Powered by Deep Web Technologies
Note: This page contains sample records for the topic "high 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

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

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

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

4

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

5

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

6

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

7

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

8

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

9

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

10

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

11

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

12

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

13

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

14

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

15

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...

16

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

17

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

18

Rotating Heat Transfer in High Aspect Ratio Rectangular Cooling...  

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

Reynolds Number (Nu Nu o ) (f f o ) 24% Increase in Cooling Performance Rotating Heat Transfer in High Aspect Ratio Rectangular Cooling Passages with Shaped Turbulators...

19

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

20

System and method for high precision isotope ratio destructive analysis  

DOE Patents (OSTI)

A system and process are disclosed that provide high accuracy and high precision destructive analysis measurements for isotope ratio determination of relative isotope abundance distributions in liquids, solids, and particulate samples. The invention utilizes a collinear probe beam to interrogate a laser ablated plume. This invention provides enhanced single-shot detection sensitivity approaching the femtogram range, and isotope ratios that can be determined at approximately 1% or better precision and accuracy (relative standard deviation).

Bushaw, Bruce A; Anheier, Norman C; Phillips, Jon R

2013-07-02T23:59:59.000Z

Note: This page contains sample records for the topic "high 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

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

22

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

23

Stability of high. beta. large aspect ratio tokamaks  

SciTech Connect

High {beta}({beta}{much gt} {epsilon}/q{sup 2}) large aspect ratio ({epsilon} {much gt} 1) tokamak equilibria are shown to be always stable to ideal M.H.D. modes that are localized about a flux surface. Both the ballooning and interchange modes are shown to be stable. This work uses the analytic high {beta} large aspect ratio tokamak equilibria developed by Cowley et.al., which are valid for arbitrary pressure and safety factor profiles. The stability results make no assumption about these profiles or the shape of the boundary. 14 refs., 4 figs.

Cowley, S.C.

1991-10-01T23:59:59.000Z

24

Cross Section to Multiplicity Ratios at Very High Energy  

E-Print Network (OSTI)

Recent data from the LHC makes it possible to examine an old speculation that at very high energy the total multiplicity and the cross section in elementary particle interactions vary in parallel with energy. Using fits incorporating the new data, it appears that the ratios of the total, elastic, and inelastic cross sections to the average multiplicity N can in fact approach constants at very high energy. The approach to the limit is however quite slow for the total and inelastic cross sections and is not yet reached at LHC energies. The elastic ratio sigma^{el}/N at 7 TeV, however, is not far from its asymptotic value.

M. M. Block; L. Stodolsky

2013-12-09T23:59:59.000Z

25

Non-tracking solar concentrator with a high concentration ratio  

DOE Patents (OSTI)

A nontracking solar concentrator with a high concentration ratio is provided. The concentrator includes a plurality of energy absorbers which communicate with a main header by which absorbed heat is removed. Undesired heat flow of those absorbers not being heated by radiant energy at a particular instant is impeded, improving the efficiency of the concentrator.

Hinterberger, Henry (Batavia, IL)

1977-01-01T23:59:59.000Z

26

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

27

Used Fuel Disposition Campaign Phase I Ring Compression Testing of High  

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

Phase I Ring Compression Testing of 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 testing is to generate data to support the development of the technical basis for extended storage and transportation of high-burnup fuel. This report highlights the results of completed Phase I testing of high-burnup M5® cladding and the revised three-year test plan. The goal of the ring compression testing is to identify process conditions that would minimize radial-hydride formation and the corresponding DBTT of high-burnup fuel cladding and to generate data and models to support the development of the technical basis for extended storage and transportation of high-burnup fuel.

28

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

29

High Efficiency, Low Emissions Homogeneous Charge Compression Ignition (HCCI) Engines  

SciTech Connect

This is the final report of the High Efficiency Clean Combustion (HECC) Research Program for the U.S. Department of Energy. Work under this co-funded program began in August 2005 and finished in July 2010. The objective of this program was to develop and demonstrate a low emission, high thermal efficiency engine system that met 2010 EPA heavy-duty on-highway truck emissions requirements (0.2g/bhp-hr NOx, 0.14g/bhp-hr HC and 0.01g/bhp-hr PM) with a thermal efficiency of 46%. To achieve this goal, development of diesel homogenous charge compression ignition (HCCI) combustion was the chosen approach. This report summarizes the development of diesel HCCI combustion and associated enabling technologies that occurred during the HECC program between August 2005 and July 2010. This program showed that although diesel HCCI with conventional US diesel fuel was not a feasible means to achieve the program objectives, the HCCI load range could be increased with a higher volatility, lower cetane number fuel, such as gasoline, if the combustion rate could be moderated to avoid excessive cylinder pressure rise rates. Given the potential efficiency and emissions benefits, continued research of combustion with low cetane number fuels and the effects of fuel distillation are recommended. The operation of diesel HCCI was only feasible at part-load due to a limited fuel injection window. A 4% fuel consumption benefit versus conventional, low-temperature combustion was realized over the achievable operating range. Several enabling technologies were developed under this program that also benefited non-HCCI combustion. The development of a 300MPa fuel injector enabled the development of extended lifted flame combustion. A design methodology for minimizing the heat transfer to jacket water, known as precision cooling, will benefit conventional combustion engines, as well as HCCI engines. An advanced combustion control system based on cylinder pressure measurements was developed. A Well-to-wheels analysis of the energy flows in a mobile vehicle system and a 2nd Law thermodynamic analysis of the engine system were also completed under this program.

None

2011-01-31T23:59:59.000Z

30

Proof-of-Concept Manufacturing and Testing of Composite Wind Generator Blades Made by HCBMP (High Compression Bladder Molded Prepreg)  

DOE Green Energy (OSTI)

Proof-of-Concept Manufacturing and Testing of Composite Wind Generator Blades Made by HCBMP (High Compression Bladder Molded Prepreg)

William C. Leighty; DOE Project Officer - Keith Bennett

2005-10-04T23:59:59.000Z

31

Dynamic compressive behavior of Pr-Nd alloy at high strain rates and temperatures  

Science Conference Proceedings (OSTI)

Based on compressive tests, static on 810 material test system and dynamic on the first compressive loading in split Hopkinson pressure bar (SHPB) tests for Pr-Nd alloy cylinder specimens at high strain rates and temperatures, this study determined a J-C type [G. R. Johnson and W. H. Cook, in Proceedings of Seventh International Symposium on Ballistics (The Hague, The Netherlands, 1983), pp. 541-547] compressive constitutive equation of Pr-Nd alloy. It was recorded by a high speed camera that the Pr-Nd alloy cylinder specimens fractured during the first compressive loading in SHPB tests at high strain rates and temperatures. From high speed camera images, the critical strains of the dynamic shearing instability for Pr-Nd alloy in SHPB tests were determined, which were consistent with that estimated by using Batra and Wei's dynamic shearing instability criterion [R. C. Batra and Z. G. Wei, Int. J. Impact Eng. 34, 448 (2007)] and the determined compressive constitutive equation of Pr-Nd alloy. The transmitted and reflected pulses of SHPB tests for Pr-Nd alloy cylinder specimens computed with the determined compressive constitutive equation of Pr-Nd alloy and Batra and Wei's dynamic shearing instability criterion could be consistent with the experimental data. The fractured Pr-Nd alloy cylinder specimens of compressive tests were investigated by using 3D supper depth digital microscope and scanning electron microscope.

Wang Huanran; Cai Canyuan; Chen Danian [Mechanics and Materials Science Research Center, Ningbo University, Ningbo, Zhejiang 315211 (China); Ma Dongfang [Mechanics and Materials Science Research Center, Ningbo University, Ningbo, Zhejiang 315211 (China); School of Civil Engineering, Henan Polytechnic University, Jiaozuo, Henan 454000 (China)

2012-07-01T23:59:59.000Z

32

Application of Principal Component Analysis to High-Resolution Infrared Measurement Compression and Retrieval  

Science Conference Proceedings (OSTI)

A simulation study is used to demonstrate the application of principal component analysis to both the compression of, and meteorological parameter retrieval from, high-resolution infrared spectra. The study discusses the fundamental aspects of ...

Hung-Lung Huang; Paolo Antonelli

2001-03-01T23:59:59.000Z

33

Laser driven quasi-isentropic compression experiments (ICE) for dynamically loading materials at high strain rates  

Science Conference Proceedings (OSTI)

We demonstrate the recently developed technique of laser driven isentropic compression (ICE) for dynamically compressing Al samples at high loading rates close to the room temperature isentrope and up to peak stresses above 100GPa. Upon analysis of the unloading profiles from a multi-stepped Al/LiF target a continuous path through Stress-Density space may be calculated. For materials with phase transformations ramp compression techniques reveals the location of equilibrium phase boundaries and provide information on the kinetics of the lattice re-ordering.

Smith, R; Eggert, J; Celliers, P; Jankowski, A; Lorenz, T; Moon, S; Edwards, M J; Collins, G

2006-03-30T23:59:59.000Z

34

Modular low aspect ratio-high beta torsatron  

DOE Patents (OSTI)

A fusion reactor device in which the toroidal magnetic field and at least a portion of the poloidal magnetic field are provided by a single set of modular coils. The coils are arranged on the surface of a low aspect ratio toroid in planes having the cylindrical coordinate relationship .phi.=.phi..sub.i +kz where k is a constant equal to each coil's pitch and .phi..sub.i is the toroidal angle at which the i'th coil intersects the z=o plane. The device may be described as a modular, high beta torsation whose screw symmetry is pointed along the systems major (z) axis. The toroid defined by the modular coils preferably has a racetrack minor cross section. When vertical field coils and preferably a toroidal plasma current are provided for magnetic field surface closure within the toroid, a vacuum magnetic field of racetrack shaped minor cross section with improved stability and beta valves is obtained.

Sheffield, George V. (Hopewell, NJ); Furth, Harold P. (Princeton, NJ)

1984-02-07T23:59:59.000Z

35

Argonne CNM Highlight: High density, high-aspect-ratio precision polyimide  

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

High density, high-aspect-ratio precision polyimide nanofilters High density, high-aspect-ratio precision polyimide nanofilters Polyimide Nanofilter SEM of a polyimide film with holes ~250 nm in diameter and ~10 µm deep. The cross-sectional cut of the channels in the front are made visible by focused ion-beam milling. Collaborative users from Creatv MicroTech, Inc. and Los Alamos National Laboratory, working with CNM's Nanofabrication & Devices Group, have demonstrated a novel fabrication process that produces high-porosity polymer nanofilters with smooth, uniform. and straight pores and high aspect ratios. Nanofilters have a wide range of applications for various size-exclusion-based separations in bioseparation and nanomedicine, such as laboratory assays, removing bacteria and viruses, drug delivery devices,

36

High transformer ratio drive beams for wakefield accelerator studies  

Science Conference Proceedings (OSTI)

For wakefield based acceleration schemes, use of an asymmetric (or linearly ramped) drive bunch current profile has been predicted to enhance the transformer ratio and generate large accelerating wakes. We discuss plans and initial results for producing such bunches using the 20 to 23 GeV electron beam at the FACET facility at SLAC National Accelerator Laboratory and sending them through plasmas and dielectric tubes to generate transformer ratios greater than 2 (the limit for symmetric bunches). The scheme proposed utilizes the final FACET chicane compressor and transverse collimation to shape the longitudinal phase space of the beam.

England, R. J.; Ng, C.-K.; Frederico, J.; Hogan, M. J.; Litos, M.; Muggli, P.; Joshi, C.; An, W.; Andonian, G.; Mori, W.; Lu, W. [SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Max Planck Institute for Physics, 80805 Munich (Germany); University of California Los Angeles, Los Angeles, CA 90095 (United States); Tsinghua University, Beijing (China)

2012-12-21T23:59:59.000Z

37

Rock compressibility, compaction, and subsidence in a high-porosity Chalk Reservoir  

SciTech Connect

A case study of the North Sea Valhall chalk reservoir demonstrates the significant impact that rock compressibility can have on field performance. Porosity reduction, reservoir interval compaction, and seabed subsidence have been observed in conjunction with reservoir pressure depletion. Full-diameter samples from a recently cut core of the unconsolidated high-porosity chalk were subjected to a series of uniaxial-strain experiments to determine compaction and PV compressibility. The laboratory measurements were corrected to field stress rates and pressure, and porosity-dependent rock-compressibility curves were developed. The uniaxial compaction data were used both in a reservoir model to recognize the significant additional reservoir energy resulting from the lithic drive of large-scale rock compaction and in a subsidence model to predict the impact of reservoir depletion on seabed displacements.

Ruddy, I. (Amoco Norway Oil Co. (US)); Andersen, M.A.; Pattillo, P.D.; Bishiawi, M. (Amoco Production Co., Tulsa, OK (USA)); Foged, N. (Danish Geotechnical Inst. (US))

1989-07-01T23:59:59.000Z

38

Modular low-aspect-ratio high-beta torsatron  

DOE Patents (OSTI)

A fusion-reactor device is described which the toroidal magnetic field and at least a portion of the poloidal magnetic field are provided by a single set of modular coils. The coils are arranged on the surface of a low-aspect-ratio toroid in planed having the cylindrical coordinate relationship phi = phi/sub i/ + kz, where k is a constant equal to each coil's pitch and phi/sub i/ is the toroidal angle at which the i'th coil intersects the z = o plane. The toroid defined by the modular coils preferably has a race track minor cross section. When vertical field coils and, preferably, a toroidal plasma current are provided for magnetic-field-surface closure within the toroid, a vacuum magnetic field of racetrack-shaped minor cross section with improved stability and beta valves is obtained.

Sheffield, G.V.

1982-04-01T23:59:59.000Z

39

Assessment of Non-Fuel, Advanced Compressed Air Energy Storage Systems to Support High Wind Penetration  

Science Conference Proceedings (OSTI)

This report summarizes the status and progress of the RD&D work at EPRI on adiabatic no-fuel Compressed Air Energy Storage (CAES) for wind integration. Bulk energy storage (BES) has latent value in the electric grid, enhances grid reliability, and is well suited to address wind integration related challenges. Without storage, extensive ramping and spinning reserve backup of thermal generators is required, at associated high costs, poor thermal performance, poor down ramp capability and high emissions. Fu...

2009-11-16T23:59:59.000Z

40

jet-compressible-gas-july25.tex 1 Liquid jet in a high Mach number air stream  

E-Print Network (OSTI)

jet-compressible-gas-july25.tex 1 Liquid jet in a high Mach number air stream T.Funada, D velocity airstream is studied assuming that the flow of the viscous gas and liquid is irrotational for the perturbations which depend on all the material properties of the incompressible liquid and compressible gas

Joseph, Daniel D.

Note: This page contains sample records for the topic "high 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

A real-time implementation of gradient domain high dynamic range compression using a local Poisson solver  

Science Conference Proceedings (OSTI)

This paper presents a real-time hardware implementation of a gradient domain dynamic range compression algorithm for high dynamic range (HDR) images. This technique works by calculating the gradients of the HDR image, manipulating those gradients, and ... Keywords: Embedded hardware, Gradient domain dynamic range compression, Poisson equation, Real time, Tone mapping operator

Lavanya Vytla; Firas Hassan; Joan E. Carletta

2013-06-01T23:59:59.000Z

42

High planarity x-ray drive for ultrafast shockless-compression experiments  

Science Conference Proceedings (OSTI)

A spatially planar ({delta}time/time{approx}0.2%) longitudinal stress drive extending over millimeter scale lengths is used to shocklessly compress an aluminum sample to a peak stress of 210 GPa over nanosecond time scales. Direct laser irradiation onto the inner wall of an Au halfraum creates an x ray distribution with a near-uniform blackbody temperature of up to 137 eV. The x rays ablate material from a low-Z foil in a region of planarity closely matched to the diameter of the halfraum. The resultant ablatively driven shock is converted into a ramp-stress-wave in a secondary aluminum target through unloading across an intermediate vacuum gap. Higher peak stresses and shorter associated risetimes result from increasing input laser energy. Ramp-compression experiments can provide single shot equation-of-state data close to the isentrope, information on the kinetics of phase transformations, and material strength at high pressures.

Smith, Raymond F.; Pollaine, Stephen M.; Moon, Stephen J.; Lorenz, K. Thomas; Celliers, Peter M.; Eggert, Jon H.; Park, Hye-Sook; Collins, Gilbert W. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States)

2007-05-15T23:59:59.000Z

43

HIGH-GRADIENT, HIGH-TRANSFORMER-RATIO, DIELECTRIC WAKE FIELD ACCELERATOR  

SciTech Connect

The Phase I work reported here responds to DoE'ss stated need "...to develop improved accelerator designs that can provide very high gradient (>200 MV/m for electrons...) acceleration of intense bunches of particles." Omega-P'�s approach to this goal is through use of a ramped train of annular electron bunches to drive a coaxial dielectric wakefield accelerator (CDWA) structure. This approach is a direct extension of the CDWA concept from acceleration in wake fields caused by a single drive bunch, to the more efficient acceleration that we predict can be realized from a tailored (or ramped) train of several drive bunches. This is possible because of a much higher transformer ratio for the latter. The CDWA structure itself has a number of unique features, including: a high accelerating gradient G, potentially with G > 1 GeV/m; continuous energy coupling from drive to test bunches without transfer structures; inherent transverse focusing forces for particles in the accelerated bunch; highly stable motion of high charge annular drive bunches; acceptable alignment tolerances for a multi-section system. What is new in the present approach is that the coaxial dielectric structure is now to be energized by-not one-�but by a short train of ramped annular-shaped drive bunches moving in the outer coaxial channel of the structure. We have shown that this allows acceleration of an electron bunch traveling along the axis in the inner channel with a markedly higher transformer ratio T than for a single drive bunch. As described in this report, the structure will be a GHz-scale prototype with cm-scale transverse dimensions that is expected to confirm principles that can be applied to the design of a future THz-scale high gradient (> 500 MV/m) accelerator with mm-scale transverse dimensions. We show here a new means to significantly increase the transformer ratio T of the device, and thereby to significantly improve its suitability as a flexible and effective component in a future high energy, high gradient accelerator facility. We predict that the T of a high gradient CDWA can be increased by a substantial factor; this enhancement is dramatically greater than what has been demonstrated heretofore. This large enhancement in T that we predict arises from using a train of three or four drive bunches in which the spacing of the bunches and their respective charges are selected according to a simple principle that requires each bunch lose energy to the wakefields at the same rate, so as not to sacrifice drive beam efficiency�¢����as would be the case if one bunch exhausted its available energy while others had not. It is anticipated that results from the study proposed here can have a direct impact on design of the dielectric accelerator in a TeV-scale collider concept, and in the accelerator for an x-ray FEL.

Jay L. Hirshfield

2012-04-12T23:59:59.000Z

44

Generation of high intensity rf pulses in the ionosphere by means of in situ compression  

SciTech Connect

We demonstrate, using a simple model, that high intensity pulses can be generated from a frequency-chirped modifier of much lower intensity by making use of the dispersive properties of the ionosphere. We show that a frequency-chirped pulse can be constructed so that its various components overtake each other at a prescribed height, resulting in large (up to one hundred times) transient intensity enhancements as compared to those achievable from a steady modifier operating at the same power. We examine briefly one possible application: the enhancement of plasma wave amplitudes which occurs as a result of the interaction of such a compressed pulse with pre-generated turbulence.

Cowley, S.C.; Perkins, F.W.; Valeo, E.J.

