Science.gov

Sample records for conversion weigh-in-motion system

  1. Static Scale Conversion Weigh-In-Motion System

    SciTech Connect

    Beshears, D.L.

    2001-05-18

    In support of the Air Mobility Battle Lab (AMBL), the Defense Advanced Research Projects Agency (DARPA) Advanced Logistics Program and the U. S. Transportation Command (USTRANSCOM), the ultimate objective of this project is to develop and demonstrate a full-scale prototype static scale conversion weigh-in-motion/Profilometry (SSC-WIM/P) system to measure and record dimensional and weight information for the Department of Defense (DoD) equipment and cargo. The Oak Ridge National Laboratory (ORNL), along with the AMBL, and Intercomp, Inc. have developed a long-range plan for developing a dual-use system which can be used as a standard static scale or an accurate weigh-in-motion system. AMBL will work to define requirements for additional activities with U.S. Transportation Command, Air Mobility Command, and the Joint Warfighting Battle Lab for both the SSC-WIM/P and a portable Weigh-in-Motion System for individual units. The funding goal is to fully fund the development of two prototype test articles (a SSC-WIM kit, and a laser profilometer) and have at least one fully operational system by the early 2002 timeframe. The objective of this portion of the project will be to develop a SSC-WIM system, which at a later date can be fully integrated with a profilometry system; to fully characterize DOD wheeled vehicles and cargo (individual axle weights, total vehicle weight, center of balance, height, width and length measurements). The program will be completed in phases with the initial AMBL/DARPA funding being used to initiate the efforts while AMBL/USTC obtains funding to complete the first generation system effort. At the completion of an initial effort, the interface hardware and the data acquisition/analysis hardware will be developed, fabricated, and system principles and basic functionality evaluated, tested, and demonstrated. Additional funding, when made available, will allow the successful completion of a first generation prototype system. This effort will be

  2. Method and appartus for converting static in-ground vehicle scales into weigh-in-motion systems

    DOEpatents

    Muhs, Jeffrey D.; Scudiere, Matthew B.; Jordan, John K.

    2002-01-01

    An apparatus and method for converting in-ground static weighing scales for vehicles to weigh-in-motion systems. The apparatus upon conversion includes the existing in-ground static scale, peripheral switches and an electronic module for automatic computation of the weight. By monitoring the velocity, tire position, axle spacing, and real time output from existing static scales as a vehicle drives over the scales, the system determines when an axle of a vehicle is on the scale at a given time, monitors the combined weight output from any given axle combination on the scale(s) at any given time, and from these measurements automatically computes the weight of each individual axle and gross vehicle weight by an integration, integration approximation, and/or signal averaging technique.

  3. Algorithm for a novel fiber-optic weigh-in-motion sensor system

    SciTech Connect

    Tobin, K.W. Jr.; Muhs, J.D.

    1991-08-01

    Over the past decade, the demand from both government and private industry for small, lightweight, vehicle weigh-in-motion (WIM) systems has grown substantially. During the 1980s several techniques for weighing vehicles in motion were developed that include piezoelectric cables, capacitive mats, and hydraulic and bending-plate load cells. These different systems have advantages and disadvantages that trade off between accuracy, physical size and system complexity. The smaller portable systems demonstrate medium to poor accuracy and repeatability while the larger more accurate systems are nonportable. A small, lightweight, and portable WIM system based on a fiber-optic pressure transducer has been developed by Oak Ridge National Laboratory (ORNL) to meet the demands of government and industry. The algorithm for extracting vehicle weight from the time-dependent sensor response is developed and presented in this report, along with data collected by the system for several classes of vehicles. These results show that the ORNL fiber-optic WIM system is a viable alternative to other commercial systems that are presently available. 5 refs., 5 figs.

  4. Advanced weigh-in-motion system for weighing vehicles at high speed

    SciTech Connect

    Beshears, D.L.; Muhs, J.D.; Scudiere, M.B.

    1998-02-01

    A state-of-the-art, Advanced Weigh-In-Motion (WIM) system has been designed, installed, and tested on the west bound side of Interstate I-75/I-40 near the Knox County Weigh Station. The project is a Cooperative Research and Development Agreement (CRADA) between Oak Ridge National Laboratory (ORNL) and International Road Dynamics, Inc. (IRD) sponsored by the Office of Uranium Programs, Facility and Technology Management Division of the Department of Energy under CRADA No. ORNL95-0364. ORNL, IRD, the Federal Highway Administration, the Tennessee Department of Safety and the Tennessee Department of Transportation have developed a National High Speed WIM Test Facility for test and evaluation of high-speed WIM systems. The WIM system under evaluation includes a Single Load Cell WIM scale system supplied and installed by IRD. ORNL developed a stand-alone, custom data acquisition system, which acquires the raw signals from IRD`s in-ground single load cell transducers. Under a separate contract with the Federal Highway Administration, ORNL designed and constructed a laboratory scale house for data collection, analysis and algorithm development. An initial advanced weight-determining algorithm has been developed. The new advanced WIM system provides improved accuracy and can reduce overall system variability by up to 30% over the existing high accuracy commercial WIM system.

  5. Accurate and portable weigh-in-motion system for manifesting air cargo

    SciTech Connect

    Nodine, R.N.; Scudiere, M.B.; Jordan, J.K.

    1995-12-01

    An automated and portable weigh-in-motion system has been developed at Oak Ridge National Laboratory for the purpose of manifesting cargo onto aircraft. The system has an accuracv range of {plus_minus} 3.0% to {plus_minus} 6.0% measuring gross vehicle weight and locating the center of balance of moving vehicles at speeds of 1 to 5 mph. This paper reviews the control/user interface system and weight determination algorithm developed to acquire, process, and interpret multiple sensor inputs. The development effort resulted in a self-zeroing, user-friendly system capable of weighing a wide range of vehicles in any random order. The control system is based on the STANDARD (STD) bus and incorporates custom-designed data acquisition and sensor fusion hardware controlled by a personal computer (PC) based single-board computer. The user interface is written in the ``C`` language to display number of axles, axle weight, axle spacing, gross weight, and center of balance. The weighing algorithm developed will function with any linear weight sensor and a set of four axle switches per sensor.

  6. Practical on-board weigh-in-motion system for commercial vehicles

    NASA Astrophysics Data System (ADS)

    Kenyon, Chase H.

    1997-01-01

    Many commercial carriers are currently operating vehicles which are overweight, creating an unsafe and illegal situation. However, the cost to law enforcement agencies to stop vehicles for roadside weight checks is prohibitive, while the cost to the nation in lost travel time adds shipping costs which are reflected in the price of every product transported by truck. Overweight trucks also become a threat to public safety when, on public highways, solid cargo breaks loose or liquid cargo leaks. The solution is an on-board monitoring system. With such a system, trucks under their legal weight limit would be allowed to travel past state borders and checkpoints without being stopped. THis would save money both in law enforcement and shipping costs to the nation as a whole. A properly designed system would also have the capability to warn both the driver and local safety and enforcement personnel when the truck is loaded beyond capacity or any other unsafe condition. This paper will detail a system that would even in early limited production be cost effective for both the law enforcement agencies and the operators of trucking fleets. In full production the systems would be cost effective even for smaller or owner/operator trucks. This is a safety system that could become standard equipment similar to seat belts, ABS, and airbags. The initial testing of sub-assemblies and sub-systems which could be deployed now for beta test has been completed.

  7. Pavement management and weigh-in-motion. Transportation research record

    SciTech Connect

    Cation, K.A.; Shahin, M.Y.; Scullion, T.; Lytton, R.L.; Butt, A.A.

    1987-01-01

    The 15 papers in the report deal with the following areas: development of a preventive maintenance algorithm for use in pavement-management systems; pavement-performance prediction model using the Markov Process; roadway modeling and data conversion for a transportation-facilities information system; development of a methodology to estimate pavement maintenance and repair costs for different ranges of pavement-condition index; new techniques for modeling pavement deterioration; pavement management at the local government level; a comprehensive ranking system for local-agency pavement management; expert system as a part of pavement management; MAPCON: a pavement-evaluation data-analysis computer system; a microcomputer procedure to analyze axle load limits and pavement damage responsibility; selected results from the first three years of the Oregon automatic monitoring demonstration project; automated acquisition of truck-tire pressure data; calibration and accuracy testing of weigh-in-motion systems; accuracy and tolerances of weigh-in-motion systems; on-site calibration of weigh-in-motion systems.

  8. Error Reduction for Weigh-In-Motion

    SciTech Connect

    Hively, Lee M; Abercrombie, Robert K; Scudiere, Matthew B; Sheldon, Frederick T

    2009-01-01

    Federal and State agencies need certifiable vehicle weights for various applications, such as highway inspections, border security, check points, and port entries. ORNL weigh-in-motion (WIM) technology was previously unable to provide certifiable weights, due to natural oscillations, such as vehicle bouncing and rocking. Recent ORNL work demonstrated a novel filter to remove these oscillations. This work shows further filtering improvements to enable certifiable weight measurements (error < 0.1%) for a higher traffic volume with less effort (elimination of redundant weighing).

  9. Error Reduction in Weigh-In-Motion

    Energy Science and Technology Software Center (ESTSC)

    2007-09-21

    Federal and State agencies need certifiable vehicle weights for various applications, such as highway inspections, border security, check points, and port entries. ORNL weigh-in-motion (WIM) technology was previously unable to provide certifiable weights, due to natural oscillations, such as vehicle bounding and rocking. Recent ORNL work demonstrated a novel filter to remove these oscillations. This work shows further filtering improvements to enable certifiable weight measurements (error < 0.1%) for a higher traffic volume with lessmore » effort (elimination of redundant weighing)« less

  10. Prototype Weigh-In-Motion Performance

    SciTech Connect

    Abercrombie, Robert K; Beshears, David L; Hively, Lee M; Scudiere, Matthew B; Sheldon, Frederick T

    2006-10-01

    Oak Ridge National Laboratory (ORNL) has developed and patented methods to weigh slowly moving vehicles. We have used this technology to produce a portable weigh-in-motion system that is robust and accurate. This report documents the performance of the second-generation portable weigh-in-motion prototype (WIM Gen II). The results of three modes of weight determination are compared in this report: WIM Gen II dynamic mode, WIM Gen II stop-and-go mode, and static (parked) mode on in-ground, static scales. The WIM dynamic mode measures axle weights as the vehicle passes over the system at speeds of 3 to 7 miles per hour (1.3 to 3.1 meters/second). The WIM stop-and-go mode measures the weight of each axle of the vehicle as the axles are successively positioned on a side-by-side pair of WIM measurement pads. In both measurement modes the center of balance (CB) and the total weight are obtained by a straight-forward calculation from axle weights and axle spacings. The performance metric is measurement error (in percent), which is defined as 100 x (sample standard deviation)/(average); see Appendix A for details. We have insufficient data to show that this metric is predictive. This report details the results of weight measurements performed in May 2005 at two sites using different types of vehicles at each site. In addition to the weight measurements, the testing enabled refinements to the test methodology and facilitated an assessment of the influence of vehicle speed on the dynamic-mode measurements. The initial test at the National Transportation Research Center in Knoxville, TN, involved measurements of passenger and light-duty commercial vehicles. A subsequent test at the Arrival/Departure Airfield Control Group (A/DACG) facility in Ft. Bragg, NC, involved military vehicles with gross weights between 3,000 and 75,000 pounds (1,356 to 33,900 kilograms) with a 20,000-pound (9,040 kilograms) limit per axle. For each vehicle, four or more separate measurements were done

  11. The Potential and Beneficial Use of Weigh-In-Motion (WIM) Systems Integrated with Radio Frequency Identification (RFID) Systems for Characterizing Disposal of Waste Debris to Optimize the Waste Shipping Process

    SciTech Connect

    Abercrombie, Robert K; Buckner Jr, Dooley; Newton, David D

    2010-01-01

    The Oak Ridge National Laboratory (ORNL) Weigh-In-Motion (WIM) system provides a portable and/or semi-portable means of accurately weighing vehicles and its cargo as each vehicle crosses the scales (while in motion), and determining (1) axle weights and (2) axle spacing for vehicles (for determination of Bridge Formula compliance), (3) total vehicle/cargo weight and (4) longitudinal center of gravity (for safety considerations). The WIM system can also weigh the above statically. Because of the automated nature of the WIM system, it eliminates the introduction of human errors caused by manual computations and data entry, adverse weather conditions, and stress. Individual vehicles can be weighed continuously at low speeds (approximately 3-10 mph) and at intervals of less than one minute. The ORNL WIM system operates and is integrated into the Bethel Jacobs Company Transportation Management and Information System (TMIS, a Radio-Frequency Identification [RFID] enabled information system). The integrated process is as follows: Truck Identification Number and Tare Weight are programmed into a RFID Tag. Handheld RFID devices interact with the RFID Tag, and Electronic Shipping Document is written to the RFID Tag. The RFID tag read by an RFID tower identifies the vehicle and its associated cargo, the specific manifest of radioactive debris for the uniquely identified vehicle. The weight of the cargo (in this case waste debris) is calculated from total vehicle weight information supplied from WIM to TMIS and is further processed into the Information System and kept for historical and archival purposes. The assembled data is the further process in downstream information systems where waste coordination activities at the Y-12 Environmental Management Waste Management Facility (EMWMF) are written to RFID Tag. All cycle time information is monitored by Transportation Operations and Security personnel.

  12. Weigh-In-Motion Waveform Capture Systems

    Energy Science and Technology Software Center (ESTSC)

    2007-09-01

    Input data is generated from multiple weight sensor signals embedded in a thin weighing pad. This information is then reduced to total weight and position of a wheel rolling over the pad. This produces a signal which includes both the wheel weight and it inertial effects due to vehicle bounce, engine noise, and other mechanical vibrations. In order to extract accurate weight information of the wheel from the extraneous information, it is necessary to firstmore » capture the waveform and then perform a form of modal analysis. This program captures the above data and formats it into a useable form for analysis.« less

  13. Automated-In-Motion Vehicle Evaluation Environment (AIMVEE) Weigh-In Motion (WIM) User Training and Testing

    Energy Science and Technology Software Center (ESTSC)

    2006-05-04

    The AIMVEE/WIM system electronically retrieves deployment information, identifies vehicle automatically, and determines total weight, individual wheel weight, individual axle weights, axle spacing, and center-of-balance for any wheeled vehicle in motion. The AIMVEE/WIM system can also perform these functions statically for both wheel vehicles and cargo with information. The AIMVEE/WIM system incorporates digital images and applies cubing algorithms to determine length, width, height for cubic dimensions of both vehicle and cargo. Once all this information ismore » stored, it electronically links to data collection and dissemination systems to provide “actual” weight and measurement information for planning, deployment, and in-transit visibility. The Static Scale Conversion (SSC) system is an unique enhancement to the AIMVEE/WIM system. It enables a SSC to weigh and measure vehicles and cargo dynamically (i.e., as they pass over the large scale and is included in the AIMVEE computer code base. The material to be copyrighted is the Automated-In-Motion Vehicle Evaluation Environment (AIMVEE)/Weigh-In-Motion User Training and Testing material. It includes instructional material in the set-up, operation and tear-down of the AIMVEE/WIM system. It also includes a final exam associated with the training.« less

  14. Automated-In-Motion Vehicle Evaluation Environment (AIMVEE) Weigh-In Motion (WIM) User Training and Testing

    SciTech Connect

    2006-05-04

    The AIMVEE/WIM system electronically retrieves deployment information, identifies vehicle automatically, and determines total weight, individual wheel weight, individual axle weights, axle spacing, and center-of-balance for any wheeled vehicle in motion. The AIMVEE/WIM system can also perform these functions statically for both wheel vehicles and cargo with information. The AIMVEE/WIM system incorporates digital images and applies cubing algorithms to determine length, width, height for cubic dimensions of both vehicle and cargo. Once all this information is stored, it electronically links to data collection and dissemination systems to provide “actual” weight and measurement information for planning, deployment, and in-transit visibility. The Static Scale Conversion (SSC) system is an unique enhancement to the AIMVEE/WIM system. It enables a SSC to weigh and measure vehicles and cargo dynamically (i.e., as they pass over the large scale and is included in the AIMVEE computer code base. The material to be copyrighted is the Automated-In-Motion Vehicle Evaluation Environment (AIMVEE)/Weigh-In-Motion User Training and Testing material. It includes instructional material in the set-up, operation and tear-down of the AIMVEE/WIM system. It also includes a final exam associated with the training.

  15. Use of Finite Elements Analysis for a Weigh-in-Motion Sensor Design

    PubMed Central

    Opitz, Rigobert; Goanta, Viorel; Carlescu, Petru; Barsanescu, Paul-Doru; Taranu, Nicolae; Banu, Oana

    2012-01-01

    High speed weigh-in-motion (WIM) sensors are utilized as components of complex traffic monitoring and measurement systems. They should be able to determine the weights on wheels, axles and vehicle gross weights, and to help the classification of vehicles (depending on the number of axles). WIM sensors must meet the following main requirements: good accuracy, high endurance, low price and easy installation in the road structure. It is not advisable to use cheap materials in constructing these devices for lower prices, since the sensors are normally working in harsh environmental conditions such as temperatures between −40 °C and +70 °C, dust, temporary water immersion, shocks and vibrations. Consequently, less expensive manufacturing technologies are recommended. Because the installation cost in the road structure is high and proportional to the WIM sensor cross section (especially with its thickness), the device needs to be made as flat as possible. The WIM sensor model presented and analyzed in this paper uses a spring element equipped with strain gages. Using Finite Element Analysis (FEA), the authors have attempted to obtain a more sensitive, reliable, lower profile and overall cheaper elastic element for a new WIM sensor. PMID:22969332

  16. Hidden Markov Modeling for Weigh-In-Motion Estimation

    SciTech Connect

    Abercrombie, Robert K; Ferragut, Erik M; Boone, Shane

    2012-01-01

    This paper describes a hidden Markov model to assist in the weight measurement error that arises from complex vehicle oscillations of a system of discrete masses. Present reduction of oscillations is by a smooth, flat, level approach and constant, slow speed in a straight line. The model uses this inherent variability to assist in determining the true total weight and individual axle weights of a vehicle. The weight distribution dynamics of a generic moving vehicle were simulated. The model estimation converged to within 1% of the true mass for simulated data. The computational demands of this method, while much greater than simple averages, took only seconds to run on a desktop computer.

  17. Weigh-in-motion scale with foot alignment features

    SciTech Connect

    Abercrombie, Robert Knox; Richardson, Gregory David; Scudiere, Matthew Bligh

    2013-03-05

    A pad is disclosed for use in a weighing system for weighing a load. The pad includes a weighing platform, load cells, and foot members. Improvements to the pad reduce or substantially eliminate rotation of one or more of the corner foot members. A flexible foot strap disposed between the corner foot members reduces rotation of the respective foot members about vertical axes through the corner foot members and couples the corner foot members such that rotation of one corner foot member results in substantially the same amount of rotation of the other corner foot member. In a strapless variant one or more fasteners prevents substantially all rotation of a foot member. In a diagonal variant, a foot strap extends between a corner foot member and the weighing platform to reduce rotation of the foot member about a vertical axis through the corner foot member.

  18. A rheology model of soft elastomeric capacitor for Weigh-In-Motion application

    NASA Astrophysics Data System (ADS)

    Kollipara, Venkata Dharmateja

    As a result of fast growing industry, there is an increase in traffic congestion and deterioration of transportation inventory. Real-time traffic characterisation could be used to amoliorate the efficiency of our transportation system. Weigh-In-Motion (WIM) systems offer the advantages of vehicle classification, speed measurement, in addition to weight measurement while vehicles are moving. In this thesis, state-of-the-art WIM systems are discussed and limitations of current technologies are identified. A Soft Elastomeric Capacitor (SEC) that works as a large scale surface strain gauge is introduced to address the limitations in existing techniques and investigated for its applicability as a WIM sensor. Though the novel SEC has potential advantages, the relationship axial strain-to-stress needs to be modeled to enable its utilization as a WIM sensor. A Zener model is selected and modified by the addition of a slider to characterize the polymer behavior. An overstress approach is used to study the resultant stress-strain response owing to its simplicity and computational benefits. Since the overstress approach is data-driven, an experimental testing scheme is used to identify the model parameters. The tests comprise three types of applied strain loading: multi step relaxation, simple relaxation and cyclic compression. Specimens with varying stiffness are employed for these tests. Numerical simulations for the cyclic compression loading are presented to assess the model performance. The model is found to be capable of reproducing the experimental data with an absolute maximum error value of 0.085 MPa for slow loading rate tests and 0.175 MPa for high loading rate tests. Comparative studies are completed to investigate the impact of patch stiffness on the mechanical behavior of the soft elastomeric capacitor patches. It is observed that as stiffness decreases, the nonlinearity in stress-strain response increases

  19. Oak Ridge National Laboratory's (ORNL) Weigh-In-Motion (WIM) Configuration and Data Management Activities

    SciTech Connect

    Abercrombie, Robert K; Sheldon, Frederick T; Schlicher, Bob G

    2006-01-01

    The Oak Ridge National Laboratory (ORNL) involvement in the Weigh-in-Motion (WIM) research with both government agencies and private companies dates back to 1989. The discussion here will focus on the US Army's current need for an automated WIM system to weigh and determine the center-of-balance for military wheeled vehicles and cargo and the expanded uses of WIM data. ORNL is addressing configuration and data management issues as they relate to deployments for both military and humanitarian activities. The transition from the previous WIM Gen I to the current Gen II system illustrates a configuration and data management solution that ensures data integration, integrity, coherence and cost effectiveness. Currently, Army units use portable and fixed scales, tape measures, and calculators to determine vehicle axle, total weights and center of balance for vehicles prior to being transshipped via railcar, ship, or airlifted. Manually weighing and measuring all vehicles subject to these transshipment operations is time-consuming, labor-intensive, hazardous and is prone to human errors (e.g., misreading scales and tape measures, calculating centers of balance and wheel, axle, and vehicle weights, recording data, and transferring data from manually prepared work sheets into an electronic data base and aggravated by adverse weather conditions). Additionally, in the context of the military, the timeliness, safety, success, and effectiveness of airborne heavy-drop operations can be significantly improved by the use of an automated system to weigh and determine center of balance of vehicles while they are in motion. The lack of a standardized airlift-weighing system for joint service use also creates redundant weighing requirements at the cost of scarce resources and time. This case study can be judiciously expanded into commercial operations related to safety and enforcement. The WIM program will provide a means for the Army to automatically identify/weigh and monitor

  20. Real-time weigh-in-motion measurement using fiber Bragg grating sensors

    NASA Astrophysics Data System (ADS)

    Huang, Ying; Palek, Leonard; Strommen, Robert; Worel, Ben; Chen, Genda

    2014-03-01

    Overloading truck loads have long been one of the key reasons for accelerating road damage, especially in rural regions where the design loads are expected to be small and in the cold regions where the wet-and-dry cycle places a significant role. To control the designed traffic loads and further guide the road design in future, periodical weight stations have been implemented for double check of the truck loads. The weight stations give chances for missing measurement of overloaded vehicles, slow down the traffic, and require additional labors. Infrastructure weight-in-motion sensors, on the other hand, keep consistent traffic flow and monitor all types of vehicles on roads. However, traditional electrical weight-in-motion sensors showed high electromagnetic interference (EMI), high dependence on environmental conditions such as moisture, and relatively short life cycle, which are unreliable for long-term weigh-inmotion measurements. Fiber Bragg grating (FBG) sensors, with unique advantages of compactness, immune to EMI and moisture, capability of quasi-distributed sensing, and long life cycle, will be a perfect candidate for long-term weigh-in-motion measurements. However, the FBG sensors also surfer from their frangible nature of glass materials for a good survive rate during sensor installation. In this study, the FBG based weight-in-motion sensors were packaged by fiber reinforced polymer (FRP) materials and further validated at MnROAD facility, Minnesota DOT (MnDOT). The design and layout of the FRP-FBG weight-in-motion sensors, their field test setup, data acquisition, and data analysis will be presented. Upon validation, the FRP-FBG sensors can be applied weigh-in-motion measurement to assistant road managements.

  1. Sampling optimization for high-speed weigh-in-motion measurements using in-pavement strain-based sensors

    NASA Astrophysics Data System (ADS)

    Zhang, Zhiming; Huang, Ying; Bridgelall, Raj; Palek, Leonard; Strommen, Robert

    2015-06-01

    Weigh-in-motion (WIM) measurement has been widely used for weight enforcement, pavement design, freight management, and intelligent transportation systems to monitor traffic in real-time. However, to use such sensors effectively, vehicles must exit the traffic stream and slow down to match their current capabilities. Hence, agencies need devices with higher vehicle passing speed capabilities to enable continuous weight measurements at mainline speeds. The current practices for data acquisition at such high speeds are fragmented. Deployment configurations and settings depend mainly on the experiences of operation engineers. To assure adequate data, most practitioners use very high frequency measurements that result in redundant samples, thereby diminishing the potential for real-time processing. The larger data memory requirements from higher sample rates also increase storage and processing costs. The field lacks a sampling design or standard to guide appropriate data acquisition of high-speed WIM measurements. This study develops the appropriate sample rate requirements as a function of the vehicle speed. Simulations and field experiments validate the methods developed. The results will serve as guidelines for future high-speed WIM measurements using in-pavement strain-based sensors.

  2. Frequency conversion system

    NASA Technical Reports Server (NTRS)

    Sanders, Steven (Inventor); Waarts, Robert G. (Inventor)

    2001-01-01

    A frequency conversion system comprises first and second gain sources providing first and second frequency radiation outputs where the second gain source receives as input the output of the first gain source and, further, the second gain source comprises a Raman or Brillouin gain fiber for wave shifting a portion of the radiation of the first frequency output into second frequency radiation output to provided a combined output of first and second frequencies. Powers are gain enhanced by the addition of a rare earth amplifier or oscillator, or a Raman/Brillouin amplifier or oscillator between the high power source and the NFM device. Further, polarization conversion using Raman or Brillouin wavelength shifting is provided to optimize frequency conversion efficiency in the NFM device.

  3. Wind energy conversion system

    DOEpatents

    Longrigg, Paul

    1987-01-01

    The wind energy conversion system includes a wind machine having a propeller connected to a generator of electric power, the propeller rotating the generator in response to force of an incident wind. The generator converts the power of the wind to electric power for use by an electric load. Circuitry for varying the duty factor of the generator output power is connected between the generator and the load to thereby alter a loading of the generator and the propeller by the electric load. Wind speed is sensed electro-optically to provide data of wind speed upwind of the propeller, to thereby permit tip speed ratio circuitry to operate the power control circuitry and thereby optimize the tip speed ratio by varying the loading of the propeller. Accordingly, the efficiency of the wind energy conversion system is maximized.

  4. Energy conversion system

    DOEpatents

    Murphy, L.M.

    1985-09-16

    The energy conversion system includes a photo-voltaic array for receiving solar radiation and converting such radiation to electrical energy. The photo-voltaic array is mounted on a stretched membrane that is held by a frame. Tracking means for orienting the photo-voltaic array in predetermined positions that provide optimal exposure to solar radiation cooperate with the frame. An enclosure formed of a radiation transmissible material includes an inside containment space that accommodates the photo-voltaic array on the stretched membrane, the frame and the tracking means, and forms a protective shield for all such components. The enclosure is preferably formed of a flexible inflatable material and maintains its preferred form, such as a dome, under the influence of a low air pressure furnished to the dome. Under this arrangement the energy conversion system is streamlined for minimizing wind resistance, sufficiently weathproof for providing protection against weather hazards such as hail, capable of using diffused light, lightweight for low-cost construction and operational with a minimal power draw.

  5. Energy conversion system

    DOEpatents

    Murphy, Lawrence M.

    1987-01-01

    The energy conversion system includes a photo-voltaic array for receiving solar radiation and converting such radiation to electrical energy. The photo-voltaic array is mounted on a stretched membrane that is held by a frame. Tracking means for orienting the photo-voltaic array in predetermined positions that provide optimal exposure to solar radiation cooperate with the frame. An enclosure formed of a radiation transmissible material includes an inside containment space that accommodates the photo-voltaic array on the stretched membrane, the frame and the tracking means, and forms a protective shield for all such components. The enclosure is preferably formed of a flexible inflatable material and maintains its preferred form, such as a dome, under the influence of a low air pressure furnished to the dome. Under this arrangement the energy conversion system is streamlined for minimizing wind resistance, sufficiently weatherproof for providing protection against weather hazards such as hail, capable of using diffused light, lightweight for low-cost construction, and operational with a minimal power draw.

  6. Frequency conversion system

    NASA Technical Reports Server (NTRS)

    Sanders, Steven (Inventor); Lang, Robert J. (Inventor)

    2001-01-01

    Laser diode pumped mid-IR wavelength sources include at least one high power, near-IR wavelength, injection and/or sources wherein one or both of such sources may be tunable providing a pump wave output beam to a quasi-phase matched (QPM) nonlinear frequency mixing (NFM) device. The NFM device may be a difference frequency mixing (DFM) device or an optical parametric oscillation (OPO) device. Wavelength tuning of at least one of the sources advantageously provides the ability for optimizing pump or injection wavelengths to match the QPM properties of the NFM device enabling a broad range of mid-IR wavelength selectivity. Also, pump powers are gain enhanced by the addition of a rare earth amplifier or oscillator, or a Raman/Brillouin amplifier or oscillator between the high power source and the NFM device. Further, polarization conversion using Raman or Brillouin wavelength shifting is provided to optimize frequency conversion efficiency in the NFM device.

  7. Biological conversion system

    DOEpatents

    Scott, C.D.

    A system for bioconversion of organic material comprises a primary bioreactor column wherein a biological active agent (zymomonas mobilis) converts the organic material (sugar) to a product (alcohol), a rejuvenator column wherein the biological activity of said biological active agent is enhanced, and means for circulating said biological active agent between said primary bioreactor column and said rejuvenator column.

  8. Laser power conversion system analysis

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Orbit to orbit and orbit to ground laser power conversion systems and power transfer are discussed. A system overview is presented. Pilot program parameters are considered: SLPS assumptions are listed, a laser SPS overview is presented, specifications are listed, and SLPS coats are considered.

  9. Ocean energy conversion systems report

    NASA Astrophysics Data System (ADS)

    1981-03-01

    Alternative power cycle concepts to the closed-cycle Rankine are evaluated and those that show potential for delivering power in a cost effective and environmentally acceptable fashion are explored. Concepts are classified according to the ocean energy resource: thermal, waves, currents, and salinity gradient. The lift of seawater entrained in a vertical steam flow provides potential energy for a conventional hydraulic turbine conversion system. Quantification of the process and assessment of potential cost must be completed to support concept evaluation. Exploratory development is completed in thermoelectricity and 2-phase nozzles for other thermal concepts. Wave energy concepts are evaluated by analysis and model testing with emphasis on pneumatic turbines and wave focussing. Several conversion approaches to ocean current energy are being evaluated.

  10. Power enhanced frequency conversion system

    NASA Technical Reports Server (NTRS)

    Sanders, Steven (Inventor); Lang, Robert J. (Inventor); Waarts, Robert G. (Inventor)

    2001-01-01

    A frequency conversion system includes at least one source providing a first near-IR wavelength output including a gain medium for providing high power amplification, such as double clad fiber amplifier, a double clad fiber laser or a semiconductor tapered amplifier to enhance the power output level of the near-IR wavelength output. The NFM device may be a difference frequency mixing (DFM) device or an optical parametric oscillation (OPO) device. Pump powers are gain enhanced by the addition of a rare earth amplifier or oscillator, or a Ra-man/Brillouin amplifier or oscillator between the high power source and the NFM device.

  11. Photoelectrochemical based direct conversion systems

    SciTech Connect

    Kocha, S.; Arent, D.; Peterson, M.

    1995-09-01

    The goal of this research is to develop a stable, cost effective, photoelectrochemical based system that will split water upon illumination, producing hydrogen and oxygen directly, using sunlight as the only energy input. This type of direct conversion system combines a photovoltaic material and an electrolyzer into a single monolithic device. We report on our studies of two multifunction multiphoton photoelectrochemical devices, one based on the ternary semiconductor gallium indium phosphide, (GaInP{sub 2}), and the other one based on amorphous silicon carbide. We also report on our studies of the solid state surface treatment of GaInP{sub 2} as well as our continuing effort to develop synthetic techniques for the attachment of transition metal complexes to the surface of semiconductor electrodes. All our surface studies are directed at controlling the interface energetics and forming stable catalytic surfaces.

  12. Static conversion systems. [for space power reactors

    NASA Technical Reports Server (NTRS)

    Ewell, R.; Mondt, J.

    1985-01-01

    Historically, all space power systems that have actually flown in space have relied on static energy conversion technology. Thus, static conversion is being considered for space nuclear power systems as well. There are four potential static conversion technologies which should be considered. These include: the alkali metal thermoelectric converter (AMTEC), the thermionic converter, the thermoelectric converter, and the thermophotovoltaic converter (TPV). These four conversion technologies will be described in brief detail along with their current status and development needs. In addition, the systems implications of using each of these conversion technologies with a space nuclear reactor power system will be evaluated and some comparisons made.

  13. Terrestrial solar thermionic energy conversion systems concept

    NASA Technical Reports Server (NTRS)

    Shimada, K.; Swerdling, M.

    1975-01-01

    Results obtained from studies of a (1) solar concentrator, (2) solar energy receiver - thermionic converter system, and (3) solar thermionic topping system are described. Peripheral subsystems, which are required for any solar energy conversion system, are also discussed.

  14. Laser power conversion system analysis, volume 1

    NASA Technical Reports Server (NTRS)

    Jones, W. S.; Morgan, L. L.; Forsyth, J. B.; Skratt, J. P.

    1979-01-01

    The orbit-to-orbit laser energy conversion system analysis established a mission model of satellites with various orbital parameters and average electrical power requirements ranging from 1 to 300 kW. The system analysis evaluated various conversion techniques, power system deployment parameters, power system electrical supplies and other critical supplies and other critical subsystems relative to various combinations of the mission model. The analysis show that the laser power system would not be competitive with current satellite power systems from weight, cost and development risk standpoints.

  15. NASA presentation. [wind energy conversion systems planning

    NASA Technical Reports Server (NTRS)

    Thomas, R. L.

    1973-01-01

    The development of a wind energy system is outlined that supplies reliable energy at a cost competitive with other energy systems. A government directed industry program with strong university support is recommended that includes meteorological studies to estimate wind energy potentials and determines favorable regions and sites for wind power installations. Key phases of the overall program are wind energy conversion systems, meteorological wind studies, energy storage systems, and environmental impact studies. Performance testing with a prototype wind energy conversion and storage system is projected for Fiscal 1977.

  16. Hydrogen turbine power conversion system assessment

    NASA Technical Reports Server (NTRS)

    Wright, D. E.; Lucci, A. D.; Campbell, J.; Lee, J. C.

    1978-01-01

    A three part technical study was conducted whereby parametric technical and economic feasibility data were developed on several power conversion systems suitable for the generation of central station electric power through the combustion of hydrogen and the use of the resulting heat energy in turbogenerator equipment. The study assessed potential applications of hydrogen-fueled power conversion systems and identified the three most promising candidates: (1) Ericsson Cycle, (2) gas turbine, and (3) direct steam injection system for fossil fuel as well as nuclear powerplants. A technical and economic evaluation was performed on the three systems from which the direct injection system (fossil fuel only) was selected for a preliminary conceptual design of an integrated hydrogen-fired power conversion system.

  17. Laser power conversion system analysis, volume 2

    NASA Technical Reports Server (NTRS)

    Jones, W. S.; Morgan, L. L.; Forsyth, J. B.; Skratt, J. P.

    1979-01-01

    The orbit-to-ground laser power conversion system analysis investigated the feasibility and cost effectiveness of converting solar energy into laser energy in space, and transmitting the laser energy to earth for conversion to electrical energy. The analysis included space laser systems with electrical outputs on the ground ranging from 100 to 10,000 MW. The space laser power system was shown to be feasible and a viable alternate to the microwave solar power satellite. The narrow laser beam provides many options and alternatives not attainable with a microwave beam.

  18. Conversion to the Metric System

    ERIC Educational Resources Information Center

    Crunkilton, John C.; Lee, Jasper S.

    1974-01-01

    The authors discuss background information about the metric system and explore the effect of metrication of agriculture in areas such as equipment calibration, chemical measurement, and marketing of agricultural products. Suggestions are given for possible leadership roles and approaches that agricultural education might take in converting to the…

  19. Synchronous generator wind energy conversion control system

    SciTech Connect

    Medeiros, A.L.R.; Lima, A.M.N.; Jacobina, C.B.; Simoes, F.J.

    1996-12-31

    This paper presents the performance evaluation and the design of the control system of a WECS (Wind Energy Conversion System) that employs a synchronous generator based on its digital simulation. The WECS discussed in this paper is connected to the utility grid through two Pulse Width Modulated (PWM) power converters. The structure of the proposed WECS enables us to achieve high performance energy conversion by: (i) maximizing the wind energy capture and (ii) minimizing the reactive power flowing between the grid and the synchronous generator. 8 refs., 19 figs.

  20. System Performance Projections for TPV Energy Conversion

    SciTech Connect

    PF Baldasaro; MW Dashiell; JE Oppenlander; JL Vell; P Fourspring; K Rahner; LR Danielson; S Burger; E Brown

    2004-06-09

    TPV technology has advanced rapidly in the last five years, with diode conversion efficiency approaching >30%, and filter efficiency of {approx}80%. These achievements have enabled repeatable testing of 20% efficient small systems, demonstrating the potential of TPV energy conversion. Near term technology gains support a 25% efficient technology demonstration in the two year timeframe. However, testing of full size systems, which includes efficiency degradation mechanisms, such as: nonuniform diode illumination, diode and filter variability, temperature non-uniformities, conduction/convection losses, and lifetime reliability processes needs to be performed. A preliminary analysis of these differential effects has been completed, and indicates a near term integrated system efficiency of {approx}15% is possible using current technology, with long term growth to 18-20%. This report addresses the system performance issues.

  1. Optical Energy Transfer and Conversion System

    NASA Technical Reports Server (NTRS)

    Stone, William C. (Inventor); Hogan, Bartholomew P. (Inventor)

    2015-01-01

    An optical power transfer system comprising a fiber spooler, a fiber optic rotary joint mechanically connected to the fiber spooler, and an electrical power extraction subsystem connected to the fiber optic rotary joint with an optical waveguide. Optical energy is generated at and transferred from a base station through fiber wrapped around the spooler, through the rotary joint, and ultimately to the power extraction system at a remote mobility platform for conversion to another form of energy.

  2. The Conversion of Wiswesser Line Notations to Ring Codes. I. The Conversion of Ring Systems

    ERIC Educational Resources Information Center

    Granito, Charles E.; And Others

    1972-01-01

    The computerized conversion of Wiswesser Line Notations to Ring Codes, using a two-part approach, and the set of computer programs generated for the conversion of ring systems are described. (9 references) (Author)

  3. A new wind energy conversion system

    NASA Technical Reports Server (NTRS)

    Smetana, F. O.

    1975-01-01

    It is presupposed that vertical axis wind energy machines will be superior to horizontal axis machines on a power output/cost basis and the design of a new wind energy machine is presented. The design employs conical cones with sharp lips and smooth surfaces to promote maximum drag and minimize skin friction. The cones are mounted on a vertical axis in such a way as to assist torque development. Storing wind energy as compressed air is thought to be optimal and reasons are: (1) the efficiency of compression is fairly high compared to the conversion of mechanical energy to electrical energy in storage batteries; (2) the release of stored energy through an air motor has high efficiency; and (3) design, construction, and maintenance of an all-mechanical system is usually simpler than for a mechanical to electrical conversion system.

  4. Volterra series modeling of power conversion systems

    SciTech Connect

    Tymerski, R. )

    1991-10-01

    This paper reports that the nonlinear control-to-output response of pulse-width modulated (PWM) conversion system is modeled via the Volterra functional series. The determination of the Volterra kernels in the transform domain is performed on a simplified state space model of the converter. The dominant component of various harmonic and intermodulation distortion frequency products in the output spectrum are derived and are expressed in terms of these kernels. Experimental results are presented confirming the modeling procedure.

  5. Flexible Conversion Ratio Fast Reactor Systems Evaluation

    SciTech Connect

    Neil Todreas; Pavel Hejzlar

    2008-06-30

    Conceptual designs of lead-cooled and liquid salt-cooled fast flexible conversion ratio reactors were developed. Both concepts have cores reated at 2400 MWt placed in a large-pool-type vessel with dual-free level, which also contains four intermediate heat exchanges coupling a primary coolant to a compact and efficient supercritical CO2 Brayton cycle power conversion system. Decay heat is removed passively using an enhanced Reactor Vessel Auxiliary Cooling System and a Passive Secondary Auxiliary Cooling System. The most important findings were that (1) it is feasible to design the lead-cooled and salt-cooled reactor with the flexible conversion ratio (CR) in the range of CR=0 and CR=1 n a manner that achieves inherent reactor shutdown in unprotected accidents, (2) the salt-cooled reactor requires Lithium thermal Expansion Modules to overcme the inherent salt coolant's large positive coolant temperature reactivity coefficient, (3) the preferable salt for fast spectrum high power density cores is NaCl-Kcl-MgCl2 as opposed to fluoride salts due to its better themal-hydraulic and neutronic characteristics, and (4) both reactor, but attain power density 3 times smaller than that of the sodium-cooled reactor.

  6. Advanced Stirling conversion systems for terrestrial applications

    NASA Technical Reports Server (NTRS)

    Shaltens, R. K.

    1987-01-01

    Under the Department of Energy's (DOE) Solar Thermal Technology Program, Sandia National Laboratories (SNLA) is developing heat engines for terrestrial Solar Distributed Heat Receivers. SNLA has identified the Stirling to be one of the most promising candidates for the terrestrial applications. The free-piston Stirling engine (FPSE) has the potential to meet the DOE goals for both performance and cost. The National Aeronautics and Space Administration (NASA) Lewis Research Center (LeRC) is conducting free-piston Stirling activities which are directed toward a dynamic power source for space applications. Space power system requirements include high efficiency, very long life, high reliability and low vibration. The FPSE has the potential for future high power space conversion systems, either solar or nuclear. Generic free-piston technology is currently being developed by LeRC for DOE/ORNL for use with a residential heat pump under an Interagency Agreement. Since 1983, the SP-100 Program (DOD/NASA/DOE) is developing dynamic power sources for space. Although both applications (heat pump and space power) appear to be quite different, their requirements complement each other. A cooperative Interagency Agreement (IAA) was signed in 1985 with NASA Lewis to provide technical management for an Advanced Stirling Conversion System (ASCS) for SNLA. Conceptual design(s) using a free-piston Stirling (FPSE), and a heat pipe will be discussed. The ASCS will be designed using technology which can reasonably be expected to be available in the 1980's.

  7. Advanced Stirling conversion systems for terrestrial applications

    SciTech Connect

    Shaltens, R.K.

    1987-01-01

    Sandia National Laboratories (SNLA) is developing heat engines for terrestrial Solar distributed Heat Receivers. SNLA has identified the Stirling to be one of the most promising candidates for the terrestrial applications. The free-piston Stirling engine (FPSE) has the potential to meet the DOE goals for both performance and cost. Free-piston Stirling activities which are directed toward a dynamic power source for the space application are being conducted. Space power system requirements include high efficiency, very long life, high reliability and low vibration. The FPSE has the potential for future high power space conversion systems, either solar or nuclear powered. Generic free-piston technology is currently being developed for use with a residential heat pump under an Interagency Agreement. Also, an overview is presented of proposed conceptual designs for the Advanced Stirling Conversion System (ASCS) using a free-piston Stirling engine and a liquid metal heat pipe receiver. Power extraction includes both a linear alternator and hydraulic output capable of delivering approximately 25 kW of electrical power to the electric utility grid. Target cost of the engine/alternator is 300 dollars per kilowatt at a manufacturing rate of 10,000 units per year. The design life of the ASCS is 60,000 h (30 y) with an engine overhaul at 40,000 h (20 y). Also discussed are the key features and characteristics of the ASCS conceptual designs.

  8. Olefin fractionation and catalytic conversion system

    SciTech Connect

    Owen, H.; Hsia, C.H.; Wright, B.S.

    1989-05-23

    A continuous catalytic system is described for converting a fraction of olefinic feedstock comprising ethylene and C/sub 3/+ olefins to heavier liquid hydrocarbon product comprising: (a) means for prefractionating the olefinic feedstock to obtain a gaseous stream rich in ethylene and a liquid stream containing C/sub 3/+ olefin; (b) means for vaporizing and contacting the liquid stream from the prefractionating step with hydrocarbon conversion oligomerization catalyst in a catalytic reactor system to provide a heavier hydrocarbon effluent stream comprising distillate, gasoline and lighter hydrocarbons; (c) means for fractionating the effluent stream to recover distillate, gasoline and lighter hydrocarbon separately; (d) means for recycling at least a portion of the recovered gasoline as a liquid sorption stream to prefractionating step (a); and (e) means for further reacting the recycled gasoline together with sorbed C/sub 3/+ olefin in the catalytic reactor system of step (b).

  9. Modeling and analysis of energy conversion systems

    SciTech Connect

    Den Braven, K.R. . Dept. of Mechanical Engineering); Stanger, S. )

    1990-10-01

    An investigation was conducted to assess the need for and the feasibility of developing a computer code that could model thermodynamic systems and predict the performance of energy conversion systems. To assess the market need for this code, representatives of a few industrial organizations were contacted, including manufacturers, system and component designers, and research personnel. Researchers and small manufacturers, designers, and installers were very interested in the possibility of using the proposed code. However, large companies were satisfied with the existing codes that they have developed for their own use. Also, a survey was conduced of available codes that could be used or possibly modified for the desired purpose. The codes were evaluated with respect to a list of desirable features, which was prepared as a result of the survey. A few publicly available codes were found that might be suitable. The development, verification, and maintenance of such a code would require a substantial, ongoing effort. 21 refs.

  10. Education System Benefits of U.S. Metric Conversion.

    ERIC Educational Resources Information Center

    Phelps, Richard P.

    1996-01-01

    U.S. metric conversion efforts are reviewed as they have affected education. Education system benefits and costs are estimated for three possible system conversion plans. The soft-conversion-to-metric plan, which drops all inch-pound instruction, appears to provide the largest net benefits. The primary benefit is in class time saved. (SLD)

  11. Ocean energy conversion systems annual research report

    SciTech Connect

    Not Available

    1981-03-01

    Alternative power cycle concepts to the closed-cycle Rankine are evaluated and those that show potential for delivering power in a cost-effective and environmentally acceptable fashion are explored. Concepts are classified according to the ocean energy resource: thermal, waves, currents, and salinity gradient. Research projects have been funded and reported in each of these areas. The lift of seawater entrained in a vertical steam flow can provide potential energy for a conventional hydraulic turbine conversion system. Quantification of the process and assessment of potential costs must be completed to support concept evaluation. Exploratory development is being completed in thermoelectricity and 2-phase nozzles for other thermal concepts. Wave energy concepts are being evaluated by analysis and model testing with present emphasis on pneumatic turbines and wave focussing. Likewise, several conversion approaches to ocean current energy are being evaluated. The use of salinity resources requires further research in membranes or the development of membraneless processes. Using the thermal resource in a Claude cycle process as a power converter is promising, and a program of R and D and subsystem development has been initiated to provide confirmation of the preliminary conclusion.

  12. Performance of Tornado Wind Energy Conversion Systems

    SciTech Connect

    Volk, T.

    1982-09-01

    The flow characteristics and power production capabilities of the Tornado Wind Energy Conversion System (TWECS) are examined. Experimental results indicate that the confined vortex in the tower of TWECS rotates approximately as a solid body and only supplements total power production, most of which comes from the tower acting as a bluff body. Wrapped tower experiments were performed by fitting a plastic shroud 360 deg around the tower from the top of the bottom inlet to the tower exit level which transformed the TWECS into a hollow, raised cylinder. Coefficient of power is compared for louvered towers vs. wrapped tower. The fact that the wrapped tower performs as well as the louvered tower suggests that it is the pressure difference between the bottom inlet region and the region above the tower (where the pressure of the ambient flow will be somewhat reduced owing to its acceleration over the bluff body of the tower) which determines the vertical force on the fluid within the tower.

  13. Open cycle ocean thermal energy conversion system

    SciTech Connect

    Wittig, J.M.

    1980-02-19

    An improved open cycle ocean thermal energy conversion system is described including a flash evaporator for vaporizing relatively warm ocean surface water and an axial flow, elastic fluid turbine having a vertical shaft and axis of rotation. The warm ocean water is transmitted to the evaporator through a first prestressed concrete skirtconduit structure circumferentially situated about the axis of rotation. The unflashed warm ocean water exits the evaporator through a second prestressed concrete skirt-conduit structure located circumferentially about and radially within the first skirt-conduit structure. The radially inner surface of the second skirt conduit structure constitutes a cylinder which functions as the turbine's outer casing and obviates the need for a conventional outer housing. The turbine includes a radially enlarged disc element attached to the shaft for supporting at least one axial row of radially directed blades through which the steam is expanded. A prestressed concrete inner casing structure of the turbine has upstream and downstream portions respectively situated upstream and downstream from the disc element. The radially outer surfaces of the inner casing portions and radially outer periphery of the axially interposed disc cooperatively form a downwardly radially inwardly tapered surface. An annular steam flowpath of increasing flow area in the downward axial direction is radially bounded by the inner and outer prestressed concrete casing structures. The inner casing portions each include a tranversely situated prestressed concrete circular wall for rotatably supporting the turbine shaft and associated structure.

  14. Garbage to hydrocarbon fuel conversion system

    SciTech Connect

    Gould, W.A.

    1986-07-15

    A garbage to hydrocarbon fuel conversion system is described which consists of: (a) a source of combustible garbage; (b) means for pulverizing the garbage; (c) a furnace to burn the garbage; (d) means for transporting the pulverized garbage to the furnace which comprises a motor operated worm feed automatic stoker; (e) a steam generating coil inside the furnace which supplies live steam to power a turbine which in turn powers an alternating current generator; and a condenser which returns remaining the steam to a liquid state for re-circulation through the steam generating coils; (f) means for collecting incompletely combusted waste gases from the furnace; precipitating out dust and light oil for re-combustion in the furnace; and, extracting hydrocarbon gas; where in the means for precipitating out dust and light oil for re-combustion in the furnace comprise a cottrell precipitator wherein oil from an external source is mixed with fine dust received from the exhaust port, wherein an electrostatic charge helps to precipitate the dust; a dust and light oil mixer which provides a homogeneous mixture; and, an oil burner mounted to the furnace whose heat output is supplied to the furnace to add energy thereto; and (g) means for burning trapped heavy gases and removing waste ash from the furnace for disposal.

  15. Open cycle ocean thermal energy conversion system

    DOEpatents

    Wittig, J. Michael

    1980-01-01

    An improved open cycle ocean thermal energy conversion system including a flash evaporator for vaporizing relatively warm ocean surface water and an axial flow, elastic fluid turbine having a vertical shaft and axis of rotation. The warm ocean water is transmitted to the evaporator through a first prestressed concrete skirt-conduit structure circumferentially situated about the axis of rotation. The unflashed warm ocean water exits the evaporator through a second prestressed concrete skirt-conduit structure located circumferentially about and radially within the first skirt-conduit structure. The radially inner surface of the second skirt conduit structure constitutes a cylinder which functions as the turbine's outer casing and obviates the need for a conventional outer housing. The turbine includes a radially enlarged disc element attached to the shaft for supporting at least one axial row of radially directed blades through which the steam is expanded. A prestressed concrete inner casing structure of the turbine has upstream and downstream portions respectively situated upstream and downstream from the disc element. The radially outer surfaces of the inner casing portions and radially outer periphery of the axially interposed disc cooperatively form a downwardly radially inwardly tapered surface. An annular steam flowpath of increasing flow area in the downward axial direction is radially bounded by the inner and outer prestressed concrete casing structures. The inner casing portions each include a transversely situated prestressed concrete circular wall for rotatably supporting the turbine shaft and associated structure. The turbine blades are substantially radially coextensive with the steam flowpath and receive steam from the evaporator through an annular array of prestressed concrete stationary vanes which extend between the inner and outer casings to provide structural support therefor and impart a desired flow direction to the steam.

  16. Open cycle ocean thermal energy conversion system

    SciTech Connect

    Wittig, J.M.

    1980-02-19

    An improved open cycle ocean thermal energy conversion system includes a flash evaporator for vaporizing relatively warm ocean surface water and an axial flow, elastic fluid turbine having a vertical shaft and axis of rotation. The warm ocean water is transmitted to the evaporator through a first prestressed concrete skirt-conduit structure circumferentially situated about the axis of rotation. The unflashed warm ocean water exits the evaporator through a second prestressed concrete skirt-conduit structure located circumferentially about and radially within the first skirt-conduit structure. The radially inner surface of the second skirt conduit structure constitutes a cylinder which functions as the turbine's outer casing and obviates the need for a conventional outer housing. The turbine includes a radially enlarged disc element attached to the shaft for supporting at least one axial row of radially directed blades through which the steam is expanded. A prestressed concrete inner casing structure of the turbine has upstream and downstream portions respectively situated upstream and downstream from the disc element. The radially outer surfaces of the inner casing portions and radially outer periphery of the axially interposed disc cooperatively form a downwardly radially inwardly tapered surface. An annular steam flow path of increasing flow area in the downward axial direction is radially bounded by the inner and outer prestressed concrete casing structures. The inner casing portions each include a transversely situated prestressed concrete circular wall for rotatably supporting the turbine shaft and associated structure. The turbine blades are substantially radially coextensive with the steam flow path and receive steam from the evaporator through an annular array of prestressed concrete stationary vanes which extend between the inner and outer casings to provide structural support there for and impart a desired flow direction to the steam. 10 figs.

  17. A Conversational Intelligent Tutoring System to Automatically Predict Learning Styles

    ERIC Educational Resources Information Center

    Latham, Annabel; Crockett, Keeley; McLean, David; Edmonds, Bruce

    2012-01-01

    This paper proposes a generic methodology and architecture for developing a novel conversational intelligent tutoring system (CITS) called Oscar that leads a tutoring conversation and dynamically predicts and adapts to a student's learning style. Oscar aims to mimic a human tutor by implicitly modelling the learning style during tutoring, and…

  18. Software conversion history of the Flight Dynamics System (FDS)

    NASA Technical Reports Server (NTRS)

    Liu, K.

    1984-01-01

    This report summarizes the overall history of the Flight Dynamics System (FDS) applications software conversion project. It describes the background and nature of the project; traces the actual course of conversion; assesses the process, product, and personnel involved; and offers suggestions for future projects. It also contains lists of pertinent reference material and examples of supporting data.

  19. 5 CFR 9901.371 - Conversion into NSPS pay system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... been determined to be below an acceptable level of competence under 5 CFR part 531, subpart D. (7) An... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Conversion into NSPS pay system. 9901.371....) An affected employee may convert from the GS system, the SL/ST system, or the SES system (or...

  20. Systems Requirement Document for the MSRE U-233 Conversion System

    SciTech Connect

    Aigner, R.D.

    2001-01-11

    The fissile material reclamation activities for the MSRE remediation project include the removal and recovery of uranium from the off-gas system, from the stored fuel salt, and finally, from the uranium-laden charcoal in the Auxiliary Charcoal Bed (ACB). Each of these operations produces an uranium/fluoride compound that is not suitable for long-term storage. The uranium-fluoride compounds can be stored for a limited period of time in pressure vessels. The interim-storage vessels are designed to handle the internal pressure buildup from gases formed by radiolysis of the uranium-fluoride compounds. The conversion process will take the pressurized vessels from interim storage and process the materials in a hot cell located at Building 4501. The gas in the vessels will be vented through chemical traps and then the traps will be processed to convert the various uranium-fluoride compounds to a stable uranium oxide form. This will be done one trap at a time. The chemical form of uranium being extracted from the off-gas system and from fuel salt fluorination process is uranium hexafluoride UF{sub 6}. During the operations at MSRE, the UF{sub 6} is chemisorbed onto sodium fluoride (NaF) traps where it forms the complex, 2NaF{center_dot}UF{sub 6}. The conversion process that will be installed in the Building 4501 Hot Cell D will recover the UF{sub 6} from the NaF traps by decomposition of the binary complex at elevated temperatures (>300 C). After the uranium is extracted from the NaF traps, it is collected in the conversion process reaction vessel. The reaction vessel is then hydrolized and heated through several step operations up to 900 C in order to convert the material to a stable uranium oxide. The ACB at MSRE contains uranium-laden charcoal with unstable C{sub x}F compounds. After extraction at MSRE, this material will be delivered to Building 4501 Hot Cell D for processing to a stable oxide. The charcoal conversion process is still under development, with mockup and

  1. 5 CFR 9901.371 - Conversion into NSPS pay system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Conversion into NSPS pay system. 9901.371 Section 9901.371 Administrative Personnel DEPARTMENT OF DEFENSE HUMAN RESOURCES MANAGEMENT AND LABOR RELATIONS SYSTEMS (DEPARTMENT OF DEFENSE-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF DEFENSE NATIONAL SECURITY PERSONNEL SYSTEM (NSPS) Pay and...

  2. High conversion efficiency ultraviolet fiber Raman oscillator--amplifier system

    SciTech Connect

    Pini, R.; Salimbeni, R.; Vannini, M.; Haider, A.F.M.Y.; Lin, C.

    1986-04-01

    High efficiency UV frequency conversion by stimulated Raman scattering in a XeCl (lambda = 308-nm) excimer laser-pumped multimode fiber is presented. The system consists of a first piece of fiber as a Stokes generator and a second as a power amplifier. Power conversion efficiencies up to 80% have been measured. Uses of fiber Raman amplifiers in the near UV are also discussed.

  3. Materials of construction for advanced coal conversion systems

    SciTech Connect

    Nangia, V.K.

    1982-01-01

    This book describes materials of construction, and materials problems for equipment used in advanced coal conversion systems. The need for cost effective industrial operation is always a prime concern, particularly in this age of energy consciousness. Industry is continually seeking improved materials for more efficient systems. The information presented here is intended to be of use in the design and planning of these systems. Coal conversion and utilization impose severe demands on construction materials because of high temperature, high pressure, corrosive/erosive, and other hostile environmental factors. Successful economic development of these processes can be achieved only to the extent that working materials can withstand increasingly more aggressive operating conditions. The book, which reviews present and past work on the behavior of materials in the environments of advanced coal conversion systems, is divided into three parts: atmospheric fluidized bed combustion, coal gasification and liquefaction, and advanced power systems.

  4. Graphic-to-digital conversion system

    NASA Technical Reports Server (NTRS)

    Rosenthal, F. L.

    1976-01-01

    Computer-controlled system allows operator to record only those data points selected. It consists of commercially available X-Y plotter, computer, and A/D and D/A converters. New component is strain gage controller and amplifier which can be adapted to existing systems.

  5. Heat Rejection Concepts for Brayton Power Conversion Systems

    NASA Technical Reports Server (NTRS)

    Siamidis, John; Mason, Lee; Beach, Duane; Yuko, James

    2005-01-01

    This paper describes potential heat rejection design concepts for closed Brayton cycle (CBC) power conversion systems. Brayton conversion systems are currently under study by NASA for Nuclear Electric Propulsion (NEP) applications. The Heat Rejection Subsystem (HRS) must dissipate waste heat generated by the power conversion system due to inefficiencies in the thermal-to-electric conversion process. Space Brayton conversion system designs tend to optimize at efficiencies of about 20 to 25 percent with radiator temperatures in the 400 to 600 K range. A notional HRS was developed for a 100 kWe-class Brayton power system that uses a pumped sodium-potassium (NaK) heat transport loop coupled to a water heat pipe radiator. The radiator panels employ a sandwich construction consisting of regularly-spaced circular heat pipes contained within two composite facesheets. Heat transfer from the NaK fluid to the heat pipes is accomplished by inserting the evaporator sections into the NaK duct channel. The paper evaluates various design parameters including heat pipe diameter, heat pipe spacing, and facesheet thickness. Parameters were varied to compare design options on the basis of NaK pump pressure rise and required power, heat pipe unit power and radial flux, radiator panel areal mass, and overall HRS mass.

  6. Preliminary evaluation of a space AMTEC power conversion system

    SciTech Connect

    Crowley, C.J. ); Sievers, R.K. )

    1991-01-10

    An original evaluation of a space solar energy source coupled with Alkali Metal Thermoelectric Conversion (AMTEC) is presented here. This study indicates that an AMTEC system would have 30 percent of the mass of a photovoltaic system and 70 percent of the mass of a Stirling cycle system at the 35-kWe level of power generation modules typical of the baseline for the U.S. Space Station. The operating temperatures and Sodium heat pipe components for solar receiver/TES hardware (currently being developed by NASA) integrate well with AMTEC power conversion. AMTEC is therefore an attractive alternative specifically for space solar power generation.

