Sample records for variable air-volume system

  1. Optimized Fan Control In Variable Air Volume HVAC Systems Using Static Pressure Resets: Strategy Selection and Savings Analysis

    E-Print Network [OSTI]

    Kimla, John

    2010-07-14T23:59:59.000Z

    The potential of static pressure reset (SPR) control to save fan energy in variable air volume HVAC systems has been well documented. Current research has focused on the creation of reset strategies depending on specific system features...

  2. Room Temperature Control During Season Switchover with Single Duct Variable Air Volume System Without Reheat 

    E-Print Network [OSTI]

    Liu, C.; Deng, S.; Claridge, D. E.; Turner, W. D.; Bruner, H.

    2003-01-01T23:59:59.000Z

    The Langford “A” building houses the College of Architecture on TAMU campus. There are ten singleduct variable air volume (VAV) air-handling units (AHUs) without reheat serving the building. The local pneumatic thermostats modulate the dampers...

  3. Analysis and characterization of ancillary service demand response strategies for variable air volume HVAC systems

    E-Print Network [OSTI]

    Blum, David H. (David Henry)

    2013-01-01T23:59:59.000Z

    Output variability and prediction difficulties with respect to solar and wind electricity resources increase the requirement of grid-scale reserve capacity and add strain to existing firm generators used for reserves and ...

  4. Application of Wireless Sensor Network (WSN) Technologies in Optimal Static Pressure Reset in Variable Air Volume (VAV) System

    E-Print Network [OSTI]

    Zheng, K.; Li, H.; Yang, H.

    2007-01-01T23:59:59.000Z

    Optimization of the static pressure reset is always critical in the pursuit of maximum savings of fan power and thermal energy consumption in a VAV system. This paper theoretically investigated three static pressure reset methods, i.e. VAV terminal...

  5. Development of models for series and parallel fan variable air volume terminal units

    E-Print Network [OSTI]

    Furr, James C., Jr

    2007-09-17T23:59:59.000Z

    Empirical models of airflow output and power consumption were developed for series and parallel fan powered variable air volume terminal units at typical design pressure conditions. A testing procedure and experimental setup were developed to test...

  6. Research on Fuzzy Regulation Strategies in the Constant Air Volume Air Conditioning System

    E-Print Network [OSTI]

    Bai, T.; Zhang, J.; Ning, N.; Tong, K.; Wu, Y.; Wang, H.

    2006-01-01T23:59:59.000Z

    The energy consumption of the constant air volume (CAV) system largely depends on the regulation strategies. Although some air conditioning systems are equipped with automatic regulation devices, others lack effective regulation strategies. To avoid...

  7. Research on Fuzzy Regulation Strategies in the Constant Air Volume Air Conditioning System 

    E-Print Network [OSTI]

    Bai, T.; Zhang, J.; Ning, N.; Tong, K.; Wu, Y.; Wang, H.

    2006-01-01T23:59:59.000Z

    The energy consumption of the constant air volume (CAV) system largely depends on the regulation strategies. Although some air conditioning systems are equipped with automatic regulation devices, others lack effective ...

  8. Control Humidity With Single-Duct, Single-Zone, Constant Air Volume System

    E-Print Network [OSTI]

    Chen, H.; Deng, S.; Bruner, H. L.; Claridge, D. E.

    2000-01-01T23:59:59.000Z

    ), which turned this inefficient, humid lecture hall into a comfortable learning environment. This case study also explores other possibilities to solve the humidity control problem with single-duct, single-zone constant air volume systems....

  9. 96 ASHRAE Transactions: Research Current duct design methods for variable air volume

    E-Print Network [OSTI]

    of the year. Conventional duct design methods do not account for the actual zone load profile. Consequently at an off-peak load condition, and the impact of varying airflow rates to the sizing of duct systems has.Hourlyairflowrequirements, part-load fan characteristics, and duct static pressure control are incorporated into the problem

  10. Variable Speed Drive Volumetric Tracking (VSDVT) for Airflow Control in Variable Air Volume (VAV) Systems 

    E-Print Network [OSTI]

    Liu, M.

    2002-01-01T23:59:59.000Z

    this method by integrating it with the static pressure reset techniques to prevent malfunctioning under several typical building operating problems. Unfortunately, this method can not be used in buildings which have pneumatic terminal box controllers...

  11. Room Temperature Control During Season Switchover with Single Duct Variable Air Volume System Without Reheat

    E-Print Network [OSTI]

    Liu, C.; Deng, S.; Claridge, D. E.; Turner, W. D.; Bruner, H.

    2003-01-01T23:59:59.000Z

    is energized in summer mode or de-energized in winter mode, the output of the PRV is 20psi or 15 psi, respectively. AHU#7 AHU#9 AHU#8 AHU#10 W E AHU#6 AHU#4 AHU #2 AHU#5 AHU#3 S Figure 3. Typical Floor Plan of the 1st through the 4th Floors where...

  12. Energy Savings for Occupancy-Based Control (OBC) of Variable-Air-Volume (VAV) Systems

    SciTech Connect (OSTI)

    Zhang, Jian; Lutes, Robert G.; Liu, Guopeng; Brambley, Michael R.

    2013-01-24T23:59:59.000Z

    This study evaluates the savings potential of occupancy based control (OBC) for large office buildings with VAV terminal boxes installed.

  13. Improving Control of a Dual-Duct Single-Fan Variable Air Volume Systems

    E-Print Network [OSTI]

    Wei, G.; Martinez, J.; Minihan, T.; Brundidge, T.; Claridge, D. E.; Turner, W. D.

    2003-01-01T23:59:59.000Z

    cold and hot air duct static pressure set points is presented. The paper also explores the interactions between the cold and hot deck temperatures and duct static pressures, and discusses the impact of non-ideal deck temperature settings on duct static...

  14. A standard simulation testbed for the evaluation of control algorithms & strategies related to variable air volume HVAC systems

    E-Print Network [OSTI]

    DeSimone, Mark

    1995-01-01T23:59:59.000Z

    The parameters for a dynamic, computer simulation model were developed. The parameters characterize the physical and geometric properties of a building shell, the internal and external building loads, the buildings secondary ...

  15. Cooperative Control of Air Flow for HVAC Systems

    E-Print Network [OSTI]

    Shuai, Liu; Lihua, Xie

    2013-01-01T23:59:59.000Z

    in a variable air volume HVAC system,” Energy, vol. 21, no.Global optimization for overall HVAC systems-part I problemGlobal optimization for overall HVAC systems-part II problem

  16. Impacts of Static Pressure Reset on VAV System Air Leakage, Fan Power and Thermal Energy - Part I: Theoretical Model and Simulation

    E-Print Network [OSTI]

    Liu, M.; Feng, J.; Wang, Z.; Wu, L.; Zheng, K.; Pang, W.

    2007-01-01T23:59:59.000Z

    As for a variable air volume (VAV) system, the air duct static pressure is a typical control variable maintained by modulating supply fan speed. The static pressure equals to the summation of the duct pressure loss downstream of the sensor...

  17. Commissioning and Diagnosis of VAV Air-Conditioning Systems

    E-Print Network [OSTI]

    Qin, J.; Wang, S.; Chan, C.; Xiao, F.

    2006-01-01T23:59:59.000Z

    This paper presents a fault detection and diagnosis (FDD) strategy based on system knowledge, qualitative states and object-oriented statistical process control (SPC) models for typical pressure-independent variable air volume (VAV) air...

  18. Simulation of the Post-Retrofit Thermal Energy Use for the University Teaching Center (UTC) Building with the Use of Simplified System Models 

    E-Print Network [OSTI]

    Katipamula, S.; Claridge, D. E.

    1991-01-01T23:59:59.000Z

    Several state owned buildings with dual-duct constant volume (DDCV) systems have been retrofitted with energy efficient variable air volume systems (VAV) as part of the Texas LoanSTAR Program. One method of determining the energy savings resulting...

  19. Integrated Demand Controlled Ventilation for Single Duct VAV System with Conference Rooms

    E-Print Network [OSTI]

    Yu, Y.; Liu, M.; Cho, Y.; Xu, K.

    2007-01-01T23:59:59.000Z

    Single duct variable air volume (VAV) systems are widely used in office buildings to achieve energy savings. It supplies proper amount of conditioned air to satisfy both the load and the ventilation requirements of each individual zone. To obtain...

  20. Optimization of supply air temperature reset schedule for a single duct VAV systems

    E-Print Network [OSTI]

    Fan, Wenshu

    2009-05-15T23:59:59.000Z

    In a single duct variable air volume (SDVAV) system, the supply air temperature is usually set as a constant value. Since this constant setpoint is selected to satisfy the maximum cooling load conditions, significant reheat will occur once...

  1. Design and evaluation of a prototype laboratory emission control device for use in a variable air volume, face velocity reducing system

    E-Print Network [OSTI]

    Lacey, Steven Edward

    2000-01-01T23:59:59.000Z

    . . . . . . . . , . . . . . . 54 75 96 APPENDIX D TURBULENCE RESULTS . . APPENDIX E PROFILE RESULTS. APPENDIX F POINT DEVIATION RESULTS. 117 138 159 APPENDIX G SPECTROPHOTOMETER CALIBRATION. . . . 180 APPENDIX H FOXBORO SAPHIRE LOWER DETECTABLE LIMIT EXPERIMENT. 185...-150 Occupational Safety and Health Administration (OSHA) 150 for carcinogens National Fire Protection Association (NFPA) "Sufficient to prevent escape of contaminants from hood" Nuclear Regulatory Comission (NRC) Reg. Guide 8. 23 100 for radioactive...

  2. Variable buoyancy system metric

    E-Print Network [OSTI]

    Jensen, Harold Franklin

    2009-01-01T23:59:59.000Z

    Over the past 20 years, underwater vehicle technology has undergone drastic improvements, and vehicles are quickly gaining popularity as a tool for numerous oceanographic tasks. Systems used on the vehicle to alter buoyancy, ...

  3. Variable frequency microwave furnace system

    DOE Patents [OSTI]

    Bible, Don W. (Clinton, TN); Lauf, Robert J. (Oak Ridge, TN)

    1994-01-01T23:59:59.000Z

    A variable frequency microwave furnace system (10) designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity (34) for testing or other selected applications. The variable frequency microwave furnace system (10) includes a microwave signal generator (12) or microwave voltage-controlled oscillator (14) for generating a low-power microwave signal for input to the microwave furnace. A first amplifier (18) may be provided to amplify the magnitude of the signal output from the microwave signal generator (12) or the microwave voltage-controlled oscillator (14). A second amplifier (20) is provided for processing the signal output by the first amplifier (18). The second amplifier (20) outputs the microwave signal input to the furnace cavity (34). In the preferred embodiment, the second amplifier (20) is a traveling-wave tube (TWT). A power supply (22) is provided for operation of the second amplifier (20). A directional coupler (24) is provided for detecting the direction of a signal and further directing the signal depending on the detected direction. A first power meter (30) is provided for measuring the power delivered to the microwave furnace (32). A second power meter (26) detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load (28).

  4. Variable frequency microwave furnace system

    DOE Patents [OSTI]

    Bible, D.W.; Lauf, R.J.

    1994-06-14T23:59:59.000Z

    A variable frequency microwave furnace system designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity for testing or other selected applications. The variable frequency microwave furnace system includes a microwave signal generator or microwave voltage-controlled oscillator for generating a low-power microwave signal for input to the microwave furnace. A first amplifier may be provided to amplify the magnitude of the signal output from the microwave signal generator or the microwave voltage-controlled oscillator. A second amplifier is provided for processing the signal output by the first amplifier. The second amplifier outputs the microwave signal input to the furnace cavity. In the preferred embodiment, the second amplifier is a traveling-wave tube (TWT). A power supply is provided for operation of the second amplifier. A directional coupler is provided for detecting the direction of a signal and further directing the signal depending on the detected direction. A first power meter is provided for measuring the power delivered to the microwave furnace. A second power meter detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load. 5 figs.

  5. AUTOMATIC VARIABLE VENTILATION CONTROL SYSTEMS BASED ON AIR QUALITY DETECTION

    E-Print Network [OSTI]

    Turiel, Isaac

    2011-01-01T23:59:59.000Z

    ~saon Automatic Variable Ventilation Control Systems Based79-3 Automatic variable ventilation control systems based onof automatic variable ventilation control systems, result in

  6. High air volume to low liquid volume aerosol collector

    DOE Patents [OSTI]

    Masquelier, Donald A. (Tracy, CA); Milanovich, Fred P. (Lafayette, CA); Willeke, Klaus (Cincinnati, OH)

    2003-01-01T23:59:59.000Z

    A high air volume to low liquid volume aerosol collector. A high volume flow of aerosol particles is drawn into an annular, centripetal slot in a collector which directs the aerosol flow into a small volume of liquid pool contained is a lower center section of the collector. The annular jet of air impinges into the liquid, imbedding initially airborne particles in the liquid. The liquid in the pool continuously circulates in the lower section of the collector by moving to the center line, then upwardly, and through assistance by a rotating deflector plate passes back into the liquid at the outer area adjacent the impinging air jet which passes upwardly through the liquid pool and through a hollow center of the collector, and is discharged via a side outlet opening. Any liquid droplets escaping with the effluent air are captured by a rotating mist eliminator and moved back toward the liquid pool. The collector includes a sensor assembly for determining, controlling, and maintaining the level of the liquid pool, and includes a lower centrally located valve assembly connected to a liquid reservoir and to an analyzer for analyzing the particles which are impinged into the liquid pool.

  7. Analysis of Innovative HVAC System Technologies and Their Application for Office Buildings in Hot and Humid Climates

    E-Print Network [OSTI]

    Tanskyi, Oleksandr

    2012-02-14T23:59:59.000Z

    air distribution system VAV ? Variable air volume VFD ? Variable frequency drive wb ? wet-bulb WERC ? Wisenbaker Engineering Research Center viii TABLE OF CONTENTS Page ABSTRACT... fulfillment of the requirements for the degree of MASTER OF SCIENCE December 2010 Major Subject: Mechanical Engineering Analysis of Innovative HVAC System Technologies and Their Application for Office...

  8. Improved Air Volume Control Logic for VAV Systems

    E-Print Network [OSTI]

    Wei, G.; Claridge, D. E.; Sakuri, Y.; M. Liu

    2000-01-01T23:59:59.000Z

    is often set at a constant value, which is adequate to provide design flow to each room. This method consumes more fan power than necessary under partial load conditions. The fan speed or inlet guide vane can also be controlled based on the maximum damper...

  9. Renewable variable speed hybrid system 

    E-Print Network [OSTI]

    Stott, Paul Anthony

    2010-01-01T23:59:59.000Z

    generator island grids, these generators will be running at a fraction of maximum output for most of the time. A new variable speed diesel generator allows for a reduction in fuel consumption at part load compared to constant speed operation. Combining...

  10. AUTOMATIC VARIABLE VENTILATION CONTROL SYSTEMS BASED ON AIR QUALITY DETECTION

    E-Print Network [OSTI]

    Turiel, Isaac

    2011-01-01T23:59:59.000Z

    saon Automatic Variable Ventilation Control Systems Based onL Kusuda, "Control Ventilation to Conserve Energy While t·79-3 Automatic variable ventilation control systems based on

  11. Demonstration of a Variable Phase Turbine Power System for Low...

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

    Demonstration of a Variable Phase Turbine Power System for Low Temperature Geothermal Resources Demonstration of a Variable Phase Turbine Power System for Low Temperature...

  12. Production-Intent Lost-Motion Variable Valve Actuation Systems...

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

    Production-Intent Lost-Motion Variable Valve Actuation Systems Production-Intent Lost-Motion Variable Valve Actuation Systems Variable valve actuation with onoff IEGR pre-bump is...

  13. Theoretical Study of a Novel Control Method of VAV Air-conditioning System Based on MATLAB

    E-Print Network [OSTI]

    Shi, Z.; Hu, S.; Wang, G.; Li, A.

    2006-01-01T23:59:59.000Z

    The main purpose of this study is to put forward a novel nonlinear feedback control strategy on controlling indoor air temperature by variable air volume. A dynamic model of a typical room for a VAV air-conditioning system is established...

  14. Variable pressure power cycle and control system

    DOE Patents [OSTI]

    Goldsberry, Fred L. (Spring, TX)

    1984-11-27T23:59:59.000Z

    A variable pressure power cycle and control system that is adjustable to a variable heat source is disclosed. The power cycle adjusts itself to the heat source so that a minimal temperature difference is maintained between the heat source fluid and the power cycle working fluid, thereby substantially matching the thermodynamic envelope of the power cycle to the thermodynamic envelope of the heat source. Adjustments are made by sensing the inlet temperature of the heat source fluid and then setting a superheated vapor temperature and pressure to achieve a minimum temperature difference between the heat source fluid and the working fluid.

  15. air volume air: Topics by E-print Network

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

    Air Preheat Economics Texas A&M University - TxSpace Summary: Retrofit air preheat systems are the most reliable and efficient means to effect significant energy...

  16. Procedure and Application for Determining the Cold Deck and Hot Deck Airflow in a Dual-Duct System

    E-Print Network [OSTI]

    Liu, G.; Mingsheng, L.

    2006-01-01T23:59:59.000Z

    This paper introduces an innovative method to determine the cold and hot airflow through a dual-duct variable air volume (VAV) system. The actual building load can be identified based on the calculated airflow and temperature for both the cold...

  17. Compact, electro-hydraulic, variable valve actuation system providing...

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

    Compact, electro-hydraulic, variable valve actuation system providing variable lift, timing and duration to enable high efficiency engine combustion control Compact,...

  18. Thermal and air quality acceptability in buildings that reduce energy by reducing minimun airflow from overhead diffusers

    E-Print Network [OSTI]

    2012-01-01T23:59:59.000Z

    for rating the performance of air outlets and inlets. ANSI/comfort with a variable air volume (VAV) system. InternalGuidelines: Advanced Variable Air Volume (VAV) Systems.

  19. Variable temperature seat climate control system

    DOE Patents [OSTI]

    Karunasiri, Tissa R. (Van Nuys, CA); Gallup, David F. (Pasadena, CA); Noles, David R. (Glendale, CA); Gregory, Christian T. (Alhambra, CA)

    1997-05-06T23:59:59.000Z

    A temperature climate control system comprises a variable temperature seat, at least one heat pump, at least one heat pump temperature sensor, and a controller. Each heat pump comprises a number of Peltier thermoelectric modules for temperature conditioning the air in a main heat exchanger and a main exchanger fan for passing the conditioned air from the main exchanger to the variable temperature seat. The Peltier modules and each main fan may be manually adjusted via a control switch or a control signal. Additionally, the temperature climate control system may comprise a number of additional temperature sensors to monitor the temperature of the ambient air surrounding the occupant as well as the temperature of the conditioned air directed to the occupant. The controller is configured to automatically regulate the operation of the Peltier modules and/or each main fan according to a temperature climate control logic designed both to maximize occupant comfort during normal operation, and minimize possible equipment damage, occupant discomfort, or occupant injury in the event of a heat pump malfunction.

  20. Strategies and Decision Support Systems for Integrating Variable...

    Open Energy Info (EERE)

    Strategies and Decision Support Systems for Integrating Variable Energy Resources in Control Centers for Reliable Grid Operations: Global Best Practices, Examples of Excellence and...

  1. ASSESSMENT OF VARIABLE EFFECTS OF SYSTEMS WITH DEMAND RESPONSE RESOURCES

    E-Print Network [OSTI]

    Gross, George

    ASSESSMENT OF VARIABLE EFFECTS OF SYSTEMS WITH DEMAND RESPONSE RESOURCES BY ANUPAMA SUNIL KOWLI B of consumers - called demand response resources (DRRs) - whose role has become increasingly important

  2. Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01T23:59:59.000Z

    Comparison of energy efficiency between variable refrigeranttheir superior energy efficiency. The variable refrigerantfew studies reporting the energy efficiency of VRF systems

  3. Optimal Controlled Variables for Polynomial Systems Johannes Jaschke, Sigurd Skogestad

    E-Print Network [OSTI]

    Skogestad, Sigurd

    Optimal Controlled Variables for Polynomial Systems Johannes J¨aschke, Sigurd Skogestad Department control enables us to separate the two problems of optimizing the system and designing the controller Abstract We present a method for finding optimal controlled variables, which are poly- nomial combinations

  4. Quantifying the Variable Effects of Systems with Demand Response Resources

    E-Print Network [OSTI]

    Gross, George

    Quantifying the Variable Effects of Systems with Demand Response Resources Anupama Kowli and George in the electricity industry. In particular, there is a new class of consumers, called demand response resources (DRRs

  5. Solar Forecasting System and Irradiance Variability Characterization

    E-Print Network [OSTI]

    and Energy Reliability As part of Cooperative Agreement No. DE-EE0003507 Under Task 3.1: Photovoltaic Systems Reliability Under Cooperative Agreement No. DE-EE0003507 Hawai`i Energy Sustainability Program Subtask 3.1 Photovoltaic Systems: Report 3 Development of data base allowing managed access to statewide PV and insolation

  6. Variable emissivity laser thermal control system

    DOE Patents [OSTI]

    Milner, Joseph R. (Livermore, CA)

    1994-01-01T23:59:59.000Z

    A laser thermal control system for a metal vapor laser maintains the wall mperature of the laser at a desired level by changing the effective emissivity of the water cooling jacket. This capability increases the overall efficiency of the laser.

  7. Variable emissivity laser thermal control system

    DOE Patents [OSTI]

    Milner, J.R.

    1994-10-25T23:59:59.000Z

    A laser thermal control system for a metal vapor laser maintains the wall temperature of the laser at a desired level by changing the effective emissivity of the water cooling jacket. This capability increases the overall efficiency of the laser. 8 figs.

  8. Measuring Advances in HVAC Distribution System Design

    SciTech Connect (OSTI)

    Franconi, E.

    1998-05-01T23:59:59.000Z

    Substantial commercial building energy savings have been achieved by improving the performance of the HV AC distribution system. The energy savings result from distribution system design improvements, advanced control capabilities, and use of variable-speed motors. Yet, much of the commercial building stock remains equipped with inefficient systems. Contributing to this is the absence of a definition for distribution system efficiency as well as the analysis methods for quantifying performance. This research investigates the application of performance indices to assess design advancements in commercial building thermal distribution systems. The index definitions are based on a first and second law of thermodynamics analysis of the system. The second law or availability analysis enables the determination of the true efficiency of the system. Availability analysis is a convenient way to make system efficiency comparisons since performance is evaluated relative to an ideal process. A TRNSYS simulation model is developed to analyze the performance of two distribution system types, a constant air volume system and a variable air volume system, that serve one floor of a large office building. Performance indices are calculated using the simulation results to compare the performance of the two systems types in several locations. Changes in index values are compared to changes in plant energy, costs, and carbon emissions to explore the ability of the indices to estimate these quantities.

  9. Comparisons of HVAC Simulations between EnergyPlus and DOE-2.2 for Data Centers

    E-Print Network [OSTI]

    Hong, Tianzhen

    2009-01-01T23:59:59.000Z

    cooling systems with and without water economizer Variable air volume systems Multiple CRAC units for the data center

  10. Electromagnetic variable degrees of freedom actuator systems and methods

    DOE Patents [OSTI]

    Montesanti, Richard C. (Pleasanton, CA); Trumper, David L. (Plaistow, NH); Kirtley, Jr., James L. (Brookline, MA)

    2009-02-17T23:59:59.000Z

    The present invention provides a variable reluctance actuator system and method that can be adapted for simultaneous rotation and translation of a moving element by applying a normal-direction magnetic flux on the moving element. In a beneficial example arrangement, the moving element includes a swing arm that carries a cutting tool at a set radius from an axis of rotation so as to produce a rotary fast tool servo that provides a tool motion in a direction substantially parallel to the surface-normal of a workpiece at the point of contact between the cutting tool and workpiece. An actuator rotates a swing arm such that a cutting tool moves toward and away from a mounted rotating workpiece in a controlled manner in order to machine the workpiece. Position sensors provide rotation and displacement information for a swing arm to a control system. A control system commands and coordinates motion of the fast tool servo with the motion of a spindle, rotating table, cross-feed slide, and in feed slide of a precision lathe.

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

    E-Print Network [OSTI]

    -Speed-Drive Chillers Tengfang Xu June 15, 2005 The project is funded by the California Energy Commission's Industrial Efficient Cleanrooms Efficient HVAC Water Systems: Variable-Speed-Drive Chillers Tengfang Xu Contents HVAC.............................................................................................. 2 Variable-Speed-Drive Chillers

  12. Energy Efficiency Improvement and Cost Saving Opportunities for the Dairy Processing Industry: An ENERGY STAR? Guide for Energy and Plant Managers

    E-Print Network [OSTI]

    Brush, Adrian

    2014-01-01T23:59:59.000Z

    VCH, New York. Carrier Aeroseal, LLC (2002). Case Studies:s HVAC system (Carrier Aeroseal 2002). Variable-air-volume

  13. Energy Efficiency Improvement and Cost Saving Opportunities for the Petrochemical Industry - An ENERGY STAR(R) Guide for Energy and Plant Managers

    E-Print Network [OSTI]

    Neelis, Maarten

    2008-01-01T23:59:59.000Z

    the Netherlands. Carrier Aeroseal (2002). Case Studies: Wests HVAC system (Carrier Aeroseal 2002). Variable-air-volume

  14. Energy Efficiency Improvement and Cost Saving Opportunities for the Dairy Processing Industry

    E-Print Network [OSTI]

    Brush, Adrian

    2012-01-01T23:59:59.000Z

    VCH, New York. Carrier Aeroseal, LLC (2002). Case Studies:s HVAC system (Carrier Aeroseal 2002). Variable-air-volume

  15. Energy Efficiency Improvement and Cost Saving Opportunities for the Fruit and Vegetable Processing Industry. An ENERGY STAR Guide for Energy and Plant Managers

    E-Print Network [OSTI]

    Masanet, Eric

    2008-01-01T23:59:59.000Z

    February. Carrier Aeroseal, LLC (2002). Case Studies: Wests HVAC system (Carrier Aeroseal 2002). Variable-air-volume

  16. Sliding Mode Power Control of Variable Speed Wind Energy Conversion Systems

    E-Print Network [OSTI]

    Boyer, Edmond

    Sliding Mode Power Control of Variable Speed Wind Energy Conversion Systems B. Beltran, T. Ahmed power generation in variable speed wind energy conversion systems (VS-WECS). These systems have two variations. Index Terms--Wind energy conversion system, power generation control, sliding mode control

  17. High Temperature Variable Conductance Heat Pipes for Radioisotope Stirling Systems

    SciTech Connect (OSTI)

    Tarau, Calin; Walker, Kara L.; Anderson, William G. [Advanced Cooling Technologies, Inc. 1046 New Holland Ave. Lancaster, PA 17601 (United States)

    2009-03-16T23:59:59.000Z

    In a Stirling radioisotope system, heat must continually be removed from the GPHS modules, to maintain the GPHS modules and surrounding insulation at acceptable temperatures. Normally, the Stirling converter provides this cooling. If the Stirling engine stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS, but also ending the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) is under development to allow multiple stops and restarts of the Stirling engine. The status of the ongoing effort in developing this technology is presented in this paper. An earlier, preliminary design had a radiator outside the Advanced Stirling Radioisotope Generator (ASRG) casing, used NaK as the working fluid, and had the reservoir located on the cold side adapter flange. The revised design has an internal radiator inside the casing, with the reservoir embedded inside the insulation. A large set of advantages are offered by this new design. In addition to reducing the overall size and mass of the VCHP, simplicity, compactness and easiness in assembling the VCHP with the ASRG are significantly enhanced. Also, the permanently elevated temperatures of the entire VCHP allows the change of the working fluid from a binary compound (NaK) to single compound (Na). The latter, by its properties, allows higher performance and further mass reduction of the system. Preliminary design and analysis shows an acceptable peak temperature of the ASRG case of 140 deg. C while the heat losses caused by the addition of the VCHP are 1.8 W.

  18. Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems

    SciTech Connect (OSTI)

    Hong, Tainzhen; Liu, Xaiobing

    2009-11-01T23:59:59.000Z

    With the current movement toward net zero energy buildings, many technologies are promoted with emphasis on their superior energy efficiency. The variable refrigerant flow (VRF) and ground source heat pump (GSHP) systems are probably the most competitive technologies among these. However, there are few studies reporting the energy efficiency of VRF systems compared with GSHP systems. In this article, a preliminary comparison of energy efficiency between the air-source VRF and GSHP systems is presented. The computer simulation results show that GSHP system is more energy efficient than the air-source VRF system for conditioning a small office building in two selected US climates. In general, GSHP system is more energy efficient than the air-source VRV system, especially when the building has significant heating loads. For buildings with less heating loads, the GSHP system could still perform better than the air-source VRF system in terms of energy efficiency, but the resulting energy savings may be marginal.

  19. High Frequency Effects of Variable Frequency Drives (VFD) on Electrical Submersible Pump (ESP) Systems

    E-Print Network [OSTI]

    Ozkentli, Esra

    2012-10-19T23:59:59.000Z

    Variable frequency drives (VFD) and subsea (umbilical) cables are frequently used in electrical submersible pump (ESP) systems for offshore platforms. There are two basic system configurations for ESP systems; VFD can be installed on the platform...

  20. System and method of modulating electrical signals using photoconductive wide bandgap semiconductors as variable resistors

    DOE Patents [OSTI]

    Harris, John Richardson; Caporaso, George J; Sampayan, Stephen E

    2013-10-22T23:59:59.000Z

    A system and method for producing modulated electrical signals. The system uses a variable resistor having a photoconductive wide bandgap semiconductor material construction whose conduction response to changes in amplitude of incident radiation is substantially linear throughout a non-saturation region to enable operation in non-avalanche mode. The system also includes a modulated radiation source, such as a modulated laser, for producing amplitude-modulated radiation with which to direct upon the variable resistor and modulate its conduction response. A voltage source and an output port, are both operably connected to the variable resistor so that an electrical signal may be produced at the output port by way of the variable resistor, either generated by activation of the variable resistor or propagating through the variable resistor. In this manner, the electrical signal is modulated by the variable resistor so as to have a waveform substantially similar to the amplitude-modulated radiation.

  1. AUTOMATIC VARIABLE VENTILATION CONTROL SYSTEMS BASED ON AIR QUALITY DETECTION

    E-Print Network [OSTI]

    Turiel, Isaac

    2011-01-01T23:59:59.000Z

    SUt1t1ARY Mechanical ventilation systems usually provide aof any 02 based ventilation system is that a ventilationwith type of ventilation system~ weather conditions, and

  2. The Effect of Pressure Difference Control on Hydraulic Stability in a Variable Flow Air Conditioning System

    E-Print Network [OSTI]

    Zhang, Z.; Fu, Y.; Chen, Y.

    2006-01-01T23:59:59.000Z

    This paper analyzes the effects of different pressure difference control methods on hydraulic stability in a variable flow air conditioning system when it is applied to different air conditioning water systems. According to control method and water...

  3. Predictive and Corrective Scheduling in Electric Energy Systems with Variable Resources 

    E-Print Network [OSTI]

    Gu, Yingzhong

    2014-11-05T23:59:59.000Z

    real-time power system operations. This dissertation focuses on introducing and testing advanced scheduling algorithms for electric power systems with high penetration of variable resources. A novel predictive and optimal corrective look-ahead dispatch...

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

    E-Print Network [OSTI]

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

    2002-01-01T23:59:59.000Z

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

  5. Numerical Analysis of a Cold Air Distribution System

    E-Print Network [OSTI]

    Zhu, L.; Li, R.; Yuan, D.

    2006-01-01T23:59:59.000Z

    Cold air distribution systems may reduce the operating energy consumption of air-conditioned air supply system and improve the outside air volume percentages and indoor air quality. However, indoor temperature patterns and velocity field are easily...

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

    DOE Patents [OSTI]

    Frank, A.A.

    1984-07-10T23:59:59.000Z

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

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

    DOE Patents [OSTI]

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

    1984-01-01T23:59:59.000Z

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

  8. Impact of the Variable Refrigerant Volume Air Conditioning System on Building Energy Efficiency

    E-Print Network [OSTI]

    Zhu, H.

    2006-01-01T23:59:59.000Z

    ICEBO2006, Shenzhen, China HVAC Technologies for Energy Efficiency Vol.IV-1-3 Impact of the Variable Refrigerant Volume Air Conditioning System on Building Energy Efficiency Huawei Zhu Zhejiang Urban and Rural Planning Design Institute... conditioning system has led to extensive criticism. 2. THE CHARACTERISTICS OF THE VARIABLE REFRIGERANT VOLUME AIR CONDITIONING SYSTEM AND ITS PRESENT APPLICATION ICEBO2006, Shenzhen, China HVAC Technologies for Energy Efficiency Vol.IV-1-3 2...

  9. A Method to Study the Effect of Renewable Resource Variability on Power System Dynamics

    E-Print Network [OSTI]

    Liberzon, Daniel

    1 A Method to Study the Effect of Renewable Resource Variability on Power System Dynamics Yu reliance on renewable resources, such as wind or solar. It is well known that the integration proposes a set-theoretic method to assess the effect of variability associated with renewable-based elec

  10. Electro-hydraulic control system for a dual-pass continuously variable transmission

    SciTech Connect (OSTI)

    Algrain, M.C.; Anderson, S.R.; Smirl, R.L.

    1991-07-16T23:59:59.000Z

    This patent describes a control system for controlling the hydraulic pressure in a dual-pass continuously variable transmission system having a plurality of drive paths from a power input to a power output, and a continuously variable component including first and second variable pulleys disposed respectively on first and second intermediate shafts, the transmission system having first and second clutches engagable to effect transition from a first drive path in which the first variable pulley is the driver pulley to a second drive path in which the second variable pulley is the driver pulley, the transmission system being releasable to effect a transition from the second drive path to the first drive path. It comprises means to provide a primary hydraulic pressure to each of the first and second variable pulleys; means for providing a secondary hydraulic pressure to each of the first and second variable pulleys; means for electrically regulating the primary and secondary pressures responsive to engine conditions; and means for directing the primary and secondary hydraulic pressures to the first and second variable pulleys in response to change of drive path.

  11. Energy-Saving Design for Pressure Difference Control in Variable Flow Air Conditioning Systems

    E-Print Network [OSTI]

    Chen, Y.; Zhang, Z.

    2006-01-01T23:59:59.000Z

    This paper analyzes energy-saving design for pressure-difference control in a variable flow air conditioning system, including the application of a pressure-difference control valve and the installation position of a pressure-difference transducer...

  12. Impact of the Variable Refrigerant Volume Air Conditioning System on Building Energy Efficiency 

    E-Print Network [OSTI]

    Zhu, H.

    2006-01-01T23:59:59.000Z

    The application of the variable refrigerant volume multi-zone air conditioning systems has met with mixed results since the publication of the Design Standard for Energy Efficiency of Public Buildings. This paper analyzes the characteristics...

  13. Predictive and Corrective Scheduling in Electric Energy Systems with Variable Resources

    E-Print Network [OSTI]

    Gu, Yingzhong

    2014-11-05T23:59:59.000Z

    In the past decade, there has been sustained efforts around the globe in developing renewable energy-based generation in power systems. However, many renewables such as wind and solar are variable resources. They pose significant challenges to near...

  14. Single-Duct Constant Air Volume System Supply Air Temperature Reset: Using Return Air Temperature or Outside Air Temperature? 

    E-Print Network [OSTI]

    Wei, G.; Turner, W. D.; Claridge, D.; Liu, M.

    2002-01-01T23:59:59.000Z

    space area. Room temperatures are controlled by pneumatic thermostats. The AHU has a minimum outside air damper and a maximum outside air damper. The minimum outside air damper is fully open when the AHU is in operation. The maximum outside air... of thermostat, and the relationship between room temperature set point and return air temperature. The Role Of Thermostat Traditional pneumatic thermostat is a proportional (P) type controller. It senses the space temperature changes and produces...

  15. Single-Duct Constant Air Volume System Supply Air Temperature Reset: Using Return Air Temperature or Outside Air Temperature?

    E-Print Network [OSTI]

    Wei, G.; Turner, W. D.; Claridge, D.; Liu, M.

    2002-01-01T23:59:59.000Z

    space area. Room temperatures are controlled by pneumatic thermostats. The AHU has a minimum outside air damper and a maximum outside air damper. The minimum outside air damper is fully open when the AHU is in operation. The maximum outside air... understand how this reset scheme responds to building load change, thus resulting in supply air temperature reset, it is helpful to explain the role of thermostat. In the following section, we explain the way how the thermostat works, the type...

  16. Method and system to estimate variables in an integrated gasification combined cycle (IGCC) plant

    DOE Patents [OSTI]

    Kumar, Aditya; Shi, Ruijie; Dokucu, Mustafa

    2013-09-17T23:59:59.000Z

    System and method to estimate variables in an integrated gasification combined cycle (IGCC) plant are provided. The system includes a sensor suite to measure respective plant input and output variables. An extended Kalman filter (EKF) receives sensed plant input variables and includes a dynamic model to generate a plurality of plant state estimates and a covariance matrix for the state estimates. A preemptive-constraining processor is configured to preemptively constrain the state estimates and covariance matrix to be free of constraint violations. A measurement-correction processor may be configured to correct constrained state estimates and a constrained covariance matrix based on processing of sensed plant output variables. The measurement-correction processor is coupled to update the dynamic model with corrected state estimates and a corrected covariance matrix. The updated dynamic model may be configured to estimate values for at least one plant variable not originally sensed by the sensor suite.

  17. Enhanced Recovery Utilizing Variable Frequency Drives and a Distributed Power System

    SciTech Connect (OSTI)

    Randy Peden; Sanjiv Shah

    2005-07-26T23:59:59.000Z

    This report describes complete results of the project entitled ''Enhanced Recovery Utilizing Variable Frequency Drives and a Distributed Power System''. This demonstration project was initiated in July 2003 and completed in March 2005. The objective of the project was to develop an integrated power production/variable frequency drive system that could easily be deployed in the oil field that would increase production and decrease operating costs. This report describes all the activities occurred and documents results of the demonstration.

