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Sample records for stand-alone power systems

  1. Development of a microprocessor controller for stand-alone photovoltaic power systems

    NASA Technical Reports Server (NTRS)

    Millner, A. R.; Kaufman, D. L.

    1984-01-01

    A controller for stand-alone photovoltaic systems has been developed using a low power CMOS microprocessor. It performs battery state of charge estimation, array control, load management, instrumentation, automatic testing, and communications functions. Array control options are sequential subarray switching and maximum power control. A calculator keypad and LCD display provides manual control, fault diagnosis and digital multimeter functions. An RS-232 port provides data logging or remote control capability. A prototype 5 kW unit has been built and tested successfully. The controller is expected to be useful in village photovoltaic power systems, large solar water pumping installations, and other battery management applications.

  2. International market assessment of stand-alone photovoltaic power systems for cottage industry applications

    NASA Technical Reports Server (NTRS)

    Philippi, T. M.

    1981-01-01

    The final result of an international assessment of the market for stand-alone photovoltaic systems in cottage industry applications is reported. Nonindustrialized countries without centrally planned economies were considered. Cottage industries were defined as small rural manufacturers, employing less than 50 people, producing consumer and simple products. The data to support this analysis were obtained from secondary and expert sources in the U.S. and in-country field investigations of the Philippines and Mexico. The near-term market for photovoltaics for rural cottage industry applications appears to be limited to demonstration projects and pilot programs, based on an in-depth study of the nature of cottage industry, its role in the rural economy, the electric energy requirements of cottage industry, and a financial analysis of stand-alone photovoltaic systems as compared to their most viable competitor, diesel driven generators. Photovoltaics are shown to be a better long-term option only for very low power requirements. Some of these uses would include clay mixers, grinders, centrifuges, lathes, power saws and lighting of a workshop.

  3. International market assessment of stand-alone photovoltaic power systems for cottage industry applications

    NASA Astrophysics Data System (ADS)

    Philippi, T. M.

    1981-11-01

    The final result of an international assessment of the market for stand-alone photovoltaic systems in cottage industry applications is reported. Nonindustrialized countries without centrally planned economies were considered. Cottage industries were defined as small rural manufacturers, employing less than 50 people, producing consumer and simple products. The data to support this analysis were obtained from secondary and expert sources in the U.S. and in-country field investigations of the Philippines and Mexico. The near-term market for photovoltaics for rural cottage industry applications appears to be limited to demonstration projects and pilot programs, based on an in-depth study of the nature of cottage industry, its role in the rural economy, the electric energy requirements of cottage industry, and a financial analysis of stand-alone photovoltaic systems as compared to their most viable competitor, diesel driven generators. Photovoltaics are shown to be a better long-term option only for very low power requirements. Some of these uses would include clay mixers, grinders, centrifuges, lathes, power saws and lighting of a workshop.

  4. Solar photovoltaic applications seminar: design, installation and operation of small, stand-alone photovoltaic power systems

    SciTech Connect

    Not Available

    1980-07-01

    This seminar material was developed primarily to provide solar photovoltaic (PV) applied engineering technology to the Federal community. An introduction to photoconductivity, semiconductors, and solar photovoltaic cells is included along with a demonstration of specific applications and application identification. The seminar details general systems design and incorporates most known information from industry, academia, and Government concerning small solar cell power system design engineering, presented in a practical and applied manner. Solar PV power system applications involve classical direct electrical energy conversion and electric power system analysis and synthesis. Presentations and examples involve a variety of disciplines including structural analysis, electric power and load analysis, reliability, sizing and optimization; and, installation, operation and maintenance. Four specific system designs are demonstrated: water pumping, domestic uses, navigational and aircraft aids, and telecommunications. All of the applications discussed are for small power requirement (under 2 kilowatts), stand-alone systems to be used in remote locations. Also presented are practical lessons gained from currently installed and operating systems, problems at sites and their resolution, a logical progression through each major phase of system acquisition, as well as thorough design reviews for each application.

  5. Stand-alone flat-plate photovoltaic power systems: System sizing and life-cycle costing methodology for Federal agencies

    NASA Technical Reports Server (NTRS)

    Borden, C. S.; Volkmer, K.; Cochrane, E. H.; Lawson, A. C.

    1984-01-01

    A simple methodology to estimate photovoltaic system size and life-cycle costs in stand-alone applications is presented. It is designed to assist engineers at Government agencies in determining the feasibility of using small stand-alone photovoltaic systems to supply ac or dc power to the load. Photovoltaic system design considerations are presented as well as the equations for sizing the flat-plate array and the battery storage to meet the required load. Cost effectiveness of a candidate photovoltaic system is based on comparison with the life-cycle cost of alternative systems. Examples of alternative systems addressed are batteries, diesel generators, the utility grid, and other renewable energy systems.

  6. Optimization of a stand-alone Solar PV-Wind-DG Hybrid System for Distributed Power Generation at Sagar Island

    NASA Astrophysics Data System (ADS)

    Roy, P. C.; Majumder, A.; Chakraborty, N.

    2010-10-01

    An estimation of a stand-alone solar PV and wind hybrid system for distributed power generation has been made based on the resources available at Sagar island, a remote area distant to grid operation. Optimization and sensitivity analysis has been made to evaluate the feasibility and size of the power generation unit. A comparison of the different modes of hybrid system has been studied. It has been estimated that Solar PV-Wind-DG hybrid system provides lesser per unit electricity cost. Capital investment is observed to be lesser when the system run with Wind-DG compared to Solar PV-DG.

  7. An Integrated Feasibility Analysis of a Stand-alone Wind Power System, including No-energy Fulfillment Cost

    NASA Astrophysics Data System (ADS)

    Kaldellis, J. K.

    2003-10-01

    Autonomous wind power systems are among the most interesting and environmentally friendly technological solutions for the electrification of remote consumers. However, the expected system operational cost is quite high, especially if the no-load rejection restriction is applied. This article describes an integrated feasibility analysis of a stand-alone wind power system, considering, beyond the total long-term operational cost of the system, the no-energy fulfilment (or the alternative energy coverage) cost of the installation. Therefore the impact of desired system reliability on the stand-alone system configuration is included. Accordingly, a detailed parametric investigation is carried out concerning the influence of the hourly no-energy fulfilment cost on the system dimensions and operational cost. Thus, by using the proposed method, one has the capability-in all practical cases-to determine the optimum wind power system configuration that minimizes the long-term total cost of the installation, considering also the influence of the local economy basic parameters.

  8. Control aspects of the Schuchuli Village stand-alone photovoltaic power system

    NASA Technical Reports Server (NTRS)

    Groumpos, P. P.; Culler, J. E.; Delombard, R.

    1984-01-01

    A photovoltaic power system in an Arizona Indian village was installed. The control subsystem of this photovoltaic power system was analyzed. The four major functions of the control subsystem are: (1) voltage regulation; (2) load management; (3) water pump control; and (4) system protection. The control subsystem functions flowcharts for the control subsystem operation, and a computer program that models the control subsystem are presented.

  9. Developed algorithm of maximum power tracking for stand-alone photovoltaic system

    SciTech Connect

    Nafeh, A.E.A.; Fahmy, F.H.; Mahgoub, O.A.; El-Zahab, E.M.A.

    1998-01-01

    The rapid increase in the cost of conventional energy sources leads to the use of nonconventional energy sources. The photovoltaic (PV) is one nonconventional source that is safe, reliable, and environmentally healthy. However, the PV system is expensive and needs a large area to operate. To solve these disadvantages, it is necessary to operate at the maximum power point (MPP) of the array. This article presents a new maximum power tracking algorithm based on the incremental conductance algorithm, which successfully operates even in cases of rapidly changing atmospheric conditions. The developed algorithm depends on the relationship between the load line and the tangent line angles of the I-V characteristic curve. A simulation program was designed to investigate the performance of the developed algorithm using mathematical models for the different system components. The simulation led to a good realization of the algorithm.

  10. A Study on Electric Power Smoothing System for Lead-Acid Battery of Stand-Alone Natural Energy Power System Using EDLC

    NASA Astrophysics Data System (ADS)

    Jia, Yan; Shibata, Ryosuke; Yamamura, Naoki; Ishida, Muneaki

    To resolve energy shortage and global warming problem, renewable natural resource and its power system has been gradually generalizing. However, the power fluctuation suppressing in short period and the balance control of consumption and supply in long period are two of main problems that need to be resolved urgently in natural energy power system. In Stand-alone Natural Energy Power System (SNEPS) with power energy storage devices, power fluctuation in short period is one of the main reasons that recharge cycle times increase and lead-acid battery early failure. Hence, to prolong the service life of lead-acid battery and improve power quality through suppressing the power fluctuation, we proposed a method of electric power smoothing for lead-acid battery of SNEPS using bi-directional Buck/Boost converter and Electric Double Layer Capacitor (EDLC) in this paper. According to the test data of existing SNEPS, a power fluctuation condition is selected and as an example to analyze the validity of the proposed method. The analysis of frequency characteristics indicates the power fluctuation is suppressed a desired range in the target frequency region. The experimental results of confirmed the feasibility of the proposed system and the results well satisfy the requirement of system design.

  11. Stand Alone Battery Thermal Management System

    SciTech Connect

    Brodie, Brad

    2015-09-30

    The objective of this project is research, development and demonstration of innovative thermal management concepts that reduce the cell or battery weight, complexity (component count) and/or cost by at least 20%. The project addresses two issues that are common problems with current state of the art lithium ion battery packs used in vehicles; low power at cold temperatures and reduced battery life when exposed to high temperatures. Typically, battery packs are “oversized” to satisfy the two issues mentioned above. The first phase of the project was spent making a battery pack simulation model using AMEsim software. The battery pack used as a benchmark was from the Fiat 500EV. FCA and NREL provided vehicle data and cell data that allowed an accurate model to be created that matched the electrical and thermal characteristics of the actual battery pack. The second phase involved using the battery model from the first phase and evaluate different thermal management concepts. In the end, a gas injection heat pump system was chosen as the dedicated thermal system to both heat and cool the battery pack. Based on the simulation model. The heat pump system could use 50% less energy to heat the battery pack in -20°C ambient conditions, and by keeping the battery cooler at hot climates, the battery pack size could be reduced by 5% and still meet the warranty requirements. During the final phase, the actual battery pack and heat pump system were installed in a test bench at DENSO to validate the simulation results. Also during this phase, the system was moved to NREL where testing was also done to validate the results. In conclusion, the heat pump system can improve “fuel economy” (for electric vehicle) by 12% average in cold climates. Also, the battery pack size, or capacity, could be reduced 5%, or if pack size is kept constant, the pack life could be increased by two years. Finally, the total battery pack and thermal system cost could be reduced 5% only if the system is integrated with the vehicle cabin air conditioning system. The reason why we were not able to achieve the 20% reduction target is because of the natural decay of the battery cell due to the number of cycles. Perhaps newer battery chemistries that are not so sensitive to cycling would have more potential for reducing the battery size due to thermal issues.

  12. Modular photovoltaic stand-alone systems: Phase 1

    NASA Technical Reports Server (NTRS)

    Naff, G. J.; Marshall, N. A.

    1983-01-01

    A family of modular stand-alone power systems that covered the range in power level from 1 kw to 14 kw was developed. Products within this family were required to be easily adaptable to different environments and applications, and were to be both reliable and cost effective. Additionally, true commonality in hardware was to be exploited, and unnecessary recurrence of design and development costs were to be minimized; thus improving hardware availability. Assurance of compatibility with large production runs, was also an underlying program goal. A secondary objective was to compile, evaluate, and determine the economic and technical status of available, and potentially available, technology options associated with the balance of systems (BOS) for stand-along photovoltaic (PV) power systems. The secondary objective not only directly supported the primary but additionally contributed to the definition and implementation of the BOS cost reduction plan.

  13. Photovoltaic stand-alone modular systems, phase 2

    NASA Technical Reports Server (NTRS)

    Naff, G. J.; Marshall, N. A.