  7. Preliminary evaluation of a space AMTEC power conversion system

    NASA Technical Reports Server (NTRS)

    Crowley, Christopher J.; Sievers, Robert K.

    1991-01-01

    As original evaluation of a space solar energy source coupled with Alkali Metal Thermoelectric Conversion (AMTEC) is presented here. This study indicates that an AMTEC system would have 30 percent of the mass of a photovoltaic system and 70 percent of the mass of a Stirling cycle system at the 35-kWe level of power generation modules typical of the baseline for the U.S. Space Station. The operating temperatures and sodium heat pipe components for solar receiver/TES hardware (currently being developed by NASA) integrate well with AMTEC power conversion. AMTEC is therefore an attractive alternative specifically for space solar power generation.

  8. Convertible, tri-mode solar conversion system

    NASA Astrophysics Data System (ADS)

    Kelly, D. A.

    A convertible, tri-mode solar collection system has been developed to provide year-round operation in the Northeastern U.S. Employing a plastic hot air duct-box in addition to conventional linear parabolic concentrators and thermal storage units, the system is able to provide wintertime hot air for residential heating and summertime steam for electrical power generation. Because of its superior utilization factor, it is expected that the device will pay back for an initial investment in a significantly shorter time than present alternatives

  9. Aeroelastic analysis of wind energy conversion systems

    NASA Technical Reports Server (NTRS)

    Dugundji, J.

    1978-01-01

    An aeroelastic investigation of horizontal axis wind turbines is described. The study is divided into two simpler areas; (1) the aeroelastic stability of a single blade on a rigid tower; and (2) the mechanical vibrations of the rotor system on a flexible tower. Some resulting instabilities and forced vibration behavior are described.

  10. A Prototype Greek Text to Greek Sign Language Conversion System

    ERIC Educational Resources Information Center

    Kouremenos, Dimitris; Fotinea, Stavroula-Evita; Efthimiou, Eleni; Ntalianis, Klimis

    2010-01-01

    In this article, a prototype Greek text to Greek Sign Language (GSL) conversion system is presented. The system is integrated into an educational platform that addresses the needs of teaching GSL grammar and was developed within the SYNENNOESE project (Efthimiou "et al." 2004a. Developing an e-learning platform for the Greek sign language. "In":…

  11. Low to high temperature energy conversion system

    NASA Technical Reports Server (NTRS)

    Miller, C. G. (Inventor)

    1977-01-01

    A method for converting heat energy from low temperature heat sources to higher temperature was developed. It consists of a decomposition chamber in which ammonia is decomposed into hydrogen and nitrogen by absorbing heat of decomposition from a low temperature energy source. A recombination reaction then takes place which increases the temperature of a fluid significantly. The system is of use for the efficient operation of compact or low capital investment turbine driven electrical generators, or in other applications, to enable chemical reactions that have a critical lower temperature to be used. The system also recovers heat energy from low temperature heat sources, such as solar collectors or geothermal sources, and converts it to high temperatures.

  12. Cogeneration Technology Alternatives Study (CTAS). Volume 4: Energy conversion systems

    NASA Technical Reports Server (NTRS)

    Brown, D. H.; Gerlaugh, H. E.; Priestley, R. R.

    1980-01-01

    Industrial processes from the largest energy consuming sectors were used as a basis for matching a similar number of energy conversion systems that are considered as candidate which can be made available by the 1985 to 2000 time period. The sectors considered included food, textiles, lumber, paper, chemicals, petroleum, glass, and primary metals. The energy conversion systems included steam and gas turbines, diesels, thermionics, stirling, closed-cycle and steam injected gas turbines, and fuel cells. Fuels considered were coal, both coal and petroleum-based residual and distillate liquid fuels, and low Btu gas obtained through the on-site gasification of coal. An attempt was made to use consistent assumptions and a consistent set of ground rules specified by NASA for determining performance and cost. The advanced and commercially available cogeneration energy conversion systems studied in CTAS are fined together with their performance, capital costs, and the research and developments required to bring them to this level of performance.

  13. Tandem filters using frequency selective surfaces for enhanced conversion efficiency in a thermophotovoltaic energy conversion system

    DOEpatents

    Dziendziel, Randolph J.; Baldasaro, Paul F.; DePoy, David M.

    2010-09-07

    This invention relates to the field of thermophotovoltaic (TPV) direct energy conversion. In particular, TPV systems use filters to minimize parasitic absorption of below bandgap energy. This invention constitutes a novel combination of front surface filters to increase TPV conversion efficiency by reflecting useless below bandgap energy while transmitting a very high percentage of the useful above bandgap energy. In particular, a frequency selective surface is used in combination with an interference filter. The frequency selective surface provides high transmission of above bandgap energy and high reflection of long wavelength below bandgap energy. The interference filter maintains high transmission of above bandgap energy and provides high reflection of short wavelength below bandgap energy and a sharp transition from high transmission to high reflection.

  14. Tandem filters using frequency selective surfaces for enhanced conversion efficiency in a thermophotovoltaic energy conversion system

    DOEpatents

    Dziendziel, Randolph J.; DePoy, David Moore; Baldasaro, Paul Francis

    2007-01-23

    This invention relates to the field of thermophotovoltaic (TPV) direct energy conversion. In particular, TPV systems use filters to minimize parasitic absorption of below bandgap energy. This invention constitutes a novel combination of front surface filters to increase TPV conversion efficiency by reflecting useless below bandgap energy while transmitting a very high percentage of the useful above bandgap energy. In particular, a frequency selective surface is used in combination with an interference filter. The frequency selective surface provides high transmission of above bandgap energy and high reflection of long wavelength below bandgap energy. The interference filter maintains high transmission of above bandgap energy and provides high reflection of short wavelength below bandgap energy and a sharp transition from high transmission to high reflection.

  15. A high-efficiency energy conversion system

    SciTech Connect

    Belcher, A.E.

    1996-12-31

    A fundamentally new method for converting pressure into rotative motion is introduced. A historical background is given and an idealized non-turbine Brayton cycle engine and associated equations are described. Salient features are explained, together with suggested applications. Concerns over global warming, unacceptable levels of air pollution, and the need for more efficient utilization of nonrenewable energy resources, are issues which continue to plague us. The situation is further exacerbated by the possibility that underdeveloped countries, under pressure to expand their economies, might adopt power generating systems which could produce high levels of emissions. This scenario could easily develop if equipment, which once complied with stringent standards, failed to be adequately maintained through the absence of a reliable technical infrastructure. The Brayton cycle manometric engine has the potential for eliminating, or at least mitigating, many of the above issues. It is therefore of considerable importance to all populations, irrespective of demographic or economic considerations. This engine is inherently simple--the engine proper has only one moving part. It has no pistons, vanes, or other such conventional occlusive devices, yet it is a positive displacement machine. Sealing is achieved by what can best be described as a series of traveling U-tube manometers. Its construction does not require precision engineering nor the use of exotic materials, making it easy to maintain with the most rudimentary resources. Rotational velocity is low, and its normal life cycle is expected to extend to several decades. These advantages more than offset the machine`s large size. It is suited only to large and medium-scale stationary applications.

  16. An improved thermionic power conversion system for space propulsion

    NASA Technical Reports Server (NTRS)

    Hsieh, T. M.; Phillips, W. M.

    1978-01-01

    A concept of an out-of-core thermionic nuclear electric power conversion system for 400 Kwe power level is being investigated for space propulsion applications. Two key features distinguish the power system design from previous thermionic power conversion concepts. First, the thermionic converters are located outside a nuclear reactor with a neutron shield inserted to reduce the radiation level on the thermionic converter matrix. Second, multiple liquid-metal heat pipes are used exclusively for both thermal power transport (from the nuclear reactor to the thermionic converters) and waste heat removal (from the thermionic converters to the space radiator); no mechanical or electromagnetic pumps are involved. The system characteristics are are compared to those of the in-core thermionic reactor system concept. In many aspects, the system characteristics, including specific weight, lifetime, dynamics control and safety features are found to be more desirable than those of the in-core system concept.

  17. Design of video interface conversion system based on FPGA

    NASA Astrophysics Data System (ADS)

    Zhao, Heng; Wang, Xiang-jun

    2014-11-01

    This paper presents a FPGA based video interface conversion system that enables the inter-conversion between digital and analog video. Cyclone IV series EP4CE22F17C chip from Altera Corporation is used as the main video processing chip, and single-chip is used as the information interaction control unit between FPGA and PC. The system is able to encode/decode messages from the PC. Technologies including video decoding/encoding circuits, bus communication protocol, data stream de-interleaving and de-interlacing, color space conversion and the Camera Link timing generator module of FPGA are introduced. The system converts Composite Video Broadcast Signal (CVBS) from the CCD camera into Low Voltage Differential Signaling (LVDS), which will be collected by the video processing unit with Camera Link interface. The processed video signals will then be inputted to system output board and displayed on the monitor.The current experiment shows that it can achieve high-quality video conversion with minimum board size.

  18. Wind Energy Conversion Systems. A Unit of Instruction.

    ERIC Educational Resources Information Center

    Greenwald, Martin

    The number of secondary schools, colleges, and universities offering courses in wind energy machine construction, repair, and installation, continues to increase. It is the purpose of this unit to include the study of wind energy conversion systems (WECS) as an integral part of related vocational and technical curriculum materials. The unit's…

  19. Compact anhydrous HCl to aqueous HCl conversion system

    DOEpatents

    Grossman, Mark W.; Speer, Richard

    1993-01-01

    The present invention is directed to an inexpensive and compact apparatus adapted for use with a .sup.196 Hg isotope separation process and the conversion of anhydrous HCl to aqueous HCl without the use of air flow to carry the HCl vapor into the converter system.

  20. Inertial confinement fusion reaction chamber and power conversion system study

    SciTech Connect

    Maya, I.; Schultz, K.R.; Battaglia, J.M.; Buksa, J.J.; Creedson, R.L.; Erlandson, O.D.; Levine, H.E.; Roelant, D.F.; Sanchez, H.W.; Schrader, S.A.

    1984-09-01

    GA Technologies has developed a conceptual ICF reactor system based on the Cascade rotating-bed reaction chamber concept. Unique features of the system design include the use of low activation SiC in a reaction chamber constructed of box-shaped tiles held together in compression by prestressing tendons to the vacuum chamber. Circulating Li/sub 2/O granules serve as the tritium breeding and energy transport material, cascading down the sides of the reaction chamber to the power conversion system. The total tritium inventory of the system is 6 kg; tritium recovery is accomplished directly from the granules via the vacuum system. A system for centrifugal throw transport of the hot Li/sub 2/O granules from the reaction chamber to the power conversion system has been developed. A number of issues were evaluated during the course of this study. These include the response of first-layer granules to the intense microexplosion surface heat flux, cost effective fabrication of Li/sub 2/O granules, tritium inventory and recovery issues, the thermodynamics of solids-flow options, vacuum versus helium-medium heat transfer, and the tradeoffs of capital cost versus efficiency for alternate heat exchange and power conversion system option. The resultant design options appear to be economically competitive, safe, and environmentally attractive.

  1. Surface plasmon polaritons mode conversion via a coupled plasmonic system

    NASA Astrophysics Data System (ADS)

    Yang, Fan; Tian, Hao

    2016-05-01

    A coupled plasmonic system for effective mode conversion between single interface surface plasmon polaritons (SPP) in a metal-dielectric waveguide and gap SPP in a metal-dielectric-metal waveguide is proposed. With the modal analysis, it is shown that the interference of the two plasmonic modes in a metal-dielectric-metal-dielectric coupled structure plays the key role in the mode conversion. With typical parameters, the conversion efficiency is as high as 61% (equivalent to 87% of the output total energy flow) at 1μm wavelength, and 1 dB bandwidth is as broad as 300 nm. The proposed structure can be used to implement an SPP mode convertor, router and beam splitter, which enables the interconnection between two important waveguides in plasmonics. The method presented here is fully-analytical, and is tested against fully-vectorial numerical results.

  2. Thermodynamic limits to the conversion of blackbody radiation by quantum systems. [with application to solar energy conversion devices

    NASA Technical Reports Server (NTRS)

    Buoncristiani, A. M.; Smith, B. T.; Byvik, C. E.

    1982-01-01

    Using general thermodynamic arguments, we analyze the conversion of the energy contained in the radiation from a blackbody to useful work by a quantum system. We show that the energy available for conversion is bounded above by the change in free energy in the incident and reradiated fields and that this free energy change depends upon the temperature of the receiving device. Universal efficiency curves giving the ultimate thermodynamic conversion efficiency of the quantum system are presented in terms of the blackbody temperature and the temperature and threshold energy of the quantum system. Application of these results is made to a variety of systems including biological photosynthetic, photovoltaic, and photoelectrochemical systems.

  3. A real-time VLC to UART protocol conversion system

    NASA Astrophysics Data System (ADS)

    Deng, Jian-zhi; Yao, Meng; Cheng, Xiao-hui; Deng, Zhuo-hong

    2016-07-01

    A real-time visible light communication (VLC) to universal asynchronous receiver/transmitter (UART) conversion system is made up of a transmitter with a light emitting diode (LED) and a receiver with a photodiode (PD), by which a VLC system is connected to traditional communication modes, and the data are transferred by wireless visible light. UART packets are converted to light packets by the modulation of a 10 kHz on-off-keying (OOK) light signal, and the data losses in the transportation are avoided by the protection of a data buffer mechanism. The experimental results reveal that the real-time VLC to UART conversion system can provide a real-time VLC transmission way for two UART devices in not less than 10 m at a baud rate not less than 19 200 Bd with stable ambient lighting at the same time.

  4. Physical Limits of Solar Energy Conversion in the Earth System.

    PubMed

    Kleidon, Axel; Miller, Lee; Gans, Fabian

    2016-01-01

    Solar energy provides by far the greatest potential for energy generation among all forms of renewable energy. Yet, just as for any form of energy conversion, it is subject to physical limits. Here we review the physical limits that determine how much energy can potentially be generated out of sunlight using a combination of thermodynamics and observed climatic variables. We first explain how the first and second law of thermodynamics constrain energy conversions and thereby the generation of renewable energy, and how this applies to the conversions of solar radiation within the Earth system. These limits are applied to the conversion of direct and diffuse solar radiation - which relates to concentrated solar power (CSP) and photovoltaic (PV) technologies as well as biomass production or any other photochemical conversion - as well as solar radiative heating, which generates atmospheric motion and thus relates to wind power technologies. When these conversion limits are applied to observed data sets of solar radiation at the land surface, it is estimated that direct concentrated solar power has a potential on land of up to 11.6 PW (1 PW=10(15) W), whereas photovoltaic power has a potential of up to 16.3 PW. Both biomass and wind power operate at much lower efficiencies, so their potentials of about 0.3 and 0.1 PW are much lower. These estimates are considerably lower than the incoming flux of solar radiation of 175 PW. When compared to a 2012 primary energy demand of 17 TW, the most direct uses of solar radiation, e.g., by CSP or PV, have thus by far the greatest potential to yield renewable energy requiring the least space to satisfy the human energy demand. Further conversions into solar-based fuels would be reduced by further losses which would lower these potentials. The substantially greater potential of solar-based renewable energy compared to other forms of renewable energy simply reflects much fewer and lower unavoidable conversion losses when solar

  5. Direct energy conversion system for D(3)-He fusion

    NASA Astrophysics Data System (ADS)

    Tomita, Y.; Shu, L. Y.; Momota, H.

    1993-11-01

    A novel and highly efficient direct energy conversion system is proposed for utilizing D(3)-He fueled fusion. In order to convert kinetic energy of ions, we applied a pair of direct energy conversion systems each of which has a cusp-type DEC and a traveling wave DEC (TWDEC). In a cusp-type DEC, electrons are separated from the escaping ions at the first line-cusp and the energy of thermal ion components is converted at the second cusp DEC. The fusion protons go through the cusp-type DEC and arrive at the TWDEC, which principle is similar to 'LINAC'. The energy of fusion protons is recovered to electricity with an efficiency of more than 70%. These DEC's bring about the high efficient fusion plant.

  6. Semiclassical quantization for a bosonic atom-molecule conversion system

    NASA Astrophysics Data System (ADS)

    Graefe, Eva-Maria; Graney, Maria; Rush, Alexander

    2015-07-01

    We consider a simple quantum model of atom-molecule conversion where bosonic atoms can combine into diatomic molecules and vice versa. The many-particle system can be expressed in terms of the generators of a deformed su(2 ) algebra, and the mean-field dynamics takes place on a deformed version of the Bloch sphere, a teardrop shaped surface with a cusp singularity. We analyze the mean-field and many-particle correspondence, which shows typical features of quantum-classical correspondence. We demonstrate that semiclassical methods can be employed to recover full many-particle features from the mean-field description in cold atom systems with atom-molecule conversion, and we derive an analytic expression for the many-particle density of states in the limit of large particle numbers.

  7. Environmental assessments of waste-to-energy conversion systems

    SciTech Connect

    Freeman, H.M.; Ananth, K.P.; Golembiewski, M.A.

    1981-03-01

    Environmental assessments were performed at five different waste-to-energy conversion systems. Emissions were characterized from refuse pyrolysis, a municipal incinerator fired with solid waste, a power plant boiler fired with wood waste and fuel oil, a steam boiler fired with coal and densified refuse derived fuel, and a power boiler fired with refuse derived fuel. Emission levels of criteria pollutants and particulates were similar to those associated with conventional fuel combustion. (2 diagrams)

  8. Analysis of dynamic effects in solar thermal energy conversion systems

    NASA Technical Reports Server (NTRS)

    Hamilton, C. L.

    1978-01-01

    The paper examines a study the purpose of which is to assess the performance of solar thermal power systems insofar as it depends on the dynamic character of system components and the solar radiation which drives them. Using a dynamic model, the daily operation of two conceptual solar conversion systems was simulated under varying operating strategies and several different time-dependent radiation intensity functions. These curves ranged from smoothly varying input of several magnitudes to input of constant total energy whose intensity oscillated with periods from 1/4 hour to 6 hours.

  9. RF System High Power Amplifier Software Conversion at Jefferson Lab

    SciTech Connect

    G. Lahti; H. Dong; T. Seegerger

    2006-10-31

    Jefferson Lab is in the process of converting the RF system from analog RF modules and non-smart high power amplifiers (HPAs) to digital RF modules and smart HPAs. The present analog RF module controls both the RF signal and the non-smart HPA hardware. The new digital RF module will only control the RF signal, so the new HPA must include embedded software. This paper will describe the conversion from a software perspective, including the initial testing, the intermediate mixed system of old and new units, and finally the totally new RF system.

  10. Penetration of wind electric conversion systems into the utility grid

    SciTech Connect

    Vachtsevanos, G.J.; Kalaitzakis, K.C.

    1985-07-01

    This paper is concerned with the development of appropriate models for the interconnected operation of wind generator clusters with an autonomous power system and simulation techniques for the study of the degree of penetration of such wind electric conversion devices when operating in parallel with the utility grid. The quality of the interconnected system performance is specified in terms of operational constraints and the resultant penetration strategy is implemented via a microprocessor-based control scheme. The strategy assures a satisfactory level of system performance while optimizing the available energy transfer from the wind generators to the utility grid.

  11. Thermoelectric Power Conversion System Combined with LNG Vaporizer

    NASA Astrophysics Data System (ADS)

    Kambe, Mitsuru; Morita, Ryo; Omoto, Kazuyuki; Koji, Yasuhiro; Yoshida, Tatsuo; Noishiki, Koji

    A conceptual design of the thermoelectric power conversion system combined with open rack type LNG (liquefied natural gas) vaporizer to make use of cold heat of LNG is presented. The system performance analysis has been made based on the thermoelectric module performance data obtained at the cryogenic thermoelectric (CTE) test rig which could realize temperature and fluid dynamic condition of the open rack type LNG vaporizer. Conventional bismuth-telluride thermoelectric modules were tested, however, each module is encapsulated in the stainless steel container to achieve water proof. Electricity production cost evaluation of the system is also discussed.

  12. Carbon balances during land conversion in early bioenergy systems

    NASA Astrophysics Data System (ADS)

    Zenone, T.; Chen, J.; Gelfand, I.; Robertson, G. P.; Hamilton, S. K.

    2012-12-01

    In this study, we established a field experiment and deployed seven eddy-covariance towers to quantify the roles of land use change and the subsequent carbon (C) balances of three different bioenergy systems (corn, switchgrass, and mixed prairie species) that were developed from two historical land use types: monocultural grasslands dominated by smooth brome (Bromus inermis Leyss) and lands in the Conservation Reserve Program (CRP). Three CRP fields and three cropland fields were converted to soybean in 2009 (conversion year) before establishing the cellulosic biofuel cropping systems in 2010 (establishment year). A CRP perennial grassland site was kept undisturbed as a reference. Conversion of CRP to soybean induced net C emissions during the conversion year (134 -262 g C m-2 yr-1), while in the same year the net C balance at the CRP grassland reference was -35 g C m-2 yr-1 (i.e., net C sequestration). The establishment of switchgrass and mixed prairie induced a cumulative C balance of -113 g C m-2 (switchgrass from CRP), 250 g C m-2 (switchgrass from cropland), 706 g C m-2 (mixed prairie from CRP), and 59 g C m-2 (mixed prairie from cropland) over the three-year study period. The cumulative three-year C balance of corn converted from CRP and from cropland was -151 g C m-2 and -183 g C m-2, respectively. Eddy flux measurements during cellulosic biofuel crop establishment reveal annual changes in C balance that cannot be detected using conventional mass balance approaches. When end-use of harvested biomass was considered, the C balances for all studied systems, except the reference site, exhibited large C emissions ranging from 150 to 990 g C m-2 over the three-year conversion phase.

  13. Spectral light management for solar energy conversion systems

    NASA Astrophysics Data System (ADS)

    Stanley, Cameron; Mojiri, Ahmad; Rosengarten, Gary

    2016-06-01

    Due to the inherent broadband nature of the solar radiation, combined with the narrow spectral sensitivity range of direct solar to electricity devices, there is a massive opportunity to manipulate the solar spectrum to increase the functionality and efficiency of solar energy conversion devices. Spectral splitting or manipulation facilitates the efficient combination of both high-temperature solar thermal systems, which can absorb over the entire solar spectrum to create heat, and photovoltaic cells, which only convert a range of wavelengths to electricity. It has only recently been possible, with the development of nanofabrication techniques, to integrate micro- and nano-photonic structures as spectrum splitters/manipulators into solar energy conversion devices. In this paper, we summarize the recent developments in beam splitting techniques, and highlight some relevant applications including combined PV-thermal collectors and efficient algae production, and suggest paths for future development in this field.

  14. Bioinspired smart gating of nanochannels toward photoelectric-conversion systems.

    PubMed

    Wen, Liping; Hou, Xu; Tian, Ye; Nie, Fu-Qiang; Song, Yanlin; Zhai, Jin; Jiang, Lei

    2010-03-01

    Learning from nature has inspired the creation of intelligent materials to better understand and imitate biology. Recent studies on bioinspired responsive surfaces that can switch between different states are shown, which open up new avenues for the development of smart materials in two dimensions. Based on this strategy, biomimetic nanochannel systems have been produced by introducing responsive molecules, which closely mimic the gating mechanism of biological nanochannels and show potential applications in many fields such as photoelectric-conversion systems demonstrated in this paper. PMID:20217833

  15. 5 CFR 9701.373 - Conversion of employees to the DHS pay system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... § 9701.373 Conversion of employees to the DHS pay system. (a) When a pay system is established under this... conversion to the new pay system, DHS must process the other action under the rules pertaining to the employee's former system before processing the conversion action. (d) An employee on a temporary...

  16. Efficient computerized model for dynamic analysis of energy conversion systems

    NASA Technical Reports Server (NTRS)

    Hughes, R. D.; Lansing, F. L.; Khan, I. R.

    1983-01-01

    In searching for the optimum parameters that minimize the total life cycle cost of an energy conversion system, various combinations of components are examined and the resulting system performance and associated economics are studied. The systems performance and economics simulation computer program (SPECS) was developed to fill this need. The program simulates the fluid flow, thermal, and electrical characteristics of a system of components on a quasi-steady state basis for a variety of energy conversion systems. A unique approach is used in which the set of characteristic equations is solved by the Newton-Raphson technique. This approach eliminates the tedious iterative loops which are found in comparable programs such as TRNSYS or SOLTES-1. Several efficient features were also incorporated such as the centralized control and energy management scheme, and analogous treatment of energy flow in electrical and mechanical components, and the modeling of components of similar fundamental characteristics using generic subroutines. Initial tests indicate that this model can be used effectively with a relatively small number of time steps and low computer cost.

  17. Efficient computerized model for dynamic analysis of energy conversion systems

    NASA Astrophysics Data System (ADS)

    Hughes, R. D.; Lansing, F. L.; Khan, I. R.

    1983-02-01

    In searching for the optimum parameters that minimize the total life cycle cost of an energy conversion system, various combinations of components are examined and the resulting system performance and associated economics are studied. The systems performance and economics simulation computer program (SPECS) was developed to fill this need. The program simulates the fluid flow, thermal, and electrical characteristics of a system of components on a quasi-steady state basis for a variety of energy conversion systems. A unique approach is used in which the set of characteristic equations is solved by the Newton-Raphson technique. This approach eliminates the tedious iterative loops which are found in comparable programs such as TRNSYS or SOLTES-1. Several efficient features were also incorporated such as the centralized control and energy management scheme, and analogous treatment of energy flow in electrical and mechanical components, and the modeling of components of similar fundamental characteristics using generic subroutines. Initial tests indicate that this model can be used effectively with a relatively small number of time steps and low computer cost.

  18. Standards for photovoltaic energy conversion systems. Final report

    SciTech Connect

    Schafft, H. A.

    1980-04-01

    This report provides the results of a search for existing domestic standards and related documents for possible application in the development of a standards base for photovoltaic energy conversion systems. The search resulted in locating about 150 test methods, recommended practices, standards, solar-thermal performance criteria, and other standards-related documents. They are listed by topic areas in the appendix. The listing was prepared to assist those involved in developing performance criteria for photovoltaic systems and in identifying methods to test system performance against these criteria. It is clear from the results of the search that few standards are directly applicable to terrestrial solar photovoltaic systems and that much standards development is required to support the commercialization of such systems.

  19. System and method for identifying, validating, weighing and characterizing moving or stationary vehicles and cargo

    DOEpatents

    Beshears, David L.; Batsell, Stephen G.; Abercrombie, Robert K.; Scudiere, Matthew B.; White, Clifford P.

    2007-12-04

    An asset identification and information infrastructure management (AI3M) device having an automated identification technology system (AIT), a Transportation Coordinators' Automated Information for Movements System II (TC-AIMS II), a weigh-in-motion system (WIM-II), and an Automated Air Load Planning system (AALPS) all in electronic communication for measuring and calculating actual asset characteristics, either statically or in-motion, and further calculating an actual load plan.

  20. Two-Stage Variable Sample-Rate Conversion System

    NASA Technical Reports Server (NTRS)

    Tkacenko, Andre

    2009-01-01

    A two-stage variable sample-rate conversion (SRC) system has been pro posed as part of a digital signal-processing system in a digital com munication radio receiver that utilizes a variety of data rates. The proposed system would be used as an interface between (1) an analog- todigital converter used in the front end of the receiver to sample an intermediatefrequency signal at a fixed input rate and (2) digita lly implemented tracking loops in subsequent stages that operate at v arious sample rates that are generally lower than the input sample r ate. This Two-Stage System would be capable of converting from an input sample rate to a desired lower output sample rate that could be var iable and not necessarily a rational fraction of the input rate.

  1. In situ conversion process utilizing a closed loop heating system

    DOEpatents

    Sandberg, Chester Ledlie; Fowler, Thomas David; Vinegar, Harold J.; Schoeber, Willen Jan Antoon Henri

    2009-08-18

    An in situ conversion system for producing hydrocarbons from a subsurface formation is described. The system includes a plurality of u-shaped wellbores in the formation. Piping is positioned in at least two of the u-shaped wellbores. A fluid circulation system is coupled to the piping. The fluid circulation system is configured to circulate hot heat transfer fluid through at least a portion of the piping to form at least one heated portion of the formation. An electrical power supply is configured to provide electrical current to at least a portion of the piping located below an overburden in the formation to resistively heat at least a portion of the piping. Heat transfers from the piping to the formation.

  2. Network generation and analysis of complex biomass conversion systems

    SciTech Connect

    Rangarajan, S.; Kaminski, T.; Van Wyk, E.; Bhan, A.; Daoutidis, P.

    2011-01-01

    A modular computational tool for automated generation and rule-based post-processing of reaction systems in biomass conversion is presented. Cheminformatics and graph theory algorithms are used to generate chemical transformations pertaining to heterogeneous and homogeneous chemistries in the automated rule-based network generator. A domain-specific language provides a user-friendly English-like chemistry specification interface to the network generator. A rule-based pathway analysis module enables the user to extract and query pathways from the reaction network. A demonstration of the features of this tool is presented using Fructose to 5-Hydroxymethylfurfural as a case study.

  3. Low cost composite materials for wind energy conversion systems

    NASA Technical Reports Server (NTRS)

    Weingart, O.

    1980-01-01

    A winding process utilizing a low-cost E-glass fabric called transverse-filament tape for low-cost production of wind turbine generators (WTG) is described. The process can be carried out continuously at high speed to produce large one-piece parts with tapered wall thicknesses on a tapered mandrel. It is being used to manufacture blades for the NASA/DOE 200-ft-diameter MOD-1 WTG and Rockwell/DOE 40-kW small wind energy conversion system (SWECS).

  4. A real time spectrum to dose conversion system

    NASA Technical Reports Server (NTRS)

    Farmer, B. J.; Johnson, J. H.; Bagwell, R. G.

    1972-01-01

    A system has been developed which permits the determination of dose in real time or near real time directly from the pulse-height output of a radiation spectrometer. The technique involves the use of the resolution matrix of a spectrometer, the radiation energy-to-dose conversion function, and the geometrical factors, although the order of matrix operations is reversed. The new technique yields a result which is mathematically identical to the standard method while requiring no matrix manipulations or resolution matrix storage in the remote computer. It utilizes only a single function for each type dose required and each geometric factor involved.

  5. Photoelectrochemical based direct conversion systems for hydrogen production

    SciTech Connect

    Kocha, S.; Peterson, M.; Arent, D.

    1996-10-01

    Photon driven, direct conversion systems consist of a light absorber and a water splitting catalyst as a monolithic system; water is split directly upon illumination. This one-step process eliminates the need to generate electricity externally and subsequently feed it to an electrolyzer. These configurations require only the piping necessary for transport of hydrogen to an external storage system or gas pipeline. This work is focused on multiphoton photoelectrochemical devices for production of hydrogen directly using sunlight and water. Two types of multijunction cells, one consisting of a-Si triple junctions and the other GaInP{sub 2}/GaAs homojunctions, were studied for the photoelectrochemical decomposition of water into hydrogen and oxygen from an aqueous electrolyte solution. To catalyze the water decomposition process, the illuminated surface of the device was modified either by addition of platinum colloids or by coating with ruthenium dioxide. These colloids have been characterized by gel electrophoresis.

  6. Segregated tandem filter for enhanced conversion efficiency in a thermophotovoltaic energy conversion system

    DOEpatents

    Brown, Edward J.; Baldasaro, Paul F.; Dziendziel, Randolph J.

    1997-01-01

    A filter system to transmit short wavelength radiation and reflect long wavelength radiation for a thermophotovoltaic energy conversion cell comprises an optically transparent substrate segregation layer with at least one coherent wavelength in optical thickness; a dielectric interference filter deposited on one side of the substrate segregation layer, the interference filter being disposed toward the source of radiation, the interference filter including a plurality of alternating layers of high and low optical index materials adapted to change from transmitting to reflecting at a nominal wavelength .lambda..sub.IF approximately equal to the bandgap wavelength .lambda..sub.g of the thermophotovoltaic cell, the interference filter being adapted to transmit incident radiation from about 0.5.lambda..sub.IF to .lambda..sub.IF and reflect from .lambda..sub.IF to about 2.lambda..sub.IF ; and a high mobility plasma filter deposited on the opposite side of the substrate segregation layer, the plasma filter being adapted to start to become reflecting at a wavelength of about 1.5.lambda..sub.IF.

  7. Segregated tandem filter for enhanced conversion efficiency in a thermophotovoltaic energy conversion system

    DOEpatents

    Brown, E.J.; Baldasaro, P.F.; Dziendziel, R.J.

    1997-12-23

    A filter system to transmit short wavelength radiation and reflect long wavelength radiation for a thermophotovoltaic energy conversion cell comprises an optically transparent substrate segregation layer with at least one coherent wavelength in optical thickness; a dielectric interference filter deposited on one side of the substrate segregation layer, the interference filter being disposed toward the source of radiation, the interference filter including a plurality of alternating layers of high and low optical index materials adapted to change from transmitting to reflecting at a nominal wavelength {lambda}{sub IF} approximately equal to the bandgap wavelength {lambda}{sub g} of the thermophotovoltaic cell, the interference filter being adapted to transmit incident radiation from about 0.5{lambda}{sub IF} to {lambda}{sub IF} and reflect from {lambda}{sub IF} to about 2{lambda}{sub IF}; and a high mobility plasma filter deposited on the opposite side of the substrate segregation layer, the plasma filter being adapted to start to become reflecting at a wavelength of about 1.5{lambda}{sub IF}. 10 figs.

  8. Segregated tandem filter for enhanced conversion efficiency in a thermophotovoltaic energy conversion system

    SciTech Connect

    Brown, E.J.; Baldasaro, P.F.; Dziendziel, R.J.

    1996-12-31

    A filter system to transmit short wavelength radiation and reflect long wavelength radiation for a thermophotovoltaic energy conversion cell comprises an optically transparent substrate segregation layer with at least one coherent wavelength in optical thickness; a dielectric interference filter deposited on one side of the substrate segregation layer, the interference filter being disposed toward the source of radiation, the interference filter including a plurality of alternating layers of high and low optical index materials adapted to change from transmitting to reflecting at a nominal wavelength {lambda}{sub IF} approximately equal to the bandgap wavelength {lambda}{sub g} of the thermophotovoltaic cell, the interference filter being adapted to transmit incident radiation from about 0.5{lambda}{sub IF} to {lambda}{sub IF} and reflect from {lambda}{sub IF} to about 2{lambda}{sub IF}; and a high mobility plasma filter deposited on the opposite side of the substrate segregation layer, the plasma filter being adapted to start to become reflecting at a wavelength of about 1.5{lambda}{sub IF}.

  9. Assessment of dynamic energy conversion systems for radioisotope heat sources

    SciTech Connect

    Thayer, G.R.; Mangeng, C.A.

    1985-06-01

    The use of dynamic conversion systems to convert the heat generated in a 7500 W(t) 90 Sr radioisotopic heat source to electricity is examined. The systems studies were Stirling; Brayton Cycle; three organic Rankines (ORCs) (Barber-Nichols/ORMAT, Sundstrand, and TRW); and an organic Rankine plus thermoelectrics. The systems were ranked for a North Warning System mission using a Los Alamos Multiattribute Decision Theory code. Three different heat source designs were used: case I with a beginning of life (BOL) source temperature of 640 C, case II with a BOL source temperature of 745/sup 0/C, and case III with a BOL source temperature of 945/sup 0/C. The Stirling engine system was the top-ranked system of cases I and II, closely followed by the ORC systems in case I and ORC plus thermoelectrics in case II. The Brayton cycle system was top-ranked for case III, with the Stirling engine system a close second. The use of /sup 238/Pu in heat source sizes of 7500 W(t) was examined and found to be questionable because of cost and material availability and because of additional requirements for analysis of safeguards and critical mass.

  10. Assessment of dynamic energy conversion systems for radioisotope heat sources

    NASA Astrophysics Data System (ADS)

    Thayer, G. R.; Mangeng, C. A.

    1985-06-01

    The use of dynamic conversion systems to convert the heat generated in a 7500 W(t) 90 Sr radioisotopic heat source to electricity is examined. The systems studies were: Stirling; Brayton cycle; three organic Rankines (ORCs) (Barber-Nichols/ORMAT, Sundstrand, and TRW); and an organic Rankine plus thermoelectrics. The systems were ranked for a North Warning System mission using a Los Alamos multiattribute decision theory code. Three different heat source designs were used: case 1 with a beginning of life (BOL) source temperature of 640 C, case 2 with a BOL source temperature of 745 C, and case 3 with a BOL source temperature of 945 C. The Stirling engine system was the top-ranked system of case 1 and 2, closely followed by the ORC systems in case 1 and ORC plus thermoelectrics in case 2. The Brayton cycle system was top-ranked for case 3, with the Stirling engine system a close second. The use of (238) Pu in heat source sizes of 7500 W(t) is examined and it is found to be questionable because of cost and material availability and because of additional requirements for anlaysis of safeguards and critical mass.

  11. Explorations of Novel Energy Conversion and Storage Systems

    NASA Astrophysics Data System (ADS)

    Duffin, Andrew Mark

    At present, the majority of the world's energy demand is met by the consumption of exhaustible fuel supplies. Consequently, it is urgent to research and develop viable alternatives. In this dissertation, I present research that addresses fundamental questions concerning how water interacts with surfaces and solutes, with the goal of identifying novel systems for energy production and storage. Electrokinetic currents are created when moving fluid entrains charge from the diffuse portion of an electric double layer and carries that charge downstream. The potential difference that develops on either end of the channel is known as the streaming potential. Chapter 2 of this dissertation focuses on electrokinetic energy production and conversion efficiency of liquid microjets. Section 1 of Chapter 2 presents proof-of-principle research demonstrating that molecular hydrogen is generated from electrokinetic currents in liquid water microjets. Hydrogen is generated when hydrated protons are preferentially carried downstream and recombine with electrons at a grounded target electrode. Both the current and hydrogen production scale nearly quadratically with flow rate, as predicted by equations derived from simple double layer theory and fluid mechanics. The efficiency is currently very low (ca 10-6) and is limited by the low electrokinetic current (˜nA). Designs to improve this efficiency are considered. Rather than chemical conversion efficiency, Section 2 of Chapter 2 investigates the electrical conversion efficiency of liquid water microjets. Typical electrokinetic energy conversion schemes measure current or voltage via electrodes in the fluid reservoirs on either side of a channel. With this design, the streaming potential drives a current against the flow of the fluid and, consequently, limits the conversion efficiency. In contrast, liquid microjets break up into droplets before reaching the downstream electrode and this eliminates the possibility for back conduction

  12. Systems definition space based power conversion systems: Executive summary

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Potential space-located systems for the generation of electrical power for use on earth were investigated. These systems were of three basic types: (1) systems producing electrical power from solar energy; (2) systems producing electrical power from nuclear reactors; (3) systems for augmenting ground-based solar power plants by orbital sunlight reflectors. Configurations implementing these concepts were developed through an optimization process intended to yield the lowest cost for each. A complete program was developed for each concept, identifying required production rates, quantities of launches, required facilities, etc. Each program was costed in order to provide the electric power cost appropriate to each concept.

  13. IGT/DOE coal-conversion systems technical data book

    SciTech Connect

    Talwalkar, A.T.

    1981-11-01

    This project was initiated by OCR to meet the needs of the emerging synthetic fuels industry and as a mechanism to conserve and make available to the public the results of large government R and D expenditures for synthetic fuels. The objective of the Data Book project is to provide a single, comprehensive source of data on coal conversion systems. These include coal gasification, coal liquefaction, fluidized-bed combustion, and coal-based MHD. It was decided that design procedures, as well as numerical data, will be included in the Data Book. The Data Book is expected to provide up-to-date data and information for research, process development, process design, engineering, construction, and operation of coal conversion processes and/or plants. Concurrently, the program is also to identify areas where data are lacking and suggest research programs to provide the required data. The data are collected from reports by DOE contractors, published literature, ad unpublished sources for critical evaluation. Literature search is carried out through various abstracts and indexes and computerized information retrieval systems. The contents of the Data Book are currently organized in ten major sections.

  14. Solid waste information and tracking system server conversion project management plan

    SciTech Connect

    MAY, D.L.

    1999-04-12

    The Project Management Plan governing the conversion of Solid Waste Information and Tracking System (SWITS) to a client-server architecture. The Solid Waste Information and Tracking System Project Management Plan (PMP) describes the background, planning and management of the SWITS conversion. Requirements and specification documentation needed for the SWITS conversion will be released as supporting documents.

  15. Design of a Capacitive Flexible Weighing Sensor for Vehicle WIM System

    PubMed Central

    Cheng, Lu; Zhang, Hongjian; Li, Qing

    2007-01-01

    With the development of the Highway Transportation and Business Trade, vehicle weigh-in-motion (WIM) technology has become a key technology and trend of measuring traffic loads. In this paper, a novel capacitive flexible weighing sensor which is light weight, smaller volume and easy to carry was applied in the vehicle WIM system. The dynamic behavior of the sensor is modeled using the Maxwell-Kelvin model because the materials of the sensor are rubbers which belong to viscoelasticity. A signal processing method based on the model is presented to overcome effects of rubber mechanical properties on the dynamic weight signal. The results showed that the measurement error is less than ±10%. All the theoretic analysis and numerical results demonstrated that appliance of this system to weigh in motion is feasible and convenient for traffic inspection.

  16. Land-use implications of wind-energy-conversion systems

    SciTech Connect

    Noun, R.J.

    1981-02-01

    An estimated 20 utilities in the United States are now investigating potential wind machine sites in their areas. Identifying sites for wind machine clusters (wind farms) involves more than just finding a location with a suitable wind resource. Consideration must also be given to the proximity of sites to existing transmission lines, environmental impacts, aesthetics, and legal concerns as well as the availability of and alternative uses for the land. These issues have made it increasingly difficult for utilities to bring conventional power plants on-line quickly. Utilities are now required, however, to give careful consideration to specific legal, social, and environmental questions raised by the siting of wind energy conversion systems (WECS).

  17. Siting handbook for small wind energy conversion systems

    SciTech Connect

    Wegley, H.L.; Ramsdell, J.V.; Orgill, M.M.; Drake, R.L.

    1980-03-01

    This handbook was written to serve as a siting guide for individuals wishing to install small wind energy conversion systems (WECS); that is, machines having a rated capacity of less than 100 kilowatts. It incorporates half a century of siting experience gained by WECS owners and manufacturers, as well as recently developed siting techniques. The user needs no technical background in meteorology or engineering to understand and apply the siting principles discussed; he needs only a knowledge of basic arithmetic and the ability to understand simple graphs and tables. By properly using the siting techniques, an owner can select a site that will yield the most power at the least installation cost, the least maintenance cost, and the least risk of damage or accidental injury.

  18. Adiabatic Berry phase in an atom-molecule conversion system

    SciTech Connect

    Fu Libin; Liu Jie

    2010-11-15

    We investigate the Berry phase of adiabatic quantum evolution in the atom-molecule conversion system that is governed by a nonlinear Schroedinger equation. We find that the Berry phase consists of two parts: the usual Berry connection term and a novel term from the nonlinearity brought forth by the atom-molecule coupling. The total geometric phase can be still viewed as the flux of the magnetic field of a monopole through the surface enclosed by a closed path in parameter space. The charge of the monopole, however, is found to be one third of the elementary charge of the usual quantized monopole. We also derive the classical Hannay angle of a geometric nature associated with the adiabatic evolution. It exactly equals minus Berry phase, indicating a novel connection between Berry phase and Hannay angle in contrast to the usual derivative form.

  19. Sodium heat pipe use in solar Stirling power conversion systems

    NASA Technical Reports Server (NTRS)

    Zimmerman, W. F.; Divakaruni, S. M.; Won, Y. S.

    1980-01-01

    Sodium heat pipes were selected for use as a thermal transport method in a focus-mounted, distributed concentrator solar Stirling power conversion system intended to produce 15-20 kWe per unit. Heat pipes were used both to receive thermal power in the solar receiver and to transmit it to a secondary heat pipe containing both latent heat salt (for up to 1.25 hours of thermal storage) and the heat exchanger of the Stirling engine. Experimental tests were performed on five solar receiver heat pipes with various internal wicking configurations. The performance of the heat pipes at various power levels and operating attitudes was investigated at temperatures near 1550 F; the unidirectional heat transfer in these heat pipes was demonstrated in normal operating attitudes and particularly in the inverted position required during overnight stowage of the concentrator.

  20. Integration of Feedstock Assembly System and Cellulosic Ethanol Conversion Models to Analyze Bioenergy System Performance

    SciTech Connect

    Jared M. Abodeely; Douglas S. McCorkle; Kenneth M. Bryden; David J. Muth; Daniel Wendt; Kevin Kenney

    2010-09-01

    Research barriers continue to exist in all phases of the emerging cellulosic ethanol biorefining industry. These barriers include the identification and development of a sustainable and abundant biomass feedstock, the assembly of viable assembly systems formatting the feedstock and moving it from the field (e.g., the forest) to the biorefinery, and improving conversion technologies. Each of these phases of cellulosic ethanol production are fundamentally connected, but computational tools used to support and inform analysis within each phase remain largely disparate. This paper discusses the integration of a feedstock assembly system modeling toolkit and an Aspen Plus® conversion process model. Many important biomass feedstock characteristics, such as composition, moisture, particle size and distribution, ash content, etc. are impacted and most effectively managed within the assembly system, but generally come at an economic cost. This integration of the assembly system and the conversion process modeling tools will facilitate a seamless investigation of the assembly system conversion process interface. Through the integrated framework, the user can design the assembly system for a particular biorefinery by specifying location, feedstock, equipment, and unit operation specifications. The assembly system modeling toolkit then provides economic valuation, and detailed biomass feedstock composition and formatting information. This data is seamlessly and dynamically used to run the Aspen Plus® conversion process model. The model can then be used to investigate the design of systems for cellulosic ethanol production from field to final product.

  1. Frequency conversion in field stabilization system for application in SC cavity of linear accelerator

    NASA Astrophysics Data System (ADS)

    Filipek, Tomasz A.

    2005-09-01

    The paper concerns frequency conversion circuits of electromagnetic field stabilization system in superconductive cavity of linear accelerator. The stabilization system consists of digital part (based on FPGA) and analog part (frequency conversions, ADC/DAC, filters). Frequency conversion circuit is analyzed. The main problem in the frequency conversion for the stabilization system are: linearity of conversion and stability. Also, second order problems are subject of analysis: control of local oscillator parameters and fluctuation of actuated signal (exposing conversion). The following work was done: analysis of individual stage parameters on field stability and external influence, simulation. The work was closed with conclusions of the major frequency conversion parameters for field stabilization. The results have been applied for field stabilization system (RF Feedback System) in TESLA Test Facility 2 and preliminary research on X-Ray Free Electron Laser.

  2. Progress on PEP-II magnet power conversion system

    SciTech Connect

    Bellomo, P.; Genova, L.; Jackson, T.; Shimer, D.

    1996-06-04

    The various power systems for supplying the PEP-II DC magnets rely exclusively on switchmode conversion, utilizing a variety of means depending on the requirements. All of the larger power supplies, ranging from 10 to 200 kW, are powered from DC sources utilizing rectified 480 V AC. Choppers can be used for the series connected strings, but for smaller groups and individual magnets, inverters driving high-frequency transformers with rectifiers comprise the best approach. All of the various systems use a ``building block`` approach of multiple standard-size units connected in series or parallel to most cost-effectively deal with a great range of voltage and current requirements. Utilization of existing infrastructure from PEP-I has been a cost-effective determinant. Equipment is being purchased either off-the-shelf, through performance specification, or by hardware purchase based on design-through-prototype. The corrector magnet power system, utilizing inexpensive, off-the-shelf, four-quadrant switching motor-controllers, has already proven very reliable: 120 of the total of 900 units have been running on the injection system for four months with no failures.

  3. Closed Brayton cycle power conversion systems for nuclear reactors :

    SciTech Connect

    Wright, Steven A.; Lipinski, Ronald J.; Vernon, Milton E.; Sanchez, Travis

    2006-04-01

    This report describes the results of a Sandia National Laboratories internally funded research program to study the coupling of nuclear reactors to gas dynamic Brayton power conversion systems. The research focused on developing integrated dynamic system models, fabricating a 10-30 kWe closed loop Brayton cycle, and validating these models by operating the Brayton test-loop. The work tasks were performed in three major areas. First, the system equations and dynamic models for reactors and Closed Brayton Cycle (CBC) systems were developed and implemented in SIMULINKTM. Within this effort, both steady state and dynamic system models for all the components (turbines, compressors, reactors, ducting, alternators, heat exchangers, and space based radiators) were developed and assembled into complete systems for gas cooled reactors, liquid metal reactors, and electrically heated simulators. Various control modules that use proportional-integral-differential (PID) feedback loops for the reactor and the power-conversion shaft speed were also developed and implemented. The simulation code is called RPCSIM (Reactor Power and Control Simulator). In the second task an open cycle commercially available Capstone C30 micro-turbine power generator was modified to provide a small inexpensive closed Brayton cycle test loop called the Sandia Brayton test-Loop (SBL-30). The Capstone gas-turbine unit housing was modified to permit the attachment of an electrical heater and a water cooled chiller to form a closed loop. The Capstone turbine, compressor, and alternator were used without modification. The Capstone systems nominal operating point is 1150 K turbine inlet temperature at 96,000 rpm. The annular recuperator and portions of the Capstone control system (inverter) and starter system also were reused. The rotational speed of the turbo-machinery is controlled by adjusting the alternator load by using the electrical grid as the load bank. The SBL-30 test loop was operated at

  4. Space-based solar power conversion and delivery systems study

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Even at reduced rates of growth, the demand for electric power is expected to more than triple between now and 1995, and to triple again over the period 1995-2020. Without the development of new power sources and advanced transmission technologies, it may not be possible to supply electric energy at prices that are conductive to generalized economic welfare. Solar power is renewable and its conversion and transmission from space may be advantageous. The goal of this study is to assess the economic merit of space-based photovoltaic systems for power generation and a power relay satellite for power transmission. In this study, satellite solar power generation and transmission systems, as represented by current configurations of the Satellite Solar Station (SSPS) and the Power Relay Satellite (PRS), are compared with current and future terrestrial power generation and transmission systems to determine their technical and economic suitability for meeting power demands in the period of 1990 and beyond while meeting ever-increasing environmental and social constraints.

  5. Methods for locating ground faults and insulation degradation condition in energy conversion systems

    DOEpatents

    Agamy, Mohamed; Elasser, Ahmed; Galbraith, Anthony William; Harfman Todorovic, Maja

    2015-08-11

    Methods for determining a ground fault or insulation degradation condition within energy conversion systems are described. A method for determining a ground fault within an energy conversion system may include, in part, a comparison of baseline waveform of differential current to a waveform of differential current during operation for a plurality of DC current carrying conductors in an energy conversion system. A method for determining insulation degradation within an energy conversion system may include, in part, a comparison of baseline frequency spectra of differential current to a frequency spectra of differential current transient at start-up for a plurality of DC current carrying conductors in an energy conversion system. In one embodiment, the energy conversion system may be a photovoltaic system.

  6. Olefin fractionation and catalytic conversion system with heat exchange means

    SciTech Connect

    Wright, B.S.; Owen, H.; Hsia, C.H

    1989-05-23

    This patent describes a continuous catalytic system for converting an olefinic feedstock comprising ethylene and C/sub 3/+ olefins to heavier liquid hydrocarbon product comprising: means for prefractionating the olefinic feedstock to obtain a gaseous stream rich in ethylene and a liquid stream containing C/sub 3/+ olefin; means for vaporizing and contacting the liquid stream from the prefractionating means with hydrocarbon conversion oligomerization catalyst in at least one exothermic catalytic reaction zone to provide a heavier hydrocarbon effluent stream comprising distillate, gasoline and lighter hydrocarbons; means for cooling and fractionating the effluent stream to recover distillate, gasoline and lighter hydrocarbons separately; means for recycling at least a portion of the recovered gasoline as a liquid sorbent stream to the prefractionating means thereby reacting the recycled gasoline together with sorbed C/sub 3/+ olefin in the catalytic reactor system; and means for exchanging heat between hot effluent from the exothermic reaction zone and fractionator liquid rich in C/sub 3/+ olefin in the prefractionator reboiler loop.

  7. Imaged Document Optical Correlation and Conversion System (IDOCCS)

    NASA Astrophysics Data System (ADS)

    Stalcup, Bruce W.; Dennis, Phillip W.; Dydyk, Robert B.

    1999-03-01

    Today, the paper document is fast becoming a thing of the past. With the rapid development of fast, inexpensive computing and storage devices, many government and private organizations are archiving their documents in electronic form (e.g., personnel records, medical records, patents, etc.). In addition, many organizations are converting their paper archives to electronic images, which are stored in a computer database. Because of this, there is a need to efficiently organize this data into comprehensive and accessible information resources. The Imaged Document Optical Correlation and Conversion System (IDOCCS) provides a total solution to the problem of managing and retrieving textual and graphic information from imaged document archives. At the heart of IDOCCS, optical correlation technology provides the search and retrieval capability of document images. The IDOCCS can be used to rapidly search for key words or phrases within the imaged document archives and can even determine the types of languages contained within a document. In addition, IDOCCS can automatically compare an input document with the archived database to determine if it is a duplicate, thereby reducing the overall resources required to maintain and access the document database. Embedded graphics on imaged pages can also be exploited, e.g., imaged documents containing an agency's seal or logo, or documents with a particular individual's signature block, can be singled out. With this dual capability, IDOCCS outperforms systems that rely on optical character recognition as a basis for indexing and storing only the textual content of documents for later retrieval.

  8. MICROTECHNOLOGY – A KEY TO SYSTEM MINIATURIZATION IN ADVANCED ENERGY RECOVERY & CONVERSION SYSTEMS

    SciTech Connect

    Hendricks, Terry J.

    2008-08-30

    Energy recovery is gaining importance in various transportation, industrial process, and military applications because of rising energy costs and geopolitical uncertainties impacting basic energy supplies. Various advanced energy recovery/conversion technologies will require high-performance heat transfer characteristics to achieve energy recovery performance targets and requirements. System analysis of thermoelectric (TE) systems quantify potential power output, conversion efficiency, specific power and power flux in a unique, useful format on maximum efficiency – power maps. Lines constant specific power and power flux and their relationship to lines of constant hot side temperature and points of maximum power were demonstrated. Regions of preferred TE design were associated with not only higher conversion efficiency, but higher specific power and power flux that motivates TE conversion designs towards use of microtechnology solutions. Water and He gas microchannel designs are investigated as potential solutions to achieve miniature TE energy recovery systems. Developing high-heat-flux thermal designs using microtechnology are key to enabling miniature energy recovery systems and should occur in parallel with on-going research in advanced energy conversion materials.

  9. Low cost composite materials for wind energy conversion systems

    SciTech Connect

    Weingart, O.

    1980-01-01

    Structural Composites Industries, Inc. (SCI) is developing new composite filament winding technology for low cost production of wind turbine generators (WTG). During 1977 the SCI TFT process was used to fabricate a 9072 kg (20,000 lb) filament-wound D-spar for a NASA/DOE 46 m (150 ft) composite wind turbine blade. In 1978 SCI designed a composite blade for the 91 m (300 ft) dia. NASA/DOE MOD-2 WTG. For the past year SCI has been under contract to NASA-Lewis Research Center to design and build two low cost 18 m (60 ft) blades for the 38 m (125 ft) dia. MOD-OA and to assess the applicability of the techniques developed for larger and smaller blades. SCI is also developing and constructing a 4-kW small wind energy conversion system (SWECS) for Rockwell International using low cost composites for the 9 m (31 ft) dia. rotor blades, 15 m (50 ft) tower and nacelle.

  10. HYLIFE-II power conversion system design and cost study

    SciTech Connect

    Hoffman, M.A. . Dept. of Mechanical, Aeronautical and Materials Engineering)

    1990-09-01

    The power conversion system for the HYLIFE-2 fusion power plant has been defined to include the IHX's (intermediate heat exchangers) and everything that support the exchange of energy from the reactor. It is referred to simply as the BOP (balance of plant) in the rest of this report. The above is a convenient division between the reactor equipment and the rest of the fusion power plant since the BOP design and cost then depend only on the specification of the thermal power to the IHX's and the temperature of the primary Flibe coolant into and out of the IHX's, and is almost independent of the details of the reactor design. The main efforts during the first year have been on the definition and thermal-hydraulics of the IHX's, the steam generators and the steam power plant, leading to the definition of a reference BOP with the molten salt, Flibe, as the primary coolant. A summary of the key results in each of these areas is given in this report.

  11. Color To Colorant Conversions In A Colorimetric Separation System

    NASA Astrophysics Data System (ADS)

    Holub, Richard; Kearsley, Wayne

    1990-06-01

    Within several years of establishment of the CIE's Standard Observer, Neugebauer based upon it a device-independent interpretation of ink mixture in halftone color reproduction. Despite limitations of the model, his approach is of fundamental importance at a time in which document preparation in distributed computing environments is coming of age. Fruition of this technology demands a device independent or colorimetric method for representing and rendering color. A commercial, digital system for implementing such an approach (Kodak Designmaster 8000) has been described and will be reviewed here with particular regard to the output of color imagery on four-color printers. Inversion of Neugebauer's model for conversion of color to device specific signals must be constrained by the color gamut of the output medium and the utilization of the black printer (Gray Component Replacement). The interaction of the black printer with the device gamut and its effect on image quality and metamerism will receive detailed consideration. It will be shown that colorimetry is a powerful tool in maintaining accurate color reproduction during substitution of black for chromatic components, but that properties of the colorants must also be considered in order to realize commercially acceptable GCR. Section 7 of the paper is an enumeration of summary conclusions.

  12. Performance analysis of fault-tolerant systems in parallel execution of conversations

    NASA Technical Reports Server (NTRS)

    Kim, K. H.; Heu, Shin; Yang, Seung M.

    1989-01-01

    The execution overhead inherent in the conversation scheme, which is a scheme for realizing fault-tolerant cooperating processes free of the domino effect, is analyzed. Multiprocessor/multicomputer systems capable of parallel execution of conversation components are considered and a queuing network model of such systems is adopted. Based on the queuing model, various performance indicators, including system throughput, average number of processors idling inside a conversation due to the synchronization required, and average time spent in the conversation, have been evaluated numerically for several application environments. The numeric results are discussed and several essential performance characteristics of the conversation scheme are derived. For example, when the number of participant processes is not large, say less than six, the system performance is highly affected by the synchronization required on the processes in a conversation, and not so much by the probability of acceptance-test failure.

  13. Near-infrared (NIR) optogenetics using up-conversion system

    NASA Astrophysics Data System (ADS)

    Hososhima, Shoko; Yuasa, Hideya; Ishizuka, Toru; Yawo, Hiromu

    2015-03-01

    Non-invasive remote control technologies designed to manipulate neural functions for a comprehensive and quantitative understanding of the neuronal network in the brain as well as for the therapy of neurological disorders have long been awaited. Recently, it has become possible to optically manipulate the neuronal activity using biological photo-reactive molecules such as channelrhodopsin-2 (ChR2). However, ChR2 and its relatives are mostly reactive to visible light which does not effectively penetrate through biological tissues. In contrast, near-infrared (NIR) light penetrates deep into the tissues because biological systems are almost transparent to light within this so-called `imaging window'. Here we used lanthanide nanoparticles (LNPs), which are composed of rare-earth elements, as luminous bodies to activate channelrhodopsins (ChRs) since they absorb low-energy NIR light to emit high-energy visible light (up-conversion). Neuron-glioma-hybrid ND-7/23 cells were cultured with LNP(NaYF4:Sc/Yb/Er) particles (peak emission, 543 nm) and transfected to express C1V1 (peak absorbance, 539 nm), a chimera of ChR1 and VChR1. The photocurrents were generated in response to NIR laser light (976 nm) to a level comparable to that evoked by a filtered Hg lamp (530-550 nm). NIR light pulses also evoked action potentials in the cultured neurons that expressed C1V1. It is suggested that the green luminescent light emitted from LNPs effectively activated C1V1 to generate the photocurrent. With the optimization of LNPs, acceptor photo-reactive biomolecules and optics, this system could be applied to non-invasively actuate neurons deep in the brain.

  14. Lunar electric power systems utilizing the SP-100 reactor coupled to dynamic conversion systems

    NASA Astrophysics Data System (ADS)

    Harty, Richard B.; Durand, Richard E.; Mason, Lee S.

    1991-09-01

    An integration study was performed by coupling an SP-100 reactor to either a Brayton or Stirling power conversion subsystem. The application was for a surface power system to supply power requirements to a lunar base. A power level of 550 kWe was selected based on the NASA Space Exploration Initiative 90-day study. Reliability studies were initially performed to determine optimum power-conversion redundancy. This study resulted in selecting three operating engines and one standby unit. Integratiaon-design studies indicated that either the Brayton or Stirling power conversion subsystem could be integrated with the SP-100 reactor. The Stirling system had an integration advantage because of smaller piping size and fewer components. The Stirling engine, however, is more complex and heavier than the Brayton rotating unit, which tends to offset the Stirling integration advantage. From a performance consideration, the Brayton had a 9-percent mass advantage and the Stirling a 50-percent radiator-area advantage.

