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


1

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

E-Print Network [OSTI]

??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… (more)

Kimla, John

2010-01-01T23:59:59.000Z

2

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

E-Print Network [OSTI]

Volume Systems.? Proceedings of ACEEE 1994 Summer Study on Energy Efficiency in Buildings, Vol. 5, pp. 219-223. 3. Liu M., Zhu Y., Claridge D.E., and White E., 1997. ?Impact of Static Pressure Set Level on HVAC Energy Consumption and Indoor... developed to ensure the air delivery to each space or zone. These methods include the static pressure control method and the damper position control method. The static pressure control method maintains a sufficient static pressure in the main duct...

Liu, M.

2002-01-01T23:59:59.000Z

3

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

E-Print Network [OSTI]

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 ...

Blum, David H. (David Henry)

2013-01-01T23:59:59.000Z

4

CALIFORNIA ENERGY Advanced Variable Air Volume  

E-Print Network [OSTI]

on VAV airside system design. Total large office building energy savings of up to 12% are achievable and controls for commercial buildings and in performing peer reviews of mechanical designs of commercial was developed as part of the Integrated Energy Systems -- Productivity and Building Science project, a Public

5

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

E-Print Network [OSTI]

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...

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

2007-01-01T23:59:59.000Z

6

Improved Air Volume Control Logic for VAV Systems  

E-Print Network [OSTI]

position of the terminal boxes. This method is called air volume control logic. Under this control logic, terminal box airflow requirements are met with reduced static pressure. Fan power consumption is minimized. However, the actual system performance also...

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

2000-01-01T23:59:59.000Z

7

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

E-Print Network [OSTI]

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...

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

2006-01-01T23:59:59.000Z

8

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

E-Print Network [OSTI]

The supply air temperature set point for a singleduct constant air volume air handling unit (AHU) system is often reset based on either return air temperature or outside air temperature in order to reduce simultaneous cooling and heating energy...

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

2002-01-01T23:59:59.000Z

9

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

E-Print Network [OSTI]

.Hourlyairflowrequirements, part-load fan characteristics, and duct static pressure control are incorporated into the problem airflow. Fan power is also influ- enced if static pressure at the end of the longest duct line for effective, energy-efficient, and comfortable heating, ventilat- ing, and air-conditioning (HVAC) systems

10

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

E-Print Network [OSTI]

The lecture hall of the Richardson Petroleum Building at Texas A&M University is a large lecture hall, with a total floor area of approximately 2500 ft^2. The lecture hall was served by a constant air volume (CAV) air handling unit (AHU) which had...

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

2000-01-01T23:59:59.000Z

11

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

SciTech Connect (OSTI)

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

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

2013-01-24T23:59:59.000Z

12

A study on static pressure reset and instability in variable air volume HVAC systems.  

E-Print Network [OSTI]

??This project began with testing five different versions of supply duct static pressure reset strategies that fall into two general categories: Proportional plus Integral control… (more)

Housholder, Brian Wayne

2011-01-01T23:59:59.000Z

13

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

E-Print Network [OSTI]

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...

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

2003-01-01T23:59:59.000Z

14

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

E-Print Network [OSTI]

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...

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

2003-01-01T23:59:59.000Z

15

System dynamics based models for selecting HVAC systems for office buildings: a life cycle assessment from carbon emissions perspective.  

E-Print Network [OSTI]

??This study aims to explore the life cycle environmental impacts of typical heating ventilation and air condition (HVAC) systems including variable air volume (VAV) system,… (more)

Chen, S

2011-01-01T23:59:59.000Z

16

An evaluation of a prototype laboratory fume hood for use in a variable air volume, face velocity reducing system  

E-Print Network [OSTI]

) 108 ( 8. 591) 76 ( 65. 101) 113 ( 14. 450) ill ( 8. 977) 111 ( 9. 934) 129 ( 18. 786) 120 ( 41. 070) 115 ( 20. 011) Run 2 Average Face Velocity, FPM, (Standard Deviation) 121 ( 21. 774) 113 ( 16. 257) 93 ( 22. 040) 118 ( 20. 418) 97... ( 35. 694) 110 ( 24. 857) 127 ( 10. 134) 97 ( 17. 972) 101 ( 14. 036) 99 ( 24. 976) 102 ( 15. 183) 96 ( 27. 524) 100 ( 17. 483) 121 ( 20. 246) 108 ( 17. 072) Run 2 Average Face Velocity, FPM, (Standard Deviation) OFF OFF OFF OFF 119...

Vickery, Cynthia Schoonmaker

2012-06-07T23:59:59.000Z

17

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

E-Print Network [OSTI]

. As the commissioning process has begun to require the prediction of savings, knowledge of the extent to which various SPR control strategies impact fan energy has become increasingly important. This research aims to document existing SPR control strategies and utilize...

Kimla, John

2010-07-14T23:59:59.000Z

18

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

E-Print Network [OSTI]

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 ...

DeSimone, Mark

1995-01-01T23:59:59.000Z

19

Cooperative Control of Air Flow for HVAC Systems  

E-Print Network [OSTI]

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

Shuai, Liu; Lihua, Xie

2013-01-01T23:59:59.000Z

20

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]

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...

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

2007-01-01T23:59:59.000Z

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


21

Commissioning and Diagnosis of VAV Air-Conditioning Systems  

E-Print Network [OSTI]

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...

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

2006-01-01T23:59:59.000Z

22

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

E-Print Network [OSTI]

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...

Fan, Wenshu

2009-05-15T23:59:59.000Z

23

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]

by the work environment and the work practices of those using the hood. Burton complied the following table, illustrating past and current recommendations from various agencies, yet recommends 100 feet per minute [FPM] along with good work practices.... " ' ~Oi t Recommended Face Velocit FPM American National Standards Institute (ANSI), Z9. 5, 1992 80-120 American Conference of Governmental Industrial Hygienists (ACGIH) 60-100 National Institute for Occupational Safety and Health (NIOSH) 100...

Lacey, Steven Edward

2012-06-07T23:59:59.000Z

24

Variable buoyancy system metric  

E-Print Network [OSTI]

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, ...

Jensen, Harold Franklin

2009-01-01T23:59:59.000Z

25

Variable frequency microwave furnace system  

DOE Patents [OSTI]

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).

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

1994-01-01T23:59:59.000Z

26

Variable frequency microwave furnace system  

DOE Patents [OSTI]

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.

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

1994-06-14T23:59:59.000Z

27

E-Print Network 3.0 - air volume air Sample Search Results  

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

Use Summary: pressure, and for modeling the change in system pressure as function of compressed air storage volume... important system variables such as system pressure and...

28

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...

29

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

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

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

30

Variable pressure power cycle and control system  

DOE Patents [OSTI]

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.

Goldsberry, Fred L. (Spring, TX)

1984-11-27T23:59:59.000Z

31

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,...

32

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

E-Print Network [OSTI]

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...

Liu, G.; Mingsheng, L.

2006-01-01T23:59:59.000Z

33

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

E-Print Network [OSTI]

for the series and parallel units, with coefficients varying by size and manufacturer. Statistical modeling utilized SAS software (2002). Fan power and airflow data were collected at downstream static pressures over a range from 0.1 to 0.5 in. w.g. (25 to 125 Pa...

Furr, James C., Jr

2007-09-17T23:59:59.000Z

34

Variable temperature seat climate control system  

DOE Patents [OSTI]

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.

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

35

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

E-Print Network [OSTI]

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.

2012-01-01T23:59:59.000Z

36

Implementation of the Laboratory Air Handling Unit Systems (LAHU)  

E-Print Network [OSTI]

Implementation of the Laboratory Air Handling Unit Systems (LAHU) Y. Cui Graduate Student Energy Systems Laboratory University of Nebraska-Lincoln Omaha, NE, USA M. Liu, Ph.D., P.E. Associate Professor Energy Systems Laboratory...-around coils [18, 19], the variable air volume (VAV) fume hoods [8-16] and the usage-based control devices (UBC) [17]. These measures have effectively reduced the cooling energy, preheat energy and fan power consumption, and sometime, improved indoor...

Cui, Y.; Liu, M.; Conger, K.

2003-01-01T23:59:59.000Z

37

ASSESSMENT OF VARIABLE EFFECTS OF SYSTEMS WITH DEMAND RESPONSE RESOURCES  

E-Print Network [OSTI]

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

Gross, George

38

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

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

th , 2012 Two-Stage Variable Compression Ratio (VCR) System to Increase Efficiency in Gasoline Powertrains DEER Conference 2012 D. Tomazic, H. Kleeberg, S. Bowyer, FEV Inc. J....

39

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

E-Print Network [OSTI]

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

Hong, Tainzhen

2010-01-01T23:59:59.000Z

40

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

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


41

Quantifying the Variable Effects of Systems with Demand Response Resources  

E-Print Network [OSTI]

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

Gross, George

42

Burner Designs and Controls for Variable Air Preheat Systems  

E-Print Network [OSTI]

and batch type melting operations resulting in cyclic or variable air preheat temperatures will be discussed. Fuel savings relating to the use of recuperation and various types of fuel/air ratio systems will also be discussed....

Lied, C. R.

1981-01-01T23:59:59.000Z

43

Variable emissivity laser thermal control system  

DOE Patents [OSTI]

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.

Milner, J.R.

1994-10-25T23:59:59.000Z

44

Commercial thermal distribution systems, Final report for CIEE/CEC  

E-Print Network [OSTI]

air-volume HVAC systems, static pressures across theIn VAY HVAC systems, the static pressures may likely changefor the Static Pressure Analysis Tool are: • HVAC schedule

Xu, T.

2011-01-01T23:59:59.000Z

45

Measuring Advances in HVAC Distribution System Design  

SciTech Connect (OSTI)

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.

Franconi, E.

1998-05-01T23:59:59.000Z

46

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

E-Print Network [OSTI]

LBNL-58636 Best Practices for Energy Efficient Cleanrooms Efficient HVAC Systems: Variable Efficient Cleanrooms Efficient HVAC Water Systems: Variable-Speed-Drive Chillers Tengfang Xu Contents HVAC.................................................................................................................................... 6 #12;HVAC Water Systems Variable-Speed-Drive Chillers Summary Cleanroom energy benchmarking data

47

Electromagnetic variable degrees of freedom actuator systems and methods  

DOE Patents [OSTI]

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.

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

2009-02-17T23:59:59.000Z

48

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

E-Print Network [OSTI]

variability. However, with the increased penetration of renewable-based generation, operational uncertainty by variability in the system supply side. Operational uncertainty is not new to power systems, e.g., demand]. For example, the highly variable nature of wind speeds not only makes the wind resource highly intermittent

Liberzon, Daniel

49

Kinematic Reduction and Planning using Symmetry for a Variable Inertia Mechanical System  

E-Print Network [OSTI]

reduction [11][7] using the system's symmetry for a simple mechanical system called the Yaw model (see FigKinematic Reduction and Planning using Symmetry for a Variable Inertia Mechanical System Ravi present controllability results and kinematic reduction for a variable inertia mechanical system. We show

50

High Temperature Variable Conductance Heat Pipes for Radioisotope Stirling Systems  

SciTech Connect (OSTI)

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.

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

51

Sliding Mode Power Control of Variable Speed Wind Energy Conversion Systems  

E-Print Network [OSTI]

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 (National Renewable Energy Laboratory) wind turbine simulator FAST (Fatigue, Aerodynamics, Structures

Boyer, Edmond

52

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

E-Print Network [OSTI]

with multiple variable-speed pumps in parallel is to minimize the pump system energy consumption by controlEnergy Efficient Control of a Boosting System with Multiple Variable-Speed Pumps in Parallel Zhenyu. The experimental results show a huge potential to improve the energy efficiency of multi-pump systems using

Yang, Zhenyu

53

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]

ESL-TR-91/12-03 ENERGY SYSTEMS LABORATORY TECHNICAL REPORT REPRINTED WITH PERMISSION Simulation of the Post-Retrofit Thermal Energy Use for the University Teaching Center (UTC) Building with the Use of Simplified System Models Srinivas Katipamula, P.... Texas 77843 (409) 845-6402. or (409) 845-3251 INTRODUCTION 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...

Katipamula, S.; Claridge, D. E.

1991-01-01T23:59:59.000Z

54

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

DOE Patents [OSTI]

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.

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

2013-10-22T23:59:59.000Z

55

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

E-Print Network [OSTI]

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...

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

2002-01-01T23:59:59.000Z

56

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

E-Print Network [OSTI]

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...

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

2006-01-01T23:59:59.000Z

57

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

DOE Patents [OSTI]

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

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

1984-01-01T23:59:59.000Z

58

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

DOE Patents [OSTI]

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

Frank, A.A.

1984-07-10T23:59:59.000Z

59

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

E-Print Network [OSTI]

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...

Zhu, H.

2006-01-01T23:59:59.000Z

60

CIP methods for hyperbolic system with variable and discontinuous coefficient  

E-Print Network [OSTI]

We propose a multi-moment method for one-dimensional hyperbolic equations with smooth coefficient and piecewise constant coefficient. The method is entirely based on the backward characteristic method and uses the solution and its derivative as unknowns and cubic Hermite interpolation for each computational cell. The exact update formula for solution and its derivative is derived and used for an efficient time integration. At points of discontinuity of wave speed we define a piecewise cubic Hermite interpolation based on immersed interface method. The method is extended to the one-dimensional Maxwell's equations with variable material properties.

Ito, Kazufumi

2011-01-01T23:59:59.000Z

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


61

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

E-Print Network [OSTI]

of the incoming radiation or energy budget noise variability at the surface. Conversely, soil heat flux is shown on the influence of landsurface energy budget errors on the soilABL system. Other numerical studiesHarmonic propagation of variability in surface energy balance within a coupled

Gentine, Pierre

62

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

E-Print Network [OSTI]

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

Liberzon, Daniel

63

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

E-Print Network [OSTI]

For many modem buildings, the chilled water loops and risers are equipped with variable speed pumping systems. How to quickly balance the loop or riser to satisfy the cooling requirement and reduce energy consumption is a very interesting topic...

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

2000-01-01T23:59:59.000Z

64

Entanglement criteria and nonlocality for multimode continuous-variable systems RID B-8901-2008  

E-Print Network [OSTI]

We demonstrate how to efficiently derive a broad class of inequalities for entanglement detection in multimode continuous variable systems. The separability conditions are established from partial transposition (PT) in combination with several...

Sun, Qingqing; Nha, Hyunchul; Zubairy, M. Suhail

2009-01-01T23:59:59.000Z

65

Analysis and Simulation of Mechanical Trains Driven by Variable Frequency Drive Systems  

E-Print Network [OSTI]

Induction motors and Variable Frequency Drives (VFDs) are widely used in industry to drive machinery trains. However, some mechanical trains driven by VFD-motor systems have encountered torsional vibration problems. This vibration can induce large...

Han, Xu

2012-02-14T23:59:59.000Z

66

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

DOE Patents [OSTI]

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.

Kumar, Aditya; Shi, Ruijie; Dokucu, Mustafa

2013-09-17T23:59:59.000Z

67

Enhanced Recovery Utilizing Variable Frequency Drives and a Distributed Power System  

SciTech Connect (OSTI)

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.

Randy Peden; Sanjiv Shah

2005-07-26T23:59:59.000Z

68

System for throttling and compensation for variable feedstock properties  

DOE Patents [OSTI]

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.

Meyer, J. W.

1981-05-05T23:59:59.000Z

69

System for throttling and compensation for variable feedstock properties  

DOE Patents [OSTI]

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.

Meyer, John W. (Palo Alto, CA)

1981-01-01T23:59:59.000Z

70

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

E-Print Network [OSTI]

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

Kumar, Ratnesh

71

The RenewElec Project: Variable Renewable Energy and the Power System  

SciTech Connect (OSTI)

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.

Apt, Jay

2014-02-14T23:59:59.000Z

72

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

SciTech Connect (OSTI)

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.

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

1994-04-01T23:59:59.000Z

73

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

E-Print Network [OSTI]

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.

F. Meyer; E. Meyer-Hofmeister

1999-07-14T23:59:59.000Z

74

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

E-Print Network [OSTI]

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

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

2014-03-04T23:59:59.000Z

75

Investigation on multi-variable decoupled temperature control system for enamelling machine with heated air circulation  

SciTech Connect (OSTI)

A lots of problems may occur frequently when controlling the temperature of the enamelling machine oven in the real industrial process, such as multi-variable coupled problem. an experimental rig with triple inputs and triple outputs was devised and a simulation modeling was established accordingly in this study,. the temperature control system based on the feedforward compensation algorithm was proposed. Experimental results have shown that the system is of high efficiency, good stability and promising application.

Li, Yang; Qin, Le; Zou, Shipeng; Long, Shijun [School of Information Engineering, Guangdong University of Technology, Guangzhou, 510006 (China)

2014-04-11T23:59:59.000Z

76

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

DOE Patents [OSTI]

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.

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

2005-05-31T23:59:59.000Z

77

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

SciTech Connect (OSTI)

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

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

2012-01-01T23:59:59.000Z

78

HVAC systems in the current stock of U. S. K-12 schools. Final report, May 91-Mar 92  

SciTech Connect (OSTI)

The report summarizes information on heating, ventilating, and air-conditioning (HVAC) systems commonly found in U.S. school buildings and the effect that operating these systems has on indoor radon levels. The report describes the ability of various HVAC systems to pressurize and ventilate classroom spaces, how they operate, and how they are controlled. Some information is given to compare systems from the standpoint of energy use, cost, and their ability to maintain stable levels of static pressure in classrooms and/or to adequately ventilate the spaces. There do not appear to be any well defined trends in types of HVAC systems involved in current school building construction and modification. Systems looked at include those using reheat and/or mixing, unit ventilators (UVs), and two-fan, dual-duct variable air volume (VAV) systems.

Parker, J.D.

1992-07-01T23:59:59.000Z

79

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

SciTech Connect (OSTI)

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.

Not Available

2013-09-01T23:59:59.000Z

80

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

E-Print Network [OSTI]

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.

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

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


81

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

E-Print Network [OSTI]

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

Hong, Tainzhen

2010-01-01T23:59:59.000Z

82

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

SciTech Connect (OSTI)

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.

Hays, Lance G

2014-07-07T23:59:59.000Z

83

The Coordinated Control of a Central Air Conditioning System Based on Variable Chilled Water Temperature and Variable Chilled Water Flow  

E-Print Network [OSTI]

At present, regulation of water flow by means of pump frequency conversion is one of the major methods for power-saving in central air conditioning systems. In this article, optimization regulation for central air conditioning system on the basis...

Liu, J.; Mai, Y.; Liu, X.

2006-01-01T23:59:59.000Z

84

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

E-Print Network [OSTI]

as other types of air source heat pumps, VRF systems needconventional packaged air source heat pumps. Typical GSHPis basically an air source heat pump), especially when the

Hong, Tainzhen

2010-01-01T23:59:59.000Z

85

Non-invasive energy meter for fixed and variable flow systems  

DOE Patents [OSTI]

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.

Menicucci, David F.; Black, Billy D.

2005-11-01T23:59:59.000Z

86

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

SciTech Connect (OSTI)

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.

Wenzel, T.

1995-07-01T23:59:59.000Z

87

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

E-Print Network [OSTI]

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.

Quyen Dinh Xuan; Zheshen Zhang; Paul L. Voss

2009-10-06T23:59:59.000Z

88

Airflow regulation in variable-speed systems for residential HVAC applications  

SciTech Connect (OSTI)

In the majority of heating, ventilating, and air-conditioning (HVAC) systems, air is the final medium for adding or extracting heat from or to the space to be air conditioned. Air is heated by passing it over a heat transfer device called a coil, which is a heat exchanger with air on the outside and the primary heating/cooling medium (water, steam, electricity, refrigerant, etc.) on the inside. One of the major factors determining heat transfer is the airflow rate, which can be controlled by mechanical means or by controlling the speed of the fan. Centrifugal fans driven by single-speed induction motors traditionally have been used in the JVAC industry but have an airflow characteristic that depends on the static pressure seen by the system. Variable-speed systems are starting to emerge as a strong alternative to traditional systems because of their ability to match the demand of the air-conditioned space, resulting in higher efficiencies and higher comfort. System efficiency can be improved by constraining the range of airflows provided by the fan or blower system in response to system pressure, that is, by controlling the airflow over the heat exchanger. This paper presents a method to regulate airflow independent of the static pressure and without the need for airflow sensors.

Becerra, R.C.; Beifus, B.L. [General Electric Co., Fort Wayne, IN (United States)

1996-11-01T23:59:59.000Z

89

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

E-Print Network [OSTI]

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

Hong, Tainzhen

2010-01-01T23:59:59.000Z

90

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

SciTech Connect (OSTI)

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.

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

2011-04-01T23:59:59.000Z

91

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

E-Print Network [OSTI]

ALLOCATION OF INVENTORY TO A VARIABLE, TIME-PHASED, ON-LINE STORAGE SYSTEM UNDER KNOWN DEMAND A Thesis By CHARLES WESLEY WHITE Submitted to the Graduate College of the Texas ASM University in partial fulfillment of the requirements... 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...

White, Charles Wesley

1968-01-01T23:59:59.000Z

92

Soft x-ray array system with variable filters for the DIII-D tokamak  

SciTech Connect (OSTI)

Recent upgrades to the soft x-ray (SXR) array system on the DIII-D tokamak are described. The system consists of two 32-channel arrays at one toroidal location and three toroidally distributed 12-channel arrays. The 32-channel arrays have been completely rebuilt to allow the switching of SXR filters without breaking vacuum. The 12-channel arrays have had upgrades performed to detectors, view slits, and data acquisition. Absolute extreme ultraviolet (AXUV) photodiodes are used as detectors in all arrays, allowing detection of photons ranging in energy from 2 eV to 10 keV. In the fixed-filter arrays, 127 {mu}m Be filters are used. In the variable-filter arrays, filter wheels are used to switch between five different possible pinhole/filter combinations.