1993-04-01T23:59:59.000Z

45

Spectral broadening and compression of high-intensity laser pulses in quasi-periodic systems with Kerr nonlinearity  

SciTech Connect

We report the results of theoretical studies and numerical simulations of optical high-power pulse compression systems based on the spectral broadening in a Kerr nonlinear medium with subsequent pulse compression in a dispersive delay line. It is shown that the effective spectral broadening requires suppressing a smallscale instability arising due to self-focusing, which is possible in quasi-periodic systems consisting of a nonlinear medium and optical relay telescopes transmitting images of the laser beam through the system. The numerical calculations have shown the possibility of broadening the spectrum, followed by 15-fold pulse compression until the instability is excited. (control of laser radiation parameters)

Vlasov, Sergei N; Koposova, E V; Yashin, V E

2012-11-30T23:59:59.000Z

46

Total-to-peak ratios of high purity germanium gamma ray detector  

E-Print Network (OSTI)

This study is concerned with the percentage of [gamma]-rays of a certain energy having their energy correctly measured by a high purity Germanium [gamma]-ray detector. The ratio between the total counts and the counts ...

Nelson, Justin Matthew, 1981-

2004-01-01T23:59:59.000Z

47

High Aspect Ratio Nano-Structured Pt-based PEM Fuel Cell Catalysts...  

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

or * nanoplates - Ni, Co, and Fe have been selected as V.D.14 High Aspect Ratio Nano-Structured Pt-Based PEM Fuel Cell Catalysts Table 1. Technical Targets for...

48

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

49

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

50

High planarity x-ray drive for ultra-fast shockless-compression experiments  

Science Conference Proceedings (OSTI)

A spatially-planar ({Delta}time/time {approx} 0.2%) longitudinal stress drive extending over millimeter scale lengths is used to shocklessly compress an aluminum sample to a peak stress of 210 GPa over nanosecond timescales. Direct laser irradiation onto the inner wall of an Au halfraum creates an x ray distribution with a near-uniform blackbody temperature of up to 137eV. The x rays ablate material from a low-Z foil in a region of planarity closely matched to the diameter of the halfraum. The resultant ablatively-driven shock is converted into a ramp-stress-wave in a secondary aluminum target through unloading across an intermediate vacuum-gap. Higher peak ramp stresses and shorter associated rise-times result from increasing input laser energy. Ramp-compression experiments can provide single shot equation-of-state data close to the isentrope, information on the kinetics of phase transformations and material strength at high pressures.

Smith, R; Pollaine, S; Moon, S; Lorenz, K T; Celliers, P; Eggert, J; Park, H; Collins, G

2007-04-03T23:59:59.000Z

51

Failure Analysis With a New Tool Geometry, X-Die, in Areas With High Tension/Compression Strains  

SciTech Connect

Sheet-metal forming involves a complex strain distribution over the part. The strains consist of tension, compression, and a mix of both. A geometry has been developed, the X-Die, in order to gain insight into the strain behavior of different materials. The X-Die enables strain paths far into the tension/compression region, thus creating the possibility to extend the experimental base both for definition and for further extrapolation of the Forming Limit Curve (FLC) in the tension/compression region, as well as to evaluate FE-simulation results for the same region.Today, evaluation of cracks is made by using FLC. In the conventional test methods, the strains only reach 40% compression (true strain) and often much lower percentages. In conventional test methods, the FLC for any region beyond these levels is extrapolated from existing data.The experimental test proposed in this work consists of a geometry, the X-die, which has shown that rates of 70% tension/compression can be reached (point 0.7/-0.7 in the FLC). Thereby, the region for prediction of cracks on the compression side can be extended in the Forming Limit Diagram (FLD). Furthermore, the strain paths are easy to follow and the limits when cracks appear can be evaluated. Furthermore, the experimental results show that the behavior depends on the material quality. Qualities such as Extreme High Strength Steel (EHSS) and Aluminum have a limited tension/compression rate due to failure in plane strain tension. Material qualities with high r-values, e.g. Mild steel and High Strength Steel (HSS), reach high tension/compression rates before failure and have regions with clearly defined strain signatures. This will be favorable for comparison with numerical simulations, especially for strain signatures in the tension/compression region. Furthermore, the experiments did not indicate any limitation in the compression region besides the one defined in the normal procedure in creation of an FLC.This geometry is favorable to calibrate simulation results, in order to analyze prediction of strains located on the left side in an FLD.

Andersson, Alf [Volvo Cars Body Components, 293 80 Olofstroem (Sweden); Lund University, 221 00 Lund (Sweden); Thilderkvist, Per [Industrial Development Center, 293 38 Olofstroem (Sweden)

2007-05-17T23:59:59.000Z

52

Probing of the hydrogen melting line at high pressures by dynamic compression  

DOE Green Energy (OSTI)

We investigate the capabilities of dynamic compression by intense heavy ion beams to yield information about the high pressure phases of hydrogen. Employing ab initio simulations and experimental data, a new wide range equation of state for hydrogen that covers solid, fluid, gas and plasma phases has been constructed for our hydrodynamic simulations. The results show that the melting line up to its maximum as well as the transition from the molecular fl fluid to the fully ionized, metallic phase can be tested with the beam parameters available at the upcoming FAIR facility at GSI-Darmstadt. Using the structural information from the ab initio simulations, we also demonstrate that x-ray scattering is capable of extracting the information about the structure and the dissociation state.

Grinenko, A; Gericke, D; Glenzer, S H; Vorberger, J

2008-06-09T23:59:59.000Z

53

3430 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 61, NO. 8, OCTOBER 2012 Experimental Validation of High-Voltage-Ratio  

E-Print Network (OSTI)

Validation of High-Voltage-Ratio Low-Input-Current-Ripple Converters for Hybrid Fuel Cell Supercapacitor

Simões, Marcelo Godoy

54

Nano-scaled graphene platelets with a high length-to-width aspect ratio  

DOE Patents (OSTI)

This invention provides a nano-scaled graphene platelet (NGP) having a thickness no greater than 100 nm and a length-to-width ratio no less than 3 (preferably greater than 10). The NGP with a high length-to-width ratio can be prepared by using a method comprising (a) intercalating a carbon fiber or graphite fiber with an intercalate to form an intercalated fiber; (b) exfoliating the intercalated fiber to obtain an exfoliated fiber comprising graphene sheets or flakes; and (c) separating the graphene sheets or flakes to obtain nano-scaled graphene platelets. The invention also provides a nanocomposite material comprising an NGP with a high length-to-width ratio. Such a nanocomposite can become electrically conductive with a small weight fraction of NGPs. Conductive composites are particularly useful for shielding of sensitive electronic equipment against electromagnetic interference (EMI) or radio frequency interference (RFI), and for electrostatic charge dissipation.

Zhamu, Aruna (Centerville, OH); Guo, Jiusheng (Centerville, OH); Jang, Bor Z. (Centerville, OH)

2010-09-07T23:59:59.000Z

55

High Efficiency Low Cost CO2 Compression Using Supersonic Shock Wave Technology  

Science Conference Proceedings (OSTI)

Development and testing results from a supersonic compressor are presented. The compressor achieved record pressure ratio for a fully-supersonic stage and successfully demonstrated the technology potential. Several tasks were performed in compliance with the DOE award objectives. A high-pressure ratio compressor was retrofitted to improve rotordynamics behavior and successfully tested. An outside review panel confirmed test results and design approach. A computational fluid dynamics code used to analyze the Ramgen supersonic flowpath was extensively and successfully modified to improve use on high-performance computing platforms. A comprehensive R&D implementation plan was developed and used to lay the groundwork for a future full-scale compressor demonstration. Conceptual design for a CO2 demonstration compressor was developed and reviewed.

Joe Williams

2010-12-31T23:59:59.000Z

56

Active high-power RF pulse compression using optically switched resonant delay lines  

DOE Green Energy (OSTI)

The authors present the design and a proof of principle experimental results of an optically controlled high power rf pulse compression system. The design should, in principle, handle few hundreds of Megawatts of power at X-band. The system is based on the switched resonant delay line theory. It employs resonant delay lines as a means of storing rf energy. The coupling to the lines is optimized for maximum energy storage during the charging phase. To discharge the lines, a high power microwave switch increases the coupling to the lines just before the start of the output pulse. The high power microwave switch, required for this system, is realized using optical excitation of an electron-hole plasma layer on the surface of a pure silicon wafer. The switch is designed to operate in the TE{sub 01} mode in a circular waveguide to avoid the edge effects present at the interface between the silicon wafer and the supporting waveguide; thus, enhancing its power handling capability.

Tantawi, S.G.; Ruth, R.D.; Vlieks, A.E. [Stanford Univ., CA (US). Stanford Linear Accelerator Center; Zolotorev, M. [Lawrence Berkeley National Lab., CA (US)

1996-11-01T23:59:59.000Z

57

Modeling of interfaces in two-dimensional problems using solid finite elements with high aspect ratio  

Science Conference Proceedings (OSTI)

The use of standard solid finite elements with a very high aspect ratio is proposed to model the behavior of thin interface regions between distinct components of composite structural members. It is shown that these elements present the same kinematics ... Keywords: Bond-slip, Damage model, Finite elements, Interface model, Reinforced concrete, Strong discontinuity

O. L. Manzoli; A. L. Gamino; E. A. Rodrigues; G. K. S. Claro

2012-03-01T23:59:59.000Z

58

Free Boundary, High Beta Equilibrium in a Large Aspect Ratio Tokamak with Nearly  

E-Print Network (OSTI)

Free Boundary, High Beta Equilibrium in a Large Aspect Ratio Tokamak with Nearly Circular Plasma Boundary H. Qin A. Reiman September 25, 1996 Abstract An analytic solution is obtained for free. In the absence of surface currents at the plasma-vacuum in- terface, the free-boundary equilibrium solution

59

Free Boundary, High Beta Equilibrium in a Large Aspect Ratio Tokamak with Nearly  

E-Print Network (OSTI)

Free Boundary, High Beta Equilibrium in a Large Aspect Ratio Tokamak with Nearly Circular Plasma Boundary H. Qin A. Reiman September 25, 1996 Abstract An analytic solution is obtained for free. In the absence of surface currents at the plasma­vacuum in­ terface, the free­boundary equilibrium solution

60

A robust numerical scheme for highly compressible magnetohydrodynamics: Nonlinear stability, implementation and tests  

E-Print Network (OSTI)

The ideal MHD equations are a central model in astrophysics, and their solution relies upon stable numerical schemes. We present an implementation of a new method, which possesses excellent stability properties. Numerical tests demonstrate that the theoretical stability properties are valid in practice with negligible compromises to accuracy. The result is a highly robust scheme with state-of-the-art efficiency. The scheme's robustness is due to entropy stability, positivity and properly discretised Powell terms. The implementation takes the form of a modification of the MHD module in the FLASH code, an adaptive mesh refinement code. We compare the new scheme with the standard FLASH implementation for MHD. Results show comparable accuracy to standard FLASH with the Roe solver, but highly improved efficiency and stability, particularly for high Mach number flows and low plasma beta. The tests include 1D shock tubes, 2D instabilities and highly supersonic, 3D turbulence. We consider turbulent flows with RMS sonic Mach numbers up to 10, typical of gas flows in the interstellar medium. We investigate both strong initial magnetic fields and magnetic field amplification by the turbulent dynamo from extremely high plasma beta. The energy spectra show a reasonable decrease in dissipation with grid refinement, and at a resolution of 512^3 grid cells we identify a narrow inertial range with the expected power-law scaling. The turbulent dynamo exhibits exponential growth of magnetic pressure, with the growth rate twice as high from solenoidal forcing than from compressive forcing. Two versions of the new scheme are presented, using relaxation-based 3-wave and 5-wave approximate Riemann solvers, respectively. The 5-wave solver is more accurate in some cases, and its computational cost is close to the 3-wave solver.

Knut Waagan; Christoph Federrath; Christian Klingenberg

2011-01-15T23:59:59.000Z

Note: This page contains sample records for the topic "high 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

Unusually high (oxidizer/Pu) ratios in the macro-residues from plutonium-droplet combustion  

Science Conference Proceedings (OSTI)

Individual submillimeter-diameter droplets of /sup 239/Pu-0.6w/o Ga alloy were laser ignited and burned during free fall through air. As with a number of other active metals, plutonium droplets burn as coherent, intensely incandescent bodies that explode near the end of combustion. Compared to many other metals, however, the explosive event with plutonium droplets is relatively mild, and, in most experiments, an essentially intact spherule of oxidized material can be retrieved afterward from the combustion chamber. The oxidizer-to-plutonium atomic ratios (O/Pu) of the exploded spherules retrieved in the experiments seem unusually high - from 3- to 5-fold greater than the pre-explosion ratios. Some possible explanations of the high apparent O/Pu ratios are: (1) the particles may have become contaminated after the explosion but before the microweighing; (2) the analyses may have been performed with only partially dissolved specimens; (3) one or more elements heavier than the oxidizer elements (i.e. Ga) may have concentrated in the post explosion residue, giving a false indication of the O/Pu ratio; (4) the specimens may be supersaturated or otherwise metastable solutions of oxygen or other oxidizers quenched in at combustion temperatures; or (5) there might be hitherto unknown hyperstoichiometric oxygen and/or nitrogen compounds of plutonium which form at high temperatures. (JMT)

Nelson, L.S.

1980-12-01T23:59:59.000Z

62

Laser-Driven Magnetic-Flux Compression in High-Energy-Density Plasmas  

E-Print Network (OSTI)

The demonstration of magnetic field compression to many tens of megagauss in cylindrical implosions of inertial confinement fusion targets is reported for the first time. The OMEGA laser [T.?R. Boehly et al., Opt. Commun. ...

Gotchev, O. V.

63

A high-resolution mapped grid algorithm for compressible multiphase flow problems  

Science Conference Proceedings (OSTI)

We describe a simple mapped-grid approach for the efficient numerical simulation of compressible multiphase flow in general multi-dimensional geometries. The algorithm uses a curvilinear coordinate formulation of the equations that is derived for the ... Keywords: 35L60, 58J45, 65M06, 65M50, 65Y15, Compressible multiphase flow, Fluid-mixture model, Mapped grids, Stiffened gas equation of state, Wave-propagation method

K. -M. Shyue

2010-11-01T23:59:59.000Z

64

ScalaTrace: Scalable Compression and Replay of Communication Traces for High Performance Computing  

Science Conference Proceedings (OSTI)

Characterizing the communication behavior of large-scale applications is a difficult and costly task due to code/system complexity and long execution times. While many tools to study this behavior have been developed, these approaches either aggregate information in a lossy way through high-level statistics or produce huge trace files that are hard to handle. We contribute an approach that provides orders of magnitude smaller, if not near-constant size, communication traces regardless of the number of nodes while preserving structural information. We introduce intra- and inter-node compression techniques of MPI events that are capable of extracting an application's communication structure. We further present a replay mechanism for the traces generated by our approach and discuss results of our implementation for BlueGene/L. Given this novel capability, we discuss its impact on communication tuning and beyond. To the best of our knowledge, such a concise representation of MPI traces in a scalable manner combined with deterministic MPI call replay are without any precedent.

Noeth, M; Ratn, P; Mueller, F; Schulz, M; de Supinski, B R

2008-05-16T23:59:59.000Z

65

Directed Self-assembly of Nanoparticles at the Polymer Surface by Highly Compressible Supercritical Carbon Dioxide  

Science Conference Proceedings (OSTI)

We report a versatile route for self-assembly of polymer-soluble nanoparticles at the polymer surface using highly compressible supercritical carbon dioxide (scCO{sub 2}). Polystyrene and poly(methyl methacrylate)-based nanocomposite thin films with functionalized polyhedral oligomeric silsesquioxane and phenyl C{sub 61} butyric acid methyl ester nanoparticles were prepared on Si substrates and exposed to scCO{sub 2} at different pressures under the isothermal condition of 36 C. The resultant structures could be then preserved by the vitrification process of the glassy polymers via quick pressure quench to atmospheric pressure and subsequently characterized by using various surface sensitive experimental techniques in air. We found that the surface segregation of these nanoparticles is induced in the close vicinity of P = 8.2 MPa where the excess absorption of the fluid into the polymers maximizes. However, when the film thickness becomes less than about 4R{sub g} thick (where R{sub g} is the radius of polymer gyration), the uniform dispersion of the nanoparticles is favorable instead even at the same CO{sub 2} conditions. We clarify that the phase transition is correlated with the emergence of a concentration gradient of the fluid at the polymer/CO{sub 2} interface and is a general phenomenon for different polymer-nanoparticle interactions.

M Asada; P Gin; M Endoh; S Satija; T Taniguchi; T Koga

2011-12-31T23:59:59.000Z

66

Light emitting diode with high aspect ratio submicron roughness for light extraction and methods of forming  

DOE Patents (OSTI)

The surface morphology of an LED light emitting surface is changed by applying a reactive ion etch (RIE) process to the light emitting surface. High aspect ratio, submicron roughness is formed on the light emitting surface by transferring a thin film metal hard-mask having submicron patterns to the surface prior to applying a reactive ion etch process. The submicron patterns in the metal hard-mask can be formed using a low cost, commercially available nano-patterned template which is transferred to the surface with the mask. After subsequently binding the mask to the surface, the template is removed and the RIE process is applied for time duration sufficient to change the morphology of the surface. The modified surface contains non-symmetric, submicron structures having high aspect ratio which increase the efficiency of the device.

Li, Ting (Ventura, CA)

2011-04-26T23:59:59.000Z

67

Light emitting diode with high aspect ratio submicron roughness for light extraction and methods of forming  

SciTech Connect

The surface morphology of an LED light emitting surface is changed by applying a reactive ion etch (RIE) process to the light emitting surface. High aspect ratio, submicron roughness is formed on the light emitting surface by transferring a thin film metal hard-mask having submicron patterns to the surface prior to applying a reactive ion etch process. The submicron patterns in the metal hard-mask can be formed using a low cost, commercially available nano-patterned template which is transferred to the surface with the mask. After subsequently binding the mask to the surface, the template is removed and the RIE process is applied for time duration sufficient to change the morphology of the surface. The modified surface contains non-symmetric, submicron structures having high aspect ratio which increase the efficiency of the device.

Li, Ting

2013-08-13T23:59:59.000Z

68

Planar silicon fabrication process for high-aspect-ratio micromachined parts  

SciTech Connect

Surface-micromachined silicon inertial sensors are limited to relatively high-G applications in part because of the fundamental limitations on proof mass imposed by the manufacturing technology. At the same time, traditional micromolding technologies such as LIGA do not lend themselves to integration with electronics, a capability which is equally necessary for high-performance inertial sensors. The silicon micromolding processes described in this report promise to offer both larger proof masses and integrability with on-chip electronics. In Sandia`s silicon micromolding process, the proof mass is formed using a mold which is first recessed into the substrate using a deep silicon trench etch, then lined with a sacrificial or etch-stop layer, and filled with mechanical polysilicon. Since the mold is recessed into the substrate, the whole micromechanical structure can be formed, planarized, and integrated with standard silicon microelectronic circuits before the release etch. In addition, unlike surface-micromachined parts, the thickness of the molded parts is limited by the depth of the trench etch (typically 10--50 {micro}m) rather than the thickness of deposited polysilicon (typically 2 {micro}m). The fact that the high-aspect-ratio section of the device is embedded in the substrate enables the monolithic integration of high-aspect-ratio parts with surface-micromachined mechanical parts, and, in the future, also electronics. The authors anticipate that such an integrated mold/surface micromachining/electronics process will offer versatile high-aspect-ratio micromachined structures that can be batch-fabricated and monolithically integrated into complex microelectromechanical systems including high-performance inertial sensing systems.

Barron, C.C.; Fleming, J.G. [Sandia National Labs., Albuquerque, NM (United States). Microelectronics Development Lab.

1997-09-01T23:59:59.000Z

69

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...

