National Library of Energy BETA

Sample records for variable compression ratio

  1. Eccentric crank variable compression ratio mechanism

    DOE Patents [OSTI]

    Lawrence, Keith Edward; Moser, William Elliott; Roozenboom, Stephan Donald; Knox, Kevin Jay

    2008-05-13

    A variable compression ratio mechanism for an internal combustion engine that has an engine block and a crankshaft is disclosed. The variable compression ratio mechanism has a plurality of eccentric disks configured to support the crankshaft. Each of the plurality of eccentric disks has at least one cylindrical portion annularly surrounded by the engine block. The variable compression ratio mechanism also has at least one actuator configured to rotate the plurality of eccentric disks.

  2. HCCI in a Variable Compression Ratio Engine: Effects of Engine...

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

    in a Variable Compression Ratio Engine: Effects of Engine Variables HCCI in a Variable Compression Ratio Engine: Effects of Engine Variables 2004 Diesel Engine Emissions Reduction ...

  3. HCCI in a Variable Compression Ratio Engine: Effects of Engine Variables |

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

    Department of Energy in a Variable Compression Ratio Engine: Effects of Engine Variables HCCI in a Variable Compression Ratio Engine: Effects of Engine Variables 2004 Diesel Engine Emissions Reduction (DEER) Conference Presentation: Southwest Research Institute 2004_deer_ryan.pdf (410.71 KB) More Documents & Publications HCCI - A Technical Review and Progress Report 2006 HCCI - Update of Progress 2005 Fuel Requirements for HCCI Engine Operation

  4. Combustion engine variable compression ratio apparatus and method

    DOE Patents [OSTI]

    Lawrence; Keith E.; Strawbridge, Bryan E.; Dutart, Charles H.

    2006-06-06

    An apparatus and method for varying a compression ratio of an engine having a block and a head mounted thereto. The apparatus and method includes a cylinder having a block portion and a head portion, a piston linearly movable in the block portion of the cylinder, a cylinder plug linearly movable in the head portion of the cylinder, and a valve located in the cylinder plug and operable to provide controlled fluid communication with the block portion of the cylinder.

  5. Two-Stage Variable Compression Ratio (VCR) System to Increase Efficiency in Gasoline Powertrains

    Broader source: Energy.gov [DOE]

    Presents two-stage variable compression ratio mechanism realized by varying the connecting rod length, description of the system layout, working principle and expected fuel savings benefits when used in current and future gasoline engine concepts

  6. Effect of Compression Ratio and Piston Geometry on RCCI load...

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

    Compression Ratio and Piston Geometry on RCCI load limit Effect of Compression Ratio and Piston Geometry on RCCI load limit Explores the effect of compression ratio and piston ...

  7. Starting low compression ratio rotary Wankel diesel engine

    SciTech Connect (OSTI)

    Kamo, R.; Yamada, T.Y.; Hamada, Y.

    1987-01-01

    The single stage rotary Wankel engine is difficult to convert into a diesel version having an adequate compression ratio and a compatible combustion chamber configuration. Past efforts in designing a rotary-type Wankel diesel engine resorted to a two-stage design. Complexity, size, weight, cost and performance penalties were some of the drawbacks of the two-stage Wankel-type diesel designs. This paper presents an approach to a single stage low compression ratio Wankel-type rotary engine. Cold starting of a low compression ratio single stage diesel Wankel becomes the key problem. It was demonstrated that the low compression single stage diesel Wankel type rotary engine can satisfactorily be cold started with a properly designed combustion chamber in the rotor and a variable heat input combustion aid.

  8. Alvar variable compression engine development. Final report

    SciTech Connect (OSTI)

    1998-03-30

    The Alvar engine is an invention by Mr. Alvar Gustafsson of Skarblacka, Sweden. It is a four stroke spark ignition internal combustion engine, having variable compression ratio and variable displacements. The compression ratio can be varied by means of small secondary cylinders and pistons which are communicating with the main combustion chambers. The secondary pistons can be phase shifted with respect to the main pistons. The engine is suitable for multi-fuel operation. Invention rights are held by Alvar Engine AB of Sweden, a company created to handle the development of the Alvar Engine. A project was conceived wherein an optimised experimental engine would be built and tested to verify the advantages claimed for the Alvar engine and also to reveal possible drawbacks, if any. Alvar Engine AB appointed Gunnar Lundholm, professor of Combustion Engines at Lund University, Lund, Sweden as principal investigator. The project could be seen as having three parts: (1) Optimisation of the engine combustion chamber geometry; (2) Design and manufacturing of the necessary engine parts; and (3) Testing of the engine in an engine laboratory NUTEK, The Swedish Board for Industrial and Technical Development granted Gunnar Lundholm, SEK 50000 (about $6700) to travel to the US to evaluate potential research and development facilities which seemed able to perform the different project tasks.

  9. Variable ratio regenerative braking device

    DOE Patents [OSTI]

    Hoppie, Lyle O.

    1981-12-15

    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.

  10. The Effects of Fuel Composition and Compression Ratio on Thermal...

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

    The Effects of Fuel Composition and Compression Ratio on Thermal Efficiency in an HCCI Engine Poster presentation at the 2007 Diesel Engine-Efficiency & Emissions Research ...

  11. Investigation of Knock limited Compression Ratio of Ethanol Gasoline Blends

    SciTech Connect (OSTI)

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

    2010-01-01

    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

  12. Variable Compression Ratio Engine | Department of Energy

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

    Initial Agency Decision concerns a whistleblower complaint filed by Luis P. Silva, a former employee of the Scientific Ecology Group (SEG) and its successor firm, GTS Duratek (GTS).(1) SEG, and then GTS, were subcontractors to Sandia Corporation at the Radioactive and Mixed Waste Management Facility (RMWMF) where Silva worked before he was laid off by GTS in August 1997. Sandia is a subsidiary of Lockheed Martin Company, the management and operating contractor at DOE's Sandia National

  13. Hige Compression Ratio Turbo Gasoline Engine Operation Using Alcohol Enhancement

    SciTech Connect (OSTI)

    Heywood, John; Jo, Young Suk; Lewis, Raymond; Bromberg, Leslie; Heywood, John

    2015-10-31

    The overall objective of this project was to quantify the potential for improving the performance and efficiency of gasoline engine technology by use of alcohols to suppress knock. Knock-free operation is obtained by direct injection of a second “anti-knock” fuel such as ethanol, which suppresses knock when, with gasoline fuel, knock would occur. Suppressing knock enables increased turbocharging, engine downsizing, and use of higher compression ratios throughout the engine’s operating map. This project combined engine testing and simulation to define knock onset conditions, with different mixtures of gasoline and alcohol, and with this information quantify the potential for improving the efficiency of turbocharged gasoline spark-ignition engines, and the on-vehicle fuel consumption reductions that could then be realized. The more focused objectives of this project were therefore to: Determine engine efficiency with aggressive turbocharging and downsizing and high compression ratio (up to a compression ratio of 13.5:1) over the engine’s operating range; Determine the knock limits of a turbocharged and downsized engine as a function of engine speed and load; Determine the amount of the knock-suppressing alcohol fuel consumed, through the use of various alcohol-gasoline and alcohol-water gasoline blends, for different driving cycles, relative to the gasoline consumed; Determine implications of using alcohol-boosted engines, with their higher efficiency operation, in both light-duty and medium-duty vehicle sectors.

  14. Effect of Compression Ratio and Piston Geometry on RCCI load limit

    Broader source: Energy.gov [DOE]

    Explores the effect of compression ratio and piston design on the practical load range of bio-fueled Reactivity Controlled Compression Ignition (RCCI) combustion.

  15. Variable valve timing in a homogenous charge compression ignition engine

    DOE Patents [OSTI]

    Lawrence, Keith E.; Faletti, James J.; Funke, Steven J.; Maloney, Ronald P.

    2004-08-03

    The present invention relates generally to the field of homogenous charge compression ignition engines, in which fuel is injected when the cylinder piston is relatively close to the bottom dead center position for its compression stroke. The fuel mixes with air in the cylinder during the compression stroke to create a relatively lean homogeneous mixture that preferably ignites when the piston is relatively close to the top dead center position. However, if the ignition event occurs either earlier or later than desired, lowered performance, engine misfire, or even engine damage, can result. The present invention utilizes internal exhaust gas recirculation and/or compression ratio control to control the timing of ignition events and combustion duration in homogeneous charge compression ignition engines. Thus, at least one electro-hydraulic assist actuator is provided that is capable of mechanically engaging at least one cam actuated intake and/or exhaust valve.

  16. Two-Stage Variable Compression Ratio (VCR) System to Increase...

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

    working principle and expected fuel savings benefits when used in current and future gasoline engine concepts deer12tomazic.pdf (1.48 MB) More Documents & Publications ...

  17. Variable compression ratio device for internal combustion engine

    DOE Patents [OSTI]

    Maloney, Ronald P.; Faletti, James J.

    2004-03-23

    An internal combustion engine, particularly suitable for use in a work machine, is provided with a combustion cylinder, a cylinder head at an end of the combustion cylinder and a primary piston reciprocally disposed within the combustion cylinder. The cylinder head includes a secondary cylinder and a secondary piston reciprocally disposed within the secondary cylinder. An actuator is coupled with the secondary piston for controlling the position of the secondary piston dependent upon the position of the primary piston. A communication port establishes fluid flow communication between the combustion cylinder and the secondary cylinder.

  18. Evaluation of Variable Compression Ratio on Energy Efficiency

    Broader source: Energy.gov [DOE]

    Poster presented at the 16th Directions in Engine-Efficiency and Emissions Research (DEER) Conference in Detroit, MI, September 27-30, 2010.

  19. Benefits and Drawbacks of Compression Ratio Reduction in PCCI Combustion Application in an Advanced LD Diesel Engine

    Broader source: Energy.gov [DOE]

    Study of the effect of compression ratio on performance of light duty diesel operating with PCCI calibration, near EURO6/Tier 2 Bin 5 NOx limits.

  20. Fact #940: August 29, 2016 Diverging Trends of Engine Compression Ratio and

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

    Gasoline Octane Rating | Department of Energy From the 1920s to the 1970s, the evolution of engines (measured by compression ratio) and the evolution of fuels (measured by octane rating) occurred in tandem. Gasoline octane improvement during that period (red markers in the graph below) was likely due to refinery technology improvement and the addition of lead, which guards against engine knocking. In 1973, the Environmental Protection Agency (EPA) mandated a reduction in the lead content of

  1. Formation of compressed flat electron beams with high transverse-emittance ratios

    SciTech Connect (OSTI)

    Zhu, J.; Piot, P.; Mihalcea, D.; Prokop, C. R.

    2014-08-01

    Flat beamsbeams with asymmetric transverse emittanceshave important applications in novel light-source concepts and advanced-acceleration schemes and could possibly alleviate the need for damping rings in lepton colliders. Over the last decade, a flat beam generation technique based on the conversion of an angular-momentum-dominated beam was proposed and experimentally tested. In this paper we explore the production of compressed flat beams. We especially investigate and optimize the flat beam transformation for beams with substantial fractional energy spread. We use as a simulation example the photoinjector of Fermilabs Advanced Superconducting Test Accelerator. The optimizations of the flat beam generation and compression at Advanced Superconducting Test Accelerator were done via start-to-end numerical simulations for bunch charges of 3.2 nC, 1.0 nC, and 20 pC at ?37??MeV. The optimized emittances of flat beams with different bunch charges were found to be 0.25???m (emittance ratio is ?400), 0.13????m, 15 nm before compression, and 0.41???m, 0.20???m, 16 nm after full compression, respectively, with peak currents as high as 5.5 kA for a 3.2?nC flat beam. These parameters are consistent with requirements needed to excite wakefields in asymmetric dielectric-lined waveguides or produce significant photon flux using small-gap micro-undulators.

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

    SciTech Connect (OSTI)

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

    1987-01-01

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

  3. True uniaxial compressive strengths of rock or coal specimens are independent of diameter-to-length ratios

    SciTech Connect (OSTI)

    Babcock, C.O.

    1991-01-01

    This paper reports that part of the compressive strength of a test specimen of rock or coal in the laboratory or a pillar in a mine comes from physical property strength and, in part, from the constraint provided by the loading stresses. Much confusion in pillar design comes from assigning the total strength change to geometry, as evidenced by the many pillar design equations with width to height as the primary variable. In tests by the U.S. Bureau of Mines, compressive strengths for cylindrical specimens of limestone, marble, sandstone, and coal were independent of the specimen test geometry when the end friction was removed. A conventional uniaxial compressive strength test between two steel platens is actually a uniaxial force and not a uniaxial stress test. The biaxial or triaxial state of stress for much of the test volume changes with the geometry of the test specimen. By removing the end friction supplied by the steel platens to the specimen, a more nearly uniaxial stress state independent of the specimen geometry is produced in the specimen. Pillar design is a constraint and physical property problem rather than a geometry problem. Roof and floor constraint are major factors in pillar design and strength.

  4. Validation of a blowby model using experimental results in motoring condition with the change of compression ratio and engine speed

    SciTech Connect (OSTI)

    Aghdam, E. Abdi; Kabir, M.M.

    2010-02-15

    Blowby and gas flow through the cylinder-piston-ring crevices are phenomena that affect the engine performance and exhaust emissions. Also these phenomena influence the cylinder pressure and temperature and the charge amount during a cycle. The study and validation of a sub-model for these phenomena in the absence of engine combustion deducts all effects arisen from the combustion event. During the current study, blowby sub-model and gas flow through crevices under motoring conditions has been noticed using a volume-orifice theory and the experimental results measured from a research engine. Blowby geometric parameters, consisting of a few critical cross-section areas (orifice areas) and volumes (top land and inter-ring crevice volumes), were measured in ambient temperature and corrected for hot running conditions. The cylinder pressure during cycle was measured by a piezoelectric pressure transducer and the low pressure parts of the cycle were measured using a piezoresistive pressure transducer for referencing purposes. The obtained results show a very good agreement between experimentally measured pressure data and model output for three compression ratios of 7.6, 10.2, 12.4 and three engine speeds of 750, 1500 and 2000 rpm, so that the maximum deviation was almost 5%. The model predicted that the maximum mass loss increased with increase of compression ratio and decreased with increase of engine speed. Also the peak mass loss position happened within the range of 3-9 CA after top dead center. After occurrence of the maximum loss, a reverse flow from the top land crevice into the cylinder was predicted in the model. (author)

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

    DOE Patents [OSTI]

    Frank, A.A.

    1984-07-10

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

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

    DOE Patents [OSTI]

    Frank, Andrew A.

    1984-01-01

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

  7. True uniaxial compressive strengths of rock or coal specimens are independent of diameter-to-length ratios. Report of Investigations/1990

    SciTech Connect (OSTI)

    Babcock, C.O.

    1990-01-01

    Part of the compressive strength of a test specimen of rock or coal in the laboratory or a pillar in a mine comes from physical property strength and, in part, from the constraint provided by the loading stresses. Much confusion in pillar design comes from assigning the total strength change to geometry, as evidenced by the many pillar design equations with width to height as the primary variable. In tests by the U.S. Bureau of Mines, compressive strengths for cylindrical specimens of limestone, marble, sandstone, and coal were independent of the specimen test geometry when the end friction was removed. A conventional uniaxial compressive strength test between two steel platens is actually a uniaxial force and not a uniaxial stress test. The biaxial or triaxial state of stress for much of the test volume changes with the geometry of the test specimen. By removing the end friction supplied by the steel platens to the specimen, a more nearly uniaxial stress state independent of the specimen geometry is produced in the specimen. Pillar design is a constraint and physical property problem rather than a geometry problem. Roof and floor constraint are major factors in pillar design and strength.

  8. DEEP, LOW MASS RATIO OVERCONTACT BINARY SYSTEMS. XIII. DZ PISCIUM WITH INTRINSIC LIGHT VARIABILITY

    SciTech Connect (OSTI)

    Yang, Y.-G.; Dai, H.-F.; Qian, S.-B.; Soonthornthum, B. E-mail: qsb@ynao.ac.cn

    2013-08-01

    New multi-color photometry for the eclipsing binary DZ Psc was performed in 2011 and 2012 using the 85 cm telescope at the Xinglong Station of the National Astronomical Observatories of China. Using the updated Wilson-Devinney (W-D) code, we deduced two sets of photometric solutions. The overcontact degree is f = 89.7({+-} 1.0)%, identifying DZ Psc as a deep, low mass ratio overcontact binary. The asymmetric light curves (i.e., LC{sub 2} in 2012) were modeled by a hot spot on the primary star. Based on all of the available light minimum times, we discovered that the orbital period of DZ Psc may be undergoing a secular period increase with a cyclic variation. The modulated period and semi-amplitude of this oscillation are P{sub mod} = 11.89({+-} 0.19) yr and A = 0.0064({+-} 0.0006) days, which may be possibly attributed to either cyclic magnetic activity or light-time effect due to the third body. The long-term period increases at a rate of dP/dt=+7.43({+-}0.17) Multiplication-Sign 10{sup -7} days yr{sup -1}, which may be interpreted as conserved mass transfer from the less massive component to the more massive one. With mass transferring, DZ Psc will finally merge into a rapid-rotation single star when J{sub spin}/J{sub orb} > 1/3.

