National Library of Energy BETA

Sample records for junction compressor station

  1. Control optimization of the cryoplant warm compressor station for EAST

    SciTech Connect (OSTI)

    Zhuang, M.; Hu, L. B.; Zhou, Z. W.; Xia, G. H. [Cryogenic Engineering Division, Institute of Plasma Physics Chinese Academy of Sciences, P.O.Box 1126,Shushanhu Road 350, Hefei, Anhui 230031 (China)

    2014-01-29

    The cryogenic control system for EAST (Experimental Advanced Superconducting Tokamak) was designed based on DeltaV DCS of Emerson Corporation. The automatic control of the cryoplant warm compressors has been implemented. However, with ever-degrading performance of critical equipment, the cryoplant operation in the partial design conditions makes the control system fluctuate and unstable. In this paper, the warm compressor control system was optimized to eliminate the pressure oscillation based on the expert PID theory.

  2. Natural Gas Compressor Stations on the Interstate Pipeline Network: Developments Since 1996

    Reports and Publications (EIA)

    2007-01-01

    This special report looks at the use of natural gas pipeline compressor stations on the interstate natural gas pipeline network that serves the lower 48 states. It examines the compression facilities added over the past 10 years and how the expansions have supported pipeline capacity growth intended to meet the increasing demand for natural gas.

  3. Assessment of gas engine drives for CNG compressors at NGV fueling stations. Final technical report, June 1993-April 1995

    SciTech Connect (OSTI)

    Keder, J.; Darrow, K.G.

    1995-06-01

    This report assesses the technical and economic issues associated with the use of gas engine drives for gas compressors at natural gas vehicle (NGV) fueling stations. The use of gas engine drives and electric motor drives is compared for typical time fill, fast fill, and combined fill applications. NGV fueling station equipment is described with an emphasis on gas engine and electric motor drives, their installation, operation, and maintenance. The economic benefits of gas engine drives and electric motor drives are compared using sensitivity and operating cost analyses. A perspective of the current market for gas engine drives is also presented, as well as several case histories.

  4. National Account Energy Alliance Final Report for the Basin Electric Project at Northern Border Pipeline Company's Compressor Station #7, North Dakota

    SciTech Connect (OSTI)

    Sweetzer, Richard [Exergy Partners Corp.; Leslie, Neil [Gas Technology Institute

    2008-02-01

    A field research test and verification project was conducted at the recovered energy generation plant at Northern Border Pipeline Company Compressor Station #7 (CS#7) near St. Anthony. Recovered energy generation plant equipment was supplied and installed by ORMAT Technologies, Inc. Basin Electric is purchasing the electricity under a purchase power agreement with an ORMAT subsidiary, which owns and operates the plant.

  5. Natural Gas Compressor Stations on the Interstate Pipeline Network: Developments Since 1996

    Gasoline and Diesel Fuel Update (EIA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustments (Billion Cubic Feet) Wyoming963Residential2, 2014ProvedYear Jan FebYear Jan Feb Mar Apr MayCompressor

  6. Unique compressor passes field test

    SciTech Connect (OSTI)

    Not Available

    1992-10-01

    Revolutionary pipeline compression concept has proved successful at a Transcontinental Gas Pipe Line facility in Alabama. In April 1992, the MOPICO electric drive compressor completed 5,000 hours of successful operation at Transcontinental Gas Pipeline's Station 100 at Billingsley, Ala. The revolutionary gas pipeline compression concept eliminates many of the traditional complexities of a pipeline compressor station and has benefits not possible with conventional compressor systems. This paper reports that this is accomplished through the integration of technologies developed over the past 10 years into a design concept unique in the industry. Ross Hill Controls Inc., Houston, provides the adjustable-speed variable frequency drive unit that allows the electric motor to operate at speeds from 6,2000 rpm to 10,000 rpm. Transco Energy Ventures, a division of Transco Energy, participated in the development and assisted in placing the prototype unit on the Transcontinental Gas Pipeline system.

  7. Centrifugal Compressors

    SciTech Connect (OSTI)

    Hastbacka, Mildred; Dieckmann, John; Bouza, Antonio

    2013-02-06

    The article discusses small high speed centrifugal compressors. This topic was covered in a previous ASHRAE Journal column (2003). This article reviews another configuration which has become an established product. The operation, energy savings and market potential of this offering are addressed as well.

  8. Supersonic compressor

    DOE Patents [OSTI]

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

    2008-02-26

    A gas compressor based on the use of a driven rotor having an axially oriented compression ramp traveling at a local supersonic inlet velocity (based on the combination of inlet gas velocity and tangential speed of the ramp) which forms a supersonic shockwave axially, between adjacent strakes. In using this method to compress inlet gas, 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 gasdyanamic flow path formed between the gas compression ramp on a strake, the shock capture lip on the adjacent strake, and captures the resultant pressure within the stationary external housing while providing a diffuser downstream of the compression ramp.

  9. Hydride compressor

    DOE Patents [OSTI]

    Powell, James R. (Wading River, NY); Salzano, Francis J. (Patchogue, NY)

    1978-01-01

    Method of producing high energy pressurized gas working fluid power from a low energy, low temperature heat source, wherein the compression energy is gained by using the low energy heat source to desorb hydrogen gas from a metal hydride bed and the desorbed hydrogen for producing power is recycled to the bed, where it is re-adsorbed, with the recycling being powered by the low energy heat source. In one embodiment, the adsorption-desorption cycle provides a chemical compressor that is powered by the low energy heat source, and the compressor is connected to a regenerative gas turbine having a high energy, high temperature heat source with the recycling being powered by the low energy heat source.

  10. RELAP5-3D Compressor Model

    SciTech Connect (OSTI)

    James E. Fisher; Cliff B. Davis; Walter L. Weaver

    2005-06-01

    A compressor model has been implemented in the RELAP5-3D© code. The model is similar to that of the existing pump model, and performs the same function on a gas as the pump performs on a single-phase or two-phase fluid. The compressor component consists of an inlet junction and a control volume, and optionally, an outlet junction. This feature permits cascading compressor components in series. The equations describing the physics of the compressor are derived from first principles. These equations are used to obtain the head, the torque, and the energy dissipation. Compressor performance is specified using a map, specific to the design of the machine, in terms of the ratio of outlet-to-inlet total (or stagnation) pressure and adiabatic efficiency as functions of rotational velocity and flow rate. The input quantities are specified in terms of dimensionless variables, which are corrected to stagnation density and stagnation sound speed. A small correction was formulated for the input of efficiency to account for the error introduced by assumption of constant density when integrating the momentum equation. Comparison of the results of steady-state operation of the compressor model to those of the MIT design calculation showed excellent agreement for both pressure ratio and power.

  11. Recirculating rotary gas compressor

    DOE Patents [OSTI]

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

    1992-01-01

    A positive displacement, recirculating Roots-type rotary gas compressor which operates on the basis of flow work compression. The compressor includes a pair of large diameter recirculation conduits (24 and 26) which return compressed discharge gas to the compressor housing (14), where it is mixed with low pressure inlet gas, thereby minimizing adiabatic heating of the gas. The compressor includes a pair of involutely lobed impellers (10 and 12) and an associated port configuration which together result in uninterrupted flow of recirculation gas. The large diameter recirculation conduits equalize gas flow velocities within the compressor and minimize gas flow losses. The compressor is particularly suited to applications requiring sustained operation at higher gas compression ratios than have previously been feasible with rotary pumps, and is particularly applicable to refrigeration or other applications requiring condensation of a vapor.

  12. Recirculating rotary gas compressor

    DOE Patents [OSTI]

    Weinbrecht, J.F.

    1992-02-25

    A positive displacement, recirculating Roots-type rotary gas compressor is described which operates on the basis of flow work compression. The compressor includes a pair of large diameter recirculation conduits which return compressed discharge gas to the compressor housing, where it is mixed with low pressure inlet gas, thereby minimizing adiabatic heating of the gas. The compressor includes a pair of involutely lobed impellers and an associated port configuration which together result in uninterrupted flow of recirculation gas. The large diameter recirculation conduits equalize gas flow velocities within the compressor and minimize gas flow losses. The compressor is particularly suited to applications requiring sustained operation at higher gas compression ratios than have previously been feasible with rotary pumps, and is particularly applicable to refrigeration or other applications requiring condensation of a vapor. 12 figs.

  13. High ratio recirculating gas compressor

    DOE Patents [OSTI]

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

    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.

  14. 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.

  15. Supersonic gas compressor

    DOE Patents [OSTI]

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

    2007-11-13

    A gas compressor based on the use of a 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. In using this method to compress inlet gas, 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 gasdyanamic flow path formed between the rim of the rotor, the strakes, and a stationary external housing. Part load efficiency is enhanced by the use of a pre-swirl compressor, and using a bypass stream to bleed a portion of the intermediate pressure gas after passing through the pre-swirl compressor back to the inlet of the pre-swirl compressor. Inlet guide vanes to the compression ramp enhance overall efficiency.

  16. Technological advancements in NGV station design

    SciTech Connect (OSTI)

    Ledbetter, G.S.; Grimmer, J.E.; Ketcham, E.T.

    1995-12-31

    Hurricane Compressors` SPRINT System (patent pending) is designed to increase the rate of flow from compressed natural gas (CNG) fuel stations and provide greater utilization of stored CNG than is available from traditional compressor stations. Using a novel method of adapting compressor operation to changes in CNG storage system pressures, this advanced technology provides an alternative mechanism for fuel delivery when demand for fuel is high. Transfer of CNG may be made at higher rates of flow than would be possible either from a pressure depleted storage system or directly from the compressor.

  17. Energy Savings for Centrifugal Compressors 

    E-Print Network [OSTI]

    Fisher, D.

    2011-01-01

    Current design improvements of both the rotating and stationary aerodynamic components of centrifugal compressors can greatly increase the efficiency of vintage machines. A centrifugal compressor built in the 1970's or 1980's might have an external...

  18. Standing wave compressor

    DOE Patents [OSTI]

    Lucas, Timothy S. (4614 River Mill Ct., Glen Allen, VA 23060)

    1991-01-01

    A compressor for compression-evaporation cooling systems, which requires no moving parts. A gaseous refrigerant inside a chamber is acoustically compressed and conveyed by means of a standing acoustic wave which is set up in the gaseous refrigerant. This standing acoustic wave can be driven either by a transducer, or by direct exposure of the gas to microwave and infrared sources, including solar energy. Input and output ports arranged along the chamber provide for the intake and discharge of the gaseous refrigerant. These ports can be provided with optional valve arrangements, so as to increase the compressor's pressure differential. The performance of the compressor in either of its transducer or electromagnetically driven configurations, can be optimized by a controlling circuit. This controlling circuit holds the wavelength of the standing acoustical wave constant, by changing the driving frequency in response to varying operating conditions.

  19. Compressor surge counter

    DOE Patents [OSTI]

    Castleberry, Kimberly N. (Harriman, TN)

    1983-01-01

    A surge counter for a rotating compressor is provided which detects surging by monitoring the vibration signal from an accelerometer mounted on the shaft bearing of the compressor. The circuit detects a rapid increase in the amplitude envelope of the vibration signal, e.g., 4 dB or greater in less than one second, which is associated with a surge onset and increments a counter. The circuit is rendered non-responsive for a period of about 5 seconds following the detection which corresponds to the duration of the surge condition. This prevents multiple registration of counts during the surge period due to rapid swings in vibration amplitude during the period.

  20. Nanotube junctions

    DOE Patents [OSTI]

    Crespi, Vincent Henry; Cohen, Marvin Lou; Louie, Steven Gwon; Zettl, Alexander Karlwalte

    2004-12-28

    The present invention comprises a new nanoscale metal-semiconductor, semiconductor-semiconductor, or metal-metal junction, designed by introducing topological or chemical defects in the atomic structure of the nanotube. Nanotubes comprising adjacent sections having differing electrical properties are described. These nanotubes can be constructed from combinations of carbon, boron, nitrogen and other elements. The nanotube can be designed having different indices on either side of a junction point in a continuous tube so that the electrical properties on either side of the junction vary in a useful fashion. For example, the inventive nanotube may be electrically conducting on one side of a junction and semiconducting on the other side. An example of a semiconductor-metal junction is a Schottky barrier. Alternatively, the nanotube may exhibit different semiconductor properties on either side of the junction. Nanotubes containing heterojunctions, Schottky barriers, and metal-metal junctions are useful for microcircuitry.

  1. Nanotube junctions

    DOE Patents [OSTI]

    Crespi, Vincent Henry (Darien, IL); Cohen, Marvin Lou (Berkeley, CA); Louie, Steven Gwon Sheng (Berkeley, CA); Zettl, Alexander Karlwalter (Kensington, CA)

    2003-01-01

    The present invention comprises a new nanoscale metal-semiconductor, semiconductor-semiconductor, or metal-metal junction, designed by introducing topological or chemical defects in the atomic structure of the nanotube. Nanotubes comprising adjacent sections having differing electrical properties are described. These nanotubes can be constructed from combinations of carbon, boron, nitrogen and other elements. The nanotube can be designed having different indices on either side of a junction point in a continuous tube so that the electrical properties on either side of the junction vary in a useful fashion. For example, the inventive nanotube may be electrically conducting on one side of a junction and semiconducting on the other side. An example of a semiconductor-metal junction is a Schottky barrier. Alternatively, the nanotube may exhibit different semiconductor properties on either side of the junction. Nanotubes containing heterojunctions, Schottky barriers, and metal-metal junctions are useful for microcircuitry.

  2. Light intensity compressor

    DOE Patents [OSTI]

    Rushford, Michael C. (Livermore, CA)

    1990-01-01

    In a system for recording images having vastly differing light intensities over the face of the image, a light intensity compressor is provided that utilizes the properties of twisted nematic liquid crystals to compress the image intensity. A photoconductor or photodiode material that is responsive to the wavelength of radiation being recorded is placed adjacent a layer of twisted nematic liquid crystal material. An electric potential applied to a pair of electrodes that are disposed outside of the liquid crystal/photoconductor arrangement to provide an electric field in the vicinity of the liquid crystal material. The electrodes are substantially transparent to the form of radiation being recorded. A pair of crossed polarizers are provided on opposite sides of the liquid crystal. The front polarizer linearly polarizes the light, while the back polarizer cooperates with the front polarizer and the liquid crystal material to compress the intensity of a viewed scene. Light incident upon the intensity compressor activates the photoconductor in proportion to the intensity of the light, thereby varying the field applied to the liquid crystal. The increased field causes the liquid crystal to have less of a twisting effect on the incident linearly polarized light, which will cause an increased percentage of the light to be absorbed by the back polarizer. The intensity of an image may be compressed by forming an image on the light intensity compressor.

  3. Advanced Hybrid Water Heater using Electrochemical Compressor...

    Energy Savers [EERE]

    Advanced Hybrid Water Heater using Electrochemical Compressor Advanced Hybrid Water Heater using Electrochemical Compressor Xergy is using its Electro Chemical Compression (ECC)...

  4. Josephson junction

    DOE Patents [OSTI]

    Wendt, J.R.; Plut, T.A.; Martens, J.S.

    1995-05-02

    A novel method for fabricating nanometer geometry electronic devices is described. Such Josephson junctions can be accurately and reproducibly manufactured employing photolithographic and direct write electron beam lithography techniques in combination with aqueous etchants. In particular, a method is described for manufacturing planar Josephson junctions from high temperature superconducting material. 10 figs.

  5. Dual capacity reciprocating compressor

    DOE Patents [OSTI]

    Wolfe, Robert W. (Wilkinsburg, PA)

    1984-01-01

    A multi-cylinder compressor 10 particularly useful in connection with northern climate heat pumps and in which different capacities are available in accordance with reversing motor 16 rotation is provided with an eccentric cam 38 on a crank pin 34 under a fraction of the connecting rods, and arranged for rotation upon the crank pin between opposite positions 180.degree. apart so that with cam rotation on the crank pin such that the crank throw is at its normal maximum value all pistons pump at full capacity, and with rotation of the crank shaft in the opposite direction the cam moves to a circumferential position on the crank pin such that the overall crank throw is zero. Pistons 24 whose connecting rods 30 ride on a crank pin 36 without a cam pump their normal rate with either crank rotational direction. Thus a small clearance volume is provided for any piston that moves when in either capacity mode of operation.

  6. Dual capacity reciprocating compressor

    DOE Patents [OSTI]

    Wolfe, R.W.

    1984-10-30

    A multi-cylinder compressor particularly useful in connection with northern climate heat pumps and in which different capacities are available in accordance with reversing motor rotation is provided with an eccentric cam on a crank pin under a fraction of the connecting rods, and arranged for rotation upon the crank pin between opposite positions 180[degree] apart so that with cam rotation on the crank pin such that the crank throw is at its normal maximum value all pistons pump at full capacity, and with rotation of the crank shaft in the opposite direction the cam moves to a circumferential position on the crank pin such that the overall crank throw is zero. Pistons whose connecting rods ride on a crank pin without a cam pump their normal rate with either crank rotational direction. Thus a small clearance volume is provided for any piston that moves when in either capacity mode of operation. 6 figs.

  7. Semi-active compressor valve

    DOE Patents [OSTI]

    Brun, Klaus (Helotes, TX); Gernentz, Ryan S. (San Antonio, TX)

    2010-07-27

    A method and system for fine-tuning the motion of suction or discharge valves associated with cylinders of a reciprocating gas compressor, such as the large compressors used for natural gas transmission. The valve's primary driving force is conventional, but the valve also uses an electromagnetic coil to sense position of the plate (or other plugging element) and to provide an opposing force prior to impact.

  8. Compressor bleed cooling fluid feed system

    DOE Patents [OSTI]

    Donahoo, Eric E; Ross, Christopher W

    2014-11-25

    A compressor bleed cooling fluid feed system for a turbine engine for directing cooling fluids from a compressor to a turbine airfoil cooling system to supply cooling fluids to one or more airfoils of a rotor assembly is disclosed. The compressor bleed cooling fluid feed system may enable cooling fluids to be exhausted from a compressor exhaust plenum through a downstream compressor bleed collection chamber and into the turbine airfoil cooling system. As such, the suction created in the compressor exhaust plenum mitigates boundary layer growth along the inner surface while providing flow of cooling fluids to the turbine airfoils.

  9. Power Characteristics of Industrial Air Compressors 

    E-Print Network [OSTI]

    Schmidt, C.; Kissock, K.

    2003-01-01

    common types of compressor control for small reciprocating and rotary air compressors, and derive relations for estimating compressed air output as a function of the type of control and motor loading. Using these relations, we develop a method to estimate...

  10. Economics of Electric Compressors for Gas Transmission 

    E-Print Network [OSTI]

    Schmeal, W. R.; Hibbs, J. J.

    1994-01-01

    Three new factors are coming together to motivate gas pipeline firms to consider electric motors for replacement of older reciprocating gas engines for compressor systems, and for new compressor installations. These factors are environmental...

  11. Water injected fuel cell system compressor

    DOE Patents [OSTI]

    Siepierski, James S. (Williamsville, NY); Moore, Barbara S. (Victor, NY); Hoch, Martin Monroe (Webster, NY)

    2001-01-01

    A fuel cell system including a dry compressor for pressurizing air supplied to the cathode side of the fuel cell. An injector sprays a controlled amount of water on to the compressor's rotor(s) to improve the energy efficiency of the compressor. The amount of water sprayed out the rotor(s) is controlled relative to the mass flow rate of air inputted to the compressor.

  12. Multiple volume compressor for hot gas engine

    DOE Patents [OSTI]

    Stotts, Robert E. (Clifton Park, NY)

    1986-01-01

    A multiple volume compressor for use in a hot gas (Stirling) engine having a plurality of different volume chambers arranged to pump down the engine when decreased power is called for and return the working gas to a storage tank or reservoir. A valve actuated bypass loop is placed over each chamber which can be opened to return gas discharged from the chamber back to the inlet thereto. By selectively actuating the bypass valves, a number of different compressor capacities can be attained without changing compressor speed whereby the capacity of the compressor can be matched to the power available from the engine which is used to drive the compressor.

  13. Oil cooled, hermetic refrigerant compressor

    DOE Patents [OSTI]

    English, William A. (Murrysville, PA); Young, Robert R. (Murrysville, PA)

    1985-01-01

    A hermetic refrigerant compressor having an electric motor and compressor assembly in a hermetic shell is cooled by oil which is first cooled in an external cooler 18 and is then delivered through the shell to the top of the motor rotor 24 where most of it is flung radially outwardly within the confined space provided by the cap 50 which channels the flow of most of the oil around the top of the stator 26 and then out to a multiplicity of holes 52 to flow down to the sump and provide further cooling of the motor and compressor. Part of the oil descends internally of the motor to the annular chamber 58 to provide oil cooling of the lower part of the motor, with this oil exiting through vent hole 62 also to the sump. Suction gas with entrained oil and liquid refrigerant therein is delivered to an oil separator 68 from which the suction gas passes by a confined path in pipe 66 to the suction plenum 64 and the separated oil drops from the separator to the sump. By providing the oil cooling of the parts, the suction gas is not used for cooling purposes and accordingly increase in superheat is substantially avoided in the passage of the suction gas through the shell to the suction plenum 64.

  14. Oil cooled, hermetic refrigerant compressor

    DOE Patents [OSTI]

    English, W.A.; Young, R.R.

    1985-05-14

    A hermetic refrigerant compressor having an electric motor and compressor assembly in a hermetic shell is cooled by oil which is first cooled in an external cooler and is then delivered through the shell to the top of the motor rotor where most of it is flung radially outwardly within the confined space provided by the cap which channels the flow of most of the oil around the top of the stator and then out to a multiplicity of holes to flow down to the sump and provide further cooling of the motor and compressor. Part of the oil descends internally of the motor to the annular chamber to provide oil cooling of the lower part of the motor, with this oil exiting through vent hole also to the sump. Suction gas with entrained oil and liquid refrigerant therein is delivered to an oil separator from which the suction gas passes by a confined path in pipe to the suction plenum and the separated oil drops from the separator to the sump. By providing the oil cooling of the parts, the suction gas is not used for cooling purposes and accordingly increase in superheat is substantially avoided in the passage of the suction gas through the shell to the suction plenum. 3 figs.

  15. Digital Dynamic Range Compressor Design--A Tutorial and Analysis

    E-Print Network [OSTI]

    Reiss, Josh

    PAPERS Digital Dynamic Range Compressor Design-- A Tutorial and Analysis DIMITRIOS GIANNOULIS formal knowledge and analysis of compressor design techniques. In this tutorial we describe several become audio engineers' favorites for certain types of signal. The analysis of compressor designs

  16. Guide to Minimizing Compressor-Based Cooling | Department of...

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

    Compressor-Based Cooling Guide to Minimizing Compressor-Based Cooling Guide describes best practices for reducing energy use and total cost of ownership for data center cooling...

  17. Low-Cost Electrochemical Compressor Utilizing Green Refrigerants...

    Office of Environmental Management (EM)

    Low-Cost Electrochemical Compressor Utilizing Green Refrigerants for HVAC Applications Low-Cost Electrochemical Compressor Utilizing Green Refrigerants for HVAC Applications...

  18. NGV stations based on mobile tube trailers: An economic analysis. Final report, June 1994-January 1995

    SciTech Connect (OSTI)

    Keder, J.; Darrow, K.

    1995-01-01

    This report assesses the technical and economic issues associated with the use of mobile tube trailers for Natural Gas Vehicle (NGV) refueling stations. Specifically, this report examines the mobile tube trailer concept developed by Pacific Cryongenics, Inc. and Pacific Gas and Electric. Mobile tube trailers are filled with compressed natural gas (CNG) at an underutilized compressor station and transported to satellite station locations. NGVs are filled at the satellite stations usig compressed gas from the tube trailer. Results of the economic analysis show that, under various operating conditions, the mobile tube trailer concept provides a cost effective alternative to NGV refueling stations with permanent compressors. In addition, the tube trailers were found to provide a substantial load for undertutilized compressor stations, resulting in reduced CNG costs at existing stations.

  19. HELIUM COMPRESSOR MONITORING SYSTEM Donna Kubik

    E-Print Network [OSTI]

    HELIUM COMPRESSOR MONITORING SYSTEM Donna Kubik Arecibo Observatory #12;1 CONTENTS 1. Design goals for Phaseloss Detection Lambda +15V Power Supply Distribution Remote Control of 120VC to Compressor Monitoring System Fiber and Network Connections #12;3 1. Design goals Helium refrigerators cool the cryogenically

  20. Refrigeration system having standing wave compressor

    DOE Patents [OSTI]

    Lucas, Timothy S. (Glen Allen, VA)

    1992-01-01

    A compression-evaporation refrigeration system, wherein gaseous compression of the refrigerant is provided by a standing wave compressor. The standing wave compressor is modified so as to provide a separate subcooling system for the refrigerant, so that efficiency losses due to flashing are reduced. Subcooling occurs when heat exchange is provided between the refrigerant and a heat pumping surface, which is exposed to the standing acoustic wave within the standing wave compressor. A variable capacity and variable discharge pressure for the standing wave compressor is provided. A control circuit simultaneously varies the capacity and discharge pressure in response to changing operating conditions, thereby maintaining the minimum discharge pressure needed for condensation to occur at any time. Thus, the power consumption of the standing wave compressor is reduced and system efficiency is improved.

  1. Probabilistic Aerothermal Design of Compressor Airfoils Victor E. Garzon

    E-Print Network [OSTI]

    Peraire, Jaime

    and operating condition uncertainty on axial compressor performance. High-fidelity models of geometric-line multi-stage axial compressor model was used to estimate the impact of geometric variability on overall compressor performance. Probabilistic loss and turning models were exercised on a six-stage compressor model

  2. Compressor ported shroud for foil bearing cooling

    DOE Patents [OSTI]

    Elpern, David G. (Los Angeles, CA); McCabe, Niall (Torrance, CA); Gee, Mark (South Pasadena, CA)

    2011-08-02

    A compressor ported shroud takes compressed air from the shroud of the compressor before it is completely compressed and delivers it to foil bearings. The compressed air has a lower pressure and temperature than compressed outlet air. The lower temperature of the air means that less air needs to be bled off from the compressor to cool the foil bearings. This increases the overall system efficiency due to the reduced mass flow requirements of the lower temperature air. By taking the air at a lower pressure, less work is lost compressing the bearing cooling air.

  3. Robust design and tolerancing of compressor blades

    E-Print Network [OSTI]

    Dow, Eric Alexander

    2015-01-01

    Variations in the geometry of compressor blades can be introduced by variability in the manufacturing process or by in-service erosion. Recent research efforts have focused on characterizing the impacts of this geometric ...

  4. Method and apparatus for starting supersonic compressors

    DOE Patents [OSTI]

    Lawlor, Shawn P

    2013-08-06

    A supersonic gas compressor with bleed gas collectors, and a method of starting the compressor. The compressor includes aerodynamic duct(s) situated for rotary movement in a casing. The aerodynamic duct(s) generate a plurality of oblique shock waves for efficiently compressing a gas at supersonic conditions. A convergent inlet is provided adjacent to a bleed gas collector, and during startup of the compressor, bypass gas is removed from the convergent inlet via the bleed gas collector, to enable supersonic shock stabilization. Once the oblique shocks are stabilized at a selected inlet relative Mach number and pressure ratio, the bleed of bypass gas from the convergent inlet via the bypass gas collectors is effectively eliminated.

  5. Probabilistic analysis of meanline compressor rotor performance

    E-Print Network [OSTI]

    Fitzgerald, Nathan Andrew, 1980-

    2004-01-01

    This thesis addresses variability in aerodynamic performance of a compressor rotor due to geometric variation. The performance of the rotor is computed using a meanline model that includes the effect of tip clearance ...

  6. Cycling Losses During Screw Air Compressor Operation 

    E-Print Network [OSTI]

    Maxwell, J. B.; Wheeler, G.; Bushnell, D.

    1995-01-01

    Air compressors use 10-13 % of a typical industrial facilities' total electricity. Because they often operate at part load, their part load efficiency significantly affects plant energy cost. An intensive study of screw ...

  7. Probabilistic aerothermal design of compressor airfoils

    E-Print Network [OSTI]

    Garzón, Víctor E., 1972-

    2003-01-01

    Despite the generally accepted notion that geometric variability is undesirable in turbomachinery airfoils, little is known in detail about its impact on aerothermal compressor performance. In this work, statistical and ...

  8. A methodology for centrifugal compressor stability prediction

    E-Print Network [OSTI]

    Benneke, Björn

    2009-01-01

    The stable operation of centrifugal compressors is limited by well-known phenomena, rotating stall and surge. Although the manifestation of the full scale instabilities is similar to the ones observed in axial machines, ...

  9. Improved return passages for multistage centrifugal compressors

    E-Print Network [OSTI]

    Glass, Benjamin W., S.M. Massachusetts Institute of Technology

    2010-01-01

    This thesis presents a design concept for return passages in multistage centrifugal compressors. Flow in a baseline return passage is analyzed to identify loss sources that have substantial potential for reduction. For the ...

  10. Hydrogen pipeline compressors annual progress report.

    SciTech Connect (OSTI)

    Fenske, G. R.; Erck, R. A.

    2011-07-15

    The objectives are: (1) develop advanced materials and coatings for hydrogen pipeline compressors; (2) achieve greater reliability, greater efficiency, and lower capital in vestment and maintenance costs in hydrogen pipeline compressors; and (3) research existing and novel hydrogen compression technologies that can improve reliability, eliminate contamination, and reduce cost. Compressors are critical components used in the production and delivery of hydrogen. Current reciprocating compressors used for pipeline delivery of hydrogen are costly, are subject to excessive wear, have poor reliability, and often require the use of lubricants that can contaminate the hydrogen (used in fuel cells). Duplicate compressors may be required to assure availability. The primary objective of this project is to identify, and develop as required, advanced materials and coatings that can achieve the friction, wear, and reliability requirements for dynamically loaded components (seal and bearings) in high-temperature, high-pressure hydrogen environments prototypical of pipeline and forecourt compressor systems. The DOE Strategic Directions for Hydrogen Delivery Workshop identified critical needs in the development of advanced hydrogen compressors - notably, the need to minimize moving parts and to address wear through new designs (centrifugal, linear, guided rotor, and electrochemical) and improved compressor materials. The DOE is supporting several compressor design studies on hydrogen pipeline compression specifically addressing oil-free designs that demonstrate compression in the 0-500 psig to 800-1200 psig range with significant improvements in efficiency, contamination, and reliability/durability. One of the designs by Mohawk Innovative Technologies Inc. (MiTi{reg_sign}) involves using oil-free foil bearings and seals in a centrifual compressor, and MiTi{reg_sign} identified the development of bearings, seals, and oil-free tribological coatings as crucial to the successful development of an advanced compressor. MiTi{reg_sign} and ANL have developed potential coatings for these rigorous applications; however, the performance of these coatings (as well as the nickel-alloy substrates) in high-temperature, high-speed hydrogen environments is unknown at this point.

  11. CNG fueling stations: The dispenser and control benefits of a systems design

    SciTech Connect (OSTI)

    Sullivan, C.D.

    1995-12-31

    A CNG station is composed of many varied pieces of equipment. It is the combined functionality and compatibility of this equipment that distinguishes a CNG fueling system from a CNG fueling station. Components include: dryer, compressor, driver, cooler, blow-down system, priority/sequencing/bypass system; storage; dispenser; and controls. Whether its a system or a station, the objective is the same: to disperse the proper amount of clean dry compressed natural gas into a vehicle quickly. This objective is sometimes overshadowed by the focus on the compressor. It is big, tangible and usually costs the most. The compressor, however is only responsible for compressing the gas, not dispensing it into the vehicle. While there are many different types of compressors on the market, some of which are very good, this paper focuses on the system design and control and its specific effects on the dispensing system.

  12. Xergy Ships First Breakthrough Water Heater Compressor to GE...

    Energy Savers [EERE]

    Xergy Ships First Breakthrough Water Heater Compressor to GE Xergy Ships First Breakthrough Water Heater Compressor to GE September 15, 2015 - 3:41pm Addthis Xergy Inc. and GE...

  13. Impact of geometric variability on compressor repeating-stage performance

    E-Print Network [OSTI]

    Vincent, Antoine, 1979-

    2003-01-01

    The impact of geometric variability on compressor performance is investigated using a compressor repeating-stage model based on well-known correlations for profile losses, endwall blockage, deviation, and the onset of ...

  14. Aerodynamic performance measurements in a counter-rotating aspirated compressor

    E-Print Network [OSTI]

    Onnée, Jean-François

    2005-01-01

    This thesis is an experimental investigation of the aerodynamic performances of a counter-rotating aspirated compressor. This compressor is implemented in a blow-down facility, which gives rigorous simulation of the ...

  15. Development of a body force model for centrifugal compressors

    E-Print Network [OSTI]

    Kottapalli, Anjaney Pramod

    2013-01-01

    This project is focused on modeling the internal ow in centrifugal compressors for the purpose of assessing the onset of rotating stall and surge. The current methods to determine centrifugal compressor stability limits ...

  16. Compressor airfoil tip clearance optimization system

    DOE Patents [OSTI]

    Little, David A.; Pu, Zhengxiang

    2015-08-18

    A compressor airfoil tip clearance optimization system for reducing a gap between a tip of a compressor airfoil and a radially adjacent component of a turbine engine is disclosed. The turbine engine may include ID and OD flowpath boundaries configured to minimize compressor airfoil tip clearances during turbine engine operation in cooperation with one or more clearance reduction systems that are configured to move the rotor assembly axially to reduce tip clearance. The configurations of the ID and OD flowpath boundaries enhance the effectiveness of the axial movement of the rotor assembly, which includes movement of the ID flowpath boundary. During operation of the turbine engine, the rotor assembly may be moved axially to increase the efficiency of the turbine engine.

  17. Active surge control of centrifugal compressors using drive torque

    E-Print Network [OSTI]

    Gravdahl, Jan Tommy

    Active surge control of centrifugal compressors using drive torque Jan Tommy Gravdahl , Olav control is presented. A centrifugal compressor driven by an electrical motor is studied, and the drive of centrifugal com- pressors, which occurs when the operating point of the compressor is located to the left

  18. Method and apparatus for starting supersonic compressors

    DOE Patents [OSTI]

    Lawlor, Shawn P. (Bellevue, WA)

    2012-04-10

    A supersonic gas compressor. The compressor includes aerodynamic duct(s) situated on a rotor journaled in a casing. The aerodynamic duct(s) generate a plurality of oblique shock waves for efficiently compressing a gas at supersonic conditions. The convergent inlet is adjacent to a bleed air collector, and during acceleration of the rotor, bypass gas is removed from the convergent inlet via a collector to enable supersonic shock stabilization. Once the oblique shocks are stabilized at a selected inlet relative Mach number and pressure ratio, the bleed of bypass gas from the convergent inlet via the bypass gas collectors is eliminated.

  19. Three-junction solar cell

    DOE Patents [OSTI]

    Ludowise, Michael J. (Cupertino, CA)

    1986-01-01

    A photovoltaic solar cell is formed in a monolithic semiconductor. The cell contains three junctions. In sequence from the light-entering face, the junctions have a high, a medium, and a low energy gap. The lower junctions are connected in series by one or more metallic members connecting the top of the lower junction through apertures to the bottom of the middle junction. The upper junction is connected in voltage opposition to the lower and middle junctions by second metallic electrodes deposited in holes 60 through the upper junction. The second electrodes are connected to an external terminal.

  20. Master Control of Multiple Air Compressors 

    E-Print Network [OSTI]

    Petzold, M. A.

    1983-01-01

    of air compressors in the most efficient manner for any air demand. This system can be further enhanced by the addition of a remote set point signal based on air-flow. This signal is calibrated to reduce the set-point during periods of low demand when...

  1. Combined cold compressor/ejector helium refrigerator

    DOE Patents [OSTI]

    Brown, D.P.

    1984-06-05

    A refrigeration apparatus having an ejector operatively connected with a cold compressor to form a two-stage pumping system. This pumping system is used to lower the pressure, and thereby the temperature of a bath of boiling refrigerant (helium). The apparatus as thus arranged and operated has substantially improved operating efficiency when compared to other processes or arrangements for achieving a similar low pressure.

  2. Viscous throughflow modeling for multistage compressor design

    SciTech Connect (OSTI)

    Howard, M.A.; Gallimore, S.J. )

    1993-04-01

    An existing throughflow method for axial compressors, which accounts for the effects of spanwise mixing using a turbulent diffusion model, has been extended to include the viscous shear force on the endwall. The use of a shear force, consistent with a no-slip condition, on the annulus walls in the throughflow calculations allows realistic predictions of the velocity and flow angle profiles near the endwalls. The annulus wall boundary layers are therefore incorporated directly into the throughflow prediction. This eliminates the need for empirical blockage factors or independent annulus boundary layer calculations. The axisymmetric prediction can be further refined by specifying realistic spanwise variations of loss coefficient and deviation to model the three-dimensional endwall effects. The resulting throughflow calculation gives realistic predictions of flow properties across the whole span of a compressor. This is confirmed by comparison with measured data from both low and high-speed multistage machines. The viscous throughflow method has been incorporated into an axial compressor design system. The method predicts the meridional velocity defects in the endwall region and consequently blading can be designed that allows for the increased incidence, and low dynamic head, near the annulus walls.

  3. METAL HYDRIDE HYDROGEN COMPRESSORS: A REVIEW

    SciTech Connect (OSTI)

    Bowman Jr, Robert C; Yartys, Dr. Volodymyr A.; Lototskyy, Dr. Michael V; Pollet, Dr. B.G.

    2014-01-01

    Metal hydride (MH) thermal sorption compression is an efficient and reliable method allowing a conversion of energy from heat into a compressed hydrogen gas. The most important component of such a thermal engine the metal hydride material itself should possess several material features in order to achieve an efficient performance in the hydrogen compression. Apart from the hydrogen storage characteristics important for every solid H storage material (e.g. gravimetric and volumetric efficiency of H storage, hydrogen sorption kinetics and effective thermal conductivity), the thermodynamics of the metal-hydrogen systems is of primary importance resulting in a temperature dependence of the absorption/desorption pressures). Several specific features should be optimized to govern the performance of the MH-compressors including synchronisation of the pressure plateaus for multi-stage compressors, reduction of slope of the isotherms and hysteresis, increase of cycling stability and life time, together with challenges in system design associated with volume expansion of the metal matrix during the hydrogenation. The present review summarises numerous papers and patent literature dealing with MH hydrogen compression technology. The review considers (a) fundamental aspects of materials development with a focus on structure and phase equilibria in the metal-hydrogen systems suitable for the hydrogen compression; and (b) applied aspects, including their consideration from the applied thermodynamic viewpoint, system design features and performances of the metal hydride compressors and major applications.

  4. IEMDC - In-Line Electric Motor Driven Compressor

    SciTech Connect (OSTI)

    Michael J. Crowley

    2004-03-31

    This report covers the fifth quarter (01/01/04 to 03/31/04) of the In-Line Electric Motor Driven Compressor (IEMDC) project. Design efforts on the IEMDC continued with compressor efforts focused on performing aerodynamic analyses. These analyses were conducted using computational fluid dynamics. Compressor efforts also entailed developing mechanical designs of components through the use of solid models and working on project deliverables. Electric motor efforts focused on the design of the magnetic bearing system, motor pressure housing, and the motor-compressor interface. The mechanical evaluation of the main interface from both the perspective of the compressor manufacturer and electric motor manufacturer indicates that an acceptable design has been achieved. All mechanical and aerodynamic design efforts have resulted in considerable progress being made towards the completion of the compressor and electric motor design and towards the successful completion of the IEMDC unit.

  5. Effect of Intake Air on Compressor Performance; Industrial Technologie...

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

    4 * August 2004 Industrial Technologies Program Suggested Actions * Inspect the entry to the compressor air intake pipe and ensure that it is free of contaminants. * Inspect the...

  6. New Compressor Concept Improves Efficiency and Operation Range

    Broader source: Energy.gov [DOE]

    Advanced turbocharger compressor design with active casing treatment and advanced mixed flow turbine design provided improved performance and efficiency over the base turbocharger

  7. Critical speed measurements in the Tevatron cold compressors

    SciTech Connect (OSTI)

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

    2006-01-01

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

  8. The unstable behavior of low and high-speed compressors

    SciTech Connect (OSTI)

    Day, I.J. . Whittle Lab.); Freeman, C. )

    1994-04-01

    By far the greater part of the understanding about stall and surge in axial compressors comes from work on low-speed laboratory machines. As a general rule, these machines do not model the compressibility effects present in high-speed compressors and therefore doubt has always existed about the application of low-speed results to high-speed machines. In recent years interest in active control has led to a number of studies of compressor stability in engine-type compressors. The instrumentation used in these experiments has been sufficiently detailed that, for the first time, adequate data are available to make direct comparisons between high-speed and low-speed compressors. This paper presents new data from an eight-stage fixed geometry engine compressor and compares then with low-speed laboratory data. The results show remarkable similarities in both the stalling and surging behavior of the two machines, particularly when the engine compressor is run at intermediate speeds. The engine results also show that, as in the laboratory tests, surge is precipitated by the onset of rotating stall. This is true even at very high speeds where it had previously been thought that surge might be the result of a blast wave moving through the compressor. This paper therefore contains new information about high-speed compressors and confirms that low-speed testing is an effective means of obtaining insight into the behavior of high-speed machines.