  15. Summary of State-of-the-Art Power Conversion Systems for Energy Storage Applications

    SciTech Connect

    Atcitty, S.; Gray-Fenner, A.; Ranade, S.

    1998-09-01

    The power conversion system (PCS) is a vital part of many energy storage systems. It serves as the interface between the storage device, an energy source, and an AC load. This report summarizes the results of an extensive study of state-of-the-art power conversion systems used for energy storage applications. The purpose of the study was to investigate the potential for cost reduction and performance improvement in these power conversion systems and to provide recommendations for fiture research and development. This report provides an overview of PCS technology, a description of several state-of-the-art power conversion systems and how they are used in specific applications, a summary of four basic configurations for l:he power conversion systems used in energy storage applications, a discussion of PCS costs and potential cost reductions, a summary of the stancku-ds and codes relevant to the technology, and recommendations for future research and development.

  16. Innovative power conversion system for the French SFR prototype, ASTRID

    SciTech Connect

    Cachon, L.; Biscarrat, C.; Morin, F.; Haubensack, D.; Rigal, E.; Moro, I.; Baque, F.; Madeleine, S.; Rodriguez, G.; Laffont, G.

    2012-07-01

    In the framework of the French Act of 28 June 2006 about nuclear materials and waste management, the prototype ASTRID (Advanced Sodium Technological Reactor for Industrial Demonstration), foreseen in operation by the 20's, will have to demonstrate not only the minor actinide transmutation capability, but also the progress made in Sodium Fast Reactor (SFR) technology on an industrial scale, by qualifying innovative options. Some of these options still require improvements, especially in the field of operability and safety. In fact, one of the main issues with the standard steam/water Power Conversion System (PCS) of SFR is the fast and energetic chemical reaction between water and sodium, which could occur in steam generators in case of tube failure. To manage the sodium/water reaction, one way consists in minimizing the impact of such event: hence studies are carried out on steam generator design, improvement of the physical knowledge of this phenomenon, development of numerical simulation to predict the reaction onset and consequences, and associated detection improvement. On the other hand, the other way consists in eliminating sodium/water reaction. In this frame, the CEA contribution to the feasibility evaluation of an alternative innovative PCS (replacing steam/water by 180 bar pressurised nitrogen) is focused on the following main topics: - The parametric study leading to nitrogen selection: the thermodynamic cycle efficiency optimisation on Brayton cycles is performed with several gases at different pressures. - The design of innovative compact heat exchangers for the gas loop: here the key points are the nuclear codification associated with inspection capability, the innovative welding process and the thermal-hydraulic and thermal-mechanic optimisations. After a general introduction of the ASTRID project, this paper presents in detail these different feasibility studies being led on the innovative gas PCS for an SFR. (authors)

  17. Chart of conversion factors: From English to metric system and metric to English system

    USGS Publications Warehouse

    U.S. Geological Survey

    1976-01-01

    The conversion factors in the following tables are for conversion of our customary (English) units of measurement to SI*units, and for convenience, reciprocals are shown for converting SI units back to the English system. The first table contains rule-of-thumb figures, useful for "getting the feel" of SI units or mental estimation. The succeeding tables contain factors accurate to 3 or more significant figures. Please refer to known reference volumes for additional accuracy, as well as for factors dealing with other scientific notation involving SI units.

  18. Novel, Integrated Reactor / Power Conversion System (LMR-AMTEC)

    SciTech Connect

    Pablo Rubiolo, Principal Investigator

    2003-03-21

    The main features of this project were the development of a long life (up to 10 years) Liquid Metal Reactor (LMR) and a static conversion subsystem comprising an Alkali Metal Thermal-to-Electric (AMTEC) topping cycle and a ThermoElectric (TE) Bottom cycle. Various coupling options of the LMR with the energy conversion subsystem were explored and, base in the performances found in this analysis, an Indirect Coupling (IC) between the LMR and the AMTEC/TE converters with Alkali Metal Boilers (AMB) was chosen as the reference design. The performance model of the fully integrated sodium-and potassium-AMTEC/TE converters shows that a combined conversion efficiency in excess of 30% could be achieved by the plant. (B204)

  19. Reception-Conversion Subsystem (RXCV) for microwave power transmission system

    NASA Technical Reports Server (NTRS)

    1975-01-01

    As part of a program to demonstrate the feasibility of power transmission from space, an approximately 25 sq m Reception-Conversion Subsystem was designed and tested. The device collects high power microwave energy, converts it into dc, and dissipates it in an instrumented demonstration load.

  20. Conversion of the Aerodynamic Preliminary Analysis System (APAS) to an IBM PC Compatible Format

    NASA Technical Reports Server (NTRS)

    Kruep, John M.

    1995-01-01

    The conversion of the Aerodynamic Preliminary Analysis System (APAS) software from a Silicon Graphics UNIX-based platform to a DOS-based IBM PC compatible is discussed. Relevant background information is given, followed by a discussion of the steps taken to accomplish the conversion and a discussion of the type of problems encountered during the conversion. A brief comparison of aerodynamic data obtained using APAS with data from another source is also made.

  1. Biomass Feedstock and Conversion Supply System Design and Analysis

    SciTech Connect

    Jacob J. Jacobson; Mohammad S. Roni; Patrick Lamers; Kara G. Cafferty

    2014-09-01

    Idaho National Laboratory (INL) supports the U.S. Department of Energy’s bioenergy research program. As part of the research program INL investigates the feedstock logistics economics and sustainability of these fuels. A series of reports were published between 2000 and 2013 to demonstrate the feedstock logistics cost. Those reports were tailored to specific feedstock and conversion process. Although those reports are different in terms of conversion, some of the process in the feedstock logistic are same for each conversion process. As a result, each report has similar information. A single report can be designed that could bring all commonality occurred in the feedstock logistics process while discussing the feedstock logistics cost for different conversion process. Therefore, this report is designed in such a way that it can capture different feedstock logistics cost while eliminating the need of writing a conversion specific design report. Previous work established the current costs based on conventional equipment and processes. The 2012 programmatic target was to demonstrate a delivered biomass logistics cost of $55/dry ton for woody biomass delivered to fast pyrolysis conversion facility. The goal was achieved by applying field and process demonstration unit-scale data from harvest, collection, storage, preprocessing, handling, and transportation operations into INL’s biomass logistics model. The goal of the 2017 Design Case is to enable expansion of biofuels production beyond highly productive resource areas by breaking the reliance of cost-competitive biofuel production on a single, low-cost feedstock. The 2017 programmatic target is to supply feedstock to the conversion facility that meets the in-feed conversion process quality specifications at a total logistics cost of $80/dry T. The $80/dry T. target encompasses total delivered feedstock cost, including both grower payment and logistics costs, while meeting all conversion in-feed quality targets

  2. Nonreciprocal conversion between microwave and optical photons in electro-optomechanical systems

    NASA Astrophysics Data System (ADS)

    Xu, Xun-Wei; Li, Yong; Chen, Ai-Xi; Liu, Yu-xi

    2016-02-01

    We propose to demonstrate nonreciprocal conversion between microwave and optical photons in an electro-optomechanical system where a microwave mode and an optical mode are coupled indirectly via two nondegenerate mechanical modes. The nonreciprocal conversion is obtained in the broken time-reversal symmetry regime, where the conversion of photons from one frequency to the other is enhanced for constructive quantum interference while the conversion in the reversal direction is suppressed due to destructive quantum interference. It is interesting that the nonreciprocal response between the microwave and optical modes in the electro-optomechanical system appears at two different frequencies with opposite directions. The proposal can be used to realize nonreciprocal conversion between photons of any two distinctive modes with different frequencies. Moreover, the electro-optomechanical system can also be used to construct a three-port circulator for three optical modes with distinctively different frequencies by adding an auxiliary optical mode coupled to one of the mechanical modes.

  3. Video-conversion channel of a synthesizing visualization system

    NASA Astrophysics Data System (ADS)

    Bogdaov, V. V.; Kovalev, A. M.; Nefedov, I. B.; Ponomarev, N. M.; Seroshtan, A. S.

    1986-08-01

    A video-conversion channel is described in which an analog video signal is generated according to the digital description of the video subject composed in terms of geometric primitives (line segments). The device contains units for the interpolation of object color, the simulation of atmospheric phenomena (e.g., fog and haze), the filtering of quantized images, and the gamma correction of the video signal.

  4. Debugging the Conversion Process: Lessons from an Administrative Information System Conversion.

    ERIC Educational Resources Information Center

    Hibbler, Fritz; Mitchell, Linda

    1995-01-01

    The process of reengineering the administrative information system at the University of Idaho required careful planning, development of a set of philosophies, and several strategies for ensuring success. The latter included a humorous symbol (a jitter bug) to express concern, improved institutional communications, and a focus on logistical issues.…

  5. Lunar electric power systems utilizing the SP-100 reactor coupled to dynamic conversion systems

    NASA Astrophysics Data System (ADS)

    Harty, Richard B.; Durand, Richard E.

    1993-03-01

    An integration study was performed by Rocketdyne under contract to NASA-LeRC. The study was concerned with coupling an SP-0100 reactor to either a Brayton or Stirling power conversion system. The application was for a surface power system to supply power requirements to a lunar base. A power level of 550 kWe was selected based on the NASA Space Exploration Initiative 90-day study. Reliability studies were initially performed to determine optimum power conversion redundancy. This study resulted in selecting three operating engines and one stand-by unit. Integration design studies indicated that either the Brayton or Stirling power conversion systems could be integrated with the PS-100 reactor. The Stirling system had an integration advantage because of smaller piping size and fewer components. The Stirling engine, however, is more complex and heavier than the Brayton rotating unit, which tends to off-set the Stirling integration advantage. From a performance consideration, the Brayton had a 9 percent mass advantage, and the Stirling had a 50 percent radiator advantage.

  6. Lunar electric power systems utilizing the SP-100 reactor coupled to dynamic conversion systems. Final report

    SciTech Connect

    Harty, R.B.; Durand, R.E.

    1993-03-01

    An integration study was performed by Rocketdyne under contract to NASA-LeRC. The study was concerned with coupling an SP-0100 reactor to either a Brayton or Stirling power conversion system. The application was for a surface power system to supply power requirements to a lunar base. A power level of 550 kWe was selected based on the NASA Space Exploration Initiative 90-day study. Reliability studies were initially performed to determine optimum power conversion redundancy. This study resulted in selecting three operating engines and one stand-by unit. Integration design studies indicated that either the Brayton or Stirling power conversion systems could be integrated with the PS-100 reactor. The Stirling system had an integration advantage because of smaller piping size and fewer components. The Stirling engine, however, is more complex and heavier than the Brayton rotating unit, which tends to off-set the Stirling integration advantage. From a performance consideration, the Brayton had a 9 percent mass advantage, and the Stirling had a 50 percent radiator advantage.

  7. Lunar electric power systems utilizing the SP-100 reactor coupled to dynamic conversion systems

    NASA Technical Reports Server (NTRS)

    Harty, Richard B.; Durand, Richard E.

    1993-01-01

    An integration study was performed by Rocketdyne under contract to NASA-LeRC. The study was concerned with coupling an SP-0100 reactor to either a Brayton or Stirling power conversion system. The application was for a surface power system to supply power requirements to a lunar base. A power level of 550 kWe was selected based on the NASA Space Exploration Initiative 90-day study. Reliability studies were initially performed to determine optimum power conversion redundancy. This study resulted in selecting three operating engines and one stand-by unit. Integration design studies indicated that either the Brayton or Stirling power conversion systems could be integrated with the PS-100 reactor. The Stirling system had an integration advantage because of smaller piping size and fewer components. The Stirling engine, however, is more complex and heavier than the Brayton rotating unit, which tends to off-set the Stirling integration advantage. From a performance consideration, the Brayton had a 9 percent mass advantage, and the Stirling had a 50 percent radiator advantage.

  8. Multi-views storage model and access methods of conversation history in converged IP messaging system

    NASA Astrophysics Data System (ADS)

    Lu, Meilian; Yang, Dong; Zhou, Xing

    2013-03-01

    Based on the analysis of the requirements of conversation history storage in CPM (Converged IP Messaging) system, a Multi-views storage model and access methods of conversation history are proposed. The storage model separates logical views from physical storage and divides the storage into system managed region and user managed region. It simultaneously supports conversation view, system pre-defined view and user-defined view of storage. The rationality and feasibility of multi-view presentation, the physical storage model and access methods are validated through the implemented prototype. It proves that, this proposal has good scalability, which will help to optimize the physical data storage structure and improve storage performance.

  9. Power conversion distribution system using a resonant high-frequency AC link

    NASA Technical Reports Server (NTRS)

    Sood, P. K.; Lipo, T. A.

    1986-01-01

    Static power conversion systems based on a resonant high frequency (HF) link offers a significant reduction in the size and weight of the equipment over that achieved with conventional approaches, especially when multiple sources and loads are to be integrated. A faster system response and absence of audible noise are the other principal characteristics of such systems. A conversion configuration based on a HF link which is suitable for applications requiring distributed power is proposed.

  10. Reliability and mass analysis of dynamic power conversion systems with parallel of standby redundancy

    NASA Technical Reports Server (NTRS)

    Juhasz, A. J.; Bloomfield, H. S.

    1985-01-01

    A combinatorial reliability approach is used to identify potential dynamic power conversion systems for space mission applications. A reliability and mass analysis is also performed, specifically for a 100 kWe nuclear Brayton power conversion system with parallel redundancy. Although this study is done for a reactor outlet temperature of 1100K, preliminary system mass estimates are also included for reactor outlet temperatures ranging up to 1500 K.

  11. Reliability and mass analysis of dynamic power conversion systems with parallel or standby redundancy

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.; Bloomfield, Harvey S.

    1987-01-01

    A combinatorial reliability approach was used to identify potential dynamic power conversion systems for space mission applications. A reliability and mass analysis was also performed, specifically for a 100-kWe nuclear Brayton power conversion system with parallel redundancy. Although this study was done for a reactor outlet temperature of 1100 K, preliminary system mass estimates are also included for reactor outlet temperatures ranging up to 1500 K.

  12. Feedstock Supply System Design and Economics for Conversion of Lignocellulosic Biomass to Hydrocarbon Fuels: Conversion Pathway: Biological Conversion of Sugars to Hydrocarbons The 2017 Design Case

    SciTech Connect

    Kevin Kenney; Kara G. Cafferty; Jacob J. Jacobson; Ian J Bonner; Garold L. Gresham; William A. Smith; David N. Thompson; Vicki S. Thompson; Jaya Shankar Tumuluru; Neal Yancey

    2013-09-01

    The U.S. Department of Energy promotes the production of a range of liquid fuels and fuel blendstocks from lignocellulosic biomass feedstocks by funding fundamental and applied research that advances the state of technology in biomass collection, conversion, and sustainability. As part of its involvement in this program, the Idaho National Laboratory (INL) investigates the feedstock logistics economics and sustainability of these fuels. Between 2000 and 2012, INL conducted a campaign to quantify the economics and sustainability of moving biomass from standing in the field or stand to the throat of the biomass conversion process. The goal of this program was to establish the current costs based on conventional equipment and processes, design improvements to the current system, and to mark annual improvements based on higher efficiencies or better designs. The 2012 programmatic target was to demonstrate a delivered biomass logistics cost of $35/dry ton. This goal was successfully achieved in 2012 by implementing field and process demonstration unit-scale data from harvest, collection, storage, preprocessing, handling, and transportation operations into INL’s biomass logistics model. Looking forward to 2017, the programmatic target is to supply biomass to the conversion facilities at a total cost of $80/dry ton and on specification with in-feed requirements. The goal of the 2017 Design Case is to enable expansion of biofuels production beyond highly productive resource areas by breaking the reliance of cost-competitive biofuel production on a single, abundant, low-cost feedstock. If this goal is not achieved, biofuel plants are destined to be small and/or clustered in select regions of the country that have a lock on low-cost feedstock. To put the 2017 cost target into perspective of past accomplishments of the cellulosic ethanol pathway, the $80 target encompasses total delivered feedstock cost, including both grower payment and logistics costs, while meeting all

  13. Technology and development requirements for advanced coal conversion systems

    NASA Technical Reports Server (NTRS)

    1981-01-01

    A compendium of coal conversion process descriptions is presented. The SRS and MC data bases were utilized to provide information paticularly in the areas of existing process designs and process evaluations. Additional information requirements were established and arrangements were made to visit process developers, pilot plants, and process development units to obtain information that was not otherwise available. Plant designs, process descriptions and operating conditions, and performance characteristics were analyzed and requirements for further development identified and evaluated to determine the impact of these requirements on the process commercialization potential from the standpoint of economics and technical feasibility. A preliminary methodology was established for the comparative technical and economic assessment of advanced processes.

  14. An Integrated System for the Treatment of Coal Conversion Wastewater

    SciTech Connect

    Henry Y. Wang; Keeran R. Srinivasan

    1999-02-25

    Treatment of mixed waste from coal conversion wastewaters involves the degradation of toxic organics and the removal of heavy metals. An integrated and cost-effective treatment scheme that can implement such a process is considered essential to promote continued development and growth of coal conversion processes without any deleterious effects on our ecosystem. We have recently developed a pH-dependent, reversible heavy metal adsorption/desorption process which promises to be a cost-effective alternative to the treatment and disposal options currently in place for these inorganic contaminants. Our work shows that: (1) Polydisperse, industrial-grade surfactants can be used in the development of novel, surfactant-coated smectitic clays containing up to 50% by weight of adsorbed surfactant, (2) Reversible adsorption and resorption of cationic (CU(II) and Cd(II)) and anionic (Cr(VI)) heavy metals from their respective aqueous solutions onto these surfactant-modified smectites can be effected using pH of the medium as a switch, and (3) These surfactant-modified smectites can be repeatedly used (up to 5 times) with only a minimal loss in their adsorption potency and with very little leaching of the adsorbed surfactants.

  15. Green farming systems for the Southeast USA using manure-to-energy conversion platforms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Livestock operations in the Southeastern USA are faced with implementing holistic solutions to address effective manure treatment through efficient energy management and safeguarding of supporting natural resources. By integrating waste-to-energy conversion platforms, future green farming systems ca...

  16. Basic and applied research related to the technology of space energy conversion systems, 1982 - 1983

    NASA Technical Reports Server (NTRS)

    Hertzberg, A.

    1983-01-01

    Topics on solar energy conversion concepts and applications are discussed. An overview of the current status and future utilization of radiation receivers for electrical energy generation, liquid droplet radiation systems, and liquid droplet heat exchangers is presented.

  17. Design, fabrication, delivery, operation and maintenance of a geothermal power conversion system

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The design, fabrication, delivery, operation and maintenance of an Hydrothermal Power Company 1250 KVA geothermal power conversion system using a helical screw expander as the prime mover is described. Hydrostatic and acceptance testing are discussed.

  18. Energy and data conversion circuits for low power sensory systems

    NASA Astrophysics Data System (ADS)

    Ghosh, Suvradip

    This dissertation focuses on the problem of increasing the lifetime of wireless sensors. This problem is addressed from two different angles: energy harvesting and data compression. Energy harvesting enables a sensor to extract energy from its environment and use it to power itself or recharge its batteries. Data compression, on the other hand, allows a sensor to save energy by reducing the radio transmission bandwidth. This dissertation proposes a fractal-based photodiode fabricated on standard CMOS process as an energy harvesting device with increased efficiency. Experiments show that, the fractal based photodiodes are 6% more efficient compared to the conventional square shaped photodiode. The fractal shape photodiode has more perimeter-to-area ratio which increases the lateral response, improving its efficiency. With increased efficiency, more current is generated but the open-circuit voltage still remains low (0.3V--0.45V depending on illumination condition). These voltages have to be boosted up to higher values if they are going to be used to power up any sensory circuit or recharge a battery. We propose a switched-inductor DC-DC converter to boost the low voltage of the photodiodes to higher voltages. The proposed circuit uses two on-chip switches and two off-chip Components: an inductor and a capacitor. Experiments show a voltage up to 2.81V can be generated from a single photodiode of 1mm2 area. The voltage booster circuit achieved a conversion efficiency of 59%. Data compression was also explored in an effort to reduce energy consumption during radio transmission. An analog-to-digital converter (ADC), which can jointly perform the tasks of digital conversion and entropy encoding, has also been proposed in this dissertation. The joint data conversion/compression help savings in area and power resources, making it suitable for on-sensor compression. The proposed converter combines a cyclic converter architecture and Golomb-Rice entropy encoder. The

  19. Reverse Conversion Schemes for Signed-Digit Number Systems: A Survey

    NASA Astrophysics Data System (ADS)

    Chakraborty, Madhu Sudan

    2016-06-01

    Although signed-digit number systems have received a considerable attention, the transformation of signed-digit numbers back into the conventional forms, known as reverse conversion, is still a performance bottleneck of signed-digit arithmetic. In this paper, a literature survey of reverse conversion schemes for signed-digit number systems is performed on the basis of the articles published from recognized platforms for the past few decades. The survey reveals some specific problems of this field, which need further investigations.

  20. Modeling of large aperture third harmonic frequency conversion of high power Nd:glass laser systems

    SciTech Connect

    Henesian, M.A.; Wegner, P.J.; Speck, D.R.; Bibeau, C.; Ehrlich, R.B.; Laumann, C.W.; Lawson, J.K.; Weiland, T.L.

    1991-03-13

    To provide high-energy, high-power beams at short wavelengths for inertial-confinement-fusion experiments, we routinely convert the 1.053-{mu}m output of the Nova, Nd:phosphate-glass, laser system to its third-harmonic wavelength. We describe performance and conversion efficiency modeling of the 3 {times} 3 arrays potassium-dihydrogen-phosphate crystal plates used for type II/type II phase-matched harmonic conversion of Nova 0.74-m diameter beams, and an alternate type I/type II phase-matching configuration that improves the third-harmonic conversion efficiency. These arrays provide energy conversion of up to 65% and intensity conversion to 70%. 19 refs., 11 figs.

  1. 5 CFR 9901.231 - Conversion of positions and employees to NSPS classification system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Conversion of positions and employees to NSPS classification system. 9901.231 Section 9901.231 Administrative Personnel DEPARTMENT OF DEFENSE... functional units may convert from the GS system, the SL/ST system, the SES system, or such other DoD...

  2. 5 CFR 9701.231 - Conversion of positions and employees to the DHS classification system.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Conversion of positions and employees to... from the GS system, a prevailing rate system, the SL/ST system, or the SES system, as provided in... position to a band and for converting SL/ST and SES positions to a band upon initial implementation of...

  3. 5 CFR 9701.231 - Conversion of positions and employees to the DHS classification system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 3 2014-01-01 2014-01-01 false Conversion of positions and employees to... from the GS system, a prevailing rate system, the SL/ST system, or the SES system, as provided in... position to a band and for converting SL/ST and SES positions to a band upon initial implementation of...

  4. 5 CFR 9701.231 - Conversion of positions and employees to the DHS classification system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 3 2012-01-01 2012-01-01 false Conversion of positions and employees to... from the GS system, a prevailing rate system, the SL/ST system, or the SES system, as provided in... position to a band and for converting SL/ST and SES positions to a band upon initial implementation of...

  5. Potassium Rankine cycle power conversion systems for lunar-Mars surface power

    SciTech Connect

    Holcomb, R.S.

    1992-07-01

    The potassium Rankine cycle has good potential for application to nuclear power systems for surface power on the moon and Mars. A substantial effort on the development of the power conversion was carried out in the 1960`s which demonstrated successful operation of components made of stainless steel at moderate temperatures. This technology could be applied in the near term to produce a 360 kW(e) power system by coupling a stainless steel power conversion system to the SP-100 reactor. Improved performance could be realized in later systems by utilizing niobium or tantalum refractory metal alloys in the reactor and power conversion system. The design characteristics and estimated mass of power systems for each of three technology levels are presented in the paper. 8 refs.

  6. Fibrous materials for selective line emission application in a thermal-electrical energy conversion system

    NASA Astrophysics Data System (ADS)

    Chen, Zheng; Adair, Peter L.; Rose, M. Frank

    1997-01-01

    Fibrous rare earth composite emitters were developed for the application of thermophotovoltaic (TPV) energy conversion to increase the energy conversion efficiency of the system. In this paper, the authors demonstrated that fibrous composite emitters, with higher selective efficiency and good mechanical properties, were fabricated using a unique material processing technology. The spectra of the emitters, as well as their mechanical properties, were investigated. Some observations in this research have indicated that by using our current technology, we are able to tailor the spectrum by designing the emitter materials. Therefore, in order to achieve high energy conversion efficiency the designed emitters can be matched to the energy bandgap of new developing photovoltaic cells.

  7. Low-temperature system for simultaneous counting of conversion electrons and backscattered γ-rays in Mossbauer effect experiment

    NASA Astrophysics Data System (ADS)

    Ruskov, Todor; Passage, Güner; Rastanawi, Abdallah; Radev, Rumen

    1994-12-01

    A system for simultaneous detection of conversion electrons, emitted after resonant exciting of 57Fe, and resonant backscattered γ-rays and X-rays, accompanying the conversion electrons, is described. The system includes a helium proportional counter, for detection of conversion electrons, and a toroidal "Keisch-type" proportional counter, connected to the vacuum part of a helium cryostat.

  8. Theme--Achieving 2020. Goal 3: All Students Are Conversationally Literate in Agriculture, Food, Fiber, and Natural Resource Systems.

    ERIC Educational Resources Information Center

    Trexler, Cary, Ed.

    2000-01-01

    Nine theme articles focus on the need for students to be conversationally literate about agriculture, food, fiber, and natural resources systems. Discusses the definition of conversational literacy, the human and institutional resources needed, and exemplary models for promoting literacy. (JOW)

  9. The Holistic Application of High Technology for Conversation, Writing, and Computer Access Aid Systems.

    ERIC Educational Resources Information Center

    Rodgers, Barry L.

    The principal thesis of this paper is that successful use of high technology for conversation, writing, and computer access aid systems requires a holistic perspective. A holistic approach is one in which all the components of the support system needed to use high technology effectively are in place. Recognizing that aid systems are tools helps…

  10. Effect of limited homology on gene conversion in a Saccharomyces cerevisiae plasmid recombination system

    SciTech Connect

    Ahn, B.Y.; Dornfeld, K.J.; Fagrelius, T.J.; Livingston, D.M.

    1988-06-01

    Plasmids containing heteroallelic copies of the Saccharomyces cerevisiae HIS3 gene undergo intramolecular gene conservation in mitotically dividing S. cerevisiae cels. The authors used this plasmid system to determine the minimum amount of homology required for gene conversion, to examine how conversion tract lengths are affected by limited homology, and to analyze the role of flanking DNA sequences on the pattern of exchange. Plasmids with homologous sequences greater than 2 kilobases have mitotic exchange rates as high as 2 x 10/sup -3/ event soper cell per generation. As the homology is reduced, the exchange rate decreases dramatically. A plasmid with 26 base pairs (bp) of homology undergones gene conversion at a rate of approximately 1 x 10/sup -10/ events per cell per generation. These studies have also shown that an 8-bp insertion mutation 13 bp from a border between homologous and nonhomologous sequences undergoes conversion, but that a similar 8-bp insertion 5 bp from a border does not. Examination of independent conversion events which occurred in plasmids with heteroallelic copies of the HIS3 gene shows that markers within 280 bp of a border between homologous and nonhomologous sequences undergo conversion less frequently than the same markers within a more extensive homologous sequence. Thus, proximity to a border between homologous and nonhomologous sequences shortens the conversion tract length.

  11. Double barrier system for an in situ conversion process

    DOEpatents

    McKinzie, Billy John [Houston, TX; Vinegar, Harold J [Bellaire, TX; Cowan, Kenneth Michael [Sugar land, TX; Deeg, Wolfgang Friedrich Johann [Houston, TX; Wong, Sau-Wai [Rijswijk, NL

    2009-05-05

    A barrier system for a subsurface treatment area is described. The barrier system includes a first barrier formed around at least a portion of the subsurface treatment area. The first barrier is configured to inhibit fluid from exiting or entering the subsurface treatment area. A second barrier is formed around at least a portion of the first barrier. A separation space exists between the first barrier and the second barrier.

  12. Photoelectrochemical based direct conversion systems for hydrogen production

    SciTech Connect

    Khaselev, O.; Bansal, A.; Kocha, S.; Turner, J.A.

    1998-08-01

    With an eye towards developing a photoelectrochemical system for hydrogen production using sunlight as the only energy input, two types of systems were studied, both involving multijunction devices. One set of cells consisted of a-Si triple junctions and the other a GaInP{sub 2}/GaAs tandem cell combination. Additional investigations were carried out on semiconductor surface modifications to move semiconductor band edges to more favorable energetic positions.

  13. Limits to solar power conversion efficiency with applications to quantum and thermal systems

    NASA Technical Reports Server (NTRS)

    Byvik, C. E.; Buoncristiani, A. M.; Smith, B. T.

    1983-01-01

    An analytical framework is presented that permits examination of the limit to the efficiency of various solar power conversion devices. Thermodynamic limits to solar power efficiency are determined for both quantum and thermal systems, and the results are applied to a variety of devices currently considered for use in space systems. The power conversion efficiency for single-threshold energy quantum systems receiving unconcentrated air mass zero solar radiation is limited to 31 percent. This limit applies to photovoltaic cells directly converting solar radiation, or indirectly, as in the case of a thermophotovoltaic system. Photoelectrochemical cells rely on an additional chemical reaction at the semiconductor-electrolyte interface, which introduces additional second-law demands and a reduction of the solar conversion efficiency. Photochemical systems exhibit even lower possible efficiencies because of their relatively narrow absorption bands. Solar-powered thermal engines in contact with an ambient reservoir at 300 K and operating at maximum power have a peak conversion efficiency of 64 percent, and this occurs for a thermal reservoir at a temperature of 2900 K. The power conversion efficiency of a solar-powered liquid metal magnetohydrodydnamic generator, a solar-powered steam turbine electric generator, and an alkali metal thermoelectric converter is discussed.

  14. Limits to solar power conversion efficiency with applications to quantum and thermal systems

    NASA Astrophysics Data System (ADS)

    Byvik, C. E.; Buoncristiani, A. M.; Smith, B. T.

    1983-12-01

    An analytical framework is presented that permits examination of the limit to the efficiency of various solar power conversion devices. Thermodynamic limits to solar power efficiency are determined for both quantum and thermal systems, and the results are applied to a variety of devices currently considered for use in space systems. The power conversion efficiency for single-threshold energy quantum systems receiving unconcentrated air mass zero solar radiation is limited to 31 percent. This limit applies to photovoltaic cells directly converting solar radiation, or indirectly, as in the case of a thermophotovoltaic system. Photoelectrochemical cells rely on an additional chemical reaction at the semiconductor-electrolyte interface, which introduces additional second-law demands and a reduction of the solar conversion efficiency. Photochemical systems exhibit even lower possible efficiencies because of their relatively narrow absorption bands. Solar-powered thermal engines in contact with an ambient reservoir at 300 K and operating at maximum power have a peak conversion efficiency of 64 percent, and this occurs for a thermal reservoir at a temperature of 2900 K. The power conversion efficiency of a solar-powered liquid metal magnetohydrodydnamic generator, a solar-powered steam turbine electric generator, and an alkali metal thermoelectric converter is discussed.

  15. Towards ontology personalization to enrich social conversations on AAC systems

    NASA Astrophysics Data System (ADS)

    Mancilla V., Daniela; Sastoque H., Sebastian; Iregui G., Marcela

    2015-01-01

    Communication is one of the essential needs of human beings. Augmentative and Alternative Communication Systems (AAC) seek to help in the generation of oral and written language to people with physical disorders that limit their natural communication. These systems present significant challenges such as: the composition of consistent messages according to syntactic and semantic rules, the improvement of message production times, the application to social contexts and, consequently, the incorporation of user-specific information. This work presents an original ontology personalization approach for an AAC instant messaging system incorporating personalized information to improve the efficacy and efficiency of the message production. This proposal is based on a projection of a general ontology into a more specific one, avoiding storage redundancy and data coupling, representing a big opportunity to enrich communication capabilities of current AAC systems. The evaluation was performed for a study case based on an AAC system for assistance in composing messages. The results show that adding user-specific information allows generation of enriched phrases, so improving the accuracy of the message, facilitating the communication process.

  16. Testing of an advanced thermochemical conversion reactor system

    SciTech Connect

    Not Available

    1990-01-01

    This report presents the results of work conducted by MTCI to verify and confirm experimentally the ability of the MTCI gasification process to effectively generate a high-quality, medium-Btu gas from a wider variety of feedstock and waste than that attainable in air-blown, direct gasification systems. The system's overall simplicity, due to the compact nature of the pulse combustor, and the high heat transfer rates attainable within the pulsating flow resonance tubes, provide a decided and near-term potential economic advantage for the MTCI indirect gasification system. The primary objective of this project was the design, construction, and testing of a Process Design Verification System for an indirectly heated, thermochemical fluid-bed reactor and a pulse combustor an an integrated system that can process alternative renewable sources of energy such as biomass, black liquor, municipal solid waste and waste hydrocarbons, including heavy oils into a useful product gas. The test objectives for the biomass portion of this program were to establish definitive performance data on biomass feedstocks covering a wide range of feedstock qualities and characteristics. The test objectives for the black liquor portion of this program were to verify the operation of the indirect gasifier on commercial black liquor containing 65 percent solids at several temperature levels and to characterize the bed carbon content, bed solids particle size and sulfur distribution as a function of gasification conditions. 6 refs., 59 figs., 29 tabs.

  17. Testing of an advanced thermochemical conversion reactor system

    NASA Astrophysics Data System (ADS)

    1990-01-01

    This report presents the results of work conducted by MTCI to verify and confirm experimentally the ability of the MTCI gasification process to effectively generate a high-quality, medium-Btu gas from a wider variety of feedstock and waste than that attainable in air-blown, direct gasification systems. The system's overall simplicity, due to the compact nature of the pulse combustor, and the high heat transfer rates attainable within the pulsating flow resonance tubes, provide a decided and near-term potential economic advantage for the MTCI indirect gasification system. The primary objective was the design, construction, and testing of a Process Design Verification System for an indirectly heated, thermochemical fluid-bed reactor and a pulse combustor an an integrated system that can process alternative renewable sources of energy such as biomass, black liquor, municipal solid waste and waste hydrocarbons, including heavy oils into a useful product gas. The test objectives for the biomass portion of this program were to establish definitive performance data on biomass feedstocks covering a wide range of feedstock qualities and characteristics. The test objectives for the black liquor portion of this program were to verify the operation of the indirect gasifier on commercial black liquor containing 65 percent solids at several temperature levels and to characterize the bed carbon content, bed solids particle size and sulfur distribution as a function of gasification conditions.

  18. Papaya drying and waste conversion system. Final report

    SciTech Connect

    Not Available

    1982-02-12

    This project, performed under United States Department of Energy Small-scale Appropriate Energy Technology Grant, involves demonstration of an integrated system using solar energy to process off-grade or reject fruit into marketable food products. The integrated system consists of three phases: (1) solar dehydration of usable fruit; (2) solar vacuum distillation of fermented wastes (peelings, rinds, skins, and seeds) to produce an ethanol fuel to use as a backup source of heat for dehydration; and (3) land reclamation by mixing stillage and compost with volcanic cinder and ash to produce on marginal land a rich soil suitable for growing more crops to dry. Although the system is not 100% complete the investigators have demonstrated that a small business can efficiently use solar energies in an integrated fashion to process waste into food, improve the quality of the land, and provide meaningful jobs in a region of very high unemployment.

  19. Characterization of solid waste conversion and cogeneration systems

    NASA Astrophysics Data System (ADS)

    1980-09-01

    Three basic technologies for recovering energy from Municipal Solid Waste (MSW) were considered: direct combustion using a waterwall incinerator in which the heat from burning refuse is converted to steam by circulating water in steel tubes jacketing the interior of the incinerator; manufacture of a relatively uniform shredded, pulverized or pelleted refuse-derived fuel (RDF) for supplemental firing in a utility boiler; and pyrolysis or destructive distillation of MSW to extract a low-Btu fuel gas. While resource recovery and energy recovery systems can be installed independently, the processes described include both energy and resource recovery systems as well as necessary pollution control equipment for gaseous emissions.

  20. Systems Analysis of Safeguards Effectiveness in a Uranium Conversion Facility

    SciTech Connect

    Elayat, H A; Lambert, H; O'Connell, W J

    2004-06-16

    The U.S. Department of Energy (DOE) is interested in developing tools and methods for potential U.S. use in designing and evaluating safeguards systems. For this goal several DOE National Laboratories are defining the characteristics of typical facilities of several size scales, and the safeguards measures and instrumentation that could be applied. Lawrence Livermore National Laboratory is providing systems modeling and analysis of facility and safeguards operations, diversion path generation, and safeguards system effectiveness. The constituent elements of diversion scenarios are structured using directed graphs (digraphs) and fault trees. Safeguards indicator probabilities are based on sampling statistics and/or measurement accuracies. Scenarios are ranked based on value and quantity of material removed and the estimated probability of non-detection. Significant scenarios, especially those involving timeliness or randomly varying order of events, are transferred to simulation analysis. Simulations show the range of conditions encountered by the safeguards measurements and inspections, e.g., the quantities of intermediate materials in temporary storage and the time sequencing of material flow. Given a diversion campaign, simulations show how much the range of the same parameters observed by the safeguards system can differ from the base-case range. The combination of digraphs, fault trees, statistics and simulation constitute a method for evaluation of the estimated benefit of alternate or additional safeguards equipment or features. A generic example illustrates the method.

  1. White Pine Co. Public School System Biomass Conversion Heating Project

    SciTech Connect

    Paul Johnson

    2005-11-01

    The White Pine County School District and the Nevada Division of Forestry agreed to develop a pilot project for Nevada using wood chips to heat the David E. Norman Elementary School in Ely, Nevada. Consideration of the project was triggered by a ''Fuels for Schools'' grant that was brought to the attention of the School District. The biomass project that was part of a district-wide energy retrofit, called for the installation of a biomass heating system for the school, while the current fuel oil system remained as back-up. Woody biomass from forest fuel reduction programs will be the main source of fuel. The heating system as planned and completed consists of a biomass steam boiler, storage facility, and an area for unloading and handling equipment necessary to deliver and load fuel. This was the first project of it's kind in Nevada. The purpose of the DOE funded project was to accomplish the following goals: (1) Fuel Efficiency: Purchase and install a fuel efficient biomass heating system. (2) Demonstration Project: Demonstrate the project and gather data to assist with further research and development of biomass technology; and (3) Education: Educate the White Pine community and others about biomass and other non-fossil fuels.

  2. A Reflective Conversation with Joe Renzulli and Sally Reis: About the Renzulli Learning System

    ERIC Educational Resources Information Center

    Renzulli, Joe; Reis, Sally; Shaughnessy, Michael F

    2014-01-01

    In this reflective conversation, Dr. Joe Renzulli and Dr. Sally Reis respond to questions about the newly developed Renzulli Learning System. They discuss the system in light of the Schoolwide Enrichment Model (SEM) and provide information regarding its use with curriculum compacting and Renzulli's "Three Ring Conceptualization of…

  3. 5 CFR 534.406 - Conversion to the SES pay system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Conversion to the SES pay system. 534.406... period beginning on or after January 1, 2004, a law enforcement officer (LEO), as defined in 5 CFR 531... UNDER OTHER SYSTEMS Pay and Performance Awards Under the Senior Executive Service § 534.406...

  4. 5 CFR 534.406 - Conversion to the SES pay system.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Conversion to the SES pay system. 534.406... period beginning on or after January 1, 2004, a law enforcement officer (LEO), as defined in 5 CFR 531... UNDER OTHER SYSTEMS Pay and Performance Awards Under the Senior Executive Service § 534.406...

  5. 5 CFR 534.406 - Conversion to the SES pay system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Conversion to the SES pay system. 534.406... period beginning on or after January 1, 2004, a law enforcement officer (LEO), as defined in 5 CFR 531... UNDER OTHER SYSTEMS Pay and Performance Awards Under the Senior Executive Service § 534.406...

  6. 5 CFR 534.406 - Conversion to the SES pay system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Conversion to the SES pay system. 534.406... period beginning on or after January 1, 2004, a law enforcement officer (LEO), as defined in 5 CFR 531... UNDER OTHER SYSTEMS Pay and Performance Awards Under the Senior Executive Service § 534.406...

  7. 5 CFR 9701.373 - Conversion of employees to the DHS pay system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM Pay and Pay Administration Transitional Provisions... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Conversion of employees to the DHS pay system. 9701.373 Section 9701.373 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY...

  8. 5 CFR 9701.373 - Conversion of employees to the DHS pay system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM Pay and Pay Administration Transitional Provisions... 5 Administrative Personnel 3 2014-01-01 2014-01-01 false Conversion of employees to the DHS pay system. 9701.373 Section 9701.373 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY...

  9. 5 CFR 9701.373 - Conversion of employees to the DHS pay system.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM Pay and Pay Administration Transitional Provisions... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Conversion of employees to the DHS pay system. 9701.373 Section 9701.373 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY...

  10. 5 CFR 534.406 - Conversion to the SES pay system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... period beginning on or after January 1, 2004, a law enforcement officer (LEO), as defined in 5 CFR 531... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Conversion to the SES pay system. 534.406... to the SES pay system. (a) On the first day of the first applicable pay period beginning on or...

  11. 5 CFR 9901.231 - Conversion of positions and employees to NSPS classification system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Conversion of positions and employees to NSPS classification system. 9901.231 Section 9901.231 Administrative Personnel DEPARTMENT OF DEFENSE HUMAN RESOURCES MANAGEMENT AND LABOR RELATIONS SYSTEMS (DEPARTMENT OF DEFENSE-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF DEFENSE NATIONAL...

  12. 5 CFR 9701.231 - Conversion of positions and employees to the DHS classification system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Conversion of positions and employees to the DHS classification system. 9701.231 Section 9701.231 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM (DEPARTMENT OF HOMELAND SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY...

  13. Farm silo application of the ''TARP'' wind energy conversion system

    SciTech Connect

    Duffy, R.E.; Butler, L.; Weisbrich, A.

    1983-08-01

    In this study, previously developed methods of determining wind turbine performance are adapted to the prediction of the performance of the silo application of the Toroidal Augmentor Rotor Platform (TARP). The system studied had three bladed turbines with untwisted, constant chord blades with a NACA 0015 airfoil section. Power coefficients of over one were predicted for two TARP configurations. The effects of varying blade chord, blade angle, and turbine angular velocity were evaluated. The economic feasibility of the silo application of the TARP was analyzed. It was found that this system could be economical in areas of high average wind velocity or where the cost of the energy available from other sources is high.

  14. Alkali Metal Thermoelectric Conversion (AMTEC) for space nuclear power systems

    NASA Technical Reports Server (NTRS)

    Bankston, C. P.; Cole, T.; Khanna, S. K.; Thakoor, A. P.

    1985-01-01

    Performance parameters of the Alkali Metal Thermoelectric Converter (AMTEC) for a 100 kW electric power system have been calculated at four technological levels assuming a heat pipe-cooled nuclear reactor heat source. The most advanced level considered would operate between 1180 K converter temperature and 711 K radiator temperature at 16 percent efficiency, and would weigh 1850 kg with a radiator area of 43 sq m. In addition, electrode research studies for the AMTEC systems have been conducted utilizing an experimental test cell of Bankston et al. (1983) and Mo and several Mo-Ti electrodes. It was found that the Mo-Ti electrodes offered no improvement in lifetime characteristics over the pure Mo electrodes, however, oxygen treatment of a degraded Mo electrode restored its specific power output to 90 percent of its original specific power and maintained this level for 60 hr, thus offering a potential for lifetime stability.

  15. Polarization conversion system with liquid-crystal geometric-phase-based cylindrical lens

    NASA Astrophysics Data System (ADS)

    Honma, Michinori; Nose, Toshiaki

    2016-01-01

    We demonstrate a polarization conversion system by utilizing the polarization-splitting function of a liquid-crystal (LC) geometric-phase-based cylindrical lens. The system was constructed by combining the LC lens with a partially rubbed cell. The operation principle includes the following two steps. (i) The incident light is first decomposed into right- and left-handed circularly polarized light (RCP and LCP, respectively) as an attribute of geometric-phase-based optical elements. (ii) Then, only the RCP light is transformed into LCP light by passing it through the partially rubbed cell; as a result, the incident unpolarized light is converted into LCP light. We experimentally reveal the feasibility of the system by evaluating the effects, on the polarization conversion capability, of the diffraction efficiency, focal length, and partially rubbed cell’s retardation. The polarization conversion efficiency was obtained to be 65% on average for 400-700 nm and a maximum of 79% at 610 nm.

  16. Foreign Language Tutoring in Oral Conversations Using Spoken Dialog Systems

    NASA Astrophysics Data System (ADS)

    Lee, Sungjin; Noh, Hyungjong; Lee, Jonghoon; Lee, Kyusong; Lee, Gary Geunbae

    Although there have been enormous investments into English education all around the world, not many differences have been made to change the English instruction style. Considering the shortcomings for the current teaching-learning methodology, we have been investigating advanced computer-assisted language learning (CALL) systems. This paper aims at summarizing a set of POSTECH approaches including theories, technologies, systems, and field studies and providing relevant pointers. On top of the state-of-the-art technologies of spoken dialog system, a variety of adaptations have been applied to overcome some problems caused by numerous errors and variations naturally produced by non-native speakers. Furthermore, a number of methods have been developed for generating educational feedback that help learners develop to be proficient. Integrating these efforts resulted in intelligent educational robots — Mero and Engkey — and virtual 3D language learning games, Pomy. To verify the effects of our approaches on students' communicative abilities, we have conducted a field study at an elementary school in Korea. The results showed that our CALL approaches can be enjoyable and fruitful activities for students. Although the results of this study bring us a step closer to understanding computer-based education, more studies are needed to consolidate the findings.

  17. Characterization of solid waste conversion and cogeneration systems

    SciTech Connect

    1980-09-01

    The primary objective of the TASE program is to determine the probable consequences to the environment and to public health and safety resulting from widespread implementation of major solar and renewable resource technologies. The specific principal Phase I objective is to determine the levels of residuals most likely to result throughout the complete energy cycle from the utilization of each of the solar and renewable resource technologies. Three basic technologies for recovering energy from M SW are considered in this study. These are: (1) direct combustion using a waterwall incinerator in which the heat from burning refuse is converted to steam by circulating water in steel tubes jacketing the interior of the incinerator; (2) manufacture of a relatively uniform shredded, pulverized or pelleted refuse-derived fuel (RDF) for supplemental firing in a utility boiler; and (3) pyrolysis or destructive distillation of MSW to extract a low-Btu fuel gas. While resource recovery and energy recovery systems can be installed independently, the processes described here include both energy and resource recovery systems as well as necessary pollution control equipment for gaseous emissions. To meet the Phase I objective, LBL staff have characterized the individual application associated with each general technology; calculated operational residuals generated by each application; determined the input capital requirements and, when possible, annual operating input requirements; and have identified the technical and institutional constraints for the widespread implementation of each application. A description is presented of the energy and material development cycle required for the implementation of each technology. The capital requirements are compiled and presented in a SEAS system format.

  18. MHD conversion of solar energy. [space electric power system

    NASA Technical Reports Server (NTRS)

    Lau, C. V.; Decher, R.

    1978-01-01

    Low temperature plasmas wherein an alkali metal vapor is a component are uniquely suited to simultaneously absorb solar radiation by coupling to the resonance lines and produce electrical power by the MHD interaction. This work is an examination of the possibility of developing space power systems which take advantage of concentrated solar power to produce electricity. It is shown that efficient cycles in which expansion work takes place at nearly constant top cycle temperature can be devised. The power density of the solar MHD generator is lower than that of conventional MHD generators because of the relatively high seed concentration required for radiation absorption and the lower flow velocity permitted to avoid total pressure losses due to heating.

  19. Pressure letdown method and device for coal conversion systems

    NASA Technical Reports Server (NTRS)

    Kendal, J. M.; Walsh, J. V. (Inventor)

    1983-01-01

    In combination with a reactor for a coal utilization system, a pressure letdown device accepts from a reactor, a polyphase fluid at an entrance pressure and an entrance velocity, and discharges the fluid from the device at a discharge pressure substantially lower than the entrance pressure and at a discharge temperature and a discharge velocity substantially equal to the entrance temperature and entrance velocity. The device is characterized by a series of pressure letdown stages including several symmetrical baffles, disposed in coaxially nested alignment. In each baffle several ports or apertures of uniform dimensions are defined. The number of ports or apertures for each baffle plate is unique with respect to the number of ports or apertures defined in each of the other baffles. The mass rate of flow for each port is a function of the area of the port, the pressure of the fluid as applied to the port, and a common pressure ratio established across the ports.

  20. Feedstock and Conversion Supply System Design and Analysis

    SciTech Connect

    J. Jacobson; R. Mohammad; K. Cafferty; K. Kenney; E. Searcy; J. Hansen

    2014-09-01

    The success of the earlier logistic pathway designs (Biochemical and Thermochemical) from a feedstock perspective was that it demonstrated that through proper equipment selection and best management practices, conventional supply systems (referred to in this report as “conventional designs,” or specifically the 2012 Conventional Design) can be successfully implemented to address dry matter loss, quality issues, and enable feedstock cost reductions that help to reduce feedstock risk of variable supply and quality and enable industry to commercialize biomass feedstock supply chains. The caveat of this success is that conventional designs depend on high density, low-cost biomass with no disruption from incremental weather. In this respect, the success of conventional designs is tied to specific, highly productive regions such as the southeastern U.S. which has traditionally supported numerous pulp and paper industries or the Midwest U.S for corn stover.

  1. Open cycle ocean thermal energy conversion system structure

    DOEpatents

    Wittig, J. Michael

    1980-01-01

    A generally mushroom-shaped, open cycle OTEC system and distilled water producer which has a skirt-conduit structure extending from the enlarged portion of the mushroom to the ocean. The enlarged part of the mushroom houses a toroidal casing flash evaporator which produces steam which expands through a vertical rotor turbine, partially situated in the center of the blossom portion and partially situated in the mushroom's stem portion. Upon expansion through the turbine, the motive steam enters a shell and tube condenser annularly disposed about the rotor axis and axially situated beneath the turbine in the stem portion. Relatively warm ocean water is circulated up through the radially outer skirt-conduit structure entering the evaporator through a radially outer portion thereof, flashing a portion thereof into motive steam, and draining the unflashed portion from the evaporator through a radially inner skirt-conduit structure. Relatively cold cooling water enters the annular condenser through the radially inner edge and travels radially outwardly into a channel situated along the radially outer edge of the condenser. The channel is also included in the radially inner skirt-conduit structure. The cooling water is segregated from the potable, motive steam condensate which can be used for human consumption or other processes requiring high purity water. The expansion energy of the motive steam is partially converted into rotational mechanical energy of the turbine rotor when the steam is expanded through the shaft attached blades. Such mechanical energy drives a generator also included in the enlarged mushroom portion for producing electrical energy. Such power generation equipment arrangement provides a compact power system from which additional benefits may be obtained by fabricating the enclosing equipment, housings and component casings from low density materials, such as prestressed concrete, to permit those casings and housings to also function as a floating

  2. Performance and economics of advanced energy conversion systems for coal and coal-derived fuels

    NASA Technical Reports Server (NTRS)

    Corman, J. C.; Fox, G. R.

    1978-01-01

    The desire to establish an efficient Energy Conversion System to utilize the fossil fuel of the future - coal - has produced many candidate systems. A comparative technical/economic evaluation was performed on the seven most attractive advanced energy conversion systems. The evaluation maintains a cycle-to-cycle consistency in both performance and economic projections. The technical information base can be employed to make program decisions regarding the most attractive concept. A reference steam power plant was analyzed to the same detail and, under the same ground rules, was used as a comparison base. The power plants were all designed to utilize coal or coal-derived fuels and were targeted to meet an environmental standard. The systems evaluated were two advanced steam systems, a potassium topping cycle, a closed cycle helium system, two open cycle gas turbine combined cycles, and an open cycle MHD system.

  3. The use of the TOPAZ II systems with different conversion and engine systems

    NASA Astrophysics Data System (ADS)

    Ponomarev-Stepnoi, Nikolai N., Dr.; Ogloblin, Boris; Kirillov, E. Y.; Thome, Frank V.

    1995-01-01

    Increase of output electric power and use of heat released in nuclear fuel for thermal jet propulsion is promising for the future development of a bimodal reactor and use of the Topaz-2 Thermionic Space Nuclear Power System (TI-SNPS). In addition to the high-temperature thermionic conversion cycle, the application of low-temperature cycles, such as a machine-type cycle using the Stirling engine and a thermoelectric cycle, is being considered. The possibility of using the Topaz-2 system as a power source for thermal jet propulsion in bimodal operation is also being examined. For low-temperature cycles, the following data are obtained: output electric parameters, geometrical and weight characteristics as a function of thermal power released in the TFE fuel cores, and the relationship of generated total electric power to the total Topaz-2 system weight. The results obtained from this data make it possible to evaluate energy potentials when applying the high-temperature and low-temperature cycles Conference on alternative powere from space; Conference to the Topaz-2 system. The most likely values of specific impulse and propulsion force in relation to hydrogen flow rate in bimodal operation are shown.

  4. Measurements of Conversion Efficiency for a Flat Plate Thermophotovoltaic System Using a Photonic Cavity Test System

    SciTech Connect

    E.J. Brown; C.T. Ballinger; S.R. Burger; G.W. Charache; L.R. Danielson; D.M. DePoy; T.J. Donovan; M. LoCascio

    2000-05-30

    The performance of a 1 cm{sup 2} thermophotovoltaic (TPV) module was recently measured in a photonic cavity test system. A conversion efficiency of 11.7% was measured at a radiator temperature of 1076 C and a module temperature of 29.9 C. This experiment achieved the highest direct measurement of efficiency for an integrated TPV system. Efficiency was calculated from the ratio of the peak (load matched) electrical power output and the heat absorption rate. Measurements of these two parameters were made simultaneously to assure the validity of the measured efficiency value. This test was conducted in a photonic cavity which mimicked a typical flat-plate TPV system. The radiator was a large, flat graphite surface. The module was affixed to the top of a copper pedestal for heat absorption measurements. The heat absorption rate was proportional to the axial temperature gradient in the pedestal under steady-state conditions. The test was run in a vacuum to eliminate conductive and convective heat transfer mechanisms. The photonic cavity provides the optimal test environment for TPV efficiency measurements because it incorporates all important physical phenomena found in an integrated TPV system: high radiator emissivity and blackbody spectral shape, photon recycling, Lambertian distribution of incident radiation and complex geometric effects. Furthermore, the large aspect ratio between radiating surface area and radiator/module spacing produces a view factor approaching unity with minimal photon leakage.

  5. An analog-to-digital conversion system with a logarithmic characteristic

    NASA Technical Reports Server (NTRS)

    Bellomo, A.

    1972-01-01

    Detailed analysis of an analog-to-digital conversion system consisting of a linear converter and a logarithmic amplifier containing nonlinear elements. It is shown that the small-signal resolution of such a system is much greater than that of linear systems used under the same conditions. A design for a low-power analog-to-digital converter operating at medium speed with a large input signal variation field is outlined.

  6. Understanding Power Electronics and Electrical Machines in Multidisciplinary Wind Energy Conversion System Courses

    ERIC Educational Resources Information Center

    Duran, M. J.; Barrero, F.; Pozo-Ruz, A.; Guzman, F.; Fernandez, J.; Guzman, H.

    2013-01-01

    Wind energy conversion systems (WECS) nowadays offer an extremely wide range of topologies, including various different types of electrical generators and power converters. Wind energy is also an application of great interest to students and with a huge potential for engineering employment. Making WECS the main center of interest when teaching…

  7. A nonlinear screen as an element for sound absorption and frequency conversion systems

    NASA Astrophysics Data System (ADS)

    Rudenko, O. V.

    2016-01-01

    The paper discusses a model for a screen with dissipative and nonlinear elastic properties that can be used in acoustic sound absorption and frequency conversion systems. Calculation and estimation schemes are explained that are necessary for understanding the functional capabilities of the device. Examples of the nonlinear elements in the screen and promising applications are described.

  8. Measurement Conversions: English and Metric Systems. Fundamentals of Occupational Mathematics. Module 9.

    ERIC Educational Resources Information Center

    Engelbrecht, Nancy; And Others

    This module is the ninth in a series of 12 learning modules designed to teach occupational mathematics. Blocks of informative material and rules are followed by examples and practice problems. The solutions to the practice problems are found at the end of the module. Specific topics covered include measurement conversions, the English system of…

  9. Collaborative Role Construction in a Conversation with Dementia: An Application of Systemic Functional Linguistics

    ERIC Educational Resources Information Center

    Muller, Nicole; Wilson, Brent T.

    2008-01-01

    This study applies the tools provided by Systemic Functional Linguistics (SFL) to the description of patterns in a conversation between a person with dementia and a person without. It shows how, in the presence of, on the one hand, considerable communicative and cognitive deficits, and on the other, a collaborative interlocutor, a person with…

  10. CO2 CH4 and N20 fluxes during land conversion in early bioenergy systems

    NASA Astrophysics Data System (ADS)

    Zenone, T.

    2012-04-01

    CO2 CH4 and N20 fluxes during land conversion in early bioenergy systems Terenzio Zenone1-2, Jiquan Chen1-2, Ilya Gelfand3-4, G. Philip Robertson3-4 1 Department of Environmental Sciences, University of Toledo, Toledo, OH USA 2 Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI USA 3 W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI USA 4Department of Crop and Soil Sciences, Michigan State University, East Lansing, MI USA Environmental sustainability of bioenergy crop cultivation represents an important challenge and is a topic of intensive scientific and political debate worldwide due to increasing societal needs for renewable energy. Despite the increasing knowledge related to potential bioenergy systems, the effect of land use change (LUC) on GHG fluxes during the conversion remains poorly understood but is likely to be substantial. In order to tackle this issue the Great lake Bioenergy Research Center (GLBRC) of the US Department of Energy (DOE) has established a field experiment and deployed a cluster of eddy-covariance towers to quantify the magnitude and changes of ecosystem carbon assimilation, loss, and balance during the conversion and establishment years in a permanent prairie and four types of candidate biofuel systems [Conservation Reserve Program (CRP) grassland, switchgrass, mixed-species restored prairie and corn]. Six sites were converted to soybean in 2009 before establishing the bioenergy systems in 2010 while one site was kept grassland as reference. Soil N2O and CH4 fluxes were measured biweekly with static chambers in four replicate locations in each fields, within the footprint of the eddy covariance tower using static chamber GHG flux protocols of the KBS LTER site. Our field observations, made between January 2009 through December 2010, showed that conversion of CRP to soybean induced net C emissions during the conversion year that ranging from 288 g C m-2, to 173 g C m-2 . while

  11. PEP-III magnet power conversion systems: Power supplies for large magnet strings

    SciTech Connect

    Jackson, T.; Saab, A.; Shimer, D.

    1995-05-01

    This paper presents the cooperative design efforts of LBL, SLAC, and LLNL on the magnet power conversion systems for PEP-II. The systems include 900 channels of correction magnet bipolar supplies and 400 unipolar supplies in the range of 5 to 500 kW. We show the decision process and technical considerations influencing the choice of power supply technologies employed. We also show the development of specifications that take maximum advantage of both the resources available and existing facilities while at the same time satisfying tight constraints for cost control, scheduling and coordination of different working groups. Switch-mode power conversion techniques will be used extensively in these systems, from the corrector supplies to the largest units if the dynamic performance specifications demand it. General system descriptions for each of the power supply ranges and for a new common control system interface and regulator are included.

  12. Status of the advanced Stirling conversion system project for 25 kW dish Stirling applications

    NASA Technical Reports Server (NTRS)

    Shaltens, Richard K.; Schreiber, Jeffrey G.

    1991-01-01

    Technology development for Stirling convertors directed toward a dynamic power source for space applications is discussed. Space power requirements include high reliability with very long life, low vibration, and high system efficiency. The free-piston Stirling engine has the potential for future high power space conversion systems, either nuclear or solar powered. Although these applications appear to be quite different, their requirements complement each other. The advanced Stirling conversion system (ASCS) project at NASA Lewis Research Center is described. Each system design features a solar receiver/liquid metal heat transport system and a free-piston Stirling convertor with a means to provide nominally 25 kW of electric power to utility grid while meeting the US Department of Energy (DOE) performance and long term cost goals. The design is compared with other ASCS designs.

  13. Assessment of risk-based capacity benefit factors associated with wind energy conversion systems

    SciTech Connect

    Billinton, R.; Chen, H.