Hollmann, E. M.; Chousal, L.; Hernandez, R. [University of California, San Diego, 9500 Gilman Dr., La Jolla, California 92093-0417 (United States); Fisher, R. K.; Jackson, G. L.; Pidcoe, S. V.; Taussig, D. A. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Lanctot, M. J. [Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94550 (United States); Shankara, J. [Institute for Plasma Research, Bhat, Gandhinagar (India)

2011-11-15T23:59:59.000Z

93

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

SciTech Connect (OSTI)

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)

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

2012-07-01T23:59:59.000Z

94

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

SciTech Connect (OSTI)

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.

Ibanez, E.; Milligan, M.

2012-09-01T23:59:59.000Z

95

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]

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...

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

96

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

E-Print Network [OSTI]

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...

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

2006-01-01T23:59:59.000Z

97

Experimental analysis of variable capacity heat pump system equipped with vapour injection and permanent magnet motor.  

E-Print Network [OSTI]

?? This study analyzes the performance of variable capacity heat pump scroll compressor which is equipped with vapour injection and permanent magnet motor. Refrigerant used… (more)

Awan, Umer Khalid

2012-01-01T23:59:59.000Z

98

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

E-Print Network [OSTI]

variability of photovoltaic (PV) plants to avoid unnecessaryhowever, occurs within PV plants. The degree of smoothingof photovoltaic (PV) plants. The workshop brought together

Mills, Andrew

2010-01-01T23:59:59.000Z

99

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

SciTech Connect (OSTI)

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.

Annamalai, H [IPRC, University of Hawaii

2014-09-15T23:59:59.000Z

100

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]

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

Hoffman, Forrest M.

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


101

Cataclysmic Variables  

E-Print Network [OSTI]

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.

Robert Connon Smith

2007-01-23T23:59:59.000Z

102

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

DOE Patents [OSTI]

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.

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

2000-01-01T23:59:59.000Z

103

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]

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

Boyer, Edmond

104

Plasma radiation dynamics with the upgraded Absolute Extreme Ultraviolet tomographical system in the Tokamak à Configuration Variable  

SciTech Connect (OSTI)

We introduce an upgraded version of a tomographical system which is built up from Absolute Extreme Ultraviolet-type (AXUV) detectors and has been installed on the Tokamak à Configuration Variable (TCV). The system is suitable for the investigation of fast radiative processes usually observed in magnetically confined high-temperature plasmas. The upgrade consists in the detector protection by movable shutters, some modifications to correct original design errors and the improvement in the data evaluation techniques. The short-term sensitivity degradation of the detectors, which is caused by the plasma radiation itself, has been monitored and found to be severe. The results provided by the system are consistent with the measurements obtained with the usual plasma radiation diagnostics installed on TCV. Additionally, the coupling between core plasma radiation and plasma-wall interaction is revealed. This was impossible with other available diagnostics on TCV.

Tal, B.; Nagy, D.; Veres, G. [Institute for Particle and Nuclear Physics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Association EURATOM, P. O. Box 49, H-1525 Budapest (Hungary)] [Institute for Particle and Nuclear Physics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Association EURATOM, P. O. Box 49, H-1525 Budapest (Hungary); Labit, B.; Chavan, R.; Duval, B. [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association EURATOM-Confédération Suisse, EPFL SB CRPP, Station 13, CH-1015 Lausanne (Switzerland)] [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association EURATOM-Confédération Suisse, EPFL SB CRPP, Station 13, CH-1015 Lausanne (Switzerland)

2013-12-15T23:59:59.000Z

105

Stability limit of room air temperature of a VAV system  

SciTech Connect (OSTI)

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.

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

106

Coping with Variability in Model-Based Systems Engineering: An Experience in Green Energy  

E-Print Network [OSTI]

ML, a leading MBSE language, for developing a product line of wind turbine systems used for the generationML and how it has been applied to an ongoing project on wind turbine systems for the generation {strujillo, xmendialdua, jdesosa}@ikerlan.es 2 Alstom Wind Power. Barcelona, Spain {jose

Egyed, Alexander

107

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

108

An Adaptive Vision System for Tracking Soccer Players from Variable Camera Settings  

E-Print Network [OSTI]

of soccer players taped on video. The system per- forms well in a multitude of application scenarios because these submodules is adding to both the reliability and the efficiency of the overall system. 1 Introduction The automatic observation of team-sport games is gaining increased attention for dif- ferent reasons

Cremers, Daniel

109

Energy Efficient Single Stack Exhaust Fan Systems (E3S3F)  

E-Print Network [OSTI]

This paper first investigates the fan energy performance of a constant air volume exhaust system. Two single stack energy efficient exhaust fan systems (E3S3F) are presented. The E3S3F-I has the static pressure sensor located at the inlet...

Wang, G.; Liu, M.

2001-01-01T23:59:59.000Z

110

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

E-Print Network [OSTI]

The objective of this study was to develop a chemical application system that could measure plant size, determine the optimum chemical rate to apply and control that application. A plant height sensor, the MEPRT growth relationship software...

Beck, Andy Dwayne

2012-06-07T23:59:59.000Z

111

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

E-Print Network [OSTI]

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

Boyer, Edmond

112

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

E-Print Network [OSTI]

) [2] Zhaoyu SHI. Adjustment and Control of Operation of Heat Supply System. Beijing: Tsinghua University Press, 1994. (In Chinese) [3] Junliang SHI. Selection of Control Valves. Beijing: China Architecture & Building Press, 1986. (In Chinese...

Chen, Y.; Zhang, Z.

2006-01-01T23:59:59.000Z

113

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

E-Print Network [OSTI]

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

Mills, Andrew

2010-01-01T23:59:59.000Z

114

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

SciTech Connect (OSTI)

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.

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

2012-12-01T23:59:59.000Z

115

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

DOE Patents [OSTI]

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.

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

1997-01-01T23:59:59.000Z

116

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]

(CAVRH), and variable volume with reheat (VAVRH), four pipe fan coil unit (FC), four pipe induction unit (FI), and a single zone air conditioning system (SZ). These calculations are presented in spreadsheets that include a running commentary so...

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

2001-01-01T23:59:59.000Z

117

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism inS-4500II FieldVacancy-InducedCloudPoissonVampireData -

118

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...

119

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

120

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]

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

Herr, Hugh

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


121

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

SciTech Connect (OSTI)

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.

Bourassa, Norman; Haves, Philip; Huang, Joe

2002-05-17T23:59:59.000Z

122

Field demonstration of optimized variable speed compressor and condenser fan control for commercial refrigeration systems. Final report  

SciTech Connect (OSTI)

The demonstration project discussed in this report consisted of two separate programs intended to examine methods of implementing variable-frequency drives (VFDs) to increase the efficiency of supermarket refrigeration racks. The first program examined the optimum control strategy for minimizing the power consumption of medium-temperature parallel compressor racks driven by VFDs. The second program, aimed at developing the optimum control strategy for variable-speed control of supermarket condenser fans.

NONE

1997-11-01T23:59:59.000Z

123

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

SciTech Connect (OSTI)

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.

Wetter, Michael

2009-02-12T23:59:59.000Z

124

Case Study: The Effective Use of an Extensive Logical rule Based Data Analytics Approach in Establishing Root Cause of Performance Issues in Widespread Deployments of Unitary Space Air Conditioning Units  

E-Print Network [OSTI]

Today a significant percentage of office spaces are air conditioned using widely deployed unitary systems, either Fan Coil Units (FCU) or Variable Air Volume (VAV) boxes, to achieve high degrees of air conditioned zonal control. However establishing...

Brady, N.

2013-01-01T23:59:59.000Z

125

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

SciTech Connect (OSTI)

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.

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

2011-05-01T23:59:59.000Z

126

Understanding Biomass Feedstock Variability  

SciTech Connect (OSTI)

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

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

2013-01-01T23:59:59.000Z

127

Understanding Biomass Feedstock Variability  

SciTech Connect (OSTI)

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

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

2013-01-01T23:59:59.000Z

128

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

E-Print Network [OSTI]

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

Tasiran, Serdar

129

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

130

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)

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.

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

2013-04-01T23:59:59.000Z

131

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

SciTech Connect (OSTI)

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.

Carlin, P.W.

1989-06-01T23:59:59.000Z

132

Quantum information with modular variables  

E-Print Network [OSTI]

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.

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

2014-06-24T23:59:59.000Z

133

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

DOE Patents [OSTI]

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.

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

2002-11-19T23:59:59.000Z

134

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

E-Print Network [OSTI]

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

Feng, Ming

135

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

SciTech Connect (OSTI)

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.

Jones, Lawrence E.

2011-12-01T23:59:59.000Z

136

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

E-Print Network [OSTI]

, 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...

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

137

Variable Crop Share Leases.  

E-Print Network [OSTI]

)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...

Sartin, Marvin; Sammons, Ray

1980-01-01T23:59:59.000Z

138

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)

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.

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

139

Strategy Guideline: Compact Air Distribution Systems  

SciTech Connect (OSTI)

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.

Burdick, A.

2013-06-01T23:59:59.000Z

140

Duct leakage impacts on VAV system performance in California large commercial buildings  

SciTech Connect (OSTI)

The purpose of this study is to evaluate the variability of duct leakage impacts on air distribution system performance for typical large commercial buildings in California. Specifically, a hybrid DOE-2/TRNSYS sequential simulation approach was used to model the energy use of a low-pressure terminal-reheat variable-air-volume (VAV) HVAC system with six duct leakage configurations (tight to leaky) in nine prototypical large office buildings (representing three construction eras in three California climates where these types of buildings are common). Combined fan power for the variable-speed-controlled supply and return fans at design conditions was assumed to be 0.8 W/cfm. Based on our analyses of the 54 simulation cases, the increase in annual fan energy is estimated to be 40 to 50% for a system with a total leakage of 19% at design conditions compared to a tight system with 5% leakage. Annual cooling plant energy also increases by about 7 to 10%, but reheat energy decreases (about 3 to 10%). In combination, the increase in total annual HVAC site energy is 2 to 14%. The total HVAC site energy use includes supply and return fan electricity consumption, chiller and cooling tower electricity consumption, boiler electricity consumption, and boiler natural gas consumption. Using year 2000 average commercial sector energy prices for California ($0.0986/kWh and $7.71/Million Btu), the energy increases result in 9 to 18% ($7,400 to $9,500) increases in HVAC system annual operating costs. Normalized by duct surface area, the increases in annual operating costs are 0.14 to 0.18 $/ft{sup 2}. Using a suggested one-time duct sealing cost of $0.20 per square foot of duct surface area, these results indicate that sealing leaky ducts in VAV systems has a simple payback period of about 1.3 years. Even with total leakage rates as low as 10%, duct sealing is still cost effective. This suggests that duct sealing should be considered at least for VAV systems with 10% or more total duct leakage. The VAV system that we simulated had perfectly insulated ducts, and maintained constant static pressure in the ducts upstream of the VAV boxes and a constant supply air temperature at the airhandler. Further evaluations of duct leakage impacts should be carried out in the future after methodologies are developed to deal with duct surface heat transfer effects, to deal with airflows entering VAV boxes from ceiling return plenums (e.g., to model parallel fan-powered VAV boxes), and to deal with static pressure reset and supply air temperature reset strategies.

Wray, Craig P.; Matson, Nance E.

2003-10-01T23:59:59.000Z

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


141

Renewable variable speed hybrid system   

E-Print Network [OSTI]

At present many remote and Island communities rely solely on diesel powered generators to provide electricity. Diesel fuel is both expensive and polluting and the constant speed operation of the diesel engine is inefficient. ...

Stott, Paul Anthony

2010-01-01T23:59:59.000Z

142

Operating Reserves and Variable Generation  

SciTech Connect (OSTI)

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

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

2011-08-01T23:59:59.000Z

143

Practical evaluation of action-angle variables  

SciTech Connect (OSTI)

A practical method is described for establishing action-angle variables for a Hamiltonian system. That is, a given nearly integrable Hamiltonian is divided into an exactly integrable system plus a perturbation in action-angle form. The transformation of variables, which is carried out using a few short trajectory integrations, permits a rapid determination of trajectory properties throughout a phase space volume.

Boozer, A.H.

1984-02-01T23:59:59.000Z

144

Energy performance of air distribution systems part II: room air stratification full scale testing  

E-Print Network [OSTI]

and are connected to a fan coil unit by flexible ductwork asvariable air volume fan coil units typically used in

Webster, Tom; Lukaschek, Wolfgang; Dickeroff, Darryl; Bauman, Fred

2007-01-01T23:59:59.000Z

145

Variable metric conjugate gradient methods  

SciTech Connect (OSTI)

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.

Barth, T.; Manteuffel, T.

1994-07-01T23:59:59.000Z

146

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]

predictions from CMIP5 Earth system models and comparisonin the Community Earth System Model: Evaluation andusing the Community Earth System Model–Biogeochemistry (

2013-01-01T23:59:59.000Z

147

Supply Fan Control for Constant Air Volume Air Handling Units  

E-Print Network [OSTI]

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...

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

2007-01-01T23:59:59.000Z

148

Variable Speed Pumping for Level Control  

E-Print Network [OSTI]

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...

Vasel, M.

1982-01-01T23:59:59.000Z

149

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]

!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

Kay, Jennifer

150

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

SciTech Connect (OSTI)

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.

Fischer, J

2005-12-21T23:59:59.000Z

151

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)

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.

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

2005-11-01T23:59:59.000Z

152

Variable Frequency Pump Drives  

E-Print Network [OSTI]

-frequency electric motor drive. What is happenin9 with variable frequency driven pun,ps is a classical illustration that evolution in technical products takes place not only because of changes in the processes served by these products, or because of innovations...-pole 3550 rpm squirrel caqe induction motor became available in the early 1930s that high pressure pumps operating at that speed could be buil t. And now, in the 1980s, the development of the solid-state, variable frequency electric motor drive...

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

153

Integrating Variable Renewable Energy: Challenges and Solutions  

SciTech Connect (OSTI)

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.

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

2013-09-01T23:59:59.000Z

154

Momentum Map and Action-Angle Variables for Nambu Dynamics  

E-Print Network [OSTI]

Momentum map is a reduction procedure that reduces the dimension of a Hamiltonian system to the lower ones. It is shown that behavior of the action-angle variables under the momentum map generates the new action-angle variables for the reduced system considered as a Nambu structure. The symmetrical top is given as an illustration.

A. Tegmen

2005-08-29T23:59:59.000Z

155

Variable depth core sampler  

DOE Patents [OSTI]

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.

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

1996-02-20T23:59:59.000Z

156

Measuring spatial variability in soil characteristics  

DOE Patents [OSTI]

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.

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

157

Orthogonal coordinate systems and separation of variables  

E-Print Network [OSTI]

. If the curvilinear component of' 7(I) in the u direction is denoted by (y&P ) , etc. , we have u' (VCP ) Cls y c)(p d. u Qu dsy Q U C) (p dv gv dsq C) CI) (v(p ) cia s Hence ( 1-5) A A A ~a, ~i a%, ~i h~ gu hz pv h3 pw We note that formula (1-5... A = i~ Ag + ie Aa + i3 A3 where for brevity we have wr itten A~ = A ~(u Av, w ) N etc . Thu s A h V ~ A = V-(i, A, ) + V ~ (i, A, ) + V (I, A, ) Using formula ( 1-5) A we see that Vu =- ? ~ A h~ A V v ha /I )VA W hs Now consider...

Gibbs, Sam Gavin

2012-06-07T23:59:59.000Z

158

The Variable Structure Systems and Cognition  

E-Print Network [OSTI]

Intent ActionApprox. Plan Application New Goal Measured Results Experience Model Refinement Correction Ford Escape Hybrid Regeneration #12;Fuel Economy Hybrid Monthly Fuel Economy Miles Driven Friction

Haykin, Simon

159

PHP: Constructs and Variables Introduction  

E-Print Network [OSTI]

PHP: Constructs and Variables Introduction This document describes: 1. the syntax and types of variables, 2. PHP control structures (i.e., conditionals and loops), 3. mixed-mode processing, 4. how to use one script from within another, 5. how to define and use functions, 6. global variables in PHP, 7

Vander Zanden, Brad

160

RESEARCH ARTICLE Development and characterization of a variable turbulence  

E-Print Network [OSTI]

(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

Lieuwen, Timothy C.

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


161

Variables Influencing HRSG Designs  

E-Print Network [OSTI]

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...

Ganapathy, V.; Rentz, J.

162

Variable Refrigerant Flow HVAC  

E-Print Network [OSTI]

Conference, San Antonio, Texas Dec. 16-18 What do they know that we don’t know? Japan 90% Over 7 Million Systems China 86% Over 17 Million Systems Europe 81% Over 7 Million Systems USA 4% .5 Million Systems ESL-KT-13-12-33 CATEE 2013: Clean Air Through...-source VRF IEER 11.5 - 17.7 19.6 9.7 10.3 10.9 10.5 IPLV - 14.2 - - SCHE - - 18.6 N/A Energy Efficiency - commercial EER ESL-KT-13-12-33 CATEE 2013: Clean Air Through Energy Efficiency Conference, San Antonio, Texas Dec. 16-18 More Comfort & Quiet ? 4 ton...

Jones, S.

2013-01-01T23:59:59.000Z

163

Present and Future Modes of Low Frequency Climate Variability  

SciTech Connect (OSTI)

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.

Cane, Mark A.

2014-02-20T23:59:59.000Z

164

Testing of a variable-stroke Stirling engine  

SciTech Connect (OSTI)

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.

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

1986-01-01T23:59:59.000Z

165

VARIABLE SPEED WIND TURBINE  

E-Print Network [OSTI]

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.

Chatinderpal Singh

166

HVAC's Variable Refrigerant Flow (VRF) Technology  

E-Print Network [OSTI]

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....2M Systems Ductless is a small percent of the U.S. HVAC market but current building and energy usage trends indicate a large growth opportunity Determining the Proper Application Worldwide Usage-Opportunity Window Unitary Chillers...

Jones, S.

2012-01-01T23:59:59.000Z

167

Intensive Variables & Nanostructuring in Magnetostructural Materials  

SciTech Connect (OSTI)

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.

Lewis, Laura

2014-08-13T23:59:59.000Z

168

Turbo-generator control with variable valve actuation  

DOE Patents [OSTI]

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.

Vuk, Carl T. (Denver, IA)

2011-02-22T23:59:59.000Z

169

Selection automatique de variables pertinentes  

E-Print Network [OSTI]

S´election automatique de variables pertinentes Vers la d´ecouverte de nouvelles modalit´es sensori-motrices corr´elations entre ses variables sensori-motrices afin d'apprendre `a r´esoudre sa t^ache d

Boyer, Edmond

170

CX-001530: Categorical Exclusion Determination | Department of...  

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

on existing structures); JJC Day Room Variable Air Volume (VAV) Retrofit; Central Library Air Handler Replacement; Library Heating, Ventilating, and Air Conditioning (HVAC)...

171

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,...

172

Flex Fuel Vehicle Systems  

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

& Variable Advanced Management Injection Injection Sensors Control Units Fuel Supply & Plastic Parts Control Transmission Engineering Gasoline Systems GSENS, GSENS-NA System...

173

Review of Variable Generation Integration Charges  

SciTech Connect (OSTI)

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.

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

2013-03-01T23:59:59.000Z

174

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

SciTech Connect (OSTI)

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

Milligan, M.; Kirby, B.

2010-08-01T23:59:59.000Z

175

Market Designs for High Levels of Variable Generation: Preprint  

SciTech Connect (OSTI)

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.

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

2014-10-01T23:59:59.000Z

176

WECC Variable Generation Planning Reference Book  

SciTech Connect (OSTI)

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.

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

2013-05-14T23:59:59.000Z

177

WECC Variable Generation Planning Reference Book: Appendices  

SciTech Connect (OSTI)

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.

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

2013-05-13T23:59:59.000Z

178

Free piston variable-stroke linear-alternator generator  

DOE Patents [OSTI]

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.

Haaland, C.M.

1998-12-15T23:59:59.000Z

179

Laboratory implementation of variable-speed wind turbine generation  

SciTech Connect (OSTI)

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.

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

180

Free piston variable-stroke linear-alternator generator  

DOE Patents [OSTI]

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.

Haaland, Carsten M. (Dadeville, AL)

1998-01-01T23:59:59.000Z

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


181

Continuous variable entanglement dynamics in structured reservoirs  

E-Print Network [OSTI]

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.

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

2009-10-13T23:59:59.000Z

182

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

183

MID-INFRARED SPECTRAL VARIABILITY ATLAS OF YOUNG STELLAR OBJECTS  

SciTech Connect (OSTI)

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.

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

184

Cataclysmic Variables from SDSS I. The First Results  

E-Print Network [OSTI]

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.

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

185

Variable frequency microwave heating apparatus  

DOE Patents [OSTI]

A variable frequency microwave heating apparatus (10) designed to allow modulation of the frequency of the microwaves introduced into a multi-mode microwave cavity (34) for testing or other selected applications. The variable frequency microwave heating apparatus (10) includes a microwave signal generator (12) and a high-power microwave amplifier (20) or a high-power microwave oscillator (14). A power supply (22) is provided for operation of the high-power microwave oscillator (14) or microwave amplifier (20). A directional coupler (24) is provided for detecting the direction and amplitude of signals incident upon and reflected from the microwave cavity (34). 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).