  18. System for throttling and compensation for variable feedstock properties

    DOE Patents [OSTI]

    Meyer, J. W.

    1981-05-05T23:59:59.000Z

    Apparatus is shown for adjusting the feed rate of pulverized feed material into a pressurized container. The apparatus also has utility for compensating for variations in the permeability of the feed material. A rotor that includes sprues with provision for controlling the pressure distribution along the sprues is located within the pressurized container. The rotor hub is connected to a drive means and a material supply means which extend through the wall of the container. A line for controlling pressure along the sprues by gas injection is connected to a chamber between sections of the sprue for controlling gas pressure at that point. The gas pressure control line is connected to a pressurized gas source and a control system external to the rotor. 10 figs.

  19. System for throttling and compensation for variable feedstock properties

    DOE Patents [OSTI]

    Meyer, John W. (Palo Alto, CA)

    1981-01-01T23:59:59.000Z

    Apparatus is shown for adjusting the feed rate of pulverized feed material into a pressurized container. The apparatus also has utility for compensating for variations in the permeability of the feed material. A rotor that includes sprues with provision for controlling the pressure distribution along the sprues is located within the pressurized container. The rotor hub is connected to a drive means and a material supply means which extend through the wall of the container. A line for controlling pressure along the sprues by gas injection is connected to a chamber between sections of the sprue for controlling gas pressure at that point. The gas pressure control line is connected to a pressurized gas source and a control system external to the rotor.

  20. Finite Bisimulation of Reactive Untimed Infinite State Systems Modeled as Automata with Variables

    E-Print Network [OSTI]

    Kumar, Ratnesh

    1 Finite Bisimulation of Reactive Untimed Infinite State Systems Modeled as Automata with Variables for reactive untimed infinite state systems called input- output extended finite automaton (I/O-EFA), which of a finite bisimilar abstraction. The results are illustrated through examples that model reactive software

  1. A Simple and Quick Chilled Water Loop Balancing for Variable Flow System

    E-Print Network [OSTI]

    Zhu, Y.; Batten, T.; Turner, W. D.; Claridge, D. E.; Liu, M.

    2000-01-01T23:59:59.000Z

    system is reduced by about 40%. Key words: chilled water, loop, riser, balancing, commissioning, cold deck, pump, energy consumption, EMCS. INTRODUCTION Variable flow pumping systems are becoming more prevalent in the chilled water loops or risers... the building owner, facility engineers or HVAC operators more opportunities to run the chilled water system more efficiently. Generally, the pump speeds are controlled by the EMCS or a stand-alone controller to maintain the differential pressure setpoints...

  2. The RenewElec Project: Variable Renewable Energy and the Power System

    SciTech Connect (OSTI)

    Apt, Jay

    2014-02-14T23:59:59.000Z

    Variable energy resources, such as wind power, now produce about 4% of U.S. electricity. They can play a significantly expanded role if the U.S. adopts a systems approach that considers affordability, security and reliability. Reaching a 20-30% renewable portfolio standard goal is possible, but not without changes in the management and regulation of the power system, including accurately assessing and preparing for the operational effects of renewable generation. The RenewElec project will help the nation make the transition to the use of significant amounts of electric generation from variable and intermittent sources of renewable power.

  3. Application of multi-variable control for automatic frequency controller of HVDC transmission system

    SciTech Connect (OSTI)

    Sanpei, Masatoshi (Electric Power Development Co., Tokyo (Japan)); Kakehi, Atsuyuki; Takeda, Hideo (Toshiba Corp., Tokyo (Japan))

    1994-04-01T23:59:59.000Z

    In an HVDC transmission system that links two ac power systems, the automatic frequency controller (AFC) calculates power to be interchanged between the two ac systems according to their frequencies thereby improving the frequency characteristics of the two power systems. This paper introduces a newly developed dc AFC system, which applies a multi-variable control to the dc system-based frequency control. It is capable of controlling the frequencies of the two ac systems optimally while maintaining their stability. This system was developed for one of Japan's HVDC transmission facilities and produced good results in a combined test using a power system simulator. The field installation will be completed in March 1993, when the AFC system will enter service.

  4. Late evolution of cataclysmic variables: the loss of AM Her systems

    E-Print Network [OSTI]

    F. Meyer; E. Meyer-Hofmeister

    1999-07-14T23:59:59.000Z

    The white dwarf in AM Her systems is strongly magnetic and keeps in synchronous rotation with the orbit by magnetic coupling to the secondary star. As the latter evolves through mass loss to a cool, degenerate brown dwarf it can no longer sustain its own magnetic field and coupling is lost. Angular momentum accreted then spins up the white dwarf and the system no longer appears as an AM Her system. Possible consequences are run-away mass transfer and mass ejection from the system. Some of the unusual cataclysmic variable systems at low orbital periods may be the outcome of this evolution.

  5. ENHANCED RECOVERY UTILIZING VARIABLE FREQUENCY DRIVES AND A DISTRIBUTED POWER SYSTEM TECHNICAL PROGRESS REPORT

    SciTech Connect (OSTI)

    Randy Peden; Sanjiv Shah

    2004-02-11T23:59:59.000Z

    This report describes the progress made during first six months of the project entitled ''Enhanced Recovery Utilizing Variable Frequency Drives and a Distributed Power System''. During this period, project plan, demonstration plan and project schedule were developed, equipment was ordered and baseline data was collected.

  6. The linear quadratic optimal control problem for linear descriptor systems with variable coefficients

    E-Print Network [OSTI]

    Kunkel, Peter

    The linear quadratic optimal control problem for linear descriptor systems with variable coefficients Peter Kunkel 3 Volker Mehrmann y 17.01.97 Abstract We study linear quadratic optimal control, 93B11, 93B40 1 Introduction In this paper we study the linear­quadratic optimal control problem

  7. Assessing the Impact of Wind Variability on Power System Small-Signal Reachability

    E-Print Network [OSTI]

    Liberzon, Daniel

    Assessing the Impact of Wind Variability on Power System Small-Signal Reachability Yu Christine-signal and transient stability [6]. In this regard, it has been acknowledged that, as the presence of wind in the power balancing in near real time [7]. This paper focuses on this last problem--the impact of wind penetration

  8. Wavelength attack on practical continuous-variable quantum-key-distribution system with a heterodyne protocol

    E-Print Network [OSTI]

    Xiang-Chun Ma; Shi-Hai Sun; Mu-Sheng Jiang; Lin-Mei Liang

    2014-03-04T23:59:59.000Z

    We present the wavelength attack on a practical continuous-variable quantum-key-distribution system with a heterodyne protocol, in which the transmittance of beam splitters at Bob's station is wavelength-dependent. Our strategy is proposed independent of but analogous to that of Huang et al. [arXiv: 1206.6550v1 [quant-ph

  9. Variable mode bi-directional and uni-directional computer communication system

    DOE Patents [OSTI]

    Cornett, Frank N.; Jenkins, Philip N.; Bowman, Terrance L.; Placek, Joseph M.; Thorson, Gregory M.

    2004-12-14T23:59:59.000Z

    A variable communication systems comprising a plurality of transceivers and a control circuit connected to the transceivers to configure the transceivers to operate in a bi-directional mode and a uni-directional mode at different times using different transfer methods to transfer data.

  10. Variable-speed wind power system with improved energy capture via multilevel conversion

    DOE Patents [OSTI]

    Erickson, Robert W.; Al-Naseem, Osama A.; Fingersh, Lee Jay

    2005-05-31T23:59:59.000Z

    A system and method for efficiently capturing electrical energy from a variable-speed generator are disclosed. The system includes a matrix converter using full-bridge, multilevel switch cells, in which semiconductor devices are clamped to a known constant DC voltage of a capacitor. The multilevel matrix converter is capable of generating multilevel voltage wave waveform of arbitrary magnitude and frequencies. The matrix converter can be controlled by using space vector modulation.

  11. Multiple-Zone Variable Refrigerant Flow System Modeling and Equipment Performance Mapping

    SciTech Connect (OSTI)

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

    2012-01-01T23:59:59.000Z

    We developed a variable refrigerant flow (VRF) vapor compression system model, which has five indoor units, one outdoor unit and one water heater. The VRF system can run simultaneous space conditioning (cooling or heating) and water heating. The indoor units and outdoor unit use fin-&-tube coil heat exchangers, and the water heater uses a tube-in-tube heat exchanger. The fin-&-tube coil heat exchangers are modeled using a segment-by-segment approach and the tube-in-tube water heater is modeled using a phase-by-phase approach. The compressor used is a variable-speed rotary design. We calibrated our model against a manufacturer s product literature. Based on the vapor compression system model, we investigated the methodology for generating VRF equipment performance maps, which can be used for energy simulations in TRNSYS and EnergyPlus, etc. In the study, the major independent variables for mapping are identified and the deviations between the simplified performance map and the actual equipment system simulation are quantified.

  12. Variable Renewable Generation can Provide Balancing Control to the Electric Power System (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2013-09-01T23:59:59.000Z

    As wind and solar plants become more common in the electric power system, they may be called on to provide grid support services to help maintain system reliability. For example, through the use of inertial response, primary frequency response, and automatic generation control (also called secondary frequency response), wind power can provide assistance in balancing the generation and load on the system. These active power (i.e., real power) control services have the potential to assist the electric power system in times of disturbances and during normal conditions while also potentially providing economic value to consumers and variable renewable generation owners. This one-page, two-sided fact sheet discusses the grid-friendly support and benefits renewables can provide to the electric power system.

  13. Quantum key distribution over 25 km with an all-fiber continuous-variable system

    E-Print Network [OSTI]

    Jerome Lodewyck; Matthieu Bloch; Raul Garcia-Patron; Simon Fossier; Evgueni Karpov; Eleni Diamanti; Thierry Debuisschert; Nicolas J. Cerf; Rosa Tualle-Brouri; Steven W. McLaughlin; Philippe Grangier

    2007-09-04T23:59:59.000Z

    We report on the implementation of a reverse-reconciliated coherent-state continuous-variable quantum key distribution system, with which we generated secret keys at a rate of more than 2 kb/s over 25 km of optical fiber. Time multiplexing is used to transmit both the signal and phase reference in the same optical fiber. Our system includes all experimental aspects required for a field implementation of a quantum key distribution setup. Real-time reverse reconciliation is achieved by using fast and efficient LDPC error correcting codes.

  14. Quantum key distribution over 25 km with an all-fiber continuous-variable system

    SciTech Connect (OSTI)

    Lodewyck, Jerome; Fossier, Simon [Thales Research and Technologies, RD 128, 91767 Palaiseau Cedex (France); Laboratoire Charles Fabry de l'Institut d'Optique-CNRS-Universite Paris-Sud, Campus Polytechnique, RD 128, 91127 Palaiseau Cedex (France); Bloch, Matthieu; McLaughlin, Steven W. [GeorgiaTech-CNRS UMI 2958, 2-3 rue Marconi, 57070 Metz (France); Garcia-Patron, Raul; Karpov, Evgueni; Cerf, Nicolas J. [Centre for Quantum Information and Communication, Ecole Polytechnique, CP 165/59, Universite libre de Bruxelles, 50 av. F. D. Roosevelt, B-1050 Brussels (Belgium); Diamanti, Eleni; Tualle-Brouri, Rosa; Grangier, Philippe [Laboratoire Charles Fabry de l'Institut d'Optique-CNRS-Universite Paris-Sud, Campus Polytechnique, RD 128, 91127 Palaiseau Cedex (France); Debuisschert, Thierry [Thales Research and Technologies, RD 128, 91767 Palaiseau Cedex (France)

    2007-10-15T23:59:59.000Z

    We report on the implementation of a reverse-reconciliated coherent-state continuous-variable quantum key distribution system, with which we generated secret keys at a rate of more than 2 kb/s over 25 km of optical fiber. Time multiplexing is used to transmit both the signal and phase reference in the same optical fiber. Our system includes all experimental aspects required for a field implementation of a quantum key distribution setup. Real-time reverse reconciliation is achieved by using fast and efficient low-density parity check error correcting codes.

  15. Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01T23:59:59.000Z

    heat pump, and the energy consumption of the whole GSHP system given the accurate information of the building, GSHP system, weather data,

  16. Recent Developments of the Modelica"Buildings" Library for Building Energy and Control Systems

    SciTech Connect (OSTI)

    Wetter, Michael; Zuo, Wangda; Nouidui, Thierry Stephane

    2011-04-01T23:59:59.000Z

    At the Modelica 2009 conference, we introduced the Buildings library, a freely available Modelica library for building energy and control systems. This paper reports the updates of the library and presents example applications for a range of heating, ventilation and air conditioning (HVAC) systems. Over the past two years, the library has been further developed. The number of HVAC components models has been doubled and various components have been revised to increase numerical robustness.The paper starts with an overview of the library architecture and a description of the main packages. To demonstrate the features of the Buildings library, applications that include multizone airflow simulation as well as supervisory and local loop control of a variable air volume (VAV) system are briefly described. The paper closes with a discussion of the current development.

  17. Demonstration of a Variable Phase Turbine Power System for Low Temperature Geothermal Resources

    SciTech Connect (OSTI)

    Hays, Lance G

    2014-07-07T23:59:59.000Z

    A variable phase turbine assembly will be designed and manufactured having a turbine, operable with transcritical, two-phase or vapor flow, and a generator – on the same shaft supported by process lubricated bearings. The assembly will be hermetically sealed and the generator cooled by the refrigerant. A compact plate-fin heat exchanger or tube and shell heat exchanger will be used to transfer heat from the geothermal fluid to the refrigerant. The demonstration turbine will be operated separately with two-phase flow and with vapor flow to demonstrate performance and applicability to the entire range of low temperature geothermal resources. The vapor leaving the turbine is condensed in a plate-fin refrigerant condenser. The heat exchanger, variable phase turbine assembly and condenser are all mounted on single skids to enable factory assembly and checkout and minimize installation costs. The system will be demonstrated using low temperature (237F) well flow from an existing large geothermal field. The net power generated, 1 megawatt, will be fed into the existing power system at the demonstration site. The system will demonstrate reliable generation of inexpensive power from low temperature resources. The system will be designed for mass manufacturing and factory assembly and should cost less than $1,200/kWe installed, when manufactured in large quantities. The estimated cost of power for 300F resources is predicted to be less than 5 cents/kWh. This should enable a substantial increase in power generated from low temperature geothermal resources.

  18. Energy Simulation of Integrated Multiple-Zone Variable Refrigerant Flow System

    SciTech Connect (OSTI)

    Shen, Bo [ORNL] [ORNL; Rice, C Keith [ORNL] [ORNL; Baxter, Van D [ORNL] [ORNL

    2013-01-01T23:59:59.000Z

    We developed a detailed steady-state system model, to simulate the performance of an integrated five-zone variable refrigerant flow (VRF)heat pump system. The system is multi-functional, capable of space cooling, space heating, combined space cooling and water heating, and dedicated water heating. Methods were developed to map the VRF performance in each mode, based on the abundant data produced by the equipment system model. The performance maps were used in TRNSYS annual energy simulations. Using TRNSYS, we have successfully setup and run cases for a multiple-split, VRF heat pump and dehumidifier combination in 5-zone houses in 5 climates that control indoor dry-bulb temperature and relative humidity. We compared the calculated energy consumptions for the VRF heat pump against that of a baseline central air source heat pump, coupled with electric water heating and the standalone dehumidifiers. In addition, we investigated multiple control scenarios for the VRF heat pump, i.e. on/off control, variable indoor air flow rate, and using different zone temperature setting schedules, etc. The energy savings for the multiple scenarios were assessed.

  19. Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01T23:59:59.000Z

    tool for geothermal water loop heat pump systems, 9thInternational IEA Heat Pump Conference, Zürich, Switzerland,Performance of ground source heat pump system in a near-zero

  20. Cooling the Planet: Opportunities for Deployment of Superefficient Room Air Conditioners

    E-Print Network [OSTI]

    Shah, Nihar

    2014-01-01T23:59:59.000Z

    HETAC, “High Efficiency Thermal Air Conditioning”, http://Refrigeration and Air Conditioning Industry Association,variable air volume air conditioning system for buildings”,

  1. air espectrometria gama: Topics by E-print Network

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

    on system knowledge, qualitative states and object-oriented statistical process control (SPC) models for typical pressure-independent variable air volume (VAV) air... Qin, J.;...

  2. The German Vowel System The Control of Token-to-Token Variability: an Experimental and Modeling Study

    E-Print Network [OSTI]

    The German Vowel System The Control of Token-to-Token Variability: an Experimental and Modeling to the motor commands (Modeling) DATA ACQUISITION AND PROCESSING Articulatory data consisted of simultaneous MEASURED ARTICULATORY VARIABILITY General trends for the majority of cases: For low vowels (see left panels

  3. Non-invasive energy meter for fixed and variable flow systems

    DOE Patents [OSTI]

    Menicucci, David F.; Black, Billy D.

    2005-11-01T23:59:59.000Z

    An energy metering method and apparatus for liquid flow systems comprising first and second segments of one or more conduits through which a liquid flows, comprising: attaching a first temperature sensor for connection to an outside of the first conduit segment; attaching a second temperature sensor for connection to an outside of the second conduit segment; via a programmable control unit, receiving data from the sensors and calculating energy data therefrom; and communicating energy data from the meter; whereby the method and apparatus operate without need to temporarily disconnect or alter the first or second conduit segments. The invention operates with both variable and fixed flow systems, and is especially useful for both active and passive solar energy systems.

  4. Analysis of national pay-as-you-drive insurance systems and other variable driving charges

    SciTech Connect (OSTI)

    Wenzel, T.

    1995-07-01T23:59:59.000Z

    Under Pay as You Drive insurance (PAYD), drivers would pay part of their automobile insurance premium as a per-gallon surcharge every time they filled their gas tank. By transfering a portion of the cost of owning a vehicle from a fixed cost to a variable cost, PAYD would discourage driving. PAYD has been proposed recently in California as a means of reforming how auto insurance is provided. PAYD proponents claim that, by forcing drivers to purchase at least part of their insurance every time they refuel their car, PAYD would reduce or eliminate the need for uninsured motorist coverage. Some versions of PAYD proposed in California have been combined with a no-fault insurance system, with the intention of further reducing premiums for the average driver. Other states have proposed PAYD systems that would base insurance premiums on annual miles driven. In this report we discuss some of the qualitative issues surrounding adoption of PAYD and other policies that would convert other fixed costs of driving (vehicle registration, safety/emission control system inspection, and driver license renewal) to variable costs. We examine the effects of these policies on two sets of objectives: objectives related to auto insurance reform, and those related to reducing fuel consumption, CO{sub 2} emissions, and vehicle miles traveled. We pay particular attention to the first objective, insurance reform, since this has generated the most interest in PAYD to date, at least at the state level.

  5. A 24 km fiber-based discretely signaled continuous variable quantum key distribution system

    E-Print Network [OSTI]

    Quyen Dinh Xuan; Zheshen Zhang; Paul L. Voss

    2009-10-06T23:59:59.000Z

    We report a continuous variable key distribution system that achieves a final secure key rate of 3.45 kb/sec over a distance of 24.2 km of optical fiber. The protocol uses discrete signaling and post-selection to improve reconciliation speed and quantifies security by means of quantum state tomography. Polarization multiplexing and a frequency translation scheme permit transmission of a continuous wave local oscillator and suppression of noise from guided acoustic wave Brillouin scattering by more than 27 dB.

  6. Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01T23:59:59.000Z

    multiple water-to-air heat pump units, which are connectedeach of the water-to-air heat pump units can run in eitheras other types of air source heat pumps, VRF systems need

  7. A nuclear wind/solar oil-shale system for variable electricity and liquid fuels production

    SciTech Connect (OSTI)

    Forsberg, C. [Massachusetts Inst. of Technology, 77 Massachusetts Ave., Cambridge, MA 012139 (United States)

    2012-07-01T23:59:59.000Z

    The recoverable reserves of oil shale in the United States exceed the total quantity of oil produced to date worldwide. Oil shale contains no oil, rather it contains kerogen which when heated decomposes into oil, gases, and a carbon char. The energy required to heat the kerogen-containing rock to produce the oil is about a quarter of the energy value of the recovered products. If fossil fuels are burned to supply this energy, the greenhouse gas releases are large relative to producing gasoline and diesel from crude oil. The oil shale can be heated underground with steam from nuclear reactors leaving the carbon char underground - a form of carbon sequestration. Because the thermal conductivity of the oil shale is low, the heating process takes months to years. This process characteristic in a system where the reactor dominates the capital costs creates the option to operate the nuclear reactor at base load while providing variable electricity to meet peak electricity demand and heat for the shale oil at times of low electricity demand. This, in turn, may enable the large scale use of renewables such as wind and solar for electricity production because the base-load nuclear plants can provide lower-cost variable backup electricity. Nuclear shale oil may reduce the greenhouse gas releases from using gasoline and diesel in half relative to gasoline and diesel produced from conventional oil. The variable electricity replaces electricity that would have been produced by fossil plants. The carbon credits from replacing fossil fuels for variable electricity production, if assigned to shale oil production, results in a carbon footprint from burning gasoline or diesel from shale oil that may half that of conventional crude oil. The U.S. imports about 10 million barrels of oil per day at a cost of a billion dollars per day. It would require about 200 GW of high-temperature nuclear heat to recover this quantity of shale oil - about two-thirds the thermal output of existing nuclear reactors in the United States. With the added variable electricity production to enable renewables, additional nuclear capacity would be required. (authors)

  8. BLOOD SAMPLING SYSTEM TROUBLESHOOTING TIPS

    E-Print Network [OSTI]

    Kay, Mark A.

    SAFESET TM BLOOD SAMPLING SYSTEM SAFESETTM TROUBLESHOOTING TIPS TO PREVENT BLOOD BACKING UP IN LINE that all air bubbles have been eliminated when priming o Invert and tap blood sampling ports to remove air volume o Reinfuse the patient's blood slowly, no faster than 1mL per second, by pressing the plunger back

  9. Probabilistic Approach to Quantifying the Contribution of Variable Generation and Transmission to System Reliability: Preprint

    SciTech Connect (OSTI)

    Ibanez, E.; Milligan, M.

    2012-09-01T23:59:59.000Z

    The increasing electrical load served by variable generation (VG), such as wind and solar energy, in the United States and many other countries has stimulated an interesting line of research to better quantify the capacity value of these resources. Methods applied traditionally to thermal units based on their average outage rates do not apply to VG because of their uncertain and non-dispatchable nature. The North American Electric Reliability Corporation's Integration of Variable Generation Task Force recently released a report that highlighted the need to develop and benchmark underlying loss-of-load expectation and related metrics that reasonably and fairly calculate the contribution to planning reserves, or capacity value, of solar and wind power. As the fraction of generation coming from VG becomes more significant, their estimated capacity value will have a larger impact on system planning. In this paper, we provide a method to include VG in traditional probabilistic-based adequacy methods. This method has been implemented in the Renewable Energy Probabilistic Resource Assessment tool developed at the National Renewable Energy Laboratory. Through an example based on the U.S. Western Interconnection, this method is applied to assess the effect that transmission can have on resource adequacy. We also analyze the interactions between available transmission and capacity value for VG.

  10. Estimating spatially-variable rate constants of denitrification in irrigated agricultural groundwater systems using an Ensemble Smoother

    E-Print Network [OSTI]

    Bau, Domenico A.

    an irrigated agricultural river-aquifer system using measurements of (i) nitrate concen- trationEstimating spatially-variable rate constants of denitrification in irrigated agricultural groundwater systems using an Ensemble Smoother Ryan T. Bailey , Domenico A. Baù, Timothy K. Gates Department

  11. Air-Side Energy Use Calculations for Four HVAC Systems: Dual Duct Constant Volume (DDCAV), Dual Duct Variable Volume (DDVAV), Constant Volume with Reheat (CAVRH0), Variable Volume with Reheat (VAVRH)

    E-Print Network [OSTI]

    Haberl, J. S.

    2001-01-01T23:59:59.000Z

    This report contains engineering calculations for four (4) air-side, heating, ventilating and air-conditioning systems (HVAC) systems, including: dual duct constant volume (DDCAV), dual duct variable volume (DDVAV), constant volume with reheat...

  12. Long term variability of Cygnus X-1: VII. Orbital variability of the focussed wind in Cyg X-1 / HDE 226868 system

    E-Print Network [OSTI]

    Grinberg, V; Hell, N; Pottschmidt, K; Böck, M; García, J A; Hanke, M; Nowak, M A; Sundqvist, J O; Townsend, R H D; Wilms, J

    2015-01-01T23:59:59.000Z

    Binary systems with an accreting compact object are a unique chance to investigate the strong, clumpy, line-driven winds of early type supergiants by using the compact object's X-rays to probe the wind structure. We analyze the two-component wind of HDE 226868, the O9.7Iab giant companion of the black hole Cyg X-1 using 4.77 Ms of RXTE observations of the system taken over the course of 16 years. Absorption changes strongly over the 5.6 d binary orbit, but also shows a large scatter at a given orbital phase, especially at superior conjunction. The orbital variability is most prominent when the black hole is in the hard X-ray state. Our data are poorer for the intermediate and soft state, but show signs for orbital variability of the absorption column in the intermediate state. We quantitatively compare the data in the hard state to a toy model of a focussed Castor-Abbott-Klein-wind: as it does not incorporate clumping, the model does not describe the observations well. A qualitative comparison to a simplified...

  13. Module Development and Simulation of the Variable Refrigerant Flow Air Conditioning System under Cooling Conditions in Energyplus

    E-Print Network [OSTI]

    Zhou, Y.; Wu, J.; Wang, R.; Shiochi, S.

    2006-01-01T23:59:59.000Z

    ICEBO2006, Shenzhen, China HVAC Technologies for Energy Efficiency Vol.IV-1-2 Module Development and Simulation of the Variable Refrigerant Flow Air Conditioning System under Cooling Conditions in Energyplus Yanping Zhou Jingyi..., especially for those who ICEBO2006, Shenzhen, China HVAC Technologies for Energy Efficiency Vol.IV-1-2 show some interest about high-efficiency systems like VRF, it becomes of interest to compare the VRF to other systems and evaluate VRF?s performance...

  14. Simplectic geometry and the canonical variables for Dirac-Nambu-Goto and Gauss-Bonnet system in string theory

    E-Print Network [OSTI]

    Alberto Escalante

    2006-07-13T23:59:59.000Z

    Using a strongly covariant formalism given by Carter for the deformations dynamics of p-branes in a curved background and a covariant and gauge invariant geometric structure constructed on the corresponding Witten's phase space, we identify the canonical variables for Dirac-Nambu-Goto [DNG] and Gauss-Bonnet [GB] system in string theory. Future extensions of the present results are outlined.

  15. Allocation of inventory to a variable, time-phased, on-line storage system under known demand

    E-Print Network [OSTI]

    White, Charles Wesley

    1968-01-01T23:59:59.000Z

    for the automotive industry are being phased into production and inventory control systems the procedures for supplying the assembly operation must be updated. An initial step in updating the precedures would be to base them on more quantitative techniques... for the degree of MASTER OF SCIENCE January, 1968 Major Subject: Industrial Engineering ALLOCATION OF INVENTORY TO A VARIABLE ~ T IME PHASED ~ ON L INE STORAGE SYSTEM UNDER KNOWN DEMAND A Thesis By CHARLES WESLEY WHITE Approved as to style...

  16. Future projection of mean and variability of the Asian Summer Monsoon and Indian Ocean Climate systems

    SciTech Connect (OSTI)

    Annamalai, H [IPRC, University of Hawaii

    2014-09-15T23:59:59.000Z

    The overall goal of this project is to assess the ability of the CMIP3/5 models to simulate the Indian-Ocean monsoon systems. The PI along with post-docs investigated research issues ranging from synoptic systems to long-term trends over the Asian monsoon region. The PI applied diagnostic tools such as moist static energy (MSE) to isolate: the moist and radiative processes responsible for extended monsoon breaks over South Asia, precursors in the ENSO-monsoon association, reasons for the drying tendency over South Asia and the possible effect on tropical Indian Ocean climate anomalies influencing certain aspects of ENSO characteristics. By diagnosing various observations and coupled model simulations, we developed working hypothesis and tested them by carrying out sensitivity experiments with both linear and nonlinear models. Possible physical and dynamical reasons for model sensitivities were deduced. On the teleconnection front, the ability of CMIP5 models in representing the monsoon-desert mechanism was examined recently. Further more, we have applied a suite of diagnostics and have performed an in depth analysis on CMIP5 integrations to isolate the possible reasons for the ENSO-monsoon linkage or lack thereof. The PI has collaborated with Dr. K.R. Sperber of PCMDI and other CLIVAR Asian-Australian monsoon panel members in understanding the ability of CMIP3/5 models in capturing monsoon and its spectrum of variability. The objective and process-based diagnostics aided in selecting models that best represent the present-day monsoon and its variability that are then employed for future projections. Two major highlights were an invitation to write a review on present understanding monsoons in a changing climate in Nature Climate Change, and identification of an east-west shift in observed monsoon rainfall (more rainfall over tropical western Pacific and drying tendency over South Asia) in the last six decades and attributing that shift to SST rise over the tropical western Pacific. On the training of post-doctoral scientists: the PI spent considerable amount of time and efforts in introducing the post-docs into climate modeling and designing the numerical experiments. With training provided and knowledge gained, post-docs worked in the project obtained long term positions elsewhere. The PI also enjoyed the experience in managing the works and educating work ethics to the younger generation. Based on the research achievements and publications, the PI gave invited talks in major international monsoon conferences/workshops, and gave lectures in various research organizations in the last six years. Finally, during the project period, the PI attended all the DOE organized PIs meeting and presented the major results. Some of the major implications of the project include: (i) Sustained observational efforts are necessary to monitor the three-dimensional moisture distribution over the Asian monsoon region that would aid in better understanding, modeling and predicting severe monsoons well in advance and (ii) process-based diagnostics lead pathways for model improvements.

  17. Real-time variable rate Pix® application system using a plant height sensor 

    E-Print Network [OSTI]

    Beck, Andy Dwayne

    2001-01-01T23:59:59.000Z

    . A cotton growth regulator (Pix) was applied at uniform and biomass-based variable rates in a replicated study that included two cotton fields. Plant mapping data was collected during the season. Plant heights were significantly shorter in areas...

  18. Novel Evaluation Methods for Complex Systems via Adaptive Sequential Exploration of Variables Interactions 

    E-Print Network [OSTI]

    Al Rashdan, Ahmad Y. M.

    2014-12-01T23:59:59.000Z

    The complex and coupled behavior of variables in the currently developing Generation IV reactors and Small Modular Reactors is becoming a major incentive to seek efficient design methods. This research develops and validates ...

  19. Performance of the beam chamber vacuum system of K = 500 cyclotron at Variable Energy Cyclotron Centre Kolkata

    SciTech Connect (OSTI)

    Pal, Gautam, E-mail: gautam.pal@vecc.gov.in; DuttaGupta, Anjan; Chakrabarti, Alok [Variable Energy Cyclotron Centre, I/AF Bidhannagar, Kolkata 700064 (India)

    2014-07-15T23:59:59.000Z

    The beam chamber of Variable Energy Cyclotron Centre, Kolkata's K = 500 superconducting cyclotron is pumped by liquid helium cooled cryopanel with liquid nitrogen cooled radiation shield. Performance of the vacuum system was evaluated by cooling the cryopanel assembly with liquid nitrogen and liquid helium. Direct measurement of beam chamber pressure is quite difficult because of space restrictions and the presence of high magnetic field. Pressure gauges were placed away from the beam chamber. The beam chamber pressure was evaluated using a Monte Carlo simulation software for vacuum system and compared with measurements. The details of the vacuum system, measurements, and estimation of pressure of the beam chamber are described in this paper.

  20. Ota City : characterizing output variability from 553 homes with residential PV systems on a distribution feeder.

    SciTech Connect (OSTI)

    Stein, Joshua S.; Miyamoto, Yusuke (Kandenko, Ibaraki, Japan); Nakashima, Eichi (Kandenko, Ibaraki, Japan); Lave, Matthew

    2011-11-01T23:59:59.000Z

    This report describes in-depth analysis of photovoltaic (PV) output variability in a high-penetration residential PV installation in the Pal Town neighborhood of Ota City, Japan. Pal Town is a unique test bed of high-penetration PV deployment. A total of 553 homes (approximately 80% of the neighborhood) have grid-connected PV totaling over 2 MW, and all are on a common distribution line. Power output at each house and irradiance at several locations were measured once per second in 2006 and 2007. Analysis of the Ota City data allowed for detailed characterization of distributed PV output variability and a better understanding of how variability scales spatially and temporally. For a highly variable test day, extreme power ramp rates (defined as the 99th percentile) were found to initially decrease with an increase in the number of houses at all timescales, but the reduction became negligible after a certain number of houses. Wavelet analysis resolved the variability reduction due to geographic diversity at various timescales, and the effect of geographic smoothing was found to be much more significant at shorter timescales.

  1. Atmospheric Carbon Dioxide Variability in the Community Earth System Model: Evaluation and Transient Dynamics during the Twentieth and Twenty-First Centuries

    E-Print Network [OSTI]

    Hoffman, Forrest M.

    Atmospheric Carbon Dioxide Variability in the Community Earth System Model: Evaluation pathways (RCPs 4.5 and 8.5) using the Community Earth System Model­Biogeochemistry (CESM1- BGC). CO2

  2. Understanding Variability and Uncertainty of Photovoltaics for Integration with the Electric Power System

    SciTech Connect (OSTI)

    Mills, Andrew; Ahlstrom, Mark; Brower, Michael; Ellis, Abraham; George, Ray; Hoff, Tom; Kroposki, Benjamin; Lenox, Carl; Miller, Nicholas; Stein, Joshua; Wan, Yih-huei

    2009-12-07T23:59:59.000Z

    Data and analysis are needed to understand the variability of photovoltaic (PV) plants to avoid unnecessary barriers to the interconnection of PV. Several datasets show clouds can cause rapid changes in solar insolation. Smoothing of rapid ramps, however, occurs within PV plants. The degree of smoothing depends on plant size. Smoothing occurs on even longer time-scales between separate plants.

  3. Harmonic propagation of variability in surface energy balance within a coupled soilvegetationatmosphere system

    E-Print Network [OSTI]

    Gentine, Pierre

    Harmonic propagation of variability in surface energy balance within a coupled energy balance. The amplitude of the noise is maximum at midday when the incoming radiative forcing results in changes in the surface energy balance through the modification of outgoing radiative, turbulent

  4. Weaving Aspect Configurations for Managing System Variability Brice Morin, Olivier Barais1

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    of the software lifecycle. 1 Introduction Variability management is a key concern in the software industry modeled. The Aspect-Oriented Software Development (AOSD) paradigm proposes to separate distinct concerns of the software life-cycle [4, 5, 8, 17, 28]: requirement, architecture, design, leading to the creation

  5. Response Surfaces for Key Controlled Variables in a Hybrid Solid Oxide Fuel Cell/Gas Turbine System

    SciTech Connect (OSTI)

    Rosen, William G.; Banta, Larry; Gorrell, Megan; Restrepo, Bernardo; Tucker, David

    2012-07-01T23:59:59.000Z

    Hybrid generation systems have been extensively modeled as a first step toward the development of automatic controls for the system. In most cases, it is impossible to validate mathematical models against real hardware because only a handful of hardware systems exist in the world. Data taken from the existing hardware has demonstrated significant nonlinearity, complex coupling between controlled variables, and sometimes non-intuitive behavior. This work exploits the capability of the HyPer hardware test bed at the National Energy Technology Laboratory (NETL) to generate data from a real recuperated gas turbine coupled with hardware simulations of a fuel cell cathode and appropriate ancillary equipment. Prior work has characterized the system only over a limited range of its operating envelope, due to the inability to manipulate multiple control inputs simultaneously. The work presented here fills the gaps using data from a 34 factorial experiment to generate quasi-continuous response surfaces describing the operating state space of the HyPer system. Polynomial correlation functions have been fitted to the data with excellent agreement. Relationships between the control inputs and critical state variables such as cathode mass flow, cathode temperature, turbine inlet and exhaust temperatures and other key system parameters are presented.

  6. Cataclysmic Variables

    E-Print Network [OSTI]

    Robert Connon Smith

    2007-01-23T23:59:59.000Z

    Cataclysmic variables are binary stars in which a relatively normal star is transferring mass to its compact companion. This interaction gives rise to a rich range of behaviour, of which the most noticeable are the outbursts that give the class its name. Novae belong to the class, as do the less well known dwarf novae and magnetic systems. Novae draw their energy from nuclear reactions, while dwarf novae rely on gravity to power their smaller eruptions. All the different classes of cataclysmic variable can be accommodated within a single framework and this article will describe the framework, review the properties of the main types of system and discuss models of the outbursts and of the long-term evolution.

  7. Strategies and a computer aided package for design and analysis of induction machines for inverter-driven variable speed systems

    SciTech Connect (OSTI)

    Zhao, Z.; Xu, L. [Ohio State Univ., Columbus, OH (United States). Dept. of Electrical Engineering; El-Antably, A. [Delphi Power Propulsion Systems, Anderson, IN (United States)

    1995-12-31T23:59:59.000Z

    Induction machines designed for inverter-driven variable speed systems is different from those powered directly from utility power lines. In this paper, the design strategies of inverter-driven induction machines are discussed. This is followed by a description of a computer aided design and analysis package specifically for this purpose. The program package permits integration design of machines with inverters, comprehensive performance analysis, and system optimization, resulting in 20--30% more power density for the induction machine than that designed for direct utility power supplies by convention method. Design and performance analysis results are presented to substantiate the conclusions.