    1998-08-01

    A Wind Energy Conversion System (WECS) has a different impact on the load carry capability of a generating system than does a conventional energy conversion system. This is mainly due to the variation in wind velocity. Two risk-based capacity indices designated as Load Carrying Capacity Benefit Ratio (LCCBR) and Equivalent Capacity Rate (ECR) are introduced in this paper. These two indices can be used to indicate capacity benefit and credit of a WECS, and thus provide valuable information for energy policy makers in decision problems involving the selection and classification of wind sites. A midpoint sectionalized technique has been developed to calculate the Incremental Peak Load Carrying Capability (IPLCC) and to assess the LCCBR and ECR. The technique is effective and usually takes only a few iterations to obtain the indices. Sequential Monte Carlo simulation is utilized to estimate the adequacy of a generating system including WECS. A small reliability test system containing WECS is utilized to illustrate the proposed technique.

  14. Structuring Health in Colorectal Cancer Screening Conversations: An Analysis of Intersecting Activity Systems

    PubMed Central

    Canary, Heather; Bullis, Connie; Cummings, Jennifer; Kinney, Anita Y.

    2016-01-01

    This study used structurating activity theory to analyze 21 conversations between genetic counselors and individuals at increased risk for familial colorectal cancer (CRC). The qualitative analysis revealed ways elements of family, primary healthcare, cancer prevention and treatment, and other systems emerged in intervention conversations as shaping CRC screening attitudes and behaviors. Results indicate that family stories, norms, and roles are resources for enacting health practices in families and that the authority of healthcare providers is a resource for making screening decisions. Conclusions include practical implications for using findings in clinical applications as well as future research directions to build on this exploratory study. PMID:27182185

  15. Brayton Power Conversion System Study to Advance Technology Readiness for Nuclear Electric Propulsion

    NASA Technical Reports Server (NTRS)

    Allen, Bog; Delventhal, Rex; Frye, Patrick

    2004-01-01

    Recently, there has been significant interest within the aerospace community to develop space based nuclear power conversion technologies especially for exploring the outer planets of our solar system where the solar energy density is very low. To investigate these technologies NASA awarded several contracts under Project Prometheus, the Nuclear Systems Program. The studies described in this paper were performed under one of those contracts, which was to investigate the use of a nuclear power conversion system based on the closed Brayton cycle (CBC).The investigation performed included BPCS (Brayton Power Conversion System) trade studies to minimize system weight and radiator area and advance the state of the art of BPCS technology. The primary requirements for studies were a power level of 100 kWe (to the PPU), a low overall power system mass and a lifetime of 15 years (10 years full power). For the radiation environment, the system was to be capable of operation in the generic space environment and withstand the extreme environments surrounding Jupiter. The studies defined a BPCS design traceable to NEP (Nuclear Electric Propulsion) requirements and suitable for future missions with a sound technology plan for technology readiness level (TRL) advancement identified. The studies assumed a turbine inlet temperature approx. 100 C above the current the state of the art capabilities with materials issues and related development tasks identified. Analyses and evaluations of six different HRS (heat rejection system) designs and three primary power management and distribution (PMAD) configurations will be discussed in the paper.

  16. Conversion of elemental mercury with a novel membrane delivery catalytic oxidation system (MDCOs).

    PubMed

    Guo, Yongfu; Yan, Naiqiang; Yang, Shijian; Qu, Zan; Wu, Zhongbiao; Liu, Yue; Liu, Ping; Jia, Jinping

    2011-01-15

    In order to overcome the shortcomings of the traditional catalytic oxidation (TCO) mode for the conversion of the trace level of elemental mercury (Hg(0)) in flue gas, we put forward a novel and unique assembly that integrated membrane delivery with catalytic oxidation systems (MDCOs), which combined the controlled delivery of oxidants with the catalytic oxidation of Hg(0). The results show that the demanded HCl for Hg(0) conversion in the MDCOs was less than 5% of that in the TCO mode, and over 90% of Hg(0) removal efficiency can be obtained in the MDCOs with less than 0.5 mg m(-3) of HCl escaped. Meanwhile, the inhibition of SO(2) to Hg(0) catalytic conversion in the MDCOs was also less significant than in the TCO. The MDCOs have high retainability for HCl, which is quite favorable to Hg(0) conversion and HCl utilization. The reaction mechanism on mercury conversion in the MDCOs is discussed. The MDCOs appear to be a promising method for emission control of elemental mercury. PMID:21158439

  17. Study of alternative system conversions for the Solar One pilot plant

    NASA Astrophysics Data System (ADS)

    1985-03-01

    The study of options for the conversion of Solar One to an advanced molten salt or liquid sodium central receiver system is described. Six options were considered for the system conversion of Solar One. Five of the options are solar stand-alone plants that add combinations of the following equipment, molten salt or liquid sodium receiver, thermal storage, and steam generator, and upgrading of the existing heliostats or the addition of advanced heliostats. The sixth option combines a molten salt receiver, molten salt storage, and steam generator with a fossil fueled energy source to provide data for hybrid (solar/fossil) operation. The results of this study indicate that several conversion options exist which will reduce the technical and economic risks associated with advanced central receiver systems. The costs of the options are not significantly different, and a comparison of the options did not identify a clear technical choice as to the best alternative. Electrical utility preferences should play a strong role in selecting the conversion option.

  18. A Comparison of Coolant Options for Brayton Power Conversion Heat Rejection Systems

    SciTech Connect

    Siamidis, John; Mason, Lee

    2006-01-20

    This paper describes potential heat rejection design concepts for Brayton power conversion systems. Brayton conversion systems are currently under study by NASA for Nuclear Electric Propulsion (NEP) and surface power applications. The Brayton Heat Rejection Subsystem (HRS) must dissipate waste heat generated by the power conversion system due to inefficiencies in the thermal-to-electric conversion process. Sodium potassium (NaK) and H2O are two coolant working fluids that have been investigated in the design of a pumped loop and heat pipe space HRS. In general NaK systems are high temperature (300 to 1000 K) low pressure systems, and H2O systems are low temperature (300 to 600 K) high pressure systems. NaK is an alkali metal with health and safety hazards that require special handling procedures. On the other hand, H2O is a common fluid, with no health hazards and no special handling procedures. This paper compares NaK and H2O for the HRS pumped loop coolant working fluid. A detailed excel analytical model, HRS{sub O}pt, was developed to evaluate the various HRS design parameters. It is capable of analyzing NaK or H2O coolant, parallel or series flow configurations, and numerous combinations of other key parameters (heat pipe spacing, diameter and radial flux, radiator facesheet thickness, fluid duct system pressure drop, system rejected power, etc.) of the HRS. This paper compares NaK against water for the HRS coolant working fluid with respect to the relative mass, performance, design and implementation issues between the two fluids.

  19. A Comparison of Coolant Options for Brayton Power Conversion Heat Rejection Systems

    NASA Technical Reports Server (NTRS)

    Siamidis, John; Mason, Lee S.

    2006-01-01

    This paper describes potential heat rejection design concepts for Brayton power conversion systems. Brayton conversion systems are currently under study by NASA for Nuclear Electric Propulsion (NEP) and surface power applications. The Brayton Heat Rejection Subsystem (HRS) must dissipate waste heat generated by the power conversion system due to inefficiencies in the thermal-to-electric conversion process. Sodium potassium (NaK) and H2O are two coolant working fluids that have been investigated in the design of a pumped loop and heat pipe space HRS. In general NaK systems are high temperature (300 to 1000 K) low pressure systems, and H2O systems are low temperature (300 to 600 K) high pressure systems. NaK is an alkali metal with health and safety hazards that require special handling procedures. On the other hand, H2O is a common fluid, with no health hazards and no special handling procedures. This paper compares NaK and H2O for the HRS pumped loop coolant working fluid. A detailed Microsoft Excel (Microsoft Corporation, Redmond, WA) analytical model, HRS_Opt, was developed to evaluate the various HRS design parameters. It is capable of analyzing NaK or H2O coolant, parallel or series flow configurations, and numerous combinations of other key parameters (heat pipe spacing, diameter and radial flux, radiator facesheet thickness, fluid duct system pressure drop, system rejected power, etc.) of the HRS. This paper compares NaK against water for the HRS coolant working fluid with respect to the relative mass, performance, design and implementation issues between the two fluids.

  20. A Comparison of Coolant Options for Brayton Power Conversion Heat Rejection Systems

    NASA Technical Reports Server (NTRS)

    Mason, Lee S.; Siamidis, John

    2006-01-01

    This paper describes potential heat rejection design concepts for Brayton power conversion systems. Brayton conversion systems are currently under study by NASA for Nuclear Electric Propulsion (NEP) and surface power applications. The Brayton Heat Rejection Subsystem (HRS) must dissipate waste heat generated by the power conversion system due to inefficiencies in the thermal-to-electric conversion process. Sodium potassium (NaK) and H2O are two coolant working fluids that have been investigated in the design of a pumped loop and heat pipe space HRS. In general NaK systems are high temperature (300 to 1000 K) low pressure systems, and H2O systems are low temperature (300 to 600 K) high pressure systems. NaK is an alkali metal with health and safety hazards that require special handling procedures. On the other hand, H2O is a common fluid, with no health hazards and no special handling procedures. This paper compares NaK and H20 for the HRS pumped loop coolant working fluid. A detailed Microsoft Excel (Microsoft Corporation, Redmond, WA) analytical model, HRS_Opt, was developed to evaluate the various HRS design parameters. It is capable of analyzing NaK or H2O coolant, parallel or series flow configurations, and numerous combinations of other key parameters (heat pipe spacing, diameter and radial flux, radiator facesheet thickness, fluid duct system pressure drop, system rejected power, etc.) of the HRS. This paper compares NaK against water for the HRS coolant working fluid with respect to the relative mass, performance, design and implementation issues between the two fluids.

  1. Brayton Power Conversion System Study to Advance Technology Readiness for Nuclear Electric Propulsion - Phase I

    SciTech Connect

    Frye, Patrick E.; Allen, Robert; Delventhal, Rex

    2005-02-06

    To investigate and mature space based nuclear power conversion technologies NASA awarded several contracts under Prometheus, the Nuclear Systems Program. The studies described in this paper were performed under one of those contracts, which was to investigate the use of a nuclear power conversion system based on the closed Brayton cycle (CBC). The conceptual design effort performed included BPCS (Brayton power conversion system) trade studies to minimize system weight and radiator area and advance the state of the art of BPCS technology. The primary requirements for studies were a power level of 100 kWe (to the PPU), a low overall power system mass (with a target of less than 3000 kg), and a lifetime of 15 years (10 years full power). For the radiation environment, the system was to operate in the generic space environment and withstand the extreme environments within the Jovian system. The studies defined a BPCS design traceable to NBP (Nuclear Electric Propulsion) requirements and suitable for future potential missions with a sound technology plan for TRL (Technical Readiness Level) advancement identified. The studies assumed a turbine inlet temperature {approx} 100C above the current the state of the art capabilities with materials issues identified and an approach for resolution developed. Analyses and evaluations of six HRS (heat rejection subsystem) concepts and PMAD (Power Management and Distribution) architecture trades will be discussed in the paper.

  2. Brayton Power Conversion System Study to Advance Technology Readiness for Nuclear Electric Propulsion — Phase I

    NASA Astrophysics Data System (ADS)

    Frye, Patrick E.; Allen, Robert; Delventhal, Rex

    2005-02-01

    To investigate and mature space based nuclear power conversion technologies NASA awarded several contracts under Prometheus, the Nuclear Systems Program. The studies described in this paper were performed under one of those contracts, which was to investigate the use of a nuclear power conversion system based on the closed Brayton cycle (CBC). The conceptual design effort performed included BPCS (Brayton power conversion system) trade studies to minimize system weight and radiator area and advance the state of the art of BPCS technology. The primary requirements for studies were a power level of 100 kWe (to the PPU), a low overall power system mass (with a target of less than 3000 kg), and a lifetime of 15 years (10 years full power). For the radiation environment, the system was to operate in the generic space environment and withstand the extreme environments within the Jovian system. The studies defined a BPCS design traceable to NBP (Nuclear Electric Propulsion) requirements and suitable for future potential missions with a sound technology plan for TRL (Technical Readiness Level) advancement identified. The studies assumed a turbine inlet temperature ˜ 100C above the current the state of the art capabilities with materials issues identified and an approach for resolution developed. Analyses and evaluations of six HRS (heat rejection subsystem) concepts and PMAD (Power Management and Distribution) architecture trades will be discussed in the paper.

  3. Megawatt Class Nuclear Space Power Systems (MCNSPS) conceptual design and evaluation report. Volume 3, technologies 2: Power conversion

    NASA Technical Reports Server (NTRS)

    Wetch, J. R.

    1988-01-01

    The major power conversion concepts considered for the Megawatt Class Nuclear Space Power System (MCNSPS) are discussed. These concepts include: (1) Rankine alkali-metal-vapor turbine alternators; (2) in-core thermionic conversion; (3) Brayton gas turbine alternators; and (4) free piston Stirling engine linear alternators. Considerations important to the coupling of these four conversion alternatives to an appropriate nuclear reactor heat source are examined along with the comparative performance characteristics of the combined systems meeting MCNSPS requirements.

  4. Safety assessment of the conversion of toll plazas to all-electronic toll collection system.

    PubMed

    Abuzwidah, Muamer; Abdel-Aty, Mohamed

    2015-07-01

    Traditional mainline toll plaza (TMTP) is considered the most high-risk location on the toll roads. Conversion from TMTP or hybrid mainline toll plaza (HMTP) to an all-electronic toll collection (AETC) system has demonstrated measured improvement in traffic operations and environmental issues. However, there is a lack of research that quantifies the safety impacts of these new tolling systems. This study evaluated the safety effectiveness of the conversion from TMTP or HMTP to AETC system. An extensive data collection was conducted that included hundred mainline toll plazas located on more than 750 miles of toll roads in Florida. Various observational before-after studies including the empirical Bayes method were applied. The results indicated that the conversion from the TMTP to an AETC system resulted in an average crash reduction of 76, 75, and 68% for total, fatal-and-injury and property damage only (PDO) crashes, respectively; for rear end and lane change related (LCR) crashes the average reductions were 80 and 74%, respectively. The conversion from HMTP to AETC system enhanced traffic safety by reducing crashes by 24, 28 and 20% of total, fatal-and-injury, and PDO crashes respectively; also, for rear end and LCR crashes, the average reductions were 15 and 22%, respectively. Overall, this paper provided an up-to-date safety impact of using different toll collection systems. The results proved that the AETC system significantly improved traffic safety for all crash categories; and changed toll plazas from the highest risk on Expressways to be similar to regular segments. PMID:25909391

  5. Cogeneration Technology Alternatives Study (CTAS). Volume 3: Energy conversion system characteristics

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Six current and thirty-six advanced energy conversion systems were defined and combined with appropriate balance of plant equipment. Twenty-six industrial processes were selected from among the high energy consuming industries to serve as a frame work for the study. Each conversion system was analyzed as a cogenerator with each industrial plant. Fuel consumption, costs, and environmental intrusion were evaluated and compared to corresponding traditional values. The advanced energy conversion technologies indicated reduced fuel consumption, costs, and emissions. Fuel energy savings of 10 to 25 percent were predicted compared to traditional on site furnaces and utility electricity. With the variety of industrial requirements, each advanced technology had attractive applications. Fuel cells indicated the greatest fuel energy savings and emission reductions. Gas turbines and combined cycles indicated high overall annual savings. Steam turbines and gas turbines produced high estimated returns. In some applications, diesels were most efficient. The advanced technologies used coal derived fuels, or coal with advanced fluid bed combustion or on site gasifications. Data and information for both current and advanced energy conversion technology are presented. Schematic and physical descriptions, performance data, equipment cost estimates, and predicted emissions are included. Technical developments which are needed to achieve commercialization in the 1985-2000 period are identified.

  6. Conversion of soil color parameters from the Munsell system to the CIE-L*a*b* system

    NASA Astrophysics Data System (ADS)

    Kirillova, N. P.; Vodyanitskii, Yu. N.; Sileva, T. M.

    2015-05-01

    The Munsell optical system is unsuitable for assessing the role of pigments in the color of soils by statistical methods. Empirical approaches to the transformation of the Munsell system have been proposed only for a limited range of color tones; they do not ensure the exact calculation of correlative relationships between pigments and soil colors. A new procedure is developed for the conversion of soil colors from the Munsell system to the CIE-L*a*b* system, which does not require data interpolation. A base of converted data covering the entire range of the Munsell color system used by soil scientists is created and maintained in the tabular form using Munsell Conversion (version 4.01) software. A more significant contribution of Fe pigments to the characterization of soil color in the CIE-L*a*b* system than in the Munsell system has been substantiated with soddy-podzolic soils as an example.

  7. Hierarchy of conversational rule violations involving utterance-based augmentative and alternative communication systems.

    PubMed

    Hoag, Linda A; Bedrosian, Jan L; McCoy, Kathleen F; Johnson, Dallas E

    2008-01-01

    This study examined the effects of using messages with conversational rule violations on attitudes toward people who used utterance-based augmentative and alternative communication (AAC) systems in transactional interactions. Specifically, the ratings were compared across messages with relevance, informativeness, and brevity violations, when latency remained constant (i.e., short). The 96 participating sales clerks viewed scripted, videotaped bookstore conversations and completed an attitude questionnaire. Results indicated that the prestored message with repeated words/phrases was rated the highest, followed by the message with excessive information; next was the message with inadequate information, followed by the message with partly relevant information. The findings may be useful to those using utterance-based systems when making message choices during interactions with service providers. Technological implications point to the development of schema/script-based systems and intelligent editing. PMID:18465368

  8. A deep space power system option based on synergistic power conversion technologies

    NASA Astrophysics Data System (ADS)

    Schreiber, Jeffrey G.

    2000-01-01

    Deep space science missions have typically used radioisotope thermoelectric generator (RTG) power systems. The RTG power system has proven itself to be a rugged and highly reliable power system over many missions, however, the thermal-to-electric conversion technology used was approximately 5% efficient. While the relatively low efficiency has some benefits in terms of system integration, there are compelling reasons why a more efficient conversion system should be pursued. The cost savings alone that are available as a result of the reduced isotope inventory are significant. The Advanced Radioisotope Power System (ARPS) project was established to fulfill this goal. Although it was not part of the ARPS project, Stirling conversion technology was being demonstrated with a low level of funding by both NASA and DOE. A power system with Stirling convertors, although intended for use with an isotope heat source, can be combined with other advanced technologies to provide a novel power system for deep space missions. An inflatable primary concentrator would be used in combination with a refractive secondary concentrator (RSC) as the heat source to power the system. The inflatable technology as a structure has made great progress for a variety of potential applications such as communications reflectors, radiators and solar arrays. The RSC has been pursued for use in solar thermal propulsion applications, and it's unique properties allow some advantageous system trades to be made. The power system proposed would completely eliminate the isotope heat source and could potentially provide power for science missions to planets as distant as Uranus. This paper will present the background and developmental status of the technologies and will then describe the power system being proposed. .

  9. A Deep Space Power System Option Based on Synergistic Power Conversion Technologies

    NASA Technical Reports Server (NTRS)

    Schreiber, Jeffrey G.

    2000-01-01

    Deep space science missions have typically used radioisotope thermoelectric generator (RTG) power systems. The RTG power system has proven itself to be a rugged and highly reliable power system over many missions, however the thermal-to-electric conversion technology used was approximately 5% efficient. While the relatively low efficiency has some benefits in terms of system integration, there are compelling reasons why a more efficient conversion system should be pursued. The cost savings alone that are available as a result of the reduced isotope inventory are significant. The Advanced Radioisotope Power System (ARPS) project was established to fulfill this goal. Although it was not part of the ARPS project, Stirling conversion technology is being demonstrated with a low level of funding by both NASA and DOE. A power system with Stirling convertors. although intended for use with an isotope heat source. can be combined with other advanced technologies to provide a novel power system for deep space missions. An inflatable primary concentrator would be used in combination with a refractive secondary concentrator (RSC) as the heat source to power the system. The inflatable technology as a structure has made great progress for a variety of potential applications such as communications reflectors, radiators and solar arrays. The RSC has been pursued for use in solar thermal propulsion applications, and it's unique properties allow some advantageous system trades to be made. The power system proposed would completely eliminate the isotope heat source and could potentially provide power for science missions to planets as distant as Uranus. This paper will present the background and developmental status of the technologies and will then describe the power system being proposed.

  10. Energy Conversion Alternatives Study (ECAS), General Electric Phase 1. Volume 2: Advanced energy conversion systems. Part 1: Open-cycle gas turbines

    NASA Technical Reports Server (NTRS)

    Brown, D. H.; Corman, J. C.

    1976-01-01

    Ten energy conversion systems are defined and analyzed in terms of efficiency. These include: open-cycle gas turbine recuperative; open-cycle gas turbine; closed-cycle gas turbine; supercritical CO2 cycle; advanced steam cycle; liquid metal topping cycle; open-cycle MHD; closed-cycle inert gas MHD; closed-cycle liquid metal MHD; and fuel cells. Results are presented.

  11. Biostirling({trademark}): A small biomass power conversion system using an advanced stirling engine

    SciTech Connect

    Johansson, L.; Ziph, B.; McKeough, W.; Houtman, W.

    1996-12-31

    Over the past decade the need for small power conversion systems to serve rural and/or remote needs has increased dramatically. The requirements for systems <100 kW are very similar, whether the need is defined as {open_quotes}rural electrification{close_quotes} in developed countries, or as {open_quotes}village power{close_quotes} in developing countries. The availability of biomass fuel resources to serve such systems is not in doubt, be they agricultural, forestry, animal or urban wastes. The main inhibiting factor has been the absence of a biomass power conversion system characterized by: reliability, cost effectiveness, low pollution, and ease of maintenance. Stirling Thermal Motors of Ann Arbor, Michigan, is recognized as the leader worldwide in the development and application of Stirling engine technology. It is currently demonstrating a {open_quotes}BioStirling({trademark}){close_quotes} Power Conversion System which combines its unique STM4-120 engine rated at 25 kW with a proven commercial gasifier. The BioStirling({trademark}) proof-of-concept demonstration is funded by DOE`s National Renewable Energy Laboratory and is to be completed in late 1996, with field demonstrations in 1997 and commercial availability 1998.

  12. Research and Technology Activities Supporting Closed-Brayton-Cycle Power Conversion System Development

    NASA Technical Reports Server (NTRS)

    Barrett, Michael J.

    2004-01-01

    The elements of Brayton technology development emphasize power conversion system risk mitigation. Risk mitigation is achieved by demonstrating system integration feasibility, subsystem/component life capability (particularly in the context of material creep) and overall spacecraft mass reduction. Closed-Brayton-cycle (CBC) power conversion technology is viewed as relatively mature. At the 2-kWe power level, a CBC conversion system Technology Readiness Level (TRL) of six (6) was achieved during the Solar Dynamic Ground Test Demonstration (SD-GTD) in 1998. A TRL 5 was demonstrated for 10 kWe-class CBC components during the development of the Brayton Rotating Unit (BRU) from 1968 to 1976. Components currently in terrestrial (open cycle) Brayton machines represent TRL 4 for similar uses in 100 kWe-class CBC space systems. Because of the baseline component and subsystem technology maturity, much of the Brayton technology task is focused on issues related to systems integration. A brief description of ongoing technology activities is given.

  13. Document Conversion Methodology.

    ERIC Educational Resources Information Center

    Bovee, Donna

    1990-01-01

    Discusses digital imaging technology and examines document database conversion considerations. Two types of document imaging systems are described: (1) a work in process system, and (2) a storage and retrieval system. Conversion methodology is outlined, and a document conversion scenario is presented as a practical guide to conversion. (LRW)

  14. Mini-BRU/BIPS 1300 watt (sub)e dynamic power conversion system development: Executive summary

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The status of the Brayton Isotope Power System (BIPS) is summarized. A 1200 watt sub e ground development unit was built and tested in a 0.000010 torr vacuum environment. Peformance mapping and 1000 hours of proof of concept system testing were completed. Specific components, primarily turbocompressor/alternator and recuperator performed according to predictions, thus achieving the design goal of 25 percent net power conversion efficiency. The system was fabricated from superalloy (Hastelloy-X and Waspaloy) thus placing it entirely within current state-of-the-art technology. The system could be flyable in the early 1980's pending flight qualification.

  15. Nutrient conversions by photosynthetic bacteria in a concentrated animal feeding operation lagoon system.

    PubMed

    Sund, J L; Evenson, C J; Strevett, K A; Nairn, R W; Athay, D; Trawinski, E

    2001-01-01

    A diurnal examination was conducted to determine the effect of photosynthetic bacteria on nutrient conversions in a two-stage concentrated animal feeding operation (CAFO) lagoon system in west-central Oklahoma. Changes in nutrients, microbial populations, and physical parameters were examined at three depths (0, 1.5, and 3.0 m) every 3 h over a 36-h period. The south lagoon (SL) was anaerobic (dissolved oxygen [DO] = 0.09 +/- 0.12 mg/L) while the north lagoon (NL) was facultative (DO ranged from 4.0-0.1 mg/L over 36-h period). Negative sulfide-sulfate (-0.85) and bacteriochlorophyll a (bchl a)-sulfate (-0.83) correlations, as well as positive bchl a-sulfide (0.87) and light intensity (I)-bchl a (0.89) correlations revealed that the SL was dominated by sulfur conversions driven by the photosynthetic purple sulfur bacteria (PSB). The correlation data was supported by diurnal trends for sulfate, sulfide, and bchl a. Both nitrogen and sulfur conversions played a role in the NL; however, nitrogen conversions appeared to dominate this system because of the activity of cyanobacteria. This was shown by positive chlorophyll a (chl a)-I (0.91) and chl a-nitrate (0.98) correlations and the negative correlation between ammonium and nitrite (-0.88). Correlation data was further supported by diurnal trends observed for chl a, DO, and ammonium. For both lagoons, the dominant photosynthetic microbial species determined which nutrient conversion processes were most important. PMID:11285928

  16. A space-based combined thermophotovoltaic electric generator and gas laser solar energy conversion system

    NASA Technical Reports Server (NTRS)

    Yesil, Oktay

    1989-01-01

    This paper describes a spaceborne energy conversion system consisting of a thermophotovoltaic electric generator and a gas laser. As a power source for the converson, the system utilizes an intermediate blackbody cavity heated to a temperature of 2000-2400 K by concentrated solar radiation. A double-layer solar cell of GaAs and Si forms a cylindrical surface concentric to this blackbody cavity, receiving the blackbody radiation and converting it into electricity with cell conversion efficiency of 50 percent or more. If the blackbody cavity encloses a laser medium, the blackbody radiation can also be used to simultaneously pump a lasing gas. The feasibility of blackbody optical pumping at 4.3 microns in a CO2-He gas mixture was experimentally demonstrated.

  17. Classical-quantum correspondence in bosonic two-mode conversion systems: Polynomial algebras and Kummer shapes

    NASA Astrophysics Data System (ADS)

    Graefe, Eva-Maria; Korsch, Hans Jürgen; Rush, Alexander

    2016-04-01

    Bosonic quantum conversion systems can be modeled by many-particle single-mode Hamiltonians describing a conversion of m molecules of type A into n molecules of type B and vice versa. These Hamiltonians are analyzed in terms of generators of a polynomially deformed su(2) algebra. In the mean-field limit of large particle numbers, these systems become classical and their Hamiltonian dynamics can again be described by polynomial deformations of a Lie algebra, where quantum commutators are replaced by Poisson brackets. The Casimir operator restricts the motion to Kummer shapes, deformed Bloch spheres with cusp singularities depending on m and n . It is demonstrated that the many-particle eigenvalues can be recovered from the mean-field dynamics using a WKB-type quantization condition. The many-particle state densities can be semiclassically approximated by the time periods of periodic orbits, which show characteristic steps and singularities related to the fixed points, whose bifurcation properties are analyzed.

  18. Improved coal conversion in CO/water systems. Quarterly report No. 2, December 4, 1984-March 3, 1985. [Polynaphthoquinone

    SciTech Connect

    Ross, D.S.; Hum, G.; Miin, T.C.

    1985-04-01

    This research program is a study of conversion mechanisms in CO/H/sub 2/O systems. We have previously reported the conversion of an Illinois No. 6 coal to toluene-soluble (TS) product at 400/sup 0/C for 20 minutes. The conversion was found to follow the water-gas-shift reaction (WGSR), CO + H/sub 2/ ..-->.. CO/sub 2/ + H/sub 2/. More specifically, the levels of conversion correlated with the degree of CO disappearance. The extent of CO being converted in the WGSR is controlled by the amount of KOH present. Ultimately, the level of conversion was controlled by varying the initial pH of the H/sub 2/O solution. The intermediate is believed to be formate, formed by the reaction of CO and KOH. Ross has postulated the mechanism of coal conversion in CO/H/sub 2/O systems in a recent review on aqueous conversion. It is suggested that the thermolysis of weak bibenzyl type bonds in coal conversion is not a significant process, but rather that reactions involving phenolic constituents in the coal are more important. We have synthesized a model polymer, polynaphthoquinone (PNQ), and have reduced it to its polyphenolic structure for studying the importance of phenolic functions and its correlation to coal conversion. The research is being performed in two tasks. In the first, we are investigating formate-promoted conversions of Illinois No. 6 coal. In the second, the reactions of the model polymer PNQ are being studied in the CO/H/sub 2/O system. Our objectives are to improve conversion effectiveness with formate and to determine the correlation of phenolic functions present in coal structures with conversion. This quarter, we have focused on the synthesis and reduction of PNQ. We are at present designing an appropriate microreactor system for the formate study. 7 refs., 1 fig., 1 tab.

  19. Novel Control for Voltage Boosted Matrix Converter based Wind Energy Conversion System with Practicality

    NASA Astrophysics Data System (ADS)

    Kumar, Vinod; Joshi, Raghuveer Raj; Yadav, Dinesh Kumar; Garg, Rahul Kumar

    2016-06-01

    This paper presents the implementation and investigation of novel voltage boosted matrix converter (MC) based permanent magnet wind energy conversion system (WECS). In this paper, on-line tuned adaptive fuzzy control algorithm cooperated with reversed MC is proposed to yield maximum energy. The control system is implemented on a dSPACE DS1104 real time board. Feasibility of the proposed system has been experimentally verified using a laboratory 1.2 kW prototype of WECS under steady-state and dynamic conditions.

  20. Thermodynamic limits for solar energy conversion by a quantum-thermal hybrid system

    NASA Technical Reports Server (NTRS)

    Byvik, C. E.; Buoncristiani, A. M.; Smith, B. T.

    1981-01-01

    The limits are presented fo air mass 1.5 conditions. A maximum conversion efficiency of 74 percent is thermodynamically achievable for the quantum device operating at 3500 K and the heat engine in contact with a reservoir at 0 K. The efficiency drops to 56 percent for a cold reservoir at approximately room temperature conditions. Hybrid system efficiencies exceed 50 percent over receiver temperatures ranging from 1400 K to 4000 K, suggesting little benefit is gained in operating the system above 1400 K. The results are applied to a system consisting of a photovoltaic solar cell in series with a heat engine.

  1. Low-temperature conversion of high-moisture biomass: Continuous reactor system results

    NASA Astrophysics Data System (ADS)

    Elliott, D. C.; Sealock, L. J., Jr.; Butner, R. S.; Baker, E. G.; Neuenschwander, G. G.

    1989-10-01

    Pacific Northwest Laboratory (PNL) is developing a low temperature, catalytic process for converting high moisture biomass feedstocks and other wet organic substances to useful gaseous fuels. This system, in which thermocatalytic conversion takes place in an aqueous environment, was designed to overcome the problems usually encountered with high water content feedstocks. The process uses a reduced nickel catalyst at temperatures as low as 350 C and pressures ranging from 2000 to 4000 psig; conditions favoring the formation of gas consisting mostly of methane. The results of numerous batch tests showed that the system could convert feedstocks not readily converted by conventional methods. Fifteen tests were conducted in a continuous reactor system to further evaluate the effectiveness of the process for high moisture biomass gasification and to obtain conversion rate data needed for process scaleup. During the tests, the complex gasification reactions were evaluated by several analytical methods. The results of these tests show that the heating value of the gas ranged from 400 to 500 Btu/scf, and if the carbon dioxide is removed, the product gas is pipeline quality. Conversion of the feedstocks was high. Engineering analysis indicates that, based on these results, a tubular reactor can be designed that should convert greater than 99 percent of the carbon fed as high moisture biomass to a gaseous product in a reaction time of less than 11 min.

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

    SciTech Connect

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

    1989-04-20

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

  3. System for thermal energy storage, space heating and cooling and power conversion

    DOEpatents

    Gruen, Dieter M.; Fields, Paul R.

    1981-04-21

    An integrated system for storing thermal energy, for space heating and cong and for power conversion is described which utilizes the reversible thermal decomposition characteristics of two hydrides having different decomposition pressures at the same temperature for energy storage and space conditioning and the expansion of high-pressure hydrogen for power conversion. The system consists of a plurality of reaction vessels, at least one containing each of the different hydrides, three loops of circulating heat transfer fluid which can be selectively coupled to the vessels for supplying the heat of decomposition from any appropriate source of thermal energy from the outside ambient environment or from the spaces to be cooled and for removing the heat of reaction to the outside ambient environment or to the spaces to be heated, and a hydrogen loop for directing the flow of hydrogen gas between the vessels. When used for power conversion, at least two vessels contain the same hydride and the hydrogen loop contains an expansion engine. The system is particularly suitable for the utilization of thermal energy supplied by solar collectors and concentrators, but may be used with any source of heat, including a source of low-grade heat.

  4. Low-temperature conversion of high-moisture biomass: Continuous reactor system results

    SciTech Connect

    Elliott, D.C.; Sealock, L.J. Jr.; Butner, R.S.; Baker, E.G.; Neuenschwander, G.G.

    1989-10-01

    Pacific Northwest Laboratory (PNL) is developing a low-temperature, catalytic process for converting high-moisture biomass feedstocks and other wet organic substances to useful gaseous fuels. This system, in which thermocatalytic conversion takes place in an aqueous environment, was designed to overcome the problems usually encountered with high-water-content feedstocks. The process uses a reduced nickel catalyst at temperatures as low as 350{degree}C and pressures ranging from 2000 to 4000 psig -- conditions favoring the formation of gas consisting mostly of methane. The results of numerous batch tests showed that the system could convert feedstocks not readily converted by conventional methods. Fifteen tests were conducted in a continuous reactor system to further evaluate the effectiveness of the process for high-moisture biomass gasification and to obtain conversion rate data needed for process scaleup. During the tests, the complex gasification reactions were evaluated by several analytical methods. The results of these tests show that the heating value of the gas ranged from 400 to 500 Btu/scf, and if the carbon dioxide is removed, the product gas is pipeline quality. Conversion of the feedstocks was high. Engineering analysis indicates that, based on these results, a tubular reactor can be designed that should convert greater than 99% of the carbon fed as high-moisture biomass to a gaseous product in a reaction time of less than 11 min.

  5. Entransy analyses of heat-work conversion systems with inner irreversible thermodynamic cycles

    NASA Astrophysics Data System (ADS)

    Cheng, Xue-Tao; Liang, Xin-Gang

    2015-12-01

    In this paper, we try to use the entransy theory to analyze the heat-work conversion systems with inner irreversible thermodynamic cycles. First, the inner irreversible thermodynamic cycles are analyzed. The influences of different inner irreversible factors on entransy loss are discussed. We find that the concept of entransy loss can be used to analyze the inner irreversible thermodynamic cycles. Then, we analyze the common heat-work conversion systems with inner irreversible thermodynamic cycles. As an example, the heat-work conversion system in which the working fluid of the thermodynamic cycles is heated and cooled by streams is analyzed. Our analyses show that larger entransy loss leads to larger output work when the total heat flow from the high temperature heat source and the corresponding equivalent temperature are fixed. Some numerical cases are presented, and the results verify the theoretical analyses. On the other hand, it is also found that larger entransy loss does not always lead to larger output work when the preconditions are not satisfied. Project supported by the National Natural Science Foundation of China (Grant Nos. 51376101 and 51356001).

  6. A grid-connected photovoltaic power conversion system with single-phase multilevel inverter

    SciTech Connect

    Beser, Ersoy; Arifoglu, Birol; Camur, Sabri; Beser, Esra Kandemir

    2010-12-15

    This paper presents a grid-connected photovoltaic (PV) power conversion system based on a single-phase multilevel inverter. The proposed system fundamentally consists of PV arrays and a single-phase multilevel inverter structure. First, configuration and structural parts of the PV assisted inverter system are introduced in detail. To produce reference output voltage waves, a simple switching strategy based on calculating switching angles is improved. By calculated switching angles, the reference signal is produced as a multilevel shaped output voltage wave. The control algorithm and operational principles of the proposed system are explained. Operating PV arrays in the same load condition is a considerable point; therefore a simulation study is performed to arrange the PV arrays. After determining the number and connection types of the PV arrays, the system is configured through the arrangement of the PV arrays. The validity of the proposed system is verified through simulations and experimental study. The results demonstrate that the system can achieve lower total harmonic distortion (THD) on the output voltage and load current, and it is capable of operating synchronous and transferring power values having different characteristic to the grid. Hence, it is suitable to use the proposed configuration as a PV power conversion system in various applications. (author)

  7. New conversion factors between human and automatic readouts of the CDMAM phantom for CR systems

    NASA Astrophysics Data System (ADS)

    Hummel, Johann; Homolka, Peter; Osanna-Elliot, Angelika; Kaar, Marcus; Semtrus, Friedrich; Figl, Michael

    2016-03-01

    Mammography screenings demand for profound image quality (IQ) assessment to guarantee their screening success. The European protocol for the quality control of the physical and technical aspects of mammography screening (EPQCM) suggests a contrast detail phantom such as the CDMAM phantom to evaluate IQ. For automatic evaluation a software is provided by the EUREF. As human and automatic readouts differ systematically conversion factors were published by the official reference organisation (EUREF). As we experienced a significant difference for these factors for Computed Radiography (CR) systems we developed an objectifying analysis software which presents the cells including the gold disks randomly in thickness and rotation. This allows to overcome the problem of an inevitable learning effect where observers know the position of the disks in advance. Applying this software, 45 computed radiography (CR) systems were evaluated and the conversion factors between human and automatic readout determined. The resulting conversion factors were compared with the ones resulting from the two methods published by EUREF. We found our conversion factors to be substantially lower than those suggested by EUREF, in particular 1.21 compared to 1.42 (EUREF EU method) and 1.62 (EUREF UK method) for 0.1 mm, and 1.40 compared to 1.73 (EUREF EU) and 1.83 (EUREF UK) for 0.25 mm disc diameter, respectively. This can result in a dose increase of up to 90% using either of these factors to adjust patient dose in order to fulfill image quality requirements. This suggests the need of an agreement on their proper application and limits the validity of the assessment methods. Therefore, we want to stress the need for clear criteria for CR systems based on appropriate studies.

  8. Experimental self-etching HEMA-free adhesive systems: cytotoxicity and degree of conversion.

    PubMed

    Barbosa, Marília Oliveira; de Carvalho, Rodrigo Varella; Demarco, Flávio Fernando; Ogliari, Fabrício Aulo; Zanchi, Cesar Henrique; Piva, Evandro; da Silva, Adriana Fernandes

    2015-01-01

    The aim of this study was to evaluate the effect of replacing 2-hydroxyethyl methacrylate (HEMA) by methacrylate surfactant monomers on the cytotoxicity and degree of conversion of two-step self-etching dentin adhesive systems. Five HEMA-free adhesive systems were tested: Bis-EMA 10, Bis-EMA 30, PEG400, PEG400UDMA, PEG1000, and a HEMA group was used as positive control. The cytotoxicity of the experimental primers, with different monomer concentrations (2 or 20 wt%), and bond resins, containing 25 wt% surfactant, was assessed using murine fibroblast cell line 3T3 and the tetrazolium assay (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)). The degree of conversion of the bond resins was analyzed using Fourier transform infrared spectroscopy. The data were submitted to statistical analysis using level of significance set at P < 0.05. The PEG 1000 group obtained higher cell viability in comparison with HEMA in the 2 % primer. The cell survival rate using 20 % primer showed that PEG1000 and BIS-EMA 10 were less cytotoxic than HEMA. With regard to the eluate from bond resin, the data showed that the groups BIS-EMA 10, BIS-EMA 30 and PEG400UDMA were less cytotoxic than HEMA. No statistically significant difference was found among degrees of conversion of the experimental groups and HEMA. PEG 1000, BIS-EMA 10 and 30 monomers showed the biological potential for use in new adhesive system formulations since they showed lower cytotoxicity and similar degree of conversion when compared with the HEMA-containing group. PMID:25589203

  9. Solid Waste Information and Tracking System Client Server Conversion Project Management Plan

    SciTech Connect

    GLASSCOCK, J.A.

    2000-02-10

    The Project Management Plan governing the conversion of SWITS to a client-server architecture. The PMP describes the background, planning and management of the SWITS conversion. Requirements and specification documentation needed for the SWITS conversion

  10. Compatibility of Niobium Alloys and Superalloys in a Flowing He-Xe Power Conversion System

    NASA Technical Reports Server (NTRS)

    Bowman, Cheryl L.; Ritzert, Frank J.; Smialek, James L.; Jaster, Mark L.; rker, Samuel P.

    2004-01-01

    Proposed concepts for an ambitious mission to explore Jupiter's three icy moons place significant demands on the various spacecraft systems. There are many challenges related to the high output power conversion systems being considered, and one example is the need to ensure system compatibility at all levels. The utilization of appropriate materials for component structures is important to ensuring long mission life. Refractory metal alloys have attractive high-temperature properties in inert environments, but these alloys are sometimes susceptible to contamination. Potential material compatibility issues exist between refractory metal candidates and more conventional alloys. Nb-1Zr has long been considered one of the most well characterized refractory alloys that is well suited for elevated-temperature use and liquid-metal compatibility. However, previous studies have suggested that niobium alloys can not co-exist in a closed system with traditional stainless steels or superalloys due to transport of contaminants. The relevance of this information to a proposed power conversion system is discussed. Also, experiments and fundamental calculations are being performed to determine contamination transport from candidate superalloys to Nb-1Zr in a closed system with an inert carrier gas. Potential protective schemes are explored to ensure system level compatibility between the refractory alloy Nb-1Zr and a nickel-based superalloy.

  11. Single-beam water vapor detection system with automatic photoelectric conversion gain control

    NASA Astrophysics Data System (ADS)

    Zhu, C. G.; Chang, J.; Wang, P. P.; Wang, Q.; Wei, W.; Liu, Z.; Zhang, S. S.

    2014-11-01

    A single-beam optical sensor system with automatic photoelectric conversion gain control is proposed for doing high reliability water vapor detection under relatively rough environmental conditions. Comparing to a dual-beam system, it can distinguish the finer photocurrent variations caused by the optical power drift and provide timely compensation by automatically adjusting the photoelectric conversion gain. This system can be rarely affected by the optical power drift caused by fluctuating ambient temperature or variation of fiber bending loss. The deviation of the single-beam system is below 1.11% when photocurrent decays due to fiber bending loss for bending radius of 5 mm, which is obviously lower than the dual-beam system (8.82%). We also demonstrate the long-term stability of the single-beam system by monitoring a 660 ppm by volume (ppmv) water vapor sample continuously for 24 h. The maximum deviation of the measured concentration during the whole testing period does not exceed 10 ppmv. Experiments have shown that the new system features better reliability and is more apt for remote sensing application which is often subject to light transmission loss.

  12. Priority depth fusion for the 2D to 3D conversion system

    NASA Astrophysics Data System (ADS)

    Chang, Yu-Lin; Chen, Wei-Yin; Chang, Jing-Ying; Tsai, Yi-Min; Lee, Chia-Lin; Chen, Liang-Gee

    2008-02-01

    For the sake of providing 3D contents for up-coming 3D display devices, a real-time automatic depth fusion 2D-to-3D conversion system is needed on the home multimedia platform. We proposed a priority depth fusion algorithm with a 2D-to-3D conversion system which generates the depth map from most of the commercial video sequences. The results from different kinds of depth reconstruction methods are integrated into one depth map by the proposed priority depth fusion algorithm. Then the depth map and the original 2D image are converted to stereo images for showing on the 3D display devices. In this paper, a 2D-to-3D conversion algorithm set is combined with the proposed depth fusion algorithm to show the improved results. With the converted 3D contents, the needs for 3D display devices will also increase. As long as the two technologies evolve, the 3D-TV era will come as soon as possible.

  13. Development of a solar receiver for a high-efficiency thermionic/thermoelectric conversion system

    SciTech Connect

    Naito, H.; Kohsaka, Y.; Cooke, D.; Arashi, H.

    1996-10-01

    Solar energy is one of the most promising energy resources on Earth and in space, because it is clean and inexhaustible. Therefore, we have been developing a solar-powered high-efficiency thermionic-thermoelectric conversion system which combines a thermionic converter (TIC) with a thermoelectric converter (TEC) to use thermal energy efficiently and to achieve high efficiency conversion. The TIC emitter must uniformly heat up to 1800 K. The TIC emitter can be heated using thermal radiation from a solar receiver maintained at a high temperature by concentrated solar irradiation. A cylindrical cavity-type solar receiver constructed from graphite was designed and heated in a vacuum by using the solar concentrator at Tohoku University. The maximum temperature of the solar receiver enclosed by a molybdenum cup reached 1965 K, which was sufficiently high to heat a TIC emitter using thermal radiation from the receiver. 4 refs., 6 figs., 1 tab.

  14. Control of modular multilevel converters for grid integration of full-scale wind energy conversion systems

    NASA Astrophysics Data System (ADS)

    Debnath, Suman

    The growing demand for wind power generation has pushed the capacity of wind turbines towards MW power levels. Higher capacity of the wind turbines necessitates operation of the generators and power electronic conversion systems at higher voltage/power levels. The power electronic conversion system of a wind energy conversion system (WECS) needs to meet the stringent requirements in terms of reliability, efficiency, scalability and ease of maintenance, power quality, and dv/dt stress on the generator/transformer. Although the multilevel converters including the neutral point clamped (NPC) converter and the active NPC converter meet most of the requirements, they fall short in reliability and scalability. Motivated by modularity/scalability feature of the modular multilevel converter (MMC), this research is to enable the MMC to meet all of the stringent requirements of the WECS by addressing their unique control challenges. This research presents systematic modeling and control of the MMC to enable it to be a potential converter topology for grid integration of full-scale WECSs. Based on the developed models, appropriate control systems for control of circulating current and capacitor voltages under fixed- and variable-frequency operations are proposed. Using the developed MMC models, a gradient-based cosimulation algorithm to optimize the gains of the developed control systems, is proposed. Performance/effectiveness of the developed models and the proposed control systems for the back-to-back MMC-based WECS are evaluated/verified based on simulations studies in the PSCAD/EMTDC software environment and experimental case studies on a laboratory-scale hardware prototype.

  15. Experimental and Analytical Performance of a Dual Brayton Power Conversion System

    NASA Technical Reports Server (NTRS)

    Lavelle, Thomas A.; Hervol, David S.; Briggs, Maxwell; Owen, A. Karl

    2009-01-01

    The interactions between two closed Brayton cycle (CBC) power conversion units (PCU) which share a common gas inventory and heat source have been studied experimentally using the Dual Brayton Power Conversion System (DBPCS) and analytically using the Closed- Cycle System Simulation (CCSS) computer code. Selected operating modes include steady-state operation at equal and unequal shaft speeds and various start-up scenarios. Equal shaft speed steady-state tests were conducted for heater exit temperatures of 840 to 950 K and speeds of 50 to 90 krpm, providing a system performance map. Unequal shaft speed steady-state testing over the same operating conditions shows that the power produced by each Brayton is sensitive to the operating conditions of the other due to redistribution of gas inventory. Startup scenarios show that starting the engines one at a time can dramatically reduce the required motoring energy. Although the DBPCS is not considered a flight-like system, these insights, as well as the operational experience gained from operating and modeling this system provide valuable information for the future development of Brayton systems.

  16. Urban Waste Conversion Systems. IGT Project 61030 final report, October 1, 1978-March 31, 1979

    SciTech Connect

    Cowen, D.S.; Daniels, E.J.; Novil, M.

    1980-02-01

    The purpose of this study was to assess the market potential of the various systems available, or under development, for converting urban wastes into synthetic gas or liquids. The primary data base for this assessment is a survey which IGT has sent out to experts in this field. The experts were asked to evaluate various conversion systems by assigning point totals to an evaluation matrix. They were also asked to summarize their work in urban waste conversion, to list critical paths which represent obstacles to be surmounted by R and D, and to assess the effect of those obstacles on the market potential of that process. Critical areas for R and D work focus on materials handling and separation techniques, and protection of equipment from abrasive, caustic, or corrosive chemicals in the wastes. Also, prohibitive capital and operating costs in some existing systems must be cited, since investor confidence is eroded by evidence of such experiences. Downtime has been excessive with many systems, stemming from feed problems brought on by the heterogeneous nature of the feedstock. Systems using homogeneous feeds have shown considerably less problems. Perhaps a critical area from a social impact point of view is, can garbage separation be instituted for the home, factory, etc. If so, the chances for waste converison systems to overcome technical problems on the front end are greatly improved, and so is the potential for market penetration.

  17. Status of the advanced Stirling conversion system project for 25 kW dish Stirling applications

    NASA Technical Reports Server (NTRS)

    Shaltens, Richard K.; Schreiber, Jeffrey G.

    1991-01-01

    Heat engines were evaluated for terrestrial Solar Distributed Heat Receivers. The Stirling engine was identified as one of the most promising heat engines for terrestrial applications. Technology development is also conducted for Stirling convertors directed toward a dynamic power source for space applications. Space power requirements include high reliability with very long life, low vibration, and high system efficiency. The free-piston Stirling engine has the potential for future high power space conversion systems, either nuclear or solar powered. Although both applications appear to be quite different, their requirements complement each other.

  18. Control strategy for a variable-speed wind energy conversion system

    NASA Technical Reports Server (NTRS)

    Jacob, A.; Veillette, D.; Rajagopalan, V.

    1979-01-01

    A control concept for a variable-speed wind energy conversion system is proposed, for which a self-exited asynchronous cage generator is used along with a system of thyristor converters. The control loops are the following: (1) regulation of the entrainment speed as function of available mechanical energy by acting on the resistance couple of the asynchronous generator; (2) control of electric power delivered to the asynchronous machine, functioning as a motor, for start-up of the vertical axis wind converter; and (3) limitation of the slip value, and by consequence, of the induction currents in the presence of sudden variations of input parameters.

  19. Tunable asymmetric mode conversion using the dark-mode of three-mode waveguide system.

    PubMed

    Kim, Joonsoo; Lee, Seung-Yeol; Lee, Yohan; Kim, Hwi; Lee, Byoungho

    2014-11-17

    A design scheme for low-reflection asymmetric mode conversion structure in three-mode waveguide system is proposed. By using a dark-mode of three-mode system, which can be interpreted in terms of destructive interference of transition amplitudes, the transmission characteristics for forward and backward directions can be designed separately. After explanation of the proposed design scheme, we demonstrate an example of asymmetric mode converter that consists of two gratings. The proposed scheme may be useful for the design of tunable asymmetric transmission devices due to its design flexibility and efficient design process. PMID:25402109

  20. Brayton Power Conversion System Parametric Design Modelling for Nuclear Electric Propulsion

    NASA Technical Reports Server (NTRS)

    Ashe, Thomas L.; Otting, William D.

    1993-01-01

    The parametrically based closed Brayton cycle (CBC) computer design model was developed for inclusion into the NASA LeRC overall Nuclear Electric Propulsion (NEP) end-to-end systems model. The code is intended to provide greater depth to the NEP system modeling which is required to more accurately predict the impact of specific technology on system performance. The CBC model is parametrically based to allow for conducting detailed optimization studies and to provide for easy integration into an overall optimizer driver routine. The power conversion model includes the modeling of the turbines, alternators, compressors, ducting, and heat exchangers (hot-side heat exchanger and recuperator). The code predicts performance to significant detail. The system characteristics determined include estimates of mass, efficiency, and the characteristic dimensions of the major power conversion system components. These characteristics are parametrically modeled as a function of input parameters such as the aerodynamic configuration (axial or radial), turbine inlet temperature, cycle temperature ratio, power level, lifetime, materials, and redundancy.

  1. Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 1: Introduction and summary and general assumptions. [energy conversion systems for electric power plants using coal - feasibility

    NASA Technical Reports Server (NTRS)

    Beecher, D. T.

    1976-01-01

    Nine advanced energy conversion concepts using coal or coal-derived fuels are summarized. They are; (1) open-cycle gas turbines, (2) combined gas-steam turbine cycles, (3) closed-cycle gas turbines, (4) metal vapor Rankine topping, (5) open-cycle MHD; (6) closed-cycle MHD; (7) liquid-metal MHD; (8) advanced steam; and (9) fuel cell systems. The economics, natural resource requirements, and performance criteria for the nine concepts are discussed.

  2. Design of a VLSI scan conversion processor for high-performance 3-D graphics systems

    SciTech Connect

    Huang, H.U.

    1988-01-01

    Scan-conversion processing is the bottleneck in the image generation process. To solve the problem of smooth shading and hidden surface elimination, a new processor architecture was invented which has been labeled as a scan-conversion processor architecture (SCP). The SCP is designed to perform hidden surface elimination and scan conversion for 64 pixels. The color intensities are dual-buffered so that when one buffer is being updated the other can be scanned out. Z-depth is used to perform the hidden surface elimination. The key operation performed by the SCP is the evaluation of linear functions of a form like F(X,Y) = A X + B Y + C. The computation is further simplified by using incremental addition. The z-depth buffer and the color buffers are incorporated onto the same chip. The SCP receives from its preprocessor the information for the definition of polygons and the computation of z-depth and RGB color intensities. Many copies of this processor will be used in a high-performance graphics system.

  3. Status of the Landsat thematic mapper and multispectral scanner archive conversion system

    USGS Publications Warehouse

    Werner, Darla J.

    1993-01-01

    The U.S. Geological Survey's EROS Data Center (EDC) manages the National Satellite Land Remote Sensing Data Archive. This archive includes Landsat thematic mapper (TM) multispectral scanner (MSS) data acquired since 1972. The Landsat archive is an important resource to global change research. To ensure long-term availability of Landsat data from the archive, the EDC specified requirements for a Thematic Mapper and Multispectral Scanner Archive Conversion System (TMACS) that would preserve the data by transcribing it to a more durable medium. In addition to media conversion, hardware and software was installed at EDC in July 1992. In December 1992, the EDC began converting Landsat MSS data from high-density, open reel instrumentation tapes to digital cassette tapes. Almost 320,000 MSS images acquired since 1979 and more than 200,000 TM images acquired since 1982 will be converted to the new medium during the next 3 years. During the media conversion process, several high-density tapes have exhibited severe binder degradation. Even though these tapes have been stored in environmentally controlled conditions, hydrolysis has occurred, resulting in "sticky oxide shed". Using a thermostatically controlled oven built at EDC, tape "baking" has been 100 percent successful and actually improves the quality of some images.

  4. From cloud-of-point coordinates to three-dimensional virtual environment: the data conversion system

    NASA Astrophysics Data System (ADS)

    Sitnik, Robert; Kujawinska, Malgorzata

    2002-02-01

    The sequential steps of conversion of data gathered by a full-field 3-D shape measurement optical system into CAD/CAM and multimedia environments are discussed. The complete triangulation algorithm, which automatically creates the triangle mesh from the input cloud of points, is described. Each block of this algorithm is explained in detail with special attention paid to the parameters controlling the quality of the data conversion process. The adaptive process of reducing the number of the triangles based on a second derivative of local curvature of an objects' surface is explained. The error analysis is discussed at each step of the cloud data processing in dependency of the algorithm initial parameters. The three algorithms that process additional color information (R,G,B) into the texture mapped on the triangle mesh is presented. The usefulness of the complete conversion process is proved by the manufacturing of an exemplary object, exporting a human 3-D face to the Internet and an example object into a 3-D virtual environment.

  5. Experimental Demonstration of Information-to-Energy Conversion in Small Fluctuating Systems

    NASA Astrophysics Data System (ADS)

    Sano, Masaki

    2015-03-01

    What is the relation between information and thermodynamics has been a long standing question in science. In 1867, J.C. Maxwell proposed a Gedanken experiment to demonstrate violation of the second law of thermodynamics by assuming a small creature called Maxwell's demon which separates hot atoms from cold atoms. In 1929, L. Szilard formulated the idea of Maxwell for a more tractable setup in which a single particle is thermally moving in a box immersed in a heat bath. He succeeded to relate information entropy and the second law of thermodynamics in this Gedanken experiment. It had led to long and intense debates on the relation among thermodynamics, information, observation, and even computation until it was clarified recently. Nevertheless, experimental realization of information-energy-conversion has been elusive. Recently, we succeeded to demonstrate the information-energy-conversion by observing Brownian motion of colloidal particles and controlling them. We introduced a feedback control protocol based on the information of Brownian particle by electric fields and found that the particle rotates against the torque exerted by an external electric field and obtains free energy larger than the amount of work performed on it. By measuring detailed process, validity of a new nonequilibrium equality concerning the feedback control has been shown. Efficiency of information-energy conversion was evaluated in this feedback system. Moreover, I will discuss on possible generalization of this cocept to information processing in cell chemotaxis.

  6. Final design of a free-piston hydraulic advanced Stirling conversion system

    NASA Astrophysics Data System (ADS)

    Wallace, D. A.; Noble, J. E.; Emigh, S. G.; Ross, B. A.; Lehmann, G. A.

    Under the US Department of Energy's (DOEs) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for solar distributed receiver systems. The final design is described of an engineering prototype advanced Stirling conversion system (ASCS) with a free-piston hydraulic engine output capable of delivering about 25 kW of electric power to a utility grid. The free-piston Stirling engine has the potential for a highly reliable engine with long life because it has only a few moving parts, has noncontacting bearings, and can be hermetically sealed. The ASCS is designed to deliver maximum power per year over a range of solar input with a design life of 30 years (60,000 h). The system includes a liquid Nak pool boiler heat transport system and a free-piston Stirling engine with high-pressure hydraulic output, coupled with a bent axis variable displacement hydraulic motor and a rotary induction generator.

  7. Studies of in-situ calcium-based sorbents in advanced pressurized coal conversion systems

    SciTech Connect

    Katta, S.; Shires, P.J.; O'Donnell, J.J.

    1992-01-01

    The overall objective of the project is to obtain experimental data on the reactions of calcium-based sorbents in gasification systems and to evaluate or develop kinetic models applicable to the commercial design of such systems. Both air-blown coal gasification systems and second generation fluid bed combustion systems (partial gasification) will be investigated, as well as subsequent stabilization of the solid wastes (calcium sulfide/ash) produced. More specifically, the objectives are to: Develop data on kinetics of in-situ desulfurization reactions; study the effect of calcium on the kinetics of carbon conversion rate; study kinetics of oxidation of CaS to CaSO[sup 4]; Develop and identify viable techniques to stabilize CaS; and, carry out further development work on most promising method and determine its commercial economics.

  8. Studies of in-situ calcium-based sorbents in advanced pressurized coal conversion systems

    SciTech Connect

    Katta, S.; Shires, P.J.; O`Donnell, J.J.

    1992-11-01

    The overall objective of the project is to obtain experimental data on the reactions of calcium-based sorbents in gasification systems and to evaluate or develop kinetic models applicable to the commercial design of such systems. Both air-blown coal gasification systems and second generation fluid bed combustion systems (partial gasification) will be investigated, as well as subsequent stabilization of the solid wastes (calcium sulfide/ash) produced. More specifically, the objectives are to: Develop data on kinetics of in-situ desulfurization reactions; study the effect of calcium on the kinetics of carbon conversion rate; study kinetics of oxidation of CaS to CaSO{sup 4}; Develop and identify viable techniques to stabilize CaS; and, carry out further development work on most promising method and determine its commercial economics.

  9. Space-Based Solar Power Conversion and Delivery Systems Study. Volume 1: Executive Summary

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The research concerning space-based solar power conversion and delivery systems is summarized. The potential concepts for a photovoltaic satellite solar power system was studied with emphasis on ground output power levels of 5,000 MW and 10,000 MW. A power relay satellite, and certain aspects of the economics of these systems were also studied. A second study phase examined in greater depth the technical and economic aspects of satellite solar power systems. Throughout this study, the focus was on the economics of satellite solar power. The results indicate technical feasibility of the concept, and provide a preliminary economic justification for the first phase of a substantial development program. A development program containing test satellites is recommended. Also, development of alternative solar cell materials (other than silicon) is recommended.

  10. Design and Use of a Large-Scale Liquid Helium Conversion System

    NASA Technical Reports Server (NTRS)

    Knudsen, P. N.