    1983-01-01

    The final hardware and system qualification phase of a two part stand-alone photovoltaic (PV) system development is covered. The final design incorporated modular, power blocks capable of expanding incrementally from 320 watts to twenty kilowatts (PK). The basic power unit (PU) was nominally rated 1.28 kWp. The controls units, power collection buses and main lugs, electrical protection subsystems, power switching, and load management circuits are housed in a common control enclosure. Photo-voltaic modules are electrically connected in a horizontal daisy-chain method via Amp Solarlok plugs mating with compatible connectors installed on the back side of each photovoltaic module. A pair of channel rails accommodate the mounting of the modules into a frameless panel support structure. Foundations are of a unique planter (tub-like) configuration to allow for world-wide deployment without restriction as to types of soil. One battery string capable of supplying approximately 240 ampere hours nominal of carryover power is specified for each basic power unit. Load prioritization and shedding circuits are included to protect critical loads and selectively shed and defer lower priority or noncritical power demands. The baseline system, operating at approximately 2 1/2 PUs (3.2 kW pk.) was installed and deployed. Qualification was successfully complete in March 1983; since that time, the demonstration system has logged approximately 3000 hours of continuous operation under load without major incident.

  14. A stochastic method for stand-alone photovoltaic system sizing

    SciTech Connect

    Cabral, Claudia Valeria Tavora; Filho, Delly Oliveira; Martins, Jose Helvecio; Toledo, Olga Moraes

    2010-09-15

    Photovoltaic systems utilize solar energy to generate electrical energy to meet load demands. Optimal sizing of these systems includes the characterization of solar radiation. Solar radiation at the Earth's surface has random characteristics and has been the focus of various academic studies. The objective of this study was to stochastically analyze parameters involved in the sizing of photovoltaic generators and develop a methodology for sizing of stand-alone photovoltaic systems. Energy storage for isolated systems and solar radiation were analyzed stochastically due to their random behavior. For the development of the methodology proposed stochastic analysis were studied including the Markov chain and beta probability density function. The obtained results were compared with those for sizing of stand-alone using from the Sandia method (deterministic), in which the stochastic model presented more reliable values. Both models present advantages and disadvantages; however, the stochastic one is more complex and provides more reliable and realistic results. (author)

  15. Study of a thermoelectric system equipped with a maximum power point tracker for stand-alone electric generation.

    NASA Astrophysics Data System (ADS)

    Favarel, C.; Champier, D.; Bédécarrats, J. P.; Kousksou, T.; Strub, F.

    2012-06-01

    According to the International Energy Agency, 1.4 billion people are without electricity in the poorest countries and 2.5 billion people rely on biomass to meet their energy needs for cooking in developing countries. The use of cooking stoves equipped with small thermoelectric generator to provide electricity for basic needs (LED, cell phone and radio charging device) is probably a solution for houses far from the power grid. The cost of connecting every house with a landline is a lot higher than dropping thermoelectric generator in each house. Thermoelectric generators have very low efficiency but for isolated houses, they might become really competitive. Our laboratory works in collaboration with plane`te-bois (a non governmental organization) which has developed energy-efficient multifunction (cooking and hot water) stoves based on traditional stoves designs. A prototype of a thermoelectric generator (Bismuth Telluride) has been designed to convert a small part of the energy heating the sanitary water into electricity. This generator can produce up to 10 watts on an adapted load. Storing this energy in a battery is necessary as the cooking stove only works a few hours each day. As the working point of the stove varies a lot during the use it is also necessary to regulate the electrical power. An electric DC DC converter has been developed with a maximum power point tracker (MPPT) in order to have a good efficiency of the electronic part of the thermoelectric generator. The theoretical efficiency of the MMPT converter is discussed. First results obtained with a hot gas generator simulating the exhaust of the combustion chamber of a cooking stove are presented in the paper.

  16. US manufacturers of commercially available stand-alone photovoltaic lighting systems

    SciTech Connect

    McNutt, P.

    1994-05-01

    This report introduces photovoltaic (PV) lighting systems, gives some specifications for ordering these systems, and provides a list of some of the manufacturers of these systems in the United States. These PV lighting systems are all commercially available. They are stand-alone systems because they are not tied to the electric utility power grid.

  17. Sizing handbook for stand-alone photovoltaic/storage systems

    NASA Astrophysics Data System (ADS)

    Chapman, R. N.

    1987-04-01

    This report details the use and development of a simplified sizing technique for stand-alone photovoltaic/storage systems. The array size and storage capacity are chosen to achieve the required loss-of-load probability (LOLP). The LOLP represents the level of confidence at which the system will satisfy the load. An LOLP of 0 means that the load will always be satisfied, and an LOLP of 1 means that the load will never be satisfied. Array sizes are read from array-sizing nomograms as a function of latitude, tilt angle, and average horizontal insolation in December (in the northern hemisphere) or June (in the southern hemisphere). Storage capacities are read from storage-sizing nomograms as a function of the required LOLP. The technique is valid for systems with a fixed tilt array, product or energy storage, and for any hourly load profile or daily load profile within a given month. The only constraint is that the average monthly load must not vary more than +-10% from month to month. The designer can choose from tilt angles from latitude minus 20 to latitude plus 20 and can choose from a range of array size/storage capacity combinations for any given LOLP.

  18. Stand-alone photovoltaic (PV) powered electrochromic window

    DOEpatents

    Benson, D.K.; Crandall, R.S.; Deb, S.K.; Stone, J.L.

    1995-01-24

    A variable transmittance double pane window includes an electrochromic material that has been deposited on one pane of the window in conjunction with an array of photovoltaic cells deposited along an edge of the pane to produce the required electric power necessary to vary the effective transmittance of the window. A battery is placed in a parallel fashion to the array of photovoltaic cells to allow the user the ability to manually override the system when a desired transmittance is desired. 11 figures.

  19. Stand-alone photovoltaic (PV) powered electrochromic window

    DOEpatents

    Benson, David K.; Crandall, Richard S.; Deb, Satyendra K.; Stone, Jack L.

    1995-01-01

    A variable transmittance double pane window includes an electrochromic material that has been deposited on one pane of the window in conjunction with an array of photovoltaic cells deposited along an edge of the pane to produce the required electric power necessary to vary the effective transmittance of the window. A battery is placed in a parallel fashion to the array of photovoltaic cells to allow the user the ability to manually override the system when a desired transmittance is desired.

  20. System design optimization for stand-alone photovoltaic systems sizing by using superstructure model

    NASA Astrophysics Data System (ADS)

    Azau, M. A. M.; Jaafar, S.; Samsudin, K.

    2013-06-01

    Although the photovoltaic (PV) systems have been increasingly installed as an alternative and renewable green power generation, the initial set up cost, maintenance cost and equipment mismatch are some of the key issues that slows down the installation in small household. This paper presents the design optimization of stand-alone photovoltaic systems using superstructure model where all possible types of technology of the equipment are captured and life cycle cost analysis is formulated as a mixed integer programming (MIP). A model for investment planning of power generation and long-term decision model are developed in order to help the system engineer to build a cost effective system.

  1. Video tracking algorithm of long-term experiment using stand-alone recording system

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Jen; Li, Yan-Chay; Huang, Ke-Nung; Jen, Sun-Lon; Young, Ming-Shing

    2008-08-01

    Many medical and behavioral applications require the ability to monitor and quantify the behavior of small animals. In general these animals are confined in small cages. Often these situations involve very large numbers of cages. Modern research facilities commonly monitor simultaneously thousands of animals over long periods of time. However, conventional systems require one personal computer per monitoring platform, which is too complex, expensive, and increases power consumption for large laboratory applications. This paper presents a simplified video tracking algorithm for long-term recording using a stand-alone system. The feature of the presented tracking algorithm revealed that computation speed is very fast data storage requirements are small, and hardware requirements are minimal. The stand-alone system automatically performs tracking and saving acquired data to a secure digital card. The proposed system is designed for video collected at a 640×480 pixel with 16 bit color resolution. The tracking result is updated every 30 frames/s. Only the locomotive data are stored. Therefore, the data storage requirements could be minimized. In addition, detection via the designed algorithm uses the Cb and Cr values of a colored marker affixed to the target to define the tracked position and allows multiobject tracking against complex backgrounds. Preliminary experiment showed that such tracking information stored by the portable and stand-alone system could provide comprehensive information on the animal's activity.

  2. Photovoltaic stand-alone systems: Preliminary engineering design handbook

    NASA Astrophysics Data System (ADS)

    Macomber, H. L.; Ruzek, J. B.; Costello, F. A.

    1981-08-01

    Component design and engineering information, including estimation and reduction strategies, FV array characteristics, and material on batteries, power handling equipment, and back up systems are presented. The data needed to begin the design process and preliminary system design considerations are discussed. These considerations include analysis of insolation and siting, system sizing, feasibility assessment and reliability engineering approaches. Information on system design procedures and applicable codes and standards is presented. Information on system installation, operation, maintenance issues, personnel and facility safety requirements and various means of calculating insolation, including computer software and statistical computations are emphasized.

  3. Status of DOE and AID stand-alone photovoltaic system field tests

    NASA Technical Reports Server (NTRS)

    Bifano, W. J.; Delombard, R.; Ratajczak, A. F.; Scudder, L. R.

    1984-01-01

    The NASA Lewis Research Center (LeRC) is managing stand-alone photovoltaic (PV) system projects sponsored by the U.S. Department of Energy (DOE) and the U.S. Agency for International Development (AID). The DOE project includes village PV power demonstration projects in Gabon (four sites) and the Marshall Islands, and PV-powered vaccine refrigerator systems in six countries. The AID project includes a large village power system, a farmhouse system and two water pumping-irrigation systems in Tunisia, a water pumping/grain grinding system in Upper Volta, five medical clinic systems in four countries, PV-powered vaccine refrigerator systems in 18 countries and a PV-powered remote earth station in Indonesia. This paper reviews these PV projects and summarizes significant findings to date.

  4. Life cycle cost analysis of a stand-alone PV system in rural Kenya

    NASA Astrophysics Data System (ADS)

    Daly, Emma

    The purpose of this quantitative research study was to determine the economic feasibility of a stand-alone PV system to electrify a rural area in Kenya. The research conducted involved a comprehensive review of all the relevant literature associated with the study. Methodologies were extrapolated from this extensive literature to develop a model for the complete design and economic analysis of a stand-alone PV system. A women's center in rural Kenya was used as a worked example to demonstrate the workings of the model. The results suggest that electrifying the center using a stand-alone PV system is an economically viable option which is encouraging for the surrounding area. This model can be used as a business model to determine the economic feasibility of a stand-alone PV system in alternative sites in Kenya.

  5. A stand-alone interactive graphics finite element modeling system

    NASA Technical Reports Server (NTRS)

    Gingerich, J. Z.; Abe, M. M.; Vinecore, R. L.; Romans, G. J.; Ratihn, B. M.

    1977-01-01

    The finite element modeling (FEM) system described here is an interactive graphics system designed for use with an intelligent terminal. It offers an economical alternative to the conventional methods (hand compilation and remote terminals) of 2 and 3-dimensional model generation. Using local computing and local storage, this FEM system allows the operator to create and display 3-dimensional models entirely off-line from the host computer. This eliminates costly on-line computer and host-processing time, and makes the user more effective by greatly reducing computer response time. The system allows model generation by down-loading node and element data from the host computer or by using the system's model generation operations for digitizing and automatic creation. The system then generates completed model information in the desired analysis package's bulk data format and transmits it to the host computer for finite element analysis.