  8. Understanding Variability and Uncertainty of Photovoltaics for Integration with the Electric Power System

    E-Print Network [OSTI]

    Mills, Andrew

    2010-01-01T23:59:59.000Z

    Design and operation of power systems with large amounts ofthe Art. IEEE Transactions on Power Systems, 22(3), 900-908.with the Electric Power System Andrew Mills 1 , Mark

  9. This booklet has been developed to serve as an aid in selecting a laboratory fume hood ventilation system.

    E-Print Network [OSTI]

    Farritor, Shane

    as an aid in selecting a laboratory fume hood ventilation system. The information is intended to be unbiased consider the whole picture -- the laboratory space, the building's ventilation system, the hood's location Ventilation System Components and Accessories Remote Blowers 13 Blower Sizing 14 Air Volume 14 Static Pressure

  10. Stability limit of room air temperature of a VAV system

    SciTech Connect (OSTI)

    Matsuba, Tadahiko; Kamimura, Kazuyuki [Yamatake-Honeywell Co., Ltd., Tokyo (Japan). Building System Div.; Kasahara, Masato; Kimbara, Akiomi; Kurosu, Shigeru [Oyama National Coll. of Technology (Japan); Murasawa, Itaru; Hashimoto, Yukihiko [Tonets Corp., Tokyo (Japan). Engineering Project Dept.

    1998-12-31T23:59:59.000Z

    To control heating, ventilating, and air-conditioning (HVAC) systems, it has been necessary to accept an analog system controlled mainly by proportional-plus-integral-plus-derivative (PID) action. However, when conventional PID controllers are replaced with new digital controllers by selecting the same PID parameters as before, the control loops have often got into hunting phenomena, which result in undamped oscillations. Unstable control characteristics (such as huntings) are thought to be one of the crucial problems faced by field operators. The PID parameters must be carefully selected to avoid instabilities. In this study, a room space is simulated as a thermal system that is air-conditioned by a variable-air-volume (VAV) control system. A dynamic room model without infiltration or exfiltration, which is directly connected to a simple air-handling unit without an economizer, is developed. To explore the possible existence of huntings, a numerical system model is formulated as a bilinear system with time-delayed feedback, and a parametric analysis of the stability limit is presented. Results are given showing the stability region affected by the selection of control and system parameters. This analysis was conducted to help us tune the PID controllers for optimal HVAC control.

  11. Collective coordinate variable for soliton-potential system in sine-Gordon model

    E-Print Network [OSTI]

    Kurosh Javidan

    2009-10-16T23:59:59.000Z

    A Collective coordinate variable for adding a space dependent potential to the sine-Gordon model is presented. Interaction of solitons with a delta function potential barrier and also delta function potential well is investigated. Most of the characters of interaction are derived analytically. We will find that the behaviour of a solitonic solution is like a point particle which is moved under the influence of a complicated effective potential. The effective potential is a function of the field initial conditions and also parameters of added potential.

  12. Variable current-voltage TPV device for use in a thermophotovoltaic energy conversion system

    DOE Patents [OSTI]

    Charache, Greg W. (Clifton Park, NY); Baldasaro, Paul F. (Clifton Park, NY); Campbell, Brian C. (Scotia, NY)

    2000-01-01T23:59:59.000Z

    A front-side or back-side illuminated variable current-voltage thermophotovoltaic device comprises a support substrate; isolation layers disposed on the support substrate; a plurality of cells disposed on the isolation layers, each of the cells including a base layer and an emitter layer; an insulating member disposed between each of the cells configured to isolate each cell from adjacent cells; an ohmic contact configured to connect each cell to another cell in series; and a spectral control device disposed on top of the cells and/or on the bottom surface of the support substrate.

  13. Variable-Speed, Low-Cost Motor for Residential HVAC Systems | Department of

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

    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 DataDepartment of Energy Your DensityEnergy U.S.-China Electric Vehicle and03/02 TUEValidation of InnovativeofEnergy Variable-Speed,

  14. Scale effects on the hydrological impact of upland afforestation and drainage using indices of flow variability Hydrology and Earth System Sciences, 7(3), 325338 (2003) EGU

    E-Print Network [OSTI]

    Boyer, Edmond

    Scale effects on the hydrological impact of upland afforestation and drainage using indices of flow variability 325 Hydrology and Earth System Sciences, 7(3), 325338 (2003) © EGU Scale effects on the hydrological impact of upland afforestation and drainage using indices of flow variability: the River Irthing

  15. aided optimum design: Topics by E-print Network

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

    Ray, H. P.; Wen, H. 1982-01-01 3 OPTIMUM DUCT DESIGN FOR VARIABLE AIR VOLUME SYSTEMS Energy Storage, Conversion and Utilization Websites Summary: OPTIMUM DUCT DESIGN FOR VARIABLE...

  16. Understanding Variability and Uncertainty of Photovoltaics for Integration with the Electric Power System

    E-Print Network [OSTI]

    Mills, Andrew

    2010-01-01T23:59:59.000Z

    per min) PV System Size (AC Nameplate, MW ) All Inverterssystems with large amounts of IEEE 1547 compliant embedded PV. Preventing large simultaneous inverter

  17. Orbital and stochastic far-UV variability in the nova-like system V3885 Sgr

    E-Print Network [OSTI]

    Prinja, R K; Richards, M T; Witherick, D K; Peck, L W

    2011-01-01T23:59:59.000Z

    Highly time-resolved time-tagged FUSE satellite spectroscopic data are analysed to establish the far-ultraviolet (FUV) absorption line characteristics of the nova-like cataclysmic variable binary, V3885 Sgr. We determine the temporal behaviour of low (Ly_beta, CIII, NIII) and high (SIV, PV, OVI) ion species, and highlight corresponding orbital phase modulated changes in these lines. On average the absorption troughs are blueshifted due to a low velocity disc wind outflow. Very rapid (~ 5 min) fluctuations in the absorption lines are isolated, which are indicative of stochastic density changes. Doppler tomograms of the FUV lines are calculated which provide evidence for structures where a gas stream interacts with the accretion disc. We conclude that the line depth and velocity changes as a function of orbital phase are consistent with an asymmetry that has its origin in a line-emitting, localised disc-stream interaction region.

  18. Real-time variable rate Pix® application system using a plant height sensor

    E-Print Network [OSTI]

    Beck, Andy Dwayne

    2001-01-01T23:59:59.000Z

    application system, the actual carrier flow rate lagged the desired rates. It was later determined that instead of using a 1-second update rate, a 3-second update rate would allow the control system to reach the setpoint before a new desired rate was received...

  19. Solar Cooling Using Variable Geometry Ejectors Centre for Sustainable Energy Systems

    E-Print Network [OSTI]

    pumps were other notable benefits. Heat pump cooling systems dominate the air-conditioning market electrically driven heat pumps to be deployed to locations such as houses where a steady source of heat may to consider solar heat driven cooling systems, most prominently since the 1990s. The Ejector Heat Pump

  20. Air-Side Energy Use Calculations for Four HVAC Systems: Dual Duct Constant Volume (DDCAV), Dual Duct Variable Volume (DDVAV), Constant Volume with Reheat (CAVRH), Variable Volume with Reheat (VAVRH), Four Pipe Fan Coil Unit (FC), Four Pipe Induction Unit (FI), and Single Zone (SZ) Systems, Revised June 2002

    E-Print Network [OSTI]

    Haberl, J. S.; Bou-Saada, T. E.; Saman, N. F.

    2001-01-01T23:59:59.000Z

    This report contains engineering calculations for seven (7) air-side, heating, ventilating and air conditioning systems (HVAC) systems, including: dual duct constant volume (DDCAV), dual duct variable volume (DDVAV), constant volume with reheat...

  1. SST subseasonal variability in the central Benguela upwelling system as inferred from satellite observations (19992009)

    E-Print Network [OSTI]

    Boyer, Edmond

    associated with the eastern flank of the semipermanent South Atlantic Anti- cyclone (SAA). Through Ekman of distinct physical and biological features, the Benguela system can be separated into three zones charac

  2. Convective variability associated with a mesoscale vortex in a midlatitude squall line system

    E-Print Network [OSTI]

    Hristova-Veleva, Svetla M.

    1994-01-01T23:59:59.000Z

    The relationship between the kinematic structure of the convective line and the mesoscale stortn-relative flow associated with an embedded mesovortex in the trailing stratiform region of the 28 May 1985 squall line system is examined using Doppler...

  3. Understanding Variability and Uncertainty of Photovoltaics for Integration with the Electric Power System

    E-Print Network [OSTI]

    Mills, Andrew

    2010-01-01T23:59:59.000Z

    solar insolation meters and similarly sited wind anemometers (scaled to create a time series of wind power output)Power Systems Clouds can cause significant ramps in solar insolation and PV plant output

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

    E-Print Network [OSTI]

    Yang, Zhenyu

    changes of (system head) set-points and operating conditions. After a number of static models- mization of multiple pumps, and proposed a Mixer Integer NonLinear Programming (MINLP) solution

  5. IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY 1 Cyclic Variability and Dynamical Instabilities in

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    by autoignition in homogeneous charge compression ignition (HCCI) engines with large amounts of residual gases. Index Terms--Internal combustion engines, nonlinear dynam- ical systems, Gaussian noise, stability on autoignition of a homogeneous mixture. This combustion mode is called homogeneous charge compression ignition

  6. Short term Variability of the Sun Earth System: An Overview of Progress Made during the CAWSES II Period

    E-Print Network [OSTI]

    Gopalswamy, Nat; Yan, Yihua

    2015-01-01T23:59:59.000Z

    This paper presents an overview of results obtained during the CAWSES II period on the short term variability of the Sun and how it affects the near Earth space environment. CAWSES II was planned to examine the behavior of the solar terrestrial system as the solar activity climbed to its maximum phase in solar cycle 24. After a deep minimum following cycle 23, the Sun climbed to a very weak maximum in terms of the sunspot number in cycle 24 (MiniMax24), so many of the results presented here refer to this weak activity in comparison with cycle 23. The short term variability that has immediate consequence to Earth and geospace manifests as solar eruptions from closed field regions and high speed streams from coronal holes. Both electromagnetic (flares) and mass emissions (coronal mass ejections, CMEs) are involved in solar eruptions, while coronal holes result in high speed streams that collide with slow wind forming the so called corotating interaction regions (CIRs). Fast CMEs affect Earth via leading shocks ...

  7. Sub-Hour Solar Data for Power System Modeling From Static Spatial Variability Analysis: Preprint

    SciTech Connect (OSTI)

    Hummon, M.; Ibanez, E.; Brinkman, G.; Lew, D.

    2012-12-01T23:59:59.000Z

    High penetration renewable integration studies need high quality solar power data with spatial-temporal correlations that are representative of a real system. This paper will summarize the research relating sequential point-source sub-hour global horizontal irradiance (GHI) values to static, spatially distributed GHI values. This research led to the development of an algorithm for generating coherent sub-hour datasets that span distances ranging from 10 km to 4,000 km. The algorithm, in brief, generates synthetic GHI values at an interval of one-minute, for a specific location, using SUNY/Clean Power Research, satellite-derived, hourly irradiance values for the nearest grid cell to that location and grid cells within 40 km.

  8. TALSPEAK EXTRACTION SYSTEM UNDER VARIABLE LOADING CONDITIONS - PART 2: SPECIATION STUDIES

    SciTech Connect (OSTI)

    Robinson, Troy A.; Bryan, Samuel A.; Levitskaia, Tatiana G.

    2011-10-03T23:59:59.000Z

    The reported investigation was performed to gain structural information on the organic phase complex species in the Trivalent Actinide-Lanthanide Separation by Phosphorus reagent Extraction from Aqueous Komplexes (TALSPEAK) process under various loading conditions. In conjunction with the distribution studies of the TALSPEAK system constituents, presented in Part 1 of this investigation, loaded bis(2-ethylhexyl) phosphoric acid (HDEHP)/isooctane was evaluated using various spectroscopic techniques including NMR, FTIR and visible absorbance spectroscopy. Liquid-liquid distribution and vapor pressure osmometry (VPO) aggregation results correlate with observed changes in the spectroscopic signatures as a function of organic phase loading and water partitioning. Explicit FTIR spectral interpretation of the HDEHP spectra is complex due to overlapping phosphorus absorbance bands, and in this work a combination of the spectroscopic techniques was utilized to elucidate the phosphorus-lanthanide complex structure and changes in speciation due to aggregation. The results from this research will benefit an overall improved prediction of the TALSPEAK process performance under flow conditions.

  9. Variable oxygen/nitrogen enriched intake air system for internal combustion engine applications

    DOE Patents [OSTI]

    Poola, Ramesh B. (Woodridge, IL); Sekar, Ramanujam R. (Naperville, IL); Cole, Roger L. (Elmhurst, IL)

    1997-01-01T23:59:59.000Z

    An air supply control system for selectively supplying ambient air, oxygen enriched air and nitrogen enriched air to an intake of an internal combustion engine includes an air mixing chamber that is in fluid communication with the air intake. At least a portion of the ambient air flowing to the mixing chamber is selectively diverted through a secondary path that includes a selectively permeable air separating membrane device due a differential pressure established across the air separating membrane. The permeable membrane device separates a portion of the nitrogen in the ambient air so that oxygen enriched air (permeate) and nitrogen enriched air (retentate) are produced. The oxygen enriched air and the nitrogen enriched air can be selectively supplied to the mixing chamber or expelled to atmosphere. Alternatively, a portion of the nitrogen enriched air can be supplied through another control valve to a monatomic-nitrogen plasma generator device so that atomic nitrogen produced from the nitrogen enriched air can be then injected into the exhaust of the engine. The oxygen enriched air or the nitrogen enriched air becomes mixed with the ambient air in the mixing chamber and then the mixed air is supplied to the intake of the engine. As a result, the air being supplied to the intake of the engine can be regulated with respect to the concentration of oxygen and/or nitrogen.

  10. A computer simulation appraisal of non-residential low energy cooling systems in California

    SciTech Connect (OSTI)

    Bourassa, Norman; Haves, Philip; Huang, Joe

    2002-05-17T23:59:59.000Z

    An appraisal of the potential performance of different Low Energy Cooling (LEC) systems in nonresidential buildings in California is being conducted using computer simulation. The paper presents results from the first phase of the study, which addressed the systems that can be modeled, with the DOE-2.1E simulation program. The following LEC technologies were simulated as variants of a conventional variable-air-volume system with vapor compression cooling and mixing ventilation in the occupied spaces: Air-side indirect and indirect/direct evaporative pre-cooling. Cool beams. Displacement ventilation. Results are presented for four populous climates, represented by Oakland, Sacramento, Pasadena and San Diego. The greatest energy savings are obtained from a combination of displacement ventilation and air-side indirect/direct evaporative pre-cooling. Cool beam systems have the lowest peak demand but do not reduce energy consumption significantly because the reduction in fan energy is offse t by a reduction in air-side free cooling. Overall, the results indicate significant opportunities for LEC technologies to reduce energy consumption and demand in nonresidential new construction and retrofit.

  11. Variable Refrigerant Flow Systems

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

    News & Events Expand News & Events Skip navigation links Smart Grid Demand Response Energy Efficiency Emerging Technologies Current Research Portfolio Behavior Based EE...

  12. Variable Refrigerant Flow Systems

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrincetonUsing Maps1 - USAF Wind Power Program Latitude: N.Data

  13. Abstract--Heart rate variability (HRV) is frequently used to measure autonomic nervous system (ANS) activity. However,

    E-Print Network [OSTI]

    1 of 4 Abstract--Heart rate variability (HRV) is frequently used to measure autonomic nervous frequency (HF) ratio with little change in mean heart rate. Results suggest that nicotine affects both components may yield erroneous results. Keywords--Autonomic regulation, heart rate variability, Lomb

  14. Modelica-based Modeling and Simulation to Support Research and Development in Building Energy and Control Systems

    SciTech Connect (OSTI)

    Wetter, Michael

    2009-02-12T23:59:59.000Z

    Traditional building simulation programs possess attributes that make them difficult to use for the design and analysis of building energy and control systems and for the support of model-based research and development of systems that may not already be implemented in these programs. This article presents characteristic features of such applications, and it shows how equation-based object-oriented modelling can meet requirements that arise in such applications. Next, the implementation of an open-source component model library for building energy systems is presented. The library has been developed using the equation-based object-oriented Modelica modelling language. Technical challenges of modelling and simulating such systems are discussed. Research needs are presented to make this technology accessible to user groups that have more stringent requirements with respect to the numerical robustness of simulation than a research community may have. Two examples are presented in which models from the here described library were used. The first example describes the design of a controller for a nonlinear model of a heating coil using model reduction and frequency domain analysis. The second example describes the tuning of control parameters for a static pressure reset controller of a variable air volume flow system. The tuning has been done by solving a non-convex optimization problem that minimizes fan energy subject to state constraints.

  15. 24 IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING, VOL. 12, NO. 1, MARCH 2004 Adaptive Control of a Variable-Impedance

    E-Print Network [OSTI]

    Herr, Hugh

    24 IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING, VOL. 12, NO. 1, MARCH 2004 spring-damper control lifts the foot to provide toe clearance. To assess the clinical effects of variable-Leg, a microprocessor-controlled artificial knee, provides amputees with an increased independence compared with passive

  16. Innovative, Cost Effective and Energy Efficient Desgin for New Construction at a Texas High School

    E-Print Network [OSTI]

    Khan, S.; Bible, M.

    2013-01-01T23:59:59.000Z

    , which includes innovative dual-duct Variable Air Volume (VAV) systems for cooling and pre-treated ventilation air delivery integrated with occupancy sensors and digital controls, and optimized HVAC controls for dynamic balancing of air and hydronic sides...

  17. Active Humidity Control Through Gas-Fired Desiccant Humidity Pump 

    E-Print Network [OSTI]

    Novosel, D.; Griffiths, W. C.

    1988-01-01T23:59:59.000Z

    applied. A comparison of passive capacity control methods to control humidity shows that only the combined face and bypass and variable air volume system shows improved performance with respect to space humidity control, dew point depression, and response...

  18. How effective is new variable modified Chaplygin gas to play the role of dark energy- A dynamical system analysis in RS II Brane model

    E-Print Network [OSTI]

    Prabir Rudra; Chayan Ranjit; Sujata Kundu

    2013-03-19T23:59:59.000Z

    Motivated by some previous works of Rudra et al we set to explore the background dynamics when dark energy in the form of New Variable Modified Chaplygin gas is coupled to dark matter with a suitable interaction in the universe described by brane cosmology. The main idea is to find out the efficiency of New variable modified Chaplygin gas to play the role of DE. As a result we resort to the technique of comparison with standard dark energy models. Here the RSII brane model have been considered as the gravity theory. An interacting model is considered in order to search for a possible solution of the cosmic coincidence problem. A dynamical system analysis is performed because of the high complexity of the system . The statefinder parameters are also calculated to classify the dark energy model. Graphs and phase diagrams are drawn to study the variations of these parameters and get an insight into the effectiveness of the dark energy model. It is also seen that the background dynamics of New Variable Modified Chaplygin gas is consistent with the late cosmic acceleration. After performing an extensive mathematical analysis, we are able to constrain the parameters of new variable modified Chaplygin gas as $mNew Variable Modified Chaplygin gas is not as effective as other Chaplygin gas models to play the role of dark energy.

  19. Final Project Report: Self-Correcting Controls for VAV System Faults Filter/Fan/Coil and VAV Box Sections

    SciTech Connect (OSTI)

    Brambley, Michael R.; Fernandez, Nicholas; Wang, Weimin; Cort, Katherine A.; Cho, Heejin; Ngo, Hung; Goddard, James K.

    2011-05-01T23:59:59.000Z

    This report addresses original research by the Pacific Northwest National Laboratory for the California Institute for Energy and Environment on self-correcting controls for variable-air-volume (VAV) heating, ventilating and air-conditioning systems and focuses specifically on air handling and VAV box components of the air side of the system. A complete set of faults for these components was compiled and a fault mode analysis performed to understand the detectable symptoms of the faults and the chain of causation. A set of 26 algorithms was developed to facilitate the automatic correction of these faults in typical commercial VAV systems. These algorithms include training tests that are used during commissioning to develop models of normal system operation, passive diagnostics used to detect the symptoms of faults, proactive diagnostics used to diagnose the cause of a fault, and finally fault correction algorithms. Ten of the twenty six algorithms were implemented in a prototype software package that interfaces with a test bed facility at PNNL's Richland, WA, laboratory. Measurement bias faults were instigated in the supply-air temperature sensor and the supply-air flow meter to test the algorithms developed. The algorithms as implemented in the laboratory software correctly detected, diagnosed and corrected these faults. Finally, an economic and impact assessment was performed for the State of California for deployment of self-correcting controls. Assuming 15% HVAC energy savings and a modeled deployment profile, 3.1-5.8 TBu of energy savings are possible by year 15.

  20. Understanding Biomass Feedstock Variability

    SciTech Connect (OSTI)

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

    2013-01-01T23:59:59.000Z

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

  1. Understanding Biomass Feedstock Variability

    SciTech Connect (OSTI)

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

    2013-01-01T23:59:59.000Z

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

  2. Cell-to-cell variability in cell death: can systems biology help us make sense of it all?

    E-Print Network [OSTI]

    ? Can multivariate analysis approaches direct the design of effective combination therapies? Can we discuss possible sources of this cell-to-cell variability as well as its implications for quantitative- ization and modeling of heterogeneous responses. State-space maps allow contextualization of protein func

  3. Characterizing and Exploiting Task-Load Variability and Correlation for Energy Management in Multi-Core Systems

    E-Print Network [OSTI]

    Tasiran, Serdar

    Characterizing and Exploiting Task-Load Variability and Correlation for Energy Management in Multi) Istanbul, Turkey Lausanne, Switzerland Abstract-- We present a hybrid energy management technique of the application. We use the stochastic models in formulating and solving the energy management prob- lem

  4. Residential Cold Climate Heat Pump with Variable-Speed Technology...

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

    Cold Climate Heat Pump with Variable-Speed Technology Residential Cold Climate Heat Pump with Variable-Speed Technology Purdue prototype system Purdue prototype system Unico...

  5. Dynamic Analysis of Hybrid Energy Systems under Flexible Operation and Variable Renewable Generation -- Part I: Dynamic Performance Analysis and Part II: Dynamic Cost

    SciTech Connect (OSTI)

    Humberto E. Garcia; Amit Mohanty; Wen-Chiao Lin; Robert S. Cherry

    2013-04-01T23:59:59.000Z

    Dynamic analysis of hybrid energy systems (HES) under flexible operation and variable renewable generation is considered in order to better understand various challenges and opportunities associated with the high system variability arising from the integration of renewable energy into the power grid. Unique consequences are addressed by devising advanced HES solutions in which multiple forms of energy commodities, such as electricity and chemical products, may be exchanged. Dynamic models of various unit operations are developed and integrated within two different HES options. One HES option, termed traditional, produces electricity only and consists of a primary heat generator (PHG) (e.g., a small modular reactor), a steam turbine generator, a wind farm, and a battery storage. The other HES option, termed advanced, includes not only the components present in the traditional option but also a chemical plant complex to repurpose excess energy for non-electricity services, such as for the production of chemical goods (e.g., transportation fuel). In either case, a given HES is connected to the power grid at a point of common coupling and requested to deliver a certain electricity generation profile as dictated by a regional power grid operator based on a predicted demand curve. Dynamic analysis of these highly-coupled HES are performed to identify their key dynamical properties and limitations and to prescribe solutions for best managing and mitigating the high variability introduced from incorporating renewable energy into the energy mix. A comparative dynamic cost analysis is also conducted to determine best HES options. The cost function includes a set of metrics for computing fixed costs, such as fixed operations and maintenance (O&M) and overnight capital costs, and also variable operational costs, such as cost of variability, variable O&M cost, and cost of environmental impact, together with revenues. Assuming different options for implementing PHG (e.g., natural gas, coal, nuclear), preliminary results identify the level of renewable penetration at which a given advanced HES option (e.g., a nuclear hybrid) becomes increasingly more economical than a traditional electricity-only generation solution. Conditions are also revealed under which carbon resources may be better utilized as carbon sources for chemical production rather than as combustion material for electricity generation.

  6. The probable source of certain spurious frequencies found in the output of a variable speed generating system using slip recovery

    SciTech Connect (OSTI)

    Carlin, P.W.

    1989-06-01T23:59:59.000Z

    As part of US Department of Energy-sponsored research on wind energy, a Mod-O wind turbine was used to drive a variable-speed, wound-rotor, induction generator. Energy resulting from the slip frequency voltage in the generator rotor was rectified to dc, inverted back to utility frequency ac, and injected into the power line. Spurious changing frequencies displayed in the generator output by a spectrum analyzer are caused by ripple on the dc link. No resonances of any of these moving frequencies were seen in spite of the presence of a bank of power factor correcting capacitors. 5 figs.

  7. Comparison of heating and cooling energy consumption by HVAC system with mixing and displacement air distribution for a restaurant dining area in different climates

    SciTech Connect (OSTI)

    Zhivov, A.M. [International Air Technologies, Inc., Savoy, IL (United States); Rymkevich, A.A. [St. Petersburg Academy of Refrigeration and Food Technology (Russian Federation). Dept. of Refrigeration Machines and Air-Conditioning Systems

    1998-12-31T23:59:59.000Z

    Different ventilation strategies to improve indoor air quality and to reduce HVAC system operating costs in a restaurant with nonsmoking and smoking areas and a bar are discussed in this paper. A generic sitting-type restaurant is used for the analysis. Prototype designs for the restaurant chain with more than 200 restaurants in different US climates were analyzed to collect the information on building envelope, dining area size, heat and contaminant sources and loads, occupancy rates, and current design practices. Four constant air volume HVAC systems wit h a constant and variable (demand-based) outdoor airflow rate, with a mixing and displacement air distribution, were compared in five representative US climates: cold (Minneapolis, MN); Maritime (Seattle, WA); moderate (Albuquerque, NM); hot-dry (Phoenix, AZ); and hot-humid (Miami, FL). For all four compared cases and climatic conditions, heating and cooling consumption by the HVAC system throughout the year-round operation was calculated and operation costs were compared. The analysis shows: Displacement air distribution allows for better indoor air quality in the breathing zone at the same outdoor air supply airflow rate due to contaminant stratification along the room height. The increase in outdoor air supply during the peak hours in Miami and Albuquerque results in an increase of both heating and cooling energy consumption. In other climates, the increase in outdoor air supply results in reduced cooling energy consumption. For the Phoenix, Minneapolis, and Seattle locations, the HVAC system operation with a variable outdoor air supply allows for a decrease in cooling consumption up to 50% and, in some cases, eliminates the use of refrigeration machines. The effect of temperature stratification on HVAC system parameters is the same for all locations; displacement ventilation systems result in decreased cooling energy consumption but increased heating consumption.

  8. Quantum information with modular variables

    E-Print Network [OSTI]

    A. Ketterer; S. P. Walborn; A. Keller; T. Coudreau; P. Milman

    2014-06-24T23:59:59.000Z

    We introduce a novel strategy, based on the use of modular variables, to encode and deterministically process quantum information using states described by continuous variables. Our formalism leads to a general recipe to adapt existing quantum information protocols, originally formulated for finite dimensional quantum systems, to infinite dimensional systems described by continuous variables. This is achieved by using non unitary and non-gaussian operators, obtained from the superposition of gaussian gates, together with adaptative manipulations in qubit systems defined in infinite dimensional Hilbert spaces. We describe in details the realization of single and two qubit gates and briefly discuss their implementation in a quantum optical set-up.

  9. System and method for cancelling the effects of stray magnetic fields from the output of a variable reluctance sensor

    DOE Patents [OSTI]

    Chen, Chingchi (Ann Arbor, MI); Degner, Michael W. (Farmington Hills, MI)

    2002-11-19T23:59:59.000Z

    A sensor system for sensing a rotation of a sensing wheel is disclosed. The sensor system has a sensing coil in juxtaposition with the sensing wheel. Moreover, the sensing coil has a sensing coil output signal indicative of the rotational speed of the sensing wheel. Further, a cancellation coil is located remotely from the sensing coil and connected in series therewith. Additionally, the cancellation coil has a cancellation coil output signal indicative of an environmental disturbance which is effecting the sensing coil output signal. The cancellation coil output signal operates to cancel the effects of the environmental disturbance on the sensing coil output signal.

  10. The importance of input variables to a neural network fault-diagnostic system for nuclear power plants

    SciTech Connect (OSTI)

    Lanc, T.L.

    1992-01-01T23:59:59.000Z

    This thesis explores safety enhancement for nuclear power plants. Emergency response systems currently in use depend mainly on automatic systems engaging when certain parameters go beyond a pre-specified safety limit. Often times the operator has little or no opportunity to react since a fast scram signal shuts down the reactor smoothly and efficiently. These accidents are of interest to technical support personnel since examining the conditions that gave rise to these situations help determine causality. In many other cases an automated fault-diagnostic advisor would be a valuable tool in assisting the technicians and operators to determine what just happened and why.

  11. The importance of input variables to a neural network fault-diagnostic system for nuclear power plants

    SciTech Connect (OSTI)

    Lanc, T.L.

    1992-12-31T23:59:59.000Z

    This thesis explores safety enhancement for nuclear power plants. Emergency response systems currently in use depend mainly on automatic systems engaging when certain parameters go beyond a pre-specified safety limit. Often times the operator has little or no opportunity to react since a fast scram signal shuts down the reactor smoothly and efficiently. These accidents are of interest to technical support personnel since examining the conditions that gave rise to these situations help determine causality. In many other cases an automated fault-diagnostic advisor would be a valuable tool in assisting the technicians and operators to determine what just happened and why.

  12. Climate variability and ocean production in the Leeuwin Current system off the west coast of Western Australia

    E-Print Network [OSTI]

    Feng, Ming

    of Western Australia M Feng1 , A M Waite2 , P A Thompson3 1 CSIRO Marine & Atmospheric Research, Floreat, WA 6014 Ming.Feng@csiro.au 2 School of Environmental Systems Engineering, University of Western Australia coast of Western Australia (WA), as well as the upper ocean stratification (mixing) and the nutrient

  13. Variable Temperature STM/AFM | EMSL

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

    STMAFM Variable Temperature STMAFM EMSL's ultra-high vacuum, variable-temperature scanning probe microscope system, or UHV VT SPM, is a state-of-the-art surface science tool...

  14. Strategy Guideline: Compact Air Distribution Systems

    SciTech Connect (OSTI)

    Burdick, A.

    2013-06-01T23:59:59.000Z

    This Strategy Guideline discusses the benefits and challenges of using a compact air distribution system to handle the reduced loads and reduced air volume needed to condition the space within an energy efficient home. Traditional systems sized by 'rule of thumb' (i.e., 1 ton of cooling per 400 ft2 of floor space) that 'wash' the exterior walls with conditioned air from floor registers cannot provide appropriate air mixing and moisture removal in low-load homes. A compact air distribution system locates the HVAC equipment centrally with shorter ducts run to interior walls, and ceiling supply outlets throw the air toward the exterior walls along the ceiling plane; alternatively, high sidewall supply outlets throw the air toward the exterior walls. Potential drawbacks include resistance from installing contractors or code officials who are unfamiliar with compact air distribution systems, as well as a lack of availability of low-cost high sidewall or ceiling supply outlets to meet the low air volumes with good throw characteristics. The decision criteria for a compact air distribution system must be determined early in the whole-house design process, considering both supply and return air design. However, careful installation of a compact air distribution system can result in lower material costs from smaller equipment, shorter duct runs, and fewer outlets; increased installation efficiencies, including ease of fitting the system into conditioned space; lower loads on a better balanced HVAC system, and overall improved energy efficiency of the home.

  15. Variable Crop Share Leases.

    E-Print Network [OSTI]

    Sartin, Marvin; Sammons, Ray

    1980-01-01T23:59:59.000Z

    )OC lAL45.7 173 1. 1224 Texas Agricultural Extension Service The Texas A&M University System Daniel C. Pfannstiel,Director colleg e Station, Texas / f , ' '~ :';,; ,,: ''': ~ " k , -~. _Variable _Crop Share _Leases ... Marvin... Sartin and Ray Sammons* Renting or leasing farmland is part of many modern farming operations and increases average farm size in U. S. agriculture. Economies of size are vitally import ant to farm operations as they strive to cope with the continuous...

  16. MASe UCRL-15037 CONTINUOUSLY VARIABLE TRANSMISSIONS: THEORY AND...

    Office of Scientific and Technical Information (OSTI)

    transmission when operating in the power recirculation mode 20 Simple manual system to control the speed ratio of a variable V-belt continuously variable transmission 21 Schematic...

  17. Strategies and Decision Support Systems for Integrating Variable Energy Resources in Control Centers for Reliable Grid Operations

    SciTech Connect (OSTI)

    Jones, Lawrence E.

    2011-12-01T23:59:59.000Z

    A variety of studies have recently evaluated the opportunities for the large-scale integration of wind energy into the US power system. These studies have included, but are not limited to, "20 Percent Wind Energy by 2030: Increasing Wind Energy's Contribution to US Electricity Supply", the "Western Wind and Solar Integration Study", and the "Eastern Wind Integration and Transmission Study." Each of these US based studies have evaluated a variety of activities that can be undertaken by utilities to help integrate wind energy.

  18. Moving-Boundary Heat Exchanger Models with Variable Outlet Phase, ASME Journal of Dynamic Systems, Measurement, and Control

    E-Print Network [OSTI]

    Eldredge, B.D; Rasmussen, B.P.; Alleyne, A.

    , MEASUREMENT, AND CON- ROL. Manuscript received June 8, 2006; final manuscript received May 22, 2008; ublished online September 24, 2008. Assoc. Editor: Huei Peng. ournal of Dynamic Systems, Measurement, and Control NOVEMBER 2008, Vol. 130 / 061003-1Brian D.... Eldredge University of Illinois at Urbana-Champaign, 158 MEB, MC-244, 1206 West Green Street, Urbana, IL 61801 e-mail: brian.eldredge@gmail.com Bryan P. Rasmussen Texas A&M University, 3123 TAMU, College Station, TX 77843-3123 e-mail: brasmussen...

  19. VARIABLE AND EXTREME IRRADIATION CONDITIONS IN THE EARLY SOLAR SYSTEM INFERRED FROM THE INITIAL ABUNDANCE OF {sup 10}Be IN ISHEYEVO CAIs

    SciTech Connect (OSTI)

    Gounelle, Matthieu [Laboratoire de Mineralogie et de Cosmochimie du Museum, CNRS and Museum National d'Histoire Naturelle, UMR 7202, CP52, 57 rue Cuvier, F-75005 Paris (France); Chaussidon, Marc; Rollion-Bard, Claire, E-mail: gounelle@mnhn.fr [Centre de Recherches Petrographiques et Geochimiques, CRPG-CNRS, BP 20, F-54501 Vandoeuvre-les-Nancy Cedex (France)

    2013-02-01T23:59:59.000Z

    A search for short-lived {sup 10}Be in 21 calcium-aluminum-rich inclusions (CAIs) from Isheyevo, a rare CB/CH chondrite, showed that only 5 CAIs had {sup 10}B/{sup 11}B ratios higher than chondritic correlating with the elemental ratio {sup 9}Be/{sup 11}B, suggestive of in situ decay of this key short-lived radionuclide. The initial ({sup 10}Be/{sup 9}Be){sub 0} ratios vary between {approx}10{sup -3} and {approx}10{sup -2} for CAI 411. The initial ratio of CAI 411 is one order of magnitude higher than the highest ratio found in CV3 CAIs, suggesting that the more likely origin of CAI 411 {sup 10}Be is early solar system irradiation. The low ({sup 26}Al/{sup 27}Al){sub 0} [{<=} 8.9 Multiplication-Sign 10{sup -7}] with which CAI 411 formed indicates that it was exposed to gradual flares with a proton fluence of a few 10{sup 19} protons cm{sup -2}, during the earliest phases of the solar system, possibly the infrared class 0. The irradiation conditions for other CAIs are less well constrained, with calculated fluences ranging between a few 10{sup 19} and 10{sup 20} protons cm{sup -2}. The variable and extreme value of the initial {sup 10}Be/{sup 9}Be ratios in carbonaceous chondrite CAIs is the reflection of the variable and extreme magnetic activity in young stars observed in the X-ray domain.

  20. Variable Definitions

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for On-Highway4,1,50022,3,,,,6,1,9,1,50022,3,,,,6,1,Decade Energy I I'26,282.1 26,672.1MonthFeet) YearDay)Data System CSV

  1. Anyonic statistics with continuous variables

    E-Print Network [OSTI]

    Jing Zhang; Changde Xie; Kunchi Peng; Peter van Loock

    2008-10-30T23:59:59.000Z

    We describe a continuous-variable scheme for simulating the Kitaev lattice model and for detecting statistics of abelian anyons. The corresponding quantum optical implementation is solely based upon Gaussian resource states and Gaussian operations, hence allowing for a highly efficient creation, manipulation, and detection of anyons. This approach extends our understanding of the control and application of anyons and it leads to the possibility for experimental proof-of-principle demonstrations of anyonic statistics using continuous-variable systems.

  2. Operating Reserves and Variable Generation

    SciTech Connect (OSTI)

    Ela, E.; Milligan, M.; Kirby, B.

    2011-08-01T23:59:59.000Z

    This report tries to first generalize the requirements of the power system as it relates to the needs of operating reserves. It also includes a survey of operating reserves and how they are managed internationally in system operations today and then how new studies and research are proposing they may be managed in the future with higher penetrations of variable generation.