    1999-01-01

    A large-scale liquid helium (LHe) to high-pressure (HP) gas conversion system has been implemented at the John F. Kennedy Space Center (KSC). Helium is used by the Space Shuttle, Titan, Atlas, and Delta programs for prelaunch processing, during launch count-down, and for postlaunch securing. The first phase of modifications to the Compressor Converter Facility (CCF), operational in April 1998, allowed the facility to accept bulk liquid helium from tanker containers and to off-load the helium at super-critical pressures. The second phase of modifications, planned to be operational by January 2001, will implement a 227-cubic-meter (m(sup 3)) on-site liquid helium storage system. This paper describes the design and operation of the current system and discusses the design and implementation for the second phase system.

  11. Systems analysis research for energy conversion and utilization technologies (ECUT). FY 1985 annual report

    SciTech Connect

    Eberhardt, J.J.; Gunn, M.E.; Levinson, T.M.

    1985-11-01

    This Annual Report highlights ECUT accomplishments in the Systems Analysis Project for FY 1985. The Systems Analysis Project was established in 1980 along with the ECUT Division. The Systems Analysis mission is to identify, analyze, and assess R and D needs and research program strategies for advanced conservation technologies. The PNL Systems Analysis staff conducts topical research, provides technical studies, and plans program activities in three areas related to energy conversion and utilization technologies: (1) technology assessment, (2) engineering analysis, and (3) project evaluation and review. This report summarizes the technical results and accomplishments of the FY 1985 projects. They relate mostly to tribology, improved ctalysts, regenerative heat exchangers, robotics and electronics industries, and bioprocessing.

  12. A summary of the ECAS performance and cost results for MHD system. [Energy Conversion Alternatives Study

    NASA Technical Reports Server (NTRS)

    Seikel, G. R.; Sovie, R. J.; Burns, R. K.; Barna, G. J.; Burkhart, J. A.; Nainiger, J. J.; Smith, J. M.

    1976-01-01

    The interagency-funded, NASA-coordinated Energy Conversion Alternatives Study (ECAS) has studied the potential of various advanced power plant concepts using coal and coal-derived fuel. Principle studies were conducted through prime contracts with the General Electric Company and the Westinghouse Electric Corporation. The results indicate that open-cycle coal-fired direct-preheat MHD systems have potentially one of the highest coal-pile-to-bus-bar efficiencies and also one of the lowest costs of electricity (COE) of the systems studied. Closed-cycle MHD systems may have the potential to approach the efficiency and COE of open-cycle MHD. The 1200-1500 F liquid-metal MHD systems studied do not appear to have the potential of exceeding the efficiency or competing with the COE of advanced steam plants.

  13. Final design of a free-piston hydraulic advanced Stirling conversion system

    NASA Technical Reports Server (NTRS)

    Wallace, D. A.; Noble, J. E.; Emigh, S. G.; Ross, B. A.; Lehmann, G. A.

    1991-01-01

    Under the US Department of Energy's (DOEs) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for solar distributed receiver systems. The final design is described of an engineering prototype advanced Stirling conversion system (ASCS) with a free-piston hydraulic engine output capable of delivering about 25 kW of electric power to a utility grid. The free-piston Stirling engine has the potential for a highly reliable engine with long life because it has only a few moving parts, has noncontacting bearings, and can be hermetically sealed. The ASCS is designed to deliver maximum power per year over a range of solar input with a design life of 30 years (60,000 h). The system includes a liquid Nak pool boiler heat transport system and a free-piston Stirling engine with high-pressure hydraulic output, coupled with a bent axis variable displacement hydraulic motor and a rotary induction generator.

  14. Feedstock Supply System Design and Economics for Conversion of Lignocellulosic Biomass to Hydrocarbon Fuels Conversion Pathway: Fast Pyrolysis and Hydrotreating Bio-Oil Pathway "The 2017 Design Case"

    SciTech Connect

    Kevin L. Kenney; Kara G. Cafferty; Jacob J. Jacobson; Ian J. Bonner; Garold L. Gresham; J. Richard Hess; William A. Smith; David N. Thompson; Vicki S. Thompson; Jaya Shankar Tumuluru; Neal Yancey

    2014-01-01

    The U.S. Department of Energy promotes the production of liquid fuels from lignocellulosic biomass feedstocks by funding fundamental and applied research that advances the state of technology in biomass sustainable supply, logistics, conversion, and overall system sustainability. As part of its involvement in this program, Idaho National Laboratory (INL) investigates the feedstock logistics economics and sustainability of these fuels. Between 2000 and 2012, INL quantified and the economics and sustainability of moving biomass from the field or stand to the throat of the conversion process using conventional equipment and processes. All previous work to 2012 was designed to improve the efficiency and decrease costs under conventional supply systems. The 2012 programmatic target was to demonstrate a biomass logistics cost of $55/dry Ton for woody biomass delivered to fast pyrolysis conversion facility. The goal was achieved by applying field and process demonstration unit-scale data from harvest, collection, storage, preprocessing, handling, and transportation operations into INL’s biomass logistics model.

  15. Glossary of terms and table of conversion factors used in design of chemical propulsion systems

    NASA Technical Reports Server (NTRS)

    Keller, R. B., Jr. (Compiler)

    1979-01-01

    The glossary presented is based entirely on terms used in the monographs on Chemical Propulsion. Significant terms relating to material properties and to material fabrication are presented. The terms are arranged in alphabetical order, with multiple word terms appearing in the normal sequence of usage; for example, ablative cooling appears as such, not as cooling, ablative, and lip seal appears as such, not as seal, lip. Conversion Factors for converting U.S. customary units to the International System of Units are presented in alphabetical order of the physical quantity (e.g., density, heat flux, specific impulse) involved.

  16. Electro-optic harmonic conversion switch for large-aperture multipass laser systems

    SciTech Connect

    Henesian, M.A.; Goldhar, J.; Haas, R.A.

    1984-08-01

    The authors have demonstrated electro-optically tuned second-harmonic generation using Type I KDP inside a plasma-electrode discharge cell. An axial voltage of +/- 52 kV is required to switch a 1.064-..mu..m beam by conversion to 0.53 ..mu..m, in agreement with theory. Electro-optically tuned harmonic generation may be combined with a recently developed transparent plasma electrode to produce a large-aperture switch for multipass laser systems. 7 references, 4 figures, 1 table.

  17. The direct conversion of sugars into 2,5-furandicarboxylic acid in a triphasic system.

    PubMed

    Yi, Guangshun; Teong, Siew Ping; Zhang, Yugen

    2015-04-13

    A one-pot conversion of sugars into 2,5-furandicarboxylic acid (FDCA) is demonstrated in a triphasic system: tetraethylammonium bromide (TEAB) or water-methyl isobutyl ketone (MIBK)-water. In this reaction, sugars are first converted into 5-hydroxymethylfurfural (HMF) in TEAB or water (Phase I). The HMF in Phase I is then extracted to MIBK (Phase II) and transferred to water (Phase III), where HMF is converted into FDCA. Phase II plays multiple roles: as a bridge for HMF extraction, transportation and purification. Overall FDCA yields of 78 % and 50 % are achieved from fructose and glucose respectively. PMID:25766123

  18. Conversion system overview assessment. Volume III. Solar thermal/coal or biomass derived fuels

    SciTech Connect

    Copeland, R. J.

    1980-02-01

    The three volumes of this report cover three distinct areas of solar energy research: solar thermoelectrics, solar-wind hybrid systems, and synthetic fuels derived with solar thermal energy. Volume III deals with the conversion of synthetic fuels with solar thermal heat. The method is a hybrid combination of solar energy with either coal or biomass. A preliminary assessment of this technology is made by calculating the cost of fuel produced as a function of the cost of coal and biomass. It is shown that within the projected ranges of coal, biomass, and solar thermal costs, there are conditions when solar synthetic fuels with solar thermal heat will become cost-competitive.

  19. Characterization of on-site digital mammography systems: Direct versus indirect conversion detectors

    NASA Astrophysics Data System (ADS)

    Youn, Hanbean; Han, Jong Chul; Yun, Seungman; Kam, Soohwa; Cho, Seungryong; Kim, Ho Kyung

    2015-06-01

    We investigated the performances of two digital mammography systems. The systems use a cesium-iodide (CsI) scintillator and an amorphous selenium ( a-Se) photoconductor for X-ray detection and are installed in the same hospital. As physical metrics, we measured the modulationtransfer function (MTF), the noise-power spectrum (NPS), and the detective quantum efficiency (DQE). In addition, we analyzed the contrast-detail performances of the two systems by using a commercial contrast-detail phantom. The CsI-based indirect conversion detector provided better MTF and DQE performances than the a-Se-based direct conversion detector whereas the former provided a poorer NPS performance than the latter. These results are explained by the fact that the CsI-based detector used an MTF restoration preprocessing algorithm. The a-Se-based detector showed better contrast-detail performance than the CsI-based detector. We believe that the highfrequency noise characteristic of a detector is more responsible for the visibility of small details than its spatial-resolution performance.

  20. Carbon Dioxide Conversion to Valuable Chemical Products over Composite Catalytic Systems

    SciTech Connect

    Dagle, Robert A.; Hu, Jianli; Jones, Susanne B.; Wilcox, Wayne A.; Frye, John G.; White, J. F.; Jiang, Juyuan; Wang, Yong

    2013-05-01

    Presented is an experimental study on catalytic conversion of carbon dioxide into methanol, ethanol and acetic acid. Catalysts having different catalytic functions were synthesized and combined in different ways to enhance selectivity to desired products. The combined catalyst system possessed the following functions: methanol synthesis, Fischer-Tropsch synthesis, water-gas-shift and hydrogenation. Results showed that the methods of integrating these catalytic functions played important role in achieving desired product selectivity. It was speculated that if methanol synthesis sites were located adjacent to the C-C chain growth sites, the formation rate of C2 oxygenates would be enhanced. The advantage of using high temperature methanol catalyst PdZnAl in the combined catalyst system was demonstrated. In the presence of PdZnAl catalyst, the combined catalyst system was stable at temperature of 380oC. It was observed that, at high temperature, kinetics favored oxygenate formation. Results implied that the process can be intensified by operating at high temperature using Pd-based methanol synthesis catalyst. Steam reforming of the byproduct organics was demonstrated as a means to provide supplemental hydrogen. Preliminary process design, simulation, and economic analysis of the proposed CO2 conversion process were carried out. Economic analysis indicates how ethanol production cost was affected by the price of CO2 and hydrogen.

  1. Safety and wind energy conversion systems with horizontal axis (HA WECS)

    NASA Astrophysics Data System (ADS)

    Eggwertz, S.; Carlsson, I.; Gustafsson, A.; Linde, M.; Lundemo, C.; Montgomerie, B.; Thor, S. E.

    1981-03-01

    Hazards imposed by a wind energy conversion system on the general public and on the operator personnel by complete collapse, by separation of fractured parts, or by pieces of ice (flying off) were calculated to provide a manual for safety evaluations. Land based large scale turbine systems with horizontal axes situated in areas with sparse population are considered. Blade material is assumed to be steel, aluminum alloy or fiber reinforced plastics; the tower being built of steel or reinforced concrete. Primary structure, function and failure modes are identified. Statistical information of loads and load combinations, strength properties of materials and geometry deviation are provided. A simplified method of risk analysis is described. The object and function of a safety system, both hardware and software, is reviewed, considering the effects of inspection and repair. The probability of being hit is evaluated, provided a fracture occurs and a risk zone is established.

  2. A closed loop system for the conversion of uranium turnings to uranyl oxy-hydroxide

    SciTech Connect

    Forman, T.M.; Sauer, N.N.; Smith, W.H.; Ogden, G.

    1997-12-31

    The machine shops at Los Alamos National Laboratory generate up to 5 Kgs of uranium turnings daily. Presently, the turnings are packed in diesel fuel in 55 gallon drums and shipped off site for treatment and disposal. In response to a request for an in-situ generator treatment plan, a three-part closed loop system has been designed to dissolve the turnings and leave them in a non-reactive form for either storage or disposal. The system uses electrochemically generated sodium hypochlorite to dissolve the turnings, converting them to uranyl oxy-hydroxide precipitate. The precipitate is continually centrifuged to separate the liquids from solids. The supernant, spent hypochlorite, feeds into the electrochemical cell, the hypochlorite is regenerated and pumped back into the dissolution reactor. This closed loop system accomplishes both conversion of the uranium turnings to an acceptable form and minimizes the treatment wastestream.

  3. Neural computing for numeric-to-symbolic conversion in control systems

    NASA Technical Reports Server (NTRS)

    Passino, Kevin M.; Sartori, Michael A.; Antsaklis, Panos J.

    1989-01-01

    A type of neural network, the multilayer perceptron, is used to classify numeric data and assign appropriate symbols to various classes. This numeric-to-symbolic conversion results in a type of information extraction, which is similar to what is called data reduction in pattern recognition. The use of the neural network as a numeric-to-symbolic converter is introduced, its application in autonomous control is discussed, and several applications are studied. The perceptron is used as a numeric-to-symbolic converter for a discrete-event system controller supervising a continuous variable dynamic system. It is also shown how the perceptron can implement fault trees, which provide useful information (alarms) in a biological system and information for failure diagnosis and control purposes in an aircraft example.

  4. Design Impacts of Stochastically-Varying Input Parameters on Advanced Thermoelectric Conversion Systems

    SciTech Connect

    Hendricks, Terry J.; Karri, Naveen K.

    2007-06-30

    Advanced, direct thermal energy conversion technologies are receiving increased research attention in order to recover waste thermal energy in advanced vehicles and industrial processes. Advanced thermoelectric (TE) systems necessarily require integrated system-level analyses to establish accurate optimum system designs. Past system-level design and analysis has relied on well-defined deterministic input parameters even though many critically important environmental and system design parameters in the above mentioned applications are often randomly variable, sometimes according to complex relationships, rather than discrete, well-known deterministic variables. This work describes new research and development creating techniques and capabilities for probabilistic design and analysis of advanced TE power generation systems to quantify the effects of randomly uncertain design inputs in determining more robust optimum TE system designs and expected outputs. Selected case studies involving stochastic TE .material properties and coupled multi-variable stochasticity in key environmental and design parameters are presented and discussed to demonstrate key impacts from considering stochastic design inputs on the TE design optimization process. Critical findings show that: 1) stochastic Gaussian input distributions may produce Gaussian or non-Gaussian outcome probability distributions for critical TE design parameters, and 2) probabilistic input considerations can create design effects that warrant significant modifications to deterministically-derived optimum TE system designs. Magnitudes and directions of these design modifications are quantified for selected TE system design analysis cases.

  5. Comparative of nuclear technology and direct energy conversion methods for space power systems. Master`s thesis

    SciTech Connect

    Reason, J.P.

    1997-06-01

    The objectives of this thesis are to investigate the theory of direct energy conversion, research the development of space nuclear power systems, evaluate the status of current systems, and draw conclusions about the feasibility and merit of using nuclear power for future space missions. Development of the earliest systems began in 1955 with the Systems for Nuclear Auxiliary Power (SNAP) Program and Project Rover. A detailed review of system design and performance is provided for the reactors and radioisotope thermoelectric generators (RTG`s) of past and current programs. Thermoelectric and thermionic energy conversion techniques have been used predominantly in space nuclear power systems. The theory of these direct energy conversion methods is analyzed. Also, the safety review procedures and regulations governing the launch of nuclear sources into space are characterized. Conclusions compare accomplished levels of system performance to theoretically predicted limits and comment on the usefulness of space nuclear power for space applications.

  6. Initial Test Results of a Dual Closed-Brayton-Cycle Power Conversion System

    NASA Technical Reports Server (NTRS)

    Johnson, Paul K.; Mason, Lee S.

    2007-01-01

    The dual Brayton power conversion system constructed for NASA Glenn Research Center (GRC) was acceptance tested April 2007 at Barber-Nichols, Inc., Arvada, Colorado. This uniquely configured conversion system is built around two modified commercial Capstone C30 microturbines and employs two closed-Brayton-cycle (CBC) converters sharing a common gas inventory and common heat source. Because both CBCs share the gas inventory, behavior of one CBC has an impact on the performance of the other CBC, especially when one CBC is standby or running at a different shaft speed. Testing performed to date includes the CBCs operating at equal and unequal shaft speeds. A test was also conducted where one CBC was capped off and the other was operated as a single CBC converter. The dual Brayton configuration generated 10.6 kWe at 75 krpm and a turbine inlet temperature of 817 K. Single Brayton operation generated 14.8 kWe at 90 krpm and a turbine inlet temperature of 925 K.

  7. A Small Fission Power System with Stirling Power Conversion for NASA Science Missions

    NASA Technical Reports Server (NTRS)

    Mason, Lee; Carmichael, Chad

    2011-01-01

    In early 2010, a joint National Aeronautics and Space Administration (NASA) and Department of Energy (DOE) study team developed a concept for a 1 kWe Fission Power System with a 15-year design life that could be available for a 2020 launch to support future NASA science missions. The baseline concept included a solid block uranium-molybdenum reactor core with embedded heat pipes and distributed thermoelectric converters directly coupled to aluminum radiator fins. A short follow-on study was conducted at NASA Glenn Research Center (GRC) to evaluate an alternative power conversion approach. The GRC study considered the use of free-piston Stirling power conversion as a substitution to the thermoelectric converters. The resulting concept enables a power increase to 3 kWe with the same reactor design and scalability to 10 kW without changing the reactor technology. This paper presents the configuration layout, system performance, mass summary, and heat transfer analysis resulting from the study.

  8. Handheld access to radiology teaching files: an automated system for format conversion and content creation

    NASA Astrophysics Data System (ADS)

    Raman, Raghav; Raman, Lalithakala; Raman, Bhargav; Gold, Garry; Beaulieu, Christopher F.

    2002-05-01

    Current handheld Personal Digital Assistants (PDAs) can be used to view radiology teaching files. We have developed a toolkit that allows rapid creation of radiology teaching files in handheld formats from existing repositories. Our toolkit incorporated a desktop converter, a web conversion server and an application programming interface (API). Our API was integrated with an existing pilot teaching file database. We evaluated our system by obtaining test DICOM and JPEG images from our PACS system, our pilot database and from personal collections and converting them on a Windows workstation (Microsoft, Redmond, CA) and on other platforms using the web server. Our toolkit anonymized, annotated and categorized images using DICOM header information and data entered by the authors. Image processing was automatically customized for the target handheld device. We used freeware handheld image viewers as well as our custom applications that allowed window/level manipulation and viewing of additional textual information. Our toolkit provides desktop and web access to image conversion tools to produce organized handheld teaching file packages for most handheld devices and our API allows existing teaching file databases to incorporate handheld compatibility. The distribution of radiology teaching files on PDAs can increase the accessibility to radiology teaching.

  9. Hybrid photovoltaic-thermoelectric system for concentrated solar energy conversion: Experimental realization and modeling

    NASA Astrophysics Data System (ADS)

    Beeri, Ofer; Rotem, Oded; Hazan, Eden; Katz, Eugene A.; Braun, Avi; Gelbstein, Yaniv

    2015-09-01

    An experimental demonstration of the combined photovoltaic (PV) and thermoelectric conversion of concentrated sunlight (with concentration factor, X, up to ˜300) into electricity is presented. The hybrid system is based on a multi-junction PV cell and a thermoelectric generator (TEG). The latter increases the electric power of the system and dissipates some of the excessive heat. For X ≤ 200, the system's maximal efficiency, ˜32%, was mostly due to the contribution from the PV cell. With increasing X and system temperature, the PV cell's efficiency decreased while that of the TEG increased. Accordingly, the direct electrical contribution of the TEG started to dominate in the total system power, reaching ˜20% at X ≈ 290. Using a simple steady state finite element modeling, the cooling effect of the TEG on the hybrid system's efficiency was proved to be even more significant than its direct electrical contribution for high solar concentrations. As a result, the total efficiency contribution of the TEG reached ˜40% at X ≈ 200. This suggests a new system optimization concept that takes into account the PV cell's temperature dependence and the trade-off between the direct electrical generation and cooling capabilities of the TEG. It is shown that the hybrid system has a real potential to exceed 50% total efficiency by using more advanced PV cells and TE materials.

  10. Status of the Advanced Stirling Conversion System Project for 25 kW dish Stirling applications

    SciTech Connect

    Shaltens, R.K.; Schreiber, J.G.

    1991-01-01

    Under the Department of Energy's (DOE) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for terrestrial Solar Heat Receivers. The Stirling engine has been identified by Sandia as one of the most promising heat engines for terrestrial applications. The Stirling engine also has the potential to meet DOE's performance and cost goals. The NASA Lewis Research Center is conducting technology development for Stirling convertors directed toward a dynamic power source for space applications. Space power requirements include high reliability with very long life, low vibration and high system efficiency. The free-piston Stirling engine has the potential for future high power space conversion systems, either nuclear or solar powered. Although both applications appear to be quite different, their requirements complement each other. NASA Lewis is providing management of the Advanced Stirling Conversion System (ASCS) Project through an Interagency Agreement (IAA) with the DOE. Parallel contracts continue with both Cummins Engine Company (CEC), Columbus, Indiana, and Stirling Technology Company (STC), Richland, Washington for the designs of an ASCS. Each system'' design features a solar receiver/liquid metal heat transport system, and a free-piston Stirling convertor with a means to provide nominally 25 kW of electric power to a utility grid while meeting DOE's performance and long-term'' cost goals. The Cummins free- piston Stirling convertor incorporates a linear alternator to directly provide the electrical output, while the STC design generates electrical power indirectly through a hydraulic pump/motor coupled to an induction generator. Both the Cummins and STC ASCS designs will use technology which can reasonably be expected to be available in the early 1990's. 17 refs., 7 figs., 3 tabs.

  11. Characterizing somatic hypermutation and gene conversion in the chicken DT40 cell system.

    PubMed

    Kothapalli, Nagarama; Fugmann, Sebastian D

    2011-01-01

    The secondary immunoglobulin gene diversification processes, somatic hypermutation (SHM), immunoglobulin gene conversion (GCV), and class switch recombination, are important for efficient humoral immune responses. They require the action of activation-induced cytidine deaminase, an enzyme that deaminates cytosine in the context of single-stranded DNA. The chicken DT40 B-cell line is an important model system for exploring the mechanisms of SHM and GCV, as both processes occur constitutively without the need for stimulation. In addition, standard gene targeting strategies can be used for defined manipulations of the DT40 genome. Thus, these cells represent an excellent model of choice for genetic studies of SHM and GCV. Problems arising from defects in early B-cell development that are of concern when using genetically engineered mice are avoided in this system. Here, we describe how to perform gene targeting in DT40 cells and how to determine the effects of such modifications on SHM and GCV. PMID:21701980

  12. Efficient catalytic system for the conversion of fructose into 5-ethoxymethylfurfural.

    PubMed

    Wang, Hongliang; Deng, Tiansheng; Wang, Yingxiong; Qi, Yongqin; Hou, Xianglin; Zhu, Yulei

    2013-05-01

    DMSO can improve the selectivity of 5-hydroxymethylfurfural (HMF) in the conversion of carbohydrates. However, one of the bottlenecks in its application is product separation. Thus a one-pot synthesis of 5-ethoxymethylfurfural (EMF) rather than HMF from fructose in ethanol-DMSO was investigated. Phosphotungstic acid was used as an effective catalyst. The yield of EMF can be reached as high as 64% in the mixed solvent system of DMSO and ethanol within 130 min at 140 °C. Ethyl levulinate (LAE) was detected as the main by-product, the yield of which increased with the reaction time, temperature and the amount of catalyst. In addition, the existence of water could significantly reduce the yield of EMF and increased the yield of LAE. Most importantly, it was discovered that EMF could be much more efficiently extracted from the reaction solvent system by some organic solvents than HMF. PMID:23567707

  13. Direct adaptive control of wind energy conversion systems using Gaussian networks.

    PubMed

    Mayosky, M A; Cancelo, I E

    1999-01-01

    Grid connected wind energy conversion systems (WECS) present interesting control demands, due to the intrinsic nonlinear characteristics of windmills and electric generators. In this paper a direct adaptive control strategy for WECS control is proposed. It is based on the combination of two control actions: a radial basis zfunction network-based adaptive controller, which drives the tracking error to zero with user specified dynamics, and a supervisory controller, based on crude bounds of the system's nonlinearities. The supervisory controller fires when the finite neural-network approximation properties cannot be guaranteed. The form of the supervisor control and the adaptation law for the neural controller are derived from a Lyapunov analysis of stability. The results are applied to a typical turbine/generator pair, showing the feasibility of the proposed solution. PMID:18252585

  14. The DC-DC conversion power system of the CMS Phase-1 pixel upgrade

    NASA Astrophysics Data System (ADS)

    Feld, L.; Karpinski, W.; Klein, K.; Lipinski, M.; Preuten, M.; Rauch, M.; Schmitz, St.; Wlochal, M.

    2015-01-01

    The pixel detector of the CMS experiment will be exchanged during the year-end technical stop in 2016/2017, as part of the experiment's Phase-1 upgrade. The new device will feature approximately twice the number of readout channels, and consequently the power consumption will be doubled. By moving to a DC-DC conversion powering scheme, it is possible to power the new pixel detector with the existing power supplies and cable plant. The power system of the Phase-1 pixel detector is described and the performance of the new components, including DC-DC converters, DC-DC converter motherboards and various power distribution boards, is detailed. The outcome of system tests in terms of electrical behaviour, thermal management and pixel module performance is discussed.

  15. Approach to the realization of a closed cycle Ocean Thermal Energy Conversion /OTEC/ system

    NASA Astrophysics Data System (ADS)

    Kajikawa, T.

    1981-08-01

    The design and operational features and goals of a Japanese 1 MWe Ocean Thermal Energy Conversion (OTEC) demonstration plant are described. Japan research and development efforts in OTEC systems are reviewed, along with results which have encouraged the decision to construct the demonstration plant. The plant is being designed for implementation in the seas around Japan, is required to function for 6 mos/yr, and will provide engineering data on the performance of both tube and shell type heat exchangers. The initial test will be run using Freon 22 as the working fluid, followed by NH3 in subsequent trials. The system will be barge-mounted and have a cooling water pipe fixed by single-point mooring. Mainly a proof of principle in large-scale OTEC, the plant will provide a test bed for environmental monitoring and power transmission through the sea, and will serve as a model for a 10 MWe plant.

  16. Limitations of power conversion systems under transient loads and impact on the pulsed tokamak power reactor

    NASA Astrophysics Data System (ADS)

    Sager, G. T.; Wong, C. P. C.; Kapich, D. D.; McDonald, C. F.; Schleicher, R. W.

    1993-11-01

    The impact of cyclic loading of the power conversion system of a helium-cooled, pulsed tokamak power plant is assessed. Design limits of key components of heat transport systems employing Rankine and Brayton thermodynamic cycles are quantified based on experience in gas-cooled fission reactor design and operation. Cyclic loads due to pulsed tokamak operation are estimated. Expected performance of the steam generator is shown to be incompatible with pulsed tokamak operation without load leveling thermal energy storage. The close cycle gas turbine is evaluated qualitatively based on performance of existing industrial and aeroderivative gas turbines. Advances in key technologies which significantly improve prospects for operation with tokamak fusion plants are reviewed.

  17. Conceptual design of an advanced Stirling conversion system for terrestrial power generation

    NASA Technical Reports Server (NTRS)

    1988-01-01

    A free piston Stirling engine coupled to an electric generator or alternator with a nominal kWe power output absorbing thermal energy from a nominal 100 square meter parabolic solar collector and supplying electric power to a utility grid was identified. The results of the conceptual design study of an Advanced Stirling Conversion System (ASCS) were documented. The objectives are as follows: define the ASCS configuration; provide a manufacturability and cost evaluation; predict ASCS performance over the range of solar input required to produce power; estimate system and major component weights; define engine and electrical power condidtioning control requirements; and define key technology needs not ready by the late 1980s in meeting efficiency, life, cost, and with goalds for the ASCS.

  18. Robust Fault Detection of Wind Energy Conversion Systems Based on Dynamic Neural Networks

    PubMed Central

    Talebi, Nasser; Sadrnia, Mohammad Ali; Darabi, Ahmad

    2014-01-01

    Occurrence of faults in wind energy conversion systems (WECSs) is inevitable. In order to detect the occurred faults at the appropriate time, avoid heavy economic losses, ensure safe system operation, prevent damage to adjacent relevant systems, and facilitate timely repair of failed components; a fault detection system (FDS) is required. Recurrent neural networks (RNNs) have gained a noticeable position in FDSs and they have been widely used for modeling of complex dynamical systems. One method for designing an FDS is to prepare a dynamic neural model emulating the normal system behavior. By comparing the outputs of the real system and neural model, incidence of the faults can be identified. In this paper, by utilizing a comprehensive dynamic model which contains both mechanical and electrical components of the WECS, an FDS is suggested using dynamic RNNs. The presented FDS detects faults of the generator's angular velocity sensor, pitch angle sensors, and pitch actuators. Robustness of the FDS is achieved by employing an adaptive threshold. Simulation results show that the proposed scheme is capable to detect the faults shortly and it has very low false and missed alarms rate. PMID:24744774

  19. Testing of an Integrated Reactor Core Simulator and Power Conversion System with Simulated Reactivity Feedback

    NASA Technical Reports Server (NTRS)

    Bragg-Sitton, Shannon M.; Hervol, David S.; Godfroy, Thomas J.

    2010-01-01

    A Direct Drive Gas-Cooled (DDG) reactor core simulator has been coupled to a Brayton Power Conversion Unit (BPCU) for integrated system testing at NASA Glenn Research Center (GRC) in Cleveland, Ohio. This is a closed-cycle system that incorporates an electrically heated reactor core module, turboalternator, recuperator, and gas cooler. Nuclear fuel elements in the gas-cooled reactor design are replaced with electric resistance heaters to simulate the heat from nuclear fuel in the corresponding fast spectrum nuclear reactor. The thermodynamic transient behavior of the integrated system was the focus of this test series. In order to better mimic the integrated response of the nuclear-fueled system, a simulated reactivity feedback control loop was implemented. Core power was controlled by a point kinetics model in which the reactivity feedback was based on core temperature measurements; the neutron generation time and the temperature feedback coefficient are provided as model inputs. These dynamic system response tests demonstrate the overall capability of a non-nuclear test facility in assessing system integration issues and characterizing integrated system response times and response characteristics.

  20. Testing of an Integrated Reactor Core Simulator and Power Conversion System with Simulated Reactivity Feedback

    NASA Technical Reports Server (NTRS)

    Bragg-Sitton, Shannon M.; Hervol, David S.; Godfroy, Thomas J.

    2009-01-01

    A Direct Drive Gas-Cooled (DDG) reactor core simulator has been coupled to a Brayton Power Conversion Unit (BPCU) for integrated system testing at NASA Glenn Research Center (GRC) in Cleveland, OH. This is a closed-cycle system that incorporates an electrically heated reactor core module, turbo alternator, recuperator, and gas cooler. Nuclear fuel elements in the gas-cooled reactor design are replaced with electric resistance heaters to simulate the heat from nuclear fuel in the corresponding fast spectrum nuclear reactor. The thermodynamic transient behavior of the integrated system was the focus of this test series. In order to better mimic the integrated response of the nuclear-fueled system, a simulated reactivity feedback control loop was implemented. Core power was controlled by a point kinetics model in which the reactivity feedback was based on core temperature measurements; the neutron generation time and the temperature feedback coefficient are provided as model inputs. These dynamic system response tests demonstrate the overall capability of a non-nuclear test facility in assessing system integration issues and characterizing integrated system response times and response characteristics.

  1. Robust fault detection of wind energy conversion systems based on dynamic neural networks.

    PubMed

    Talebi, Nasser; Sadrnia, Mohammad Ali; Darabi, Ahmad

    2014-01-01

    Occurrence of faults in wind energy conversion systems (WECSs) is inevitable. In order to detect the occurred faults at the appropriate time, avoid heavy economic losses, ensure safe system operation, prevent damage to adjacent relevant systems, and facilitate timely repair of failed components; a fault detection system (FDS) is required. Recurrent neural networks (RNNs) have gained a noticeable position in FDSs and they have been widely used for modeling of complex dynamical systems. One method for designing an FDS is to prepare a dynamic neural model emulating the normal system behavior. By comparing the outputs of the real system and neural model, incidence of the faults can be identified. In this paper, by utilizing a comprehensive dynamic model which contains both mechanical and electrical components of the WECS, an FDS is suggested using dynamic RNNs. The presented FDS detects faults of the generator's angular velocity sensor, pitch angle sensors, and pitch actuators. Robustness of the FDS is achieved by employing an adaptive threshold. Simulation results show that the proposed scheme is capable to detect the faults shortly and it has very low false and missed alarms rate. PMID:24744774

  2. Properties and Frequency Conversion of High-Brightness Diode-Laser Systems

    NASA Astrophysics Data System (ADS)

    Boller, Klaus-Jochen; Beier, Bernard; Wallenstein, Richard

    An overview of recent developments in the field of high-power, high-brightness diode-lasers, and the optically nonlinear conversion of their output into other wavelength ranges, is given. We describe the generation of continuous-wave (CW) laser beams at power levels of several hundreds of milliwatts to several watts with near-perfect spatial and spectral properties using Master-Oscillator Power-Amplifier (MOPA) systems. With single- or double-stage systems, using amplifiers of tapered or rectangular geometry, up to 2.85 W high-brightness radiation is generated at wavelengths around 810nm with AlGaAs diodes. Even higher powers, up to 5.2W of single-frequency and high spatial quality beams at 925nm, are obtained with InGaAs diodes. We describe the basic properties of the oscillators and amplifiers used. A strict proof-of-quality for the diode radiation is provided by direct and efficient nonlinear optical conversion of the diode MOPA output into other wavelength ranges. We review recent experiments with the highest power levels obtained so far by direct frequency doubling of diode radiation. In these experiments, 100mW single-frequency ultraviolet light at 403nm was generated, as well as 1W of single-frequency blue radiation at 465nm. Nonlinear conversion of diode radiation into widely tunable infrared radiation has recently yielded record values. We review the efficient generation of widely tunable single-frequency radiation in the infrared with diode-pumped Optical Parametric Oscillators (OPOs). With this system, single-frequency output radiation with powers of more than 0.5W was generated, widely tunable around wavelengths of 2.1,m and 1.65,m and with excellent spectral and spatial quality. These developments are clear indicators of recent advances in the field of high-brightness diode-MOPA systems, and may emphasize their future central importance for applications within a vast range of optical

  3. Pilot-scale bioelectrochemical system for efficient conversion of 4-chloronitrobenzene.

    PubMed

    Yuan, Yuan; You, Shi-Jie; Zhang, Jin-Na; Gong, Xiao-Bo; Wang, Xiu-Heng; Ren, Nan-Qi

    2015-01-01

    4-Chloronitrobenzene (4-CNB) is one of the highly toxic contaminants that may lead to acute, chronic or persistent physiological toxicity to ecology and environment. Conventional methods for removing 4-CNB from aquatic environment may be problematic due to inefficiency, high cost and low sustainability. This study develops a pilot-scale bioelectrochemical system (BES, effective volume of 18 L) and examines its performance of bioelectrochemical transformation of 4-CNB to 4-chloroaniline (4-CAN) under continuous operation. The results demonstrate that the initial 4-CNB concentration in the influent and hydraulic retention time (HRT) has a significant impact on 4-CNB reduction and 4-CAN formation. Compared with the conventional anaerobic process in the absence of external power supplied, the 4-CNB conversion efficiency can be enhanced with power supplied due to microbial-mediated electron transfer at the negative cathode potential. At a voltage of 0.4 V and HRT of 48 h, the 4-CNB reduction and 4-CAN formation efficiency reached 99% and 94.1%, respectively. Based on a small external voltage applied, the pilot-scale BES is effective in the conversion of 4-CNB to 4-CAN, an intermediate that is of less toxicity and higher bioavailability for subsequent treatment. This study provides a new strategy and methods for eliminating 4-CNB, making wastewater treatment more economical and more sustainable. PMID:25650667

  4. Surface Decontamination of System Components in Uranium Conversion Plant at KAERI

    SciTech Connect

    Choi, W. K.; Kim, K. N.; Won, H. J.; Jung, C. H.; Oh, W. Z.

    2003-02-25

    A chemical decontamination process using nitric acid solution was selected as in-situ technology for recycle or release with authorization of a large amount of metallic waste including process system components such as tanks, piping, etc., which is generated by dismantling a retired uranium conversion plant at Korea Atomic Energy Research Institute (KAERI). The applicability of nitric acid solution for surface decontamination of metallic wastes contaminated with uranium compounds was evaluated through the basic research on the dissolution of UO2 and ammonium uranyl carbonate (AUC) powder. Decontamination performance was verified by using the specimens contaminated with such uranium compounds as UO2 and AUC taken from the uranium conversion plant. Dissolution rate of UO2 powder is notably enhanced by the addition of H2O2 as an oxidant even in the condition of a low concentration of nitric acid and low temperature compared with those in a nitric acid solution without H2O2. AUC powders dissolve easily in nitric acid solutions until the solution pH attains about 2.5 {approx} 3. Above that solution pH, however, the uranium concentration in the solution is lowered drastically by precipitation as a form of U3(NH3)4O9 . 5H2O. Decontamination performance tests for the specimens contaminated with UO2 and AUC were quite successful with the application of decontamination conditions obtained through the basic studies on the dissolution of UO2 and AUC powders.

  5. Inertial confinement fusion reaction chamber and power conversion system study. Final report

    SciTech Connect

    Maya, I.; Schultz, K.R.; Bourque, R.F.; Cheng, E.T.; Creedon, R.L.; Norman, J.H.; Price, R.J.; Porter, J.; Schuster, H.L.; Simnad, M.J.

    1985-10-01

    This report summarizes the results of the second year of a two-year study on the design and evaluation of the Cascade concept as a commercial inertial confinement fusion (ICF) reactor. We developed a reactor design based on the Cascade reaction chamber concept that would be competitive in terms of both capital and operating costs, safe and environmentally acceptable in terms of hazard to the public, occupational exposure and radioactive waste production, and highly efficient. The Cascade reaction chamber is a double-cone-shaped rotating drum. The granulated solid blanket materials inside the rotating chamber are held against the walls by centrifugal force. The fusion energy is captured in a blanket of solid carbon, BeO, and LiAlO/sub 2/ granules. These granules are circulated to the primary side of a ceramic heat exchanger. Primary-side granule temperatures range from 1285 K at the LiAlO/sub 2/ granule heat exchanger outlet to 1600 K at the carbon granule heat exchanger inlet. The secondary side consists of a closed-cycle gas turbine power conversion system with helium working fluid, operating at 1300 K peak outlet temperature and achieving a thermal power conversion efficiency of 55%. The net plant efficiency is 49%. The reference design is a plant producing 1500 MW of D-T fusion power and delivering 815 MW of electrical power for sale to the utility grid. 88 refs., 44 figs., 47 tabs.

  6. Evaluating mountain goat dairy systems for conversion to the organic model, using a multicriteria method.

    PubMed

    Mena, Y; Nahed, J; Ruiz, F A; Sánchez-Muñoz, J B; Ruiz-Rojas, J L; Castel, J M

    2012-04-01

    Organic farming conserves natural resources, promotes biodiversity, guarantees animal welfare and obtains healthy products from raw materials through natural processes. In order to evaluate possibilities of increasing organic animal production, this study proposes a farm-scale multicriteria method for assessing the conversion of dairy goat systems to the organic model. In addition, a case study in the Northern Sierra of Seville, southern Spain, is analysed. A consensus of expert opinions and a field survey are used to validate a list of potential indicators and issues for assessing the conversion, which consider not only the European Community regulations for organic livestock farming, but also agroecological principles. As a result, the method includes 56 variables integrated in nine indicators: Nutritional management, Sustainable pasture management, Soil fertility and contamination, Weed and pest control, Disease prevention, Breeds and reproduction, Animal welfare, Food safety and Marketing and management. The nine indicators are finally integrated in a global index named OLPI (Organic Livestock Proximity Index). Application of the method to a case study with 24 goat farms reveals an OLPI value of 46.5% for dairy goat farms located in mountain areas of southern Spain. The aspects that differ most from the agroecological model include soil management, animal nutrition and product marketing. Results of the case study indicate that the proposed method is easy to implement and is useful for quantifying the approximation of conventional farms to an organic model. PMID:22436287

  7. Design of a pool boiler heat transport system for a 25 kWe advanced Stirling conversion system

    NASA Astrophysics Data System (ADS)

    Anderson, W. G.; Rosenfeld, J. H.; Noble, J.; Kesseli, J.

    The overall operating temperature and efficiency of solar-powered Stirling engines can be improved by adding a heat transport system to more uniformly supply heat to the heater head tubes. One heat transport system with favorable characteristics is an alkali metal pool boiler. An alkali metal pool boiler heat transport system was designed for a 25-kW advanced Stirling conversion system (ASCS). Solar energy concentrated on the absorber dome boils a eutectic mixture of sodium and potassium. The alkali metal vapors condense on the heater head tubes, supplying the Stirling engine with a uniform heat flux at a constant temperature. Boiling stability is achieved with the use of an enhanced boiling surface and noncondensible gas.

  8. Design of a pool boiler heat transport system for a 25 kWe advanced Stirling conversion system

    NASA Technical Reports Server (NTRS)

    Anderson, W. G.; Rosenfeld, J. H.; Noble, J.; Kesseli, J.

    1991-01-01

    The overall operating temperature and efficiency of solar-powered Stirling engines can be improved by adding a heat transport system to more uniformly supply heat to the heater head tubes. One heat transport system with favorable characteristics is an alkali metal pool boiler. An alkali metal pool boiler heat transport system was designed for a 25-kW advanced Stirling conversion system (ASCS). Solar energy concentrated on the absorber dome boils a eutectic mixture of sodium and potassium. The alkali metal vapors condense on the heater head tubes, supplying the Stirling engine with a uniform heat flux at a constant temperature. Boiling stability is achieved with the use of an enhanced boiling surface and noncondensible gas.

  9. Preliminary design of an advanced Stirling system for terrestrial solar energy conversion

    NASA Astrophysics Data System (ADS)

    White, M. A.; Noble, J. E.; Emigh, S. G.; Ross, B. A.; Lehmann, G. A.

    A preliminary design was generated for an advanced Stirling conversion system (ASCS) that will be capable of delivering about 25 kW of electric power to an electric utility grid. Stirling engines are being evaluated for terrestrial solar applications. A two-year task to complete detailed design, fabrication, assembly and testing of an ASCS prototype began in April, 1990. The ASCS is designed to deliver maximum power per year over a range of solar inputs with a design life of 30 years (60,000 h). The ACSC has a long-term cost goal of about $450 per kilowatt, exclusive of the 11-m parabolic dish concentrator. The proposed system includes a Stirling engine with high-pressure hydraulic output, coupled with a bent axis variable displacement hydraulic motor and a rotary induction generator. The major thrusts of the preliminary design are described, including material selection for the hot-end components, heat transport system (reflux pool boiler) design, system thermal response, improved manufacturability, FMECA/FTA analysis, updated manufacturing cost estimate, and predicted system performance.

  10. Materials considerations for molten salt accelerator-based plutonium conversion systems

    SciTech Connect

    DiStefano, J.R.; DeVan, J.H.; Keiser, J.R.; Klueh, R.L.; Eatherly, W.P.

    1995-03-01

    Accelerator-driven transmutation technology (ADTT) refers to a concept for a system that uses a blanket assembly driven by a source of neutrons produced when high-energy protons from an accelerator strike a heavy metal target. One application for such a system is called Accelerator-Based Plutonium Conversion, or ABC. Currently, the version of this concept being proposed by the Los Alamos National Laboratory features a liquid lead target material and a blanket fuel of molten fluorides that contain plutonium. Thus, the materials to be used in such a system must have, in addition to adequate mechanical strength, corrosion resistance to molten lead, corrosion resistance to molten fluoride salts, and resistance to radiation damage. In this report the corrosion properties of liquid lead and the LiF-BeF{sub 2} molten salt system are reviewed in the context of candidate materials for the above application. Background information has been drawn from extensive past studies. The system operating temperature, type of protective environment, and oxidation potential of the salt are shown to be critical design considerations. Factors such as the generation of fission products and transmutation of salt components also significantly affect corrosion behavior, and procedures for inhibiting their effects are discussed. In view of the potential for extreme conditions relative to neutron fluxes and energies that can occur in an ADTT, a knowledge of radiation effects is a most important factor. Present information for potential materials selections is summarized.

  11. Materials considerations for molten salt accelerator-based plutonium conversion systems

    SciTech Connect

    DiStefano, J.R.; DeVan, J.H.; Keiser, J.R.; Klueh, R.L.; Eatherly, W.P.

    1995-02-01

    Accelerator-driven transmutation technology (ADTT) refers to a concept for a system that uses a blanket assembly driven by a source of neutrons produced when high-energy protons from an accelerator strike a heavy metal target. One application for such a system is called Accelerator-Based Plutonium Conversion, or ABC. Currently, the version of this concept being proposed by the Los Alamos National Laboratory features a liquid lead target material and a blanket fuel of molten fluorides that contain plutonium. Thus, the materials to be used in such a system must have, in addition to adequate mechanical strength, corrosion resistance to molten lead, corrosion resistance to molten fluoride salts, and resistance to radiation damage. In this report the corrosion properties of liquid lead and the LiF-BeF{sub 2} molten salt system are reviewed in the context of candidate materials for the above application. Background information has been drawn from extensive past studies. The system operating temperature, type of protective environment, and oxidation potential of the salt are shown to be critical design considerations. Factors such as the generation of fission products and transmutation of salt components also significantly affect corrosion behavior, and procedures for inhibiting their effects are discussed. In view of the potential for extreme conditions relative to neutron fluxes and energies that can occur in an ADTT, a knowledge of radiation effects is a most important factor. Present information for potential materials selections is summarized.

  12. Preliminary design of an advanced Stirling system for terrestrial solar energy conversion

    NASA Technical Reports Server (NTRS)

    White, M. A.; Noble, J. E.; Emigh, S. G.; Ross, B. A.; Lehmann, G. A.

    1990-01-01

    A preliminary design was generated for an advanced Stirling conversion system (ASCS) that will be capable of delivering about 25 kW of electric power to an electric utility grid. Stirling engines are being evaluated for terrestrial solar applications. A two-year task to complete detailed design, fabrication, assembly and testing of an ASCS prototype began in April, 1990. The ASCS is designed to deliver maximum power per year over a range of solar inputs with a design life of 30 years (60,000 h). The ACSC has a long-term cost goal of about $450 per kilowatt, exclusive of the 11-m parabolic dish concentrator. The proposed system includes a Stirling engine with high-pressure hydraulic output, coupled with a bent axis variable displacement hydraulic motor and a rotary induction generator. The major thrusts of the preliminary design are described, including material selection for the hot-end components, heat transport system (reflux pool boiler) design, system thermal response, improved manufacturability, FMECA/FTA analysis, updated manufacturing cost estimate, and predicted system performance.

  13. Performance of a Kilowatt-Class Stirling Power Conversion System in a Thermodynamically-Coupled Configuration

    NASA Astrophysics Data System (ADS)

    Geng, S. M.; Briggs, M. H.; Hervol, D. S.

    A pair of 1kWe free-piston Stirling power convertors has been modified into a thermodynamically coupled configuration, and performance map testing has been completed. This is the same configuration planned for the full-scale 12 kWe power conversion unit (PCU) that will be used in the Fission Power System Technology Demonstration Unit (TDU). The 1-kWe convertors were operated over a range of conditions to evaluate the effects of thermodynamic coupling on convertor performance and to identify any possible control challenges. The thermodynamically coupled convertor showed no measurable difference in performance from the baseline data collected when the engines were separate and no major control issues were encountered during operation. The results of this test are guiding controller development and instrumentation selection for the TDU.

  14. Enzyme conversion of lignocellulosic plant materials for resource recovery in a controlled ecological life support system

    NASA Astrophysics Data System (ADS)

    Kohlmann, K. L.; Westgate, P.; Velayudhan, A.; Weil, J.; Sarikaya, A.; Brewer, M. A.; Hendrickson, R. L.; Ladisch, M. R.

    1996-01-01

    A large amount of inedible plant material composed primarily of the carbohydrate materials cellulose, hemicellulose, and lignin is generated as a result of plant growth in a Controlled Ecological Life-Support System (CELSS). Cellulose is a linear homopolymer of glucose, which when properly processed will yield glucose, a valuable sugar because it can be added directly to human diets. Hemicellulose is a heteropolymer of hexoses and pentoses that can be treated to give a sugar mixture that is potentially a valuable fermentable carbon source. Such fermentations yield desirable supplements to the edible products from hydroponically-grown plants such as rapeseed, soybean, cowpea, or rice. Lignin is a three-dimensionally branched aromatic polymer, composed of phenyl propane units, which is susceptible to bioconversion through the growth of the white rot fungus, Pluerotus ostreatus. Processing conditions, that include both a hot water pretreatment and fungal growth and that lead to the facile conversion of plant polysaccharides to glucose, are presented.

  15. Enzyme conversion of lignocellulosic plant materials for resource recovery in a Controlled Ecological Life Support System

    NASA Technical Reports Server (NTRS)

    Kohlmann, K. L.; Westgate, P.; Velayudhan, A.; Weil, J.; Sarikaya, A.; Brewer, M. A.; Hendrickson, R. L.; Ladisch, M. R.; Mitchell, C. A. (Principal Investigator)

    1996-01-01

    A large amount of inedible plant material composed primarily of the carbohydrate materials cellulose, hemicellulose, and lignin is generated as a result of plant growth in a Controlled Ecological Life-Support System (CELSS). Cellulose is a linear homopolymer of glucose, which when properly processed will yield glucose, a valuable sugar because it can be added directly to human diets. Hemicellulose is a heteropolymer of hexoses and pentoses that can be treated to give a sugar mixture that is potentially a valuable fermentable carbon source. Such fermentations yield desirable supplements to the edible products from hydroponically-grown plants such as rapeseed, soybean, cowpea, or rice. Lignin is a three-dimensionally branched aromatic polymer, composed of phenyl propane units, which is susceptible to bioconversion through the growth of the white rot fungus, Pluerotus ostreatus. Processing conditions, that include both a hot water pretreatment and fungal growth and that lead to the facile conversion of plant polysaccharides to glucose, are presented.

  16. Conversations with the community: the Methodist Hospital System's experience with social media.

    PubMed

    Angelle, Denny; Rose, Clare L

    2011-01-01

    The Methodist Hospital System has maintained a social media presence on Facebook, Twitter, and YouTube since 2009. After initial unofficial excursions into the world of social media, we discovered that social media can be a useful tool to extend a conversation with our patients and the community at large and share our hospital's culture with a larger base of like-minded people. But with this new power comes a heightened responsibility--platforms that can potentially reach millions of viewers and readers also provide a potential for misuse that can jeopardize patient privacy and place hospitals at risk. Because of their unique restrictions, even hospitals that use the tools regularly have much left to learn about social media. With constant monitoring and stewardship and a commitment to educating staff, hospitals can effectively use social media tools for marketing and education. PMID:22256507

  17. Energy transducer for hydraulic wind power conversion system and instrumentation therefor

    SciTech Connect

    Woodhull, W. M.

    1985-05-07

    A manually adjustable constriction or orifice to provide a means for optimizing the hydraulic power being converted to heat in a hydraulic windpower conversion system. The hydraulics and constriction are arranged to obtain the proer conditions necessary so that pressure head is converted to velocity head with the sum of the two remaining constant. Instrumentation to facilitate this optimizing adjustment process. A combination of a pump-speed transducer and a pressure-sensing transducer, along with appropriate electronic circuitry is described which provides an output display of the power being converted to heat. Instrumentation to accumulate and display the total energy converted to heat. Electronic devices and display equipment transform hydraulic power signals into energy signals, totalize the energy signals over time, and periodically display the accumulated energy count.

  18. Nonlinear Predictive Control of Wind Energy Conversion System Using Dfig with Aerodynamic Torque Observer

    NASA Astrophysics Data System (ADS)

    Kamel, Ouari; Mohand, Ouhrouche; Toufik, Rekioua; Taib, Nabil

    2015-01-01

    In order to improvement of the performances for wind energy conversions systems (WECS), an advanced control techniques must be used. In this paper, as an alternative to conventional PI-type control methods, a nonlinear predictive control (NPC) approach is developed for DFIG-based wind turbine. To enhance the robustness of the controller, a disturbance observer is designed to estimate the aerodynamic torque which is considered as an unknown perturbation. An explicitly analytical form of the optimal predictive controller is given consequently on-line optimization is not necessary The DFIG is fed through the rotor windings by a back-to-back converter controlled by Pulse Width Modulation (PWM), where the stator winding is directly connected to the grid. The presented simulation results show a good performance in trajectory tracking of the proposed strategy and rejection of disturbances is successfully achieved.

  19. The UTRC wind energy conversion system performance analysis for horizontal axis wind turbines (WECSPER)

    NASA Technical Reports Server (NTRS)

    Egolf, T. A.; Landgrebe, A. J.

    1981-01-01

    The theory for the UTRC Energy Conversion System Performance Analysis (WECSPER) for the prediction of horizontal axis wind turbine performance is presented. Major features of the analysis are the ability to: (1) treat the wind turbine blades as lifting lines with a prescribed wake model; (2) solve for the wake-induced inflow and blade circulation using real nonlinear airfoil data; and (3) iterate internally to obtain a compatible wake transport velocity and blade loading solution. This analysis also provides an approximate treatment of wake distortions due to tower shadow or wind shear profiles. Finally, selected results of internal UTRC application of the analysis to existing wind turbines and correlation with limited test data are described.

  20. Performance of a Kilowatt-Class Stirling Power Conversion System in a Thermodynamically Coupled Configuration

    NASA Technical Reports Server (NTRS)

    Geng, Steven M.; Briggs, Maxwell H.; Hervol, David S.

    2011-01-01

    A pair of 1-kWe free-piston Stirling power convertors has been modified into a thermodynamically coupled configuration, and performance map testing has been completed. This is the same configuration planned for the full-scale 12-kWe power conversion unit (PCU) that will be used in the Fission Power System Technology Demonstration Unit (TDU). The 1-kWe convertors were operated over a range of conditions to evaluate the effects of thermodynamic coupling on convertor performance and to identify any possible control challenges. The thermodynamically coupled convertor showed no measureable difference in performance from the baseline data collected when the engines were separate, and no major control issues were encountered during operation. The results of this test are guiding controller development and instrumentation selection for the TDU.

  1. Engineering Spectral Control Using Front Surface Filters for Maximum TPV Energy Conversion System Performance

    SciTech Connect

    T Rahmlow, Jr; J Lazo-Wasem, E Gratrix; J Azarkevich; E Brown; D DePoy; D Eno; P Fourspring; J Parrington; R Mahorter; B Wernsman

    2004-10-14

    Energy conversion efficiencies of better than 23% have been demonstrated for small scale tests of a few thermophotovoltaic (TPV) cells using front surface, tandem filters [1, 2]. The engineering challenge is to build this level of efficiency into arrays of cells that provide useful levels of energy. Variations in cell and filter performance will degrade TPV array performance. Repeated fabrication runs of several filters each provide an initial quantification of the fabrication variation for front surface, tandem filters for TPV spectral control. For three performance statistics, within-run variation was measured to be 0.7-1.4 percent, and run-to-run variation was measured to be 0.5-3.2 percent. Fabrication runs using a mask have been shown to reduce variation across interference filters from as high as 8-10 percent to less than 1.5 percent. Finally, several system design and assembly approaches are described to further reduce variation.

  2. Modeling of the interplay between single-file diffusion and conversion reaction in mesoporous systems

    SciTech Connect

    Wang, Jing

    2013-01-11

    We analyze the spatiotemporal behavior of species concentrations in a diffusion-mediated conversion reaction which occurs at catalytic sites within linear pores of nanometer diameter. A strict single-file (no passing) constraint occurs in the diffusion within such narrow pores. Both transient and steady-state behavior is precisely characterized by kinetic Monte Carlo simulations of a spatially discrete lattice–gas model for this reaction–diffusion process considering various distributions of catalytic sites. Exact hierarchical master equations can also be developed for this model. Their analysis, after application of mean-field type truncation approximations, produces discrete reaction–diffusion type equations (mf-RDE). For slowly varying concentrations, we further develop coarse-grained continuum hydrodynamic reaction–diffusion equations (h-RDE) incorporating a precise treatment of single-file diffusion (SFD) in this multispecies system. Noting the shortcomings of mf-RDE and h-RDE, we then develop a generalized hydrodynamic (GH) formulation of appropriate gh-RDE which incorporates an unconventional description of chemical diffusion in mixed-component quasi-single-file systems based on a refined picture of tracer diffusion for finite-length pores. The gh-RDE elucidate the non-exponential decay of the steady-state reactant concentration into the pore and the non-mean-field scaling of the reactant penetration depth. Then an extended model of a catalytic conversion reaction within a functionalized nanoporous material is developed to assess the effect of varying the reaction product – pore interior interaction from attractive to repulsive. The analysis is performed utilizing the generalized hydrodynamic formulation of the reaction-diffusion equations which can reliably capture the complex interplay between reaction and restricted transport for both irreversible and reversible reactions.

  3. Truck co-generation system based on combustion heated thermoelectric conversion

    SciTech Connect

    Meleta, Ye.A.; Yarygin, V.I.; Klepikov, V.V.; Wolff, L.R.

    1997-12-31

    Among the micro-co-generation systems using direct conversion of combustion heat into electricity (thermionic, thermoelectric converters) and fuel cells with an electric power of up to several kW, only the thermoelectric co-generation systems have a demonstrated life-time of up to 10 years. This is one of the most important factors making these systems a more likely commercialization candidate. The report deals with a conceptual design of a combustion heated thermoelectric cogeneration system to be applied in vehicles (truck, trailer, yacht, etc.). The authors named these systems the Thermoelectric Transport Co-generation Systems (TTCS). The report is concerned with one example of these systems--the Thermoelectric Truck Co-generation System (TT-kCS) designed to support the lives of both the driver and the car, when operating in the northern regions. In particular, the TT-kCS should provide the start-up of the cold engine of a truck at an ambient temperature of down to 50 C below zero and create comfortable conditions for a driver during the long-term halts and in emergency situations. The estimates made for a standard truck with an engine of 210 HP employed in Russia showed that the TT-kCS should generate {approximately}600 W of electrical power and {approximately}18 kW of heat. The report deals with two options for the thermoelectric converter design: one of them using the planar geometry of thermoelectric batteries, and the other one using a radial-cylindrical thermoelectric battery configuration. The economic feasibility of the TT-kCS application is based on a considerable reduction in fuel consumption of the TT-kCS equipped truck as compared to that of a conventional truck when the engine is idling. Another advantage is the prolongation of the engine`s service life.

  4. Enzymic conversion of ethanol to acetaldehyde as a model recovery system

    SciTech Connect

    Kierstan, M.

    1982-10-01

    Ethanol is readily produced by use of traditional fermentation processes using yeasts, and more recently by use of immobilized cell systems. However, the product concentrations obtained in these systems are limited by the inhibitory effects on the microorganisms of the product, ethanol. Furthermore, the dilute product concentrations thus obtained combined with the relatively high boiling point of ethanol result in systems which require a high degree of energy input for product recovery. Recent advances in genetic engineering techniques offer opportunities for improving the characteristics of the yeasts used in ethanol production. These techniques also provide the potential for improving the production yields of microbial enzymes for specific applications. With this consideration in mind work was undertaken on an enzymic system for removal from a fermentation media of an ethanol product which also results in upgrading of the product. Conversion of ethanol to acetaldehyde can be achieved without the involvement of nicotinamide cofactors by use of the enzyme alcohol oxidase obtainable from Candida boidinii. The product acetaldehyde has a relatively low boiling point (21 degrees C) and, therefore, readily evaporates from systems operating above this temperature. This is compatible with normal operating temperatures for ethanol production. The acetaldehyde so produced can then be readily condensed and be utilized or chemically converted to other products. The production of acetaldehyde is accompanied by production of hydrogen peroxide. The effect of the removal of this product, by the use of catalase, on the primary process was also investigated. The system outlined has potential for development into an immobilized enzyme or cell system which may be made compatible with an immobilized Saccharomyces cerevisiae system for improved efficiency of glucose utilization.

  5. Advances in defining a closed Brayton conversion system for future ARIANE 5 space nuclear power applications

    SciTech Connect

    Tilliette, Z.P.

    1987-01-01

    The present European ARIANE space program will expand into the large ARIANE 5 launch vehicle from 1995. It is assumed that important associated missions would require the generation of 200 kWe or more in space during several years at the very beginning of the next century. For this reason, in 1983, the French C.N.E.S. (Centre National d'Etudes Spatiales) and C.E.A. (Commissariat a l'Energie Atomique) have initiated preliminary studies of a space nuclear power system. The currently selected conversion system is a closed Brayton cycle. Reasons for this choice are given: high efficiency of a dynamic system; monophasic, inert working fluid; extensive turbomachinery experience, etc. A key aspect of the project is the adaptation to heat rejection conditions, namely to the radiator geometry which depends upon the dimensions of the ARIANE 5 spacecraft. In addition to usual concepts already studied for space applications, another cycle arrangement is being investigated which could offer satisfactory compromises among many considerations, increase the efficiency of the system, and make it more attractive as far as the specific mass (kg/lWe), the specific radiator area (m/sup 2//kWe), and various technological aspects are concerned. Comparative details are presented.