Bible, Don W. (Clinton, TN); Lauf, Robert J. (Oak Ridge, TN); Johnson, Arvid C. (Lake in the Hills, IL); Thigpen, Larry T. (Angier, NC)

1999-01-01T23:59:59.000Z

186

Massive Variability Surveys from Venezuela  

E-Print Network [OSTI]

At the Venezuela National Astronomical Observatory we are carrying out variability surveys spanning many hundreds of square degrees near the celestial equator, using an 8k x 8k CCD Mosaic Camera optimized for drift-scanning on a 1m Schmidt telescope. Among the initial efforts was a project to obtain the first moderately deep, homogeneous sample of young stars over an area of ~180sqr.deg. encompassing the entire Orion OB1 association, one of the nearest and most active regions of star formation. The results show that variability is a powerful technique to identify pre-main sequence populations, specially in sparse areas devoid of gas and dust. We are currently developing a massive database, equipped with web-based data mining tools, that will make our data and results available to the astronomical community.

Cesar Briceno

2003-04-03T23:59:59.000Z

187

Review of Probability Random Variable  

E-Print Network [OSTI]

at close 4) Height of wheel going over a rocky road #12;3 Random Variable Non-examples 1) `Heads' or `Tails' on coin 2) Red or Black ball from urn But we can make these into RV's Basic Idea ­ don't know · Temperature · Wheel height #12;5 Given Continuous RV X... What is the probability that X = x0 ? Oddity : P

Fowler, Mark

188

Variable flexure-based fluid filter  

DOE Patents [OSTI]

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.

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

2007-03-13T23:59:59.000Z

189

HEART RATE VARIABILITY AS DETERMINISM WITH JUMP STOCHASTIC PARAMETERS  

E-Print Network [OSTI]

HEART RATE VARIABILITY AS DETERMINISM WITH JUMP STOCHASTIC PARAMETERS JIONGXUAN ZHENG, JOE SKUFCA, AND ERIK BOLLT§ Abstract. We use measured heart rate information (RR intervals) to develop a one with persistence which causes the heart rate and rhythm system to wander about a bifurcation point. We propose

Bollt, Erik

190

Effective Theories of Coupled Classical and Quantum Variables  

E-Print Network [OSTI]

We address the issue of coupling variables which are essentially classical to variables that are quantum. Two approaches are discussed. In the first (based on collaborative work with L.Di\\'osi), continuous quantum measurement theory is used to construct a phenomenological description of the interaction of a quasiclassical variable $X$ with a quantum variable $x$, where the quasiclassical nature of $X$ is assumed to have come about as a result of decoherence. The state of the quantum subsystem evolves according to the stochastic non-linear Schr\\"odinger equation of a continuously measured system, and the classical system couples to a stochastic c-number $\\x (t)$ representing the imprecisely measured value of $x$. The theory gives intuitively sensible results even when the quantum system starts out in a superposition of well-separated localized states. The second approach involves a derivation of an effective theory from the underlying quantum theory of the combined quasiclassical--quantum system, and uses the decoherent histories approach to quantum theory.

J. J. Halliwell

1998-08-26T23:59:59.000Z

191

Variable Latency Turbo Codes for Wireless Multimedia Applications  

E-Print Network [OSTI]

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

Valenti, Matthew C.

192

Best Practices for Energy Efficient Cleanrooms: Variable Speed Pumping  

E-Print Network [OSTI]

efficiency of chilled water and condenser pumps, along with chiller efficiency and cooling tower efficiency, operate, and control water-pumping systems to achieve high efficiency and to lower life-cycle costsLBNL-58637 Best Practices for Energy Efficient Cleanrooms: Variable Speed Pumping Tengfang Xu June

193

Resilient engineered systems: the development of an inherent system property  

E-Print Network [OSTI]

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...

Mitchell, Susan McAlpin

2007-09-17T23:59:59.000Z

194

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]

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.

Slavek M. Rucinski; Carla Maceroni

2000-06-16T23:59:59.000Z

195

Principal Components Instrumental Variable Estimation  

E-Print Network [OSTI]

of the main results are displayed in two appendices. 2 Econometric Framework Consider the simultaneous equations model y = X? + u and X = Z?+ V , (1) 1 An advantage of such general structure is that the ‘large-sample’ condition used in previous studies Kn/ p n... ? 0, where Kn is the number of instruments and n is the sample size, is not required in our asymptotic approximations. 4 where y is the n × 1 vector containing n observations of the dependent variable; X is the n × G matrix with observations...

Winkelried, Diego; Smith, Richard J.

2011-01-31T23:59:59.000Z

196

Variable Average Absolute Percent Differences  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism inS-4500II FieldVacancy-InducedCloudPoissonVampire Power1 -Variable

197

Variable Mass Theories of Gravity  

E-Print Network [OSTI]

Several attempts to construct theories of gravity with variable mass are considered. The theoretical impacts of allowing the rest mass to vary with respect to time or an appropriate curve parameter are examined in the framework of Newtonian and Einsteinian gravity theories. In further steps, scalar-tensor theories are examined with respect to their relation to the variation of the mass and in an ultimate step, an additional coordinate is introduced and its possible relation to the mass is examined, yielding a five dimensional space-time-matter theory.

M. Leclerc

2002-12-03T23:59:59.000Z

198

Interannual variability in tropospheric nitrous oxide  

E-Print Network [OSTI]

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 ...

Thompson, R. L.

199

Utility Variable Generation Integration Group Fall Technical...  

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

Technical Workshop Utility Variable Generation Integration Group Fall Technical Workshop October 15, 2014 9:00AM CDT to October 17, 2014 3:00PM CDT The Utility Variable Generation...

200

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

E-Print Network [OSTI]

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...

Mayfield, William Lloyd

1951-01-01T23:59:59.000Z

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


201

Experimental Study of the Circulation Air Volume of Recirculation Evaporative Cooling  

E-Print Network [OSTI]

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...

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

2006-01-01T23:59:59.000Z

202

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

SciTech Connect (OSTI)

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.

Not Available

2012-09-01T23:59:59.000Z

203

Variable ratio regenerative braking device  

DOE Patents [OSTI]

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

Hoppie, Lyle O. (Birmingham, MI)

1981-12-15T23:59:59.000Z

204

Variable delivery, fixed displacement pump  

DOE Patents [OSTI]

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.

Sommars, Mark F. (Sparland, IL)

2001-01-01T23:59:59.000Z

205

Continuously variable focal length lens  

DOE Patents [OSTI]

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.

Adams, Bernhard W; Chollet, Matthieu C

2013-12-17T23:59:59.000Z

206

Variable residence time vortex combustor  

DOE Patents [OSTI]

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.

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

1987-01-01T23:59:59.000Z

207

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...

208

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

E-Print Network [OSTI]

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

Kohfeld, Karen

209

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

E-Print Network [OSTI]

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.

Nairwita Mazumder; Subenoy Chakraborty

2009-07-16T23:59:59.000Z

210

ESTIMATION OF EXHAUST MANIFOLD PRESSURE IN TURBOCHARGED GASOLINE ENGINES WITH VARIABLE VALVE TIMING  

E-Print Network [OSTI]

ESTIMATION OF EXHAUST MANIFOLD PRESSURE IN TURBOCHARGED GASOLINE ENGINES WITH VARIABLE VALVE TIMING in turbocharged gasoline engines with variable valve timing requires knowledge of exhaust mani- fold pressure, Pe control systems for gasoline engines rely heavily on feedforward air-fuel ratio (A/F) control to meet

Grizzle, Jessy W.

211

Variable-amplitude oscillatory shear response of amorphous materials  

E-Print Network [OSTI]

Variable-amplitude oscillatory shear tests are emerging as powerful tools to investigate and quantify the nonlinear rheology of amorphous solids, complex fluids and biological materials. Quite a few recent experimental and atomistic simulation studies demonstrated that at low shear amplitudes, an amorphous solid settles into an amplitude- and initial conditions-dependent dissipative limit cycle, in which back-and-forth localized particle rearrangements periodically bring the system to the same state. At sufficiently large shear amplitudes, the amorphous system loses memory of the initial conditions, exhibits chaotic particle motions accompanied by diffusive behavior and settles into a stochastic steady-state. The two regimes are separated by a transition amplitude, possibly characterized by some critical-like features. Here we argue that these observations support some of the physical assumptions embodied in the nonequilibrium thermodynamic, internal-variables based, Shear-Transformation-Zone model of amorphous visco-plasticity; most notably that "flow defects" in amorphous solids are characterized by internal states between which they can make transitions, and that structural evolution is driven by dissipation associated with plastic deformation. We present a rather extensive theoretical analysis of the thermodynamic Shear-Transformation-Zone model for a variable-amplitude oscillatory shear protocol, highlighting its success in accounting for various experimental and simulational observations, as well as its limitations. Our results offer a continuum-level theoretical framework for interpreting the variable-amplitude oscillatory shear response of amorphous solids and may promote additional developments.

Nathan Perchikov; Eran Bouchbinder

2014-04-13T23:59:59.000Z

212

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

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

Fuels Practical Full Time HCCI Operation Will Require Specific HCCI Fuel Low Octane gasoline Experimental Variables Experimental Variables Engine Variables Intake Manifold...

213

HERSCHEL OBSERVATIONS OF CATACLYSMIC VARIABLES  

SciTech Connect (OSTI)

We have used the PACS instrument on the Herschel Space Observatory to observe eight cataclysmic variables at 70 and 160 {mu}m. Of these eight objects, only AM Her was detected. We have combined the Herschel results with ground-based, Spitzer, and WISE observations to construct spectral energy distributions for all of the targets. For the two dwarf novae in the sample, SS Cyg and U Gem, we find that their infrared luminosities are completely dominated by their secondary stars. For the two highly magnetic 'polars' in our survey, AM Her and EF Eri, we find that their mid-infrared excesses, previously attributed to circumbinary dust emission, can be fully explained by cyclotron emission. The WISE light curves for both sources show large, orbitally modulated variations that are identically phased to their near-IR light curves. We propose that significant emission from the lowest cyclotron harmonics (n {<=} 3) is present in EF Eri and AM Her. Previously, such emission would have been presumed to be optically thick, and not provide significant orbitally modulated flux. This suggests that the accretion onto polars is more complicated than assumed in the simple models developed for these two sources. We develop a model for the near-/mid-IR light curves for WZ Sge with an L2 donor star that shows that the ellipsoidal variations from its secondary star are detected. We conclude that none of the targets surveyed have dusty circumbinary disks.

Harrison, Thomas E.; Hamilton, Ryan T. [Department of Astronomy, New Mexico State University, Box 30001, MSC 4500, Las Cruces, NM 88003-8001 (United States); Tappert, Claus [Departamento de Fisica y Astronomia, Universidad de Valparaiso, Avda. Gran Bretana 1111, Valparaiso (Chile); Hoffman, Douglas I. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Campbell, Ryan K., E-mail: tharriso@nmsu.edu, E-mail: rthamilt@nmsu.edu, E-mail: claus.tappert@uv.cl, E-mail: dhoffman@ipac.caltech.edu, E-mail: Ryan.Campbell@humobldt.edu [Department of Physics and Astronomy, Humboldt State University, 1 Harpst St., Arcata, CA 95521 (United States)

2013-01-01T23:59:59.000Z

214

Eccentric crank variable compression ratio mechanism  

DOE Patents [OSTI]

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.

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

215

Interaction between the molecular coherent states for a discrete variable harmonic oscillator and the coherent radiation  

SciTech Connect (OSTI)

We used the dicrete variable three-dimmensional Charlier oscillator. For a system of molecules interacting with the coherent radiation field the temporal variation of the refractive index has been established.

Draganescu, Gheorghe Eugen [Department of Mechanics, Polytechnic University of Timisoara, Bd M Viteazu No1, Timisoara and Department of Physics, West University of Timisoara (Romania)

2012-08-17T23:59:59.000Z

216

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

E-Print Network [OSTI]

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

Mills, Andrew

2010-01-01T23:59:59.000Z

217

Development of an infrared absorption spectroscope based on linear variable filters  

E-Print Network [OSTI]

and used as independent variables. We characterize the system on a number of performance metrics, uncovering its detection limits and resolving power. We present calibration methods to estimate the concentration of analytes in a matrix of absorbing species...

Nogueira, Felipe Guimaraes

2009-05-15T23:59:59.000Z

218

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

E-Print Network [OSTI]

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...

Joshi, Praveen Sudhakar

2012-06-07T23:59:59.000Z

219

String Method with Collective variables from Normal Modes : Application to Alanine Dipeptide  

E-Print Network [OSTI]

approximation of the original system. To obtain the eigenvectors/eigen- values that are ordered according. In this paper, we present a method of semi-automatically determining collective variable set which can be used

Izaguirre, Jesús A.

220

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

SciTech Connect (OSTI)

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.

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

2011-08-15T23:59:59.000Z

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


221

Variable-Period Undulators For Synchrotron Radiation  

DOE Patents [OSTI]

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.

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

2005-02-22T23:59:59.000Z

222

Variable-Period Undulators for Synchrotron Radiation  

SciTech Connect (OSTI)

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.

Shenoy, Gopal; Lewellen, John; Shu, Deming; Vinokurov, Nikolai

2005-02-22T23:59:59.000Z

223

Multivector Functions of a Real Variable  

E-Print Network [OSTI]

This paper is an introduction to the theory of multivector functions of a real variable. The notions of limit, continuity and derivative for these objects are given. The theory of multivector functions of a real variable, even being similar to the usual theory of vector functions of a real variable, has some subtle issues which make its presentation worhtwhile.We refer in particular to the derivative rules involving exterior and Clifford products, and also to the rule for derivation of a composition of an ordinary scalar function with a multivector function of a real variable.

A. M. Moya; V. V. Fernández; W. A. Rodrigues Jr

2002-12-17T23:59:59.000Z

224

Hybrid Bayesian Networks with Linear Deterministic Variables  

E-Print Network [OSTI]

Conference (UAI-05), 2005, AUAI Press, Arlington, VA. 136 Y X Z Figure 2: A Bayesian Network Representation of the Mixed Distribution for X. this example, Y is a discrete variable with state space ? Y = {1,2,3}, Z is a real-valued variable, and X is a... conditionally deterministic variable whose condi- tional distribution is described as follows: X |{y,z} = y if y =1,2 and X |{y,z} = z if y =3. Potentials of the type described above are used in this paper to represent distributions of variables in hy- brid...

Cobb, Barry R.; Shenoy, Prakash P.

2005-07-01T23:59:59.000Z

225

Lithium battery management system  

DOE Patents [OSTI]

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.

Dougherty, Thomas J. (Waukesha, WI)

2012-05-08T23:59:59.000Z

226

3, 19151942, 2006 Longterm variability  

E-Print Network [OSTI]

, 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

Paris-Sud XI, Université de

227

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

E-Print Network [OSTI]

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.

P. C. Schmidtke; A. P. Cowley

2006-05-16T23:59:59.000Z

228

SLUDGE BATCH 7B GLASS VARIABILITY STUDY  

SciTech Connect (OSTI)

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.

Johnson, F.; Edwards, T.

2011-10-25T23:59:59.000Z

229

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

230

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

SciTech Connect (OSTI)

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.

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

231

Solar Dynamics Observatory/ Extreme Ultraviolet Variability Experiment  

E-Print Network [OSTI]

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

Mojzsis, Stephen J.

232

Quantum Computing and Hidden Variables Scott Aaronson #  

E-Print Network [OSTI]

Quantum Computing and Hidden Variables Scott Aaronson # Institute for Advanced Study, Princeton of a hidden variable, then we could e#ciently solve problems that are believed to be intractable even powerful than the quantum computing model. PACS numbers: 03.65.Ta, 03.65.Ud, 03.67.Lx, 02.70.­c I

Aaronson, Scott

233

Deutsch-Jozsa algorithm for continuous variables  

E-Print Network [OSTI]

We present an idealized quantum continuous variable analog of the Deutsch-Jozsa algorithm which can be implemented on a perfect continuous variable quantum computer. Using the Fourier transformation and XOR gate appropriate for continuous spectra we show that under ideal operation to infinite precision that there is an infinite reduction in number of query calls in this scheme.

Arun K. Pati; Samuel L. Braunstein

2002-07-18T23:59:59.000Z

234

The Galex Ultraviolet Variability (GUVV) Catalog  

E-Print Network [OSTI]

We present Version 1.0 of the NASA Galaxy Evolution Explorer (GALEX) ultraviolet variability catalog (GUVV) that contains information on 84 time-variable and transient sources gained with simultaneous near and far ultraviolet photometric observations. These time-variable sources were serendipitously revealed in the various 1.2 degree star fields currently being surveyed by the GALEX satellite in two ultraviolet bands (NUV 1750-2750A, FUV 1350-1750A) with limiting AB magnitudes of 23-25. The largest-amplitude variable objects presently detected by GALEX are M-dwarf flare stars, which can brighten by 5-10 mag in both the NUV and FUV bands during short duration (< 500s) outbursts. Other types of large-amplitude ultraviolet variable objects include ab-type RR Lyrae stars, which can vary periodically by 2-5mag in the GALEX FUV band. This first GUVV catalog lists galactic positions and possible source identifications in order to provide the astronomical community with a list of time-variable objects that can now be repeatedly observed at other wavelengths. We expect the total number of time-variable source detections to increase as the GALEX mission progresses, such that later version numbers of the GUVV catalog will contain substantially more variable sources.

Barry Y. Welsh; Jonathan M. Wheatley; Kenneth Heafield; Mark Seibert; Stanley E. Browne; Samir Salim; R. Michael Rich; Tom A. Barlow; Luciana Bianchi; Yong-Ik Byun; Jose Donas; Karl Forster; Peter G. Friedman; Timothy M. Heckman; Patrick N. Jelinsky; Young-Wook Lee; Barry F. Madore; Roger F. Malina; D. Christopher Martin; Bruno Milliard; Patrick Morrissey; Susan G. Neff; David Schiminovich; Oswald H. W. Siegmund; Todd Small; Alex S. Szalay; Ted K. Wyder

2005-04-21T23:59:59.000Z

235

THE MULTI-USE STEINEL VARIABLE TEMPERATURE  

E-Print Network [OSTI]

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

Kleinfeld, David

236

THE MULTI-USE STEINEL VARIABLE TEMPERATURE  

E-Print Network [OSTI]

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

Kleinfeld, David

237

On local-hidden-variable no-go theorems  

E-Print Network [OSTI]

The strongest attack against quantum mechanics came in 1935 in the form of a paper by Einstein, Podolsky and Rosen. It was argued that the theory of quantum mechanics could not be called a complete theory of Nature, for every element of reality is not represented in the formalism as such. The authors then put forth a proposition: we must search for a theory where, upon knowing everything about the system, including possible hidden variables, one could make precise predictions concerning elements of reality. This project was ultimatly doomed in 1964 with the work of Bell Bell, who showed that the most general local hidden variable theory could not reproduce correlations that arise in quantum mechanics. There exist mainly three forms of no-go theorems for local hidden variable theories. Although almost every physicist knows the consequences of these no-go theorems, not every physicist is aware of the distinctions between the three or even their exact definitions. Thus we will discuss here the three principal forms of no-go theorems for local hidden variable theories of Nature. We will define Bell inequalities, Bell inequalities without inequalities and pseudo-telepathy. A discussion of the similarities and differences will follow.

A. A. Methot

2005-11-07T23:59:59.000Z

238

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

SciTech Connect (OSTI)

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.

Not Available

2014-10-01T23:59:59.000Z

239

A comparison of two variables in relaxation  

E-Print Network [OSTI]

A COMPARISON OF TWO VARIABLES IN RELAXATION A Thesis by PAUL EDWIN TURNER Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE May 1974 Major Subject...: Psychology A COMPARiSON OF TWO VARIABLES IN RELAXATION A Thesis by PAUL EDWIN TURNER Approved as to style and content by: (Chairman of Committ Head of Dep tment Member ?2 J L, ~Xi~ Member M-. ~~2 y May 1974 ABSTRACT A Comparison of Two Variable...

Turner, Paul Edwin

1974-01-01T23:59:59.000Z

240

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

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

& Publications Expanding Robust HCCI Operation (Delphi CRADA) Rapid Compression Machine A Key Experimental Device to Effectively Collaborate with Basic Energy Sciences...

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


241

Antarctic Circumpolar Current System and its Response to Atmospheric Variability  

E-Print Network [OSTI]

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...

Kim, Yong Sun 1976-

2012-08-16T23:59:59.000Z

242

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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Office of InspectorConcentrating SolarElectric Coop, Inc Place: MissouriPrograms | OpenSEI) JumpTexas

243

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 Data Center Home Page on Delicious Rank EERE:YearRound-Up fromDepartmentTieCelebrate Earth Codestheat Two AluminumWHAT:Energy1

244

Strategies and Decision Support Systems for Integrating Variable...  

Open Energy Info (EERE)

Topics: Best Practices Resource Type: Lessons learnedbest practices, Publications, Technical report Website: www1.eere.energy.govwindpdfsdoewindintegrationreport.pdf Cost:...

245

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 Data Center Home Page on Delicious Rank EERE:YearRound-UpHeat PumpRecord ofESPC ENABLE: ECM Summary ECMWearthe ApplicationEnergy 1Thermally

246

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 on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision has beenFfe2fb55-352f-473b-a2dd-50ae8b27f0a6 No revisionWind,Soils andOpen Energy Information

247

Variable volume architecture : expanding the boundary  

E-Print Network [OSTI]

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. ...

Saheba, Asheshh (Asheshh Mohit), 1972-

2001-01-01T23:59:59.000Z

248

Inserting Group Variables into Fluid Mechanics  

E-Print Network [OSTI]

A fluid, like a quark-gluon plasma, may possess degrees of freedom indexed by a group variable, which retains its identity even in the fluid/continuum description. Conventional Eulerian fluid mechanics is extended to encompass this possibility.

R. Jackiw

2004-10-28T23:59:59.000Z

249

Energy Savings of Variable Speed Motors  

E-Print Network [OSTI]

This paper investigates the energy savings available by utilizing variable speed motors on pump and fan applications. Conventional control of flow or pressure in process plants is normally accomplished by throttling the various streams with control...

Fishel, F. D.