  6. Charactrization of a Li-ion battery based stand-alone a-Si photovoltaic system

    NASA Astrophysics Data System (ADS)

    Hamid Vishkasougheh, Mehdi; Tunaboylu, Bahadir

    2014-11-01

    The number of photovoltaic (PV) system installations is increasing rapidly. As more people learn about this versatile and often cost-effective power option, this trend will accelerate. This document presents a recommended design for a battery based stand-alone photovoltaic system (BSPV). BSPV system has the ability to be applied in different areas, including warning signals, lighting, refrigeration, communication, residential water pumping, remote sensing, and cathodic protection. The presented calculation method gives a proper idea for a system sizing technique. Based on application load, different scenarios are possible for designing a BSPV system. In this study, a battery based stand-alone system was designed. The electricity generation part is three a-Si panels, which are connected in parallel, and for the storage part LFP (lithium iron phosphate) battery was used. The high power LFP battery packs are 40 cells each 8S5P (configured 8 series 5 parallel). Each individual pack weighs 0.5 kg and is 25.6 V. In order to evaluate the efficiency of a-Si panels with respect to the temperature and the solar irradiation, cities of Istanbul, Ankara and Adana in Turkey were selected. Temperature and solar irradiation were gathered from reliable sources and by using translation equations, current and voltage output of panels were calculated. As a result of these calculations, current and energy outputs were computed by considering an average efficient solar irradiation time value per day in Turkey. The calculated power values were inserted to a battery cycler system, and the behavior of high power LFP batteries in a time sequence of 7.2 h was evaluated. The charging and discharging cycles were obtained and their behavior was discussed. According to the results, Istanbul has the lowest number of peak month's energy, it followed by Ankara, and ultimately Adana has the highest number of peak months and energy storage. It was observed during the tests that values up to 4 A was discharged by battery packages in a full discharge cycle depending on application and required load.

  7. Information systems for the materials management department: stand-alone and enterprise resource planning systems.

    PubMed

    2005-03-01

    Materials management information systems (MMISs) incorporate information tools that hospitals can use to automate certain business processes, increase staff compliance with these processes, and identify opportunities for cost savings. Recently, there has been a push by hospital administration to purchase enterprise resource planning (ERP) systems, information systems that promise to integrate many more facets of healthcare business. We offer this article to help materials managers, administrators, and others involved with information system selection understand the changes that have taken place in materials management information systems, decide whether they need a new system and, if so, whether a stand-alone MMIS or an ERP system will be the best choice. PMID:15887634

  8. Space crew radiation exposure analysis system based on a commercial stand-alone CAD system

    NASA Astrophysics Data System (ADS)

    Appleby, Matthew H.; Golightly, Michael J.; Hardy, Alva C.

    1992-07-01

    Major improvements have recently been completed in the approach to spacecraft shielding analysis. A Computer-Aided Design (CAD)-based system has been developed for determining the shielding provided to any point within or external to the spacecraft. Shielding analysis is performed using a commercially available stand-alone CAD system and a customized ray-tracing subroutine contained within a standard engineering modeling software package. This improved shielding analysis technique has been used in several vehicle design projects such as a Mars transfer habitat, pressurized lunar rover, and the redesigned Space Station. Results of these analyses are provided to demonstrate the applicability and versatility of the system.

  9. Space crew radiation exposure analysis system based on a commercial stand-alone CAD system

    NASA Technical Reports Server (NTRS)

    Appleby, Matthew H.; Golightly, Michael J.; Hardy, Alva C.

    1992-01-01

    Major improvements have recently been completed in the approach to spacecraft shielding analysis. A Computer-Aided Design (CAD)-based system has been developed for determining the shielding provided to any point within or external to the spacecraft. Shielding analysis is performed using a commercially available stand-alone CAD system and a customized ray-tracing subroutine contained within a standard engineering modeling software package. This improved shielding analysis technique has been used in several vehicle design projects such as a Mars transfer habitat, pressurized lunar rover, and the redesigned Space Station. Results of these analyses are provided to demonstrate the applicability and versatility of the system.

  10. Dynamic load management and optimum sizing of stand-alone hybrid PV/wind system

    NASA Astrophysics Data System (ADS)

    Kaplani, E.; Ntafogiannis, P.; Pappas, K.; Diamantopoulos, N.

    2015-12-01

    Simulation algorithms for the sizing of stand-alone hybrid PV/Wind systems are a powerful tool in evaluating the optimum configuration that would cover the energy demand with a predefined reliability level at the lowest cost. Several parameters such as the interval of the simulation (day, day-night, hourly) and the consumption profile may significantly affect the optimum configuration. This paper examines the effect of these parameters within an optimum sizing simulation algorithm developed. The effect of these parameters was particularly evident at low battery capacities, which involve optimum configurations resulting in minimum cost. Furthermore, shift-able loads in the hourly-based weekly profile assumed in this study were identified, and a dynamic load management functionality was developed. In this approach, loads that could be shifted through time were dynamically allocated during periods of excess energy production by the hybrid PV/Wind system. The results showed an increase in system reliability from 95% to 97% when load shifting was introduced. Finally, sizing the system for only the static (non-shift-able loads) proved to withstand the addition of the extra shift-able loads while retaining the 95% reliability level when the load management functionality was introduced. Thus, a smaller installation with lower cost is achieved.

  11. Design of stand-alone brackish water desalination wind energy system for Jordan

    SciTech Connect

    Habali, S.M.; Saleh, I.A.

    1994-06-01

    More than 100 underground water wells drilled in Jordan are known to have brackish water with total desolved solids (TDS) over 1500 ppm but not greater than 4000 ppm. The world standard for potable water limits the TDS count to 500 ppm in addition to being free from live microorganisms or dangerous mineral and organic substances. A reverse osmosis desalination scheme powered by a stand-alone wind energy converter (WEC) is proposed to produce fresh water water from wells located in potentially high-wind sites. The purpose of this study if to present the main design parameters and economic estimates of a wind-assisted RO system using a diesel engine as the baseline energy source and an electric wind turbine for the wind energy source. It is found that brackish water pumping and desalinating using WECs costs 0.67 to 1.16 JD/m[sup 3] (JD = Jordanian Dinar, 1US$ = 0.68 JD), which is less than using conventional diesel engines especially in remote areas. In addition, the wind-reverse osmosis system becomes more economically feasible for higher annual production rates or in good wind regimes.

  12. Stand-alone WIreless Magnetometer System: Concept Design and Development Status

    NASA Astrophysics Data System (ADS)

    Anderson, B. J.; Carkhuff, B. G.; Rhodes, E.; Korth, H.

    2007-12-01

    The Stand-alone WIreless Magnetometer System (SWIMS) is intended to serve as a technology suitable for large scale deployment for magnetometer networks in sub-auroral latitudes with minimal logistical support and maintenance. SWIMS is based on a new magnetometer developed and licensed by JHU/APL. A SWIMS installation will consist of up to three solar/battery powered Sensor Modules (SM) each equipped with a new Mirror Image Differential Induction Amplitude Magnetometer (MIDIAM). The SMs are linked via wireless, radio frequency (RF) connection to a Central Node (CN). The RF link allows wireless installation over distances up to 300 meters between SMs. The CN may communicate either via land lines or wireless links to a central data facility. Because each SM is wireless, SWIMS can use more than one SM at a single site to discriminate against local noise sources. The present project objective is to develop a prototype SWIMS system of three SMs communicating via local RF link to a CN. The MIDIAM has yielded sub-nT performance with less than 1W power consumption in continuous operation. A conceptual system design using commercial solar/batter power system and RF communication components has been developed that is expected to achieve continuous operation at 1- second or higher rate sampling using a moderately sized solar cell array, 12" x 18", and a 6"x6"x4" AGM battery (144 W-hour). By monitoring the battery depth of discharge and duty cycling MIDIAM as required if incident effective power is low due to inclement conditions, the SM is expected to support continuous unattended operation with no coarser than one sample per minute on as little as four hours of sunlight every ten days.

  13. System Simulation by Recursive Feedback: Coupling A Set of Stand-Alone Subsystem Simulations

    NASA Technical Reports Server (NTRS)

    Nixon, Douglas D.; Hanson, John M. (Technical Monitor)

    2002-01-01

    Recursive feedback is defined and discussed as a framework for development of specific algorithms and procedures that propagate the time-domain solution for a dynamical system simulation consisting of multiple numerically coupled self-contained stand-alone subsystem simulations. A satellite motion example containing three subsystems (other dynamics, attitude dynamics, and aerodynamics) has been defined and constructed using this approach. Conventional solution methods are used in the subsystem simulations. Centralized and distributed versions of coupling structure have been addressed. Numerical results are evaluated by direct comparison with a standard total-system simultaneous-solution approach.

  14. System Simulation by Recursive Feedback: Coupling a Set of Stand-Alone Subsystem Simulations

    NASA Technical Reports Server (NTRS)

    Nixon, Douglas D.; Ryan, Stephen G. (Technical Monitor)

    2002-01-01

    Recursive feedback is defined and discussed as a framework for development of specific algorithms and procedures that propagate the time-domain solution for a dynamical system simulation consisting of multiple numerically coupled, self-contained, stand-alone subsystem simulations. A satellite motion example containing three subsystems (orbit dynamics, attitude dynamics, and aerodynamics) has been defined and constructed using this approach. Conventional solution methods are used in the subsystem simulations. Centralized and distributed versions of coupling structure have been addressed. Numerical results are evaluated by direct comparison with a standard total-system, simultaneous-solution approach.

  15. Dynamic response of a stand-alone wind energy conversion system with battery energy storage to a wind gust

    SciTech Connect

    Borowy, B.S.; Salameh, Z.M.

    1997-03-01

    A mathematical model of each element of the Stand-Alone Wind Energy Conversion System is developed. The model variables are expressed in the d-q rotor reference frame. The wind turbine was considered as the only source of power in this study. Using this model the system response to a recorded wind gust is investigated by calculating the generator current, the rectifier current, the load current, the battery charging current, and the battery voltage. The calculated results are then verified by comparing them with the actual values obtained from the data acquisition system. A good agreement was achieved between the experimental and the analytical results.

  16. Stand-alone digital data storage control system including user control interface

    NASA Technical Reports Server (NTRS)

    Wright, Kenneth D. (Inventor); Gray, David L. (Inventor)

    1994-01-01

    A storage control system includes an apparatus and method for user control of a storage interface to operate a storage medium to store data obtained by a real-time data acquisition system. Digital data received in serial format from the data acquisition system is first converted to a parallel format and then provided to the storage interface. The operation of the storage interface is controlled in accordance with instructions based on user control input from a user. Also, a user status output is displayed in accordance with storage data obtained from the storage interface. By allowing the user to control and monitor the operation of the storage interface, a stand-alone, user-controllable data storage system is provided for storing the digital data obtained by a real-time data acquisition system.

  17. System Simulation by Recursive Feedback: Coupling a Set of Stand-Alone Subsystem Simulations

    NASA Technical Reports Server (NTRS)

    Nixon, D. D.

    2001-01-01

    Conventional construction of digital dynamic system simulations often involves collecting differential equations that model each subsystem, arran g them to a standard form, and obtaining their numerical gin solution as a single coupled, total-system simultaneous set. Simulation by numerical coupling of independent stand-alone subsimulations is a fundamentally different approach that is attractive because, among other things, the architecture naturally facilitates high fidelity, broad scope, and discipline independence. Recursive feedback is defined and discussed as a candidate approach to multidiscipline dynamic system simulation by numerical coupling of self-contained, single-discipline subsystem simulations. A satellite motion example containing three subsystems (orbit dynamics, attitude dynamics, and aerodynamics) has been defined and constructed using this approach. Conventional solution methods are used in the subsystem simulations. Distributed and centralized implementations of coupling have been considered. Numerical results are evaluated by direct comparison with a standard total-system, simultaneous-solution approach.

  18. Study of locally manufactured motor vehicle batteries in stand alone home photovoltaic systems

    SciTech Connect

    Fernandez, S.

    1999-07-01

    Analysis of voltage, current, specific gravity, and temperature was performed on locally manufactured lead acid batteries operating in stand alone home photovoltaic (SAHPV) systems in the Dominican Republic. While voltage, charge/discharge current, and specific gravity of most batteries were within reasonable limits, there were indications of batteries spending an excessive time discharged and some incidents of overcharge. During charging above 1 amp, ambient temperatures were 6 to 13 C above the optimal operating temperature (25 C) and battery temperatures were 9 to 20 C above 25 C. Examination of worn out batteries from these SAHPV systems revealed that the majority had deteriorated positive plates and/or sulfation, while a smaller number showed signs of spalling. High temperature was determined to be a significant factor contributing to the premature failure of locally manufactured lead acid batteries operating in these systems.

  19. Performance of a 268Wp stand-alone PV system test facility

    SciTech Connect

    Adanu, K.G.