  6. An effective biphase system accelerates hesperidinase-catalyzed conversion of rutin to isoquercitrin.

    PubMed

    Wang, Jun; Gong, An; Yang, Cai-Feng; Bao, Qi; Shi, Xin-Yi; Han, Bei-Bei; Wu, Xiang-Yang; Wu, Fu-An

    2015-01-01

    Isoquercitrin is a rare, natural ingredient with several biological activities that is a key precursor for the synthesis of enzymatically modified isoquercitrin (EMIQ). The enzymatic production of isoquercitrin from rutin catalyzed by hesperidinase is feasible; however, the bioprocess is hindered by low substrate concentration and a long reaction time. Thus, a novel biphase system consisting of [Bmim][BF4]:glycine-sodium hydroxide (pH 9) (10:90, v/v) and glyceryl triacetate (1:1, v/v) was initially established for isoquercitrin production. The biotransformation product was identified using liquid chromatography-mass spectrometry, and the bonding mechanism of the enzyme and substrate was inferred using circular dichroism spectra and kinetic parameters. The highest rutin conversion of 99.5% and isoquercitrin yield of 93.9% were obtained after 3 h. The reaction route is environmentally benign and mild, and the biphase system could be reused. The substrate concentration was increased 2.6-fold, the reaction time was reduced to three tenths the original time. The three-dimensional structure of hesperidinase was changed in the biphase system, which α-helix and random content were reduced and β-sheet content was increased. Thus, the developed biphase system can effectively strengthen the hesperidinase-catalyzed synthesis of isoquercitrin with high yield. PMID:25731802

  7. The Liquid Droplet Radiator - an Ultralightweight Heat Rejection System for Efficient Energy Conversion in Space

    NASA Technical Reports Server (NTRS)

    Mattick, A. T.; Hertzberg, A.

    1984-01-01

    A heat rejection system for space is described which uses a recirculating free stream of liquid droplets in place of a solid surface to radiate waste heat. By using sufficiently small droplets ( 100 micron diameter) of low vapor pressure liquids the radiating droplet sheet can be made many times lighter than the lightest solid surface radiators (heat pipes). The liquid droplet radiator (LDR) is less vulnerable to damage by micrometeoroids than solid surface radiators, and may be transported into space far more efficiently. Analyses are presented of LDR applications in thermal and photovoltaic energy conversion which indicate that fluid handling components (droplet generator, droplet collector, heat exchanger, and pump) may comprise most of the radiator system mass. Even the unoptimized models employed yield LDR system masses less than heat pipe radiator system masses, and significant improvement is expected using design approaches that incorporate fluid handling components more efficiently. Technical problems (e.g., spacecraft contamination and electrostatic deflection of droplets) unique to this method of heat rejectioon are discussed and solutions are suggested.

  8. The liquid droplet radiator - An ultralightweight heat rejection system for efficient energy conversion in space

    NASA Technical Reports Server (NTRS)

    Mattick, A. T.; Hertzberg, A.

    1981-01-01

    A heat rejection system for space is described which uses a recirculating free stream of liquid droplets in place of a solid surface to radiate waste heat. By using sufficiently small droplets (less than about 100 micron diameter) of low vapor pressure liquids (tin, tin-lead-bismuth eutectics, vacuum oils) the radiating droplet sheet can be made many times lighter than the lightest solid surface radiators (heat pipes). The liquid droplet radiator (LDR) is less vulnerable to damage by micrometeoroids than solid surface radiators, and may be transported into space far more efficiently. Analyses are presented of LDR applications in thermal and photovoltaic energy conversion which indicate that fluid handling components (droplet generator, droplet collector, heat exchanger, and pump) may comprise most of the radiator system mass. Even the unoptimized models employed yield LDR system masses less than heat pipe radiator system masses, and significant improvement is expected using design approaches that incorporate fluid handling components more efficiently. Technical problems (e.g., spacecraft contamination and electrostatic deflection of droplets) unique to this method of heat rejection are discussed and solutions are suggested.

  9. An effective biphase system accelerates hesperidinase-catalyzed conversion of rutin to isoquercitrin

    PubMed Central

    Wang, Jun; Gong, An; Yang, Cai-Feng; Bao, Qi; Shi, Xin-Yi; Han, Bei-Bei; Wu, Xiang-Yang; Wu, Fu-An

    2015-01-01

    Isoquercitrin is a rare, natural ingredient with several biological activities that is a key precursor for the synthesis of enzymatically modified isoquercitrin (EMIQ). The enzymatic production of isoquercitrin from rutin catalyzed by hesperidinase is feasible; however, the bioprocess is hindered by low substrate concentration and a long reaction time. Thus, a novel biphase system consisting of [Bmim][BF4]:glycine-sodium hydroxide (pH 9) (10:90, v/v) and glyceryl triacetate (1:1, v/v) was initially established for isoquercitrin production. The biotransformation product was identified using liquid chromatography-mass spectrometry, and the bonding mechanism of the enzyme and substrate was inferred using circular dichroism spectra and kinetic parameters. The highest rutin conversion of 99.5% and isoquercitrin yield of 93.9% were obtained after 3 h. The reaction route is environmentally benign and mild, and the biphase system could be reused. The substrate concentration was increased 2.6-fold, the reaction time was reduced to three tenths the original time. The three-dimensional structure of hesperidinase was changed in the biphase system, which α-helix and random content were reduced and β-sheet content was increased. Thus, the developed biphase system can effectively strengthen the hesperidinase-catalyzed synthesis of isoquercitrin with high yield. PMID:25731802

  10. Operational Curves for HTGR's Coupled to Closed Brayton Cycle Power Conversion Systems

    SciTech Connect

    Wright, Steven A.; Lipinski, Ronald J.

    2006-07-01

    Gas Cooled Reactors (GCR) that drive Closed Brayton Cycle (CBC) systems are being evaluated by the Department of Energy (DOE) Next Generation Program for high-efficiency electricity generation. This paper describes the operational performance of measured and predicted closed Brayton cycles. The measured results were obtained from an electrically driven closed Brayton cycle test loop that Sandia fabricated and has operating within the laboratories. The predicted behavior is based on integrated dynamic system models that are capable of predicting both the transient and steady state behavior of reactor driven Brayton cycle systems. Sandia contracted Barber Nichols Corporation to modify a Capstone C30 open-cycle Brayton engine so that it could be operated in a closed loop. We are currently operating the test loop to validate the models and to study control issues. Operation of the test-loop and developing the system models has allowed Sandia to develop and validate a set of tools and models that are being used to determine how nuclear reactors operate with gas turbine power conversion systems. Both measured and modeled operational performance curves will be presented to show how the electrical load (or power generated) varies as a function of shaft speed for various turbine inlet temperatures and for a fixed fill gas inventory. The measured and modeled behavior of the test loop both reveal the non-linear nature of the reactor and Brayton cycle loop because for a fixed electrical load there are two shaft speeds that can produce this steady-state power. Closer examination of the system of equations shows that only one of these steady-state solutions is dynamically stable. An active electronic control system will be required to operate at the more efficient but dynamically unstable point, and some means of controlling the flow via inventory control or bypass flow valves will also be required. (authors)

  11. Systems definition space-based power conversion systems. [for satellite power transmission to earth

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Potential space-located systems for the generation of electrical power for use on Earth are discussed and include: (1) systems producing electrical power from solar energy; (2) systems producing electrical power from nuclear reactors; and (3) systems for augmenting ground-based solar power plants by orbital sunlight reflectors. Systems (1) and (2) would utilize a microwave beam system to transmit their output to Earth. Configurations implementing these concepts were developed through an optimization process intended to yield the lowest cost for each. A complete program was developed for each concept, identifying required production rates, quantities of launches, required facilities, etc. Each program was costed in order to provide the electric power cost appropriate to each concept.

  12. Wavelength conversion in modulated coupled-resonator systems and their design via an equivalent linear filter representation.

    PubMed

    Wade, Mark T; Zeng, Xiaoge; Popović, Miloš A

    2015-01-01

    We propose wavelength converters based on modulated coupled resonators that achieve conversion by matching the modulation frequency to the frequency splitting of the supermodes of the unmodulated system. Using temporal coupled-mode theory, we show that these time-variant systems have an equivalent linear, time-invariant filter representation that simplifies the optimal engineering of design parameters for realistic systems. Applying our model to carrier plasma-dispersion modulators as an example implementation, we calculate conversion efficiencies between -5.4 and -1.7  dB for intrinsic quality factors of 10(4)-10(6). We show that the ratio of the resonance shift to the total linewidth is the most important parameter when determining conversion efficiency. Finally, we discuss how this model can be used to design devices such as frequency shifters, widely tunable radio frequency oscillators, and frequency combs. PMID:25531621

  13. Conceptual design of free-piston Stirling conversion system for solar power units

    NASA Astrophysics Data System (ADS)

    Loktionov, Iu. V.

    A conversion system has been conceptually designed for solar power units of the dish-Stirling type. The main design objectives were to demonstrate the possibility of attaining such performance characteristics as low manufacturing and life cycle costs, high reliability, long life, high efficiency, power output stability, self-balance, automatic (or self-) start-up, and easy maintenance. The system design includes a heat transfer and utilization subsystem with a solar receiver, a free-piston engine, an electric power generation subsystem, and a control subsystem. The working fluid is helium. The structural material is stainless steel for hot elements, aluminum alloys and plastics for others. The electric generation subunit can be fabricated in three options: with an induction linear alternator, with a permanent magnet linear alternator, and with a serial rotated induction generator and a hydraulic drive subsystem. The heat transfer system is based on heat pipes or the reflux boiler principle. Several models of heat transfer units using a liquid metal (Na or Na-K) have been created and demonstrated.

  14. Preliminary designs for 25 kWe advanced Stirling conversion systems for dish electric applications

    NASA Technical Reports Server (NTRS)

    Shaltens, Richard K.; Schreiber, Jeffrey G.

    1990-01-01

    Under the Department of Energy's (DOE) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for terrestrial Solar Distributed Heat Receivers. The Stirling engine has been identified by Sandia as one of the most promising engines for terrestrial applications. The Stirling engine also has the potential to meet DOE's performance and cost goals. The NASA Lewis Research Center is conducting Stirling engine technology development activities directed toward a dynamic power source for space applications. Space power systems requirements include high reliability, very long life, low vibration and high efficiency. The free-piston Stirling engine has the potential for future high power space conversion systems, either nuclear or solar powered. Although both applications appear to be quite different, their requirements complement each other. Preliminary designs feature a free-piston Stirling engine, a liquid metal heat transport system, and a means to provide nominally 25 kW electric power to a utility grid while meeting DOE's performance and long term cost goals. The Cummins design incorporates a linear alternator to provide the electrical output, while the STC design generates electrical power indirectly through a hydraulic pump/motor coupled to an induction generator. Both designs for the ASCS's will use technology which can reasonably be expected to be available in the early 1990's

  15. Design and Fabrication of a 5-kWe Free-Piston Stirling Power Conversion System

    NASA Technical Reports Server (NTRS)

    Chapman, Peter A.; Walter, Thomas J.; Brandhorst, Henry W., Jr.

    2008-01-01

    Progress in the design and fabrication of a 5-kWe free-piston Stirling power conversion system is described. A scaled-down version of the successful 12.5-kWe Component Test Power Converter (CTPC) developed under NAS3-25463, this single cylinder prototype incorporates cost effective and readily available materials (steel versus beryllium) and components (a commercial linear alternator). The design consists of a displacer suspended on internally pumped gas bearings and a power piston/alternator supported on flexures. Non-contacting clearance seals are used between internal volumes. Heat to and from the prototype is supplied via pumped liquid loops passing through shell and tube heat exchangers. The control system incorporates several novel ideas such as a pulse start capability and a piston stroke set point control strategy that provides the ability to throttle the engine to match the required output power. It also ensures stable response to various disturbances such as electrical load variations while providing useful data regarding the position of both power piston and displacer. All design and analysis activities are complete and fabrication is underway. Prototype test is planned for summer 2008 at Foster-Miller to characterize the dynamics and steady-state operation of the prototype and determine maximum power output and system efficiency. Further tests will then be performed at Auburn University to determine start-up and shutdown characteristics and assess transient response to temperature and load variations.

  16. Impact of thermal energy storage properties on solar dynamic space power conversion system mass

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.; Coles-Hamilton, Carolyn E.; Lacy, Dovie E.

    1987-01-01

    A 16 parameter solar concentrator/heat receiver mass model is used in conjunction with Stirling and Brayton Power Conversion System (PCS) performance and mass computer codes to determine the effect of thermal energy storage (TES) material property changes on overall PCS mass as a function of steady state electrical power output. Included in the PCS mass model are component masses as a function of thermal power for: concentrator, heat receiver, heat exchangers (source unless integral with heat receiver, heat sink, regenerator), heat engine units with optional parallel redundancy, power conditioning and control (PC and C), PC and C radiator, main radiator, and structure. Critical TES properties are: melting temperature, heat of fusion, density of the liquid phase, and the ratio of solid-to-liquid density. Preliminary results indicate that even though overalll system efficiency increases with TES melting temperature up to 1400 K for concentrator surface accuracies of 1 mrad or better, reductions in the overall system mass beyond that achievable with lithium fluoride (LiF) can be accomplished only if the heat of fusion is at least 800 kJ/kg and the liquid density is comparable to that of LiF (1880 kg/cu m.

  17. Impact of thermal energy storage properties on solar dynamic space power conversion system mass

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.; Coles-Hamilton, Carolyn E.; Lacy, Dovie E.

    1987-01-01

    A 16 parameter solar concentrator/heat receiver mass model is used in conjunction with Stirling and Brayton Power Conversion System (PCS) performance and mass computer codes to determine the effect of thermal energy storage (TES) material property changes on overall PCS mass as a function of steady state electrical power output. Included in the PCS mass model are component masses as a function of thermal power for: concentrator, heat receiver, heat exchangers (source unless integral with heat receiver, heat sink, regenerator), heat engine units with optional parallel redundancy, power conditioning and control (PC and C), PC and C radiator, main radiator, and structure. Critical TES properties are: melting temperature, heat of fusion, density of the liquid phase, and the ratio of solid-to-liquid density. Preliminary results indicate that even though overall system efficiency increases with TES melting temperature up to 1400 K for concentrator surface accuracies of 1 mrad or better, reductions in the overall system mass beyond that achievable with lithium fluoride (LiF) can be accomplished only if the heat of fusion is at least 800 kJ/kg and the liquid density is comparable to that of LiF (1800 kg/cu m).

  18. Preliminary designs for 25 kWe advanced Stirling conversion systems for dish electric applications

    NASA Technical Reports Server (NTRS)

    Shaltens, Richard K.; Schreiber, Jeffrey G.

    1990-01-01

    Under the Department of Energy's (DOE) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for terrestrial Solar Distributed Heat Receivers. The Stirling engine has been identified by Sandia as one of the most promising engines for terrestrial applications. The Stirling engine also has the potential to meet DOE's performance and cost goals. The NASA Lewis Research Center is conducting Stirling engine technology development activities directed toward a dynamic power source for space applications. Space power systems requirements include high reliability, very long life, low vibration and high efficiency. The free-piston Stirling engine has the potential for future high power space conversion systems, either nuclear or solar powered. Although both applications appear to be quite different, their requirements complement each other. Preliminary designs feature a free-piston Stirling engine, a liquid metal heat transport system, and a means to provide nominally 25 kW electric power to a utility grid while meeting DOE's performance and long term cost goals. The Cummins design incorporates a linear alternator to provide the electrical output, while the STC design generates electrical power indirectly through a hydraulic pump/motor coupled to an induction generator. Both designs for the ASCS's will use technology which can reasonably be expected to be available in the early 1990's.

  19. Thermoelectric generator placed on the human body: system modeling and energy conversion improvements

    NASA Astrophysics Data System (ADS)

    Lossec, M.; Multon, B.; Ben Ahmed, H.; Goupil, C.

    2010-10-01

    This paper focuses on the production of electricity using a thermoelectric generator placed on the human body connected to a dc-dc converter. The small difference in temperature between the hot heat source (e.g. the human body, Tb = 37 °C) and the cold heat source (e.g. ambient air, Ta = 22 °C), associated with a poor quality thermal coupling (mainly with the cold source), leads to a very low temperature gradient at the thermoelectric generator terminals and hence low productivity. Under these use conditions, the present article proposes an analysis of various ways to improve productivity given a surface capture system. Furthermore, we demonstrated, in this particular context, that maximizing the recovered electric power proves to be a different problem from that of maximizing efficiency, e.g. the figure of merit Z. We therefore define a new factor ZE, depending on the physical characteristics of thermoelectric materials, that maximizes electric power in the particular case where the thermal coupling is poor. Finally, this study highlights the benefit of sub-optimization of the power extracted from the thermoelectric generator to further improve efficiency of the overall system. We show that, given the conversion efficiency of the dc-dc converter, the maximum power point of the overall system is no more reached when the output voltage of the thermoelectric generator is equal to half of its electromotive force.

  20. Preliminary designs for 25 kWe advanced Stirling conversion systems for dish electric applications

    NASA Astrophysics Data System (ADS)

    Shaltens, Richard K.; Schreiber, Jeffrey G.

    Under the Department of Energy's (DOE) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for terrestrial Solar Distributed Heat Receivers. The Stirling engine has been identified by Sandia as one of the most promising engines for terrestrial applications. The Stirling engine also has the potential to meet DOE's performance and cost goals. The NASA Lewis Research Center is conducting Stirling engine technology development activities directed toward a dynamic power source for space applications. Space power systems requirements include high reliability, very long life, low vibration and high efficiency. The free-piston Stirling engine has the potential for future high power space conversion systems, either nuclear or solar powered. Although both applications appear to be quite different, their requirements complement each other. Preliminary designs feature a free-piston Stirling engine, a liquid metal heat transport system, and a means to provide nominally 25 kW electric power to a utility grid while meeting DOE's performance and long term cost goals. The Cummins design incorporates a linear alternator to provide the electrical output, while the STC design generates electrical power indirectly through a hydraulic pump/motor coupled to an induction generator. Both designs for the ASCS's will use technology which can reasonably be expected to be available in the early 1990's.

  1. A geopressured-geothermal, solar conversion system to produce potable water

    NASA Astrophysics Data System (ADS)

    Nitschke, George Samuel

    A design is presented for recovering Geopressured-Geothermal (GPGT) reservoir brines for conversion into solar ponds to renewably power coastal seawater desalination. The hot, gas-cut, high-pressure GPGT brine is flowed through a well-bore to surface systems which concentrate the brine in multi-effect evaporators and recover the gas. The gas and distilled water are used for thermal enhanced oil recovery, and the concentrated brine is used to construct solar ponds. The thermal energy from the solar ponds is used to produce electricity, which is then used to renewably power coastal desalination plants for large-scale potable water production from the sea. The design is proposed for deployment in California and Texas, where the two largest U.S. GPGT basins exist. Projections show that the design fully deployed in California could provide 5 MAF/y (million acre-ft per year) while yielding a 45% Rate of Return (combined oil and water revenues); the California municipal water load is 10 MAF/y. The dissertation contains a feasibility study of the design approach, supported by engineering analyses and simulation models, included in the appendices. A range of systems configurations and GPGT flow conditions are modeled to illustrate how the approach lends itself to modular implementation, i.e., incrementally installing a single system, tens of systems, up to 1000 systems, which corresponds to full deployment in California for the scenario analyzed. The dissertation includes a method for launching and piloting the approach, starting from a single system installation.

  2. Development of an oscillating-vane concept as an innovative wind-energy-conversion system

    SciTech Connect

    Bielawa, R.L.

    1982-03-01

    The practicality is investigated of an oscillating vane wind energy conversion system, which incorporated the bending-torsion flutter characteristics of a cantilevered wing. The system, characterized by relatively large response amplitudes, employs a construction scheme based on the high fatigue strength characteristics of a composite material. Results are presented of experimental and analytic studies to provide technical data upon which we can assess the concept. Two variants of the concepts are examined: single-vane and split-vane configurations. The experimental results consist of the mechanical power generation and dynamic response and stress characteristics for a model having a span of approximately one meter. Two complementary analyses are described: (1) a linear flutter eigensolution to calculate conditions for self-start and flutter response amplitude ratios; and (2) a nonlinear time-history analysis to calculate output power characteristics. Results of correlation studies of these analyses with the acquired test data are presented. It is concluded that the concept is technically practical.

  3. Model predictive control of bidirectional isolated DC-DC converter for energy conversion system

    NASA Astrophysics Data System (ADS)

    Akter, Parvez; Uddin, Muslem; Mekhilef, Saad; Tan, Nadia Mei Lin; Akagi, Hirofumi

    2015-08-01

    Model predictive control (MPC) is a powerful and emerging control algorithm in the field of power converters and energy conversion systems. This paper proposes a model predictive algorithm to control the power flow between the high-voltage and low-voltage DC buses of a bidirectional isolated full-bridge DC-DC converter. The predictive control algorithm utilises the discrete nature of the power converters and predicts the future nature of the system, which are compared with the references to calculate the cost function. The switching state that minimises the cost function is selected for firing the converter in the next sampling time period. The proposed MPC bidirectional DC-DC converter is simulated with MATLAB/Simulink and further verified with a 2.5 kW experimental configuration. Both the simulation and experimental results confirm that the proposed MPC algorithm of the DC-DC converter reduces reactive power by avoiding the phase shift between primary and secondary sides of the high-frequency transformer and allow power transfer with unity power factor. Finally, an efficiency comparison is performed between the MPC and dual-phase-shift-based pulse-width modulation controlled DC-DC converter which ensures the effectiveness of the MPC controller.

  4. Ecological and socio-economic functions across tropical land use systems after rainforest conversion

    PubMed Central

    Rembold, Katja; Allen, Kara; Beckschäfer, Philip; Buchori, Damayanti; Clough, Yann; Faust, Heiko; Fauzi, Anas M.; Gunawan, Dodo; Hertel, Dietrich; Irawan, Bambang; Jaya, I. Nengah S.; Klarner, Bernhard; Kleinn, Christoph; Knohl, Alexander; Kotowska, Martyna M.; Krashevska, Valentyna; Krishna, Vijesh; Leuschner, Christoph; Lorenz, Wolfram; Meijide, Ana; Melati, Dian; Nomura, Miki; Pérez-Cruzado, César; Qaim, Matin; Siregar, Iskandar Z.; Steinebach, Stefanie; Tjoa, Aiyen; Tscharntke, Teja; Wick, Barbara; Wiegand, Kerstin; Kreft, Holger; Scheu, Stefan

    2016-01-01

    Tropical lowland rainforests are increasingly threatened by the expansion of agriculture and the extraction of natural resources. In Jambi Province, Indonesia, the interdisciplinary EFForTS project focuses on the ecological and socio-economic dimensions of rainforest conversion to jungle rubber agroforests and monoculture plantations of rubber and oil palm. Our data confirm that rainforest transformation and land use intensification lead to substantial losses in biodiversity and related ecosystem functions, such as decreased above- and below-ground carbon stocks. Owing to rapid step-wise transformation from forests to agroforests to monoculture plantations and renewal of each plantation type every few decades, the converted land use systems are continuously dynamic, thus hampering the adaptation of animal and plant communities. On the other hand, agricultural rainforest transformation systems provide increased income and access to education, especially for migrant smallholders. Jungle rubber and rubber monocultures are associated with higher financial land productivity but lower financial labour productivity compared to oil palm, which influences crop choice: smallholders that are labour-scarce would prefer oil palm while land-scarce smallholders would prefer rubber. Collecting long-term data in an interdisciplinary context enables us to provide decision-makers and stakeholders with scientific insights to facilitate the reconciliation between economic interests and ecological sustainability in tropical agricultural landscapes. PMID:27114577

  5. Control Strategies for Smoothing of Output Power of Wind Energy Conversion Systems

    NASA Astrophysics Data System (ADS)

    Pratap, Alok; Urasaki, Naomitsu; Senju, Tomonobu

    2013-10-01

    This article presents a control method for output power smoothing of a wind energy conversion system (WECS) with a permanent magnet synchronous generator (PMSG) using the inertia of wind turbine and the pitch control. The WECS used in this article adopts an AC-DC-AC converter system. The generator-side converter controls the torque of the PMSG, while the grid-side inverter controls the DC-link and grid voltages. For the generator-side converter, the torque command is determined by using the fuzzy logic. The inputs of the fuzzy logic are the operating point of the rotational speed of the PMSG and the difference between the wind turbine torque and the generator torque. By means of the proposed method, the generator torque is smoothed, and the kinetic energy stored by the inertia of the wind turbine can be utilized to smooth the output power fluctuations of the PMSG. In addition, the wind turbines shaft stress is mitigated compared to a conventional maximum power point tracking control. Effectiveness of the proposed method is verified by the numerical simulations.

  6. Spontaneous Parametric Down-Conversion to Create a Quantum Key Distribution System

    NASA Astrophysics Data System (ADS)

    Salgado, Erik; Aragoneses, Andres, , Dr.

    Quantum Key Distribution (QKD) aims to share a secret key between two parties in a secure manner. It provides security benefits over classical communication systems. We have constructed a QKD system that uses quantum entanglement to ensure security against eavesdroppers. We use polarization to encode the binary information of an encryption key. This key is secure due to the quantum properties of light. We use the process of spontaneous parametric down-conversion (SPDC) to create entangled photon pairs. Experimentally, we fire pump (laser) photons through a nonlinear crystal, where there exists a probability of them being annihilated and spontaneously generating two entangled photons of lower energies. A coincidence measurement between two entangled photons indicates the successful transfer of one bit of information, and a coincidence measurement between two disparate photons indicates an error in data transfer. We aim to optimize data transfer rate and reduce error rate. The project is still in development and we look forward to collecting data in the near future.

  7. Space-based solar power conversion and delivery systems study. Volume 5: Economic analysis

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Space-based solar power conversion and delivery systems are studied along with a variety of economic and programmatic issues relevant to their development and deployment. The costs, uncertainties and risks associated with the current photovoltaic Satellite Solar Power System (SSPS) configuration, and issues affecting the development of an economically viable SSPS development program are addressed. In particular, the desirability of low earth orbit (LEO) and geosynchronous (GEO) test satellites is examined and critical technology areas are identified. The development of SSPS unit production (nth item), and operation and maintenance cost models suitable for incorporation into a risk assessment (Monte Carlo) model (RAM) are reported. The RAM was then used to evaluate the current SSPS configuration expected costs and cost-risk associated with this configuration. By examining differential costs and cost-risk as a function of postulated technology developments, the critical technologies, that is, those which drive costs and/or cost-risk, are identified. It is shown that the key technology area deals with productivity in space, that is, the ability to fabricate and assemble large structures in space, not, as might be expected, with some hardware component technology.

  8. Ecological and socio-economic functions across tropical land use systems after rainforest conversion.

    PubMed

    Drescher, Jochen; Rembold, Katja; Allen, Kara; Beckschäfer, Philip; Buchori, Damayanti; Clough, Yann; Faust, Heiko; Fauzi, Anas M; Gunawan, Dodo; Hertel, Dietrich; Irawan, Bambang; Jaya, I Nengah S; Klarner, Bernhard; Kleinn, Christoph; Knohl, Alexander; Kotowska, Martyna M; Krashevska, Valentyna; Krishna, Vijesh; Leuschner, Christoph; Lorenz, Wolfram; Meijide, Ana; Melati, Dian; Nomura, Miki; Pérez-Cruzado, César; Qaim, Matin; Siregar, Iskandar Z; Steinebach, Stefanie; Tjoa, Aiyen; Tscharntke, Teja; Wick, Barbara; Wiegand, Kerstin; Kreft, Holger; Scheu, Stefan

    2016-05-19

    Tropical lowland rainforests are increasingly threatened by the expansion of agriculture and the extraction of natural resources. In Jambi Province, Indonesia, the interdisciplinary EFForTS project focuses on the ecological and socio-economic dimensions of rainforest conversion to jungle rubber agroforests and monoculture plantations of rubber and oil palm. Our data confirm that rainforest transformation and land use intensification lead to substantial losses in biodiversity and related ecosystem functions, such as decreased above- and below-ground carbon stocks. Owing to rapid step-wise transformation from forests to agroforests to monoculture plantations and renewal of each plantation type every few decades, the converted land use systems are continuously dynamic, thus hampering the adaptation of animal and plant communities. On the other hand, agricultural rainforest transformation systems provide increased income and access to education, especially for migrant smallholders. Jungle rubber and rubber monocultures are associated with higher financial land productivity but lower financial labour productivity compared to oil palm, which influences crop choice: smallholders that are labour-scarce would prefer oil palm while land-scarce smallholders would prefer rubber. Collecting long-term data in an interdisciplinary context enables us to provide decision-makers and stakeholders with scientific insights to facilitate the reconciliation between economic interests and ecological sustainability in tropical agricultural landscapes. PMID:27114577

  9. Review of electrochemical energy conversion and storage for ocean thermal and wind energy systems

    NASA Astrophysics Data System (ADS)

    Landgrebe, A. R.; Donley, S. W.

    A literature review on electrochemical storage techniques related to ocean thermal (OTEC) and wind energy conversion systems (WECS) is presented. Battery use for WECS is foreseen because of siting size, variable capacity, quiet operation, and high efficiency; high cost and the necessity for further input voltage regulation is noted, as are prospects for technology transfer from existing programs for photovoltaic panel battery development. Fuel cells, which can run on hydrogen, ammonia, methanol, naphtha, etc., are encouraging because capacity increases are possible by simple addition of more fuel, and high thermal efficiency. Electrolytic use is seen as a cheap replacement source of electricity for metals refining and brine electrolysis. Systems of energy 'bridges' for OTEC plants, to transmit power to users, are reviewed as redox-flow, lithium-water-air, and aluminum batteries, fuel cells, electrolytic hydrogen, methane, and ammonia production, and the use of OTECs as power sources for floating factories. Directions of future research are indicated, noting that WECS will be in commercial production by 1985, while OTEC is far term, around 2025.

  10. Thermodynamic systems analysis of open-cycle Ocean Thermal Energy Conversion (OTEC)

    NASA Astrophysics Data System (ADS)

    Parsons, B. K.; Bharathan, D.; Althof, J. A.

    1985-09-01

    This report describes an updated thermal-hydraulic systems analysis program called OTECSYS that studies the integrated performance of an open-cycle ocean thermal energy conversion (OTEC) plant, specifically, the effects of component performance, design parameters, and site specific resource data on the total system performance and plant size. OTECSYS can size the various open-cycle power cycle and hydraulic components. Models for the evaporator, mist eliminator, turbine-generator diffuser, direct-contact condenser, exhaust compressors, seawater pumps, and seawater piping are included, as are evaluations of the pressure drops associated with the intercomponent connections. It can also determine the required steam, cold seawater, and warm seawater flow rates. OTECSYS uses an approach similar to earlier work and integrates the most up-to-date developments in component performance and configuration. The program format allows the user to examine subsystem concepts not currently included by creating new component models. It will be useful to the OTEC plant designer who wants to quantify the design point sizing, performance, and power production using site-specific resource data. Detailed design trade-offs are easily evaluated, and several examples of these types of investigations are presented using plant size and power as criteria.

  11. Kinetic conversion of CO to CH4 in the Solar System

    NASA Technical Reports Server (NTRS)

    Yung, Y. L.; Allen, M.; Pinto, J. P.

    1991-01-01

    Some of the most interesting chemistry in the Solar System involves changes in the oxidation state of the simple carbon species. The chemical pathways for the conversion of CH4 to CO and CO2 are for the most part known. The reverse process, the reduction of CO to CH4, is, however, poorly understood. This is surprising in view of the importance of the reduction process in the chemistry of the Solar System. Recently we investigated the chemical kinetics of a hitherto unsuspected reaction. It is argued that the formation of the methoxy radical (CH3O) from H+H2CO may play an essential role in the reduction of CO to CH4. The rate coefficient for this reaction has been estimated using the approximate theory of J. Troe and transition state theory. We will discuss the implications of this reaction for the chemistry of CO on Jupiter, in the solar nebula, for interpreting the laboratory experiments of A. Bar-Nun and A. Shaviv and A. Bar-Nun and S. Chang, and for organic synthesis in the prebiotic terrestrial atmosphere. The possible relation of CO reduction in the solar nebula and polyoxymethylene observed in comet Halley will be discussed.

  12. Stabilization of Wind Energy Conversion System with Hydrogen Generator by Using EDLC Energy Storage System

    NASA Astrophysics Data System (ADS)

    Shishido, Seiji; Takahashi, Rion; Murata, Toshiaki; Tamura, Junji; Sugimasa, Masatoshi; Komura, Akiyoshi; Futami, Motoo; Ichinose, Masaya; Ide, Kazumasa

    The spread of wind power generation is progressed hugely in recent years from a viewpoint of environmental problems including global warming. Though wind power is considered as a very prospective energy source, wind power fluctuation due to the random fluctuation of wind speed has still created some problems. Therefore, research has been performed how to smooth the wind power fluctuation. This paper proposes Energy Capacitor System (ECS) for the smoothing of wind power which consists of Electric Double-Layer Capacitor (EDLC) and power electronics devices and works as an electric power storage system. Moreover, hydrogen has received much attention in recent years from a viewpoint of exhaustion problem of fossil fuel. Therefore it is also proposed that a hydrogen generator is installed at the wind farm to generate hydrogen. In this paper, the effectiveness of the proposed system is verified by the simulation analyses using PSCAD/EMTDC.

  13. Photon-conversion and sensitization evaluation of Eu³⁺ in a borate glass system.

    PubMed

    Tian, Y M; Shen, L F; Pun, E Y B; Lin, H

    2016-02-20

    Photon conversion is exhibited in a borate (LKZBSB) glass system containing Eu(3+), and the enhanced characteristic emissions of Eu(3+) with the codoping of Ce(3+) have been verified. A large Judd-Ofelt intensity parameter Ω2 of Eu(3+) indicates a high asymmetrical and strong covalent environment around rare-earth (RE) ions in LKZBSB glasses and spontaneous emission probability and a maximum emission cross section of the dominant 5D0→7F2 transition were derived to be 370  s(-1) and 1.28×10(-21)  cm2, respectively, revealing the potential UV→visible photon-conversion capacity of Eu(3+). Absolutely quantitative evaluation illustrates that Eu(3+) is a favorable photon-conversion center to achieve high photon-conversion efficiency. The addition of Ce(3+) is beneficial to realizing effective red emission of Eu(3+), which possesses commercial value by decreasing the dopant of expensive europium compounds. As an expectation, this photon-conversion LKZBSB glass system can promote the development of a photon downconversion layer for solar cells, which are particularly used in outer space with intense UV radiation. PMID:26906599

  14. Pool boiler heat transport system for a 25 kWe advanced Stirling conversion system

    NASA Astrophysics Data System (ADS)

    Anderson, W. G.; Rosenfeld, J. H.; Saaski, E. L.; Noble, J.; Tower, L.

    Experiments to determine alkali metal/enhanced surface combinations that have stable boiling at the temperatures and heat fluxes that occur in the Stirling engine are reported. Two enhanced surfaces and two alkali metal working fluids were evaluated. The enhanced surfaces were an EDM hole covered surface and a sintered-powder-metal porous layer surface. The working fluids tested were potassium and eutectic sodium-potasium alloy (NaK), both with and without undissolved noncondensible gas. Noncondensible gas (He and Xe) was added to the system to provide gas in the nucleation sites, preventing quenching of the sites. The experiments demonstrated the potential of an alkali metal pool boiler heat transport system for use in a solar-powered Stirling engine. The most favorable fluid/surface combination tested was NaK boiling on a -100 +140 mesh 304L stainless steel sintered porous layer with no undissolved noncondensible gas. This combination provided stable, high-performance boiling at the operating temperature of 700 C. Heat fluxes into the system ranged from 10 to 50 W/sq cm. The transition from free convection to nucleate boiling occurred at temperatures near 540 C. Based on these experiments, a pool boiler was designed for a full-scale 25-kWe Stirling system.

  15. Pool boiler heat transport system for a 25 kWe advanced Stirling conversion system

    NASA Technical Reports Server (NTRS)

    Anderson, W. G.; Rosenfeld, J. H.; Saaski, E. L.; Noble, J.; Tower, L.

    1990-01-01

    Experiments to determine alkali metal/enhanced surface combinations that have stable boiling at the temperatures and heat fluxes that occur in the Stirling engine are reported. Two enhanced surfaces and two alkali metal working fluids were evaluated. The enhanced surfaces were an EDM hole covered surface and a sintered-powder-metal porous layer surface. The working fluids tested were potassium and eutectic sodium-potasium alloy (NaK), both with and without undissolved noncondensible gas. Noncondensible gas (He and Xe) was added to the system to provide gas in the nucleation sites, preventing quenching of the sites. The experiments demonstrated the potential of an alkali metal pool boiler heat transport system for use in a solar-powered Stirling engine. The most favorable fluid/surface combination tested was NaK boiling on a -100 +140 mesh 304L stainless steel sintered porous layer with no undissolved noncondensible gas. This combination provided stable, high-performance boiling at the operating temperature of 700 C. Heat fluxes into the system ranged from 10 to 50 W/sq cm. The transition from free convection to nucleate boiling occurred at temperatures near 540 C. Based on these experiments, a pool boiler was designed for a full-scale 25-kWe Stirling system.

  16. Solar-energy conversion system provides electrical power and thermal control for life-support systems

    NASA Technical Reports Server (NTRS)

    Davis, B. K.

    1974-01-01

    System utilizes Freon cycle and includes boiler turbogenerator with heat exchanger, regenerator and thermal-control heat exchangers, low-pressure and boiler-feed pumps, and condenser. Exchanger may be of interest to engineers and scientists investigating new energy sources.

  17. Power Control and Optimization of Photovoltaic and Wind Energy Conversion Systems

    NASA Astrophysics Data System (ADS)

    Ghaffari, Azad

    Power map and Maximum Power Point (MPP) of Photovoltaic (PV) and Wind Energy Conversion Systems (WECS) highly depend on system dynamics and environmental parameters, e.g., solar irradiance, temperature, and wind speed. Power optimization algorithms for PV systems and WECS are collectively known as Maximum Power Point Tracking (MPPT) algorithm. Gradient-based Extremum Seeking (ES), as a non-model-based MPPT algorithm, governs the system to its peak point on the steepest descent curve regardless of changes of the system dynamics and variations of the environmental parameters. Since the power map shape defines the gradient vector, then a close estimate of the power map shape is needed to create user assignable transients in the MPPT algorithm. The Hessian gives a precise estimate of the power map in a neighborhood around the MPP. The estimate of the inverse of the Hessian in combination with the estimate of the gradient vector are the key parts to implement the Newton-based ES algorithm. Hence, we generate an estimate of the Hessian using our proposed perturbation matrix. Also, we introduce a dynamic estimator to calculate the inverse of the Hessian which is an essential part of our algorithm. We present various simulations and experiments on the micro-converter PV systems to verify the validity of our proposed algorithm. The ES scheme can also be used in combination with other control algorithms to achieve desired closed-loop performance. The WECS dynamics is slow which causes even slower response time for the MPPT based on the ES. Hence, we present a control scheme, extended from Field-Oriented Control (FOC), in combination with feedback linearization to reduce the convergence time of the closed-loop system. Furthermore, the nonlinear control prevents magnetic saturation of the stator of the Induction Generator (IG). The proposed control algorithm in combination with the ES guarantees the closed-loop system robustness with respect to high level parameter uncertainty

  18. NUCLEAR CONVERSION APPARATUS

    DOEpatents

    Seaborg, G.T.

    1960-09-13

    A nuclear conversion apparatus is described which comprises a body of neutron moderator, tubes extending therethrough, uranium in the tubes, a fluid- circulating system associated with the tubes, a thorium-containing fluid coolant in the system and tubes, and means for withdrawing the fluid from the system and replacing it in the system whereby thorium conversion products may be recovered.

  19. Thermophotovoltaic energy conversion system having a heavily doped n-type region

    DOEpatents

    DePoy, David M.; Charache, Greg W.; Baldasaro, Paul F.

    2000-01-01

    A thermophotovoltaic (TPV) energy conversion semiconductor device is provided which incorporates a heavily doped n-type region and which, as a consequence, has improved TPV conversion efficiency. The thermophotovoltaic energy conversion device includes an emitter layer having first and second opposed sides and a base layer in contact with the first side of the emitter layer. A highly doped n-type cap layer is formed on the second side of the emitter layer or, in another embodiment, a heavily doped n-type emitter layer takes the place of the cap layer.

  20. Converse Piezoelectricity

    NASA Astrophysics Data System (ADS)

    Springborg, Michael; Kirtman, Bernard

    2013-03-01

    Piezoelectricity results from a coupling between responses to mechanical and electric perturbations and leads to changes in the polarization due to strain or stress or, alternatively, the occurrence of strain as a function of an applied external, electrostatic field (i.e., converse piezoelectricity). Theoretical studies of those properties for extended systems require accordingly that their dipole moment or polarization can be calculated. However, whereas the definition of the operator for the dipole moment for any finite system is trivial, it is only within the last 2 decades that the expressions for the equivalent operator in the independent-particle approximation for the infinite and periodic system have been presented. Here, we demonstrate that the so called branch dependence of the polarization for the infinite, periodic system is related to physical observables in contrast to what often is assumed. This is related to the finding that converse piezoelectric properties depend both on the surfaces of the samples of interest even for samples with size well above the thermodynamic limit. However, we shall demonstrate that these properties can be calculated without explicitly taking the surfaces into account. Both the foundations and results for real system shall be presented.

  1. The Subjective Evaluation Experiments on an Automatic Video Editing System Using Vision-based Head Tracking for Multiparty Conversations

    NASA Astrophysics Data System (ADS)

    Takemae, Yoshinao; Otsuka, Kazuhiro; Yamato, Junji; Ozawa, Shinji

    This paper presents experiments conducted to evaluate an automatic video editing system, founded on vision-based head tracking, that clearly conveys face-to-face multiparty conversations, such as meetings, to viewers. Systems that archive meetings and teleconferences to effectively facilitate human communication are attracting considerable interest. Conventional systems use a fixed-viewpoint camera and simple camera selection based on participants' utterances. Unfortunately, they fail to adequately convey who is talking to whom and nonverbal information about participants etc., to viewers. To solve this problem, we previously proposed an automatic video editing system using vision-based head tracking. This paper describes subjective evaluation experiments in which videos of entire conversations with 3 participants were presented to viewers; the results confirm the effectiveness of our system.

  2. Rapid cell-surface prion protein conversion revealed using a novel cell system

    PubMed Central

    Goold, R.; Rabbanian, S.; Sutton, L.; Andre, R.; Arora, P.; Moonga, J.; Clarke, A.R.; Schiavo, G.; Jat, P.; Collinge, J.; Tabrizi, S.J.

    2011-01-01

    Prion diseases are fatal neurodegenerative disorders with unique transmissible properties. The infectious and pathological agent is thought to be a misfolded conformer of the prion protein. Little is known about the initial events in prion infection because the infecting prion source has been immunologically indistinguishable from normal cellular prion protein (PrPC). Here we develop a unique cell system in which epitope-tagged PrPC is expressed in a PrP knockdown (KD) neuroblastoma cell line. The tagged PrPC, when expressed in our PrP-KD cells, supports prion replication with the production of bona fide epitope-tagged infectious misfolded PrP (PrPSc). Using this epitope-tagged PrPSc, we study the earliest events in cellular prion infection and PrP misfolding. We show that prion infection of cells is extremely rapid occurring within 1 min of prion exposure, and we demonstrate that the plasma membrane is the primary site of prion conversion. PMID:21505437

  3. A Supercritical CO{sub 2} Cycle- a Promising Power Conversion System for Generation IV Reactors

    SciTech Connect

    Hejzlar, Pavel; Dostal, Vaclav; Driscoll, Michael J.

    2006-07-01

    Advances in power conversion systems (PCS) for Generation IV power plants are of high importance because of their impact on plant specific capital cost reduction, which can be more significant than the cost savings achieved through the modifications of the nuclear island itself. One such PCS candidate, especially attractive for reactor outlet temperatures in the range of 550 to 650 deg C, is applicable to lead-alloy, sodium, or liquid salt-cooled reactors, as well as direct-cycle CO{sub 2} cooled reactors. The efficiencies achievable in this medium temperature range exceed those of conventional Brayton cycles and supercritical steam Rankine cycles and are comparable to those of conventional helium Brayton cycles at turbine inlet temperatures of 800 to 900 deg C. The S-CO{sub 2} recompression cycle under evaluation at MIT, is described with its advantages, drawbacks and R and D needs. The cycle is shown to excel in efficiency, simplicity and compactness which projects to cost savings, and in lower sensitivity of efficiency to core bypass flow, component pressure losses and flow maldistribution in recuperators. On the other hand, the cycle is highly recuperative and thus requires very compact heat exchangers, poses challenges to design of piping for large units, and its control and part load operation is more complicated. (authors)

  4. Use of a DBMS (data base management system) to aid in the software conversion process

    SciTech Connect

    Huntley, A.F.; Bryant, R.A.; Buhrmaster, M.A.; Christian, J.L.; Hume, R.

    1987-02-01

    Procedures are described that provide for the automated conversion of a screen library containing over a thousand screen display definitions to a new screen definition software package. The first step is to extract the screen definition information from the original screen package. This information is then loaded into a data base management system (DBMS). The information is manipulated as necessary and output in a format that can be utilized by the new screen package. A major benefit of the procedures developed is that a DBMS allows bulk updates of multiple screen definitions to be performed. Both the source and target screen packages provide only for the updating of individual screens. Although the procedures described apply to the problem of converting screen definitions for a specific application using the two specific screen definition software packages, the flexibility inherent in a DBMS allows its use in solving many such complex problems. The concept can be modified to allow possibilities limited only by the creativity of the DBMS users and the information contained in the data base.

  5. Design and Off-design Performance of 100 Kwe-class Brayton Power Conversion Systems

    NASA Technical Reports Server (NTRS)

    Johnson, Paul K.; Mason, Lee S.

    2005-01-01

    The NASA Glenn Research Center in-house computer model Closed Cycle Engine Program (CCEP) was used to explore the design trade space and off-design performance characteristics of 100 kWe-class recuperated Closed Brayton Cycle (CBC) power conversion systems. Input variables for a potential design point included the number of operating units (1, 2, 4), cycle peak pressure (0.5, 1, 2 MPa), and turbo-alternator shaft speed (30, 45, 60 kRPM). The design point analysis assumed a fixed turbine inlet temperature (1150 K), compressor inlet temperature (400 K), working-fluid molecular weight (40 g/mol), compressor pressure ratio (2.0), recuperator effectiveness (0.95), and a Sodium-Potassium (NaK) pumped-loop radiator. The design point options were compared on the basis of thermal input power, radiator area, and mass. For a nominal design point with defined Brayton components and radiator area, off-design cases were examined by reducing turbine inlet temperature (as low as 900 K), reducing shaft speed (as low as 50% of nominal), and circulating a percentage (up to 20%) of the compressor exit flow back to the gas cooler. The off-design examination sought approaches to reduce thermal input power without freezing the radiator.

  6. Design and Off-Design Performance of 100 kWe-Class Brayton Power Conversion Systems

    NASA Astrophysics Data System (ADS)

    Johnson, Paul K.; Mason, Lee S.

    2005-02-01

    The NASA Glenn Research Center in-house computer model Closed Cycle Engine Program (CCEP) was used to explore the design trade space and off-design performance characteristics of 100 kWe-class recuperated Closed Brayton Cycle (CBC) power conversion systems. Input variables for a potential design point included the number of operating units (1, 2, 4), cycle peak pressure (0.5, 1, 2 MPa), and turbo-alternator shaft speed (30,45, 60 kRPM). The design point analysis assumed a fixed turbine inlet temperature (1150 K), compressor inlet temperature (400 K), helium-xenon working-fluid molecular weight (40 g/mol), compressor pressure ratio (2.0), recuperator effectiveness (0.95), and a Sodium-Potassium (NaK) pumped-loop radiator. The design point options were compared on the basis of thermal input power, radiator area, and mass. For a nominal design point with defined Brayton components and radiator area, off-design cases were examined by reducing turbine inlet temperature (as low as 900 K), reducing shaft speed (as low as 50% of nominal), and circulating a percentage (up to 20%) of the compressor exit flow back to the gas cooler. The off-design examination sought approaches to reduce thermal input power without freezing the radiator.

  7. Design and Off-Design Performance of 100 kWe-Class Brayton Power Conversion Systems

    NASA Technical Reports Server (NTRS)

    Johnson, Paul K.; Mason, Lee S.

    2005-01-01

    The NASA Glenn Research Center in-house computer model Closed Cycle Engine Program (CCEP) was used to explore the design trade space and off-design performance characteristics of 100 kWe-class recuperated Closed Brayton Cycle (CBC) power conversion systems. Input variables for a potential design point included the number of operating units (1, 2, 4), cycle peak pressure (0.5, 1, 2 MPa), and turbo-alternator shaft speed (30, 45, 60 kRPM). The design point analysis assumed a fixed turbine inlet temperature (1150 K), compressor inlet temperature (400 K), helium-xenon working-fluid molecular weight (40 g/mol), compressor pressure ratio (2.0), recuperator effectiveness (0.95), and a Sodium-Potassium (NaK) pumped-loop radiator. The design point options were compared on the basis of thermal input power, radiator area, and mass. For a nominal design point with defined Brayton components and radiator area, off-design cases were examined by reducing turbine inlet temperature (as low as 900 K), reducing shaft speed (as low as 50 percent of nominal), and circulating a percentage (up to 20 percent) of the compressor exit flow back to the gas cooler. The off-design examination sought approaches to reduce thermal input power without freezing the radiator.

  8. Conversational sensemaking

    NASA Astrophysics Data System (ADS)

    Preece, Alun; Webberley, Will; Braines, Dave

    2015-05-01

    Recent advances in natural language question-answering systems and context-aware mobile apps create opportunities for improved sensemaking in a tactical setting. Users equipped with mobile devices act as both sensors (able to acquire information) and effectors (able to act in situ), operating alone or in collectives. The currently- dominant technical approaches follow either a pull model (e.g. Apple's Siri or IBM's Watson which respond to users' natural language queries) or a push model (e.g. Google's Now which sends notifications to a user based on their context). There is growing recognition that users need more flexible styles of conversational interaction, where they are able to freely ask or tell, be asked or told, seek explanations and clarifications. Ideally such conversations should involve a mix of human and machine agents, able to collaborate in collective sensemaking activities with as few barriers as possible. Desirable capabilities include adding new knowledge, collaboratively building models, invoking specific services, and drawing inferences. As a step towards this goal, we collect evidence from a number of recent pilot studies including natural experiments (e.g. situation awareness in the context of organised protests) and synthetic experiments (e.g. human and machine agents collaborating in information seeking and spot reporting). We identify some principles and areas of future research for "conversational sensemaking".

  9. SYSTEM FOR CONVERSION OF UF$sub 4$ TO UF$sub 6$

    DOEpatents

    Brater, D.G.; Pike, J.W.

    1958-12-01

    Method and apparatus are presented for rapid and complete conversion of solid, powdered uranium tetrafiuorlde to uranlum hexafluorlde by treating the UF/ sub 4/ with fluorine gas at a temperature of about 800 icient laborato C.

  10. Dentin bond strength and degree of conversion evaluation of experimental self-etch adhesive systems

    PubMed Central

    Yazdi, Fatemeh-Maleknejad; Atai, Mohammad; Zeynali, Mahsa

    2015-01-01

    Background The aim of this study was to investigate the effect of different concentrations of 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) monomer in one-step self-etch experimental adhesives on dentinal microshear bond strength (µSBS), their degree of conversion and bonded micro structure. Material and Methods Composite resin cylinders (Clearfil AP-X) were bonded on human sound molar dentinal surfaces by using five experimental one-step self-etching adhesives (1-SEAs) containing 0% (E0), 5% (E5), 10% (E10), 15% (E15), 20% (E20) (by weight) 10-MDP monomer and Clearfil S3 Bond (CS3) as a control. After 24 hours, microshear bond strength was tested. The degree of conversion was also measured using Fourier transform infrared spectroscopy. Interfacial ultrastructure was observed under a scanning electron microscope in all the groups. Results A higher microshear bond strength was observed with adhesives containing 10% and 15% 10-MDP in comparison to study groups (P<.05). Clearfil S3 Bond and 10% MDP had a significantly greater degree of conversion than other groups (P<.05). Conclusions The amount of functional monomer in 1-SEAs influences both the bonding performance and degree of conversion; 10% 10-MDP showed the best combination of bond strength and degree of conversion. Key words:Self-etch adhesives, 10-MDP, bond strength, degree of conversion. PMID:26155340

  11. Microbial community response to chlorine conversion in a chloraminated drinking water distribution system.

    PubMed

    Wang, Hong; Proctor, Caitlin R; Edwards, Marc A; Pryor, Marsha; Santo Domingo, Jorge W; Ryu, Hodon; Camper, Anne K; Olson, Andrew; Pruden, Amy

    2014-09-16

    Temporary conversion to chlorine (i.e., "chlorine burn") is a common approach to controlling nitrification in chloraminated drinking water distribution systems, yet its effectiveness and mode(s) of action are not fully understood. This study characterized occurrence of nitrifying populations before, during and after a chlorine burn at 46 sites in a chloraminated distribution system with varying pipe materials and levels of observed nitrification. Quantitative polymerase chain reaction analysis of gene markers present in nitrifying populations indicated higher frequency of detection of ammonia oxidizing bacteria (AOB) (72% of samples) relative to ammonia oxidizing archaea (AOA) (28% of samples). Nitrospira nitrite oxidizing bacteria (NOB) were detected at 45% of samples, while presence of Nitrobacter NOB could not be confirmed at any of the samples. During the chlorine burn, the numbers of AOA, AOB, and Nitrospira greatly reduced (i.e., 0.8-2.4 log). However, rapid and continued regrowth of AOB and Nitrospira were observed along with nitrite production in the bulk water within four months after the chlorine burn, and nitrification outbreaks appeared to worsen 6-12 months later, even after adopting a twice annual burn program. Although high throughput sequencing of 16S rRNA genes revealed a distinct community shift and higher diversity index during the chlorine burn, it steadily returned towards a condition more similar to pre-burn than burn stage. Significant factors associated with nitrifier and microbial community composition included water age and sampling location type, but not pipe material. Overall, these results indicate that there is limited long-term effect of chlorine burns on nitrifying populations and the broader microbial community. PMID:25118569

  12. Technology Development Program for an Advanced Potassium Rankine Power Conversion System Compatible with Several Space Reactor Designs

    SciTech Connect

    Yoder, G.L.

    2005-10-03

    This report documents the work performed during the first phase of the National Aeronautics and Space Administration (NASA), National Research Announcement (NRA) Technology Development Program for an Advanced Potassium Rankine Power Conversion System Compatible with Several Space Reactor Designs. The document includes an optimization of both 100-kW{sub e} and 250-kW{sub e} (at the propulsion unit) Rankine cycle power conversion systems. In order to perform the mass optimization of these systems, several parametric evaluations of different design options were investigated. These options included feed and reheat, vapor superheat levels entering the turbine, three different material types, and multiple heat rejection system designs. The overall masses of these Nb-1%Zr systems are approximately 3100 kg and 6300 kg for the 100- kW{sub e} and 250-kW{sub e} systems, respectively, each with two totally redundant power conversion units, including the mass of the single reactor and shield. Initial conceptual designs for each of the components were developed in order to estimate component masses. In addition, an overall system concept was presented that was designed to fit within the launch envelope of a heavy lift vehicle. A technology development plan is presented in the report that describes the major efforts that are required to reach a technology readiness level of 6. A 10-year development plan was proposed.

  13. Real time implementation and control validation of the wind energy conversion system

    NASA Astrophysics Data System (ADS)

    Sattar, Adnan

    The purpose of the thesis is to analyze dynamic and transient characteristics of wind energy conversion systems including the stability issues in real time environment using the Real Time Digital Simulator (RTDS). There are different power system simulation tools available in the market. Real time digital simulator (RTDS) is one of the powerful tools among those. RTDS simulator has a Graphical User Interface called RSCAD which contains detail component model library for both power system and control relevant analysis. The hardware is based upon the digital signal processors mounted in the racks. RTDS simulator has the advantage of interfacing the real world signals from the external devices, hence used to test the protection and control system equipments. Dynamic and transient characteristics of the fixed and variable speed wind turbine generating systems (WTGSs) are analyzed, in this thesis. Static Synchronous Compensator (STATCOM) as a flexible ac transmission system (FACTS) device is used to enhance the fault ride through (FRT) capability of the fixed speed wind farm. Two level voltage source converter based STATCOM is modeled in both VSC small time-step and VSC large time-step of RTDS. The simulation results of the RTDS model system are compared with the off-line EMTP software i.e. PSCAD/EMTDC. A new operational scheme for a MW class grid-connected variable speed wind turbine driven permanent magnet synchronous generator (VSWT-PMSG) is developed. VSWT-PMSG uses fully controlled frequency converters for the grid interfacing and thus have the ability to control the real and reactive powers simultaneously. Frequency converters are modeled in the VSC small time-step of the RTDS and three phase realistic grid is adopted with RSCAD simulation through the use of optical analogue digital converter (OADC) card of the RTDS. Steady state and LVRT characteristics are carried out to validate the proposed operational scheme. Simulation results show good agreement with real

  14. Solar energy conversion systems engineering and economic analysis radiative energy input/thermal electric output computation. Volume III

    SciTech Connect

    Russo, G.

    1982-09-01

    The direct energy flux analytical model, an analysis of the results, and a brief description of a non-steady state model of a thermal solar energy conversion system implemented on a code, SIRR2, as well as the coupling of CIRR2 which computes global solar flux on a collector and SIRR2 are presented. It is shown how the CIRR2 and, mainly, the SIRR2 codes may be used for a proper design of a solar collector system. (LEW)

  15. Energy conversion alternatives study

    NASA Technical Reports Server (NTRS)

    Shure, L. T.

    1979-01-01

    Comparison of coal based energy systems is given. Study identifies and compares various advanced energy conversion systems using coal or coal derived fuels for baselaoad electric power generation. Energy Conversion Alternatives Study (ECAS) reports provede government, industry, and general public with technically consistent basis for comparison of system's options of interest for fossilfired electric-utility application.

  16. Sperry Low Temperature Geothermal Conversion System, Phase 1 and Phase II. Final report. Volume III. Systems description

    SciTech Connect

    Matthews, H.B.

    1984-01-01

    The major fraction of hydrothermal resources that have the prospect of being economically useful for the generation of electricity are in the 300/sup 0/F to 425/sup 0/F temperature range. Cost-effective conversion of the geothermal energy to electricity requires the conception and reduction to practice of new ideas to improve conversion efficiency, enhance brine flow, reduce plant costs, increase plant availability, and shorten the time between investment and return. The problems addressed during past activities are those inherent in the geothermal environment, in the binary fluid cycle, in the difficulty of efficiently converting the energy of a low-temperature resource, and in geothermal economics. Explained in detail in this document, some of these problems are: the energy expended by the down-hole pump; the difficulty in designing reliable down-hole equipment; fouling of heat-exchanger surfaces by geothermal fluids; the unavailability of condenser cooling water at most geothermal sites; the large portion of the available energy used by the feed pump in a binary system; the pinch effect - a loss in available energy in transferring heat from water to an organic fluid; flow losses in fluids that carry only a small amount of useful energy to begin with; high heat-exchanger costs - the lower the temperature interval of the cycle, the higher the heat exchanger costs in $/kW (actually, more than inversely proportional); the complexity and cost of the many auxiliary elements of proposed geothermal plants; and the unfortunate cash flow vs. investment curve caused by the many years of investment required to bring a field into production before any income is realized.

  17. Supercritical Carbon Dioxide Brayton Power Conversion Cycle Design for Optimized Battery-Type Integral Reactor System

    SciTech Connect

    Kim, Won J.; Kim, Tae W.; Sohn, Myoung S.; Suh, Kune Y.