  9. LNG to CNG refueling stations

    SciTech Connect (OSTI)

    Branson, J.D. [ECOGAS Corp., Austin, TX (United States)

    1995-12-31

    While the fleet operator is concerned about the environment, he or she is going to make the choice based primarily on economics. Which fuel provides the lowest total operating cost? The calculation of this costing must include the price-per-gallon of the fuel delivered, as well as the tangible and intangible components of fuel delivery, such as downtime for vehicles during the refueling process, idle time for drivers during refueling, emissions costings resulting from compressor oil blow-by, inclusion of non-combustible constituents in the CNG, and energy consumption during the refueling process. Also, the upfront capital requirement of similar delivery capabilities must be compared. The use of LNG as the base resource for the delivered CNG, in conjunction with the utilization of a fully temperature-compressed LNG/CNG refueling system, eliminates many of the perceived shortfalls of CNG. An LNG/CNG refueling center designed to match the capabilities of the compressor-based station will have approximately the same initial capital requirement. However, because it derives its CNG sales product from the {minus}260 F LNG base product, thus availing itself of the natural physical properties of the cryogenic product, all other economic elements of the system favor the LNG/CNG product.

  10. FEASIBILITY OF SOLAR-FIRED, COMPRESSOR-ASSISTED

    E-Print Network [OSTI]

    FEASIBILITY OF SOLAR-FIRED, COMPRESSOR-ASSISTED ABSORPTION CHILLERS Prepared For: California Energy REPORT (FAR) FEASIBILITY OF SOLAR FIRED, COMPRESSOR ASSISTED ABSORPTION CHILLERS EISG AWARDEE Bergquam.csus.edu Principal Investigator: James Bergquam AUTHOR EISG Program Administrator Grant #: 99-15 Grant Funding: $75

  11. POWER CHARACTERISTICS OF INDUSTRIAL AIR COMPRESSORS Chris Schmidt

    E-Print Network [OSTI]

    Kissock, Kelly

    POWER CHARACTERISTICS OF INDUSTRIAL AIR COMPRESSORS Chris Schmidt Graduate Assistant / Project of Mechanical and Aerospace Engineering University of Dayton Dayton, Ohio ABSTRACT The power draw to energy input, which we call the average operating efficiency, based on input power to the compressor

  12. Introducing Back-up to Active Compressor Surge Control System

    E-Print Network [OSTI]

    Gravdahl, Jan Tommy

    to compressor blades and bearings. Most industrial compressors are equipped with a surge avoidance system by recycling flow from downstream to upstream when the operating point reach a surge control line Jager This work was supported Siemens Oil and Gas Solutions Offshore through the Siemens

  13. Modeling and Control of Surge and Rotating Stall in Compressors

    E-Print Network [OSTI]

    Gravdahl, Jan Tommy

    Modeling and Control of Surge and Rotating Stall in Compressors Dr.ing. thesis Jan Tommy Gravdahl varying disturbances in mass ow and pressure. A novel model for an axial compression system with non-constant compressor speed is derived by extending the Moore-Greitzer model. Rotating stall and surge is studied

  14. Small core axial compressors for high efficiency jet aircraft

    E-Print Network [OSTI]

    DiOrio, Austin Graf

    2012-01-01

    This thesis quantifies mechanisms that limit efficiency in small core axial compressors, defined here as compressor exit corrected flow between 1.5 and 3.0 lbm/s. The first part of the thesis describes why a small engine ...

  15. Drive actuation in active control of centrifugal compressors Jan Tommy Gravdahl and Olav Egeland

    E-Print Network [OSTI]

    Gravdahl, Jan Tommy

    Pipeline compressor map for natural gas (=1.3) System trajectory Throttle line Surge line Compressor map does not cross this line. Usually a recycle valve around the compressor is used as actuation. A simulation of active surge control on a industrial size nat- ural gas pipeline compressor using drive torque

  16. Surge recovery techniques for the Tevatron cold compressors

    SciTech Connect (OSTI)

    Martinez, A.; Klebaner, A.L.; Makara, J.N.; Theilacker, J.C.; /Fermilab

    2006-01-01

    The Fermilab Tevatron cryogenic system utilizes high-speed centrifugal cold compressors, made by Ishikawajima-Harima Heavy Industries Co. Ltd. (IHI), for high-energy operations [1]. The compressor is designed to pump 60 g/s of 3.6 K saturated helium vapor at a pressure ratio of 2.8, with an off-design range of 40 to 70 g/s and operating speeds between 40 and 95 krpm. Since initial commissioning in 1993, Tevatron transient conditions such as quench recovery have led to multiple-location machine trips as a result of the cold compressors entering the surge regime. Historically, compressors operating at lower inlet pressures and higher speeds have been especially susceptible to these machine trips and it was not uncommon to have multiple compressor trips during large multiple-house quenches. In order to cope with these events and limit accelerator down time, surge recovery techniques have been implemented in an attempt to prevent the compressors from tripping once the machine entered this surge regime. This paper discusses the different methods of surge recovery that have been employed. Data from tests performed at the Cryogenic Test Facility at Fermilab as well as actual Tevatron operational data were utilized. In order to aid in the determination of the surge region, a full mapping study was undertaken to characterize the entire pressure field of the cold compressor. These techniques were then implemented and tested at several locations in the Tevatron with some success.

  17. Pressure field study of the Tevatron cold compressors

    SciTech Connect (OSTI)

    Klebaner, A.L.; Martinez, A.; Soyars, W.M.; Theilacker, J.C.; /Fermilab

    2003-01-01

    The Fermilab Tevatron cryogenic system utilizes high-speed centrifugal cold compressors, manufactured by Ishikawajima-Harima Heavy Industries Co. Ltd. (IHI), for high-energy operations [1]. The compressor is designed to pump 60 g/sec of 3.6 K saturated helium vapor at a pressure ratio of 2.8, with an off-design range of 40 to 70 g/sec. Operating speeds are between 40 and 95 krpm, with a speed of 80 krpm at the design point. Different heat loads and magnet quench performance of each of the twenty-four satellite refrigerators dictates different process pressure and flow rates of the cold compressors. Reducing the process flow rate can cause the centrifugal cold compressor to stop pumping and subsequently surge. Tests have been conducted at the Cryogenic Test Facility at Fermilab to map the pressure field and appropriate efficiency of the IHI hydrodynamic cold compressor. The information allows tuning of each of the twenty-four Tevatron satellite refrigerators to avoid cold compressor operation near the surge and choke lines. A new impeller has also been tested. The Tevatron cold compressor pressure field and efficiency data with the new impeller are presented in this paper.

  18. Simultaneous Robust Design and Tolerancing of Compressor Blades

    E-Print Network [OSTI]

    Wang, Qiqi

    The manufacturing processes used to create compressor blades inevitably introduce geometric variability to the blade surface. In addition to increasing the performance variability, it has been observed that introducing ...

  19. Characterization of unsteady flow processes in a centrifugal compressor stage

    E-Print Network [OSTI]

    Gould, Kenneth A. (Kenneth Arthur)

    2006-01-01

    Numerical experiments have been implemented to characterize the unsteady loading on the rotating impeller blades in a modem centrifugal compressor. These consist of unsteady Reynolds-averaged Navier Stokes simulations of ...

  20. Forced response predictions in modern centrifugal compressor design

    E-Print Network [OSTI]

    Smythe, Caitlin J. (Caitlin Jeanne)

    2005-01-01

    A computational interrogation of the time-averaged and time-unsteady flow fields of two centrifugal compressors of nearly identical design (the enhanced, which encountered aeromechanical difficulty, and production, which ...

  1. Return channel loss reduction in multi-stage centrifugal compressors

    E-Print Network [OSTI]

    Aubry, Anne-Raphaëlle

    2012-01-01

    This thesis presents concepts for improving the performance of return channels in multi-stage centrifugal compressors. Geometries have been developed to reduce both separation and viscous losses. A number of different ...

  2. Multi-parameter control for centrifugal compressor performance optimization

    E-Print Network [OSTI]

    Mannai, Sébastien (Sébastien Karim)

    2014-01-01

    The potential performance benefit of actuating inlet guide vane (IGV) angle, variable diffuser vane (VDV) angle and impeller speed to implement a multi-parameter control on a centrifugal compressor system is assessed. The ...

  3. New Twin Screw Compressor Design by Deviation Function Method

    E-Print Network [OSTI]

    Huang, Chih-Yung

    2015-01-01

    Gear Geometry," Transaction of ASME: Journal of Mechanical Design,Gear Pump," Trans. ASME Journal of Mechanisms, and Transmissions, and Automation in Design,design is an oil-free compressor and is driven by a pair of timing gears.

  4. Energy conversion using thermal transpiration : optimization of a Knudsen compressor

    E-Print Network [OSTI]

    Klein, Toby A. (Toby Anna)

    2012-01-01

    Knudsen compressors are devices without any moving parts that use the nanoscale phenomenon of thermal transpiration to pump or compress a gas. Thermal transpiration takes place when a gas is in contact with a solid boundary ...

  5. Active control of tip clearance flow in axial compressors

    E-Print Network [OSTI]

    Bae, Jinwoo W

    2001-01-01

    Control of compressor tip clearance flows is explored in a linear cascade using three types of fluidic actuators; Normal Synthetic Jet (NSJ; unsteady jet normal to the mean flow with zero net mass flux), Directed Synthetic ...

  6. Non-intrusive fault detection in reciprocating compressors

    E-Print Network [OSTI]

    Schantz, Christopher James

    2011-01-01

    This thesis presents a set of techniques for non-intrusive sensing and fault detection in reciprocating compressors driven by induction motors. The procedures developed here are "non-intrusive" because they rely only on ...

  7. Development Of A Centrifugal Hydrogen Pipeline Gas Compressor

    SciTech Connect (OSTI)

    Di Bella, Francis A.

    2015-04-16

    Concepts NREC (CN) has completed a Department of Energy (DOE) sponsored project to analyze, design, and fabricate a pipeline capacity hydrogen compressor. The pipeline compressor is a critical component in the DOE strategy to provide sufficient quantities of hydrogen to support the expected shift in transportation fuels from liquid and natural gas to hydrogen. The hydrogen would be generated by renewable energy (solar, wind, and perhaps even tidal or ocean), and would be electrolyzed from water. The hydrogen would then be transported to the population centers in the U.S., where fuel-cell vehicles are expected to become popular and necessary to relieve dependency on fossil fuels. The specifications for the required pipeline hydrogen compressor indicates a need for a small package that is efficient, less costly, and more reliable than what is available in the form of a multi-cylinder, reciprocating (positive displacement) compressor for compressing hydrogen in the gas industry.

  8. Hyper dispersion pulse compressor for chirped pulse amplification systems

    DOE Patents [OSTI]

    Barty, Christopher P. J. (Hayward, CA)

    2011-11-29

    A grating pulse compressor configuration is introduced for increasing the optical dispersion for a given footprint and to make practical the application for chirped pulse amplification (CPA) to quasi-narrow bandwidth materials, such as Nd:YAG. The grating configurations often use cascaded pairs of gratings to increase angular dispersion an order of magnitude or more. Increased angular dispersion allows for decreased grating separation and a smaller compressor footprint.

  9. Development of Inexpensive Turbo Compressor/Expanders for Industrial Use 

    E-Print Network [OSTI]

    Jacox, J. W.

    1991-01-01

    designed, coordinated and partially performed by NUCON. The turbocharger consists of a radial inflow turbine and a centrifugal compressor mounted on a common shaft supported on oil lubricated floating bushing type journal bearings. The axial thrust.... The TCE performance was not as serious a problem, except to achieve both high and matched efficiency for the expander AND compressor when operated in the reverse mode. Locating a cost effective mass produced TCE was the most difficult of the three...

  10. ADVANCED COMPRESSOR ENGINE CONTROLS TO ENHANCE OPERATION, RELIABILITY AND INTEGRITY

    SciTech Connect (OSTI)

    Gary D. Bourn; Jess W. Gingrich; Jack A. Smith

    2004-03-01

    This document is the final report for the ''Advanced Compressor Engine Controls to Enhance Operation, Reliability, and Integrity'' project. SwRI conducted this project for DOE in conjunction with Cooper Compression, under DOE contract number DE-FC26-03NT41859. This report addresses an investigation of engine controls for integral compressor engines and the development of control strategies that implement closed-loop NOX emissions feedback.

  11. An analytical model of axial compressor off-design performance

    SciTech Connect (OSTI)

    Camp, T.R.; Horlock, J.H. . Whittle Lab.)

    1994-07-01

    An analysis is presented of the off-design performance of multistage axial-flow compressors. It is based on an analytical solution, valid for small perturbations in operating conditions from the design point, and provides an insight into the effects of choices made during the compressor design process on performance and off-design stage matching. It is shown that the mean design value of stage loading coefficient ([psi] = [Delta]h[sub 0]/U[sup 2]) has a dominant effect on off-design performance, whereas the stage-wise distribution of stage loading coefficient and the design value of flow coefficient have little influence. The powerful effects of variable stator vanes on stage-matching are also demonstrated and these results are shown to agree well with previous work. The slope of the working line of a gas turbine engine, overlaid on overall compressor characteristics, is shown to have a strong effect on the off-design stage-matching through the compressor. The model is also used to analyze design changes to the compressor geometry and to show how errors in estimates of annulus blockage, decided during the design process, have less effect on compressor performance than has previously been thought.

  12. Downhole steam generator having a downhole oxidant compressor

    DOE Patents [OSTI]

    Fox, Ronald L. (Albuquerque, NM)

    1983-01-01

    Apparatus and method for generation of steam in a borehole for penetration into an earth formation wherein a downhole oxidant compressor is used to compress relatively low pressure (atmospheric) oxidant, such as air, to a relatively high pressure prior to mixing with fuel for combustion. The multi-stage compressor receives motive power through a shaft driven by a gas turbine powered by the hot expanding combustion gases. The main flow of compressed oxidant passes through a velocity increasing nozzle formed by a reduced central section of the compressor housing. An oxidant bypass feedpipe leading to peripheral oxidant injection nozzles of the combustion chamber are also provided. The downhole compressor allows effective steam generation in deep wells without need for high pressure surface compressors. Feedback preheater means are provided for preheating fuel in a preheat chamber. Preheating of the water occurs in both a water feed line running from aboveground and in a countercurrent water flow channel surrounding the combustor assembly. The countercurrent water flow channels advantageously serve to cool the combustion chamber wall. The water is injected through slotted inlets along the combustion chamber wall to provide an unstable boundary layer and stripping of the water from the wall for efficient steam generation. Pressure responsive doors are provided at the steam outlet for closing and sealing the combustion chamber from entry of reservoir fluids in the event of a flameout.

  13. Development of an Electrochemical Separator and Compressor

    SciTech Connect (OSTI)

    Trent Molter

    2011-04-28

    Global conversion to sustainable energy is likely to result in a hydrogen-based economy that supports U.S. energy security objectives while simultaneously avoiding harmful carbon emissions. A key hurdle to successful implementation of a hydrogen economy is the low-cost generation, storage, and distribution of hydrogen. One of the most difficult requirements of this transformation is achieving economical, high density hydrogen storage in passenger vehicles. Transportation applications may require compression and storage of high purity hydrogen up to 12,000 psi. Hydrogen production choices range from centralized low-pressure generation of relatively impure gas in large quantities from steam-methane reformer plants to distributed generation of hydrogen under moderate pressure using water electrolysis. The Electrochemical Hydrogen Separator + Compressor (EHS+C) technology separates hydrogen from impurities and then compresses it to high pressure without any moving parts. The Phase I effort resulted in the construction and demonstration of a laboratory-scale hardware that can separate and compress hydrogen from reformate streams. The completion of Phase I has demonstrated at the laboratory scale the efficient separation and compression of hydrogen in a cost effective manner. This was achieved by optimizing the design of the Electrochemical Hydrogen Compression (EHC) cell hardware and verified by parametric testing in single cell hardware. A broad range of commercial applications exist for reclamation of hydrogen. One use this technology would be in combination with commercial fuel cells resulting in a source of clean power, heat, and compressed hydrogen. Other applications include the reclamation of hydrogen from power plants and other industrial equipment where it is used for cooling, recovery of process hydrogen from heat treating processes, and semiconductor fabrication lines. Hydrogen can also be recovered from reformate streams and cryogenic boil-offs using this technology.

  14. Design and operation of a counter-rotating aspirated compressor blowdown test facility

    E-Print Network [OSTI]

    Parker, David V. (David Vickery)

    2005-01-01

    A unique counter-rotating aspirated compressor was tested in a blowdown facility at the Gas Turbine Laboratory at MIT. The facility expanded on experience from previous blowdown turbine and blowdown compressor experiments. ...

  15. Application of a design optimization strategy to multi-stage compressor matching

    E-Print Network [OSTI]

    Bert, Jérôme

    2006-01-01

    A major challenge in the design of multi-stage compressors is the matching of stages to enable stable operation over a large range of mass flows and operating conditions. Particularly in turbofan low-pressure compressors, ...

  16. Optimal dimensionless design and analysis of jet ejectors as compressors and thrust augmenters 

    E-Print Network [OSTI]

    Mohan, Ganesh

    2006-08-16

    A jet ejector may be used as a compressor or to enhance thrust of watercraft or aircraft. Optimization of jet ejectors as compressors and thrust augmenters was conducted using the software GAMBIT (Computer Aided Engineering (CAE) tool for geometry...

  17. Turbo-alternator-compressor design for supercritical high density working fluids

    DOE Patents [OSTI]

    Wright, Steven A.; Fuller, Robert L.

    2013-03-19

    Techniques for generating power are provided. Such techniques involve a thermodynamic system including a housing, a turbine positioned in a turbine cavity of the housing, a compressor positioned in a compressor cavity of the housing, and an alternator positioned in a rotor cavity between the turbine and compressor cavities. The compressor has a high-pressure face facing an inlet of the compressor cavity and a low-pressure face on an opposite side thereof. The alternator has a rotor shaft operatively connected to the turbine and compressor, and is supported in the housing by bearings. Ridges extending from the low-pressure face of the compressor may be provided for balancing thrust across the compressor. Seals may be positioned about the alternator for selectively leaking fluid into the rotor cavity to reduce the temperature therein.

  18. Josephson junction Q-spoiler

    DOE Patents [OSTI]

    Clarke, J.; Hilbert, C.; Hahn, E.L.; Sleator, T.

    1986-03-25

    An automatic Q-spoiler comprising at least one Josephson tunnel junction connected in an LC circuit for flow of resonant current therethrough. When in use in a system for detecting the magnetic resonance of a gyromagnetic particle system, a high energy pulse of high frequency energy irradiating the particle system will cause the critical current through the Josephson tunnel junctions to be exceeded, causing the tunnel junctions to act as resistors and thereby damp the ringing of the high-Q detection circuit after the pulse. When the current has damped to below the critical current, the Josephson tunnel junctions revert to their zero-resistance state, restoring the Q of the detection circuit and enabling the low energy magnetic resonance signals to be detected.

  19. Josephson junction Q-spoiler

    DOE Patents [OSTI]

    Clarke, John (Berkeley, CA); Hilbert, Claude (Austin, TX); Hahn, Erwin L. (Berkeley, CA); Sleator, Tycho (Berkeley, CA)

    1988-01-01

    An automatic Q-spoiler comprising at least one Josephson tunnel junction connected in an LC circuit for flow of resonant current therethrough. When in use in a system for detecting the magnetic resonance of a gyromagnetic particle system, a high energy pulse of high frequency energy irradiating the particle system will cause the critical current through the Josephson tunnel junctions to be exceeded, causing the tunnel junctions to act as resistors and thereby damp the ringing of the high-Q detection circuit after the pulse. When the current has damped to below the critical current, the Josephson tunnel junctions revert to their zero-resistance state, restoring the Q of the detection circuit and enabling the low energy magnetic resonance signals to be detected.

  20. Investigation of Non-synchronous Vibration Mechanism for a High Speed Axial Compressor Using Delayed DES

    E-Print Network [OSTI]

    Zha, Gecheng

    Investigation of Non-synchronous Vibration Mechanism for a High Speed Axial Compressor Using compressor. DDES is a hybrid model for turbulence simulation, which uses RANS model within the wall boundary a torsion moment causing NSV. 1 Introduction Non-synchronous vibration of axial fan/compressor is a non

  1. A Moore-Greitzer axial compressor model with spool Jan Tommy Gravdahl and Olav Egeland

    E-Print Network [OSTI]

    Gravdahl, Jan Tommy

    A Moore-Greitzer axial compressor model with spool dynamics. Jan Tommy Gravdahl and Olav Egeland applies to centrifugal compressors. It seems that the modeling and control of an axial com- pression) Table 1: Development in compressor stall/surge- control. A=Axial, C=Centrifugal, M=Modeling, C

  2. High Speed Compressors P.B. Bailey, M. W. Dadd, C. R. Stone.

    E-Print Network [OSTI]

    of the compressor. The `Oxford' type clearance seal/flexure bearing compressors are typically operated close to the main piston. Use of such a gas spring has some disadvantages: there is a second piston of small compact cryocooler compressors. INTRODUCTION The "Oxford" type of flexure bearing/clearance seal

  3. Test results on a supercharged compressor for commercial refrigeration

    SciTech Connect (OSTI)

    Andrews, J.W.; Butcher, T.A.; Wilhelm, W.G. )

    1989-01-01

    This paper reports on a project whose objective was to quantify the technical benefits of using refrigerant R-502 in a supercharged reciprocating compressor for commercial refrigeration applications. The supercharged compressor concept used a special heat exchanger that subcools the major portion of the liquid refrigerant leaving the condenser. This subcooling is achieved by flashing the remaining portion of the condensed liquid through an expansion valve, thereby cooling it, and using it to absorb heat from the rest of the refrigerant. This supercharged stream is then fed to the cylinders through ports in the cylinder walls that are uncovered when the piston reaches bottom dead center.

  4. High-current, low-energy synchrotrons and compressor rings

    SciTech Connect (OSTI)

    Kustom, R.L.

    1984-05-01

    The primary application of high-current, low-energy synchrotrons and linac compressor rings is as proton drivers for pulsed-spallation neutron sources. They operate in the range of 500 to 1500 MeV with extracted beam repetition rates between 12 to 100 Hz. The time-averaged currents on target are a few tens of microamperes today, soon will be a few thousand in the future. The characteristics for the accelerators and compressor rings, their limitations, and existing and proposed major facilities are described. 22 references, 5 figures, 6 tables.

  5. Compressor Selection and Equipment Sizing for Cold Climate Heat Pumps

    SciTech Connect (OSTI)

    Shen, Bo [ORNL] [ORNL; Abdelaziz, Omar [ORNL] [ORNL; Rice, C Keith [ORNL] [ORNL

    2014-01-01

    In order to limit heating capacity degradation at -25 C (-13 F) ambient to 25%, compared to the nominal rating point capacity at 8.3 C (47 F), an extensive array of design and sizing options were investigated, based on fundamental equipment system modeling and building energy simulation. Sixteen equipment design options were evaluated in one commercial building and one residential building, respectively in seven cities. The energy simulation results were compared to three baseline cases: 100% electric resistance heating, a 9.6 HSPF single-speed heat pump unit, and 90% AFUE gas heating system. The general recommendation is that variable-speed compressors and tandem compressors, sized such that their rated heating capacity at a low speed matching the building design cooling load, are able to achieve the capacity goal at low ambient temperatures by over-speeding, for example, a home with a 3.0 ton design cooling load, a tandem heat pump could meet this cooling load running a single compressor, while running both compressors to meet heating load at low ambient temperatures in a cold climate. Energy savings and electric resistance heat reductions vary with building types, energy codes and climate zones. Oversizing a heat pump can result in larger energy saving in a less energy efficient building and colder regions due to reducing electric resistance heating. However, in a more energy-efficient building or for buildings in warmer climates, one has to consider balance between reduction of resistance heat and addition of cyclic loss.

  6. Scroll compressor modelling for heat pumps using hydrocarbons as refrigerants

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Scroll compressor modelling for heat pumps using hydrocarbons as refrigerants Paul BYRNE and to install heat pumps in unoccupied spaces. Nevertheless manufacturers keep working on components for hydrocarbons. In the frame of a research project on heat pumps for simultaneous heating and cooling, an R407C

  7. Speed and surge control for a low order centrifugal compressor model Jan Tommy Gravdahl and Olav Egeland

    E-Print Network [OSTI]

    Gravdahl, Jan Tommy

    a model for axial compressor mass ow and pressure rise was presented. In 13] it was shown that the modelSpeed and surge control for a low order centrifugal compressor model Jan Tommy Gravdahl and Olav of the compressor. First a low order centrifugal compressor model is presented where the states are mass ow

  8. 83-9E9-TOPIC-P3 Unrestricted DOMslon ManagerHIGH-EFFICIENCY DUAL-STROKE COMPRESSOR

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    , two-capacity,.three cylinder, reciprocating piston, hermetic compressor for the advanced electric heat-pump

  9. IEMDC -IN-LINE ELECTRIC MOTOR DRIVEN COMPRESSOR

    SciTech Connect (OSTI)

    Michael J. Crowley; Prem N. Bansal; John E. Tessaro

    2004-01-01

    Dresser-Rand completed the preliminary aerodynamic flowpath of the volute and inlet design for the compressor section. This has resulted in considerable progress being made on the development of the compressor section and ultimately towards the successful integration of the IEMDC System design. Significant effort was put forth in the design of aerodynamic components which resulted in a design that meets the limits of aerodynamically induced radial forces previously established. Substantial effort has begun on the mechanical design of the compressor pressure containing case and other internal components. These efforts show progression towards the successful integration of a centrifugal compressor and variable speed electric motor ventilated by the process gas. All efforts continue to confirm the feasibility of the IEMDC system design. During the third quarter reporting period, the focus was to further refine the motor design and to ensure that the IEMDC rotor system supported on magnetic bearing is in compliance with the critical speed and vibration requirements of the API standards 617 and 541. Consequently specification to design magnetic bearings was developed and an RFQ to three magnetic bearing suppliers was issued. Considerable work was also performed to complete preliminary reports on some of the deliverable tasks under phase 1.0. These include specification for the VFD, RFQ for the magnetic bearings, and preliminary write-up for motor instrumentation and control schematic. In order to estimate motor efficiency at various operating points, plots of calculated motor losses, and motor cooling gas flow rates were also prepared. Preliminary evaluations of motor support concepts were performed via FEA to determine modal frequencies. Presentation was made at DOE Morgantown on August 12, 2003 to provide project status update. Preparations for the IEMDC motor-compressor presentation, at the GMRC conference in Salt Lake City to be held on October 5, 2003, were also started. Detailed calculations of cooling gas flow requirements for the motor and magnetic bearings, per several new operating points designated by DR, confirmed that the required gas flow was within the compressor design guidelines. Previous thrust load calculations had confirmed that the magnetic thrust bearing design load capacity of 6,000 lb. was sufficient to handle the net thrust load produced by the motor and compressor pressure loading. Thus the design data that has been generated, for the variable speed 10 MW 12,000 rpm motor, during the last three quarters, continue to confirm the feasibility of an efficient and robust motor design.

  10. M Station, Austin 

    E-Print Network [OSTI]

    Mathon, S.

    2011-01-01

    $300 ID LL SS WE EA MR EQ AE LEED Platinum (Standard) 90 ID LL SS WE EA MR EQ AE LEED Platinum (Standard) LEED Platinum (M Station) 9081 ID LL SS WE EA MR EQ AE LEED Platinum (Standard) LEED Platinum (M Station) M Station 9081 108 ID LL... SS WE EA MR EQ AE LEED Platinum (Standard) LEED Platinum (M Station) M Station 9081 10849 $0.00/sf Planning ID LL SS WE EA MR EQ AE LEED Platinum (Standard) LEED Platinum (M Station) M Station 9081 10849 $0.00/sf Planning Location ID...

  11. IEMDC IN-LINE ELECTRIC MOTOR DRIVEN COMPRESSOR

    SciTech Connect (OSTI)

    Michael J. Crowley; Prem N. Bansal

    2004-10-01

    This report contains the final project summary and deliverables required by the award for the development of an In-line Electric Motor Driven Compressor (IEMDC). Extensive work was undertaken during the course of the project to develop the motor and the compressor section of the IEMDC unit. Multiple design iterations were performed to design an electric motor for operation in a natural gas environment and to successfully integrate the motor with a compressor. During the project execution, many challenges were successfully overcome in order to achieve the project goals and to maintain the system design integrity. Some of the challenges included limiting the magnitude of the compressor aerodynamic loading for appropriate sizing of the magnetic bearings, achieving a compact motor rotor size to meet the rotor dynamic requirements of API standards, devising a motor cooling scheme using high pressure natural gas, minimizing the impact of cooling on system efficiency, and balancing the system thrust loads for the magnetic thrust bearing. Design methods that were used on the project included validated state-of-the-art techniques such as finite element analysis and computational fluid dynamics along with the combined expertise of both Curtiss-Wright Electro-Mechanical Corporation and Dresser-Rand Company. One of the most significant areas of work undertaken on the project was the development of the unit configuration for the system. Determining the configuration of the unit was a significant step in achieving integration of the electric motor into a totally enclosed compression system. Product review of the IEMDC unit configuration was performed during the course of the development process; this led to an alternate design configuration. The alternate configuration is a modular design with the electric motor and compressor section each being primarily contained in its own pressure containing case. This new concept resolved the previous conflict between the aerodynamic flow passage requirements and electric motor requirements for support and utilities by bounding the flowpath within the compressor section. However most importantly, the benefits delivered by the new design remained the same as those proposed by the goals of the project. In addition, this alternate configuration resulted in the achievement of a few additional advantages over the original concept such as easier maintenance, operation, and installation. Interaction and feedback solicited from target clients regarding the unit configuration supports the fact that the design addresses industry issues regarding accessibility, maintainability, preferred operating practice, and increased reliability.

  12. High Technology Centrifugal Compressor for Commercial Air Conditioning Systems

    SciTech Connect (OSTI)

    Ruckes, John

    2006-04-15

    R&D Dynamics, Bloomfield, CT in partnership with the State of Connecticut has been developing a high technology, oil-free, energy-efficient centrifugal compressor called CENVA for commercial air conditioning systems under a program funded by the US Department of Energy. The CENVA compressor applies the foil bearing technology used in all modern aircraft, civil and military, air conditioning systems. The CENVA compressor will enhance the efficiency of water and air cooled chillers, packaged roof top units, and other air conditioning systems by providing an 18% reduction in energy consumption in the unit capacity range of 25 to 350 tons of refrigeration The technical approach for CENVA involved the design and development of a high-speed, oil-free foil gas bearing-supported two-stage centrifugal compressor, CENVA encompassed the following high technologies, which are not currently utilized in commercial air conditioning systems: Foil gas bearings operating in HFC-134a; Efficient centrifugal impellers and diffusers; High speed motors and drives; and System integration of above technologies. Extensive design, development and testing efforts were carried out. Significant accomplishments achieved under this program are: (1) A total of 26 builds and over 200 tests were successfully completed with successively improved designs; (2) Use of foil gas bearings in refrigerant R134a was successfully proven; (3) A high speed, high power permanent magnet motor was developed; (4) An encoder was used for signal feedback between motor and controller. Due to temperature limitations of the encoder, the compressor could not operate at higher speed and in turn at higher pressure. In order to alleviate this problem a unique sensorless controller was developed; (5) This controller has successfully been tested as stand alone; however, it has not yet been integrated and tested as a system; (6) The compressor successfully operated at water cooled condensing temperatures Due to temperature limitations of the encoder, it could not be operated at air cooled condensing temperatures. (7) The two-stage impellers/diffusers worked well separately but combined did not match well.

  13. The Junction Diode Basic Operation

    E-Print Network [OSTI]

    Leach Jr.,W. Marshall

    biased diode. Figure 1(b) shows the diode with a battery connected across it. The polarity of the battery in the p-type side away from the junction. No current can flow. The diode is said to be reverse biased. Figure 1(c) shows the diode with the battery polarity reversed. The battery now tends to cancel out

  14. Linear Gain for the Microbunching Instability in an RF Compressor

    SciTech Connect (OSTI)

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

    2009-05-01

    Velocity (or rf) compression has been suggested as a technique for bunch compression complementary to the more established technique involving magnetic chicanes and represents an important research item being investigated at the SPARC test facility. One of the aspects of this technique still not sufficiently understood is its possible impact on the microbunching instability. The purpose of this report is to present the analytical framework for investigating this instability in rf compressors. We use methods similar to those successfully applied to magnetic compressors and derive some integral equations yielding the gain for the instability in linear approximation. The focus here is on the derivation of the relevant equations. Although examples of solutions to these equations are provided we defer a more comprehensive discussion of their implication to a future report. The present study is part of a larger effort for a more comprehensive investigation that eventually will include macroparticle simulations and experiments.

  15. IEMDC-IN-LINE ELECTRIC MOTOR DRIVEN COMPRESSOR

    SciTech Connect (OSTI)

    Michael J. Crowley; Prem N. Bansal; John E. Tessaro

    2003-06-01

    During this reporting period, significant progress has been made towards the development of the IEMDC System design. Considerable effort was put forth by Curtiss-Wright EMD in the resolution of the technical issue of aerodynamically induced radial forces. This has provided a design basis with which to establish the radial magnetic bearing load capacity and the rotordynamic design. Dresser-Rand has made considerable progress on the flowpath design for the compressor section particularly on the volute and inlet aerodynamic design. All efforts show progression towards the successful integration of a centrifugal compressor and variable speed electric motor ventilated by the process gas. These efforts continue to confirm the feasibility of the IEMDC system design.

  16. Quasi-Optical 34-GHz Rf Pulse Compressor

    SciTech Connect (OSTI)

    Hirshfield, Jay L

    2007-06-19

    Designs have been carried out on non-high-vacuum, low-power versions of three- and four-mirror quasi-optical passive and active Ka-band pulse compressors, and prototypes built and tested based on these designs. The active element is a quasi-optical grating employing gas discharge tubes in the gratings. Power gains of about 3:1 were observed experimentally for the passive designs, and about 7:1 with the active designs. High-power, high-vacuum versions of the three-and four-mirror quasi-optical pulse compressors were built and tested at low power. These now await installation and testing using multi-MW power from the 34-GHz magnicon.

  17. RF modulation studies on the S band pulse compressor

    E-Print Network [OSTI]

    Shu, G; Pei, S; Xiao, O

    2015-01-01

    An S band SLED-type pulse compressor has been manufactured by IHEP to challenge the 100 MW maximum input power, which means the output peak power is about 500 MW at the phase reversal time. In order to deal with the RF breakdown problem, the dual side-wall coupling irises model was used. To further improve the reliability at very high power, amplitude modulation and phase modulation with flat-top output were taken into account. The RF modulation studies on an S-band SLED are presented in this paper. Furthermore, a method is developed by using the CST Microwave Studio transient solver to simulate the time response of the pulse compressor, which can be a verification of the modulate theory. In addition, the experimental setup was constructed and the flat-top output is obtained in the low power tests.

  18. RF modulation studies on the S band pulse compressor

    E-Print Network [OSTI]

    G. Shu; F. Zhao; S. Pei; O. Xiao

    2015-05-28

    An S band SLED-type pulse compressor has been manufactured by IHEP to challenge the 100 MW maximum input power, which means the output peak power is about 500 MW at the phase reversal time. In order to deal with the RF breakdown problem, the dual side-wall coupling irises model was used. To further improve the reliability at very high power, amplitude modulation and phase modulation with flat-top output were taken into account. The RF modulation studies on an S-band SLED are presented in this paper. Furthermore, a method is developed by using the CST Microwave Studio transient solver to simulate the time response of the pulse compressor, which can be a verification of the modulate theory. In addition, the experimental setup was constructed and the flat-top output is obtained in the low power tests.

  19. Plasma Switch for High-Power Active Pulse Compressor

    SciTech Connect (OSTI)

    Hirshfield, Jay L. [Omega-P, Inc.] [Omega-P, Inc.

    2013-11-04

    Results are presented from experiments carried out at the Naval Research Laboratory X-band magnicon facility on a two-channel X-band active RF pulse compressor that employed plasma switches. Experimental evidence is shown to validate the basic goals of the project, which include: simultaneous firing of plasma switches in both channels of the RF circuit, operation of quasi-optical 3-dB hybrid directional coupler coherent superposition of RF compressed pulses from both channels, and operation of the X-band magnicon directly in the RF pulse compressor. For incident 1.2 ?s pulses in the range 0.63 ? 1.35 MW, compressed pulses of peak powers 5.7 ? 11.3 MW were obtained, corresponding to peak power gain ratios of 8.3 ? 9.3. Insufficient bakeout and conditioning of the high-power RF circuit prevented experiments from being conducted at higher RF input power levels.

  20. Heat powered refrigeration compressor. Semi-annual technical report

    SciTech Connect (OSTI)

    Goad, R.R.

    1981-01-01

    The objective of this program is to develop and improve the design of previously started prototypes of the Heat Powered Refrigeration Compressor. To build this prototype and ready it for testing by the University of Evansville is another goal. This prototype will be of similar capacity as the compressor that will eventually be commercially produced. This unit can operate on almost any moderate temperature water heat source. This heat source could include such applications as industrial waste heat, solar, wood burning stove, resistance electrical heat produced by a windmill, or even perhaps heat put out by the condenser of another refrigeration system. Work performed in the past four months has consisted of: engineering of HX-1; comparisons of specifications from different companies to ensure state of the art applications of parts for project; coordinating project requirements with machine shop; designing condenser; and partial assembly of HX-1.

  1. Turbine inter-disk cavity cooling air compressor

    DOE Patents [OSTI]

    Little, David Allen (Oviedo, FL)

    2001-01-01

    A combustion turbine may have a cooling circuit for directing a cooling medium through the combustion turbine to cool various components of the combustion turbine. This cooling circuit may include a compressor, a combustor shell and a component of the combustion turbine to be cooled. This component may be a rotating blade of the combustion turbine. A pressure changing mechanism is disposed in the combustion turbine between the component to be cooled and the combustor shell. The cooling medium preferably flows from the compressor to the combustor shell, through a cooler, the component to the cooled and the pressure changing mechanism. After flowing through the pressure changing mechanism, the cooling medium is returned to the combustor shell. The pressure changing mechanism preferably changes the pressure of the cooling medium from a pressure at which it is exhausted from the component to be cooled to approximately that of the combustor shell.

  2. Downhole steam generator having a downhole oxidant compressor

    DOE Patents [OSTI]

    Fox, R.L.

    1981-01-07

    Am improved apparatus is described for the downhole injection of steam into boreholes, for tertiary oil recovery. It includes an oxidant supply, a fuel supply, an igniter, a water supply, an oxidant compressor, and a combustor assembly. The apparatus is designed for efficiency, preheating of the water, and cooling of the combustion chamber walls. The steam outlet to the borehole is provided with pressure-responsive doors for closing the outlet in response to flameout. (DLC)

  3. Screw Type Steam Compressors for Mechanical Vapor Recompression (MVR) Systems 

    E-Print Network [OSTI]

    Kawamura, K.; Apaloo, Thomas-L.

    1986-01-01

    hand, is not affected by such problem. No special mist separator is required and, at the same time, the wet or saturated vapor compression is possible, and does not affect the efficiency of the SSHP. (3) Stability of performance for a wide... COMPRESSORS FOR MECHANICAL VAPOR RECOMPRESSION (MVR) SYSTEMS K. KAWAMURA AND THOMAS-L. APALOO MYCOM CORPORATION, LOS ANGELES, CALIFORNIA MATSUDA, MAYEKAWA MFG. CO., TOKYO, JAPAN ABSTRACT In processes of evaporation, distillation or drying, steam...

  4. Modeling shrouded stator cavity flows in axial-flow compressors

    SciTech Connect (OSTI)

    Wellborn, S.R.; Tolchinsky, I.; Okiishi, T.H.

    2000-01-01

    Experiments and computational analyses were completed to understand the nature of shrouded stator cavity flows. From this understanding, a one-dimensional model of the flow through shrouded stator cavities was developed. This model estimates the leakage mass flow, temperature rise, and angular momentum increase through the cavity, given geometry parameters and the flow conditions at the interface between the cavity and primary flow path. This cavity model consists of two components, one that estimates the flow characteristics through the labyrinth seals and the other that predicts the transfer of momentum due to windage. A description of the one-dimensional model is given. The incorporation and use of the one-dimensional model in a multistage compressor primary flow analysis tool is described. The combination of this model and the primary flow solver was used to reliably simulate the significant impact on performance of the increase of hub seal leakage in a twelve-stage axial-flow compressor. Observed higher temperatures of the hub region fluid, different stage matching, and lower overall efficiencies and core flow than expected could be correctly linked to increased hub seal clearance with this new technique. The importance of including these leakage flows in compressor simulations is shown.

  5. A new endwall model for axial compressor throughflow calculations

    SciTech Connect (OSTI)

    Dunham, J.

    1995-10-01

    It is well recognized that the endwall regions of a compressor--in which the annulus wall flow interacts with the mainstream flow--have a major influence on its efficiency and surge margin. Despite many attempts over the years to predict the very complex flow patterns in the endwall regions, current compressor design methods still rely largely on empirical estimates of the aerodynamic losses and flow angle deviations in these regions. This paper describes a new phenomenological model of the key endwall flow phenomena treated in a circumferentially averaged way. It starts from Hirsch and de Ruyck`s annulus wall boundary layer approach, but makes some important changes. The secondary vorticities arising from passage secondary flows and from tip clearance flows are calculated. Then the radial interchanges of momentum, energy, and entropy arising from both diffusion and convection are estimated. The model is incorporated into a streamline curvature program. The empirical blade force defect terms in the boundary layers are selected from cascade data. The effectiveness of the method is illustrated by comparing the predictions with experimental results on both low-speed and high-speed multistage compressors. It is found that the radial variation of flow parameters is quite well predicted, and so is the overall performance, except when significant endwall stall occurs.