    1994-12-31

    This paper reports on studies carried out on a 268 Wp stand-alone PV test facility installed at the University of Ghana. Parameters measured include solar irradiance, ambient temperature, cell temperature, array voltage, battery voltage, and energy output from array. An automatic data acquisition system was used to record the data. The purpose of this study was to determine the effect on performance of a PV array due to seasonal climatic changes: for example, effect due to dust during the period when dust-laden winds blow from the Sahara desert to most sub-saharan West African countries. The reduced intensity of the solar radiation as would be expected reduced the total array output during the harmattan and the rainy seasons. No visible changes were observed in the PV modules themselves over the period of study, but one of the junction boxes attached to the modules had become severely corroded.

  20. Fundamental-Frequency-Modulated Six-Level Diode-Clamped Multilevel Inverter for Three-Phase Stand-Alone Photovoltaic System

    SciTech Connect

    Ozdemir, Engin; Ozdemir, Sule; Tolbert, Leon M

    2009-01-01

    This paper presents a fundamental-frequency-modulated diode-clamped multilevel inverter (DCMLI) scheme for a three-phase stand-alone photovoltaic (PV) system. The system consists of five series-connected PV modules, a six-level DCMLI generating fundamental-modulation staircase three-phase output voltages, and a three-phase induction motor as the load. In order to validate the proposed concept, simulation studies and experimental measurements using a small-scale laboratory prototype are also presented. The results show the feasibility of the fundamental frequency switching application in three-phase stand-alone PV power systems.

  1. The Stand-Alone Microprocessor System: A Valuable Tool in College Admissions and Recruitment.

    ERIC Educational Resources Information Center

    Garrett, Larry Neal

    1983-01-01

    The stand-alone microprocessor is seen as one innovative tool that can be used both in the organizational management of decline and in meeting specific organizational needs such as those of the admissions director and staff. The term "microprocessor" is defined. (MLW)

  2. A new stand-alone QEXAFS data acquisition system for in situ studies.

    PubMed

    Sttzel, Jan; Ltzenkirchen-Hecht, Dirk; Frahm, Ronald

    2011-03-01

    To meet the demands of the QEXAFS (quick-scanning extended X-ray absorption fine structure) technique for a fast, user-friendly and flexible data acquisition a new stand-alone system with new software exploiting a multi-functional USB board was designed. The chosen approach allows the scanning of several analogue and digital data sources with up to 500000 samples each second over hours storable in binary or ASCII format without any dead-time. At the same time it is possible to visualize the acquired data instantaneously which provides a maximum of interactivity during the running experiment and also optimal conditions to select the best suited beamline and detector settings prior to each measurement. Furthermore, the QEXAFS monochromator and typically three current amplifiers are entirely controlled by the new software so that all monochromator settings can be synchronized with the data acquisition enabling programmed scans with alternating parameter sets. This versatile concept also enables the user to react immediately to changes in the sample during in situ studies. An interface to a three-axis stepper motor control unit is additionally included to control a sample stage which can again be synchronized with the data acquisition. Thus, spatially resolved scans and the usage of scan tools for sample alignment are feasible with the new system. Typical examples to demonstrate the features of the new data acquisition system are presented, the designed graphical user interface is described in detail and, furthermore, the crucial design parameters of a typical QEXAFS set-up are discussed. PMID:21335902

  3. A stand-alone demography and landscape structure module for Earth system models

    NASA Astrophysics Data System (ADS)

    Nieradzik, L. P.; Haverd, V.; Smith, B.; Cook, G. D.; Briggs, P.; Roxburgh, S.; Liedloff, A.; Meyer, C.; Canadell, J.

    2013-12-01

    We propose and demonstrate a new approach for the simulation of woody ecosystem stand dynamics, demography and disturbance-mediated heterogeneity suitable for continental to global applications and designed for coupling to the terrestrial ecosystem component of any earth system model (Haverd et al., 2013). The approach is encoded in a model called Populations-Order-Physiology (POP). We demonstrate the behaviour and performance of POP coupled to the Community Atmosphere Biosphere Land Exchange model (CABLE) for two contrasting applications: (i) to the Northern Australian Tropical Transect, featuring gradients in savanna vegetation cover, rainfall and fire disturbance and (ii) to a set of globally distributed forest locations coinciding with observations of forest biomass allometry. Along the Northern Australian Tropical Transect, CABLE-POP is able to simultaneously reproduce observation-based estimates of key functional and structural variables, namely gross primary production, tree foliage projective cover, basal area and maximum tree height. This application particularly demonstrates the ability of POP to quantify the contributions of drought and fire to tree mortality. Drought is manifested as an increase in mortality due to a decline in growth efficiency, while fires are treated as partial disturbance events, with tree mortality depending on tree size and fire intensity. In the application to global forests, POP is integrated with global forest data by calibrating it against paired observations of stem biomass and number density. The calibrated POP model is then coupled with CABLE and the coupled model is evaluated against leaf-stem allometry observations from forest stands ranging in age from 20 to 400 years. Results indicate that, in contrast to simulations from many global land surface models (Wolf et al., 2011), simulated biomass pools conform well with observed allometry. We conclude that POP, which can readily be coupled to the terrestrial carbon cycle component of any LSM, represents a significant advance in our ability to use in-situ and remotely sensed observations of biomass and individual level parameters (e.g. crown-size, tree-height, stem diameter) as constraints on the terrestrial carbon cycle. Haverd, V., B. Smith, G. Cook, P. Briggs, L. Nieradzik, S. Roxburgh, A. Liedloff, C. Meyer, and J. G. Canadell, A stand-alone tree demography and landscape structure module for Earth system models, submitted to Geophys. Res. Let., 2013 Wolf, A., P. Ciais, V. Bellassen, N. Delbart, C.B. Field, and J.A. Berry, Forest biomass allometry in global land surface models, Global Biogeochem. Cycles, 25, GB3015, doi:10.1029/2010GB003917, 2011

  4. Stand-Alone Front-End System for High-Frequency, High-Frame-Rate Coded Excitation Ultrasonic Imaging

    PubMed Central

    Park, Jinhyoung; Hu, Changhong; Shung, K. Kirk

    2012-01-01

    A stand-alone front-end system for high-frequency coded excitation imaging was implemented to achieve a wider dynamic range. The system included an arbitrary waveform amplifier, an arbitrary waveform generator, an analog receiver, a motor position interpreter, a motor controller and power supplies. The digitized arbitrary waveforms at a sampling rate of 150 MHz could be programmed and converted to an analog signal. The pulse was subsequently amplified to excite an ultrasound transducer, and the maximum output voltage level achieved was 120 Vpp. The bandwidth of the arbitrary waveform amplifier was from 1 to 70 MHz. The noise figure of the preamplifier was less than 7.7 dB and the bandwidth was 95 MHz. Phantoms and biological tissues were imaged at a frame rate as high as 68 frames per second (fps) to evaluate the performance of the system. During the measurement, 40-MHz lithium niobate (LiNbO3) single-element lightweight (<0.28 g) transducers were utilized. The wire target measurement showed that the −6-dB axial resolution of a chirp-coded excitation was 50 µm and lateral resolution was 120 µm. The echo signal-to-noise ratios were found to be 54 and 65 dB for the short burst and coded excitation, respectively. The contrast resolution in a sphere phantom study was estimated to be 24 dB for the chirp-coded excitation and 15 dB for the short burst modes. In an in vivo study, zebrafish and mouse hearts were imaged. Boundaries of the zebrafish heart in the image could be differentiated because of the low-noise operation of the implemented system. In mouse heart images, valves and chambers could be readily visualized with the coded excitation. PMID:23443698

  5. Stand-alone development system using a KIM-1 microcomputer module

    NASA Technical Reports Server (NTRS)

    Nickum, J. D.

    1978-01-01

    A small microprocessor-based system designed to: contain all or most of the interface hardware, designed to be easy to access and modify the hardware, to be capable of being strapped to the seat of a small general aviation aircraft, and to be independent of the aircraft power system is described. The system is used to develop a low cost Loran C sensor processor, but is designed such that the Loran interface boards may be removed and other hardware interfaces inserted into the same connectors. This flexibility is achieved through memory-mapping techniques into the microprocessor.

  6. Comparison of two stand-alone CADe systems at multiple operating points

    NASA Astrophysics Data System (ADS)

    Sahiner, Berkman; Chen, Weijie; Pezeshk, Aria; Petrick, Nicholas

    2015-03-01

    Computer-aided detection (CADe) systems are typically designed to work at a given operating point: The device displays a mark if and only if the level of suspiciousness of a region of interest is above a fixed threshold. To compare the standalone performances of two systems, one approach is to select the parameters of the systems to yield a target false-positive rate that defines the operating point, and to compare the sensitivities at that operating point. Increasingly, CADe developers offer multiple operating points, which necessitates the comparison of two CADe systems involving multiple comparisons. To control the Type I error, multiple-comparison correction is needed for keeping the family-wise error rate (FWER) less than a given alpha-level. The sensitivities of a single modality at different operating points are correlated. In addition, the sensitivities of the two modalities at the same or different operating points are also likely to be correlated. It has been shown in the literature that when test statistics are correlated, well-known methods for controlling the FWER are conservative. In this study, we compared the FWER and power of three methods, namely the Bonferroni, step-up, and adjusted step-up methods in comparing the sensitivities of two CADe systems at multiple operating points, where the adjusted step-up method uses the estimated correlations. Our results indicate that the adjusted step-up method has a substantial advantage over other the two methods both in terms of the FWER and power.

  7. NASA preprototype redox storage system for a photovoltaic stand-alone application

    NASA Technical Reports Server (NTRS)

    Hagedorn, N. H.

    1981-01-01

    A 1 kW preprototype redox storage system underwent characterization tests and was operated as the storage device for a 5 kW (peak) photovoltaic array. The system is described and performance data are presented. Loss mechanisms are discussed and simple design changes leading to significant increases in efficiency are suggested. The effects on system performance of nonequilibrium between the predominant species of complexed chromic ion in the negative electrode reactant solution are indicated.

  8. Estimation of the potential array output charge in the performance analysis of stand-alone photovoltaic systems without MPPT (Case study: Mediterranean climate)

    SciTech Connect

    Munoz, F.J.; Echbarthi, I.; Nofuentes, G.; Fuentes, M.; Aguilera, J.

    2009-11-15

    The potential array output energy, E{sub P}, stated by the Joint Research Centre (JRC) in their European Guidelines for the Assessment of Photovoltaic Plants and the IEC Standard 61724 does not estimate properly the potential array output of stand-alone photovoltaic (SAPV) systems without maximum power point tracker (MPPT) as it is the case for SAPV systems with MPPT and grid connected systems. In this way, the main purpose of this paper is to validate an expression that compromises simplicity and accuracy when estimating the potential array output of SAPV systems without MPPT. This issue can be of high interest to photovoltaic (PV) practitioners and experts as it can improve the analysis performance of this type of systems, helping to discriminate better the different losses in this kind of systems. Furthermore, a study of the array potential estimation through different expressions will be developed in order to evaluate which matches better the array potential output in SAPV system without MPPT. Although the analysis will be focused especially in Mediterranean climates, it will be derived some general conclusions that can be considered in other climates. (author)

  9. Comparison between solar utilization of a closed microalgae-based bio-loop and that of a stand-alone photovoltaic system.

    PubMed

    Jin, Qiang; Chen, Lei; Li, Aimin; Liu, Fuqiang; Long, Chao; Shan, Aidang; Borthwick, Alistair G L

    2015-05-01

    This study compared the solar energy utilization of a closed microalgae-based bio-loop for energy efficient production of biogas with fertilizer recovery against that of a stand-alone photovoltaic (PV) system. The comparison was made from the perspective of broad life cycle assessment, simultaneously taking exergy to be the functional unit. The results indicated that the bio-loop was more environmentally competitive than an equivalent stand-alone PV system, but had higher economic cost due to high energy consumption during the operational phase. To fix the problem, a patented, interior pressurization scheduling method was used to operate the bio-loop, with microalgae and aerobic bacterial placed together in the same reactor. As a result, the overall environmental impact and total investment were respectively reduced by more than 75% and 84%, a vast improvement on the bio-loop. PMID:25465781

  10. A new technique based on Artificial Bee Colony Algorithm for optimal sizing of stand-alone photovoltaic system

    PubMed Central

    Mohamed, Ahmed F.; Elarini, Mahdi M.; Othman, Ahmed M.