  9. Compressed Air

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

    Lighting Compressed Air ESUE Motors Federal Agriculture Compressed Air Compressed Air Roadmap The Bonneville Power Administration created the roadmap to help utilities find energy...

  10. 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

    SciTech Connect (OSTI)

    Winoto, Winoto; Tan, Sugata; Shen, Youqin; Radosz, Maciej; Hong, Kunlun; Mays, Jimmy

    2009-01-01

    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.

  11. Dynamic control of a homogeneous charge compression ignition engine

    DOE Patents [OSTI]

    Duffy, Kevin P.; Mehresh, Parag; Schuh, David; Kieser, Andrew J.; Hergart, Carl-Anders; Hardy, William L.; Rodman, Anthony; Liechty, Michael P.

    2008-06-03

    A homogenous charge compression ignition engine is operated by compressing a charge mixture of air, exhaust and fuel in a combustion chamber to an autoignition condition of the fuel. The engine may facilitate a transition from a first combination of speed and load to a second combination of speed and load by changing the charge mixture and compression ratio. This may be accomplished in a consecutive engine cycle by adjusting both a fuel injector control signal and a variable valve control signal away from a nominal variable valve control signal. Thereafter in one or more subsequent engine cycles, more sluggish adjustments are made to at least one of a geometric compression ratio control signal and an exhaust gas recirculation control signal to allow the variable valve control signal to be readjusted back toward its nominal variable valve control signal setting. By readjusting the variable valve control signal back toward its nominal setting, the engine will be ready for another transition to a new combination of engine speed and load.

  12. Compression embedding

    DOE Patents [OSTI]

    Sandford, M.T. II; Handel, T.G.; Bradley, J.N.

    1998-07-07

    A method and apparatus for embedding auxiliary information into the digital representation of host data created by a lossy compression technique and a method and apparatus for constructing auxiliary data from the correspondence between values in a digital key-pair table with integer index values existing in a representation of host data created by a lossy compression technique are disclosed. The methods apply to data compressed with algorithms based on series expansion, quantization to a finite number of symbols, and entropy coding. Lossy compression methods represent the original data as ordered sequences of blocks containing integer indices having redundancy and uncertainty of value by one unit, allowing indices which are adjacent in value to be manipulated to encode auxiliary data. Also included is a method to improve the efficiency of lossy compression algorithms by embedding white noise into the integer indices. Lossy compression methods use loss-less compression to reduce to the final size the intermediate representation as indices. The efficiency of the loss-less compression, known also as entropy coding compression, is increased by manipulating the indices at the intermediate stage. Manipulation of the intermediate representation improves lossy compression performance by 1 to 10%. 21 figs.

  13. Compression embedding

    DOE Patents [OSTI]

    Sandford, II, Maxwell T.; Handel, Theodore G.; Bradley, Jonathan N.

    1998-01-01

    A method and apparatus for embedding auxiliary information into the digital representation of host data created by a lossy compression technique and a method and apparatus for constructing auxiliary data from the correspondence between values in a digital key-pair table with integer index values existing in a representation of host data created by a lossy compression technique. The methods apply to data compressed with algorithms based on series expansion, quantization to a finite number of symbols, and entropy coding. Lossy compression methods represent the original data as ordered sequences of blocks containing integer indices having redundancy and uncertainty of value by one unit, allowing indices which are adjacent in value to be manipulated to encode auxiliary data. Also included is a method to improve the efficiency of lossy compression algorithms by embedding white noise into the integer indices. Lossy compression methods use loss-less compression to reduce to the final size the intermediate representation as indices. The efficiency of the loss-less compression, known also as entropy coding compression, is increased by manipulating the indices at the intermediate stage. Manipulation of the intermediate representation improves lossy compression performance by 1 to 10%.

  14. Compression embedding

    DOE Patents [OSTI]

    Sandford, M.T. II; Handel, T.G.; Bradley, J.N.

    1998-03-10

    A method of embedding auxiliary information into the digital representation of host data created by a lossy compression technique is disclosed. The method applies to data compressed with lossy algorithms based on series expansion, quantization to a finite number of symbols, and entropy coding. Lossy compression methods represent the original data as integer indices having redundancy and uncertainty in value by one unit. Indices which are adjacent in value are manipulated to encode auxiliary data. By a substantially reverse process, the embedded auxiliary data can be retrieved easily by an authorized user. Lossy compression methods use loss-less compressions known also as entropy coding, to reduce to the final size the intermediate representation as indices. The efficiency of the compression entropy coding, known also as entropy coding is increased by manipulating the indices at the intermediate stage in the manner taught by the method. 11 figs.

  15. Compression embedding

    DOE Patents [OSTI]

    Sandford, II, Maxwell T.; Handel, Theodore G.; Bradley, Jonathan N.

    1998-01-01

    A method of embedding auxiliary information into the digital representation of host data created by a lossy compression technique. The method applies to data compressed with lossy algorithms based on series expansion, quantization to a finite number of symbols, and entropy coding. Lossy compression methods represent the original data as integer indices having redundancy and uncertainty in value by one unit. Indices which are adjacent in value are manipulated to encode auxiliary data. By a substantially reverse process, the embedded auxiliary data can be retrieved easily by an authorized user. Lossy compression methods use loss-less compressions known also as entropy coding, to reduce to the final size the intermediate representation as indices. The efficiency of the compression entropy coding, known also as entropy coding is increased by manipulating the indices at the intermediate stage in the manner taught by the method.

  16. Chapter 22: Compressed Air Evaluation Protocol

    SciTech Connect (OSTI)

    Benton, N.

    2014-11-01

    Compressed-air systems are used widely throughout industry for many operations, including pneumatic tools, packaging and automation equipment, conveyors, and other industrial process operations. Compressed-air systems are defined as a group of subsystems composed of air compressors, air treatment equipment, controls, piping, pneumatic tools, pneumatically powered machinery, and process applications using compressed air. A compressed-air system has three primary functional subsystems: supply, distribution, and demand. Air compressors are the primary energy consumers in a compressed-air system and are the primary focus of this protocol. The two compressed-air energy efficiency measures specifically addressed in this protocol are: high-efficiency/variable speed drive (VSD) compressor replacing modulating compressor; compressed-air leak survey and repairs. This protocol provides direction on how to reliably verify savings from these two measures using a consistent approach for each.

  17. X-ray emission line spectroscopy of cataclysmic variables. II. Temperatures and densities from line ratios in the Chandra HETG band

    SciTech Connect (OSTI)

    Schlegel, E. M.; Shipley, H. V.; Rana, V. R.; Barrett, P. E.; Singh, K. P. E-mail: vrana@srl.caltech.edu E-mail: singh@tifr.res.in

    2014-12-10

    We summarize the results of a line-by-line fitting analysis of the available spectra obtained using the Chandra High-Energy Transmission Grating. We confirm the existence of broad ionization and electron temperature ranges and high number densities in cataclysmic variables (CVs) of all subtypes. Temperatures range from ∼0.4 keV to ∼5-10 keV or more with a broad range detected in any given CV. In other words, single-temperature models do not describe the line emission. Number densities also cover a broad range, from 10{sup 12} to >10{sup 16} cm{sup –3}. We demonstrate that much of the plasma is in a nonequilibrium state; the Fe emission, however, may arise from plasma in the ionization equilibrium.

  18. High Efficiency Fuel Reactivity Controlled Compression Ignition...

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

    An optimized dual-fuel PCCI concept, RCCI, is proposed. deer10reitz.pdf (960.46 KB) More Documents & Publications Effect of Compression Ratio and Piston Geometry on RCCI load ...

  19. High load operation in a homogeneous charge compression ignition engine

    SciTech Connect (OSTI)

    Duffy, Kevin P.; Kieser, Andrew J.; Liechty, Michael P.; Hardy, William L.; Rodman, Anthony; Hergart, Carl-Anders

    2008-12-23

    A homogeneous charge compression ignition engine is set up by first identifying combinations of compression ratio and exhaust gas percentages for each speed and load across the engines operating range. These identified ratios and exhaust gas percentages can then be converted into geometric compression ratio controller settings and exhaust gas recirculation rate controller settings that are mapped against speed and load, and made available to the electronic

  20. High Efficiency Fuel Reactivity Controlled Compression Ignition Combustion

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

    | Department of Energy Fuel Reactivity Controlled Compression Ignition Combustion High Efficiency Fuel Reactivity Controlled Compression Ignition Combustion An optimized dual-fuel PCCI concept, RCCI, is proposed. deer10_reitz.pdf (960.46 KB) More Documents & Publications Effect of Compression Ratio and Piston Geometry on RCCI load limit Optimization of Advanced Diesel Engine Combustion Strategies Comparison of Conventional Diesel and Reactivity Controlled Compression Ignition (RCCI)

  1. A New Approach for Fingerprint Image Compression

    SciTech Connect (OSTI)

    Mazieres, Bertrand

    1997-12-01

    The FBI has been collecting fingerprint cards since 1924 and now has over 200 million of them. Digitized with 8 bits of grayscale resolution at 500 dots per inch, it means 2000 terabytes of information. Also, without any compression, transmitting a 10 Mb card over a 9600 baud connection will need 3 hours. Hence we need a compression and a compression as close to lossless as possible: all fingerprint details must be kept. A lossless compression usually do not give a better compression ratio than 2:1, which is not sufficient. Compressing these images with the JPEG standard leads to artefacts which appear even at low compression rates. Therefore the FBI has chosen in 1993 a scheme of compression based on a wavelet transform, followed by a scalar quantization and an entropy coding : the so-called WSQ. This scheme allows to achieve compression ratios of 20:1 without any perceptible loss of quality. The publication of the FBI specifies a decoder, which means that many parameters can be changed in the encoding process: the type of analysis/reconstruction filters, the way the bit allocation is made, the number of Huffman tables used for the entropy coding. The first encoder used 9/7 filters for the wavelet transform and did the bit allocation using a high-rate bit assumption. Since the transform is made into 64 subbands, quite a lot of bands receive only a few bits even at an archival quality compression rate of 0.75 bit/pixel. Thus, after a brief overview of the standard, we will discuss a new approach for the bit-allocation that seems to make more sense where theory is concerned. Then we will talk about some implementation aspects, particularly for the new entropy coder and the features that allow other applications than fingerprint image compression. Finally, we will compare the performances of the new encoder to those of the first encoder.

  2. 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

    SciTech Connect (OSTI)

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

    2007-12-31

    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

  3. Conducting fiber compression tester

    DOE Patents [OSTI]

    DeTeresa, Steven J.

    1990-01-01

    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.

  4. Minimize Compressed Air Leaks

    Office of Energy Efficiency and Renewable Energy (EERE)

    This tip sheet outlines a strategy for compressed air leak detection and provides a formula for cost savings calculations.

  5. Microbunching and RF Compression

    SciTech Connect (OSTI)

    Venturini, M.; Migliorati, M.; Ronsivalle, C.; Ferrario, M.; Vaccarezza, C.

    2010-05-23

    Velocity bunching (or RF compression) represents a promising technique complementary to magnetic compression to achieve the high peak current required in the linac drivers for FELs. Here we report on recent progress aimed at characterizing the RF compression from the point of view of the microbunching instability. We emphasize the development of a linear theory for the gain function of the instability and its validation against macroparticle simulations that represents a useful tool in the evaluation of the compression schemes for FEL sources.

  6. RATIO COMPUTER

    DOE Patents [OSTI]

    Post, R.F.

    1958-11-11

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

  7. Compressed gas manifold

    DOE Patents [OSTI]

    Hildebrand, Richard J.; Wozniak, John J.

    2001-01-01

    A compressed gas storage cell interconnecting manifold including a thermally activated pressure relief device, a manual safety shut-off valve, and a port for connecting the compressed gas storage cells to a motor vehicle power source and to a refueling adapter. The manifold is mechanically and pneumatically connected to a compressed gas storage cell by a bolt including a gas passage therein.

  8. A Natural Gas, High Compression Ratio, High Efficiency ICRE

    Broader source: Energy.gov [DOE]

    Using natural gas and gasoline modeling, indications are that a free piston-floating stroke engine configuration can realize engine efficiency greater than 60 percent.

  9. Benefits and Drawbacks of Compression Ratio Reduction in PCCI...

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

    PDF icon deer08beatrice.pdf More Documents & Publications Slide Title Bringing the Low NOx Diesel Under Control Multicylinder Diesel Engine for Low Temperature Combustion ...

  10. Modeling and Analysis of Natural Gas and Gasoline In A High Compression

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

    Ratio High Efficiency ICRE | Department of Energy and Analysis of Natural Gas and Gasoline In A High Compression Ratio High Efficiency ICRE Modeling and Analysis of Natural Gas and Gasoline In A High Compression Ratio High Efficiency ICRE performance of a high compression ratio (32:1 to 74:1) high efficiency (50 to 60% BTE) ICRE operating on natural gas and gasoline p-02_fitzgerald.pdf (283.34 KB) More Documents & Publications A Natural Gas, High Compression Ratio, High Efficiency ICRE

  11. Compression Technology and Needs

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

    M ohawk Innovative Technology, Inc. HYDROGEN TRANSMISSION AND DISTRIBUTION WORKSHOP NATIONAL RENEWABLE ENERGY LABORATORY GOLDEN, COLORADO COMPRESSION TECHNOLOGY AND NEEDS Hooshang Heshmat, PH.D. February 25 TH , 2014 ® M ohawk Innovative Technology, Inc. * Overall pipeline delivery steps, production to file up * Different types of compressors * Pipeline compressor development steps and accomplishments * Need for Forecourt Compression system * Other major components: drive, sealing, pipeline,

  12. Fundamentals of Compressed Air Systems

    Broader source: Energy.gov [DOE]

    Find out how a compressed air system works and the benefits of optimal compressed air system performance. This initial class demonstrates how to compute the current cost of your plant's compressed...

  13. Parallel Tensor Compression for Large-Scale Scientific Data.

    SciTech Connect (OSTI)

    Kolda, Tamara G.; Ballard, Grey; Austin, Woody Nathan

    2015-10-01

    As parallel computing trends towards the exascale, scientific data produced by high-fidelity simulations are growing increasingly massive. For instance, a simulation on a three-dimensional spatial grid with 512 points per dimension that tracks 64 variables per grid point for 128 time steps yields 8 TB of data. By viewing the data as a dense five way tensor, we can compute a Tucker decomposition to find inherent low-dimensional multilinear structure, achieving compression ratios of up to 10000 on real-world data sets with negligible loss in accuracy. So that we can operate on such massive data, we present the first-ever distributed memory parallel implementation for the Tucker decomposition, whose key computations correspond to parallel linear algebra operations, albeit with nonstandard data layouts. Our approach specifies a data distribution for tensors that avoids any tensor data redistribution, either locally or in parallel. We provide accompanying analysis of the computation and communication costs of the algorithms. To demonstrate the compression and accuracy of the method, we apply our approach to real-world data sets from combustion science simulations. We also provide detailed performance results, including parallel performance in both weak and strong scaling experiments.

  14. Compressible Astrophysics Simulation Code

    Energy Science and Technology Software Center (OSTI)

    2007-07-18

    This is an astrophysics simulation code involving a radiation diffusion module developed at LLNL coupled to compressible hydrodynamics and adaptive mesh infrastructure developed at LBNL. One intended application is to neutrino diffusion in core collapse supernovae.

  15. Image compression technique

    DOE Patents [OSTI]

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

    1997-03-25

    An image is compressed by identifying edge pixels of the image; creating a filled edge array of pixels each of the pixels in the filled edge array which corresponds to an edge pixel having a value equal to the value of a pixel of the image array selected in response to the edge pixel, and each of the pixels in the filled edge array which does not correspond to an edge pixel having a value which is a weighted average of the values of surrounding pixels in the filled edge array which do correspond to edge pixels; and subtracting the filled edge array from the image array to create a difference array. The edge file and the difference array are then separately compressed and transmitted or stored. The original image is later reconstructed by creating a preliminary array in response to the received edge file, and adding the preliminary array to the received difference array. Filling is accomplished by solving Laplace`s equation using a multi-grid technique. Contour and difference file coding techniques also are described. The techniques can be used in a method for processing a plurality of images by selecting a respective compression approach for each image, compressing each of the images according to the compression approach selected, and transmitting each of the images as compressed, in correspondence with an indication of the approach selected for the image. 16 figs.