  6. An analysis of axial compressor fouling and a blade cleaning method

    SciTech Connect (OSTI)

    Tarabrin, A.P.; Schurovsky, V.A.; Bodrov, A.I.; Stalder, J.P.

    1998-04-01

    The paper describes the phenomenon of axial compressor fouling due to aerosols contained in the air. Key parameters having effect on the level of fouling are determined. A mathematical model of a progressive compressor fouling using the stage-by-stage calculation method is developed. Calculation results on the influence of fouling on the compressor performance are presented. A new index of sensitivity of axial compressors to fouling is suggested. The paper gives information about Turbotect`s deposit cleaning method of compressor blading and the results of its application on an operating industrial gas turbine. Regular on-line and off-line washings of the compressor flow path made it possible to maintain a high level of engine efficiency and output.

  7. Simulating Energy Efficient Control of Multiple-Compressor Compressed Air Systems 

    E-Print Network [OSTI]

    Murphy, S.

    2015-01-01

    with multiple compressors contain greater opportunity for controls optimization. The three main types of multiple- compressor control strategies which will be discussed in this paper are: pressure band control, network sequencer control, and automatic..., the basic principles and control algorithms are detailed for pressure band control, network sequencer control, and automatic sequencer control strategies for multiple-compressor compressed air systems. Finally, a case study is presented demonstrating...

  8. Dual capacity compressor with reversible motor and controls arrangement therefor

    DOE Patents [OSTI]

    Sisk, Francis J. (Washington Township, Fayette County, PA)

    1980-12-02

    A hermetic reciprocating compressor such as may be used in heat pump applications is provided for dual capacity operation by providing the crankpin of the crankshaft with an eccentric ring rotatably mounted thereon, and with the end of the connecting rod opposite the piston encompassing the outer circumference of the eccentric ring, with means limiting the rotation of the eccentric ring upon the crankpin between one end point and an opposite angularly displaced end point to provide different values of eccentricity depending upon which end point the eccentric ring is rotated to upon the crankpin, and a reversible motor in the hermetic shell of the compressor for rotating the crankshaft, the motor operating in one direction effecting the angular displacement of the eccentric ring relative to the crankpin to the one end point, and in the opposite direction effecting the angular displacement of the eccentric ring relative to the crankpin to the opposite end point, this arrangement automatically giving different stroke lengths depending upon the direction of motor rotation. The mechanical structure of the arrangement may take various forms including at least one in which any impact of reversal is reduced by utilizing lubricant passages and chambers at the interface area of the crankpin and eccentric ring to provide a dashpot effect. In the main intended application of the arrangement according to the invention, that is, in a refrigerating or air conditioning system, it is desirable to insure a delay during reversal of the direction of compressor operation. A control arrangement is provided in which the control system controls the direction of motor operation in accordance with temperature conditions, the system including control means for effecting operation in a low capacity direction or alternatively in a high capacity direction in response to one set, and another set, respectively, of temperature conditions and with timer means delaying a restart of the compressor motor for at least a predetermined time in response to a condition of the control means operative to initiate a change in the operating direction of the compressor when it restarts.

  9. Rotor dynamic analysis of GCEP (Gas Centrifuge Enrichment Plant) Tails Withdrawal Test Facility AC-12 compressor

    SciTech Connect (OSTI)

    Spencer, J.W.

    1982-01-22

    The reliable operation of the centrifugal compressors utilized in the gaseous diffusion process is of great importance due to the critical function of these machines in product and tails withdrawal, cascade purge and evacuation processes, the purge cascade and product booster applications. The same compressors will be used in equally important applications within the Gas Centrifuge Enrichment Plant (GCEP). In response to concern over the excessive vibration exhibited by the AC-12 compressor in the No. 3 position of the GCEP Tails Withdrawal Test Facility, a rotor-bearing dynamic analysis was performed on the compressor. This analysis included the acquisition and reduction of compressor vibration data, characterization and modeling of the rotorbearing system, a computer dynamic study, and recommendations for machine modification. The compressor dynamic analysis was performed for rotor speeds of 9000 rpm and 7200 to 7800 rpm, which includes all possible opreating speeds of the compressor in the GCEP Test Facility. While the analysis was performed on this particular AC-12 compressor, the results should be pertinent to other AC-12 applications as well. Similar diagnostic and analytical techniques can be used to evaluate operation of other types of centrifugal compressors.

  10. String Junctions and Holographic Interfaces

    E-Print Network [OSTI]

    Marco Chiodaroli; Michael Gutperle; Ling-Yan Hung; Darya Krym

    2010-11-22

    In this paper we study half-BPS type IIB supergravity solutions with multiple $AdS_3\\times S^3\\times M_4$ asymptotic regions, where $M_4$ is either $T^4$ or $K_3$. These solutions were first constructed in [1] and have geometries given by the warped product of $AdS_2 \\times S^2 \\times M_4 $ over $\\Sigma$, where $\\Sigma$ is a Riemann surface. We show that the holographic boundary has the structure of a star graph, i.e. $n$ half-lines joined at a point. The attractor mechanism and the relation of the solutions to junctions of self-dual strings in six-dimensional supergravity are discussed. The solutions of [1] are constructed introducing two meromorphic and two harmonic functions defined on $\\Sigma$. We focus our analysis on solutions corresponding to junctions of three different conformal field theories and show that the conditions for having a solution charged only under Ramond-Ramond three-form fields reduce to relations involving the positions of the poles and the residues of the relevant harmonic and meromorphic functions. The degeneration limit in which some of the poles collide is analyzed in detail. Finally, we calculate the holographic boundary entropy for a junction of three CFTs and obtain a simple expression in terms of poles and residues.

  11. Background review on compressors for gas engine-driven heat pumps. Technical report, September 1985-March 1986

    SciTech Connect (OSTI)

    Hall, R.L.; Swain, J.C.

    1986-04-01

    The investigation focused on the efficiency and durability of various types of open-shaft compressors for potential application to residential and light commercial gas-engine-driven heat-pump applications. Variable speed efficiency data for hermetic, semihermetic, and open shaft compressors were obtained from the public literature and from compressor manufacturers in the US, Japan, and in Europe. Efficiency comparisons based upon refrigerants R12 and R22 at a fixed compressor pressure ratio indicate that reciprocating compressors have the highest coefficients of performance (COP's) for compressor speeds ranging from 1000 to 2500 rpm. Scroll and Wankel compressors appear to offer the highest COP's above 2500 rpm. An important finding of the work is that open shaft compressors with proven life and reliability for residential gas engine heat-pump applications do not appear to be available as production units.

  12. Three-dimensional flow visualization in a centrifugal compressor 

    E-Print Network [OSTI]

    Trevillion, William Lee

    1976-01-01

    of this boundary layer problem should enable designers to design compressors with higher efficiencies and larger surge-to-stall margins. Wiesner Stodola Busemann Eck 0. 9 B 0 m 0. 8 pfleiderer Senoo a Nakase ~ ~ 0. 7 ~ Experimental results 0. 6 0... increase during its flow through the impeller. The outer diameter of the rotor, D , was designed to be 7. 00 inches with an exit blade height, b2, of 0. 50 inches. The hub and blades were machined from aluminum and polished to aid observation...

  13. Passivity based compressor surge control using a close-coupled valve

    E-Print Network [OSTI]

    Gravdahl, Jan Tommy

    Passivity based compressor surge control using a close-coupled valve Jan Tommy Gravdahl and Olav-coupled valve. The analysis shows that the system has certain passivity properties which leads to a simple controller for the close- coupled valve. 1 Introduction If the ow through a compressor is throttled

  14. Design of a Free Piston Pneumatic Compressor as a Mobile Robot Power Supply

    E-Print Network [OSTI]

    Barth, Eric J.

    technology is intended to provide a compact pneumatic power supply source appropriate for human-scale robotsDesign of a Free Piston Pneumatic Compressor as a Mobile Robot Power Supply Jose A. Riofrio.j.barth@vanderbilt.edu Abstract ­ The design of a free piston compressor (FPC) intended as a pneumatic power supply

  15. 1275, Page 1 ANALYSIS AND DEVELOPMENT OF A TURBIVO COMPRESSOR FOR MVR

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    dryers is the use of a compressor with high efficiency in an open cycle and at high evaporating development issue. Typical clothe dryers consume 750 Wh/kg of dry clothes. Dryers with thermodynamic cycle can-stage configuration for high flow rate and high compression power (> 100 kW) [2]. Volumetric compressors are divided

  16. High Fidelity Modeling of Blade Row Interaction in a Transonic Compressor

    E-Print Network [OSTI]

    Cincinnati, University of

    High Fidelity Modeling of Blade Row Interaction in a Transonic Compressor Michael G. List on the compressor. Three dierent axial spacings between the rotor and the upstream blade row have been simulated of Cincinnati, Cincinnati, OH, 45221 In order to accurately model the physics associated with losses

  17. A Model of Compressor Blade Row Interaction with Shock Induced Vortex Shedding

    E-Print Network [OSTI]

    Cincinnati, University of

    A Model of Compressor Blade Row Interaction with Shock Induced Vortex Shedding Mark G. Turner". The mid and far spacings represent typical axial gaps found in operational fans and compressors. However behind a stator are modeled. The model is based on a Burger vortex core model for shed vortices

  18. Performance Testing of Jefferson Lab 12 GeV Helium Screw Compressors

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

    Knudsen, P.; Ganni, V.; Dixon, K.; Norton, R.; Creel, J.

    2015-08-10

    Oil injected screw compressors have essentially superseded all other types of compressors in modern helium refrigeration systems due to their large displacement capacity, reliability, minimal vibration, and capability of handling helium's high heat of compression. At the present state of compressor system designs for helium refrigeration systems, typically two-thirds of the lost input power is due to the compression system. It is important to understand the isothermal and volumetric efficiencies of these machines to help properly design the compression system to match the refrigeration process. It is also important to identify those primary compressor skid exergetic loss mechanisms which maymore »be reduced, thereby offering the possibility of significantly reducing the input power to helium refrigeration processes which are extremely energy intensive. This paper summarizes the results collected during the commissioning of the new compressor system for Jefferson Lab's (JLab's) 12 GeV upgrade. The compressor skid packages were designed by JLab and built to print by industry. They incorporate a number of modifications not typical of helium screw compressor packages and most importantly allow a very wide range of operation so that JLab's patented Floating Pressure Process can be fully utilized. This paper also summarizes key features of the skid design that allow this process and facilitate the maintenance and reliability of these helium compressor systems.« less

  19. Testing and modeling of compressors for low-lift cooling applications

    E-Print Network [OSTI]

    Willingham, Ryan Alexander

    2009-01-01

    In this thesis, an inverter-driven variable speed scroll compressor is tested on a de-superheater test stand to determine its performance in areas of low-lift and low compressor speed. The goal is to adapt this test stand ...

  20. Bunch Compressor for the TESLA Linear Collider W. Decking, G. Hoffstaetter, T. Limberg

    E-Print Network [OSTI]

    Hoffstaetter, Georg

    Bunch Compressor for the TESLA Linear Collider W. Decking, G. Hoffstaetter, T. Limberg DESY, Notkestraße 85, 22603 Hamburg, Germany September 2000 Abstract TESLA-2000-40 (2000) We discuss different bunch compression systems for the TESLA collider. The best alternative is a wiggler type compressor, where we list

  1. 2009-32-0176/20097176 Miniature HCCI Free-Piston Engine Compressor

    E-Print Network [OSTI]

    Durfee, William K.

    -cycle combustion is used. Free-piston engine compressor Accumulator Rotary actuator #12;SETC2009 ComparedSETC2009 2009-32-0176/20097176 Miniature HCCI Free-Piston Engine Compressor For Orthosis Application Lei Tian, David B. Kittelson, William K. Durfee Mechanical Engineering, University of Minnesota

  2. IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY, VOL. 7, NO. 5, SEPTEMBER 1999 567 Centrifugal Compressor Surge and Speed Control

    E-Print Network [OSTI]

    Gravdahl, Jan Tommy

    IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY, VOL. 7, NO. 5, SEPTEMBER 1999 567 Centrifugal of the compressor. First a low-order centrifugal compressor model is presented where the states are mass flow] showed that it is also applicable to centrifugal compressors. The model has two states, normalized mass

  3. Performance analysis of a series of hermetic reciprocating compressors working with R290 (propane) and R407C

    E-Print Network [OSTI]

    Fernández de Córdoba, Pedro

    Performance analysis of a series of hermetic reciprocating compressors working with R290 (propane with propane as refrigerant are analyzed in terms of the compressor model developed by [E. Navarro, E. Granryd. In addition, a comparison study between propane and R407C was carried out for one compressor and the observed

  4. Compressor discharge bleed air circuit in gas turbine plants and related method

    DOE Patents [OSTI]

    Anand, Ashok Kumar (Niskayuna, NY); Berrahou, Philip Fadhel (Latham, NY); Jandrisevits, Michael (Clifton Park, NY)

    2002-01-01

    A gas turbine system that includes a compressor, a turbine component and a load, wherein fuel and compressor discharge bleed air are supplied to a combustor and gaseous products of combustion are introduced into the turbine component and subsequently exhausted to atmosphere. A compressor discharge bleed air circuit removes bleed air from the compressor and supplies one portion of the bleed air to the combustor and another portion of the compressor discharge bleed air to an exhaust stack of the turbine component in a single cycle system, or to a heat recovery steam generator in a combined cycle system. In both systems, the bleed air diverted from the combustor may be expanded in an air expander to reduce pressure upstream of the exhaust stack or heat recovery steam generator.

  5. Compressor discharge bleed air circuit in gas turbine plants and related method

    DOE Patents [OSTI]

    Anand, Ashok Kumar (Niskayuna, NY); Berrahou, Philip Fadhel (Latham, NY); Jandrisevits, Michael (Clifton Park, NY)

    2003-04-08

    A gas turbine system that includes a compressor, a turbine component and a load, wherein fuel and compressor discharge bleed air are supplied to a combustor and gaseous products of combustion are introduced into the turbine component and subsequently exhausted to atmosphere. A compressor discharge bleed air circuit removes bleed air from the compressor and supplies one portion of the bleed air to the combustor and another portion of the compressor discharge bleed air to an exhaust stack of the turbine component in a single cycle system, or to a heat recovery steam generator in a combined cycle system. In both systems, the bleed air diverted from the combustor may be expanded in an air expander to reduce pressure upstream of the exhaust stack or heat recovery steam generator.

  6. The use of neural nets for matching compressors with diesel engines

    SciTech Connect (OSTI)

    Nelson, S.A. II; Filipi, Z.S.; Assanis, D.N.

    1996-12-31

    A technique which uses trained neural nets to model the compressor in the context of a turbocharged diesel engine simulation is introduced. This technique replaces the usual interpolation of compressor maps with the evaluation of a smooth mathematical function, thus providing engine simulations with greater robustness and flexibility. Following presentation of the methodology, the proposed neural net technique is validated against data from a truck type, 6-cylinder, 14 liter diesel engine. Furthermore, with the introduction of an additional parameter, the proposed neural net can be trained to simulate an entire family of compressors. As a demonstration, five compressors of different sizes are represented with the neural net model, and used for matching calculations with intercooled and non-intercooled engine configurations at different speeds. This novel approach readily allows for evaluation of various options prior to prototype production, and is thus a powerful design tool for selection of the best compressor for a given diesel engine system.

  7. Method for shallow junction formation

    DOE Patents [OSTI]

    Weiner, K.H.

    1996-10-29

    A doping sequence is disclosed that reduces the cost and complexity of forming source/drain regions in complementary metal oxide silicon (CMOS) integrated circuit technologies. The process combines the use of patterned excimer laser annealing, dopant-saturated spin-on glass, silicide contact structures and interference effects creates by thin dielectric layers to produce source and drain junctions that are ultrashallow in depth but exhibit low sheet and contact resistance. The process utilizes no photolithography and can be achieved without the use of expensive vacuum equipment. The process margins are wide, and yield loss due to contact of the ultrashallow dopants is eliminated. 8 figs.

  8. Detector for flow abnormalities in gaseous diffusion plant compressors

    DOE Patents [OSTI]

    Smith, Stephen F. (Loudon, TN); Castleberry, Kim N. (Harriman, TN)

    1998-01-01

    A detector detects a flow abnormality in a plant compressor which outputs a motor current signal. The detector includes a demodulator/lowpass filter demodulating and filtering the motor current signal producing a demodulated signal, and first, second, third and fourth bandpass filters connected to the demodulator/lowpass filter, and filtering the demodulated signal in accordance with first, second, third and fourth bandpass frequencies generating first, second, third and fourth filtered signals having first, second, third and fourth amplitudes. The detector also includes first, second, third and fourth amplitude detectors connected to the first, second, third and fourth bandpass filters respectively, and detecting the first, second, third and fourth amplitudes, and first and second adders connected to the first and fourth amplitude detectors and the second and third amplitude detectors respectively, and adding the first and fourth amplitudes and the second and third amplitudes respectively generating first and second added signals. Finally, the detector includes a comparator, connected to the first and second adders, and comparing the first and second added signals and detecting the abnormal condition in the plant compressor when the second added signal exceeds the first added signal by a predetermined value.

  9. Detector for flow abnormalities in gaseous diffusion plant compressors

    DOE Patents [OSTI]

    Smith, S.F.; Castleberry, K.N.

    1998-06-16

    A detector detects a flow abnormality in a plant compressor which outputs a motor current signal. The detector includes a demodulator/lowpass filter demodulating and filtering the motor current signal producing a demodulated signal, and first, second, third and fourth bandpass filters connected to the demodulator/lowpass filter, and filtering the demodulated signal in accordance with first, second, third and fourth bandpass frequencies generating first, second, third and fourth filtered signals having first, second, third and fourth amplitudes. The detector also includes first, second, third and fourth amplitude detectors connected to the first, second, third and fourth bandpass filters respectively, and detecting the first, second, third and fourth amplitudes, and first and second adders connected to the first and fourth amplitude detectors and the second and third amplitude detectors respectively, and adding the first and fourth amplitudes and the second and third amplitudes respectively generating first and second added signals. Finally, the detector includes a comparator, connected to the first and second adders, and comparing the first and second added signals and detecting the abnormal condition in the plant compressor when the second added signal exceeds the first added signal by a predetermined value. 6 figs.

  10. Solar Junction Develops World Record Setting Concentrated Photovoltaic...

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

    Solar Junction Develops World Record Setting Concentrated Photovoltaic Solar Cell Solar Junction Develops World Record Setting Concentrated Photovoltaic Solar Cell April 18, 2013 -...

  11. Grand Junction Office Founder Honored at the Philip C. Leahy...

    Office of Environmental Management (EM)

    Grand Junction Office Founder Honored at the Philip C. Leahy Memorial Park Dedication and Open House Grand Junction Office Founder Honored at the Philip C. Leahy Memorial Park...

  12. Hydrogen Refueling Station Costs in Shanghai

    E-Print Network [OSTI]

    Weinert, Jonathan X.; Shaojun, Liu; Ogden, J; Jianxin, Ma

    2006-01-01

    high-pressure stationary hydrogen storage tanks. The storage10] reviewed the hydrogen storage and the delivery cost forwhich applies to hydrogen storage vessels and compressors.

  13. Hydrogen refueling station costs in Shanghai

    E-Print Network [OSTI]

    Weinert, Jonathan X.; Shaojun, Liu; Ogden, Joan M; Jianxin, Ma

    2007-01-01

    N I [10] reviewed the hydrogen storage and the delivery costwhich applies to hydrogen storage vessels and compressors.high-pressure gaseous hydrogen storage contain- ers, and a

  14. Hydrogen Refueling Station Costs in Shanghai

    E-Print Network [OSTI]

    Weinert, Jonathan X.; Shaojun, Liu; Ogden, Joan M; Jianxin, Ma

    2006-01-01

    10] reviewed the hydrogen storage and the delivery cost forwhich applies to hydrogen storage vessels and compressors.high-pressure gaseous hydrogen storage containers, and a

  15. INCREASED FLEXIBILITY OF TURBO-COMPRESSORS IN NATURAL GAS TRANSMISSION THROUGH DIRECT SURGE CONTROL

    SciTech Connect (OSTI)

    Robert J. McKee; Danny M. Deffenbaugh

    2004-12-01

    This annual progress report describes the third year's technical progress in a three-year program. This report introduces the benefits of improved surge detection and summarizes what is known about internal flows as surge precursors in centrifugal compressors. Early research results and findings concerning surge in centrifugal compressors and possible precursors to surge are presented. Laboratory test results in modern compressors with 3D impellers are described in detail and used to show the changes in internal flow patterns that occur as a compressor approaches surge. It was found that older compressors with recessed impeller blading (2D geometry) do not have the same accessible flow patterns. The laboratory test results indicate a large increase in potential operating range for modern compressors. This annual report also presents results from the field testing conducted during the course of this third year. The field test results showed similar changes in the surge probe strain signals and the same type, although of less magnitude, of indication that the compressor is approaching surge. An algorithm for identifying the nearness of surge has been proposed and evaluated with the available data. This project is co-funded by the Gas Machinery Research Council (GMRC) and by Siemens Energy and Automation (Siemens). The results of the project include a step-by-step process for design, sizing, and installation of surge detection probes and for implementation of the direct surge control in centrifugal compressor controllers. This work is considered a step towards the successful implementation of direct surge control for improved flexibility and efficiency in natural gas transmission compressors.

  16. Rotor whirl forces induced by the tip clearance effect in axial flow compressors

    SciTech Connect (OSTI)

    Ehrich, F. )

    1993-10-01

    It is now widely recognized that destabilizing forces, tending to generate forward rotor whirl, are generated in axial flow turbines as a result of the nonuniform torque induced by the nonuniform tip-clearance in a deflected rotor--the so called Thomas/Alford force. It is also recognized that there will be a similar effect in axial flow compressors, but qualitative considerations cannot definitively establish the magnitude or even the direction of the induced whirling forces--that is, if they will tend to forward or backward whirl. Applying a parallel compressor model to simulate the operation of a compressor rotor deflected radially in its clearance, it is possible to derive a quantitative estimate of the proportionality factor [beta] which relates the Thomas/Alford force in axial flow compressors (i.e., the tangential force generated by a radial deflection of the rotor) to the torque level in the compressor. The analysis makes use of experimental data from the GE Aircraft Engines Low Speed Research Compressor facility comparing the performance of three different axial flow compressors, each with four stages (typical of a mid-block of an aircraft gas turbine compressor) at two different clearances. It is found that the value of [beta] is in the range of +0.27 to [minus]0.71 in the vicinity of the stages' nominal operating line and +0.08 to [minus]1.25 in the vicinity of the stages' operation at peak efficiency. The value of [beta] reaches a level of between [minus]1.16 and [minus]3.36 as the compressor is operated near its stalled condition.

  17. Towards development of an incipient surge detection device for centrifugal compressors 

    E-Print Network [OSTI]

    Hassinger, David Alan

    1978-01-01

    the centrifugal compressor does have a higher pressure ratio, the axial flow compressor has a The citations on the following pages follow the style of t. h ASME Jo 1 f E~ f po Surge Line / ( I I I I / / / / / / / ncreasin m 0 0 e '4 C4 8 0 D...TOWARDS DEVELOPMENT OF AN INCIPIENT SURGE DETECTION DEVICE FOR CENTRIFUGAL COMPRESSORS A Thesis DAVID ALAN HASSINGER Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER...

  18. 241-U-701 new compressor building and instrument air piping analyses

    SciTech Connect (OSTI)

    Huang, F.H.

    1994-08-25

    Building anchorage analysis is performed to qualify the design of the new compressor building foundation given in the ECN ``241-U-701 New Compressor Building.`` Recommendations for some changes in the ECN are made accordingly. Calculations show that the 6-in.-slab is capable of supporting the pipe supports, and that the building foundation, air compressor and dryer anchorage, and electric rack are adequate structurally. Analysis also shows that the instrument air piping and pipe supports for the compressed air system meet the applicable code requirements and are acceptable. The building is for the U-Farm instrument air systems.

  19. Hydraulic accumulator-compressor for geopressured enhanced oil recovery

    DOE Patents [OSTI]

    Goldsberry, Fred L. (Spring, TX)

    1988-01-01

    A hydraulic accumulator-compressor vessel using geothermal brine under pressure as a piston to compress waste (CO.sub.2 rich) gas is used in a system having a plurality of gas separators in tandem to recover pipeline quality gas from geothermal brine. A first high pressure separator feeds gas to a membrance separator which separates low pressure waste gas from high pressure quality gas. A second separator produces low pressure waste gas. Waste gas from both separators is combined and fed into the vessel through a port at the top as the vessel is drained for another compression cycle. High pressure brine is then admitted into the vessel through a port at the bottom of the vessel. Check valves control the flow of low pressure waste gas into the vessel and high pressure waste gas out of the vessel.

  20. Stretchers and compressors for ultra-high power laser systems

    SciTech Connect (OSTI)

    Yakovlev, I V [Institute of Applied Physics, Russian Academy of Sciences, Nizhnii Novgorod (Russian Federation)

    2014-05-30

    This review is concerned with pulse stretchers and compressors as key components of ultra-high power laser facilities that take advantage of chirped-pulse amplification. The potentialities, characteristics, configurations and methods for the matching and alignment of these devices are examined, with particular attention to the history of the optics of ultra-short, ultra-intense pulses before and after 1985, when the chirped-pulse amplification method was proposed, which drastically changed the view of the feasibility of creating ultra-high power laser sources. The review is intended primarily for young scientists and experts who begin to address the amplification and compression of chirped pulses, experts in laser optics and all who are interested in scientific achievements in the field of ultra-high power laser systems. (review)

  1. Forging of compressor blades: Temperature and ram velocity effects

    SciTech Connect (OSTI)

    Saigal, A.; Zhen, K.; Chan, T.S.

    1995-07-01

    Forging is one of the most widely used manufacturing process for making high-strength, structurally integrated, impact and creep-resistant Ti-6Al-4V compressor blades for jet engines. In addition, in modern metal forming technology, finite element analysis method and computer modeling are being extensively employed for initial evaluation and optimization of various processes, including forging. In this study, DEFORM, a rigid viscoplastic two-dimensional finite element code was used to study the effects of initial die temperature and initial ram velocity on the forging process. For a given billet, die temperature and ram velocity influence the strain rate, temperature distribution,and thus the flow stress of the material. The die temperature and the ram velocity were varied over the range 300 to 700 F and 15--25 in./sec, respectively, to estimate the maximum forging load and the total energy required to forge compressor blades. The ram velocity was assumed to vary linearly as a function of stroke. Based on the analysis,it was found the increasing the die temperature from 300 to 700 F decreases the forging loads by 19.9 percent and increases the average temperature of the workpiece by 43 F. Similarly, increasing the initial ram velocity from 15 to 25 in./sec decreases the forging loads by 25.2 percent and increases the average temperature of the workpiece by 36 F. The nodal temperature distribution is bimodal in each case. The forging energy required to forge the blades is approximately 18 kips *in./in.

  2. Microwave Photon Counter Based on Josephson Junctions

    E-Print Network [OSTI]

    Y. -F. Chen; D. Hover; S. Sendelbach; L. Maurer; S. T. Merkel; E. J. Pritchett; F. K. Wilhelm; R. McDermott

    2011-11-07

    We describe a microwave photon counter based on the current-biased Josephson junction. The junction is tuned to absorb single microwave photons from the incident field, after which it tunnels into a classically observable voltage state. Using two such detectors, we have performed a microwave version of the Hanbury Brown and Twiss experiment at 4 GHz and demonstrated a clear signature of photon bunching for a thermal source. The design is readily scalable to tens of parallelized junctions, a configuration that would allow number-resolved counting of microwave photons.

  3. Thermoelectric efficiency of critical quantum junctions

    E-Print Network [OSTI]

    Mihail Mintchev; Luca Santoni; Paul Sorba

    2013-10-30

    We derive the efficiency at maximal power of a scale-invariant (critical) quantum junction in exact form. Both Fermi and Bose statistics are considered. We show that time-reversal invariance is spontaneously broken. For fermions we implement a new mechanism for efficiency enhancement above the Curzon-Ahlborn bound, based on a shift of the particle energy in each heat reservoir, proportional to its temperature. In this setting fermionic junctions can even reach at maximal power the Carnot efficiency. The bosonic junctions at maximal power turn out to be less efficient then the fermionic ones.

  4. Tunnel junction multiple wavelength light-emitting diodes

    DOE Patents [OSTI]

    Olson, Jerry M. (Lakewood, CO); Kurtz, Sarah R. (Golden, CO)

    1992-01-01

    A multiple wavelength LED having a monolithic cascade cell structure comprising at least two p-n junctions, wherein each of said at least two p-n junctions have substantially different band gaps, and electrical connector means by which said at least two p-n junctions may be collectively energized; and wherein said diode comprises a tunnel junction or interconnect.

  5. Tunnel junction multiple wavelength light-emitting diodes

    DOE Patents [OSTI]

    Olson, J.M.; Kurtz, S.R.

    1992-11-24

    A multiple wavelength LED having a monolithic cascade cell structure comprising at least two p-n junctions, wherein each of said at least two p-n junctions have substantially different band gaps, and electrical connector means by which said at least two p-n junctions may be collectively energized; and wherein said diode comprises a tunnel junction or interconnect. 5 figs.

  6. Effects of rotor tip blade loading variation on compressor stage performance

    E-Print Network [OSTI]

    Tiralap, Aniwat

    2015-01-01

    Changes in loss generation associated with altering the rotor tip loading of an embedded compressor stage is assessed. Steady and unsteady three-dimensional computations, complemented by control volume analyses, for varying ...

  7. Optimal Design and Tolerancing of Compressor Blades Subject to Manufacturing Variability

    E-Print Network [OSTI]

    Wang, Qiqi

    This paper presents a computational approach for optimal robust design and tolerancing of turbomachinery compressor blades that are subject to geometric variability. This approach simultaneously determines the optimal blade ...

  8. Adjustable Speed- A Tool for Saving Energy Losses in Pumps, Fans, Fans, Blowers and Compressors 

    E-Print Network [OSTI]

    Hickok, H. N.

    1985-01-01

    Petroleum and chemical plants of today are effectively cutting energy losses in their plants thermally, electrically, and mechanically in their process equipment. In rotating process equipment such as pumps, fans, compressors, and blowers, much...

  9. Forced response of a centrifugal compressor stage due to the impeller-diffuser interaction

    E-Print Network [OSTI]

    Walton, Edward James

    2014-01-01

    The unsteady pressure field experienced by a centrifugal compressor stage can be dominated by of the impeller-diffuser interaction. The energy of the unsteady field, under certain aerodynamic and structural conditions, is ...

  10. Effects of upstream wake phasing on the performance of transonic compressors

    E-Print Network [OSTI]

    Nolan, Sean Patrick Rock

    2009-01-01

    The effect of the upstream wake phase on the work input (i.e., rise in stagnation enthalpy across the blade row) of a transonic rotor is examined computationally and analytically. It is found that the compressor work depends ...

  11. Impact of unsteady flow processes on the performance of a high speed axial flow compressor

    E-Print Network [OSTI]

    Botros, Barbara Brenda

    2008-01-01

    This thesis examines the unsteady interactions between blade rows in a high Mach number, highly-loaded compressor stage. Two straight vane/rotor configurations with different axial spacing between vane and rotor are ...

  12. Discharge characteristics and dynamics of compressive plasma streams generated by a compact magnetoplasma compressor

    SciTech Connect (OSTI)

    Garkusha, I. E.; Tereshin, V. I.; Chebotarev, V. V.; Solyakov, D. G.; Petrov, Yu. V.; Ladygina, M. S.; Marchenko, A. K.; Staltsov, V. V.; Yelisyeyev, D. V. [National Academy of Sciences of Ukraine, Institute of Plasma Physics, National Science Center 'Kharkiv Institute of Physics and Technology,' (Ukraine)

    2011-11-15

    Results from experimental studies of a compact magnetoplasma compressor designed for operation with heavy gases are presented. The integral characteristics of the discharge and the energy contents and other parameters of the generated xenon plasma streams are determined.

  13. Effect of circumferential groove casing treatment parameters on axial compressor flow range

    E-Print Network [OSTI]

    Hanley, Brian K. (Brian Kyle)

    2010-01-01

    The impact on compressor flow range of circumferential casing grooves of varying groove depth, groove axial location, and groove axial extent is assessed against that of a smooth casing wall using computational experiments. ...

  14. Development of a transonic front stage of an axial flow compressor for industrial gas turbines

    SciTech Connect (OSTI)

    Katoh, Y.; Ishii, H.; Tsuda, Y.; Yanagida, M. . Mechanical Engineering Research Lab.); Kashiwabara, Y. . Dept. of Mechanical Systems Engineering)

    1994-10-01

    This paper describes the aerodynamic blade design of a highly loaded three-stage compressor, which is a model compressor for the front stage of an industrial gas turbine. Test results are presented that confirm design performance. Some surge and rotating stall measurement results are also discussed. The first stator blade in this test compressor operates in the high subsonic range at the inlet. To reduce the pressure loss due to blade surface shock waves, a shock-free airfoil is designed to replace the first stator blade in an NACA-65 airfoil in a three-stage compressor. Comparison of the performance of both blades shows that the shock-free airfoil blade reduces pressure loss. This paper also presents some experimental results for MCA (multicircular arc) airfoils, which are used for first rotor blades.

  15. Measurement of the three-dimensional tip region flow field in an axial compressor

    SciTech Connect (OSTI)

    Stauter, R.C. )

    1993-07-01

    A two-color, five-beam LDV system has been configured to make simultaneous three-component velocity measurements of the flow field in a two-stage axial compressor model. The system has been used to make time-resolved measurements both between compressor blade rows and within the rotating blade passages in an axial compressor. The data show the nature and behavior of the complex, three-dimensional flow phenomena present in the tip region of a compressor as the convect downstream. In particular, the nature of the tip leakage vortex is apparent, being manifested by high blockage as well as the expected vortical motion. The data indicate that the radial flows associated with the tip leakage vortex begin to decrease while within the rotor passage, and that they temporarily increase aft of the passage.

  16. Effects of rotor tip clearance on an embedded compressor stage performance

    E-Print Network [OSTI]

    Sakulkaew, Sitanun

    2012-01-01

    Compressor efficiency variation with rotor tip gap is assessed using numerical simulations on an embedded stage representative of that in a large industrial gas turbine with Reynolds number being approximately 2 x 106 to ...

  17. An improved blade passage model for estimating off-design axial compressor performance

    E-Print Network [OSTI]

    Brand, Maximilian Lewis

    2013-01-01

    Accurate estimates of multistage axial compressor performance at off-design operating conditions are essential to the determination of key performance metrics of aircraft gas turbine engines, such as fuel burn, thrust ...

  18. A novel design methodology for enhanced compressor performance based on a dynamic stability metric

    E-Print Network [OSTI]

    Castiella Ruiz de Velasco, Juan Carlos, 1978-

    2005-01-01

    (cont.) compressor design optimization framework allows a versatile definition of the objective function such that any combination of pressure ratio, efficiency and dynamic stability can be prescribed at various operating ...

  19. Three-dimensional rotating stall inception and effects of rotating tip clearance asymmetry in axial compressors

    E-Print Network [OSTI]

    Gordon, Kenneth A. (Kenneth Andrew), 1970-

    1999-01-01

    The effects of two types of flow nonuniformity on stall inception behavior were assessed with linearized stability analyses of two compressor flow models. Response to rotating tip clearance asymmetries induced by a whirling ...

  20. Characterization of the flow field response to vaneless space reduction in centrifugal compressors

    E-Print Network [OSTI]

    Villanueva V., Alfonso D. (Villanueva Villarreal)

    2006-01-01

    The unsteady three-dimensional flow field for two centrifugal compressors of nearly identical design (one with a marginally smaller impeller-diffuser gap) is interrogated to assess the difference in the time averaged ...

  1. Characterization of unsteady loading due to impeller-diffuser interaction in centrifugal compressors

    E-Print Network [OSTI]

    Lusardi, Christopher (Christopher Dean)

    2012-01-01

    Time dependent simulations are used to characterize the unsteady impeller blade loading due to imipeller-diffuser interaction in centrifugal compressor stages. The capability of simulations are assessed by comparing results ...

  2. Using Outside Air for Flooded Oil Screw Compressors at an Industrial Facility 

    E-Print Network [OSTI]

    Hunt, D. G.; Terry, S.

    2014-01-01

    A study has been performed to determine if inlet air temperature provides an increase in compressor efficiency, seen through reduced power for some specified mass flow. A theoretical analysis suggests that power is not a function of volumetric flow...

  3. Three-dimensional hybrid grid generator and unstructured flow solver for compressors and turbines 

    E-Print Network [OSTI]

    Kim, Kyusup

    2005-02-17

    . The Menter?s k ?? model is implemented to simulate the turbulence e?ects. The ?ow solver is validated against the analytical and experimental results. A parametric study is performed for a high speed centrifugal compressor....

  4. Stage effects on stalling and recovery of a high-speed 10-stage axial-flow compressor

    SciTech Connect (OSTI)

    Copenhaver, W.W.

    1988-01-01

    Results of a high-speed 10-stage axial-flow compressor test involving overall compressor and individual stage performance while stalling and operating in quasi-steady rotating stall are described. Test procedures and data-acquisition methods used to obtain the dynamic stalling and quasi-steady in-stall data are explained. Unstalled and in-stall time-averaged data obtained from the compressor operating at five different shaft speeds and one off-schedule variable vane condition are presented. Effects of compressor speed and variable geometry on overall compressor in-stall pressure rise and hysteresis extent are illustrated through the use of quasi-steady-stage temperature rise and pressure-rise characteristics. Results indicate that individual stage performance during overall compressor rotating stall operation varies considerably throughout the length of the compressor. The measured high-speed 10-stage test compressor individual stage pressure and temperature characteristics were input into a stage-by-stage dynamic compressor performance model. Comparison of the model results and measured pressures provided the additional validation necessary to demonstrate the model's ability to predict high-speed multistage compressor stalling and in-stall performance.

  5. Development of Versatile Compressor Modeling using Approximation Techniques for Alternative Refrigerants Evaluation

    SciTech Connect (OSTI)

    Abdelaziz, Omar; Shrestha, Som S

    2014-01-01

    Refrigerants are the life-blood of vapor compression systems that are widely used in Heating, Ventilation, Air-Conditioning, and Refrigeration (HVAC&R) applications. The HVAC&R community is currently transitioning from main-stream refrigerants that have high Global Warming Potential (GWP) to alternative lower-GWP refrigerants. During this transition, it is important to account for the life cycle climate performance of alternative refrigerants since their performance will be different than that of higher-GWP refrigerants. This requires the evaluation of the system performance with the new refrigerants. Unfortunately, it is extremely difficult to predict the realistic performance of new alternative refrigerants without experimental validation. One of the main challenges in this regard is modeling the compressor performance with high fidelity due to the complex interaction of operating parameters, geometry, boundary conditions, and fluid properties. High fidelity compressor models are computationally expensive and require significant pre-processing to evaluate the performance of alternative refrigerants. This paper presents a new approach to modeling compressor performance when alternative refrigerants are used. The new modeling concept relies on using existing compressor performance to create an approximate model that captures the dependence of compressor performance on key operating parameters and fluid properties. The model can be built using a myriad of approximation techniques. This paper focuses on Kriging-based techniques to develop higher fidelity approximate compressor models. Baseline and at least one alternative refrigerant performance data are used to build the model. The model accuracy was evaluated by comparing the model results with compressor performance data using other refrigerants. Preliminary results show that the approximate model can predict the compressor mass flow rate and power consumption within 5%.

  6. Tip clearance flows in axial compressors: stall inception and stability enhancement

    E-Print Network [OSTI]

    Weichert, Stephanie April

    2012-02-07

    and 91 figures. Part of this dissertation has been presented in the following publication: Weichert, S., Day, I. & Freeman, C. (2011) Self-Regulating Casing Treat- ment for Axial Compressor Stability Enhancement. Proceedings of ASME Turbo Expo 2011, June... -span if unspecified W Rotor Relative Flow Velocity, mid-span if unspecified xii Superscripts and Subscripts 0 Stagnation condition 1 Rotor inlet conditions 2 Rotor exit, stator inlet conditions 3 Stator exit conditions a1 Deverson compressor bellmouth inlet d2...