  3. Variable Valve Actuation

    SciTech Connect (OSTI)

    Jeffrey Gutterman; A. J. Lasley

    2008-08-31T23:59:59.000Z

    Many approaches exist to enable advanced mode, low temperature combustion systems for diesel engines - such as premixed charge compression ignition (PCCI), Homogeneous Charge Compression Ignition (HCCI) or other HCCI-like combustion modes. The fuel properties and the quantity, distribution and temperature profile of air, fuel and residual fraction in the cylinder can have a marked effect on the heat release rate and combustion phasing. Figure 1 shows that a systems approach is required for HCCI-like combustion. While the exact requirements remain unclear (and will vary depending on fuel, engine size and application), some form of substantially variable valve actuation is a likely element in such a system. Variable valve actuation, for both intake and exhaust valve events, is a potent tool for controlling the parameters that are critical to HCCI-like combustion and expanding its operational range. Additionally, VVA can be used to optimize the combustion process as well as exhaust temperatures and impact the after treatment system requirements and its associated cost. Delphi Corporation has major manufacturing and product development and applied R&D expertise in the valve train area. Historical R&D experience includes the development of fully variable electro-hydraulic valve train on research engines as well as several generations of mechanical VVA for gasoline systems. This experience has enabled us to evaluate various implementations and determine the strengths and weaknesses of each. While a fully variable electro-hydraulic valve train system might be the 'ideal' solution technically for maximum flexibility in the timing and control of the valve events, its complexity, associated costs, and high power consumption make its implementation on low cost high volume applications unlikely. Conversely, a simple mechanical system might be a low cost solution but not deliver the flexibility required for HCCI operation. After modeling more than 200 variations of the mechanism it was determined that the single cam design did not have enough flexibility to satisfy three critical OEM requirements simultaneously, (maximum valve lift variation, intake valve opening timing and valve closing duration), and a new approach would be necessary. After numerous internal design reviews including several with the OEM a dual cam design was developed that had the flexibility to meet all motion requirements. The second cam added complexity to the mechanism however the cost was offset by the deletion of the electric motor required in the previous design. New patent applications including detailed drawings and potential valve motion profiles were generated and alternate two cam designs were proposed and evaluated for function, cost, reliability and durability. Hardware was designed and built and testing of sample hardware was successfully completed on an engine test stand. The mechanism developed during the course of this investigation can be applied by Original Equipment Manufacturers, (OEM), to their advanced diesel engines with the ultimate goal of reducing emissions and improving fuel economy. The objectives are: (1) Develop an optimal, cost effective, variable valve actuation (VVA) system for advanced low temperature diesel combustion processes. (2) Design and model alternative mechanical approaches and down-select for optimum design. (3) Build and demonstrate a mechanism capable of application on running engines.

  4. Energy Analysis and Energy Conservation Options for the Addition to Records Storage Building 

    E-Print Network [OSTI]

    Farzad, M.; O'Neal, D. L.

    1986-01-01T23:59:59.000Z

    with the HVAC system. Two Air Handling Units (AHU) are used for Storage building. The AHU schedules are shown in Table 2.4. Heat pumps are used in the Office area. The Coefficient Of Performance (COP) for the heat pumps is assumed to be 2.0. The temperature...-D BUILDING MONTHLY LOADS SUMMARY VARIABLE AIR VOLUME HEAT PUMP SYSTEMS STATE PROJECT, BASE CASE REPORT- SS-A SYSTEM MONTHLY LOADS SUMMARY FOR FLOOR-G VARIABLE AIR VOLUME HEAT PUMP SYSTEMS STATE PROJECT, BASE CASE REPORT- SS-A SYSTEM MONTHLY LOADS SUMMARY...

  5. Variable metric conjugate gradient methods

    SciTech Connect (OSTI)

    Barth, T.; Manteuffel, T.

    1994-07-01T23:59:59.000Z

    1.1 Motivation. In this paper we present a framework that includes many well known iterative methods for the solution of nonsymmetric linear systems of equations, Ax = b. Section 2 begins with a brief review of the conjugate gradient method. Next, we describe a broader class of methods, known as projection methods, to which the conjugate gradient (CG) method and most conjugate gradient-like methods belong. The concept of a method having either a fixed or a variable metric is introduced. Methods that have a metric are referred to as either fixed or variable metric methods. Some relationships between projection methods and fixed (variable) metric methods are discussed. The main emphasis of the remainder of this paper is on variable metric methods. In Section 3 we show how the biconjugate gradient (BCG), and the quasi-minimal residual (QMR) methods fit into this framework as variable metric methods. By modifying the underlying Lanczos biorthogonalization process used in the implementation of BCG and QMR, we obtain other variable metric methods. These, we refer to as generalizations of BCG and QMR.

  6. Atmospheric Carbon Dioxide Variability in the Community Earth System Model: Evaluation and Transient Dynamics during the Twentieth and Twenty-First Centuries

    E-Print Network [OSTI]

    2013-01-01T23:59:59.000Z

    in the Community Earth System Model: Evaluation andpredictions from CMIP5 Earth system models and comparisonusing the Community Earth System Model–Biogeochemistry (

  7. Control Strategies for Centrifugal Pumps with Variable Flow Rate...

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

    This tip sheet discusses control strategies for centrifugal pumps with variable flow rate requirements in pumping systems and includes installation considerations. PUMPING SYSTEMS...

  8. Supply Fan Control for Constant Air Volume Air Handling Units

    E-Print Network [OSTI]

    Cho, Y.; Wang, G.; Liu, M.

    2007-01-01T23:59:59.000Z

    there is fixed VFD speed, as shown in Table 1 and Figure 11. On the other hand, the energy consumption is 3,896,493 Btu/hr when there is dynamic VFD speed. The thermal energy consumption of dynamic VFD speed is less than that of the fixed VFD speed by 44... %. Therefore, when the supply fan speed control is optimized, thermal energy can be reduced. Table 1. Comparison data of thermal energy consumption Floor Fixed VFD speed (Btu/hr) Dynamic VFD speed (Btu/hr) Energy saving (%) PLF 784,891 502,611 36...

  9. Variable Speed Pumping for Level Control 

    E-Print Network [OSTI]

    Vasel, M.

    1982-01-01T23:59:59.000Z

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

  10. Variable Speed Pumping for Level Control

    E-Print Network [OSTI]

    Vasel, M.

    1982-01-01T23:59:59.000Z

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

  11. Ashtekar's variables without spin

    E-Print Network [OSTI]

    Thomas Schucker

    2009-06-26T23:59:59.000Z

    Ashtekar's variables are shown to arise naturally from a 3+1 split of general relativity in the Einstein-Cartan formulation. Thereby spinors are exorcised.

  12. Automatic Commissioning of Multiple VAV Terminals

    E-Print Network [OSTI]

    Qin, J.; Wang, S.

    2004-01-01T23:59:59.000Z

    A site survey on a modern operating commercial building screened 261 ineffective VAV (Variable Air Volume) boxes (20.9% of the total boxes in the building) and summarized ten typical faults for VAV air-conditioning system(s) resulting in energy...

  13. The! Community! Earth! System! Model! (CESM)! Large! Ensemble! Project:! A! Community!3! Resource!for!Studying!Climate!Change!in!the!Presence!of!Internal!Climate!Variability!4!

    E-Print Network [OSTI]

    Kay, Jennifer

    !1! !2! The! Community! Earth! System! Model! (CESM)! Large! Ensemble! Project:! A! Community!3!Earth!System!Model!(CESM)!community!designed!the!CESM!Large!Ensemble!39! (CESMWLE)!with!the!explicit

  14. Field Test and Performance Verification: Integrated Active Desiccant Rooftop Hybrid System Installed in a School - Final Report: Phase 4A

    SciTech Connect (OSTI)

    Fischer, J

    2005-12-21T23:59:59.000Z

    This report summarizes the results of a field verification pilot site investigation that involved the installation of a hybrid integrated active desiccant/vapor-compression rooftop heating, ventilation, and air-conditioning (HVAC) unit at an elementary school in the Atlanta Georgia area. For years, the school had experienced serious humidity and indoor air quality (IAQ) problems that had resulted in occupant complaints and microbial (mold) remediation. The outdoor air louvers of the original HVAC units had been closed in an attempt to improve humidity control within the space. The existing vapor compression variable air volume system was replaced by the integrated active desiccant rooftop (IADR) system that was described in detail in an Oak Ridge National Laboratory (ORNL) report published in 2004 (Fischer and Sand 2004). The IADR system and all space conditions have been monitored remotely for more than a year. The hybrid system was able to maintain both the space temperature and humidity as desired while delivering the outdoor air ventilation rate required by American Society of Heating, Refrigerating and Air-Conditioning Engineers Standard 62. The performance level of the IADR unit and the overall system energy efficiency was measured and found to be very high. A comprehensive IAQ investigation was completed by the Georgia Tech Research Institute before and after the system retrofit. Before-and-after data resulting from this investigation confirmed a significant improvement in IAQ, humidity control, and occupant comfort. These observations were reported by building occupants and are echoed in a letter to ORNL from the school district energy manager. The IADR system was easily retrofitted in place of the original rooftop system using a custom curb adapter. All work was completed in-house by the school's maintenance staff over one weekend. A subsequent cost analysis completed for the school district by the design engineer of record concluded that the IADR system being investigated was actually less expensive to install than other less-efficient options, most of which were unable to deliver the required ventilation while maintaining the desired space humidity levels.

  15. Energy Savings of Variable Speed Motors

    E-Print Network [OSTI]

    Fishel, F. D.

    1979-01-01T23:59:59.000Z

    pump) The input horsepower from the electrical system can be calculated using Equation (3). static head + frictional head + control valve Input HP = ::"\\;;=~..l... motor, conduit, and wire. Motors in the 25-350 HP range are best suited to VFD Systems. As the cost of energy increases and the relative cost savings of variable speed systems increase, the application of these systems should be more widespread. 281...

  16. Design and Test of DC Voltage Link Conversion System and Brushless Doubly-Fed Induction Generator for Variable-Speed Wind Energy Applications: August 1999--May 2003

    SciTech Connect (OSTI)

    Lipo, T.A.; Panda, D.; Zarko, D.

    2005-11-01T23:59:59.000Z

    This report describes four low-cost alternative power converters for processing the power developed by a doubly fed wound-rotor induction generator for wind energy conversion systems.

  17. PNNL-22072 Prepared for the U.S. Department of Energy under Contract DE-AC05-76RL01830

    E-Print Network [OSTI]

    or heating, but the minimum for ventilation should always be met. In practice, control system integrators for large office buildings with variable-air-volume (VAV) heating, ventilating and air-conditioning (HVAC-flow rate that ensures the ventilation requirements of the occupants of the zone served are met

  18. Prediction of Room Air Diffusion for Reduced Diffuser Flow Rates 

    E-Print Network [OSTI]

    Gangisetti, Kavita

    2011-02-22T23:59:59.000Z

    and analytical tool for investigating ventilation inside the system and thus to increase thermal comfort and improve indoor air quality. The room air supply diffuser flow rates can be reduced for less loading with the help of a variable air volume unit...

  19. IEEE TRANSACTIONS ON VERY LARGE SCALE INTEGRATION (VLSI) SYSTEMS, VOL. 13, NO. 6, JUNE 2005 765 VARIABILITY RESULTS FOR DUAL-THRESHOLD VOLTAGE ALLOCATION

    E-Print Network [OSTI]

    Dueck, Gerhard W.

    IEEE TRANSACTIONS ON VERY LARGE SCALE INTEGRATION (VLSI) SYSTEMS, VOL. 13, NO. 6, JUNE 2005 765, and M. I. Elmasry, "Dynamic and leakage power reduction in MTCMOS circuits using an automated effi. 1997. [6] Q. Wang and S. B. K. Vrudhula, "Static power optimization of deep submicron CMOS circuits

  20. Dimensional variability of production steel castings

    SciTech Connect (OSTI)

    Peters, F.E.; Risteu, J.W.; Vaupel, W.G.; DeMeter, E.C.; Voigt, R.C.

    1994-12-31T23:59:59.000Z

    Work is ongoing to characterize the dimensional variability of steel casting features. Data are being collected from castings produced at representative Steel Founders` Society of America foundries. Initial results based on more than 12,500 production casting feature measurements are presented for carbon and low alloy steel castings produced in green sand, no-bake, and shell molds. A comprehensive database of casting, pattern, and feature variables has been developed so that the influence of the variables on dimensional variability can be determined. Measurement system analysis is conducted to insure that large measurement error is not reported as dimensional variability. Results indicate that the dimensional variability of production casting features is less than indicated in current US (SFSA) and international (ISO) standards. Feature length, casting weight, parting line and molding process all strongly influence dimensional variability. Corresponding pattern measurements indicate that the actual shrinkage amount for casting features varies considerably. This variation in shrinkage will strongly influence the ability of the foundry to satisfy customer dimensional requirements.

  1. Variable nonlinear resistances

    E-Print Network [OSTI]

    Howard, James Edgar

    1955-01-01T23:59:59.000Z

    VARIETAL". NONLINEAR RESIS'IANCES A Thes1s JA'. 4ES EDGAR HOWARD as to style and content by Head Department January 1955 LIBRARY A 4 IS COLLEGE PF TEXAS VARIABLE NONLINEAR RESISTANCES A Thesis By JAMES EDGAR HOWARD Submitted...

  2. ULTRACAM photometry of eclipsing cataclysmic variable stars

    E-Print Network [OSTI]

    William James Feline

    2008-06-04T23:59:59.000Z

    The accurate determination of the masses of cataclysmic variable stars is critical to our understanding of their origin, evolution and behaviour. Observations of cataclysmic variables also afford an excellent opportunity to constrain theoretical physical models of the accretion discs housed in these systems. In particular, the brightness distributions of the accretion discs of eclipsing systems can be mapped at a spatial resolution unachievable in any other astrophysical situation. This thesis addresses both of these important topics via the analysis of the light curves of six eclipsing dwarf novae, obtained using ULTRACAM, a novel high-speed imaging photometer.

  3. Integrating Variable Renewable Energy: Challenges and Solutions

    SciTech Connect (OSTI)

    Bird, L.; Milligan, M.; Lew, D.

    2013-09-01T23:59:59.000Z

    In the U.S., a number of utilities are adopting higher penetrations of renewables, driven in part by state policies. While power systems have been designed to handle the variable nature of loads, the additional supply-side variability and uncertainty can pose new challenges for utilities and system operators. However, a variety of operational and technical solutions exist to help integrate higher penetrations of wind and solar generation. This paper explores renewable energy integration challenges and mitigation strategies that have been implemented in the U.S. and internationally, including forecasting, demand response, flexible generation, larger balancing areas or balancing area cooperation, and operational practices such as fast scheduling and dispatch.

  4. Coordinated Variable Structure Switching Attacks for Smart Grid

    E-Print Network [OSTI]

    Liu, Shan

    2013-02-11T23:59:59.000Z

    or more relays and circuit breakers of a power system to disrupt operation. Existence of this switching vulnerability is dependent on the local structure of the power grid. Variable structure systems theory is employed to effectively model the cyber...

  5. Measuring spatial variability in soil characteristics

    DOE Patents [OSTI]

    Hoskinson, Reed L. (Rigby, ID); Svoboda, John M. (Idaho Falls, ID); Sawyer, J. Wayne (Hampton, VA); Hess, John R. (Ashton, ID); Hess, J. Richard (Idaho Falls, ID)

    2002-01-01T23:59:59.000Z

    The present invention provides systems and methods for measuring a load force associated with pulling a farm implement through soil that is used to generate a spatially variable map that represents the spatial variability of the physical characteristics of the soil. An instrumented hitch pin configured to measure a load force is provided that measures the load force generated by a farm implement when the farm implement is connected with a tractor and pulled through or across soil. Each time a load force is measured, a global positioning system identifies the location of the measurement. This data is stored and analyzed to generate a spatially variable map of the soil. This map is representative of the physical characteristics of the soil, which are inferred from the magnitude of the load force.

  6. Variable depth core sampler

    DOE Patents [OSTI]

    Bourgeois, P.M.; Reger, R.J.

    1996-02-20T23:59:59.000Z

    A variable depth core sampler apparatus is described comprising a first circular hole saw member, having longitudinal sections that collapses to form a point and capture a sample, and a second circular hole saw member residing inside said first hole saw member to support the longitudinal sections of said first hole saw member and prevent them from collapsing to form a point. The second hole saw member may be raised and lowered inside said first hole saw member. 7 figs.

  7. Variable Frequency Pump Drives

    E-Print Network [OSTI]

    Karassik, I. J.; Petraccaro, L. L.; McGuire, J. T.

    . In a conventional pump and driver arrangement (for example, a centrifugal pump coupled to an AC induction motor'with no speed control provision), the motor runs at. a constant speed, which is determined by the incoming line frequency, and the pump... when it is needed. LONG RANGE DESIGN TRENDS The growing use of variable-frequency electric motor drives will permit the integration of 60 and 50 cycle pump lines. One important concern for future improvements is the growing possibility...

  8. Industrial applications of variable frequency microwave energy in materials processing

    SciTech Connect (OSTI)

    Fathi, Z.; Tucker, D.A.; Lewis, W.A.; Wei, J.B. [Lambda Technologies, Inc., Raleigh, NC (United States)

    1996-12-31T23:59:59.000Z

    A review of some market-driven research, process applications and systems development is provided. The variable frequency microwave processing concepts are briefly described. Industrial processing using variable frequency microwave energy in the areas of polymerization, composite processing, bonding and plasma is discussed. Analytical applications inherent in the use of variable frequency and its control are demonstrated in the areas of materials signature analysis for volumetric cure monitoring.

  9. Texas LoanSTAR Monitoring & Analysis Program- Improving the Performance of Retrofits by Providing Operator Feedback from Measured Data

    E-Print Network [OSTI]

    Challa, V.; Abbas, M.; Athar, A.; Claridge, D.; Haberl, J.

    pumping. Under the new system it is conditioned by four groups of air conditioning equipment consisting of eight variable volume single duct AHUs (75 hp each), twelve variable volume dual duct AHUs (two IDO hp and ten 75 hp), four variable volume hot.... The building was retrofiUed with a double-duct variable air volume HVAC system in March 1991. Under the new system the, building is served by twelve variable-volume dual-duct air handling units (40 hp each) along with len 36 hp constant volume systems. TIle...

  10. Orthogonal coordinate systems and separation of variables

    E-Print Network [OSTI]

    Gibbs, Sam Gavin

    1960-01-01T23:59:59.000Z

    The writer wishes to acknowledge the help and friendly counsel of the chairman of his committee, Professor Robert E. Basye. iU Convae rlt s on No tat ion Equations, theorem ? i lie strati ons, etc . are numberec consecutively in ee h chapter. v... function. Then we define grad &P =P(I) = i P + j c) Ax div A =ll'dA =- ? e ? ~ + c)x Qy A + k t QA Tle identities which we requir-. are listed below". A A A ~ (A + B) =Q'A +7 B tvt X (A + B) =VXA +'UXB V ~ ( &I) A ) = (V&( ). A +P (P A) ~X($ A...

  11. RESEARCH ARTICLE Development and characterization of a variable turbulence

    E-Print Network [OSTI]

    Lieuwen, Timothy C.

    (7):1037­1048, 2009), where variable blockage ratio slots are located upstream of a contoured nozzle. Vortical A Nozzle exit area E Power spectral density ReD Geometric Reynolds number Rel Turbulent Reynolds number SLRESEARCH ARTICLE Development and characterization of a variable turbulence generation system A

  12. CX-006014: Categorical Exclusion Determination | Department of...

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

    approved); and 3(A) Broughton Municipal Building (132 East Broughton Street) Light Emitting Diode (LED) lighting, variable air volume air handling fans, fluorescent lighting,...

  13. Development of Diagnostic Rules for a Dry Bulb Economizer Mixed Air Loop

    E-Print Network [OSTI]

    Underwood, D.

    1990-01-01T23:59:59.000Z

    knowledge base for a two fan variable air volume (VAV) air handling unit. Rules for the mixed air loop with a dry bulb economizer are presented....

  14. Present and Future Modes of Low Frequency Climate Variability

    SciTech Connect (OSTI)

    Cane, Mark A.

    2014-02-20T23:59:59.000Z

    This project addressed area (1) of the FOA, “Interaction of Climate Change and Low Frequency Modes of Natural Climate Variability”. Our overarching objective is to detect, describe and understand the changes in low frequency variability between model simulations of the preindustrial climate and simulations of a doubled CO2 climate. The deliverables are a set of papers providing a dynamical characterization of interannual, decadal, and multidecadal variability in coupled models with attention to the changes in this low frequency variability between pre-industrial concentrations of greenhouse gases and a doubling of atmospheric concentrations of CO2. The principle mode of analysis, singular vector decomposition, is designed to advance our physical, mechanistic understanding. This study will include external natural variability due to solar and volcanic aerosol variations as well as variability internal to the climate system. An important byproduct is a set of analysis tools for estimating global singular vector structures from the archived output of model simulations.

  15. Variables Influencing HRSG Designs

    E-Print Network [OSTI]

    Ganapathy, V.; Rentz, J.

    Heat Recovery Steam Generators (HRSG's) are widely used in chemical plants, refineries, incineration and cogeneration systems and in general for recovering energy from waste gas streams. In applications such as hydrogen or sulfuric acid plants...

  16. Testing of a variable-stroke Stirling engine

    SciTech Connect (OSTI)

    Thieme, L.G.; Allen, D.J.

    1986-01-01T23:59:59.000Z

    Testing of a variable-stroke Stirling engine at NASA Lewis has been completed. In support of the US Department of Energy's Stirling Engine Highway Vehicle Systems Program, the engine was tested for about 70 hr total with both helium and hydrogen working fluids over a range of pressures and strokes. A direct comparison was made of part-load efficiencies obtained with variable-stroke and variable-pressure operation. Two failures with the variable-angle swash-plate drive system limited testing to low power levels. These failures are not thought to be caused by problems inherent in the variable-stroke concept but they do emphasize the need for careful design in the area of the crossheads where the failures occurred. This paper describes these failures and the efforts to resolve the associated problems, and presents test results that were obtained. 5 refs., 17 figs.

  17. Continuous variable entanglement on a chip

    E-Print Network [OSTI]

    Genta Masada; Kazunori Miyata; Alberto Politi; Toshikazu Hashimoto; Jeremy L. O'Brien; Akira Furusawa

    2015-05-29T23:59:59.000Z

    Encoding quantum information in continuous variables (CV)---as the quadrature of electromagnetic fields---is a powerful approach to quantum information science and technology. CV entanglement---light beams in Einstein-Podolsky-Rosen (EPR) states---is a key resource for quantum information protocols; and enables hybridisation between CV and single photon discrete variable (DV) qubit systems. However, CV systems are currently limited by their implementation in free-space optical networks: increased complexity, low loss, high-precision alignment and stability, as well as hybridisation, demand an alternative approach. Here we show an integrated photonic implementation of the key capabilities for CV quantum technologies---generation and characterisation of EPR beams in a photonic chip. Combined with integrated squeezing and non-Gaussian operation, these results open the way to universal quantum information processing with light.

  18. Intensive Variables & Nanostructuring in Magnetostructural Materials

    SciTech Connect (OSTI)

    Lewis, Laura

    2014-08-13T23:59:59.000Z

    Over the course of this project, fundamental inquiry was carried out to investigate, understand and predict the effects of intensive variables, including the structural scale, on magnetostructural phase transitions in the model system of equiatomic FeRh. These transitions comprise simultaneous magnetic and structural phase changes that have their origins in very strong orbital-lattice coupling and thus may be driven by a plurality of effects.

  19. Turbo-generator control with variable valve actuation

    DOE Patents [OSTI]

    Vuk, Carl T. (Denver, IA)

    2011-02-22T23:59:59.000Z

    An internal combustion engine incorporating a turbo-generator and one or more variably activated exhaust valves. The exhaust valves are adapted to variably release exhaust gases from a combustion cylinder during a combustion cycle to an exhaust system. The turbo-generator is adapted to receive exhaust gases from the exhaust system and rotationally harness energy therefrom to produce electrical power. A controller is adapted to command the exhaust valve to variably open in response to a desired output for the turbo-generator.

  20. VARIABLE SPEED WIND TURBINE

    E-Print Network [OSTI]

    Chatinderpal Singh

    Wind energy is currently the fastest-growing renewable source of energy in India; India is a key market for the wind industry, presenting substantial opportunities for both the international and domestic players. In India the research is carried out on wind energy utilization on big ways.There are still many unsolved challenges in expanding wind power, and there are numerous problems of interest to systems and control researchers. In this paper we study the pitch control mechanism of wind turbine. The pitch control system is one of the most widely used control techniques to regulate the output power of a wind turbine generator. The pitch angle is controlled to keep the generator power at rated power by reducing the angle of the blades. By regulating, the angle of stalling, fast torque changes from the wind will be reutilized. It also describes the design of the pitch controller and discusses the response of the pitch-controlled system to wind velocity variations. The pitch control system is found to have a large output power variation and a large settling time.

  1. Variable Refrigerant Flow HVAC

    E-Print Network [OSTI]

    Jones, S.

    2013-01-01T23:59:59.000Z

    heat pump utilizing VFD Inverter Compressors and LEV’s Unlike conventional commercial and residential HVAC systems in the USA The predominate method of cooling and heating in the world ESL-KT-13-12-33 CATEE 2013: Clean Air Through Energy Efficiency... Conference, San Antonio, Texas Dec. 16-18 Heat Pump operation at lower ambient conditions -13 -4 5 17 23 32 41 470 0.2 0.4 0.6 0.8 1 1.2 Residential Heating Capacity at Low Temperatures MUZ-FE18NA MUZ-FE09NA MUZ-FE12NA Unitary Outdoor Temperature (F...

  2. Variable rate CELP speech coding using widely variable parameter updates

    E-Print Network [OSTI]

    Moodie, Myron L.

    1995-01-01T23:59:59.000Z

    bit rates for a given quality level. This work develops new techniques, referred to as widely variable CELP parameter updates, which dynamically adapt the transmit frequency of the CELP spectral parameters to the characteristics of the input speech...

  3. Review of Variable Generation Integration Charges

    SciTech Connect (OSTI)

    Porter, K.; Fink, S.; Buckley, M.; Rogers, J.; Hodge, B. M.

    2013-03-01T23:59:59.000Z

    The growth of wind and solar generation in the United States, and the expectation of continued growth of these technologies, dictates that the future power system will be operated in a somewhat different manner because of increased variability and uncertainty. A small number of balancing authorities have attempted to determine an 'integration cost' to account for these changes to their current operating practices. Some balancing authorities directly charge wind and solar generators for integration charges, whereas others add integration charges to projected costs of wind and solar in integrated resource plans or in competitive solicitations for generation. This report reviews the balancing authorities that have calculated variable generation integration charges and broadly compares and contrasts the methodologies they used to determine their specific integration charges. The report also profiles each balancing authority and how they derived wind and solar integration charges.

  4. Changes in the Economic Value of Variable Generation at High Penetration Levels: A Pilot Case Study of California

    E-Print Network [OSTI]

    Mills, Andrew

    2013-01-01T23:59:59.000Z

    to a power system based on load, VG profile, and capacitiespower system operations and dispatch with variable generation, including hourly generation and load profiles,

  5. A Wavelet-Based Variability Model (WVM) for Solar PV Power Plants

    E-Print Network [OSTI]

    Lave, Matthew; Kleissl, Jan; Stein, Joshua S

    2013-01-01T23:59:59.000Z

    Power characteristics of PV ensembles: experiences from theproduction of 100 grid connected PV systems distributed overHoff and R. Perez, "Modeling PV Fleet Output Variability,"

  6. Market Characteristics for Efficient Integration of Variable Generation in the Western Interconnection

    SciTech Connect (OSTI)

    Milligan, M.; Kirby, B.

    2010-08-01T23:59:59.000Z

    The overriding purpose of this report is to establish the physical requirements of a power system that can accommodate high levels of variable generation.

  7. Market Designs for High Levels of Variable Generation: Preprint

    SciTech Connect (OSTI)

    Milligan, M.; Holttinen, H.; Kiviluoma, J.; Orths, A.; Lynch, M.; Soder, L.

    2014-10-01T23:59:59.000Z

    Variable renewable generation is increasing in penetration in modern power systems, leading to higher variability in the supply and price of electricity as well as lower average spot prices. This raises new challenges, particularly in ensuring sufficient capacity and flexibility from conventional technologies. Because the fixed costs and lifetimes of electricity generation investments are significant, designing markets and regulations that ensure the efficient integration of renewable generation is a significant challenge. This papers reviews the state of play of market designs for high levels of variable generation in the United States and Europe and considers new developments in both regions.

  8. Unwinding the Spin on Variable Speed Drive Air Compressors

    E-Print Network [OSTI]

    Beals, C. E.

    2006-01-01T23:59:59.000Z

    Unwinding the Spin on Variable Speed Drive Air Compressors By Chris E. Beals, President, Air System Management, Inc Over the past several years, the variable speed drive (VSD) compressor has become a frequent choice for new compressor... purchases. The VSD compressor’s popularity is partly due to rising energy prices and its efficiency as a trim compressor. Unfortunately, much of the VSD compressor’s popularity is a result of spin applied by the marketers. For example, sales...

  9. WECC Variable Generation Planning Reference Book

    SciTech Connect (OSTI)

    Makarov, Yuri V.; Du, Pengwei; Etingov, Pavel V.; Ma, Jian; Vyakaranam, Bharat

    2013-05-14T23:59:59.000Z

    This planning reference book is a document reflecting a Western Electricity Coordination Council (WECC) effort to put together multiple sources of information and provide a clear, systemic, comprehensive outline of the problems, both existing and anticipated; their impacts on the system; currently used and proposed solutions by the industry and research community; planning practices; new technologies, equipment, and standards; and expected future trends. This living (periodically updated) document could help WECC and other practicing engineers, especially the younger generation of engineers joining the workforce, to get familiar with a large variety of information related to the integration of variable resources into the WECC system, bypassing in part the need for time-consuming information gathering and learning processes from more experienced engineers or from the literature.

  10. Managing Variability throughout the Software Development Lifecycle

    E-Print Network [OSTI]

    Managing Variability throughout the Software Development Lifecycle Neil Loughran and Awais Rashid levels of the software development lifecycle, especially when new requirements arise. We believe of the software development lifecycle. Moreover, the effects of variability and, in particular, new variabilities

  11. WECC Variable Generation Planning Reference Book: Appendices

    SciTech Connect (OSTI)

    Makarov, Yuri V.; Du, Pengwei; Etingov, Pavel V.; Ma, Jian; Vyakaranam, Bharat

    2013-05-13T23:59:59.000Z

    The document titled “WECC Variable Generation Planning Reference Book”. This book is divided into two volumes; one is the main document (volume 1)and the other is appendices (volume 2). The main document is a collection of the best practices and the information regarding the application and impact of variables generation on power system planning. This volume (appendices) has additional information on the following topics: Probabilistic load flow problems. 2. Additional useful indices. 3. high-impact low-frequency (HILF) events. 4. Examples of wide-area nomograms. 5. Transmission line ratings, types of dynamic rating methods. 6. Relative costs per MW-km of different electric power transmission technologies. 7. Ultra-high voltage (UHV) transmission. 8.High voltage direct current (VSC-HVDC). 9. HVDC. 10. Rewiring of existing transmission lines. 11. High-temperature low sag (HTLS) conductors. 12. The direct method and energy functions for transient stability analysis in power systems. 13.Blackouts caused by voltage instability. 14. Algorithm for parameter continuation predictor-corrector methods. 15. Approximation techniques available for security regions. 16. Impacts of wind power on power system small signals stability. 17. FIDVR. 18. FACTS. 19. European planning standard and practices. 20. International experience in wind and solar energy sources. 21. Western Renewable Energy Zones (WREZ). 22. various energy storage technologies. 23. demand response. 24. BA consolidation and cooperation options. 25. generator power management requirements and 26. European planning guidelines.

  12. alfalfa supply system: Topics by E-print Network

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

    effective and precise manner in order to deliver supplies and equipment to intended ... Eaton, Joshua A. N. (Joshua Andrew Norman) 2012-01-01 106 Single-Duct Constant Air Volume...

  13. Terminal Box Airflow Reset: An Effective Operation and Control Strategy for Comfort Improvement and Energy Conservation

    E-Print Network [OSTI]

    Liu, M.; Abbas, M.; Zhu, Y.; Claridge, D. E.

    2002-01-01T23:59:59.000Z

    for constant air volume terminal boxes during unoccupied hours. Authors have implemented the airflow reset in dual duct variable air volume terminal boxes [Abbas and Liu, 1996], in dual duct constant air volume terminal boxes [Liu and Zhu, 1998...], and in single duct terminal boxes [Zhu et. al, 2000]. This paper presents schedules of airflow reset for typical terminal boxes, models of potential energy savings, and issues of implementation AIRFLOW RESET The value of airflow reset depends on terminal...

  14. Laboratory implementation of variable-speed wind turbine generation

    SciTech Connect (OSTI)

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

    1996-07-01T23:59:59.000Z

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

  15. Free piston variable-stroke linear-alternator generator

    DOE Patents [OSTI]

    Haaland, Carsten M. (Dadeville, AL)

    1998-01-01T23:59:59.000Z

    A free-piston variable stroke linear-alternator AC power generator for a combustion engine. An alternator mechanism and oscillator system generates AC current. The oscillation system includes two oscillation devices each having a combustion cylinder and a flying turnbuckle. The flying turnbuckle moves in accordance with the oscillation device. The alternator system is a linear alternator coupled between the two oscillation devices by a slotted connecting rod.

  16. Free piston variable-stroke linear-alternator generator

    DOE Patents [OSTI]

    Haaland, C.M.

    1998-12-15T23:59:59.000Z

    A free-piston variable stroke linear-alternator AC power generator for a combustion engine is described. An alternator mechanism and oscillator system generates AC current. The oscillation system includes two oscillation devices each having a combustion cylinder and a flying turnbuckle. The flying turnbuckle moves in accordance with the oscillation device. The alternator system is a linear alternator coupled between the two oscillation devices by a slotted connecting rod. 8 figs.

  17. Variable Structure Control of a

    E-Print Network [OSTI]

    Ge, Shuzhi Sam

    . INTRODUCTION Modelling and control of flexible link manipulators have been studied intensively controller for regulation of a flexible beam. Due to its simplicity and robustness to parametricVariable Structure Control of a Distributed-Parameter Flexible Beam S. S. Ge,* T. H. Lee, G. Zhu, F

  18. Double-periodic blue variables in the Magellanic Clouds

    E-Print Network [OSTI]

    R. E. Mennickent; G. Pietrzynski; M. Diaz; W. Gieren

    2002-12-09T23:59:59.000Z

    We report the discovery, based on an inspection of the OGLE-II database, of a group of blue variables in the Magellanic Clouds showing simultaneously two kinds of photometric variability: a short-term cyclic variability with typical amplitude $\\Delta I \\sim$ 0.05 mag and period $P_{1}$ between 4 and 16 days and a sinusoidal, long-term cyclic oscillation with much larger amplitude $\\Delta I \\sim$ 0.2 mag with period $P_{2}$ in the range of 150-1000 days. We find that both periods seems to be coupled through the relationship $P_{2}$ = 35.2 $\\pm$ 0.8 $P_{1}$. In general, the short term variability is reminiscent of those shown by Algol-type binaries. We propose that the long-term oscillation could arise in the precession of a elliptical disc fed by a Roche-lobe filling companion in a low mass ratio Algol system.

  19. Continuous variable entanglement dynamics in structured reservoirs

    E-Print Network [OSTI]

    R. Vasile; S. Olivares; M. G. A. Paris; S. Maniscalco

    2009-10-13T23:59:59.000Z

    We address the evolution of entanglement in bimodal continuous variable quantum systems interacting with two independent structured reservoirs. We derive an analytic expression for the entanglement of formation without performing the Markov and the secular approximations and study in details the entanglement dynamics for various types of structured reservoirs and for different reservoir temperatures, assuming the two modes initially excited in a twin-beam state. Our analytic solution allows us to identify three dynamical regimes characterized by different behaviors of the entanglement: the entanglement sudden death, the non-Markovian revival and the non-secular revival regimes. Remarkably, we find that, contrarily to the Markovian case, the short-time system-reservoir correlations in some cases destroy quickly the initial entanglement even at zero temperature.

  20. Wind Power Variability, Its Cost, and Effect on Power Plant Emissions

    E-Print Network [OSTI]

    Wind Power Variability, Its Cost, and Effect on Power Plant Emissions A Dissertation Submitted The recent growth in wind power is transforming the operation of electricity systems by introducing. As a result, system operators are learning in real-time how to incorporate wind power and its variability

  1. MID-INFRARED SPECTRAL VARIABILITY ATLAS OF YOUNG STELLAR OBJECTS

    SciTech Connect (OSTI)

    Kospal, A. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA, Leiden (Netherlands); Abraham, P.; Kun, M.; Moor, A. [Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, P.O. Box 67, 1525 Budapest (Hungary); Acosta-Pulido, J. A. [Instituto de Astrofisica de Canarias, Via Lactea s/n, 38200 La Laguna, Tenerife (Spain); Dullemond, C. P. [Institut fuer Theoretische Astrophysik, Zentrum fuer Astronomie der Universitaet Heidelberg, Albert-Ueberle-Str. 2, 69120 Heidelberg (Germany); Henning, Th.; Leinert, Ch. [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, 69117 Heidelberg (Germany); Turner, N. J., E-mail: akospal@rssd.esa.int [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2012-08-01T23:59:59.000Z

    Optical and near-infrared variability is a well-known property of young stellar objects. However, a growing number of recent studies claim that a considerable fraction of them also exhibit mid-infrared flux changes. With the aim of studying and interpreting variability on a decadal timescale, here we present a mid-infrared spectral atlas containing observations of 68 low- and intermediate-mass young stellar objects. The atlas consists of 2.5-11.6 {mu}m low-resolution spectra obtained with the ISOPHOT-S instrument on board the Infrared Space Observatory (ISO) between 1996 and 1998, as well as 5.2-14.5 {mu}m low-resolution spectra obtained with the Infrared Spectrograph instrument on board the Spitzer Space Telescope between 2004 and 2007. The observations were retrieved from the ISO and Spitzer archives and were post-processed interactively by our own routines. For those 47 objects where multi-epoch spectra were available, we analyze mid-infrared spectral variability on annual and/or decadal timescales. We identify 37 variable candidate sources. Many stars show wavelength-independent flux changes, possibly due to variable accretion rates. In several systems, all exhibiting 10 {mu}m silicate emission, the variability of the 6-8 {mu}m continuum, and the silicate feature exhibit different amplitudes. A possible explanation is variable shadowing of the silicate-emitting region by an inner disk structure of changing height or extra silicate emission from dust clouds in the disk atmosphere. Our results suggest that mid-infrared variability, in particular, the wavelength-dependent changes, is more ubiquitous than was known before. Interpreting this variability is a new possibility for exploring the structure of the disk and its dynamical processes.