70

Adding aggressive error correction to a high-performance compressing flash file system  

Science Conference Proceedings (OSTI)

While NAND flash memories have rapidly increased in both capacity and performance and are increasingly used as a storage device in many embedded systems, their reliability has decreased both because of increased density and the use of multi-level cells ... Keywords: compression, file system, nand flash memory, non-volatile memory, reliability

Yangwook Kang; Ethan L. Miller

2009-10-01T23:59:59.000Z

71

Alpha and gamma radiation effects on air-water systems at high gas/liquid ratios  

SciTech Connect

Radiolysis tests were conducted on air-water systems to examine the effects of radiation on liquid phase chemistry under high gas/liquid volume (G/L) ratios that are characteristic of an unsaturated nuclear waste repository setting. Test parameters included temperatures of 25, 90, and 200{degrees}C; gamma vs. alpha radiation; dose rates of {approximately}3500 and 50,000 rad/h; and G/L ratios of 10 and 100. Formate, oxalate, and total organic carbon contents increased during irradiation of the air-water systems in gamma and alpha tests at low-dose rate ({approximately}3500 rad/h). Increases in organic components were not observed for tests run at 200{degrees}C or high-dose rates (50,000 rad/h). In the tests where increases in organics occurred, the formate and oxalate were preferentially enriched in solutions that were rinsed from the test vessel walls. Nitrate (NO{sub 3}{sup {minus}}) is the dominant anion produced during the radiolysis reactions. Significant nitrite (NO{sub 2}{sup {minus}}) also occurs in some high-dose rate tests, with the reduced form of nitrogen possibly resulting from reactions with the test vessels. These results indicate that nitrogen acids are being produced and concentrated in the limited quantities of solution present in the tests. Nitrate + nitrite production varied inversely with temperature, with the lowest quantities being detected for the higher temperature tests. The G(NO{sub 3}{sup {minus}} + NO{sub 2}{sup {minus}}) values for the 25, 90, and 200{degrees}C experiments with gamma radiation are 3.2 {+-} 0.7, 1.3 {+-} 1.0, and 0.4 {+-} 0.3, respectively. Thus, the elevated temperatures expected early in the life of a repository may counteract pH decreases resulting from nitrogen acid production. Little variation was observed in G values as a function of dose rate or gas/liquid ratio.

Wronkiewicz, D.J.; Bates, J.K.

1993-08-01T23:59:59.000Z

72

Recoil Polarization Measurements of the Proton Electromagnetic Form Factor Ratio to High Momentum Transfer  

DOE Green Energy (OSTI)

The electromagnetic form factors of the nucleon characterize the effect of its internal structure on its response to an electromagnetic probe as studied in elastic electronnucleon scattering. These form factors are functions of the squared four-momentum transfer Q2 between the electron and the proton. The two main classes of observables of this reaction are the scattering cross section and polarization asymmetries, both of which are sensitive to the form factors in different ways. When considering large f momentum transfers, double-polarization observables offer superior sensitivity to the electric form factor. This thesis reports the results of a new measurement of the ratio of the electric and magnetic form factors of the proton at high momentum transfer using the recoil polarization technique. A polarized electron beam was scattered from a liquid hydrogen target, transferring polarization to the recoiling protons. These protons were detected in a magnetic spectrometer which was used to reconstruct their kinematics, including their scattering angles and momenta, and the position of the interaction vertex. A proton polarimeter measured the polarization of the recoiling protons by measuring the azimuthal asymmetry in the angular distribution of protons scattered in CH2 analyzers. The scattered electron was detected in a large acceptance electromagnetic calorimeter in order to suppress inelastic backgrounds. The measured ratio of the transverse and longitudinal polarization components of the scattered proton is directly proportional to the ratio of form factors GpE=GpM. The measurements reported in this thesis took place at Q2 =5.2, 6.7, and 8.5 GeV2, and represent the most accurate measurements of GpE in this Q2 region to date.

Andrew Puckett

2010-02-01T23:59:59.000Z

73

Physics Basis for High-Beta, Low-Aspect-Ratio Stellarator Experiments  

SciTech Connect

High-beta, low-aspect-ratio (compact) stellarators are promising solutions to the problem of developing a magnetic plasma configuration for magnetic fusion power plants that can be sustained in steady-state without disrupting. These concepts combine features of stellarators and advanced tokamaks and have aspect ratios similar to those of tokamaks (2-4). They are based on computed plasma configurations that are shaped in three dimensions to provide desired stability and transport properties. Experiments are planned as part of a program to develop this concept. A beta = 4% quasi-axisymmetric plasma configuration has been evaluated for the National Compact Stellarator Experiment (NCSX). It has a substantial bootstrap current and is shaped to stabilize ballooning, external kink, vertical, and neoclassical tearing modes without feedback or close-fitting conductors. Quasi-omnigeneous plasma configurations stable to ballooning modes at beta = 4% have been evaluated for the Quasi-Omnigeneous Stellarator (QOS) experiment. These equilibria have relatively low bootstrap currents and are insensitive to changes in beta. Coil configurations have been calculated that reconstruct these plasma configurations, preserving their important physics properties. Theory- and experiment-based confinement analyses are used to evaluate the technical capabilities needed to reach target plasma conditions. The physics basis for these complementary experiments is described.

A. Brooks; A.H. Reiman; G.H. Neilson; M.C. Zarnstorff; et al

1999-11-01T23:59:59.000Z

74

Synthesis and Electric Field-Manipulation of High Aspect Ratio Barium Titanate  

E-Print Network (OSTI)

The objective of this thesis is to develop high dielectric constant nanoparticle dispersion for switchable aircraft antenna systems. Two steps were designed to achieve the objective. First, obtain high dielectric, high aspect ratio nanoparticles and disperse them in dielectric oil medium. Second, manipulate the particle-oil dispersion using an external alternating current (AC) electric field to increase the effective dielectric constant. In order to obtain high dielectric dispersions, different sizes and shapes of titanium dioxide (TiO2) and barium titanate (BaTiO3) nanoparticles were purchased and measured. However, after a number of experiments detailed in the thesis, it was found that none of the commercially available nanoparticles could satisfy our requirements for a minimum effective dielectric constant. Thus, to achieve the goals above, we synthesized high aspect ratio BaTiO3 nanowires with BaC2O4 and TiO2 powders as precursors using a molten salt method. The as-synthesized BaTiO3 nanowires were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive spectroscopy (EDS) mapping. The nanowires have a diameter ranging from 100 nm to 300 nm, and their lengths range from 1.5 micrometers to 5 micrometers. Mechanical stirring and bath sonication were used to obtain even colloidal dispersions. Different concentrations of BaTiO3 nanoparticles well dispersed in the oil medium were successfully manipulated using AC electric field. To monitor the change in microstructure of BaTiO3 nanoparticles, optical microscopy was used to observe the alignment of particles in the sample under the applied electric field. Various parameters including the magnitude, frequency, and duration of the electric field, and the concentration of BaTiO3 nanoparticles were investigated to achieve the optimal alignment of nanoparticles. The experimental results were validated by theoretical analysis using Maxwell-Garnett mixing rule. It was demonstrated that the effective dielectric constant of the colloidal dispersions would increase with the increase of the magnitude, frequency and duration of applied electric field. Synthesized BaTiO3 nanowire-based dispersions exhibit significant enhancement of the effective dielectric constant compared to other colloidal materials. The effective dielectric constant of 5 wt percent BaTiO3-oil dispersions could reach up to 10 when aligned at 1000 V/mm electric field at 1 kHz frequency for 1 hour.

Li, Junjia

2011-05-01T23:59:59.000Z

75

Shock compression of quartz in the high-pressure fluid regime  

Science Conference Proceedings (OSTI)

The Hugoniot of quartz has been measured using laser-driven shock waves with pressures from 2 to 15 Mbars. Within this pressure range silica transforms from a liquid near melt into a dense plasma. Results are in good agreement with previous studies in part of this range performed using explosive- and nuclear-driven shocks indicating the absence of time-dependent effects for time scales between several hundred picoseconds and several hundred microseconds. These data combined with earlier data at lower pressures clearly show the increasing compressibility of silica as it transitions from solid to liquid to dense plasma regimes.

Hicks, D.G.; Boehly, T.R.; Celliers, P.M.; Eggert, J.H.; Vianello, E.; Meyerhofer, D. D.; Collins, G. W. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Laboratory for Laser Energetics, University of Rochester, New York 14623 (United States); Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Laboratory for Laser Energetics, University of Rochester, New York 14623 (United States) and Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States); Laboratory for Laser Energetics, University of Rochester, New York 14623, Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States) and Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627 (United States); Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2005-08-15T23:59:59.000Z

76

Pulse compression with a high-energy Nd:YAG regenerative amplifier system  

Science Conference Proceedings (OSTI)

We describe a method for the generation of readily synchronizable, near-transform-limited, 1064-nm, 6-mJ pulses with {lt}20-ps duration at a repetition rate of 20 Hz. The method employs chirped pulse amplification of spectrally broadened and temporally stretched pulses from a cw mode-locked Nd:YAG laser in a commercial Nd:YAG regenerative amplifier followed by pulse compression with a grating pair. Linear amplification subsequent to regenerative amplification is not required with this method, although higher energies would be easily obtained. {copyright} 1997 Optical Society of America

Venturo, V.A.; Joly, A.G.; Ray, D. [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999 K2-14, Richland, Washington 99352 (United States)

1997-07-01T23:59:59.000Z

77

MHD EQUILIBRIUM AND STABILITY CONSIDERATIONS FOR HIGH-ASPECT-RATIO ARIES-I TOKAMAK REACTORS  

DOE Green Energy (OSTI)

Browse > Conferences> Fusion Engineering, 1989. Pro Back to Results MHD equilibrium and stability considerations for high-aspect-ratio ARIES-I tokamak reactors .102446 searchabstract .Peng, Y.-K.M. ; Strickler, D.J. ; Hogan, J.T. ; Whitson, J.C. ; Bathke, C.G. ; Evans, K., Jr. ; Jardin, S.C. ; Klasky, M. ; Leuer, J.A. ; Oak Ridge Nat. Lab., TN This paper appears in: Fusion Engineering, 1989. Proceedings., IEEE Thirteenth Symposium on Issue Date : 2-6 Oct 1989 On page(s): 1278 - 1282 vol.2 Meeting Date : 02 Oct 1989-06 Oct 1989 INSPEC Accession Number: 3809362 Digital Object Identifier : 10.1109/FUSION.1989.102446 Date of Current Version : 06 August 2002 Abstract The requirements of (1) an external poloidal-field coil (PFC) system with minimum stored energy, (2) double-null divertor plasmas with elongated D shape, (3) adequate passive stabilization of plasma vertical displacement by a vacuum vessel located behind the blanket zone, and (4) an enhanced plasma beta limit in the first stability regime are incorporated in the Advanced Reactor Innovation and Evaluation Study-I (ARIES-I) concept for a high-field tokamak reactor with high aspect ratio (A=4.5). The plasma current and pressure profiles are also made consistent with enhanced bootstrap current and reduced current drive power by means of ion cyclotron wave or neutral beam injection. These lead to plasmas characterized by an elongation of 1.8 to the divertor X-point, a triangularity of 0.7, a safety factor of ~1.5, a safety factor at the edge >4, a plasma beta of ~2%, and a poloidal beta of ~0.5. With a plasma current of 11 MA, a toroidal field of 13 T at the major radius of 6.5 m, and over 3.5 m of clearance between the PFCs and the plasma edge, the stored energy in the PFC system ranges from 20 GJ during plasma operation at low beta, to 12 GJ during plasma operation at high beta.

Peng, Yueng Kay Martin [ORNL; Strickler, Dennis J [ORNL

1990-01-01T23:59:59.000Z

78

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

79

MHD equilibrium and stability considerations for high-aspect-ratio ARIES-I tokamak reactors  

SciTech Connect

The requirements of an external poloidal field coil (PFC) system with minimum stored energy, double-null divertor plasmas with elongated D shape, adequate passive stabilization of plasma vertical displacement by a vacuum vessel located behind the blanket zone, and an enhanced plasma beta limit in the first stability regime are incorporated in the ARIES-I concept for a high-field tokamak reactor with high aspect ratio (A = 4.5). The plasma current and pressure profiles are also made consistent with enhanced bootstrap current I{sub bs} and reduced current drive power by means of ion cyclotron wave (ICW) or neutral beam (NB) injection. These lead to plasmas characterized by an elongation k{sub x} of 1.8 to the divertor X-point, a triangularity {delta}{sub x} of 0.7, a safety factor q on axis of q{sub 0} {approx} 1.5, a safety factor at the edge q{sub 95} > 4, a plasma beta {beta} {approx} 2%, and a poloidal beta given by {epsilon}{beta}{sub p} {approx} 0.5 ({epsilon} = 1/A). With a plasma current I{sub p} of 11 MA, a toroidal field B{sub t} of 13 T at the major radius R{sub 0} of 6.5 m, and over 3.5 m of clearance between the PFCs and the plasma edge, the stored energy in the PFC system ranges from 20 GJ during plasma operation at low beta to 12 GJ during plasma operation at high beta. 16 refs., 6 figs., 2 tabs.

Peng, Y.K.M.; Strickler, D.J.; Hogan, J.T.; Whitson, J.C.; Bathke, C.G.; Evans, K. Jr.; Jardin, S.C.; Klasky, M.; Leuer, J.A. (Oak Ridge National Lab., TN (USA); Los Alamos National Lab., NM (USA); Argonne National Lab., IL (USA); Princeton Univ., NJ (USA). Plasma Physics Lab.; Rensselaer Polytechnic Inst., Troy, NY (USA); General Atomics, San Diego, CA (USA))

1989-01-01T23:59:59.000Z

80

Bubble confinement in flow boiling of FC-72 in a ''rectangular'' microchannel of high aspect ratio  

SciTech Connect

Boiling in microchannels remains elusive due to the lack of full understanding of the mechanisms involved. A powerful tool in achieving better comprehension of the mechanisms is detailed imaging and analysis of the two-phase flow at a fundamental level. Boiling is induced in a single microchannel geometry (hydraulic diameter 727 {mu}m), using a refrigerant FC-72, to investigate the effect of channel confinement on bubble growth. A transparent, metallic, conductive deposit has been developed on the exterior of the rectangular microchannel, allowing simultaneous uniform heating and visualisation to be achieved. The data presented in this paper is for a particular case with a uniform heat flux applied to the microchannel and inlet liquid mass flowrate held constant. In conjunction with obtaining high-speed images and videos, sensitive pressure sensors are used to record the pressure drop across the microchannel over time. Bubble nucleation and growth, as well as periodic slug flow, are observed in the microchannel test section. The periodic pressure fluctuations evidenced across the microchannel are caused by the bubble dynamics and instances of vapour blockage during confined bubble growth in the channel. The variation of the aspect ratio and the interface velocities of the growing vapour slug over time, are all observed and analysed. We follow visually the nucleation and subsequent both 'free' and 'confined' growth of a vapour bubble during flow boiling of FC-72 in a microchannel, from analysis of our results, images and video sequences with the corresponding pressure data obtained. (author)

Barber, Jacqueline [School of Engineering, University of Edinburgh, The King's Buildings, Mayfield Road, Edinburgh, EH9 3JL (United Kingdom); Aix-Marseille Universite (UI, UII) - CNRS Laboratoire IUSTI, UMR 6595, 5 Rue Enrico Fermi, Marseille 13453 (France); Brutin, David; Tadrist, Lounes [Aix-Marseille Universite (UI, UII) - CNRS Laboratoire IUSTI, UMR 6595, 5 Rue Enrico Fermi, Marseille 13453 (France); Sefiane, Khellil [School of Engineering, University of Edinburgh, The King's Buildings, Mayfield Road, Edinburgh, EH9 3JL (United Kingdom)

2010-11-15T23:59:59.000Z

Note: This page contains sample records for the topic "high 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

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

82

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

83

A HIGH SIGNAL-TO-NOISE RATIO COMPOSITE SPECTRUM OF GAMMA-RAY BURST AFTERGLOWS  

SciTech Connect

We present a composite spectrum of 60 long duration gamma-ray burst (GRB) afterglows with redshifts in the range 0.35 < z < 6.7 observed with low-resolution optical spectra. The composite spectrum covers the wavelength range 700-6600 A in the rest frame and has a mean signal-to-noise ratio of 150 per 1 A pixel and reaches a maximum of {approx}300 in the range 2500-3500 A. Equivalent widths are measured from metal absorption lines from the Ly{alpha} line to {approx}5200 A, and associated metal and hydrogen lines are identified between the Lyman break and Ly{alpha} line. The average transmission within the Lyman forest is consistent with that found along quasar lines of sight. We find a temporal variation in fine-structure lines when dividing the sample into bursts observed within 2 hr from their trigger and those observed later. Other lines in the predominantly neutral gas show variations too, but this is most likely a random effect caused by weighting of individual strong absorption lines and which mimics a temporal variation. Bursts characterized with high- or low-prompt GRB energy release produce afterglows with similar absorption line strengths, and likewise for bursts with bright or faint optical afterglows. Bursts defined as dark from their optical to X-ray spectral index have stronger absorption lines relative to the optically bright bursts. The composite spectrum has strong Ca II and Mg II absorption lines as commonly found in dusty galaxies, however, we find no evidence for dust or a significant molecular content based on the non-detection of diffuse interstellar bands. Compared to starburst galaxy spectra, the GRB composite has much stronger fine-structure lines, while metal absorption lines are weaker.

Christensen, L. [Excellence Cluster Universe, Technische Universitaet Muenchen, Bolzmanstrasse 2, 85748 Garching (Germany); Fynbo, J. P. U. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen Oe (Denmark); Prochaska, J. X. [Department of Astronomy and Astrophysics, UCO/Lick Observatory, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States); Thoene, C. C.; De Ugarte Postigo, A. [INAF - Osservatorio Astronomico di Brera, via E. Bianchi 46, 23807, Merate (Italy); Jakobsson, P., E-mail: lise.christensen@ph.tum.de [Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Dunhagi 5, IS-107 Reykjavik (Iceland)

2011-02-01T23:59:59.000Z

84

HIGH LATITUDE ULYSSES OBSERVATIONS OF THE H/HE INTENSITY RATIO UNDER SOLAR MINIMUM AND SOLAR MAXIMUM CONDITIONS  

DOE Green Energy (OSTI)

We analyze measurements of the 0.5-1.0 MeV/nucleon H/He intensity ratio from the Ulysses spacecraft during its first (1992-94) and second (1999-2000) ascent to southern high latitude regions of the heliosphere. These cover a broad range of heliocentric distances (from 5.2 to 2.0 AU) and out-of-ecliptic latitudes (from 18{degree}S to 80{degree}S). During Ulysses' first southern pass, the HI-SCALE instrument measured a series of enhanced particle fluxes associated with the passage of a recurrent corotating interaction region (CIR). Low values ({approximately}6) of the H/He ratio were observed in these recurrent corotating events, with a clear minimum following the passage of the corotating reverse shock. When Ulysses reached high southern latitudes (>40{degree}S), the H/He ratio always remained below {approximately}10 except during two transient solar events that brought the ratio to high (>20) values. Ulysses' second southern pass was characterized by a higher average value of the H/He ratio. No recurrent pattern was observed in the energetic ion intensity which was dominated by the occurrence of transient events of solar origin. Numerous CIRs, many of which were bounded by forward and reverse shock pairs, were still observed in the solar wind and magnetic field data. The arrival of those CIRs at Ulysses did not always result in a decrease of the H/He ratio; on the contrary, many CIRs showed a higher H/He ratio than some transient events. Within a CIR, however, the H/He ratio usually increased around the forward shock and decreased towards the reverse shock. Throughout the second ascent to southern heliolatitudes, the H/He ratio seldom decreased below {approximately}10 even at high latitudes (>40{degree}S). We interpret these higher values of the H/He ratio in terms of the increasing level of solar activity together with the poor definition and short life that corotating solar wind structures have under solar maximum conditions. The global filling of the heliosphere by transient solar events and the fact that in 1999-2000 Ulysses observed only intermediate (<650 km s{sup {minus}1}) solar wind speed (whose contents in pick-up He is less energetic than in the fast solar wind streams observed in 1992-1994) favored the protons with respect to alpha particles. Hence the fact that the average values of the H/He ratio observed by Ulysses during the rising phase of the solar cycle (1999-2000) were higher than those observed during the declining phase (1992-1994).