1979-01-01T23:59:59.000Z

250

Variable-Rate State Gasoline Taxes  

E-Print Network [OSTI]

J Bradshaw, "SLate ’F~es’ Gasoline Tax So ~t Wdl Rise," TheVarlable-Rate State Gasoline Taxers Jeffrey Ang-Olson MartinVariable-Rate State Gasoline Taxes Jeffrey Ang-Olson

Ang-Olson, Jeffrey; Wachs, Martin; Taylor, Brian D.

2000-01-01T23:59:59.000Z

251

UselessVariable Elimination Olin Shivers  

E-Print Network [OSTI]

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

Shivers, Olin

252

Hybrid permanent magnet and variable reluctance generator  

SciTech Connect (OSTI)

This patent describes a hybrid electrical generator. It comprises: a permanent magnet generator having a permanent magnet rotor mounted on a shaft, the permanent magnet generator providing an output voltage over an operating range which falls in response to an increasing electrical load; a variable reluctance generator having a rotor mounted on the shaft with excitation of a stator of the variable reluctance generator being provided from the permanent magnet generator, the variable reluctance generator providing an output voltage which varies in response to an increasing electrical load over an operating range; and a voltage regulator, responsive to combined output voltages of the generators, for controlling the output voltage provided by the variable reluctance generator.

Vaidya, J.; Belanger, D.J.

1990-09-25T23:59:59.000Z

253

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

E-Print Network [OSTI]

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.

Rafail V. Abramov

2011-08-14T23:59:59.000Z

254

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

SciTech Connect (OSTI)

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.

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

2011-08-16T23:59:59.000Z

255

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

E-Print Network [OSTI]

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

Lave, Matthew; Kleissl, Jan

2013-01-01T23:59:59.000Z

256

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

E-Print Network [OSTI]

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

Liberzon, Daniel

257

Interannual variability of Caribbean rainfall, ENSO and the Atlantic Ocean  

E-Print Network [OSTI]

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

Columbia University

258

On the practice of dichotomization of quantitative variables  

E-Print Network [OSTI]

The authors examine the practice of dichotomization of quantitative measures, wherein relationships among variables are examined after 1 or more variables have been converted to dichotomous variables by splitting the sample ...

MacCallum, R. C.; Zhang, S.; Preacher, K. J.; Rucker, D. D.

2002-01-01T23:59:59.000Z

259

Software Enabled Virtually Variable Displacement Pumps -Theoretical and Experimental Studies  

E-Print Network [OSTI]

Software Enabled Virtually Variable Displacement Pumps - Theoretical and Experimental Studies the functional equivalent of a variable displacement pump. This approach combines a fixed displacement pump valve control, without many of the shortcomings of commercially available variable displacement pumps

Li, Perry Y.

260

The use of 'race' as a variable in biomedical research  

E-Print Network [OSTI]

be used as a variable in biomedical research but mainly toRace’ as a Variable in Biomedical Research A dissertationRace’ as a Variable in Biomedical Research…………. Manifest,

Efstathiou, Sophia

2009-01-01T23:59:59.000Z

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


261

Pitch-controlled variable-speed wind turbine generation  

SciTech Connect (OSTI)

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.

Muljadi, E.; Butterfield, C.P.

2000-03-01T23:59:59.000Z

262

Lateral Control of Heavy Vehicles for Automated Systems  

E-Print Network [OSTI]

system tracks the desired front wheel steering angle (? 1 ) exactly, then the sliding variable will asymptotically converg to a ball,

Hingwe, Pushkar; Wang, Jen-Yu; Tai, Meihua; Tomizuka, Masayoshi

2003-01-01T23:59:59.000Z

263

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...

264

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...

265

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...

266

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...

267

Advanced Variable Speed Air-Source Integrated Heat Pump 2013...  

Energy Savers [EERE]

Advanced Variable Speed Air-Source Integrated Heat Pump 2013 Peer Review Advanced Variable Speed Air-Source Integrated Heat Pump 2013 Peer Review Emerging Technologies Project for...

268

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

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

Control Strategies for Centrifugal Pumps with Variable Flow Rate Requirements Control Strategies for Centrifugal Pumps with Variable Flow Rate Requirements This tip sheet discusses...

269

GEOCHEMICAL MODELING OF F AREA SEEPAGE BASIN COMPOSITION AND VARIABILITY  

SciTech Connect (OSTI)

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.

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

2012-05-08T23:59:59.000Z

270

Variable energy constant current accelerator structure  

DOE Patents [OSTI]

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.

Anderson, O.A.

1988-07-13T23:59:59.000Z

271

A new variable in flow analysis  

E-Print Network [OSTI]

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.

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

2006-06-20T23:59:59.000Z

272

INTERANNUAL VARIABILITY IN GLOBAL SOIL RESPIRATION (1980-1994) Interannual Variability in Global Soil  

E-Print Network [OSTI]

INTERANNUAL VARIABILITY IN GLOBAL SOIL RESPIRATION (1980-1994) NDP-081 Interannual Variability in Global Soil Respiration on a 0.5 Degree Grid Cell Basis (1980-1994) Contributed by: James W. Raich 1, Tennessee 37831-6335. The ORNL is managed by UT-Battelle, LLC for the U.S. DEPARTMENT OF ENERGY under

273

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

SciTech Connect (OSTI)

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.

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

1996-11-01T23:59:59.000Z

274

Heart Rate Variability Malvin Carl Teich  

E-Print Network [OSTI]

Heart Rate Variability Malvin Carl Teich Boston University and Columbia University http, Grasmere, UK, 2005 #12;CONGESTIVE HEART FAILURE INABILITY OF HEART TO INCREASE CARDIAC OUTPUT IN PROPORTION of breath Swelling in legs General fatigue and weakness Clinical diagnostics: Ascultate heart Carotid pulse

Teich, Malvin C.

275

Hydrologically Sensitive Areas: Variable Source Area Hydrology  

E-Print Network [OSTI]

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

Walter, M.Todd

276

The Sun is an active, variable,  

E-Print Network [OSTI]

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

Christian, Eric

277

Chapter 18: Variable Frequency Drive Evaluation Protocol  

SciTech Connect (OSTI)

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.

Romberger, J.

2014-11-01T23:59:59.000Z

278

Markovian feedback to control continuous variable entanglement  

E-Print Network [OSTI]

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.

Stefano Mancini

2005-04-18T23:59:59.000Z

279

Variable Light-Cone Theory of Gravity  

E-Print Network [OSTI]

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.

I. T. Drummond

1999-08-20T23:59:59.000Z

280

An Exploratory Study of Variability in Safety  

E-Print Network [OSTI]

An Exploratory Study of Variability in Safety Culture among Clinician types and Patient Care of the current study was to (a) examine how different types of care providers viewed the safety culture of their unit, and (b) examine the relationship between hospital safety culture and patient satisfaction

von der Heydt, Rüdiger

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


281

Original article Variability of digestibility criteria  

E-Print Network [OSTI]

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

Boyer, Edmond

282

3. Hydrogeomorphic Variability and River Restoration  

E-Print Network [OSTI]

. 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

Montgomery, David R.

283

Climate Change and Variability Lake Ice, Fishes  

E-Print Network [OSTI]

#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

Sheridan, Jennifer

284

Gowdy phenomenology in scale-invariant variables  

E-Print Network [OSTI]

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.

Lars Andersson; Henk van Elst; Claes Uggla

2003-10-30T23:59:59.000Z

285

Modeling variable density effects in turbulent flames -- Some basic considerations  

SciTech Connect (OSTI)

The paper discusses the basic physical phenomena involved in pressure-density interactions, and presents models of pressure-velocity, pressure-scalar, baroclinic and dilatation effects for variable density low Mach-number turbulence. Their implementation in the {kappa}-{epsilon} framework is then described and their performance evaluated. The models assume that both scalar transport and turbulence generation arising from pressure-density interactions in flames are caused by the motion of large scale turbulent thermals superposed on the normal turbulence mechanism. The velocity of the thermals is related directly to the mean pressure gradient and local density differences in the flames. It is furthermore assumed that the correction for dilatation effects in the {kappa}-{epsilon} system can be determined from the constraint of conservation of the angular momentum of turbulence per unit mass. Simple corrections of the {kappa}-{epsilon} system are proposed for fast chemistry diffusion and premixed flames subject to variable pressure gradients, which offer substantial improvements in the predictions of the flames. some problems remain, particularly in predictions of turbulence in premixed flames, owing to large scale instabilities of the flames observed in the experiments.

Chomiak, J.; Nisbet, J.R. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Thermo and Fluid Dynamics] [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Thermo and Fluid Dynamics

1995-08-01T23:59:59.000Z

286

IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 43, NO. 4, APRIL 2008 881 Exploring Variability and Performance  

E-Print Network [OSTI]

IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 43, NO. 4, APRIL 2008 881 Exploring Variability consumption of these systems ultimately limits form factor, battery life, and complexity. It is therefore

Austin, Todd M.

287

Correlated spectral variability in brown dwarfs  

E-Print Network [OSTI]

Models of brown dwarf atmospheres suggest they exhibit complex physical behaviour. Observations have shown that they are indeed dynamic, displaying small photometric variations over timescales of hours. Here I report results of infrared (0.95-1.64 micron) spectrophotometric monitoring of four field L and T dwarfs spanning timescales of 0.1-5.5 hrs, the goal being to learn more about the physical nature of this variability. Spectra are analysed differentially with respect to a simultaneously observed reference source in order to remove Earth-atmospheric variations. The variability amplitude detected is typically 2-10%, depending on the source and wavelength. I analyse the data for correlated variations between spectral indices. This approach is more robust than single band or chisq analyses, because it does not assume an amplitude for the (often uncertain) noise level (although the significance test still assumes a shape for the noise power spectrum). Three of the four targets show significant evidence for correlated variability. Some of this can be associated with specific features including Fe, FeH, VO and KI, and there is good evidence for intrinsic variability in water and possibly also methan. Yet some of this variability covers a broader spectral range which would be consistent with dust opacity variations. The underlying common cause is plausibly localized temperature or composition fluctuations caused by convection. Looking at the high signal-to-noise ratio stacked spectra we see many previously identified spectral features of L and T dwarfs, such as KI, NaI, FeH, water and methane. In particular we may have detected methane absorption at 1.3-1.4 micron in the L5 dwarf SDSS 0539-0059.

C. A. L. Bailer-Jones

2007-11-28T23:59:59.000Z

288

Modeling of ECM Controlled Series Fan-powered VAV Terminal Units  

E-Print Network [OSTI]

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...

Yin, Peng

2011-10-21T23:59:59.000Z

289

Energy Efficiency Improvement and Cost Saving Opportunities for the Pharmaceutical Industry. An ENERGY STAR Guide for Energy and Plant Managers  

E-Print Network [OSTI]

for its cooling tower water. Solar air heating. Solar airSolar air heating Building insulation Restriction of sash openings Variable-air-volume hoods Improved filtration quality and efficiency Cooling towers

Galitsky, Christina

2008-01-01T23:59:59.000Z

290

Diagnosis of Effectiveness of HVAC System and Energy Performance of Osaka-Gas Building through Retro-Commissioning Part 1 Outline of HVAC Systems and Diagnosis of Energy Efficiency of Air Systems  

E-Print Network [OSTI]

-22b AC-22a AC-22b INV Output 97% (58.2Hz) 84% (50.4Hz) 70% (40.8Hz) Air volume at the outlet duct 87,848 m3/h 56,968 m3/h 42,635 m3/h Power consumption 70.0kW 46.8kW 20.6kW Outlet static pressure 854Pa 798Pa 802Pa 5F MD... 2013 Note 1: Circles (?) in Figure 6.1 represent operating points of the fans alone. Triangles (?) represent operating air volumes calculated based on the fan’s static pressure. Note 2: Numbers in boxes ??? represent air volume measurement...

Hatanaka,T.; Aoki,K; Matsuda, N.; Yamaha,M.; Tanaka,H.; Nakahara,N.

2014-01-01T23:59:59.000Z

291

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

E-Print Network [OSTI]

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 ...

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

2009-01-01T23:59:59.000Z

292

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

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

293

The Evolutionary Status of M3 RR Lyrae Variables: Breakdown of the Canonical Framework?  

E-Print Network [OSTI]

In order to test the prevailing paradigm of horizontal-branch (HB) stellar evolution, we use the large databases of measured RR Lyrae parameters for the globular cluster M3 (NGC 5272) recently provided by Bakos et al. and Corwin & Carney. We compare the observed distribution of fundamentalized periods against the predictions of synthetic HBs. The observed distribution shows a sharp peak at P_f ~ 0.55 d, which is primarily due to the RRab variables, whereas the model predictions instead indicate that the distribution should be more uniform in P_f, with a buildup of variables with shorter periods (P_f < 0.5 d). Detailed statistical tests show, for the first time, that the observed and predicted distributions are incompatible with one another at a high significance level. We show that the sharp peak in the M3 period distribution receives a significant contribution from the Blazhko variables in the cluster. We also show that M15 (NGC 7078) and M68 (NGC 4590) show similar peaks in their P_f distributions, which in spite of being located at a similar P_f value as M3's, can be primarily ascribed to the RRc variables. Again similar to M3, a demise of RRc variables towards the blue edge of the instability strip is present in these two globulars. This is again in sharp contrast with the evolutionary scenario, which also foresees a strong buildup of RRc variables with short periods in OoII globulars. We speculate that, in OoI systems, RRab variables may get "trapped" close to the transition line between RRab and RRc pulsators as they evolve to the blue, whereas in OoII systems it is the RRc variables that may get "trapped" instead, as they evolve to the red, before changing their pulsation mode to RRab. Such a scenario is supported by the available CMDs and Bailey diagrams for M3, M15, and M68.

M. Catelan

2003-09-05T23:59:59.000Z

294

NEAR-INFRARED VARIABILITY AMONG YOUNG STELLAR OBJECTS IN THE STAR FORMATION REGION CYGNUS OB7  

SciTech Connect (OSTI)

We present an analysis of near-infrared time-series photometry in J, H, and K bands for about 100 epochs of a 1 Degree-Sign Multiplication-Sign 1 Degree-Sign region of the Lynds 1003/1004 dark cloud in the Cygnus OB7 region. Augmented by data from the Wide-field Infrared Survey Explorer, we identify 96 candidate disk bearing young stellar objects (YSOs) in the region. Of these, 30 are clearly Class I or earlier. Using the Wide-Field Imaging Camera on the United Kingdom Infrared Telescope, we were able to obtain photometry over three observing seasons, with photometric uncertainty better than 0.05 mag down to J Almost-Equal-To 17. We study detailed light curves and color trajectories of {approx}50 of the YSOs in the monitored field. We investigate the variability and periodicity of the YSOs and find the data are consistent with all YSOs being variable in these wavelengths on timescales of a few years. We divide the variability into four observational classes: (1) stars with periodic variability stable over long timescales, (2) variables which exhibit short-lived cyclic behavior, (3) long-duration variables, and (4) stochastic variables. Some YSO variability defies simple classification. We can explain much of the observed variability as being due to dynamic and rotational changes in the disk, including an asymmetric or changing blocking fraction, changes to the inner disk hole size, as well as changes to the accretion rate. Overall, we find that the Class I:Class II ratio of the cluster is consistent with an age of <1 Myr, with at least one individual, wildly varying source {approx}100, 000 yr old. We have also discovered a Class II eclipsing binary system with a period of 17.87 days.

Wolk, Scott J.; Rice, Thomas S. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Aspin, Colin [Institute for Astronomy, University of Hawaii at Manoa, 640 North Aohoku Place, Hilo, HI 96720 (United States)

2013-08-20T23:59:59.000Z

295

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...

296

IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 12, NO. 1, JANUARY 1997 87 Fuzzy Logic Based Intelligent Control of a Variable  

E-Print Network [OSTI]

system. The generation system has fuzzy logic control with vector control in the inner loops. A fuzzyIEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 12, NO. 1, JANUARY 1997 87 Fuzzy Logic Based a variable speed wind genera- tion system where fuzzy logic principles are used for efficiency optimization

Simões, Marcelo Godoy

297

The VISTA Variables in the Via Lactea survey: A first glance on stellar variability  

E-Print Network [OSTI]

VISTA Variables in the Via Lactea (VVV) is an ESO public near-infrared variability survey of the Galactic bulge and an adjacent area of the southern mid-plane. It will produce a deep atlas in the ZYJHKs filters, and a Ks-band time-series database of ~10^9 point sources, among which >~10^6 are expected to be variable. One of VVV's immediate scientific goals is to provide accurate light curves of primary distance indicators, such as RR Lyrae stars, and utilize these data to produce a 3-D map of the surveyed area and, ultimately, trace the structure of the inner Galaxy. We give, based on the first ~1.5 years of the 5-yr-long survey, an early assessment on the basic properties and the overall quality of the VVV photometric time-series, and use these data to put an estimate of the fraction of variable stellar sources.

Dekany, I; Minniti, D

2011-01-01T23:59:59.000Z

298

Thermodynamics in variable speed of light theories  

E-Print Network [OSTI]

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.

Juan Racker; Pablo Sisterna; Hector Vucetich

2009-11-30T23:59:59.000Z

299

Correlated spectral variability in brown dwarfs  

E-Print Network [OSTI]

Models of brown dwarf atmospheres suggest they exhibit complex physical behaviour. Observations have shown that they are indeed dynamic, displaying small photometric variations over timescales of hours. Here I report results of infrared (0.95-1.64 micron) spectrophotometric monitoring of four field L and T dwarfs spanning timescales of 0.1-5.5 hrs, the goal being to learn more about the physical nature of this variability. Spectra are analysed differentially with respect to a simultaneously observed reference source in order to remove Earth-atmospheric variations. The variability amplitude detected is typically 2-10%, depending on the source and wavelength. I analyse the data for correlated variations between spectral indices. This approach is more robust than single band or chisq analyses, because it does not assume an amplitude for the (often uncertain) noise level (although the significance test still assumes a shape for the noise power spectrum). Three of the four targets show significant evidence for cor...

Bailer-Jones, C A L

2007-01-01T23:59:59.000Z

300

X-ray variability in M87  

E-Print Network [OSTI]

We present the evidence for X-ray variability from the core and from knot A in the M87 jet based on data from two observations with the Einstein Observatory High Resolution Imager (HRI) and three observations with the ROSAT HRI. The core intensity showed a 16% increase in 17 months ('79-'80); a 12% increase in the 3 years '92 to '95; and a 17% drop in the last half of 1995. The intensity of knot A appears to have decreased by 16% between 92Jun and 95Dec. Although the core variability is consistent with general expectations for AGN nuclei, the changes in knot A provide constraints on the x-ray emission process and geometry. Thus we predict that the x-ray morphology of knot A will differ significantly from the radio and optical structure.

D. E. Harris; J. A. Biretta; W. Junor

1996-12-05T23:59:59.000Z

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


301

Thermodynamics in variable speed of light theories  

SciTech Connect (OSTI)

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.

Racker, Juan [CONICET, Centro Atomico Bariloche, Avenida Bustillo 9500 (8400), San Carlos De Bariloche (Argentina); Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, Paseo del Bosque S/N (1900), La Plata (Argentina); Sisterna, Pablo [Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350 (7600), Mar del Plata (Argentina); Vucetich, Hector [Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, Paseo del Bosque S/N (1900), La Plata (Argentina)

2009-10-15T23:59:59.000Z

302

Variable aperture collimator for high energy radiation  

DOE Patents [OSTI]

An apparatus is disclosed providing a variable aperture energy beam collimator. A plurality of beam opaque blocks are in sliding interface edge contact to form a variable aperture. The blocks may be offset at the apex angle to provide a non-equilateral aperture. A plurality of collimator block assemblies may be employed for providing a channel defining a collimated beam. Adjacent assemblies are inverted front-to-back with respect to one another for preventing noncollimated energy from emerging from the apparatus. An adjustment mechanism comprises a cable attached to at least one block and a hand wheel mechanism for operating the cable. The blocks are supported by guide rods engaging slide brackets on the blocks. The guide rods are pivotally connected at each end to intermediate actuators supported on rotatable shafts to change the shape of the aperture. A divergent collimated beam may be obtained by adjusting the apertures of adjacent stages to be unequal.

Hill, Ronald A. (Albuquerque, NM)

1984-05-22T23:59:59.000Z

303

Teleportation using continuous variable quantum cloning machine  

E-Print Network [OSTI]

We show that an unknown quantum state in phase space can be teleported via three-mode entanglement generated by continuous variable quantum cloning machine (transformation). Further, proceeding with our teleportation protocol we are able to improve the fidelity of teleportation obtained by Loock et.al. [Phys.Rev.Lett. 84, 3482(2000)]. Also we study here the entanglement between the two output copies from cloning machine.

Satyabrata Adhikari

2008-02-15T23:59:59.000Z

304

Multivector Functions of a Multivector Variable  

E-Print Network [OSTI]

In this paper we develop with considerable details a theory of multivector functions of a $p$-vector variable. The concepts of limit, continuity and differentiability are rigorously studied. Several important types of derivatives for these multivector functions are introduced, as e.g., the $A$% -directional derivative (where $A$ is a $p$-vector) and the generalized concepts of curl, divergence and gradient. The derivation rules for different types of products of multivector functions and for compositon of multivector functions are proved.

A. M. Moya; V. V. Fernández; W. A. Rodrigues Jr

2002-12-18T23:59:59.000Z

305

Hidden Variables and Quantum Statistics Nature  

E-Print Network [OSTI]

It is shown that the nature of quantum statistics can be clarified by assuming the existence of a background of random gravitational fields and waves, distributed isotropically in the space. This background is responsible for correlating phases of oscillations of identical microobjects. If such a background of random gravitational fields and waves is considered as hidden variables then taking it into account leads to the Bell-type inequalities that are fairly consistent with the experimental data.