  7. Refrigeration system with a compressor-pump unit and a liquid-injection desuperheating line

    DOE Patents [OSTI]

    Gaul, Christopher J. (Thornton, CO)

    2001-01-01

    The refrigeration system includes a compressor-pump unit and/or a liquid-injection assembly. The refrigeration system is a vapor-compression refrigeration system that includes an expansion device, an evaporator, a compressor, a condenser, and a liquid pump between the condenser and the expansion device. The liquid pump improves efficiency of the refrigeration system by increasing the pressure of, thus subcooling, the liquid refrigerant delivered from the condenser to the expansion device. The liquid pump and the compressor are driven by a single driving device and, in this regard, are coupled to a single shaft of a driving device, such as a belt-drive, an engine, or an electric motor. While the driving device may be separately contained, in a preferred embodiment, the liquid pump, the compressor, and the driving device (i.e., an electric motor) are contained within a single sealable housing having pump and driving device cooling paths to subcool liquid refrigerant discharged from the liquid pump and to control the operating temperature of the driving device. In another aspect of the present invention, a liquid injection assembly is included in a refrigeration system to divert liquid refrigerant from the discharge of a liquid pressure amplification pump to a compressor discharge pathway within a compressor housing to desuperheat refrigerant vapor to the saturation point within the compressor housing. The liquid injection assembly includes a liquid injection pipe with a control valve to meter the volume of diverted liquid refrigerant. The liquid injection assembly may also include a feedback controller with a microprocessor responsive to a pressure sensor and a temperature sensor both positioned between the compressor to operate the control valve to maintain the refrigerant at or near saturation.

  8. Approaches Toward Achieving Optimum Efficiency in Rerates of Large Centrifugal Compressors 

    E-Print Network [OSTI]

    Rudisel, D. A.

    1996-01-01

    outcome. Figure 7 Case 3 Compressor Schematic Once the boundaries were established, and feasible methods of working within those constraints identified, the expected installed cost for the machine replacement was determined, and the project found... in the 10,000 to 50,000 horsepower range. When new, the machines are aerodynamically and mechanically designed and built to the state of the art as it exists at that time. However, these compressor casings are commonly rerated in later years when...

  9. Development of a dry linear compressor for GM and pulse tube cryocoolers

    E-Print Network [OSTI]

    Höhne, Jens

    2015-01-01

    Pressure Wave Systems GmbH has developed a dry compressor for GM and pulse tube cryocoolers. The concept is based on hydraulically driven metal bellows in which the Helium working gas is compressed. The system is operated in the region of 1 kW of electrical input power and has been successfully tested with a SHI RDK-101D GM cryocooler cold head. Set-up, performance and reliability of the compressor system will be discussed.

  10. Semiconductor tunnel junction with enhancement layer

    DOE Patents [OSTI]

    Klem, John F. (Sandia Park, NM); Zolper, John C. (Albuquerque, NM)

    1997-01-01

    The incorporation of a pseudomorphic GaAsSb layer in a runnel diode structure affords a new degree of freedom in designing runnel junctions for p-n junction device interconnects. Previously only doping levels could be varied to control the tunneling properties. This invention uses the valence band alignment band of the GaAsSb with respect to the surrounding materials to greatly relax the doping requirements for tunneling.

  11. Semiconductor tunnel junction with enhancement layer

    DOE Patents [OSTI]

    Klem, J.F.; Zolper, J.C.

    1997-10-21

    The incorporation of a pseudomorphic GaAsSb layer in a runnel diode structure affords a new degree of freedom in designing runnel junctions for p-n junction device interconnects. Previously only doping levels could be varied to control the tunneling properties. This invention uses the valence band alignment band of the GaAsSb with respect to the surrounding materials to greatly relax the doping requirements for tunneling. 5 figs.

  12. Multi-junction solar cell device

    DOE Patents [OSTI]

    Friedman, Daniel J. (Lakewood, CO); Geisz, John F. (Wheat Ridge, CO)

    2007-12-18

    A multi-junction solar cell device (10) is provided. The multi-junction solar cell device (10) comprises either two or three active solar cells connected in series in a monolithic structure. The multi-junction device (10) comprises a bottom active cell (20) having a single-crystal silicon substrate base and an emitter layer (23). The multi-junction device (10) further comprises one or two subsequent active cells each having a base layer (32) and an emitter layer (23) with interconnecting tunnel junctions between each active cell. At least one layer that forms each of the top and middle active cells is composed of a single-crystal III-V semiconductor alloy that is substantially lattice-matched to the silicon substrate (22). The polarity of the active p-n junction cells is either p-on-n or n-on-p. The present invention further includes a method for substantially lattice matching single-crystal III-V semiconductor layers with the silicon substrate (22) by including boron and/or nitrogen in the chemical structure of these layers.

  13. Active stabilization of rotating stall in a three-stage axial compressor

    SciTech Connect (OSTI)

    Haynes, J.M.; Hendricks, G.J.; Epstein, A.H. . Gas Turbine Lab.)

    1994-04-01

    A three-stage, low-speed axial research compressor has been actively stabilized by damping low-amplitude circumferentially traveling waves, which can grow into rotating stall. Using a circumferential array of hot-wire sensors, and an array of high-speed individually positioned control vanes as the actuator, the first and second spatial harmonics of the compressor were stabilized down to a characteristic slope of 0.9, yielding an 8 percent increase in operating flow range. Stabilization of the third spatial harmonic did not alter the stalling flow coefficient. The actuators were also used open loop to determine the forced response behavior of the compressor. A system identification procedure applied to the forced response data then yielded the compressor transfer function. The Moore-Greitzer two-dimensional stability model was modified as suggested by the measurements to include the effect of blade row time lags on the compressor dynamics. This modified Moore-Greitzer model was then used to predict both the open and closed-loop dynamic response of the compressor. The model predictions agreed closely with the experimental results. In particular, the model predicted both the mass flow at stall without control and the design parameters needed by, and the range extension realized from, active control.

  14. Apparatus and methods for cooling and sealing rotary helical screw compressors

    DOE Patents [OSTI]

    Fresco, Anthony N. (P.O. Box 734, Upton, NY 11973)

    1997-01-01

    In a compression system which incorporates a rotary helical screw compressor, and for any type of gas or refrigerant, the working liquid oil is atomized through nozzles suspended in, and parallel to, the suction gas flow, or alternatively the nozzles are mounted on the suction piping. In either case, the aim is to create positively a homogeneous mixture of oil droplets to maximize the effectiveness of the working liquid oil in improving the isothermal and volumetric efficiencies. The oil stream to be atomized may first be degassed at compressor discharge pressure by heating within a pressure vessel and recovering the energy added by using the outgoing oil stream to heat the incoming oil stream. The stripped gas is typically returned to the compressor discharge flow. In the preferred case, the compressor rotors both contain a hollow cavity through which working liquid oil is injected into channels along the edges of the rotors, thereby forming a continuous and positive seal between the rotor edges and the compressor casing. In the alternative method, working liquid oil is injected either in the same direction as the rotor rotation or counter to rotor rotation through channels in the compressor casing which are tangential to the rotor edges and parallel to the rotor centerlines or alternatively the channel paths coincide with the helical path of the rotor edges.

  15. Apparatus and methods for cooling and sealing rotary helical screw compressors

    DOE Patents [OSTI]

    Fresco, A.N.

    1997-08-05

    In a compression system which incorporates a rotary helical screw compressor, and for any type of gas or refrigerant, the working liquid oil is atomized through nozzles suspended in, and parallel to, the suction gas flow, or alternatively the nozzles are mounted on the suction piping. In either case, the aim is to create positively a homogeneous mixture of oil droplets to maximize the effectiveness of the working liquid oil in improving the isothermal and volumetric efficiencies. The oil stream to be atomized may first be degassed at compressor discharge pressure by heating within a pressure vessel and recovering the energy added by using the outgoing oil stream to heat the incoming oil stream. The stripped gas is typically returned to the compressor discharge flow. In the preferred case, the compressor rotors both contain a hollow cavity through which working liquid oil is injected into channels along the edges of the rotors, thereby forming a continuous and positive seal between the rotor edges and the compressor casing. In the alternative method, working liquid oil is injected either in the same direction as the rotor rotation or counter to rotor rotation through channels in the compressor casing which are tangential to the rotor edges and parallel to the rotor center lines or alternatively the channel paths coincide with the helical path of the rotor edges. 14 figs.

  16. Compressor Calorimeter Test of R-404A Alternatives ARM-31a, D2Y-65, L-40, and R32 + R-134a Mixture using a Scroll Compressor

    SciTech Connect (OSTI)

    Shrestha, Som S [ORNL; Sharma, Vishaldeep [ORNL; Abdelaziz, Omar [ORNL

    2013-08-01

    As a contribution to the AHRI Low-GWP Alternative Refrigerants Evaluation Program (AREP), this study compares the performance of four lower-GWP alternative refrigerants, ARM-31a, D2Y-65, L-40, and R-32 + R-134a mixture, to that of refrigerant R-404A (baseline) in a scroll compressor designed for medium temperature refrigeration applications. These comparisons were carried out via compressor calorimeter tests performed on a compressor designed for refrigerant R-404A and having a nominal rated capacity of 23,500 Btu/hr. Tests were conducted over a suction dew point temperature range of -10 F to 35 F in 5 F increments and a discharge dew point temperature range of 70 F to 140 F in 10 F increments. All the tests were performed with 20 F superheat, 40 F superheat, and 65 F suction temperature. A liquid subcooling level of 10 F to 15 F was maintained for all the test conditions. However, the cooling capacities reported in this study are normalized for 0 F subcooling. The tests showed that the compressor energy efficiency ratio (EER) and cooling capacity with all four alternative refrigerants tested are higher at higher saturation suction and saturation discharge temperature and lower at lower saturation suction and saturation discharge temperature, compared to that of R-404A. Discharge temperatures of all the alternative refrigerants were higher than that of R-404A at all test conditions.

  17. Methods for the fabrication of thermally stable magnetic tunnel junctions

    DOE Patents [OSTI]

    Chang, Y. Austin (Middleton, WI); Yang, Jianhua J. (Madison, WI); Ladwig, Peter F. (Hutchinson, MN)

    2009-08-25

    Magnetic tunnel junctions and method for making the magnetic tunnel junctions are provided. The magnetic tunnel junctions are characterized by a tunnel barrier oxide layer sandwiched between two ferromagnetic layers. The methods used to fabricate the magnetic tunnel junctions are capable of completely and selectively oxidizing a tunnel junction precursor material using an oxidizing gas containing a mixture of gases to provide a tunnel junction oxide without oxidizing the adjacent ferromagnetic materials. In some embodiments the gas mixture is a mixture of CO and CO.sub.2 or a mixture of H.sub.2 and H.sub.2O.

  18. Junction-side illuminated silicon detector arrays

    DOE Patents [OSTI]

    Iwanczyk, Jan S.; Patt, Bradley E.; Tull, Carolyn

    2004-03-30

    A junction-side illuminated detector array of pixelated detectors is constructed on a silicon wafer. A junction contact on the front-side may cover the whole detector array, and may be used as an entrance window for light, x-ray, gamma ray and/or other particles. The back-side has an array of individual ohmic contact pixels. Each of the ohmic contact pixels on the back-side may be surrounded by a grid or a ring of junction separation implants. Effective pixel size may be changed by separately biasing different sections of the grid. A scintillator may be coupled directly to the entrance window while readout electronics may be coupled directly to the ohmic contact pixels. The detector array may be used as a radiation hardened detector for high-energy physics research or as avalanche imaging arrays.

  19. INCREASED FLEXIBILITY OF TURBO-COMPRESSORS IN NATURAL GAS TRANSMISSION THROUGH DIRECT SURGE CONTROL

    SciTech Connect (OSTI)

    Robert J. Mckee; Danny M. Deffenbaugh

    2003-12-01

    This annual progress report describes the second year's technical progress in a three-year program. This report summarizes what is known about internal flows as surge precursors in centrifugal compressors and focuses on accessing factors that affect pre-surge detection. An attempt is made in this analysis to identify and quantify factors concerning compressor design and operations that affect the detection of pre-surge conditions. This progress report presents results from recent laboratory tests conducted during the course of this second year. This project is co-funded by the Gas Machinery Research Council (GMRC) and by Siemens Energy and Automation (Siemens). The most recently available measured pre-surge internal flow data is parameterized to help identify factors that affect the indications that a compressor is approaching surge. Theoretical arguments are applied to access the factors that influence surge precursors and surge initiation in different centrifugal compressors. This work is considered a step in accessing the factors that affect the success or limitations of pre-surge detection in natural gas pipeline compressors.

  20. INCREASED FLEXIBILITY OF TURBO-COMPRESSORS IN NATURAL GAS TRANSMISSION THROUGH DIRECT SURGE CONTROL

    SciTech Connect (OSTI)

    Robert J. McKee; Shane P. Siebenaler; Danny M. Deffenbaugh

    2005-02-25

    The objective of this Direct Surge Control project was to develop a new internal method to avoid surge of pipeline compressors. This method will safely expand the range and flexibility of compressor operations, while minimizing wasteful recycle flow at the lower end of the operating envelope. The approach is to sense the onset of surge with a probe that directly measures re-circulation at the impeller inlet. The signals from the probe are used by a controller to allow operation at low flow conditions without resorting to a predictive method requiring excessive margin to activate a recycle valve. The sensor developed and demonstrated during this project was a simple, rugged, and sensitive drag probe. Experiments conducted in a laboratory compressor clearly showed the effectiveness of the technique. Subsequent field demonstrations indicated that the increase in range without the need to recycle flow was on the order of 19% to 25%. The cost benefit of applying the direct surge control technology appears to be as much as $120 per hour per compressor for operation without the current level of recycle flow. This could amount to approximately $85 million per year for the U.S. Natural Gas Transmission industry, if direct surge control systems are applied to most pipeline centrifugal compressors.

  1. A study of spike and modal stall phenomena in a low-speed axial compressor

    SciTech Connect (OSTI)

    Camp, T.R.; Day, I.J.

    1998-07-01

    This paper presents a study of stall inception mechanisms in a low-speed axial compressor. Previous work has identified two common flow breakdown sequences, the first associated with a short length-scale disturbance known as a spike, and the second with a longer length-scale disturbance known as a modal oscillation. In this paper the physical differences between these two mechanisms are illustrated with detailed measurements. Experimental results are also presented that relate the occurrence of the two stalling mechanisms to the operating conditions of the compressor. It is shown that the stability criteria for the two disturbances are different: Long length-scale disturbances are related to a two-dimensional instability of the whole compression system, while short length-scale disturbances indicate a three-dimensional breakdown of the flow-field associated with high rotor incidence angles. Based on the experimental measurements, a simple model is proposed that explains the type of stall inception pattern observed in a particular compressor. Measurements from a single-stage low-speed compressor and from a multistage high-speed compressor are presented in support of the model.

  2. Dynamic control of rotating stall in axial flow compressors using aeromechanical feedback

    SciTech Connect (OSTI)

    Gysling, D.L.; Greitzer, E.M.

    1995-07-01

    Dynamic control of rotating stall in an axial flow compressor has been implemented using aeromechanical feedback. The control strategy developed used an array of wall jets, upstream of a single-stage compressor, which were regulated by locally reacting reed valves. These reed valves responded to the small-amplitude flow-field pressure perturbations that precede rotating stall. The valve design was such that the combined system, compressor plus reed valve controller, was stable under operating conditions that had been unstable without feedback. A 10 percent decrease in the stalling flow coefficient was obtained using the control strategy, and the extension of stall flow range was achieved with no measurable change in the steady-state performance of the compression system. The experiments demonstrate the first use of aeromechanical feedback to extend the stable operating range of an axial flow compressor, and the first use of local feedback and dynamic compensation techniques to suppress rotating stall. The design of the experiment was based on a two-dimensional stall inception model, which incorporated the effect of the aeromechanical feedback. The physical mechanism for rotating stall in axial flow compressors was examined with focus on the role of dynamic feedback in stabilizing compression system instability. As predicted and experimentally demonstrated, the effectiveness of the aeromechanical control strategy depends on a set of nondimensional control parameters that determine the interaction of the control strategy and the rotating stall dynamics.

  3. Macroscopic quantum tunneling in spin filter ferromagnetic Josephson junctions

    E-Print Network [OSTI]

    Massarotti, D.; Pal, A.; Rotoli, G.; Longobordi, L.; Blamire, M. G.; Tafuri, F.

    2015-06-09

    junctions and the demonstration of triplet supercurrents have suggested the potential of a dissipationless version of spintronics based on unconventional superconductivity. Here we demonstrate evidence for active quantum applications of S-F-S junctions...

  4. Stabilization of Ion Concentration Polarization Using a Heterogeneous Nanoporous Junction

    E-Print Network [OSTI]

    Kim, Pilnam

    We demonstrate a recycled ion-flux through heterogeneous nanoporous junctions, which induce stable ion concentration polarization with an electric field. The nanoporous junctions are based on integration of ionic hydrogels ...

  5. An ab-initio analysis of bimetallic oligoaniline molecular junctions 

    E-Print Network [OSTI]

    Wang, Michael Wei-Lueng

    2007-09-17

    The electron transport characteristics of Oligoaniline molecular junctions terminated with thiol-ends are analyzed with the density functional theory and the Green's function approach. The molecular junction consists of ...

  6. Complementary junction heterostructure field-effect transistor

    DOE Patents [OSTI]

    Baca, A.G.; Drummond, T.J.; Robertson, P.J.; Zipperian, T.E.

    1995-12-26

    A complimentary pair of compound semiconductor junction heterostructure field-effect transistors and a method for their manufacture are disclosed. The p-channel junction heterostructure field-effect transistor uses a strained layer to split the degeneracy of the valence band for a greatly improved hole mobility and speed. The n-channel device is formed by a compatible process after removing the strained layer. In this manner, both types of transistors may be independently optimized. Ion implantation is used to form the transistor active and isolation regions for both types of complimentary devices. The invention has uses for the development of low power, high-speed digital integrated circuits. 10 figs.

  7. Complementary junction heterostructure field-effect transistor

    DOE Patents [OSTI]

    Baca, Albert G. (Albuquerque, NM); Drummond, Timothy J. (Albuquerque, NM); Robertson, Perry J. (Albuquerque, NM); Zipperian, Thomas E. (Albuquerque, NM)

    1995-01-01

    A complimentary pair of compound semiconductor junction heterostructure field-effect transistors and a method for their manufacture are disclosed. The p-channel junction heterostructure field-effect transistor uses a strained layer to split the degeneracy of the valence band for a greatly improved hole mobility and speed. The n-channel device is formed by a compatible process after removing the strained layer. In this manner, both types of transistors may be independently optimized. Ion implantation is used to form the transistor active and isolation regions for both types of complimentary devices. The invention has uses for the development of low power, high-speed digital integrated circuits.

  8. Hydrogen Energy Stations: Poly-Production of Electricity, Hydrogen, and Thermal Energy

    E-Print Network [OSTI]

    Lipman, Timothy; Brooks, Cameron

    2006-01-01

    compressor Compressed hydrogen storage Figure 2: High-compressor Compressed hydrogen storage Clean Energy Group lduction, and a hydrogen compression, storage, and Energy

  9. Hydrogen Filling Station

    SciTech Connect (OSTI)

    Boehm, Robert F; Sabacky, Bruce; Anderson II, Everett B; Haberman, David; Al-Hassin, Mowafak; He, Xiaoming; Morriseau, Brian

    2010-02-24

    Hydrogen is an environmentally attractive transportation fuel that has the potential to displace fossil fuels. The Freedom CAR and Freedom FUEL initiatives emphasize the importance of hydrogen as a future transportation fuel. Presently, Las Vegas has one hydrogen fueling station powered by natural gas. However, the use of traditional sources of energy to produce hydrogen does not maximize the benefit. The hydrogen fueling station developed under this grant used electrolysis units and solar energy to produce hydrogen fuel. Water and electricity are furnished to the unit and the output is hydrogen and oxygen. Three vehicles were converted to utilize the hydrogen produced at the station. The vehicles were all equipped with different types of technologies. The vehicles were used in the day-to-day operation of the Las Vegas Valley Water District and monitoring was performed on efficiency, reliability and maintenance requirements. The research and demonstration utilized for the reconfiguration of these vehicles could lead to new technologies in vehicle development that could make hydrogen-fueled vehicles more cost effective, economical, efficient and more widely used. In order to advance the development of a hydrogen future in Southern Nevada, project partners recognized a need to bring various entities involved in hydrogen development and deployment together as a means of sharing knowledge and eliminating duplication of efforts. A road-mapping session was held in Las Vegas in June 2006. The Nevada State Energy Office, representatives from DOE, DOE contractors and LANL, NETL, NREL were present. Leadership from the National hydrogen Association Board of Directors also attended. As a result of this session, a roadmap for hydrogen development was created. This roadmap has the ability to become a tool for use by other road-mapping efforts in the hydrogen community. It could also become a standard template for other states or even countries to approach planning for a hydrogen future. Project partners also conducted a workshop on hydrogen safety and permitting. This provided an opportunity for the various permitting agencies and end users to gather to share experiences and knowledge. As a result of this workshop, the permitting process for the hydrogen filling station on the Las Vegas Valley Water District’s land was done more efficiently and those who would be responsible for the operation were better educated on the safety and reliability of hydrogen production and storage. The lessons learned in permitting the filling station and conducting this workshop provided a basis for future hydrogen projects in the region. Continuing efforts to increase the working pressure of electrolysis and efficiency have been pursued. Research was also performed on improving the cost, efficiency and durability of Proton Exchange Membrane (PEM) hydrogen technology. Research elements focused upon PEM membranes, electrodes/catalysts, membrane-electrode assemblies, seals, bipolar plates, utilization of renewable power, reliability issues, scale, and advanced conversion topics. Additionally, direct solar-to-hydrogen conversion research to demonstrate stable and efficient photoelectrochemistry (PEC) hydrogen production systems based on a number of optional concepts was performed. Candidate PEC concepts included technical obstacles such as inefficient photocatalysis, inadequate photocurrent due to non-optimal material band gap energies, rapid electron-hole recombination, reduced hole mobility and diminished operational lifetimes of surface materials exposed to electrolytes. Project Objective 1: Design, build, operate hydrogen filling station Project Objective 2: Perform research and development for utilizing solar technologies on the hydrogen filling station and convert two utility vehicles for use by the station operators Project Objective 3: Increase capacity of hydrogen filling station; add additional vehicle; conduct safety workshop; develop a roadmap for hydrogen development; accelerate the development of photovoltaic components Project Objective 4:

  10. High voltage series connected tandem junction solar battery

    DOE Patents [OSTI]

    Hanak, Joseph J. (Lawrenceville, NJ)

    1982-01-01

    A high voltage series connected tandem junction solar battery which comprises a plurality of strips of tandem junction solar cells of hydrogenated amorphous silicon having one optical path and electrically interconnected by a tunnel junction. The layers of hydrogenated amorphous silicon, arranged in a tandem configuration, can have the same bandgap or differing bandgaps. The tandem junction strip solar cells are series connected to produce a solar battery of any desired voltage.

  11. Transmission eigenvalue distributions in highly conductive molecular junctions

    E-Print Network [OSTI]

    Bergfield, Justin P; Barr, Joshua D; Stafford, Charles A

    2012-01-01

    Transmission eigenvalue distributions in highly conductivesingle-molecule junction; transmission eigenchannels Openuniquely characterized by its transmission eigenvalues ? n .

  12. Evaluation of sensors for NGV and fueling station applications. Topical report, November 1994-January 1996

    SciTech Connect (OSTI)

    Huebler, J.E.; Blazek, C.F.

    1996-05-01

    The commercial success of the Natural Gas Vehicles (NGV) requires the availability of sensors to make critical measurements, such as mass flow, gas composition, temperature, pressure, moisture, density, engine load, strain, etc. Engine, engine control, compressor, and dispenser manufacturers and fueling station packagers were surveyed to determine sensor use and needs. Their general comments on needed sensor improvements, detailed sensor specifications, and sensor priorities are given. Exhaust oxygen, mass flow, and gas composition were identified as the sensors of most concern. Because they deal with issues unique to NGV technology, evaluation of sensor technologies was limited to gas composition sensors. Sensor of principal concern for this application included: (1) on-board, in-line, feed forward devices and (2) fueling station monitors. Through an extensive survey, a baseline of information on gas composition sensors and emerging technologies for the NGV community was developed.

  13. EA-0930: Facility Operations at the U.S. DOE Grand Junction Projects Office, Grand Junction, Colorado

    Broader source: Energy.gov [DOE]

    This EA evaluates the environmental impacts of the proposal to expand and upgrade the U.S. Department of Energy's Grand Junction Projects Office facilities and operations in Grand Junction, Colorado.

  14. Development of a Hybrid Compressor/Expander Module for Automotive Fuel Cell Applications

    SciTech Connect (OSTI)

    McTaggart, Paul

    2004-12-31

    In this program TIAX LLC conducted the development of an advanced technology compressor/expander for supplying compressed air to Proton Exchange Membrane (PEM) fuel cells in transportation applications. The overall objective of this program was to develop a hybrid compressor/expander module, based on both scroll and high-speed turbomachinery technologies, which will combine the strengths of each technology to create a concept with superior performance at minimal size and cost. The resulting system was expected to have efficiency and pressure delivery capability comparable to that of a scroll-only machine, at significantly reduced system size and weight when compared to scroll-only designs. Based on the results of detailed designs and analyses of the critical system elements, the Hybrid Compressor/Expander Module concept was projected to deliver significant improvements in weight, volume and manufacturing cost relative to previous generation systems.

  15. A Five-Leg Inverter for Driving a Traction Motor and a Compressor Motor

    SciTech Connect (OSTI)

    Su, Gui-Jia; Hsu, John S

    2006-01-01

    This paper presents an integrated inverter for speed control of a traction motor and a compressor motor to reduce the compressor drive cost in EV/HEV applications. The inverter comprises five phase-legs; three of which are for control of a three-phase traction motor and the remaining two for a two-phase compressor motor with three terminals. The common terminal of the two-phase motor is tied to the neutral point of the three-phase traction motor to eliminate the requirement of a third phase leg. Further cost savings are made possible by sharing the switching devices, dc bus filter capacitors, gate drive power supplies, and control circuit. Simulation and experimental results are included to verify that speed control of the two motors is independent from each other.

  16. Variable gas spring for matching power output from FPSE to load of refrigerant compressor

    DOE Patents [OSTI]

    Chen, Gong (Athens, OH); Beale, William T. (Athens, OH)

    1990-01-01

    The power output of a free piston Stirling engine is matched to a gas compressor which it drives and its stroke amplitude is made relatively constant as a function of power by connecting a gas spring to the drive linkage from the engine to the compressor. The gas spring is connected to the compressor through a passageway in which a valve is interposed. The valve is linked to the drive linkage so it is opened when the stroke amplitude exceeds a selected limit. This allows compressed gas to enter the spring, increase its spring constant, thus opposing stroke increase and reducing the phase lead of the displacer ahead of the piston to reduce power output and match it to a reduced load power demand.

  17. Variable gas spring for matching power output from FPSE to load of refrigerant compressor

    DOE Patents [OSTI]

    Chen, G.; Beale, W.T.

    1990-04-03

    The power output of a free piston Stirling engine is matched to a gas compressor which it drives and its stroke amplitude is made relatively constant as a function of power by connecting a gas spring to the drive linkage from the engine to the compressor. The gas spring is connected to the compressor through a passageway in which a valve is interposed. The valve is linked to the drive linkage so it is opened when the stroke amplitude exceeds a selected limit. This allows compressed gas to enter the spring, increase its spring constant, thus opposing stroke increase and reducing the phase lead of the displacer ahead of the piston to reduce power output and match it to a reduced load power demand. 6 figs.

  18. Gas Spring Losses in Linear Clearance Seal Compressors P.B. Bailey, M.W. Dadd, J.S. Reed*

    E-Print Network [OSTI]

    1 Gas Spring Losses in Linear Clearance Seal Compressors P.B. Bailey, M.W. Dadd, J.S. Reed* , C, and the simplest demonstration of this can be observed in a gas spring. Our understanding of these gas spring with a clearance seal linear compressor attached to a plain gas spring volume. The static flow through

  19. Flow Integrating Section for a Gas Turbine Engine in Which Turbine Blades are Cooled by Full Compressor Flow

    SciTech Connect (OSTI)

    Steward, W. Gene

    1999-11-14

    Routing of full compressor flow through hollow turbine blades achieves unusually effective blade cooling and allows a significant increase in turbine inlet gas temperature and, hence, engine efficiency. The invention, ''flow integrating section'' alleviates the turbine dissipation of kinetic energy of air jets leaving the hollow blades as they enter the compressor diffuser.

  20. Improving performance and rotordynamic characteristics of injection compressors via much longer balance-piston and division-wall seals 

    E-Print Network [OSTI]

    Rodrigues Rodrigues, Margarita

    2009-05-15

    Predictions are presented for a selected compressor using longer hole-pattern seals with L/D ratios from 0.5 to 2.5. Results were obtained for back-to-back and in-line compressors with the seal located at mid-span and at ...

  1. Strawberries at Troupe Station

    E-Print Network [OSTI]

    Green, Edward C.

    1904-01-01

    THE TEXAS A&M UNIVERSITY SYSTEM DANIEL C. PFANNSTIEL, DIRECTOR COLLEGE STATION, TEXAS I COVER Kenneth Hoffman, Extension demonstrator, and Hollis Duke, Atascosa County Extension agent, inspect a field of Fresno strawberries in Poteet. as Strawberries... George Ray McEachern and Bluefford G. Hancock* ery vigorous plant and can r a wide range of conditions. However, a profitable crop, definite practices are strawberry plant has three basic parts-tlle wn, and leaves. The roots are shallow and rbing...

  2. Tandem junction amorphous silicon solar cells

    DOE Patents [OSTI]

    Hanak, Joseph J. (Lawrenceville, NJ)

    1981-01-01

    An amorphous silicon solar cell has an active body with two or a series of layers of hydrogenated amorphous silicon arranged in a tandem stacked configuration with one optical path and electrically interconnected by a tunnel junction. The layers of hydrogenated amorphous silicon arranged in tandem configuration can have the same bandgap or differing bandgaps.

  3. Josephson Junctions Fabricated by Focussed Ion Beam

    E-Print Network [OSTI]

    Hadfield, Robert Hugh

    at temperature T: ??? ? ??? ??= T2k ?(T) eR TI BN C tanh )( 2 ? , (2.26) where RN is the normal state resistance of the junction (temperature independent in low TC devices) and ? is the energy gap of the (identical) superconducting electrodes. BCS theory...

  4. Gallium nitride junction field-effect transistor

    DOE Patents [OSTI]

    Zolper, J.C.; Shul, R.J.

    1999-02-02

    An ion implanted gallium-nitride (GaN) junction field-effect transistor (JFET) and method of making the same are disclosed. Also disclosed are various ion implants, both n- and p-type, together with or without phosphorus co-implantation, in selected III-V semiconductor materials. 19 figs.

  5. Gallium nitride junction field-effect transistor

    DOE Patents [OSTI]

    Zolper, John C. (Albuquerque, NM); Shul, Randy J. (Albuquerque, NM)

    1999-01-01

    An all-ion implanted gallium-nitride (GaN) junction field-effect transistor (JFET) and method of making the same. Also disclosed are various ion implants, both n- and p-type, together with or without phosphorous co-implantation, in selected III-V semiconductor materials.

  6. Measuring Vacuum Polarization with Josephson Junctions

    SciTech Connect (OSTI)

    Penin, Alexander A. [Department of Physics, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada) and Institute for Nuclear Research of Russian Academy of Sciences, 117312 Moscow (Russian Federation)

    2010-03-05

    We argue that the vacuum polarization by the virtual electron-positron pairs can be measured by studying a Josephson junction in a strong magnetic field. The vacuum polarization results in a weak dependence of the Josephson constant on the magnetic field strength which is within the reach of the existing experimental techniques.

  7. JUNCTION TREE ALGORITHM Tuesday, September 9, 2008

    E-Print Network [OSTI]

    Cevher, Volkan

    graph G = (NG, EG) to an undi- rected graph G = (NG, EG) plays an important role in the junction tree. More formally, the transformation from G to G requires the addition (to EG) of two sets, EGG and EGG). They are properly defined EGG := (Xi, Xj) N2 : Xk N : (Xi, Xk) EG and (Xj, Xk) EG EGG := (Xj, Xk) N2 : (Xj, Xk

  8. p-n Junction Heterostructure Device Physics Model of a Four Junction Melissa J. Griggs*, Brendan M. Kayes, and Harry A. Atwater

    E-Print Network [OSTI]

    Atwater, Harry

    portion of the solar spectrum more effectively (see Fig. 1). High efficiency triple junction solar cellsp-n Junction Heterostructure Device Physics Model of a Four Junction Solar Cell Melissa J. Griggs-n junction device physics model for GaInP/GaAs/GaInAsP/GaInAs four junction solar cells. The model employs

  9. Stability analysis and testing of a train of centrifugal compressors for high pressure gas injection

    SciTech Connect (OSTI)

    Memmott, E.A. [Dresser-Rand Co., Olean, NY (United States)

    1999-07-01

    This paper describes the rotor dynamic stability analysis and the PTC-10 Class 1 test of a three body centrifugal compressor train for high pressure natural gas injection services. This train had a full load full pressure string test on hydrocarbon gases to a final discharge pressure of 500 BAR (7250 PSIA). Each compressor is of the back to back configuration, and is equipped with tilting pad seals, damper bearings, and a honeycomb labyrinth at the division wall with shunt holes. The driver is a gas turbine.

  10. High efficiency, low frequency linear compressor proposed for Gifford-McMahon and pulse tube cryocoolers

    SciTech Connect (OSTI)

    Höhne, Jens

    2014-01-29

    In order to reduce the amount of greenhouse gas emissions, which are most likely the cause of substantial global warming, a reduction of overall energy consumption is crucial. Low frequency Gifford-McMahon and pulse tube cryocoolers are usually powered by a scroll compressor together with a rotary valve. It has been theoretically shown that the efficiency losses within the rotary valve can be close to 50%{sup 1}. In order to eliminate these losses we propose to use a low frequency linear compressor, which directly generates the pressure wave without using a rotary valve. First results of this development will be presented.

  11. System for lubrication of a brake air compressor associated with a turbocharged internal combustion engine

    SciTech Connect (OSTI)

    Spencer, J.C.

    1992-10-13

    This patent describes a system for use with a vehicle which includes a turbocharged internal combustion engine having a lubricating system wherein lubricating oil from an engine oil reservoir is circulated within the engine and also to and from an associated brake system air compressor which supplies compressed air for operation of the vehicle air braking system. This patent describes improvement in passing supercharged air to an oil crankcase of the air compressor to cause lubricating oil to drain therefrom and return to the engine oil reservoir.

  12. Transit Infrastructure Finance Through Station Location Auctions

    E-Print Network [OSTI]

    Ian Carlton

    2009-01-01

    Numerous route and station options Strong real estate marketreal estate market Transit friendly constituents Numerous route and station options

  13. Oriel UV Exposure Station

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass mapSpeeding access toOctoberConsumption (Million CubicLSDOriel UV Exposure Station

  14. NOISE CONTROL METHODS FOR A RECIPROCATING AIR COMPRESSOR USED IN FUEL CELL AUXILIARY POWER UNIT (APU)

    E-Print Network [OSTI]

    Carver, Jeffrey C.

    NOISE CONTROL METHODS FOR A RECIPROCATING AIR COMPRESSOR USED IN FUEL CELL AUXILIARY POWER UNIT What is Fuel Cell APU? Why use APU? To reduce overall noise levels in a fuel cell auxiliary power unit (APU) Main Components Foundation Power source Microphones Spectrum analyzer Stack of fuel cells

  15. Bond Graph Modeling of Centrifugal Compressor System Nur Uddin and Jan Tommy Gravdahl

    E-Print Network [OSTI]

    Gravdahl, Jan Tommy

    . A model of a compression system with recycle flow is derived in this work. 1. INTRODUCTION Compressors are widely applied in industries, for exam- ples in pipeline natural gas transportation system, extraction in oil fields, and process chemical and petrochemical plants [1]. A model of a compression system

  16. Two results on compressor surge control with disturbance rejection Jan Tommy Gravdahl and Olav Egeland

    E-Print Network [OSTI]

    Gravdahl, Jan Tommy

    ] that the surge model of 7], which was derived for an axial compression system and is going to be usedTwo results on compressor surge control with disturbance rejection Jan Tommy Gravdahl and Olav- bilities. First, constant disturbances are included in the Greitzer model, and adaptive backstepping is em

  17. Evolution of pulse shapes during compressor scans in a CPA system and control of electron

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    Evolution of pulse shapes during compressor scans in a CPA system and control of electron Ti:sapphire laser pulses has been controlled by appropriate choice of the higher order spectral phase The delicate details of the envelope function of ultrashort light pulses (`pulse shape') play an important role

  18. OPTIMAL CONTROL EXPERIMENTATION OF COMPRESSION TRAJECTORIES FOR A LIQUID PISTON AIR COMPRESSOR

    E-Print Network [OSTI]

    Li, Perry Y.

    compressor is the critical part of a Compressed Air En- ergy Storage (CAES) system. Efficient and fast Storage (CAES) system for offshore wind turbine that has recently been proposed in [1,2]. In the proposed CAES system, high pressure (20-30MPa) compressed air is stored in a dual chamber storage vessel

  19. STUDY OF WORKING FLUID MIXTURES AND HIGH TEMPERATURE WORKING FLUIDS FOR COMPRESSOR DRIVEN SYSTEMS

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    Discussion 17 Heat transfer in condensation 19 References 20 3. SYSTEM ASPECTS OF HEAT PUMPS WITH NONAZEOTROPIC MIXTURES 23 Conclusions 32 4. RECENT DEVELOPMENTS IN THE FIELD OF HIGH TEMPERATURE HEAT PUMPS 33 study with finite heat exchanger areas and realistic compressor efficiencies 50 Industrial case 51 Space

  20. Reducing Air Compressor Work by Using Inlet Air Cooling and Dehumidification 

    E-Print Network [OSTI]

    Hardy, Mark James

    2011-02-22

    both vapor compression and absorption cycle chillers to cool and dehumidify the inlet air. The results show that the performance increases as much as 8 percent for the compressor system with absorption inlet cooling and as much as 5 percent when using...

  1. Vibrational Heat Transport in Molecular Junctions

    E-Print Network [OSTI]

    Segal, Dvira

    2015-01-01

    We review studies of vibrational energy transfer in a molecular junction geometry, consisting of a molecule bridging two heat reservoirs, solids or large chemical compounds. This setup is of interest for applications in molecular electronics, thermoelectrics, and nanophononics, and for addressing basic questions in the theory of classical and quantum transport. Calculations show that system size, disorder, structure, dimensionality, internal anharmonicities, contact interaction, and quantum coherent effects, are factors that interplay to determine the predominant mechanism (ballistic/diffusive), effectiveness (poor/good) and functionality (linear/nonlinear) of thermal conduction at the nanoscale. We review recent experiments and relevant calculations of quantum heat transfer in molecular junctions. We recount the Landauer approach, appropriate for the study of elastic (harmonic) phononic transport, and outline techniques which incorporate molecular anharmonicities. Theoretical methods are described along with...

  2. Junction conditions in extended Teleparallel gravities

    SciTech Connect (OSTI)

    De la Cruz-Dombriz, Álvaro; Dunsby, Peter K.S.; Sáez-Gómez, Diego E-mail: peter.dunsby@uct.ac.za

    2014-12-01

    In the context of extended Teleparallel gravity theories, we address the issue of junction conditions required to guarantee the correct matching of different regions of spacetime. In the absence of shells/branes, these conditions turn out to be more restrictive than their counterparts in General Relativity as in other extended theories of gravity. In fact, the general junction conditions on the matching hypersurfaces depend on the underlying theory and a new condition on the induced tetrads in order to avoid delta-like distributions in the field equations. This result imposes strict consequences on the viability of standard solutions such as the Einstein-Straus-like construction. We find that the continuity of the scalar torsion is required in order to recover the usual General Relativity results.

  3. Non-Lagrangian Theories from Brane Junctions

    E-Print Network [OSTI]

    Ling Bao; Vladimir Mitev; Elli Pomoni; Masato Taki; Futoshi Yagi

    2013-11-08

    In this article we use 5-brane junctions to study the 5D T_N SCFTs corresponding to the 5D N=1 uplift of the 4D N=2 strongly coupled gauge theories, which are obtained by compactifying N M5 branes on a sphere with three full punctures. Even though these theories have no Lagrangian description, by using the 5-brane junctions proposed by Benini, Benvenuti and Tachikawa, we are able to derive their Seiberg-Witten curves and Nekrasov partition functions. We cross-check our results with the 5D superconformal index proposed by Kim, Kim and Lee. Through the AGTW correspondence, we discuss the relations between 5D superconformal indices and n-point functions of the q-deformed W_N Toda theories.

  4. Semiconductor junction formation by directed heat

    DOE Patents [OSTI]

    Campbell, Robert B. (Pittsburgh, PA)

    1988-03-24

    The process of the invention includes applying precursors 6 with N- and P-type dopants therein to a silicon web 2, with the web 2 then being baked in an oven 10 to drive off excessive solvents, and the web 2 is then heated using a pulsed high intensity light in a mechanism 12 at 1100.degree.-1150.degree. C. for about 10 seconds to simultaneously form semiconductor junctions in both faces of the web.

  5. Effects of nonaxisymmetric tip clearance on axial compressor performance and stability

    SciTech Connect (OSTI)

    Graf, M.B.; Wong, T.S.; Greitzer, E.M.; Marble, F.E.; Tan, C.S.; Shin, H.W.; Wisler, D.C.