J. GOSLING; D. LARIO; ET AL

2001-03-01T23:59:59.000Z

85

High precision measurement of the proton elastic form factor ratio at low Q˛  

E-Print Network (OSTI)

Experiment E08-007 measured the proton elastic form factor ratio [mu]GE/GM in the range of Q2 = 0.3-0.7(GeV/c)2 by recoil polarimetry. Data were taken in 2008 at the Thomas Jefferson National Accelerator Facility in Virginia, ...

Zhan, Xiaohui

2010-01-01T23:59:59.000Z

86

High-Spectral Resolution Lidar Measurement of Tropospheric Backscatter Ratio Using Barium Atomic Blocking Filters  

Science Conference Proceedings (OSTI)

Initial measurements of the aerosol backscatter ratio using a new atomic barium filter (FWHM from 2.0–3.0 GHz at 553.7 nm) in conjunction with a narrowband-pulsed dye laser system are reported. Using analog detection and a 0.2 m diameter ...

R. J. Alvarez II; L. M. Caldwell; V. H. Li; D. A. Krueger; C. Y. She

1990-12-01T23:59:59.000Z

87

High Temperature Compressive Behavior of Ni-Fe-Cr-Al Powder ...  

Science Conference Proceedings (OSTI)

K2: Microstructural Development of Plutonium Alloys via Cooling Curve Analysis · K3: Preparation of High Purity Tellurium by Zone Refining Process.

88

Accepted to Combustion and Flame Feb. 11, 2004 Demonstration of a Free-Piston Rapid Compression Facility for the Study of High  

E-Print Network (OSTI)

Accepted to Combustion and Flame Feb. 11, 2004 Demonstration of a Free-Piston Rapid Compression Facility for the Study of High Temperature Combustion Phenomena M. T. Donovan, X. He, B. T. Zigler, T. R developed at the University of Michigan (UM) for use in studying high-temperature combustion phenomena

Wooldridge, Margaret S.

89

Numerical Study of Compressible Mixing Layers Using High-Order WENO Schemes  

Science Conference Proceedings (OSTI)

This paper reports high resolution simulations using fifth-order weighted essentially non-oscillatory (WENO) schemes with a third-order TVD Runge-Kutta method to examine the features of turbulent mixing layers. The implementation of high-order WENO schemes ... Keywords: DNS, Mixing layer, Shock-waves, WENO schemes

Arnab Chaudhuri; Abdellah Hadjadj; Ashwin Chinnayya; Sandrine Palerm

2011-05-01T23:59:59.000Z

90

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

91

Two Channel Dielectric-Lined Rectangular High Transformer Ratio Accelerator Structure Experiment  

SciTech Connect

Current status of a two-channel cm-scale rectangular dielectric lined wakefield accelerator structure is described. This structure is installed at the Argonne Wakefield Accelerator facility (AWA), and is presently being evaluated. The device has a transformer ratio of {approx}12.5:1. When driven by a {approx}50 nC single drive bunch it is expected to obtain {approx}6 MV/m acceleration gradient. Related issues are discussed.

Shchelkunov, S. V.; LaPointe, M. A. [Beam Physics Laboratory, Yale University, 272 Whitney Avenue, New Haven, CT 06511 (United States); Hirshfield, J. L. [Beam Physics Laboratory, Yale University, 272 Whitney Avenue, New Haven, CT 06511 (United States); Omega-P, Inc., 258 Bradley St., New Haven, CT 06510 (United States); Marshall, T. C. [Columbia University, New York, NY 10027 (United States); Omega-P, Inc., 258 Bradley St., New Haven, CT 06510 (United States); Sotnikov, G. [NSC Kharkov Institute of Physics and Technology, Kharkov (Ukraine); Omega-P, Inc., 258 Bradley St., New Haven, CT 06510 (United States); Gai, Wei; Conde, M.; Power, J.; Mihalcea, D. [Argonne National Laboratory, Argonne, IL 60439 (United States)

2010-11-04T23:59:59.000Z

92

A High-Speed FPGA-Based Lossless Data Compression Design for the X-ray Spectrometer Solar Energy Spectra  

Science Conference Proceedings (OSTI)

In order to meet the real-time compression requirements effectively for the solar energy spectrum data of the X-ray spectrometer used as a key payload of Chang'E Mission, the design and implementation of the bit wise OR algorithm based on FPGA is presented ... Keywords: data compression, X-ray spectrometer, bitwise OR algorithm, FPGA

RuiMin Ma; HuanYu Wang

2011-09-01T23:59:59.000Z

93

High Precision Measurement of the Proton Elastic Form Factor Ratio at Low Q2  

DOE Green Energy (OSTI)

Experiment E08-007 measured the proton elastic form factor ratio ?pGE/GM in the range of Q2 = 0.3?0.7(GeV/c)2 by recoil polarimetry. Data were taken in 2008 at the Thomas Jefferson National Accelerator Facility in Virginia, USA. A 1.2 GeV polarized electron beam was scattered off a cryogenic hydrogen target. The recoil proton was detected in the left HRS in coincidence with the elasticly scattered electrons tagged by the BigBite spectrometer. The proton polarization was measured by the focal plane polarimeter (FPP). In this low Q2 region, previous measurement from Jefferson Lab Hall A (LEDEX) along with various fits and calculations indicate substantial deviations of the ratio from unity. For this new measurement, the proposed statistical uncertainty (< 1%) was achieved. These new results are a few percent lower than expected from previous world data and fits, which indicate a smaller GEp at this region. Beyond the intrinsic interest in nucleon structure, the new results also have implications in determining the proton Zemach radius and the strangeness form factors from parity violation experiments.

Xiaohui Zhan

2010-01-31T23:59:59.000Z

94

Compressive Creep Performance and High Temperature Dimensional Stability of Conventional Silica Refractories  

Science Conference Proceedings (OSTI)

Furnace designers and refractory engineers recognize that optimized furnace superstructure design and refractory selection are needed as glass production furnaces are continually striving toward greater output and efficiencies. Harsher operating conditions test refractories to the limit, while changing production technology (such as the conversion to oxy-fuel from traditional air-fuel firing) can alter the way the materials perform. Refractories for both oxy- and air-fuel fired furnace superstructures are subjected to high temperatures during service that may cause them to excessively creep or subside if the refractory material is not creep resistant, or if it is subjected to high stress, or both. Furnace designers can ensure that superstructure structural integrity is maintained if the creep behavior of the refractory material is well understood and well represented by appropriate engineering creep models. Several issues limit the abilities of furnace designers to (1) choose the optimum refractory for their applications, (2) optimize the engineering design, or (3) predict the service mechanical integrity of their furnace superstructures. Published engineering creep data are essentially non-existent for almost all commercially available refractories used for glass furnace superstructures. The limited data that do exist are supplied by the various refractory suppliers. Unfortunately, these suppliers generally have different ways of conducting their mechanical testing and they also interpret and report their data differently; this makes it hard for furnace designers to draw fair comparisons between competing grades of candidate refractories. Furthermore, the refractory supplier's data are often not available in a form that can be readily used for furnace design and for the prediction and design of long-term structural integrity of furnace superstructures. With the aim of providing such comparable data, the US DOE's Office of Industrial Technology and its Advanced Industrial Materials program is sponsoring work to conduct creep testing and analysis on refractories of interest to the glass industry. An earlier stage of the project involved identifying which refractories to test and this is described elsewhere. Conventional silica was one such identified refractory category, and the present report describes the creep behavior of this class of refractories. To portray a more complete understanding of how these refractories perform at service temperatures, their fundamental corrosion resistances, dimensional stabilities, and microstructure were characterized as well.

Karakus, M.; Kirkland, T.P.; Liu, K.C.; Moore, R.E.; Pint, B.A.; Wereszczak, A.A.

1999-03-01T23:59:59.000Z

95

Material test machine for tension-compression tests at high temperature  

DOE Patents (OSTI)

Apparatus providing a device for testing the properties of material specimens at high temperatures and pressures in controlled water chemistries includes, inter alia, an autoclave housing the specimen which is being tested. The specimen is connected to a pull rod which couples out of the autoclave to an external assembly which includes one or more transducers, a force balance chamber and a piston type actuator. The pull rod feeds through the force balance chamber and is compensated thereby for the pressure conditions existing within the autoclave and tending to eject the pull rod therefrom. The upper end of the push rod is connected to the actuator through elements containing a transducer comprising a linear variable differential transformer (LVDT). The housing and coil assembly of the LVDT is coupled to a tube which runs through a central bore of the pull rod into the autoclave where it is connected to one side of the specimen. The movable core of the LVDT is coupled to a stem which runs through the tube where it is then connected to the other side of the specimen through a coupling member. A transducer in the form of a load cell including one or more strain gages is located on a necked-down portion of the upper part of the pull rod intermediate the LVDT and force balance chamber.

Cioletti, Olisse C. (Pittsburgh, PA)

1988-01-01T23:59:59.000Z

96

Global dynamics of high area-to-mass ratios GEO space debris by means of the MEGNO indicator  

E-Print Network (OSTI)

In this paper we provide an extensive analysis of the global dynamics of high-area-to-mass ratios geosynchronous (GEO) space debris, applying a recent technique developed by Cincotta et al. (2000), Mean Exponential Growth factor of Nearby Orbits (MEGNO), which provides an efficient tool to investigate both regular and chaotic components of the phase space. We compute a stability atlas, for a large set of near-geosynchronous space debris by numerically computing the MEGNO indicator, to provide an accurate understanding of the location of stable and unstable orbits as well as the timescale of their exponential divergence in case of chaotic motion. The results improve the analysis presented in Breiter et al. (2005a) notably by considering the particular case of high-area-to-mass ratios space debris. The results indicate that chaotic orbits region can be highly relevant, especially for very high area-to-mass ratios. Then, we provide some numerical investigations and an analytical theory which lead to a detailed understanding of the resonance structures appearing in the phase space. These analyses bring to the fore a relevant class of secondary resonances on both sides of the well-known pendulum-like pattern of geostationary space debris, leading to complex dynamics of such objects.

S. Valk; N. Delsate; A. Lemaitre; T. Carletti

2008-10-10T23:59:59.000Z

97

Characterisation of high aspect ratio non-conductive ceramic microstructures made by spark erosion  

Science Conference Proceedings (OSTI)

The spark erosion process is widely used for micro structuring. Its possibility to structure materials independent of their material properties like high hardness or melting temperature enables to address a large material diversity. However the process ...

T. Hösel; P. Cvancara; T. Ganz; C. Müller; H. Reinecke

2011-02-01T23:59:59.000Z

98

High-aspect-ratio silicon-cell metallization technical status report. Final report  

DOE Green Energy (OSTI)

Two features of the silicon concentrator solar cell are addressed which affect output at high concentration levels. The first is the development of narrow but high electroplated grid lines with improved conductivity. The object is a reduction in cell series resistance without increase in shadowing. This goal is accomplished by electroplating through a thick photo resist mask to produce lines .7 mil wide by .7 mil high. Advance pulse plating techniques are combined with pure silver plating baths to produce a deposit conductivity equal to the bulk silver conductivity (a 1.5 to 2 X improvement over conventional silver plating). The second feature is a double diffused selectively textured front surface. This development employs a deep diffusion in the silicon under the grid lines. Only the non grid line open area is selectively texture etched removing the deep junction. This open textured area is then given a second shallow diffusion for optimum cell efficiency. This selective procedure maintains the original highly polished wafer surface under the grid lines so that high resolution narrow grid lines are possible. The double diffusion protects the junction from metal diffusion while enabling the optimum shallow junction in the illuminated regions. Combining these two features has produced a large area concentrator cells (8 cm/sup 2/) with peak efficiency above 16% and exhibiting a broad peak efficiency extending from 50 to 175 suns above 15%.

Not Available

1982-01-01T23:59:59.000Z

99

Large-area fabrication of high aspect ratio tantalum photonic crystals for high-temperature selective emitters  

E-Print Network (OSTI)

The authors present highly selective emitters based on two-dimensional tantalum (Ta) photonic crystals, fabricated on 2 in. polycrystalline Ta substrates, for high-temperature applications, e.g., thermophotovoltaic energy ...

Rinnerbauer, Veronika

100

A novel apparatus for in situ compression of submicron structures and particles in a high resolution SEM  

SciTech Connect

We report on the development and characterization of a novel in situ manipulation device to perform stressing experiments on the submicron scale inside a high resolution field emission scanning electron microscope. The instrument comprises two main assembly groups: an upper part for positioning and moving a mounted probe and a force sensor as well as a specimen support as lower part. The upper part consists of a closed loop tripod piezoelectric scanner mounted on a self-locking coarse positioning stage. Two interlocked steel springs and a linear variable differential transformer measuring the springs' deflections compose the lower part of the instrument. This arrangement acts as force-sensor and sample support. In comparison to already well-established concepts a wide measuring range is covered by adjusting the spring constant between 30 N/m and 50000 N/m. Moreover, the new device offers striking advantages with respect to force calibration and sample deformation measurements. Force calibration is performed using the eigenfrequency of the force detection system directly inside the SEM. Deformation data are obtained with high accuracy by simultaneously recording displacements above and below the specimen. The detrimental apparatus compliance is determined, and the influence on measured data subsequently minimized: an easy to validate two-springs-in-series model is used for data correction. A force resolution in normal direction of 100 nN accompanied by a sample deformation resolution of 5 nm can be achieved with the instrument using an appropriate load cell stiffness. The capabilities and versatility of this instrument are exemplified by compression experiments performed on submicron amorphous silica particles.

Romeis, S.; Paul, J.; Ziener, M.; Peukert, W. [Institute of Particle Technology, University of Erlangen-Nuremberg, Cauerstr. 4, 91058 Erlangen (Germany)

2012-09-15T23:59:59.000Z

Note: This page contains sample records for the topic "high 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

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

102

Fluid-Structure Interaction Modeling of High-Aspect Ratio Nuclear Fuel Plates Using COMSOL  

SciTech Connect

The High Flux Isotope Reactor at the Oak Ridge National Lab is in the research stage of converting its fuel from high-enriched uranium to low-enriched uranium. Due to different physical properties of the new fuel and changes to the internal fuel plate design, the current safety basis must be re-evaluated through rigorous computational analyses. One of the areas being explored is the fluid-structure interaction phenomenon due to the interaction of thin fuel plates (50 mils thickness) and the cooling fluid (water). Detailed computational fluid dynamics and fluid-structure interaction simulations have only recently become feasible due to improved numerical algorithms and advancements in computing technology. For many reasons including the already built-in fluid-structure interaction module, COMSOL has been chosen for this complex problem. COMSOL's ability to solve multiphysics problems using a fully-coupled and implicit solution algorithm is crucial in obtaining a stable and accurate solution. Our initial findings show that COMSOL can accurately model such problems due to its ability to closely couple the fluid dynamics and the structural dynamics problems.

Curtis, Franklin G [ORNL] ORNL; Ekici, Kivanc [ORNL] ORNL; Freels, James D [ORNL] ORNL

2013-01-01T23:59:59.000Z

103

Fabrication and characterization of analyzer gratings with high aspect ratios for phase contrast imaging using a Talbot interferometer  

Science Conference Proceedings (OSTI)

In recent years, X-ray imaging based on the differential phase contrast gained more and more attention to be used in X-ray imaging. Among other techniques like crystal-based diffraction and propagation methods, the grating based Talbot interferometry offers an approach measuring phase modulations of X-rays while passing low absorbing objects. The Talbot interferometer yields for highly efficient X-ray imaging signals for hard X-rays with energies above 10 keV. One factor with high impact on the imaging performance of such grating interferometers is the gratings quality. We introduce a fabrication process allowing both, the fabrication of phase modulating and analyzer gratings with high aspect ratios, up to 100. Structural deviations from the optimal geometry of the gratings are investigated and their influence on the obtained image quality is discussed.

Kenntner, Johannes; Altapova, Venera; Grund, Thomas; Pantenburg, Franz Josef; Meiser, Jan; Baumbach, Tilo; Mohr, Juergen [Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology (IMT), 76021 Karlsruhe (Germany); Karlsruhe Institute of Technology (KIT), Laboratory for Application of Synchrotron Radiation, 76128 Karlsruhe (Germany); Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology (IMT), 76021 Karlsruhe (Germany); Karlsruhe Institute of Technology (KIT), Laboratory for Application of Synchrotron Radiation, 76128 Karlsruhe (Germany); Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology (IMT), 76021 Karlsruhe (Germany)

2012-05-17T23:59:59.000Z

104

A high order kinetic flux-vector splitting method for the reduced five-equation model of compressible two-fluid flows  

Science Conference Proceedings (OSTI)

We present a high order kinetic flux-vector splitting (KFVS) scheme for the numerical solution of a conservative interface-capturing five-equation model of compressible two-fluid flows. This model was initially introduced by Wackers and Koren (2004) ... Keywords: 35L45, 35L65, 35L67, 65M99, 65Y99, 76T99, Central schemes, Conservation laws, Five-equation model, Hyperbolic systems, Kinetic flux-vector splitting schemes, Shock solutions

Shamsul Qamar; Munshoor Ahmed

2009-12-01T23:59:59.000Z

105

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

106

Additional Reserve Recovery Using New Polymer Treatment on High Water Oil Ratio Wells in Alameda Field, Kingman County, Kansas  

SciTech Connect

The Chemical Flooding process, like a polymer treatment, as a tertiary (enhanced) oil recovery process can be a very good solution based on the condition of this field and its low cost compared to the drilling of new wells. It is an improved water flooding method in which high molecular-weight (macro-size molecules) and water-soluble polymers are added to the injection water to improve the mobility ratio by enhancing the viscosity of the water and by reducing permeability in invaded zones during the process. In other words, it can improve the sweep efficiency by reducing the water mobility. This polymer treatment can be performed on the same active oil producer well rather than on an injector well in the existence of strong water drive in the formation. Some parameters must be considered before any polymer job is performed such as: formation temperature, permeability, oil gravity and viscosity, location and formation thickness of the well, amount of remaining recoverable oil, fluid levels, well productivity, water oil ratio (WOR) and existence of water drive. This improved oil recovery technique has been used widely and has significant potential to extend reservoir life by increasing the oil production and decreasing the water cut. This new technology has the greatest potential in reservoirs that are moderately heterogeneous, contain moderately viscous oils, and have adverse water-oil mobility ratios. For example, many wells in Kansas's Arbuckle formation had similar treatments and we have seen very effective results. In addition, there were previous polymer treatments conducted by Texaco in Alameda Field on a number of wells throughout the Viola-Simpson formation in the early 70's. Most of the treatments proved to be very successful.