T. F. Kamalov

2007-03-14T23:59:59.000Z

306

SOLVING SYSTEMS OF NONLINEAR EQUATIONS WITH ...  

E-Print Network [OSTI]

Nov 2, 2006 ... an exothermic first-order irreversible reaction. When certain variables are eliminated, the model results in a system of two nonlinear equations.

2006-11-02T23:59:59.000Z

307

Software Product Line Engineering for Long-lived, Sustainable Systems  

E-Print Network [OSTI]

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

Lutz, Robyn R.

308

EPR-Steering measure for two-mode continuous variable states  

E-Print Network [OSTI]

Steering is a manifestation of quantum correlations that embodies the Einstein-Podolsky-Rosen (EPR) paradox. While there have been recent attempts to quantify steering, continuous variable systems remained elusive. We introduce a steering measure for two-mode continuous variable systems that is valid for arbitrary states. The measure is based on the violation of an optimized variance test for the EPR paradox, and admits a computable and experimentally friendly lower bound only depending on the second moments of the state, which reduces to a recently proposed quantifier of steerability by Gaussian measurements. We further show that Gaussian states are extremal with respect to our measure, minimizing it among all continuous variable states with fixed second moments. As a byproduct of our analysis, we generalize and relate well-known EPR-steering criteria. Finally an operational interpretation is provided, as the proposed measure is shown to quantify the optimal guaranteed key rate in semi-device independent qua...

Kogias, Ioannis

2014-01-01T23:59:59.000Z

309

EPR-Steering measure for two-mode continuous variable states  

E-Print Network [OSTI]

Steering is a manifestation of quantum correlations that embodies the Einstein-Podolsky-Rosen (EPR) paradox. While there have been recent attempts to quantify steering, continuous variable systems remained elusive. We introduce a steering measure for two-mode continuous variable systems that is valid for arbitrary states. The measure is based on the violation of an optimized variance test for the EPR paradox, and admits a computable and experimentally friendly lower bound only depending on the second moments of the state, which reduces to a recently proposed quantifier of steerability by Gaussian measurements. We further show that Gaussian states are extremal with respect to our measure, minimizing it among all continuous variable states with fixed second moments. As a byproduct of our analysis, we generalize and relate well-known EPR-steering criteria. Finally an operational interpretation is provided, as the proposed measure is shown to quantify the optimal guaranteed key rate in semi-device independent quantum key distribution.

Ioannis Kogias; Gerardo Adesso

2014-11-03T23:59:59.000Z

310

Infrared Properties of Cataclysmic Variables from 2MASS Results from the 2nd Incremental Data Release  

E-Print Network [OSTI]

Because accretion-generated luminosity dominates the radiated energy of most cataclysmic variables, they have been ``traditionally'' observed primarily at short wavelengths. Infrared observations of cataclysmic variables contribute to the understanding of key system components that are expected to radiate at these wavelengths, such as the cool outer disk, accretion stream, and secondary star. We have compiled the J, H, and Ks photometry of all cataclysmic variables located in the sky coverage of the 2 Micron All Sky Survey (2MASS) 2nd Incremental Data Release. This data comprises 251 systems with reliably identified near-IR counterparts and S/N > 10 photometry in one or more of the three near-IR bands.

Hoard, D W; Clark, L L; Bowers, T P; Bowers, Timothy P.

2001-01-01T23:59:59.000Z

311

Variable speed wind turbine generator with zero-sequence filter  

DOE Patents [OSTI]

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.

Muljadi, E.

1998-08-25T23:59:59.000Z

312

Variable speed wind turbine generator with zero-sequence filter  

DOE Patents [OSTI]

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.

Muljadi, Eduard (Golden, CO)

1998-01-01T23:59:59.000Z

313

Variable Speed Wind Turbine Generator with Zero-sequence Filter  

DOE Patents [OSTI]

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.

Muljadi, Eduard (Golden, CO)

1998-08-25T23:59:59.000Z

314

Variable diameter wind turbine rotor blades  

DOE Patents [OSTI]

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.

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

2005-12-06T23:59:59.000Z

315

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

E-Print Network [OSTI]

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

Rohling, Eelco

316

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

E-Print Network [OSTI]

of electrical power flow in the machine. Cost is a driving factor in the design of such a system, and the power frequency than PWM as well. II. VARIABLE­SPEED ELECTRIC MACHINE DRIVES While the choice of driveSimplified Modelling and Control of a Synchronous Machine with Variable­Speed Six­Step Drive

Sanders, Seth

317

Integrated Analysis for the Design of Reusable TPS based on Variable Transpiration Cooling for Hypersonic Cruise  

E-Print Network [OSTI]

with the high dynamic pressure flight trajectories, generates surface temperatures for which the strength1 Integrated Analysis for the Design of Reusable TPS based on Variable Transpiration Cooling of hypersonic air-breathing vehicles presents formidable challenges. Reusable thermal protection systems (TPS

Texas at Arlington, University of

318

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

319

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

E-Print Network [OSTI]

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

Parasuraman, Raja

320

Energy-aware Allocation of Dynamic Variables in Partitioned Memory Architectures  

E-Print Network [OSTI]

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

Simha, Rahul

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


321

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

E-Print Network [OSTI]

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

Kreinovich, Vladik

322

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.

323

Variability in continuous traffic monitoring data  

SciTech Connect (OSTI)

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.

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

324

Heart Rate Variability Analysis Using Threshold of Wavelet Package Coefficients  

E-Print Network [OSTI]

In this paper, a new efficient feature extraction method based on the adaptive threshold of wavelet package coefficients is presented. This paper especially deals with the assessment of autonomic nervous system using the background variation of the signal Heart Rate Variability HRV extracted from the wavelet package coefficients. The application of a wavelet package transform allows us to obtain a time-frequency representation of the signal, which provides better insight in the frequency distribution of the signal with time. A 6 level decomposition of HRV was achieved with db4 as mother wavelet, and the above two bands LF and HF were combined in 12 specialized frequencies sub-bands obtained in wavelet package transform. Features extracted from these coefficients can efficiently represent the characteristics of the original signal. ANOVA statistical test is used for the evaluation of proposed algorithm.

Kheder, G; Massoued, M Ben; Samet, M

2009-01-01T23:59:59.000Z

325

Method for curing polymers using variable-frequency microwave heating  

DOE Patents [OSTI]

A method for curing polymers incorporating a variable frequency microwave furnace system designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity is disclosed. By varying the frequency of the microwave signal, non-uniformities within the cavity are minimized, thereby achieving a more uniform cure throughout the workpiece. 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. The furnace cavity may be adapted to be used to cure materials defining a continuous sheet or which require compressive forces during curing. 15 figs.

Lauf, R.J.; Bible, D.W.; Paulauskas, F.L.

1998-02-24T23:59:59.000Z

326

Method for curing polymers using variable-frequency microwave heating  

DOE Patents [OSTI]

A method for curing polymers (11) incorporating a variable frequency microwave furnace system (10) designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity (34). By varying the frequency of the microwave signal, non-uniformities within the cavity (34) are minimized, thereby achieving a more uniform cure throughout the workpiece (36). 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. The furnace cavity (34) may be adapted to be used to cure materials defining a continuous sheet or which require compressive forces during curing.

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

1998-01-01T23:59:59.000Z

327

Payback enormous for variable-frequency motor drives  

SciTech Connect (OSTI)

The City Utilities of Springfield's (Mo) 200-MW Southwest power station is a 200-MW plant anchored around a single coal-fired steam generator and its major support systems, including an electrostatic precipitator (ESP) and two wet limestone scrubbers. In the late 1980s, engineers at Southwest began evaluating the feasibility of installing variable-frequency drives (VFD) to reduce the plant's parasitic load and boost overall performance. This article reports on VFDs installed to control the induced draft (i-d) and forced-draft (f-d) fan motors at the plant. The devices have surpassed the utility's expectations by reducing parasitic load, improving combustion control, and increasing overall plant reliability. Virtually every major plant component--including the ESPs and scrubbers--performs better as a result of the retrofit.

Collins, S.

1993-02-01T23:59:59.000Z

328

Identification of building applications for a variable-conductance insulation  

SciTech Connect (OSTI)

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.

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

329

Allocating Variability and Reserve Requirements (Presentation)  

SciTech Connect (OSTI)

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.

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

2011-10-01T23:59:59.000Z

330

Adhesive bonding using variable frequency microwave energy  

DOE Patents [OSTI]

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.

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

331

Long-Term Wind Power Variability  

SciTech Connect (OSTI)

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.

Wan, Y. H.

2012-01-01T23:59:59.000Z

332

Plasma heating in a variable magnetic field  

SciTech Connect (OSTI)

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.

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

333

Adhesive bonding using variable frequency microwave energy  

DOE Patents [OSTI]

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.

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

1998-09-08T23:59:59.000Z

334

Adhesive bonding using variable frequency microwave energy  

DOE Patents [OSTI]

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.

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

1998-08-25T23:59:59.000Z

335

A variable parameter thermionic energy converter  

E-Print Network [OSTI]

A VARIABLE PARAMETER THERMIONIC ENERGY CONVERTER A Thesis By Bobby Joe Bragg Submitted to the Graduate School of the Texas A 8c M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE August, 1967 Major... LIST OF FIGURES FIGURE 1. SIMPLE SCHEMATIC OF A THERMIONIC CONVERTER PAGE 2. POWER VS SPACING WITH A MINIMUM POWER POINT 3. POWER VS SPACING WITH NO MINIMUM POWER POINT 4. CONVERTER MOTIVE DIAGRAM~ O'E = 5. CONVERTER MOTIVE DIAGRAM~ 6. CONVERTER...

Bragg, Bobby Joe

1967-01-01T23:59:59.000Z

336

Crystal diffraction lens with variable focal length  

DOE Patents [OSTI]

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.

Smither, R.K.

1991-04-02T23:59:59.000Z

337

Variable Temperature UHV STM/AFM | EMSL  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered energy consumption by sectorlongUpdatesValley wins 2015 Science BowlVariable

338

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

SciTech Connect (OSTI)

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.

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

1995-06-01T23:59:59.000Z

339

Shape Changing and Accelerating Solitons in the Integrable Variable Mass Sine-Gordon Model  

SciTech Connect (OSTI)

The sine-Gordon model with a variable mass (VMSG) appears in many physical systems, ranging from the current through a nonuniform Josephson junction to DNA-promoter dynamics. Such models are usually nonintegrable with solutions found numerically or perturbatively. We construct a class of VMSG models, integrable at both the classical and the quantum levels with exact soliton solutions, which can accelerate and change their shape, width, and amplitude simulating realistic inhomogeneous systems at certain limits.

Kundu, Anjan [Theory Group, Saha Institute of Nuclear Physics, Calcutta (India)

2007-10-12T23:59:59.000Z

340

Wave spectral energy variability in the northeast Peter D. Bromirski  

E-Print Network [OSTI]

Wave spectral energy variability in the northeast Pacific Peter D. Bromirski Integrative January 2005; published 8 March 2005. [1] The dominant characteristics of wave energy variability] s wave spectral energy components are considered separately. Empirical orthogonal function (EOF) analyses

Bromirski, Peter D.

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


341

Benchmarking Variable Cost Performance in an Industrial Power Plant  

E-Print Network [OSTI]

One of the most perplexing problems for industrial power plants committed to improving competitiveness is measuring variable cost performance over time. Because variable costs like fuel and electricity represent the overwhelming majority of power...

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

342

Bayesian variable selection in clustering via dirichlet process mixture models  

E-Print Network [OSTI]

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...

Kim, Sinae

2007-09-17T23:59:59.000Z

343

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

SciTech Connect (OSTI)

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.

Miller, M.

2012-07-01T23:59:59.000Z

344

New Report: Integrating Variable Wind Energy into the Grid |...  

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

Report: Integrating Variable Wind Energy into the Grid New Report: Integrating Variable Wind Energy into the Grid December 19, 2011 - 2:00pm Addthis The Energy Department and...

345

Intraseasonal variability in South America recorded in stable water isotopes  

E-Print Network [OSTI]

Intraseasonal variability in South America recorded in stable water isotopes Christophe Sturm,1 cores (South America) has illustrated the key role such archives can play in past climate South America, highlighting the internal atmospheric variability, as opposed to external forcing

Sturm, Christophe "Kristof"

346

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

SciTech Connect (OSTI)

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.

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

2012-04-01T23:59:59.000Z

347

Dynamical dark energy or variable cosmological parameters?  

E-Print Network [OSTI]

One of the main aims in the next generation of precision cosmology experiments will be an accurate determination of the equation of state (EOS) for the dark energy (DE). If the latter is dynamical, the resulting barotropic index \\omega should exhibit a non-trivial evolution with the redshift. Usually this is interpreted as a sign that the mechanism responsible for the DE is related to some dynamical scalar field, and in some cases this field may behave non-canonically (phantom field). Present observations seem to favor an evolving DE with a potential phantom phase near our time. In the literature there is a plethora of dynamical models trying to describe this behavior. Here we show that the simplest option, namely a model with a variable cosmological term, \\Lambda=\\Lambda(t), leads in general to a non-trivial effective EOS, with index \\omega_e, which may naturally account for these data features. We prove that in this case there is always a ``crossing'' of the \\omega_e=-1 barrier near our time. We also show how this effect is modulated (or even completely controled) by a variable Newton's constant G=G(t).

Joan Sola; Hrvoje Stefancic

2005-12-21T23:59:59.000Z

348

Variably insulating portable heater/cooler  

DOE Patents [OSTI]

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.

Potter, Thomas F. (Denver, CO)

1998-01-01T23:59:59.000Z

349

Variably insulating portable heater/cooler  

DOE Patents [OSTI]

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.

Potter, T.F.

1998-09-29T23:59:59.000Z

350

IS ACTIVE REGION CORE VARIABILITY AGE DEPENDENT?  

SciTech Connect (OSTI)

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.

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

351

Interannual variability of Caribbean rainfall, ENSO and the Atlantic Ocean  

E-Print Network [OSTI]

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

Columbia University

352

The EUV and X-ray Emission of Nonmagnetic Cataclysmic Variables  

E-Print Network [OSTI]

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.

Christopher W. Mauche

1997-09-11T23:59:59.000Z

353

Unifying parameter estimation and the Deutsch-Jozsa algorithm for continuous variables  

E-Print Network [OSTI]

We reveal a close relationship between quantum metrology and the Deutsch-Jozsa algorithm on continuous variable quantum systems. We develop a general procedure, characterized by two parameters, that unifies parameter estimation and the Deutsch-Jozsa algorithm. Depending on which parameter we keep constant, the procedure implements either the parameter estimation protocol or the Deutsch-Jozsa algorithm. The parameter estimation part of the procedure attains the Heisenberg limit and is therefore optimal. Due to the use of approximate normalizable continuous variable eigenstates the Deutsch-Jozsa algorithm is probabilistic. The procedure estimates a value of an unknown parameter and solves the Deutsch-Jozsa problem without the use of any entanglement.

Marcin Zwierz; Carlos A. Pérez-Delgado; Pieter Kok

2010-08-19T23:59:59.000Z

354

What measures climate? A variety of variables including their variability and extreme values determine climate for  

E-Print Network [OSTI]

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

Allan, Richard P.

355

Imprecise Reliability Assessment and Decision-Making when the Type of the Probability Distribution of the Random Variables is  

E-Print Network [OSTI]

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

Nikolaidis, Efstratios

356

Variable Interactions in Query-Driven Visualization  

SciTech Connect (OSTI)

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.

Bethel, E. Wes; Gosink, Luke J.; Anderson, John C.; Joy, Kenneth I.

2007-10-25T23:59:59.000Z

357

Improvements of the Variable Thermal Resistance  

E-Print Network [OSTI]

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.

Székely, V; Kollar, E

2008-01-01T23:59:59.000Z

358

Improvements of the Variable Thermal Resistance  

E-Print Network [OSTI]

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.

V. Szekely; S. Torok; E. Kollar

2008-01-07T23:59:59.000Z

359

Variable-field permanent magnet dipole  

SciTech Connect (OSTI)

A new concept for a variable-field permanent-magnet dipole (VFPMD) has been designed, fabricated, and tested at Los Alamos. The VFPMD is a C-shaped sector magnet with iron poles separated by a large block of magnet material (SmCo). The central field can be continuously varied from 0.07 T to 0.3 T by moving an iron shunt closer or further away from the back of the magnet. The shunt is specially shaped to make the dependence of the dipole field strength on the shunt position as linear as possible. The dipole has a 2.8 cm high by 8 cm wide aperture with {approximately}10 cm long poles.

Barlow, D.B.; Kraus, R.H. Jr.; Meyer, R.E.

1993-10-01T23:59:59.000Z

360

Dissecting magnetar variability with Bayesian hierarchical models  

E-Print Network [OSTI]

Neutron stars are a prime laboratory for testing physical processes under conditions of strong gravity, high density, and extreme magnetic fields. Among the zoo of neutron star phenomena, magnetars stand out for their bursting behaviour, ranging from extremely bright, rare giant flares to numerous, less energetic recurrent bursts. The exact trigger and emission mechanisms for these bursts are not known; favoured models involve either a crust fracture and subsequent energy release into the magnetosphere, or explosive reconnection of magnetic field lines. In the absence of a predictive model, understanding the physical processes responsible for magnetar burst variability is difficult. Here, we develop an empirical model that decomposes magnetar bursts into a superposition of small spike-like features with a simple functional form, where the number of model components is itself part of the inference problem. The cascades of spikes that we model might be formed by avalanches of reconnection, or crust rupture afte...

Huppenkothen, D; Hogg, D W; Murray, I; Frean, M; Elenbaas, C; Watts, A L; Levin, Y; van der Horst, A J; Kouveliotou, C

2015-01-01T23:59:59.000Z

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


361

Modular design of biological systems  

E-Print Network [OSTI]

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 ...

Norville, Julie Erin, 1980-

2012-01-01T23:59:59.000Z

362

Cyclic Variability During the Transition Between Spark-ignited Combustion and HCCI  

SciTech Connect (OSTI)

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.

Edwards, Kevin Dean [ORNL; Daw, C Stuart [ORNL; Wagner, Robert M [ORNL; Green Jr, Johney Boyd [ORNL

2006-01-01T23:59:59.000Z

363

Climate dynamics and fluid mechanics: Natural variability and related uncertainties  

E-Print Network [OSTI]

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.

Michael Ghil; Mickaël D. Chekroun; Eric Simonnet

2010-06-15T23:59:59.000Z

364

Energy storage connection system  

DOE Patents [OSTI]

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.

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

365

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

E-Print Network [OSTI]

simulation with credible software programs is a proven feasible way to get quantitative comparison of the energy

Hong, Tainzhen

2010-01-01T23:59:59.000Z

366

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

E-Print Network [OSTI]

the current movement toward net zero energy buildings, manyThe movement towards net zero energy buildings brings

Hong, Tainzhen

2010-01-01T23:59:59.000Z

367

Statistical Characterization of Solar Photovoltaic Power Variability at Small Timescales: Preprint  

SciTech Connect (OSTI)

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.

Shedd, S.; Hodge, B.-M.; Florita, A.; Orwig, K.

2012-08-01T23:59:59.000Z

368

Plant variability and bio-fuel properties  

SciTech Connect (OSTI)

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.

Agblevor, F.A.; Besler-Guran, S.; Wiselogel, A.E. [National Renewable Energy Lab., Golden, CO (United States)

1995-11-01T23:59:59.000Z

369

Impacts of Variability and Uncertainty in Solar Photovoltaic Generation at Multiple Timescales  

SciTech Connect (OSTI)

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.

Ela, E.; Diakov, V.; Ibanez, E.; Heaney, M.

2013-05-01T23:59:59.000Z

370

White dwarf masses in cataclysmic variables  

E-Print Network [OSTI]

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...

Wijnen, T P G; Schreiber, M R

2015-01-01T23:59:59.000Z

371

Integrating Variable Renewable Energy in Electric Power Markets: Best Practices from International Experience, Summary for Policymakers  

SciTech Connect (OSTI)

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.

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

2012-04-01T23:59:59.000Z

372

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

373

A mini-survey for variability in early L dwarfs  

E-Print Network [OSTI]

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.

F. J. Clarke; B. R. Oppenheimer; C. G. Tinney

2002-05-27T23:59:59.000Z

374

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...

375

Multiscale modeling of spatially variable water and energy balance processes  

E-Print Network [OSTI]

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

Famiglietti, J. S; Wood, E. F

1994-01-01T23:59:59.000Z

376

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...

377

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...

378

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...

379

Process for applying control variables having fractal structures  

DOE Patents [OSTI]

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.

Bullock, IV, Jonathan S. (Oak Ridge, TN); Lawson, Roger L. (Oliver Springs, TN)

1996-01-01T23:59:59.000Z

380

Process for applying control variables having fractal structures  

DOE Patents [OSTI]

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.

Bullock, J.S. IV; Lawson, R.L.

1996-01-23T23:59:59.000Z

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


381

18.112 Functions of a Complex Variable, Fall 2005  

E-Print Network [OSTI]

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 ...

Helgason, Sigurdur, 1927-

382

18.112 Functions of a Complex Variable, Fall 2006  

E-Print Network [OSTI]

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 ...

Helgason, Sigurdur, 1927-

383

Polymorphic Typing of Variables and References GEOFFREY SMITH  

E-Print Network [OSTI]

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

Smith, Geoffrey

384

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

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

of variable orifice fuel injector are described that will extend the operation maps of early PCCI combustion and enable dual-mode combustion over full operating maps....

385

Variable Charge Soils: Their Mineralogy, Chemistry and Management  

SciTech Connect (OSTI)

In this article, the mineralogy, chemistry and management of variable charge soils that are spread throughout the world are treated in details.

Qafoku, Nik; Van Ranst, Eric; Noble, Andrew; Baert, Geert

2004-07-01T23:59:59.000Z

386

Characterization of proper optimal elements with variable ordering ...  