  16. Image compression technique

    DOE Patents [OSTI]

    Fu, Chi-Yung; Petrich, Loren I.

    1997-01-01

    An image is compressed by identifying edge pixels of the image; creating a filled edge array of pixels each of the pixels in the filled edge array which corresponds to an edge pixel having a value equal to the value of a pixel of the image array selected in response to the edge pixel, and each of the pixels in the filled edge array which does not correspond to an edge pixel having a value which is a weighted average of the values of surrounding pixels in the filled edge array which do correspond to edge pixels; and subtracting the filled edge array from the image array to create a difference array. The edge file and the difference array are then separately compressed and transmitted or stored. The original image is later reconstructed by creating a preliminary array in response to the received edge file, and adding the preliminary array to the received difference array. Filling is accomplished by solving Laplace's equation using a multi-grid technique. Contour and difference file coding techniques also are described. The techniques can be used in a method for processing a plurality of images by selecting a respective compression approach for each image, compressing each of the images according to the compression approach selected, and transmitting each of the images as compressed, in correspondence with an indication of the approach selected for the image.

  17. Isentropic Compression of Argon

    SciTech Connect (OSTI)

    H. Oona; J.C. Solem; L.R. Veeser, C.A. Ekdahl; P.J. Rodriquez; S.M. Younger; W. Lewis; W.D. Turley

    1997-08-01

    We are studying the transition of argon from an insulator to a conductor by compressing the frozen gas isentropically to pressures at which neighboring atomic orbitals overlap sufficiently to allow some electron motion between atoms. Argon and the other rare gases have closed electron shells and therefore remain montomic, even when they solidify. Their simple structure makes it likely that any measured change in conductivity is due to changes in the atomic structure, not in molecular configuration. As the crystal is compressed the band gap closes, allowing increased conductivity. We have begun research to determine the conductivity at high pressures, and it is our intention to determine the compression at which the crystal becomes a metal.

  18. Wavelet/scalar quantization compression standard for fingerprint images

    SciTech Connect (OSTI)

    Brislawn, C.M.

    1996-06-12

    US Federal Bureau of Investigation (FBI) has recently formulated a national standard for digitization and compression of gray-scale fingerprint images. Fingerprints are scanned at a spatial resolution of 500 dots per inch, with 8 bits of gray-scale resolution. The compression algorithm for the resulting digital images is based on adaptive uniform scalar quantization of a discrete wavelet transform subband decomposition (wavelet/scalar quantization method). The FBI standard produces archival-quality images at compression ratios of around 15 to 1 and will allow the current database of paper fingerprint cards to be replaced by digital imagery. The compression standard specifies a class of potential encoders and a universal decoder with sufficient generality to reconstruct compressed images produced by any compliant encoder, allowing flexibility for future improvements in encoder technology. A compliance testing program is also being implemented to ensure high standards of image quality and interchangeability of data between different implementations.

  19. Compressed Air System Control Strategies

    Office of Energy Efficiency and Renewable Energy (EERE)

    This tip sheet briefly discusses compressed air system control strategies as a means to improving and maintaining system performance.

  20. Stability Of Plasma Configurations During Compression

    SciTech Connect (OSTI)

    Ruden, E L; Hammer, J H

    2006-10-27

    Magnetized Target Fusion (MTF) efforts are based on calculations showing that the addition of a closed magnetic field reduces the driver pressure and rise time requirements for inertial confinement fusion by reducing thermal conductivity. Instabilities that result in convective bulk transport at the Alphen time scale are of particular concern since they are much faster than the implosion time. Such instabilities may occur during compression due to, for example, an increase in the plasma-magnetic pressure ratio {beta} or, in the case of a rotating plasma, spin-up due to angular momentum conservation. Details depend on the magnetic field topology and compression geometry. A hard core z pinch with purely azimuthal magnetic field can theoretically be made that relaxes into a wall supported diffuse profile satisfying the Kadomtsev criterion for the stability of m = 0 modes, which is theoretically preserved during cylindrical outer wall compression. The center conductor radius and current must also be large enough to keep the {beta} below stability limits to stabilize modes with m > 0. The stability of m > 0 modes actually improves during compression. A disadvantage of this geometry, though, is plasma contact with the solid boundaries. In addition to the risk of high Z impurity contamination during the (turbulent) relaxation process, contact thereafter can cause plasma pressure near the outer surface to drop, violating the Kadomtsev criterion locally. The resultant m = 0 instability can then convect impurities inward. Also, the center conductor (which is not part of the Kadomtsev profile) can go m = 0 unstable, convecting impurities outward. One way to mitigate impurity convection is to instead use a Woltjer-Taylor minimum magnetic energy configuration (spheromak). The sheared magnetic field inhibits convection, and the need for the center conductor is eliminated. The plasma, however, would likely still have to be wall supported due to unfavorable {beta} scaling during

  1. International magnetic pulse compression

    SciTech Connect (OSTI)

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

    1991-04-01

    Although pulsed-power engineering traditionally has been practiced by a fairly small, close community in the areas of defense and energy research, it is becoming more common in high-power, high-energy commercial pursuits such as material processing and lasers. This paper is a synopsis of the Feb. 12--14, 1990 workshop on magnetic switching as it applies primarily to pulse compression (power transformation). 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.

  2. Compressed Air Systems

    Broader source: Energy.gov [DOE]

    There are incentives for variable frequency drive screw compressors (10-40 HP), air receivers/tanks for load/no-load compressors, cycling refrigerated dryers (up to 200 CFM capacity), no-loss...

  3. Magnetic compression laser driving circuit

    DOE Patents [OSTI]

    Ball, Don G.; Birx, Dan; Cook, Edward G.

    1993-01-01

    A magnetic compression laser driving circuit is disclosed. The magnetic compression laser driving circuit compresses voltage pulses in the range of 1.5 microseconds at 20 Kilovolts of amplitude to pulses in the range of 40 nanoseconds and 60 Kilovolts of amplitude. The magnetic compression laser driving circuit includes a multi-stage magnetic switch where the last stage includes a switch having at least two turns which has larger saturated inductance with less core material so that the efficiency of the circuit and hence the laser is increased.

  4. Magnetic compression laser driving circuit

    DOE Patents [OSTI]

    Ball, D.G.; Birx, D.; Cook, E.G.

    1993-01-05

    A magnetic compression laser driving circuit is disclosed. The magnetic compression laser driving circuit compresses voltage pulses in the range of 1.5 microseconds at 20 kilovolts of amplitude to pulses in the range of 40 nanoseconds and 60 kilovolts of amplitude. The magnetic compression laser driving circuit includes a multi-stage magnetic switch where the last stage includes a switch having at least two turns which has larger saturated inductance with less core material so that the efficiency of the circuit and hence the laser is increased.

  5. General Compression | Open Energy Information

    Open Energy Info (EERE)

    Newton, Massachusetts Zip: 2458 Product: Massachusetts-based developer of compressed air energy storage systems. Coordinates: 43.996685, -87.803724 Show Map Loading map......

  6. Edge compression manifold apparatus

    SciTech Connect (OSTI)

    Renzi, Ronald F.

    2004-12-21

    A manifold for connecting external capillaries to the inlet and/or outlet ports of a microfluidic device for high pressure applications is provided. The fluid connector for coupling at least one fluid conduit to a corresponding port of a substrate that includes: (i) a manifold comprising one or more channels extending therethrough wherein each channel is at least partially threaded, (ii) one or more threaded ferrules each defining a bore extending therethrough with each ferrule supporting a fluid conduit wherein each ferrule is threaded into a channel of the manifold, (iii) a substrate having one or more ports on its upper surface wherein the substrate is positioned below the manifold so that the one or more ports is aligned with the one or more channels of the manifold, and (iv) device to apply an axial compressive force to the substrate to couple the one or more ports of the substrate to a corresponding proximal end of a fluid conduit.

  7. Edge compression manifold apparatus

    SciTech Connect (OSTI)

    Renzi, Ronald F.

    2007-02-27

    A manifold for connecting external capillaries to the inlet and/or outlet ports of a microfluidic device for high pressure applications is provided. The fluid connector for coupling at least one fluid conduit to a corresponding port of a substrate that includes: (i) a manifold comprising one or more channels extending therethrough wherein each channel is at least partially threaded, (ii) one or more threaded ferrules each defining a bore extending therethrough with each ferrule supporting a fluid conduit wherein each ferrule is threaded into a channel of the manifold, (iii) a substrate having one or more ports on its upper surface wherein the substrate is positioned below the manifold so that the one or more ports is aligned with the one or more channels of the manifold, and (iv) device to apply an axial compressive force to the substrate to couple the one or more ports of the substrate to a corresponding proximal end of a fluid conduit.

  8. Population attribute compression

    DOE Patents [OSTI]

    White, James M.; Faber, Vance; Saltzman, Jeffrey S.

    1995-01-01

    An image population having a large number of attributes is processed to form a display population with a predetermined smaller number of attributes that represent the larger number of attributes. In a particular application, the color values in an image are compressed for storage in a discrete look-up table (LUT). Color space containing the LUT color values is successively subdivided into smaller volumes until a plurality of volumes are formed, each having no more than a preselected maximum number of color values. Image pixel color values can then be rapidly placed in a volume with only a relatively few LUT values from which a nearest neighbor is selected. Image color values are assigned 8 bit pointers to their closest LUT value whereby data processing requires only the 8 bit pointer value to provide 24 bit color values from the LUT.

  9. ARM - Measurement - Isotope ratio

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

    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 State, Atmospheric Carbon 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

  10. R&D Strategies for Compressed, Cryo-Compressed and Cryo-Sorbent...

    Office of Environmental Management (EM)

    R&D Strategies for Compressed, Cryo-Compressed and Cryo-Sorbent Hydrogen Storage Technologies Workshops R&D Strategies for Compressed, Cryo-Compressed and Cryo-Sorbent Hydrogen ...

  11. Advances in compressible turbulent mixing

    SciTech Connect (OSTI)

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

    1992-01-01

    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.

  12. Microfabricated Optical Compressive Load Sensors (Conference...

    Office of Scientific and Technical Information (OSTI)

    Microfabricated Optical Compressive Load Sensors Citation Details In-Document Search Title: Microfabricated Optical Compressive Load Sensors Authors: Cole, G D ; Lin, K L ; ...

  13. Spectroscopic Evidence for Negative Electronic Compressibility...

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

    Spectroscopic Evidence for Negative Electronic Compressibility in a Quasi-three-dimensional Spin-orbit Correlated Metal Tuesday, June 30, 2015 Negative compressibility is a sign of...

  14. Linear phase compressive filter

    DOE Patents [OSTI]

    McEwan, Thomas E.

    1995-01-01

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

  15. Linear phase compressive filter

    DOE Patents [OSTI]

    McEwan, T.E.

    1995-06-06

    A phase linear filter for soliton suppression is in the form of a laddered series of stages of non-commensurate low pass filters with each low pass filter having a series coupled inductance (L) and a reverse biased, voltage dependent varactor diode, to ground which acts as a variable capacitance (C). L and C values are set to levels which correspond to a linear or conventional phase linear filter. Inductance is mapped directly from that of an equivalent nonlinear transmission line and capacitance is mapped from the linear case using a large signal equivalent of a nonlinear transmission line. 2 figs.

  16. Compressed/Liquid Hydrogen Tanks

    Broader source: Energy.gov [DOE]

    Currently, DOE's physical hydrogen storage R&D focuses on the development of high-pressure (10,000 psi) composite tanks, cryo-compressed tanks, conformable tanks, and other advanced concepts...

  17. Microsoft Word - Negative_compressibility

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

    compressibility (NEC) in a three dimensional spin-orbit correlated metal (Sr 1-x La x ) 3 Ir 2 O 7 , utilizing the high-resolution angle- resolved photoemission spectroscopy...

  18. Compressed gas fuel storage system

    DOE Patents [OSTI]

    Wozniak, John J.; Tiller, Dale B.; Wienhold, Paul D.; Hildebrand, Richard J.

    2001-01-01

    A compressed gas vehicle fuel storage system comprised of a plurality of compressed gas pressure cells supported by shock-absorbing foam positioned within a shape-conforming container. The container is dimensioned relative to the compressed gas pressure cells whereby a radial air gap surrounds each compressed gas pressure cell. The radial air gap allows pressure-induced expansion of the pressure cells without resulting in the application of pressure to adjacent pressure cells or physical pressure to the container. The pressure cells are interconnected by a gas control assembly including a thermally activated pressure relief device, a manual safety shut-off valve, and means for connecting the fuel storage system to a vehicle power source and a refueling adapter. The gas control assembly is enclosed by a protective cover attached to the container. The system is attached to the vehicle with straps to enable the chassis to deform as intended in a high-speed collision.

  19. Compressed Hydrogen Storage Workshop Agenda

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

    Monday, February 14, 2011 - Compressed Hydrogen Storage Purpose: Identify strategies and R&D needs for lowering the cost of high pressure hydrogen storage systems. Meeting scope includes the on-board system including but limited to its design, materials of construction, manufacturing processes and operating specifications. The meeting scope does not include the refueling infrastructure, such as hydrogen dispensing, compression and cooling, nor the vehicle powertrain, such as fuel cell, ICE

  20. The FBI compression standard for digitized fingerprint images

    SciTech Connect (OSTI)

    Brislawn, C.M.; Bradley, J.N.; Onyshczak, R.J.; Hopper, T.

    1996-10-01

    The FBI has formulated national standards for digitization and compression of gray-scale fingerprint images. The compression algorithm for the digitized images is based on adaptive uniform scalar quantization of a discrete wavelet transform subband decomposition, a technique referred to as the wavelet/scalar quantization method. The algorithm produces archival-quality images at compression ratios of around 15 to 1 and will allow the current database of paper fingerprint cards to be replaced by digital imagery. A compliance testing program is also being implemented to ensure high standards of image quality and interchangeability of data between different implementations. We will review the current status of the FBI standard, including the compliance testing process and the details of the first-generation encoder.

  1. Gas turbine power plant with supersonic shock compression ramps

    DOE Patents [OSTI]

    Lawlor, Shawn P.; Novaresi, Mark A.; Cornelius, Charles C.

    2008-10-14

    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.

  2. Fixed-rate compressed floating-point arrays

    Energy Science and Technology Software Center (OSTI)

    2014-03-30

    ZFP is a library for lossy compression of single- and double-precision floating-point data. One of the unique features of ZFP is its support for fixed-rate compression, which enables random read and write access at the granularity of small blocks of values. Using a C++ interface, this allows declaring compressed arrays (1D, 2D, and 3D arrays are supported) that through operator overloading can be treated just like conventional, uncompressed arrays, but which allow the user tomore » specify the exact number of bits to allocate to the array. ZFP also has variable-rate fixed-precision and fixed-accuracy modes, which allow the user to specify a tolerance on the relative or absolute error.« less

  3. QUASAR OPTICAL VARIABILITY IN THE PALOMAR-QUEST SURVEY (Journal...

    Office of Scientific and Technical Information (OSTI)

    Quasar variability amplitude is seen to decrease with Eddington ratio as a step function with a transition around Eddington ratio of 0.5. The higher variability at low Eddington ...

  4. Training: Compressed Air Systems | Department of Energy

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

    Compressed Air Systems Training: Compressed Air Systems April 16, 2014 - 6:32pm Addthis Learn about the diverse training sessions offered. The courses are taught by highly qualified instructors who have met rigorous standards. View additional compressed air system resources. Compressed Air Systems Tools Training - 2-hour webcast Availability: Online webcast A two-hour webcast on the use of the Compressed Air Challenge (CAC®) Toolkit and the AIRMaster+ software tool is available that introduces

  5. Simple Limits on Achieving A Quasi-Linear Magnetic Compression for an FEL Driver

    SciTech Connect (OSTI)

    Sun, Yipeng; /SLAC

    2012-02-16

    Free electron lasers (FEL) need a very bright electron beam in three dimensions and a high peak charge density. In order to compress an initially longer electron bunch generated from the photoinjector, magnetic bunch compression systems are widely employed. In this paper, first harmonic RF linearization and its associated requirements are reviewed. Meanwhile it is also briefly discussed what is the relation between a proper initial bunch length and main RF frequency, when a harmonic RF linearization is included. Then given a reasonable bunch compression ratio, a proper initial bunch length as a function of the main RF frequency and RF phase is estimated analytically by several approaches, assuming that no harmonic RF section is needed to linearize the energy modulation introduced during main RF acceleration, and at the same time still linearly compress the bunch length. Next the upper limit of the bunch compression ratio in a single stage is evaluated analytically. The analytical relations derived on choosing a proper initial bunch length as a function of main RF frequency are confirmed by numerical simulation. These simple limit provide rough estimations and may be beneficial for choosing bunch compression ratios in different stages of an FEL driver, especially in a first stage bunch compression where there is usually a harmonic RF linearization applied. It may also be useful in evaluating the possibility of low charge operation mode without any harmonic RF linearization, where a shorter initial bunch length can be achieved from the photoinjector.

