particular, n-heptane and iso-octane. We have focused our attention on n-heptane in order to systematically redevelop the chemistry and thermochemistry for this C{sub 7} isomer with the intention of extending our greater knowledge gained to the other eight isomers. The addition of new reaction types, that were not included previously, has had a significant impact on the simulations, particularly at low temperatures.

Silke, E J; Curran, H J; Simmie, J M; Pitz, W J; Westbrook, C K

2005-05-10T23:59:59.000Z

460

Degree of compression and energy efficiency of a capillary compressor of femtosecond laser pulses  

Science Conference Proceedings (OSTI)

A relation between the degree of pulse compression and energy efficiency is derived for femtosecond laser pulse compressors that utilise spectral broadening of pulses in a gas-filled capillary. We show that the degree of compression has a maximum at an energy efficiency from 15% to 30%. A 15-fold compression of a 290-fs pulse with an energy efficiency of 24% is demonstrated.

Konyashchenko, Aleksandr V; Kostryukov, P V; Losev, Leonid L; Tenyakov, S Yu

2011-11-30T23:59:59.000Z

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461

The Prospects of Alternatives to Vapor Compression Technology for Space Cooling and Food Refrigeration Applications  

DOE Green Energy (OSTI)

Five alternatives to vapor compression technology were qualitatively evaluated to determine their prospects for being better than vapor compression for space cooling and food refrigeration applications. The results of the assessment are summarized in the report. Overall, thermoacoustic and magnetic technologies were judged to have the best prospects for competing with vapor compression technology, with thermotunneling, thermoelectric, and thermionic technologies trailing behind in that order.

Brown, Daryl R.; Dirks, James A.; Fernandez, Nicholas; Stout, Tyson E.

2010-03-31T23:59:59.000Z

462

Comparative Global Warming Impacts of Electric Vapor-Compression and Direct-fired Absorption Equipment  

Science Conference Proceedings (OSTI)

This report compares the global warming impacts of electric vapor-compression and gas-fired absorption-cycle equipment for commercial cooling applications. Absorption chillers do not use ozone depleting refrigerants but substitution of alternative refrigerants in electrically driven vapor-compression cycle equipment also offers radically reduced or eliminated potential for stratospheric ozone depletion. Therefore, when comparing absorption-cycle and vapor-compression equipment, net global warming impacts...

1994-03-01T23:59:59.000Z

463

Method of controlling coherent synchroton radiation-driven degradation of beam quality during bunch length compression  

DOE Patents (OSTI)

A method of avoiding CSR induced beam quality defects in free electron laser operation by a) controlling the rate of compression and b) using a novel means of integrating the compression with the remainder of the transport system: both are accomplished by means of dispersion modulation. A large dispersion is created in the penultimate dipole magnet of the compression region leading to rapid compression; this large dispersion is demagnified and dispersion suppression performed in a final small dipole. As a result, the bunch is short for only a small angular extent of the transport, and the resulting CSR excitation is small.

Douglas, David R. (Newport News, VA); Tennant, Christopher D. (Williamsburg, VA)

2012-07-10T23:59:59.000Z

464

The Effect of a Pulsed Electric Current on the Compressive Behavior ...  

Science Conference Proceedings (OSTI)

Quasi-static compressive tests with multiple pulses of electric current with a constant pulse period are conducted. Two different electric pulse conditions, ...

465

Washington Metropolitan Area Transit Authority: Compressed Natural Gas Transit Bus Evaluation  

DOE Green Energy (OSTI)

Evaluates compressed natural gas (CNG) powered transit buses at Washington Metropolitan Area Transit Authority (WMATA), providing a comparison between them and standard diesel transit buses.

Chandler, K.; Eberts, E.; Melendez, M.

2006-04-01T23:59:59.000Z

466

Customer Retention Strategies of Compressed Natural Gas (CNG) in a Developing Country (Pakistan).  

E-Print Network (OSTI)

?? Background: Statistics say that Pakistan is the third largest user of compressed natural gas, its increased demand has encouraged investment in this sector. Number of… (more)

Naveed-ur-Rehman, Muhammad

2013-01-01T23:59:59.000Z

467

Survey for the development of compressed natural gas systems (CNG) for vehicles.  

E-Print Network (OSTI)

??Compressed Natural Gas (CNG) vehicles have been used internationally by fleets for decades. The use of CNG vehicles results in less petroleum consumption, resulting in… (more)

Abulamosha, A.M.

2005-01-01T23:59:59.000Z

468

Thermal Integration of CO2 Compression Processes with Coal-Fired...  

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

Thermal Integration of CO 2 Compression Processes with Coal-Fired Power Plants Equipped with Carbon Capture Background Increased attention is being placed on research into...

469

Energy Tips: Determine the Cost of Compressed Air for Your Plant...  

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

Senior care resources Small business resources State and local government resources Energy Tips: Determine the Cost of Compressed Air for Your Plant energy tips cover page This...

470

Influence of the molecular structure of biofuels on combustion in a compression ignition engine.  

E-Print Network (OSTI)

??This thesis presents an experimental study on the influence of the molecular structure of potential biofuels on combustion in a compression ignition engine. The molecular… (more)

Schönborn, A.

2009-01-01T23:59:59.000Z

471

A study into the permeability and compressibility of Australian bagasse pulp.  

E-Print Network (OSTI)

??This is an experimental study into the permeability and compressibility properties of bag