E-Print Network [OSTI]

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.

2015-01-14T23:59:59.000Z

387

Sandia National Laboratories: wavelet variability model  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administrationcontroller systems controller systems Scaled Wind Farmoutputwaterwavelet

388

The Long Period AM Her-like Cataclysmic Variable RXJ051541+0104.6  

E-Print Network [OSTI]

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.

F. M. Walter; S. J. Wolk; N. R. Adams

1994-08-29T23:59:59.000Z

389

Indian Monsoon Depression: Climatology and Variability  

SciTech Connect (OSTI)

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.

Yoon, Jin-Ho; Huang, Wan-Ru (Judy) [Judy

2012-03-09T23:59:59.000Z

390

Hybrid electromagnetic transient simulation with the state variable representation of HVDC converter plant  

SciTech Connect (OSTI)

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.

Zavahir, J.M.; Arrillaga, J.; Watson, N.R. (Univ. of Canterbury, Christchurch (New Zealand))

1993-07-01T23:59:59.000Z

391

Mass Market Demand Response and Variable Generation Integration Issues: A Scoping Study  

SciTech Connect (OSTI)

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.

Cappers, Peter; Mills, Andrew; Goldman, Charles; Wiser, Ryan; Eto, Joseph H.

2011-09-10T23:59:59.000Z

392

optimization of discrete control systems with varying structure  

E-Print Network [OSTI]

(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.

xx

2004-12-16T23:59:59.000Z

393

Electron cyclotron emission spectrometry on the Tokamak a Configuration Variable  

SciTech Connect (OSTI)

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.

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

394

Variable current speed controller for eddy current motors  

DOE Patents [OSTI]

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.

Gerth, H.L.; Bailey, J.M.; Casstevens, J.M.; Dixon, J.H.; Griffith, B.O.; Igou, R.E.

1982-03-12T23:59:59.000Z

395

Applications of Geostatistics What is different about environmental variables  

E-Print Network [OSTI]

in spoil/tailings/surroundings ­ Similar to modeling common in mining 3. Air ­ Similar to underground water techniques from machine learning · Examples MinE 422: Modeling Environmental Variables Resources: -Some there Types of variables of interest · Contaminants/pollution · Radiation · Precipitation · Temperature

Boisvert, Jeff

396

The variable and conserved interfaces of modeled olfactory receptor proteins  

E-Print Network [OSTI]

of the odorants' contact residues in OR proteins remained unavailable. Due to the lack of X-ray crystallographicThe variable and conserved interfaces of modeled olfactory receptor proteins YITZHAK PILPEL models of other G-protein-coupled receptors, allows us to analyze the OR amino acid variability patterns

Church, George M.

397

Testing Dependence Among Serially Correlated Multi-category Variables  

E-Print Network [OSTI]

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...

Pesaran, M Hashem; Timmermann, Allan

398

Rank/sparsity minimization and latent variable graphical model selection  

E-Print Network [OSTI]

Rank/sparsity minimization and latent variable graphical model selection Pablo A. Parrilo · Complication: latent variables · Rank/sparsity decomposition, and generalizations · Convex optimization cond. on other vars. 1 3 2 4 Sparse Low-rank Concentration matrix #12;Proposal for modeling · Decompose

Parrilo, Pablo A.

399

Weaving Variability into Domain Metamodels Brice Morin1  

E-Print Network [OSTI]

greater learning curve for DSMLs stakeholders and a significant overhead in product line engineering. We should be designed, validated, implemented rapidly, at a low cost. The Soft- ware Product Line [1] (SPL variability capabilities. In particular we detail how variability is woven and how to perform product line

Paris-Sud XI, Université de

400

Assessment of genetic variability in a traditional cassava (Manihot esculenta  

E-Print Network [OSTI]

and of their interaction with ecological factors on the structure and evolutionary dynamics of the genetic variability the importance of the interaction between human and ecological factors in the dynamics of this diversityAssessment of genetic variability in a traditional cassava (Manihot esculenta Crantz) farming

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


401

Holographic Dark Energy Model with Modified Variable Chaplygin Gas  

E-Print Network [OSTI]

In this letter we consider a correspondence between holographic dark energy and variable modified Chaplygin gas to obtain a holographic dark energy model of the universe. The corresponding potential of the scalar field has been reconstructed which describes the modified variable Chaplygin gas. The stability of the holographic dark energy in this case is also discussed.

B. C. Paul

2010-06-17T23:59:59.000Z

402

RESEARCH ARTICLE Empirical assessment of short-term variability from  

E-Print Network [OSTI]

Variability of solar power is a key driver in increasing the cost of integrating solar power into the electric, we characterize the variability in power output of six photovoltaic plants in the USA and Canada, already generate 9% and 22% of their electricity from wind and solar power and have found means to address

403

Solar activity and earth rotation variability R. Abarca del Rioa,  

E-Print Network [OSTI]

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

Dai, Aiguo

404

A Variable Cell Model for Simulating Gas Condensate Reservoir Performance  

E-Print Network [OSTI]

, 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 for simulating gas relatively high, near-constant, oil saturation in condensate reeervoir performance has been

Al-Majed, Abdulaziz Abdullah

405

Instrumental Variables and the Search for Identification: From Supply and  

E-Print Network [OSTI]

and demand for flaxseed, the source of linseed oil.2 Wright noted the difficulty of obtaining estimatesInstrumental Variables and the Search for Identification: From Supply and Demand to Natural variables involved attempts to estimate demand and supply curves.1 Economists such as P.G. Wright, Henry

Ahmad, Sajjad

406

Device-Independent Quantum Cryptography for Continuous Variables  

E-Print Network [OSTI]

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.

Kevin Marshall; Christian Weedbrook

2014-05-27T23:59:59.000Z

407

STOCHASTIC VARIABILITY IN X-RAY EMISSION FROM THE BLACK HOLE BINARY GRS 1915+105  

SciTech Connect (OSTI)

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.

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

408

A Deep Catalog of Variable Stars in a 0.66deg^2 Lupus Field  

E-Print Network [OSTI]

We have conducted a wide-field photometric survey in a single 52'x52' field towards the Lupus Galactic Plane in an effort to detect transiting Hot Jupiter planets. The planet Lupus-TR-3b was identified from this work. The dataset also led to the detection of 494 field variables, all of which are new discoveries. This paper presents an overview of the project, along with the total catalog of variables, which comprises 190 eclipsing binaries (of contact, semi-contact and detached configurations), 51 miscellaneous pulsators of various types, 237 long period variables (P>=2d), 11 delta Scuti stars, 4 field RR Lyrae (3 disk and 1 halo) and 1 irregular variable. Our survey provides a complete catalog of W UMa eclipsing binaries in the field to V=18.8, which display a Gaussian period distribution of 0.277+/-0.036d. Several binary systems are likely composed of equal mass M-dwarf components and others display evidence of mass transfer. We find 17 candidate blue stragglers and one binary that has the shortest period known, 0.2009d (V=20.9). The frequency of eclipsing binaries (all types) is found to be 1.7+/-0.4x10^{-3} per star, substantially higher (by a factor of 3-10) than previously determined in the haloes of the globular clusters 47 Tuc and omega Cen. This indicates that cluster dynamics aids mass segregation and binary destruction.

David T. F. Weldrake; Daniel D. R. Bayliss

2007-11-29T23:59:59.000Z

409

Atomic filtering for hybrid continuous-variable/discrete-variable quantum optics  

E-Print Network [OSTI]

We demonstrate atomic filtering of frequency-degenerate photon pairs from a sub-threshold optical parametric oscillator (OPO). The filter, a modified Faraday anomalous dispersion optical filter (FADOF), achieves 70% peak transmission simultaneous with 57 dB out-of-band rejection and a 445 MHz transmission bandwidth. When applied to the OPO output, only the degenerate mode, containing one-mode squeezed vacuum, falls in the filter pass-band; all other modes are strongly suppressed. The high transmission preserves non-classical continuous-variable features, e.g. squeezing or non-gaussianity, while the high spectral purity allows reliable discrete-variable detection and heralding. Correlation and atomic absorption measurements indicate a spectral purity of 96% for the individual photons, and 98% for the photon pairs. These capabilities will enable generation of atom-resonant hybrid states, e.g. "Schr\\"odinger kittens" obtained by photon subtraction from squeezed vacuum, making these exotic states available for quantum networking and atomic quantum metrology applications.

Joanna A. Zieli?ska; Federica A. Beduini; Vito Giovanni Lucivero; Morgan W. Mitchell

2014-09-04T23:59:59.000Z

410

Active optical zoom system  

DOE Patents [OSTI]

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.

Wick, David V.

2005-12-20T23:59:59.000Z

411

Solar Reserve Methodology for Renewable Energy Integration Studies Based on Sub-Hourly Variability Analysis: Preprint  

SciTech Connect (OSTI)

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.

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

2012-08-01T23:59:59.000Z

412

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

413

Load sensing system  

DOE Patents [OSTI]

A load sensing system inexpensively monitors the weight and temperature of stored nuclear material for long periods of time in widely variable environments. The system can include an electrostatic load cell that encodes weight and temperature into a digital signal which is sent to a remote monitor via a coaxial cable. The same cable is used to supply the load cell with power. When multiple load cells are used, vast

Sohns, Carl W. (Oak Ridge, TN); Nodine, Robert N. (Knoxville, TN); Wallace, Steven Allen (Knoxville, TN)

1999-01-01T23:59:59.000Z

414

VARIABILITY OF KD VALUES IN CEMENTITIOUS MATERIALS AND SEDIMENTS  

SciTech Connect (OSTI)

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

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

2012-02-02T23:59:59.000Z

415

VARIABLE SPEED INTEGRATED INTELLIGENT HVAC BLOWER  

SciTech Connect (OSTI)

This comprehensive topical report discusses the key findings in the development of a intelligent integrated blower for HVAC applications. The benefits of rearward inclined blades over that of traditional forward inclined blades is well documented and a prototype blower design is presented. A comparison of the proposed blower to that of three typical units from the industry is presented. The design of the blower housing is also addressed and the impact of size limitations on static efficiency is discussed. Issues of air flow controllability in the rearward inclined blower is addressed and a solution to this problem is proposed. Several motor design options are discussed including inside-out radial flux designs and novel axial flux designs, all are focused on the various blower needs. The control of the motor-blower and airflow through the use of a high density inverter stage and modern digital signal processor is presented. The key technical challenges of the approach are discussed. The use of the motor as a sensor in the larger heating/ventilating system is also discussed. Diagnostic results for both the motor itself and the blower system are presented.

Shixiao Wang; Herman Wiegman; Wilson Wu; John Down; Luana Iorio; Asha Devarajan; Jing Wang; Ralph Carl; Charlie Stephens; Jeannine Jones; Paul Szczesny

2001-11-14T23:59:59.000Z

416

Abstract Efficiency issues of variable-capacitance micromotors are discussed in context of combined drive and motor  

E-Print Network [OSTI]

motors, electric drives, efficiency I. INTRODUCTION An active area of research for commercial of combined drive and motor interaction. It is shown that variable-capacitance motors ideally have nearly, the drive system consisting of both the motor and electronics is not ideal when considering different

Chapman, Patrick

417

Convex-Based Thermal Management for 3D MPSoCs Using DVFS and Variable-Flow Liquid Cooling  

E-Print Network [OSTI]

energy by up to 50% compared with tradi- tional state-of-the-art liquid cooling techniques. The proposedConvex-Based Thermal Management for 3D MPSoCs Using DVFS and Variable-Flow Liquid Cooling Francesco multi-processors system on chip (MPSoCs) using microfluidic cooling. The controller uses dynamic volt

De Micheli, Giovanni

418

Spatial and temporal variability of annual greenhouse gas fluxes from a constructed wetland in an arid region  

E-Print Network [OSTI]

(CO2). - Many constructed treatment wetland systems (CWS) have been developed to remove nutrients fromSpatial and temporal variability of annual greenhouse gas fluxes from a constructed wetland of Sustainability, 3Wetland Ecosystem Ecology Lab, Arizona State University, Tempe, AZ, USA. - Wetlands support

Hall, Sharon J.

419

Conservation Theory Process Control Using Variable Frequency Drives  

E-Print Network [OSTI]

name from the vari able DC voltage which the rectifier section pro duces. Variable DC voltage is required in order to produce controlled AC with the volts per hz ratio constant. To operate an AC motor over a speed range from 5-60 hz and still... be capable of producing con stant torque,the ratio: Volts ~ = Constant must be satisfied. The rectifier and inverter stages work in concert to produce variable voltage, variable frequency AC power. The linear relation ship between voltage and frequency...

Myers, N. S.

1980-01-01T23:59:59.000Z

420

Time resolved spectroscopy of the variable brown dwarf Kelu-1  

E-Print Network [OSTI]

We report the results of observations designed to investigate the spectroscopic signatures of dust clouds on the L2 brown dwarf Kelu-1. Time resolved medium resolution spectra show no significant evidence of variability in the dust sensitive TiO, CrH and FeH bandheads on the timescale of 1--24 hours. We do however report periodic variability in the psuedo-equivelent width of H-alpha consistent with the 1.8 hour rotation period previously reported for this object Clarke, Tinney & Tolley (2002). Near-contemporaneous I-band photometry shows evidence for non-periodic variability at the level of 2%.

F. J. Clarke; C. G. Tinney; S. T. Hodgkin

2003-01-09T23:59:59.000Z

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


421

ENSEMBLE VARIABILITY OF NEAR-INFRARED-SELECTED ACTIVE GALACTIC NUCLEI  

SciTech Connect (OSTI)

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

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

2012-03-01T23:59:59.000Z

422

Extremes in Chaotic Dynamical Systems  

E-Print Network [OSTI]

Extremes in Chaotic Dynamical Systems Valerio Lucarini valerio.lucarini@uni-hamburg.de D. Faranda Vortragsthema Datum #12;1. Introduction 2. Classical Theory: Extreme Values for i.i.d. Variables 3. Extreme Values in Dynamical Systems: Theoretical Background 4. Numerical Algorithms for studying Extremes 5

423

Unifying parameter estimation and the Deutsch-Jozsa algorithm for continuous variables  

SciTech Connect (OSTI)

We reveal a close relationship between quantum metrology and the Deutsch-Jozsa algorithm on continuous-variable quantum systems. We develop a general procedure, characterized by two parameters, that unifies parameter estimation and the Deutsch-Jozsa algorithm. Depending on which parameter we keep constant, the procedure implements either the parameter-estimation protocol or the Deutsch-Jozsa algorithm. The parameter-estimation part of the procedure attains the Heisenberg limit and is therefore optimal. Due to the use of approximate normalizable continuous-variable eigenstates, the Deutsch-Jozsa algorithm is probabilistic. The procedure estimates a value of an unknown parameter and solves the Deutsch-Jozsa problem without the use of any entanglement.

Zwierz, Marcin; Perez-Delgado, Carlos A.; Kok, Pieter [Department of Physics and Astronomy, University of Sheffield, Hounsfield Road, Sheffield S3 7RH (United Kingdom)

2010-10-15T23:59:59.000Z

424

The SMARTS Multi-epoch Optical Spectroscopy Atlas (SAMOSA): Using Emission Line Variability to Probe the Location of the Blazar Gamma-emitting Region  

E-Print Network [OSTI]

We present multi-epoch optical spectroscopy of seven southern Fermi-monitored blazars from 2008 - 2013 using the Small and Medium Aperture Research Telescope System (SMARTS), with supplemental spectroscopy and polarization data from the Steward Observatory. We find that the emission lines are much less variable than the continuum; 4 of 7 blazars had no detectable emission line variability over the 5 years. This is consistent with photoionization primarily by an accretion disk, allowing us to use the lines as a probe of disk activity. Comparing optical emission line flux with Fermi $\\gamma$-ray flux and optical polarized flux, we investigate whether relativistic jet variability is related to the accretion flow. In general, we see no such dependence, suggesting the jet variability is likely caused by internal processes like turbulence or shock acceleration rather than a variable accretion rate. However, three sources showed statistically significant emission line flares in close temporal proximity to very large...

Isler, Jedidah C; Bailyn, C; Smith, P S; Coppi, P; Brady, M; Macpherson, E; Hasan, I; Buxton, M

2015-01-01T23:59:59.000Z

425

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

426

Multi-variable optimization of pressurized oxy-coal combustion  

E-Print Network [OSTI]

Simultaneous multi-variable gradient-based optimization with multi-start is performed on a 300 MWe wet-recycling pressurized oxy-coal combustion process with carbon capture and sequestration. The model accounts for realistic ...

Zebian, Hussam

2011-01-01T23:59:59.000Z

427

Variable Selection and Inference for Multi-period Forecasting Problems  

E-Print Network [OSTI]

Variable Selection and Inference for Multi-period Forecasting Problems? M. Hashem Pesaran Cambridge University and USC Andreas Pick De Nederlandsche Bank and Cambridge University, CIMF Allan Timmermann UC San Diego and CREATES January 26, 2009...

Pesaran, M Hashem; Pick, Andreas; Timmermann, Allan

428

Stochastic Estimation of Multi-Variable Human Ankle Mechanical Impedance  

E-Print Network [OSTI]

This article presents preliminary stochastic estimates of the multi-variable human ankle mechanical impedance. We employed Anklebot, a rehabilitation robot for the ankle, to provide torque perturbations. Time histories of ...

Rastgaar Aagaah, Mohammad

429

The Variable Vector Countermeasure Suit for space habitation and exploration  

E-Print Network [OSTI]

The Variable Vector Countermeasure Suit (V2Suit) is a countermeasure suit for sensorimotor adaptation and musculoskeletal deconditioning in microgravity. The V2suit will consist of modules containing arrays of control ...

Vasquez, Rebecca (Rebecca Ann)

2014-01-01T23:59:59.000Z

430

Variable Frequency Motor Drives: Harmonics, Power Factor, and Energy Efficiency  

E-Print Network [OSTI]

Variable frequency motor drives (VFD's) have been on the market for many years. Early versions were unreliable and prone to failure. Relatively recent developments in Pulse-Width Modulated (PWM) waveform technology have improved VFD reliability...

Massey, G. W.

431

Modeling and Estimating Current Harmonics of Variable Electronic Loads  

E-Print Network [OSTI]

This paper develops a model for relating input current harmonic content to real power consumption for variable electronic loads, specifically for loads' actively controlled inverters energized by an uncontrolled rectification ...

Wichakool, Warit

432

The variability of warm absorbers in Active Galactic Nuclei  

E-Print Network [OSTI]

This thesis presents three studies of warm (photoionized) absorber variability in Active Galactic Nuclei (AGN) using high-resolution X-ray spectra provided by the Chandra High Energy Transmission Grating (HETG). The first ...

Gibson, Robert R. (Robert Ross)

2006-01-01T23:59:59.000Z

433

Reduction of tropical land region precipitation variability via transpiration  

E-Print Network [OSTI]

Tropical rainforests are known to exhibit low intraseasonal precipitation variability compared with oceanic areas with similar mean precipitation in observations and models. In the present study, the potential role of ...

Lee, Jung-Eun

434

Managing forecast variability in a build-to-order environment  

E-Print Network [OSTI]

In any production environment, managing demand variability is a delicate balancing act. Firms must constantly weigh potential obsolescence costs of unused inventory (should sales not materialize) against potential expedite ...

Einhorn, Marshall

2007-01-01T23:59:59.000Z

435

Renormalization group maps for Ising models in lattice gas variables  

E-Print Network [OSTI]

Real space renormalization group maps, e.g., the majority rule transformation, map Ising type models to Ising type models on a coarser lattice. We show that each coefficient of the renormalized Hamiltonian in the lattice gas variables depends on only a finite number of values of the renormalized Hamiltonian. We introduce a method which computes the values of the renormalized Hamiltonian with high accuracy and so computes the coefficients in the lattice gas variables with high accuracy. For the critical nearest neighbor Ising model on the square lattice with the majority rule transformation, we compute over 1,000 different coefficients in the lattice gas variable representation of the renormalized Hamiltonian and study the decay of these coefficients. We find that they decay exponentially in some sense but with a slow decay rate. We also show that the coefficients in the spin variables are sensitive to the truncation method used to compute them.

Tom Kennedy

2009-05-15T23:59:59.000Z

436

alleles causing variable: Topics by E-print Network  

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

age of a neutral allele as a function of its Slatkin, Montgomery 13 Entropy Shows that Global Warming Should Cause Increased Variability in the Weather Physics (arXiv) Summary:...

437

Studies of climate variability in a simple coupled model  

E-Print Network [OSTI]

The mechanisms of variability of a coupled atmosphere-ocean model are investigated through the study of two coupled configurations: an aquaplanet in which gyres are absent, and an aquaplanet in which a ridge extending from ...

Abiven, Claude

2007-01-01T23:59:59.000Z

438

A New Luminous Blue Variable in M31  

E-Print Network [OSTI]

We report the fifth confirmed Luminous Blue Variable/S Doradus variable in M31. In 2006, J004526.62+415006.3 had the spectrum of hot Fe II emission line star with strong P Cygni profiles in the Balmer lines. In 2010, its absorption line spectrum resembled an early A-type supergiant with H and Fe II emission lines with strong P Cygni profiles, and in 2013 the spectrum had fully transitioned to an F-type supergiant due to the formation of the optically thick, cool wind which characterizes LBVs at maximum light. The photometric record supports the LBV/S Dor nature of the variability. Its bolometric luminosity ~ -9.65 mag places it on the HR Diagram near the known LBVs, AE And, Var C in M33 and S Dor.