    2006-07-01

    Supercritical carbon dioxide (SCO{sub 2}) promises a high power conversion efficiency of the recompression Brayton cycle due to its excellent compressibility reducing the compression work at the bottom of the cycle and to a higher density than helium or steam decreasing the component size. Therefore, the high SCO{sub 2} Brayton cycle efficiency as high as 45 % furnishes small sized nuclear reactors with economical benefits on the plant construction and maintenance. A 23 MWth BORIS (Battery Optimized Reactor Integral System) is being developed as a multipurpose reactor. BORIS, an integral-type optimized fast reactor with an ultra long life core, is coupled to the SCO{sub 2} Brayton cycle needing less room relative to the Rankine steam cycle because of its smaller components. The SCO{sub 2} Brayton cycle of BORIS consists of a 16 MW turbine, a 32 MW high temperature recuperator, a 14 MW low temperature recuperator, an 11 MW pre-cooler and 2 and 2.8 MW compressors. Entering six heat exchangers between primary and secondary system at 19.9 MPa and 663 K, the SCO{sub 2} leaves the heat exchangers at 19.9 MPa and 823 K. The promising secondary system efficiency of 45 % was calculated by a theoretical method in which the main parameters include pressure, temperature, heater power, the turbine's, recuperators' and compressors' efficiencies, and the flow split ratio of SCO{sub 2} going out from the low temperature recuperator. Test loop SOLOS (Shell-and-tube Overall Layout Optimization Study) is utilized to develop advanced techniques needed to adopt the shell-and-tube type heat exchanger in the secondary loop of BORIS by studying the SCO{sub 2} behavior from both thermal and hydrodynamic points of view. Concurrently, a computational fluid dynamics (CFD) code analysis is being conducted to develop an optimal analytical method of the SCO{sub 2} turbine efficiency having the parameters of flow characteristics of SCO{sub 2} passing through buckets of the turbine. These

  18. Modeling and controller design of a wind energy conversion system including a matrix converter

    NASA Astrophysics Data System (ADS)

    Barakati, S. Masoud

    In this thesis, a grid-connected wind-energy converter system including a matrix converter is proposed. The matrix converter, as a power electronic converter, is used to interface the induction generator with the grid and control the wind turbine shaft speed. At a given wind velocity, the mechanical power available from a wind turbine is a function of its shaft speed. Through the matrix converter, the terminal voltage and frequency of the induction generator is controlled, based on a constant V/f strategy, to adjust the turbine shaft speed and accordingly, control the active power injected into the grid to track maximum power for all wind velocities. The power factor at the interface with the grid is also controlled by the matrix converter to either ensure purely active power injection into the grid for optimal utilization of the installed wind turbine capacity or assist in regulation of voltage at the point of connection. Furthermore, the reactive power requirements of the induction generator are satisfied by the matrix converter to avoid use of self-excitation capacitors. The thesis addresses two dynamic models: a comprehensive dynamic model for a matrix converter and an overall dynamical model for the proposed wind turbine system. The developed matrix converter dynamic model is valid for both steady-state and transient analyses, and includes all required functions, i.e., control of the output voltage, output frequency, and input displacement power factor. The model is in the qdo reference frame for the matrix converter input and output voltage and current fundamental components. The validity of this model is confirmed by comparing the results obtained from the developed model and a simplified fundamental-frequency equivalent circuit-based model. In developing the overall dynamic model of the proposed wind turbine system, individual models of the mechanical aerodynamic conversion, drive train, matrix converter, and squirrel-cage induction generator are developed

  19. Research and evaluation of biomass resources/conversion/utilization systems. Biomass allocation model. Volume 1: Test and appendices A & B

    NASA Astrophysics Data System (ADS)

    Stringer, R. P.; Ahn, Y. K.; Chen, H. T.; Helm, R. W.; Nelson, E. T.; Shields, K. J.

    1981-08-01

    A biomass allocation model was developed to show the most profitable combination of biomass feedstocks, thermochemical conversion processes, and fuel products to serve the seasonal conditions in a regional market. This optimization model provides a tool for quickly calculating which of a large number of potential biomass missions is the most profitable mission. Other components of the system serve as a convenient storage and retrieval mechanism for biomass marketing and thermochemical conversion processing data. The system can be accessed through the use of a computer terminal, or it could be adapted to a microprocessor. A User's Manual for the system is included. Biomass derived fuels included in the data base are the following: medium Btu gas, low Btu gas, substitute natural gas, ammonia, methanol, electricity, gasoline, and fuel oil.

  20. Gas Turbine Energy Conversion Systems for Nuclear Power Plants Applicable to LiFTR Liquid Fluoride Thorium Reactor Technology

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.

    2014-01-01

    This panel plans to cover thermal energy and electric power production issues facing our nation and the world over the next decades, with relevant technologies ranging from near term to mid-and far term.Although the main focus will be on ground based plants to provide baseload electric power, energy conversion systems (ECS) for space are also included, with solar- or nuclear energy sources for output power levels ranging tens of Watts to kilo-Watts for unmanned spacecraft, and eventual mega-Watts for lunar outposts and planetary surface colonies. Implications of these technologies on future terrestrial energy systems, combined with advanced fracking, are touched upon.Thorium based reactors, and nuclear fusion along with suitable gas turbine energy conversion systems (ECS) will also be considered by the panelists. The characteristics of the above mentioned ECS will be described, both in terms of their overall energy utilization effectiveness and also with regard to climactic effects due to exhaust emissions.

  1. Development of a system for characterizing biomass quality of lignocellulosic feedstocks for biochemical conversion

    NASA Astrophysics Data System (ADS)

    Murphy, Patrick Thomas

    The purpose of this research was twofold: (i) to develop a system for screening lignocellulosic biomass feedstocks for biochemical conversion to biofuels and (ii) to evaluate brown midrib corn stover as feedstock for ethanol production. In the first study (Chapter 2), we investigated the potential of corn stover from bm1-4 hybrids for increased ethanol production and reduced pretreatment intensity compared to corn stover from the isogenic normal hybrid. Corn stover from hybrid W64A X A619 and respective isogenic bm hybrids was pretreated by aqueous ammonia steeping using ammonium hydroxide concentrations from 0 to 30%, by weight, and the resulting residues underwent simultaneous saccharification and cofermentation (SSCF) to ethanol. Dry matter (DM) digested by SSCF increased with increasing ammonium hydroxide concentration across all genotypes (P>0.0001) from 277 g kg-1 DM in the control to 439 g kg-1 DM in the 30% ammonium hydroxide pretreatment. The bm corn stover materials averaged 373 g kg-1 DM of DM digested by SSCF compared with 335 g kg-1 DM for the normal corn stover (P<0.0001). Of the bm mutations, bm3 had (i) the greatest effect on cell-wall carbohydrate hydrolysis of corn stover, (ii) the lowest initial cell-wall carbohydrate concentration, (iii) the lowest dry matter remaining after pretreatment, and (iv) the highest amount of monosaccharides released during enzymatic hydrolysis. However, bm corn stover did not reduce the severity of aqueous ammonia steeping pretreatment needed to maximize DM hydrolysis during SSCF compared with normal corn stover. In the remaining studies (Chapters 3 thru 5), a system for analyzing the quality of lignocellulosic biomass feedstocks for biochemical conversion to biofuels (i.e., pretreatment, enzymatic hydrolysis, and fermentation) was developed. To accomplish this, a carbohydrate availability model was developed to characterize feedstock quality. The model partitions carbohydrates within a feedstock material into

  2. Nonthermal plasma systems and methods for natural gas and heavy hydrocarbon co-conversion

    DOEpatents

    Kong, Peter C.; Nelson, Lee O.; Detering, Brent A.

    2005-05-24

    A reactor for reactive co-conversion of heavy hydrocarbons and hydrocarbon gases and includes a dielectric barrier discharge plasma cell having a pair of electrodes separated by a dielectric material and passageway therebetween. An inlet is provided for feeding heavy hydrocarbons and other reactive materials to the passageway of the discharge plasma cell, and an outlet is provided for discharging reaction products from the reactor. A packed bed catalyst may optionally be used in the reactor to increase efficiency of conversion. The reactor can be modified to allow use of a variety of light sources for providing ultraviolet light within the discharge plasma cell. Methods for upgrading heavy hydrocarbons are also disclosed.

  3. Bulk single crystal ternary substrates for a thermophotovoltaic energy conversion system

    DOEpatents

    Charache, Greg W.; Baldasaro, Paul F.; Nichols, Greg J.

    1998-01-01

    A thermophotovoltaic energy conversion device and a method for making the device. The device includes a substrate formed from a bulk single crystal material having a bandgap (E.sub.g) of 0.4 eVconversion device includes a host substrate formed from a bulk single crystal material and lattice-matched ternary or quaternary III-V semiconductor active layers.

  4. Bulk single crystal ternary substrates for a thermophotovoltaic energy conversion system

    DOEpatents

    Charache, G.W.; Baldasaro, P.F.; Nichols, G.J.

    1998-06-23

    A thermophotovoltaic energy conversion device and a method for making the device are disclosed. The device includes a substrate formed from a bulk single crystal material having a bandgap (E{sub g}) of 0.4 eV < E{sub g} < 0.7 eV and an emitter fabricated on the substrate formed from one of a p-type or an n-type material. Another thermophotovoltaic energy conversion device includes a host substrate formed from a bulk single crystal material and lattice-matched ternary or quaternary III-V semiconductor active layers. 12 figs.

  5. Conversion of linear time-invariant time-delay feedback systems into delay-differential equations with commensurate delays

    NASA Astrophysics Data System (ADS)

    Yamazaki, Tatsuya; Hagiwara, Tomomichi

    2014-08-01

    A new stability analysis method of time-delay systems (TDSs) called the monodromy operator approach has been studied under the assumption that a TDS is represented as a time-delay feedback system consisting of a finite-dimensional linear time-invariant (LTI) system and a pure delay. For applying this approach to TDSs described by delay-differential equations (DDEs), the problem of converting DDEs into representation as time-delay feedback systems has been studied. With regard to such a problem, it was shown that, under discontinuous initial functions, it is natural to define the solutions of DDEs in two different ways, and the above conversion problem was solved for each of these two definitions. More precisely, the solution of a DDE was represented as either the state of the finite-dimensional part of a time-delay feedback system or a part of the output of another time-delay feedback system, depending on which definition of the DDE solution one is talking about. Motivated by the importance in establishing a thorough relationship between time-delay feedback systems and DDEs, this paper discusses the opposite problem of converting time-delay feedback systems into representation as DDEs, including the discussions about the conversion of the initial conditions. We show that the state of (the finite-dimensional part of) a time-delay feedback system can be represented as the solution of a DDE in the sense of one of the two definitions, while its 'essential' output can be represented as that of another DDE in the sense of the other type of definition. Rigorously speaking, however, it is also shown that the latter representation is possible regardless of the initial conditions, while some initial condition could prevent the conversion into the former representation. This study hence establishes that the representation of TDSs as time-delay feedback systems possesses higher ability than that with DDEs, as description methods for LTI TDSs with commensurate delays.

  6. Conversion of plutonium-containing materials into borosilicate glass using the glass material oxidation and dissolution system

    SciTech Connect

    Forsberg, C.W.; Beahm, E.C.; Parker, G.W.

    1996-01-27

    The end of the cold war has resulted in excess plutonium-containing materials (PCMs) in multiple chemical forms. Major problems are associated with the long-term management of these materials: safeguards and nonproliferation issues; health, environment, and safety concerns; waste management requirements; and high storage costs. These issues can be addressed by conversion of the PCMs to glass: however, conventional glass processes require oxide-like feed materials. Conversion of PCMs to oxide-like materials followed by vitrification is a complex and expensive process. A new vitrification process has been invented, the Glass Material Oxidation and Dissolution System (GMODS) to allow direct conversion of PCMs to glass. GMODS directly converts metals, ceramics, and amorphous solids to glass; oxidizes organics with the residue converted to glass; and converts chlorides to borosilicate glass and a secondary sodium chloride stream. Laboratory work has demonstrated the conversion of cerium (a plutonium surrogate), uranium (a plutonium surrogate), Zircaloy, stainless steel, multiple oxides, and other materials to glass. Equipment options have been identified for processing rates between 1 and 100,000 t/y. Significant work, including a pilot plant, is required to develop GMODS for applications at an industrial scale.

  7. Simulating the conversion of rural settlements to town land based on multi-agent systems and cellular automata.

    PubMed

    Liu, Yaolin; Kong, Xuesong; Liu, Yanfang; Chen, Yiyun

    2013-01-01

    Rapid urbanization in China has triggered the conversion of land from rural to urban use, particularly the conversion of rural settlements to town land. This conversion is the result of the joint effects of the geographic environment and agents involving the government, investors, and farmers. To understand the dynamic interaction dominated by agents and to predict the future landscape of town expansion, a small town land-planning model is proposed based on the integration of multi-agent systems (MAS) and cellular automata (CA). The MAS-CA model links the decision-making behaviors of agents with the neighbor effect of CA. The interaction rules are projected by analyzing the preference conflicts among agents. To better illustrate the effects of the geographic environment, neighborhood, and agent behavior, a comparative analysis between the CA and MAS-CA models in three different towns is presented, revealing interesting patterns in terms of quantity, spatial characteristics, and the coordinating process. The simulation of rural settlements conversion to town land through modeling agent decision and human-environment interaction is very useful for understanding the mechanisms of rural-urban land-use change in developing countries. This process can assist town planners in formulating appropriate development plans. PMID:24244472

  8. What are Middle School Students Talking About During Clicker Questions? Characterizing Small-Group Conversations Mediated by Classroom Response Systems

    NASA Astrophysics Data System (ADS)

    Barth-Cohen, Lauren A.; Smith, Michelle K.; Capps, Daniel K.; Lewin, Justin D.; Shemwell, Jonathan T.; Stetzer, MacKenzie R.

    2016-02-01

    There is a growing interest in using classroom response systems or clickers in science classrooms at both the university and K-12 levels. Typically, when instructors use this technology, students are asked to answer and discuss clicker questions with their peers. The existing literature on using clickers at the K-12 level has largely focused on the efficacy of clicker implementation, with few studies investigating collaboration and discourse among students. To expand on this work, we investigated the question: Does clicker use promote productive peer discussion among middle school science students? Specifically, we collected data from middle school students in a physical science course. Students were asked to answer a clicker question individually, discuss the question with their peers, answer the same question again, and then subsequently answer a new matched-pair question individually. We audio recorded the peer conversations to characterize the nature of the student discourse. To analyze these conversations, we used a grounded analysis approach and drew on literature about collaborative knowledge co-construction. The analysis of the conversations revealed that middle school students talked about science content and collaboratively discussed ideas. Furthermore, the majority of conversations, both ones that positively and negatively impacted student performance, contained evidence of collaborative knowledge co-construction.

  9. Simulating the Conversion of Rural Settlements to Town Land Based on Multi-Agent Systems and Cellular Automata

    PubMed Central

    Liu, Yaolin; Kong, Xuesong; Liu, Yanfang; Chen, Yiyun

    2013-01-01

    Rapid urbanization in China has triggered the conversion of land from rural to urban use, particularly the conversion of rural settlements to town land. This conversion is the result of the joint effects of the geographic environment and agents involving the government, investors, and farmers. To understand the dynamic interaction dominated by agents and to predict the future landscape of town expansion, a small town land-planning model is proposed based on the integration of multi-agent systems (MAS) and cellular automata (CA). The MAS-CA model links the decision-making behaviors of agents with the neighbor effect of CA. The interaction rules are projected by analyzing the preference conflicts among agents. To better illustrate the effects of the geographic environment, neighborhood, and agent behavior, a comparative analysis between the CA and MAS-CA models in three different towns is presented, revealing interesting patterns in terms of quantity, spatial characteristics, and the coordinating process. The simulation of rural settlements conversion to town land through modeling agent decision and human-environment interaction is very useful for understanding the mechanisms of rural-urban land-use change in developing countries. This process can assist town planners in formulating appropriate development plans. PMID:24244472

  10. Design of a highly stable, high-conversion-efficiency, optical parametric chirped-pulse amplification system with good beam quality.

    PubMed

    Guardalben, M; Keegan, J; Waxer, L; Bagnoud, V; Begishev, I; Puth, J; Zuegel, J

    2003-10-01

    An optical parametric chirped-pulse amplifier (OPCPA) design that provides 40% pump-to-signal conversion efficiency and over-500-mJ signal energy at 1054 nm for front-end injection into a Nd:glass amplifier chain is presented. This OPCPA system is currently being built as the prototype front end for the OMEGA EP (extended performance) laser system at the University of Rochester's Laboratory for Laser Energetics. Using a three-dimensional spatial and temporal numerical model, several design considerations necessary to achieve high conversion efficiency, good output stability, and good beam quality are discussed. The dependence of OPCPA output on the pump beam's spatiotemporal shape and the relative size of seed and pump beams is described. This includes the effects of pump intensity modulation and pump-signal walk-off. The trade-off among efficiency, stability, and low output beam intensity modulation is discussed. PMID:19471364

  11. 2D materials. Graphene, related two-dimensional crystals, and hybrid systems for energy conversion and storage.

    PubMed

    Bonaccorso, Francesco; Colombo, Luigi; Yu, Guihua; Stoller, Meryl; Tozzini, Valentina; Ferrari, Andrea C; Ruoff, Rodney S; Pellegrini, Vittorio

    2015-01-01

    Graphene and related two-dimensional crystals and hybrid systems showcase several key properties that can address emerging energy needs, in particular for the ever growing market of portable and wearable energy conversion and storage devices. Graphene's flexibility, large surface area, and chemical stability, combined with its excellent electrical and thermal conductivity, make it promising as a catalyst in fuel and dye-sensitized solar cells. Chemically functionalized graphene can also improve storage and diffusion of ionic species and electric charge in batteries and supercapacitors. Two-dimensional crystals provide optoelectronic and photocatalytic properties complementing those of graphene, enabling the realization of ultrathin-film photovoltaic devices or systems for hydrogen production. Here, we review the use of graphene and related materials for energy conversion and storage, outlining the roadmap for future applications. PMID:25554791

  12. Photoactivation Studies of Zinc Porphyrin-Myoglobin System and Its Application for Light-Chemical Energy Conversion

    PubMed Central

    Chang, Chin-Hao; Hu, Yi-Ting; Lo, Chen-Fu; Luo, Liyang; Lin, Hung-Ming; Chang, Cheng-Hsiang; Lin, Ching-Yao; Diau, Eric Wei-Guang; Wu, Tung-Kung

    2011-01-01

    An artificial zinc porphyrin-myoglobin-based photo-chemical energy conversion system, consisting of ZnPP-Mb or ZnPE1-Mb as a photosensitizer, NADP+ as an electron acceptor, and triethanolamine as an electron donor, has been constructed to mimic photosystem I. The photoirradiated product is able to reduce a single-electron acceptor protein cytochrome c, but cannot catalyze the two-electron reduction of acetaldehyde by alcohol dehydrogenase, thus demonstrating a single electron transfer mechanism. Furthermore, the artificial system can bifunctionally promote oxidoredox reactions, depending on the presence or absence of a sacrificial electron donor, thus suggesting its potential application in electrochemical regeneration steps involved in chemical transformation and/or energy conversion. PMID:22043177

  13. Advanced medium-voltage bidirectional dc-dc conversion systems for future electric energy delivery and management systems

    NASA Astrophysics Data System (ADS)

    Fan, Haifeng

    2011-12-01

    The distributed renewable energy generation and utilization are constantly growing, and are expected to be integrated with the conventional grid. The growing pressure for innovative solutions will demand power electronics to take an even larger role in future electric energy delivery and management systems, since power electronics are required for the conversion and control of electric energy by most dispersed generation systems Furthermore, power electronics systems can provide additional intelligent energy management, grid stability and power quality capabilities. Medium-voltage isolated dc-dc converter will become one of the key interfaces for grid components with moderate power ratings. To address the demand of medium voltage (MV) and high power capability for future electric energy delivery and management systems, the power electronics community and industry have been reacting in two different ways: developing semiconductor technology or directly connecting devices in series/parallel to reach higher nominal voltages and currents while maintaining conventional converter topologies; and by developing new converter topologies with traditional semiconductor technology, known as multilevel converters or modular converters. The modular approach uses the well-known, mature, and cheaper power semiconductor devices by adopting new converter topologies. The main advantages of the modular approach include: significant improvement in reliability by introducing desired level of redundancy; standardization of components leading to reduction in manufacturing cost and time; power systems can be easily reconfigured to support varying input-output specifications; and possibly higher efficiency and power density of the overall system. Input-series output-parallel (ISOP) modular configuration is a good choice to realize MV to low voltage (LV) conversion for utility application. However, challenges still remain. First of all, for the high-frequency MV utility application, the low

  14. Electro-mechanical energy conversion system having a permanent magnet machine with stator, resonant transfer link and energy converter controls

    DOEpatents

    Skeist, S. Merrill; Baker, Richard H.

    2006-01-10

    An electro-mechanical energy conversion system coupled between an energy source and an energy load comprising an energy converter device including a permanent magnet induction machine coupled between the energy source and the energy load to convert the energy from the energy source and to transfer the converted energy to the energy load and an energy transfer multiplexer to control the flow of power or energy through the permanent magnetic induction machine.

  15. Low-cost conversion of the Polaroid MD-4 land camera to a digital gel documentation system.

    PubMed

    Porch, Timothy G; Erpelding, John E

    2006-04-30

    A simple, inexpensive design is presented for the rapid conversion of the popular MD-4 Polaroid land camera to a high quality digital gel documentation system. Images of ethidium bromide stained DNA gels captured using the digital system were compared to images captured on Polaroid instant film. Resolution and sensitivity were enhanced using the digital system. In addition to the low cost and superior image quality of the digital system, there is also the added convenience of real-time image viewing through the swivel LCD of the digital camera, wide flexibility of gel sizes, accurate automatic focusing, variable image resolution, and consistent ease of use and quality. Images can be directly imported to a computer by using the USB port on the digital camera, further enhancing the potential of the digital system for documentation, analysis, and archiving. The system is appropriate for use as a start-up gel documentation system and for routine gel analysis. PMID:16472866

  16. Conversing with Computers

    NASA Technical Reports Server (NTRS)

    2004-01-01

    I/NET, Inc., is making the dream of natural human-computer conversation a practical reality. Through a combination of advanced artificial intelligence research and practical software design, I/NET has taken the complexity out of developing advanced, natural language interfaces. Conversational capabilities like pronoun resolution, anaphora and ellipsis processing, and dialog management that were once available only in the laboratory can now be brought to any application with any speech recognition system using I/NET s conversational engine middleware.

  17. Parametric down-conversion and polariton pair generation in optomechanical systems.

    PubMed

    Liu, Yong-Chun; Xiao, Yun-Feng; Chen, You-Ling; Yu, Xiao-Chong; Gong, Qihuang

    2013-08-23

    We demonstrate that the nonlinear optomechanical interaction leads to parametric down-conversion, capable of generating polariton pairs formed by photons and phonons. The nonlinearity is resonantly enhanced through frequency matching, and such parametric down-conversion does not require the stringent condition that the single-photon optomechanical coupling strength g be on the order of the mechanical resonance frequency ω(m). We provide analytical results for the frequency matching condition and derive the nonlinear coefficient. Numerical simulations on polariton pair generation are presented, showing that photonlike polaritons, phononlike polaritons, and mixed photon-phonon polaritons can be selectively generated. Such nonlinear interaction offers a promising way for harnessing the optomechanical nonlinearity to manipulate photons and phonons. PMID:24010437

  18. Plasmonic hot carrier dynamics in solid-state and chemical systems for energy conversion

    NASA Astrophysics Data System (ADS)

    Narang, Prineha; Sundararaman, Ravishankar; Atwater, Harry A.

    2016-06-01

    Surface plasmons provide a pathway to efficiently absorb and confine light in metallic nanostructures, thereby bridging photonics to the nano scale. The decay of surface plasmons generates energetic `hot' carriers, which can drive chemical reactions or be injected into semiconductors for nano-scale photochemical or photovoltaic energy conversion. Novel plasmonic hot carrier devices and architectures continue to be demonstrated, but the complexity of the underlying processes make a complete microscopic understanding of all the mechanisms and design considerations for such devices extremely challenging.Here,we review the theoretical and computational efforts to understand and model plasmonic hot carrier devices.We split the problem into three steps: hot carrier generation, transport and collection, and review theoretical approaches with the appropriate level of detail for each step along with their predictions.We identify the key advances necessary to complete the microscopic mechanistic picture and facilitate the design of the next generation of devices and materials for plasmonic energy conversion.

  19. IECEC '83; Proceedings of the Eighteenth Intersociety Energy Conversion Engineering Conference, Orlando, FL, August 21-26, 1983. Volume 1 - Thermal energy systems

    NASA Astrophysics Data System (ADS)

    Among the topics discussed are the nuclear fuel cycle, advanced nuclear reactor designs, developments in central status power reactors, space nuclear reactors, magnetohydrodynamic devices, thermionic devices, thermoelectric devices, geothermal systems, solar thermal energy conversion systems, ocean thermal energy conversion (OTEC) developments, and advanced energy conversion concepts. Among the specific questions covered under these topic headings are a design concept for an advanced light water breeder reactor, energy conversion in MW-sized space power systems, directionally solidified cermet electrodes for thermionic energy converters, boron-based high temperature thermoelectric materials, geothermal energy commercialization, solar Stirling cycle power conversion, and OTEC production of methanol. For individual items see A84-30027 to A84-30055

  20. Development of Integrated Online Monitoring Systems for Detection of Diversion at Natural Uranium Conversion Facilities

    SciTech Connect

    Dewji, Shaheen A; Lee, Denise L; Croft, Stephen; McElroy, Robert Dennis; Hertel, Nolan; Chapman, Jeffrey Allen; Cleveland, Steven L

    2013-01-01

    Recent work at Oak Ridge National Laboratory (ORNL) has focused on some source term modeling of uranyl nitrate (UN) as part of a comprehensive validation effort employing gamma-ray detector instrumentation for the detection of diversion from declared conversion activities. Conversion, the process by which natural uranium ore (yellowcake) is purified and converted through a series of chemical processes into uranium hexafluoride gas (UF6), has historically been excluded from the nuclear safeguards requirements of the 235U-based nuclear fuel cycle. The undeclared diversion of this product material could potentially provide feedstock for a clandestine weapons program for state or non-state entities. Given the changing global political environment and the increased availability of dual-use nuclear technology, the International Atomic Energy Agency has evolved its policies to emphasize safeguarding this potential feedstock material in response to dynamic and evolving potential diversion pathways. To meet the demand for instrumentation testing at conversion facilities, ORNL developed the Uranyl Nitrate Calibration Loop Equipment (UNCLE) facility to simulate the full-scale operating conditions of a purified uranium-bearing aqueous stream exiting the solvent extraction process in a natural uranium conversion plant. This work investigates gamma-ray signatures of UN circulating in the UNCLE facility and evaluates detector instrumentation sensitivity to UN for safeguards applications. These detector validation activities include assessing detector responses to the UN gamma-ray signatures for spectrometers based on sodium iodide, lanthanum bromide, and germanium detectors. The results of measurements under static and dynamic operating conditions at concentrations ranging from 10-90g U/L of naturally enriched UN will be presented. A range of gamma-ray lines was examined and self-attenuation factors were calculated, in addition to attenuation for transmission measurement of

  1. Solar electric and thermal conversion system in close proximity to the consumer. [solar panels on house roofs

    NASA Technical Reports Server (NTRS)

    Boeer, K. W.

    1975-01-01

    Solar cells may be used to convert sunlight directly into electrical energy and into lowgrade heat to be used for large-scale terrestrial solar-energy conversion. Both forms of energy can be utilized if such cells are deployed in close proximity to the consumer (rooftop). Cadmium-sulfide/copper-sulfide (CdS/Cu2S) solar cells are an example of cells which may be produced inexpensively enough to become economically attractive. Cell parameters relevant for combined solar conversion are presented. Critical issues, such as production yield, life expectancy, and stability of performance, are discussed. Systems-design parameters related to operating temperatures are analyzed. First results obtained on Solar One, the experimental house of the University of Delaware, are given. Economic aspects are discussed. Different modes of operation are discussed in respect to the power utility and consumer incentives.

  2. Influence of the photoinitiator system and light photoactivation units on the degree of conversion of dental composites.

    PubMed

    Porto, Isabel Cristina Celerino de Moraes; Soares, Luis Eduardo Silva; Martin, Airton Abrahão; Cavalli, Vanessa; Liporoni, Priscila Christiane Suzy

    2010-01-01

    The aim of this study was to observe the influence of two light polymerization units (LED or halogen light) on the degree of conversion (DC) of three dental composites with lighter shades and a different photoinitiator system. The top (T) and bottom (B) surfaces of 60 discs of composite resin (Filtek™ Supreme, Filtek™ Z250, Tetric™ Ceram Bleach) cured either by LED or by halogen lamp (HL) were studied using an FT-Raman spectrometer. The degree of conversion (DC) was evaluated by following the changes in the intensity of the methacrylate C=C stretching mode at 1640 cm⁻¹. The calculated DC ranged from 54.2% (B) to 73.4% (T) and from 60.2% (B) to 76.6% (T) for the LED and HL, respectively. LED and halogen devices were able to produce an adequate DC for all the resins tested. PMID:21180971

  3. Development of optimal enzymatic and microbial conversion systems for biofuel production

    NASA Astrophysics Data System (ADS)

    Aramrueang, Natthiporn

    The increase in demand for fuels, along with the concerns over the depletion of fossil fuels and the environmental problems associated with the use of the petroleum-based fuels, has driven the exploitation of clean and renewable energy. Through a collaboration project with Mendota Bioenergy LLC to produce advanced biofuel from sugar beet and other locally grown crops in the Central Valley of California through demonstration and commercial-scale biorefineries, the present study focused on the investigation of selected potential biomass as biofuel feedstock and development of bioconversion systems for sustainable biofuel production. For an efficient biomass-to-biofuel conversion process, three important steps, which are central to this research, must be considered: feedstock characterization, enzymatic hydrolysis of the feedstock, and the bioconversion process. The first part of the research focused on the characterization of various lignocellulosic biomass as feedstocks and investigated their potential ethanol yields. Physical characteristics and chemical composition were analyzed for four sugar beet varieties, three melon varieties, tomato, Jose tall wheatgrass, wheat hay, and wheat straw. Melons and tomato are those products discarded by the growers or processors due to poor quality. The mass-based ethanol potential of each feedstock was determined based on the composition. The high sugar-containing feedstocks are sugar beet roots, melons, and tomato, containing 72%, 63%, and 42% average soluble sugars on a dry basis, respectively. Thus, for these crops, the soluble sugars are the main substrate for ethanol production. The potential ethanol yields, on average, for sugar beet roots, melons, and tomato are 591, 526, and 448 L ethanol/metric ton dry basis (d.b.), respectively. Lignocellulosic biomass, including Jose Tall wheatgrass and wheat straw, are composed primarily of cellulose (27-39% d.b.) and hemicellulose (26-30% d.b.). The ethanol yields from these

  4. Development of optimal enzymatic and microbial conversion systems for biofuel production

    NASA Astrophysics Data System (ADS)

    Aramrueang, Natthiporn

    The increase in demand for fuels, along with the concerns over the depletion of fossil fuels and the environmental problems associated with the use of the petroleum-based fuels, has driven the exploitation of clean and renewable energy. Through a collaboration project with Mendota Bioenergy LLC to produce advanced biofuel from sugar beet and other locally grown crops in the Central Valley of California through demonstration and commercial-scale biorefineries, the present study focused on the investigation of selected potential biomass as biofuel feedstock and development of bioconversion systems for sustainable biofuel production. For an efficient biomass-to-biofuel conversion process, three important steps, which are central to this research, must be considered: feedstock characterization, enzymatic hydrolysis of the feedstock, and the bioconversion process. The first part of the research focused on the characterization of various lignocellulosic biomass as feedstocks and investigated their potential ethanol yields. Physical characteristics and chemical composition were analyzed for four sugar beet varieties, three melon varieties, tomato, Jose tall wheatgrass, wheat hay, and wheat straw. Melons and tomato are those products discarded by the growers or processors due to poor quality. The mass-based ethanol potential of each feedstock was determined based on the composition. The high sugar-containing feedstocks are sugar beet roots, melons, and tomato, containing 72%, 63%, and 42% average soluble sugars on a dry basis, respectively. Thus, for these crops, the soluble sugars are the main substrate for ethanol production. The potential ethanol yields, on average, for sugar beet roots, melons, and tomato are 591, 526, and 448 L ethanol/metric ton dry basis (d.b.), respectively. Lignocellulosic biomass, including Jose Tall wheatgrass and wheat straw, are composed primarily of cellulose (27-39% d.b.) and hemicellulose (26-30% d.b.). The ethanol yields from these

  5. Conversion of Hanford site well locations to Washington coordinate system of 1983, South Zone 1991 (WCS83S)

    SciTech Connect

    Burnett, R.A.; Tzemos, S.; Dietz, L.A.

    1993-12-01

    Past construction and survey practices have resulted in the use of multiple local coordinate systems for measuring and reporting the horizontal position of wells and other facilities and locations on the Hanford Site. This report describes the development of a coordinate transformation process and algorithm and its application to the conversion of the horizontal coordinates of Hanford site wells from the various local coordinate systems and datums to a single standard coordinate system, the Washington Coordinate system of 1983, South Zone 1991 (WCS83S). The coordinate transformation algorithm, implemented as a computer program called CTRANS, uses standard two-dimensional translation, rotation, and scaling transformation equations and can be applied to any set of horizontal point locations. For each point to be transformed, the coefficients of the transformation equations are calculated locally, using the coordinates of the three nearest registration points (points with known locations in both coordinate systems). The report contains a discussion of efforts to verify and validate both the software and the well location data, a description of the methods used to estimate transformation and registration point accuracy, instructions for using the computer program, and a summary of the Hanford well conversion results for each local coordinate system and datum. Also included are the results of using recent U.S. Army Corps of Engineers survey data to obtain estimated measures of location errors in wells for which the local coordinate data source is undocumented, unverified, and therefore of unknown accuracy.

  6. A comparison of energy conversion systems for meeting the power requirements of manned rover for Mars missions

    NASA Technical Reports Server (NTRS)

    El-Genk, Mohamed S.; Morley, Nicholas; Cataldo, Robert; Bloomfield, Harvey

    1990-01-01

    Several types of conversion systems of interest for a nuclear Mars manned application are examined, including: free-piston Stirling engines (FPSE), He/Xe closed Brayton cycle (CBC), CO2 open Brayton, and SiGe/GaP thermoelectric systems. Optimization studies were conducted to determine the impact of the conversion system on the overall mass of the nuclear power system and the mobility power requirement of the rover vehicle. The results of an analysis of a manned Mars rover equipped with a nuclear reactor power system show that the free-piston Stirling engine and the He/Xe closed Brayton cycle are the best available options for minimizing the overall mass and electric power requirements of the rover vehicle. While the current development of Brayton technology is further advanced than that of FPSE, the FPSE could provide approximately 13.5 percent lower mass than the He/Xe closed Brayton system. Results show that a specific mass of 160 is achievable with FPSE, for which the mass of the radiation shield (2.8 tons) is about half that for He/Xe CBC (5 tons).

  7. Basic research on ceramic materials for energy storage and conversion systems. Progress report, December 1, 1979-November 30, 1980

    SciTech Connect

    Whitmore, D.H.

    1980-12-01

    The present research program involves utilizing appropriate experimental probes for measuring the movement of ionic and electronic charge carriers in ceramic materials suitable for solid electrolyte and electrode applications in high-performance, secondary battery and fuel cell systems. Special emphasis is placed on developing: (1) a better understanding of the effects of structure, impurities and composition on charge carrier transport mechanisms in such materials; and (2) detailed knowledge of the kinetics and mechanism of reactions occurring (on a microscopic scale) at the electrode-electrolyte interfaces of energy storage and conversion systems.

  8. Protection of quantum information and optimal singlet conversion through higher-dimensional quantum systems and environment monitoring

    SciTech Connect

    Mascarenhas, E.; Marques, B.; Santos, M. Franca; Cavalcanti, D.; Cunha, M. Terra

    2010-03-15

    We study how to protect quantum information in quantum systems subjected to local dissipation. We show that combining the use of three-level systems, environment monitoring, and local feedback can fully and deterministically protect any available quantum information, including entanglement initially shared by different parties. These results can represent a gain in resources and/or distances in quantum communication protocols such as quantum repeaters and teleportation as well as time for quantum memories. Finally, we show that monitoring local environments physically implements the optimum singlet conversion protocol, which is essential for classical entanglement percolation.

  9. A dynamical systems proof of Kraft-McMillan inequality and its converse for prefix-free codes.

    PubMed

    Nagaraj, Nithin

    2009-03-01

    Uniquely decodable codes are central to lossless data compression in both classical and quantum communication systems. The Kraft-McMillan inequality is a basic result in information theory which gives a necessary and sufficient condition for a code to be uniquely decodable and also has a quantum analogue. In this letter, we provide a novel dynamical systems proof of this inequality and its converse for prefix-free codes (no codeword is a prefix of another-the popular Huffman codes are an example). For constrained sources, the problem is still open. PMID:19335000

  10. Digital computer study of nuclear reactor thermal transients during startup of 60-kWe Brayton power conversion system

    NASA Technical Reports Server (NTRS)

    Jefferies, K. S.; Tew, R. C.

    1974-01-01

    A digital computer study was made of reactor thermal transients during startup of the Brayton power conversion loop of a 60-kWe reactor Brayton power system. A startup procedure requiring the least Brayton system complication was tried first; this procedure caused violations of design limits on key reactor variables. Several modifications of this procedure were then found which caused no design limit violations. These modifications involved: (1) using a slower rate of increase in gas flow; (2) increasing the initial reactor power level to make the reactor respond faster; and (3) appropriate reactor control drum manipulation during the startup transient.

  11. A dynamical systems proof of Kraft-McMillan inequality and its converse for prefix-free codes

    NASA Astrophysics Data System (ADS)

    Nagaraj, Nithin

    2009-03-01

    Uniquely decodable codes are central to lossless data compression in both classical and quantum communication systems. The Kraft-McMillan inequality is a basic result in information theory which gives a necessary and sufficient condition for a code to be uniquely decodable and also has a quantum analogue. In this letter, we provide a novel dynamical systems proof of this inequality and its converse for prefix-free codes (no codeword is a prefix of another—the popular Huffman codes are an example). For constrained sources, the problem is still open.

  12. Degree of conversion of simplified contemporary adhesive systems as influenced by extended air-activated or passive solvent volatilization modes.

    PubMed

    Borges, Boniek C D; Souza-Junior, Eduardo Jose; Brandt, William C; Loguercio, Alessandro D; Montes, Marcos A J R; Puppin-Rontani, Regina M; Sinhoreti, Mario Alexandre Coelho

    2012-01-01

    This study evaluated the effect of five methods of solvent volatilization on the degree of conversion (DC) of nine one-bottle adhesive systems using Fourier transform infrared/attenuated total reflectance (FTIR/ATR) analysis. Nine adhesives were tested: Adper Single Bond 2 (SB), Adper Easy One (EO), One Up Bond F Plus (OUP), One Coat Bond SL (OC), XP Bond (XP), Ambar (AM), Natural Bond (NB), GO, and Stae. The adhesive systems were applied to a zinc-selenide pellet and 1) cured without solvent volatilization, 2) left undisturbed for 10 seconds before curing, 3) left undisturbed for 60 seconds before curing, 4) air-dried with an air stream for 10 seconds before curing, and 5) air-dried with an air stream for 60 seconds before curing. FTIR/ATR spectra were obtained, and the DC was calculated by comparing the aliphatic bonds/reference peaks before and after light activation for 10 seconds (FlashLite 1401). The DC means of each material were analyzed by one-way analysis of variance and post hoc Tukey test (p<0.05). The DC of GO and Stae adhesive systems was not affected by the five evaporation conditions. Air-drying for 60 seconds before curing yielded the highest DC for SB, EO, and OC. Extended solvent volatilization time (60 seconds) either with or without air-drying before curing provided the highest DC for AM, NB, XP, and OUP. Thus, the monomer conversion of adhesive systems was material dependent. In general, the 60-second passive or active air-drying modes to volatilize solvents before curing enhanced the degree of conversion for the one-bottle simplified adhesive systems. PMID:22313268

  13. CdTe and si Solar Cell Performance Comparison in a New System for Solar Energy Conversion and Storage

    NASA Astrophysics Data System (ADS)

    Morales-Sánchez, E.; González-Hernández, J.; Ramírez-Bon, R.; Espinoza-Beltrán, F.; Vorobiev, Y.; Morales-Acevedo, A.; Gorley, Petro; Kovalyuk, Z.; Horley, Paul

    A new system for the effective conversion and storage of solar energy using CdTe and Si based photovoltaic solar cells and the Li-Bi2Se3 rechargable batteries was created and studied. PV Solar Cells with the different types of structure and barrier were studied (Shottky. MIS with thin insulating layer, and p-n junction), employing low-temperature and high-temperature technological cycles. The influence of the technological details upon the electrical parameters as well as the efficiency and stability of their performance were analyzed, and also the condition for improving the efficiency were found. In particular, it was established that Zn-doping of CdTe and the Al alloying to Si at 800°C have a profound effect upon the PV cell characteristics. The influence of the recombination in different parts of the cell upon the cell's efficiency and the recombination dependence upon the technological features were investigated. A comparison of the performance and fabrication cost of the new systems for solar energy conversion and storage with others using conventional cells and batteries is made. It is shown that newly developed systems could provide a global efficiency close to that for traditional ones, with simpler and cheaper technology. With some modifications of the technology, we expect to get even higher efficiencies and a wider system operation temperature range. The possibilities are discussed for the creation of a hybrid energy conversion system on the basis of our cells and batteries, with an overall efficiency of transformation of solar-to-electric energy around 40%.

  14. Half-time Tc-99m sestamibi imaging with a direct conversion molecular breast imaging system

    PubMed Central

    2014-01-01

    Background In an effort to reduce necessary acquisition time to perform molecular breast imaging (MBI), we compared diagnostic performance of MBI performed with standard 10-min-per-view acquisitions and half-time 5-min-per-view acquisitions, with and without wide beam reconstruction (WBR) processing. Methods Eighty-two bilateral, two-view MBI studies were reviewed. Studies were performed with 300 MBq Tc-99 m sestamibi and a direct conversion molecular breast imaging (DC-MBI) system. Acquisitions were 10 min-per-view; the first half of each was extracted to create 5-min-per-view datasets, and WBR processing was applied. The 10-min-, 5-min-, and 5-min-per-view WBR studies were independently interpreted in a randomized, blinded fashion by two radiologists. Assessments of 1 to 5 were assigned; 4 and 5 were considered test positive. Background parenchymal uptake, lesion type, distribution of non-mass lesions, lesion intensity, and image quality were described. Results Considering detection of all malignant and benign lesions, 5 min-per-view MBI had lower sensitivity (mean of 70% vs. 85% (p ≤ 0.04) for two readers) and lower area under curve (AUC) (mean of 92.7 vs. 99.6, p ≤ 0.01) but had similar specificity (p = 1.0). WBR processing did not alter sensitivity, specificity, or AUC obtained at 5 min-per-view. Overall agreement in final assessment between 5-min-per-view and 10-min-per-view acquisition types was near perfect (κ = 0.82 to 0.89); however, fair to moderate agreement was observed for assessment category 3 (probably benign) (κ = 0.24 to 0.48). Of 33 malignant lesions, 6 (18%) were changed from assessment of 4 or 5 with 10-min-per-view MBI to assessment of 3 with 5-min-per-view MBI. Image quality of 5-min-per-view studies was reduced compared to 10-min-per-view studies for both readers (3.24 vs. 3.98, p < 0.0001 and 3.60 vs. 3.91, p < 0.0001). WBR processing improved image quality for one reader (3.85 vs. 3.24, p < 0

  15. Motor starting a Brayton cycle power conversion system using a static inverter

    NASA Technical Reports Server (NTRS)

    Curreri, J. S.; Edkin, R. A.; Kruchowy, R.

    1973-01-01

    The power conversion module of a 2- to 15-kWe Brayton engine was motor started using a three-phase, 400-hertz static inverter as the power source. Motor-static tests were conducted for initial gas loop pressures of 10, 14, and 17 N/sq cm (15, 20, and 25 psia) over a range of initial turbine inlet temperatures from 366 to 550 K (200 to 530 F). The data are presented to show the effects of temperature and pressure on the motor-start characteristics of the rotating unit. Electrical characteristics during motoring are also discussed.

  16. Catalytic conversion reactions in nanoporous systems with concentration-dependent selectivity: Statistical mechanical modeling

    NASA Astrophysics Data System (ADS)

    García, Andrés; Wang, Jing; Windus, Theresa L.; Sadow, Aaron D.; Evans, James W.

    2016-05-01

    Statistical mechanical modeling is developed to describe a catalytic conversion reaction A →Bc or Bt with concentration-dependent selectivity of the products, Bc or Bt, where reaction occurs inside catalytic particles traversed by narrow linear nanopores. The associated restricted diffusive transport, which in the extreme case is described by single-file diffusion, naturally induces strong concentration gradients. Furthermore, by comparing kinetic Monte Carlo simulation results with analytic treatments, selectivity is shown to be impacted by strong spatial correlations induced by restricted diffusivity in the presence of reaction and also by a subtle clustering of reactants, A .

  17. Catalytic conversion reactions in nanoporous systems with concentration-dependent selectivity: Statistical mechanical modeling

    DOE PAGESBeta

    Garcia, Andres; Wang, Jing; Windus, Theresa L.; Sadow, Aaron D.; Evans, James W.

    2016-05-20

    Statistical mechanical modeling is developed to describe a catalytic conversion reaction A → Bc or Bt with concentration-dependent selectivity of the products, Bc or Bt, where reaction occurs inside catalytic particles traversed by narrow linear nanopores. The associated restricted diffusive transport, which in the extreme case is described by single-file diffusion, naturally induces strong concentration gradients. Hence, by comparing kinetic Monte Carlo simulation results with analytic treatments, selectivity is shown to be impacted by strong spatial correlations induced by restricted diffusivity in the presence of reaction and also by a subtle clustering of reactants, A.

  18. Lapped substrate for enhanced backsurface reflectivity in a thermophotovoltaic energy conversion system

    DOEpatents

    Baldasaro, Paul F; Brown, Edward J; Charache, Greg W; DePoy, David M

    2000-01-01

    A method for fabricating a thermophotovoltaic energy conversion cell including a thin semiconductor wafer substrate (10) having a thickness (.beta.) calculated to decrease the free carrier absorption on a heavily doped substrate; wherein the top surface of the semiconductor wafer substrate is provided with a thermophotovoltaic device (11), a metallized grid (12) and optionally an antireflective (AR) overcoating; and, the bottom surface (10') of the semiconductor wafer substrate (10) is provided with a highly reflecting coating which may comprise a metal coating (14) or a combined dielectric/metal coating (17).

  19. Lapped substrate for enhanced backsurface reflectivity in a thermophotovoltaic energy conversion system

    DOEpatents

    Baldasaro, Paul F; Brown, Edward J; Charache, Greg W; DePoy, David M

    2000-09-05

    A method for fabricating a thermophotovoltaic energy conversion cell including a thin semiconductor wafer substrate (10) having a thickness (.beta.) calculated to decrease the free carrier absorption on a heavily doped substrate; wherein the top surface of the semiconductor wafer substrate is provided with a thermophotovoltaic device (11), a metallized grid (12) and optionally an antireflective (AR) overcoating; and, the bottom surface (10') of the semiconductor wafer substrate (10) is provided with a highly reflecting coating which may comprise a metal coating (14) or a combined dielectric/metal coating (17).

  20. Improved coal conversion in CO/water systems. Quarterly report No. 6, December 4, 1985-March 3, 1986

    SciTech Connect

    Ross, D.S.; McMillen, D.F.; Hum, G.; Miin, T.C.

    1986-08-01

    This report describes the results of initial studies designed to test the suggestion that the effectiveness of CO/water/base systems in coal conversion can be attributed to the susceptibility of the keto-forms of phenolic coal structures to reaction with hydride- and electron-transfer reagents. The dealkylation, deoxygenation, and coupling or retrograde reactions of p-benzylphenol, 9-phenanthrol, o.o'-biphenol, 2-methyl-l-naphthol, and veratrole (1,2-dimethoxybenzene) have been studied as representative of classes important in coal conversion. Experiments were conducted in fused silica ampoules and stainless steel microautoclaves using at least two donor solvents (typically tetralin and tetralin/THQ) and in CO/H/sub 2/O/KOH systems. Comparison of the conversion rates in the organic and aqueous systems led to the conclusions summarized below: Both dealkylation and deoxygenations can be faster in CO/H/sub 2/O/KOH systems. Dealkylation rate appears to correlate with the amount of base, possibly due to nucleophilic displacement. Deoxygenation is not accelerated when dealkylation is a viable alternative. H/sub 2/O/Base can substantially accelerate coupling reactions. This tendency is moderated by CO. Alkylated polyoxygenated structures undergo rapid Ar-O cleavage. The results of our study suggest that the increased pyrolysis yields reported on methylation of low-rank coals are due not only to protection of hydroxyls from coupling reactions but are also due to enhanced cleavage of the strong Ar-O bonds. These results suggest that the facile dissolution of subbituminous coals in alcoholic KOH media could well be due to reactions of partially alkylated polyphenolic structures rather than to hydrolysis of esters, as has been previously asserted. 18 refs., 3 figs., 6 tabs.

  1. Low Temperature Catalytic Ethanol Conversion Over Ceria-Supported Platinum, Rhodium, and Tin-Based Nanoparticle Systems

    NASA Astrophysics Data System (ADS)

    Mahmoud, Eugene Leo Draine

    Due to the feasibility of ethanol production in the United States, ethanol has become more attractive as a fuel source and a possible energy carrier within the hydrogen economy. Ethanol can be stored easily in liquid form, and can be internally pre-formed prior to usage in low temperature (200°C--400°C) solid acid and polymer electrolyte membrane fuel cells. However, complete electrochemical oxidation of ethanol remains a challenge. Prior research of ethanol reforming at high temperatures (> 400°C) has identified several metallic and oxide-based catalyst systems that improve ethanol conversion, hydrogen production, and catalyst stability. In this study, ceria-supported platinum, rhodium, and tin-based nanoparticle catalyst systems will be developed and analyzed in their performance as low-temperature ethanol reforming catalysts for fuel cell applications. Metallic nanoparticle alloys were synthesized with ceria supports to produce the catalyst systems studied. Gas phase byproducts of catalytic ethanol reforming were analyzed for temperature-dependent trends and chemical reaction kinetic parameters. Results of catalytic data indicate that catalyst composition plays a significant role in low-temperature ethanol conversion. Analysis of byproduct yields demonstrate how ethanol steam reforming over bimetallic catalyst systems (platinum-tin and rhodium-tin) results in higher hydrogen selectivity than was yielded over single-metal catalysts. Additionally, oxidative steam reforming results reveal a correlation between catalyst composition, byproduct yield, and ethanol conversion. By analyzing the role of temperature and reactant composition on byproduct yields from ethanol reforming, this study also proposes how these parameters may contribute to optimal catalytic ethanol reforming.

  2. FIS/ANFIS Based Optimal Control for Maximum Power Extraction in Variable-speed Wind Energy Conversion System

    NASA Astrophysics Data System (ADS)

    Nadhir, Ahmad; Naba, Agus; Hiyama, Takashi

    An optimal control for maximizing extraction of power in variable-speed wind energy conversion system is presented. Intelligent gradient detection by fuzzy inference system (FIS) in maximum power point tracking control is proposed to achieve power curve operating near optimal point. Speed rotor reference can be adjusted by maximum power point tracking fuzzy controller (MPPTFC) such that the turbine operates around maximum power. Power curve model can be modelled by using adaptive neuro fuzzy inference system (ANFIS). It is required to simply well estimate just a few number of maximum power points corresponding to optimum generator rotor speed under varying wind speed, implying its training can be done with less effort. Using the trained fuzzy model, some estimated maximum power points as well as their corresponding generator rotor speed and wind speed are determined, from which a linear wind speed feedback controller (LWSFC) capable of producing optimum generator speed can be obtained. Applied to a squirrel-cage induction generator based wind energy conversion system, MPPTFC and LWSFC could maximize extraction of the wind energy, verified by a power coefficient stay at its maximum almost all the time and an actual power line close to a maximum power efficiency line reference.

  3. Plasmonic hot carrier dynamics in solid-state and chemical systems for energy conversion

    DOE PAGESBeta

    Narang, Prineha; Sundararaman, Ravishankar; Atwater, Harry A.

    2016-06-11

    Surface plasmons provide a pathway to efficiently absorb and confine light in metallic nanostructures, thereby bridging photonics to the nano scale. The decay of surface plasmons generates energetic ‘hot’ carriers, which can drive chemical reactions or be injected into semiconductors for nano-scale photochemical or photovoltaic energy conversion. Novel plasmonic hot carrier devices and architectures continue to be demonstrated, but the complexity of the underlying processes make a complete microscopic understanding of all the mechanisms and design considerations for such devices extremely challenging.Here,we review the theoretical and computational efforts to understand and model plasmonic hot carrier devices.We split the problem intomore » three steps: hot carrier generation, transport and collection, and review theoretical approaches with the appropriate level of detail for each step along with their predictions. As a result, we identify the key advances necessary to complete the microscopic mechanistic picture and facilitate the design of the next generation of devices and materials for plasmonic energy conversion.« less

  4. A linear discrete dynamic system model for temporal gene interaction and regulatory network influence in response to bioethanol conversion inhibitor HMF for ethanologenic yeast

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A linear discrete dynamic system model is constructed to represent the temporal interactions among significantly expressed genes in response to bioethanol conversion inhibitor 5-hydroxymethylfurfural for ethanologenic yeast Saccharomyces cerevisiae. This study identifies the most significant linear...

  5. Comparison of conceptual designs for 25 kWe advanced Stirling conversion systems for dish electric application

    NASA Technical Reports Server (NTRS)

    Shaltens, Richard K.; Schreiber, Jeffrey G.

    1989-01-01

    The Advanced Stirling Conversion System (ASCS) Project is managed by NASA Lewis Research Center through a cooperative interagency agreement with DOE. Conceptual designs for the ASCS's were completed under parallel contracts in 1987 by Mechanical Technology Inc. (MTI) of Latham, NY, and Stirling Technology Company (STC) of Richland, WA. Each design features a free-piston Stirling engine, a liquid metal heat pipe receiver, and a means to provide about 25 kW of electric power to a utility grid while meeting DOE's long term performance and cost goals. An independent assessment showed that both designs are manufacturable and have the potential to easily meet DOE's long term cost goals.

  6. Development of A Flexible System for the Simultaneous Conversion of Biomass to Industrial Chemicals and the Production of Industrial Biocatalysts

    SciTech Connect

    Gao, Johnway; Hooker, Brian S.; Skeen, R S.; Anderson, D B.; Lankey, R. L.; Anastas, P. T.

    2002-01-01

    A flexible system was developed for the simultaneous conversion of biomass to industrial chemicals and the production of industrial biocatalysts. In particular, the expression of a bacterial enzyme, beta-glucuronidase (GUS), was investigated using a genetically modified starch-degrading Saccharomyces strain in suspension cultures in starch media. Different sources of starch including corn and waste potato starch were used for yeast biomass accumulation and GUS expression studies under controls of inducible and constitutive promoters. A thermostable bacterial cellulase, Acidothermus cellulolyticus E1 endoglucanase gene was also cloned into an episomal plasmid expression vector and expressed in the starch-degrading Saccharomyces strain.

  7. W-band OFDM Radio-over-Fiber system with power detector for vector signal down-conversion.

    PubMed

    Lin, Chun-Ting; Wu, Meng-Fan; Ho, Chun-Hung; Li, Che-Hao; Lin, Chi-Hsiang; Huang, Hou-Tzu

    2015-06-01

    This Letter proposes a W-band OFDM RoF system at 103.5 GHz employing power detector to support vector signal down-conversion. Additional RF tone is generated and transmitted from central office to replace the local oscillator at a wireless receiver. With a proper frequency gap and power ratio between the RF tone and the OFDM-modulated signal, the impact from signal-to-signal beating interference can be minimized. The data rate can achieve a 40 Gbps 16 QAM OFDM signal over 25 km fiber and 2 m wireless transmission. PMID:26030536

  8. Comparison of conceptual designs for 25 kWe advanced Stirling conversion systems for dish electric applications

    NASA Technical Reports Server (NTRS)

    Shaltens, Richard K.; Schreiber, Jeffrey G.

    1989-01-01

    The Advanced Stirling Conversion System (ASCS) Project is managed by NASA Lewis Research Center through a cooperative interagency agreement with DOE. Conceptual designs for the ASCS's were completed under parallel contracts in 1987 by Mechanical Technology Inc. (MTI) of Latham, NY, and Stirling Technology Company (STC) of Richland, WA. Each design features a free-piston Stirling engine, a liquid metal heat pipe receiver, and a means to provide about 25 kW of electric power to a utility grid while meeting DOE's long term performance and cost goals. An independent assessment showed that both designs are manufacturable and have the potential to easily meet DOE's long term cost goals.

  9. Design definition of a microwave power reception and conversion system for use on a high altitude powered platform

    NASA Technical Reports Server (NTRS)

    Brown, W. C.

    1981-01-01

    The design definition of a microwave power reception and conversion system for use on high altitude powered platform is presented. The study includes an initial design, construction and test effort on a thin film, printed circuit rectenna. A study of a low altitude demonstration of an airborne rectenna was made starting with the assumption that a fifty foot mechanically steerable parabolic reflector at the Wallops Flight Center would be retrofitted with a low microwave power source consisting of a five kilowatt commercially available magnetron and that a small blimp would be used to support the rectenna.

  10. Theoretical analysis of solar-driven natural convection energy conversion systems

    SciTech Connect

    Jacobs, E.W.; Lasier, D.D.

    1984-01-01

    This report presents a theoretical study of solar-powered natural convection tower (chimney) performance. Both heated and cooled towers are analyzed; the latter uses evaporating water as the cooling mechanism. The results, which are applicable to any open-cycle configuration, show that the ideal conversion efficiencies of both heated and cooled natural convection towers are linear functions of height. The performance of a heated tower in an adiabatic atmosphere ideally approaches the Carnot efficiency limit of approx. = 3.4%/km (1.0%/1000 ft). Including water pumping requirements, the ideal limit to cooled tower performance is approx. = 2.75%/km (0.85%/1000 ft). Ambient atmospheric conditions such as vertical temperature gradient (lapse rate) and relative humidity can have significantly adverse effects on natural convection tower performance. The combined effects of lapse rate and ambient relative humidity are especially important to cooled natural convection towers.

  11. Direct micellar systems as a tool to improve the efficiency of aromatic substrate conversion for fine chemicals production.

    PubMed

    Berti, D; Randazzo, D; Briganti, F; Baglioni, P; Scozzafava, A; Di Gennaro, P; Galli, E; Bestetti, G

    2000-04-01

    Whole-cell bioconversion of naphthalene to (+)-cis-(1R,2S)-dihydroxy-1,2-dihydronaphthalene by Escherichia coli JM109(pPS1778) recombinant strain, carrying naphthalene dioxygenase and regulatory genes cloned from Pseudomonas fluorescens N3, in direct micellar systems is optimized as an example of fine chemicals bioproduction from scarcely water-soluble substrates. The oxygen insertion into the aromatic substrate, which stops at the enantiomerically pure cis dihydroxylated product, is performed in direct microemulsion systems, where a non-ionic surfactant stabilizes naphthalene containing oil droplets in an aqueous medium. These media provide an increased substrate solubility so that a homogeneous reaction can be carried out, while not affecting bacteria viability and performances. The influence of the chemical nature of the oil is investigated. The phase behavior of the direct microemulsion system was monitored for three different oils as a function their volume fraction and characterized through light scattering. The addition of isopropyl palmitate, oleic acid, or glyceryl trioleate, 0.6-1.2% v/v to the micellar systems, led to an increase of the substrate concentration in the solution and particularly its bioavailability, allowing faster catalytic conversions. All these systems resulted in being suitable for catalytic conversions of aromatic compounds. Although the nature of the oil does have a deep effect on the phase behavior of the micellar systems, in the present investigation no differences in the yields and in the rates of product formation of the enzymatic system were observed on changing the oil, thus showing that in this case the substrate concentration or bioavailability is not the rate-limiting step. PMID:10830854

  12. Demonstration of simultaneous mode conversion and demultiplexing for mode and wavelength division multiplexing systems based on tilted few-mode fiber Bragg gratings.

    PubMed

    Gao, Ya; Sun, Junqiang; Chen, Guodong; Sima, Chaotan

    2015-04-20

    We experimentally demonstrate mode conversion by exploiting optical reflection of tilted few-mode fiber Bragg grating (FM-FBG). Mode conversions from LP(01) mode to higher symmetric and asymmetric modes are achieved, and more than 99.5% conversion efficiency from LP(01) to LP(11) mode is obtained using a 1.6°-tilted FM-FBG. Influences of the weakly tilted FM-FBG parameters on the property of mode conversion is analyzed and discussed. A simultaneous mode conversion and demultiplexing scheme for 4-mode × 3-wavelength multiplexing transmission is proposed and the modal crosstalk is analyzed based on the transmission spectra of the tilted FM-FBGs. The proposed approach shows potential applications in mode and wavelength division multiplexing communication systems. PMID:25969037

  13. 5 CFR 9701.373 - Conversion of employees to the DHS pay system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... system. 9701.373 Section 9701.373 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM (DEPARTMENT OF HOMELAND SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM Pay and Pay Administration Transitional...