  2. Cataclysmic Variables from SDSS I. The First Results

    E-Print Network [OSTI]

    Szkody, P; Agüeros, M A; Covarrubias, R; Bentz, M; Hawley, S; Margon, B; Voges, W; Henden, A A; Knapp, G R; Vanden Berk, Daniel E; Rest, A; Miknaitis, G; Magnier, E; Brinkmann, J; Csabai, I; Harvanek, M J; Hindsley, R; Hennessy, G S; Ivezic, Z; Kleinman, S J; Lamb, D Q; Long, D; Newman, P R; Neilsen, E H; Nichol, R C; Nitta, A; Schneider, D P; Snedden, S A; York, D G

    2002-01-01T23:59:59.000Z

    The commissioning year of the Sloan Digital Sky Survey has demonstrated that many cataclysmic variables have been missed in previous surveys with brighter limits. We report the identification of 22 cataclysmic variables, of which 19 are new discoveries and 3 are known systems (SW UMa, BH Lyn and Vir4). A compendium of positions, colors and characteristics of these systems obtained from the SDSS photometry and spectroscopy is presented along with data obtained during follow-up studies with the Apache Point Observatory (APO) and Manastash Ridge Observatory (MRO) telescopes. We have determined orbital periods for 3 of the new systems: two show dwarf nova outbursts, and the third is a likely magnetic system with eclipses of its region of line emission. Based on these results, we expect the completed survey to locate at least 400 new CVs. Most of these will be faint systems with low accretion rates that will provide new constraints on binary evolution models.

  3. Cranial Variability in Amazonian Marmosets

    E-Print Network [OSTI]

    Aguiar, John Marshall

    2011-02-22T23:59:59.000Z

    (Callithrix, Callitrichidae) have been discovered in recent years, as well as the exceptional dwarf marmoset Callibella humilis. Most of these species were described on the basis of their pelage and presumed separation by major rivers. I performed... analyses of craniometric variables by taxa and by river basins, in order to determine if there are significant cranial distinctions between taxa separated by rivers. I analyzed quantitative cranial and mandibular characters of Callibella humilis...

  4. Variable flexure-based fluid filter

    DOE Patents [OSTI]

    Brown, Steve B.; Colston Jr., Billy W.; Marshall, Graham; Wolcott, Duane

    2007-03-13T23:59:59.000Z

    An apparatus and method for filtering particles from a fluid comprises a fluid inlet, a fluid outlet, a variable size passage between the fluid inlet and the fluid outlet, and means for adjusting the size of the variable size passage for filtering the particles from the fluid. An inlet fluid flow stream is introduced to a fixture with a variable size passage. The size of the variable size passage is set so that the fluid passes through the variable size passage but the particles do not pass through the variable size passage.

  5. Variable-energy drift-tube linear accelerator

    DOE Patents [OSTI]

    Swenson, Donald A. (Los Alamos, NM); Boyd, Jr., Thomas J. (Los Alamos, NM); Potter, James M. (Los Alamos, NM); Stovall, James E. (Los Alamos, NM)

    1984-01-01T23:59:59.000Z

    A linear accelerator system includes a plurality of post-coupled drift-tubes wherein each post coupler is bistably positionable to either of two positions which result in different field distributions. With binary control over a plurality of post couplers, a significant accumlative effect in the resulting field distribution is achieved yielding a variable-energy drift-tube linear accelerator.

  6. Model Predictive Control of Variable Density Multiphase Flows Governed by

    E-Print Network [OSTI]

    Hinze, Michael

    of model predictive control (MPC) consists in steering or keeping the state of a dynamical systemModel Predictive Control of Variable Density Multiphase Flows Governed by Diffuse Interface Models appearing in the model predictive control strategy. The resulting control concept is known as instantaneous

  7. A method for robust variable selection with significance assessment

    E-Print Network [OSTI]

    Rosasco, Lorenzo

    and control. Such an analy- sis encompasses, at least two steps, gene selection and model assessment. When architecture to assess the statistical significance of the model via cross validation and permutation testing. Finally we challenge the system on real data experiments, and study its performance when changing variable

  8. Modeling a Snap-Action, Variable-Delay Switch

    E-Print Network [OSTI]

    Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America, 2, Cambridge, Massachusetts, United States of America When exposed to tumor necrosis factor (TNF) or TNFModeling a Snap-Action, Variable-Delay Switch Controlling Extrinsic Cell Death John G. Albeck1

  9. Less Acres and Variable Yield Mark Ohio's Crops

    E-Print Network [OSTI]

    Jones, Michelle

    developing technologies and cropping systems that are efficient in capturing solar energy, sus- tainable overLess Acres and Variable Yield Mark Ohio's Crops From 1994 to 2004, the combined acreage of soybean Pathology Dr. Mark Loux Horticulture and Crop Science Dr. Robert Mullen School of Natural Resources Dr. Mark

  10. Variable Latency Turbo Codes for Wireless Multimedia Applications

    E-Print Network [OSTI]

    Valenti, Matthew C.

    Variable Latency Turbo Codes for Wireless Multimedia Applications Matthew C. Valenti and Brian D acceptable latency and Bit Error Rate BER or Frame Error Rate FER. In turbo coded systems a tradeo between an adaptive turbo coding strategy for wire- less multimedia communications that incor- porates a set

  11. Variable Stars in the Field of the Globular Cluster NGC 3201

    E-Print Network [OSTI]

    Kaspar von Braun; Mario Mateo

    2001-09-25T23:59:59.000Z

    We report on the discovery and analysis of 14 short-period variable stars in the field of the southern globular cluster NGC 3201, located within roughly two magnitudes on either side of the main-sequence turnoff. 11 of these variable stars are eclipsing binaries, one is an RR Lyrae, and two are thus far unclassified systems. Among the eclipsing binary stars, nine are of the W Ursa Majoris (W UMa) type, one an Algol (EA) system, and one a detached system. Using spectroscopic follow-up observations as well as analysis of the variables' locations in the color-magnitude diagram of the cluster, we find that only one variable star (a W UMa type blue straggler) is actually a member of NGC 3201. We present the phased photometry lightcurves for all the variable star systems as well as their locations in the field-of-view and in the color-magnitude diagram.

  12. Resilient engineered systems: the development of an inherent system property

    E-Print Network [OSTI]

    Mitchell, Susan McAlpin

    2007-09-17T23:59:59.000Z

    was defined as the amount of energy a system can store before reaching a point of instability. The energy input into each system as well as the system�s exergy were used to develop system stress and system strain variables. Process variable changes...

  13. Interannual variability in tropospheric nitrous oxide

    E-Print Network [OSTI]

    Thompson, R. L.

    Observations of tropospheric N2O mixing ratio show significant variability on interannual timescales (0.2?ppb, 1 standard deviation). We found that interannual variability in N2O is weakly correlated with that in CFC-12 ...

  14. Thermoacoustic tomography, variable sound speed Plamen Stefanov

    E-Print Network [OSTI]

    Stefanov, Plamen

    Thermoacoustic tomography, variable sound speed Plamen Stefanov Purdue University Based on a joint work with Gunther Uhlmann Plamen Stefanov (Purdue University ) Thermoacoustic tomography, variable sound speed 1 / 18 #12;Formulation Main Problem Thermoacoustic Tomography In thermoacoustic tomography

  15. Eclipsing Binaries in the OGLE Variable Star Catalogs.V. Long-Period Beta Lyrae-type Systems in the Small Magellanic Cloud and the PLC-beta Relation

    E-Print Network [OSTI]

    Slavek M. Rucinski; Carla Maceroni

    2000-06-16T23:59:59.000Z

    Thirty eight long-period (P>10 days), apparently contact binary stars discovered by the OGLE-II project in the SMC appear to be Beta Lyrae-type systems with ellipsoidal variations of the cool components dominating over eclipse effects in the systemic light variations and in the total luminosity. A new period-luminosity- color (PLC) relation has been established for these systems; we call it the PLC-beta relation, to distinguish it from the Cepheid relation. Two versions of the PLC-beta relation - based on the (B-V)0 or (V-I)0 color indices - have been calibrated for 33 systems with (V-I)0>0.25 spanning the orbital period range of 11 to 181 days. The relations can provide maximum-light, absolute-magnitude estimates accurate to epsilon-M_V~0.35 mag. within the approximate range -3PLC-beta relation can offer an auxiliary and entirely independent method of distance determination to nearby stellar systems rich in massive stars. The sample of the long-period Beta Lyrae systems in the SMC analyzed in this paper is currently the best defined and uniform known sequence of such binaries.

  16. The relationship of air temperature and air volume to the rate of drying rice in sacks

    E-Print Network [OSTI]

    Mayfield, William Lloyd

    1951-01-01T23:59:59.000Z

    operation to a stoiiture content, ef 19 to, 14 per eemt. "She eaoJee w~e ~~;. ;ogpu;Ih dtiring. the '&yield, epeMMen for each test, At the end of the drying peribd, s composite simple 5 r n'ne, 'tegen fron. each ~i4r:, for;~ii~, . determ4nsMem ~8 later... ~ 0 XQO. I 1'15. h +1, 8 1%4. 5 1/0, 5 1~9&JI 1OV~ XMQ gp, ss N. , '7G gg, 65 g). , 4Q Q6. 48 QO;51 $6, 41 19. 75 (VS sLin ) 19. VT ('l. 5 'min. ) 14 62 (Ts min. ) XQ 44 , X5? x1AS a '. gutsy. Isagles fojt'~i'etige detereinstiona...

  17. Experimental Study of the Circulation Air Volume of Recirculation Evaporative Cooling

    E-Print Network [OSTI]

    Xiong, J.; Liu, Z.; Wang, C.; Chen, G.

    2006-01-01T23:59:59.000Z

    This paper introduces the technology of re-circulation evaporative cooling (REC), which uses a portion of supply air as secondary air to make cool water used to indirectly cool outside air through a heat exchanger. The circulation volume...

  18. Radial Velocity Variability of Field Brown Dwarfs

    E-Print Network [OSTI]

    Prato, L; Rice, E L; McLean, I S; Kirkpatrick, J D; Burgasser, A J; Kim, S S

    2015-01-01T23:59:59.000Z

    We present paper six of the NIRSPEC Brown Dwarf Spectroscopic Survey, an analysis of multi-epoch, high-resolution (R~20,000) spectra of 25 field dwarf systems (3 late-type M dwarfs, 16 L dwarfs, and 6 T dwarfs) taken with the NIRSPEC infrared spectrograph at the W. M. Keck Observatory. With a radial velocity precision of ~2 km/s, we are sensitive to brown dwarf companions in orbits with periods of a few years or less given a mass ratio of 0.5 or greater. We do not detect any spectroscopic binary brown dwarfs in the sample. Given our target properties, and the frequency and cadence of observations, we use a Monte Carlo simulation to determine the detection probability of our sample. Even with a null detection result, our 1 sigma upper limit for very low mass binary frequency is 18%. Our targets included 7 known, wide brown dwarf binary systems. No significant radial velocity variability was measured in our multi-epoch observations of these systems, even for those pairs for which our data spanned a significant ...

  19. Automated Demand Response Technology Demonstration Project for Small and Medium Commercial Buildings

    E-Print Network [OSTI]

    Page, Janie

    2012-01-01T23:59:59.000Z

    Power [kW] Actual OAT_MA BL 10/10 BL Constant air volume system cycling is also seen in the load profile 

  20. Integration of Variable Generation and Cost-Causation (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-09-01T23:59:59.000Z

    Variable renewable energy generation sources, such as wind and solar energy, provide benefits such as reduced environmental impact, zero fuel consumption, and low and stable costs. Advances in both technologies can reduce capital costs and provide significant control capabilities. However, their variability and uncertainty - which change with weather conditions, time of day, and season - can cause an increase in power system operating costs compared to a fully controllable power plant. Although a number of studies have assessed integration costs, calculating them correctly is challenging because it is difficult to accurately develop a baseline scenario without variable generation that properly accounts for the energy value. It is also difficult to appropriately allocate costs given the complex, nonlinear interactions between resources and loads.

  1. analysis system tool: Topics by E-print Network

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

    to analyse LCA variability of energy systems Physics Websites Summary: variability in LCA are sensitivity analysis (SA). However, when dealing with environmental impact...

  2. Application Performance Variability on Hopper

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

    system with roughly 6300 compute nodes. In normal day to day operations, Hopper can be running hundreds of individual applications at any given time. Some users have reported...

  3. Variable residence time vortex combustor

    DOE Patents [OSTI]

    Melconian, Jerry O. (76 Beaver Rd., Reading, MA 01867)

    1987-01-01T23:59:59.000Z

    A variable residence time vortex combustor including a primary combustion chamber for containing a combustion vortex, and a plurality of louvres peripherally disposed about the primary combustion chamber and longitudinally distributed along its primary axis. The louvres are inclined to impel air about the primary combustion chamber to cool its interior surfaces and to impel air inwardly to assist in driving the combustion vortex in a first rotational direction and to feed combustion in the primary combustion chamber. The vortex combustor also includes a second combustion chamber having a secondary zone and a narrowed waist region in the primary combustion chamber interconnecting the output of the primary combustion chamber with the secondary zone for passing only lower density particles and trapping higher density particles in the combustion vortex in the primary combustion chamber for substantial combustion.

  4. Variable delivery, fixed displacement pump

    DOE Patents [OSTI]

    Sommars, Mark F. (Sparland, IL)

    2001-01-01T23:59:59.000Z

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

  5. Continuously variable focal length lens

    DOE Patents [OSTI]

    Adams, Bernhard W; Chollet, Matthieu C

    2013-12-17T23:59:59.000Z

    A material preferably in crystal form having a low atomic number such as beryllium (Z=4) provides for the focusing of x-rays in a continuously variable manner. The material is provided with plural spaced curvilinear, optically matched slots and/or recesses through which an x-ray beam is directed. The focal length of the material may be decreased or increased by increasing or decreasing, respectively, the number of slots (or recesses) through which the x-ray beam is directed, while fine tuning of the focal length is accomplished by rotation of the material so as to change the path length of the x-ray beam through the aligned cylindrical slows. X-ray analysis of a fixed point in a solid material may be performed by scanning the energy of the x-ray beam while rotating the material to maintain the beam's focal point at a fixed point in the specimen undergoing analysis.

  6. Variable ratio regenerative braking device

    DOE Patents [OSTI]

    Hoppie, Lyle O. (Birmingham, MI)

    1981-12-15T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Kohfeld, Karen

    and Long-term Variability in Relation to Hydroelectric Reservoir Inflows on Wind Power in the Pacific through diversification. In hydroelectric dominated systems, like the PNW, the benefits of wind power can diversification can be maximized. Keywords: Wind power; Hydroelectricity; Renewable energy; Climate variability

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

    E-Print Network [OSTI]

    Hansen, René Rydhof

    Modelling and Analysis of Variable Speed Wind Turbines with Induction Generator during Grid Fault to the grid connection of wind turbines. The second chapter elucidates recent thinking in the area of grid Risø National Laboratory Vestas Wind Systems A/S #12;#12;I Modelling and Analysis of Variable Speed

  9. Thermodynamics of the Universe Filled with Perfect Fluid Having Variable Equation of State

    E-Print Network [OSTI]

    Nairwita Mazumder; Subenoy Chakraborty

    2009-07-16T23:59:59.000Z

    We study the thermodynamics of the universe containing perfect fluid with equation of state $p=\\omega\\rho,\\omega$ is variable. Here we choose $\\omega$ to be a function of the red shift variable $z$ and four different choices of $\\omega$ has been investigated. Also the laws of thermodynamics are examined considering the universe bounded by the horizon (apparent) as a thermodynamical system.

  10. Systems

    E-Print Network [OSTI]

    Chapter 1. Systems. 1.1. On Line. In this introductory section we will pose no exercises, but instead, will detail. how to use Maple to solve problems in linear ...

  11. NERC Presentation: Accommodating High Levels of Variable Generation...

    Office of Environmental Management (EM)

    of variable electricity eneration. Variable resources are types of electric power generation that rely on an uncontrolled, "variable" fuel (e.g. wind, sunlight, waves, tidal...

  12. Examining Uncertainty in Demand Response Baseline Models and Variability in Automated Response to Dynamic Pricing

    SciTech Connect (OSTI)

    Mathieu, Johanna L.; Callaway, Duncan S.; Kiliccote, Sila

    2011-08-15T23:59:59.000Z

    Controlling electric loads to deliver power system services presents a number of interesting challenges. For example, changes in electricity consumption of Commercial and Industrial (C&I) facilities are usually estimated using counterfactual baseline models, and model uncertainty makes it difficult to precisely quantify control responsiveness. Moreover, C&I facilities exhibit variability in their response. This paper seeks to understand baseline model error and demand-side variability in responses to open-loop control signals (i.e. dynamic prices). Using a regression-based baseline model, we define several Demand Response (DR) parameters, which characterize changes in electricity use on DR days, and then present a method for computing the error associated with DR parameter estimates. In addition to analyzing the magnitude of DR parameter error, we develop a metric to determine how much observed DR parameter variability is attributable to real event-to-event variability versus simply baseline model error. Using data from 38 C&I facilities that participated in an automated DR program in California, we find that DR parameter errors are large. For most facilities, observed DR parameter variability is likely explained by baseline model error, not real DR parameter variability; however, a number of facilities exhibit real DR parameter variability. In some cases, the aggregate population of C&I facilities exhibits real DR parameter variability, resulting in implications for the system operator with respect to both resource planning and system stability.

  13. Direct comparison of Neural Network, Fuzzy Logic and Model Prediction Variable Structure vortex flow controllers

    E-Print Network [OSTI]

    Joshi, Praveen Sudhakar

    1999-01-01T23:59:59.000Z

    Predictive Variable Structure and Fuzzy Logic based controllers for the same benchmark problem. Evaluation criteria consist of closed-loop system performance, activity level of the VFC nozzles, ease of controller synthesis, time required to synthesize...

  14. Implications of Wide-Area Geographic Diversity for Short- Term Variability of Solar Power

    E-Print Network [OSTI]

    Mills, Andrew

    2010-01-01T23:59:59.000Z

    2010. Quantifying PV power output variability. Solar EnergyOutput power correlation between adjacent wind power plants. Journal of Solarpower system demonstrate that scaling the output from an individual solar

  15. The Variable Vector Countermeasure Suit (V2Suit) for space habitation and exploration

    E-Print Network [OSTI]

    Duda, Kevin R.

    The “Variable Vector Countermeasure Suit (V2Suit) for Space Habitation and Exploration” is a novel system concept that provides a platform for integrating sensors and actuators with daily astronaut intravehicular activities ...

  16. Liquid crystal variable retarders in atomic scattering

    SciTech Connect (OSTI)

    Furst, J.E.; Yu, D.H.; Hayes, P.A.; DSouza, C.M.; Williams, J.F. [Physics Department, Centre for Atomic, Molecular, and Surface Physics, The University of Western Australia, Nedlands. WA. 6907 (Australia)] [Physics Department, Centre for Atomic, Molecular, and Surface Physics, The University of Western Australia, Nedlands. WA. 6907 (Australia)

    1996-11-01T23:59:59.000Z

    The applications of liquid crystal variable retarders in the production of spin-polarized electrons and in the determination of the polarization of optical radiation from atoms excited by polarized electrons are discussed. The advantages of using liquid crystal variable retarders in the measurement of Stokes parameters are insensitivity to the incident photon direction, large transmission diameter, variable retardation over large wavelength range without mechanical movement, and {ital in} {ital situ} calibration. {copyright} {ital 1996 American Institute of Physics.}

  17. Eccentric crank variable compression ratio mechanism

    DOE Patents [OSTI]

    Lawrence, Keith Edward (Kobe, JP); Moser, William Elliott (Peoria, IL); Roozenboom, Stephan Donald (Washington, IL); Knox, Kevin Jay (Peoria, IL)

    2008-05-13T23:59:59.000Z

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

  18. Variable-Period Undulators For Synchrotron Radiation

    DOE Patents [OSTI]

    Shenoy, Gopal (Naperville, IL); Lewellen, John (Plainfield, IL); Shu, Deming (Darien, IL); Vinokurov, Nikolai (Novosibirsk, RU)

    2005-02-22T23:59:59.000Z

    A new and improved undulator design is provided that enables a variable period length for the production of synchrotron radiation from both medium-energy and high-energy storage rings. The variable period length is achieved using a staggered array of pole pieces made up of high permeability material, permanent magnet material, or an electromagnetic structure. The pole pieces are separated by a variable width space. The sum of the variable width space and the pole width would therefore define the period of the undulator. Features and advantages of the invention include broad photon energy tunability, constant power operation and constant brilliance operation.

  19. Variable Temperature UHV STM/AFM | EMSL

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

    Temperature UHV STMAFM The Omicron variable temperature ultra-high vacuum (UHV) scanning tunneling microscope (VTSTM) is designed to study the structure of both clean and...

  20. Optimization Online - Global Optimization via Slack Variables

    E-Print Network [OSTI]

    Isaac Siwale

    2014-08-01T23:59:59.000Z

    Aug 1, 2014 ... Citation: Siwale, I. (2014). Global optimization via slack variables. Technical Report No. RD-16-2013, London: Apex Research Ltd. Download: ...

  1. Photometric Variability of Be/X-ray-Pulsar Binaries in the SMC

    E-Print Network [OSTI]

    P. C. Schmidtke; A. P. Cowley

    2006-05-16T23:59:59.000Z

    We have studied the photometric variability of ten SMC Be/X-ray pulsars using MACHO and OGLE-II data. For some of these systems we have found periodic behavior, including orbital outbursts and/or nonradial pulsations (NRP) of the Be star. For others we were unable to identify any clear photometric periodicity, although their longterm light curves show significant structure. We present periodograms, phase dispersion minimization (PDM) variances, and folded light curves for the systems which exhibit periodic photometric variability.

  2. A study of state variable participation in limit-cycle of induction motor

    E-Print Network [OSTI]

    Krishnendu Chakrabarty; Urmila Kar

    2014-10-24T23:59:59.000Z

    The paper presents bifurcation behavior of a single phase induction motor. This paper also attempts to discuss the bifurcation behavior of the system based on the evolution of different state variables. The bifurcation diagrams drawn looking at different state variables are different in terms of periodicity and route to chaos. The knowledge of the dynamics of the system obtained from bifurcation diagrams give useful guidelines to control the operation of the induction motor depending on the need of an application for better performance.

  3. STFC Introductory Summer School m.j.owens@reading.ac.uk18 Sept 2012 Solar Variability and

    E-Print Network [OSTI]

    STFC Introductory Summer School m.j.owens@reading.ac.uk18 Sept 2012 Solar Variability and Climate · The climate system · Solar variability · Solar effects on climate ­ Regional and global effects · The future? #12;STFC Introductory Summer School m.j.owens@reading.ac.uk Climate system #12;The source of much

  4. THE CARINA PROJECT. VI. THE HELIUM-BURNING VARIABLE STARS

    SciTech Connect (OSTI)

    Coppola, G.; Marconi, M.; Ripepi, V.; Dall'Ora, M.; Musella, I. [INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, I-80131 Napoli (Italy); Stetson, P. B. [Dominion Astrophysical Observatory, NRC-Herzberg, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Bono, G.; Buonanno, R. [Dipartimento di Fisica-Universita di Roma Tor Vergata, Via della Ricerca Scientifica 1, I-00133 Roma (Italy); Fabrizio, M. [INAF-Osservatorio Astronomico di Collurania, via M. Maggini, I-64100 Teramo (Italy); Ferraro, I.; Iannicola, G.; Pulone, L. [INAF-Osservatorio Astronomico di Roma, Via Frascati 33, I-00040 Monte Porzio Catone (Italy); Fiorentino, G. [INAF-Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Monelli, M. [Instituto de Astrofisica de Canarias, Calle Via Lactea s/n, E-38205 La Laguna, Tenerife (Spain); Nonino, M. [INAF-Osservatorio Astronomico di Trieste, via G. B. Tiepolo 11, I-40131 Trieste (Italy); Thevenin, F. [Universite de Nice-Sophia Antipolis, Lab. Lagrange, UMR 7293, Observatoire de la Cote dAzur, BP 4229, F-06304 Nice (France); Walker, A. R., E-mail: coppola@na.astro.it [Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, Casilla 603, La Serena (Chile)

    2013-09-20T23:59:59.000Z

    We present new optical (BVI) time-series data for the evolved variable stars in the Carina dwarf spheroidal galaxy. The quality of the data and the observing strategy allowed us to identify 14 new variable stars. Eight out of the 14 are RR Lyrae (RRL) stars, 4 are Anomalous Cepheids (ACs), and 2 are geometrical variables. Comparison of the period distribution for the entire sample of RRLs with similar distributions in nearby dwarf spheroidal galaxies and in the Large Magellanic Cloud indicates that the old stellar populations in these systems share similar properties. This finding is also supported by the RRL distribution in the Bailey diagram. On the other hand, the period distribution and the Bailey diagram of ACs display significant differences among the above stellar systems. This evidence suggests that the properties of intermediate-age stellar populations might be affected both by environmental effects and structural parameters. We use the BV Period-Wesenheit (PW) relation of RRLs together with evolutionary prescriptions and find a true distance modulus of 20.09 {+-} 0.07 (intrinsic) {+-} 0.1 (statistical) mag that agrees quite well with similar estimates available in the literature. We identified four peculiar variables. Taking into account their position in the Bailey diagram and in the BV PW relation, two of them (V14 and V149) appear to be candidate ACs, while two (V158 and V182) might be peculiar RRLs. In particular, the variable V158 has a period and a V-band amplitude very similar to the low-mass RRL-RRLR-02792-recently identified by Pietrzynski et al. in the Galactic bulge.

  5. Lithium battery management system

    DOE Patents [OSTI]

    Dougherty, Thomas J. (Waukesha, WI)

    2012-05-08T23:59:59.000Z

    Provided is a system for managing a lithium battery system having a plurality of cells. The battery system comprises a variable-resistance element electrically connected to a cell and located proximate a portion of the cell; and a device for determining, utilizing the variable-resistance element, whether the temperature of the cell has exceeded a predetermined threshold. A method of managing the temperature of a lithium battery system is also included.

  6. SLUDGE BATCH 7B GLASS VARIABILITY STUDY

    SciTech Connect (OSTI)

    Johnson, F.; Edwards, T.

    2011-10-25T23:59:59.000Z

    The Defense Waste Processing Facility (DWPF) is preparing to initiate processing Sludge Batch 7b (SB7b). In support of the upcoming processing, the Savannah River National Laboratory (SRNL) provided a recommendation to utilize Frits 418 with a 6% Na{sub 2}O addition (26 wt% Na{sub 2}O in sludge) and 702 with a 4% Na{sub 2}O addition (24 wt% Na{sub 2}O in sludge) to process SB7b. This recommendation was based on assessments of the compositional projections for SB7b available at the time from the Savannah River Remediation (SRR). To support qualification of SB7b, SRNL executed a variability study to assess the applicability of the current durability models for SB7b. The durability models were assessed over the expected composition range of SB7b, including potential caustic additions, combined with Frits 702 and 418 over a 32-40% waste loading (WL) range. Thirty four glasses were selected based on Frits 418 and 702 coupled with the sludge projections with an additional 4-6% Na{sub 2}O to reflect the potential caustic addition. Six of these glasses, based on average nominal sludge compositions including the appropriate caustic addition, were developed for both Frit 418 and Frit 702 at 32, 36 and 40% WL to provide coverage in the center of the anticipated SB7b glass region. All glasses were fabricated and characterized using chemical composition analysis, X-ray diffraction (XRD) and the Product Consistency Test (PCT). To comply with the DWPF Glass Product Control Program, a total of thirty four glasses were fabricated to assess the applicability of the current DWPF PCCS durability models. Based on the measured PCT response, all of the glasses were acceptable with respect to the Environmental Assessment (EA) benchmark glass regardless of thermal history. The NL[B] values of the SB7b variability study glasses were less than 1.99 g/L as compared to 16.695 g/L for EA. A small number of the D-optimally selected 'outer layer' extreme vertices (EV) glasses were not predictable using the current Product Composition Control System (PCCS) models for durability, but were acceptable compared to the EA glass when tested. These glasses fell outside of the lower 95% confidence band, which demonstrates conservatism in the model. A few of the glasses fell outside of the upper 95% confidence band; however, these particular glasses have normalized release values that were much lower than the values of EA and should be of no practical concern. Per the requirements of the DWPF Glass Product Control Program, the PCCS durability models have been shown to be applicable to the SB7b sludge system with a range of Na{sub 2}O concentrations blended with Frits 418 or 702. PCT results from the glasses fabricated as part of the variability study were shown to be predictable by the current DWPF PCCS models and/or acceptable with respect to the EA benchmark glass regardless of thermal history or compositional view.

  7. Envera Variable Compression Ratio Engine

    SciTech Connect (OSTI)

    Charles Mendler

    2011-03-15T23:59:59.000Z

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

  8. 3, 19151942, 2006 Longterm variability

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    , 690041, Radio st., 7, Russia, 2 Delft University of Technology, Faculty of Civil Engineering, Section of about 2­3 yr and 6­8 yr that are ac- companied by statistically significant changes in such monthly, there is uncertainty in the question how climatic systems evolve. The potential reliability of climate models can

  9. THE MULTI-USE STEINEL VARIABLE TEMPERATURE

    E-Print Network [OSTI]

    Kleinfeld, David

    THE MULTI-USE STEINEL VARIABLE TEMPERATURE ELECTRONICALLY CONTROLLED HEAT GUNTEMPERATURE RANGE 212 at the outlet nozzle will bum flesh. Do not tum on Heat Gun with hand in front of nozzle. DO NOT USE NEAR equipment Specifications Temperature Variable from 212" F to 1100° F Watts 1500W Weight 1.5 lbs. Supply

  10. THE MULTI-USE STEINEL VARIABLE TEMPERATURE

    E-Print Network [OSTI]

    Kleinfeld, David

    THE MULTI-USE STEINEL VARIABLE TEMPERATURE ELECTRONICALLY CONTROLLED HEAT GUNTEMPERATURE RANGE 212 at the outlet nozzle will bum flesh. Do not tum on Heat Gun with hand in front of nozzle. DO NOT USE NEAR equipment Specifications Temperature Variable from 212° F to 1100° F Watts 1500W Weight 1.5 lbs. Supply

  11. Solar Dynamics Observatory/ Extreme Ultraviolet Variability Experiment

    E-Print Network [OSTI]

    Mojzsis, Stephen J.

    Solar Dynamics Observatory/ EVE Extreme Ultraviolet Variability Experiment Frequently Asked and model solar extreme ultraviolet irradiance variations due to solar flares, solar rotation, and solar and structure of the Sun. What is solar variability? Solar radiation varies on all time scales ranging from

  12. Boosting Search with Variable Elimination. ? Javier Larrosa

    E-Print Network [OSTI]

    Dechter, Rina

    Boosting Search with Variable Elimination. ? Javier Larrosa Dep. Llenguatges i Sistemes Inform#12ElimSearchS;k, a hybrid meta- algorithm that combines search and variable elimination. The param- eter S names from the constraint graph. We also provide experimental evidence that the hybrid algorithm can

  13. Boosting Search with Variable Elimination. ? Javier Larrosa

    E-Print Network [OSTI]

    Dechter, Rina

    Boosting Search with Variable Elimination. ? Javier Larrosa Dep. Llenguatges i Sistemes Inform of variables, reduces the search tree size. In this paper we introduce VarElimSearch(S;k), a hybrid meta the constraint graph. We also provide experimental evidence that the hybrid algorithm can outperform state

  14. Variable frequency microprocessor clock generator

    SciTech Connect (OSTI)

    Branson, C.N.

    1989-04-04T23:59:59.000Z

    A microprocessor-based system is described comprising: a digital central microprocessor provided with a clock input and having a rate of operation determined by the frequency of a clock signal input thereto; memory means operably coupled to the central microprocessor for storing programs respectively including a plurality of instructions and addressable by the central microprocessor; peripheral device operably connected to the central microprocessor, the first peripheral device being addressable by the central microprocessor for control thereby; a system clock generator for generating a digital reference clock signal having a reference frequency rate; and frequency rate reduction circuit means connected between the clock generator and the clock input of the central microprocessor for selectively dividing the reference clock signal to generate a microprocessor clock signal as an input to the central microprocessor for clocking the central microprocessor.

  15. Accumulation of entanglement in a continuous variable memory

    E-Print Network [OSTI]

    M. Paternostro; M. S. Kim; G. M. Palma

    2006-12-06T23:59:59.000Z

    We study the accumulation of entanglement in a memory device built out of two continuous variable (CV) systems. We address the case of a qubit mediating an indirect joint interaction between the CV systems. We show that, in striking contrast with respect to registers built out of bidimensional Hilbert spaces, entanglement superior to a single ebit can be efficiently accumulated in the memory, even though no entangled resource is used. We study the protocol in an immediately implementable setup, assessing the effects of the main imperfections.

  16. Integrating Variable Renewable Energy in Electric Power Markets: Best Practices from International Experience (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2014-10-01T23:59:59.000Z

    Many countries--reflecting very different geographies, markets, and power systems--are successfully managing high levels of variable renewable energy (RE) on the grid. Australia (South Australia), Denmark, Germany, Ireland, Spain, and the United States (Colorado and Texas), for example, have effectively integrated variable RE utilizing diverse approaches. Analysis of the results from these case studies reveals a wide range of mechanisms that can be used to accommodate high penetrations of variable RE (e.g., from new market designs to centralized planning). Nevertheless, the myriad approaches collectively suggest that governments can best enable variable RE grid integration by implementing best practices in five areas of intervention: lead public engagement, particularly for new transmission; coordinate and integrate planning; develop rules for market evolution that enable system flexibility; expand access to diverse resources and geographic footprint of operations; and improve system operations.

  17. Lessons Learned From the Continuous Commissioning of a Multi-Functional Commercial Building 

    E-Print Network [OSTI]

    Liu, C.; Deng, S.; Claridge, D. E.; Turner, W. D.

    2000-01-01T23:59:59.000Z

    and AHU-5 are constant air volume systems with local pneumatic control. There is one chilled water pump with a variable frequency drive (VFD) and one constant speed hot water pump in the basement. There are 38 exhaust fans on the roof. Thirty... in 1967, the air- handling systems were installed with pneumatic control. In 1996, control systems for AHU-1, AHU- 2, AHU-3 and chilled water system were retrofitted I with DDC. The problems and issues identified when we 1 commissioned this building...

  18. Sandia National Laboratories: Systems Engineering

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

    Systems Engineering Sandia Offers Approach to Help Utilities Understand Effects of PV Variability on the Grid On March 7, 2013, in DETL, Distribution Grid Integration, Energy,...

  19. Analysis of two basic variables of timeout 

    E-Print Network [OSTI]

    Zella, William Francis

    1974-01-01T23:59:59.000Z

    ANALYSIS OF TWO BASIC VARIABLES OF TIMEOUT A Thesis WILLIAM FRANCIS ZELLA Submitted to the Graduate College of Texas AaM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE August l974 Major Subjects... Psychology ANALYSI QF TWQ BASIC VARIABLES CF TINEQU '. A Thesis V/ILLIAM FRANCIS ZELLA Approved as to s+yle and content bye Chairman of Commi, ee Head of De artment) (Membe Member) Member ABSTRACT Analysis of Two Basic Variables of Timeout. (August...

  20. Regular graphs maximize the variability of random neural networks

    E-Print Network [OSTI]

    Gilles Wainrib; Mathieu Galtier

    2014-12-17T23:59:59.000Z

    In this work we study the dynamics of systems composed of numerous interacting elements interconnected through a random weighted directed graph, such as models of random neural networks. We develop an original theoretical approach based on a combination of a classical mean-field theory originally developed in the context of dynamical spin-glass models, and the heterogeneous mean-field theory developed to study epidemic propagation on graphs. Our main result is that, surprisingly, increasing the variance of the in-degree distribution does not result in a more variable dynamical behavior, but on the contrary that the most variable behaviors are obtained in the regular graph setting. We further study how the dynamical complexity of the attractors is influenced by the statistical properties of the in-degree distribution.

  1. UselessVariable Elimination Olin Shivers

    E-Print Network [OSTI]

    Shivers, Olin

    flow analysis on the CPS inter­ mediate form. (I use a CPS representation essentially identical­passing style (CPS) intermediate representations, continuation variables are frequently passed around loops

  2. Continuously-Variable Series-Elastic Actuator

    E-Print Network [OSTI]

    Mooney, Luke M.

    Actuator efficiency is an important factor in the design of powered leg prostheses, orthoses, exoskeletons, and legged robots. A continuously-variable series-elastic actuator (CV-SEA) is presented as an efficient actuator ...

  3. Utility Variable Generation Integration Group Fall Technical...

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

    15, 2014 9:00AM CDT to October 17, 2014 3:00PM CDT The Utility Variable Generation Integration Group (UVIG) Fall Technical Workshop in San Antonio, Texas will provide attendees...