Humphreys, Roberta M; Gordon, Michael S

2015-01-01T23:59:59.000Z

439

Blazar Variability and Evolution in the GeV Regime  

E-Print Network [OSTI]

One of the most important problem of the blazar astrophysics is to understand the physical origin of the blazar sequence. In this study, we focus on the GeV gamma-ray variability of blazars and evolution perspective we search the relation between the redshift and the variability amplitude of blazars for each blazar subclass. We analyzed the Fermi-LAT data of the TeV blazars and the bright AGNs (flux $\\geq$ 4$\\times10^{-9}$ cm$^{-2}$s$^{-1}$) selected from the 2LAC (the 2nd LAT AGN catalog) data base. As a result, we found a hint of the correlation between the redshift and the variability amplitude in the FSRQs. Furthermore the BL Lacs which have relatively lower peak frequency of the synchrotron radiation and relatively lower redshift, have a tendency to have a smaller variability amplitude.

Tsujimoto, S; Nishijima, K; Kodani, K

2015-01-01T23:59:59.000Z

440

Impact of geometric variability on compressor repeating-stage performance  

E-Print Network [OSTI]

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

Vincent, Antoine, 1979-

2003-01-01T23:59:59.000Z

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


441

Original article Genetic variability and stability of poultry  

E-Print Network [OSTI]

Original article Genetic variability and stability of poultry feeding related characters in wheat the characters affecting poultry feeding, except phosphorus, genotypic effects were highly significant. However content and yield, no antagonism between productivity and poultry feeding related characters appeared

Paris-Sud XI, Université de

442

Analysis of Variability and Uncertainty in Wind Power Forecasting: An International Comparison: Preprint  

SciTech Connect (OSTI)

One of the critical challenges of wind power integration is the variable and uncertain nature of the resource. This paper investigates the variability and uncertainty in wind forecasting for multiple power systems in six countries. An extensive comparison of wind forecasting is performed among the six power systems by analyzing the following scenarios: (i) wind forecast errors throughout a year; (ii) forecast errors at a specific time of day throughout a year; (iii) forecast errors at peak and off-peak hours of a day; (iv) forecast errors in different seasons; (v) extreme forecasts with large overforecast or underforecast errors; and (vi) forecast errors when wind power generation is at different percentages of the total wind capacity. The kernel density estimation method is adopted to characterize the distribution of forecast errors. The results show that the level of uncertainty and the forecast error distribution vary among different power systems and scenarios. In addition, for most power systems, (i) there is a tendency to underforecast in winter; and (ii) the forecasts in winter generally have more uncertainty than the forecasts in summer.

Zhang, J.; Hodge, B. M.; Gomez-Lazaro, E.; Lovholm, A. L.; Berge, E.; Miettinen, J.; Holttinen, H.; Cutululis, N.; Litong-Palima, M.; Sorensen, P.; Dobschinski, J.

2013-10-01T23:59:59.000Z

443

Coefficient quantization effects in block state variable digital filters  

E-Print Network [OSTI]

COEFFICIENT QUANTIZATION EFFECTS IN BLOCK STATE VARIABLE DIGITAL FILTERS A Thesis by KAB JOO LEE Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE August 1991 Major Subject: Electrical Engineering COEFFICIENT QIJANTIZATIOU EFFECTS IN l3LOCI~ STATE VARIABLE DIGITAL FILTERS A Thesis hs IiAB JOO LEE Approved as to style and content by: WVilliam G. )3liss (Chair of Comnaittee) Norman C...

Lee, Kab Joo

2012-06-07T23:59:59.000Z

444

A STATE VARIABLE DESCRIPTION OF THE RHIC RF CONTROL LOOPS.  

SciTech Connect (OSTI)

The beam transfer function changes during the RHIC ramp. The response of the RF control loops changes as a result. A state-variable description of the beam and the RF control loops was developed. This description was used to generate a set of feedback matrices that keeps the response of the RF control loops constant during the ramp. This paper describes the state-variable description and its use in determining the K matrices.

SCHULTHEISS,C.; BRENNAN,J.M.

2002-06-02T23:59:59.000Z

445

El Niño Southern Oscillation Variability from 1871-2008  

E-Print Network [OSTI]

EL NI?O SOUTHERN OSCILLATION VARIABILITY FROM 1871-2008 A Dissertation by SULAGNA RAY Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR..., Ping Chang Achim Stoessel Ramalingam Saravanan Head of Department, Piers Chapman December 2011 Major Subject: Oceanography iii ABSTRACT El Ni?o Southern Oscillation Variability from 1871-2008. (December 2011) Sulagna Ray, B.S.; M...

Ray, Sulagna

2012-02-14T23:59:59.000Z

446

Variable Renewable Energy: a Regulatory Roadmap (Fact Sheet)  

SciTech Connect (OSTI)

There is not a one-size-fits-all approach to the regulation of variable renewable energy (VRE), but international experience reveals many approaches that are proving successful. Drawing upon research and experiences from various international contexts, the 21st Century Power Partnership in conjunction with the Clean Energy Solutions Center and Clean Energy Regulators Initiative identified key issues and ideas that have emerged as variable deployment has grown. The Power Partnership research, published in 2014, identified four broad categories of regulatory issues.

Not Available

2014-10-01T23:59:59.000Z

447

Explaining finite state machine characteristics using variable structure control  

SciTech Connect (OSTI)

This paper describes how variable structure control can be used to describe the overall behavior of multiple autonomous robotic vehicles with simple finite state machine rules. The importance of this result is that it allows for the design of provably asymptotically stable group behaviors from a set of simple control laws and appropriate switching points with variable structure control. The ability to prove convergence to a goal is especially important for applications such as locating military targets or land mines.

Feddema, J.T.; Robinett, R.D.; Driessen, B.J.

1997-10-01T23:59:59.000Z

448

ASSOCIATING LONG-TERM {gamma}-RAY VARIABILITY WITH THE SUPERORBITAL PERIOD OF LS I +61 Degree-Sign 303  

SciTech Connect (OSTI)

Gamma-ray binaries are stellar systems for which the spectral energy distribution (discounting the thermal stellar emission) peaks at high energies. Detected from radio to TeV gamma rays, the {gamma}-ray binary LS I +61 Degree-Sign 303 is highly variable across all frequencies. One aspect of this system's variability is the modulation of its emission with the timescale set by the {approx}26.4960 day orbital period. Here we show that, during the time of our observations, the {gamma}-ray emission of LS I +61 Degree-Sign 303 also presents a sinusoidal variability consistent with the previously known superorbital period of 1667 days. This modulation is more prominently seen at orbital phases around apastron, whereas it does not introduce a visible change close to periastron. It is also found in the appearance and disappearance of variability at the orbital period in the power spectrum of the data. This behavior could be explained by a quasi-cyclical evolution of the equatorial outflow of the Be companion star, whose features influence the conditions for generating gamma rays. These findings open the possibility to use {gamma}-ray observations to study the outflows of massive stars in eccentric binary systems.

Ackermann, M.; Buehler, R. [Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany); Ajello, M. [Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720-7450 (United States); Ballet, J.; Casandjian, J. M. [Laboratoire AIM, CEA-IRFU/CNRS/Universite Paris Diderot, Service d'Astrophysique, CEA Saclay, F-91191 Gif sur Yvette (France); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Bastieri, D.; Buson, S. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Bellazzini, R.; Bregeon, J. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bonamente, E.; Cecchi, C. [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy); Brandt, T. J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Brigida, M. [Dipartimento di Fisica ''M. Merlin'' dell'Universita e del Politecnico di Bari, I-70126 Bari (Italy); Bruel, P. [Laboratoire Leprince-Ringuet, Ecole polytechnique, CNRS/IN2P3, F-91128 Palaiseau (France); Caliandro, G. A. [Institute of Space Sciences (IEEE-CSIC), Campus UAB, E-08193 Barcelona (Spain); Cameron, R. A. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Caraveo, P. A. [INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica, I-20133 Milano (Italy); Cavazzuti, E. [Agenzia Spaziale Italiana (ASI) Science Data Center, I-00044 Frascati (Roma) (Italy); Chekhtman, A., E-mail: andrea.caliandro@ieec.uab.es, E-mail: hadasch@ieec.uab.es, E-mail: dtorres@ieec.uab.es [Center for Earth Observing and Space Research, College of Science, George Mason University, Fairfax, VA 22030 (United States); and others

2013-08-20T23:59:59.000Z

449

Occupant Response to Window Control Signaling Systems  

E-Print Network [OSTI]

Air Conditioning   Fan coil units, variable refrigerant active cooling via fan coil units and radiant panels, system to perimeter fan coil units, and “open”  mode for 

Ackerly, Katherine

2012-01-01T23:59:59.000Z

450

Safety equipment list for the light duty utility arm system  

SciTech Connect (OSTI)

The initial issue (Revision 0) of this Safety Equipment List (SEL) for the Light Duty Utility Arm (LDUA) requires an explanation for both its existence and its being what it is. All LDUA documentation leading up to creation of this SEL, and the SEL itself, is predicated on the LDUA only being approved for use in waste tanks designated as Facility Group 3, i.e., it is not approved for use in Facility Group 1 or 2 waste tanks. Facility Group 3 tanks are those in which a spontaneous or induced hydrogen gas release would be small, localized, and would not exceed 25% of the LFL when mixed with the remaining air volume in the dome space; exceeding these parameters is considered unlikely. Thus, from a NFPA flammable gas environment perspective the waste tank interior is not classified as a hazardous location. Furthermore, a hazards identification and evaluation (HNF-SD-WM-HIE-010, REV 0) performed for the LDUA system concluded that the consequences of actual LDUA system postulated accidents in Flammable Gas Facility Group 3 waste tanks would have either NO IMPACT or LOW IMPACT on the offsite public and onsite worker. Therefore, from a flammable gas perspective, there is not a rationale for classifying any of SSCs associated with the LDUA as either Safety Class (SC) or Safety Significant (SS) SSCs, which, by default, categorizes them as General Service (GS) SSCs. It follows then, based on current PHMC procedures (HNF-PRO-704 and HNF-IP-0842, Vol IV, Section 5.2) for SEL creation and content, and from a flammable gas perspective, that an SEL is NOT REQ@D HOWEVER!!! There is both a precedent and a prudency to capture all SSCS, which although GS, contribute to a Defense-In-Depth (DID) approach to the design and use of equipment in potentially flammable gas environments. This Revision 0 of the LDUA SEL has been created to capture these SSCs and they are designated as GS-DID in this document. The specific reasons for doing this are listed.

Barnes, G.A.

1998-03-02T23:59:59.000Z

451

Combined permeable pavement and ground source heat pump systems   

E-Print Network [OSTI]

The PhD thesis focuses on the performance assessment of permeable pavement systems incorporating ground source heat pumps (GSHP). The relatively high variability of temperature in these systems allows for the survival of pathogenic organisms within...

Grabowiecki, Piotr

2010-01-01T23:59:59.000Z

452

Abstract--This paper proposes a novel heuristic algorithm that helps alleviate the need for integer variables in a reactive power  

E-Print Network [OSTI]

integrated systems, the cost of reactive power was generally embedded within the electricity tariff, while for integer variables in a reactive power procurement model for an Independent System Operator in deregulated electricity markets. The heuristic scheme works on a three-step approach involving the calculation of marginal

Cañizares, Claudio A.

453

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

E-Print Network [OSTI]

. The advantages of the proposed system are reduced harmonic injection to power grid, wide speed operation range. It can be directly applied to wind power generators, small-scale hydroelectric generators, stand Identifier 10.1109/TIA.2004.824504 Fig. 1. Traditional wind power generation systems. (a) Variable

Mi, Chunting "Chris"

454

Systems and methods for controlling energy use in a building management system using energy budgets  

DOE Patents [OSTI]

Systems and methods for limiting power consumption by a heating, ventilation, and air conditioning (HVAC) subsystem of a building are shown and described. A feedback controller is used to generate a manipulated variable based on an energy use setpoint and a measured energy use. The manipulated variable may be used for adjusting the operation of an HVAC device.

Wenzel, Michael J; Drees, Kirk H

2014-09-23T23:59:59.000Z

455

Predicting scorpion sting incidence in an endemic region using climatological variables*  

E-Print Network [OSTI]

Predicting scorpion sting incidence in an endemic region using climatological variables* G. CHOWELL in Mexico. We analysed the significance of climatological variables to predict the incidence of scorpion seasonal pattern that correlates to climatological variables. An increase in scorpion activity

Chowell, Gerardo

456

Operations for inference in continuous Bayesian networks with linear deterministic variables  

E-Print Network [OSTI]

An important class of continuous Bayesian networks are those that have linear conditionally deterministic variables (a variable that is a linear deterministic function of its parents). In this case, the joint density function for the variables...

Cobb, Barry R.; Shenoy, Prakash P.

2006-05-01T23:59:59.000Z

457

Analyzing and simulating the variability of solar irradiance and solar PV powerplants  

E-Print Network [OSTI]

Term Variability of Solar Power. , 2010. [20] A. Mills, M.Term Variability of Solar Power. , 2010. [7] R. Perez, S.Term Variability of Solar Power, LBNL Report No. 3884E, (

Lave, Matthew S.

2012-01-01T23:59:59.000Z

458

Mass Market Demand Response and Variable Generation Integration Issues: A Scoping Study  

E-Print Network [OSTI]

Smart Grid, and specifically AMI, can play in mitigating variable generation integrationSmart Grid could be the “silver bullet” for mitigating variable generation integrationSmart Grid could be the “silver bullet” for mitigating variable generation integration

Cappers, Peter

2012-01-01T23:59:59.000Z

459

Variable Emission from a Gaseous Disc around a Metal-Polluted White Dwarf  

E-Print Network [OSTI]

We present the discovery of strongly variable emission lines from a gaseous disc around the DA white dwarf SDSS J1617+1620, a star previously found to have an infrared excess indicative of a dusty debris disc formed by the tidal disruption of a rocky planetary body. Time-series spectroscopy obtained during the period 2006-2014 has shown the appearance of strong double-peaked Ca II emission lines in 2008. The lines were weak, at best, during earlier observations, and monotonically faded through the remainder of our monitoring. Our observations represent unambiguous evidence for short-term variability in the debris environment of evolved planetary systems. Possible explanations for this extraordinary variability include the impact onto the dusty disc of either a single small rocky planetesimal, or of material from a highly eccentric debris tail. The increase in flux from the emission lines is sufficient that similar events could be detected in the broadband photometry of ongoing and future large-area time domai...

Wilson, David J; Koester, Detlev; Raddi, Roberto; Breedt, Elmé; Southworth, John; Parsons, Steven G

2014-01-01T23:59:59.000Z

460

Control of entity interactions in a hierarchical variable resolution simulation  

SciTech Connect (OSTI)

There has long been interest in variable resolution modeling to support military analysis for a broad range of interest areas. Despite the ever-present desire for models of greater fidelity at the expense of analysis and computation resources, models of moderate to low fidelity are still required at many levels of decision-making. Problems can arise due to the issue of consistency among the family of models used for analysis. To address this and other problems, models of variable resolution have been suggested. However, such variable resolution architectures inherently carry their own set of issues which must be resolved in order to be useful. First, what are the structural requirements for a variable resolution model; and second, how are interactions between entities governed, especially when the entities have different resolutions? This paper addresses these issues and discusses key mechanisms needed to develop a variable resolution combat simulation that meets several core requirements for such models: seamless aggregation/disaggregation, appropriate interactions between entities of differing resolution, and control of the aggregation/disaggregation process.

Powell, D.R.

1997-08-01T23:59:59.000Z

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


461

Control of entity interactions in a hierarchical variable resolution simulation  

SciTech Connect (OSTI)

There has long been interest in variable resolution modeling to support military analysis for a broad range of interest areas. Despite the ever-present desire for models of greater fidelity at the expense of analysis and computation resources, models of moderate to low fidelity are still required at many levels of decision-making. Problems can arise due to the issue of consistency among the family of models used for analysis. To address this and other problems, models of variable resolution have been suggested. However, such variable resolution architectures inherently carry their own set of issues which must be resolved in order to be useful. First, what are the structural requirements for a variable resolution model; and second, how are interactions between entities governed, especially when the entities have different resolutions? This paper addresses these issues and discusses key mechanisms needed to develop a variable resolution combat simulation that meets several core requirements for such models: seamless aggregation/disaggregation, appropriate interactions between entities of differing resolution, and control of the aggregation/disaggregation process.

Powell, D.R.

1997-10-01T23:59:59.000Z

462

A PHOTOMETRICALLY AND MORPHOLOGICALLY VARIABLE INFRARED NEBULA IN L483  

SciTech Connect (OSTI)

We present narrow and broad K-band observations of the Class 0/I source IRAS 18148-0440 that span 17 years. The infrared nebula associated with this protostar in the L483 dark cloud is both morphologically and photometrically variable on a timescale of only a few months. This nebula appears to be an infrared analog to other well known optically visible variable nebulae associated with young stars, such as Hubble's Variable Nebula. Along with Cepheus A, this is one of the first large variable nebulae to be found that is only visible in the infrared. The variability of this nebula is most likely due to changing illumination of the cloud rather than any motion of the structure in the nebula. Both morphological and photometric changes are observed on a timescale only a few times longer than the light crossing time of the nebula, suggesting very rapid intrinsic changes in the illumination of the nebula. Our narrowband observations also found that H{sub 2} knots are found nearly twice as far to the east of the source as to its west, and that H{sub 2} emission extends farther east of the source than the previously known CO outflow.

Connelley, Michael S. [NASA Ames Research Center, MS 245-6, Moffett Field, CA 94035 (United States); Hodapp, Klaus W. [University of Hawaii Institute for Astronomy, 640 N. Aohoku Pl., Hilo, HI 96720 (United States); Fuller, Gary A. [Jodrell Bank Centre for Astrophysics, Alan Turing Building, University of Manchester, Manchester, M13 9PL (United Kingdom)

2009-03-15T23:59:59.000Z

463

Superconducting fault current-limiter with variable shunt impedance  

DOE Patents [OSTI]

A superconducting fault current-limiter is provided, including a superconducting element configured to resistively or inductively limit a fault current, and one or more variable-impedance shunts electrically coupled in parallel with the superconducting element. The variable-impedance shunt(s) is configured to present a first impedance during a superconducting state of the superconducting element and a second impedance during a normal resistive state of the superconducting element. The superconducting element transitions from the superconducting state to the normal resistive state responsive to the fault current, and responsive thereto, the variable-impedance shunt(s) transitions from the first to the second impedance. The second impedance of the variable-impedance shunt(s) is a lower impedance than the first impedance, which facilitates current flow through the variable-impedance shunt(s) during a recovery transition of the superconducting element from the normal resistive state to the superconducting state, and thus, facilitates recovery of the superconducting element under load.

Llambes, Juan Carlos H; Xiong, Xuming

2013-11-19T23:59:59.000Z

464

A single dimensionless variable for solar chimney power plant modeling  

SciTech Connect (OSTI)

The solar chimney power plant is a relatively new technology for generating electricity from solar energy. In this paper dimensional analysis is used together with engineering intuition to combine eight primitive variables into only one dimensionless variable that establishes a dynamic similarity between a prototype and its scaled models. Three physical configurations of the plant were numerically tested for similarity: fully geometrically similar, partially geometrically similar, and dissimilar types. The values of the proposed dimensionless variable for all these cases were found to be nominally equal to unity. The value for the physical plant actually built and tested previously was also evaluated and found to be about the same as that of the numerical simulations, suggesting the validity of the proposition. The physical meaning of this dimensionless (similarity) variable is also interpreted; and the connection between the Richardson number and this new variable was found. It was found also that, for a fixed solar heat flux, different-sized models that are fully or partially geometrically similar share an equal excess temperature across the roof outlet. (author)

Koonsrisuk, Atit; Chitsomboon, Tawit [School of Mechanical Engineering, Institute of Engineering, Suranaree University of Technology, Muang District, Nakhon Ratchasima 30000 (Thailand)

2009-12-15T23:59:59.000Z

465

Variables Affecting Smooth Particle Hydrodynamics Simulation of High-Velocity Flyer Plate Impact Experiments  

SciTech Connect (OSTI)

This paper describes our work to characterize the variables affecting the smoothed particle hydrodynamics (SPH) method in the LS-DYNA package for simulating high-velocity flyer plate impact experiments. LS-DYNA simulations are compared with one-dimensional experimental data of an oxygen-free high-conductivity (OFHC) copper flyer plate impacting another plate of the same material. The comparison is made by measuring the velocity of a point on the back surface of the impact plate using the velocity interferometer system for any reflector (VISAR) technique.

Somasundaram, Deepak S [UNLV; Trabia, Mohamed [UNLV; O'Toole, Brendan [UNLV; Hixson, Robert S [NSTec

2014-01-23T23:59:59.000Z

466

Traffic Management System Performance November 11, 2002  

E-Print Network [OSTI]

Traffic Management System Performance November 11, 2002 David Levinson1 Wei Chen2 Department uses regression analysis to evaluate long-run traffic management system performance. Three important traffic management systems in the Twin Cities metro area - Ramp Metering, Variable Message Signs (VMS

Levinson, David M.

467

Accelerating the transformation of power systems  

E-Print Network [OSTI]

-connected variable renewable energy (primarily, wind and solar). All power systems have some inherent level to achieve. Both wind and solar generation output vary significantly over the course of hours to days with wind energy in the system. Solar energy will cause qualitatively similar impacts on the power system

468

Analysis Methodology for Balancing Authority Cooperation in High Penetration of Variable Generation  

SciTech Connect (OSTI)

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 means various forms of collaboration between individual BAs must 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 ACE diversity interchange (ADI), wind only BA, BA consolidation, dynamic scheduling, regulation and load following sharing, extreme event impact study are discussed in this report. The objective of such strategies is to allow individual BAs within a large power grid to help each other deal 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 performances of different virtual BA strategies. The report builds a systematic framework for evaluating BA consolidation and coordination. Results for case studies show that significant economic and reliability benefits can be gained. The merits and limitation of each virtual BA strategy are investigated. The report provides guidelines for the power industry to evaluate the coordination or consolidation method. The application of the developed strategies in cooperation with several regional BAs is in progress for several off-spring projects.