  6. Reconnection in compressible plasmas: Extended conversion region

    SciTech Connect (OSTI)

    Birn, J.; Hesse, M.; Zenitani, S.

    2011-11-15

    The classical Sweet-Parker approach to steady-state magnetic reconnection is extended into the regime of large resistivity (small magnetic Reynolds or Lundquist number) when the aspect ratio between the outflow and inflow scale, {delta} = d/L, approaches unity. In a previous paper [Paper I, Hesse et al., Phys. Plasmas 18, 042104 (2011)], the vicinity of the dissipation site (''diffusion region'') was investigated. In this paper, the approach is extended to cover larger sites, in which the energy transfer and conversion is not confined to the diffusion region. Consistent with the results of Paper I, we find that increasing aspect ratio {delta} is associated with increasing compression, increasing reconnection rate for low {beta}, but slightly decreasing rate for higher {beta}, decreasing outflow speed, and increasing outflow magnetic field. These trends are stronger for lower {beta}. Deviations from the traditional Sweet-Parker limit {delta}{yields} 0 become significant for R{sub m}<{approx}10, where R{sub m} is the magnetic Reynolds number (Lundquist number) based on the half-thickness of the current layer responsible for the Ohmic dissipation. They are also more significant for small {gamma}, that is, for increasing compressibility. In contrast to the results of Paper I, but consistent with earlier results for {delta}<<1, we find that in this limit the outflow speed is given by the Alfven speed {nu}{sub A} in the inflow region and the energy conversion is given by an even split of Poynting flux into enthalpy flux and bulk kinetic energy flux. However, with increasing {delta} the conversion to enthalpy flux becomes more and more dominant.

  7. Compressive behavior of fine sand.

    SciTech Connect (OSTI)

    Martin, Bradley E.; Kabir, Md. E.; Song, Bo; Chen, Wayne

    2010-04-01

    The compressive mechanical response of fine sand is experimentally investigated. The strain rate, initial density, stress state, and moisture level are systematically varied. A Kolsky bar was modified to obtain uniaxial and triaxial compressive response at high strain rates. A controlled loading pulse allows the specimen to acquire stress equilibrium and constant strain-rates. The results show that the compressive response of the fine sand is not sensitive to strain rate under the loading conditions in this study, but significantly dependent on the moisture content, initial density and lateral confinement. Partially saturated sand is more compliant than dry sand. Similar trends were reported in the quasi-static regime for experiments conducted at comparable specimen conditions. The sand becomes stiffer as initial density and/or confinement pressure increases. The sand particle size become smaller after hydrostatic pressure and further smaller after dynamic axial loading.

  8. Compressing the Inert Doublet Model

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

    Blinov, Nikita; Kozaczuk, Jonathan; Morrissey, David E.; de la Puente, Alejandro

    2016-02-16

    The Inert Doublet Model relies on a discrete symmetry to prevent couplings of the new scalars to Standard Model fermions. We found that this stabilizes the lightest inert state, which can then contribute to the observed dark matter density. In the presence of additional approximate symmetries, the resulting spectrum of exotic scalars can be compressed. Here, we study the phenomenological and cosmological implications of this scenario. In conclusion, we derive new limits on the compressed Inert Doublet Model from LEP, and outline the prospects for exclusion and discovery of this model at dark matter experiments, the LHC, and future colliders.

  9. Compressing the Inert Doublet Model

    SciTech Connect (OSTI)

    Blinov, Nikita; Morrissey, David E.; de la Puente, Alejandro

    2015-10-29

    The Inert Doublet Model relies on a discrete symmetry to prevent couplings of the new scalars to Standard Model fermions. We found that this stabilizes the lightest inert state, which can then contribute to the observed dark matter density. In the presence of additional approximate symmetries, the resulting spectrum of exotic scalars can be compressed. Here, we study the phenomenological and cosmological implications of this scenario. Furthermore, we derive new limits on the compressed Inert Doublet Model from LEP, and outline the prospects for exclusion and discovery of this model at dark matter experiments, the LHC, and future colliders.

  10. Compressive passive millimeter wave imager

    DOE Patents [OSTI]

    Gopalsami, Nachappa; Liao, Shaolin; Elmer, Thomas W; Koehl, Eugene R; Heifetz, Alexander; Raptis, Apostolos C

    2015-01-27

    A compressive scanning approach for millimeter wave imaging and sensing. A Hadamard mask is positioned to receive millimeter waves from an object to be imaged. A subset of the full set of Hadamard acquisitions is sampled. The subset is used to reconstruct an image representing the object.

  11. Peak power ratio generator

    DOE Patents [OSTI]

    Moyer, Robert D.

    1985-01-01

    A peak power ratio generator is described for measuring, in combination with a conventional power meter, the peak power level of extremely narrow pulses in the gigahertz radio frequency bands. The present invention in a preferred embodiment utilizes a tunnel diode and a back diode combination in a detector circuit as the only high speed elements. The high speed tunnel diode provides a bistable signal and serves as a memory device of the input pulses for the remaining, slower components. A hybrid digital and analog loop maintains the peak power level of a reference channel at a known amount. Thus, by measuring the average power levels of the reference signal and the source signal, the peak power level of the source signal can be determined.

  12. Peak power ratio generator

    DOE Patents [OSTI]

    Moyer, R.D.

    A peak power ratio generator is described for measuring, in combination with a conventional power meter, the peak power level of extremely narrow pulses in the gigahertz radio frequency bands. The present invention in a preferred embodiment utilizes a tunnel diode and a back diode combination in a detector circuit as the only high speed elements. The high speed tunnel diode provides a bistable signal and serves as a memory device of the input pulses for the remaining, slower components. A hybrid digital and analog loop maintains the peak power level of a reference channel at a known amount. Thus, by measuring the average power levels of the reference signal and the source signal, the peak power level of the source signal can be determined.

  13. Variable delivery, fixed displacement pump

    DOE Patents [OSTI]

    Sommars, Mark F.

    2001-01-01

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

  14. The wavelet/scalar quantization compression standard for digital fingerprint images

    SciTech Connect (OSTI)

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

    1994-04-01

    A new digital image compression standard has been adopted by the US Federal Bureau of Investigation for use on digitized gray-scale fingerprint images. The algorithm is based on adaptive uniform scalar quantization of a discrete wavelet transform image decomposition and is referred to as the wavelet/scalar quantization standard. The standard produces archival quality images at compression ratios of around 20:1 and will allow the FBI to replace their current database of paper fingerprint cards with digital imagery.

  15. Face compression yield strength of the copper-Inconel composite specimen

    SciTech Connect (OSTI)

    Horie, T.

    1987-05-01

    A new equation for the face compression yield strength of copper-Inconel composite material has been derived. Elastic-plastic finite element analyses were also made for composite specimens with various aspect ratios to examine the edge effect of the specimen. According to the results of both the new equation and the analyses, the face compression yield strength of the composite should be decreased by about 25% from the value obtained with Becker's equation.

  16. ADVANCED RECIPROCATING COMPRESSION TECHNOLOGY (ARCT)

    SciTech Connect (OSTI)

    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

    2005-12-01

    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

  17. Advanced Management of Compressed Air Systems

    Broader source: Energy.gov [DOE]

    Find out how a compressed air system works and the benefits of optimal compressed air system performance. This training is designed to help end users as well as industry solution providers learn...

  18. Compressive strength of carbon fibers (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Conference: Compressive strength of carbon fibers Citation Details In-Document Search Title: Compressive strength of carbon fibers Direct transverse compressive test of pitch-based ...

  19. Improving Compressed Air System Performance Third Edition | Department...

    Energy Savers [EERE]

    Compressed Air System Performance Third Edition Improving Compressed Air System Performance Third Edition PDF icon Improving Compressed Air Sourcebook version 3.pdf More Documents ...

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

    DOE Patents [OSTI]

    Gonczy, John D.; Markley, Finley W.; McCaw, William R.; Niemann, Ralph C.

    1992-01-01

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

  1. Electrochemical Hydrogen Compression (EHC) | Department of Energy

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

    Electrochemical Hydrogen Compression (EHC) Electrochemical Hydrogen Compression (EHC) This presentation by Pinakin Patel and Ludwig Lipp of Fuel Cell Energy was given at the DOE Hydrogen Compression, Storage, and Dispensing Workshop on March 20, 2013. csd_workshop_4_patel.pdf (368.07 KB) More Documents & Publications Small Business Innovation Research (SBIR) Award Success Story: FuelCell Energy Inc. 2013 Hydrogen Compression, Storage, and Dispensing Cost Reduction Workshop Final Report

  2. Compressed Air Best Practices Tools Overview

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

    Compressed Air Best Practices Tools Compressed Air Challenge® DOE AIRMaster+ Software CAC LogTool Software Date: May 15, 2007 Instructor: Tom Taranto Agenda Training Webcast Introduction Introduction of Tools - 10 minutes Compressed Air Challenge ® Tools - 25 minutes AIRMaster+ Software Tool - 25 minutes LogTool v2 - 25 minutes ESA Process - 20 minutes Q&A / Summary - 15 minutes Training Web Cast Series Purpose: To provide information on Compressed Air BestPractices tools used during DOE's

  3. Compressed Air Systems | Department of Energy

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

    Technical Assistance » Compressed Air Systems Compressed Air Systems Applying best energy management practices and purchasing energy-efficient equipment can lead to significant savings in compressed air systems. Use the software tools, training, and publications listed below to improve performance and save energy. Compressed Air Tools Tools to Assess Your Energy System AIRMaster+ Tool AIRMaster+ LogTool Qualified Specialists Qualified Specialists have passed a rigorous competency examination on

  4. Gaseous Hydrogen Compression | Department of Energy

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

    » Gaseous Hydrogen Compression Gaseous Hydrogen Compression Hydrogen is typically produced at relatively low pressures (20-30 bar) and must be compressed prior to transport. Most compressors used today for gaseous hydrogen compression are either positive displacement compressors or centrifugal compressors. Positive displacement compressors can be reciprocating or rotary. Reciprocating compressors use a motor with a linear drive to move a piston or a diaphragm back and forth. This motion

  5. Practicality of magnetic compression for plasma density control

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

    Gueroult, Renaud; Fisch, Nathaniel J.

    2016-03-16

    Here, plasma densification through magnetic compression has been suggested for time-resolved control of the wave properties in plasma-based accelerators [P. F. Schmit and N. J. Fisch, Phys. Rev. Lett. 109, 255003 (2012)]. Using particle in cell simulations with real mass ratio, the practicality of large magnetic compression on timescales shorter than the ion gyro-period is investigated. For compression times shorter than the transit time of a compressional Alfven wave across the plasma slab, results show the formation of two counter-propagating shock waves, leading to a highly non-uniform plasma density profile. Furthermore, the plasma slab displays large hydromagnetic like oscillations aftermore » the driving field has reached steady state. Peak compression is obtained when the two shocks collide in the mid-plane. At this instant, very large plasma heating is observed, and the plasmaβ is estimated to be about 1. Although these results point out a densification mechanism quite different and more complex than initially envisioned, these features still might be advantageous in particle accelerators.« less

  6. Forecourt Storage and Compression Options

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

    Forecourt Storage and Compression Options DOE and FreedomCAR & Fuel Partnership Hydrogen Delivery and On-Board Storage Analysis Workshop DOE Headquarters 25 January 2006 Mark E. Richards Gas Technology Institute 2 Overview > Project objectives > Gaseous delivery configurations > Analysis tool: CASCADE H2 Pro > Station demand profiles > Operational analysis results - Compressor-storage relationships - Vehicle fueling times - Temperature effects > Cost profiles >

  7. Compressed air energy storage system

    DOE Patents [OSTI]

    Ahrens, Frederick W.; Kartsounes, George T.

    1981-01-01

    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.

  8. Compressed air energy storage system

    DOE Patents [OSTI]

    Ahrens, F.W.; Kartsounes, G.T.

    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 combustion reciprocating engine is operated at high pressure and a low pressure turbine and compressor are also employed for air compression and power generation.

  9. Compressive and shear buckling analysis of metal matrix composite sandwich panels under different thermal environments

    SciTech Connect (OSTI)

    Ko, W.L.; Jackson, R.H.

    1993-06-01

    Combined inplane compressive and shear buckling analysis was conducted on flat rectangular sandwich panels using the Raleigh-Ritz minimum energy method with a consideration of transverse shear effect of the sandwich core. The sandwich panels were fabricated with titanium honeycomb core and laminated metal matrix composite face sheets. The results show that slightly slender (along unidirectional compressive loading axis) rectangular sandwich panels have the most desirable stiffness-to-weight ratios for aerospace structural applications; the degradation of buckling strength of sandwich panels with rising temperature is faster in shear than in compression; and the fiber orientation of the face sheets for optimum combined-load buckling strength of sandwich panels is a strong function of both loading condition and panel aspect ratio. Under the same specific weight and panel aspect ratio, a sandwich panel with metal matrix composite face sheets has much higher buckling strength than one having monolithic face sheets.

  10. Analyzing Your Compressed Air System | Department of Energy

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

    Analyzing Your Compressed Air System Analyzing Your Compressed Air System This tip sheet outlines the process to analyze industrial compressed air systems and ensure proper system configuration. COMPRESSED AIR TIP SHEET #4 Analyzing Your Compressed Air System (August 2004) (243.47 KB) More Documents & Publications Compressed Air System Control Strategies Determining the Right Air Quality for Your Compressed Air System Determine the Cost of Compressed Air for Your Plant

  11. Variable Valve Actuation

    SciTech Connect (OSTI)

    Jeffrey Gutterman; A. J. Lasley

    2008-08-31

    Many approaches exist to enable advanced mode, low temperature combustion systems for diesel engines - such as premixed charge compression ignition (PCCI), Homogeneous Charge Compression Ignition (HCCI) or other HCCI-like combustion modes. The fuel properties and the quantity, distribution and temperature profile of air, fuel and residual fraction in the cylinder can have a marked effect on the heat release rate and combustion phasing. Figure 1 shows that a systems approach is required for HCCI-like combustion. While the exact requirements remain unclear (and will vary depending on fuel, engine size and application), some form of substantially variable valve actuation is a likely element in such a system. Variable valve actuation, for both intake and exhaust valve events, is a potent tool for controlling the parameters that are critical to HCCI-like combustion and expanding its operational range. Additionally, VVA can be used to optimize the combustion process as well as exhaust temperatures and impact the after treatment system requirements and its associated cost. Delphi Corporation has major manufacturing and product development and applied R&D expertise in the valve train area. Historical R&D experience includes the development of fully variable electro-hydraulic valve train on research engines as well as several generations of mechanical VVA for gasoline systems. This experience has enabled us to evaluate various implementations and determine the strengths and weaknesses of each. While a fully variable electro-hydraulic valve train system might be the 'ideal' solution technically for maximum flexibility in the timing and control of the valve events, its complexity, associated costs, and high power consumption make its implementation on low cost high volume applications unlikely. Conversely, a simple mechanical system might be a low cost solution but not deliver the flexibility required for HCCI operation. After modeling more than 200 variations of the

  12. Vehicle Technologies Office Merit Review 2014: High Compression Ratio Turbo Gasoline Engine Operation Using Alcohol Enhancement

    Broader source: Energy.gov [DOE]

    Presentation given by Massachusetts Institute of Technology at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about high...

  13. The Effects of Fuel Composition and Compression Ratio on Thermal Efficiency in an HCCI Engine

    Broader source: Energy.gov [DOE]

    Poster presentation at the 2007 Diesel Engine-Efficiency & Emissions Research Conference (DEER 2007). 13-16 August, 2007, Detroit, Michigan. Sponsored by the U.S. Department of Energy's (DOE) Office of FreedomCAR and Vehicle Technologies (OFCVT).