James Spillane

2005-10-01T23:59:59.000Z

107

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

108

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

109

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

110

High C/O Ratio and Weak Thermal Inversion in the Very Hot Atmosphere of Exoplanet WASP-12b  

E-Print Network (OSTI)

The carbon-to-oxygen ratio (C/O) in a planet provides critical information about its primordial origins and subsequent evolution. A primordial C/O greater than 0.8 causes a carbide-dominated interior as opposed to a silicate-dominated composition as found on Earth, and the atmospheres can also differ from those in the Solar System. The solar C/O is 0.54. Here we report an analysis of dayside multi-wavelength photometry of the transiting hot-Jupiter WASP-12b that reveals C/O >= 1 in its atmosphere. The atmosphere is abundant in CO. It is depleted in water vapor and enhanced in methane by over two orders of magnitude each compared to a solar-abundance chemical-equilibrium model at the expected temperatures. We also find that the extremely irradiated atmosphere (T > 2,500 K) of WASP-12b lacks a prominent thermal inversion, or a stratosphere, and has very efficient day- night energy circulation. The absence of a strong thermal inversion is in stark contrast to theoretical predictions for the most highly irradiate...

Madhusudhan, Nikku; Stevenson, Kevin B; Nymeyer, Sarah; Campo, Christopher J; Wheatley, Peter J; Deming, Drake; Blecic, Jasmina; Hardy, Ryan A; Lust, Nate B; Anderson, David R; Collier-Cameron, Andrew; Britt, Christopher B T; Bowman, William C; Hebb, Leslie; Hellier, Coel; Maxted, Pierre F L; Pollacco, Don; West, Richard G

2010-01-01T23:59:59.000Z

111

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

112

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

113

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.

114

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

115

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

116

Kalman-filtered compressive sensing for high resolution estimation of anthropogenic greenhouse gas emissions from sparse measurements.  

SciTech Connect

The estimation of fossil-fuel CO2 emissions (ffCO2) from limited ground-based and satellite measurements of CO2 concentrations will form a key component of the monitoring of treaties aimed at the abatement of greenhouse gas emissions. The limited nature of the measured data leads to a severely-underdetermined estimation problem. If the estimation is performed at fine spatial resolutions, it can also be computationally expensive. In order to enable such estimations, advances are needed in the spatial representation of ffCO2 emissions, scalable inversion algorithms and the identification of observables to measure. To that end, we investigate parsimonious spatial parameterizations of ffCO2 emissions which can be used in atmospheric inversions. We devise and test three random field models, based on wavelets, Gaussian kernels and covariance structures derived from easily-observed proxies of human activity. In doing so, we constructed a novel inversion algorithm, based on compressive sensing and sparse reconstruction, to perform the estimation. We also address scalable ensemble Kalman filters as an inversion mechanism and quantify the impact of Gaussian assumptions inherent in them. We find that the assumption does not impact the estimates of mean ffCO2 source strengths appreciably, but a comparison with Markov chain Monte Carlo estimates show significant differences in the variance of the source strengths. Finally, we study if the very different spatial natures of biogenic and ffCO2 emissions can be used to estimate them, in a disaggregated fashion, solely from CO2 concentration measurements, without extra information from products of incomplete combustion e.g., CO. We find that this is possible during the winter months, though the errors can be as large as 50%.

Ray, Jaideep; Lee, Jina; Lefantzi, Sophia; Yadav, Vineet [Carnegie Institution for Science, Stanford, CA; Michalak, Anna M. [Carnegie Institution for Science, Stanford, CA; van Bloemen Waanders, Bart Gustaaf [Sandia National Laboratories, Albuquerque NM; McKenna, Sean Andrew [IBM Research, Mulhuddart, Dublin, Ireland

2013-09-01T23:59:59.000Z

117

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

118

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

119

The Effect of High Rotational Speed on the Performance of Straight-through Labyrinth Seals for Compressible and Incompressible Flow  

E-Print Network (OSTI)

The leakage flow through straight through labyrinth seals with tooth on stator was investigated by performing CFD simulations .ANSYS Fluent is used to simulate the fluid flow through straight through Labyrinth seals. The effect of seal geometry on discharge coefficient, carry over coefficient and expansion factor is studied by varying clearance, pitch, tooth height, tooth width ,Reynolds number and rotor speed. Derived quantities Such as carry over coefficient, coefficient of discharge and expansion factor are analyzed as a function of the tooth with preceding cavity to predict the effectiveness of the seal. To understand the effect of varying seal geometries and swirl, 2D CFD simulations were performed. It was found that the clearance to pitch ratio is a strong geometry factor which affect the performance of the seal. The carryover coefficient which describes the portion of kinetic energy carried over from one cavity to the next is also examined. It was found to be a function of Reynolds number and shaft speed. Discharge coefficient describes the losses which occur when fluid flows through the cavity and under the tooth. Just like the carryover coefficient, it is also discovered that it is a strong function of Reynolds number and shaft speed.

Obidigbo, Ekene R.

2012-05-01T23:59:59.000Z

120

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

Note: This page contains sample records for the topic "high 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

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

122

Applications of High-Resolution Electrospray Ionization Mass Spectrometry to Measurements of Average Oxygen to Carbon Ratios in Secondary Organic Aerosols  

Science Conference Proceedings (OSTI)

The applicability of high resolution electrospray ionization mass spectrometry (HR ESI-MS) to measurements of the average oxygen to carbon ratio (O/C) in organic aerosols was investigated. Solutions with known average O/C containing up to 10 standard compounds representative of secondary organic aerosol (SOA) were analyzed and corresponding electrospray ionization efficiencies were quantified. The assumption of equal ionization efficiency commonly used in estimating O/C ratios of organic aerosols was found to be reasonably accurate. We found that the accuracy of the measured O/C ratios increases by averaging the values obtained from both (+) and (-) modes. A correlation was found between the ratio of the ionization efficiencies in the positive and negative ESI modes with the octanol-water partition constant, and more importantly, with the compound's O/C. To demonstrate the utility of this correlation for estimating average O/C values of unknown mixtures, we analyzed the ESI (+) and ESI (-) data for SOA produced by oxidation of limonene and isoprene and compared to online O/C measurements using an aerosol mass spectrometer (AMS). This work demonstrates that the accuracy of the HR ESI-MS methods is comparable to that of the AMS, with the added benefit of molecular identification of the aerosol constituents.

Bateman, Adam P.; Laskin, Julia; Laskin, Alexander; Nizkorodov, Sergey

2012-07-02T23:59:59.000Z

123

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

124

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

125

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

126

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

127

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

128

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

129

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

130

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

131

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

132

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 ...

133

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

134

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

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

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

137

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

138

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

139

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

140

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

Note: This page contains sample records for the topic "high 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

On-Site Calibration for High Precision Measurements of Water Vapor Isotope Ratios Using Off-Axis Cavity-Enhanced Absorption Spectroscopy  

Science Conference Proceedings (OSTI)

Stable isotope ratio measurements of atmospheric water vapor (?18Ov and ?2Hv) are scarce relative to those in precipitation. This limitation is rapidly changing due to advances in absorption spectroscopy technology and the development of ...

Joshua Rambo; Chun-Ta Lai; James Farlin; Matt Schroeder; Ken Bible

2011-11-01T23:59:59.000Z

142

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

143

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

144

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

145

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

146

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....

147

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

148

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

149

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

150

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

151

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

152

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

153

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

154

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-mřller; James R. Markusen; Jan Rose Skaksen

2004-01-01T23:59:59.000Z

155

Percutaneous Vertebroplasty and Bone Cement Leakage: Clinical Experience with a New High-Viscosity Bone Cement and Delivery System for Vertebral Augmentation in Benign and Malignant Compression Fractures  

Science Conference Proceedings (OSTI)

The aim of this study was to assess the feasibility of and venous leakage reduction in percutaneous vertebroplasty (PV) using a new high-viscosity bone cement (PMMA). PV has been used effectively for pain relief in osteoporotic and malignant vertebral fractures. Cement extrusion is a common problem and can lead to complications. Sixty patients (52 female; mean age, 72.2 {+-} 7.2) suffering from osteoporosis (46), malignancy (12), and angiomas (2), divided into two groups (A and B), underwent PV on 190 vertebrae (86 dorsal, 104 lumbar). In Group A, PV with high-viscosity PMMA (Confidence, Disc-O-Tech, Israel) was used. This PMMA was injected by a proprietary delivery system, a hydraulic saline-filled screw injector. In Group B, a standard low-viscosity PMMA was used. Postprocedural CT was carried out to detect PMMA leakages and complications. Fisher's exact test and Wilcoxon rank test were used to assess significant differences (p PV was feasible, achieving good clinical outcome (p < 0.0001) without major complications. In Group A, postprocedural CT showed an asymptomatic leak in the venous structures of 8 of 98 (8.2%) treated vertebrae; a discoidal leak occurred in 6 of 98 (6.1%). In Group B, a venous leak was seen in 38 of 92 (41.3%) and a discoidal leak in 12 of 92 (13.0%). Reduction of venous leak obtained by high-viscosity PMMA was highly significant (p < 0.0001), whereas this result was not significant (p = 0.14) related to the disc. The high-viscosity PMMA system is safe and effective for clinical use, allowing a significant reduction of extravasation rate and, thus, leakage-related complications.

Anselmetti, Giovanni Carlo, E-mail: giovanni.anselmetti@ircc.i [Institute for Cancer Research and Treatment (IRCC), Interventional Radiology Unit (Italy); Zoarski, Gregg [University of Maryland, Radiology and Radiological Science (United States); Manca, Antonio [Institute for Cancer Research and Treatment (IRCC), Radiology Unit (Italy); Masala, Salvatore [University 'Tor Vergata', Radiology Unit and Interventional Radiology Unit (Italy); Eminefendic, Haris; Russo, Filippo; Regge, Daniele [Institute for Cancer Research and Treatment (IRCC), Radiology Unit (Italy)

2008-09-15T23:59:59.000Z

156

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

157

High-resolution numerical methods for compressible multi-phase flow in hierarchical porous media. Progress report, September 1993--September 1994  

SciTech Connect

This is the second year in the proposed three-year effort to develop high-resolution numerical methods for multi-phase flow in hierarchical porous media. The issues being addressed in this research are: Computational efficiency: Field-scale simulation of enhanced oil recovery, whether for energy production or aquifer remediation, is typically highly under-resolved. This is because rock transport properties vary on many scales, and because current numerical methods have low resolution. Effective media properties: Since porous media are formed through complex geologic processes, they involve significant uncertainty and scale-dependence. Given this uncertainty, knowledge of ensemble averages of flow in porous media can be preferable to knowledge of flow in specific realizations of the reservoir. However, current models of effective properties do not represent the observed behavior very well. Relative permeability models present a good example of this problem. In practice, these models seldom provide realistic representations of hysteresis, interfacial tension effects or three-phase flow; there are no models that represent well all three effects simultaneously.

Trangenstein, J.A.

1994-03-15T23:59:59.000Z

158

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

159

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

160

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

Note: This page contains sample records for the topic "high 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

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

162

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...

163

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":""}]}

164

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...

165

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

166

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

167

Compressive Sensing Based High Resolution Channel Estimation ...  

E-Print Network (OSTI)

estimation architecture. We first provide the motivation, as well as the CS ...... security, and smart grid communication. Dr. Han is an Associate Editor of IEEE ...

168

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

169

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

170

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

171

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

172

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

173

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...

174

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

175

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

176

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

177

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

178

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

179

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

180

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

Note: This page contains sample records for the topic "high 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

Fragmentation of multiply charged hydrocarbon molecules C{sub n}H{sup q+} (n{<=} 4, q{<=} 9) produced in high-velocity collisions: Branching ratios and kinetic energy release of the H{sup +} fragment  

Science Conference Proceedings (OSTI)

Fragmentation branching ratios for channels involving H{sup +} emission and associated kinetic energy release of the H{sup +} fragment [KER(H{sup +})] have been measured for multicharged C{sub n}H{sup q+} molecules produced in high velocity (3.6 a.u.) collisions between C{sub n}H{sup +} projectiles and helium atoms. For CH{sup q+} (q{=} 5), inner-shell ionization contributed in a prominent way to the ion production. In these two cases it was shown that measured KER(H{sup +}) were in good agreement with PCCM predictions when those were corrected for Auger relaxation with the same Auger lifetime value as in CH{sup 3+}.

Beroff, K.; Pino, T.; Carpentier, Y. [Institut des Sciences Moleculaires d'Orsay (ISMO), UMR CNRS 8214, Universite Paris Sud 11, bat.210, F-91405 Orsay Cedex (France); Van-Oanh, N. T. [Laboratoire de Chimie Physique (LCP), UMR CNRS 8000, Universite Paris Sud 11, Bat.349, F-91405 Orsay Cedex (France); Chabot, M.; Tuna, T.; Martinet, G. [Institut de Physique Nucleaire d'Orsay (IPNO), IN2P3- CNRS, Universite Paris Sud 11, F-91406 Orsay Cedex (France); Le Padellec, A. [Institut de Recherche en Astrophysique et Planetologie (IRAP), UMR CNRS 5187, Universite de Toulouse, 9 avenue du Colonel Roche, F-31028 Toulouse Cedex 9 (France); Lavergne, L. [Laboratoire de Physique Nucleaire et de Hautes Energies (LPNHE) UPMC, UPD, CNRS-IN2P3, 4 Place Jussieu, F-75005 Paris (France)

2011-09-15T23:59:59.000Z

182

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

183

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

184

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

185

ISOBAR hybrid compression-I/O interleaving for large-scale parallel I/O optimization  

Science Conference Proceedings (OSTI)

Current peta-scale data analytics frameworks suffer from a significant performance bottleneck due to an imbalance between their enormous computational power and limited I/O bandwidth. Using data compression schemes to reduce the amount of I/O activity ... Keywords: high performance computing, hybrid interleaving, i/o, isobar, lossless compression, staging

Eric R. Schendel; Saurabh V. Pendse; John Jenkins; David A. Boyuka, II; Zhenhuan Gong; Sriram Lakshminarasimhan; Qing Liu; Hemanth Kolla; Jackie Chen; Scott Klasky; Robert Ross; Nagiza F. Samatova

2012-06-01T23:59:59.000Z

186

On compressing data in wireless sensor networks for energy efficiency and real time delivery  

Science Conference Proceedings (OSTI)

Wireless sensor networks possess significant limitations in storage, bandwidth, processing, and energy. Additionally, real-time sensor network applications such as monitoring poisonous gas leaks cannot tolerate high latency. While some good data compression ... Keywords: Compression, Latency, Real-time, Wireless sensor network

Tommy Szalapski; Sanjay Madria

2013-06-01T23:59:59.000Z

187

A robust, colocated, implicit algorithm for direct numerical simulation of compressible, turbulent flows  

Science Conference Proceedings (OSTI)

A non-dissipative, robust, implicit algorithm is proposed for direct numerical and large-eddy simulation of compressible turbulent flows. The algorithm addresses the problems caused by low Mach numbers and under-resolved high Reynolds numbers. It colocates ... Keywords: All-Mach number, Compressible turbulence, Direct numerical simulation, Discrete energy conservation, Large-eddy simulation, Non-dissipative

Yucheng Hou; Krishnan Mahesh

2005-05-01T23:59:59.000Z

188

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

189

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

190

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%.

191

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

192

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

193

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

194

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

195

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

196

Highly Compressed Ion Beam for High Energy Density Science  

E-Print Network (OSTI)

discuss plans toward a user facility for target experiments.a rep-rated (>10Hz) user facility. [18] R. C. Davidson, et

2005-01-01T23:59:59.000Z

197

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

198

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.

199

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...

200

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 "high 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

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...

202

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

203

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

204

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

205

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

206

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

207

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

208

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

209

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

210

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

211

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

212

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

213

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

214

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

215

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

216

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

217

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

218

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

219

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

220

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

Note: This page contains sample records for the topic "high 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

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

222

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

223

Properties of Fluid Deuterium under Double-Shock Compression to Several Mbar  

Science Conference Proceedings (OSTI)

The compressibility of fluid deuterium up to several Mbar has been probed using laser-driven shock waves reflected from a quartz anvil. Combining high-precision ({approx} 1 %) shock velocity measurements with the double-shock technique, where differences in equation of state (EOS) models are magnified, has allowed us to accurately discriminate between various theoretical predictions. Our data are consistent with EOS models that show approximately fourfold compression on the principal Hugoniot from 0.7 to 1 Mbar; however, our results indicate that deuterium has a higher compressibility than predicted by these models for single shock pressures between 1 and 2.5 Mbar.

Vianello, E; Celliers, P M; Hicks, D G; Boehly, T R; Collins, T B; Moon, S J; Eggert, J H; Collins, G W; Meyerhofer, D D

2004-02-03T23:59:59.000Z

224

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

225

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...

226

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...

227

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

228

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 ...

229

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...

230

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...

231

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...

232

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...

233

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

234

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

235

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

236

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

237

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

238

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

239

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

240

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

Note: This page contains sample records for the topic "high 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

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

242

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

243

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

244

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

245

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

246

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

247

Temperature Measurements of Shock Compressed Liquid Deuterium up to 230 GPa  

Science Conference Proceedings (OSTI)

Pyrometric measurements of single-shock-compressed liquid deuterium reveal that shock front temperatures T increase from 0.47 to 4.4eV as the pressure P increases from 31 to 230GPa. Where deuterium becomes both conducting and highly compressible, 30{50 Gpa , where the optical reflectivity is saturated, there is an increase in the rate that T increases with P .

Collins, G. W.; Celliers, P. M.; Da Silva, L. B.; Cauble, R.; Gold, D. M.; Foord, M. E.; Holmes, N. C.; Hammel, B. A.; Wallace, R. J.; Ng, A.

2001-10-15T23:59:59.000Z

248

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

249

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

250

Observation of Enhanced Transformer Ratio in Collinear Wakefield Acceleration  

Science Conference Proceedings (OSTI)

One approach to future high energy particle accelerators is based on the wakefield principle: a leading high-charge drive bunch is used to excite fields in an accelerating structure or plasma that in turn accelerates a trailing low-charge witness bunch. The transformer ratio R is defined as the ratio of the maximum energy gain of the witness bunch to the maximum energy loss of the drive bunch. In general, Rtransformer ratio limitation. We report here the first experimental study of the ramped bunch train (RBT) technique in a dielectric based accelerating structure. A single drive bunch was replaced by two bunches with charge ratio of 1 ratio 2.5 and a separation of 10.5 wavelengths of the fundamental mode. An average measured transformer ratio enhancement by a factor of 1.31 over the single drive bunch case was obtained.

Jing, C.; Kanareykin, A.; Schoessow, P. [Euclid Techlabs LLC, Solon, Ohio 44139 (United States); Power, J. G.; Conde, M.; Yusof, Z.; Gai, W. [High Energy Physics Division, Argonne National Laboratory, Argonne, Illinois-60439 (United States)

2007-04-06T23:59:59.000Z

251

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

252

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

253

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

254

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

255

CONVERSION RATIOS IN SLIGHTLY ENRICHED URANIUM, WATER MODERATED LATTICES  

SciTech Connect

An experiment is described in which the conversion ratios were measured using highly enriched U-Al foils as catchers. Data are included on the ratios of epi-cadmium to sub-cadmium fission rates of U/sup 235/ in l% enriched U light water moderated lattices, and on conversion ratios of 1% enriched U light water moderated lattices. (J.R.D.)

Tassan, S.