    2013-01-01

    One of the most recent optimization techniques applied to the optimal design of photovoltaic system to supply an isolated load demand is the Artificial Bee Colony Algorithm (ABC). The proposed methodology is applied to optimize the cost of the PV system including photovoltaic, a battery bank, a battery charger controller, and inverter. Two objective functions are proposed: the first one is the PV module output power which is to be maximized and the second one is the life cycle cost (LCC) which is to be minimized. The analysis is performed based on measured solar radiation and ambient temperature measured at Helwan city, Egypt. A comparison between ABC algorithm and Genetic Algorithm (GA) optimal results is done. Another location is selected which is Zagazig city to check the validity of ABC algorithm in any location. The ABC is more optimal than GA. The results encouraged the use of the PV systems to electrify the rural sites of Egypt. PMID:25685507

  11. A new technique based on Artificial Bee Colony Algorithm for optimal sizing of stand-alone photovoltaic system.

    PubMed

    Mohamed, Ahmed F; Elarini, Mahdi M; Othman, Ahmed M

    2014-05-01

    One of the most recent optimization techniques applied to the optimal design of photovoltaic system to supply an isolated load demand is the Artificial Bee Colony Algorithm (ABC). The proposed methodology is applied to optimize the cost of the PV system including photovoltaic, a battery bank, a battery charger controller, and inverter. Two objective functions are proposed: the first one is the PV module output power which is to be maximized and the second one is the life cycle cost (LCC) which is to be minimized. The analysis is performed based on measured solar radiation and ambient temperature measured at Helwan city, Egypt. A comparison between ABC algorithm and Genetic Algorithm (GA) optimal results is done. Another location is selected which is Zagazig city to check the validity of ABC algorithm in any location. The ABC is more optimal than GA. The results encouraged the use of the PV systems to electrify the rural sites of Egypt. PMID:25685507

  12. Standing alone with prosodic help*

    PubMed Central

    Frazier, Lyn; Clifton, Charles; Carlson, Katy; Harris, Jesse A.

    2013-01-01

    Two partially independent issues are addressed in two auditory rating studies: under what circumstances is a sub-string of a sentence identified as a stand-alone sentence, and under what circumstances do globally ill-formed but ‘locally coherent’ analyses (Tabor, Galantucci, & Richardson., 2004) emerge? A new type of locally coherent structure is established in Experiment 1, where a that-less complement clause is at least temporarily analyzed as a stand-alone sentence when it corresponds to a prosodic phrase. In Experiment 2, reduced relative clause structures like those in Tabor et al. were investigated. As in Experiment 1, the root sentence (mis-)analyses emerged most frequently when the locally coherent clause corresponded to a prosodic phrase. However, a substantial number of locally coherent analyses emerged even without prosodic help, especially in examples with for-datives (which do not grammatically permit a reduced relative clause structure for some speakers). Overall, the results suggest that prosodic grouping of constituents encourages analysis of a sub-string as a root sentence, and raise the question of whether all local coherence structures involve analysis of an utterance-final sub-string as a root sentence. PMID:24729648

  13. Stand-alone totally thoracoscopic left atrial appendage exclusion using a novel clipping system in patients with high risk of stroke – initial experience and literature review

    PubMed Central

    Suwalski, Piotr; Drobiński, Dominik; Rozbicka, Joanna; Sypuła, Sławomir; Liszka, Irena; Smoczyński, Radosław; Staromłyński, Jakub; Walecka, Irena; Kosior, Dariusz

    2015-01-01

    Introduction Atrial fibrillation (AF) is the most common clinically relevant arrhythmia and it is strongly associated with stroke. Left atrial appendage (LAA) is considered to be the most often source of thrombotic material. In recent decades a number surgical, percutaneous and hybrid approaches for LAA occlusion have been described revealing very different level of success and showing a variety of challenges associated with this matter. We present the first Polish experience with the stand-alone totally thoracoscopic LAA exclusion using novel clipping system. Material and methods Four patients (one male) in mean age of 74 (± 13) years with long-standing persistent and chronic AF were admitted for totally thoracoscopic LAA exclusion. All patients had significant comorbidities and the history of the oral anticoagulation intolerance or suboptimal/unstable level (CHA2DS2-VASC > 5, HAS_BLED > 3). Three procedures were performed through totally thoracoscopic access. In one patient due to massive adhesions in the left pleura we performed minithoracotomy in fourth left intercostal space. In two months follow-up we observed no mortality, no strokes and no bleedings. Results In all patient total exclusion of LAA with no residual remnant was confirmed. The “skin-to-skin” procedural time took on average 40, minimum 20 minutes. Patients were extubated directly or within two hours after procedure. All patients were discharged early in a good condition. Conclusions Our initial first experience with the novel totally thoracoscopic clipping system for stand-alone LAA exclusion is very promising showing very high efficacy and good safety profile. PMID:26855643

  14. Optimal design of proportional-integral controllers for stand-alone solid oxide fuel cell power plant using differential evolution algorithm.

    PubMed

    Ahmed, Ashik; Ullah, Md Shahid

    2016-01-01

    This paper proposes the application of differential evolution (DE) algorithm for the optimal tuning of proportional-integral (PI) controller designed to improve the small signal dynamic response of a stand-alone solid oxide fuel cell (SOFC) system. The small signal model of the study system is derived and considered for the controller design as the target here is to track small variations in SOFC load current. Two PI controllers are incorporated in the feedback loops of hydrogen and oxygen partial pressures with an aim to improve the small signal dynamic responses. The controller design problem is formulated as the minimization of an eigenvalue based objective function where the target is to find out the optimal gains of the PI controllers in such a way that the discrepancy of the obtained and desired eigenvalues are minimized. Eigenvalue and time domain simulations are presented for both open-loop and closed loop systems. To test the efficacy of DE over other optimization tools, the results obtained with DE are compared with those obtained by particle swarm optimization (PSO) algorithm and invasive weed optimization (IWO) algorithm. Three different types of load disturbances are considered for the time domain based results to investigate the performances of different optimizers under different sorts of load variations. Moreover, non-parametric statistical analyses, namely, one sample Kolmogorov-Smirnov (KS) test and paired sample t test are used to identify the statistical advantage of one optimizer over the other for the problem under study. The presented results suggest the supremacy of DE over PSO and IWO in finding the optimal solution. PMID:27066389

  15. Evaluation of a stand-alone computer-aided detection system for acute intra-cranial hemorrhage in emergency environments

    NASA Astrophysics Data System (ADS)

    Fernandez, James; Deshpande, Ruchi; Wang, Ximing; Liu, Brent; Brazaitis, Michael; Munter, Fletcher; Liu, Margaret

    2011-03-01

    Acute intra-cranial hemorrhage (AIH) may result from traumatic brain injury (TBI). Successful management of AIH depends heavily on the speed and accuracy of diagnosis. Timely diagnosis in emergency environments in both civilian and military settings is difficult primarily due to severe time restraints and lack of resources. Often, diagnosis is performed by emergency physicians rather than trained radiologists. As a result, added support in the form of computer-aided detection (CAD) would greatly enhance the decision-making process and help in providing faster and more accurate diagnosis of AIH. This paper discusses the implementation of a CAD system in an emergency environment, and its efficacy in aiding in the detection of AIH.

  16. Solar photovoltaics: Stand alone applications

    NASA Astrophysics Data System (ADS)

    Deyo, J. N.

    1980-11-01

    The Lewis Research Center involvement in space photovoltaic research and development and in using photovoltaics for terrestrial applications is described with emphasis on applications in which the normal source of power may be a diesel generator, batteries, or other types of power not connected to a utility grid. Once an application is processed, technology is developed and demonstrated with a user who participates in the cost and furnishes the site. Projects completed related to instruments, communication, refrigeration, and highways, are described as well as warning systems, weather stations, fire lookouts, and village power systems. A commercially available photovoltaic powered electric fence charger is the result of Lewis research and development.

  17. The Impact of Course Delivery Systems on Student Achievement and Sense of Community: A Comparison of Learning Community versus Stand-Alone Classroom Settings in an Open-Enrollment Inner City Public Community College

    ERIC Educational Resources Information Center

    Bandyopadhyay, Pamela

    2010-01-01

    This study examined the effects of two types of course delivery systems (learning community classroom environments versus stand-alone classroom environments) on the achievement of students who were simultaneously enrolled in remedial and college-level social science courses at an inner city open-enrollment public community college. This study was…

  18. DOE and AID stand-alone photovoltaic activities

    NASA Technical Reports Server (NTRS)

    Bifano, W. J.; Ratajczak, A. F.

    1983-01-01

    The NASA Lewis Research Center (LeRC) is managing stand-alone photovoltaic (PV) system activities sponsored by the U.S. Department of Energy (DOE) and the U.S. Agency for International Development (AID). The DOE project includes village PV power demonstration projects in Gabon (four sites) and the Marshall Islands, PV-powered medical refrigerators in six countries, PV system microprocessor control development activities and PV-hybrid system assessments. The AID project includes a large village system in Tunisia, a water pumping/grain grinding project in Upper Volta, five medical clinics in four countries, PV-powered remote earth station application. These PV activities and summarizes significant findings to data are reviewed.

  19. A Stand-Alone Demography and Landscape Structure Module for Earth System Models: Integration with Inventory Data from Temperate and Boreal Forests

    NASA Astrophysics Data System (ADS)

    Haverd, V. E.; Smith, B.; Nieradzik, L. P.; Briggs, P.

    2014-12-01

    Poorly constrained rates of biomass turnover are a key limitation of Earth system models (ESM). In light of this, we recently proposed a new approach encoded in a model called Populations-Order-Physiology (POP), for the simulation of woody ecosystem stand dynamics, demography and disturbance-mediated heterogeneity. POP is suitable for continental to global applications and designed for coupling to the terrestrial ecosystem component of any ESM. POP bridges the gap between first generation Dynamic Vegetation Models (DVMs) with simple large-area parameterisations of woody biomass (typically used in current ESMs) and complex second generation DVMs, that explicitly simulate demographic processes and landscape heterogeneity of forests. The key simplification in the POP approach, compared with second-generation DVMs, is to compute physiological processes such as assimilation at grid-scale (with CABLE or a similar land surface model), but to partition the grid-scale biomass increment among age classes defined at sub grid-scale, each subject to its own dynamics. POP was successfully demonstrated along a savanna transect in northern Australia, replicating the effects of strong rainfall and fire disturbance gradients on observed stand productivity and structure. Here, we extend the application of POP to a range of forest types around the globe, employing paired observations of stem biomass and density from forest inventory data to calibrate model parameters governing stand demography and biomass evolution. The calibrated POP model is then coupled to the CABLE land surface model and the combined model (CABLE-POP) is evaluated against leaf-stem allometry observations from forest stands ranging in age from 3 to 200 years. Results indicate that simulated biomass pools conform well with observed allometry. We conclude that POP represents an ecologically plausible and efficient alternative to large-area parameterisations of woody biomass turnover, typically used in current ESMs. Haverd, V., Smith, B., Briggs, P.R., Nieradzik, L.P, 2014. A stand-alone tree demography and landscape structure module for Earth system models: integeration with inventory data from temperate and boreal forests. Biogeosciences, 11: 1-17.

  20. A Power Regulation and Droop Mode Control Method for a Stand-Alone Load Fed from a PV-Current Source Inverter

    NASA Astrophysics Data System (ADS)

    Khayamy, Mehdy; Ojo, Olorunfemi

    2015-04-01

    A current source inverter fed from photovoltaic cells is proposed to power an autonomous load when operating under either power regulation or voltage and frequency drooping modes. Input-output linearization technique is applied to the overall nonlinear system to achieve a globally stable system under feasible operating conditions. After obtaining the steady-state model that demarcates the modes of operation, computer Simulation results for variations in irradiance and the load power of the controlled system are generated in which an acceptable dynamic response of the power generator system under the two modes of operation is observed.