Makarov, Yuri V.; Etingov, Pavel V.; Zhou, Ning; Ma, Jian; Samaan, Nader A.; Diao, Ruisheng; Malhara, Sunita V.; Guttromson, Ross T.; Du, Pengwei; Sastry, Chellury

2010-02-01T23:59:59.000Z

469

Intra-hour wind power variability assessment using the conditional range metric : quantification, forecasting and applications.  

E-Print Network [OSTI]

??The research presented herein concentrates on the quantification, assessment and forecasting of intra-hour wind power variability. Wind power is intrinsically variable and, due to the… (more)

Boutsika, Thekla

2013-01-01T23:59:59.000Z

470

Performance of Variable Capacity Heat Pumps in a Mixed Humid Climate  

SciTech Connect (OSTI)

Variable capacity heat pumps represent the next wave of technology for heat pumps. In this report, the performance of two variable capacity heat pumps (HPs) is compared to that of a single or two stage baseline system. The units were installed in two existing research houses located in Knoxville, TN. These houses were instrumented to collect energy use and temperature data while both the baseline systems and variable capacity systems were installed. The homes had computer controlled simulated occupancy, which provided consistent schedules for hot water use and lighting. The temperature control and energy use of the systems were compared during both the heating and cooling seasons. Multiple linear regression models were used along with TMY3 data for Knoxville, TN in order to normalize the effect that the outdoor air temperature has on energy use. This enables a prediction of each system's energy use over a year with the same weather. The first system was a multi-split system consisting of 8 indoor units and a single outdoor unit. This system replaced a 16 SEER single stage HP with a zoning system, which served as the baseline. Data was collected on the baseline system from August 2009 to December 2010 and on the multi-split system from January 2011 to January 2012. Soon after the installation of the multi-split system, some of the smaller rooms began over-conditioning. This was determined to be caused by a small amount of continuous refrigerant flow to all of the indoor units when the outdoor unit was running regardless of whether they were calling for heat. This, coupled with the fact that the indoor fans run continuously, was providing enough heat in some rooms to exceed the set point. In order to address this, the indoor fans were disabled when not actively heating per the manufacturer's recommendation. Based on the measured data, the multi-split system was predicted to use 40% more energy in the heating season and 16% more energy in the cooling season than the baseline system, for the typical meteorological year weather data. The AHRI ratings indicated that the baseline system would perform slightly better than the multi-split system, but not by as large of a margin as seen in this study. The multi-split system was able to maintain more consistent temperature throughout the house than the baseline system, but it did allow relative humidity levels to increase above 60% in the summer. The second system was a split system with an inverter driven compressor and a single ducted air handler. This unit replaced a 16 SEER two stage HP with a zoning system. Data was collected on the baseline system from July 2009 to November 2010 and on the ducted inverter system from December 2010 to January 2012. The ducted inverter system did not offer a zone controller, so it functioned as a single zone system. Due to this fact, the registers had to be manually adjusted in order to better maintain consistent temperatures between the two levels of the house. The predicted heating season energy use for the ducted inverter system, based on the measured energy use, was 30% less than that of the baseline system for the typical meteorological year. However, the baseline system was unable to operate in its high stage due to a wiring issue with the zone controller. This resulted in additional resistance heat use during the winter and therefore higher energy use than would be expected in a properly performing unit. The AHRI ratings would indicate that the baseline system would use less energy than the ducted inverter system, which is opposite to the results of this study. During the cooling season, the ducted inverter system was predicted to use 23% more energy than the baseline system during the typical meteorological year. This is also opposite of the results expected by comparing the AHRI ratings. After a detailed comparison of the ducted inverter system's power use compared to that of a recently installed identical system at a retro-fit study house, there is concern that the unit is not operating as intended. The power use and cycles indicate t

Munk, Jeffrey D [ORNL; Gehl, Anthony C [ORNL; Jackson, Roderick K [ORNL

2012-04-01T23:59:59.000Z

471

Removing the Microlensing Blending-Parallax Degeneracy Using Source Variability  

E-Print Network [OSTI]

Microlensing event MACHO 97-SMC-1 is one of the rare microlensing events for which the source is a variable star, simply because most variable stars are systematically eliminated from microlensing studies. Using observational data for this event, we show that the intrinsic variability of a microlensed star is a powerful tool to constrain the nature of the lens by breaking the degeneracy between the microlens parallax and the blended light. We also present a statistical test for discriminating the location of the lens based on the \\chi^2 contours of the vector \\Lambda, the inverse of the projected velocity. We find that while SMC self lensing is somewhat favored, neither location can be ruled out with good confidence.

Assef, R J; Afonso, C; Albert, J N; Andersen, J; Ansari, R; Aubourg, E; Bareyre, P; Beaulieu, J P; Charlot, X; Coutures, C; Ferlet, R; Fouqué, P; Glicenstein, J F; Goldman, B; Graff, D; Gros, M; Haïssinski, J; Hamadache, C; De Kat, J; Le Guillou, Laurent; Lesquoy, E; Loup, C; Magneville, C; Marquette, J B; Maurice, E; Maury, A; Milsztajn, A; Moniez, M; Palanque-Delabrouille, Nathalie; Perdereau, O; Rahal, Y R; Rich, J; Spiro, M; Tisserand, P; Vidal-Madjar, A; Vigroux, L; Zylberajch, S; Bennett, D P; Becker, A C; Griest, K; Vandehei, T; Welch, D L; Udalski, A; Szymanski, M K; Kubiak, M; Pietrzynski, G; Soszynski, I; Szewczyk, O; Wyrzykowski, L

2006-01-01T23:59:59.000Z

472

Towards the Light Front Variables for High Energy Production Processes  

E-Print Network [OSTI]

Scale invariant presentation of inclusive spectra in terms of light front variables is proposed. The variables introduced go over to the well-known scaling variables x_F = 2p_z/sqrt(s) and x_T=2p_T/sqrt{s} in the high p_z and high p_T limits respectively. So Some surface is found in the phase space of produced pi-mesons in the inclusive reaction anti p p -> pi+- X at 22.4 GeV/c, which separates two groups of particles with significantly different characteristics. In one of these regions a naive statistical model seems to be in a good agreement with data, whereas it fails in the second region. Key words: Light front, inclusive, hadron-hadron, electron-positron, relativistic heavy ions, deep inelastic.

N. S. Amaglobeli; S. M. Esakia; V. R. Garsevanishvili; G. O. Kuratashvili; N. K. Kutsidi; R. A. Kvatadze; Yu V. Tevzadze; T. P. Topuria

1997-03-21T23:59:59.000Z

473

The role of an accretion disk in AGN variability  

E-Print Network [OSTI]

Optically thick accretion disks are considered to be important ingredients of luminous AGN. The claim of their existence is well supported by observations and recent years brought some progress in understanding of their dynamics. However, the role of accretion disks in optical/UV/X-ray variability of AGN is not quite clear. Most probably, in short timescales the disk reprocesses the variable X-ray flux but at longer timescales the variations of the disk structure lead directly to optical/UV variations as well as affect, or even create, the X-ray variability pattern. We urgently need a considerable progress in time-dependent disk models to close the gap between the theory and the stream of data coming from the AGN monitoring.

B. Czerny

2004-09-10T23:59:59.000Z

474

Quantum simulation of quantum field theory using continuous variables  

E-Print Network [OSTI]

Much progress has been made in the field of quantum computing using continuous variables over the last couple of years. This includes the generation of extremely large entangled cluster states (10,000 modes, in fact) as well as a fault tolerant architecture. This has led to the point that continuous-variable quantum computing can indeed be thought of as a viable alternative for universal quantum computing. With that in mind, we present a new algorithm for continuous-variable quantum computers which gives an exponential speedup over the best known classical methods. Specifically, this relates to efficiently calculating the scattering amplitudes in scalar bosonic quantum field theory, a problem that is believed to be hard using a classical computer. Building on this, we give an experimental implementation based on cluster states that is feasible with today's technology.

Kevin Marshall; Raphael Pooser; George Siopsis; Christian Weedbrook

2015-03-27T23:59:59.000Z

475

Towards the Light Front Variables for High Energy Production Processes  

E-Print Network [OSTI]

Scale invariant presentation of inclusive spectra in terms of light front variables is proposed. The variables introduced go over to the well-known scaling variables x_F = 2p_z/sqrt(s) and x_T=2p_T/sqrt{s} in the high p_z and high p_T limits respectively. So Some surface is found in the phase space of produced pi-mesons in the inclusive reaction anti p p -> pi+- X at 22.4 GeV/c, which separates two groups of particles with significantly different characteristics. In one of these regions a naive statistical model seems to be in a good agreement with data, whereas it fails in the second region. Key words: Light front, inclusive, hadron-hadron, electron-positron, relativistic heavy ions, deep inelastic.

Amaglobeli, N S; Garsevanishvili, V R; Kuratashvili, G O; Kutsidi, N K; Kvatadze, R A; Tevzadze, Yu V; Topuria, T P; Tevzadze, Yu V.

1998-01-01T23:59:59.000Z

476

Green Scheduling: Scheduling of Control Systems for Peak Power Reduction  

E-Print Network [OSTI]

approach to fine-grained coordination of energy demand by scheduling energy consuming control systems of the system variables only, control system execution (i.e. when energy is supplied to the system-Scheduling; Energy Systems; Peak Power Reduction; Load Balancing; I. INTRODUCTION During a major sporting event

Pappas, George J.

477

On Efficient Bandwidth Allocation for Traffic Variability in Datacenters  

E-Print Network [OSTI]

and Technology. 2 Ministry of Education Key Laboratory for Earth System Modeling, and Center for Earth System

Lui, John C.S.

478

NREL Variability and Reserves Analysis for the Western Interconnect (Presentation)  

SciTech Connect (OSTI)

Additional variability and uncertainty increase reserve requirements. In this light, this presentation discusses how use of generation reserves can be optimized for managing variability and uncertainty. Conclusions of this presentation are: (1) Provided a method for calculating additional reserve requirements due to wind and solar production; (2) Method is based on statistical analysis of historical time series data; (3) Reserves are dynamic, produced for each hour; (4) Reserve time series are calculated from and synchronized to simulation data; (5) PROMOD can not model directly, but workarounds exist for regulation and spin; and (6) Other production modeling packages have varying capability for reserves modeling.

Milligan, M.; King, J.

2011-10-01T23:59:59.000Z

479

On the near infrared variability of chemically peculiar stars  

E-Print Network [OSTI]

Some CP stars have recently been discovered by Catalano et al. (1991) to be variable also in the near infrared, although with smaller amplitudes than in the visible. Hence an observational campaign was started in which the infrared light variability of a number of CP2 and CP4 stars has been investigated at the ESO-La Silla Observatory in the bands J, H, and K. As a general result, infrared variations show the same behavior in all three filters but amplitudes are smaller than in the visible.

F. A. Catalano; F. Leone

1998-05-06T23:59:59.000Z

480

Implementing the DC Mode in Cosmological Simulations with Supercomoving Variables  

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

As emphasized by previous studies, proper treatment of the density fluctuation on the fundamental scale of a cosmological simulation volume - the 'DC mode' - is critical for accurate modeling of spatial correlations on scales ~> 10% of simulation box size. We provide further illustration of the effects of the DC mode on the abundance of halos in small boxes and show that it is straightforward to incorporate this mode in cosmological codes that use the 'supercomoving' variables. The equations governing evolution of dark matter and baryons recast with these variables are particularly simple and include the expansion factor, and hence the effect of the DC mode, explicitly only in the Poisson equation.

Gnedin, Nickolay Y.; Kravtsov, Andrey V.; Rudd, Douglas H.

2011-06-02T23:59:59.000Z

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


481

Multiwavelength Monitoring of the Dwarf Seyfert 1 Galaxy NGC 4395. IV. The Variable UV Absorption Lines  

E-Print Network [OSTI]

We report the detection of variable UV absorption lines in NGC 4395, based on UV observations with the HST STIS carried out in April and July, 2004, as part of a reverberation-mapping campaign. Low-ionization lines of O I, N I, Si II, C II, and Fe II, are present in the low-state spectra (April 2004) at a velocity v_shift=-250 km/s (system A_l), and additional high-ionization lines of C IV and N V appear in the high-state spectra (July 2004) at v_shift=-250 km/s (system A_h) and at v_shift=-840 km/s (system B). The absence of absorption from the low metastable levels of Si II implies a density <~10^3 cm^(-3) for system A_l, indicating a location outside the narrow line region (NLR). System A_h is peculiar as only N V absorption is clearly detected. A high N V/C IV absorption ratio is expected for a high metallicity absorber, but this is excluded here as the metallicity of the host galaxy and of the nuclear gas is significantly subsolar. A simple acceptable model for systems A_h and B is an absorber located between the broad line region (BLR) and the NLR, which absorbs only the continuum and the BLR. At the low-state the strong narrow emission lines of C IV and N V dominate the spectrum, making the absorption invisible. At the high-state the absorbed continuum and BLR emission dominate the spectrum. Thus, the change in the observed absorption does not reflect a change in the absorber, but rather a change in the continuum and BLR emission from behind the absorber, relative to the emission from the NLR in front of the absorber. Studies of the absorption line variability in highly variable objects can thus break the degeneracy in the absorber distance determination inherent to single epoch studies.

Alexei Baskin; Ari Laor

2008-04-01T23:59:59.000Z

482

A Method for On-Going Commissioning of VRV Package Systems Using a Simulation Model  

E-Print Network [OSTI]

Variable refrigerant volume (VRV) systems, which have several indoor units and a single outdoor unit, have become very popular HVAC systems in Japan. However, some systems may be operated under inefficient conditions and consume excessive energy...

Yamaha, M.; Sekiyama, K.; Misaki, S.

2006-01-01T23:59:59.000Z

483

Nonlinear System Modeling, Optimal Cam Design, and Advanced System Control for an Electromechanical Engine Valve Drive  

E-Print Network [OSTI]

A cam-based shear force-actuated electromechanical valve drive system offering variable valve timing in internal combustion engines was previously proposed and demonstrated. To transform this concept into a competitive ...

Qiu, Yihui

484

Relationship between gradient and EM steps in latent variable models.  

E-Print Network [OSTI]

includes random search, standard gradient­based algorithms, line search methods such as conjugate gradient to to first order method operat­ ing on the gradient of a locally reshaped likelihood function. DirectRelationship between gradient and EM steps in latent variable models. Ruslan Salakhutdinov Sam

Roweis, Sam

485

Relationship between gradient and EM steps in latent variable models.  

E-Print Network [OSTI]

includes random search, standard gradient-based algorithms, line search methods such as conjugate gradient to to first order method operat- ing on the gradient of a locally reshaped likelihood function. DirectRelationship between gradient and EM steps in latent variable models. Ruslan Salakhutdinov Sam

Roweis, Sam

486

Vector Boson Fusion Higgs Production at the LHC - Mass Variables  

E-Print Network [OSTI]

There exist substantial backgrounds to the vector boson fusion production of Higgs at the LHC. Mass variables are studied which may alleviate the need to assume a spin zero WW resonance in order to achieve a sufficient signal to noise ratio in the two jet plus two lepton and missing energy final state.

Dan Green

2005-01-12T23:59:59.000Z

487

Total Solar Irradiance Variability and the Solar Activity Cycle  

E-Print Network [OSTI]

It is suggested that the solar variability is due to the perturbed nature of the solar core and this variability is provided by the variability of the solar neutrino flux from the solar neutrino detectors i.e., Homestake, Superkamiokande, SAGE and GALLEX-GNO. The solar neutrino flux in the standard solar model (SSM) was calculated on the assumption of L_nu (neutrino luminosity) = L_gamma (optical luminosity) which implies that if there is a change in optical luminosity then solar neutrino flux data will also be changed. An internal dynamo due to the cyclic variation of nuclear energy generation inside the core of the sun is responsible for the solar activity cycle was suggested and thus the internal magnetic field is also variable. Again the changes in the nuclear energy generation induce structural changes that result in variations of the global solar parameters i.e., luminosity, radius and temperatures etc. From the analysis of total solar irradiance (TSI) data during the year from 1970 to 2003 we have found five phases within the solar activity cycle. The first phase (I) starts before two years from the sunspot minimum. The second phase (II) starts at the time of sunspot minimum and phase (III) starts before 2/3 years from sunspot maximum whereas phase (IV) starts at sunspot maximum and fifth phase (V) starts at after 2-3 years from sunspot maximum.

Probhas Raychaudhuri

2006-05-06T23:59:59.000Z

488

Optimal Scheduling under Variable Electricity Pricing and Availability  

E-Print Network [OSTI]

due dates · Location of event points ­ At demand points ­ At some energy pricing/availability levels periods with same energy pricing/power level · Only valid for single stage plants November 11, 2009 EnergyOptimal Scheduling under Variable Electricity Pricing and Availability Pedro M. Castro Iiro

Grossmann, Ignacio E.

489

Tidal Stage Variability of Fecal Coliform and Chlorophyll a  

E-Print Network [OSTI]

leachates, leaking sewer mains, wild and do- mestic animal wastes, and runo. However, the inter- action environmental hazards, to enter an estuarine environment characterized by high variability regarding temperature to understanding both the basic ecology of tidal creeks and the applied aspects of sampling protocols and pollutant

Mallin, Michael

490

Offshore Series Wind Turbine Variable Hub heights & rotor diameters  

E-Print Network [OSTI]

3.6MW Offshore Series Wind Turbine GE Energy #12;Feature Variable Hub heights & rotor diameters-savings feature, considering the rigors of offshore power generation. The 3.6 MW offshore wind turbine also, for both on and offshore use. Special features include... As the world's first commercially available wind

Firestone, Jeremy

491

Sources of Variability for the Single -Comparator Method in a  

E-Print Network [OSTI]

· RlM-M-2141 Sources of Variability for the Single - Comparator Method in a Heavy Water Reactor E for neutron acti- vation analysis were installed in the reactor DR 3, which is a heavy water cooled are located in the vertical tubes extending into the heavy water as shown in Fig. 1. Their characteristic

492

Thermoelectric Properties of Superlattice Materials with Variably Spaced Layers  

E-Print Network [OSTI]

Thermoelectric Properties of Superlattice Materials with Variably Spaced Layers T.D. Musho Interdisciplinary Materials Science, Vanderbilt University, Nashville, Tennessee 37212, USA D.G. Walker Department of electronic level alignment. We have investigated the thermoelectric proper- ties of VSSL structures using

Walker, D. Greg

493

Interannual variability of photosynthesis across Africa and its attribution  

E-Print Network [OSTI]

on understanding surface sources and sinks of CO2 and the biosphere's ability to offset anthropogenic carbon is thought to be a large source of interannual variability in the global carbon cycle, only vaguely.1029/2008JG000718. 1. Introduction [2] The rise of atmospheric carbon dioxide, its relation to global warming

Collett Jr., Jeffrey L.

494

Control of Variable Geometry Turbocharged Diesel Engines for Reduced Emissions  

E-Print Network [OSTI]

torque output as compared to (non-turbocharged) naturally aspirated engines 13]. The power generated- ifold pressure, increased power generation by the turbine and increased ow of air from compressorControl of Variable Geometry Turbocharged Diesel Engines for Reduced Emissions A.G. Stefanopoulouz

Stefanopoulou, Anna

495

Variability of urea concentration in camel milk in Kazakhstan  

E-Print Network [OSTI]

Note Variability of urea concentration in camel milk in Kazakhstan Bernard FAYE 1*, Gaukhar University Al Farabi, 71 av. Al-Farabi, 050040 Almaty, Kazakhstan Received 12 February 2010 ­ Revised 4 March interpretable variation factors. In 102 milk samples collected in Kazakhstan, at four seasons of the year

Paris-Sud XI, Université de

496

Red giant variables: OGLE--II and MACHO  

E-Print Network [OSTI]

We review the recent impact of microlensing projects on our understanding of pulsating red giant stars. Discussed are red giant stars' pulsation properties (period--luminosity relations, period changes, mode switchings), Red Giant Branch pulsations, metallicity effects and the use of red giant variables to explore galactic structure.

L. L. Kiss; P. Lah

2005-09-21T23:59:59.000Z

497

Adaptive Calculation of Variable Coefficients Elliptic Differential Equations via Wavelets  

E-Print Network [OSTI]

Description Generating a "good" discrete representation for continuous operators is one of the basic problemsAdaptive Calculation of Variable Coefficients Elliptic Differential Equations via Wavelets Amir rather than in the original physical space can speed up the performance of the sparse solver by a factor

Averbuch, Amir

498

Capturing Variability in Business Process Models: The Provop Approach  

E-Print Network [OSTI]

Capturing Variability in Business Process Models: The Provop Approach Alena Hallerbach1 , Thomas be transferred to cross-organizational business processes as well [4]. A business process model captures models there exists a multitude of tools like ARIS Business Architect [5], ADONIS [6], and Web

Ulm, Universität

499

Variable Responses of Lowland Tropical Forest Nutrient Status  

E-Print Network [OSTI]

Variable Responses of Lowland Tropical Forest Nutrient Status to to play a key role in nutrient retention. We discuss our findings in the context of possible impacts Springer Science+Business Media, LLC 387 #12;growth not only alters forests' nutrient demands but also

Harms, Kyle E.

500

Smoluchowski-Kramers approximation in the case of variable friction  

E-Print Network [OSTI]

We consider the small mass asymptotics (Smoluchowski-Kramers approximation) for the Langevin equation with a variable friction coefficient. The limit of the solution in the classical sense does not exist in this case. We study a modification of the Smoluchowski-Kramers approximation. Some applications of the Smoluchowski-Kramers approximation to problems with fast oscillating or discontinuous coefficients are considered.

Mark Freidlin; Wenqing Hu

2012-03-03T23:59:59.000Z