1963-10-31T23:59:59.000Z

256

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

257

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

258

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

259

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

260

D.D. Luong et al. / Journal of Alloys and Compounds 550 (2013) 412422 412 Development of high performance lightweight aluminum alloy/SiC hollow sphere syntactic foams and compressive  

E-Print Network (OSTI)

with silicon carbide hollow spheres (SiCHS) is investigated for quasi-static (10-3 s-1 ) and high strain rate in increased interest in these materials. Particles, whiskers, short fibers, and continuous fibers of SiC have

Gupta, Nikhil

Note: This page contains sample records for the topic "high 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

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

262

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

263

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

264

Poisson's ratio and porosity at Coso geothermal area, California | Open  

Open Energy Info (EERE)

Poisson's ratio and porosity at Coso geothermal area, California Poisson's ratio and porosity at Coso geothermal area, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Poisson's ratio and porosity at Coso geothermal area, California Details Activities (1) Areas (1) Regions (0) Abstract: High-resolution, three-dimensional, compressional and shear wave velocity models, derived from microearthquake traveltimes, are used to map the distribution of Poisson's ratio and porosity at Coso Geothermal Area, Inyo County, California. Spatial resolution of the three-dimensional Poisson's ratio and porosity distributions is estimated to be 0.5 km horizontally and 0.8 km vertically. Model uncertainties, + or -1% in the interior and + or -2.3% around the edge of the model, are estimated by a jackknife method. We use perturbations of r = V p /V s ratio and Psi = V p

265

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

266

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

267

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

268

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

269

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

270

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

271

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

272

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

273

Non-US data compression and coding research. FASAC Technical Assessment Report  

Science Conference Proceedings (OSTI)

This assessment of recent data compression and coding research outside the United States examines fundamental and applied work in the basic areas of signal decomposition, quantization, lossless compression, and error control, as well as application development efforts in image/video compression and speech/audio compression. Seven computer scientists and engineers who are active in development of these technologies in US academia, government, and industry carried out the assessment. Strong industrial and academic research groups in Western Europe, Israel, and the Pacific Rim are active in the worldwide search for compression algorithms that provide good tradeoffs among fidelity, bit rate, and computational complexity, though the theoretical roots and virtually all of the classical compression algorithms were developed in the United States. Certain areas, such as segmentation coding, model-based coding, and trellis-coded modulation, have developed earlier or in more depth outside the United States, though the United States has maintained its early lead in most areas of theory and algorithm development. Researchers abroad are active in other currently popular areas, such as quantizer design techniques based on neural networks and signal decompositions based on fractals and wavelets, but, in most cases, either similar research is or has been going on in the United States, or the work has not led to useful improvements in compression performance. Because there is a high degree of international cooperation and interaction in this field, good ideas spread rapidly across borders (both ways) through international conferences, journals, and technical exchanges. Though there have been no fundamental data compression breakthroughs in the past five years--outside or inside the United State--there have been an enormous number of significant improvements in both places in the tradeoffs among fidelity, bit rate, and computational complexity.

Gray, R.M.; Cohn, M.; Craver, L.W.; Gersho, A.; Lookabaugh, T.; Pollara, F.; Vetterli, M.

1993-11-01T23:59:59.000Z

274

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

275

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

276

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

277

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

278

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

279

Experimental Investigation of Fuel-Reactivity Controlled Compression Ignition (RCCI) Combustion Mode in a Multi-Cylinder, Light-Duty Diesel Engine  

DOE Green Energy (OSTI)

An experimental study was performed to provide the combustion and emission characteristics resulting from fuel-reactivity controlled compression ignition (RCCI) combustion mode utilizing dual-fuel approach in a light-duty, multi-cylinder diesel engine. In-cylinder fuel blending using port fuel injection of gasoline before intake valve opening (IVO) and early-cycle, direct injection of diesel fuel was used as the charge preparation and fuel blending strategy. In order to achieve the desired auto-ignition quality through the stratification of the fuel-air equivalence ratio ( ), blends of commercially available gasoline and diesel fuel were used. Engine experiments were performed at an engine speed of 2300rpm and an engine load of 4.3bar brake mean effective pressure (BMEP). It was found that significant reduction in both nitrogen oxide (NOx) and particulate matter (PM) was realized successfully through the RCCI combustion mode even without applying exhaust gas recirculation (EGR). However, high carbon monoxide (CO) and hydrocarbon (HC) emissions were observed. The low combustion gas temperature during the expansion and exhaust processes seemed to be the dominant source of high CO emissions in the RCCI combustion mode. The high HC emissions during the RCCI combustion mode could be due to the increased combustion quenching layer thickness as well as the -stratification at the periphery of the combustion chamber. The slightly higher brake thermal efficiency (BTE) of the RCCI combustion mode was observed than the other combustion modes, such as the conventional diesel combustion (CDC) mode, and single-fuel, premixed charge compression ignition (PCCI) combustion mode. The parametric study of the RCCI combustion mode revealed that the combustion phasing and/or the peak cylinder pressure rise rate of the RCCI combustion mode could be controlled by several physical parameters premixed ratio (rp), intake swirl intensity, and start of injection (SOI) timing of directly injected fuel unlike other low temperature combustion (LTC) strategies.

Cho, Kukwon [ORNL; Curran, Scott [ORNL; Prikhodko, Vitaly Y [ORNL; Sluder, Scott [ORNL; Parks, II, James E [ORNL; Wagner, Robert M [ORNL

2011-01-01T23:59:59.000Z

280

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

Note: This page contains sample records for the topic "high 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

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

282

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

283

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

284

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

285

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...

286

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

287

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...

288

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

289

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

290

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

291

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...

292

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

293

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.

294

Shock waves in a Z-pinch and the formation of high energy density plasma  

Science Conference Proceedings (OSTI)

A Z-pinch liner, imploding onto a target plasma, evolves in a step-wise manner, producing a stable, magneto-inertial, high-energy-density plasma compression. The typical configuration is a cylindrical, high-atomic-number liner imploding onto a low-atomic-number target. The parameters for a terawatt-class machine (e.g., Zebra at the University of Nevada, Reno, Nevada Terawatt Facility) have been simulated. The 2-1/2 D MHD code, MACH2, was used to study this configuration. The requirements are for an initial radius of a few mm for stable implosion; the material densities properly distributed, so that the target is effectively heated initially by shock heating and finally by adiabatic compression; and the liner's thickness adjusted to promote radial current transport and subsequent current amplification in the target. Since the shock velocity is smaller in the liner, than in the target, a stable-shock forms at the interface, allowing the central load to accelerate magnetically and inertially, producing a magneto-inertial implosion and high-energy density plasma. Comparing the implosion dynamics of a low-Z target with those of a high-Z target demonstrates the role of shock waves in terms of compression and heating. In the case of a high-Z target, the shock wave does not play a significant heating role. The shock waves carry current and transport the magnetic field, producing a high density on-axis, at relatively low temperature. Whereas, in the case of a low-Z target, the fast moving shock wave preheats the target during the initial implosion phase, and the later adiabatic compression further heats the target to very high energy density. As a result, the compression ratio required for heating the low-Z plasma to very high energy densities is greatly reduced.

Rahman, H. U. [Magneto-Inertial Fusion Technologies Inc. (MIFTI), Irvine, California 92612 (United States) and Department of Physics, University of California Irvine, Irvine, California 92697 (United States); Wessel, F. J. [Department of Physics, University of California Irvine, Irvine California 92697 (United States); Ney, P. [Mount San Jacinto College, Menifee, California 92584 (United States); Presura, R. [University of Nevada, Reno, 1664 N. Virginia St., Reno, Nevada 89557-0208 (United States); Ellahi, Rahmat [Department of Mathematics and Statistics, FBAS, IIU, Islamabad (Pakistan) and Department of Mechanical Engineering, University of California Riverside, Riverside, California 92521 (United States); Shukla, P. K. [Department of Mechanical and Aerospace Engineering and Center for Energy Research, University of California San Diego, La Jolla, California 92093 (United States)

2012-12-15T23:59:59.000Z

295

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

296

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

297

Effects of the Ti/Al atomic ratio on the properties of gradient (Ti,Al)N films synthesized by ion beam assisted deposition  

SciTech Connect

Gradient (Ti,Al)N films were prepared on high speed steel (HSS) and Si (111) wafers by using two Ar{sup +} beams to sputter a titanium target and an aluminum target separately, and a third N{sup +} beam to simultaneously bombard the growing film to assist deposition. The effects of the Ti/Al atomic ratio in the films on properties such as hardness, stress, and adhesion strength were investigated systematically. The results indicated that both the hardness and the adhesion of gradient (Ti,Al)N films to steel substrates exhibited {open_quotes}peak{close_quotes} type changes with an increase of the Ti/Al atomic ratio, and a maximum hardness of 3780thinspkgfthinspmm{sup {minus}2} was reached at a Ti/Al ratio of 5.35. The compressive stress of gradient (Ti,Al)N films increased with increasing Al content in the films. It was found that extreme hardness, high adhesion strength and low stress gradient (Ti,Al)N films can be synthesized on low temperature HSS steel by using the ion beam assisted deposition process.

He, X.; Shu, L.; Xie, Z.W. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

1999-03-01T23:59:59.000Z

298

Laser-driven shock experiments in pre-compressed water: Implications for magnetic field generation in Icy Giant planets  

SciTech Connect

Laser-driven shock compression of pre-compressed water (up to 1 GPa precompression) produces high-pressure, -temperature conditions in the water inducing two optical phenomena: opacity and reflectivity in the initially transparent water. The onset of reflectivity at infrared wavelengths can be interpreted as a semi-conductor to electronic conductor transition in water and is found at pressures above {approx}130 GPa for single-shocked samples pre-compressed to 1 GPa. This electronic conduction provides an additional contribution to the conductivity required for magnetic field generation in Icy Giant planets like Uranus and Neptune.

Lee, K; Benedetti, L R; Jeanloz, R; Celliers, P M; Eggert, J H; Hicks, D G; Moon, S J; Mackinnon, A; Henry, E; Koenig, M; Benuzzi-Mounaix, A; Collins, G W

2005-11-10T23:59:59.000Z

299

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

300

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. Magańa-Loaiza; Gregory A. Howland; Mehul Malik; John C. Howell; Robert W. Boyd

2013-06-10T23:59:59.000Z

Note: This page contains sample records for the topic "high 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

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

302

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

303

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

304

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

305

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

306

Isotropic Thermal Expansivity and Anisotropic Compressibility of ReB2  

SciTech Connect

We experimentally investigated some of the mechanical properties of ReB{sub 2} under high temperature/pressure (T/P) conditions. High-T experiments (up to 600 C at 1 atm) were carried out in a high-T oven attached to a conventional X-ray diffractometer whereas high-P experiments (up to about 42 GPa at 25 C) were conducted in a diamond-anvil cell using synchrotron X-ray radiation. High-T data suggest a highly isotopic thermal expansivity whereas high-P data suggest a highly anisotropic compressibility for ReB{sub 2}.

X Liu; W Liu; Q He; L Deng; H Wang; D He; B Li

2011-12-31T23:59:59.000Z

307

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

308

Analysis of the transient compressible vapor flow in heat pipe  

SciTech Connect

The transient compressible one-dimensional vapor flow dynamics in a heat pipe is modeled. The numerical results are obtained by using the implicit non-iterative Beam-Warming finite difference method. The model is tested for simulated heat pipe vapor flow and actual vapor flow in cylindrical heat pipes. A good comparison of the present transient results for the simulated heat pipe vapor flow with the previous results of a two-dimensional numerical model is achieved and the steady state results are in agreement with the existing experimental data. The transient behavior of the vapor flow under subsonic, sonic, and supersonic speeds and high mass flow rates are successfully predicted. The one-dimensional model also describes the vapor flow dynamics in cylindrical heat pipes at high temperatures.

Jang, J.H.; Faghri, A. [Wright State Univ., Dayton, OH (United States); Chang, W.S. [Wright Research and Development Center, Wright-Patterson, OH (United States)

1989-07-01T23:59:59.000Z

309

Defect Analysis of Vehicle Compressed Natural Gas Composite Cylinder  

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

Defect Analysis of Vehicle Defect Analysis of Vehicle Compressed Natural Gas Composite Cylinder A China Paper on Type 4 Cylinder, translated and presented by J. P. Hsu, PhD, Smart Chemistry Reason for Defect Analysis of CNG Composite Cylinder * Safety Issue - Four explosion accidents of auto used CNG composite material cylinders resulting huge personnel and vehicles loss. * Low Compliance Rate - Inspect 12119 Auto used CNG composite cylinders and only 3868 are qualified with compliance rate of 32%. Plastic CNG Composite Cylinder Process Fitting Internal Plastic Liner External Composite Layer Metal Fitting HDPE Cylinder Liner * HDPE has a high density, great stiffness, good anti-permeability and high melting point, but poor environmental stress cracking Resistance (ESCR). * The defects of cylinder liner quality can be

310

Hydrodynamical modeling of targets compression to high densities  

E-Print Network (OSTI)

by composite schemes on moving grid. Both models also include heat conductivity. The quotidian equation, E is total energy and heat flux W is given by W = - grad T (2) where T is temperature and is heat note that for most presented computations the heat conductivity is negligible. The above system

Limpouch, Jiri

311

High Performance Mica-based Compressive Seals for Solid ...  

The National Energy Technology Laboratory selected PNNL as the national laboratory to support its SOFC program, ...

312

High Performance Mica-based Compressive Seals - Available ...  

Computers & Electronics; Consumer Products; Energy & Utilities; Manufacturing & Warehousing; Presentation(s) SOFC Development at PNNL ...

313

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

314

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

315

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

316

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...

317

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...

318

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

319

Technical assessment of compressed hydrogen storage tank systems for automotive applications.  

DOE Green Energy (OSTI)

The performance and cost of compressed hydrogen storage tank systems has been assessed and compared to the U.S. Department of Energy (DOE) 2010, 2015, and ultimate targets for automotive applications. The on-board performance and high-volume manufacturing cost were determined for compressed hydrogen tanks with design pressures of 350 bar ({approx}5000 psi) and 700 bar ({approx}10,000 psi) capable of storing 5.6 kg of usable hydrogen. The off-board performance and cost of delivering compressed hydrogen was determined for hydrogen produced by central steam methane reforming (SMR). The main conclusions of the assessment are that the 350-bar compressed storage system has the potential to meet the 2010 and 2015 targets for system gravimetric capacity but will not likely meet any of the system targets for volumetric capacity or cost, given our base case assumptions. The 700-bar compressed storage system has the potential to meet only the 2010 target for system gravimetric capacity and is not likely to meet any of the system targets for volumetric capacity or cost, despite the fact that its volumetric capacity is much higher than that of the 350-bar system. Both the 350-bar and 700-bar systems come close to meeting the Well-to-Tank (WTT) efficiency target, but fall short by about 5%. These results are summarized.

Hua, T. Q.; Ahluwalia, R. K.; Peng, J. K.; Kromer, M.; Lasher, S.; McKenney, K.; Law, K.; Sinha, J. (Nuclear Engineering Division); (TIAX, LLC)

2011-02-09T23:59:59.000Z

320

Improving Compressed Air Energy Efficiency in Automotive Plants - Practical Examples and Implementation  

SciTech Connect

The automotive industry is the largest industry in the United States in terms of the dollar value of production [1]. U.S. automakers face tremendous pressure from foreign competitors, which have an increasing manufacturing presence in this country. The Big Three North American Original Equipment Manufacturers (OEMs) General Motors, Ford, and Chrysler are reacting to declining sales figures and economic strain by working more efficiently and seeking out opportunities to reduce production costs without negatively affecting the production volume or the quality of the product. Successful, cost-effective investment and implementation of the energy efficiency technologies and practices meet the challenge of maintaining the output of high quality product with reduced production costs. Automotive stamping and assembly plants are typically large users of compressed air with annual compressed air utility bills in the range of $2M per year per plant. This paper focuses on practical methods that the authors have researched, analyzed and implemented to improve compressed air system efficiency in automobile manufacturing facilities. It describes typical compressed air systems in automotive stamping and assembly plants, and compares these systems to best practices. The paper then presents a series of examples, organized using the method of inside-out approach, which strategically identifies the energy savings in the compressed air system by first minimizing end-use demand, then minimizing distribution losses, and finally making improvements to primary energy conversion equipment, the air compressor plant.

Alkadi, Nasr E [ORNL; Kissock, Professor Kelly [University of Dayton, Ohio

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high 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

Technical assessment of compressed hydrogen storage tank systems for automotive applications.  

Science Conference Proceedings (OSTI)

The performance and cost of compressed hydrogen storage tank systems has been assessed and compared to the U.S. Department of Energy (DOE) 2010, 2015, and ultimate targets for automotive applications. The on-board performance and high-volume manufacturing cost were determined for compressed hydrogen tanks with design pressures of 350 bar ({approx}5000 psi) and 700 bar ({approx}10,000 psi) capable of storing 5.6 kg of usable hydrogen. The off-board performance and cost of delivering compressed hydrogen was determined for hydrogen produced by central steam methane reforming (SMR). The main conclusions of the assessment are that the 350-bar compressed storage system has the potential to meet the 2010 and 2015 targets for system gravimetric capacity but will not likely meet any of the system targets for volumetric capacity or cost, given our base case assumptions. The 700-bar compressed storage system has the potential to meet only the 2010 target for system gravimetric capacity and is not likely to meet any of the system targets for volumetric capacity or cost, despite the fact that its volumetric capacity is much higher than that of the 350-bar system. Both the 350-bar and 700-bar systems come close to meeting the Well-to-Tank (WTT) efficiency target, but fall short by about 5%.

Hua, T.; Ahluwalia, R.; Peng, J. K.; Kromer, M.; Lasher, S.; McKenney, K.; Law, K.; Sinha, J. (Nuclear Engineering Division); (TIAX LLC)

2011-02-01T23:59:59.000Z

322

Properties of Fluid Deuterium Under Double-Shock Compression to Several Mbar  

Science Conference Proceedings (OSTI)

The compressibility of fluid deuterium up to several Mbar has been probed using laser-driven shock waves reflected from a quartz anvil. Combining high-precision (~1%) shock velocity measurements with the double-shock technique, where differences in equation of state (EOS) models are magnified, has allowed better discrimination between theoretical predictions in the second-shock regime.

Boehly, T.R.; Hicks, D.G.; Celliers, P.M.; Collins, T.J.B.; Earley, R.; Eggert, J.H.; Jacobs-Perkins, D.; Moon, S.J.; Vianello, E.; Meyerhofer, D.D.; Collins, G.W.

2004-08-24T23:59:59.000Z

323

ISABELA-QA: query-driven analytics with ISABELA-compressed extreme-scale scientific data  

Science Conference Proceedings (OSTI)

Efficient analytics of scientific data from extreme-scale simulations is quickly becoming a top-notch priority. The increasing simulation output data sizes demand for a paradigm shift in how analytics is conducted. In this paper, we argue that query-driven ... Keywords: compression, data reduction, data-intensive computing, high performance applications, query-driven analytics

Sriram Lakshminarasimhan; John Jenkins; Isha Arkatkar; Zhenhuan Gong; Hemanth Kolla; Seung-Hoe Ku; Stephane Ethier; Jackie Chen; C. S. Chang; Scott Klasky; Robert Latham; Robert Ross; Nagiza F. Samatova

2011-11-01T23:59:59.000Z

324

Compressing the incompressible with ISABELA: in-situ reduction of spatio-temporal data  

Science Conference Proceedings (OSTI)

Modern large-scale scientific simulations running on HPC systems generate data in the order of terabytes during a single run. To lessen the I/O load during a simulation run, scientists are forced to capture data infrequently, thereby making data collection ... Keywords: B-spline, data-intensive application, high performance computing, in-situ processing, lossy compression

Sriram Lakshminarasimhan; Neil Shah; Stephane Ethier; Scott Klasky; Rob Latham; Rob Ross; Nagiza F. Samatova

2011-08-01T23:59:59.000Z

325

Detailed Analysis and Control Issues of Homogeneous Charge Compression Ignition (HCCI)  

DOE Green Energy (OSTI)

Homogeneous charge compression ignition (HCCI) is a new combustion technology that may develop as an alternative to diesel engines with high efficiency and low NOx and particulate matter emissions. This paper describes the HCCI research activities being currently pursued at Lawrence Livermore National Laboratory and at the University of California Berkeley. Current activities include analysis as well as experimental work.