  1. Broadly tunable, high-power terahertz radiation up to 73 K from a stand-alone Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+δ} mesa

    SciTech Connect

    Kitamura, T.; Watanabe, C.; Ishida, K.; Sekimoto, S.; Asanuma, K.; Yasui, T.; Nakade, K.; Shibano, Y.; Saiwai, Y.; Kashiwagi, T.; Minami, H.; Kadowaki, K.; Yamamoto, T.; Tsujimoto, M.; Klemm, R. A.

    2014-11-17

    High-power, continuous, broadly tunable THz radiation from 0.29 to 1.06 THz, was obtained from the outer current-voltage characteristic (IVC) branch of a single stand-alone mesa of the high-transition temperature T{sub c} superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+δ}. The particular metallic film structures placed both beneath and atop the mesas resulted in more efficient heat dissipation, higher allowed applied dc voltages, larger IVC loops, wider emission temperature ranges, and much broader emission frequency tunability than obtained previously.

  2. A control strategy for PV stand-alone applications

    NASA Astrophysics Data System (ADS)

    Slouma, S.; Baccar, H.

    2015-04-01

    This paper proposes a stand-alone photovoltaic (PV) system study in domestic applications. Because of the decrease in power of photovoltaic module as a consequence of changes in solar radiation and temperature which affect the photovoltaic module performance, the design and control of DC-DC buck converter was proposed for providing power to the load from a photovoltaic source.In fact, the control of this converter is carried out with integrated MPPT (Maximum Power Point Tracking) algorithm which ensures a maximum energy generated by the PV arrays. Moreover, the output stage is composed by a battery energy storage system, dc-ac inverter, LCL filter which enables higher efficiency, low distortion ac waveforms and low leakage currents. The control strategy adopted is cascade control composed by two regulation loops.Simulations performed with PSIM software were able to validate the control system.The realization and testing of the photovoltaic system were achieved in the Photovoltaic laboratory of the Centre for Research and Energy Technologies at the Technopark Borj Cedria. Experimental results verify the effeciency of the proposed system.

  3. Control of stand alone synchronous generators at optimum speed

    SciTech Connect

    Khor, J.G.; Cirstea, M.N.; McCormick, M.

    1998-07-01

    This paper describes the study and design of an electronic control system which allows diesel engine driven stand alone synchronous generators to operate at optimum speed. A control scheme which can isolate the final output frequency of the system from the effects of speed variations is simulated and designed. The proposed design aims to improve the efficiency of diesel engine driven generators by allowing optimum speed operation.

  4. Stand-alone sensors monitor for combustible gas leaks

    SciTech Connect

    Not Available

    1991-01-01

    Elizabeth Gas Co., a gas distribution company in New Jersey, has added a network of combustible gas sensors to a computer system already in place for continuous monitoring of gas leaks. The computer center at the company's Erie St. facility controls all dispatching, which includes routing gas through the system and controlling gas pressure. The system uses redundant Hewlett-Packard A900 central processing units (CPU), 6 monitors, including a Mitsubishi 35-in. color monitor, and Fisher control software. The company's primary tank farm, which contains over a million gallons of propane and LNG, is located near several chemical plants, an oil refinery and a residential neighborhood. To monitor for combustible leaks at the site, the company installed 49 stand-alone combustible gas sensors manufactured by Mine Safety Appliances Co. (MSA) of Pittsburgh, Pa. The sensors are designed to measure the concentrations of propane and LNG and trigger alarms at 20% of the lower explosive limit (LEL). The sensors are diffusion types that sample ambient air rather than drawing in samples through a pump. Using the principle of catalytic oxidation, the sensors produce a signal proportional to the concentration of combustible gas in the atmosphere. If gas is detected above 20% of the LEL, a relay driver signal is sent into a remote annunciator panel which contains LED alarm displays for each sensor. The remote annunciator panel also houses a 24 VDC power supply.

  5. Testing the stand-alone microbeam at Columbia University.

    PubMed

    Garty, G; Ross, G J; Bigelow, A W; Randers-Pehrson, G; Brenner, D J

    2006-01-01

    The stand-alone microbeam at Columbia University presents a novel approach to biological microbeam irradiation studies. Foregoing a conventional accelerator as a source of energetic ions, a small, high-specific-activity, alpha emitter is used. Alpha particles emitted from this source are focused using a compound magnetic lens consisting of 24 permanent magnets arranged in two quadrupole triplets. Using a 'home made' 6.5 mCi polonium source, a 1 alpha particle s(-1), 10 microm diameter microbeam can, in principle, be realised. As the alpha source energy is constant, once the microbeam has been set up, no further adjustments are necessary apart from a periodic replacement of the source. The use of permanent magnets eliminates the need for bulky power supplies and cooling systems required by other types of ion lenses and greatly simplifies operation. It also makes the microbeam simple and cheap enough to be realised in any large lab. The Microbeam design as well as first tests of its performance, using an accelerator-based beam are presented here. PMID:17189277

  6. Cruzan: clear and convincing? Missouri stands alone.

    PubMed

    Colby, W H

    1990-01-01

    In its September/October 1990 issue, the Hastings Center Report published six brief essays, with a short introduction by Courtney S. Campbell, under the collective title of "Cruzan: clear and convincing?" The individual authors and titles are: William H. Colby, "Missouri stands alone"; Pete Busalacchi, "How can they?"; Charles Baron, "On taking substituted judgment seriously"; John A. Robertson, "Cruzan: no rights violated"; Ronald E. Cranford, "A hostage to technology"; and Joanne Lynn and Jacqueline Glover, "Cruzan and caring for others." These articles present a range of responses from participants, parents, constitutional scholars, and caregivers to the U.S. Supreme Court's decision in Cruzan v. Director, Missouri Department of Health (June 25, 1990). William H. Colby is the attorney who represented the Cruzan family throughout its legal battle to have Nancy's feeding tube removed. PMID:2121666

  7. 45 CFR 155.1065 - Stand-alone dental plans.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 1 2014-10-01 2014-10-01 false Stand-alone dental plans. 155.1065 Section 155... Functions: Certification of Qualified Health Plans 155.1065 Stand-alone dental plans. (a) General...) Offering options. The Exchange may allow the dental plan to be offered (1) As a stand-alone dental...

  8. CAD-based stand-alone spacecraft radiation exposure analysis system: An application of the early man-tended Space Station

    NASA Astrophysics Data System (ADS)

    Appleby, M. H.; Golightly, M. J.; Hardy, A. C.

    Major improvements have been completed in the approach to analyses and simulation of spacecraft radiation shielding and exposure. A computer-aided design (CAD)-based system has been developed for determining the amount of shielding provided by a spacecraft and simulating transmission of an incident radiation environment to any point within or external to the vehicle. Shielding analysis is performed using a customized ray-tracing subroutine contained within a standard engineering modeling software package. This improved shielding analysis technique has been used in several vehicle design programs such as a Mars transfer habitat, pressurized lunar rover, and the redesigned international Space Station. Results of analysis performed for the Space Station astronaut exposure assessment are provided to demonastrate the applicability and versatility of the system.

  9. CAD-based stand-alone spacecraft radiation exposure analysis system: An application of the early man-tended Space Station

    NASA Technical Reports Server (NTRS)

    Appleby, M. H.; Golightly, M. J.; Hardy, A. C.

    1993-01-01

    Major improvements have been completed in the approach to analyses and simulation of spacecraft radiation shielding and exposure. A computer-aided design (CAD)-based system has been developed for determining the amount of shielding provided by a spacecraft and simulating transmission of an incident radiation environment to any point within or external to the vehicle. Shielding analysis is performed using a customized ray-tracing subroutine contained within a standard engineering modeling software package. This improved shielding analysis technique has been used in several vehicle design programs such as a Mars transfer habitat, pressurized lunar rover, and the redesigned international Space Station. Results of analysis performed for the Space Station astronaut exposure assessment are provided to demonastrate the applicability and versatility of the system.

  10. Multi-site evaluation of a computer aided detection (CAD) algorithm for small acute intra-cranial hemorrhage and development of a stand-alone CAD system ready for deployment in a clinical environment

    NASA Astrophysics Data System (ADS)

    Deshpande, Ruchi R.; Fernandez, James; Lee, Joon K.; Chan, Tao; Liu, Brent J.; Huang, H. K.

    2010-03-01

    Timely detection of Acute Intra-cranial Hemorrhage (AIH) in an emergency environment is essential for the triage of patients suffering from Traumatic Brain Injury. Moreover, the small size of lesions and lack of experience on the reader's part could lead to difficulties in the detection of AIH. A CT based CAD algorithm for the detection of AIH has been developed in order to improve upon the current standard of identification and treatment of AIH. A retrospective analysis of the algorithm has already been carried out with 135 AIH CT studies with 135 matched normal head CT studies from the Los Angeles County General Hospital/ University of Southern California Hospital System (LAC/USC). In the next step, AIH studies have been collected from Walter Reed Army Medical Center, and are currently being processed using the AIH CAD system as part of implementing a multi-site assessment and evaluation of the performance of the algorithm. The sensitivity and specificity numbers from the Walter Reed study will be compared with the numbers from the LAC/USC study to determine if there are differences in the presentation and detection due to the difference in the nature of trauma between the two sites. Simultaneously, a stand-alone system with a user friendly GUI has been developed to facilitate implementation in a clinical setting.

  11. 45 CFR 155.1065 - Stand-alone dental plans.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 1 2013-10-01 2013-10-01 false Stand-alone dental plans. 155.1065 Section 155... Functions: Certification of Qualified Health Plans § 155.1065 Stand-alone dental plans. (a) General... QHP certification standards, including § 155.1020(c), except for any certification requirement...

  12. 45 CFR 155.1065 - Stand-alone dental plans.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 1 2012-10-01 2012-10-01 false Stand-alone dental plans. 155.1065 Section 155... Functions: Certification of Qualified Health Plans § 155.1065 Stand-alone dental plans. (a) General... QHP certification standards, including § 155.1020(c), except for any certification requirement...

  13. 39 CFR 122.2 - Stand-alone special services.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 39 Postal Service 1 2012-07-01 2012-07-01 false Stand-alone special services. 122.2 Section 122.2 Postal Service UNITED STATES POSTAL SERVICE POST OFFICE SERVICES SERVICE STANDARDS FOR MARKET-DOMINANT SPECIAL SERVICES PRODUCTS 122.2 Stand-alone special services. (a) The service standard for P. O....

  14. 29 CFR 778.104 - Each workweek stands alone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 3 2011-07-01 2011-07-01 false Each workweek stands alone. 778.104 Section 778.104 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR STATEMENTS OF GENERAL... Requirements Introductory 778.104 Each workweek stands alone. The Act takes a single workweek as its...

  15. 29 CFR 778.104 - Each workweek stands alone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 3 2013-07-01 2013-07-01 false Each workweek stands alone. 778.104 Section 778.104 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR STATEMENTS OF GENERAL... Requirements Introductory 778.104 Each workweek stands alone. The Act takes a single workweek as its...

  16. 29 CFR 778.104 - Each workweek stands alone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 3 2012-07-01 2012-07-01 false Each workweek stands alone. 778.104 Section 778.104 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR STATEMENTS OF GENERAL... Requirements Introductory 778.104 Each workweek stands alone. The Act takes a single workweek as its...

  17. 29 CFR 778.104 - Each workweek stands alone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Each workweek stands alone. 778.104 Section 778.104 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR STATEMENTS OF GENERAL... Requirements Introductory 778.104 Each workweek stands alone. The Act takes a single workweek as its...

  18. 39 CFR 122.2 - Stand-alone special services.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 39 Postal Service 1 2013-07-01 2013-07-01 false Stand-alone special services. 122.2 Section 122.2 Postal Service UNITED STATES POSTAL SERVICE POST OFFICE SERVICES SERVICE STANDARDS FOR MARKET-DOMINANT SPECIAL SERVICES PRODUCTS 122.2 Stand-alone special services. (a) The service standard for P. O....