    1998-10-01

    The effects of circumferentially nonuniform tip clearance on axial compressor performance and stability have been investigated experimentally and analytically. A theoretical model for compressor behavior with nonaxisymmetric tip clearance has been developed and used to design a series of first-of-a-kind experiments on a four-stage, low-speed compressor. The experiments and computational results together show clearly the central physical features and controlling parameters of compressor response to nonaxisymmetric tip clearance. It was found that the loss in stall margin was more severe than that estimated based on average clearance. The stall point was, in fact, closer to that obtained with uniform clearance at the maximum clearance level. The circumferential length scale of the tip clearance (and accompanying flow asymmetry) was an important factor in determining the stall margin reduction. For the same average clearance, the loss in peak pressure rise was 50 percent higher for an asymmetry with fundamental wavelength equal to the compressor circumference than with wavelength equal to one-half the circumference. The clearance asymmetry had much less of an effect on peak efficiency; the measured maximum efficiency decrease obtained was less than 0.4 percent compared to the 8 percent decrease in peak pressure rise due to the asymmetric clearance. The efficiency penalty due to nonaxisymmetric tip clearance was thus close to that obtained with a uniform clearance at the circumferentially averaged level. The theoretical model accurately captured the decreases in both steady-state pressure rise and stable operating range which are associated with clearance asymmetry.

  6. Highly Charged Ion (HCI) Modified Tunnel Junctions

    SciTech Connect (OSTI)

    Pomeroy, J. M.; Grube, H. [Atomic Physics Division, National Institute of Standards and Technology (NIST) 100 Bureau Dr., MS 8423, Gaithersburg, MD 20899-8423 (United States)

    2009-03-10

    The neutralization energy carried by highly charged ions (HCIs) provides an alternative method for localizing energy on a target's surface, producing features and modifying surfaces with fluences and kinetic energy damage that are negligible compared to singly ionized atoms. Since each HCI can deposit an enormous amount of energy into a small volume of the surface (e.g., Xe{sup 44+} delivers 51 keV of neutralization energy per HCI), each individual HCI's interaction with the target can produce a nanoscale feature. Many studies of HCI-surface features have characterized some basic principles of this unique ion-surface interaction, but the activity reported here has been focused on studying ensembles of HCI features in ultra-thin insulating films by fabricating multi-layer tunnel junction devices. The ultra-thin insulating barriers allow current to flow by tunneling, providing a very sensitive means of detecting changes in the barrier due to highly charged ion irradiation and, conversely, HCI modification provides a method of finely tuning the transparency of the tunnel junctions that spans several orders of magnitude for devices produced from a single process recipe. Systematic variation of junction bias, temperature, magnetic field and other parameters provides determination of the transport mechanism, defect densities, and magnetic properties of these nano-features and this novel approach to device fabrication.

  7. UIC/HALSTED CTA STATION

    E-Print Network [OSTI]

    Illinois at Chicago, University of

    UIC/HALSTED CTA STATION TAYLOR STREET ROOSEVELT ROAD POLK STREET MILLERSTREET CARPENTERSTREET VERNON PARK HARRISON STREET EISENHOWER EXPRESSWAY I-290 DANRYANEXPRESSWAYI-90/94 POLK STREET MORGANSTREET

  8. PacificSouthwestResearchStationPrograms Pacific Southwest Research Station

    E-Print Network [OSTI]

    PacificSouthwestResearchStationPrograms Pacific Southwest Research Station Publications List Air Pollution and Global Change Impacts on Western Forest Ecosystems Center for Urban Forest Research Chemical branch of the USDA Forest Service in the states of California and Hawaii and the U.S.-affiliat- ed

  9. Alan a. Blggs Agriculture Canada, Research Station, Vineland Station, Ontario

    E-Print Network [OSTI]

    Biggs, Alan R.

    Alan a. Blggs Agriculture Canada, Research Station, Vineland Station, Ontario IntegratedApproach to Controlling LeucostomaCankerof Peachin Ontario Peach (Prunuspersica (L.) Batsch) is the third most valuable fruit crop in Ontario, Canada, following appIes (Matus domestica Barkh.) and grapes (Vizisspp.). In 1988

  10. Single P-N junction tandem photovoltaic device

    DOE Patents [OSTI]

    Walukiewicz, Wladyslaw (Kensington, CA); Ager, III, Joel W. (Berkeley, CA); Yu, Kin Man (Lafayette, CA)

    2011-10-18

    A single P-N junction solar cell is provided having two depletion regions for charge separation while allowing the electrons and holes to recombine such that the voltages associated with both depletion regions of the solar cell will add together. The single p-n junction solar cell includes an alloy of either InGaN or InAlN formed on one side of the P-N junction with Si formed on the other side in order to produce characteristics of a two junction (2J) tandem solar cell through only a single P-N junction. A single P-N junction solar cell having tandem solar cell characteristics will achieve power conversion efficiencies exceeding 30%.

  11. Single P-N junction tandem photovoltaic device

    DOE Patents [OSTI]

    Walukiewicz, Wladyslaw (Kensington, CA); Ager, III, Joel W. (Berkeley, CA); Yu, Kin Man (Lafayette, CA)

    2012-03-06

    A single P-N junction solar cell is provided having two depletion regions for charge separation while allowing the electrons and holes to recombine such that the voltages associated with both depletion regions of the solar cell will add together. The single p-n junction solar cell includes an alloy of either InGaN or InAlN formed on one side of the P-N junction with Si formed on the other side in order to produce characteristics of a two junction (2J) tandem solar cell through only a single P-N junction. A single P-N junction solar cell having tandem solar cell characteristics will achieve power conversion efficiencies exceeding 30%.

  12. Fabrication of magnetic tunnel junctions with epitaxial and textured ferromagnetic layers

    DOE Patents [OSTI]

    Chang, Y. Austin (Middleton, WI); Yang, Jianhua Joshua (Madison, WI)

    2008-11-11

    This invention relates to magnetic tunnel junctions and methods for making the magnetic tunnel junctions. The magnetic tunnel junctions include a tunnel barrier oxide layer sandwiched between two ferromagnetic layers both of which are epitaxial or textured with respect to the underlying substrate upon which the magnetic tunnel junctions are grown. The magnetic tunnel junctions provide improved magnetic properties, sharper interfaces and few defects.

  13. Spin Torques in Magnetic and Superconducting Tunnel Junctions

    E-Print Network [OSTI]

    Hoffman, Silas Eli

    2012-01-01

    Tunnel Junctions for Spintronic Memories and Beyond. ” IEEEto their application in spintronic devices. Injecting a spinforecasts a new kind of spintronic device that manipulates

  14. Phonon Bottleneck in Graphene-Based Josephson Junctions at Millikelvin

    Office of Scientific and Technical Information (OSTI)

    Phonon Bottleneck in Graphene-Based Josephson Junctions at Millikelvin Temperatures Borzenets, I. V.; Coskun, U. C.; Mebrahtu, H. T.; Bomze, Yu. V.; Smirnov, A. I.; Finkelstein, G....

  15. Limiting and realistic efficiencies of multi-junction solar Photonic Materials Group, FOM institute AMOLF, Amsterdam

    E-Print Network [OSTI]

    Polman, Albert

    Limiting and realistic efficiencies of multi-junction solar cells Photonic Materials Group, FOM of multi-junction solar cells, varying the number of subcells, the concentration of solar light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.4 Multi-junction Solar cells

  16. Japanese and American competition in the development of scroll compressors and its impact on the American air conditioning industry

    SciTech Connect (OSTI)

    Ushimaru, Kenji )

    1990-02-01

    This report examines the technological development of scroll compressors and its impact on the air conditioning equipment industry. Scroll compressors, although considered to be the compressors of the future for energy-efficient residential heat pumps and possibly for many other applications, are difficult to manufacture on a volume-production base. The manufacturing process requires computer-aided, numerically controlled tools for high-precision fabrication of major parts. Japan implemented a global strategy for dominating the technological world market in the 1970s, and scroll compressor technology benefited from the advent of new-generation machine tools. As a result, if American manufacturers of scroll compressors purchase or are essentially forced to purchase numerically controlled tools from Japan in the future, they will then become dependent on their own competitors because the same Japanese conglomerates that make numerically controlled tools also make scroll compressors. This study illustrates the importance of the basic machine tool industry to the health of the US economy. Without a strong machine tool industry, it is difficult for American manufacturers to put innovations, whether patented or not, into production. As we experience transformation in the air conditioning and refrigeration market, it will be critical to establish a consistent national policy to provide healthy competition among producers, to promote innovation within the industry, to enhance assimilation of new technology, and to eliminate practices that are incompatible with these goals. 72 refs., 8 figs., 1 tab.

  17. Phonon interference effects in molecular junctions

    SciTech Connect (OSTI)

    Markussen, Troels

    2013-12-28

    We study coherent phonon transport through organic, ?-conjugated molecules. Using first principles calculations and Green's function methods, we find that the phonon transmission function in cross-conjugated molecules, like meta-connected benzene, exhibits destructive quantum interference features very analogous to those observed theoretically and experimentally for electron transport in similar molecules. The destructive interference features observed in four different cross-conjugated molecules significantly reduce the thermal conductance with respect to linear conjugated analogues. Such control of the thermal conductance by chemical modifications could be important for thermoelectric applications of molecular junctions.

  18. On-Chip Josephson Junction Microwave Switch

    E-Print Network [OSTI]

    O. Naaman; M. O. Abutaleb; C. Kirby; M. Rennie

    2015-12-04

    The authors report on the design and measurement of a reflective single-pole single-throw microwave switch with no internal power dissipation, based on a superconducting circuit containing a single Josephson junction. The data demonstrate the switch operation with 2 GHz instantaneous bandwidth centered at 10 GHz, low insertion loss, and better than 20 dB on/off ratio. The switch's measured performance agrees well with simulations for input powers up to -100 dBm. An extension of the demonstrated circuit to implement a single-pole double-throw switch is shown in simulation.

  19. Hazard analysis of compressed natural gas fueling systems and fueling procedures used at retail gasoline service stations. Final report

    SciTech Connect (OSTI)

    NONE

    1995-04-28

    An evaluation of the hazards associated with operations of a typical compressed natural gas (CNG) fueling station is presented. The evaluation includes identification of a typical CNG fueling system; a comparison of the typical system with ANSI/NFPA (American National Standards Institute/National Fire Protection Association) Standard 52, Compressed Natural Gas (CNG) Vehicular Fuel System, requirements; a review of CNG industry safety experience as identified in current literature; hazard identification of potential internal (CNG system-specific causes) and external (interface of co-located causes) events leading to potential accidents; and an analysis of potential accident scenarios as determined from the hazard evaluation. The study considers CNG dispensing equipment and associated equipment, including the compressor station, storate vessels, and fill pressure sensing system.

  20. Analysis of instability inception in high-speed multistage axial-flow compressors

    SciTech Connect (OSTI)

    Hendricks, G.J.; Sabnis, J.S.; Feulner, M.R.

    1997-10-01

    A nonlinear, two-dimensional, compressible dynamic model has been developed to study rotating stall/surge inception and development in high-speed, multistage, axial flow compressors. The flow dynamics are represented by the unsteady Euler equations, solved in each interblade row gap and inlet and exit ducts as two-dimensional domains, and in each blade passage as a one-dimensional domain. The resulting equations are solved on a computational grid. The boundary conditions between domains are represented by ideal turning coupled with empirical loss and deviation correlations. Results are presented comparing model simulations to instability inception data of an eleven stage, high-pressure-ratio compressor operating at both part and full power, and the results analyzed in the context of a linear modal analysis.

  1. VRF on-site Measurement by Compressor Curve Method of VRF and the applications-APCBC 

    E-Print Network [OSTI]

    Kan,Y.; Shiochi,S.

    2014-01-01

    by Compressor Curve Method and Its Application Sumio Shiochi (Daikin Industries,ltd.) Yurino Kan* (Daikin Industries,ltd.) APCBC presentation in ICEBO (Asia Pacific Conference on Building Commissioning) Sept. 2014, Beijing, China ESL-IC-14...-09-34 Proceedings of the 14th International Conference for Enhanced Building Operations, Beijing, China, September 14-17, 2014 ICEBO 2014 Beijing + APCBC Meeting 2014.9.15-16 1. Background and Purpose of This Study ?Background? Stereotype of VRF from Architectural...

  2. Modeling for control of rotating stall in high-speed multistage axial compressors

    SciTech Connect (OSTI)

    Feulner, M.R.; Hendricks, G.J.; Paduano, J.D.

    1996-01-01

    Using a two-dimensional compressible flow representation of axial compressor dynamics, a control-theoretic input-output model is derived, which is of general utility in rotating stall/surge active control studies. The derivation presented here begins with a review of the fluid dynamic model, which is a two-dimensional stage stacking technique that accounts for blade row pressure rise, loss, and deviation as well as blade row and interblade row compressible flow. This model is extended to include the effects of the upstream and downstream geometry and boundary conditions, and then manipulated into a transfer function form that dynamically relates actuator motion to sensor measurements. Key relationships in this input-output form are then approximated using rational polynomials. Further manipulation yields an approximate model in standard form for studying active control of rotating stall and surge. As an example of high current relevance, the transfer function from an array of jet actuators to an array of static pressure sensors is derived. Numerical examples are also presented, including a demonstration of the importance of proper choice of sensor and actuator locations, as well as a comparison between sensor types. Under a variety of conditions, it was found that sensor locations near the front of the compressor or in the downstream gap are consistently the best choices, based on a quadratic optimization criterion and a specific three-stage compressor model. The modeling and evaluation procedures presented here are a first step toward a rigorous approach to the design of active control systems for high-speed axial compressors.

  3. Compressor Calorimeter Test of R-410A Alternatives R-32, DR-5, and L-41a

    SciTech Connect (OSTI)

    Shrestha, Som S [ORNL; Mahderekal, Isaac [ORNL; Sharma, Vishaldeep [ORNL; Abdelaziz, Omar [ORNL

    2013-02-01

    As a contribution to the AHRI Low-GWP Alternative Refrigerants Evaluation Program (AREP), this study compares performance of alternative refrigerants R32, DR-5, and L-41A to that of refrigerant R-410A (baseline) in a scroll compressor designed for air-conditioning and heat pump applications. Compressor calorimeter tests were performed to evaluate the performance of the lower-GWP alternative refrigerants in place of the common refrigerant R-410A in a 36,000 Btu/hr compressor calorimeter using a compressor having a nominal rated capacity of 21,300 Btu/hr. Tests were conducted over a suction dew point temperature range of 10 F to 55 F in 5 F increments and a discharge dew point temperature range of 70 F to 140 F in 10 F increments. All the tests were performed with 20 F superheat, 40 F superheat and 65 F suction temperature. A liquid subcooling level of 15 F was maintained for all the test conditions. The tests showed that performance of these three lower-GWP alternative refrigerants is comparable to that of R-410A. For the 20 F superheat and 15 F subcooling test conditions, EERs of R32, DR-5, and L-41A were 90% to 99%, 96% to 99%, and 94% to 101%, respectively, compared to that of R-410A. Similarly, cooling capacities of R32, DR-5, and L-41A were 98% to 103%, 92% to 96%, and 84% to 92%, respectively, compared to that of R-410A.

  4. A modified post damping ring bunch compressor beamline for the TESLA linear collider

    SciTech Connect (OSTI)

    Philippe R.-G. Piot; Winfried Decking

    2004-03-23

    We propose a modified bunch compressor beamline, downstream of the damping ring, for the TESLA linear collider. This modified beamline uses a third harmonic radio-frequency section based on the 3.9 GHz superconducting cavity under development at Fermilab. In our design the beam deceleration is about {approx}50 MeV instead of {approx}450 MeV in the original design proposed.

  5. Practical exergy analysis of centrifugal compressor performance using ASME-PTC-10 data

    SciTech Connect (OSTI)

    Carranti, F.J. [Hoffman Air and Filtration Systems, Syracuse, NY (United States)

    1997-07-01

    It has been shown that measures of performance currently in use for industrial and process compressors do not give a true measure of energy utilization, and that the required assumptions of isentropic or adiabatic behavior are now always valid. A better indication of machine or process performance can be achieved using exergetic (second law) efficiencies and by employing the second law of thermodynamics to indicate the nature of irreversibilities and entropy generation in the compression process. In this type of analysis, performance is related to an environmental equilibrium condition, or dead state. Often, the differences between avoidable and unavoidable irreversibilities ca be interpreted from these results. A general overview of the techniques involved in exergy analysis as applied to compressors and blowers is presented. A practical method to allow the calculation of exergetic efficiencies by manufacturers and end users is demonstrated using data from ASME Power Test Code input. These data are often readily available from compressor manufacturers for both design and off-design conditions, or can sometimes be obtained from field measurements. The calculations involved are simple and straightforward, and can demonstrate the energy usage situation for a variety of conditions. Here off-design is taken to mean at different rates of flow, as well as at different environmental states. The techniques presented are also applicable to many other equipment and process types.

  6. Bifurcation analysis of surge and rotating stall in axial flow compressors

    SciTech Connect (OSTI)

    Abed, E.H. ); Houpt, P.K. . Corporate Research and Development Center); Hosny, W.M. . Engine Operability Div.)

    1993-10-01

    The surge and rotating stall post-instability behaviors of axial flow compressors are investigated from a bifurcation-theoretic perspective, using a model and system data presented by Greitzer (1976a). For this model, a sequence of local and global bifurcations of the nonlinear system dynamics is uncovered. This includes a global bifurcation of a pair of large-amplitude periodic solutions. Resulting from this bifurcation are a stable oscillation (surge) and an unstable oscillation (antisurge). The latter oscillation is found to have a deciding significance regarding the particular post-instability behavior experienced by the compressor. These results are used to reconstruct Greitzer's (1976b) findings regarding the manner in which post-instability behavior depends on system parameters. Although the model does not directly reflect non axisymmetric dynamics, use of a steady-state compressor characteristic approximating the measured characteristic of Greitzer (1976a) is found to result in conclusions that compare well with observation. Thus, the paper gives a convenient and simple explanation of the boundary between surge and rotating stall behaviors, without the use of more intricate models and analyses including non axisymmetric flow dynamics.

  7. Rotating stall control of an axial flow compressor using pulsed air injection

    SciTech Connect (OSTI)

    D`Andrea, R.; Behnken, R.L.

    1997-10-01

    This paper presents the use of pulsed air injection to control rotating stall in a low-speed, axial flow compressor. In the first part of the paper, the injection of air is modeled as an unsteady shift of the compressor characteristic, and incorporated into a low dimensional model of the compressor. By observing the change in the bifurcation behavior of this model subject to nonlinear feedback, the viability of various air injection orientations is established. An orientation consistent with this analysis is then used for feedback control. By measuring the unsteady pressures near the rotor face, a control algorithm determines the magnitude and phase of the first mode of rotating stall and controls the injection of air in the front of the rotor face. Experimental results show that this technique eliminates the hysteresis loop normally associated with rotating stall. A parametric study is used to determine the optimal control parameters for suppression of stall. The resulting control strategy is also shown to suppress surge when a plenum is present. Using a high-fidelity model, the main features of the experimental results are duplicated via simulations.

  8. Junction adhesion molecule expression influences hematopoietic and endothelial commitment of murine embryonic stem cells

    E-Print Network [OSTI]

    Stankovich, Basha Lorraine

    2009-01-01

    OF CALIFORNIA, MERCED Junction Adhesion Molecule Expressionstem cells. Junction adhesion molecules influence cell fateBirchmeier W. Balancing cell adhesion and Wnt signaling, the

  9. Josephson junctions in high-T/sub c/ superconductors

    DOE Patents [OSTI]

    Falco, C.M.; Lee, T.W.

    1981-01-14

    The invention includes a high T/sub c/ Josephson sperconducting junction as well as the method and apparatus which provides the junction by application of a closely controlled and monitored electrical discharge to a microbridge region connecting two portions of a superconducting film.

  10. Energy Department Launches Alternative Fueling Station Locator...

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

    Launches Alternative Fueling Station Locator App Energy Department Launches Alternative Fueling Station Locator App November 7, 2013 - 11:16am Addthis As part of the Obama...

  11. Hydrogen Refueling Station Costs in Shanghai

    E-Print Network [OSTI]

    Weinert, Jonathan X.; Shaojun, Liu; Ogden, Joan M; Jianxin, Ma

    2006-01-01

    04 Hydrogen Refueling Station Costs in Shanghai Jonathan X.Hydrogen Refueling Station Costs in Shanghai Jonathan X.voltage connections) Capital costs for this equipment must

  12. Hydrogen refueling station costs in Shanghai

    E-Print Network [OSTI]

    Weinert, Jonathan X.; Shaojun, Liu; Ogden, Joan M; Jianxin, Ma

    2007-01-01

    Kingdom; 2004. [8] Amos W. Costs of storing and transportingcon- nections). Capital costs for this equipment must bein an analysis of station costs. Total station construction

  13. Mechanical deformations of boron nitride nanotubes in crossed junctions

    SciTech Connect (OSTI)

    Zhao, Yadong; Chen, Xiaoming; Ke, Changhong; Park, Cheol; Fay, Catharine C.; Stupkiewicz, Stanislaw

    2014-04-28

    We present a study of the mechanical deformations of boron nitride nanotubes (BNNTs) in crossed junctions. The structure and deformation of the crossed tubes in the junction are characterized by using atomic force microscopy. Our results show that the total tube heights are reduced by 20%–33% at the crossed junctions formed by double-walled BNNTs with outer diameters in the range of 2.21–4.67?nm. The measured tube height reduction is found to be in a nearly linear relationship with the summation of the outer diameters of the two tubes forming the junction. The contact force between the two tubes in the junction is estimated based on contact mechanics theories and found to be within the range of 4.2–7.6 nN. The Young's modulus of BNNTs and their binding strengths with the substrate are quantified, based on the deformation profile of the upper tube in the junction, and are found to be 1.07?±?0.11 TPa and 0.18–0.29 nJ/m, respectively. Finally, we perform finite element simulations on the mechanical deformations of the crossed BNNT junctions. The numerical simulation results are consistent with both the experimental measurements and the analytical analysis. The results reported in this paper contribute to a better understanding of the structural and mechanical properties of BNNTs and to the pursuit of their applications.

  14. Effect of current injection into thin-film Josephson junctions

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

    Kogan, V. G.; Mints, R. G.

    2014-11-11

    New thin-film Josephson junctions have recently been tested in which the current injected into one of the junction banks governs Josephson phenomena. One thus can continuously manage the phase distribution at the junction by changing the injected current. Our method of calculating the distribution of injected currents is also proposed for a half-infinite thin-film strip with source-sink points at arbitrary positions at the film edges. The strip width W is assumed small relative to ?=2?2/d;? is the bulk London penetration depth of the film material and d is the film thickness.

  15. Internally-cooled centrifugal compressor with cooling jacket formed in the diaphragm

    DOE Patents [OSTI]

    Moore, James J.; Lerche, Andrew H.; Moreland, Brian S.

    2014-08-26

    An internally-cooled centrifugal compressor having a shaped casing and a diaphragm disposed within the shaped casing having a gas side and a coolant side so that heat from a gas flowing though the gas side is extracted via the coolant side. An impeller disposed within the diaphragm has a stage inlet on one side and a stage outlet for delivering a pressurized gas to a downstream connection. The coolant side of the diaphragm includes at least one passageway for directing a coolant in a substantially counter-flow direction from the flow of gas through the gas side.

  16. ACEEE Summer Study on Energy in Industry, West Point, NY, July 19-22. 1 Modeling and Simulation of Air Compressor Energy Use

    E-Print Network [OSTI]

    Kissock, Kelly

    of Air Compressor Energy Use Chris Schmidt, Energy & Resource Solutions, Inc. Kelly Kissock, Department compressor energy use to estimate energy savings in compressed air systems from air use reduction and other of this method to estimate energy savings from changing control modes and reducing air use is described

  17. Types of Stations and Activities at Each: 1) Short Station

    E-Print Network [OSTI]

    ) from starboard A-Frame­ Hydro Team · Fe CTD cast (1) at some locations - Wu · VPR cast (1) from stern A camera deployed from ice-Cooper/Grebmier team · If necessary, small boat work to access ice- Gradinger small boat ­ Moran At 5-6 Open Water Stations: · Van Veen Grab sampling from stern A-frame, 3/8" wire, 3

  18. Profiling the Thermoelectric Power of Semiconductor Junctions with

    E-Print Network [OSTI]

    components or hazardous working fluids. Developing new thermoelectric mate- rials with high figures of merit S is governed by local carrier statistics, SThEM allows us to profile precise elec- tronic junction locations

  19. Epithelial cell polarity and cell junctions in drosophila

    E-Print Network [OSTI]

    Tepass, Ulrich; Tanentzapf­ , Guy; Ward, Robert; Fehon, Richard G.

    2001-12-01

    to the most detailed understanding of these processes in a whole animal model system to date. Asymmetry of the plasma membrane and the differentiation of membrane domains and cellular junctions are controlled by protein complexes that assemble around...

  20. Anomalous supercurrent from Majorana states in topological insulator Josephson junctions

    E-Print Network [OSTI]

    Potter, Andrew C.

    We propose a Josephson junction setup based on a topological insulator (TI) thin film to detect Majorana states that exploits the unique helical and extended nature of the TI surface state. When the magnetic flux through ...

  1. Electron transport in normal-metal/superconductor junctions 

    E-Print Network [OSTI]

    Yan, XZ; Zhao, HW; Hu, Chia-Ren.

    2000-01-01

    On the basis of the Keldysh method of nonequilibrium systems, we develop a theory of electron tunneling in normal-metal-superconductor junctions. By using the tunneling Hamiltonian model (being appropriate for the tight-binding systems...

  2. Power dissipation in a single molecule junction: Tracking energy levels

    E-Print Network [OSTI]

    Yaghoob Naimi; Javad Vahedi

    2014-12-05

    Motivated by recent work [Lee et al. Nature {\\bf 489}, 209 (2013)], on asymmetry features of heat dissipation in the electrodes of molecular junctions, we put forward an idea as a result of heat dissipation in the electrodes. Based on tight-binding model and a generalized Green's function formalism, we describe the conditions under which heat dissipation shows symmetry characteristic and does not depend on the bias polarity. We also show the power dissipated in the junction can be used to detect which energy levels of molecule junction play more or less role in the transmission process. We present this idea by studying a simple toy model and Au-$C_{60}$-Au junction.

  3. EA-1037: Uranium Lease Management Program, Grand Junction, Colorado

    Broader source: Energy.gov [DOE]

    This EA evaluates the environmental impacts of the U.S. Department of Energy's Grand Junction Projects Office's proposal to maintain and preserve the nation's immediately accessible supply of...

  4. Phase diagram of Josephson junction between

    Office of Scientific and Technical Information (OSTI)

    diagram of Josephson junction betweensandssuperconductors in the dirty limit...

  5. Corrigendum Corrigendum to "Gap junction-mediated electrical transmission

    E-Print Network [OSTI]

    Rash, John E.

    Corrigendum Corrigendum to "Gap junction-mediated electrical transmission: Regulatory mechanisms, show variability in the electrical conductance of the synaptic transmission, even though the pre chemical component. Thus, electrical synapses from neighboring club endings coexist at different degrees

  6. Metal-Semiconductor junctions tlu@math.pku.edu.cn

    E-Print Network [OSTI]

    Lu, Tiao

    of Ec and Ev and also changes EFi n=ni e -q F - kT , p=ni e q F- kT n-p 2ni = e -F1 Metal-Semiconductor junctions tlu@math.pku.edu.cn homepage: dsec.pku.edu.cn/~tlu blog: http://hi.baidu.com/motioo #12;2 - Many of the properties of pn junctions can be realized by forming an appropriate metal

  7. EA-1338: Transfer of the Department of Energy Grand Junction Office to Non-DOE Ownership, Grand Junction, Colorado

    Broader source: Energy.gov [DOE]

    This EA evaluates the environmental impacts for the proposed transfer of real and personal property at the U.S. Department of Energy's Grand Junction Office to non-DOE ownership.

  8. LIQUIDSLIQUIDS GISAXSGISAXSGISAXS/WAXS station

    E-Print Network [OSTI]

    Ohta, Shigemi

    LIQUIDSLIQUIDS GISAXSGISAXSGISAXS/WAXS station: * Energy range: 2.1 to 24 keV * Low divergence mode 60m 55m 50m 45m 40m 35m 30m SAXS SAXS SCD SSA VFM HFM DCMKB's Gi-SAXS/WAXS sample Liquids sample Gi

  9. NOAA PMEL Station Chemistry Data

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Quinn, Patricia

    Submicron and supermicron samples are analyzed by ion chromatography for Cl-, NO3-, SO4-2, Na+, NH4+, K+, Mg2+, and Ca+2. The analysis of MSA-, Br-, and oxalate has been added to some stations. Samples also are analyzed for total mass by gravimetric analysis at 55 +/- 5% RH.

  10. Mobile Alternative Fueling Station Locator

    SciTech Connect (OSTI)

    Not Available

    2009-04-01

    The Department of Energy's Alternative Fueling Station Locator is available on-the-go via cell phones, BlackBerrys, or other personal handheld devices. The mobile locator allows users to find the five closest biodiesel, electricity, E85, hydrogen, natural gas, and propane fueling sites using Google technology.

  11. NOAA PMEL Station Chemistry Data

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Quinn, Patricia

    2008-04-04

    Submicron and supermicron samples are analyzed by ion chromatography for Cl-, NO3-, SO4-2, Na+, NH4+, K+, Mg2+, and Ca+2. The analysis of MSA-, Br-, and oxalate has been added to some stations. Samples also are analyzed for total mass by gravimetric analysis at 55 +/- 5% RH.

  12. FINAL DESIGN OF ILC RTML EXTRACTION LINE FOR SINGLE STAGE BUNCH COMPRESSOR

    SciTech Connect (OSTI)

    Seletskiy, S.; Solyak, N.

    2011-03-28

    The use of single stage bunch compressor (BC) in the International Linear Collider (ILC) Damping Ring to the Main Linac beamline (RTML) requires new design for the extraction line (EL). The EL located downstream of the BC will be used for both an emergency abort dumping of the beam and the tune-up continuous train-by-train extraction. It must accept both compressed and uncompressed beam with energy spread of 3.54% and 0.15% respectively. In this paper we report the final design that allowed minimizing the length of such extraction line while offsetting the beam dumps from the main line by 5m distance required for acceptable radiation level in the service tunnel. Proposed extraction line can accommodate beams with different energy spreads at the same time providing the beam size suitable for the aluminum ball dump window. We described the final design of the ILC RTML extraction line located downstream of the new single-stage bunch compressor. The extraction line is only 24m long and is capable of accepting and transmitting 220kW of beam power. The EL can be used for both fast intra-train and continual extraction, and is capable of accepting both 0.15% and 3.54% energy spread beams at 5MeV and 4.37MeV respectively.

  13. Viscous throughflow modeling of axial compressor bladerows using a tangential blade force hypothesis

    SciTech Connect (OSTI)

    Gallimore, S.J.

    1998-10-01

    This paper describes the modeling of axial compressor blade rows in an axisymmetric viscous throughflow method. The basic method, which has been reported previously, includes the effects of spanwise mixing, using a turbulent diffusion model, and endwall shear within the throughflow calculation. The blades are modeled using a combination of existing two-dimensional blade performance predictions for loss and deviation away from the annulus walls and a novel approach using tangential blade forces in the endwall regions. Relatively simple assumptions about the behavior of the tangential static pressure force imposed by the blades allow the secondary deviations produced by tip clearance flows and the boundary layer flows at fixed blade ends to be calculated in the axisymmetric model. Additional losses are assigned in these regions based on the calculated deviations. The resulting method gives realistic radial distributions of loss and deviation across the whole span at both design and off-design operating conditions, providing a quick method of estimating the magnitudes of these effects in the preliminary design process. Results from the method are compared to measured data in low and high-speed compressors and multistage three-dimensional viscous CFD predictions.

  14. Numerical simulation of the compressor coil of the plasma dynamic accelerator

    SciTech Connect (OSTI)

    Thomas, P.

    1997-01-01

    The plasma dynamic accelerator accelerates a plasma to very high velocities in a coaxial accelerator and then compresses it in a compressor coil, achieving high densities. The axial component of the current distribution, extending from the tip of the coaxial accelerator`s center electrode to the coil turns, causes compressing forces, the radial component yields accelerating forces. The rapid change of the coil current induces azimuthal eddy currents in the plasma that interact with the coil`s magnetic field, again yielding Lorentz forces. Aerodynamic compression may also be an important effect. A new two-dimensional magnetohydrodynamics code is used to investigate which of these effects are really important for the compression. The code allows one to simulate all effects mentioned separately and in combination. In a first step only aerodynamic compression is considered. Then each electromagnetic effect is imposed on the system. Finally, a complete simulation of the compressor coil is performed. The analysis of the results provides new insights in the way the coil operates. This paper presents important aspects of the mathematical model and of the numerical implementation and reports results.

  15. Dynamically balanced, hydraulically driven compressor/pump apparatus for resonant free piston Stirling engines

    DOE Patents [OSTI]

    Corey, John A. (North Troy, NY)

    1984-05-29

    A compressor, pump, or alternator apparatus is designed for use with a resonant free piston Stirling engine so as to isolate apparatus fluid from the periodically pressurized working fluid of the Stirling engine. The apparatus housing has a first side closed by a power coupling flexible diaphragm (the engine working member) and a second side closed by a flexible diaphragm gas spring. A reciprocally movable piston is disposed in a transverse cylinder in the housing and moves substantially at right angles relative to the flexible diaphragms. An incompressible fluid fills the housing which is divided into two separate chambers by suitable ports. One chamber provides fluid coupling between the power diaphragm of the RFPSE and the piston and the second chamber provides fluid coupling between the gas spring diaphragm and the opposite side of the piston. The working members of a gas compressor, pump, or alternator are driven by the piston. Sealing and wearing parts of the apparatus are mounted at the external ends of the transverse cylinder in a double acting arrangement for accessibility. An annular counterweight is mounted externally of the reciprocally movable piston and is driven by incompressible fluid coupling in a direction opposite to the piston so as to damp out transverse vibrations.

  16. COMPARATIVE COSTS OF CALIFORNIA CENTRAL STATION ELECTRICITY

    E-Print Network [OSTI]

    Laughlin, Robert B.

    CALIFORNIA ENERGY COMMISSION COMPARATIVE COSTS OF CALIFORNIA CENTRAL STATION ELECTRICITY GENERATION and Anitha Rednam, Comparative Costs of California Central Station Electricity Generation Technologies................................................................................................... 1 CHAPTER 1: Summary of Technology Costs

  17. Experimental Study of Heat Transfer Enhancement in a Liquid Piston Compressor/Expander Using Porous Media Inserts

    E-Print Network [OSTI]

    Li, Perry Y.

    or a compressor for compressed natural gas (CNG). Highlights · Porous medias role to improve compres- sor is the predominant contribution to im- provements Keywords: Liquid piston, porous media, gas compression / expansion combined with natural gas in a gas turbine to boost9 combustion e ciency. As a storage device, its e -10

  18. Abstract--For a Compressed Air Energy Storage (CAES) approach to be viable, the air compressor/expander must be

    E-Print Network [OSTI]

    Li, Perry Y.

    Abstract-- For a Compressed Air Energy Storage (CAES) approach to be viable, the air compressor (CAES) system for offshore wind turbine has been proposed in [1, 2] (Fig. 1). It uses the open Storage (CAES) System for Offshore Wind Turbine Although the heat transfer models above are reasonable

  19. Envelope amplifier design for wireless base-station power amplifiers

    E-Print Network [OSTI]

    Hsia, Chin

    2010-01-01

    Base Station Power Amplifiers . . . . . . . . . . . .for High Efficiency Bbase Station Power Amplifiers,” in IEEEfor Wireless Base-Station Power Amplifiers A dissertation

  20. Rocky Mountain Research Station 20142017 Strategic Framework

    E-Print Network [OSTI]

    Rocky Mountain Research Station 2014­2017 Strategic Framework #12;Rocky Mountain Research Station 240 West Prospect Fort Collins, CO 80526 (970) 498-1100 www.fs.fed.us/rmrs High mountain lake at GLEES (Glacier Lakes Ecosystem Experiments Site) #12;1ROCKY MOUNTAIN RESEARCH STATION -- 2014­2017 STRATEg

    1. Design and development of a four-cell sorption compressor based J-T cooler using R134a as working fluid

      SciTech Connect (OSTI)

      Mehta, R. N.; Bapat, S. L.; Atrey, M. D.

      2014-01-29

      The need of a cooler with no electromagnetic interference and practically zero vibration has led to sorption compressor based Joule-Thomson (J-T) coolers. These are useful for sophisticated electronic, ground based and space borne systems. In a Sorption compressor, adsorbed gases are desorbed into a confined volume by raising temperature of the sorption bed resulting in an increase in pressure of the liberated gas. In order to have the system (compressor) functioning on a continuous basis, with almost a constant gas flow rate, multiple cells are used with the adaptation of Temperature Swing Adsorption (TSA) process. As the mass of the desorbed gas dictates the compressor throughput, a combination of sorbent material with high adsorption capacity for a chosen gas or gas mixture has to be selected for efficient operation of the compressor. Commercially available (coconut-shell base) activated carbon has been selected for the present application. The characterization study for variation of discharge pressure is used to design the Four-cell sorption compressor based cryocooler with a desired output. Apart from compressor, the system includes a) After cooler b) Return gas heat exchanger c) capillary tube as the J-T expansion device and d) Evaporator.

    2. Measure Guideline: Optimizing the Configuration of Flexible Duct Junction Boxes

      SciTech Connect (OSTI)

      Beach, R.; Burdick, A.

      2014-03-01

      This measure guideline offers additional recommendations to heating, ventilation, and air conditioning (HVAC) system designers for optimizing flexible duct, constant-volume HVAC systems using junction boxes within Air Conditioning Contractors of America (ACCA) Manual D guidance (Rutkowski, H. Manual D -- Residential Duct Systems, 3rd edition, Version 1.00. Arlington, VA: Air Conditioning Contractors of America, 2009.). IBACOS used computational fluid dynamics software to explore and develop guidance to better control the airflow effects of factors that may impact pressure losses within junction boxes among various design configurations (Beach, R., Prahl, D., and Lange, R. CFD Analysis of Flexible Duct Junction Box Design. Golden, CO: National Renewable Energy Laboratory, submitted for publication 2013). These recommendations can help to ensure that a system aligns more closely with the design and the occupants' comfort expectations. Specifically, the recommendations described herein show how to configure a rectangular box with four outlets, a triangular box with three outlets, metal wyes with two outlets, and multiple configurations for more than four outlets. Designers of HVAC systems, contractors who are fabricating junction boxes on site, and anyone using the ACCA Manual D process for sizing duct runs will find this measure guideline invaluable for more accurately minimizing pressure losses when using junction boxes with flexible ducts.

    3. Modeling pedestrian flows in train stations: The example of Lausanne railway station

      E-Print Network [OSTI]

      Bierlaire, Michel

      Modeling pedestrian flows in train stations: The example of Lausanne railway station Flurin S, April 15 ­ 17, 2015 #12;Modeling pedestrian flows in train stations: The example of Lausanne railway Engineering EPFL ­ Ecole Polytechnique Fédérale de Lausanne Modeling pedestrian flows in train stations

    4. Self-latching eccentric cam for dual stroke compressor or pump

      DOE Patents [OSTI]

      Sisk, Francis J. (San Mateo, CA)

      1985-01-01

      For a dual capacity refrigerant compressor of the type which has an eccentric cam rotatable on a crankpin between two opposite positions which changes the total eccentricity of the crankpin and cam so as to obtain two different stroke lengths, the rotation of the cam on the crankpin being effected by a reversal of motor operation, the cam moves through an angle of about 270.degree. around the crankpin so that a centrifugal force torque tending to hold the cam in place is available at least in the reduced stroke length position of the cam, and by providing lightening cavities and eccentric weightings, the center of mass 74 of the cam can be shifted to obtain the centrifugal torque in the proper direction at both the maximum and reduced stroke positions.

    5. Cryogenic Viscous Compressor Development and Modeling for the ITER Vacuum System

      SciTech Connect (OSTI)

      Baylor, Larry R [ORNL; Meitner, Steven J [ORNL; Barbier, Charlotte N [ORNL; Combs, Stephen Kirk [ORNL; Duckworth, Robert C [ORNL; Edgemon, Timothy D [ORNL; Rasmussen, David A [ORNL; Hechler, Michael P [ORNL; Kersevan, R. [ITER Organization, Cadarache, France; Dremel, M. [General Atomics, San Diego; Pearce, R.J.H. [General Atomics, San Diego; Boissin, Jean Claude [Consultant

      2011-01-01

      The ITER vacuum system requires a roughing pump system that can pump the exhaust gas from the torus cryopumps to the tritium exhaust processing plant. The gas will have a high tritium content and therefore conventional vacuum pumps are not suitable. A pump called a cryogenic viscous compressor (CVC) is being designed for the roughing system to pump from ~500 Pa to 10 Pa at flow rates of 200 Pa-m3/ s. A unique feature of this pump is that is allows any helium in the gas to flow through the pump where it is sent to the detritiation system before exhausting to atmosphere. A small scale prototype of the CVC is being tested for heat transfer characteristics and compared to modeling results to ensure reliable operation of the full scale CVC. Keywords- ITER; vacuum; fuel cycle

    6. Dynamics of Longitudinal Phase-Space Modulations in an rf Compressor for Electron Beams

      SciTech Connect (OSTI)

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

      2010-05-21

      Free Electron Lasers (FELs) operating in the UV or x-ray radiation spectrum require peak beam currents that are generally higher than those obtainable by present electron sources, thus making bunch compression necessary. Compression, however, may heighten the effects of collective forces and degrade the beam quality. In this paper they provide a framework for investigating some of these effects in rf compressors by focusing on the longitudinal dynamics of small-amplitude density perturbations, which have the potential to cause the disruptive appearance of the so-called microbunching instability. They develop a linear theory valid for low-to-moderate compression factors under the assumption of a 1D impedance model of longitudinal space charge and provide validation against macroparticle simulations.