Aceves, Salvador M.; Flowers, Daniel L.; Martinez-Frias, Joel; Espinosa-Loza, Francisco; Dibble, Robert

2002-08-25T23:59:59.000Z

326

Massively parallel direct numerical simulations of forced compressible turbulence: a hybrid MPI/OpenMP approach  

Science Conference Proceedings (OSTI)

A highly scalable simulation code for turbulent flows which solves the fully compressible Navier-Stokes equations is presented. The code, which supports one, two and three dimensional domain decompositions is shown to scale well on up to 262,144 cores. ... Keywords: direct numerical simulations, multilevel parallelism, parallel performance, turbulent flows

Shriram Jagannathan; Diego A. Donzis

2012-07-01T23:59:59.000Z

327

An Artificial Compressibility Method for the Spectral Difference Solution of Unsteady Incompressible  

E-Print Network (OSTI)

. An artificial compressibility method (ACM) is employed in order to treat the inviscid fluxes using added with the ACM (SD-ACM) is able to accurately simulate 2D incompressible steady and unsteady viscous, such as micro air vehi- cle, wind turbine and tidal turbine blades, high-order unstructured methods become

Jameson, Antony

328

Nanostructure of Solid Precipitates Obtained by Expansion of Polystyrene-block-Polybutadiene Solutions in Near Critical Propane: Block Ratio and Micellar Solution Effects  

Science Conference Proceedings (OSTI)

In contrast to incompressible liquid solutions, compressible near-critical solutions of block copolymers allow for controlling rapid structure transformations with pressure alone. For example, when dissolved in near-critical propane, polystyrene-block-polybutadiene can form a random molecular solution at high pressures, a micellar solution at moderate pressures, and a solvent-free precipitate at low pressures. In contrast to the unstructured virgin copolymer, such a propane-treated precipitate rapidly self-assembles toward structures characteristic of equilibrated block copolymers, such as lamellae, spheres, or cylinders, which depend on the block ratio rather than on the decompression rate or temperature, at least within the rate and temperature ranges investigated in this work. At lower temperatures, however, say below 40 C, glass transition of the styrene-butadiene diblocks can inhibit independent structure formation, while crystallization of their hydrogenated-butadiene analogues can preserve the micellar-solution structure.

Green, Jade [University of Wyoming, Laramie; Tyrrell, Zachary [University of Wyoming, Laramie; Radosz, Maciej [University of Wyoming, Laramie; Hong, Kunlun [ORNL; Mays, Jimmy [ORNL

2011-01-01T23:59:59.000Z

329

Monitoring System Used to Optimize Compressed Air System Efficiency, Cut Costs  

E-Print Network (OSTI)

In 1994, Thomson Consumer Electronics (RCA), an international manufacturer of electronics equipment purchased a UtillTRACK® Monitoring System for a plant in Indianapolis, Indiana. The system monitored gas and electric meters, substations, main feeders, and major equipment and systems including compressed air. For the compressed air system, monitored data included compressor amps, electrical demand and consumption, pressure and airflow. The resulting UtiliTRACK® reports and graphs showed a significant variation in system efficiency depending upon the demand for air (day of week, time of day, production schedule) and which compressor or compressors were operating. By working with the boiler plant operators and making minor modifications to the existing compressor controls, the operating sequence was modified to maintain high system efficiency under all operating conditions. Monitored data after the changes were made showed a 20% reduction in compressed air system operating costs.

Holmes, W. A.

1998-04-01T23:59:59.000Z

330

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

331

High voltage feedthrough bushing  

DOE Patents (OSTI)

A feedthrough bushing for a high voltage diode provides for using compression sealing for all sealing surfaces. A diode assembly includes a central conductor extending through the bushing and a grading ring assembly circumferentially surrounding and coaxial with the central conductor. A flexible conductive plate extends between and compressively seals against the central conductor and the grading ring assembly, wherein the flexibility of the plate allows inner and outer portions of the plate to axially translate for compression sealing against the central conductor and the grading ring assembly, respectively. The inner portion of the plate is bolted to the central conductor for affecting sealing. A compression beam is also bolted to the central conductor and engages the outer portion of the plate to urge the outer portion toward the grading ring assembly to obtain compression sealing therebetween.

Brucker, J.P.

1991-12-31T23:59:59.000Z

332

Application of Compressed Sensing to 2-D Ultrasonic Propagation Imaging System data  

Science Conference Proceedings (OSTI)

The Ultrasonic Propagation Imaging (UPI) System is a unique, non-contact, laser-based ultrasonic excitation and measurement system developed for structural health monitoring applications. The UPI system imparts laser-induced ultrasonic excitations at user-defined locations on a structure of interest. The response of these excitations is then measured by piezoelectric transducers. By using appropriate data reconstruction techniques, a time-evolving image of the response can be generated. A representative measurement of a plate might contain 800x800 spatial data measurement locations and each measurement location might be sampled at 500 instances in time. The result is a total of 640,000 measurement locations and 320,000,000 unique measurements. This is clearly a very large set of data to collect, store in memory and process. The value of these ultrasonic response images for structural health monitoring applications makes tackling these challenges worthwhile. Recently compressed sensing has presented itself as a candidate solution for directly collecting relevant information from sparse, high-dimensional measurements. The main idea behind compressed sensing is that by directly collecting a relatively small number of coefficients it is possible to reconstruct the original measurement. The coefficients are obtained from linear combinations of (what would have been the original direct) measurements. Often compressed sensing research is simulated by generating compressed coefficients from conventionally collected measurements. The simulation approach is necessary because the direct collection of compressed coefficients often requires compressed sensing analog front-ends that are currently not commercially available. The ability of the UPI system to make measurements at user-defined locations presents a unique capability on which compressed measurement techniques may be directly applied. The application of compressed sensing techniques on this data holds the potential to reduce the number of required measurement locations, reduce the time to make measurements, reduce the memory required to store the measurements, and possibly reduce the computational burden to classify the measurements. This work considers the appropriate selection of the signal dictionary used for signal reconstruction, and performs an evaluation of compressed sensing technique's ability to reconstruct ultrasonic images using fewer measurements than would be needed using traditional Nyquist-limited data collection techniques.

Mascarenas, David D. [Los Alamos National Laboratory; Farrar, Charles R. [Los Alamos National Laboratory; Chong, See Yenn [Engineering Institute-Korea; Lee, J.R. [Engineering Institute-Korea; Park, Gyu Hae [Los Alamos National Laboratory; Flynn, Eric B. [Los Alamos National Laboratory

2012-06-29T23:59:59.000Z

333

Radio frequency pulse compression experiments at SLAC (Stanford Linear Accelerator Center)  

Science Conference Proceedings (OSTI)

Proposed future positron-electron linear colliders would be capable of investigating fundamental processes of interest in the 0.5--5 TeV beam-energy range. At the SLAC Linear Collider (SLC) gradient of about 20 MV/m this would imply prohibitive lengths of about 50--250 kilometers per linac. We can reduce the length by increasing the gradient but this implies high peak power, on the order of 400-- to 1000-MW at X-Band. One possible way to generate high peak power is to generate a relatively long pulse at a relatively low power and compress it into a short pulse with higher peak power. It is possible to compress before DC to RF conversion, as is done using magnetic switching for induction linacs, or after DC to RF conversion, as is done for the SLC. Using RF pulse compression it is possible to boost the 50-- to 100-MW output that has already been obtained from high-power X-Band klystrons the levels required by the linear colliders. In this note only radio frequency pulse compression (RFPC) is considered.

Farkas, Z.D.; Lavine, T.L.; Menegat, A.; Miller, R.H.; Nantista, C.; Spalek, G.; Wilson, P.B.

1991-01-01T23:59:59.000Z

334

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

335

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

336

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

337

Young's modulus, Poisson's ratio, and residual stress and strain in (111)-oriented scandium nitride thin films on silicon  

E-Print Network (OSTI)

cyclotron resonance MBE which typically generate N2 + species with high kinetic energies. The causes of compressive stress in this case may instead be related to a trend commonly observed in vapor-deposited thin films. Such films typically experience... with the strain information hich is found to be 270±25 GPa. Residual m growth temperature and film thickness#2; d by the differential thermal contraction ic compressive stresses generated during .1063/1.2217106#5; Accurate determination of residual stresses...

Moram, M A; Barber, Z H; Humphreys, C J; Joyce, T B; Chalker, P R

2006-07-21T23:59:59.000Z

338

Compressive Creep Response of T1000G/RS-14 Graphite/Polycyanate Composite Materials  

SciTech Connect

The response of a T1000G/RS-14 graphite/polycyanate composite material system to transverse compressive loads is quantified via experimentation. The primary objective of the work was to quantify the effects of process environment and test environment on the T1000G/RS-14 compressive creep response. Tests were conducted on both the neat resin and the composite material system. In addition to the creep tests, static compressive strength tests were conducted to define the stress-strain response. The creep behavior for the RS-14 resin was quantified by conducting a series of tests to study the effects of different process environments (air and nitrogen), different cure temperatures, and different test environments (air and vacuum). The combined effect on the RS-14 resin compressive creep of processing in nitrogen and testing under vacuum versus processing in air and testing in air was a 47% decrease in the creep strain after 2177 hr. The test environment appeared to have a greater effect on the resin creep than the process environment. Following the conclusion of the resin creep tests, composite transverse compressive creep tests were conducted. The composite creep test cylinder was post-cured in a nitrogen environment prior to machining test specimens and all tests were conducted in a vacuum environment. The series of tests investigated the effects of initial stress level and test temperature on the creep behavior. At the end of the 2000-hr tests at 275{degrees}F on specimens stressed at 10,000 psi, the nitrogen-processed and vacuum-tested conditions reduced the composite transverse compressive creep strain by 19% compared to processing in air and testing in air. The effects of process and test environment on the creep behavior are not as great for the composite system as they were for the neat resin, primarily because of the low resin content in the composite material system. At the 275{degrees}F test temperature there was a significant increase in the composite transverse compressive creep strain between the 6000-psi and 10,000-psi stress levels. Despite the reduction in creep strains due to processing in a nitrogen environment, dimensional stability of the T1000G/RS-14 composite at high transverse compressive stress levels and high temperatures may still be an issue when selecting this system for future applications.

Starbuck, J.M.

1998-01-01T23:59:59.000Z

339

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

340

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

Note: This page contains sample records for the topic "high 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

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

342

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

343

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

344

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.

345

High Aspect Ratio Metallic Structures for Use as Transparent ...  

Metallic structures that can be used as transparent electrodes or to enhance the performance of solar ... more energy efficient ... indium tin oxide ...

346

High Aspect Ratio Metallic Structures for Use as Transparent ...  

Polymer-based photovoltaic devices have received intense interest in recent years because of their potential to provide low-cost solar energy conversion, flexibility ...

347

Design Considerations for High Step-Down ratio Buck Regulators  

E-Print Network (OSTI)

The buck or step-down DC-DC converter is the workhorse switching power supply topology. It utilizes two switches (two FETS or one FET and one diode) along with an output inductor and output capacitor. Whether you look at a large computer server, a personal desktop or a laptop computer, a cell phone or a GPS unit all will contain a buck converter in one form or another. This paper will discuss the synchronous buck topology, design considerations, component selection followed by a small signal model of buck converter. Issues that are important in optimizing the efficiency of the design for example MOSFET selection, the impact that the MOSFET driver plays in improving the efficiency will be examined. The paper will finish by contrasting various control architectures.

Khanna, R

2008-01-01T23:59:59.000Z

348

High Aspect Ratio Metallic Structures for Use as Transparent ...  

# Flexible (can be fabricated on flexible substrates) Applications and Industries Solar cell manufacturing; solid state lighting; optical systems.

349

Direct To Digital Holography For High Aspect Ratio Inspection ...  

Science Conference Proceedings (OSTI)

... effects • Investigating using full wave 3-D finite difference time domain approach – For example Tempest Page 12. Comparison of 1-D TL theory with ...

350

Air flow in a high aspect ratio heat sink  

E-Print Network (OSTI)

The increasing heat output of modern electronics requires concomitant advances in heat sinking technology: reductions in thermal resistance and required pumping power are necessary. This research covers the development of ...

Allison, Jonathan Michael

2010-01-01T23:59:59.000Z

351

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

352

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

353

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

354

Fast mode assignment for quality scalable extension of the high efficiency video coding (HEVC) standard: a Bayesian approach  

Science Conference Proceedings (OSTI)

The new compression standard, known as the High Efficiency Video Coding (HEVC), aims at significantly improving the compression efficiency compared to previous standards. There has been significant interest in developing a scalable version of this standard. ... Keywords: low complexity compression, machine learning, scalable HEVC, video compression

H. R. Tohidypour, H. Bashashati, M. T. Pourazad, P. Nasiopoulos

2013-09-01T23:59:59.000Z

355

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

356

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...

357

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,...

358

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

359

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...

360

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 ...

Note: This page contains sample records for the topic "high 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.


361

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...

362

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 ...

363

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 ...

364

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):...

365

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.

366

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

367

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 ...

368

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...

369

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, ...

370

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...

371

Increasing the transformer ratio at the Argonne wakefield accelerator.  

SciTech Connect

The transformer ratio is defined as the ratio of the maximum energy gain of the witness bunch to the maximum energy loss experienced by the drive bunch (or a bunch within a multidrive bunch train). This plays an important role in the collinear wakefield acceleration scheme. A high transformer ratio is desirable since it leads to a higher overall efficiency under similar conditions (e.g. the same beam loading, the same structure, etc.). One technique to enhance the transformer ratio beyond the ordinary limit of 2 is to use a ramped bunch train. The first experimental demonstration observed a transformer ratio only marginally above 2 due to the mismatch between the drive microbunch length and the frequency of the accelerating structure [C. Jing, A. Kanareykin, J. Power, M. Conde, Z. Yusof, P. Schoessow, and W. Gai, Phys. Rev. Lett. 98, 144801 (2007)]. Recently, we revisited this experiment with an optimized microbunch length using a UV laser stacking technique at the Argonne Wakefield Accelerator facility and measured a transformer ratio of 3.4. Measurements and data analysis from these experiments are presented in detail.

Power, J.G.; Conde, M.; Liu, W.; Yusof, Z.; Gai, W.; Jing, C.; Kanareykin, A. (High Energy Physics); (Euclid Techlabs, LLC)

2011-01-01T23:59:59.000Z

372

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

373

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

374

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

375

Measurement of density, temperature, and electrical conductivity of a shock-compressed nonideal nitrogen plasma in the megabar pressure range  

Science Conference Proceedings (OSTI)

Kinematic and thermodynamic parameters of shock-compressed liquid nitrogen are measured behind the front of a plane shock wave using plane wave and hemispherical shock wave generators. In these experiments, high values of compression parameters (shock-compressed hydrogen density {approx} 3.25 g/cm{sup 3} and temperature T{approx} 56000 K at a pressure of P {approx} 265 GPa) are attained. The density, pressure, temperature, and electrical conductivity of the nonideal plasma of shock-compressed liquid nitrogen are measured. A nearly isochoric behavior of the nitrogen shock adiabat is observed in the pressure range P = 100-300 GPa. The thermodynamics of shock-compressed nitrogen is an alyzed using the model of the equation of state in the quasi-chemical representation (SAHA code) as well as the semiempirical wide-range equation of state developed at the Institute of Experimental Physics. Experimental results are interpreted on the basis of calculations as the fixation of the boundary of transition of shock-compressed nitrogen from the polymer phase to the state of a strongly nonideal plasma at P {approx} 100 GPa, {approx} 3.4 g/cm{sup 3}.

Mochalov, M. A.; Zhernokletov, M. V.; Il'kaev, R. I.; Mikhailov, A. L. [Institute of Experimental Physics, Russian Federal Nuclear Center (Russian Federation); Fortov, V. E. [Russian Academy of Sciences (IVTAN), Joint Institute for High Temperatures (Russian Federation); Gryaznov, V. K. [Russian Academy of Sciences, Chernogolovka, Institute of Problems of Chemical Physics (Russian Federation); Iosilevskiy, I. L., E-mail: ilios@orc.r [Russian Academy of Sciences (IVTAN), Joint Institute for High Temperatures (Russian Federation); Mezhevov, A. B.; Kovalev, A. E.; Kirshanov, S. I.; Grigor'eva, Yu. A.; Novikov, M. G.; Shuikin, A. N. [Institute of Experimental Physics, Russian Federal Nuclear Center (Russian Federation)

2010-01-15T23:59:59.000Z

376

Dynamic Tensile Extrusion of High-density Polyethylene  

Science Conference Proceedings (OSTI)

Depending on the extrusion ratios and velocities HDPE damage varies gross ... Characterization of the Dynamic Behavior of Recycled Polypropylene-based Composites ... Shock Compression Behavior of Bi-material Powder Composites with ...

377

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

378

High-pressure coal fuel processor development  

DOE Green Energy (OSTI)

Caterpillar shares DOE/METC interest in demonstrating the technology required to displace petroleum-based engine fuels with various forms of low cost coal. Current DOE/METC programs on mild gasification and coal-water-slurries are addressing two approaches to this end. Engine and fuel processor system concept studies by Caterpillar have identified a third, potentially promising, option. This option includes high-pressure fuel processing of run-of-the-mine coal and direct injection of the resulting low-Btu gas stream into an ignition assisted, high compression ratio diesel engine. The compactness and predicted efficiency of the system make it suitable for application to line-haul railroad locomotives. A successful conclusion of the program will enable further component development work and full-scale system demonstrations of this potentially important technology. This paper covers the work on fuel processor rig testing completed in FY92.

Greenhalgh, M.L.; Wen, C.S.; Smith, L.

1992-12-31T23:59:59.000Z

379

High-pressure coal fuel processor development  

DOE Green Energy (OSTI)

Caterpillar shares DOE/METC interest in demonstrating the technology required to displace petroleum-based engine fuels with various forms of low cost coal. Current DOE/METC programs on mild gasification and coal-water-slurries are addressing two approaches to this end. Engine and fuel processor system concept studies by Caterpillar have identified a third, potentially promising, option. This option includes high-pressure fuel processing of run-of-the-mine coal and direct injection of the resulting low-Btu gas stream into an ignition assisted, high compression ratio diesel engine. The compactness and predicted efficiency of the system make it suitable for application to line-haul railroad locomotives. A successful conclusion of the program will enable further component development work and full-scale system demonstrations of this potentially important technology. This paper covers the work on fuel processor rig testing completed in FY92.

Greenhalgh, M.L.; Wen, C.S.; Smith, L.

1992-01-01T23:59:59.000Z

380

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

Note: This page contains sample records for the topic "high 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

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

382

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

383

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

384

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.

385

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

386

Direct Injection Compressed Ignition Diesel Automotive Technology Education GATE Program  

DOE Green Energy (OSTI)

The underlying goal of this project was to provide multi-disciplinary engineering training for graduate students in the area of internal combustion engines, specifically in direct injection compression ignition engines. The program was designed to educate highly qualified engineers and scientists that will seek to overcome technological barriers preventing the development and production of cost-effective high-efficiency vehicles for the US. market. Further, these highly qualified engineers and scientists will foster an educational process to train a future workforce of automotive engineering professionals who are knowledgeable about and have experience in developing and commercializing critical advanced automotive technologies. Eight objectives were defined to accomplish this goal: (1) Develop an interdisciplinary internal combustion engine curriculum emphasizing direct injected combustion ignited diesel engines. (2) Encourage and promote interdisciplinary interaction of the faculty. (3) Offer a Ph.D. degree in internal combustion engines based upon an interdisciplinary curriculum. (4) Promote strong interaction with industry, develop a sense of responsibility with industry and pursue a self sustaining program. (5) Establish collaborative arrangements and network universities active in internal combustion engine study. (6) Further Enhance a First Class educational facility. (7) Establish ''off-campus'' M.S. and Ph.D. engine programs of study at various industrial sites. (8) Extend and Enhance the Graduate Experience.