  14. Commercial Compressed Air Systems Program

    Broader source: Energy.gov [DOE]

    There are incentives for variable frequency drive screw compressors (10-40 HP), air receivers/tanks for load/no-load screw and vane compressors, cycling refrigerated thermal mass dryers (up to 30...

  15. Non-Vapor Compression HVAC Technologies Report

    Broader source: Energy.gov [DOE]

    While vapor-compression technologies have served heating, ventilation, and air-conditioning (HVAC) needs very effectively, and have been the dominant HVAC technology for close to 100 years, the conventional refrigerants used in vapor-compression equipment contribute to global climate change when released to the atmosphere. The Building Technologies Office is evaluating low-global warming potential (GWP) alternatives to vapor-compression technologies.

  16. Case Study - Compressed Natural Gas Refuse Fleets

    SciTech Connect (OSTI)

    Laughlin, M; Burnham, A.

    2014-02-01

    This case study explores the use of heavy-duty refuse trucks fueled by compressed natural gas highlighting three fleets from very different types of organizations.

  17. Compressed Air Storage Strategies | Department of Energy

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

    Strategies (August 2004) (258.48 KB) More Documents & Publications Compressed Air System Control Strategies Stabilizing System Pressure Effect of Intake on Compressor Performance

  18. Compressed Air Storage Strategies; Industrial Technologies Program...

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

    9 * August 2004 Industrial Technologies Program Suggested Actions * Review the plant's compressed air demand patterns to determine whether storage would be benefcial. * Examine the ...

  19. Preventive Maintenance Strategies for Compressed Air Systems...

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

    Suggested Actions * Establish a regular, well-organized maintenance program in accordance ... that all compressed air system maintenance needs are performed properly, on ...

  20. Optimization of Storage vs. Compression Capacity

    Broader source: Energy.gov [DOE]

    This presentation by Amgad Elgowainy of Argonne National Laboratory was given at the DOE Hydrogen Compression, Storage, and Dispensing Workshop in March 2013.

  1. Hydrogen Compression, Storage, and Dispensing Cost Reduction...

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

    Hydrogen Compression, Storage, and Dispensing Cost Reduction Workshop Addendum Document states additional feedback on the worksop received via a request for information issued in ...

  2. Determining the Right Air Quality for Your Compressed Air System - Compressed Air Tip Sheet #5

    SciTech Connect (OSTI)

    2004-08-01

    BestPractices Program tip sheet discussing how to determine the right air quality for compressed air systems.

  3. Compression molding of aerogel microspheres

    DOE Patents [OSTI]

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

    1998-03-24

    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.

  4. Compression molding of aerogel microspheres

    DOE Patents [OSTI]

    Pekala, Richard W.; Hrubesh, Lawrence W.

    1998-03-24

    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.

  5. Shock compression of liquid hydrazine

    SciTech Connect (OSTI)

    Garcia, B.O.; Chavez, D.J.

    1995-01-01

    Liquid hydrazine (N{sub 2}H{sub 4}) is a propellant used by the Air Force and NASA for aerospace propulsion and power systems. Because the propellant modules that contain the hydrazine can be subject to debris impacts during their use, the shock states that can occur in the hydrazine need to be characterized to safely predict its response. Several shock compression experiments have been conducted in an attempt to investigate the detonability of liquid hydrazine; however, the experiments results disagree. Therefore, in this study, we reproduced each experiment numerically to evaluate in detail the shock wave profiles generated in the liquid hydrazine. This paper presents the results of each numerical simulation and compares the results to those obtained in experiment. We also present the methodology of our approach, which includes chemical kinetic experiments, chemical equilibrium calculations, and characterization of the equation of state of liquid hydrazine.

  6. Compressed natural gas (CNG) measurement

    SciTech Connect (OSTI)

    Husain, Z.D.; Goodson, F.D.

    1995-12-01

    The increased level of environmental awareness has raised concerns about pollution. One area of high attention is the internal combustion engine. The internal combustion engine in and of itself is not a major pollution threat. However, the vast number of motor vehicles in use release large quantities of pollutants. Recent technological advances in ignition and engine controls coupled with unleaded fuels and catalytic converters have reduced vehicular emissions significantly. Alternate fuels have the potential to produce even greater reductions in emissions. The Natural Gas Vehicle (NGV) has been a significant alternative to accomplish the goal of cleaner combustion. Of the many alternative fuels under investigation, compressed natural gas (CNG) has demonstrated the lowest levels of emission. The only vehicle certified by the State of California as an Ultra Low Emission Vehicle (ULEV) was powered by CNG. The California emissions tests of the ULEV-CNG vehicle revealed the following concentrations: Non-Methane Hydrocarbons 0.005 grams/mile Carbon Monoxide 0.300 grams/mile Nitrogen Oxides 0.040 grams/mile. Unfortunately, CNG vehicles will not gain significant popularity until compressed natural gas is readily available in convenient locations in urban areas and in proximity to the Interstate highway system. Approximately 150,000 gasoline filling stations exist in the United States while number of CNG stations is about 1000 and many of those CNG stations are limited to fleet service only. Discussion in this paper concentrates on CNG flow measurement for fuel dispensers. Since the regulatory changes and market demands affect the flow metering and dispenser station design those aspects are discussed. The CNG industry faces a number of challenges.

  7. Survey of data compression techniques

    SciTech Connect (OSTI)

    Gryder, R.; Hake, K.

    1991-09-01

    PM-AIM must provide to customers in a timely fashion information about Army acquisitions. This paper discusses ways that PM-AIM can reduce the volume of data that must be transmitted between sites. Although this paper primarily discusses techniques of data compression, it also briefly discusses other options for meeting the PM-AIM requirements. The options available to PM-AIM, in addition to hardware and software data compression, include less-frequent updates, distribution of partial updates, distributed data base design, and intelligent network design. Any option that enhances the performance of the PM-AIM network is worthy of consideration. The recommendations of this paper apply to the PM-AIM project in three phases: the current phase, the target phase, and the objective phase. Each recommendation will be identified as (1) appropriate for the current phase, (2) considered for implementation during the target phase, or (3) a feature that should be part of the objective phase of PM-AIM's design. The current phase includes only those measures that can be taken with the installed leased lines. The target phase includes those measures that can be taken in transferring the traffic from the leased lines to the DSNET environment with minimal changes in the current design. The objective phase includes all the things that should be done as a matter of course. The objective phase for PM-AIM appears to be a distributed data base with data for each site stored locally and all sites having access to all data.

  8. Survey of data compression techniques

    SciTech Connect (OSTI)

    Gryder, R.; Hake, K.

    1991-09-01

    PM-AIM must provide to customers in a timely fashion information about Army acquisitions. This paper discusses ways that PM-AIM can reduce the volume of data that must be transmitted between sites. Although this paper primarily discusses techniques of data compression, it also briefly discusses other options for meeting the PM-AIM requirements. The options available to PM-AIM, in addition to hardware and software data compression, include less-frequent updates, distribution of partial updates, distributed data base design, and intelligent network design. Any option that enhances the performance of the PM-AIM network is worthy of consideration. The recommendations of this paper apply to the PM-AIM project in three phases: the current phase, the target phase, and the objective phase. Each recommendation will be identified as (1) appropriate for the current phase, (2) considered for implementation during the target phase, or (3) a feature that should be part of the objective phase of PM-AIM`s design. The current phase includes only those measures that can be taken with the installed leased lines. The target phase includes those measures that can be taken in transferring the traffic from the leased lines to the DSNET environment with minimal changes in the current design. The objective phase includes all the things that should be done as a matter of course. The objective phase for PM-AIM appears to be a distributed data base with data for each site stored locally and all sites having access to all data.

  9. A Space-Charge-Neutralizing Plasma for Beam Drift Compression

    SciTech Connect (OSTI)

    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.

    2008-08-01

    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.

  10. Bunch length compression method for free electron lasers to avoid parasitic compressions

    SciTech Connect (OSTI)

    Douglas, David R.; Benson, Stephen; Nguyen, Dinh Cong; Tennant, Christopher; Wilson, Guy

    2015-05-26

    A method of bunch length compression method for a free electron laser (FEL) that avoids parasitic compressions by 1) applying acceleration on the falling portion of the RF waveform, 2) compressing using a positive momentum compaction (R.sub.56>0), and 3) compensating for aberration by using nonlinear magnets in the compressor beam line.

  11. Novel Concepts for the Compression of Large Volumes of Carbon Dioxide

    SciTech Connect (OSTI)

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

    2007-09-30

    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.

  12. Hardware compression using common portions of data

    DOE Patents [OSTI]

    Chang, Jichuan; Viswanathan, Krishnamurthy

    2015-03-24

    Methods and devices are provided for data compression. Data compression can include receiving a plurality of data chunks, sampling at least some of the plurality of data chunks extracting a common portion from a number of the plurality of data chunks based on the sampling, and storing a remainder of the plurality of data chunks in memory.

  13. Sudden Viscous Dissipation of Compressing Turbulence

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

    Davidovits, Seth; Fisch, Nathaniel J.

    2016-03-11

    Here we report compression of turbulent plasma can amplify the turbulent kinetic energy, if the compression is fast compared to the viscous dissipation time of the turbulent eddies. A sudden viscous dissipation mechanism is demonstrated, whereby this amplified turbulent kinetic energy is rapidly converted into thermal energy, suggesting a new paradigm for fast ignition inertial fusion.

  14. Vertical Variability of Aerosols and Water Vapor Over the Southern...

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

    Vertical Variability of Aerosols and Water Vapor Over the Southern Great Plains R. A. ... Abstract We use Raman lidar profiles of water vapor mixing ratio, relative humidity, ...

  15. High ratio recirculating gas compressor

    DOE Patents [OSTI]

    Weinbrecht, John F.

    1989-01-01

    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.

  16. High ratio recirculating gas compressor

    DOE Patents [OSTI]

    Weinbrecht, J.F.

    1989-08-22

    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.

  17. Energy Balance Bowen Ratio System

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

    0 Energy Balance Bowen Ratio System Estimates of surface energy fluxes are a primary product of the data collection systems at the ARM SGP CART site. Surface fluxes tell ...

  18. Shock compression profiles in ceramics

    SciTech Connect (OSTI)

    Grady, D.E.; Moody, R.L.

    1996-03-01

    An investigation of the shock compression properties of high-strength ceramics has been performed using controlled planar impact techniques. In a typical experimental configuration, a ceramic target disc is held stationary, and it is struck by plates of either a similar ceramic or by plates of a well-characterized metal. All tests were performed using either a single-stage propellant gun or a two-stage light-gas gun. Particle velocity histories were measured with laser velocity interferometry (VISAR) at the interface between the back of the target ceramic and a calibrated VISAR window material. Peak impact stresses achieved in these experiments range from about 3 to 70 GPa. Ceramics tested under shock impact loading include: Al{sub 2}O{sub 3}, AlN, B{sub 4}C, SiC, Si{sub 3}N{sub 4}, TiB{sub 2}, WC and ZrO{sub 2}. This report compiles the VISAR wave profiles and experimental impact parameters within a database-useful for response model development, computational model validation studies, and independent assessment of the physics of dynamic deformation on high-strength, brittle solids.

  19. PHELIX for flux compression studies

    SciTech Connect (OSTI)

    Turchi, Peter J; Rousculp, Christopher L; Reinovsky, Robert E; Reass, William A; Griego, Jeffrey R; Oro, David M; Merrill, Frank E

    2010-06-28

    PHELIX (Precision High Energy-density Liner Implosion eXperiment) is a concept for studying electromagnetic implosions using proton radiography. This approach requires a portable pulsed power and liner implosion apparatus that can be operated in conjunction with an 800 MeV proton beam at the Los Alamos Neutron Science Center. The high resolution (< 100 micron) provided by proton radiography combined with similar precision of liner implosions driven electromagnetically can permit close comparisons of multi-frame experimental data and numerical simulations within a single dynamic event. To achieve a portable implosion system for use at high energy-density in a proton laboratory area requires sub-megajoule energies applied to implosions only a few cms in radial and axial dimension. The associated inductance changes are therefore relatively modest, so a current step-up transformer arrangement is employed to avoid excessive loss to parasitic inductances that are relatively large for low-energy banks comprising only several capacitors and switches. We describe the design, construction and operation of the PHELIX system and discuss application to liner-driven, magnetic flux compression experiments. For the latter, the ability of strong magnetic fields to deflect the proton beam may offer a novel technique for measurement of field distributions near perturbed surfaces.

  20. General Compression Looks at Energy Storage from a Different Angle |

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

    Department of Energy 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

  1. Compressed Hydrogen Storage Workshop Agenda | Department of Energy

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

    Compressed Hydrogen Storage Workshop Agenda Compressed Hydrogen Storage Workshop Agenda Agenda for the first day of the R&D Strategies for Compressed, Cryo-Compressed and Cryo-Sorbent Hydrogen Storage Technologies Workshops on February 14 and 15, 2011. compressed_hydrogen2011_day1_agenda.pdf (10.98 KB) More Documents & Publications Cryogenic Hydrogen Storage Systems Workshop Agenda Research and Development Strategies for Compressed & Cryo-Hydrogen Storage Systems - Workshop Summary

  2. Cryo-Compressed Hydrogen Storage: Performance and Cost Review | Department

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

    of Energy Compressed Hydrogen Storage: Performance and Cost Review Cryo-Compressed Hydrogen Storage: Performance and Cost Review Presented at the R&D Strategies for Compressed, Cryo-Compressed and Cryo-Sorbent Hydrogen Storage Technologies Workshops on February 14 and 15, 2011. compressed_hydrogen2011_8_ahluwalia.pdf (1.1 MB) More Documents & Publications Technical Assessment of Cryo-Compressed Hydrogen Storage Tank Systems for Automotive Applications Technical Assessment of Organic

  3. Logarithmic compression methods for spectral data

    DOE Patents [OSTI]

    Dunham, Mark E.

    2003-01-01

    A method is provided for logarithmic compression, transmission, and expansion of spectral data. A log Gabor transformation is made of incoming time series data to output spectral phase and logarithmic magnitude values. The output phase and logarithmic magnitude values are compressed by selecting only magnitude values above a selected threshold and corresponding phase values to transmit compressed phase and logarithmic magnitude values. A reverse log Gabor transformation is then performed on the transmitted phase and logarithmic magnitude values to output transmitted time series data to a user.

  4. An efficient compression scheme for bitmap indices

    SciTech Connect (OSTI)

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

    2004-04-13

    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

  5. Modulation compression for short wavelength harmonic generation

    SciTech Connect (OSTI)

    Qiang, J.

    2010-01-11

    Laser modulator is used to seed free electron lasers. In this paper, we propose a scheme to compress the initial laser modulation in the longitudinal phase space by using two opposite sign bunch compressors and two opposite sign energy chirpers. This scheme could potentially reduce the initial modulation wavelength by a factor of C and increase the energy modulation amplitude by a factor of C, where C is the compression factor of the first bunch compressor. Such a compressed energy modulation can be directly used to generate short wavelength current modulation with a large bunching factor.

  6. Compressed Gas Safety for Experimental Fusion Facilities

    SciTech Connect (OSTI)

    Cadwallader, L.C.

    2005-05-15

    Experimental fusion facilities present a variety of hazards to the operators and staff. There are unique or specialized hazards, including magnetic fields, cryogens, radio frequency emissions, and vacuum reservoirs. There are also more general industrial hazards, such as a wide variety of electrical power, pressurized air and cooling water systems in use, there are crane and hoist loads, working at height, and handling compressed gas cylinders. This paper outlines the projectile hazard associated with compressed gas cylinders and methods of treatment to provide for compressed gas safety. This information should be of interest to personnel at both magnetic and inertial fusion experiments.

  7. 2016 - LNG Export, Compressed Natural Gas (CNG), Re-Exports ...

    Energy Savers [EERE]

    - LNG Export, Compressed Natural Gas (CNG), Re-Exports & Long Term Natural Gas Applications 2016 - LNG Export, Compressed Natural Gas (CNG), Re-Exports & Long Term Natural Gas ...

  8. Compression set in Gas Blown Condensation Cured Polysiloxane...

    Office of Scientific and Technical Information (OSTI)

    Compression set in Gas Blown Condensation Cured Polysiloxane Elastomers Citation Details In-Document Search Title: Compression set in Gas Blown Condensation Cured Polysiloxane ...

  9. H2A Delivery: Forecourt Compression & Storage Optimization (Part...

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

    Delivery: Forecourt Compression & Storage Optimization (Part II) H2A Delivery: Forecourt Compression & Storage Optimization (Part II) Presentation by Matthew Hooks of TIAX at the...