  19. 29 CFR 778.104 - Each workweek stands alone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 3 2014-07-01 2014-07-01 false Each workweek stands alone. 778.104 Section 778.104 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR STATEMENTS OF GENERAL... Requirements Introductory 778.104 Each workweek stands alone. The Act takes a single workweek as its...

  20. 39 CFR 122.2 - Stand-alone special services.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 39 Postal Service 1 2014-07-01 2014-07-01 false Stand-alone special services. 122.2 Section 122.2 Postal Service UNITED STATES POSTAL SERVICE POST OFFICE SERVICES SERVICE STANDARDS FOR MARKET-DOMINANT SPECIAL SERVICES PRODUCTS 122.2 Stand-alone special services. (a) The service standard for P. O....

  1. Executive Summary of The Use of Educational Software in Adult Literacy Programs: A Comparison of Integrated Learning Systems and Stand-Alone Software=Resume du Rapport Intitule: L'Utilisation de Didacticiels dans les Programmes d'Alphabetisation des Adultes: Une Comparaison Entre les Systemes Integres d'Apprentissage et les Logiciels Autonomes.

    ERIC Educational Resources Information Center

    Millar, Diane

    The pros and cons of integrated learning systems (ILS) and stand-alone software for adult literacy instruction were examined in a comparative analysis that focused on their use in adult literacy programs in Canada. The comparison focused on the following variables: achievement gains in reading; changes in students' attitudes toward computers;…

  2. Executive Summary of The Use of Educational Software in Adult Literacy Programs: A Comparison of Integrated Learning Systems and Stand-Alone Software=Resume du Rapport Intitule: L'Utilisation de Didacticiels dans les Programmes d'Alphabetisation des Adultes: Une Comparaison Entre les Systemes Integres d'Apprentissage et les Logiciels Autonomes.

    ERIC Educational Resources Information Center

    Millar, Diane

    The pros and cons of integrated learning systems (ILS) and stand-alone software for adult literacy instruction were examined in a comparative analysis that focused on their use in adult literacy programs in Canada. The comparison focused on the following variables: achievement gains in reading; changes in students' attitudes toward computers;

  3. Efficient line-connected voltage-conditioner with minimum disturbance transfer to stand-alone mode

    NASA Astrophysics Data System (ADS)

    Baronijan, Armen

    1998-12-01

    This thesis deals with a novel efficient line-connected voltage-conditioning system (VCS) with minimum disturbance transfer to stand-alone mode. The proposed VCS is used for conditioning a terminal voltage of the critical load on the equipment level. It offers advantages over a conventional rectifier-inverter system in terms of efficiency/harmonic generation and over existing line-connected systems in terms of transfer time/dynamic response. To the author's best knowledge, the concept of a solid-state breaker realized with the controlled turn-on/turn-off switch has been introduced for the first time in this thesis. By using the proposed power converter topology, controller structure independent of the load parameters and line-disturbance detection method, the system conforms to the different susceptibility requirements of the critical equipment. A detailed power circuit and controller description of the proposed current-source-inverter voltage-conditioning system (CSI-VCS) are given. A steady-state analysis of the proposed system is performed including the higher order harmonics. A system controller is designed in order to achieve the two objectives that follow. The first objective is to provide the fast transfer from the line-connected mode to the stand-alone mode in the case of line disturbance. The second objective is to obtain the fast transient response under load disturbance and to provide, in the steady-state, the output voltage of low total harmonic distortion. Proposed is one algorithm for synchronization to the line voltage fully implemented in software. A novel line-voltage. disturbance detection scheme is developed and implemented in software. A 1kVA DSP-controlled laboratory prototype is built to verify the theoretically obtained results. A systematic design procedure and design example are presented and validated using a computer simulation.

  4. Stand-Alone Cages for Anterior Cervical Fusion: Are There No Problems?

    PubMed Central

    Han, Sang Youp; Lee, Cheol Young; Kim, Hong Rye; Park, Dong Ho

    2016-01-01

    Objective There are complications in stand-alone cage assisted anterior cervical discectomy and fusion (ACDF), such as cage subsidence and kyphosis. Here we report our clinical result on ACDF, comparing with stand-alone cages and with cervical plate system for degenerative cervical spine diseases. Methods Patients with degenerative cervical disease who were diagnosed and treated in Konyang University Hospital between January 2004 and December 2014 were included in this study. Patients who had operation in single level ACDF were selected. Patients scored the degree of pain using visual analog scale before and after the surgery. Subsidence was defined as ≥3-mm decrease of the segmental height, and cervical kyphosis was defined as progression of ≥5° at 12 months after postoperative follow-up compared to that measured at the immediate postoperative period. Results A total of 81 patients were enrolled for this study. Forty-five patients were included in a cervical plate group and the others were in stand-alone cage group. There was no statistical difference in pain score between the 2 groups. Segmental subsidence was observed in 7 patients (15.6%) in plate-assisted cervical fusion group, and 13 patients (36.1%) in stand-alone cage group. Segmental kyphosis was observed in 4 patients (8.9%) in plate-assisted cervical fusion group, and 10 patients (27.8%) in stand-alone cage group. There was statistical difference between the 2 groups. Conclusion There was no difference in pain between 2 groups. But stand-alone case group showed higher incidence rate than plate-assisted cervical fusion group in segmental subsidence and cervical kyphosis. When designing cervical fusion, more attention should be given selecting the surgical technique. PMID:27123025

  5. The Stand-Alone Pressure Measurement Device, a digital memory telemeter for assessing Shuttle structural dynamics

    NASA Astrophysics Data System (ADS)

    Havey, Gary; Tanji, Todd; Olson, Richard; Wald, Jerry

    The Stand-Alone Pressure Measurement Device (SAPMD) is a microminiaturized recorder which has in association with the requisite miniature sensor been used to collect absolute Space Shuttle pressure data over various points of the Orbiter's surface during ascent. The SAPMD is entirely self-contained, incorporating its own sensor, power supply, self-starting sensor, nonvolatile memory for sensor data, and a real-time clock for time reference; it is also sufficiently small, at 6.28 x 1.5 x 0.5 in., to be mounted beneath The Shuttle Orbiter's thermal protection system tiles. Data acquired during Shuttle ascent is recovered after the mission without removal of the SAPMD. Strain gages, vibration gages, and differential pressure gages can be incorporated by the device.

  6. 39 CFR 122.2 - Stand-alone special services.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Postal Service UNITED STATES POSTAL SERVICE POST OFFICE SERVICES SERVICE STANDARDS FOR MARKET-DOMINANT SPECIAL SERVICES PRODUCTS § 122.2 Stand-alone special services. (a) The service standard for P. O. BoxTM...” publicly posted at the Post OfficeTM location that includes the box section. (b) The service standard...

  7. 39 CFR 122.2 - Stand-alone special services.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Postal Service UNITED STATES POSTAL SERVICE POST OFFICE SERVICES SERVICE STANDARDS FOR MARKET-DOMINANT SPECIAL SERVICES PRODUCTS § 122.2 Stand-alone special services. (a) The service standard for P. O. BoxTM...” publicly posted at the Post OfficeTM location that includes the box section. (b) The service standard...

  8. Stand-alone LLIF Lateral Cage Migration: A Case Report.

    PubMed

    Towers, Wendy S; Kurtom, Khalid H

    2015-01-01

    Lateral approaches to the lumbar disc space have become popular in recent years with very few reported complications. We report on a rare case of a stand-alone cage migration. A 77-year-old female presented with a right L2-3 radiculopathy that was refractory to maximum medical management. This was secondary to foraminal compression at L2-3 and L3-4 due to degenerative disc disease and levoscoliosis, as well as Grade 1 spondylolisthesis at both levels. A left-sided approach lateral lumbar interbody fusion was performed at L2-3 and L3-4 using a lordotic polyetheretherketone (PEEK) graft (50 mm length x 18 mm width x 9 mm height) packed with demineralized bone matrix (DBM). A contralateral release of the annulus fibrosis was performed during the decompression prior to graft insertion. Postoperative anteroposterior and lateral x-ray imaging confirmed good position of interbody grafts, correction of scoliosis as well as spondylolisthesis, and restoration of disc height achieving foraminal indirect decompression. A routine postoperative x-ray at three months demonstrated asymptomatic ipsilateral cage migration at the L2-3 level with evidence of arthrodesis in the disc space. This was managed conservatively without further surgical intervention. Placement of a lateral plate or interbody intradiscal plating system in patients with scoliosis and significant coronal deformity is an option that can be considered to prevent this rare LLIF complication. Moreover, asymptomatic cage migration may be conservatively managed without reoperation. PMID:26623202

  9. 21 CFR 801.50 - Labeling requirements for stand-alone software.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Labeling requirements for stand-alone software....50 Labeling requirements for stand-alone software. (a) Stand-alone software that is not distributed... in packaged form, stand-alone software regulated as a medical device must provide its unique...

  10. Hanford tank initiative cone penetrometer stand alone grouting module

    SciTech Connect

    CALLAWAY, W.S.

    1998-10-15

    The HTI subsurface characterization task will use the Hanford Cone Penetrometer platform (CPP) to deploy contaminant sensor and soil sampling probes into the vadose zone surrounding SST 241-AX-104. Closure of the resulting penetration holes may be stipulated by WAC requirements. A stand alone grouting capability deployable by the CPP has been developed. This qualification test plan defines testing of this capability to be performed at the Immobilized Low Activity Waste Disposal Complex.

  11. Fuzzy logic multiobjective optimization for stand-alone photovoltaic plants

    SciTech Connect

    Tina, G.; Adorno, G.; Ragusa, C.

    1998-07-01

    The power generation by renewable energy sources involves a wide series of technical and economic problems, which condition its applications on a vast scale. Photovoltaic power generation presents many problems hardly to solve, such as: high cost in generating power and the power quality. In this background it is to insert the topic of optimal dimensioning of the PV power plants, meaning the achievement of an acceptable compromise between the power quality and the plant costs. This problem affects above all the small and medium size plants, such as: stand-alone PV domestic supply, where an incorrect dimensioning may cause difficulties to the functionality of the plant or higher costs. In this paper a method of optimal dimensioning of a PV power plant with battery storage is shown, but it is suitable to optimise also hybrid plants, which are based on the simultaneous presence of other and different energy sources. The project variables are the area and tilt of the PV modules and the accumulator capacity, whereas the project quality indexes (the objects to optimise) are the total plant cost and the supplied ratio of the electrical load. The calculation of the total ratio of load supplied was tackled using the availability method, which seems to be the one which best allows to make a long-term forecast, because of the systematic experimental studies over the last forty years and because of it correlates the solar radiation variability in the course of the day and of the year with the producible power. The economic cost has been calculated considering the plant's technical life, referring to current money all the future costs (by LCC, Life-Cycle Costing, method) and annualising them (by ALCC, Annualise Life-Cycle Costing, method) in order to obtain a total cost per kWh to compare with other power source costs. Particularly, the PV plant's cost has been related to the ALCC cost in case of supplying the electrical load connected to national grid. Since the objects of optimisation compete, it is applied a multiobjective optimisation technique, based on the fuzzy-logic theory. This technique requires to represent every optimisation object by a fuzzy-set which expresses the connection between the objects' value and the corresponding degree of satisfaction. In conclusion, the definition of a global fuzzy-set, which expresses the confluence between these values, allows to fix a single quality index to every project configuration. The discretion of the planner's selection has been fixed by the belonging functions to fuzzy-sets. These functions try to weigh, for every object, the judgement's classes, by themselves inaccurate, such as the concepts of satisfaction (referring to the power quality object) and of acceptable (referring to the cost object). The quality index, obtained in this way, reaches its maximum value using a deterministic scalar optimisation procedure, which leads the evolution of the project variables towards the best configuration. The optimisation method has been tested considering different kinds of site configurations with different values of the electrical loads, of the yearly power demand, of the distance from the grid and of the variable solar cells cost.