  14. Conversion of glucose into furans in the presence of AlCl3 in an ethanol-water solvent system.

    PubMed

    Yang, Yu; Hu, Changwei; Abu-Omar, Mahdi M

    2012-07-01

    Glucose was converted into furans (5-hydroxymethylfurfural and 5-ethoxymethylfurfural) in the presence of AlCl(3) in an ethanol-water solvent system. The system showed high activity for the conversion of glucose into furans but low activity for the subsequent formation of LAs (levulinic acid and ethyl levulinate). High furans yield of 57% with low LAs yield of 11% can be obtained at 160 °C within 15 min. Glucose-based disaccharides (sucrose, maltose and cellobiose) and polysaccharides (starch but not cellulose) can also be converted to furans effectively under the same condition. AlCl(3) can be used to prepare furans from biomass-derived compounds in ethanol-water, a green solvent system. PMID:22609675

  15. A comparison of Stirling engines for use with a 25 kW dish-electric conversion system

    NASA Technical Reports Server (NTRS)

    Shaltens, Richard K.

    1987-01-01

    Two designs for an advanced Stirling conversion system (ASCS) are described. The objective of the ASCS is to generate about 25 kW of electric power to an electric utility grid at an engine/alternator target cost of $300.00/kW at the manufacturing rate of 10,000 unit/yr. Both designs contain a free-piston Stirling engine (FPSE), a heat transport system, solar receiver, a means to generate electric power, the necessary auxiliaries, and a control system. The major differences between the two concepts are: one uses a 25 kWe single-piston FPSE which incorporates a linear alternator to directly convert the energy to electricity on the utility grid; and in the second design, electrical power is generated indirectly using a hydraulic output to a ground based hydraulic motor coupled to a rotating alternator. Diagrams of the two designs are presented.

  16. 5 CFR 9701.231 - Conversion of positions and employees to the DHS classification system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM (DEPARTMENT OF HOMELAND SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM Classification...

  17. Improved direct torque control of an induction generator used in a wind conversion system connected to the grid.

    PubMed

    Abdelli, Radia; Rekioua, Djamila; Rekioua, Toufik; Tounzi, Abdelmounaïm

    2013-07-01

    This paper presents a modulated hysteresis direct torque control (MHDTC) applied to an induction generator (IG) used in wind energy conversion systems (WECs) connected to the electrical grid through a back-to-back converter. The principle of this strategy consists in superposing to the torque reference a triangular signal, as in the PWM strategy, with the desired switching frequency. This new modulated reference is compared to the estimated torque by using a hysteresis controller as in the classical direct torque control (DTC). The aim of this new approach is to lead to a constant frequency and low THD in grid current with a unit power factor and a minimum voltage variation despite the wind variation. To highlight the effectiveness of the proposed method, a comparison was made with classical DTC and field oriented control method (FOC). The obtained simulation results, with a variable wind profile, show an adequate dynamic of the conversion system using the proposed method compared to the classical approaches. PMID:23615169

  18. Space-based solar power conversion and delivery systems (study), engineering analysis

    NASA Technical Reports Server (NTRS)

    Nathan, C. A.

    1975-01-01

    A systems analysis of synchronous, orbit-based power generation and relay systems that could be operational in the 1990's is described along with a comparison with earth-based systems to be operational in the same time frame. Operational and economic requirements for the orbiting systems and near term research activities which will be required to assure feasibility, development, launch and operational capabilities of such systems in the post- 1990 time frame are examined.

  19. Design and performance of a no-single-failure control system for the mini-Brayton power conversion system. [for spacecraft power supplies

    NASA Technical Reports Server (NTRS)

    Brichenough, A. G.

    1975-01-01

    The control system consists of the ac-dc conversion, voltage regulation, speed regulation through parasitic load control, and overload control. A no-single-failure configuration was developed to attain the required reliability for a 10-year design life of unattended operation. The design principles, complete schematics, and performance are reported. Testing was performed on an alternator simulator pending construction of the actual Mini-Brayton alternator.

  20. Metric Conversion

    Atmospheric Science Data Center

    2013-03-12

    ... 1,000,000 1,000,000 micrometers nano- 1,000,000,000 1,000,000,000 nanometers ... conversions, see the National Institute of Standards and Technology (NIST) Special Publications: NIST Guide to SI Units: ...

  1. Spin-symmetry conversion and internal rotation in high J molecular systems

    NASA Astrophysics Data System (ADS)

    Mitchell, Justin; Harter, William

    2006-05-01

    Dynamics and spectra of molecules with internal rotation or rovibrational coupling is approximately modeled by rigid or semi-rigid rotors with attached gyroscopes. Using Rotational Energy (RE)^1 surfaces, high resolution molecular spectra for high angular momentum show two distinct but related phenomena; spin-symmetry conversion and internal rotation. For both cases the high total angular momentum allows for transitions that would otherwise be forbidden. Molecular body-frame J-localization effects associated with tight energy level-clusters dominate the rovibronic spectra of high symmetry molecules, particularly spherical tops at J>10. ^2 The effects include large and widespread spin-symmetry mixing contrary to conventional wisdom^3 about weak nuclear moments. Such effects are discussed showing how RE surface plots may predict them even at low J. Classical dynamics of axially constrained rotors are approximated by intersecting rotational-energy-surfaces (RES) that have (J-S).B.(J-S) forms in the limit of constraints that do no work. Semi-classical eigensolutions are compared to those found by direct diagonalization. ^1 W.G Hater, in Handbook of Atomic, Molecular and Optical Physics, edited by G.W.F Drake (Springer, Germany 2006) ^2 W. G. Harter, Phys. Rev. A24,192-262(1981). ^3 G. Herzberg, Infrared and Raman Spectra (VanNostrand 1945) pp. 458,463.

  2. Conversion factors from counts to chemical ratios for the EURITRACK tagged neutron inspection system

    NASA Astrophysics Data System (ADS)

    El Kanawati, W.; Perot, B.; Carasco, C.; Eleon, C.; Valkovic, V.; Sudac, D.; Obhodas, J.

    2011-10-01

    The EURopean Illicit TRAfficking Countermeasures Kit (EURITRACK) uses 14 MeV neutrons produced by the 3H(d,n) 4H fusion reaction to detect explosives and narcotics in cargo containers. Reactions induced by fast neutrons produce gamma rays, which are detected in coincidence with the associated alpha particle to determine the neutron direction. In addition, the neutron path length is obtained from a time-of-flight measurement, thus allowing the origin of the gamma rays inside the container to be determined. Information concerning the chemical composition of the target material is obtained from the analysis of the energy spectrum. The carbon, oxygen, and nitrogen relative count contributions must be converted to chemical proportions to distinguish illicit and benign organic materials. An extensive set of conversion factors based on Monte Carlo numerical simulations has been calculated, taking into account neutron slowing down and photon attenuation in the cargo materials. An experimental validation of the method is presented by comparing the measured chemical fractions of known materials, in the form of bare samples or hidden in a cargo container, to their real chemical composition. Examples of application to real cargo containers are also reported, as well as simulated data with explosives and illicit drugs.

  3. Ultrafast electronic state conversion at room temperature utilizing hidden state in cuprate ladder system

    PubMed Central

    Fukaya, R.; Okimoto, Y.; Kunitomo, M.; Onda, K.; Ishikawa, T.; Koshihara, S.; Hashimoto, H.; Ishihara, S.; Isayama, A.; Yui, H.; Sasagawa, T.

    2015-01-01

    Photo-control of material properties on femto- (10−15) and pico- (10−12) second timescales at room temperature has been a long-sought goal of materials science. Here we demonstrate a unique ultrafast conversion between the metallic and insulating state and the emergence of a hidden insulating state by tuning the carrier coherence in a wide temperature range in the two-leg ladder superconductor Sr14-xCaxCu24O41 through femtosecond time-resolved reflection spectroscopy. We also propose a theoretical scenario that can explain the experimental results. The calculations indicate that the holes injected by the ultrashort light reduce the coherence among the inherent hole pairs and result in suppression of conductivity, which is opposite to the conventional photocarrier-doping mechanism. By using trains of ultrashort laser pulses, we successively tune the carrier coherence to within 1 picosecond. Control of hole-pair coherence is shown to be a realistic strategy for tuning the electronic state on ultrafast timescales at room temperature. PMID:26481604

  4. Proceedings of the fourth biennial conference and workshop on wind energy conversion systems

    SciTech Connect

    Kottler, Jr., R. J.

    1980-06-01

    Separate abstracts are included for papers presented concerning research and development requirements and utility interface and institutional issues for small-scale systems; design requirements and research and development requirements for large-scale systems; economic and operational requirements of large-scale wind systems; wind characteristics and wind energy siting; international activities; wind energy applications in agriculture; federal commercialization and decentralization plans; and wind energy innovative systems.

  5. An integrated, semi-automated approach to thermochemical conversion research for sustainable farming systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An integrated, semi-automated system is presented for the rapid and efficient testing and production of research-scale quantities of biochar. This biochar, produced from agricultural waste materials, can easily be incorporated in future sustainable livestock farming systems. These farming systems wi...

  6. Spacelab Program: Conversion of Spacelab to packet data format. Flight system study

    NASA Technical Reports Server (NTRS)

    1981-01-01

    A study of packetization of the Spacelab data handling system, including the alternate approaches considered and the supporting rationale, is described. It is concluded that it is well within today's state of the art in microelectronics to implement either a full or hybrid packet data system on board the Spacelab. Of the two, the hybrid system is preferred because of the significant cost saving.

  7. Polarization insensitive all-optical up-conversion for ROF systems based on parallel pump FWM in a SOA.

    PubMed

    Lu, Jia; Dong, Ze; Cao, Zizheng; Chen, Lin; Wen, Shuangchun; Yu, Jianguo

    2009-04-27

    We have proposed and experimentally investigated polarization insensitive all-optical up-conversion for ROF system based on FWM in a semiconductor optical amplifier (SOA). The parallel pump is generated based on odd-order optical sidebands and carrier suppression using an external intensity modulator and a cascaded optical filter. Therefore, the two pumps are always parallel and phase locked, which makes system polarization insensitive. After FWM in a SOA and optical filtering, similar to single sideband (SSB) 40 GHz optical millimeter-wave is generated only using 10 GHz RF as local oscillator (LO). The receiver sensitivity at a BER of 10(-9) for the up-converted signals is -28.4 dBm. The power penalty for the up-converted downstream signals is smaller than 1 dBm after 20 km SSMF-28 transmission. PMID:19399069

  8. Energy conversion with solid oxide fuel cell systems: A review of concepts amd outlooks for the short- and long-term

    SciTech Connect

    Adams, II, Thomas A.; Nease, Jake; Tucker, David; Barton, Paul I.

    2013-01-01

    A review of energy conversion systems which use solid oxide fuel cells (SOFCs) as their primary electricity generation component is presented. The systems reviewed are largely geared for development and use in the short- and long-term future. These include systems for bulk power generation, distributed power generation, and systems integrated with other forms of energy conversion such as fuel production. The potential incorporation of CO{sub 2} capture and sequestration technologies and the influences of potential government policies are also discussed.

  9. Prospects for the development of independent power supply systems on the basis of solid fuel thermal conversion technology

    NASA Astrophysics Data System (ADS)

    Sultanguzin, I. A.; Fedyukhin, A. V.; Kurzanov, S. Yu.; Gyulmaliev, A. M.; Stepanova, T. A.; Tumanovsky, V. A.; Titov, D. P.

    2015-05-01

    Theoretical principles of using solid fuel for organizing independent power supply to small settlements and industrial consumers are considered. Thermogravimetric experiments have been carried out for a few types of wood with determining the universal kinetic parameters characterizing the pyrolysis process. A procedure for describing the solid fuel thermal decomposition process has been proposed that is based on writing the equations of four independent parallel thermal decomposition reactions for each component of the initial raw material. A software package has been developed using which the calorific value, composition, and volume of the gas produced in the thermal conversion of solid fuels can be estimated. The impact of operating parameters on the synthesis gas composition has been evaluated. It has been found that increasing the thermal conversion temperature results in a higher calorific value of the obtained gas per unit weight of the feedstock. A qualitative and quantitative comparison of the computational model and the results obtained during experimental studies on the existing gasifier has been carried out. It is shown that the parameters of gas obtained on the test bench are consistent with the calculated ones in both the amount of gas and its chemical energy. The combined-cycle power plant flow chart involving the biomass gasification process has been numerically simulated in the Aspen Plus computer program, and calculations aimed at determining the optimal operating parameters of different thermal process circuit components and of the entire CCP system were performed.

  10. Coal conversion systems design and process modeling. Volume 1: Application of MPPR and Aspen computer models

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The development of a coal gasification system design and mass and energy balance simulation program for the TVA and other similar facilities is described. The materials-process-product model (MPPM) and the advanced system for process engineering (ASPEN) computer program were selected from available steady state and dynamic models. The MPPM was selected to serve as the basis for development of system level design model structure because it provided the capability for process block material and energy balance and high-level systems sizing and costing. The ASPEN simulation serves as the basis for assessing detailed component models for the system design modeling program. The ASPEN components were analyzed to identify particular process blocks and data packages (physical properties) which could be extracted and used in the system design modeling program. While ASPEN physical properties calculation routines are capable of generating physical properties required for process simulation, not all required physical property data are available, and must be user-entered.

  11. System Design for a Nuclear Electric Spacecraft Utilizing Out-of-core Thermionic Conversion

    NASA Technical Reports Server (NTRS)

    Estabrook, W. C.; Phillips, W. M.; Hsieh, T.

    1976-01-01

    Basic guidelines are presented for a nuclear space power system which utilizes heat pipes to transport thermal power from a fast nuclear reactor to an out of core thermionic converter array. Design parameters are discussed for the nuclear reactor, heat pipes, thermionic converters, shields (neutron and gamma), waste heat rejection systems, and the electrical bus bar-cable system required to transport the high current/low voltage power to the processing equipment. Dimensions are compatible with shuttle payload bay constraints.

  12. Photochemical solar energy conversion utilizing semiconductors localized in membrane-mimetic systems

    SciTech Connect

    Fendler, J.H.

    1991-08-31

    Extending the frontiers of colloidal photochemistry and colloidal electrochemistry to solar photochemistry research had been the main objective of this research. More specific objectives of this proposal include the examination of semiconductor-particle-mediated photoelectron transfer and photoelectric effects in different membrane mimetic systems. Emphasis had been placed on developing bilayer lipid membranes and Langmuir-Blodgett films as new membrane-mimetic systems, as well as on the characterization and utilization of these systems.

  13. 600 KWe Organic Rankine Cycle Waste Heat Power Conversion System. Final report

    SciTech Connect

    Not Available

    1983-11-01

    The events and accomplishments of the Sundstrand 600 KWe Organic Rankine Cycle Systems are described. The ORC systems are compatible with diesel engine power plants and the Crane Co. glazing furnaces as waste heat sources. Field site personnel continue to demonstrate their ability to maintain and operate ORC system hardware. The ORC programmable sequencers can be programmed via phone lines from Rockford. This was successfully demonstrated using the Crane system. The hours of operation continued to increase. Separate abstracts were prepared for individual reports.

  14. Design techniques for modular integrated utility systems. [energy production and conversion efficiency

    NASA Technical Reports Server (NTRS)

    Wolfer, B. M.

    1977-01-01

    Features basic to the integrated utility system, such as solid waste incineration, heat recovery and usage, and water recycling/treatment, are compared in terms of cost, fuel conservation, and efficiency to conventional utility systems in the same mean-climatic area of Washington, D. C. The larger of the two apartment complexes selected for the test showed the more favorable results in the three areas of comparison. Restrictions concerning the sole use of currently available technology are hypothetically removed to consider the introduction and possible advantages of certain advanced techniques in an integrated utility system; recommendations are made and costs are estimated for each type of system.

  15. ADVANCED GASIFICATION-BASED FUEL CONVERSION AND ELECTRIC ENERGY PRODUCTION SYSTEM

    SciTech Connect

    Joseph Rabovitser; Bruce Bryan

    2002-10-01

    Boise Paper Solutions and the Gas Technology Institute (GTI) are cooperating to develop, demonstrate and place in continuous operation an advanced biomass gasification-based power generation system suitable for near-term commercial deployment in the Forest Products Industry. The system will be used in conjunction with, rather than in place of, existing wood waste fired boilers and flue gas cleanup systems. The novel system will include three advanced technological components based on GTI's RENUGAS{reg_sign} and three-stage stoker combustion technologies, and a gas turbine-based power generation concept developed in DOE's High Performance Power System (HIPPS) program. The system has, as its objective, to avoid the major hurdles of high-pressure gasification, i.e., high-pressure fuel feeding and ash removal, and hot gas cleaning that are typical for conventional IGCC power generation. It aims to also minimize capital intensity and technology risks. The system is intended to meet the immediate needs of the forest products industry for highly efficient and environmentally friendly electricity and steam generation systems utilizing existing wood waste as fuel resources. The overall objective of this project is to demonstrate the commercial applicability of an advanced biomass gasification-based power generation system at Boise Paper Solutions' pulp and paper mill located at DeRidder, Louisiana.

  16. Laser energy conversion

    NASA Technical Reports Server (NTRS)

    Jalufka, N. W.

    1989-01-01

    The conversion of laser energy to other, more useful, forms is an important element of any space power transmission system employing lasers. In general the user, at the receiving sight, will require the energy in a form other than laser radiation. In particular, conversion to rocket power and electricity are considered to be two major areas where one must consider various conversion techniques. Three systems (photovoltaic cells, MHD generators, and gas turbines) have been identified as the laser-to-electricity conversion systems that appear to meet most of the criteria for a space-based system. The laser thruster also shows considerable promise as a space propulsion system. At this time one cannot predict which of the three laser-to-electric converters will be best suited to particular mission needs. All three systems have some particular advantages, as well as disadvantages. It would be prudent to continue research on all three systems, as well as the laser rocket thruster. Research on novel energy conversion systems, such as the optical rectenna and the reverse free-electron laser, should continue due to their potential for high payoff.

  17. The Mercury Laser System: An Average power, gas-cooled, Yb:S-FAP based system with frequency conversion and wavefront correction

    SciTech Connect

    Bibeau, C; Bayramian, A; Armstrong, P; Ault, E; Beach, R; Benapfl, M; Campbell, R; Dawson, J; Ebbers, C; Freitas, B; Kent, R; Liao, Z; Ladran, T; Menapace, J; Molander, B; Moses, E; Oberhelman, S; Payne, S; Peterson, N; Schaffers, K; Stolz, C; Sutton, S; Tassano, J; Telford, S; Utterback, E; Randles, M

    2005-08-31

    We report on the operation of the Mercury laser with fourteen 4 x 6 cm{sup 2} Yb:S-FAP amplifier slabs pumped by eight 100 kW peak power diode arrays. The system was continuously run at 55 J and 10 Hz for several hours, (2 x 10{sup 5} cumulative shots) with over 80% of the energy in a 6 times diffraction limited spot at 1.047 um. Improved optical quality was achieved in Yb:S-FAP amplifiers with magneto-rheological finishing, a deterministic polishing method. In addition, average power frequency conversion employing YCOB was demonstrated at 50% conversion efficiency or 22.6 J at 10 Hz.

  18. Three-phase power conversion system for utility-interconnected PV applications. Phase 1 technical progress report, 1 October 1995--17 April 1997

    SciTech Connect

    Porter, D.G.; Meyer, H.; Leang, W.

    1998-02-01

    This report describes work performed by Omnion Power Corporation under Phase 1 of a two-phase subcontract. During this phase, Omnion researchers: designed an advanced product specification to guide prototype design and development; analyzed field failure data with Omnion`s hard-switched insulated-Gate Bipolar Transistor technology hardware to better understand where design improvements were needed; presented and reviewed product specifications with key customers/users; drafted a working product specification to serve as a baseline in developing the new power conversion system; developed the core-resonant converter technology in conjunction with Soft Switching Technologies Corp.; designed a 100-kW prototype power conversion system; designed a prototype system package; initiated interaction with vendors to optimize component selection and specifications; initiated the preparation of design documentation; built the prototype core-resonant converter and initiated preliminary testing; and initiated the assembly of a 1-kW prototype power conversion system. This work has demonstrated the potential of the soft-switching resonant DC link (RDCL) inverter and its application to a three-phase utility-interconnected PV power conversion system. The RDCL inverter has demonstrated its advantage over hard-switching pulse-width modulated inverters in terms of efficiency and audible noise. With proper package design and manufacturing process design and implementation, the RDCL power conversion system has the potential to be low-cost and reliable with superior performance.

  19. 2 Critical Stages for a Successful ILS Migration: System Profiling and Data Conversion

    ERIC Educational Resources Information Center

    Zhu, Qin

    2004-01-01

    Systems migration is a fact of life in the library world for various reasons. One of the more recent challenges spurring integrated library systems (ILS) upgrades comes when patrons find new functionality on other Web sites and then expect to search library sites in the same fashion. The migration process entails the following stages: system…

  20. Model for Calculating Electrolytic Shunt Path Losses in Large Electrochemical Energy Conversion Systems

    NASA Technical Reports Server (NTRS)

    Prokopius, P. R.

    1976-01-01

    Generalized analysis and solution techniques were developed to evaluate the shunt power losses in electrochemical systems designed with a common or circulating electrolyte supply. Sample data are presented for a hypothetical bulk energy storage redox system, and the general applicability of the analysis technique is discussed.

  1. ADVANCED GASIFICATION-BASED FUEL CONVERSION AND ELECTRIC ENERGY PRODUCTION SYSTEM

    SciTech Connect

    Joseph Rabovitser; Bruce Bryan

    2002-01-01

    Boise Cascade Corporation and the Gas Technology Institute (GTI) are cooperating to develop, demonstrate and place in continuous operation an advanced biomass gasification-based power generation system suitable for near-term commercial deployment in the Forest Products Industry. The system will be used in conjunction with, rather than in place of, existing wood waste fired boilers and flue gas cleanup systems. The novel system will include three advanced technological components based on GTI's RENUGAS{reg_sign} and METHANE de-NOX{reg_sign} technologies, and a gas turbine-based power generation concept developed in DOE's High Performance Power System (HIPPS) program. The system has, as its objective, to avoid the major hurdles of high-pressure gasification, i.e., high-pressure fuel feeding and ash removal, and hot gas cleaning that are typical for conventional IGCC power generation. It aims to also minimize capital intensity and technology risks. The system is intended to meet the immediate needs of the forest products industry for highly efficient and environmentally friendly electricity and steam generation systems utilizing existing wood waste as fuel resources.

  2. Space-based solar power conversion and delivery systems study. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    Hazelrigg, G. A., Jr.

    1976-01-01

    The technical and economic aspects of satellite solar power systems are presented with a focus on the current configuration 5000 MW system. The technical studies include analyses of the orbital system structures, control and stationkeeping, and the formulation of program plans and costs for input to the economic analyses. The economic analyses centered about the development and use of a risk analysis model for a system cost assessment, identification of critical issues and technologies, and to provide information for programmatic decision making. A preliminary economic examination of some utility interface issues is included. Under the present state-of-knowledge, it is possible to formulate a program plan for the development of a satellite solar power system that can be economically justified. The key area of technological uncertainty is man's ability to fabricate and assemble large structures in space.

  3. Multi-criteria assessment of energy conversion systems by means of thermodynamic, economic and environmental parameters

    NASA Astrophysics Data System (ADS)

    Becerra Lopez, Humberto Ruben

    2007-12-01

    High expansion of power demand is expected in the Upper Rio Grande region (El Paso, Hudspeth, Culberson, Jeff Davis, Presidio and Brewster counties) as a result of both electrical demand growth and decommissioning of installed capacity. On the supply side a notable deployment of renewable power technologies can be projected owing to the recent introduction of a new energy policy in Texas, which attempts to reach 10,000 installed-MWe of renewable capacity for 2025. Power generation fueled by natural-gas might consistently expand due to the encouraged use of this fuel. In this context the array of participating technologies can be optimized, which, within a sustainability framework, translates into a multidimensional problem. The solution to the problem is presented through this dissertation in two main parts. The first part solves the thermodynamic-environmental problem through developing a dynamic model to project maximum allowable expansion of technologies. Predetermined alternatives include diverse renewable energy technologies (wind turbine, photovoltaic conversion, hybrid solar thermal parabolic trough, and solid oxide fuel cells), a conventional fossil-fuel technology (natural gas combined-cycle), and a breakthrough fossil-fuel technology (solid oxide fuel cells). The analysis is based on the concept of cumulative exergy consumption, expanded to include abatement of emissions. A Gompertz sigmoid growth is assumed and constrained by both exergetic self-sustenance and regional energy resource availability. This part of the analysis assumes that power demand expansion is met by full deployment of alternative technologies backed up by conventional technology. Results show that through a proper allowance for exergy reinvestment the power demand expansion may be met largely by alternative technologies minimizing the primary resource depletion. The second part of the study makes use of the dynamic model to support a multi-objective optimization routine, where the

  4. Methods and systems for producing fluid from an in situ conversion process

    DOEpatents

    Fairbanks, Michael David [Katy, TX; Keltner, Thomas Joseph [Spring, TX

    2011-05-17

    A system that includes a plurality of heat sources configured to heat a portion of a formation is described. At least one production well is in the formation. A bottom portion of the production well is a sump in an underburden of the formation below the heated portion of the formation. Fluids from the heated portion of the formation are allowed to flow into the sump. A pump system has an inlet in the sump. A production conduit is coupled to the pump system. The production conduit is configured to transport fluids in the sump out of the formation.

  5. Methods and systems for producing fluid from an in situ conversion process

    DOEpatents

    Fairbanks, Michael David; Keltner, Thomas Joseph; McKinzie, II, Billy John; Hirshblond, Stephen Palmer

    2012-07-31

    A system configured to heat a portion of a formation includes a plurality of heat sources. At least one production well is in the formation. A bottom portion of the production well is a sump in an underburden of the formation below the heated portion of the formation. Fluids from the heated portion of the formation are allowed to flow into the sump. A pump system has an inlet in the sump. A production conduit is coupled to the pump system. The production conduit is configured to transport fluids in the sump out of the formation.

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

    DOEpatents

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

    2005-05-31

    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.

  7. Develop the dual fuel conversion system for high output, medium speed diesel engines. Final report

    SciTech Connect

    1998-07-16

    The original plan for the project involved design modifications to an existing system to enhance its performance and increase the limit of power that was achieved by the original design and to apply the higher performance product to the full sized engine and test its performance. The new system would also be applied to a different engine model. The specific work would include the redesign of gas injectors, piston configurations and two types of igniters, engine instrumentation, monitoring and testing.

  8. Advanced Control of Permanent Magnet Synchronous Generators for Variable Speed Wind Energy Conversion Systems

    NASA Astrophysics Data System (ADS)

    Hostettler, Jacob

    Various environmental and economic factors have lead to increased global investment in alternative energy technologies such as solar and wind power. Although methodologies for synchronous generator control are well researched, wind turbines present control systems challenges not presented by traditional generation. The varying nature of wind makes achieving synchronism with the existing electrical power grid a greater challenge. Departing from early use of induction machines, permanent magnet synchronous generators have become the focus of power systems and control systems research into wind energy systems. This is due to their self excited nature, along with their high power density. The problem of grid synchronism is alleviated through the use of high performance power electronic converters. In achievement of the optimal levels of efficiency, advanced control systems techniques oer promise over more traditional approaches. Research into sliding mode control, and linear matrix inequalities with nite time boundedness and Hinfinity performance criteria, when applied to the dynamical models of the system, demonstrate the potential of these control methodologies as future avenues for achieving higher levels of performance and eciency in wind energy.

  9. Comparison of conceptual designs for 25 kWe Advanced Stirling Conversion Systems for dish electric applications

    SciTech Connect

    Shaltens, R.K.; Schreiber, J.G.

    1989-01-01

    The Advanced Stirling Conversion System (ASCS) Project is managed by NASA Lewis Research Center through a cooperative Interagency Agreement with DOE. Conceptual designs for the ASCS's were completed under parallel contracts in 1987 by Mechanical Technology Inc. (MTI) of Latham, NY, and Stirling Technology Company (STC) of Richland, WA. Each design features a free-piston Stirling engine, a liquid metal heat pipe receiver, and a means to provide about 25 kW of electric power to a utility grid while meeting DOE's long term performance and cost goals. An independent assessment showed that both designs are manufacturable and have the potential to easily meet DOE's long term cost goals. 9 refs., 12 figs., 4 tabs.

  10. Nature-Inspired Design of Artificial Solar-to-Fuel Conversion Systems based on Copper Phosphate Microflowers.

    PubMed

    Wang, Jing; Zhu, Ting; Ho, Ghim Wei

    2016-07-01

    Phosphates play significant roles in plant photosynthesis by mediating electron transportation and furnishing energy for CO2 reduction. Motivated by this, we demonstrate herein an artificial solar-to-fuel conversion system, involving versatile copper phosphate microflowers as template and titanium dioxide nanoparticles as host photocatalyst. The elaborate flowerlike architectures, coupled with a unique proton-reduction cycle from interchangeability of different species of orthophosphate ions, not only offer a 2D nanosheet platform for an optimal heterostructure interface but also effectively augment charge-carrier transfer, thereby contributing to enhanced photoactivity and hydrogen generation. These nature-inspired, phosphate-derived nanocomposites advance the synthesis of a large variety of functional materials, which holds great potential for photochemical, photoelectric and catalytic applications. PMID:27225314

  11. High-temperature corrosion and applications of nickel and iron aluminides in coal-conversion power systems

    SciTech Connect

    Natesan, K.; Tortorelli, P.F.

    1996-10-01

    Nickel and iron aluminide intermetallics are being developed for use as structural materials and/or as cladding for conventional engineering alloys. In addition to strength advantages, these materials exhibit excellent resistance to corrosion in single- and multioxidant environments at elevated temperatures by the formation of slow-growing, adherent alumina scales. Corrosion resistance in a given environment is strongly dependent on the composition of the alloy and on the nature of the corrosive species prevalent in the service environment. This paper presents a comprehensive review of the current status of the corrosion performance of these intermetallics in oxidizing, sulfidizing, and multicomponent gas environments of typical coal-conversion systems. Mechanisms of scale development/breakdown, performance envelopes for long-term usage of these materials, approaches to modifying the surfaces of engineering alloys by cladding or coating them with intermetallics, and in-service experience with these materials are emphasized.

  12. A 15 kWe (nominal) solar thermal-electric power conversion concept definition study: Steam Rankin reciprocator system

    NASA Technical Reports Server (NTRS)

    Wingenback, W.; Carter, J., Jr.

    1979-01-01

    A conceptual design of a 3600 rpm reciprocation expander was developed for maximum thermal input power of 80 kW. The conceptual design covered two engine configurations; a single cylinder design for simple cycle operation and a two cylinder design for reheat cycle operation. The reheat expander contains a high pressure cylinder and a low pressure cylinder with steam being reheated to the initial inlet temperature after expansion in the high pressure cylinder. Power generation is accomplished with a three-phase induction motor coupled directly to the expander and connected electrically to the public utility power grid. The expander, generator, water pump and control system weigh 297 kg and are dish mounted. The steam condenser, water tank and accessory pumps are ground based. Maximum heat engine efficiency is 33 percent: maximum power conversion efficiency is 30 percent. Total cost is $3,307 or $138 per kW of maximum output power.

  13. Conceptual design of an Advanced Stirling Conversion System for terrestrial power generation

    SciTech Connect

    Not Available

    1988-01-01

    This report describes the conceptual design of a system for converting solar energy into electricity using a free-piston Stirling engine directly coupled to a linear alternator. The system is designed for mounting at the focal plane of a 100 m/sup 2/ parabolic solar collector. It includes a receiver which is integrated with the engine heater head. Heat transfer from receiver to engine involves boiling liquid sodium at the heater surface of the receiver and condensing sodium vapor on the engine heater tubes. A sintered wick is located on the back surface of the receiver face to distribute the sodium and gravity is used to return the condensed sodium to a sump within the receiver. The system is connected to a utility power grid. The net power output from the system is 23.2 kWe at the design point (75 kWt into the receiver). Maximum power output is 26.7 kWe at the peak insolation level. Annual output is approximately 60,000 kWh for a site at Albuquerque, New Mexico. The manufacturing cost for the System has been estimated at approximately $8500 (1984 dollars). The installed cost goal is $13,000 (1984 dollars). Costs at the conceptual design level are only approximate but the estimates indicate that acceptable costs are attainable. 2 refs.

  14. Frequency up-conversion of optical microwaves for multichannel optical microwave system on a WDM network

    NASA Astrophysics Data System (ADS)

    Shin, Myunghun; Kumar, Prem

    2012-07-01

    We propose a multichannel optical microwave system employing a frequency up-converting optoelectronic oscillator (FU-OEO) [FU-OEO: frequency up-converting optoelectronic oscillator] as a low-phase noise local oscillator (LO) and a multichannel frequency up-converter. Employing the FU-OEO, we demonstrated an optical microwave system capable of 16 optical microwave links in the C-band on a WDM network; the generated optical microwaves were distributed to their designated remote stations according to the channel wavelength. When the FU-OEO was used as the system LO, the phase noise of the optical microwaves was under -80 dBc/Hz at a 10 kHz offset from a 20 GHz carrier frequency. As a frequency up-converter, the FU-OEO simultaneously up-converted all optical data channels at a 1.25 Gbps data rate for optical microwaves in the 20 GHz band of an optical carrier suppression mode having almost 100% modulation depth. The overall system performance was verified by measuring the bit error rates (BER) of the data recovered from optical microwaves received through single-mode fibers. The measured BER indicated that the system can transmit over 50 km with a power penalty of less than 1 dB. This method can be useful for high-frequency applications where the generation and transmission of optical microwaves are greatly restricted by optical or electrical bandwidths.

  15. A Comparison of the Performance Capabilities of Radioisotope Energy Conversion Systems, Betavoltaic Cells, and other Nuclear Batteries

    SciTech Connect

    Steinfelds, Eric V; Prelas, Mark A.; Sudarshan, Loyalka K.; Tompson, Robert V.

    2006-07-01

    In this paper we compare the potential performance capabilities of several types of nuclear batteries to the Radioisotope Thermocouple Generators (RTG's) currently in use. There have been theoretical evaluations of, and some experimental testing of, several types of nuclear batteries including Radioisotope Energy Conversion Systems (RECS), Direct Energy Conversion (DEC) systems, and Betavoltaic Power Cells (BPC's). It has been theoretically shown, and to some extent experimentally demonstrated, that RECS, capacitive DEC systems, and possibly BPC's are all potentially capable of efficiencies well above the 9% maximum efficiency demonstrated to date in RTG's customized for deep space probe applications. Even though RTG's have proven their reliability and have respectable power to mass ratios, it is desirable to attain efficiencies of at least 25% in typical applications. High fuel efficiency is needed to minimize the quantities of radioisotopic or nuclear fuels in the systems, to maximize power to mass ratios, and to minimize housing requirements. It has been shown that RECS can attain electric power generation efficiencies greater than 18% for devices which use Sr-90 fuel and where the accompanying material is less than roughly twice the mass of the Sr-90 fuel. Other radioisotopic fuels such as Pu-238 or Kr-85 can also be placed into RECS in order to attain efficiencies over 18%. With the likely exception of one fuel investigated by the authors, all of the promising candidates for RECS fuels can attain electric power to mass ratios greater than 15 W kg{sup -1}. It has been claimed recently [1] that the efficiency of tritium-fueled BPC's can be as high as 25%. While this is impressive and tritium has the benefit of being a 'soft' radioisotopic fuel, the silicon wafer that holds the tritium would have to be considerably more massive than the tritium contained within it and immediately adjacent to the wafer. Considering realistic mass requirements for the presence of

  16. A Fast linking approach for CMYK to CMYK conversion preserving black separation in ICC color management system

    NASA Astrophysics Data System (ADS)

    Zeng, Huanzhao

    2003-12-01

    In the linking step of the standard ICC color management workflow for CMYK to CMYK conversion, a CMM takes an AToBn tag (n = 0, 1, or 2) from a source ICC profile to convert a color from the source color space to PCS (profile connection space), and then takes a BToAn tag from the destination ICC profile to convert the color from PCS to the destination color space. This approach may give satisfactory result perceptually or colorimetrically. However, it does not preserve the K channel for CMYK to CMYK conversion, which is often required in graphic art"s market. The problem is that the structure of a BtoAn tag is designed to convert colors from PCS to a device color space ignoring the K values from the source color space. Different approaches have been developed to control K in CMYK to CMYK printing, yet none of them well fits into the "Profile - PCS - Profile" model in the ICC color management system. A traditional approach is to transform the source CMYK to the destination CMYK by 1-D TRC curves and GCR/UCR tables. This method is so simple that it cannot accurately transform colors perceptually or colorimetrically. Another method is to build a 4-D CMYK to CMYK closed-loop lookup table (LUT) (or a deviceLink ICC profile) for the color transformation. However, this approach does not fit into opened color management workflows for it ties the source and the destination color spaces in the color characterization step. A specialized CMM may preserve K for a limit number of colors by mapping those CMYK colors to some carefully chosen PCS colors in both the AToBi tag and the BToAi tag. A more complete solution is to move to smart linking in which gamut mapping is performed in the real-time linking at a CMM. This method seems to solve all problems existed in the CMYK to CMYK conversion. However, it introduces new problems: 1) gamut mapping at real-time linking is often unacceptable slow; 2) gamut mapping may not be optimized or may be unreliable; 3) manual adjustment for

  17. Space-based solar power conversion and delivery systems study. Volume 2: Engineering analysis

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The technical and economic feasibility of Satellite Solar Power Systems was studied with emphasis on the analysis and definition of an integrated strawman configuration concept, from which credible cost data could be estimated. Specifically, system concepts for each of the major subprogram areas were formulated, analyzed, and iterated to the degree necessary for establishing an overall, workable baseline system design. Cost data were estimated for the baseline and used to conduct economic analyses. The baseline concept selected was a 5-GW crystal silicon truss-type photovoltaic configuration, which represented the most mature concept available. The overall results and major findings, and the results of technical analyses performed during the final phase of the study efforts are reported.

  18. Conversion method of powder inelastic scattering data for one-dimensional systems

    SciTech Connect

    Tomiyasu, Dr. Keisuke; Fujita, Prof. Masaki; Kolesnikov, Alexander I; Bewley, Robert I.; Bull, Dr. Martyn J.; Bennington, Dr. Stephen M.

    2009-01-01

    Extracting dispersive magnetic excitations from inelastic neutron scattering data usually requires large single crystals. We present a simple yet powerful method for extracting such information from polycrystalline or powder data for one-dimensional systems. We demonstrate the effectiveness of this data treatment by extracting dispersion curves from powder inelastic neutron scattering data on the one-dimensional spin-half systems: CuGeO3 and Rb2Cu2Mo3O12. For many such materials it is not possible to grow sufficiently large crystals and this method offers a quick and efficient way to study their magnetic excitations.

  19. Micro/Nano-Scale Phase Change Systems for Thermal Management and Solar Energy Conversion Applications

    NASA Astrophysics Data System (ADS)

    Coso, Dusan

    The first part of the dissertation presents a study that implements micro and nano scale engineered surfaces for enhancement of evaporation and boiling phase change heat transfer in both capillary wick structures and pool boiling systems. Capillary wicking surfaces are integral components of heat pipes and vapor chamber thermal spreaders often used for thermal management of microelectronic devices. In addition, pool boiling systems can be encountered in immersion cooling systems which are becoming more commonly investigated for thermal management applications of microelectronic devices and even data centers. The latent heat associated with the change of state from liquid to vapor, and the small temperature differences required to drive this process yield great heat transfer characteristics. Additionally, since no external energy is required to drive the phase change process, these systems are great for portable devices and favorable for reduction of cost and energy consumption over alternate thermal management technologies. Most state of the art capillary wicks used in these devices are typically constructed from sintered copper media. These porous structures yield high surface areas of thin liquid film where evaporation occurs, thus promoting phase change heat transfer. However, thermal interfaces at particle point contacts formed during the sintering process and complex liquid/vapor flow within these wick structures yield high thermal and liquid flow resistances and limit the maximum heat flux they can dissipate. In capillary wicks the maximum heat flux is typically governed by the capillary or boiling limits and engineering surfaces that delay these limitations and yield structures with large surface areas of thin liquid film where phase change heat transfer is promoted is highly desired. In this study, biporous media consisting of microscale pin fins separated by microchannels are examined as candidate structures for the evaporator wick of a vapor chamber heat

  20. Alkali metal pool boiler life tests for a 25 kWe advanced Stirling conversion system

    NASA Astrophysics Data System (ADS)

    Anderson, W. G.; Rosenfeld, J. H.; Noble, J.

    The overall operating temperature and efficiency of solar-powered Stirling engines can be improved by adding an alkali metal pool boiler heat transport system to supply heat more uniformly to the heater head tubes. One issue with liquid metal pool boilers is unstable boiling. Stable boiling is obtained with an enhanced boiling surface containing nucleation sites that promote continuous boiling. Over longer time periods, it is possible that the boiling behavior of the system will change. An 800-h life test was conducted to verify that pool boiling with the chosen fluid/surface combination remains stable as the system ages. The apparatus uses NaK boiling on a - 100 + 140 stainless steel sintered porous layer, with the addition of a small amount of xenon. Pool boiling remained stable to the end of life test. The pool boiler life test included a total of 82 cold starts, to simulate startup each morning, and 60 warm restarts, to simulate cloud cover transients. The behavior of the cold and warm starts showed no significant changes during the life test. In the experiments, the fluid/surface combination provided stable, high-performance boiling at the operating temperature of 700 C. Based on these experiments, a pool boiler was designed for a full-scale 25-kWe Stirling system.

  1. Sperry low temperature geothermal conversion system, phase 1 and phase 2. Volume 6: Economic studies

    NASA Astrophysics Data System (ADS)

    Harvey, C.; McBee, W.

    The basic thrust of the studies represented was to compare the overall economics of the Gravity Head system with that of optimized conventional binary generating plants. The study is site-specific to the East Mesa geothermal reservoir. It begins with an analysis of optimum individual well production based on the known characteristics of the reservoir. The limiting factors at East Mesa are reservoir drawdown and maximum practical brine pump impeller setting depth. Using the 1300 gpm, 360(0) F resource as a starting point, detailed cost estimates and performance calculations were made for the Gravity Head and various conventional alternative well-head systems. The most cost effective of the conventional alternatives was found to be a 700 psi cycle using R114 as the working fluid (actually optimized at 682 psi). The study is in two parts. In Part 1, emphasis is placed on the economic sensitivities of the compared systems to variations in capital cost, O and M cost, avoided energy inflation rates, and brine cost. In Part 2, a somewhat more rigorous attempt is made to derive the actual economic performance of the systems under more realistic circumstances with contingencies, cost penalties, and multiple-unit developments added.

  2. Space-Based Solar Power Conversion and Delivery Systems Study. Volume 3: Microwave Power Transmission Studies

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The Microwave Fower Beam Ionosphere effects and critical interfaces between th Microwave Power Transmission System (MPTS) and the Satellite were studied as part of the NASA/MSFC continuing research on the feasibility of power transmission from geosynchronous orbit. Theoretical predications of ionospheric modifications produced by the direct interaction of the MPTS on the earth's upper atmosphere are used to determine their impact on the performance of the Microwave Power Beam and Pilot Beam System as well as on other RF systems effected by the ionosphere. A technology program to quantitatively define these interactions is developed. Critical interface areas between the MPTS and the satellite which could have a major impact on cost and performance of the power system are idenfified and analyzed. The areas selected include: use of either a 20 kV versus 40 kV Amplitron, thermal blockage effects of Amplitron heat radiation by the satellite structure, effect of dielectric carry-through structure on power beam, and effect of material sublimation on performance of the Amplitron in Geosynchronous Orbit.

  3. Revival of the biological sunlight-to-biogas energy conversion system.

    PubMed

    De Schamphelaire, Liesje; Verstraete, Willy

    2009-06-01

    In the quest for renewable resources, algae are increasingly receiving attention. Their high growth rate, high CO(2) fixation and their lack of requirement for fertile soil surface represent several advantages as compared to conventional (energy) crops. Through their ability to store large amounts of oils, they qualify as a source for biodiesel. Algal biomass, however, can also be used as such, namely as a substrate for anaerobic digestion. In the present research, we investigated the use of algae for energy generation in a stand-alone, closed-loop system. The system encompasses an algal growth unit for biomass production, an anaerobic digestion unit to convert the biomass to biogas and a microbial fuel cell to polish the effluent of the digester. Nutrients set free during digestion can accordingly be returned to the algal growth unit for a sustained algal growth. Hence, a system is presented that continuously transforms solar energy into energy-rich biogas and electricity. Algal productivities of 24-30 ton VS ha(-1) year(-1) were reached, while 0.5 N m(3) biogas could be produced kg(-1) algal VS. The system described resulted in a power plant with a potential capacity of about 9 kW ha(-1) of solar algal panel, with prospects of 23 kW ha(-1). PMID:19180645

  4. Alkali metal pool boiler life tests for a 25 kWe advanced Stirling conversion system

    NASA Technical Reports Server (NTRS)

    Anderson, W. G.; Rosenfeld, J. H.; Noble, J.

    1991-01-01

    The overall operating temperature and efficiency of solar-powered Stirling engines can be improved by adding an alkali metal pool boiler heat transport system to supply heat more uniformly to the heater head tubes. One issue with liquid metal pool boilers is unstable boiling. Stable boiling is obtained with an enhanced boiling surface containing nucleation sites that promote continuous boiling. Over longer time periods, it is possible that the boiling behavior of the system will change. An 800-h life test was conducted to verify that pool boiling with the chosen fluid/surface combination remains stable as the system ages. The apparatus uses NaK boiling on a - 100 + 140 stainless steel sintered porous layer, with the addition of a small amount of xenon. Pool boiling remained stable to the end of life test. The pool boiler life test included a total of 82 cold starts, to simulate startup each morning, and 60 warm restarts, to simulate cloud cover transients. The behavior of the cold and warm starts showed no significant changes during the life test. In the experiments, the fluid/surface combination provided stable, high-performance boiling at the operating temperature of 700 C. Based on these experiments, a pool boiler was designed for a full-scale 25-kWe Stirling system.

  5. 5 CFR 9901.372 - Conversion or movement out of NSPS pay system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... MANAGEMENT AND LABOR RELATIONS SYSTEMS (DEPARTMENT OF DEFENSE-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF... using GS pay retention rules in 5 CFR part 536 (if the employee is eligible for pay retention under... to a GS position under this section to the extent provided under 5 CFR part 531, subpart D....

  6. High efficiency vapor-fed AMTEC system for direct conversion. Appendices for final report

    SciTech Connect

    Anderson, W.G.; Bland, J.J.

    1997-05-23

    This report consists of four appendices for the final report. They are: Appendix A: 700 C Vapor-Fed AMTEC Cell Calculations; Appendix B: 700 C Vapor-Fed AMTEC Cell Parts Drawings; Appendix C: 800 C Vapor-Fed AMTEC Cell Calculations; and Appendix D: 800 C Wick-Pumped AMTEC Cell System Design.

  7. Design, simulation, analysis and optimization of transportation system for a biomass to ethanol conversion plant

    NASA Astrophysics Data System (ADS)

    Ravula, Poorna P.

    The US Department of Energy has set an ambitious goal of replacing 30% of current petroleum consumption with biomass and its products by the year 2030. To achieve this goal, various systems capable of handling biomass at this magnitude have to be designed and built. The transportation system for a cotton gin was studied and modeled with the current management policy (FIFO) used by the gin to gain understanding of a logistic system where the processing plant (gin) pays for the transportation of the feedstock. Alternate management policies for transporting cotton modules showed significant time savings of 24% in days-to-haul. To design a logistics system and management strategy that will minimize the cost of biomass delivery (round bales of switchgrass), a seven-county region in southern Piedmont region of Virginia was selected as the location for a 50 Mg/h bioprocessing plant which operates 24 h/day, 7 days/week. Some of the equipment are not be commercially available and need to be developed. The transport equipment (trucks, loaders and unloaders) was defined and the operational parameters estimated. One hundred and fifty-five secondary storage locations (SSLs) along with a 3.2-km procurement area for each SSL were determined for the region. The travel time from each SSL to the plant was calculated based on a network flow analysis. Seven different policies (strategies) for scheduling loaders were studied. The two key variables were maximum number of trucks required and the maximum at-plant inventory. Five policies were based on "Shortest Travel Time - Longest Travel Time" allocation and two policies were based on "Sector-based" allocation. Policies generating schedules with minimum truck requirement and at-plant storage were simulated. A discrete event simulation model for the logistic system was constructed and the productive operating times for system equipment and inventory was computed. Lowest delivered cost was 14.68/Mg with truck cost averaging 8.44/Mg and

  8. ADVANCED GASIFICATION-BASED FUEL CONVERSION AND ELECTRIC ENERGY PRODUCTION SYSTEM

    SciTech Connect

    Joseph Rabovitser; Bruce Bryan

    2003-04-01

    The objective of this project is the development and commercial demonstration of an advanced biomass gasification-based power generation system at Boise Cascade Corporation's pulp and paper mill in DeRidder, Louisiana. The advanced power generation system is intended to meet the immediate needs of the forest products industry for highly efficient and environmentally friendly electricity and steam generation systems utilizing existing wood waste as the primary fuel resource. The novel system is based on three advanced technology components: GTI's RENUGAS{reg_sign} and 3-stage solid fuels combustion technologies coupled with one of the power generation approaches used in DOE's HIPPS program. Phase 1 of the project is a technical and economic evaluation of the system at the DeRidder site. A Continuation Application will be submitted at the conclusion of Phase 1 for authorization to proceed to testing and design in Phase 2. Phase 2 includes pilot-scale verification of selected system components and preparation of a detailed engineering design and cost estimate for retrofit of the advanced power system at the DeRidder mill. Phase 3 will complete procurement and construction of the system at the DeRidder site along with all required permitting activities. Phase 4 of the project will included plant commissioning, startup and demonstration operations. Design information for the Gasification Island was completed during the quarter. Two vendor quotations were received for the bark/hog fuel dryers. A final layout plan for the major equipment was developed and submitted to DeRidder for review and approval. The Institute of Paper Science and Technology (IPST) completed a subcontract for a laboratory study on VOC emissions from wood waste drying using bark from the DeRidder mill. Samples of DeRidder's lime mud and green liquor dregs were collected and analyzed in GTI's laboratory. It was determined that lime mud is far too fine to be utilized as inert bed material in the

  9. 25 CFR Appendix A to Subpart B - Allowable Uses of IRR Program Funds

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., portable weigh-in-motion systems, hand held data collection units, related hardware and software, etc. 23... IRR Program. 24. Force account and day labor work, including materials and equipment rental, being... transportation facilities such as permanent weigh-in-motion systems, informational signs,...

  10. Conversation Classes.

    ERIC Educational Resources Information Center

    Xia, Jiang

    1998-01-01

    Describes an activity for use in the conversational English-as-a-foreign-language classroom. The activity involves having each student say one or two sentences that continues a story being made up as the activity goes along. Students were positive about the activity, because saying only one or two sentences helped them not to feel pressured or…

  11. A 20-KW Wind Energy Conversion System (WECS) at the Marine Corps Air Station, Kaneohe, Hawaii

    NASA Astrophysics Data System (ADS)

    Pal, D.

    1983-01-01

    The wind turbine generator chosen for the evaluation was a horizontal-axis-propeller-downwind rotor driving a three-phase, self-excited alternator through a step-up gear box. The alternator is fed into the base power distribution system through a three-phase, line-communtated-synchronous inverter using SCRs. The site has moderate wind conditions with an annual average windspeed of 12 to 14 mph, and the WECS turbine has a relatively high (29 mph) rated windspeed. The 20-kW WECS systems was primarily designed to obtain operating experience with, and maintenance information on, a 20-kW-sized WECS. This report describes in detail the experience gained and lessons learned during the field evaluation.

  12. Discriminators for the Accelerator-Based Conversion (ABC) concept using a subcritical molten salt system

    SciTech Connect

    Arthur, E.; Busksa, J.; Davidson, W.; Poston, D.

    1995-05-01

    Discriminators are described that quantify enhancements added to plutonium destruction and/or nuclear waste transmutation systems through use of an accelerator/fluid fuel combination. This combination produces a robust and flexible nuclear system capable of the destruction of all major long-lived actinides (including plutonium) and fission products. The discriminators discussed in this report are (1) impact of subcritical operation on safety, (2) impact of subcritical and fluid fuel operation on plutonium burnout scenarios, and (3) neutron economy enhancements brought about by subcritical operation. Neutron economy enhancements are quantified through assessment of long-term dose reduction resulting from transmutation of key fission products along with relaxation of processing frequencies afforded by subcritical operation.

  13. In situ conversion process systems utilizing wellbores in at least two regions of a formation

    DOEpatents

    Vinegar, Harold J.; Hsu, Chia-Fu

    2011-09-27

    A system for heating a subsurface formation is described. The system includes a plurality of elongated heaters located in a plurality of openings in the formation. At least two of the heaters are substantially parallel to each other for at least a portion of the lengths of the heaters. At least two of the heaters have first end portions in a first region of the formation and second end portions in a second region of the formation. A source of time-varying current is configured to apply time-varying current to at least two of the heaters. The first end portions of at least two heaters are configured to have substantially the same voltage applied to them. The second portions of at least two heaters are configured to have substantially the same voltage applied to them.

  14. Bifunctional polyacrylonitrile fiber-mediated conversion of sucrose to 5-hydroxymethylfurfural in mixed-aqueous systems.

    PubMed

    Shi, Xian-Lei; Zhang, Min; Lin, Huikun; Tao, Minli; Li, Yongdan; Zhang, Wenqin

    2015-03-01

    A highly efficient catalytic system composed of a bifunctional polyacrylonitrile fiber (PANF-PA[BnBr]) and a metal chloride was employed to produce 5-hydroxymethylfurfural (HMF) from sucrose in mixed-aqueous systems. The promoter of PANF-PA[BnBr] incorporates protonic acid groups that promote the hydrolysis of the glycosidic bond to convert sucrose into glucose and fructose, and then catalyzes fructose dehydration to HMF, while the ammonium moiety may promote synergetically with the metal chloride the isomerization of glucose to fructose and transfer HMF from the aqueous to the organic phase. The detailed characterization by elemental analysis, FTIR spectroscopy, and SEM confirmed the rangeability of the fiber promoter during the modification and utilization processes. Excellent results in terms of high yield (72.8%) of HMF, superior recyclability (6 cycles) of the process, and effective scale-up and simple separation procedures of the catalytic system were obtained. Moreover, the prominent features (high strength, good flexibility, etc.) of the fibers are very attractive for fix-bed reactor. PMID:25573698

  15. Photochemical energy conversion by membrane-bound photoredox systems. Final report

    SciTech Connect

    Tollin, G.

    1994-06-16

    This project has received DOE support since July 1, 1978. During this period, 40 papers have been published dealing predominantly with chlorophyll-photosensitized electron transfer reactions in a variety of media (solutions, polymer films, lipid bilayer membranes). The overall theme of this work has been to develop mechanistic strategies f or photochemical energy storage via chlorophyll, using the green plant photosynthetic system as a paradigm for designing in vitro systems. Microheterogeneous lipid vesicle suspensions allow ready application of time-resolved optical spectroscopy to follow the course of light-induced electron transfer processes. Both the yields and the lifetimes of electron transfer products were markedly improved in the vesicle systems. In subsequent studies, this compartmentalization was favorably manipulated by controlling the electrical charge on the membrane surface, by controlling the solubility properties of the acceptors, by varying the lipid composition, by using mediators to create a concentration gradient to carry electrons from within the bilayer to the aqueous medium, and by incorporating secondary electron acceptors into the aqueous phase.

  16. Evaluation of protein disulfide conversion in vitro using a continuous flow dialysis system.

    PubMed

    Jiang, Xinzhao Grace; Wang, Tian; Kaltenbrunner, Oliver; Chen, Kenneth; Flynn, Gregory C; Huang, Gang

    2013-01-15

    Recombinant therapeutic proteins are heterogeneous due to chemical and physical modifications. Understanding the impact of these modifications on drug safety and efficacy is critical for optimal process development and for setting reasonable specification limits. In this study, we describe the development of an in vitro continuous flow dialysis system to evaluate potential in vivo behavior of thiol adducted species and incorrectly disulfide bonded species of therapeutic proteins. The system is capable of maintaining the low-level cysteine concentrations found in human blood. Liabilities of cysteamine adducted species, incorrectly disulfide bonded species, and the correctly disulfide bonded form of an Fc-fusion protein were studied using this system. Results showed that 90% of the cysteamine adduct converted into the correctly disulfide bonded form and incorrectly disulfide bonded species in approximately 4 h under physiological conditions. Approximately 50% of incorrectly disulfide bonded species converted into the correctly bonded form in 2 days. These results provide valuable information on potential in vivo stability of the cysteamine adduct, incorrectly disulfide bonded species, and the correctly bonded form of the Fc-fusion protein. These are important considerations when evaluating the criticality of product quality attributes. PMID:23022378

  17. FGD system retrofit of the Dalhousie Station Units 1&2, an Orimulsion conversion

    SciTech Connect

    Legere, M.; Rich, T.J.; Nischt, W.

    1995-06-01

    The Dalhousie Thermal Station is an electric generating station owned and operated by New Brunswick Power. The station consists of two boiler units, Unit 1 having a capacity of 100 MW and Unit 2 having a capacity of 215 MW. Both units were converted to burn Orimulsion{trademark} due to the economics of the fuel. Unit 1 returned to service in August, 1994, while Unit 2 returned to service in September, 1994 burning the new fuel. In order to comply with Canadian National Government through Environment Canada emissions standards, New Brunswick Power decided to install a flue gas desulfurization (FGD) system consisting of a single 315 MW absorber module utilizing limestone forced oxidation (LSFO) technology. The unit is designed to generate a marketable grade gypsum product. This paper describes Orimulsion{trademark} and the modifications required to convert the Dalhousie station to Orimulsion{trademark} firing. The FGD system is described and the philosophy used to ensure high reliability in the system is discussed. Commissioning and operational performance results are also presented.

  18. Self Adaptive Air Turbine for Wave Energy Conversion Using Shutter Valve and OWC Heoght Control System

    SciTech Connect

    Di Bella, Francis A

    2014-09-29

    An oscillating water column (OWC) is one of the most technically viable options for converting wave energy into useful electric power. The OWC system uses the wave energy to “push or pull” air through a high-speed turbine, as illustrated in Figure 1. The turbine is typically a bi-directional turbine, such as a Wells turbine or an advanced Dennis-Auld turbine, as developed by Oceanlinx Ltd. (Oceanlinx), a major developer of OWC systems and a major collaborator with Concepts NREC (CN) in Phase II of this STTR effort. Prior to awarding the STTR to CN, work was underway by CN and Oceanlinx to produce a mechanical linkage mechanism that can be cost-effectively manufactured, and can articulate turbine blades to improve wave energy capture. The articulation is controlled by monitoring the chamber pressure. Funding has been made available from the U.S. Department of Energy (DOE) to CN (DOE DE-FG-08GO18171) to co-share the development of a blade articulation mechanism for the purpose of increasing energy recovery. However, articulating the blades is only one of the many effective design improvements that can be made to the composite subsystems that constitute the turbine generator system.

  19. Direct Conversion Technology

    SciTech Connect

    Back, L.H.; Fabris, G.; Ryan, M.A.

    1992-07-01

    The overall objective of the Direct Conversion Technology task is to develop an experimentally verified technology base for promising direct conversion systems that have potential application for energy conservation in the end-use sectors. Initially, two systems were selected for exploratory research and advanced development. These are Alkali Metal Thermal-to-Electric Converter (AMTEC) and Two-Phase Liquid Metal MD Generator (LMMHD). This report describes progress that has been made during the first six months of 1992 on research activities associated with these two systems. (GHH)

  20. On the rejection of internal and external disturbances in a wind energy conversion system with direct-driven PMSG.

    PubMed

    Li, Shengquan; Zhang, Kezhao; Li, Juan; Liu, Chao

    2016-03-01

    This paper deals with the critical issue in a wind energy conversion system (WECS) based on a direct-driven permanent magnet synchronous generator (PMSG): the rejection of lumped disturbance, including the system uncertainties in the internal dynamics and unknown external forces. To simultaneously track the motor speed in real time and capture the maximum power, a maximum power point tracking strategy is proposed based on active disturbance rejection control (ADRC) theory. In real application, system inertia, drive torque and some other parameters change in a wide range with the variations of disturbances and wind speeds, which substantially degrade the performance of WECS. The ADRC design must incorporate the available model information into an extended state observer (ESO) to compensate the lumped disturbance efficiently. Based on this principle, a model-compensation ADRC is proposed in this paper. Simulation study is conducted to evaluate the performance of the proposed control strategy. It is shown that the effect of lumped disturbance is compensated in a more effective way compared with the traditional ADRC approach. PMID:26775089