  10. Defect Analysis of Vehicle Compressed Natural Gas Composite Cylinder...

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

    Defect Analysis of Vehicle Compressed Natural Gas Composite Cylinder Defect Analysis of Vehicle Compressed Natural Gas Composite Cylinder These slides were presented at the Onboard ...

  11. Rotary Vapor Compression Cycle Technology: A Pathway to Ultra...

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

    Rotary Vapor Compression Cycle Technology: A Pathway to Ultra-Efficient Air Conditioning, Heating and Refrigeration Rotary Vapor Compression Cycle Technology: A Pathway to...

  12. NJ Compressed Natural Gas Refuse Trucks, Shuttle Buses and Infrastruct...

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

    icon arravt051tifeinberg2011p.pdf More Documents & Publications NJ Compressed Natural Gas Refuse Trucks, Shuttle Buses and Infrastructure NJ Compressed Natural Gas Refuse ...

  13. Shock compression of precompressed deuterium (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Conference: Shock compression of precompressed deuterium Citation Details In-Document Search Title: Shock compression of precompressed deuterium Here we report quasi-isentropic ...

  14. Business Case for Compressed Natural Gas in Municipal Fleets...

    Open Energy Info (EERE)

    Business Case for Compressed Natural Gas in Municipal Fleets Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Business Case for Compressed Natural Gas in Municipal Fleets...

  15. Guidelines for Conversion of Diesel Buses to Compressed Natural...

    Open Energy Info (EERE)

    Conversion of Diesel Buses to Compressed Natural Gas Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Guidelines for Conversion of Diesel Buses to Compressed Natural Gas...

  16. Technical Assessment: Cryo-Compressed Hydrogen Storage for Vehicular...

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

    Cryo-Compressed Hydrogen Storage: Performance and Cost Review Technical Assessment of Cryo-Compressed Hydrogen Storage Tank Systems for Automotive Applications High-Pressure Tube ...

  17. Improving Compressed Air System Performance: A Sourcebook for...

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

    Industry, Third Edition Improving Compressed Air System Performance: A Sourcebook for Industry, Third Edition AMO's "Improving Compressed Air System Performance: A Sourcebook for ...

  18. Determine the Cost of Compressed Air for Your Plant | Department...

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

    This tip sheet discusses a method for determining the cost of compressed air at industrial ... More Documents & Publications Compressed Air System Control Strategies Select an ...

  19. Robust ferromagnetism in the compressed permanent magnet Sm 2...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Robust ferromagnetism in the compressed permanent magnet Sm 2 Co 17 Citation Details In-Document Search Title: Robust ferromagnetism in the compressed permanent ...

  20. Webinar January 26: Update to the 700 bar Compressed Hydrogen...

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

    January 26: Update to the 700 bar Compressed Hydrogen Storage System Cost Projection Webinar January 26: Update to the 700 bar Compressed Hydrogen Storage System Cost Projection ...

  1. High Fidelity Modeling of Premixed Charge Compression Ignition...

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

    Fidelity Modeling of Premixed Charge Compression Ignition Engines High Fidelity Modeling of Premixed Charge Compression Ignition Engines Most accurate and detailed chemical kinetic ...

  2. Generation of Coherent X-Ray Radiation through Modulation Compression...

    Office of Scientific and Technical Information (OSTI)

    Generation of Coherent X-Ray Radiation through Modulation Compression Citation Details In-Document Search Title: Generation of Coherent X-Ray Radiation through Modulation Compression ...

  3. Evaluation of the Compressed Air Challenge(R) Training Program...

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

    This Evaluation of the Compressed Air Challenge Training Program was prepared with the ... Evaluation of the Compressed Air Challenge Training Program i ii Table of Contents ...

  4. Compressive Shear Test to Accurately Measure Adhesion of PV Encapsulan...

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

    Compressive Shear Test to Accurately Measure Adhesion of PV Encapsulants Compressive Shear Test to Accurately Measure Adhesion of PV Encapsulants Presented at the PV Module ...

  5. Pdc - The Worldwide Leader in Hydrogen Refueling Station Compression...

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

    Pdc - The Worldwide Leader in Hydrogen Refueling Station Compression Pdc - The Worldwide Leader in Hydrogen Refueling Station Compression This presentation by Matther Weaver of Pdc ...

  6. Onboard Type IV Compressed Hydrogen Storage System Cost Analysis...

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

    Onboard Type IV Compressed Hydrogen Storage System Cost Analysis Webinar Onboard Type IV Compressed Hydrogen Storage System Cost Analysis Webinar Access the recording and download ...

  7. Extreme dynamic compression with a low energy laser pulse (Conference...

    Office of Scientific and Technical Information (OSTI)

    Conference: Extreme dynamic compression with a low energy laser pulse Citation Details In-Document Search Title: Extreme dynamic compression with a low energy laser pulse You ...

  8. A Multicomponent Blend as a Diesel Fuel Surrogate for Compression...

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

    A Multicomponent Blend as a Diesel Fuel Surrogate for Compression Ignition Engine Applications Title A Multicomponent Blend as a Diesel Fuel Surrogate for Compression Ignition...

  9. 2013 Hydrogen Compression, Storage, and Dispensing Cost Reduction...

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

    Hydrogen Compression, Storage, and Dispensing Cost Reduction Workshop Final Report 2013 Hydrogen Compression, Storage, and Dispensing Cost Reduction Workshop Final Report ...

  10. POSTPONED: Webinar January 26: Update to the 700 bar Compressed...

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

    POSTPONED: Webinar January 26: Update to the 700 bar Compressed Hydrogen Storage System Cost Projection POSTPONED: Webinar January 26: Update to the 700 bar Compressed Hydrogen ...

  11. NJ Compressed Natural Gas Refuse Trucks, Shuttle Buses and Infrastruct...

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

    NJ Compressed Natural Gas Refuse Trucks, Shuttle Buses and Infrastructure NJ Compressed Natural Gas Refuse Trucks, Shuttle Buses and Infrastructure 2012 DOE Hydrogen and Fuel Cells ...

  12. Evaluation of the Compressed Air Challenge Training Program

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

    ... aware of compressed air system efficien- cy measures prior to attending the CAC training. ... Compressed air system efficien- cy and consulting services represented a very small ...

  13. Graphene physics and insulator-metal transition in compressed...

    Office of Scientific and Technical Information (OSTI)

    Graphene physics and insulator-metal transition in compressed hydrogen Title: Graphene physics and insulator-metal transition in compressed hydrogen Authors: Naumov, Ivan I. ; ...

  14. Open Issues in the Development of Safety Standards for Compressed...

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

    Issues in the Development of Safety Standards for Compressed Hydrogen Storage at SAE-International Open Issues in the Development of Safety Standards for Compressed Hydrogen...

  15. Relativistic laser pulse compression in magnetized plasmas

    SciTech Connect (OSTI)

    Liang, Yun; Sang, Hai-Bo Wan, Feng; Lv, Chong; Xie, Bai-Song

    2015-07-15

    The self-compression of a weak relativistic Gaussian laser pulse propagating in a magnetized plasma is investigated. The nonlinear Schrödinger equation, which describes the laser pulse amplitude evolution, is deduced and solved numerically. The pulse compression is observed in the cases of both left- and right-hand circular polarized lasers. It is found that the compressed velocity is increased for the left-hand circular polarized laser fields, while decreased for the right-hand ones, which is reinforced as the enhancement of the external magnetic field. We find a 100 fs left-hand circular polarized laser pulse is compressed in a magnetized (1757 T) plasma medium by more than ten times. The results in this paper indicate the possibility of generating particularly intense and short pulses.

  16. Pulse compression and prepulse suppression apparatus

    DOE Patents [OSTI]

    Dane, Clifford B.; Hackel, Lloyd A.; George, Edward V.; Miller, John L.; Krupke, William F.

    1993-01-01

    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).

  17. Method for compression of binary data

    DOE Patents [OSTI]

    Berlin, G.J.

    1996-03-26

    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.

  18. Pulse compression and prepulse suppression apparatus

    DOE Patents [OSTI]

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

    1993-11-09

    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).

  19. Seneca Compressed Air Energy Storage (CAES) Project

    SciTech Connect (OSTI)

    2012-11-30

    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.

  20. Method for compression of binary data

    DOE Patents [OSTI]

    Berlin, Gary J.

    1996-01-01

    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.

  1. Method and apparatus for signal compression

    DOE Patents [OSTI]

    Carangelo, R.M.

    1994-02-08

    The method and apparatus of the invention effects compression of an analog electrical signal (e.g., representing an interferogram) by introducing into it a component that is a cubic function thereof, normally as a nonlinear negative signal in a feedback loop of an Op Amp. The compressed signal will most desirably be digitized and then digitally decompressed so as to produce a signal that emulates the original. 8 figures.

  2. Method and apparatus for signal compression

    DOE Patents [OSTI]

    Carangelo, Robert M.

    1994-02-08

    The method and apparatus of the invention effects compression of an analog electrical signal (e.g., representing an interferogram) by introducing into it a component that is a cubic function thereof, normally as a nonlinear negative signal in a feedback loop of an Op Amp. The compressed signal will most desirably be digitized and then digitally decompressed so as to produce a signal that emulates the original.

  3. Nonlinear compressions in merging plasma jets

    SciTech Connect (OSTI)

    Messer, S.; Case, A.; Wu, L.; Brockington, S.; Witherspoon, F. D.

    2013-03-15

    We investigate the dynamics of merging supersonic plasma jets using an analytic model. The merging structures exhibit supersonic, nonlinear compressions which may steepen into full shocks. We estimate the distance necessary to form such shocks and the resulting jump conditions. These theoretical models are compared to experimental observations and simulated dynamics. We also use those models to extrapolate behavior of the jet-merging compressions in a Plasma Jet Magneto-Inertial Fusion reactor.

  4. Lossy compression of weak lensing data

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

    Vanderveld, R. Ali; Bernstein, Gary M.; Stoughton, Chris; Rhodes, Jason; Massey, Richard; Dobke, Benjamin M.

    2011-07-12

    Future orbiting observatories will survey large areas of sky in order to constrain the physics of dark matter and dark energy using weak gravitational lensing and other methods. Lossy compression of the resultant data will improve the cost and feasibility of transmitting the images through the space communication network. We evaluate the consequences of the lossy compression algorithm of Bernstein et al. (2010) for the high-precision measurement of weak-lensing galaxy ellipticities. This square-root algorithm compresses each pixel independently, and the information discarded is by construction less than the Poisson error from photon shot noise. For simulated space-based images (without cosmicmore » rays) digitized to the typical 16 bits per pixel, application of the lossy compression followed by image-wise lossless compression yields images with only 2.4 bits per pixel, a factor of 6.7 compression. We demonstrate that this compression introduces no bias in the sky background. The compression introduces a small amount of additional digitization noise to the images, and we demonstrate a corresponding small increase in ellipticity measurement noise. The ellipticity measurement method is biased by the addition of noise, so the additional digitization noise is expected to induce a multiplicative bias on the galaxies measured ellipticities. After correcting for this known noise-induced bias, we find a residual multiplicative ellipticity bias of m {approx} -4 x 10-4. This bias is small when compared to the many other issues that precision weak lensing surveys must confront, and furthermore we expect it to be reduced further with better calibration of ellipticity measurement methods.« less

  5. Premix charge, compression ignition combustion system optimization |

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

    Department of Energy Premix charge, compression ignition combustion system optimization Premix charge, compression ignition combustion system optimization Presentation given at DEER 2006, August 20-24, 2006, Detroit, Michigan. Sponsored by the U.S. DOE's EERE FreedomCar and Fuel Partnership and 21st Century Truck Programs. 2006_deer_gustafson.pdf (1.47 MB) More Documents & Publications Advanced Combustion Technology to Enable High Efficiency Clean Combustion Heavy-Duty HCCI Development

  6. Compressing bitmap indexes for faster search operations

    SciTech Connect (OSTI)

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

    2002-04-25

    In this paper, we study the effects of compression on bitmap indexes. The main operations on the bitmaps during query processing are bitwise logical operations such as AND, OR, NOT, etc. Using the general purpose compression schemes, such as gzip, the logical operations on the compressed bitmaps are much slower than on the uncompressed bitmaps. Specialized compression schemes, like the byte-aligned bitmap code(BBC), are usually faster in performing logical operations than the general purpose schemes, but in many cases they are still orders of magnitude slower than the uncompressed scheme. To make the compressed bitmap indexes operate more efficiently, we designed a CPU-friendly scheme which we refer to as the word-aligned hybrid code (WAH). Tests on both synthetic and real application data show that the new scheme significantly outperforms well-known compression schemes at a modest increase in storage space. Compared to BBC, a scheme well-known for its operational efficiency, WAH performs logical operations about 12 times faster and uses only 60 percent more space. Compared to the uncompressed scheme, in most test cases WAH is faster while still using less space. We further verified with additional tests that the improvement in logical operation speed translates to similar improvement in query processing speed.

  7. DRIVE CYCLE EFFICIENCY AND EMISSIONS ESTIMATES FOR REACTIVITY CONTROLLED COMPRESSION IGNITION IN A MULTI-CYLINDER LIGHT-DUTY DIESEL ENGINE

    SciTech Connect (OSTI)

    Curran, Scott; Briggs, Thomas E; Cho, Kukwon; Wagner, Robert M

    2011-01-01

    In-cylinder blending of gasoline and diesel to achieve Reactivity Controlled Compression Ignition (RCCI) has been shown to reduce NOx and PM emissions while maintaining or improving brake thermal efficiency as compared to conventional diesel combustion (CDC). The RCCI concept has an advantage over many advanced combustion strategies in that by varying both the percent of premixed gasoline and EGR rate, stable combustion can be extended over more of the light-duty drive cycle load range. Changing the percent premixed gasoline changes the fuel reactivity stratification in the cylinder providing further control of combustion phasing and pressure rise rate than the use of EGR alone. This paper examines the combustion and emissions performance of light-duty diesel engine using direct injected diesel fuel and port injected gasoline to carry out RCCI for steady-state engine conditions which are consistent with a light-duty drive cycle. A GM 1.9L four-cylinder engine with the stock compression ratio of 17.5:1, common rail diesel injection system, high-pressure EGR system and variable geometry turbocharger was modified to allow for port fuel injection with gasoline. Engine-out emissions, engine performance and combustion behavior for RCCI operation is compared against both CDC and a premixed charge compression ignition (PCCI) strategy which relies on high levels of EGR dilution. The effect of percent of premixed gasoline, EGR rate, boost level, intake mixture temperature, combustion phasing and pressure rise rate is investigated for RCCI combustion for the light-duty modal points. Engine-out emissions of NOx and PM were found to be considerably lower for RCCI operation as compared to CDC and PCCI, while HC and CO emissions were higher. Brake thermal efficiency was similar or higher for many of the modal conditions for RCCI operation. The emissions results are used to estimate hot-start FTP-75 emissions levels with RCCI and are compared against CDC and PCCI modes.

  8. A dedicated compression device for high resolution X-ray tomography of compressed gas diffusion layers

    SciTech Connect (OSTI)

    Tötzke, C.; Manke, I.; Banhart, J.; Gaiselmann, G.; Schmidt, V.; Bohner, J.; Müller, B. R.; Kupsch, A.; Hentschel, M. P.; Lehnert, W.

    2015-04-15

    We present an experimental approach to study the three-dimensional microstructure of gas diffusion layer (GDL) materials under realistic compression conditions. A dedicated compression device was designed that allows for synchrotron-tomographic investigation of circular samples under well-defined compression conditions. The tomographic data provide the experimental basis for stochastic modeling of nonwoven GDL materials. A plain compression tool is used to study the fiber courses in the material at different compression stages. Transport relevant geometrical parameters, such as porosity, pore size, and tortuosity distributions, are exemplarily evaluated for a GDL sample in the uncompressed state and for a compression of 30 vol.%. To mimic the geometry of the flow-field, we employed a compression punch with an integrated channel-rib-profile. It turned out that the GDL material is homogeneously compressed under the ribs, however, much less compressed underneath the channel. GDL fibers extend far into the channel volume where they might interfere with the convective gas transport and the removal of liquid water from the cell.

  9. Video compression of coronary angiograms based on discrete wavelet transform with block classification

    SciTech Connect (OSTI)

    Ho, B.K.T.; Tsai, M.J.; Wei, J.; Ma, M.; Saipetch, P.