  4. Variable volume architecture : expanding the boundary

    E-Print Network [OSTI]

    Saheba, Asheshh (Asheshh Mohit), 1972-

    2001-01-01T23:59:59.000Z

    Research into the creation of a Variable Volume Architecture is explored through a series of proposals and projects. An argument is established to develop the means and methods of achieving an architecture of transformation. ...

  5. The Cloud Computing and Other Variables

    E-Print Network [OSTI]

    Borjon-Kubota, Martha Estela

    2011-01-01T23:59:59.000Z

    12. Fragments in Six 13. Cloud Computing 14. Phase 15.Note 48. Devoured vi Cloud Computing and other Variables I.moment. Lasts hours. Cloud Computing Just there Over the

  6. IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, VOL. 40, NO. 2, MARCH/APRIL 2004 565 Modeling and Control of a Variable-Speed

    E-Print Network [OSTI]

    Mi, Chunting "Chris"

    -alone diesel and gasoline generators, and aerospace and naval power generation systems where a variable speed and Control of a Variable-Speed Constant-Frequency Synchronous Generator With Brushless Exciter Chunting Mi-frequency power generation system for renewable and distributed energy applications. The generation system

  7. Antarctic Circumpolar Current System and its Response to Atmospheric Variability

    E-Print Network [OSTI]

    Kim, Yong Sun 1976-

    2012-08-16T23:59:59.000Z

    in the meridional location of ACC fronts is observed in the Pacific sector in association to minor sea surface cooling trends. Therefore, unlike in the Indian sector, the regional Pacific Ocean response is significantly sensitive to dominant atmospheric forcing...

  8. Reducing variability in equipment availability at Intel using systems optimization

    E-Print Network [OSTI]

    Kwong, William W. M

    2004-01-01T23:59:59.000Z

    Equipment management is an important driver behind operational efficiency, since capital equipment makes up about 40% of the average semiconductor manufacturer's total assets. The main goal of this project is to reduce ...

  9. Burner Designs and Controls for Variable Air Preheat Systems

    E-Print Network [OSTI]

    Lied, C. R.

    1981-01-01T23:59:59.000Z

    This paper will deal with various ways of reducing fuel costs for direct fired furnaces. Burner design relating to existing furnaces, new furnaces designed to operate initially on cold air with the ability to add preheated air in the future...

  10. Model-Checking Systems with Unbounded Variables without Abstraction

    E-Print Network [OSTI]

    Pierre, Laurence

    Pierre2 1 CMI/Universit´e de Provence 39 Rue Joliot-Curie 13453 Marseille cedex 13 - France Magali.Contensin@cmi of a model-checker for the modal - calculus with a theorem prover, first theoretical results were reported

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

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

    Simulation Results - Europe 14 1 0 0 1 1 0 1 2 0 1 3 0 1 4 0 1 5 0 1 6 0 CO 2 Emission gkm Base fixed CR NEDC -5.6% -5.9% -5.7% -5.8% -5.5% WLTP -5.1% -5.2% -4.5% -5.0%...

  12. Compact, electro-hydraulic, variable valve actuation system providing

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

    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 DataDepartment of Energy Your Density Isn't Your Destiny: Theof"Wave the WhiteNational| DepartmentCommunities WHAT:Commute1

  13. Efficient Thermally Variable Cooling System | Department of Energy

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

    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 DataDepartment of Energy Your Density Isn't Your Destiny:RevisedAdvisory BoardNucleate Boiling Efficient Cooling in EnginesEnergy 0

  14. Strategies and Decision Support Systems for Integrating Variable Energy

    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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit with formSoutheastern IL ElecStrategic Capital InvestmentsStrategic Energy

  15. Empowering Variable Renewables: Options for Flexible Electricity Systems |

    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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision| OpenElectromagneticElmwood CUSD8 Sector:Open Energy

  16. Ashtekar's New Variables and Positive Energy

    E-Print Network [OSTI]

    James M. Nester; Roh-Suan Tung; Yuan Zhong Zhang

    1994-01-07T23:59:59.000Z

    We discuss earlier unsuccessful attempts to formulate a positive gravitational energy proof in terms of the New Variables of Ashtekar. We also point out the difficulties of a Witten spinor type proof. We then use the special orthonormal frame gauge conditions to obtain a locally positive expression for the New Variables Hamiltonian and thereby a ``localization'' of gravitational energy as well as a positive energy proof.

  17. HVAC's Variable Refrigerant Flow (VRF) Technology

    E-Print Network [OSTI]

    Jones, S.

    2012-01-01T23:59:59.000Z

    1 Comfort by Design Steve Jones Commercial Sales Manager for Mitsubishi Southwest Business Unit HVAC?s Variable Refrigerant Flow (VRF) Technology HVAC Industry Overview HVAC Market Dollar Volume $18 Billion Source:;NABH Research... Moveable Ductless 5 VRF Technology Overview 6 What is VRF Technology? Variable Refrigerant Flow More Comfort, Less Energy Usage 8 INVERTER-driven Compressor Time R oo m T em pe ra tur e ? Enables capacity operation as low as 4% ? Sizing...

  18. Suppression of chaos at slow variables by rapidly mixing fast dynamics through linear energy-preserving coupling

    E-Print Network [OSTI]

    Rafail V. Abramov

    2011-08-14T23:59:59.000Z

    Chaotic multiscale dynamical systems are common in many areas of science, one of the examples being the interaction of the low-frequency dynamics in the atmosphere with the fast turbulent weather dynamics. One of the key questions about chaotic multiscale systems is how the fast dynamics affects chaos at the slow variables, and, therefore, impacts uncertainty and predictability of the slow dynamics. Here we demonstrate that the linear slow-fast coupling with the total energy conservation property promotes the suppression of chaos at the slow variables through the rapid mixing at the fast variables, both theoretically and through numerical simulations. A suitable mathematical framework is developed, connecting the slow dynamics on the tangent subspaces to the infinite-time linear response of the mean state to a constant external forcing at the fast variables. Additionally, it is shown that the uncoupled dynamics for the slow variables may remain chaotic while the complete multiscale system loses chaos and becomes completely predictable at the slow variables through increasing chaos and turbulence at the fast variables. This result contradicts the common sense intuition, where, naturally, one would think that coupling a slow weakly chaotic system with another much faster and much stronger mixing system would result in general increase of chaos at the slow variables.

  19. Potential Reductions in Variability with Alternative Approaches to Balancing Area Cooperation with High Penetrations of Variable Generation

    SciTech Connect (OSTI)

    Milligan, M.; Kirby, B.; Beuning, S.

    2010-08-01T23:59:59.000Z

    The work described in this report was performed by the National Renewable Energy Laboratory (NREL) and funded by the Office of the Energy Efficiency and Renewable Energy, U.S. Department of Energy (EERE DOE). This project is a joint project with the Pacific Northwest National Laboratory. This report evaluates the physical characteristics that improve the ability of the power system to absorb variable generation. It then uses evidence from electricity markets in the Eastern Interconnection of the United States to show how large, fast energy markets can help with integration. The concept of Virtual Balancing Area is introduced, a concept that covers a broad range of cooperative measures that can be undertaken by balancing areas to help manage variability.

  20. Variability in Automated Responses of Commercial Buildings and Industrial Facilities to Dynamic Electricity Prices

    SciTech Connect (OSTI)

    Mathieu, Johanna L.; Callaway, Duncan S.; Kiliccote, Sila

    2011-08-16T23:59:59.000Z

    Changes in the electricity consumption of commercial buildings and industrial facilities (C&I facilities) during Demand Response (DR) events are usually estimated using counterfactual baseline models. Model error makes it difficult to precisely quantify these changes in consumption and understand if C&I facilities exhibit event-to-event variability in their response to DR signals. This paper seeks to understand baseline model error and DR variability in C&I facilities facing dynamic electricity prices. Using a regression-based baseline model, we present a method to compute the error associated with estimates of several DR parameters. We also develop a metric to determine how much observed DR variability results from baseline model error rather than real variability in response. We analyze 38 C&I facilities participating in an automated DR program and find that DR parameter errors are large. Though some facilities exhibit real DR variability, most observed variability results from baseline model error. Therefore, facilities with variable DR parameters may actually respond consistently from event to event. Consequently, in DR programs in which repeatability is valued, individual buildings may be performing better than previously thought. In some cases, however, aggregations of C&I facilities exhibit real DR variability, which could create challenges for power system operation.

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

    E-Print Network [OSTI]

    Sanders, Seth

    systems. A scheme for control of electrical power flow is proposed for machines with variable­speed six (e.g. in implement- ing torque or power control), the mechanical dynamics of the model can to select a drive scheme before embarking on the system modelling and subsequent control design. Each drive

  2. A Set-Theoretic Framework to Assess the Impact of Variable Generation on the Power Flow

    E-Print Network [OSTI]

    Liberzon, Daniel

    penetration of renewable resources of electricity, such as wind and solar, into existing power systems. Since renewable resources vary in rated power output and point of grid interconnection, they affect power systems1 A Set-Theoretic Framework to Assess the Impact of Variable Generation on the Power Flow Xichen

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

    E-Print Network [OSTI]

    Lave, Matthew; Kleissl, Jan

    2013-01-01T23:59:59.000Z

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

  4. Interannual variability of Caribbean rainfall, ENSO and the Atlantic Ocean

    E-Print Network [OSTI]

    Columbia University

    Interannual variability of Caribbean rainfall, ENSO and the Atlantic Ocean Alessandra Giannini variability of Caribbean-Central Americanrainfall are examined. The atmosphericcirculation over this region- ature (SST) variability associated with Caribbean rainfall, as selected by canonical correlation

  5. Pitch-controlled variable-speed wind turbine generation

    SciTech Connect (OSTI)

    Muljadi, E.; Butterfield, C.P.

    2000-03-01T23:59:59.000Z

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

  6. Abstract--The integration of variable renewable generation sources continues to be a significant area of focus for power

    E-Print Network [OSTI]

    by this variability, wind generation often requires additional balancing resources to compensate for the variability of additional wind generation into the Northwest Power Pool. It quantifies the number of vehicles required area of focus for power system planning. Renewable portfolio standards and initiatives to reduce

  7. Performance of ECM controlled VAV fan powered terminal units

    E-Print Network [OSTI]

    Cramlet, Andrew Charles

    2009-05-15T23:59:59.000Z

    Empirical performance models of fan airflow, primary airflow and power consumption were developed for series and parallel variable air volume fan powered terminal units. An experimental setup and test procedure were created to test the terminal...

  8. Modeling of ECM Controlled Series Fan-powered VAV Terminal Units

    E-Print Network [OSTI]

    Yin, Peng

    2011-10-21T23:59:59.000Z

    Semi-empirical models for series fan-powered variable air volume terminal units (FPTUs) were developed based on models of the primary, plenum, fan airflow and the fan power consumption. The experimental setups and test procedures were developed...

  9. Simulation of radiant cooling performance with evaporative cooling sources

    E-Print Network [OSTI]

    Moore, Timothy

    2008-01-01T23:59:59.000Z

    vs. variable air volume) Dry-bulb temperature Dew-pointvia motor electronics) Wet-bulb temperature Waterside freewarm and the peaking outdoor wet-bulb temperature limits the

  10. Cosmological perturbations of a perfect fluid and noncommutative variables

    SciTech Connect (OSTI)

    De Felice, Antonio; Gerard, Jean-Marc; Suyama, Teruaki [Centre for Particle Physics and Phenomenology (CP3), Universite catholique de Louvain, Chemin du Cyclotron 2, B-1348 Louvain-la-Neuve (Belgium)

    2010-03-15T23:59:59.000Z

    We describe the linear cosmological perturbations of a perfect fluid at the level of an action, providing thus an alternative to the standard approach based only on the equations of motion. This action is suited not only to perfect fluids with a barotropic equation of state, but also to those for which the pressure depends on two thermodynamical variables. By quantizing the system we find that (1) some perturbation fields exhibit a noncommutativity quite analogous to the one observed for a charged particle moving in a strong magnetic field, (2) local curvature and pressure perturbations cannot be measured simultaneously, (3) ghosts appear if the null energy condition is violated.

  11. Kepler and the long-period variables

    SciTech Connect (OSTI)

    Hartig, Erich; Lebzelter, Thomas [University of Vienna, Department of Astrophysics, Türkenschanzstrasse 17, A-1180 Vienna (Austria); Cash, Jennifer [Department of Biological and Physical Sciences, South Carolina State University, P.O. Box 7024, Orangeburg, SC 29117 (United States); Hinkle, Kenneth H.; Mighell, Kenneth J. [National Optical Astronomy Observatories, P.O. Box 26732, Tucson, AZ 85726 (United States); Walter, Donald K., E-mail: erich.hartig@univie.ac.at, E-mail: thomas.lebzelter@univie.ac.at, E-mail: jcash@physics.scsu.edu, E-mail: hinkle@noao.edu, E-mail: mighell@noao.edu, E-mail: dkw@physics.scsu.edu [Department of Biological and Physical Sciences, South Carolina State University, P.O. Box 7296, Orangeburg, SC 29117 (United States)

    2014-12-01T23:59:59.000Z

    High-precision Kepler photometry is used to explore the details of asymptotic giant branch (AGB) light curves. Since AGB variability has a typical timescale on the order of a year, we discuss at length the removal of long-term trends and quarterly changes in Kepler data. Photometry for a small sample of nine semi-regular (SR) AGB stars is examined using a 30 minute cadence over a period of 45 months. While undergoing long-period variations of many magnitudes, the light curves are shown to be smooth at the millimagnitude level over much shorter time intervals. No flares or other rapid events were detected on a sub-day timescale. The shortest AGB period detected is on the order of 100 days. All the SR variables in our sample are shown to have multiple modes. This is always the first overtone, typically combined with the fundamental. A second common characteristic of SR variables is shown to be the simultaneous excitation of multiple closely separated periods for the same overtone mode. Approximately half the sample had a much longer variation in the light curve, likely a long secondary period (LSP). The light curves were all well represented by a combination of sinusoids. However, the properties of the sinusoids are time variable, with irregular variations present at low levels. No non-radial pulsations were detected. It is argued that the LSP variation seen in many SR variables is intrinsic to the star and linked to multiple mode pulsation.

  12. Impact of subgrid-scale radiative heating variability on the...

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

    subgrid-scale radiative heating variability on the stratocumulus-to-trade cumulus transition in climate models. Impact of subgrid-scale radiative heating variability on the...

  13. Enabling High Efficiency Clean Combustion with Micro-Variable...

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

    Combustion with Micro-Variable Circular-Orifice (MVCO) Fuel Injector and Adaptive PCCI Enabling High Efficiency Clean Combustion with Micro-Variable Circular-Orifice (MVCO) Fuel...

  14. Sources of Technical Variability in Quantitative LC-MS Proteomics...

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

    Sources of Technical Variability in Quantitative LC-MS Proteomics: Human Brain Tissue Sample Analysis. Sources of Technical Variability in Quantitative LC-MS Proteomics: Human...

  15. Microstructural Response of Variably Hydrated Ca-Rich Montmorillonite...

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

    Microstructural Response of Variably Hydrated Ca-Rich Montmorillonite to Supercritical CO2. Microstructural Response of Variably Hydrated Ca-Rich Montmorillonite to Supercritical...

  16. Ocean color and atmospheric dimethyl sulfide: On their mesoscale variability

    E-Print Network [OSTI]

    Matrai, Patricia A; Balch, William M; Cooper, David J; Saltzman, Eric S

    1993-01-01T23:59:59.000Z

    periods of' time, covering mesoscale Campbell, J. W. and W.Dimethyl Sulfide' On Their Mesoscale Variability PATRICIA A.Miami, Miami, Florida The mesoscale variability of dimethyl

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

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

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

  18. Adaptation to Climate Variability and Change: A Guidance Manual...

    Open Energy Info (EERE)

    to Climate Variability and Change: A Guidance Manual for Development Planning Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Adaptation to Climate Variability and...

  19. GEOCHEMICAL MODELING OF F AREA SEEPAGE BASIN COMPOSITION AND VARIABILITY

    SciTech Connect (OSTI)

    Millings, M.; Denham, M.; Looney, B.

    2012-05-08T23:59:59.000Z

    From the 1950s through 1989, the F Area Seepage Basins at the Savannah River Site (SRS) received low level radioactive wastes resulting from processing nuclear materials. Discharges of process wastes to the F Area Seepage Basins followed by subsequent mixing processes within the basins and eventual infiltration into the subsurface resulted in contamination of the underlying vadose zone and downgradient groundwater. For simulating contaminant behavior and subsurface transport, a quantitative understanding of the interrelated discharge-mixing-infiltration system along with the resulting chemistry of fluids entering the subsurface is needed. An example of this need emerged as the F Area Seepage Basins was selected as a key case study demonstration site for the Advanced Simulation Capability for Environmental Management (ASCEM) Program. This modeling evaluation explored the importance of the wide variability in bulk wastewater chemistry as it propagated through the basins. The results are intended to generally improve and refine the conceptualization of infiltration of chemical wastes from seepage basins receiving variable waste streams and to specifically support the ASCEM case study model for the F Area Seepage Basins. Specific goals of this work included: (1) develop a technically-based 'charge-balanced' nominal source term chemistry for water infiltrating into the subsurface during basin operations, (2) estimate the nature of short term and long term variability in infiltrating water to support scenario development for uncertainty quantification (i.e., UQ analysis), (3) identify key geochemical factors that control overall basin water chemistry and the projected variability/stability, and (4) link wastewater chemistry to the subsurface based on monitoring well data. Results from this study provide data and understanding that can be used in further modeling efforts of the F Area groundwater plume. As identified in this study, key geochemical factors affecting basin chemistry and variability included: (1) the nature or chemistry of the waste streams, (2) the open system of the basins, and (3) duration of discharge of the waste stream types. Mixing models of the archetype waste streams indicated that the overall basin system would likely remain acidic much of the time. Only an extended periods of predominantly alkaline waste discharge (e.g., >70% alkaline waste) would dramatically alter the average pH of wastewater entering the basins. Short term and long term variability were evaluated by performing multiple stepwise modeling runs to calculate the oscillation of bulk chemistry in the basins in response to short term variations in waste stream chemistry. Short term (1/2 month and 1 month) oscillations in the waste stream types only affected the chemistry in Basin 1; little variation was observed in Basin 2 and 3. As the largest basin, Basin 3 is considered the primary source to the groundwater. Modeling showed that the fluctuation in chemistry of the waste streams is not directly representative of the source term to the groundwater (i.e. Basin 3). The sequence of receiving basins and the large volume of water in Basin 3 'smooth' or nullify the short term variability in waste stream composition. As part of this study, a technically-based 'charge-balanced' nominal source term chemistry was developed for Basin 3 for a narrow range of pH (2.7 to 3.4). An example is also provided of how these data could be used to quantify uncertainty over the long term variations in waste stream chemistry and hence, Basin 3 chemistry.

  20. Variable energy constant current accelerator structure

    DOE Patents [OSTI]

    Anderson, O.A.

    1988-07-13T23:59:59.000Z

    A variable energy, constant current ion beam accelerator structure is disclosed comprising an ion source capable of providing the desired ions, a pre-accelerator for establishing an initial energy level, a matching/pumping module having means for focusing means for maintaining the beam current, and at least one main accelerator module for continuing beam focus, with means capable of variably imparting acceleration to the beam so that a constant beam output current is maintained independent of the variable output energy. In a preferred embodiment, quadrupole electrodes are provided in both the matching/pumping module and the one or more accelerator modules, and are formed using four opposing cylinder electrodes which extend parallel to the beam axis and are spaced around the beam at 90/degree/ intervals with opposing electrodes maintained at the same potential. 12 figs., 3 tabs.

  1. Pearle's Hidden-Variable Model Revisited

    E-Print Network [OSTI]

    Richard D. Gill

    2015-05-19T23:59:59.000Z

    Pearle (1970) gave an example of a local hidden variables model which exactly reproduced the singlet correlations of quantum theory, through the device of data-rejection: particles can fail to be detected in a way which depends on the hidden variables carried by the particles and on the measurement settings. If the experimenter computes correlations between measurement outcomes of particle pairs for which both particles are detected, he is actually looking at a subsample of particle pairs, determined by interaction involving both measurement settings and the hidden variables carried in the particles. We correct a mistake in Pearle's formulas (a normalization error) and more importantly show that the model is more simple than first appears. We illustrate with visualisations of the model and with a small simulation experiment, with code in the statistical programming language R included in the paper. Open problems are discussed.

  2. A new variable in flow analysis

    E-Print Network [OSTI]

    Q. H. Zhang; L. Huo; W. N. Zhang

    2006-06-20T23:59:59.000Z

    We have used a simple spectrum distribution which was derived from a hydrodynamical equation\\cite{Csorgo} to fit the data of the STAR group. It is found that it can fit the $v_2$ of STAR group very well. We have found that $v_2$ is sensitive to both the effective temperature of particles and the expanding velocity. We have suggested a new variable ${\\bf z}$ to be used in the flow analysis. This new variable will measure the correlation of particles momentum components. We have also shown that one of the $x$ or $y$ direction in the reaction plane is the direction which has the largest variance.

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

    SciTech Connect (OSTI)

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

    1996-11-01T23:59:59.000Z

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

  4. Markovian feedback to control continuous variable entanglement

    E-Print Network [OSTI]

    Stefano Mancini

    2005-04-18T23:59:59.000Z

    We present a model to realize quantum feedback control of continuous variable entanglement. It consists of two interacting bosonic modes subject to amplitude damping and achieving entangled Gaussian steady state. The possibility to greatly improve the degree of entanglement by means of Markovian (direct) feedback is then shown.

  5. The Sun is an active, variable,

    E-Print Network [OSTI]

    Christian, Eric

    The Sun is an active, variable, magnetic star with oscillations on its surface and deep within its the physical processes of the Sun-Earth connection. Visit Us on the Web: Solar Terrestrial Probes Program: http://stp.gsfc.nasa.gov For More Information, See: Sun-Earth Connection: http://sec.gsfc.nasa.gov Living With a Star: http

  6. Original article Variability of digestibility criteria

    E-Print Network [OSTI]

    Boyer, Edmond

    Original article Variability of digestibility criteria in maize elite hybrids submitted of various in vitro digestibility criteria used to estimate genotypic variation in silage maize elite hybrids and in vitro digestibility of whole-plant and cell-walls were pre- dicted by near infra-red reflectance

  7. Solitary waves propagating over variable Roger Grimshaw

    E-Print Network [OSTI]

    Solitary waves propagating over variable topography Roger Grimshaw Loughborough University waves that can propagate steadily over long distances. They were first observed by Russell in 1837 in a now famous report [26] on his observations of a solitary wave propagating along a Scottish canal

  8. Climate Change and Variability Lake Ice, Fishes

    E-Print Network [OSTI]

    Sheridan, Jennifer

    #12;Climate Change and Variability Lake Ice, Fishes and Water Levels John J. Magnuson Center to everything else." #12;The Invisible Present The Invisible Place Magnuson 2006 #12;Ice-on Day 2007 Peter W. Schmitz Photo Local Lake Mendota #12;Ice Breakup 2010 Lake Mendota March 20 #12;March 21 Ice Breakup 2010

  9. Gowdy phenomenology in scale-invariant variables

    E-Print Network [OSTI]

    Lars Andersson; Henk van Elst; Claes Uggla

    2003-10-30T23:59:59.000Z

    The dynamics of Gowdy vacuum spacetimes is considered in terms of Hubble-normalized scale-invariant variables, using the timelike area temporal gauge. The resulting state space formulation provides for a simple mechanism for the formation of ``false'' and ``true spikes'' in the approach to the singularity, and a geometrical formulation for the local attractor.

  10. Hydrologically Sensitive Areas: Variable Source Area Hydrology

    E-Print Network [OSTI]

    Walter, M.Todd

    Hydrologically Sensitive Areas: Variable Source Area Hydrology Implications for Water Quality Risk hydrology was developed and applied to the New York City (NYC) water supply watersheds. According and are therefore hydrologically sensitive with respect to their potential to transport contaminants to perennial

  11. 3. Hydrogeomorphic Variability and River Restoration

    E-Print Network [OSTI]

    Montgomery, David R.

    . It is difficult to design effective stream and channel restoration measures, or evaluate project performance expansion of efforts in and expenditures for stream restoration. Increasingly, resto- ration efforts focus39 3. Hydrogeomorphic Variability and River Restoration D. R. MONTGOMERY1 AND S. M. BOLTON2

  12. Chapter 18: Variable Frequency Drive Evaluation Protocol

    SciTech Connect (OSTI)

    Romberger, J.

    2014-11-01T23:59:59.000Z

    An adjustable-speed drive (ASD) includes all devices that vary the speed of a rotating load, including those that vary the motor speed and linkage devices that allow constant motor speed while varying the load speed. The Variable Frequency Drive Evaluation Protocol presented here addresses evaluation issues for variable-frequency drives (VFDs) installed on commercial and industrial motor-driven centrifugal fans and pumps for which torque varies with speed. Constant torque load applications, such as those for positive displacement pumps, are not covered by this protocol. Other ASD devices, such as magnetic drive, eddy current drives, variable belt sheave drives, or direct current motor variable voltage drives, are also not addressed. The VFD is by far the most common type of ASD hardware. With VFD speed control on a centrifugal fan or pump motor, energy use follows the affinity laws, which state that the motor electricity demand is a cubic relationship to speed under ideal conditions. Therefore, if the motor runs at 75% speed, the motor demand will ideally be reduced to 42% of full load power; however, with other losses it is about 49% of full load power.

  13. Variable Light-Cone Theory of Gravity

    E-Print Network [OSTI]

    I. T. Drummond

    1999-08-20T23:59:59.000Z

    We show how to reformulate Variable Speed of Light Theories (VSLT) in a covariant fashion as Variable Light-Cone Theories (VLCT) by introducing two vierbein bundles each associated with a distinct metric. The basic gravitational action relates to one bundle while matter propagates relative to the other in a conventional way. The variability of the speed of light is represented by the variability of the matter light-cone relative to the gravitational light-cone. The two bundles are related locally by an element M, of SL(4,R). The dynamics of the field M is that of a SL(4,R)-sigma model gauged with respect to local (orthochronous) Lorentz transformations on each of the bundles. Only the ``massless'' version of the model with a single new coupling, F, that has the same dimensions as Newton's constant $G_N$, is considered in this paper. When F vanishes the theory reduces to standard General Relativity. We verify that the modified Bianchi identities of the model are consistent with the standard conservation law for the matter energy-momentum tensor in its own background metric. The implications of the model for some simple applications are examined, the Newtonian limit, the flat FRW universe and the spherically symmetric static solution.

  14. The Variable Selection Problem Edward I. George

    E-Print Network [OSTI]

    George, Edward I.

    The Variable Selection Problem Edward I. George Journal of the American Statistical Association-1459%28200012%2995%3A452%3C1304%3ATVSP%3E2.0.CO%3B2-1 Journal of the American Statistical Association is currently published by American Statistical Association. Your use of the JSTOR archive indicates your acceptance

  15. Variable Length Path Coupling Thomas P. Hayes

    E-Print Network [OSTI]

    Hayes, Thomas

    length path coupling theorem, we im- prove the upper bound on the mixing time of the Glauber dynamics . By a "coupling" for this chain, we will mean a joint stochastic process (Xt, Yt) on × such that eachVariable Length Path Coupling Thomas P. Hayes Eric Vigoda July 17, 2006 Abstract We present a new

  16. Exploiting Variable Stiffness in Explosive Movement Tasks

    E-Print Network [OSTI]

    Vijayakumar, Sethu

    robots. The proposed methodology is applied to a ball- throwing task where we demonstrate that: (i, with the motivation of (i) improving safety of robots and humans (by providing an intrinsic compliance) [26], (iiExploiting Variable Stiffness in Explosive Movement Tasks David J. Braun, Matthew Howard and Sethu

  17. Advanced modeling ,control, and design of an electromechanical engine value drive system with a limited-angle actuator

    E-Print Network [OSTI]

    Qiu, Yihui, Ph. D. Massachusetts Institute of Technology

    2009-01-01T23:59:59.000Z

    This thesis addresses a specific variable valve actuation (VVA) system ---- an electromechanical valvetrain ---- in order to provide variable valve timing (VVT) in internal combustion (IC) engines. This electromechanical ...

  18. IEEE TRANSACTIONS ON ENERGY CONVERSION, VOL. 23, NO. 2, JUNE 2008 551 Sliding Mode Power Control of Variable-Speed Wind

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    in variable-speed wind energy conversion sys- tems (VS-WECS). These systems have two operation regions de of Variable-Speed Wind Energy Conversion Systems Brice Beltran, Tarek Ahmed-Ali, and Mohamed El Hachemi (newton meter). Tg Generator torque in the rotor side (newton meter). Ths High-speed torque (newton meter

  19. Systems Science and Engineering

    E-Print Network [OSTI]

    Suzuki, Masatsugu

    . Analysis of Variability in Systems II 4 ISE 370. Industrial Automation and Control .4 Humanities or social447 Systems Science and Industrial Engineering UNDERGRADUATE PROGRAMS The bachelor of science program in industrial and systems engineering is a new program within the Watson School. The curriculum

  20. Sandia National Laboratories: wavelet variability model

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

    Solar Newsletter, Systems Analysis Sandians Mathew Lave and Joshua Stein ( both in the Photovoltaics and Distributed Systems Dept.) along with Jan Kleissl (University of...

  1. Sandia National Laboratories: identify policy variables that...

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

    PV system purchases Price Premiums for Solar Home Sales On February 25, 2015, in Energy, News, News & Events, Partnership, Photovoltaic, Renewable Energy, Solar, Systems...

  2. Thermodynamics in variable speed of light theories

    E-Print Network [OSTI]

    Juan Racker; Pablo Sisterna; Hector Vucetich

    2009-11-30T23:59:59.000Z

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

  3. Continuous-variable private quantum channel

    SciTech Connect (OSTI)

    Bradler, Kamil [Instituto de Fisica, UNAM, Apdo. Postal 20-364, Mexico DF 01000 (Mexico); Department of Optics, Palacky University, 17. listopadu 50, 77200 Olomouc (Czech Republic)

    2005-10-15T23:59:59.000Z

    In this paper we introduce the concept of quantum private channel within the continuous variables framework (CVPQC) and investigate its properties. In terms of CVPQC we naturally define a 'maximally' mixed state in phase space together with its explicit construction and show that for increasing number of encryption operations (which sets the length of a shared key between Alice and Bob) the encrypted state is arbitrarily close to the maximally mixed state in the sense of the Hilbert-Schmidt distance. We bring the exact solution for the distance dependence and give also a rough estimate of the necessary number of bits of the shared secret key (i.e., how much classical resources are needed for an approximate encryption of a generally unknown continuous-variable state). The definition of the CVPQC is analyzed from the Holevo bound point of view which determines an upper bound of information about an incoming state an eavesdropper is able to get from his optimal measurement.

  4. Software Product Line Engineering for Long-lived, Sustainable Systems

    E-Print Network [OSTI]

    Lutz, Robyn R.

    Software Product Line Engineering for Long-lived, Sustainable Systems Robyn Lutz1,2, David Weiss1 system, long-lived system, variability, commonality/variability analysis. 1 Introduction Sustainable and requirements, distinguishes sustainable systems from legacy systems. Accordingly we use the term long-lived

  5. Variable metric methods for automatic history matching

    E-Print Network [OSTI]

    Armasu, Razvan

    1985-01-01T23:59:59.000Z

    . Automatic history matching codes presently in use employ steepest descent with optimal control, and although they were proven superior to others, their performance is not entirely satisfactory due to the poor rate of convergence as the performance index... rates of convergence when compared to the steepest descent They can be made to start out as steepest descent and end up as a second order algorithm, using functional and gradient information only, In this work several variable metric algorithms...

  6. Thermoacoustic tomography with variable sound speed

    E-Print Network [OSTI]

    Stefanov, Plamen

    2009-01-01T23:59:59.000Z

    We study the mathematical model of thermoacoustic tomography in media with a variable speed for a fixed time interval, greater than the diameter of the domain. In case of measurements on the whole boundary, we give an explicit solution in terms of a Neumann series expansion. We give necessary and sufficient conditions for uniqueness and stability when the measurements are taken on a part of the boundary.

  7. Thermoacoustic tomography with variable sound speed

    E-Print Network [OSTI]

    Plamen Stefanov; Gunther Uhlmann

    2009-05-30T23:59:59.000Z

    We study the mathematical model of thermoacoustic tomography in media with a variable speed for a fixed time interval, greater than the diameter of the domain. In case of measurements on the whole boundary, we give an explicit solution in terms of a Neumann series expansion. We give necessary and sufficient conditions for uniqueness and stability when the measurements are taken on a part of the boundary.

  8. HIGH LEVEL WASTE SLUDGE BATCH 4 VARIABILITY STUDY

    SciTech Connect (OSTI)

    Fox, K; Tommy Edwards, T; David Peeler, D; David Best, D; Irene Reamer, I; Phyllis Workman, P

    2006-10-02T23:59:59.000Z

    The Defense Waste Processing Facility (DWPF) is preparing for vitrification of High Level Waste (HLW) Sludge Batch 4 (SB4) in early FY2007. To support this process, the Savannah River National Laboratory (SRNL) has provided a recommendation to utilize Frit 503 for vitrifying this sludge batch, based on the composition projection provided by the Liquid Waste Organization on June 22, 2006. Frit 418 was also recommended for possible use during the transition from SB3 to SB4. A critical step in the SB4 qualification process is to demonstrate the applicability of the durability models, which are used as part of the DWPF's process control strategy, to the glass system of interest via a variability study. A variability study is an experimentally-driven assessment of the predictability and acceptability of the quality of the vitrified waste product that is anticipated from the processing of a sludge batch. At the DWPF, the durability of the vitrified waste product is not directly measured. Instead, the durability is predicted using a set of models that relate the Product Consistency Test (PCT) response of a glass to the chemical composition of that glass. In addition, a glass sample is taken during the processing of that sludge batch, the sample is transmitted to SRNL, and the durability is measured to confirm acceptance. The objective of a variability study is to demonstrate that these models are applicable to the glass composition region anticipated during the processing of the sludge batch - in this case the Frit 503 - SB4 compositional region. The success of this demonstration allows the DWPF to confidently rely on the predictions of the durability/composition models as they are used in the control of the DWPF process.

  9. Variable energy constant current accelerator structure

    DOE Patents [OSTI]

    Anderson, Oscar A. (Berkeley, CA)

    1990-01-01T23:59:59.000Z

    A variable energy, constant current ion beam accelerator structure is disclosed comprising an ion source capable of providing the desired ions, a pre-accelerator for establishing an initial energy level, a matching/pumping module having means for focusing means for maintaining the beam current, and at least one main accelerator module for continuing beam focus, with means capable of variably imparting acceleration to the beam so that a constant beam output current is maintained independent of the variable output energy. In a preferred embodiment, quadrupole electrodes are provided in both the matching/pumping module and the one or more accelerator modules, and are formed using four opposing cylinder electrodes which extend parallel to the beam axis and are spaced around the beam at 90.degree. intervals with opposing electrodes maintained at the same potential. Adjacent cylinder electrodes of the quadrupole structure are maintained at different potentials to thereby reshape the cross section of the charged particle beam to an ellipse in cross section at the mid point along each quadrupole electrode unit in the accelerator modules. The beam is maintained in focus by alternating the major axis of the ellipse along the x and y axis respectively at adjacent quadrupoles. In another embodiment, electrostatic ring electrodes may be utilized instead of the quadrupole electrodes.

  10. Variable speed wind turbine generator with zero-sequence filter

    DOE Patents [OSTI]

    Muljadi, E.

    1998-08-25T23:59:59.000Z

    A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility. 14 figs.

  11. Variable speed wind turbine generator with zero-sequence filter

    DOE Patents [OSTI]

    Muljadi, Eduard (Golden, CO)

    1998-01-01T23:59:59.000Z

    A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility.

  12. Variable Speed Wind Turbine Generator with Zero-sequence Filter

    DOE Patents [OSTI]

    Muljadi, Eduard (Golden, CO)

    1998-08-25T23:59:59.000Z

    A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility.