    7. High-Power Plasma Switch for 11.4 GHz Microwave Pulse Compressor

      SciTech Connect (OSTI)

      Jay L. Hirshfield

      2010-03-04

      Results obtained in several experiments on active RF pulse compression at X-band using a magnicon as the high-power RF source are presented. In these experiments, microwave energy was stored in high-Q TE01 and TE02 modes of two parallel-fed resonators, and then discharged using switches activated with rapidly fired plasma discharge tubes. Designs and high-power tests of several versions of the compressor are described. In these experiments, coherent pulse superposition was demonstrated at a 5–9 MW level of incident power. The compressed pulses observed had powers of 50–70 MW and durations of 40–70 ns. Peak power gains were measured to be in the range of 7:1–11:1 with efficiency in the range of 50–63%.

    8. Measurement and computation of heat transfer in high-pressure compressor drum geometries with axial throughflow

      SciTech Connect (OSTI)

      Long, C.A.; Morse, A.P.; Tucker, P.G.

      1997-01-01

      This paper makes comparisons between CFD computations and experimental measurements of heat transfer for the axial throughflow of cooling air in a high-pressure compressor spool rig and a plane cavity rig. The heat transfer measurements are produced using fluxmeters and by the conduction solution method from surface temperature measurements. Numerical predictions are made by solving the Navier-Stokes equations in a full three-dimensional, time-dependent form using the finite-volume method. Convergence is accelerated using a multigrid algorithm and turbulence modeled using a simple mixing length formulation. Notwithstanding systematic differences between the measurements and the computations, the level of agreement can be regarded as promising in view of the acknowledged uncertainties in the experimental data, the limitations of the turbulence model and, perhaps more importantly, the modest grid densities used for the computations.

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

      DOE Patents [OSTI]

      Ecker, Amir L. (Dallas, TX)

      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.

    10. Self-latching eccentric cam for dual stroke compressor or pump

      DOE Patents [OSTI]

      Sisk, F.J.

      1985-01-22

      For a dual capacity refrigerant compressor of the type which has an eccentric cam rotatable on a crankpin between two opposite positions which changes the total eccentricity of the crankpin and cam so as to obtain two different stroke lengths, the rotation of the cam on the crankpin being effected by a reversal of motor operation, the cam moves through an angle of about 270[degree] around the crankpin so that a centrifugal force torque tending to hold the cam in place is available at least in the reduced stroke length position of the cam, and by providing lightening cavities and eccentric weightings, the center of mass of the cam can be shifted to obtain the centrifugal torque in the proper direction at both the maximum and reduced stroke positions. 7 figs.

    11. Superpoissonian shot noise in organic magnetic tunnel junctions

      SciTech Connect (OSTI)

      Cascales, Juan Pedro; Martinez, Isidoro; Aliev, Farkhad G.; Hong, Jhen-Yong; Lin, Minn-Tsong; Szczepa?ski, Tomasz; Dugaev, Vitalii K.; Barna?, Józef

      2014-12-08

      Organic molecules have recently revolutionized ways to create new spintronic devices. Despite intense studies, the statistics of tunneling electrons through organic barriers remains unclear. Here, we investigate conductance and shot noise in magnetic tunnel junctions with 3,4,9,10-perylene-teracarboxylic dianhydride (PTCDA) barriers a few nm thick. For junctions in the electron tunneling regime, with magnetoresistance ratios between 10% and 40%, we observe superpoissonian shot noise. The Fano factor exceeds in 1.5–2 times the maximum values reported for magnetic tunnel junctions with inorganic barriers, indicating spin dependent bunching in tunneling. We explain our main findings in terms of a model which includes tunneling through a two level (or multilevel) system, originated from interfacial bonds of the PTCDA molecules. Our results suggest that interfaces play an important role in the control of shot noise when electrons tunnel through organic barriers.

    12. Junction-based field emission structure for field emission display

      DOE Patents [OSTI]

      Dinh, Long N. (Concord, CA); Balooch, Mehdi (Berkeley, CA); McLean, II, William (Oakland, CA); Schildbach, Marcus A. (Livermore, CA)

      2002-01-01

      A junction-based field emission display, wherein the junctions are formed by depositing a semiconducting or dielectric, low work function, negative electron affinity (NEA) silicon-based compound film (SBCF) onto a metal or n-type semiconductor substrate. The SBCF can be doped to become a p-type semiconductor. A small forward bias voltage is applied across the junction so that electron transport is from the substrate into the SBCF region. Upon entering into this NEA region, many electrons are released into the vacuum level above the SBCF surface and accelerated toward a positively biased phosphor screen anode, hence lighting up the phosphor screen for display. To turn off, simply switch off the applied potential across the SBCF/substrate. May be used for field emission flat panel displays.

    13. Single Molecule Junctions: Probing Contact Chemistry and Fundamental Circuit Laws

      SciTech Connect (OSTI)

      Hybertsen M. S.

      2013-04-11

      By exploiting selective link chemistry, formation of single molecule junctions with reproducible conductance has become established. Systematic studies reveal the structure-conductance relationships for diverse molecules. I will draw on experiments from my collaborators at Columbia University, atomic-scale calculations and theory to describe progress in two areas. First, I will describe a novel route to form single molecule junctions, based on SnMe3 terminated molecules, in which gold directly bonds to carbon in the molecule backbone resulting in near ideal contact resistance [1]. Second, comparison of the conductance of junctions formed with molecular species containing either one backbone or two backbones in parallel allows demonstration of the role of quantum interference in the conductance superposition law at the molecular scale [2].

    14. Environmental Audit of the Grand Junction Projects Office

      SciTech Connect (OSTI)

      Not Available

      1991-08-01

      The Grand Junction Projects Office (GJPO) is located in Mesa County, Colorado, immediately south and west of the Grand Junction city limits. The US Atomic Energy Commission (AEC) established the Colorado Raw Materials Office at the present-day Grand Junction Projects Office in 1947, to aid in the development of a viable domestic uranium industry. Activities at the site included sampling uranium concentrate; pilot-plant milling research, including testing and processing of uranium ores; and operation of a uranium mill pilot plant from 1954 to 1958. The last shipment of uranium concentrate was sent from GJPO in January, 1975. Since that time the site has been utilized to support various DOE programs, such as the former National Uranium Resource Evaluation (NURE) Program, the Uranium Mill Tailings Remedial Action Project (UMTRAP), the Surplus Facilities Management Program (SFMP), and the Technical Measurements Center (TMC). All known contamination at GJPO is believed to be the result of the past uranium milling, analyses, and storage activities. Hazards associated with the wastes impounded at GJPO include surface and ground-water contamination and potential radon and gamma-radiation exposure. This report documents the results of the Baseline Environmental Audit conducted at Grand Junction Projects Office (GJPO) located in Grand Junction, Colorado. The Grand Junction Baseline Environmental Audit was conducted from May 28 to June 12, 1991, by the Office of Environmental Audit (EH-24). This Audit evaluated environmental programs and activities at GJPO, as well as GJPO activities at the State-Owned Temporary Repository. 4 figs., 12 tabs.

    15. Taipei terminal rail station : casting an urban gateway

      E-Print Network [OSTI]

      Tsai, May Deanna

      1991-01-01

      Access is a key issue in the design of railway stations. The evolution of the train station typology, has resulted in many types of stations based on the development of the stations' access. Since rail travel on a larger ...

    16. Regulation of specific connexins differentially alters gap junction permeability and endothelial cell function

      E-Print Network [OSTI]

      Elihu, David Morad

      2006-01-01

      While many have explored how vascular processes alter gap junction communication and composition few have analyzed the role of specific gap junction connexin proteins in regulating cellular communication and wound healing. ...

    17. Estimating commuter rail demand to Kendall Square along the Grand Junction Corridor

      E-Print Network [OSTI]

      Bockelie, Adam

      2012-01-01

      Since acquiring the Grand Junction Railroad in June 2010 from CSX, the Massachusetts Bay Transit Authority (MBTA) has explored the possibility of using the line for commuter rail service. In addition the Grand Junction ...

    18. Computer-assisted data acquisition on Josephson junctions

      SciTech Connect (OSTI)

      Pagano, S. ); Costabile, G.; Fedullo, V.

      1989-09-01

      An automatic digital data-acquisition system for the test and characterization of superconducting Josephson tunnel junctions is presented. The key feature is represented by the high degree of interaction of the measurement system with the device under test. This is accomplished by an iterated sequence of data acquisitions, automatic analysis, and subsequent modifications of the control signals in the device. In this way, the basic calibration and the value of the relevant quantities involved with the Josephson junction are automatically determined. A connection with a host computer makes possible more complex data analysis, while the full control of the experiment by a dedicated computer allows the operator to perform nonroutine procedures.

    19. Timber Mountain Precipitation Monitoring Station

      SciTech Connect (OSTI)

      Lyles, Brad; McCurdy, Greg; Chapman, Jenny; Miller, Julianne

      2012-01-01

      A precipitation monitoring station was placed on the west flank of Timber Mountain during the year 2010. It is located in an isolated highland area near the western border of the Nevada National Security Site (NNSS), south of Pahute Mesa. The cost of the equipment, permitting, and installation was provided by the Environmental Monitoring Systems Initiative (EMSI) project. Data collection, analysis, and maintenance of the station during fiscal year 2011 was funded by the U.S. Department of Energy, National Nuclear Security Administration, Nevada Site Office Environmental Restoration, Soils Activity. The station is located near the western headwaters of Forty Mile Wash on the Nevada Test and Training Range (NTTR). Overland flows from precipitation events that occur in the Timber Mountain high elevation area cross several of the contaminated Soils project CAU (Corrective Action Unit) sites located in the Forty Mile Wash watershed. Rain-on-snow events in the early winter and spring around Timber Mountain have contributed to several significant flow events in Forty Mile Wash. The data from the new precipitation gauge at Timber Mountain will provide important information for determining runoff response to precipitation events in this area of the NNSS. Timber Mountain is also a groundwater recharge area, and estimation of recharge from precipitation was important for the EMSI project in determining groundwater flowpaths and designing effective groundwater monitoring for Yucca Mountain. Recharge estimation additionally provides benefit to the Underground Test Area Sub-project analysis of groundwater flow direction and velocity from nuclear test areas on Pahute Mesa. Additionally, this site provides data that has been used during wild fire events and provided a singular monitoring location of the extreme precipitation events during December 2010 (see data section for more details). This letter report provides a summary of the site location, equipment, and data collected in fiscal year 2011.

    20. TM-mode coupling to a Josephson junction S. J. Lewandowski

      E-Print Network [OSTI]

      Boyer, Edmond

      of the junction electrodes. to the j unction was provided by two leads immersed in superconducting solder, which

    1. Optimized Triple-Junction Solar Cells Using Inverted Metamorphic Approach (Presentation)

      SciTech Connect (OSTI)

      Geisz, J. F.

      2008-11-01

      Record efficiencies with triple-junction inverted metamorphic designs, modeling useful to optimize, and consider operating conditions before choosing design.

    2. Pilgrim Station | Open Energy Information

      Open Energy Info (EERE)

      AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsourceII JumpQuarterly SmartDB-2, Blue Mountain GeothermalPilger Estates HotStation Jump

    3. OPTIMIZATION OF a-SiGe BASED TRIPLE, TANDEM AND SINGLE-JUNCTION SOLAR Xunming Deng

      E-Print Network [OSTI]

      Deng, Xunming

      OPTIMIZATION OF a-SiGe BASED TRIPLE, TANDEM AND SINGLE-JUNCTION SOLAR CELLS Xunming Deng Department, tandem and triple-junction a-SiGe based solar cells and materials [6-19]. Much of the research is also light and bias voltage for the measurement of multiple-junction cells. Materials characterization using

    4. Design of photonic metamaterial multi-junction solar cells using rigorous coupled wave analysis

      E-Print Network [OSTI]

      Lansey, Eli

      Design of photonic metamaterial multi-junction solar cells using rigorous coupled wave analysis Eli a horizontally-oriented multi-junction solar cell by creating an array of cavities tuned with targeted CMs of New York, New York, NY, USA 10031 August 26, 2010 ABSTRACT We have developed a method to design multi-junction

    5. PHYSICAL REVIEW B 84, 195428 (2011) Semiclassical magnetotransport in graphene n-p junctions

      E-Print Network [OSTI]

      Ullmo, Denis

      2011-01-01

      PHYSICAL REVIEW B 84, 195428 (2011) Semiclassical magnetotransport in graphene n- p junctions n-p junctions in the quantum Hall regime. This framework is known to experimentally exhibit, creating a n-p junction at the regions' interface, an ideal setup to study Klein tunneling. Using a strong

    6. Development status of triple-junction solar cells optimized for low intensity low temperature applications

      E-Print Network [OSTI]

      Development status of triple-junction solar cells optimized for low intensity low temperature triple-junction solar cells manufactured by AZUR SPACE Solar Power GmbH under low intensity low unusable for deep space missions. Fig. 1: Example of a flat spot effect present in a triple- junction solar

    7. DESIGN APPROACHES AND MATERIALS PROCESSES FOR ULTRAHIGH EFFICIENCY LATTICE MISMATCHED MULTI-JUNCTION SOLAR CELLS

      E-Print Network [OSTI]

      Atwater, Harry

      of the minority carrier lifetime. INTRODUCTION High efficiency triple junction solar cells have recently been heterostructures grown in a multi-junction solar cell-like structure by MOCVD. Initial solar cell data are also of the materials used in multi-junction solar cells must be optimized to efficiently absorb as much of the solar

    8. LOSS ANALYSIS OF BACK-CONTACT BACK-JUNCTION THIN-FILM MONOCRYSTALLINE SILICON SOLAR CELLS

      E-Print Network [OSTI]

      LOSS ANALYSIS OF BACK-CONTACT BACK-JUNCTION THIN-FILM MONOCRYSTALLINE SILICON SOLAR CELLS F. Haase losses in back-contact back- junction monocrystalline thin-film silicon solar cells. The cells are made for back-contact back- junction (BC BJ) monocrystalline thin-film silicon solar cells using the PSI process

    9. Nanowire-Based Molecular Monolayer Junctions: Synthesis, Assembly, and Electrical Characterization

      E-Print Network [OSTI]

      (phenylene vinylene) (OPV) were prepared by replicating the pores of sub-40 nm diameter polycarbonate track etched that the conductance of junctions formed with -conjugated oligomers are several orders of magnitude larger than the saturated alkanes, with the OPV junctions having the highest conductance. The molecular wire junction

    10. Mechanical tugging force regulates the size of cellcell junctions

      E-Print Network [OSTI]

      Chen, Christopher S.

      Mechanical tugging force regulates the size of cell­cell junctions Zhijun Liua,1 , John L. Tanb,1 through the generation of mechanical forces at sites of cell­matrix and cell­cell contact. While increased mechanical load- ing at cell­matrix adhesions results in focal adhesion growth, whether forces drive changes

    11. ALTERNATIVE MATERIALS FOR RAMP-EDGE SNS JUNCTIONS

      SciTech Connect (OSTI)

      Jia, Q.; Fan, Y.

      1999-06-01

      We report on the processing optimization and fabrication of ramp-edge high-temperature superconducting junctions by using alternative materials for both superconductor electrodes and normal-metal barrier. By using Ag-doped YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} (Ag:YBCO) as electrodes and a cation-modified compound of (Pr{sub y}Gd{sub 0.6{minus}y})Ca{sub 0.4}Ba{sub 1.6}La{sub 0.4}Cu{sub 3}O{sub 7} (y = 0.4, 0.5, and 0.6) as a normal-metal barrier, high-temperature superconducting Josephson junctions have been fabricated in a ramp-edge superconductor/normal-metal/superconductor (SNS) configuration. By using Ag:YBCO as electrodes, we have found that the processing controllability /reproducibility and the stability of the SNS junctions are improved substantially. The junctions fabricated with these alternative materials show well-defined RSJ-like current vs voltage characteristics at liquid nitrogen temperature.

    12. Back-contacted back-junction silicon solar cells

      E-Print Network [OSTI]

      Johansen, Tom Henning

      electricity from BC-BJ silicon solar cells cost-competitive with electBack-contacted back-junction silicon solar cells Krister Mangersnes THESIS submitted in partial nearly four years as a Ph.D. student at the Institute for Energy Technology (IFE), Department of Solar

    13. Performance model assessment for multi-junction concentrating photovoltaic systems.

      SciTech Connect (OSTI)

      Riley, Daniel M.; McConnell, Robert.; Sahm, Aaron; Crawford, Clark; King, David L.; Cameron, Christopher P.; Foresi, James S.

      2010-03-01

      Four approaches to modeling multi-junction concentrating photovoltaic system performance are assessed by comparing modeled performance to measured performance. Measured weather, irradiance, and system performance data were collected on two systems over a one month period. Residual analysis is used to assess the models and to identify opportunities for model improvement.

    14. PARAMETRIC EXCITATION OF PLASMA OSCILLATIONS IN JOSEPHSON JUNCTIONS

      E-Print Network [OSTI]

      Boyer, Edmond

      b. ' FIG. 3. - (a) 03B1c tan çoo vs. 2/Q at co = 2 cop. Straight line : theory. Circles : analog harmonic generation with big amplitude may be understood from a discussion of the stability properties frequency FIG. 1. - The junction model. For the analog R = 500 il, Io = 1 mA, C = 100 nF, and k = « 2 e

    15. Gap junction-mediated electrical transmission: Regulatory mechanisms and plasticity

      E-Print Network [OSTI]

      Rash, John E.

      Gap junction-mediated electrical transmission: Regulatory mechanisms and plasticity Alberto E of synaptic transmission: chemical and electrical. While most efforts have been dedicated to the understanding in revised form 16 May 2012 Accepted 23 May 2012 Available online 31 May 2012 Keywords: Electrical synapse

    16. Photo-Thermoelectric Effect at a Graphene Interface Junction

      E-Print Network [OSTI]

      McEuen, Paul L.

      Photo-Thermoelectric Effect at a Graphene Interface Junction Xiaodong Xu, Nathaniel M. Gabor increase at the cryogenic temperature as compared to room temperature. Assuming the thermoelectric power predictions. KEYWORDS Graphene, photocurrent, photo-thermoelectric effect D evices that convert photons

    17. Numerical simulations of output pulse extraction from a high-power microwave compressor with a plasma switch

      SciTech Connect (OSTI)

      Shlapakovski, Anatoli; Beilin, Leonid; Bliokh, Yuri; Donskoy, Moshe; Krasik, Yakov E. [Physics Department, Technion, Haifa 32000 (Israel); Hadas, Yoav [Department of Applied Physics, Rafael, PO Box 2250, Haifa 31021 (Israel); Schamiloglu, Edl [Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, New Mexico 87131 (United States)

      2014-05-07

      Numerical simulations of the process of electromagnetic energy release from a high-power microwave pulse compressor comprising a gas-filled cavity and interference switch were carried out. A microwave plasma discharge in a rectangular waveguide H-plane tee was modeled with the use of the fully electromagnetic particle-in-cell code MAGIC. The gas ionization, plasma evolution, and interaction with RF fields accumulated within the compressor were simulated using different approaches provided by the MAGIC code: particle-in-cell approach accounting for electron-neutral collisions, gas conductivity model based on the concept of mobility, and hybrid modeling. The dependences of the microwave output pulse peak power and waveform on parameters that can be controlled in experiments, such as an external ionization rate, RF field amplitude, and background gas pressure, were investigated.

    18. Dynamic Optimization in Gas Pipeline Networks EWO MEETING, Spring 2012

      E-Print Network [OSTI]

      Grossmann, Ignacio E.

      , consumers and compressor stations Compressor Stations Processing Plants Customers 3 Suppliers: Continuous flow of gas into network. Customers: Chemical industries, Power plants, Residential/commercial heating: Flow demands must be satisfied at a contract pressure. Compressor Stations: Compression of gas

    19. Hydrogen refueling station costs in Shanghai

      E-Print Network [OSTI]

      Weinert, Jonathan X.; Shaojun, Liu; Ogden, Joan M; Jianxin, Ma

      2007-01-01

      station and equipment costs Capital equipment costs Non-a function of capital cost and is therefore represented intechnology and therefore capital cost and maintenance cost

    20. Reference Designs for Hydrogen Fueling Stations

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

      and piping & instrumentation diagrams * Ancillary Results - Near-term FCEV rollout scenario analysis year-by-year - Near-term hydrogen station rollout analysis year-by-year...

    1. Illinois Nuclear Profile - Byron Generating Station

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

      Byron Generating Station" ,"Summer capacity (mw)","Net generation (thousand mwh)","Summer capacity factor (percent)","Type","Commercial operation date","License expiration date"...

    2. Illinois Nuclear Profile - Dresden Generating Station

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

      Dresden Generating Station" "Unit","Summer capacity (mw)","Net generation (thousand mwh)","Summer capacity factor (percent)","Type","Commercial operation date","License expiration...

    3. Illinois Nuclear Profile - Braidwood Generation Station

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

      Braidwood Generation Station" "Unit","Summer capacity (mw)","Net generation (thousand mwh)","Summer capacity factor (percent)","Type","Commercial operation date","License...

    4. Kansas Nuclear Profile - Wolf Creek Generating Station

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

      April 2012" "Next Release Date: February 2013" "Wolf Creek Generating Station" "Unit","Summer capacity (mw)","Net generation (thousand mwh)","Summer capacity factor...

    5. Illinois Nuclear Profile - Clinton Power Station

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

      Clinton Power Station" "Unit","Summer capacity (mw)","Net generation (thousand mwh)","Summer capacity factor (percent)","Type","Commercial operation date","License expiration date"...

    6. Washington Nuclear Profile - Columbia Generating Station

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

      Columbia Generating Station" "Unit","Summer capacity (mw)","Net generation (thousand mwh)","Summer capacity factor (percent)","Type","Commercial operation date","License expiration...

    7. Massachusetts Nuclear Profile - Pilgrim Nuclear Power Station

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

      Pilgrim Nuclear Power Station" "Unit","Summer capacity (mw)","Net generation (thousand mwh)","Summer cpacity factor (percent)","Type","Commercial operation date","License...

    8. Hydrogen Refueling Station Costs in Shanghai

      E-Print Network [OSTI]

      Weinert, Jonathan X.; Shaojun, Liu; Ogden, J; Jianxin, Ma

      2006-01-01

      production equipment (e.g. electrolyzer, steam reformer) (iffeedstock costs differences. Electrolyzer stations yield theuses an alkaline electrolyzer powered by grid electricity to

    9. Hydrogen refueling station costs in Shanghai

      E-Print Network [OSTI]

      Weinert, Jonathan X.; Shaojun, Liu; Ogden, Joan M; Jianxin, Ma

      2007-01-01

      production equipment (e.g. electrolyzer, steam reformer) (iffeedstock costs differences. Electrolyzer stations yield theuses an alkaline electrolyzer powered by grid electricity to

    10. Hydrogen Fueling Infrastructure Research and Station Technology...

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

      An Overview of the Hydrogen Fueling Infrastructure Research and Station Technology (H2FIRST) Project" held on November 18, 2014. Hydrogen Fueling Infrastructure Research and...

    11. Station Footprint: Separation Distances, Storage Options, and...

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

      & Publications Light Duty Fuel Cell Electric Vehicle Hydrogen Fueling Protocol H2FIRST Reference Station Design Task: Project Deliverable 2-2 On-Board Storage Systems Analysis...

    12. NREL Dedicates Advanced Hydrogen Fueling Station | Community...

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

      NREL Dedicates Advanced Hydrogen Fueling Station Ceremony Coincides With National Hydrogen and Fuel Cell Day October 8, 2015 The Energy Department's National Renewable Energy...

    13. Reference Designs for Hydrogen Fueling Stations Webinar

      Broader source: Energy.gov [DOE]

      Access the recording and download the presentation slides from the Fuel Cell Technologies Office webinar "Reference Designs for Hydrogen Fueling Stations" held on October 13, 2015.

    14. Reliability Design and Case Study of a Refrigerator Compressor Subjected to Repetitive Loads, International Journal of Refrigeration 

      E-Print Network [OSTI]

      Woo, S.; O'Neal, D.L.; Pecht, M.

      2009-01-01

      Control Parameters C1: Compressor specifications C2: Condenser specifications C3: Capillary specifications C4: Evaporator specifications Fig. 2 – Parameter diagram of refrigeration cycle.To introduce the Bx life, the characteristic life in the Weibull... ofcharacteristic life in Eq. (4). When the number of failed samples is below four, it follows the Poisson distribution (Ryu and Chang, 2005). At a sixty-percent confidence level, the characteristic life is defined as on refrigeration cycle.cycles and the number...

    15. Rocky Mountain Research Station Publishing Services Categories of Serial Station Publications

      E-Print Network [OSTI]

      Rocky Mountain Research Station ­ Publishing Services Categories of Serial Station Publications forestry public Information of a technical nature, but not necessarily an original report. Computer (Proc.) Forestry technicians/ practitioners, landowners, homeowners, general public Compilation

    16. Atomically wired molecular junctions: Connecting a single organic molecule by chains of metal atoms

      E-Print Network [OSTI]

      Yelin, Tamar; Kuritz, Natalia; Korytár, Richard; Bagrets, Alexei; Evers, Ferdinand; Kronik, Leeor; Tal, Oren

      2015-01-01

      Using a break junction technique, we find a clear signature for the formation of conducting hybrid junctions composed of a single organic molecule (benzene, naphthalene or anthracene) connected to chains of platinum atoms. The hybrid junctions exhibit metallic-like conductance (~0.1-1G0), which is rather insensitive to further elongation by additional atoms. At low bias voltage the hybrid junctions can be elongated significantly beyond the length of the bare atomic chains. Ab initio calculations reveal that benzene based hybrid junctions have a significant binding energy and high structural flexibility that may contribute to the survival of the hybrid junction during the elongation process. The fabrication of hybrid junctions opens the way for combining the different properties of atomic chains and organic molecules to realize a new class of atomic scale interfaces.

    17. Geotechnical Engineering at the Waterways Experiment Station

      E-Print Network [OSTI]

      motions, advanced methods of site characterization, liquefaction po tentia l of fine-grained and gra vellyGEOSPEC Geotechnical Engineering at the Waterways Experiment Station The Geotechnical Laboratory at the U.S. Army Engineer Waterways Experi ment Station (WES) was founded in 1932 and currently

    18. Station GPS permanente IPG Paris DGF Uchile

      E-Print Network [OSTI]

      Vigny, Christophe

      and autonomous energy (battery and solar panel). HISTORIC Semi-permanent GPS station installed since 08­DEC- 2007.08295 - 68.92680 DESCRIPTION North Chile II region, semipermanent GPS station from IPGP / DGF network telephone nearby NONO Electric power nearby NONO equipment storage available YESYES possibility of leaving

    19. FERROELECTRIC SWITCH FOR A HIGH-POWER Ka-BAND ACTIVE PULSE COMPRESSOR

      SciTech Connect (OSTI)

      Hirshfield, Jay L.

      2013-12-18

      Results are presented for design of a high-power microwave switch for operation at 34.3 GHz, intended for use in an active RF pulse compressor. The active element in the switch is a ring of ferroelectric material, whose dielectric constant can be rapidly changed by application of a high-voltage pulse. As envisioned, two of these switches would be built into a pair of delay lines, as in SLED-II at SLAC, so as to allow 30-MW ?s-length Ka-band pulses to be compressed in time by a factor-of-9 and multiplied in amplitude to generate 200 MW peak power pulses. Such high-power pulses could be used for testing and evaluation of high-gradient mm-wave accelerator structures, for example. Evaluation of the switch design was carried out with an X-band (11.43 GHz) prototype, built to incorporate all the features required for the Ka-band version.

    20. Formation of the compression zone in a plasma flow generated by a magnetoplasma compressor

      SciTech Connect (OSTI)

      Solyakov, D. G. Petrov, Yu. V.; Garkusha, I. E.; Chebotarev, V. V.; Ladygina, M. S.; Cherednichenko, T. N.; Morgal’, Ya. I.; Kulik, N. V.; Stal’tsov, V. V.; Eliseev, D. V.

      2013-12-15

      Processes occurring in a plasma flow generated by a magnetoplasma compressor (MPC) during the formation of the compression zone are discussed. The paper presents results of measurements of the spatial distribution of the electric current in the plasma flow, the temporal and spatial (along the flow) distributions of the plasma density, and the profiles of the velocity of individual flow layers along the system axis. The spatial distribution of the electromagnetic force in the flow is analyzed. It is shown that the plasma flow is decelerated when approaching the compression zone and reaccelerated after passing it. In this case, the plasma flow velocity decreases from ? = (2–3) × 10{sup 7} cm/s at the MPC output to ? < 10{sup 6} cm/s in the region of maximum compression and then again increases to 10{sup 7} cm/s at a distance of 15–17 cm from the MPC output. In some MPC operating modes, a displacement of the magnetic field from the compression zone and the formation of toroidal electric current vortices in the plasma flow after passing the compression zone were detected.

    1. Aerodynamically induced radial forces in a centrifugal gas compressor: Part 2 -- Computational investigation

      SciTech Connect (OSTI)

      Flathers, M.B.; Bache, G.E.

      1999-10-01

      Radial loads and direction of a centrifugal gas compressor containing a high specific speed mixed flow impeller and a single tongue volute were determined both experimentally and computationally at both design and off-design conditions. The experimental methodology was developed in conjunction with a traditional ASME PTC-10 closed-loop test to determine radial load and direction. The experimental study is detailed in Part 1 of this paper (Moore and Flathers, 1998). The computational method employs a commercially available, fully three-dimensional viscous code to analyze the impeller and the volute interaction. An uncoupled scheme was initially used where the impeller and volute were analyzed as separate models using a common vaneless diffuser geometry. The two calculations were then repeated until the boundary conditions at a chosen location in the common vaneless diffuser were nearly the same. Subsequently, a coupled scheme was used where the entire stage geometry was analyzed in one calculation, thus eliminating the need for manual iteration of the two independent calculations. In addition to radial load and direction information, this computational procedure also provided aerodynamic stage performance. The effect of impeller front face and rear face cavities was also quantified. The paper will discuss computational procedures, including grid generation and boundary conditions, as well as comparisons of the various computational schemes to experiment. The results of this study will show the limitations and benefits of Computational Fluid Dynamics (CFD) for determination of radial load, direction, and aerodynamic stage performance.

    2. MHD compressor---expander conversion system integrated with GCR inside a deployable reflector

      SciTech Connect (OSTI)

      Tuninetti, G. . Research Div.); Botta, E.; Criscuolo, C.; Riscossa, P. . Nuclear Div.); Giammanco, F. . Dipt. di Fisica); Rosa-Clot, M. . Dipt. di Fisica)

      1989-04-20

      This work originates from the proposal MHD Compressor-Expander Conversion System Integrated with a GCR Inside a Deployable Reflector''. The proposal concerned an innovative concept of nuclear, closed-cycle MHD converter for power generation on space-based systems in the multi-megawatt range. The basic element of this converter is the Power Conversion Unit (PCU) consisting of a gas core reactor directly coupled to an MHD expansion channel. Integrated with the PCU, a deployable reflector provides reactivity control. The working fluid could be either uranium hexafluoride or a mixture of uranium hexafluoride and helium, added to enhance the heat transfer properties. The original Statement of Work, which concerned the whole conversion system, was subsequently redirected and focused on the basic mechanisms of neutronics, reactivity control, ionization and electrical conductivity in the PCU. Furthermore, the study was required to be inherently generic such that the study was required to be inherently generic such that the analysis an results can be applied to various nuclear reactor and/or MHD channel designs''.

    3. Multi-bottle, no compressor, mean pressure control system for a Stirling engine

      SciTech Connect (OSTI)

      Corey, John A.

      1990-01-01

      The invention relates to an apparatus for mean pressure control of a Stirling engine without the need for a compressor. The invention includes a multi-tank system in which there is at least one high pressure level tank and one low pressure level tank wherein gas flows through a maximum pressure and supply line from the engine to the high pressure tank when a first valve is opened until the maximum pressure of the engine drops below that of the high pressure tank opening an inlet regulator to permit gas flow from the engine to the low pressure tank. When gas flows toward the engine it flows through the minimum pressure supply line 2 when a second valve is opened from the low pressure tank until the tank reaches the engine's minimum pressure level at which time the outlet regulator opens permitting gas to be supplied from the high pressure tank to the engine. Check valves between the two tanks prevent any backflow of gas from occurring.

    4. Fluid handling device useful as a pump, compressor or rotary engine

      SciTech Connect (OSTI)

      Whitfield, R.R.

      1986-12-23

      This patent describes a fluid handling device having variable volume chambers for use as a pump, compressor or rotary engine which comprises: a. a first rotary shaft member supported by bearings and carrying variable volume chamber forming components having at least a pair of angularly disposed flat surfaces and a curvilinear shell portion, b. a second rotary shaft member supported by bearings and carrying variable volume chamber forming components having at least a pair of angularly disposed flat surfaces and a curvilinear shell portion, (1) the shaft members being disposed at an angle other than 180/sup 0/ to one another, c. a centrally disposed disk member forming a plurality of variable volume chambers with the flat surfaces of the variable volume chamber forming components, (1) the centrally disposed disk member carrying a curvilinear shell member engageable in sealing relationship with the curvilinear shell portions of each of the variable volume chamber forming components, (2) and the centrally disposed disk member being journalled within bearings carried by a pair of yoke members externally of the curvilinear shell member carried by the disk member and with one of the yoke members being displaced 90/sup 0/ with respect to the other yoke member, (3) one of the yoke members being attached to the first rotary shaft member and the other of the yoke members being attached to the second rotary shaft member.

    5. Topological p-n junctions in helical edge states

      E-Print Network [OSTI]

      Disha Wadhawan; Poonam Mehta; Sourin Das

      2015-10-08

      Quantum spin Hall effect is endowed with topologically protected edge modes with gapless Dirac spectrum. Applying a magnetic field locally along the edge leads to a gapped edge spectrum with opposite parity for winding of spin texture for conduction and valence band. Using Pancharatnam's prescription for geometric phase it is shown that mismatch of this parity across a $p$-$n$ junction, which could be engineered into the edge by electrical gate induced doping, leads to a phase dependence in the two-terminal conductance which is purely topological (0 or $\\pi$). This fact results in a ${\\mathbb{Z}}_2$ classification of such junctions with an associated duality. Current asymmetry measurements which are shown to be robust against electron-electron interactions are proposed to infer this topology.

    6. Origin of subgap current in an SIS junction

      SciTech Connect (OSTI)

      Suzuki, Toyoaki; Noguchi, Takashi; Matsuo, Hiroshi [National Institutes of Natural Sciences/National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo, 181-8588 (Japan)

      2009-12-16

      According to the BCS theory, the subgap current in an SIS junction is reduced exponentially as the temperature decreases. However, experimentally, the reduction is saturated below a certain temperature. This phenomenon was a bottleneck in the development of sensitive SIS photon detectors with NEP of 10{sup -19} W/{radical}(Hz) at 650 GHz, because the NEP is limited by the shot noise in the subgap current. To investigate the origin of the residual subgap current under various temperatures we have measured I-V curves of a Nb/Al-AlN/Nb junction. Obtained I-V curves have been reproduced by a model: single-and two-particle tunneling under reduced quasiparticle lifetime. Our result suggests that increasing the lifetime is essential to reduce the subgap current. One of possible methods to increase the lifetime is to form an epitaxial Nb film.

    7. Towards understanding junction degradation in cadmium telluride solar cells

      SciTech Connect (OSTI)

      Nardone, Marco

      2014-06-21

      A degradation mechanism in cadmium telluride (CdTe/CdS) solar cells is investigated using time-dependent numerical modeling to simulate various temperature, bias, and illumination stress conditions. The physical mechanism is based on defect generation rates that are proportional to nonequilibrium charge carrier concentrations. It is found that a commonly observed degradation mode for CdTe/CdS solar cells can be reproduced only if defects are allowed to form in a narrow region of the absorber layer close to the CdTe/CdS junction. A key aspect of this junction degradation is that both mid-gap donor and shallow acceptor-type defects must be generated simultaneously in response to photo-excitation or applied bias. The numerical approach employed here can be extended to study other mechanisms for any photovoltaic technology.

    8. Strain designed Josephson $?$ junction qubits with topological insulators

      E-Print Network [OSTI]

      Colin Benjamin

      2015-06-23

      A Josephson qubit is designed via the application of a tensile strain to a topological insulator surface sandwiched between two s-wave superconductors. The strain applied leads to a shift in the Dirac point without changing the pre-existing conducting states, on the surface of a topological insulator. Strain applied can be tuned to form a $\\pi$ junction in such a structure. Combining two such junctions in a ring architecture leads to the ground state of the ring being in doubly degenerate state- the "0" and "1" states of a qubit. A qubit designed this way is quite easily controlled via the tunable strain applied. We report on the conditions necessary to design such a qubit. Finally the operating time of a single qubit phase gate is derived.

    9. Grain boundary and triple junction diffusion in nanocrystalline copper

      SciTech Connect (OSTI)

      Wegner, M. Leuthold, J.; Peterlechner, M.; Divinski, S. V.; Song, X.; Wilde, G.

      2014-09-07

      Grain boundary and triple junction diffusion in nanocrystalline Cu samples with grain sizes, ?d?, of ?35 and ?44?nm produced by spark plasma sintering were investigated by the radiotracer method using the {sup 63}Ni isotope. The measured diffusivities, D{sub eff}, are comparable with those determined previously for Ni grain boundary diffusion in well-annealed, high purity, coarse grained, polycrystalline copper, substantiating the absence of a grain size effect on the kinetic properties of grain boundaries in a nanocrystalline material at grain sizes d???35?nm. Simultaneously, the analysis predicts that if triple junction diffusion of Ni in Cu is enhanced with respect to the corresponding grain boundary diffusion rate, it is still less than 500?D{sub gb} within the temperature interval from 420?K to 470?K.

    10. Junction Transport in Epitaxial Film Silicon Heterojunction Solar Cells

      SciTech Connect (OSTI)

      Young, D. L.; Li, J. V.; Teplin, C. W.; Stradins, P.; Branz, H. M.

      2011-01-01

      We report our progress toward low-temperature HWCVD epitaxial film silicon solar cells on inexpensive seed layers, with a focus on the junction transport physics exhibited by our devices. Heterojunctions of i/p hydrogenated amorphous Si (a-Si) on our n-type epitaxial crystal Si on n{sup ++} Si wafers show space-charge-region recombination, tunneling or diffusive transport depending on both epitaxial Si quality and the applied forward voltage.

    11. Junction Transport in Epitaxial Film Silicon Heterojunction Solar Cells: Preprint

      SciTech Connect (OSTI)

      Young, D. L.; Li, J. V.; Teplin, C. W.; Stradins, P.; Branz, H. M.

      2011-07-01

      We report our progress toward low-temperature HWCVD epitaxial film silicon solar cells on inexpensive seed layers, with a focus on the junction transport physics exhibited by our devices. Heterojunctions of i/p hydrogenated amorphous Si (a-Si) on our n-type epitaxial crystal Si on n++ Si wafers show space-charge-region recombination, tunneling or diffusive transport depending on both epitaxial Si quality and the applied forward voltage.

    12. High speed imager test station

      DOE Patents [OSTI]

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

      1995-11-14

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

    13. High speed imager test station

      DOE Patents [OSTI]

      Yates, George J. (Santa Fe, NM); Albright, Kevin L. (Los Alamos, NM); Turko, Bojan T. (Moraga, CA)

      1995-01-01

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

    14. Burner balancing Salem Harbor Station

      SciTech Connect (OSTI)

      Sload, A.W.; Dube, R.J.

      1995-12-31

      The traditional method of burner balancing is first to determine the fuel distribution, then to measure the economizer outlet excess oxygen distribution and to adjust the burners accordingly. Fuel distribution is typically measured by clean and dirty air probing. Coal pipe flow can then be adjusted, if necessary, through the use of coal pipe orificing or by other means. Primary air flow must be adjusted to meet the design criteria of the burner. Once coal pipe flow is balanced to within the desired criteria, secondary air flow to individual burners can be changed by adjusting windbox dampers, burner registers, shrouds or other devices in the secondary air stream. This paper discusses problems encountered in measuring excess O{sub 2} at the economizer outlet. It is important to recognize that O{sub 2} measurements at the economizer outlet, by themselves, can be very misleading. If measurement problems are suspected or encountered, an alternate approach similar to that described should be considered. The alternate method is not only useful for burner balancing but also can be used to help in calibrating the plant excess O{sub 2} instruments and provide an on line means of cross-checking excess air measurements. Balanced burners operate closer to their design stoichiometry, providing better NO{sub x} reduction. For Salem Harbor Station, this means a significant saving in urea consumption.

    15. Joint measurement of current-phase relations and transport properties of hybrid junctions using a three junctions superconducting quantum interference device

      SciTech Connect (OSTI)

      Basset, J.; Delagrange, R.; Weil, R.; Kasumov, A.; Bouchiat, H.; Deblock, R.