    1996-12-01

    A new method of video compression for angiographic images has been developed to achieve high compression ratio ({approximately}20:1) while eliminating block artifacts which leads to loss of diagnostic accuracy. This method adopts motion picture experts group`s (MPEG`s) motion compensated prediction to take advantage of frame to frame correlation. However, in contrast to MPEG, the error images arising from mismatches in the motion estimation are encoded by discrete wavelet transform (DWT) rather than block discrete cosine transform (DCT). Furthermore, the authors developed a classification scheme which label each block in an image as intra, error, or background type and encode it accordingly. This hybrid coding can significantly improve the compression efficiency in certain cases. This method can be generalized for any dynamic image sequences applications sensitive to block artifacts.

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

    DOE Patents [OSTI]

    Gonczy, J.D.; Markley, F.W.; McCaw, W.R.; Niemann, R.C.

    1992-04-21

    An apparatus for evaluating the tensile and compressive properties of material samples at very low or cryogenic temperatures employs a stationary frame and a dewar mounted below the frame. A pair of coaxial cylindrical tubes extend downward towards the bottom of the dewar. A compressive or tensile load is generated hydraulically and is transmitted by the inner tube to the material sample. The material sample is located near the bottom of the dewar in a liquid refrigerant bath. The apparatus employs a displacement measuring device, such as a linear variable differential transformer, to measure the deformation of the material sample relative to the amount of compressive or tensile force applied to the sample. 7 figs.

  11. Forecourt Storage and Compression Options | Department of Energy

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

    Storage and Compression Options Forecourt Storage and Compression Options Presentation by Mark Richards on forecourt storage and compression options. wkshp_storage_richards.pdf (832.74 KB) More Documents & Publications H2A Delivery: Forecourt Compression & Storage Optimization (Part II) H2A Delivery Models and Results Hydrogen Delivery Infrastructure Option Analysis

  12. THE TURBULENT DYNAMO IN HIGHLY COMPRESSIBLE SUPERSONIC PLASMAS

    SciTech Connect (OSTI)

    Federrath, Christoph; Schober, Jennifer; Bovino, Stefano; Schleicher, Dominik R. G.

    2014-12-20

    The turbulent dynamo may explain the origin of cosmic magnetism. While the exponential amplification of magnetic fields has been studied for incompressible gases, little is known about dynamo action in highly compressible, supersonic plasmas, such as the interstellar medium of galaxies and the early universe. Here we perform the first quantitative comparison of theoretical models of the dynamo growth rate and saturation level with three-dimensional magnetohydrodynamical simulations of supersonic turbulence with grid resolutions of up to 1024{sup 3} cells. We obtain numerical convergence and find that dynamo action occurs for both low and high magnetic Prandtl numbers Pm = ?/? = 0.1-10 (the ratio of viscous to magnetic dissipation), which had so far only been seen for Pm ? 1 in supersonic turbulence. We measure the critical magnetic Reynolds number, Rm{sub crit}=129{sub ?31}{sup +43}, showing that the compressible dynamo is almost as efficient as in incompressible gas. Considering the physical conditions of the present and early universe, we conclude that magnetic fields need to be taken into account during structure formation from the early to the present cosmic ages, because they suppress gas fragmentation and drive powerful jets and outflows, both greatly affecting the initial mass function of stars.

  13. Alternative Fuels Data Center: Compressed Natural Gas Fueling Stations

    Alternative Fuels and Advanced Vehicles Data Center [Office of Energy Efficiency and Renewable Energy (EERE)]

    Natural Gas Printable Version Share this resource Send a link to Alternative Fuels Data Center: 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

  14. Preventive Maintenance Strategies for Compressed Air Systems | Department

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

    of Energy Preventive Maintenance Strategies for Compressed Air Systems Preventive Maintenance Strategies for Compressed Air Systems This tip sheet discusses preventive maintenance strategies for compressed air systems to avoid high equipment repair and replacement costs. COMPRESSED AIR TIP SHEET #6 Preventive Maintenance Strategies for Compressed Air Systems (August 2004) (245.23 KB) More Documents & Publications Effect of Intake on Compressor Performance Maintaining System Air Quality

  15. NOVEL CONCEPTS FOR THE COMPRESSION OF LARGE VOLUMES OF CARBON DIOXIDE-PHASE III

    SciTech Connect (OSTI)

    Moore, J. Jeffrey; Allison, Timothy; Evans, Neal; Moreland, Brian; Hernandez, Augusto; Day, Meera; Ridens, Brandon

    2014-06-30

    In the effort to reduce the release of CO2 greenhouse gases to the atmosphere, sequestration of CO2 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 8-12% 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 CO2 compression concepts is to reliably boost the pressure of CO2 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 CO2 while removing the heat of compression internal to the compressor. The highpressure ratio, due to the delivery pressure of the CO2 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 inter-stage cooling is desirable. While isothermal compression has been utilized in some services, it has not been optimized for the IGCC environment. Phase I of this project determined the optimum compressor configuration and developed technology concepts for internal heat removal. Other compression options using liquefied CO2 and cryogenic pumping were explored as well. Preliminary analysis indicated up to a 35% reduction in power is possible with the new concepts being considered. In the Phase II program, two experimental test rigs were developed to investigate the two concepts further. A new pump loop facility was constructed to qualify a cryogenic turbopump for use on liquid CO2. Also, an internally cooled compressor diaphragm was developed and tested in a closed loop compressor facility using CO2. Both test programs

  16. Dynamic time expansion and compression using nonlinear waveguides

    DOE Patents [OSTI]

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

    2004-06-22

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

  17. Dynamic Time Expansion and Compression Using Nonlinear Waveguides

    DOE Patents [OSTI]

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

    2004-06-22

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

  18. Inelastic response of silicon to shock compression

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

    Higginbotham, Andrew; Stubley, P. G.; Comley, A. J.; Eggert, J. H.; Foster, J. M.; Kalantar, D. H.; McGonegle, D.; Patel, S.; Peacock, L. J.; Rothman, S. D.; et al

    2016-04-13

    The elastic and inelastic response of [001] oriented silicon to laser compression has been a topic of considerable discussion for well over a decade, yet there has been little progress in understanding the basic behaviour of this apparently simple material. We present experimental x-ray diffraction data showing complex elastic strain profiles in laser compressed samples on nanosecond timescales. We also present molecular dynamics and elasticity code modelling which suggests that a pressure induced phase transition is the cause of the previously reported ‘anomalous’ elastic waves. Moreover, this interpretation allows for measurement of the kinetic timescales for transition. Lastly, this modelmore » is also discussed in the wider context of reported deformation of silicon to rapid compression in the literature.« less

  19. Fuel cell stack compressive loading system

    DOE Patents [OSTI]

    Fahle, Ronald W.; Reiser, Carl A.

    1982-01-01

    A fuel cell module comprising a stack of fuel cells with reactant gas manifolds sealed against the external surfaces of the stack includes a constraint system for providing a compressive load on the stack wherein the constraint system maintains the stack at a constant height (after thermal expansion) and allows the compressive load to decrease with time as a result of the creep characteristics of the stack. Relative motion between the manifold sealing edges and the stack surface is virtually eliminated by this constraint system; however it can only be used with a stack having considerable resiliency and appropriate thermal expansion and creep characteristics.

  20. Techniques for optically compressing light intensity ranges

    DOE Patents [OSTI]

    Rushford, M.C.

    1989-03-28

    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.

  1. Techniques for optically compressing light intensity ranges

    DOE Patents [OSTI]

    Rushford, Michael C.

    1989-01-01

    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.

  2. Fast electron microscopy via compressive sensing

    DOE Patents [OSTI]

    Larson, Kurt W; Anderson, Hyrum S; Wheeler, Jason W

    2014-12-09

    Various technologies described herein pertain to compressive sensing electron microscopy. A compressive sensing electron microscope includes a multi-beam generator and a detector. The multi-beam generator emits a sequence of electron patterns over time. Each of the electron patterns can include a plurality of electron beams, where the plurality of electron beams is configured to impart a spatially varying electron density on a sample. Further, the spatially varying electron density varies between each of the electron patterns in the sequence. Moreover, the detector collects signals respectively corresponding to interactions between the sample and each of the electron patterns in the sequence.

  3. INTEGRATED 15KV SIC VSD AND HIGH-SPEED MW MOTOR FOR GAS COMPRESSION SYSTEMS

    Broader source: Energy.gov [DOE]

    Eaton Corporation – Arden, NC A 15 kilovolt (kV) SiC variable-speed drive will be integrated with a high-speed megawatt motor for gas compression applications. This new drive technology will be developed and tested to operate at greater than 99% efficiency and achieve 10 times the power density of competing drives, providing an integrated, highly-efficient motor and drive system for natural gas applications. Fact sheet coming soon.

  4. Internal combustion engine with compound air compression

    SciTech Connect (OSTI)

    Paul, M.A.; Paul, A.

    1991-10-15

    This patent describes an internal combustion engine in combination with a compound air compression system. It comprises: a reciprocator with at least one cylinder, at least one piston reciprocal in the cylinder and a combustion chamber formed in substantial part by portions of the piston and cylinder, the reciprocator having a drive shaft; a rotary compressor having a drive shaft mechanically coupled to the drive shaft of the reciprocator, the rotary compressor having a Wankel-type, three-lobe, epitrochiodal configuration sides having a conduit conjected to the reciprocator for supplying compressed air to the reciprocator; a turbocharged with a gas turbine and a turbocompressor, the turbocompressor having an air conduit connected to the expander side of the rotary compressor; and a bypass conduit with a valve means connecting the turbocharger to the reciprocator for supplying compressed air directly to the reciprocator wherein the drive shaft of the reciprocator and the drive shaft of the compressor have connecting means for transmitting mechanical energy to the reciprocator at mid to high operating speeds of the engine when the turbocharge supplies compressed air to the rotary compressor and, at least in part, drives the rotary compressor.

  5. Weather-Corrected Performance Ratio

    SciTech Connect (OSTI)

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

    2013-04-01

    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.

  6. Heat pump employing optimal refrigerant compressor for low pressure ratio applications

    DOE Patents [OSTI]

    Ecker, Amir L.

    1982-01-01

    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.

  7. Determine the Cost of Compressed Air for Your Plant; Industrial...

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

    and load duty cycle. * Use a systems approach while operating and maintaining a compressed air system. * Adopt a plant-wide compressed air management policy to cut costs and ...

  8. 2014 - LNG Export, Compressed Natural Gas (CNG), Re-Exports ...

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

    2014 - LNG Export, Compressed Natural Gas (CNG), Re-Exports & Long Term Natural Gas Applications 2014 - LNG Export, Compressed Natural Gas (CNG), Re-Exports & Long Term Natural Gas ...

  9. 2015 - LNG Export, Compressed Natural Gas (CNG), Re-Exports ...

    Energy Savers [EERE]

    5 - LNG Export, Compressed Natural Gas (CNG), Re-Exports & Long Term Natural Gas Applications 2015 - LNG Export, Compressed Natural Gas (CNG), Re-Exports & Long Term Natural Gas...

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

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

    Record | Princeton Plasma Physics Lab National Ignition Facility (NIF): Under Pressure: Ramp-Compression Smashes Record American Fusion News Category: National Ignition Facility Link: National Ignition Facility (NIF): Under Pressure: Ramp-Compression Smashes Record

  11. Specialized control panels designed for on-site compression of...

    Office of Scientific and Technical Information (OSTI)

    Specialized control panels designed for on-site compression of natural gas Citation Details In-Document Search Title: Specialized control panels designed for on-site compression of ...

  12. Crystal structure and compressibility of lead dioxide up to 140...

    Office of Scientific and Technical Information (OSTI)

    Crystal structure and compressibility of lead dioxide up to 140 GPa Citation Details In-Document Search Title: Crystal structure and compressibility of lead dioxide up to 140 GPa ...

  13. 2016 - LNG Export, Compressed Natural Gas (CNG), Re-Exports ...

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

    6 - LNG Export, Compressed Natural Gas (CNG), Re-Exports & Long Term Natural Gas Applications 2016 - LNG Export, Compressed Natural Gas (CNG), Re-Exports & Long Term Natural Gas ...

  14. Guidelines for Selecting a Compressed Air System Service Provider

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

    ... see first hand the type of repair shop and parts warehouse with which you will be dealing. ... of Compressed Air Systems and Advanced Management of Compressed Air Systems training to ...

  15. Cryo-Compressed Hydrogen Storage: Performance and Cost Review

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

    R.K. Ahluwalia, J-K Peng and T. Q. Hua Compressed and Cryo-Compressed Hydrogen Storage Workshop Crystal City Marriott, Arlington VA February 14-15, 2011 This presentation does not ...

  16. Summary of Compression Testing of U-10Mo

    SciTech Connect (OSTI)

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

    2012-10-31

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

  17. IMPROVING COMPRESSED AIR SYSTEM PERFORMANCE: A SOURCEBOOK FOR INDUSTRY

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

    IMPROVING COMPRESSED AIR SYSTEM PERFORMANCE: A SOURCEBOOK FOR INDUSTRY Improving Compressed Air System Performance A Sourcebook for Industry Third Edition U.S. DEPARTMENT OF ENERGY Energy Efficiency & Renewable Energy ADVANCED MANUFACTURING OFFICE IMPROVING COMPRESSED AIR SYSTEM PERFORMANCE: A SOURCEBOOK FOR INDUSTRY ACKNOWLEDGEMENTS Improving Compressed Air System Performance: A Sourcebook for Industry is a cooperative effort of the U.S. Department of Energy's Office of Energy Efficiency

  18. Pdc - The Worldwide Leader in Hydrogen Refueling Station Compression |

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

    Department of Energy Pdc - The Worldwide Leader in Hydrogen Refueling Station Compression Pdc - The Worldwide Leader in Hydrogen Refueling Station Compression This presentation by Matther Weaver of Pdc Machines Inc. was given at the was given at the DOE Hydrogen Compression, Storage, and Dispensing Workshop in March 2013. csd_workshop_3_weaver.pdf (1.36 MB) More Documents & Publications 2013 Hydrogen Compression, Storage, and Dispensing Cost Reduction Workshop Final Report CX-100223

  19. Dynamic Time Expansion and Compression Using Nonlinear Waveguides...

    Office of Scientific and Technical Information (OSTI)

    Country of Publication: United States Language: English Subject: 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AMPLITUDES; COMPRESSION; REFRACTIVE INDEX; VELOCITY; ...

  20. Fact Sheet: Isothermal Compressed Air Energy Storage (August 2013) |

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

    Department of Energy Isothermal Compressed Air Energy Storage (August 2013) Fact Sheet: Isothermal Compressed Air Energy Storage (August 2013) SustainX will demonstrate an isothermal compressed air energy storage (ICAES) system. The system captures the heat from compression in water and stores the captured heat until it is needed again for expansion. Storing the captured heat eliminates the need for a gas combustion turbine and improves efficiency. For more information about how OE performs

  1. Onboard Type IV Compressed Hydrogen Storage System Cost Analysis Webinar |

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

    Department of Energy Onboard Type IV Compressed Hydrogen Storage System Cost Analysis Webinar Onboard Type IV Compressed Hydrogen Storage System Cost Analysis Webinar Access the recording and download the presentation slides from the Fuel Cell Technologies Office webinar "Update to the 700 bar Compressed Hydrogen Storage System Cost Projection" held on February 25, 2016. Onboard Type IV Compressed Hydrogen Storage System Cost Analysis Webinar Slides (2.59 MB) More Documents &

  2. Hydrogen Compression, Storage, and Dispensing Cost Reduction Workshop Addendum

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

    Compression, Storage, and Dispensing Cost Reduction Workshop P a g e | 1 Addendum The Department of Energy's Fuel Cell Technologies Office received additional feedback on compression, storage, and dispensing needs through a request for information (RFI) issued in June 2013. Compression Among the additional needs identified for compression were research and demonstration (R&D) in the following area:  Proton exchange membrane development to allow for high pressure electrolysis to reduce the

  3. 2013 Hydrogen Compression, Storage, and Dispensing Cost Reduction Workshop

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

    Final Report | Department of Energy Hydrogen Compression, Storage, and Dispensing Cost Reduction Workshop Final Report 2013 Hydrogen Compression, Storage, and Dispensing Cost Reduction Workshop Final Report Proceedings from the Hydrogen Compression, Storage, and Dispensing Cost Reduction Workshop held March 20-21, 2013, at Argonne National Laboratory. 2013_csd_workshop_report.pdf (2.03 MB) More Documents & Publications Hydrogen Compression, Storage, and Dispensing Cost Reduction Workshop

  4. Pre-In-Plant Training Webinar (Compressed Air): Presentation Slides |

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

    Department of Energy Pre-In-Plant Training Webinar (Compressed Air): Presentation Slides Pre-In-Plant Training Webinar (Compressed Air): Presentation Slides The presentation slides from a pre-In-Plant Training webinar hosted by Better Plants on March 3, 2015. The webinar covered the basics of finding energy savings in Compressed Air systems and introduces the AIRMaster+ software tool. Pre-In-Plant Training Webinar (Compressed Air) (3.96 MB) More Documents & Publications AIRMaster+ Tool

  5. Determining the Right Air Quality for Your Compressed Air System

    Broader source: Energy.gov [DOE]

    This tip sheet outlines the main factors for determining the right air quality for compressed air systems.