  13. EFFECTS OF VARIABLE-PRIORITY TRAINING ON AUTOMATION-RELATED COMPLACENCY: PERFORMANCE AND EYE MOVEMENTS

    E-Print Network [OSTI]

    Parasuraman, Raja

    2-346 EFFECTS OF VARIABLE-PRIORITY TRAINING ON AUTOMATION-RELATED COMPLACENCY: PERFORMANCE AND EYE in reducing automation-related complacency was examined. Participants were trained under one of three). They subsequently monitored an automated system while simultaneously performidg tracking and fuel management tasks

  14. Control-Oriented Model of a Dual Equal Variable Cam Timing Spark Ignition Engine

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    control 1 Introduction. Modern automobile engines must satisfy the challenging and often con icting goals) 248-3611, Phone: (313) 322-1977 y Control Systems Laboratory, Department of Electrical EngineeringControl-Oriented Model of a Dual Equal Variable Cam Timing Spark Ignition Engine A. G

  15. Energy-aware Allocation of Dynamic Variables in Partitioned Memory Architectures

    E-Print Network [OSTI]

    Simha, Rahul

    Energy-aware Allocation of Dynamic Variables in Partitioned Memory Architectures Renato Levy This paper addresses the problem of minimizing the energy consumption by the memory subsystem in an embedded system. While significant work in the literature has addressed compiler driven energy aware allocation

  16. Timed Event Graphs with variable resources: asymptotic behavior, representation in (min,+)

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    -1032" #12;1. Introduction Timed Event Graphs (TEG's), which constitute a subclass of timed Petri nets precisely, we define a class of timed Petri nets, called TEG's with variable resources, which can be likened to linear time-varying systems over ´Ñ Ò ·µ algebra - a particular dioid. These graphs (TEG's on which

  17. Interannual variability of Arctic sea ice export into the East Greenland Current

    E-Print Network [OSTI]

    Rohling, Eelco

    Interannual variability of Arctic sea ice export into the East Greenland Current K. A. Cox,1 J. D cycle, Arctic sea ice decline, and increasing Greenland glacial melt. Here we use new d18 O data from the East Greenland Current system at Cape Farewell and Denmark Strait to determine the relative proportions

  18. Ecology and the ratchet of events: Climate variability, niche dimensions, and species distributions

    E-Print Network [OSTI]

    Ecology and the ratchet of events: Climate variability, niche dimensions, and species distributionsDepartment of Botany and Program in Ecology and dWyoming Water Resources Data System and Wyoming State Climate Office superimposed on anthropogenic trends. Predicting ecological and biogeographic responses to these changes

  19. Spatial variability in soil heat flux at three Inner Mongolia steppe ecosystems

    E-Print Network [OSTI]

    Chen, Jiquan

    Spatial variability in soil heat flux at three Inner Mongolia steppe ecosystems Changliang Shao a-covariance Grassland Inner Mongolia a b s t r a c t Closing the energy budget at flux measurement sites is problematic system within the footprints of three Eddy-covariance towers located in the steppe of Inner Mongolia

  20. SYNTHESIS Disturbance-driven changes in the variability of ecological patterns and processes

    E-Print Network [OSTI]

    Fraterrigo, Jennifer

    by considering disturbance extent, frequency and intensity, as well as ecosystem recovery, and thereby capturesREVIEW AND SYNTHESIS Disturbance-driven changes in the variability of ecological patterns Understanding how disturbance shapes the dynamics of ecological systems is of fundamental importance in ecology

  1. Increased Climate Variability Is More Visible Than Global Warming: A General

    E-Print Network [OSTI]

    Kreinovich, Vladik

    Increased Climate Variability Is More Visible Than Global Warming: A General System@utep.edu Abstract While global warming is a statistically confirmed long-term phenomenon, its most visible than the global warming itself. 1 Formulation of the Problem What is global warming. The term "global

  2. May 2013 PSERC Webinar: Managing Wind Variability with Self-Reserves and Responsive Demand

    Broader source: Energy.gov [DOE]

    The DOE-funded Power Systems Engineering Research Center (PSERC) is offering a free public webinar on managing wind variability in energy production. The webinar will be held Tuesday, May 7, 2013 from 2-3 p.m. No pre-registration is necessary.

  3. Variable diameter wind turbine rotor blades

    DOE Patents [OSTI]

    Jamieson, Peter McKeich; Hornzee-Jones, Chris; Moroz, Emilian M.; Blakemore, Ralph W.

    2005-12-06T23:59:59.000Z

    A system and method for changing wind turbine rotor diameters to meet changing wind speeds and control system loads is disclosed. The rotor blades on the wind turbine are able to adjust length by extensions nested within or containing the base blade. The blades can have more than one extension in a variety of configurations. A cable winching system, a hydraulic system, a pneumatic system, inflatable or elastic extensions, and a spring-loaded jack knife deployment are some of the methods of adjustment. The extension is also protected from lightning by a grounding system.

  4. Identification of building applications for a variable-conductance insulation

    SciTech Connect (OSTI)

    Potter, T.F. [National Renewable Energy Lab., Golden, CO (United States); Tuluca, A. [Winter (Steven) Associates, Inc., New York, NY (United States)

    1992-07-01T23:59:59.000Z

    Recent experiments have confirmed the feasibility of controllable, reversible disabling of a vacuum insulation panel, which may result in the development of energy-efficient building envelope components. These components could extend the managed energy exchange through the building envelope from about 30% (typical with fenestration systems in commercial buildings), to as much as 90% of the gross wall and roof areas. Further investigation will be required to optimized the thermal response and the magnitude of the R-value swing (from a difference between insulating and conducting insulating values of 4 to as high as a factor of 100). The potential for energy reduction by using the variable-conductance insulation in the building envelope is discussed, and other potential building applications are mentioned.

  5. Utility-Based Wireless Resource Allocation for Variable Rate Transmission

    E-Print Network [OSTI]

    Zhang, Xiaolu; Ng, Chun Sum

    2007-01-01T23:59:59.000Z

    For most wireless services with variable rate transmission, both average rate and rate oscillation are important performance metrics. The traditional performance criterion, utility of average transmission rate, boosts the average rate but also results in high rate oscillations. We introduce a utility function of instantaneous transmission rates. It is capable of facilitating the resource allocation with flexible combinations of average rate and rate oscillation. Based on the new utility, we consider the time and power allocation in a time-shared wireless network. Two adaptation policies are developed, namely, time sharing (TS) and joint time sharing and power control (JTPC). An extension to quantized time sharing with limited channel feedback (QTSL) for practical systems is also discussed. Simulation results show that by controlling the concavity of the utility function, a tradeoff between the average rate and rate oscillation can be easily made.

  6. Storage of LWR spent fuel in air. Volume 3, Results from exposure of spent fuel to fluorine-contaminated air

    SciTech Connect (OSTI)

    Cunningham, M.E.; Thomas, L.E.

    1995-06-01T23:59:59.000Z

    The Behavior of Spent Fuel in Storage (BSFS) Project has conducted research to develop data on spent nuclear fuel (irradiated U0{sub 2}) that could be used to support design, licensing, and operation of dry storage installations. Test Series B conducted by the BSFS Project was designed as a long-term study of the oxidation of spent fuel exposed to air. It was discovered after the exposures were completed in September 1990 that the test specimens had been exposed to an atmosphere of bottled air contaminated with an unknown quantity of fluorine. This exposure resulted in the test specimens reacting with both the oxygen and the fluorine in the oven atmospheres. The apparent source of the fluorine was gamma radiation-induced chemical decomposition of the fluoro-elastomer gaskets used to seal the oven doors. This chemical decomposition apparently released hydrofluoric acid (HF) vapor into the oven atmospheres. Because the Test Series B specimens were exposed to a fluorine-contaminated oven atmosphere and reacted with the fluorine, it is recommended that the Test Series B data not be used to develop time-temperature limits for exposure of spent nuclear fuel to air. This report has been prepared to document Test Series B and present the collected data and observations.

  7. Storage of LWR spent fuel in air: Volume 1: Design and operation of a spent fuel oxidation test facility

    SciTech Connect (OSTI)

    Thornhill, C.K.; Campbell, T.K.; Thornhill, R.E.

    1988-12-01T23:59:59.000Z

    This report describes the design and operation and technical accomplishments of a spent-fuel oxidation test facility at the Pacific Northwest Laboratory. The objective of the experiments conducted in this facility was to develop a data base for determining spent-fuel dry storage temperature limits by characterizing the oxidation behavior of light-water reactor (LWR) spent fuels in air. These data are needed to support licensing of dry storage in air as an alternative to spent-fuel storage in water pools. They are to be used to develop and validate predictive models of spent-fuel behavior during dry air storage in an Independent Spent Fuel Storage Installation (ISFSI). The present licensed alternative to pool storage of spent fuel is dry storage in an inert gas environment, which is called inerted dry storage (IDS). Licensed air storage, however, would not require monitoring for maintenance of an inert-gas environment (which IDS requires) but does require the development of allowable temperature limits below which UO/sub 2/ oxidation in breached fuel rods would not become a problem. Scoping tests at PNL with nonirradiated UO/sub 2/ pellets and spent-fuel fragment specimens identified the need for a statistically designed test matrix with test temperatures bounding anticipated maximum acceptable air-storage temperatures. This facility was designed and operated to satisfy that need. 7 refs.

  8. Variability in continuous traffic monitoring data

    SciTech Connect (OSTI)

    Wright, T.; Hu, P.S. [Oak Ridge National Lab., TN (United States); Young, J. [Tennessee Univ., Knoxville, TN (United States)

    1996-07-01T23:59:59.000Z

    Each state in the United States can be viewed as a universe of road segments. For each road segment in each state, it is desired to know various traffic characteristics based on count data, classification count data, and weigh-in-motion data. These data are absolutely essential for highway design, maintenance, safety, and planning. Given no cost constraints, each road segment would be continuously monitored every day of the year. However, in practice, a few road segments are monitored continuously every day of the year to produce annual characteristics of traffic flow. The remaining road segments are monitored for one or two days each year, and this resulting data are `adjusted` (using factors based on data collected from the continuously monitored road segments) to produce estimates of annual characteristics. With this general approach, each state strives to provide estimates of annual characteristics for each road segment within its jurisdiction. In 1985, the Federal Highway Administration (FHWA) published the Traffic Monitoring Guide to assist states in achieving this end. As with almost any data collection effort, the monitoring data suffers from errors from many sources. In this paper, we report some empirical findings in a research project sponsored by the FHWA. This research project studied the variability in the traffic data from the continuously monitored road segments from state(s) and, the extent to which this variability is transferred to and affects the precision of the data produced from the road segments which are monitored only one or two days each year. The ultimate hope is that states will eventually be able to not only publish an estimate of a characteristic such as Average Annual Daily Traffic (AADT) for each road segment, but also that each estimate will be accompanied by a statement expressing how good the estimate is in terms of its estimated variability or precision, which will likely be expressed as a coefficient of variation.

  9. Microsoft Word - Connecting Variable Generating Resources to...

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

    Background The Bonneville Power Administration (BPA) has about 1,700 megawatts of wind power operating on its system today. Wind power in BPA's system is set to reach 3,000 MW by...

  10. Allocating Variability and Reserve Requirements (Presentation)

    SciTech Connect (OSTI)

    Kirby, B.; King, J.; Milligan, M.

    2011-10-01T23:59:59.000Z

    This presentation describes how you could conceivably allocate variability and reserve requirements, including how to allocate aggregation benefits. Conclusions of this presentation are: (1) Aggregation provides benefits because individual requirements are not 100% correlated; (2) Method needed to allocate reduced requirement among participants; (3) Differences between allocation results are subtle - (a) Not immediately obvious which method is 'better'; (b) Many are numerically 'correct', they sum to the physical requirement; (c) Many are not 'fair', Results depend on sub-aggregation and/or the order individuals are included; and (4) Vector allocation method is simple and fair.

  11. Adhesive bonding using variable frequency microwave energy

    DOE Patents [OSTI]

    Lauf, Robert J. (Oak Ridge, TN); McMillan, April D. (Knoxville, TN); Paulauskas, Felix L. (Oak Ridge, TN); Fathi, Zakaryae (Cary, NC); Wei, Jianghua (Raleigh, NC)

    1998-01-01T23:59:59.000Z

    Methods of facilitating the adhesive bonding of various components with variable frequency microwave energy are disclosed. The time required to cure a polymeric adhesive is decreased by placing components to be bonded via the adhesive in a microwave heating apparatus having a multimode cavity and irradiated with microwaves of varying frequencies. Methods of uniformly heating various articles having conductive fibers disposed therein are provided. Microwave energy may be selectively oriented to enter an edge portion of an article having conductive fibers therein. An edge portion of an article having conductive fibers therein may be selectively shielded from microwave energy.

  12. Crystal diffraction lens with variable focal length

    DOE Patents [OSTI]

    Smither, R.K.

    1991-04-02T23:59:59.000Z

    A method and apparatus for altering the focal length of a focusing element of one of a plurality of pre-determined focal lengths by changing heat transfer within selected portions of the element by controlled quantities is disclosed. Control over heat transfer is accomplished by manipulating one or more of a number of variables, including: the amount of heat or cold applied to surfaces; type of fluids pumped through channels for heating and cooling; temperatures, directions of flow and rates of flow of fluids; and placement of channels. 19 figures.

  13. Long-Term Wind Power Variability

    SciTech Connect (OSTI)

    Wan, Y. H.

    2012-01-01T23:59:59.000Z

    The National Renewable Energy Laboratory started collecting wind power data from large commercial wind power plants (WPPs) in southwest Minnesota with dedicated dataloggers and communication links in the spring of 2000. Over the years, additional WPPs in other areas were added to and removed from the data collection effort. The longest data stream of actual wind plant output is more than 10 years. The resulting data have been used to analyze wind power fluctuations, frequency distribution of changes, the effects of spatial diversity, and wind power ancillary services. This report uses the multi-year wind power data to examine long-term wind power variability.

  14. Plasma heating in a variable magnetic field

    SciTech Connect (OSTI)

    Kichigin, G. N., E-mail: king@iszf.irk.ru [Russian Academy of Sciences, Institute of Solar-Terrestrial Physics (Russian Federation)

    2013-05-15T23:59:59.000Z

    The problem of particle acceleration in a periodically variable magnetic field that either takes a zero value or passes through zero is considered. It is shown that, each time the field [0]passes through zero, the particle energy increases abruptly. This process can be regarded as heating in the course of which plasma particles acquire significant energy within one field period. This mechanism of plasma heating takes place in the absence of collisions between plasma particles and is analogous to the mechanism of magnetic pumping in collisional plasma considered by Alfven.

  15. Adhesive bonding using variable frequency microwave energy

    DOE Patents [OSTI]

    Lauf, R.J.; McMillan, A.D.; Paulauskas, F.L.; Fathi, Z.; Wei, J.

    1998-09-08T23:59:59.000Z

    Methods of facilitating the adhesive bonding of various components with variable frequency microwave energy are disclosed. The time required to cure a polymeric adhesive is decreased by placing components to be bonded via the adhesive in a microwave heating apparatus having a multimode cavity and irradiated with microwaves of varying frequencies. Methods of uniformly heating various articles having conductive fibers disposed therein are provided. Microwave energy may be selectively oriented to enter an edge portion of an article having conductive fibers therein. An edge portion of an article having conductive fibers therein may be selectively shielded from microwave energy. 26 figs.

  16. Adhesive bonding using variable frequency microwave energy

    DOE Patents [OSTI]

    Lauf, R.J.; McMillan, A.D.; Paulauskas, F.L.; Fathi, Z.; Wei, J.

    1998-08-25T23:59:59.000Z

    Methods of facilitating the adhesive bonding of various components with variable frequency microwave energy are disclosed. The time required to cure a polymeric adhesive is decreased by placing components to be bonded via the adhesive in a microwave heating apparatus having a multimode cavity and irradiated with microwaves of varying frequencies. Methods of uniformly heating various articles having conductive fibers disposed therein are provided. Microwave energy may be selectively oriented to enter an edge portion of an article having conductive fibers therein. An edge portion of an article having conductive fibers therein may be selectively shielded from microwave energy. 26 figs.

  17. Role of Smarter Grids in Variable Renewable Resource Integration (Presentation)

    SciTech Connect (OSTI)

    Miller, M.

    2012-07-01T23:59:59.000Z

    This presentation discusses the role of smarter grids in variable renewable resource integration and references material from a forthcoming ISGAN issue paper: Smart Grid Contributions to Variable Renewable Resource Integration, co-written by the presenter and currently in review.

  18. Bayesian variable selection in clustering via dirichlet process mixture models

    E-Print Network [OSTI]

    Kim, Sinae

    2007-09-17T23:59:59.000Z

    simultane- ously. I use Dirichlet process mixture models to define the cluster structure and to introduce in the model a latent binary vector to identify discriminating variables. I update the variable selection index using a Metropolis algorithm and obtain...

  19. Integrating Variable Renewable Energy in Electric Power Markets: Best Practices from International Experience

    SciTech Connect (OSTI)

    Cochran, J.; Bird, L.; Heeter, J.; Arent, D. A.

    2012-04-01T23:59:59.000Z

    Many countries -- reflecting very different geographies, markets, and power systems -- are successfully managing high levels of variable renewable energy on the electric grid, including that from wind and solar energy. This study documents the diverse approaches to effective integration of variable renewable energy among six countries -- Australia (South Australia), Denmark, Germany, Ireland, Spain, and the United States (Western region-Colorado and Texas)-- and summarizes policy best practices that energy ministers and other stakeholders can pursue to ensure that electricity markets and power systems can effectively coevolve with increasing penetrations of variable renewable energy. Each country has crafted its own combination of policies, market designs, and system operations to achieve the system reliability and flexibility needed to successfully integrate renewables. Notwithstanding this diversity, the approaches taken by the countries studied all coalesce around five strategic areas: lead public engagement, particularly for new transmission; coordinate and integrate planning; develop rules for market evolution that enable system flexibility; expand access to diverse resources and geographic footprint of operations; and improve system operations. The ability to maintain a broad ecosystem perspective, to organize and make available the wealth of experiences, and to ensure a clear path from analysis to enactment should be the primary focus going forward.

  20. The EUV and X-ray Emission of Nonmagnetic Cataclysmic Variables

    E-Print Network [OSTI]

    Christopher W. Mauche

    1997-09-11T23:59:59.000Z

    Recent results are presented and discussed regarding the EUV and X-ray emission of nonmagnetic cataclysmic variables. Emphasis is given to high accretion rate systems (novalike variables and dwarf novae in outburst), and to a number of apparent discrepancies between observations and the theory of the boundary layer between the accretion disk and the surface of the white dwarf. Discussed are EUV and X-ray light curves, dwarf nova oscillations, and spectra, with new and previously unpublished results on SS Cyg and OY Car.

  1. Jose Groh (Geneva Observatory, Switzerland) Luminous Blue Variables

    E-Print Network [OSTI]

    Crowther, Paul

    Jose Groh (Geneva Observatory, Switzerland) Luminous Blue Variables: massive stars extremely close Groh - Luminous BlueVariables: massive stars extremely close to the Eddington limit JD2:Very massive Jose Groh - Luminous BlueVariables: massive stars extremely close to the Eddington limit JD2:Very

  2. Variable ventilation induces endogenous surfactant release in normal guinea pigs

    E-Print Network [OSTI]

    Lutchen, Kenneth

    Variable ventilation induces endogenous surfactant release in normal guinea pigs Stephen P. Arold,1. Alencar, Kenneth R. Lutchen, and Edward P. Ingenito. Variable ventilation induces endogenous surfactant.00036.2003.--Variable or noisy ventilation, which includes random breath-to-breath variations in tidal

  3. Interannual variability of Caribbean rainfall, ENSO and the Atlantic Ocean

    E-Print Network [OSTI]

    Columbia University

    Interannual variability of Caribbean rainfall, ENSO and the Atlantic Ocean Alessandra Giannini the interannual variability of Caribbean­Central American rainfall are examined. The atmospheric circulation over) and sea surface temper­ ature (SST) variability associated with Caribbean rainfall, as selected

  4. GLOBAL PATTERN OF MESOSCALE VARIABILITY IN SEA SURFACE HEIGHT

    E-Print Network [OSTI]

    Kaplan, Alexey

    GLOBAL PATTERN OF MESOSCALE VARIABILITY IN SEA SURFACE HEIGHT AND ITS DYNAMICAL CAUSES Alexey separate the mesoscale variability of sea surface heights into its spatial and temporal components of mesoscale variability in different areas to dynamical causes. Major portion of it can be explained

  5. Variably insulating portable heater/cooler

    DOE Patents [OSTI]

    Potter, Thomas F. (Denver, CO)

    1998-01-01T23:59:59.000Z

    A compact vacuum insulation panel comprising a chamber enclosed by two sheets of metal, glass-like spaces disposed in the chamber between the sidewalls, and a high-grade vacuum in the chamber includes apparatus and methods for enabling and disabling, or turning "on" and "off" the thermal insulating capability of the panel. One type of enabling and disabling apparatus and method includes a metal hydride for releasing hydrogen gas into the chamber in response to heat, and a hydrogen grate between the metal hydride and the chamber for selectively preventing and allowing return of the hydrogen gas to the metal hydride. Another type of enabling and disabling apparatus and method includes a variable emissivity coating on the sheets of metal in which the emissivity is controllably variable by heat or electricity. Still another type of enabling and disabling apparatus and method includes metal-to-metal contact devices that can be actuated to establish or break metal-to-metal heat paths or thermal short circuits between the metal sidewalls.

  6. Variably insulating portable heater/cooler

    DOE Patents [OSTI]

    Potter, T.F.

    1998-09-29T23:59:59.000Z

    A compact vacuum insulation panel is described comprising a chamber enclosed by two sheets of metal, glass-like spaces disposed in the chamber between the sidewalls, and a high-grade vacuum in the chamber includes apparatus and methods for enabling and disabling, or turning ``on`` and ``off`` the thermal insulating capability of the panel. One type of enabling and disabling apparatus and method includes a metal hydride for releasing hydrogen gas into the chamber in response to heat, and a hydrogen grate between the metal hydride and the chamber for selectively preventing and allowing return of the hydrogen gas to the metal hydride. Another type of enabling and disabling apparatus and method includes a variable emissivity coating on the sheets of metal in which the emissivity is controllably variable by heat or electricity. Still another type of enabling and disabling apparatus and method includes metal-to-metal contact devices that can be actuated to establish or break metal-to-metal heat paths or thermal short circuits between the metal sidewalls. 25 figs.

  7. IS ACTIVE REGION CORE VARIABILITY AGE DEPENDENT?

    SciTech Connect (OSTI)

    Ugarte-Urra, Ignacio [College of Science, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States); Warren, Harry P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2012-12-10T23:59:59.000Z

    The presence of both steady and transient loops in active region cores has been reported from soft X-ray and extreme-ultraviolet observations of the solar corona. The relationship between the different loop populations, however, remains an open question. We present an investigation of the short-term variability of loops in the core of two active regions in the context of their long-term evolution. We take advantage of the nearly full Sun observations of STEREO and Solar Dynamics Observatory spacecraft to track these active regions as they rotate around the Sun multiple times. We then diagnose the variability of the active region cores at several instances of their lifetime using EIS/Hinode spectral capabilities. We inspect a broad range of temperatures, including for the first time spatially and temporally resolved images of Ca XIV and Ca XV lines. We find that the active region cores become fainter and steadier with time. The significant emission measure at high temperatures that is not correlated with a comparable increase at low temperatures suggests that high-frequency heating is viable. The presence, however, during the early stages, of an enhanced emission measure in the ''hot'' (3.0-4.5 MK) and ''cool'' (0.6-0.9 MK) components suggests that low-frequency heating also plays a significant role. Our results explain why there have been recent studies supporting both heating scenarios.

  8. IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 12, NO. 1, JANUARY 1997 87 Fuzzy Logic Based Intelligent Control of a Variable

    E-Print Network [OSTI]

    Simões, Marcelo Godoy

    constant speed wind turbines (horizontal or vertical axis) that were coupled to squirrel cage induction gives robust speed control against wind gust and turbine oscillatory torque. The complete control system and control, the total energy capture in a variable speed wind turbine (VSWT) system is larger and, therefore

  9. Modeling and Control of a Spark Ignition Engine with Variable Cam Timing A. G. Stefanopoulou, J. A. Cooky

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    and multivariable. The control scheme jointly manages fuel and cam position. 1 Introduction. Modern automobile external exhaust gas recirculation (EGR) systems commonly used for NOx reduction. Control SystemsModeling and Control of a Spark Ignition Engine with Variable Cam Timing A. G. Stefanopoulou, J. A

  10. Imprecise Reliability Assessment and Decision-Making when the Type of the Probability Distribution of the Random Variables is

    E-Print Network [OSTI]

    Nikolaidis, Efstratios

    the upper and lower bounds of the reliability of a system involving such variables. A method for modeling, is formulated and solved in order to estimate the minimum and maximum values of a system's reliability1 Imprecise Reliability Assessment and Decision-Making when the Type of the Probability

  11. What measures climate? A variety of variables including their variability and extreme values determine climate for

    E-Print Network [OSTI]

    Allan, Richard P.

    climate zones? The sun is the ultimate power source for the climate "machine". The uneven distribution conditions. Typical variables to consider are temperature (maximum, miniumum), precipitation (includes rain, sleet, snow, hail, etc), sunlight/cloudiness, wind, humidity, ice cover, sea temperature, etc... Many

  12. Improvements of the Variable Thermal Resistance

    E-Print Network [OSTI]

    Székely, V; Kollar, E

    2008-01-01T23:59:59.000Z

    A flat mounting unit with electronically variable thermal resistance [1] has been presented in the last year [2]. The design was based on a Peltier cell and the appropriate control electronics and software. The device is devoted especially to the thermal characterization of packages, e.g. in dual cold plate arrangements. Although this design meets the requirements of the static measurement we are intended to improve its parameters as the settling time and dynamic thermal impedance and the range of realized thermal resistance. The new design applies the heat flux sensor developed by our team as well [3], making easier the control of the device. This development allows even the realization of negative thermal resistances.

  13. Improvements of the Variable Thermal Resistance

    E-Print Network [OSTI]

    V. Szekely; S. Torok; E. Kollar

    2008-01-07T23:59:59.000Z

    A flat mounting unit with electronically variable thermal resistance [1] has been presented in the last year [2]. The design was based on a Peltier cell and the appropriate control electronics and software. The device is devoted especially to the thermal characterization of packages, e.g. in dual cold plate arrangements. Although this design meets the requirements of the static measurement we are intended to improve its parameters as the settling time and dynamic thermal impedance and the range of realized thermal resistance. The new design applies the heat flux sensor developed by our team as well [3], making easier the control of the device. This development allows even the realization of negative thermal resistances.

  14. Variable Interactions in Query-Driven Visualization

    SciTech Connect (OSTI)

    Bethel, E. Wes; Gosink, Luke J.; Anderson, John C.; Joy, Kenneth I.

    2007-10-25T23:59:59.000Z

    One fundamental element of scientific inquiry is discoveringrelationships, particularly the interactions between different variablesin observed or simulated phenomena. Building upon our prior work in thefield of Query-Driven Visualization, where visual data analysisprocessing is focused on subsets of large data deemed to be"scientifically interesting," this new work focuses on a novel knowledgediscovery capability suitable for use with petascale class datasets. Itenables visual presentation of the presence or absence of relationships(correlations) between variables in data subsets produced by Query-Drivenmethodologies. This technique holds great potential for enablingknowledge discovery from large and complex datasets currently emergingfrom SciDAC and INCITE projects. It is sufficiently generally to beapplicable to any time of complex, time-varying, multivariate data fromstructured, unstructured or adaptive grids.

  15. Analyzing of Balancing Authorities Cooperation Methods with High Variable Generation Penetration

    SciTech Connect (OSTI)

    Makarov, Yuri V.; Zhou, Ning; Etingov, Pavel V.; Samaan, Nader A.; Ma, Jian; Diao, Ruisheng; Guttromson, Ross T.

    2010-11-02T23:59:59.000Z

    With the rapidly growing penetration level of wind and solar generation, the challenges of managing variability and the uncertainty of intermittent renewable generation become more and more significant. The problem of power variability and uncertainty gets exacerbated when each balancing authority (BA) works locally and separately to balance its own subsystem. The virtual BA concept is based on various forms of collaboration between individual BAs to manage power variability and uncertainty. The virtual BA will have a wide area control capability in managing its operational balancing requirements in different time frames. This coordination results in the improvement of efficiency and reliability of power system operation while facilitating the high level integration of green, intermittent energy resources. Several strategies for virtual BA implementation, such as Area Control Error (ACE) diversity interchange (ADI), variable generation only BA, BA consolidation, dynamic scheduling, and regulation and load following sharing are discussed in this paper. The objective of such strategies is to allow individual BAs within a large power grid to help each other dealing with power variability. Innovative methods have been developed to simulate the balancing operation of BAs. These methods evaluate the BA operation through a number of metrics such as capacity, ramp rate, ramp duration, energy and cycling requirements to evaluate the performance of different virtual BA strategies.

  16. Cyclic Variability During the Transition Between Spark-ignited Combustion and HCCI

    SciTech Connect (OSTI)

    Edwards, Kevin Dean [ORNL; Daw, C Stuart [ORNL; Wagner, Robert M [ORNL; Green Jr, Johney Boyd [ORNL

    2006-01-01T23:59:59.000Z

    Experimental observations of cyclic variability are described for the transition between conventional spark-ignited (SI) propagating-flame combustion and homogeneous charge compression ignition (HCCI) combustion in a single-cylinder, stoichiometrically fueled, gasoline engine. The engine under study is equipped with a fully variable valve actuation (VVA) system which was used to control the levels of internal exhaust gas recirculation (EGR) to achieve the transition from conventional SI to HCCI. Engine operation in both SI and HCCI modes was observed to be very stable with only minor, stochastic cyclic variability. However, during transitions between these modes, operation was observed to be highly unstable with high levels of cyclic variability and occasionally the engine could not sustain combustion. Analysis of the observed cyclic variability suggests that the transition between SI and HCCI can be described as a sequence of bifurcations in a low-dimensional dynamic map. The deterministic nature of the instabilities observed during the transition suggest that it is possible to make accurate, short-term predictions of combustion performance allowing for the possibility of developing on-line diagnostics and proactive control algorithms for expanding stable HCCI operation and improving transitions between conventional combustion modes and HCCI.

  17. Periodic Flux Variability of Stars due to the Reflex Doppler Effect Induced by Planetary Companions

    E-Print Network [OSTI]

    Abraham Loeb; B. Scott Gaudi

    2003-03-28T23:59:59.000Z

    Upcoming space-based photometric satellites offer the possibility of detecting continuum flux variability at the micro-magnitude level. We show that the Doppler flux variability induced by the reflex motion of stars due to planetary companions has an amplitude of (3-alpha)K/c, where K is the reflex radial velocity amplitude and alpha is the logarithmic slope of source spectral flux in the observed frequency band. For many of the known close-in planetary systems with periods less than ~0.2 years, the periodic Doppler variability is of order a micromagnitude, and is significant relative to the variability caused by reflected light from the planetary companion. For companions with periods greater than ~0.2 years, the Doppler signal is larger than the reflected light signal. We show that the future photometric satellites should reach the sensitivity to detect this Doppler variability. In particular, the Kepler satellite should have the photon-noise sensitivity to detect at a signal-to-noise ratio > 5, all planets with minimum mass greater than 5 Jupiter masses, and periods less than 0.1 years around the 10,000 main-sequence stars with spectral types A through K and apparent magnitude V<12 in its field-of-view.

  18. Modular design of biological systems

    E-Print Network [OSTI]

    Norville, Julie Erin, 1980-

    2012-01-01T23:59:59.000Z

    The focus of my research is the development of technology for building compound biological systems from simpler pieces. I designed BioScaffold parts, a family of variable regions that can be inserted into a DNA sequence ...

  19. Climate dynamics and fluid mechanics: Natural variability and related uncertainties

    E-Print Network [OSTI]

    Michael Ghil; Mickaël D. Chekroun; Eric Simonnet

    2010-06-15T23:59:59.000Z

    The purpose of this review-and-research paper is twofold: (i) to review the role played in climate dynamics by fluid-dynamical models; and (ii) to contribute to the understanding and reduction of the uncertainties in future climate-change projections. To illustrate the first point, we focus on the large-scale, wind-driven flow of the mid-latitude oceans which contribute in a crucial way to Earth's climate, and to changes therein. We study the low-frequency variability (LFV) of the wind-driven, double-gyre circulation in mid-latitude ocean basins, via the bifurcation sequence that leads from steady states through periodic solutions and on to the chaotic, irregular flows documented in the observations. This sequence involves local, pitchfork and Hopf bifurcations, as well as global, homoclinic ones. The natural climate variability induced by the LFV of the ocean circulation is but one of the causes of uncertainties in climate projections. Another major cause of such uncertainties could reside in the structural instability in the topological sense, of the equations governing climate dynamics, including but not restricted to those of atmospheric and ocean dynamics. We propose a novel approach to understand, and possibly reduce, these uncertainties, based on the concepts and methods of random dynamical systems theory. As a very first step, we study the effect of noise on the topological classes of the Arnol'd family of circle maps, a paradigmatic model of frequency locking as occurring in the nonlinear interactions between the El Nino-Southern Oscillations (ENSO) and the seasonal cycle. It is shown that the maps' fine-grained resonant landscape is smoothed by the noise, thus permitting their coarse-grained classification. This result is consistent with stabilizing effects of stochastic parametrization obtained in modeling of ENSO phenomenon via some general circulation models.

  20. Statistical Characterization of Solar Photovoltaic Power Variability at Small Timescales: Preprint

    SciTech Connect (OSTI)

    Shedd, S.; Hodge, B.-M.; Florita, A.; Orwig, K.

    2012-08-01T23:59:59.000Z

    Integrating large amounts of variable and uncertain solar photovoltaic power into the electricity grid is a growing concern for power system operators in a number of different regions. Power system operators typically accommodate variability, whether from load, wind, or solar, by carrying reserves that can quickly change their output to match the changes in the solar resource. At timescales in the seconds-to-minutes range, this is known as regulation reserve. Previous studies have shown that increasing the geographic diversity of solar resources can reduce the short term-variability of the power output. As the price of solar has decreased, the emergence of very large PV plants (greater than 10 MW) has become more common. These plants present an interesting case because they are large enough to exhibit some spatial smoothing by themselves. This work examines the variability of solar PV output among different arrays in a large ({approx}50 MW) PV plant in the western United States, including the correlation in power output changes between different arrays, as well as the aggregated plant output, at timescales ranging from one second to five minutes.

  1. Energy storage connection system

    DOE Patents [OSTI]

    Benedict, Eric L.; Borland, Nicholas P.; Dale, Magdelena; Freeman, Belvin; Kite, Kim A.; Petter, Jeffrey K.; Taylor, Brendan F.

    2012-07-03T23:59:59.000Z

    A power system for connecting a variable voltage power source, such as a power controller, with a plurality of energy storage devices, at least two of which have a different initial voltage than the output voltage of the variable voltage power source. The power system includes a controller that increases the output voltage of the variable voltage power source. When such output voltage is substantially equal to the initial voltage of a first one of the energy storage devices, the controller sends a signal that causes a switch to connect the variable voltage power source with the first one of the energy storage devices. The controller then causes the output voltage of the variable voltage power source to continue increasing. When the output voltage is substantially equal to the initial voltage of a second one of the energy storage devices, the controller sends a signal that causes a switch to connect the variable voltage power source with the second one of the energy storage devices.

  2. Impacts of Variability and Uncertainty in Solar Photovoltaic Generation at Multiple Timescales

    SciTech Connect (OSTI)

    Ela, E.; Diakov, V.; Ibanez, E.; Heaney, M.

    2013-05-01T23:59:59.000Z

    The characteristics of variability and uncertainty of PV solar power have been studied extensively. These characteristics can create challenges for system operators who must ensure a balance between generation and demand while obeying power system constraints at the lowest possible cost. A number of studies have looked at the impact of wind power plants, and some recent studies have also included solar PV. The simulations that are used in these studies, however, are typically fixed to one time resolution. This makes it difficult to analyze the variability across several timescales. In this study, we use a simulation tool that has the ability to evaluate both the economic and reliability impacts of PV variability and uncertainty at multiple timescales. This information should help system operators better prepare for increases of PV on their systems and develop improved mitigation strategies to better integrate PV with enhanced reliability. Another goal of this study is to understand how different mitigation strategies and methods can improve the integration of solar power more reliably and efficiently.

  3. Multi-color Near Infra-red Intra-day and Short Term Variability of the Blazar S5 0716+714

    E-Print Network [OSTI]

    Alok C. Gupta; Sang-Mok Cha; Sungho Lee; Ho Jin; Soojong Pak; Seoung-hyun Cho; Bongkon Moon; Youngsik Park; In-Soo Yuk; Uk-won Nam; Jaemann Kyeong

    2008-09-19T23:59:59.000Z

    In this paper, we report results of our near-infrared (NIR) photometric variability studies of the BL Lacertae object S5 0716+714. NIR photometric observations spread over 7 nights during our observing run April 2-9, 2007 at 1.8 meter telescope equipped with KASINICS (Korea Astronomy and Space Science Institute Near Infrared Camera System) and J, H, and Ks filters at Bohyunsan Optical Astronomy Observatory (BOAO), South Korea. We searched for intra-day variability, short term variability and color variability in the BL Lac object. We have not detected any genuine intra-day variability in any of J, H, and Ks passbands in our observing run. Significant short term variability ~ 32.6%, 20.5% and 18.2% have been detected in J, H, Ks passbands, respectively, and ~ 11.9% in (J-H) color.

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

    DOE Patents [OSTI]

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

    1997-01-01T23:59:59.000Z

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

  5. Variable effect desorber-resorber absorption cycle

    DOE Patents [OSTI]

    Biermann, Wendell J. (Fayetteville, NY)

    1985-01-01T23:59:59.000Z

    An absorption refrigeration system has an intermediate temperature desorber-resorber pair. A valve between the desorber-resorber pair is modulated to control the capacity for load matching.

  6. Plant variability and bio-fuel properties

    SciTech Connect (OSTI)

    Agblevor, F.A.; Besler-Guran, S.; Wiselogel, A.E. [National Renewable Energy Lab., Golden, CO (United States)

    1995-11-01T23:59:59.000Z

    Thermochemically converting biomass feedstocks to fuels is one of the major thrusts of renewable energy research at the National Renewable Energy Laboratory. Among several thermochemical routes is the fast pyrolysis process which produces liquid fuels from woody and herbaceous biomass feedstocks. Because of the large variability in the composition of biomass feedstocks due to plant variety and environmental factors, it is important to assess how these variabilities affect the properties of thermochemical liquid fuels (bio-oils) produced from these resources. Similar varieties of switchgrass (Panicum virgatum L.) that were grown at three different locations and three hybrid poplar clones that were grown at one location were used in these studies. The feedstocks were pyrolyzed in a fluidized bed reactor at 500{degrees}C. The gas products were analyzed on-line and the liquid products were analyzed for elemental composition and higher heating values. Apart from small difference in the yield of char/ash, the yields of pyrolysis oils and gases were similar for switchgrass feedstocks grown at all three locations. The char/ash yields ranged from 21.1 to 22.9%; total liquids (organic liquids + water) yields ranged from 59%-60.5%; and the gas yields ranged from 11%-12% (wt). The higher heating values (HHVs) of the oils were similar (24.3-24.6 MJ/kg). For the hybrid poplar feedstocks, total liquids (65%-69%), char/ash (10%-11%), and gas yields (15.6%-17%) were similar for all three poplar clones; however, the elemental composition and the HHVs of the pyrolysis oils had statistically significant differences. The NC5260 pyrolysis oils had lower HHV (22.0{+-}0.5 MG/kg) compared to the DN clones (23.2{+-}0.3 MJ/kg). The yields of total liquids and organics for the three clones were higher than those for the switchgrass feedstocks. The gas yields for the hybrid poplar clones were higher than for the switchgrass, but had compositions similar to those of the switchgrass feedstocks.