Carl L. Anderson

2006-09-25T23:59:59.000Z

387

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

388

high  

Gasoline and Diesel Fuel Update (EIA)

0 0 Summary Our short-term outlook for a wide array of energy prices has been adjusted upward as international and domestic energy supply conditions have tightened. We think that crude oil prices are as likely as not to end the year $2 to $3 per barrel higher than our previous projections. Thus, we think that the probability of West Texas Intermediate costing an average of $30 per barrel or more at midwinter is about 50 percent. On their current track, heating oil prices are likely to be about 30 percent above year-ago levels in the fourth quarter. Prices for Q1 2001 seem more likely now to match or exceed the high level seen in Q1 2000. Tight oil markets this year and an inherent propensity for high gas utilization in incremental power supply have resulted in rising North American natural gas

389

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

390

Medium effects on charged pion ratio in heavy ion collisions  

E-Print Network (OSTI)

We have recently studied in the delta-resonance--nucleon-hole model the dependence of the pion spectral function in hot dense asymmetric nuclear matter on the charge of the pion due to the pion p-wave interaction in nuclear medium. In a thermal model, this isospin-dependent effect enhances the ratio of negatively charged to positively charged pions in neutron-rich nuclear matter, and the effect is comparable to that due to the uncertainties in the theoretically predicted stiffness of nuclear symmetry energy at high densities. This effect is, however, reversed if we also take into account the s-wave interaction of the pion in nuclear medium as given by chiral perturbation theory, resulting instead in a slightly reduced ratio of negatively charged to positively charged pions. Relevance of our results to the determination of the nuclear symmetry energy from the ratio of negatively to positively charged pions produced in heavy ion collisions is discussed.

Che Ming Ko; Yongseok Oh; Jun Xu

2010-02-01T23:59:59.000Z

391

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

392

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

393

Crystal structure of graphite under room-temperature compression and decompression  

Science Conference Proceedings (OSTI)

Recently, sophisticated theoretical computational studies have proposed several new crystal structures of carbon (e.g., bct-C{sub 4}, H-, M-, R-, S-, W-, and Z-carbon). However, until now, there lacked experimental evidence to verify the predicted high-pressure structures for cold-compressed elemental carbon at least up to 50 GPa. Here we present direct experimental evidence that this enigmatic high-pressure structure is currently only consistent with M-carbon, one of the proposed carbon structures. Furthermore, we show that this phase transition is extremely sluggish, which led to the observed broad x-ray diffraction peaks in previous studies and hindered the proper identification of the post-graphite phase in cold-compressed carbon.

Wang, Yuejian; Panzik, Joseph E.; Kiefer, Boris; Lee, Kanani K.M. (Yale); (New Mexico State)

2012-10-23T23:59:59.000Z

394

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

395

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

396

high  

Gasoline and Diesel Fuel Update (EIA)

0 0 Highlights International Oil Markets Prices. We have raised our world oil price projection by about $2 per barrel for this month because of assumed greater compliance by OPEC to targeted cuts, especially for the second quarter of 2000 (Figure 1). The expected decline in world petroleum inventories continues (Figure 2), and, given the generally stiff resolve of OPEC members to maintain production cuts, any sign of a turnaround in stocks may be postponed until later this year than previously assumed (Q3 instead of Q2). Our current estimate for the average import cost this past January is now $25 per barrel, a nearly $15-per-barrel increase from January 1999. Crude oil prices are expected to remain at relatively high levels for the first half of 2000, but

397

Gasoline surrogate modeling of gasoline ignition in a rapid compression machine and comparison to experiments  

DOE Green Energy (OSTI)

The use of gasoline in homogeneous charge compression ignition engines (HCCI) and in duel fuel diesel - gasoline engines, has increased the need to understand its compression ignition processes under engine-like conditions. These processes need to be studied under well-controlled conditions in order to quantify low temperature heat release and to provide fundamental validation data for chemical kinetic models. With this in mind, an experimental campaign has been undertaken in a rapid compression machine (RCM) to measure the ignition of gasoline mixtures over a wide range of compression temperatures and for different compression pressures. By measuring the pressure history during ignition, information on the first stage ignition (when observed) and second stage ignition are captured along with information on the phasing of the heat release. Heat release processes during ignition are important because gasoline is known to exhibit low temperature heat release, intermediate temperature heat release and high temperature heat release. In an HCCI engine, the occurrence of low-temperature and intermediate-temperature heat release can be exploited to obtain higher load operation and has become a topic of much interest for engine researchers. Consequently, it is important to understand these processes under well-controlled conditions. A four-component gasoline surrogate model (including n-heptane, iso-octane, toluene, and 2-pentene) has been developed to simulate real gasolines. An appropriate surrogate mixture of the four components has been developed to simulate the specific gasoline used in the RCM experiments. This chemical kinetic surrogate model was then used to simulate the RCM experimental results for real gasoline. The experimental and modeling results covered ultra-lean to stoichiometric mixtures, compressed temperatures of 640-950 K, and compression pressures of 20 and 40 bar. The agreement between the experiments and model is encouraging in terms of first-stage (when observed) and second-stage ignition delay times and of heat release rate. The experimental and computational results are used to gain insight into low and intermediate temperature processes during gasoline ignition.

Mehl, M; Kukkadapu, G; Kumar, K; Sarathy, S M; Pitz, W J; Sung, S J

2011-09-15T23:59:59.000Z

398

Matched metal die compression molded structural random fiber sheet molding compound flywheel. [Patent application  

DOE Patents (OSTI)

A flywheel is described that is useful for energy storage in a hybrid vehicle automotive power system or in some stationary applications. The flywheel has a body of essentially planar isotropic high strength structural random fiber sheet molding compound (SMC-R). The flywheel may be economically produced by a matched metal die compression molding process. The flywheel makes energy intensive efficient use of a fiber/resin composite while having a shape designed by theory assuming planar isotropy.

Kulkarni, S.V.; Christensen, R.M.; Toland, R.H.

1980-09-24T23:59:59.000Z

399

Matched metal die compression molded structural random fiber sheet molding compound flywheel  

DOE Patents (OSTI)

A flywheel (10) is described that is useful for energy storage in a hybrid vehicle automotive power system or in some stationary applications. The flywheel (10) has a body of essentially planar isotropic high strength structural random fiber sheet molding compound (SMC-R). The flywheel (10) may be economically produced by a matched metal die compression molding process. The flywheel (10) makes energy intensive efficient use of a fiber/resin composite while having a shape designed by theory assuming planar isotropy.

Kulkarni, Satish V. (San Ramon, CA); Christensen, Richard M. (Danville, CA); Toland, Richard H. (West Chester, PA)

1985-01-01T23:59:59.000Z

400

Open-Cycle Vapor Compression Heat Pump System  

E-Print Network (OSTI)

In many industrial processes, large quantities of energy are often wasted in the form of low pressure steam and low-grade heat. Economical recovery of these waste energy sources is often difficult due to such factors as low temperature levels and contamination of the steam. In industrial processes that utilize steam directly or as a mode of energy transport, waste energy can be efficiently recovered and upgraded in the form of high-pressure steam by means of an open-cycle steam heat pump system. Recovery and upgrading of these waste steam or heat sources offer a great potential for energy conservation. Thermo Electron has developed, under sponsorship by the Gas Research Institute, Southern California Gas Company, and the Consolidated Natural Gas Service Company, an open-cycle steam heat pump to recover this waste energy in the form of high-pressure process steam. The system utilizes excess low-pressure steam (or that produced from an excess heat source with a waste heat boiler) and compresses this steam to the desired pressure level for process use. The compressor is driven by a gas turbine or gas engine prime mover. To enhance the system performance, the prime mover exhaust and/or cooling jacket heat is recovered to generate additional process steam or hot water. Utilizing the Thermo Electron system, fuel consumption can be 30 percent lower in comparison to a direct-fired boiler. Simple payback periods of 1 to 3 years are generally found for most applications.

Pasquinelli, D. M.; Becker, F. E.

1983-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high 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

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

402

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

403

Compression testing of a sintered Ti6Al4V powder compact for biomedical applications  

Science Conference Proceedings (OSTI)

In this study, the compression deformation behavior of a Ti6Al4V powder compact, prepared by the sintering of cold compacted atomized spherical particles (100-200 {mu}m) and containing 36-38% porosity, was investigated at quasi-static (1.6x10{sup -3}-1.6x10{sup -1} s{sup -1}) and high strain rates (300 and 900 s{sup -1}) using, respectively, conventional mechanical testing and Split Hopkinson Pressure Bar techniques. Microscopic studies of as-received powder and sintered powder compact showed that sintering at high temperature (1200 deg. C) and subsequent slow rate of cooling in the furnace changed the microstructure of powder from the acicular alpha ({alpha}) to the Widmanstaetten ({alpha}+{beta}) microstructure. In compression testing, at both quasi-static and high strain rates, the compact failed via shear bands formed along the diagonal axis, 45 deg. to the loading direction. Increasing the strain rate was found to increase both the flow stress and compressive strength of the compact but it did not affect the critical strain for shear localization. Microscopic analyses of failed samples and deformed but not failed samples of the compact further showed that fracture occurred in a ductile (dimpled) mode consisting of void initiation and growth in {alpha} phase and/or at the {alpha}/{beta} interface and macrocracking by void coalescence in the interparticle bond region.

Guden, M. [Department of Mechanical Engineering, Izmir Institute of Technology, Gulbahce Koyu, Urla, Izmir (Turkey); Center for Materials Research, Izmir Institute of Technology, Gulbahce Koyu, Urla, Izmir (Turkey); E-mail: mustafaguden@iyte.edu.tr; Celik, E. [Materials Science and Engineering Program, Izmir Institute of Technology, Gulbahce Koyu, Urla, Izmir (Turkey); Akar, E. [Department of Mechanical Engineering, Izmir Institute of Technology, Gulbahce Koyu, Urla, Izmir (Turkey); Cetiner, S. [Hipokrat A.S., 407/6 Sok., No:10, Pinarbasi, Izmir (Turkey)

2005-05-15T23:59:59.000Z

404

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

405

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

406

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

407

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

408

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

409

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

410

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

411

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

412

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

413

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

414

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,

415

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

416

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

417

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

418

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

419

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

420

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.

Note: This page contains sample records for the topic "high 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

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

422

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...

423

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

424

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

425

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

426

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

427

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

428

Melting of Dense Hydrogen during Heavy Ion Beam-Driven Compression  

DOE Green Energy (OSTI)

Until now the thermodynamic and structural properties of hydrogen continue to be understood unsatisfactory. A number of complex high pressure phases at relatively low temperatures has been confirmed [1]. However, conclusive answers on the existence of a plasma phase transition, the dissociation of hydrogen molecules at high densities, the metallization in the solid, and the melting line for pressures above 70GPa are still missing. A particularly interesting behavior has been predicted for the melting line at high pressures where it has a maximum and its slope changes sign [2]. In Ref. [3], we have shown that these states can be created using cylindrical compression driven by heavy ion beams. Employing ab initio simulations [4] and experimental data, a new wide range equation of state for hydrogen was constructed [3]. This new hydrogen EOS combined with hydrodynamic simulations is then used to describe the compression of hydrogen in LAPLAS targets [5] driven by heavy ion beams to be generated at the FAIR. The results shown in Fig. 1 indicate that the melting line up to its maximum as well as the transition from molecular fluids to fully ionized plasmas can be tested. By carefully tuning the number of particles in the beam, the compression can be adjusted to yield states at the solid-liquid phase transition (compare panels (a) and (b) in Fig. 1). This allows one to test the shape of the melting line beyond its maximum. It was demonstrated [3] that x-ray scattering [6] can be used to distinguish between the molecular solid and liquid phases as well as the metallic states. Hydrodynamic simulations have also highlighted the importance of temperature diagnostics, as it is more sensitive to the EOS than the density based diagnostic methods. Different materials have been considered as absorber. Although lead might seem to be the natural choice, the simulations show that aluminium is also a feasible option if slightly less compression is sufficient. Moreover, aluminium offers further options for testing by x-ray scattering and, thus, might be favorable compared to lead drivers. In summary, valuable information on the properties of high-density hydrogen can be obtained by dynamic compression with heavy ion beams. The long standing questions of the plasma phase transition, melting, and metallization can be addressed. The calculated Jupiter isentrope shown in Fig. 1 indicates that such experiments would be also highly beneficial for the giant planet modeling.

Grinenko, A; Gericke, D O; Vorberger, J; Glenzer, S H

2009-03-02T23:59:59.000Z

429

Generalized b-spline subdivision-surface wavelets and lossless compression  

SciTech Connect

We present a new construction of wavelets on arbitrary two-manifold topology for geometry compression. The constructed wavelets generalize symmetric tensor product wavelets with associated B-spline scaling functions to irregular polygonal base mesh domains. The wavelets and scaling functions are tensor products almost everywhere, except in the neighborhoods of some extraordinary points (points of valence unequal four) in the base mesh that defines the topology. The compression of arbitrary polygonal meshes representing isosurfaces of scalar-valued trivariate functions is a primary application. The main contribution of this paper is the generalization of lifted symmetric tensor product B-spline wavelets to two-manifold geometries. Surfaces composed of B-spline patches can easily be converted to this scheme. We present a lossless compression method for geometries with or without associated functions like color, texture, or normals. The new wavelet transform is highly efficient and can represent surfaces at any level of resolution with high degrees of continuity, except at a finite number of extraordinary points in the base mesh. In the neighborhoods of these points detail can be added to the surface to approximate any degree of continuity.

Bertram, M; Duchaineau, M A; Hamann, B; Joy, K I

1999-11-24T23:59:59.000Z

430

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

431

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

432

High-resolution magnetohydrodynamic equilibrium code for unity beta plasmas  

E-Print Network (OSTI)

vertical field limits the plasma beta for non elongatedbeta equilibrium numerical procedure High-? configurations have extreme Shafranov shifts, compressing the flux surfaces on the low field

Gourdain, P A

2006-01-01T23:59:59.000Z

433

Intense synchrotron radiation from a magnetically compressed relativistic electron layer  

SciTech Connect

Using a simple model of a relativistic electron layer rotating in an axial magnetic field, energy gain by an increasing magnetic field and energy loss by synchrotron radiation were considered. For a typical example, initial conditions were approximately 8 MeV electron in approximately 14 kG magnetic field, at a layer radius of approximately 20 mm, and final conditions were approximately 4 MG magnetic field approximately 100 MeV electron layer energy at a layer radius of approximately 1.0 mm. In the final state, the intense 1-10 keV synchrotron radiation imposes an electron energy loss time constant of approximately 100 nanoseconds. In order to achieve these conditions in practice, the magnetic field must be compressed by an imploding conducting liner; preferably two flying rings in order to allow the synchrotron radiation to escape through the midplane. The synchrotron radiation loss rate imposes a lower limit to the liner implosion velocity required to achieve a given final electron energy (approximately 1 cm/$mu$sec in the above example). In addition, if the electron ring can be made sufficiently strong (field reversed), the synchrotron radiation would be a unique source of high intensity soft x-radiation. (auth)

Shearer, J.W.; Nowak, D.A.; Garelis, E.; Condit, W.C.

1975-10-01T23:59:59.000Z

434

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

435

Hall effect in a strong magnetic field: Direct comparisons of compressible magnetohydrodynamics and the reduced Hall magnetohydrodynamic equations  

SciTech Connect

In this work we numerically test a model of Hall magnetohydrodynamics in the presence of a strong mean magnetic field: the reduced Hall magnetohydrodynamic model (RHMHD) derived by [Gomez et al., Phys. Plasmas 15, 102303 (2008)] with the addition of weak compressible effects. The main advantage of this model lies in the reduction of computational cost. Nevertheless, up until now the degree of agreement with the original Hall MHD system and the range of validity in a regime of turbulence were not established. In this work direct numerical simulations of three-dimensional Hall MHD turbulence in the presence of a strong mean magnetic field are compared with simulations of the weak compressible RHMHD model. The results show that the degree of agreement is very high (when the different assumptions of RHMHD, such as spectral anisotropy, are satisfied). Nevertheless, when the initial conditions are isotropic but the mean magnetic field is maintained strong, the results differ at the beginning but asymptotically reach a good agreement at relatively short times. We also found evidence that the compressibility still plays a role in the dynamics of these systems, and the weak compressible RHMHD model is able to capture these effects. In conclusion the weak compressible RHMHD model is a valid approximation of the Hall MHD turbulence in the relevant physical context.

Martin, L. N.; Dmitruk, P. [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (Argentina) and IFIBA, CONICET, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Gomez, D. O. [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (Argentina) and IFIBA, CONICET, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Instituto de Astronomia y Fisica del Espacio, Ciudad Universitaria, 1428 Buenos Aires (Argentina)

2010-11-15T23:59:59.000Z

436

Low-pressure-ratio regenerative exhaust-heated gas turbine. Final report  

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

437

Dimension-Independent Positive-Partial-Transpose Probability Ratios  

E-Print Network (OSTI)

We conduct quasi-Monte Carlo numerical integrations in two very high (80 and 79)-dimensional domains -- the parameter spaces of rank-9 and rank-8 qutrit-qutrit (9 x 9) density matrices. We, then, estimate the ratio of the probability -- in terms of the Hilbert-Schmidt metric -- that a generic rank-9 density matrix has a positive partial transpose (PPT) to the probability that a generic rank-8 density matrix has a PPT (a precondition to separability/nonentanglement). Close examination of the numerical results generated -- despite certain large fluctuations -- indicates that the true ratio may, in fact, be 2. Our earlier investigation (eprint quant-ph/0410238) also yielded estimates close to 2 of the comparable ratios for qubit-qubit and qubit-qutrit pairs (the only two cases where the PPT condition fully implies separability). Therefore, it merits conjecturing (as Zyczkowski was the first to do) that such Hilbert-Schmidt (rank-NM/rank-(NM-1)) PPT probability ratios are 2 for all NM-dimensional quantum systems.

Paul B. Slater

2005-05-13T23:59:59.000Z

438

The proton form factor ratio results from Jefferson Lab  

Science Conference Proceedings (OSTI)

The ratio of the proton form factors, GE p/GMp, has been measured extensively, from Q2 of 0.5 GeV2 to 8.5 GeV2, at the Jefferson Laboratory, using the polarization transfer method. This ratio is extracted directly from the measured ratio of the transverse and longitudinal polarization components of the recoiling proton in elastic electron-proton scattering. The polarization transfer results are of unprecedented high precision and accuracy, due in large part to the small systematic uncertainties associated with the experimental technique. There is an approved experiment at JLab, GEP(5), to continue the ratio measurements to 12 GeV2. A dedicated experimental setup, the Super Bigbite Spectrometer (SBS), will be built for this purpose. It will be equipped with a focal plane polarimeter to measure the polarization of the recoil protons. The scattered electrons will be detected in an electromagnetic calorimeter. In this presentation, I will review the status of the proton elastic electromagnetic form factors and discuss a number of theoretical approaches to describe nucleon form factors.

Vina Punjabi

2012-09-01T23:59:59.000Z

439

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

440

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

Note: This page contains sample records for the topic "high 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

Performance of Compression Fittings at Elevated Temperatures  

Science Conference Proceedings (OSTI)

One of the alternatives for increasing power flow on an existing transmission line is to raise the operating temperature of its conductor. The effects of high operating temperature on the conductor, however, include loss of conductor strength and reduction in conductor clearance to ground. The high temperature also affects the short- and long-term performance of the conductor connections and conductor accessories. EPRI’s base-funded project “Effect of High-Temperature Cycling on Conductor Systems” provid...

2009-08-05T23:59:59.000Z

442

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.

443

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

444