      2014-07-14

      We propose a scheme to measure both the current-phase relation and differential conductance dI/dV of a superconducting junction, in the normal and the superconducting states. This is done using a dc Superconducting Quantum Interference Device with two Josephson junctions in parallel with the device under investigation and three contacts. As a demonstration, we measure the current-phase relation and dI/dV of a small Josephson junction and a carbon nanotube junction. In this latter case, in a regime where the nanotube is well conducting, we show that the non-sinusoidal current phase relation we find is consistent with the theory for a weak link, using the transmission extracted from the differential conductance in the normal state. This method holds great promise for future investigations of the current-phase relation of more exotic junctions.

    16. Environmental assessment of facility operations at the U.S. Department of Energy Grand Junction Projects Office, Grand Junction, Colorado

      SciTech Connect (OSTI)

      1996-06-01

      The US Department of Energy (DOE) has prepared a sitewide environmental assessment (EA) of the proposed action to continue and expand present-day activities on the DOE Grand Junction Projects Office (GJPO) facility in Grand Junction, Colorado. Because DOE-GJPO regularly proposes and conducts many different on-site activities, DOE decided to evaluate these activities in one sitewide EA rather than in multiple, activity-specific documents. On the basis of the information and analyses presented in the EA, DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment, as defined by the National Environmental Policy Act (NEPA) of 1969. Therefore, preparation of an environmental impact statement is not required for facility operations, and DOE is issuing this Finding of No Significant Impact (FONSI).

    17. Model based multivariable controller for large scale compression stations. Design and experimental validation on the LHC 18KW cryorefrigerator

      SciTech Connect (OSTI)

      Bonne, François; Bonnay, Patrick [INAC, SBT, UMR-E 9004 CEA/UJF-Grenoble, 17 rue des Martyrs, 38054 Grenoble (France); Alamir, Mazen [Gipsa-Lab, Control Systems Department, CNRS-University of Grenoble, 11, rue des Mathématiques, BP 46, 38402 Saint Martin d'Hères (France); Bradu, Benjamin [CERN, CH-1211 Genève 23 (Switzerland)

      2014-01-29

      In this paper, a multivariable model-based non-linear controller for Warm Compression Stations (WCS) is proposed. The strategy is to replace all the PID loops controlling the WCS with an optimally designed model-based multivariable loop. This new strategy leads to high stability and fast disturbance rejection such as those induced by a turbine or a compressor stop, a key-aspect in the case of large scale cryogenic refrigeration. The proposed control scheme can be used to have precise control of every pressure in normal operation or to stabilize and control the cryoplant under high variation of thermal loads (such as a pulsed heat load expected to take place in future fusion reactors such as those expected in the cryogenic cooling systems of the International Thermonuclear Experimental Reactor ITER or the Japan Torus-60 Super Advanced fusion experiment JT-60SA). The paper details how to set the WCS model up to synthesize the Linear Quadratic Optimal feedback gain and how to use it. After preliminary tuning at CEA-Grenoble on the 400W@1.8K helium test facility, the controller has been implemented on a Schneider PLC and fully tested first on the CERN's real-time simulator. Then, it was experimentally validated on a real CERN cryoplant. The efficiency of the solution is experimentally assessed using a reasonable operating scenario of start and stop of compressors and cryogenic turbines. This work is partially supported through the European Fusion Development Agreement (EFDA) Goal Oriented Training Program, task agreement WP10-GOT-GIRO.

    18. Process for direct integration of a thin-film silicon p-n junction diode with a magnetic tunnel junction

      DOE Patents [OSTI]

      Toet, Daniel; Sigmon, Thomas W.

      2004-12-07

      A process for direct integration of a thin-film silicon p-n junction diode with a magnetic tunnel junction for use in advanced magnetic random access memory (MRAM) cells for high performance, non-volatile memory arrays. The process is based on pulsed laser processing for the fabrication of vertical polycrystalline silicon electronic device structures, in particular p-n junction diodes, on films of metals deposited onto low temperature-substrates such as ceramics, dielectrics, glass, or polymers. The process preserves underlayers and structures onto which the devices are typically deposited, such as silicon integrated circuits. The process involves the low temperature deposition of at least one layer of silicon, either in an amorphous or a polycrystalline phase on a metal layer. Dopants may be introduced in the silicon film during or after deposition. The film is then irradiated with short pulse laser energy that is efficiently absorbed in the silicon, which results in the crystallization of the film and simultaneously in the activation of the dopants via ultrafast melting and solidification. The silicon film can be patterned either before or after crystallization.

    19. Process for direct integration of a thin-film silicon p-n junction diode with a magnetic tunnel junction

      DOE Patents [OSTI]

      Toet, Daniel (Mountain View, CA); Sigmon, Thomas W. (Albuquerque, NM)

      2003-01-01

      A process for direct integration of a thin-film silicon p-n junction diode with a magnetic tunnel junction for use in advanced magnetic random access memory (MRAM) cells for high performance, non-volatile memory arrays. The process is based on pulsed laser processing for the fabrication of vertical polycrystalline silicon electronic device structures, in particular p-n junction diodes, on films of metals deposited onto low temperature-substrates such as ceramics, dielectrics, glass, or polymers. The process preserves underlayers and structures onto which the devices are typically deposited, such as silicon integrated circuits. The process involves the low temperature deposition of at least one layer of silicon, either in an amorphous or a polycrystalline phase on a metal layer. Dopants may be introduced in the silicon film during or after deposition. The film is then irradiated with short pulse laser energy that is efficiently absorbed in the silicon, which results in the crystallization of the film and simultaneously in the activation of the dopants via ultrafast melting and solidification. The silicon film can be patterned either before or after crystallization.

    20. Process For Direct Integration Of A Thin-Film Silicon P-N Junction Diode With A Magnetic Tunnel Junction

      DOE Patents [OSTI]

      Toet, Daniel (Mountain View, CA); Sigmon, Thomas W. (Albuquerque, NM)

      2005-08-23

      A process for direct integration of a thin-film silicon p-n junction diode with a magnetic tunnel junction for use in advanced magnetic random access memory (MRAM) cells for high performance, non-volatile memory arrays. The process is based on pulsed laser processing for the fabrication of vertical polycrystalline silicon electronic device structures, in particular p-n junction diodes, on films of metals deposited onto low temperature-substrates such as ceramics, dielectrics, glass, or polymers. The process preserves underlayers and structures onto which the devices are typically deposited, such as silicon integrated circuits. The process involves the low temperature deposition of at least one layer of silicon, either in an amorphous or a polycrystalline phase on a metal layer. Dopants may be introduced in the silicon film during or after deposition. The film is then irradiated with short pulse laser energy that is efficiently absorbed in the silicon, which results in the crystallization of the film and simultaneously in the activation of the dopants via ultrafast melting and solidification. The silicon film can be patterned either before or after crystallization.

    1. Evaluation of static mixer flow enhancements for cryogenic viscous compressor prototype for ITER vacuum system

      SciTech Connect (OSTI)

      Duckworth, Robert C.; Baylor, Larry R.; Meitner, Steven J.; Combs, Stephen K.; Ha, Tam; Morrow, Michael; Biewer, T. [Fusion and Materials for Nuclear System Division, Oak Ridge National Laboratory, Oak Ridge (United States); Rasmussen, David A.; Hechler, Michael P. [U.S. ITER Project Office, Oak Ridge National Laboratory, Oak Ridge (United States); Pearce, Robert J. H.; Dremel, Mattias [ITER Organization, 13115 St. Paul-lez-Durance (France); Boissin, J.-C. [Consultant, Grenoble (France)

      2014-01-29

      As part of the U.S. ITER contribution to the vacuum systems for the ITER fusion project, a cryogenic viscous compressor (CVC) is being designed and fabricated to cryopump hydrogenic gases in the torus and neutral beam exhaust streams and to regenerate the collected gases to controlled pressures such that they can be mechanically pumped with controlled flows to the tritium reprocessing facility. One critical element of the CVC design that required additional investigation was the determination of flow rates of the low pressure (up to 1000 Pa) exhaust stream that would allow for complete pumping of hydrogenic gases while permitting trace levels of helium to pass through the CVC to be pumped by conventional vacuum pumps. A sub-scale prototype test facility was utilized to determine the effectiveness of a static mixer pump tube concept, which consisted of a series of rotated twisted elements brazed into a 2-mm thick, 5-cm diameter stainless steel tube. Cold helium gas flow provided by a dewar and helium transfer line was used to cool the exterior of the static mixer pump tube. Deuterium gas was mixed with helium gas through flow controllers at different concentrations while the composition of the exhaust gas was monitored with a Penning gauge and optical spectrometer to determine the effectiveness of the static mixer. It was found that with tube wall temperatures between 6 K and 9 K, the deuterium gas was completely cryopumped and only helium passed through the tube. These results have been used to design the cooling geometry and the static mixer pump tubes in the full-scale CVC prototype.

    2. Evaluation of Static Mixer Flow Enhancements for Cryogenic Viscous Compressor Prototype for ITER Vacuum System

      SciTech Connect (OSTI)

      Duckworth, Robert C [ORNL] [ORNL; Baylor, Larry R [ORNL] [ORNL; Meitner, Steven J [ORNL] [ORNL; Combs, Stephen Kirk [ORNL] [ORNL; Ha, Tam T [ORNL] [ORNL; Morrow, Michael [ORNL] [ORNL; Biewer, Theodore M [ORNL] [ORNL; Rasmussen, David A [ORNL] [ORNL; Hechler, Michael P [ORNL] [ORNL; Pearce, R.J.H. [ITER Organization, Cadarache, France] [ITER Organization, Cadarache, France; Dremel, M. [ITER Organization, Cadarache, France] [ITER Organization, Cadarache, France; Boissin, Jean Claude [Consultant] [Consultant

      2014-01-01

      As part of the U.S. ITER contribution to the vacuum systems for the ITER fusion project, a cryogenic viscous compressor (CVC) is being designed and fabricated to cryopump hydrogenic gases in the torus and neutral beam exhaust streams and to regenerate the collected gases to controlled pressures such that they can be mechanically pumped with controlled flows to the tritium reprocessing facility. One critical element of the CVC design that required additional investigation was the determination of flow rates of the low pressure (50 to 1000 Pa) exhaust stream that would allow for complete pumping of hydrogenic gases while permitting trace levels of helium to pass through the CVC to be pumped by conventional vacuum pumps. A sub-scale prototype test facility was utilized to determine the effectiveness of a static mixer pump tube concept, which consisted of a series of rotated twisted elements brazed into a 2-mm thick, 5-cm diameter stainless steel tube. Cold helium gas flow provided by a dewar and helium transfer line was used to cool the exterior of the static mixer pump tube. Deuterium gas was mixed with helium gas through flow controllers at different concentrations while the composition of the exhaust gas was monitored with a Penning gauge and optical spectrometer to determine the effectiveness of the static mixer. It was found that with tube wall temperatures between 6 K and 9 K, the deuterium gas was completely cryopumped and only helium passed through the tube. These results have been used to design the cooling geometry and the static mixer pump tubes in the full-scale CVC prototype

    3. Fuel Station of the Future- Innovative Approach to Fuel Cell...

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

      Station of the Future- Innovative Approach to Fuel Cell Technology Unveiled in California Fuel Station of the Future- Innovative Approach to Fuel Cell Technology Unveiled in...

    4. Trona Injection Tests: Mirant Potomac River Station, Unit 1,...

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

      Trona Injection Tests: Mirant Potomac River Station, Unit 1, November 12 to December 23, 2005, Summary Report Trona Injection Tests: Mirant Potomac River Station, Unit 1, November...

    5. The Status of Renewable Hydrogen and Energy Station Technologies...

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

      The Status of Renewable Hydrogen and Energy Station Technologies and Policy Recommendations The Status of Renewable Hydrogen and Energy Station Technologies and Policy...

    6. Puge County Gongdefang Hydropower Station Investment and Development...

      Open Energy Info (EERE)

      Puge County Gongdefang Hydropower Station Investment and Development Co Ltd Jump to: navigation, search Name: Puge County Gongdefang Hydropower Station Investment and Development...

    7. Hydrogen Fueling Station in Honolulu, Hawaii Feasibility Analysis...

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

      Fueling Station in Honolulu, Hawaii Feasibility Analysis Hydrogen Fueling Station in Honolulu, Hawaii Feasibility Analysis This feasibility report assesses the technical and...

    8. License Amendment Request for Storing Exelon Sister Nuclear Stations...

      Office of Scientific and Technical Information (OSTI)

      License Amendment Request for Storing Exelon Sister Nuclear Stations Class BC LLRW in the LaSalle Station Interim Radwaste Storage Facility - 13620 Citation Details In-Document...

    9. Alternative Fueling Station Locator App Provides Info at Your...

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

      stations that offer electricity, natural gas, biodiesel, E85, propane, or hydrogen. | Energy Department The Alternative Fueling Station Locator iPhone app helps you find...

    10. GaInNAs Junctions for Next-Generation Concentrators: Progress and Prospects

      SciTech Connect (OSTI)

      Friedman, D. J.; Ptak, A. J.; Kurtz, S. R.; Geisz, J. F.; Kiehl, J.

      2005-08-01

      We discuss progress in the development of GaInNAs junctions for application in next-generation multijunction concentrator cells. A significant development is the demonstration of near-100% internal quantum efficiencies in junctions grown by molecular-beam epitaxy. Testing at high currents validates the compatibility of these devices with concentrator operation. The efficiencies of several next-generation multijunction structures incorporating these state-of-the-art GaInNAs junctions are projected.

    11. Hydrogen Refueling Station Costs in Shanghai

      E-Print Network [OSTI]

      Weinert, Jonathan X.; Shaojun, Liu; Ogden, J; Jianxin, Ma

      2006-01-01

      Well-to-wheels analysis of hydrogen based fuel-cell vehicleJP, et al. Distributed Hydrogen Fueling Systems Analysis,”Year 2006 UCD—ITS—RR—06—04 Hydrogen Refueling Station Costs

    12. COMPARATIVE COSTS OF CALIFORNIA CENTRAL STATION ELECTRICITY

      E-Print Network [OSTI]

      CALIFORNIA ENERGY COMMISSION COMPARATIVE COSTS OF CALIFORNIA CENTRAL STATION ELECTRICITY GENERATIONCann Please use the following citation for this report: Klein, Joel. 2009. Comparative Costs of California............................................................................................................................1 Changes in the Cost of Generation Model

    13. Comment on "Analysis of quantum coherent semiconductor quantum dot p-i-n junction photovoltaic cells"

      E-Print Network [OSTI]

      Scully, Marlan O

      2010-01-01

      This is a comment on PRL paper by A.P. Kirk "Analysis of quantum coherent semiconductor quantum dot p-i-n junction photovoltaic cells"

    14. Single-Particle Tunneling in Doped Graphene-Insulator-Graphene Junctions R. M. Feenstra*

      E-Print Network [OSTI]

      Feenstra, Randall

      -insulator-graphene (GIG) tunnel junctions. * feenstra@cmu.edu djena@nd.edu ggu1@utk.edu Published in J. Appl. Phys. 111

    15. SU-E-T-426: Dose Delivery Accuracy in Breast Field Junction for...

      Office of Scientific and Technical Information (OSTI)

      distribution along the field junction in a half beam irradiation technique for breast cancer patients receiving radiation to the breast or chest wall (CW) and the supraclavicular...

    16. (Surveying isolated diesel power stations in Guatemala)

      SciTech Connect (OSTI)

      Waddle, D.B.

      1990-02-26

      I travelled to Guatemala City, Guatemala, to lead a team of specialists to study the operating, administrative, and management efficiency of isolated diesel power plants, operated by Instituto Nacional de Electrificacion (INDE). The study is part of a global initiative managed jointly by the Agency for International Development and the World Bank. The power plants were audited, including INDE's largest isolated diesel station, and two, much smaller municipal and privately owned stations. I returned to Oak Ridge on February 22, 1990.

    17. Wintering Steer Calves at the Spur Station

      E-Print Network [OSTI]

      Jones, J. H.; Fisher, C. E.; Marion, P. T.

      1956-01-01

      at the Spur Station SUMMARY Winter maintenance experiments were conducted with 1,034 steer calves at the Spur station dur. ing the 14-year period from the fall of 1941 to the spring of 1955. Results of these comparative trials, in most instances, were... made approximately the same gain during the winter as heavy calves averaging 466 pounds. Wheat pasture provided the lowest cost of winter maintenance for calves. Sorghum fields and na- tive grass supplemented with cottonseed cake were intermediate...

    18. Solar and Infrared Radiation Station (SIRS) Handbook

      SciTech Connect (OSTI)

      Stoffel, T

      2005-07-01

      The Solar Infrared Radiation Station (SIRS) provides continuous measurements of broadband shortwave (solar) and longwave (atmospheric or infrared) irradiances for downwelling and upwelling components. The following six irradiance measurements are collected from a network of stations to help determine the total radiative flux exchange within the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Climate Research Facility: • Direct normal shortwave (solar beam) • Diffuse horizontal shortwave (sky) • Global horizontal shortwave (total hemispheric) • Upwelling shortwave (reflected) • Downwelling longwave (atmospheric infrared) • Upwelling longwave (surface infrared)

    19. Utilities respond to nuclear station blackout rule

      SciTech Connect (OSTI)

      Rubin, A.M.; Beasley, B.; Tenera, L.P

      1990-02-01

      The authors discuss how nuclear plants in the United States have taken actions to respond to the NRC Station Blackout Rule, 10CFR50.63. The rule requires that each light water cooled nuclear power plant licensed to operate must be able to withstand for a specified duration and recover from a station blackout. Station blackout is defined as the complete loss of a-c power to the essential and non-essential switch-gear buses in a nuclear power plant. A station blackout results from the loss of all off-site power as well as the on-site emergency a-c power system. There are two basic approaches to meeting the station blackout rule. One is to cope with a station blackout independent of a-c power. Coping, as it is called, means the ability of a plant to achieve and maintain a safe shutdown condition. The second approach is to provide an alternate a-c power source (AAC).

    20. Formation of Porous Layers by Electrochemical Etching of Germanium and Gallium Arsenide for Cleave Engineered Layer Transfer (CELT) Application in High Efficiency Multi-Junction Solar Cells

      E-Print Network [OSTI]

      Fong, David Michael

      2012-01-01

      Application in High Efficiency Multi-Junction Solar Cells AApplication in High Efficiency Multi-Junction Solar Cells Bycost of high efficiency multi-junction solar cells through a

    1. Formation of Porous Layers by Electrochemical Etching of Germanium and Gallium Arsenide for Cleave Engineered Layer Transfer (CELT) Application in High Efficiency Multi-Junction Solar Cells

      E-Print Network [OSTI]

      Fong, David Michael

      2012-01-01

      Efficiency Multi-Junction Solar Cells A thesis submitted inHigh Efficiency Multi-Junction Solar Cells By David Michaelsubstrate costs of multi-junction solar cells by recycling

    2. Formation of Porous Layers by Electrochemical Etching of Germanium and Gallium Arsenide for Cleave Engineered Layer Transfer (CELT) Application in High Efficiency Multi-Junction Solar Cells

      E-Print Network [OSTI]

      Fong, David Michael

      2012-01-01

      technique for LM triple junction solar cell grown on porousAnother common triple-junction solar cell utilizes a GaAstechnique for LM triple junction solar cell grown on porous

    3. Dynamics of Josephson junction systems in the computational subspace

      E-Print Network [OSTI]

      Wang Xiang-Bin; Matsumoto Keiji; Fan Heng; Y. Nakamura

      2001-12-05

      The quantum dynamics of the Josephson junction system in the computational subspace is investigated. A scheme for the controlled not operation is given for two capasitively coupled SQUIDs. In this system, there is no systematic error for the two qubit operation. For the inductively coupled SQUIDs, the effective Hamiltonian causes systematic errors in the computational subspace for the two qubit operation. Using the purterbation theory, we construct a more precise effective Hamiltonian. This new effective Hamiltonian reduces the systematic error to the level much lower than the threshold of the fault resilent quantum computation.

    4. Essex Junction, Vermont: Energy Resources | Open Energy Information

      Open Energy Info (EERE)

      AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTIONRobertsdale, AlabamaETEC GmbH JumpEllenville,Power Corp Jump to:SIBRErwin,CompanyVirginia:Junction,

    5. Iron Junction, Minnesota: Energy Resources | Open Energy Information

      Open Energy Info (EERE)

      AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View NewTexas: Energy ResourcesOrder at 8, 13RenewableIrem Geothermal Power PlantUtah:Junction,

    6. Princeton Junction, New Jersey: Energy Resources | Open Energy Information

      Open Energy Info (EERE)

      AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History ViewMayo, Maryland:NPIProtectio1975)Energy Technology JumpWilliam County, Virginia: EnergyJunction,

    7. Pacific Junction, Iowa: Energy Resources | Open Energy Information

      Open Energy Info (EERE)

      AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History ViewMayo, Maryland:NPIProtectio Program | OpenWisconsin:NewOverPPSEnergyFuel Cell CorpJunction,

    8. Grand Junction, Colorado, Processing Site and Disposal Sites Fact Sheet

      Office of Legacy Management (LM)

      AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield Municipal Gas &SCE-SessionsSouthReport for the t-) S/,,5 'a C O M P R E H E N S I551Grand Junction,

    9. Apache Junction, Arizona: Energy Resources | Open Energy Information

      Open Energy Info (EERE)

      AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoop IncIowaWisconsin: EnergyYork Jump| Open EnergyNew Jersey:AntiguaAnyangJunction,

    10. IMPROVEMENT TO PIPELINE COMPRESSOR ENGINE RELIABILITY THROUGH RETROFIT MICRO-PILOT IGNITION SYSTEM-PHASE I

      SciTech Connect (OSTI)

      Ted Bestor

      2003-03-04

      This report documents the first year's effort towards a 3-year program to develop micropilot ignition systems for existing pipeline compressor engines. In essence, all Phase I goals and objectives were met. We intend to proceed with the Phase II research plan, as set forth by the applicable Research Management Plan. The objective for Phase I was to demonstrate the feasibility of micropilot ignition for large bore, slow speed engines operating at low compression ratios. The primary elements of Micropilot Phase I were to develop a single-cylinder test chamber to study the injection of pilot fuel into a combustion cylinder and to develop, install and test a multi-cylinder micropilot ignition system for a 4-cylinder, natural gas test engine. In all, there were twelve (12) tasks defined and executed to support these two (2) primarily elements in a stepwise fashion. Task-specific approaches and results are documented in this report. Research activities for Micropilot Phase I were conducted with the understanding that the efforts are expected to result in a commercial product to capture and disseminate the efficiency and environmental benefits of this new technology. An extensive state-of-art review was conducted to leverage the existing body of knowledge of micropilot ignition with respect to retrofit applications. Additionally, commercially-available fuel injection products were identified and applied to the program where appropriate. This approach will minimize the overall time-to-market requirements, while meeting performance and cost criteria. The four-cylinder prototype data was encouraging for the micro-pilot ignition technology when compared to spark ignition. Initial testing results showed: (1) Brake specific fuel consumption of natural gas was improved from standard spark ignition across the map, 1% at full load and 5% at 70% load. (2) 0% misfires for all points on micropilot ignition. Fuel savings were most likely due to this percent misfire improvement. (3) THC (Total Hydrocarbon) emissions were improved significantly at light load, 38% at 70% load. (4) VOC (Volatile Organic Compounds) emissions were improved above 80% load. (5) Coefficient of Variance for the IMEP (Indicated Mean Effective Pressure) was significantly less at lower loads, 76% less at 70%. These preliminary results will be substantiated and enhanced during Phase II of the Micropilot Ignition program.

    11. Optimal Base Station Density for Power Efficiency in Cellular Networks

      E-Print Network [OSTI]

      Haenggi, Martin

      Optimal Base Station Density for Power Efficiency in Cellular Networks Sanglap Sarkar, Radha, power consumption, power efficiency, optimal base station density. I. INTRODUCTION Cell size reduction by increasing the number of macro base stations or adding tiers of low powered base stations. There are two

    12. Competitive Charging Station Pricing for Plug-in Electric Vehicles

      E-Print Network [OSTI]

      Huang, Jianwei

      Competitive Charging Station Pricing for Plug-in Electric Vehicles Wei Yuan, Member, IEEE, Jianwei considers the problem of charging station pricing and station selection of plug-in electric vehicles (PEVs). Every PEV needs to select a charging station by con- sidering the charging prices, waiting times

    13. Hydrogen Fueling - Coming Soon to a Station Near You (Brochure)

      SciTech Connect (OSTI)

      Not Available

      2009-04-01

      Fact sheet providing information useful to local permitting officials facing hydrogen fueling station proposals.

    14. Station GPS permanente IPG Paris DGF Uchile UNAP Iquique

      E-Print Network [OSTI]

      Vigny, Christophe

      Colocated with seismic station. Pilar constructed in reinforced concrete. Inox 12 cm rod (Delmont type

    15. In this thesis, our goal was to fabricate Josephson junction that can be stably processed at 300C or higher. With the purpose of integrating Josephson junction fabrication with current semiconductor circuit fabrication

      E-Print Network [OSTI]

      /Hf-HfOx/Nb superconductor tunnel Josephson junctions that can be grown or processed at elevated temperatures. Also elevated

    16. Inverted GaInP/(In)GaAs/InGaAs Triple-Junction Solar Cells with Low-Stress Metamorphic Bottom Junctions: Preprint

      SciTech Connect (OSTI)

      Geisz, J. F.; Kurtz, S. R.; Wanlass, M. W.; Ward, J. S.; Duda, A.; Friedman, D. J.; Olson, J. M.; McMahon, W. E.; Moriarty, T. E.; Kiehl, J. T.; Romero, M. J.; Norman, A. G.; Jones, K. M.

      2008-05-01

      We demonstrate high efficiency performance in two ultra-thin, Ge-free III-V semiconductor triple-junction solar cell device designs grown in an inverted configuration. Low-stress metamorphic junctions were engineered to achieve excellent photovoltaic performance with less than 3 x 106 cm-2 threading dislocations. The first design with band gaps of 1.83/1.40/1.00 eV, containing a single metamorphic junction, achieved 33.8% and 39.2% efficiencies under the standard one-sun global spectrum and concentrated direct spectrum at 131 suns, respectively. The second design with band gaps of 1.83/1.34/0.89 eV, containing two metamorphic junctions achieved 33.2% and 40.1% efficiencies under the standard one-sun global spectrum and concentrated direct spectrum at 143 suns, respectively.

    17. Station blackout transients in the semiscale facility

      SciTech Connect (OSTI)

      Chapman, J.C.

      1985-12-01

      The test results of station blackout transients conducted in the Semiscale MOD-2B facility are discussed in this report. The Semiscale MOD-2B facility simulates a pressurized water reactor (PWR) power plant. The experiments were initiated from conditions typical of PWR plant operating conditions (primary pressure of 15.2 MPa (2205 psi) and cold leg fluid temperature of 550 K (530F)). Five station blackout experiments were conducted, Three tests in the Power Loss (PL) Test Series and the two Primary Boil-off (PBO) Tests. The responses of these tests were analyzed and compared. However, only one test response (S-PL-2) is presented and discussed in detail. The S-PL-2 experiment is characterized by examining the responses of the primary and secondary pressures and fluid temperatures, the pressurizer liquid level, the primary fluid distribution, and the core thermal behavior. The mechanisms driving the S-PL-2 responses, the main elements of the station blackout transient, the influences of initial and boundary conditions and other transient that may appear similar to a station blackout are also discussed. Information pertinent to station blackout nuclear safety issues is presented in the report. 13 refs., 44 figs.

    18. ABUNDANCE AND ULTRASTRUCTURAL DIVERSITY OF NEURONAL GAP JUNCTIONS IN THE OFF AND ON SUBLAMINAE OF THE

      E-Print Network [OSTI]

      Rash, John E.

      retina. In the inner plexiform layer (IPL), ultrastructurally-identified gap junctions were reported primarily in the functionally-defined and anatomically-distinct ON sublamina, with few reported in the OFF an- alyze the morphologies and distributions of neuronal gap junctions in the IPL of adult rat

    19. Leakage Current and Dopant Activation Characterization of SDE/Halo CMOS Junctions with

      E-Print Network [OSTI]

      Schroder, Dieter K.

      by trap assisted and band-to-band tunneling. The reduced thermal budget of IRTP allows junction formation is described by high electron and hole recombination-generation in the end-of-range (EOR) damage layer enhanced/cm^) for high sub-junction doping due to band-to- band and trap-assisted tunnehng [1,2,3] compromises

    20. Molecular Rectification in a Metal-Insulator-Metal Junction Based on Self-Assembled Monolayers

      E-Print Network [OSTI]

      Jacobs, Heiko O.

      Molecular Rectification in a Metal-Insulator-Metal Junction Based on Self-Assembled Monolayers Received April 8, 2002 Abstract: An electrical junction formed by mechanical contact between two self-assembled. The hypothesis underlying this design is based on the relative energies of the highest occupied molecular orbital

    1. Low temperature junction growth using hot-wire chemical vapor deposition

      DOE Patents [OSTI]

      Wang, Qi; Page, Matthew; Iwaniczko, Eugene; Wang, Tihu; Yan, Yanfa

      2014-02-04

      A system and a process for forming a semi-conductor device, and solar cells (10) formed thereby. The process includes preparing a substrate (12) for deposition of a junction layer (14); forming the junction layer (14) on the substrate (12) using hot wire chemical vapor deposition; and, finishing the semi-conductor device.

    2. Photovoltaic nanopillar radial junction diode architecture enhanced by integrating semiconductor quantum dot nanocrystals as light harvesters

      E-Print Network [OSTI]

      Demir, Hilmi Volkan

      Photovoltaic nanopillar radial junction diode architecture enhanced by integrating semiconductor- and Nano-systems Programme, Singapore-MIT Alliance, Singapore 117576 Received 22 June 2010; accepted 10 hybridized, radial p-n junction based, nanopillar solar cells with photovoltaic performance enhanced

    3. Holographic model of hybrid and coexisting s-wave and p-wave Josephson junction

      E-Print Network [OSTI]

      Shuai Liu; Yong-Qiang Wang

      2015-10-27

      In this paper the holographic model for hybrid and coexisting s-wave and p-wave Josephson junction is constructed by a triplet charged scalar field coupled with a non-Abelian $SU(2)$ gauge fields in (3+1)-dimensional AdS spacetime. Depending on the value of chemical potential $\\mu$, one can show that there are four types of junctions (s+p-N-s+p, s+p-N-s, s+p-N-p and s-N-p). We show that DC current of all the hybrid and coexisting s-wave and p-wave junctions is proportional to the sine of the phase difference across the junction. In addition, the maximum current and the total condensation decays with the width of junction exponentially, respectively. For s+p-N-s and s-N-p junction, the maximum current decreases with growing temperature. Moreover, we find that the maximum current increases with growing temperature for s+p-N-s+p and s+p-N-p junction, which is in the different manner as the behaviour of s+p-N-s and s-N-p junction.

    4. Novel applications of the Josephson Effect: Ferroelectric Characterisation and Capacitively Shunted Grain Boundary Junctions

      E-Print Network [OSTI]

      McBrien, Philip Francis

      This thesis describes applications of the ac Josephson effect. Firstly, results are presented from bicrystal grain boundary YBa2Cu3O7-d junctions shunted with a YBa2Cu3O7-d/SrTiO3/Au multilayer external capacitor, to make a junction with a...

    5. Physical model of back line-contact front-junction solar cells Andres Cuevas

      E-Print Network [OSTI]

      electron-collector region is made by thermal dif- fusion of phosphorus, and the localized metal contactsPhysical model of back line-contact front-junction solar cells Andres Cuevas Citation: J. Appl-junction solar cells Andres Cuevasa) Research School of Engineering, The Australian National University, Canberra

    6. Junction conditions in General Relativity with spin sources

      E-Print Network [OSTI]

      Alex Giacomini; Ricardo Troncoso; Steven Willison

      2006-05-16

      The junction conditions for General Relativity in the presence of domain walls with intrinsic spin are derived in three and higher dimensions. A stress tensor and a spin current can be defined just by requiring the existence of a well defined volume element instead of an induced metric, so as to allow for generic torsion sources. In general, when the torsion is localized on the domain wall, it is necessary to relax the continuity of the tangential components of the vielbein. In fact it is found that the spin current is proportional to the jump in the vielbein and the stress-energy tensor is proportional to the jump in the spin connection. The consistency of the junction conditions implies a constraint between the direction of flow of energy and the orientation of the spin. As an application, we derive the circularly symmetric solutions for both the rotating string with tension and the spinning dust string in three dimensions. The rotating string with tension generates a rotating truncated cone outside and a flat space-time with inevitable frame dragging inside. In the case of a string made of spinning dust, in opposition to the previous case no frame dragging is present inside, so that in this sense, the dragging effect can be "shielded" by considering spinning instead of rotating sources. Both solutions are consistently lifted as cylinders in the four-dimensional case.

    7. Josephson junction of non-Abelian superconductors and non-Abelian Josephson vortices

      E-Print Network [OSTI]

      Muneto Nitta

      2015-08-06

      A Josephson junction is made of two superconductors sandwiching an insulator, and a Josephson vortex is a magnetic vortex (flux tube) absorbed into the Josephson junction, whose dynamics can be described by the sine-Gordon equation. In a field theory framework, a flexible Josephson junction was proposed, in which the Josephson junction is represented by a domain wall separating two condensations and a Josephson vortex is a sine-Gordon soliton in the domain wall effective theory. In this paper, we propose a Josephson junction of non-Abelian color superconductors, that is described by a non-Abelian domain wall, and show that a non-Abelian vortex (color magnetic flux tube) absorbed into it is a non-Abelian Josephson vortex represented as a non-Abelian sine-Gordon soliton in the domain wall effective theory, that is the $U(N)$ principal chiral model.

    8. Josephson junction of non-Abelian superconductors and non-Abelian Josephson vortices

      E-Print Network [OSTI]

      Nitta, Muneto

      2015-01-01

      A Josephson junction is made of two superconductors sandwiching an insulator, and a Josephson vortex is a magnetic vortex absorbed into the Josephson junction, whose dynamics can be described by the sine-Gordon equation. In a field theory framework, a flexible Josephson junction was proposed, in which the Josephson junction is represented by a domain wall separating two condensations and a Josephson vortex is a sine-Gordon soliton in the domain wall effective theory. In this paper, we propose a Josephson junction of non-Abelian color superconductors, that is described by a non-Abelian domain wall, and show that a non-Abelian vortex (color magnetic flux tube) absorbed into it is a non-Abelian Josephson vortex represented as a non-Abelian sine-Gordon soliton in the domain wall effective theory.

    9. E-cadherin junction formation involves an active kinetic nucleation process

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

      Biswas, Kabir H.; Hartman, Kevin L.; Yu, Cheng -han; Harrison, Oliver J.; Song, Hang; Smith, Adam W.; Huang, William Y. C.; Lin, Wan -Chen; Guo, Zhenhuan; Padmanabhan, Anup; et al

      2015-08-19

      Epithelial (E)-cadherin-mediated cell–cell junctions play important roles in the development and maintenance of tissue structure in multicellular organisms. E-cadherin adhesion is thus a key element of the cellular microenvironment that provides both mechanical and biochemical signaling inputs. Here, we report in vitro reconstitution of junction-like structures between native E-cadherin in living cells and the extracellular domain of E-cadherin in a supported membrane. Junction formation in this hybrid live cell-supported membrane configuration requires both active processes within the living cell and a supported membrane with low E-cad-ECD mobility. The hybrid junctions recruit ?-catenin and exhibit remodeled cortical actin. Observations suggest thatmore »the initial stages of junction formation in this hybrid system depend on the trans but not the cis interactions between E-cadherin molecules, and proceed via a nucleation process in which protrusion and retraction of filopodia play a key role.« less

    10. Dispersion mechanisms of a tidal river junction in the Sacramento–San Joaquin Delta, California

      SciTech Connect (OSTI)

      Gleichauf, Karla T.; Wolfram, Philip J.; Monsen, Nancy E.; Fringer, Oliver B.; Monismith, Stephen G.

      2014-12-17

      In branching channel networks, such as in the Sacramento–San Joaquin River Delta, junction flow dynamics contribute to dispersion of ecologically important entities such as fish, pollutants, nutrients, salt, sediment, and phytoplankton. Flow transport through a junction largely arises from velocity phasing in the form of divergent flow between junction channels for a portion of the tidal cycle. Field observations in the Georgiana Slough junction, which is composed of the North and South Mokelumne rivers, Georgiana Slough, and the Mokelumne River, show that flow phasing differences between these rivers arise from operational, riverine, and tidal forcing. A combination of Acoustic Doppler Current Profile (ADCP) boat transecting and moored ADCPs over a spring–neap tidal cycle (May to June 2012) monitored the variability of spatial and temporal velocity, respectively. Two complementary drifter studies enabled assessment of local transport through the junction to identify small-scale intrajunction dynamics. We supplemented field results with numerical simulations using the SUNTANS model to demonstrate the importance of phasing offsets for junction transport and dispersion. Different phasing of inflows to the junction resulted in scalar patchiness that is characteristic of MacVean and Stacey’s (2011) advective tidal trapping. Furthermore, we observed small-scale junction flow features including a recirculation zone and shear layer, which play an important role in intra-junction mixing over time scales shorter than the tidal cycle (i.e., super-tidal time scales). Thus, the study period spanned open- and closed-gate operations at the Delta Cross Channel. Synthesis of field observations and modeling efforts suggest that management operations related to the Delta Cross Channel can strongly affect transport in the Delta by modifying the relative contributions of tidal and riverine flows, thereby changing the junction flow phasing.

    11. Dispersion mechanisms of a tidal river junction in the Sacramento–San Joaquin Delta, California

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

      Gleichauf, Karla T.; Wolfram, Philip J.; Monsen, Nancy E.; Fringer, Oliver B.; Monismith, Stephen G.

      2014-12-17

      In branching channel networks, such as in the Sacramento–San Joaquin River Delta, junction flow dynamics contribute to dispersion of ecologically important entities such as fish, pollutants, nutrients, salt, sediment, and phytoplankton. Flow transport through a junction largely arises from velocity phasing in the form of divergent flow between junction channels for a portion of the tidal cycle. Field observations in the Georgiana Slough junction, which is composed of the North and South Mokelumne rivers, Georgiana Slough, and the Mokelumne River, show that flow phasing differences between these rivers arise from operational, riverine, and tidal forcing. A combination of Acoustic Dopplermore »Current Profile (ADCP) boat transecting and moored ADCPs over a spring–neap tidal cycle (May to June 2012) monitored the variability of spatial and temporal velocity, respectively. Two complementary drifter studies enabled assessment of local transport through the junction to identify small-scale intrajunction dynamics. We supplemented field results with numerical simulations using the SUNTANS model to demonstrate the importance of phasing offsets for junction transport and dispersion. Different phasing of inflows to the junction resulted in scalar patchiness that is characteristic of MacVean and Stacey’s (2011) advective tidal trapping. Furthermore, we observed small-scale junction flow features including a recirculation zone and shear layer, which play an important role in intra-junction mixing over time scales shorter than the tidal cycle (i.e., super-tidal time scales). Thus, the study period spanned open- and closed-gate operations at the Delta Cross Channel. Synthesis of field observations and modeling efforts suggest that management operations related to the Delta Cross Channel can strongly affect transport in the Delta by modifying the relative contributions of tidal and riverine flows, thereby changing the junction flow phasing.« less

    12. 2014-03-12 Issuance: Energy Conservation Standards for Commercial and Industrial Air Compressors; Notice of Public Meeting and Extension of Comment Period

      Broader source: Energy.gov [DOE]

      This document is a pre-publication Federal Register notice of public meeting and extension of public comment period regarding energy conservation standards for commercial and industrial air compressors, as issued by the Deputy Assistant Secretary for Energy Efficiency on March 12, 2014.

    13. Refueling stations for natural gas vehicles

      SciTech Connect (OSTI)

      Blazek, C.F.; Kinast, J.A.; Biederman, R.T.; Jasionowski, W.

      1991-01-01

      The unavailability of natural gas vehicle (NGV) refueling stations constitutes one of the major barriers to the wide spread utilization of natural gas in the transportation market. The purpose of this paper is to review and evaluate the current technical and economic status of compressed natural gas vehicle refueling stations and to identify the components or design features that offer the greatest potential for performance improvements and/or cost reductions. Both fast-fill- and slow-fill-type refueling systems will be discussed. 4 refs., 10 figs., 6 tabs.

    14. Pump station for radioactive waste water

      DOE Patents [OSTI]

      Whitton, John P.; Klos, Dean M.; Carrara, Danny T.; Minno, John J.

      2003-11-18

      A pump station for transferring radioactive particle containing waste water, includes: (a.) an enclosed sump having a vertically elongated right frusto conical wall surface and a bottom surface and (b.) a submersible volute centrifugal pump having a horizontally rotating impeller and a volute exterior surface. The sump interior surface, the bottom surface and the volute exterior surface are made of stainless steel having a 30 Ra or finer surface finish. A 15 Ra finish has been found to be most cost effective. The pump station is used for transferring waste water, without accumulation of radioactive fines.