  7. Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01T23:59:59.000Z

    dual compressor available on the market Compared with the selected building, a more energy efficient building will have lower space cooling and heating

  8. Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01T23:59:59.000Z

    movement toward net zero energy buildings, many technologiesmovement towards net zero energy buildings brings tremendous

  9. Linear rank inequalities on five or more variables

    E-Print Network [OSTI]

    Dougherty, Randall; Zeger, Kenneth

    2009-01-01T23:59:59.000Z

    Ranks of subspaces of vector spaces satisfy all linear inequalities satisfied by entropies (including the standard Shannon inequalities) and an additional inequality due to Ingleton. It is known that the Shannon and Ingleton inequalities generate all such linear rank inequalities on up to four variables, but it has been an open question whether additional inequalities hold for the case of five or more variables. Here we give a list of 24 inequalities which, together with the Shannon and Ingleton inequalities, generate all linear rank inequalities on five variables. We also give a partial list of linear rank inequalities on six variables and general results which produce such inequalities on an arbitrary number of variables; we prove that there are essentially new inequalities at each number of variables beyond four (a result also proved recently by Kinser).

  10. The Coordinated Control of a Central Air Conditioning System Based on Variable Chilled Water Temperature and Variable Chilled Water Flow 

    E-Print Network [OSTI]

    Liu, J.; Mai, Y.; Liu, X.

    2006-01-01T23:59:59.000Z

    energy consumption of chiller and chiller water pump was taken as the objective function of the optimization model. The performance characteristics of a chiller, water pump, regulation valve and pipeline are taken into account, and the optimization...

  11. The Coordinated Control of a Central Air Conditioning System Based on Variable Chilled Water Temperature and Variable Chilled Water Flow

    E-Print Network [OSTI]

    Liu, J.; Mai, Y.; Liu, X.

    2006-01-01T23:59:59.000Z

    energy consumption of chiller and chiller water pump was taken as the objective function of the optimization model. The performance characteristics of a chiller, water pump, regulation valve and pipeline are taken into account, and the optimization...

  12. Integrating Variable Renewable Energy in Electric Power Markets: Best Practices from International Experience, Summary for Policymakers

    SciTech Connect (OSTI)

    Cochran, J.; Bird, L.; Heeter, J.; Arent, D. A.

    2012-04-01T23:59:59.000Z

    Many countries -- reflecting very different geographies, markets, and power systems -- are successfully managing high levels of variable renewable energy on the electric grid, including that from wind and solar energy. This document summarizes policy best practices that energy ministers and other stakeholders can pursue to ensure that electricity markets and power systems can effectively coevolve with increasing penetrations of variable renewable energy. There is no one-size-fits-all approach; each country studied has crafted its own combination of policies, market designs, and system operations to achieve the system reliability and flexibility needed to successfully integrate renewables. Notwithstanding this diversity, the approaches taken by the countries studied all coalesce around five strategic areas: lead public engagement, particularly for new transmission; coordinate and integrate planning; develop rules for market evolution that enable system flexibility; expand access to diverse resources and geographic footprint of operations; and improve system operations. This study also emphatically underscores the value of countries sharing their experiences. The more diverse and robust the experience base from which a country can draw, the more likely that it will be able to implement an appropriate, optimized, and system-wide approach.

  13. White dwarf masses in cataclysmic variables

    E-Print Network [OSTI]

    Wijnen, T P G; Schreiber, M R

    2015-01-01T23:59:59.000Z

    The white dwarf (WD) mass distribution of cataclysmic variables (CVs) has recently been found to dramatically disagree with the predictions of the standard CV formation model. The high mean WD mass among CVs is not imprinted in the currently observed sample of CV progenitors and cannot be attributed to selection effects. Two possibilities have been put forward: either the WD grows in mass during CV evolution, or in a significant fraction of cases, CV formation is preceded by a (short) phase of thermal time-scale mass transfer (TTMT) in which the WD gains a sufficient amount of mass. We investigate if either of these two scenarios can bring theoretical predictions and observations into agreement. We employed binary population synthesis models to simulate the present intrinsic CV population. We incorporated aspects specific to CV evolution such as an appropriate mass-radius relation of the donor star and a more detailed prescription for the critical mass ratio for dynamically unstable mass transfer. We also imp...

  14. A mini-survey for variability in early L dwarfs

    E-Print Network [OSTI]

    F. J. Clarke; B. R. Oppenheimer; C. G. Tinney

    2002-05-27T23:59:59.000Z

    We report differential I-band photometry of four early L-dwarfs obtained to study variability. We detect variability on the timescale of hours in two objects, 2M0746425+200032 (at a level of 0.007 mag -- 6.5 sigma) and 2M1108307+683017 (0.012 mag -- 5 sigma). We also place upper limits of 0.02 mag (1 sigma) on the variability of two others.

  15. Managing Variable Energy Resources to Increase Renewable Electricity's

    E-Print Network [OSTI]

    Managing Variable Energy Resources to Increase Renewable Electricity's Contribution to the Grid P o Contribution of Renewable Energy to Total Electricity Generation? 15 ManaGInG VaRIablE EnERGy REsouRCEs 16 What l i c y m a k e r G u i d e #12;Variable energy resources, such as wind power, now produce about 3

  16. MAS 108 Probability I Continuous random variables Summary

    E-Print Network [OSTI]

    Bailey, R. A.

    when a number is chosen at random from the interval [a,b], with all values equally likely. · p.d.f. f if x > b. · E(X) = (a+b)/2, Var(X) = (b-a)2/12. Normal random variable N(µ,2) (Lindley and Scott, TableMAS 108 Probability I Continuous random variables Summary Uniform random variable U[a,b] · Occurs

  17. The Long Period AM Her-like Cataclysmic Variable RXJ051541+0104.6

    E-Print Network [OSTI]

    F. M. Walter; S. J. Wolk; N. R. Adams

    1994-08-29T23:59:59.000Z

    We report the discovery of a new catacysmic variable system, RXJ051541+0104.6. The optical spectrum has a blue continuum with superposed H~I and He~I and II emission lines. The soft X-ray spectrum is well fit with a 50~eV black body. The X-ray and optical data are suggestive of an AM~Herculis system. The X-ray light curve shows extreme variability on timescales of seconds, and suggests an orbital period of order 8~hours, nearly twice that of the longest catalogued AM~Her period. When bright, the X-ray light curve breaks up into a series of discrete bursts, which may be due to accretion of dense blobs of material of about 10$^{17}$~gm mass.

  18. antibody variable region: Topics by E-print Network

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

    Summary: -seasonal climate variability: simulation and prediction using POAMA-2 Andrew Marshall Debbie Hudson, Matthew management Can POAMA help fill the gap? 12;Background...

  19. Joint Variable Selection for Data Envelope Analysis via Group Sparsity

    E-Print Network [OSTI]

    Irene Song

    2014-02-15T23:59:59.000Z

    highly correlated variables and does not care which one is selected (Zou and Hastie 2005). Hence, an approach ...... Health Services Management. Research ...

  20. Process for applying control variables having fractal structures

    DOE Patents [OSTI]

    Bullock, IV, Jonathan S. (Oak Ridge, TN); Lawson, Roger L. (Oliver Springs, TN)

    1996-01-01T23:59:59.000Z

    A process and apparatus for the application of a control variable having a fractal structure to a body or process. The process of the present invention comprises the steps of generating a control variable having a fractal structure and applying the control variable to a body or process reacting in accordance with the control variable. The process is applicable to electroforming where first, second and successive pulsed-currents are applied to cause the deposition of material onto a substrate, such that the first pulsed-current, the second pulsed-current, and successive pulsed currents form a fractal pulsed-current waveform.

  1. Process for applying control variables having fractal structures

    DOE Patents [OSTI]

    Bullock, J.S. IV; Lawson, R.L.

    1996-01-23T23:59:59.000Z

    A process and apparatus are disclosed for the application of a control variable having a fractal structure to a body or process. The process of the present invention comprises the steps of generating a control variable having a fractal structure and applying the control variable to a body or process reacting in accordance with the control variable. The process is applicable to electroforming where first, second and successive pulsed-currents are applied to cause the deposition of material onto a substrate, such that the first pulsed-current, the second pulsed-current, and successive pulsed currents form a fractal pulsed-current waveform. 3 figs.

  2. 18.112 Functions of a Complex Variable, Fall 2005

    E-Print Network [OSTI]

    Helgason, Sigurdur, 1927-

    The basic properties of functions of one complex variable. Cauchy's theorem, holomorphic and meromorphic functions, residues, contour integrals, conformal mapping. Infinite series and products, the gamma function, the ...

  3. 18.112 Functions of a Complex Variable, Fall 2006

    E-Print Network [OSTI]

    Helgason, Sigurdur, 1927-

    The basic properties of functions of one complex variable. Cauchy's theorem, holomorphic and meromorphic functions, residues, contour integrals, conformal mapping. Infinite series and products, the gamma function, the ...

  4. Polymorphic Typing of Variables and References GEOFFREY SMITH

    E-Print Network [OSTI]

    Smith, Geoffrey

    Polymorphic Typing of Variables and References GEOFFREY SMITH Florida International University reflect the views of the National Science Foundation. Authors' addresses: G. Smith, School of Computer

  5. Variable Charge Soils: Their Mineralogy, Chemistry and Management

    SciTech Connect (OSTI)

    Qafoku, Nik; Van Ranst, Eric; Noble, Andrew; Baert, Geert

    2004-07-01T23:59:59.000Z

    In this article, the mineralogy, chemistry and management of variable charge soils that are spread throughout the world are treated in details.

  6. artritis reumatoide variables: Topics by E-print Network

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

    Summary: Many particle physics analyses which need to discriminate some background process from a signal ignore event-by-event resolutions of kinematic variables. Adding...

  7. algunas variables relacionadas: Topics by E-print Network

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

    Summary: Many particle physics analyses which need to discriminate some background process from a signal ignore event-by-event resolutions of kinematic variables. Adding...

  8. Multiscale modeling of spatially variable water and energy balance processes

    E-Print Network [OSTI]

    Famiglietti, J. S; Wood, E. F

    1994-01-01T23:59:59.000Z

    MULTISCALE WATER AND ENERGY BALANCE MODELING Wood, E. F. ,spatially variable water and energy balance processes J. S.modeling. Water and energy balance models are developed at

  9. atlantic oscillation variability: Topics by E-print Network

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

    human-induced global warming, or a combination of both factors, have been suggested. Several previous studies have discussed observed multidecadal variability in the...

  10. additive genetic variability: Topics by E-print Network

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

    the evolution of centrifugal... pumps and their application. The fundamentals of variable speed centrifugal pump operation are reviewed, then the advantages and evaluation...

  11. antibody variable gene: Topics by E-print Network

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

    in the evolution of centrifugal... pumps and their application. The fundamentals of variable speed centrifugal pump operation are reviewed, then the advantages and evaluation...

  12. antibodies demonstrate variable: Topics by E-print Network

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

    in the evolution of centrifugal... pumps and their application. The fundamentals of variable speed centrifugal pump operation are reviewed, then the advantages and evaluation...

  13. A MONTE CARLO SIMULATION OF WATER FLOW IN VARIABLY ...

    E-Print Network [OSTI]

    1910-10-30T23:59:59.000Z

    Field studies in soils sciences and hydrology during the last two decades have demonstrated extensive variability in saturated and unsaturated hydraulic ...

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

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

    Pump 2013 Peer Review Advanced Variable Speed Air-Source Integrated Heat Pump 2013 Peer Review Emerging Technologies Project for the 2013 Building Technologies Office's Program...

  15. anatomic variables affecting: Topics by E-print Network

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

    of variable impedance prosthetic sockets for trans-tibial amputees : polyjet matrix 3D printing of comfortable prosthetic sockets using digital anatomical data MIT - DSpace...

  16. Optimal combined wind power forecasts using exogeneous variables

    E-Print Network [OSTI]

    Optimal combined wind power forecasts using exogeneous variables Fannar ¨Orn Thordarson Kongens of the thesis is combined wind power forecasts using informations from meteorological forecasts. Lyngby, January

  17. Variability in Ultrasound Education among Emergency Medicine Residencies

    E-Print Network [OSTI]

    Ahern, Matthew; Mallin, Michael P; Weitzel, Scott; Madsen, Troy; Hunt, Pat

    2010-01-01T23:59:59.000Z

    Journal of Emergency Medicine Variability in UltrasoundDivision of Emergency Medicine, 30 South 1500 East Rm1C026,Training in Emergency Medicine Resideny Programs. Acad Emerg

  18. Characterization of proper optimal elements with variable ordering ...

    E-Print Network [OSTI]

    2015-01-14T23:59:59.000Z

    Page 1 ... Vector optimization problems with such variable ordering structures are the topic of this manuscript. .... tions and their relations are the topic of Sect. 3.

  19. Estimation and Control of Diesel Engine Processes Utilizing Variable...

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

    for multi-cylinder variable geometry turbocharged diesel engine with cooled EGR and flexible intake valve actuation developed to capture dynamic effects of gas exchange actuators...

  20. The effects of psychological stress and isometric muscle tension on somatic and cardiovascular variables

    E-Print Network [OSTI]

    Pittenger, David Jett

    1981-01-01T23:59:59.000Z

    is irrelevant (Lynch, Schuri, 5 D'Anna, 1976; Obr1st, Webb, Sutterer 6 Howard, 1970). As a consequence, the effects of potential somatic artifacts on car- diovascular functions during conditioning has been ignored. Early work us1ng infrahumans for autonomic... research with humans has been for the most part limited. The results of current research (eg. Boudewyns, 1976) suggests that psychological and somatic variables are interrelated, and that analysis of changes in the autonomic system must include a study...

  1. Supplemental Simulation Case Studies of Dynamic Evaporator Modeling Paradigms with Variable Fluid Phases 

    E-Print Network [OSTI]

    Rodriguez, E.; Rasmussen, B.

    2015-01-01T23:59:59.000Z

    1Supplemental Simulation Case Studies of Dynamic Evaporator Modeling Paradigms with Variable Fluid Phases Erik Rodriguez1, Bryan Rasmussen2 The purpose of this document is to present a multitude of case studies comparing evaporator modeling... which uses two-phase region density to trigger mass conservative switching. Nine case studies are performed through a combination of three different refrigerants, three different physical system parameters, and three different operating conditions...

  2. Hybrid electromagnetic transient simulation with the state variable representation of HVDC converter plant

    SciTech Connect (OSTI)

    Zavahir, J.M.; Arrillaga, J.; Watson, N.R. (Univ. of Canterbury, Christchurch (New Zealand))

    1993-07-01T23:59:59.000Z

    The two alternative methods in current use for the transient simulation of HVdc power systems are Electromagnetic Transient Programs and State Variable Analysis. A hybrid algorithm is described in this paper which combines the two methods selecting their best features. The relative performances of conventional and hybrid algorithms are discussed. Simulation results of typical back-to back HVdc link show that the hybrid representation provides more stable, accurate and efficient solutions.

  3. Hamiltonian control systems From modeling to analysis and control

    E-Print Network [OSTI]

    Knobloch,Jürgen

    Hamiltonian control systems From modeling to analysis and control Arjan van der Schaft Johann-based modeling 3 Definition of port-Hamiltonian systems 4 Scattering: from power variables to wave variables 5, University of Groningen, the Netherlands DiHamiltonian control systems Elgersburg School, March, 2012 1 / 108

  4. ELEG620: Solar Electric Systems University of Delaware, ECE Spring 2008 C. Honsberg PV System Components

    E-Print Network [OSTI]

    Honsberg, Christiana

    · Batteries required if (1) load profile solar radiation profile and (2) to mitigate effect of variability · PV System components: ­ PV Modules ­ Batteries ­ Power Conditioning ­ Loads ­ Balance of systems #12

  5. Mass Market Demand Response and Variable Generation Integration Issues: A Scoping Study

    SciTech Connect (OSTI)

    Cappers, Peter; Mills, Andrew; Goldman, Charles; Wiser, Ryan; Eto, Joseph H.

    2011-09-10T23:59:59.000Z

    This scoping study focuses on the policy issues inherent in the claims made by some Smart Grid proponents that the demand response potential of mass market customers which is enabled by widespread implementation of Advanced Metering Infrastructure (AMI) through the Smart Grid could be the “silver bullet” for mitigating variable generation integration issues. In terms of approach, we will: identify key issues associated with integrating large amounts of variable generation into the bulk power system; identify demand response opportunities made more readily available to mass market customers through widespread deployment of AMI systems and how they can affect the bulk power system; assess the extent to which these mass market Demand Response (DR) opportunities can mitigate Variable Generation (VG) integration issues in the near-term and what electricity market structures and regulatory practices could be changed to further expand the ability for DR to mitigate VG integration issues over the long term; and provide a qualitative comparison of DR and other approaches to mitigate VG integration issues.

  6. Indian Monsoon Depression: Climatology and Variability

    SciTech Connect (OSTI)

    Yoon, Jin-Ho; Huang, Wan-Ru (Judy) [Judy

    2012-03-09T23:59:59.000Z

    The monsoon climate is traditionally characterized by large seasonal rainfall and reversal of wind direction (e.g., Krishnamurti 1979). Most importantly this rainfall is the major source of fresh water to various human activities such as agriculture. The Indian subcontinent resides at the core of the Southeast Asian summer monsoon system, with the monsoon trough extended from northern India across Indochina to the Western Tropical Pacific (WTP). Large fraction of annual rainfall occurs during the summer monsoon season, i.e., June - August with two distinct maxima. One is located over the Bay of Bengal with rainfall extending northwestward into eastern and central India, and the other along the west coast of India where the lower level moist wind meets the Western Ghat Mountains (Saha and Bavardeckar 1976). The rest of the Indian subcontinent receives relatively less rainfall. Various weather systems such as tropical cyclones and weak disturbances contribute to monsoon rainfall (Ramage 1971). Among these systems, the most efficient rain-producing system is known as the Indian monsoon depression (hereafter MD). This MD is critical for monsoon rainfall because: (i) it occurs about six times during each summer monsoon season, (ii) it propagates deeply into the continent and produces large amounts of rainfall along its track, and (iii) about half of the monsoon rainfall is contributed to by the MDs (e.g., Krishnamurti 1979). Therefore, understanding various properties of the MD is a key towards comprehending the veracity of the Indian summer monsoon and especially its hydrological process.

  7. Real-Time Dispatchability of Bulk Power Systems with Volatile ...

    E-Print Network [OSTI]

    2015-03-16T23:59:59.000Z

    the concept of real-time dispatchability (RTDA) of power systems with variable energy resources .... eration control, economic dispatch and unit commitment. Ref

  8. optimization of discrete control systems with varying structure

    E-Print Network [OSTI]

    xx

    2004-12-16T23:59:59.000Z

    (in russian). 4. Mansimov, K.B., Maharramov, Sh.F.: Necessary conditions of optimality for discrete system with variable structure and rolling right end of the path.

  9. Compatible and Cost-Effective Fault Diagnostic Solutions for...

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

    Unit-Constant Air Volume Systems - 2014 BTO Peer Review Presenter: Jin Wen, Drexel University The goal of this project is to develop and demonstrate a library of diagnostics...

  10. Variable current speed controller for eddy current motors

    DOE Patents [OSTI]

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

    1982-03-12T23:59:59.000Z

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

  11. Electron cyclotron emission spectrometry on the Tokamak a Configuration Variable

    SciTech Connect (OSTI)

    Klimanov, I.; Porte, L.; Alberti, S.; Blanchard, P.; Fasoli, A.; Goodman, T.P. [Centre de Recherches en Physique des Plasmas (CRPP), Association EURATOM-Confederation Suisse, Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015, Lausanne (Switzerland)

    2005-09-15T23:59:59.000Z

    Electron cyclotron emission (ECE) measurements are an important component of the diagnostic suite on the Tokamak a Configuration Variable (TCV) [F. Hoffman et al., Plasma Phys. Controlled Fusion 36, B277 (1994)]. A recently installed, 24-channel dual-conversion heterodyne radiometer covering the radio frequency range 65-100 GHz and viewing from the low-field side (LFS) of the tokamak greatly enhances the system and, in combination with an existing radiometer viewing from the high-field side (HFS), allows simultaneous measurements of emission from the HFS and LFS. In addition, the new radiometer has multiple lines of sight that can receive the emission perpendicular to the toroidal magnetic field as well as with a finite k{sub parallel} (wave vector parallel to magnetic field). Such flexibility allows the LFS radiometer to make standard measurements of thermal emission and nonstandard measurements of nonthermal, anisotropic emission. The toroidal line of sight allows access to overdense plasma via mode converted emission. The enhanced ECE diagnostic is described and examples of measurements made in various configurations are presented.

  12. Feasibility of wavelet expansion methods to treat the energy variable

    SciTech Connect (OSTI)

    Van Rooijen, W. F. G. [Research Inst. of Nuclear Engineering, Univ. of Fukui, Kanawa-cho 1-2-4, 914-0055, Fukui-ken, Tsuruga-shi (Japan)

    2012-07-01T23:59:59.000Z

    This paper discusses the use of the Discrete Wavelet Transform (DWT) to implement a functional expansion of the energy variable in neutron transport. The motivation of the work is to investigate the possibility of adapting the expansion level of the neutron flux in a material region to the complexity of the cross section in that region. If such an adaptive treatment is possible, 'simple' material regions (e.g., moderator regions) require little effort, while a detailed treatment is used for 'complex' regions (e.g., fuel regions). Our investigations show that in fact adaptivity cannot be achieved. The most fundamental reason is that in a multi-region system, the energy dependence of the cross section in a material region does not imply that the neutron flux in that region has a similar energy dependence. If it is chosen to sacrifice adaptivity, then the DWT method can be very accurate, but the complexity of such a method is higher than that of an equivalent hyper-fine group calculation. The conclusion is thus that, unfortunately, the DWT approach is not very practical. (authors)

  13. ANALYSIS OF VARIABILITY IN PRECASTING AND INSTALLATION OF PILE FOUNDATIONS

    E-Print Network [OSTI]

    Tommelein, Iris D.

    1 ANALYSIS OF VARIABILITY IN PRECASTING AND INSTALLATION OF PILE FOUNDATIONS Hasan Kaplan1-stressed precast foundation piles using data collected on a building project that comprised the installation of more than 340 piles. The objective is to assess the presence of product and process variability

  14. EQUIVALENCE RELATIONS FOR TWO VARIABLE REAL ANALYTIC FUNCTION GERMS

    E-Print Network [OSTI]

    EQUIVALENCE RELATIONS FOR TWO VARIABLE REAL ANALYTIC FUNCTION GERMS SATOSHI KOIKE & ADAM PARUSI´NSKI Abstract. For two variable real analytic function germs we compare the blow- analytic equivalence in the sense of Kuo to the other natural equivalence relations. Our main theorem states that C1 equivalent

  15. Indifference fee rate for variable annuities Etienne CHEVALIER

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Introduced in the 1970s in the United States (see [22]), variable annuities are equity-linked contractsIndifference fee rate for variable annuities Etienne CHEVALIER Thomas LIM Ricardo ROMO ROMERO method for indifference fees. We focus on the guaranteed minimum death benefits and the guaranteed

  16. Density regulation in annual plant communities under variable resource levels

    E-Print Network [OSTI]

    Novoplansky, Ariel

    Density regulation in annual plant communities under variable resource levels Hagit Shilo. E. and Turkington, R. 2005. Density regulation in annual plant communities under variable resource levels. Á/ Oikos 108: 241Á/252. Density regulation is assumed to be common, but is very rarely tested

  17. Truss topology design with integer variables made easy*

    E-Print Network [OSTI]

    2010-05-12T23:59:59.000Z

    conditions depending both on the state variable (displacement) and the design variable. (thickness). ..... t = double(t); pic(par,t);. The SDP code used in all our .... finished PLATO-N project (see project website www.plato-n.org for details).

  18. A Variable Cell Model for Simulating Gas Condensate Reservoir Performance

    E-Print Network [OSTI]

    Al-Majed, Abdulaziz Abdullah

    maturation profiles, which ie exhibitpd when gas pressure. Between this region near tha wellbore, SPE-~~~ SPE 21428 A Variable Cell Model for Simulating Gas Condensate Reservoir Performance A of depletion performance of gas condensate reservoirs report the existence of a A variable cell model

  19. Interannual variability of photosynthesis across Africa and its attribution

    E-Print Network [OSTI]

    Collett Jr., Jeffrey L.

    Interannual variability of photosynthesis across Africa and its attribution Christopher A. Williams of photosynthesis across the African continent during the period 1982­2003. Acute soil water stress emerges as the primary factor driving interannual variability of photosynthesis for most of Africa. Southern savannas

  20. RESEARCH ARTICLE Empirical assessment of short-term variability from

    E-Print Network [OSTI]

    -term variability; PV plant ramp rate; daily aggregate ramp rate; inverter shells *Correspondence Rob van HaarenRESEARCH ARTICLE Empirical assessment of short-term variability from utility-scale solar PV plants and the output from 390 inverters. We use a simple metric, "daily aggregate ramp rate" to quantify, categorize

  1. Wave spectral energy variability in the northeast Peter D. Bromirski

    E-Print Network [OSTI]

    Bromirski, Peter D.

    January 2005; published 8 March 2005. [1] The dominant characteristics of wave energy variability of monthly wave energy anomalies reveal that all three wave energy components exhibit similar patterns of spatial variability. The dominant mode represents coherent heightened (or diminished) wave energy along

  2. Variability of hot mix asphalt produced with reclaimed asphalt pavement

    E-Print Network [OSTI]

    Yang, Guiqin

    1999-01-01T23:59:59.000Z

    percent does not significantly influence the mix variability; it is desirable to use a large percentage of RAP in the Type S-I mix, i.e., more than 40% RAP; iii) On the average, the aggregate variability increases after transportation and stockpiling...

  3. Testing Dependence Among Serially Correlated Multi-category Variables

    E-Print Network [OSTI]

    Pesaran, M Hashem; Timmermann, Allan

    Testing Dependence Among Serially Correlated Multi-category Variables M. Hashem Pesaran and Allan Timmermann July 2006 CWPE 0648 Testing Dependence Among Serially Correlated... Multi-category Variables? M. Hashem Pesaran Cambridge University Allan Timmermann University of California, San Diego July 3, 2006 ?We benefitted from the comments of Herman van Dijk and Adrian Pagan and from participants at the Econometric Institute...

  4. Ground surface temperatures in Canada: Spatial and temporal variability

    E-Print Network [OSTI]

    Long, Bernard

    show that the ground has warmed about 0.7 K in the last 100 years. Spatial variability is significant temperatures in Canada: Spatial and temporal variability, Geophys. Res. Lett., 30(10), 1499, doi:10.1029/2003GL inferred from geothermal data have shown that the study of perturbations to the Earth's energy balance

  5. Simulation and characterization of the Adriatic Sea mesoscale variability

    E-Print Network [OSTI]

    Cushman-Roisin, Benoit

    Simulation and characterization of the Adriatic Sea mesoscale variability Benoit Cushman-Roisin,1 resolve the mesoscale variability because the grid size falls below the first baroclinic deformation in two larger-scale models. The present simulations demonstrate that the DieCAST model allows mesoscale

  6. Solar activity and earth rotation variability R. Abarca del Rioa,

    E-Print Network [OSTI]

    Dai, Aiguo

    to secular times scales, meteorological and climatic data are correlated with solar variability (see reviews changes in solar output could be amplified in the Earth's atmosphere. In fact, at wavelengths not visibleSolar activity and earth rotation variability R. Abarca del Rioa, *, D. Gambisb , D. Salsteinc , P

  7. American Institute of Aeronautics and Astronautics Fluidic Variable Inertia Flywheel

    E-Print Network [OSTI]

    Van de Ven, James D.

    American Institute of Aeronautics and Astronautics 1 Fluidic Variable Inertia Flywheel James D. Van for many applications from hybrid vehicles to off-peak electric power to rotating machinery. A flywheel. This work proposes a novel self-governing fluidic variable inertia flywheel that can maintain a constant

  8. STOCHASTIC VARIABILITY IN X-RAY EMISSION FROM THE BLACK HOLE BINARY GRS 1915+105

    SciTech Connect (OSTI)

    Polyakov, Yuriy S. [USPolyResearch, Ashland, PA 17921 (United States); Neilsen, Joseph [MIT Kavli Institute for Astrophysics and Space Research, Cambridge, MA 02139 (United States); Timashev, Serge F., E-mail: ypolyakov@uspolyresearch.com [Karpov Institute of Physical Chemistry, Moscow 103064 (Russian Federation)

    2012-06-15T23:59:59.000Z

    We examine stochastic variability in the dynamics of X-ray emission from the black hole system GRS 1915+105, a strongly variable microquasar commonly used for studying relativistic jets and the physics of black hole accretion. The analysis of sample observations for 13 different states in both soft (low) and hard (high) energy bands is performed by flicker-noise spectroscopy (FNS), a phenomenological time series analysis method operating on structure functions and power spectrum estimates. We find the values of FNS parameters, including the Hurst exponent, flicker-noise parameter, and characteristic timescales, for each observation based on multiple 2500 s continuous data segments. We identify four modes of stochastic variability driven by dissipative processes that may be related to viscosity fluctuations in the accretion disk around the black hole: random (RN), power-law (1F), one-scale (1S), and two-scale (2S). The variability modes are generally the same in soft and hard energy bands of the same observation. We discuss the potential for future FNS studies of accreting black holes.

  9. Device-Independent Quantum Cryptography for Continuous Variables

    E-Print Network [OSTI]

    Kevin Marshall; Christian Weedbrook

    2014-05-27T23:59:59.000Z

    We present the first device-independent quantum cryptography protocol for continuous variables. Our scheme is based on the Gottesman-Kitaev-Preskill encoding scheme whereby a qubit is embedded in the infinite-dimensional space of a quantum harmonic oscillator. The novel application of discrete-variable device-independent quantum key distribution to this encoding enables a continuous-variable analogue. Since the security of this protocol is based on discrete-variables we inherit by default security against collective attacks and, under certain memoryless assumptions, coherent attacks. We find that our protocol is valid over the same distances as its discrete-variable counterpart, except that we are able to take advantage of high efficiency commercially available detectors where, for the most part, only homodyne detection is required. This offers the potential of removing the difficulty in closing the loopholes associated with Bell inequalities.

  10. Mythical Maia, ultrashort and 53 PSC variables. Lecture 4

    SciTech Connect (OSTI)

    Cox, A.N.

    1983-03-14T23:59:59.000Z

    Moving down the main sequence from the ..beta.. Cephei variables, we come to later B-type stars. The suspicion of variability for these stars goes back to Vogel in 1891 who studied the radial velocities of Vega. Since that time there have been numerous studies of Vega (Wisniewski and Johnson 1979, Fernie 1981) and other B and early A stars which hint at variability in both radial velocity and light. Since Struve (1955) discussed these stars 28 years ago, they have been called the Maia stars after the Pleiades star that he thought was the prototype. The uncertainty in their actual variability has led Breger (1980) to call them the mythical Maia variables.

  11. Two-state on-off intermittency caused by unstable dimension variability in periodically forced drift waves

    SciTech Connect (OSTI)

    Galuzio, P. P.; Lopes, S. R.; Viana, R. L. [Departamento de Fisica, Universidade Federal do Parana, Caixa Postal 19044, 81531-990 Curitiba, Parana (Brazil)

    2011-11-15T23:59:59.000Z

    Certain high-dimensional dynamical systems present two or more attractors characterized by different energy branches. For some parameter values the dynamics oscillates between these two branches in a seemingly random fashion, a phenomenon called two-state on-off intermittency. In this work we show that the dynamical mechanism underlying this intermittency involves the severe breakdown of hyperbolicity of the attractors through a mechanism known as unstable dimension variability. We characterize the parametric evolution of this variability using statistical properties of the finite-time Lyapunov exponents. As a model system that exhibits this behavior we consider periodically forced and damped drift waves. In this spatiotemporal example there is a low-dimensional chaotic attractor that is created by an interior crisis, already presenting unstable dimension variability.

  12. Solar Reserve Methodology for Renewable Energy Integration Studies Based on Sub-Hourly Variability Analysis: Preprint

    SciTech Connect (OSTI)

    Ibanez, E.; Brinkman, G.; Hummon, M.; Lew, D.

    2012-08-01T23:59:59.000Z

    Increasing penetrations of wind a solar energy are raising concerns among electric system operators because of the variability and uncertainty associated with power sources. Previous work focused on the quantification of reserves for systems with wind power. This paper presents a new methodology that allows the determination of necessary reserves for high penetrations of photovoltaic (PV) power and compares it to the wind-based methodology. The solar reserve methodology is applied to Phase 2 of the Western Wind and Solar Integration Study. A summary of the results is included.

  13. A New Bifurcation Analysis for Power System Dynamic Voltage Stability Studies

    E-Print Network [OSTI]

    a specific system configuration and the operation condition. For a power system, the typical state variables are the time dependent generator voltages (For different generator models, the variables of generator voltages as the variables of the exciter, speed governor and so on; sometimes the dynamics of the load behavior will also

  14. Flare System Optimization

    E-Print Network [OSTI]

    Aegerter, R.

    Flare losses are typically the largest source of variable losses in a refinery or chemical plant. Since most plant flare systems are complex, there can be many opportunities to reduce costs. Losses to the flare can include process gases, fuel gas...

  15. VARIABILITY OF KD VALUES IN CEMENTITIOUS MATERIALS AND SEDIMENTS

    SciTech Connect (OSTI)

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

    2012-02-02T23:59:59.000Z

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

  16. THE BERLIN EXOPLANET SEARCH TELESCOPE II CATALOG OF VARIABLE STARS. I. CHARACTERIZATION OF THREE SOUTHERN TARGET FIELDS

    SciTech Connect (OSTI)

    Fruth, T.; Cabrera, J.; Csizmadia, Sz.; Dreyer, C.; Eigmüller, P.; Erikson, A.; Kabath, P.; Kirste, S.; Pasternacki, T.; Rauer, H.; Titz-Weider, R. [Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt, Rutherfordstr. 2, D-12489 Berlin (Germany); Chini, R.; Lemke, R. [Astronomisches Institut, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Murphy, M., E-mail: thomas.fruth@dlr.de [Departamento de Física, Universidad Católica del Norte, P.O. 1280, Antofagasta (Chile)

    2013-11-01T23:59:59.000Z

    A photometric survey of three southern target fields with BEST II yielded the detection of 2406 previously unknown variable stars and an additional 617 stars with suspected variability. This study presents a catalog including their coordinates, magnitudes, light curves, ephemerides, amplitudes, and type of variability. In addition, the variability of 17 known objects is confirmed, thus validating the results. The catalog contains a number of known and new variables that are of interest for further astrophysical investigations, in order to, e.g., search for additional bodies in eclipsing binary systems, or to test stellar interior models. Altogether, 209,070 stars were monitored with BEST II during a total of 128 nights in 2009/2010. The overall variability fraction of 1.2%-1.5% in these target fields is well comparable to similar ground-based photometric surveys. Within the main magnitude range of R in [11, 17], we identify 0.67(3)% of all stars to be eclipsing binaries, which indicates a completeness of about one third for this particular type in comparison to space surveys.

  17. Active optical zoom system

    DOE Patents [OSTI]

    Wick, David V.

    2005-12-20T23:59:59.000Z

    An active optical zoom system changes the magnification (or effective focal length) of an optical imaging system by utilizing two or more active optics in a conventional optical system. The system can create relatively large changes in system magnification with very small changes in the focal lengths of individual active elements by leveraging the optical power of the conventional optical elements (e.g., passive lenses and mirrors) surrounding the active optics. The active optics serve primarily as variable focal-length lenses or mirrors, although adding other aberrations enables increased utility. The active optics can either be LC SLMs, used in a transmissive optical zoom system, or DMs, used in a reflective optical zoom system. By appropriately designing the optical system, the variable focal-length lenses or mirrors can provide the flexibility necessary to change the overall system focal length (i.e., effective focal length), and therefore magnification, that is normally accomplished with mechanical motion in conventional zoom lenses. The active optics can provide additional flexibility by allowing magnification to occur anywhere within the FOV of the system, not just on-axis as in a conventional system.

  18. Abstract--this paper proposes a MIMO linear quadratic regulator (LQR) controller designed for a horizontal variable

    E-Print Network [OSTI]

    Boyer, Edmond

    with the trade-off between the wind energy conversion maximization and the minimization of the fatigue Tipical wind turbine power curve Therefore, in this regime, the system is multivariable and multi for a horizontal variable speed wind turbine with focus on the operating range referring to the above rated wind

  19. Task Modeling in Imitation Learning using Latent Variable Models Carl Henrik Ek, Dan Song, Kai Huebner and Danica Kragic

    E-Print Network [OSTI]

    Ek, Carl Henrik

    in the sensorimotor systems, [4] proposed a coherent control, trajectory optimization, and action planningTask Modeling in Imitation Learning using Latent Variable Models Carl Henrik Ek, Dan Song, Kai about different manipulation tasks from scene observations. In this paper we present a probabilistic

  20. Radiometric Correctionradiometric correction Radiometric correction is important to ensure that terrestrial variables retrieved from optical satellite sensor

    E-Print Network [OSTI]

    Coburn, Craig

    that terrestrial variables retrieved from optical satellite sensor systems are calibrated to a common physical interactions. Radiometric corrections of optical sensor data consider sensor radiometric calibration, surface reflectance propagated through the atmosphere to the satellite sensor. Given that the optical properties