  6. Compressive stress system for a gas turbine engine

    SciTech Connect (OSTI)

    Hogberg, Nicholas Alvin

    2015-03-24

    The present application provides a compressive stress system for a gas turbine engine. The compressive stress system may include a first bucket attached to a rotor, a second bucket attached to the rotor, the first and the second buckets defining a shank pocket therebetween, and a compressive stress spring positioned within the shank pocket.

  7. Production-Intent Lost-Motion Variable Valve Actuation Systems | Department

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

    of Energy Production-Intent Lost-Motion Variable Valve Actuation Systems Production-Intent Lost-Motion Variable Valve Actuation Systems Variable valve actuation with on/off IEGR pre-bump is an enabling technology for HCCI, PCCI, LTC and other advanced combustion techniques, and designs for production-intent equipment have been developed deer09_ernest.pdf (149.78 KB) More Documents & Publications Expanding Robust HCCI Operation (Delphi CRADA) Rapid Compression Machine … A Key

  8. NEUTRON SOURCE USING MAGNETIC COMPRESSION OF PLASMA

    DOE Patents [OSTI]

    Quinn, W.E.; Elmore, W.C.; Little, E.M.; Boyer, K.; Tuck, J.L.

    1961-10-31

    A fusion reactor is described that utilizes compression and heating of an ionized thermonuclear fuel by an externally applied magnetic field, thus avoiding reliance on the pinch effect and its associated instability problems. The device consists of a gas-confining ceramic container surrounded by a single circumferential coil having a shape such as to produce a magnetic mirror geometry. A sinusoidally-oscillating, exponentially-damped current is passed circumferentially around the container, through the coil, inducing a circumferential current in the gas. Maximum compression and plasma temperature are obtained at the peak of the current oscillations, coinciding with maximum magnetic field intensity. Enhanced temperatures are obtained in the second and succeeding half cycles because the thermal energy accumulates from one half cycle to the next. (AEC)

  9. Towards efficient backward-in-time adjoint computations using data compression techniques

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

    Cyr, E. C.; Shadid, J. N.; Wildey, T.

    2014-12-16

    In the context of a posteriori error estimation for nonlinear time-dependent partial differential equations, the state-of-the-practice is to use adjoint approaches which require the solution of a backward-in-time problem defined by a linearization of the forward problem. One of the major obstacles in the practical application of these approaches, we found, is the need to store, or recompute, the forward solution to define the adjoint problem and to evaluate the error representation. Our study considers the use of data compression techniques to approximate forward solutions employed in the backward-in-time integration. The development derives an error representation that accounts for themore » difference between the standard-approach and the compressed approximation of the forward solution. This representation is algorithmically similar to the standard representation and only requires the computation of the quantity of interest for the forward solution and the data-compressed reconstructed solution (i.e. scalar quantities that can be evaluated as the forward problem is integrated). This approach is then compared with existing techniques, such as checkpointing and time-averaged adjoints. Lastly, we provide numerical results indicating the potential efficiency of our approach on a transient diffusion–reaction equation and on the Navier–Stokes equations. These results demonstrate memory compression ratios up to 450×450× while maintaining reasonable accuracy in the error-estimates.« less

  10. Compression of ground-motion data

    SciTech Connect (OSTI)

    Long, J.W.

    1981-04-01

    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.

  11. COMPRESSION SEAL AND SEALING MATERIAL THEREFOR

    DOE Patents [OSTI]

    Branin, T.G.

    1962-05-29

    This patent relates to compression seal and more particularly to a seaiing material therefor. The sealing surface is a coating consisting of alternate layers of gold and of a non-gold metal having similar plastic flow properties under pressure as gold. The coating is substantially free from oxidation effects when exposed to ambient atmosphere and does not become brittle when worked, as in a valve. (AEC)

  12. Method and apparatus for compressing ions

    SciTech Connect (OSTI)

    Garimella, Sandilya V. B.; Ibrahim, Yehia M.; Anderson, Gordon A.; Smith, Richard D.

    2015-06-23

    A method and apparatus for compressing ions inside an ion mobility device is disclosed. Ions are introduced into the mobility device. The ions are subjected to a non-constant electric field to form a potential gradient along a portion of the device so that ions with similar mobilities bunch together into sharper peaks while maintaining separation between other ions. The potential gradient progressively increases or decreases along the length of the device.

  13. Combined rankine and vapor compression cycles

    DOE Patents [OSTI]

    Radcliff, Thomas D.; Biederman, Bruce P.; Brasz, Joost J.

    2005-04-19

    An organic rankine cycle system is combined with a vapor compression cycle system with the turbine generator of the organic rankine cycle generating the power necessary to operate the motor of the refrigerant compressor. The vapor compression cycle is applied with its evaporator cooling the inlet air into a gas turbine, and the organic rankine cycle is applied to receive heat from a gas turbine exhaust to heat its boiler within one embodiment, a common condenser is used for the organic rankine cycle and the vapor compression cycle, with a common refrigerant, R-245a being circulated within both systems. In another embodiment, the turbine driven generator has a common shaft connected to the compressor to thereby eliminate the need for a separate motor to drive the compressor. In another embodiment, an organic rankine cycle system is applied to an internal combustion engine to cool the fluids thereof, and the turbo charged air is cooled first by the organic rankine cycle system and then by an air conditioner prior to passing into the intake of the engine.

  14. A Bunch Compression Method for Free Electron Lasers that Avoids Parasitic Compressions

    SciTech Connect (OSTI)

    Benson, Stephen V.; Douglas, David R.; Tennant, Christopher D.; Wilson, Frederick G.; Nguyen, Dinh

    2015-09-01

    Virtually all existing high energy (>few MeV) linac-driven FELs compress the electron bunch length though the use of off-crest acceleration on the rising side of the RF waveform followed by transport through a magnetic chicane. This approach has at least three flaws: 1) it is difficult to correct aberrations- particularly RF curvature, 2) rising side acceleration exacerbates space charge-induced distortion of the longitudinal phase space, and 3) all achromatic "negative compaction" compressors create parasitic compression during the final compression process, increasing the CSR-induced emittance growth. One can avoid these deficiencies by using acceleration on the falling side of the RF waveform and a compressor with M56>0. This approach offers multiple advantages: 1) It is readily achieved in beam lines supporting simple schemes for aberration compensation, 2) Longitudinal space charge (LSC)-induced phase space distortion tends, on the falling side of the RF waveform, to enhance the chirp, and 3) Compressors with M56>0 can be configured to avoid spurious over-compression. We will discuss this bunch compression scheme in detail and give results of a successful beam test in April 2012 using the JLab UV Demo FEL

  15. Method for preventing jamming conditions in a compression device

    DOE Patents [OSTI]

    Williams, Paul M.; Faller, Kenneth M.; Bauer, Edward J.

    2002-06-18

    A compression device for feeding a waste material to a reactor includes a waste material feed assembly having a hopper, a supply tube and a compression tube. Each of the supply and compression tubes includes feed-inlet and feed-outlet ends. A feed-discharge valve assembly is located between the feed-outlet end of the compression tube and the reactor. A feed auger-screw extends axially in the supply tube between the feed-inlet and feed-outlet ends thereof. A compression auger-screw extends axially in the compression tube between the feed-inlet and feed-outlet ends thereof. The compression tube is sloped downwardly towards the reactor to drain fluid from the waste material to the reactor and is oriented at generally right angle to the supply tube such that the feed-outlet end of the supply tube is adjacent to the feed-inlet end of the compression tube. A programmable logic controller is provided for controlling the rotational speed of the feed and compression auger-screws for selectively varying the compression of the waste material and for overcoming jamming conditions within either the supply tube or the compression tube.

  16. Compression device for feeding a waste material to a reactor

    DOE Patents [OSTI]

    Williams, Paul M.; Faller, Kenneth M.; Bauer, Edward J.

    2001-08-21

    A compression device for feeding a waste material to a reactor includes a waste material feed assembly having a hopper, a supply tube and a compression tube. Each of the supply and compression tubes includes feed-inlet and feed-outlet ends. A feed-discharge valve assembly is located between the feed-outlet end of the compression tube and the reactor. A feed auger-screw extends axially in the supply tube between the feed-inlet and feed-outlet ends thereof. A compression auger-screw extends axially in the compression tube between the feed-inlet and feed-outlet ends thereof. The compression tube is sloped downwardly towards the reactor to drain fluid from the waste material to the reactor and is oriented at generally right angle to the supply tube such that the feed-outlet end of the supply tube is adjacent to the feed-inlet end of the compression tube. A programmable logic controller is provided for controlling the rotational speed of the feed and compression auger-screws for selectively varying the compression of the waste material and for overcoming jamming conditions within either the supply tube or the compression tube.

  17. Thermodynamic analysis of cascade microcryocoolers with low pressure ratios

    SciTech Connect (OSTI)

    Radebaugh, Ray

    2014-01-29

    The vapor-compression cycle for refrigeration near ambient temperature achieves high efficiency because the isenthalpic expansion of the condensed liquid is a rather efficient process. However, temperatures are limited to about 200 K with a single-stage system. Temperatures down to 77 K are possible with many stages. In the case of microcryocoolers using microcompressors, pressure ratios are usually limited to about 6 or less. As a result, even more stages are required to reach 77 K. If the microcompressors can be fabricated with low-cost wafer-level techniques, then the use of many stages with separate compressors may become a viable option for achieving temperatures of 77 K with high efficiency. We analyze the ideal thermodynamic efficiency of a cascade Joule-Thomson system for various temperatures down to 77 K and with low pressure ratios. About nine stages are required for 77 K, but fewer stages are also analyzed for operation at higher temperatures. For 77 K, an ideal second-law efficiency of 83 % of Carnot is possible with perfect recuperative heat exchangers and 65 % of Carnot is possible with no recuperative heat exchangers. The results are compared with calculated efficiencies in mixed-refrigerant cryocoolers over the range of 77 K to 200 K. Refrigeration at intermediate temperatures is also available. The use of single-component fluids in each of the stages is expected to eliminate the problem of pulsating flow and temperature oscillations experienced in microcryocoolers using mixed refrigerants.

  18. Homogenous charge compression ignition engine having a cylinder including a high compression space

    DOE Patents [OSTI]

    Agama, Jorge R.; Fiveland, Scott B.; Maloney, Ronald P.; Faletti, James J.; Clarke, John M.

    2003-12-30

    The present invention relates generally to the field of homogeneous charge compression engines. In these engines, fuel is injected upstream or directly into the cylinder when the power piston is relatively close to its bottom dead center position. The fuel mixes with air in the cylinder as the power piston advances to create a relatively lean homogeneous mixture that preferably ignites when the power piston is relatively close to the top dead center position. However, if the ignition event occurs either earlier or later than desired, lowered performance, engine misfire, or even engine damage, can result. Thus, the present invention divides the homogeneous charge between a controlled volume higher compression space and a lower compression space to better control the start of ignition.

  19. VARIABLE TIME DELAY MEANS

    DOE Patents [OSTI]

    Clemensen, R.E.

    1959-11-01

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

  20. Variable Frequency Drives

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

    Marketing Toolkit The Benefits of Variable Frequency Drives (VFDs) VFDs help adjust motor speeds to match loads and improve efficiency while conserving energy. The benefits...

  1. International magnetic pulse compression workshop: (Proceedings)

    SciTech Connect (OSTI)

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

    1991-04-01

    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.

  2. Low emissions compression ignited engine technology

    DOE Patents [OSTI]

    Coleman, Gerald N.; Kilkenny, Jonathan P.; Fluga, Eric C.; Duffy, Kevin P.

    2007-04-03

    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.

  3. Coke cake behavior under compressive forces

    SciTech Connect (OSTI)

    Watakabe, S.; Takeda, T.; Itaya, H.; Suginobe, H.

    1997-12-31

    The deformation of the coke cake and load on the side wall during pushing were studied using an electric furnace equipped with a movable wall. Coke cake was found to deform in three stages under compressive forces. The coke cake was shortened in the pushing direction in the cake deformation stage, and load was generated on the side walls in the high wall load stage. Secondary cracks in the coke cake were found to prevent load transmission on the wall. The maximum load transmission rate was controlled by adjusting the maximum fluidity and mean reflectance of the blended coal.

  4. Optimization of Storage vs. Compression Capacity

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

    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 0 100 200 300 400 500 600 700 800 900 0 15 30 45 60 75 90 105 120 135 150 Mass (Kg) Pressure (bar) and Temperature (K) Time (Sec) Low Pressure Cascade Mid Pressure Cascade High Pressure Pressure Mass Temperature Temperature Temperature 2 0 1 2 3 4 5 6 0 10 20 30 40 50 60 70 80 90 0 15 30 45 60 75 90 105 120 135 150 Mass (Kg)

  5. Experimental Investigation of Effect of Injection Parameters, Compression Ratio and Ultra-cooled EGR on CI Engine Performance and Emissions

    Broader source: Energy.gov [DOE]

    Low temperature combustion, simultaneous reduction of NOx and PM, in CI engines is achieved with moderate rate of ultra-cooled EGR

  6. Experimental investigation of piston heat transfer under conventional diesel and reactivity-controlled compression ignition combustion regimes

    SciTech Connect (OSTI)

    Splitter, Derek A; Hendricks, Terry Lee; Ghandhi, Jaal B

    2014-01-01

    . However, for reactivity-controlled compression ignition, the mean surface temperature increased with changes in boost suggesting that equivalence ratio affects steady-state heat transfer.

  7. Frequency extrapolation by nonconvex compressive sensing

    SciTech Connect (OSTI)

    Chartrand, Rick; Sidky, Emil Y; Pan, Xiaochaun

    2010-12-03

    Tomographic imaging modalities sample subjects with a discrete, finite set of measurements, while the underlying object function is continuous. Because of this, inversion of the imaging model, even under ideal conditions, necessarily entails approximation. The error incurred by this approximation can be important when there is rapid variation in the object function or when the objects of interest are small. In this work, we investigate this issue with the Fourier transform (FT), which can be taken as the imaging model for magnetic resonance imaging (MRl) or some forms of wave imaging. Compressive sensing has been successful for inverting this data model when only a sparse set of samples are available. We apply the compressive sensing principle to a somewhat related problem of frequency extrapolation, where the object function is represented by a super-resolution grid with many more pixels than FT measurements. The image on the super-resolution grid is obtained through nonconvex minimization. The method fully utilizes the available FT samples, while controlling aliasing and ringing. The algorithm is demonstrated with continuous FT samples of the Shepp-Logan phantom with additional small, high-contrast objects.

  8. Shock compression of [001] single crystal silicon

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

    Zhao, S.; Remington, B.; Hahn, E. N.; Kad, B.; Bringa, E. M.; Meyers, M. A.

    2016-03-14

    Silicon is ubiquitous in our advanced technological society, yet our current understanding of change to its mechanical response at extreme pressures and strain-rates is far from complete. This is due to its brittleness, making recovery experiments difficult. High-power, short-duration, laser-driven, shock compression and recovery experiments on [001] silicon (using impedance-matched momentum traps) unveiled remarkable structural changes observed by transmission electron microscopy. As laser energy increases, corresponding to an increase in peak shock pressure, the following plastic responses are are observed: surface cleavage along {111} planes, dislocations and stacking faults; bands of amorphized material initially forming on crystallographic orientations consistent withmore » dislocation slip; and coarse regions of amorphized material. Molecular dynamics simulations approach equivalent length and time scales to laser experiments and reveal the evolution of shock-induced partial dislocations and their crucial role in the preliminary stages of amorphization. Furthermore, application of coupled hydrostatic and shear stresses produce amorphization below the hydrostatically determined critical melting pressure under dynamic shock compression.« less

  9. Fuel cell separator with compressible sealing flanges

    DOE Patents [OSTI]

    Mientek, A.P.

    1984-03-30

    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.

  10. Fuel cell separator with compressible sealing flanges

    DOE Patents [OSTI]

    Mientek, Anthony P.

    1985-04-30

    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.