    15. All-optical half-adder based on photonic mode junction Xianji Piao, Sunkyu Yu, and Namkyoo Park*

      E-Print Network [OSTI]

      Park, Namkyoo

      with the bi-level dynamic mode-conversion across the junction. 1. Introduction Junction structures, which is the core building block for the Arithmetic Logic Unit. Different with previous works in the photonic domain conversion. 2. Design Strategy and Results Fig. 1. Multi-junction realization of monolithic half-adder; (a

    16. MODELING OF TRIPLE JUNCTION A-SI SOLAR CELLS USING ASA: ANALYSIS OF DEVICE PERFORMANCE UNDER VARIOUS FAILURE SCENARIOS

      E-Print Network [OSTI]

      Deng, Xunming

      solar cells and/or the comparison of these predicted results with real multi-junction devices have beenMODELING OF TRIPLE JUNCTION A-SI SOLAR CELLS USING ASA: ANALYSIS OF DEVICE PERFORMANCE UNDER, University of Toledo, Toledo, OH 43606 ABSTRACT Triple junction a-Si solar cells have been modeled

    17. Nanobonding for Multi-Junction Solar Cells at Room Temperature T. Yu, M. M. R. Howlader*, F. Zhang, M. Bakr

      E-Print Network [OSTI]

      Howlader, Matiar R

      Nanobonding for Multi-Junction Solar Cells at Room Temperature T. Yu, M. M. R. Howlader*, F. Zhang of the interfacial properties of Si/GaAs indicates its potential use on the fabrication of multi-junction solar cells types of solar cells being studied, semiconductor multi-junction solar cells are gaining special

    18. Cooperative Research between NREL and Solar Junction Corp: Cooperative Research and Development Final Report, CRADA Number CRD-08-306

      SciTech Connect (OSTI)

      Friedman, D.

      2015-03-01

      NREL and Solar Junction Corp. will perform cooperative research on materials and devices that are alternatives to standard approaches with the goal of improving solar cell efficiency while lowering cost. The general purpose of this work is to model the performance of a multi-junction concentrator cell of Solar Junction, Inc. design under normal concentrator operating conditions.

    19. IMPROVEMENT TO PIPELINE COMPRESSOR ENGINE RELIABILITY THROUGH RETROFIT MICRO-PILOT IGNITION SYSTEM

      SciTech Connect (OSTI)

      Ted Bestor

      2004-06-01

      This report documents the second year's effort towards a 3-year program to develop micropilot ignition systems for existing pipeline compressor engines. In essence, all Phase II goals and objectives were met. We intend to proceed with the Phase III research plan, as set forth by the applicable Research Management Plan. The objective for Phase II was to further develop and optimize the micropilot ignition system for large bore, slow speed engines operating at low compression ratios. The primary elements of Micropilot Phase II were to evaluate the results for the 4-cylinder system prototype developed for Phase I, then optimize this system to demonstrate the technology's readiness for the field demonstration phase. In all, there were twelve (12) tasks defined and executed to support objectives in a stepwise fashion. Task-specific approaches and results are documented in this report. Research activities for Micropilot Phase II were conducted with the understanding that the efforts are expected to result in a commercial product to capture and disseminate the efficiency and environmental benefits of this new technology. Commercially-available fuel injection products were identified and applied to the program where appropriate. Modifications to existing engine components were kept to a minimum. This approach will minimize the overall time-to-market requirements, while meeting performance and cost criteria. The optimized four-cylinder system data demonstrated significant progress compared to Phase I results, as well as traditional spark ignition systems. An extensive testing program at the EECL using the GMV-4 test engine demonstrated that: (1) In general, the engine operated more stable fewer misfires and partial combustion events when using the 3-hole injectors compared to the 5-hole injectors used in Phase I. (2) The engine had, in general, a wider range of operation with the 3-hole injectors. Minimum operational boost levels were approximately 5''Hg lower and the minimum pilot quantity that the engine would operate on was roughly cut in half. (3) A successful concept demonstration of engine lube oil pilot injection was performed where the minimum operational boost was reduced by another 5''Hg to a boost level of 3''Hg; this is, depending on altitude, in the range of boost levels of many blower and piston scavenged low BMEP engines. (4) Micropilot ignition compares very favorably to other ignitions systems. The performance of micropilot ignition with mechanical gas admission valves is very similar to the performance of precombustion chamber ignition with high pressure fuel injection. Compared to spark ignition with mechanical gas admission valves the lean limit of operation is extended by about 5''Hg. These laboratory results will be enhanced, demonstrated and commercialized by others, with management and support from CSU, during Phase III of the Micropilot Ignition program.

    20. The Village Base Station Kurtis Heimerl

      E-Print Network [OSTI]

      California at Berkeley, University of

      deployment due to low power requirements that enable local generation via solar or wind; · explicit support. At around 20W, its power consumption is low enough to avoid diesel genera- tors and the corresponding damaging equipment [2]. We propose operating the entire base station on solely wind or solar power, which

    1. City of College Station's Thermographic Mobile Scan 

      E-Print Network [OSTI]

      Shear, C. K.

      1986-01-01

      During the first quarter of 1986, the City of College Station conducted a thermographic mobile scan of the entire city. A thermographic mobile scan is a process by which heat loss/heat gain data is accumulated by a vehicle traveling the city...

    2. Technical Design Report, Second Target Station

      SciTech Connect (OSTI)

      Galambos, John D.; Anderson, David E.; Bechtol, D.; Bethea, Katie L.; Brown, N.; Carden, W. F.; Chae, Steven M.; Clark, A.; Counce, Deborah M.; Craft, K.; Crofford, Mark T.; Collins, Richard M.; Cousineau, Sarah M.; Curry, Douglas E.; Cutler, Roy I.; Dayton, Michael J.; Dean, Robert A.; Deibele, Craig E.; Doleans, Marc; Dye, T.; Eason, Bob H.; Eckroth, James A.; Fincrock, C.; Fritts, S.; Gallmeier, Franz X.; Gawne, Ken R.; Hartman, Steven M.; Herwig, Kenneth W.; Hess, S.; Holmes, Jeffrey A.; Horak, Charlie M.; Howell, Matthew P.; Iverson, Erik B.; Jacobs, Lorelei L.; Jones, Larry C.; Johnson, B.; Johnson, S.; Kasemir, Kay; Kim, Sang-Ho; Laughon, Gregory J.; Lu, W.; Mahoney, Kelly L.; Mammosser, John; McManamy, T.; Michilini, M.; Middendorf, Mark E.; O'Neal, Ed; Nemec, B.; Peters, Roy Cecil; Plum, Michael A.; Reagan, G.; Remec, Igor; Rennich, Mark J.; Riemer, Bernie; Saethre, Robert B.; Schubert, James Phillip; Shishlo, Andrei P.; Smith, C. Craig; Strong, William Herb; Tallant, Kathie M.; Tennant, David Alan; Thibadeau, Barbara M.; Trumble, S.; Trotter, Steven M.; Wang, Z.; Webb, Steven B.; Williams, Derrick C.; White, Karen S.; Zhao, Jinkui

      2015-01-01

      The Second Target Station (STS) is a proposed upgrade for SNS. It includes a doubling of the accelerator power and an additional instrument hall. The new instrument hall will receive a 467 kW 10 Hz beam. The parameters and preliminary design aspects of the STS are presented for the accelerator, target systems, instrument hall, instruments and civil construction aspects.

    3. COMPARATIVE COSTS OF CALIFORNIA CENTRAL STATION ELECTRICITY

      E-Print Network [OSTI]

      CALIFORNIA ENERGY COMMISSION COMPARATIVE COSTS OF CALIFORNIA CENTRAL STATION ELECTRICITY GENERATION in this paper. #12;ABSTRACT In this 2007 report of the cost of generation of electricity for California located technologies, California Energy Commission staff provides levelized costs, including the cost assumptions

    4. TEST STATION SALE OF PERFORMANCE TESTED BULLS

      E-Print Network [OSTI]

      Tennessee, University of

      in the test had to meet minimum performance requirements. Those were: CREEP NON-CREEP Adj 205 day wt. 560 520AS-B428 U T BULL TEST STATION SALE OF PERFORMANCE TESTED BULLS THURSDAY, MARCH 8, 2012 12:00 NOON IN GREENEVILLE AND KNOXVILLE LIVESTOCK CENTER http://animalscience.ag.utk.edu/ (For video) #12;UT BULL TEST

    5. Economic Analysis of Hydrogen Energy Station Concepts: Are "H 2E-Stations" a Key Link to a Hydrogen Fuel Cell Vehicle Infrastructure?

      E-Print Network [OSTI]

      Lipman, Timothy E.; Edwards, Jennifer L.; Kammen, Daniel M.

      2002-01-01

      ECONOMIC ANALYSIS OF HYDROGEN ENERGY STATION CONCEPTS: ARE 'Economic Analysis of Hydrogen Energy Station Concepts: Are “the concept of the “hydrogen energy station”(H 2 E-Station).

    6. Contactless electronic transport in a bio-molecular junction

      SciTech Connect (OSTI)

      Hossain, Faruque M., E-mail: fhossain@unimelb.edu.au; Al-Dirini, Feras; Skafidas, Efstratios [Department of Electrical and Electronic Engineering, The University of Melbourne, Parkville 3010 (Australia); Center for Neural Engineering (CfNE), The University of Melbourne, Parkville 3010 (Australia)

      2014-07-28

      Molecular electronics hold promise for next generation ultra-low power, nano-scale integrated electronics. The main challenge in molecular electronics is to make a reliable interface between molecules and metal electrodes. Interfacing metals and molecules detrimentally affects the characteristics of nano-scale molecular electronic devices. It is therefore essential to investigate alternative arrangements such as contact-less tunneling gaps wherever such configurations are feasible. We conduct ab initio density functional theory and non-equilibrium Green's functions calculations to investigate the transport properties of a biocompatible glycine molecular junction. By analyzing the localized molecular orbital energy distributions and transmission probabilities in the transport-gap, we find a glycine molecule confined between two gold electrodes, without making a contact, is energetically stable and possesses high tunneling current resembling an excellent ohmic-like interface.

    7. Chemical Fabrication of Heterometallic Nanogaps for Molecular Transport Junctions

      SciTech Connect (OSTI)

      Chen, Xiaodong; Yeganeh, Sina; Qin, Lidong; Li, Shuzhou; Xue, Can; Braunschweig, Adam B.; Schatz, George C.; Ratner, Mark A.; Mirkin, Chad A.

      2009-01-01

      We report a simple and reproducible method for fabricating heterometallic nanogaps, which are made of two different metal nanorods separated by a nanometer-sized gap. The method is based upon on-wire lithography, which is a chemically enabled technique used to synthesize a wide variety of nanowire-based structures (e.g., nanogaps and disk arrays). This method can be used to fabricate pairs of metallic electrodes, which exhibit distinct work functions and are separated by gaps as small as 2 nm. Furthermore, we demonstrate that a symmetric thiol-terminated molecule can be assembled into such heterometallic nanogaps to form molecular transport junctions (MTJs) that exhibit molecular diode behavior. Theoretical calculations demonstrate that the coupling strength between gold and sulfur (Au-S) is 2.5 times stronger than that of Pt-S. In addition, the structures form Raman hot spots in the gap, allowing the spectroscopic characterization of the molecules that make up the MTJs.

    8. An analysis of railroad accident dynamics in College Station, Texas 

      E-Print Network [OSTI]

      Brown, Hart Stefan

      1998-01-01

      The intersection between the Union Pacific Railroad (UP) Valley Junction line and Texas A&M University (TAMU) poses a significant potential or risk to the people who utilize the campus. The line carried over I 1,000 loads ...

    9. Stability of winding cosmic wall lattices with X type junctions

      E-Print Network [OSTI]

      Brandon Carter

      2009-11-30

      This work confirms the stability of a class of domain wall lattice models that can produce accelerated cosmological expansion, with pressure to density ratio $w=-1/3$ at early times, and with $w=-2/3$ at late times when the lattice scale becomes large compared to the wall thickness. For walls of tension $T_{I}$, the relevant X type junctions could be unstable (for a sufficiently acute intersection angle $\\alpha$) against separation into a pair of Y type junctions joined by a compound wall, only if the tension $T_{II}$ of the latter were less than $2T_{I}$ (and for an approximately right-angled intersection if it were less that $\\sqrt{2} T_{I}$) which can not occur in the class considered here. In an extensive category of multicomponent scalar field models of forced harmonic (linear or non-linear) type it is shown how the relevant tension -- which is the same as the surface energy density $U$ of the wall -- can be calculated as the minimum (geodesic) distance between the relevant vacuum states as measured on the space of field values $\\Phi^i$ using a positive definite (Riemannian) energy metric $dU^2=\\tilde G_{ij} d\\Phi^i d\\Phi^j$ that is obtained from the usual kinetic metric (which is flat for a model with ordinary linear kinetic part) by application of a conformal factor proportional to the relevant potential function $V$. For suitably periodic potential functions there will be corresponding periodic configurations -- with parallel walls characterised by incrementation of a winding number -- in which the condition for stability of large scale bunching modes is shown to be satisfied automatically. It is suggested that such a configuration -- with a lattice lengthscale comparable to intergalactic separation distances -- might have been produced by a late stage of cosmological inflation.

    10. Improved blade profile loss and deviation angle models for advanced transonic compressor bladings. Part 1: A model for subsonic flow

      SciTech Connect (OSTI)

      Koenig, W.M.; Hennecke, D.K.; Fottner, L.

      1996-01-01

      New blading concepts as used in modern transonic axial-flow compressors require improved loss and deviation angle correlations. The new model presented in this paper incorporates several elements and treats blade-row flows having subsonic and supersonic inlet conditions separately. In the first part of this paper two proved and well-established profile loss correlations for subsonic flows are extended to quasi-two-dimensional conditions and to custom-tailored blade designs. Instead of a deviation angle correlation, a simple method based on singularities is utilized. The comparison between the new model and a recently published model demonstrates the improved accuracy in prediction of cascade performance achieved by the new model.

    11. Improved blade profile loss and deviation angle models for advanced transonic compressor bladings. Part 2: A model for supersonic flow

      SciTech Connect (OSTI)

      Koenig, W.M.; Hennecke, D.K.; Fottner, L.

      1996-01-01

      New blading concepts as used in modern transonic axial-flow compressors require improved loss and deviation angle correlations. The new model presented in this paper incorporates several elements and treats blade-row flows having subsonic and supersonic inlet conditions separately. The second part of the present report focuses on the extension of a well-known correlation for cascade losses at supersonic inlet flows. It was originally established for DCA bladings and is now modified to reflect the flow situation in blade rows having low-cambered, arbitrarily designed blades including precompression blades. Finally, the steady loss increase from subsonic to supersonic inlet-flow velocities demonstrates the matched performance of the different correlations of the new model.

    12. Comprehensive Compressor Calorimeter Testing of Lower-GWP Alternative Refrigerants for Heat Pump and Medium Temperature Refrigeration Applications

      SciTech Connect (OSTI)

      Shrestha, Som S; Sharma, Vishaldeep; Abdelaziz, Omar

      2014-01-01

      In response to environmental concerns raised by the use of refrigerants with high Global Warming Potential (GWP), the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) has launched an industry-wide cooperative research program, referred to as the Low-GWP Alternative Refrigerants Evaluation Program (AREP), to identify and evaluate promising alternative refrigerants for major product categories. This paper reports one of the Oak Ridge National Laboratory (ORNL) contributions to AREP. It compares performance of alternative refrigerants to that of R-410A and R-404A for heat pump and medium temperature applications, respectively. The alternatives reported in this paper are: R-32, DR-5, and L-41a for R-410A and ARM-31a, D2Y-65, L-40, and a mixture of R-32 and R-134a for R-404A. All performance comparison tests were conducted using scroll compressors of ~1.85 tons (6.5 kW) cooling capacity. Tests were conducted over a range of combinations of saturation suction and saturation discharge temperatures for both compressors. The tests showed that, in general, energy efficiency ratio (EER) and cooling capacity of R-410A alternative refrigerants were slightly lower than that of the baseline refrigerant with a moderate increases in discharge temperature. On the other hand, R-404A alternative refrigerants showed relative performance dependence on saturation suction and saturation discharge temperatures and larger increases in discharge temperature than for the R-410A alternatives. This paper summarizes the relative performance of all alternative refrigerants compared to their respective baseline.

    13. An Assessment of the Near-Term Costs of Hydrogen Refueling Stations and Station Components

      E-Print Network [OSTI]

      Weinert, Jonathan X.; Lipman, Timothy

      2006-01-01

      economics. Summary of Results Costs are calculated for sevenTable ES-1. Station costs are presented both individually (was selected because the costs provided by Fuel Cell Energy

    14. Improved method of preparing p-i-n junctions in amorphous silicon semiconductors

      DOE Patents [OSTI]

      Madan, A.

      1984-12-10

      A method of preparing p/sup +/-i-n/sup +/ junctions for amorphous silicon semiconductors includes depositing amorphous silicon on a thin layer of trivalent material, such as aluminum, indium, or gallium at a temperature in the range of 200/sup 0/C to 250/sup 0/C. At this temperature, the layer of trivalent material diffuses into the amorphous silicon to form a graded p/sup +/-i junction. A layer of n-type doped material is then deposited onto the intrinsic amorphous silicon layer in a conventional manner to finish forming the p/sup +/-i-n/sup +/ junction.

    15. Reduced low frequency noise in electron beam evaporated MgO magnetic tunnel junctions

      SciTech Connect (OSTI)

      Diao, Z.; Feng, J. F.; Kurt, H.; Feng, G.; Coey, J. M. D. [CRANN and School of Physics, Trinity College, Dublin 2 (Ireland)

      2010-05-17

      We compare low frequency noise in magnetic tunnel junctions with MgO barriers prepared by electron-beam evaporation with those prepared by radiofrequency sputtering, both showing a high tunneling magnetoresistance. The normalized noise parameter in the parallel state of junctions with evaporated barriers is at least one order of magnitude lower than that in junctions with sputtered barriers, and exhibits a weaker bias dependence. The lowest normalized noise is in the 10{sup -11} mum{sup 2} range. A lower density of oxygen vacancies acting as charge trap states in the evaporated MgO is responsible for the lower noise.

    16. Realistic-contact-induced enhancement of rectifying in carbon-nanotube/graphene-nanoribbon junctions

      SciTech Connect (OSTI)

      Zhang, Xiang-Hua [School of Physics and Microelectronics Science, Hunan University, Changsha 410082 (China); Department of Electrical and Information Engineering, Hunan Institute of Engineering, Xiangtan 411101 (China); Li, Xiao-Fei, E-mail: xfli@theochem.kth.se [School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054 (China); Wang, Ling-Ling, E-mail: llwang@hnu.edu.cn; Xu, Liang; Luo, Kai-Wu [School of Physics and Microelectronics Science, Hunan University, Changsha 410082 (China)

      2014-03-10

      Carbon-nanotube/graphene-nanoribbon junctions were recently fabricated by the controllable etching of single-walled carbon-nanotubes [Wei et al., Nat. Commun. 4, 1374 (2013)] and their electronic transport properties were studied here. First principles results reveal that the transmission function of the junctions show a heavy dependence on the shape of contacts, but rectifying is an inherent property which is insensitive to the details of contacts. Interestingly, the rectifying ratio is largely enhanced in the junction with a realistic contact and the enhancement is insensitive to the details of contact structures. The stability of rectifying suggests a significant feasibility to manufacture realistic all-carbon rectifiers in nanoelectronics.

    17. Formation of Porous Layers by Electrochemical Etching of Germanium and Gallium Arsenide for Cleave Engineered Layer Transfer (CELT) Application in High Efficiency Multi-Junction Solar Cells

      E-Print Network [OSTI]

      Fong, David Michael

      2012-01-01

      Motivation Multi-junction (MJ) solar cells show particular promise as a future clean renewable energy

    18. Aberration-corrected transmission electron microscopy analyses of GaAs/Si interfaces in wafer-bonded multi-junction solar cells

      E-Print Network [OSTI]

      Dunin-Borkowski, Rafal E.

      -bonded multi-junction solar cells Dietrich Häussler a , Lothar Houben b , Stephanie Essig c , Mert Kurttepeli online 20 July 2013 Keywords: Multi-junction solar cell Wafer bonding Interfaces Aberration corrected and composition fluctuations near interfaces in wafer-bonded multi-junction solar cells. Multi-junction solar

    19. VELO[city] : rethinking the multi-modal urban station

      E-Print Network [OSTI]

      Dickson, Amanda, 1974-

      2003-01-01

      Train travel was once integral to the urban condition. Railway stations and rural depots were designed as machines for efficiency and it was within the station that one could escape the chaos of the city to become a part ...

    20. Fact #816: February 10, 2014 Natural Gas Refueling Stations Grow...

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

      6: February 10, 2014 Natural Gas Refueling Stations Grow Over the Last Ten Years Fact 816: February 10, 2014 Natural Gas Refueling Stations Grow Over the Last Ten Years In 2003...

    1. Webinar October 13: Reference Designs for Hydrogen Fueling Stations...

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

      titled "Reference Designs for Hydrogen Fueling Stations" on Tuesday, October 13, from 12 to 1 p.m. Eastern Daylight Time (EDT). The goal of the H2FIRST Reference Station Design...

    2. H2FIRST Reference Station Design Task: Project Deliverable 2...

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

      Reference Station Design Task: Project Deliverable 2-2 H2FIRST Reference Station Design Task: Project Deliverable 2-2 This H2FIRST project report, published in April 2015, presents...

    3. Which way is up : towards accessible wayfinding in transit stations

      E-Print Network [OSTI]

      Leven, Dalia (Dalia Beth)

      2006-01-01

      Passengers' most frequent interaction with a rail transit system is at its stations, which represent the beginning, the end and sometimes the middle of transit trips. The design of these stations can greatly affect a user's ...

    4. Station GPS permanente IPG Paris DGF Uchile UNAP Iquique

      E-Print Network [OSTI]

      Vigny, Christophe

      .691 DESCRIPTION Permanent GPS station North Chili I region. MONUMENTATION Inox 12 cm rod (Delmont type) scealed

    5. Station GPS permanente IPG Paris DGF Uchile UNAP Iquique

      E-Print Network [OSTI]

      Vigny, Christophe

      Colocated with seismic station. Bedrock. Inox 12 cm rod (Delmont type) scealed in bedrock. PG-A1 antena

    6. Hydrogen Energy Stations: Poly-Production of Electricity, Hydrogen, and Thermal Energy

      E-Print Network [OSTI]

      Lipman, Timothy; Brooks, Cameron

      2006-01-01

      shaving and backup power, and the station is expected toor “onsite power”), energy stations offer a potentially moreCharacteristics of Energy Station Power Technologies Low/

    7. Plug-In Electric Vehicle Handbook for Public Charging Station Hosts

      SciTech Connect (OSTI)

      2012-04-01

      This handbook answers basic questions about plug-in electric vehicles, charging stations, charging equipment, and considerations for station owners, property owners, and station hosts.

    8. Plug-In Electric Vehicle Handbook for Public Charging Station Hosts (Brochure)

      SciTech Connect (OSTI)

      Not Available

      2012-04-01

      This handbook answers basic questions about plug-in electric vehicles, charging stations, charging equipment, and considerations for station owners, property owners, and station hosts.

    9. Central Station DHC Phase 1 feasibility

      SciTech Connect (OSTI)

      Henderson, H.L.

      1992-03-01

      This project assisted a private real estate developer in technically assessing the feasibility of integrating a central DHC system into a proposed 72 acre area mixed-use Planned Development (Central Station) just south of the Chicago Central Business District (Loop). The technical assessment concluded that a district heating and cooling system for Central Station will be feasible, provided that a major anchor load can be connected to the system. The system conceived for the site employs a modular approach that adjusts production capacity to actual load growth. The design concept includes gas-fired boilers for heating, gas turbine driven chillers for base loading, electric motor driven chillers for peaking, steam turbines for peak power and back pressure operation, and chilled water storage. Energy will be supplied to the users in the form of steam or low temperature hot water for heating, and low temperature chilled water for cooling.

    10. BIOMASS COGASIFICATION AT POLK POWER STATION

      SciTech Connect (OSTI)

      John McDaniel

      2002-05-01

      Part of a closed loop biomass crop was recently harvested to produce electricity in Tampa Electric's Polk Power Station Unit No.1. No technical impediments to incorporating a small percentage of biomass into Polk Power Station's fuel mix were identified. Appropriate dedicated storage and handling equipment would be required for routine biomass use. Polk Unit No.1 is an integrated gasification combined cycle (IGCC) power plant. IGCC is a new approach to generating electricity cleanly from solid fuels such as coal, petroleum coke, The purpose of this experiment was to demonstrate the Polk Unit No.1 could process biomass as a fraction of its fuel without an adverse impact on availability and plant performance. The biomass chosen for the test was part of a crop of closed loop Eucalyptus trees.

    11. Fort Collins CSU Campus Weather Station Commemoration and Open House

      E-Print Network [OSTI]

      Collett Jr., Jeffrey L.

      Fort Collins CSU Campus Weather Station Commemoration and Open House Please join us in celebrating the fascinating history and important scientific contributions of the Campus Weather Station to Colorado State, July 28, 2014 from 3 - 6 p.m. with remarks at 3:30 p.m. At the Campus Weather Station*** Community Open

    12. Power-aware Base Station Positioning for Sensor Networks

      E-Print Network [OSTI]

      Bogdanov, Andrej

      Power-aware Base Station Positioning for Sensor Networks Andrej Bogdanov Elitza Maneva Samantha station, where the data can be processed. There are several power metrics that one can consider optimizing consider the problem of positioning data collecting base stations in a sensor network. We show

    13. Xcel Energy Comanche Station: Pueblo, Colorado (Data)

      DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

      Stoffel, T.; Andreas, A.

      A partnership with industry and U.S. Department of Energy's National Renewable Energy Laboratory (NREL) to collect solar data to support future solar power generation in the United States. The measurement station monitors global horizontal, direct normal, and diffuse horizontal irradiance to define the amount of solar energy that hits this particular location. The solar measurement instrumentation is also accompanied by meteorological monitoring equipment to provide scientists with a complete picture of the solar power possibilities.

    14. Xcel Energy Comanche Station: Pueblo, Colorado (Data)

      DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

      Stoffel, T.; Andreas, A.

      2007-06-20

      A partnership with industry and U.S. Department of Energy's National Renewable Energy Laboratory (NREL) to collect solar data to support future solar power generation in the United States. The measurement station monitors global horizontal, direct normal, and diffuse horizontal irradiance to define the amount of solar energy that hits this particular location. The solar measurement instrumentation is also accompanied by meteorological monitoring equipment to provide scientists with a complete picture of the solar power possibilities.

    15. Reykjanes Geothermal Power Station | Open Energy Information

      Open Energy Info (EERE)

      AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onRAPID/Geothermal/Exploration/ColoradoRemsenburg-Speonk, New York: EnergyOpenReykjanes Geothermal Power Station Jump to:

    16. Alternative Fueling Station Locator | Department of Energy

      Energy Savers [EERE]

      AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematics And StatisticsProgram ManagerCorridor Designations in 11Alternative Fueling Station Locator

    17. Nanopillar Photovoltaics: Photon Management and Junction Engineering for Next-Generation Solar Cells

      E-Print Network [OSTI]

      Mariani, Giacomo

      2013-01-01

      photovoltaics: cohesive optical and electrical investigation of the complete solarphotovoltaics represents an emerging alternative to standard solarPhotovoltaics: Photon Management and Junction Engineering for Next-Generation Solar

    18. EFFECT OF PREPARATION PARAMETERS ON LIGHT SENSITIVITY IN SUPERCONDUCTIVE TUNNEL JUNCTIONS

      E-Print Network [OSTI]

      Paris-Sud XI, Université de

      , Italy Résumé. 2014 Des jonctions « tunnel » supraconductrices utilisant du sulfure de cadmium et du al. [17] have considered semiconductor barriers for low capacitance tunnel junctions. Light can be depo- sited in ultra high vacuum systems without fear of contamination. Work

    19. Device characterization for design optimization of 4 junction inverted metamorphic concentrator solar cells

      SciTech Connect (OSTI)

      Geisz, John F.; France, Ryan M.; Steiner, Myles A.; Friedman, Daniel J.; García, Iván

      2014-09-26

      Quantitative electroluminescence (EL) and luminescent coupling (LC) analysis, along with more conventional characterization techniques, are combined to completely characterize the subcell JV curves within a fourjunction (4J) inverted metamorphic solar cell (IMM). The 4J performance under arbitrary spectral conditions can be predicted from these subcell JV curves. The internal radiative efficiency (IRE) of each junction has been determined as a function of current density from the external radiative efficiency using optical modeling, but this required the accurate determination of the individual junction current densities during the EL measurement as affected by LC. These measurement and analysis techniques can be applied to any multijunction solar cell. The 4J IMM solar cell used to illustrate these techniques showed excellent junction quality as exhibited by high IRE and a one-sun AM1.5D efficiency of 36.3%. This device operates up to 1000 suns without limitations due to any of the three tunnel junctions.

    20. Highly efficient organic multi-junction solar cells with a thiophene based donor material

      SciTech Connect (OSTI)

      Meerheim, Rico Körner, Christian; Leo, Karl

      2014-08-11

      The efficiency of organic solar cells can be increased by serial stacked subcells even upon using the same absorber material. For the multi-junction devices presented here, we use the small molecule donor material DCV5T-Me. The subcell currents were matched by optical transfer matrix simulation, allowing an efficiency increase from 8.3% for a single junction up to 9.7% for a triple junction cell. The external quantum efficiency of the subcells, measured under appropriate light bias illumination, is spectrally shifted due to the microcavity of the complete stack, resulting in a broadband response and an increased cell current. The increase of the power conversion efficiency upon device stacking is even stronger for large area cells due to higher influence of the resistance of the indium tin oxide anode, emphasizing the advantage of multi-junction devices for large-area applications.

    1. A market analysis for high efficiency multi-junction solar cells grown on SiGe

      E-Print Network [OSTI]

      Judkins, Zachara Steele

      2007-01-01

      Applications, markets and a cost model are presented for III-V multi-junction solar cells built on compositionally graded SiGe buffer layers currently being developed by professors Steven Ringell of Ohio State University ...

    2. Dispersion Mechanisms of a Tidal River Junction in the Sacramento–San Joaquin Delta, California

      E-Print Network [OSTI]

      Gleichauf, Karla T.; Wolfram, Phillip J.; Monsen, Nancy E.; Fringer, Oliver B.; Monismith, Stephen G.

      2014-01-01

      a Tidal River Junction in the Sacramento–San Joaquin Delta,networks, such as in the Sacramento–San Joaquin River Delta,transport and fate in the Sacramento–San Joaquin delta using

    3. Back to the crossroads of Flatbush--the junction--student housing for Brooklyn College

      E-Print Network [OSTI]

      Campbell, Keith A. (Keith Anthony)

      1988-01-01

      The crossroads of Flatbush (often called The Junction) is a five point intersection of vehicular and pedestrian traffic. A crossroad where ethnic groups step beyond subtle neighborhood boundaries and merge to use public ...

    4. Spin-polarized tunneling in MgO-based tunnel junctions with superconducting electrodes

      E-Print Network [OSTI]

      Schebaum, Oliver

      We prepared magnetic tunnel junctions with one ferromagnetic and one superconducting Al–Si electrode. Pure cobalt electrodes were compared with a Co–Fe–B alloy and the Heusler compound Co[subscript 2]FeAl. The polarization ...

    5. Universal transport signatures of Majorana fermions in superconductor-Luttinger liquid junctions

      E-Print Network [OSTI]

      Universal transport signatures of Majorana fermions in superconductor-Luttinger liquid junctions, University of California, Irvine, CA 92697 3 Institute of Quantum Information, California Institute of Technology, Pasadena, CA 91125 4 Department of Physics, California Institute of Technology, Pasadena, CA

    6. Direct imaging of coherent quantum transport in graphene p?n?p junctions

      E-Print Network [OSTI]

      Herbschleb, E. D.; Puddy, R. K.; Marconcini, P.; Griffiths, J. P.; Jones, G. A. C.; Macucci, M.; Smith, C. G.; Connolly, M. R.

      2015-09-11

      We use electrostatic lithography to fabricate a graphene p-n-p junction and exploit the coherence of weakly confined Dirac quasiparticles to image the underlying scattering potential using low-temperature scanning gate microscopy. The tip...

    7. Compound Josephson-junction coupler for flux qubits with minimal crosstalk

      E-Print Network [OSTI]

      Harris, R.; Lanting, T.; Berkley, A. J.; Johansson, J.; Johnson, M. W.; Bunyk, P.; Ladizinsky, E.; Oh, T.; Han, Siyuan

      2009-08-20

      An improved tunable coupling element for building networks of coupled rf-superconducting quantum interference device (rf-SQUID) flux qubits has been experimentally demonstrated. This new form of coupler, based on the compound Josephson-junction rf...

    8. 0.7-eV GaInAs Junction for a GaInP/GaAs/GaInAs(1eV)/GaInAs(0.7eV) Four-Junction Solar Cell

      SciTech Connect (OSTI)

      Friedman, D. J.; Geisz, J. F.; Norman, A. G.; Wanlass, M. W.; Kurtz, S. R.

      2006-01-01

      We discuss recent developments in III-V multijunction solar cells, focusing on adding a fourth junction to the Ga{sub 0.5}In{sub 0.5} P/GaAs/Ga{sub 0.75}In{sub 0.25}As inverted three-junction cell. This cell, grown inverted on GaAs so that the lattice-mismatched Ga{sub 0.75}In{sub 0.25}As third junction is the last one grown, has demonstrated 38% efficiency, and 40% is likely in the near future. To achieve still further gains, a lower-bandgap Ga{sub x}In{sub 1-x}As fourth junction could be added to the three-junction structure for a four-junction cell whose efficiency could exceed 45% under concentration. Here, we present the initial development of the Ga{sub x}In{sub 1-x}As fourth junction. Junctions of various bandgaps ranging from 0.88 to 0.73 eV were grown, in order to study the effect of the different amounts of lattice mismatch. At a bandgap of 0.88 eV, junctions were obtained with very encouraging {approx}80% quantum efficiency, 57% fill factor, and 0.36 eV open-circuit voltage. The device performance degrades with decreasing bandgap (i.e., increasing lattice mismatch). We model the four-junction device efficiency vs. fourth junction bandgap to show that an 0.7-eV fourth-junction bandgap, while optimal if it could be achieved in practice, is not necessary; an 0.9-eV bandgap would still permit significant gains in multijunction cell efficiency while being easier to achieve than the lower-bandgap junction.

    9. Antenna unit and radio base station therewith

      DOE Patents [OSTI]

      Kuwahara, Mikio; Doi, Nobukazu; Suzuki, Toshiro; Ishida, Yuji; Inoue, Takashi; Niida, Sumaru

      2007-04-10

      Phase and amplitude deviations, which are generated, for example, by cables connecting an array antenna of a CDMA base station and the base station, are calibrated in the baseband. The base station comprises: an antenna apparatus 1; couplers 2; an RF unit 3 that converts a receive signal to a baseband signal, converts a transmit signal to a radio frequency, and performs power control; an A/D converter 4 for converting a receive signal to a digital signal; a receive beam form unit 6 that multiplies the receive signal by semi-fixed weight; a despreader 7 for this signal input; a time-space demodulator 8 for demodulating user data; a despreader 9 for probe signal; a space modulator 14 for user data; a spreader 13 for user signal; a channel combiner 12; a Tx calibrater 11 for controlling calibration of a signal; a D/A converter 10; a unit 16 for calculation of correlation matrix for generating a probe signal used for controlling an Rx calibration system and a TX calibration system; a spreader 17 for probe signal; a power control unit 18; a D/A converter 19; an RF unit 20 for probe signal; an A/D converter 21 for signal from the couplers 2; and a despreader 22.

    10. Single-junction solar cells with the optimum band gap for terrestrial concentrator applications

      DOE Patents [OSTI]

      Wanlass, Mark W. (Golden, CO)

      1994-01-01

      A single-junction solar cell having the ideal band gap for terrestrial concentrator applications. Computer modeling studies of single-junction solar cells have shown that the presence of absorption bands in the direct spectrum has the effect of "pinning" the optimum band gap for a wide range of operating conditions at a value of 1.14.+-.0.02 eV. Efficiencies exceeding 30% may be possible at high concentration ratios for devices with the ideal band gap.

    11. Hanna Franberg-Delahaye SPIRAL 2 production station 4th HPTW 2011 Page 1 SPIRAL 2 production station

      E-Print Network [OSTI]

      McDonald, Kirk

      Hanna Franberg-Delahaye SPIRAL 2 production station ­ 4th HPTW 2011 Page 1 SPIRAL 2 production station Hanna Frånberg Delahaye Radioactive beam production GANIL-SPIRAL 2, Caen, France May 3, 2011 #12;Hanna Franberg-Delahaye SPIRAL 2 production station ­ 4th HPTW 2011 Page 2 Lay out of the presentation

    12. Structured chaos in a devil's staircase of the Josephson junction

      SciTech Connect (OSTI)

      Shukrinov, Yu. M. [BLTP, JINR, Dubna, Moscow Region 141980 (Russian Federation); Botha, A. E., E-mail: bothaae@unisa.ac.za [Department of Physics, University of South Africa, Science Campus, Private Bag X6, Florida Park 1710 (South Africa); Medvedeva, S. Yu. [BLTP, JINR, Dubna, Moscow Region 141980 (Russian Federation); Moscow Institute of Physics and Technology (State University), Dolgoprudny, Moscow Region 141700 (Russian Federation); Kolahchi, M. R. [Institute for Advanced Studies in Basic Sciences, P.O. Box 45195-1159, Zanjan (Iran, Islamic Republic of); Irie, A. [Department of Electrical and Electronic Systems Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya 321-8585 (Japan)

      2014-09-01

      The phase dynamics of Josephson junctions (JJs) under external electromagnetic radiation is studied through numerical simulations. Current-voltage characteristics, Lyapunov exponents, and Poincaré sections are analyzed in detail. It is found that the subharmonic Shapiro steps at certain parameters are separated by structured chaotic windows. By performing a linear regression on the linear part of the data, a fractal dimension of D?=?0.868 is obtained, with an uncertainty of ±0.012. The chaotic regions exhibit scaling similarity, and it is shown that the devil's staircase of the system can form a backbone that unifies and explains the highly correlated and structured chaotic behavior. These features suggest a system possessing multiple complete devil's staircases. The onset of chaos for subharmonic steps occurs through the Feigenbaum period doubling scenario. Universality in the sequence of periodic windows is also demonstrated. Finally, the influence of the radiation and JJ parameters on the structured chaos is investigated, and it is concluded that the structured chaos is a stable formation over a wide range of parameter values.

    13. Spin Josephson effect in topological superconductor-ferromagnet junction

      SciTech Connect (OSTI)

      Ren, C. D.; Wang, J.

      2014-03-21

      The composite topological superconductor (TS), made of one-dimensional spin-orbit coupled nanowire with proximity-induced s-wave superconductivity, is not a pure p-wave superconductor but still has a suppressed s-wave pairing. We propose to probe the spin texture of the p-wave pairing in this composite TS by examining possible spin supercurrents in an unbiased TS/ferromagnet junction. It is found that both the exchange-coupling induced and spin-flip reflection induced spin currents exist in the setup and survive even in the topological phase. We showed that besides the nontrivial p-wave pairing state accounting for Majorana Fermions, there shall be a trivial p-wave pairing state that contributes to spin supercurrent. The trivial p-wave pairing state is diagnosed from the mixing effect between the suppressed s-wave pairing and the topologically nontrivial p-wave pairing. The d vector of the TS is proved not to be rigorously perpendicular to the spin projection of p-wave pairings. Our findings are also confirmed by the Kitaev's p-wave model with a nonzero s-wave pairing.

    14. Polk power station syngas cooling system

      SciTech Connect (OSTI)

      Jenkins, S.D.

      1995-01-01

      Tampa Electric Company (TEC) is in the site development and construction phase of the new Polk Power Station Unit No. 1. This will be the first unit at a new site and will use Integrated Gasification Combined Cycle (IGCC) Technology. The unit will utilize Texaco`s oxygen-blown, entrained-flow coal gasification, along with combined cycle power generation, to produce nominal 260MW. Integral to the gasification process is the syngas cooling system. The design, integration, fabrication, transportation, and erection of this equipment have provided and continue to provide major challenges for this project.

    15. Repowering of the Midland Nuclear Station 

      E-Print Network [OSTI]

      Gatlin, C. E. Jr.; Vellender, G. C.; Mooney, J. A.

      1988-01-01

      , Michigan The conversion of the Midland Nuclear Station to a combined cycle power facility is the first of its kind. The eXisting nuclear steam turbine, combined with new, natural-gas-fired gas turbines, will create the largest cogeneration facility... in the midst of a repa..'erin;J that will convert it to a natural gas-fired carbined cycle cogeneration plant. 'Ihe nuclear project started in 1967 as a two unit plant utilizin;J pressurized water reactors to supply 1,357 MW of electric generatin...

    16. Farinello Geothermal Power Station | Open Energy Information

      Open Energy Info (EERE)

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    17. Nesjavellir Geothermal Power Station | Open Energy Information

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    18. Boyd Station LLC | Open Energy Information

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    19. Alternative Fuels Data Center: Biodiesel Fueling Stations

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

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    20. Alternative Fuels Data Center: Ethanol Fueling Stations

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