  12. Magnetic field measurements near stand-alone transformer stations.

    PubMed

    Kandel, Shaiela; Hareuveny, Ronen; Yitzhak, Nir-Mordechay; Ruppin, Raphael

    2013-12-01

    Extremely low-frequency (ELF) magnetic field (MF) measurements around and above three stand-alone 22/0.4-kV transformer stations have been performed. The low-voltage (LV) cables between the transformer and the LV switchgear were found to be the major source of strong ELF MFs of limited spatial extent. The strong fields measured above the transformer stations support the assessment method, to be used in future epidemiological studies, of classifying apartments located right above the transformer stations as highly exposed to MFs. The results of the MF measurements above the ground around the transformer stations provide a basis for the assessment of the option of implementing precautionary procedures. PMID:23836796

  13. 49 CFR 1111.8 - Procedural schedule in stand-alone cost cases.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 8 2013-10-01 2013-10-01 false Procedural schedule in stand-alone cost cases... 1111.8 Procedural schedule in stand-alone cost cases. (a) Procedural schedule. Absent a specific order by the Board, the following general procedural schedule will apply in stand-alone cost cases: Day...

  14. 49 CFR 1111.8 - Procedural schedule in stand-alone cost cases.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 8 2012-10-01 2012-10-01 false Procedural schedule in stand-alone cost cases... 1111.8 Procedural schedule in stand-alone cost cases. (a) Procedural schedule. Absent a specific order by the Board, the following general procedural schedule will apply in stand-alone cost cases: Day...

  15. 49 CFR 1111.8 - Procedural schedule in stand-alone cost cases.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 8 2014-10-01 2014-10-01 false Procedural schedule in stand-alone cost cases... 1111.8 Procedural schedule in stand-alone cost cases. (a) Procedural schedule. Absent a specific order by the Board, the following general procedural schedule will apply in stand-alone cost cases: Day...

  16. 45 CFR 156.150 - Application to stand-alone dental plans inside the Exchange.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 1 2014-10-01 2014-10-01 false Application to stand-alone dental plans inside the... STANDARDS RELATED TO EXCHANGES Essential Health Benefits Package 156.150 Application to stand-alone dental plans inside the Exchange. (a) Annual limitation on cost-sharing. For a stand-alone dental plan...

  17. 49 CFR 1111.8 - Procedural schedule in stand-alone cost cases.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 8 2011-10-01 2011-10-01 false Procedural schedule in stand-alone cost cases... 1111.8 Procedural schedule in stand-alone cost cases. (a) Procedural schedule. Absent a specific order by the Board, the following general procedural schedule will apply in stand-alone cost cases: Day...

  18. 45 CFR 156.150 - Application to stand-alone dental plans inside the Exchange.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 1 2013-10-01 2013-10-01 false Application to stand-alone dental plans inside the... STANDARDS RELATED TO EXCHANGES Essential Health Benefits Package 156.150 Application to stand-alone dental plans inside the Exchange. (a) Annual limitation on cost-sharing. A stand-alone dental plan covering...

  19. A Task-Oriented Framework for Stand-Alone Technology Integration Classes

    ERIC Educational Resources Information Center

    Hammond, Thomas C.

    2007-01-01

    A long-standing challenge for schools of education is how to prepare teachers to effectively integrate technology into classroom instruction. A widespread practice in training preservice teachers is the stand-alone technology class. These classes have evolved over time. This article suggests a further development in stand-alone technology classes:…

  20. Stand-alone microprocessor controlled fast sweep Langmuir probe driver

    NASA Astrophysics Data System (ADS)

    Cheetham, A. D.; Davidson, L.; Jakobsen, J.; Lund, T.; Rayner, J. P.

    1997-09-01

    This article describes a power supply and data logger for a Langmuir probe interfaced to a personal computer. The system provides a voltage sweep range from -125 to +100 V in 100 steps in a time ˜0.15 s. Restricted sweep ranges and single point operation are also possible. Probe current measurements are in the range from -1.0 to +100 mA with a precision of 5 μA on the most sensitive range, while the voltage may be set with a precision of 56 mV. Novel features of the system include: the use of integrate-and-dump techniques to implement the process of analog-to-digital conversion and to provide effective noise suppression; a solution to the problem of floating the power supply on top of the potential developed across the grounded current sensing resistor based on the power supply rejection ratio characteristics of a high voltage operational amplifier; and the development of an interface and control board employing the GPIB protocol to communicate with a host computer. Successful operation of the system has been demonstrated in the electrically noisy environment of a helicon plasma source.

  1. Study of Stand-Alone Microgrid under Condition of Faults on Distribution Line

    NASA Astrophysics Data System (ADS)

    Malla, S. G.; Bhende, C. N.

    2014-10-01

    The behavior of stand-alone microgrid is analyzed under the condition of faults on distribution feeders. During fault since battery is not able to maintain dc-link voltage within limit, the resistive dump load control is presented to do so. An inverter control is proposed to maintain balanced voltages at PCC under the unbalanced load condition and to reduce voltage unbalance factor (VUF) at load points. The proposed inverter control also has facility to protect itself from high fault current. Existing maximum power point tracker (MPPT) algorithm is modified to limit the speed of generator during fault. Extensive simulation results using MATLAB/SIMULINK established that the performance of the controllers is quite satisfactory under different fault conditions as well as unbalanced load conditions.

  2. Real-time GPS seismology with a stand-alone receiver: A preliminary feasibility demonstration

    NASA Astrophysics Data System (ADS)

    Colosimo, G.; Crespi, M.; Mazzoni, A.

    2011-11-01

    We show the feasibility of a real-time estimation of waveforms and coseismic displacements, within a few centimeters in accuracy, with a stand-alone dual-frequency Global Positioning System (GPS) receiver using a so-called "variometric" approach. The approach is based on time single-differences of carrier phase observations collected at a high-rate (1 Hz or more) using a stand-alone receiver, and on standard GPS broadcast products (orbits and clocks), which are ancillary information routinely available in real time. In the approach, first, the time series of epoch-by-epoch displacements are estimated. Then, provided that the collected observations are continuous, they can be summed over the interval (limited to a few minutes) over which an earthquake occurs. Since epoch-by-epoch displacements divided by the interval between consecutive epochs are essentially equal to the epoch-by-epoch velocities, this is equivalent to saying that we are using the GPS receiver as a velocimeter. Estimation biases, due to the possible mismodeling of various intervening effects (such as multipath, residual clock errors, orbit errors, and atmospheric errors), accumulate over time and display their signature as a trend in coseismic displacements. The trend can be considered linear and easily removed, at least for short intervals. Since the proposed approach (named VADASE (Variometric Approach for Displacements Analysis Stand-alone Engine)) does not require either additional technological complexity or a centralized data analysis, in principle it can be embedded into GPS receiver firmware, thereby providing a significant contribution to tsunami warning and other hazard assessment systems. After a preliminary test using a simulated example, the effectiveness of this approach was proven using real data. We analyzed the 1 Hz GPS data recorded by the International Global Navigation Satellite Systems Service station BREW during the Denali Fault, Alaska, earthquake (Mw 7.9, 3 November, 2002, 22:12:41 UTC), as well as the 5 Hz data collected by some of the stations of the University NAVSTAR Consortium-Plate Boundary Observatory network and the California Real Time Network during the Baja California, Mexico, earthquake (Mw 7.2, 4 April, 2010, 22:40:42 UTC). Comparisons of the results obtained using VADASE, as well as other already well-established approaches, displayed agreement to within a few centimeters.

  3. A simple model for the energy supply of a stand-alone house using a hybrid wind-solar power system

    NASA Astrophysics Data System (ADS)

    Beke, Tamas

    2016-01-01

    A research project for secondary school students involving both physical measurements and modelling is presented. The problem to be solved is whether and how a typical house can be supplied with energy off-grid, based entirely on renewable energy sources, more specifically, on solar and wind energy, while using relatively simple devices, namely, photovoltaic modules, wind turbines and accumulators. To this end our students carried out a long term measurement series in order to assess the typical energy consumption of houses. Further, the number of solar modules and wind turbines, and the necessary accumulator capacity, was estimated.

  4. Stand Alone Pressure Measurement Device (SAPMD) for the space shuttle Orbiter, part 2

    NASA Technical Reports Server (NTRS)

    Tomlinson, Bill

    1989-01-01

    The Stand Alone Pressure Measurement Device (SAPMD) specifications are examined. The HP.SAPMD GSE software is listed; the HP/SGA readme program is presented; and the SPMD acceptance test procedure is described.

  5. She stands alone: Pakistani woman film director, Shireen Pasha.

    PubMed

    Mustafa, A

    1995-01-01

    This article describes the activities of film director Shireen Pasha in promoting truth in the mass media in Pakistan. Pasha is described as one who finds it inexcusable in a state-subsidized system that national problems of poverty are not aired openly. Pasha has pursued the goal of exposing the real lives of Pakistanis on film in contrast to the publicly aired segments of "pretty girls in nice drawing rooms." Foreign channels available through satellite communications technology are viewed by Pasha as inappropriate with regard to people's needs and uncreative. Pakistan began with one channel, PTV, which recently refused to air her documentary on living conditions in Pakistan's rural areas "The Travelogue Pakistan." "The Walled City of Lahore" was her film about life in the old city. Both films poetically depicted the honor of humans and their struggle to stay alive. Some of her documentaries are made to show the value of indigenous skills, centuries old know-how, and traditions, regardless of the poverty. Pasha is described as fighting with PTV management over use of resources. Pasha desires to invest in training people to do documentaries or be more field-oriented rather than investing in equipment. Pasha joined PTV in 1975 and left in 1990. Pasha is recognized for her isolation as a woman in the business world, her commitment to exposing remote cultures and truth, and the odds she must confront in attaining her goals. Pasha is committed to doing extensive research, usually conducted during the summer months, in order to construct a credible story line that is produced usually during the winter months. One model of film story line is defined as one where women are portrayed as starting from an indigenous skill or knowledge and shifting to a greater position of power and control over their lives. Pasha believes that people who make films have the responsibility to evoke a reaction in people and to offer solutions. Two acclaimed films, which were supported by USAID and the government, were "Before It's Too Late" and "Only One Way." Both deal with resource issues and the environment. She is currently director of her own film house, The Film Makers, in Lahore. After graduating from the National College of Arts in 1968, she furthered her education in the US in the history of art. PMID:12290699

  6. Market assessment of photovoltaic power systems for agricultural applications in Nigeria

    NASA Technical Reports Server (NTRS)

    Staples, D.; Steingass, H.; Nolfi, J.

    1981-01-01

    The market potential for stand-alone photovoltaic systems in agriculture was studied. Information is presented on technical and economically feasible applications, and assessments of the business, government and financial climate for photovoltaic sales. It is concluded that the market for stand-alone systems will be large because of the availability of captial and the high premium placed on high reliability, low maintenance power systems. Various specific applications are described, mostly related to agriculture.

  7. Non-union rate with stand-alone lateral lumbar interbody fusion.

    PubMed

    Watkins, Robert; Watkins, Robert; Hanna, Robert

    2014-12-01

    Retrospective radiographic analysis.To determine the fusion rate of stand-alone lateral lumbar interbody fusion (LLIF). Biomechanical studies have indicated that LLIF may be more stable than anterior or transforaminal lumbar interbody fusion. Early clinical reports of stand-alone LLIF have shown success in obtaining fusion and indirectly decompressing nerve roots. A consecutive case series of stand-alone LLIF was analyzed with chart and radiographic review. Non-union was determined by symptomatology consistent with non-union and absence of bridging bone on the CT scan. Thirty-nine levels of stand alone LLIF were performed in 23 patients. Eleven patients received 1-level surgery, 7 patients received 2-level surgery, 3 patients received 3-level surgery, and 1 patient received 4-level surgery. Excluding 1 infected case, we analyzed 37 levels of stand alone LLIF in 22 patients. Non-union incidence was 7 levels in 6 patients. Non-union rate was 7/37 (19%) per level and 6/22 (27%) per patient. While our study population was relatively low, a non-union rate of 19% to 27% is concerning for modern spine surgery. Currently in our practice, we occasionally still perform stand-alone LLIF utilizing 22 mm wide grafts in low-demand levels in non-smoking and non-osteoporotic patients. However, in a majority of patients, we provide supplemental fixation: bilateral pedicle screws in most patients and unilateral pedicle screws or spinous process plates in some patients. PMID:25546670

  8. Non-Union Rate With Stand-Alone Lateral Lumbar Interbody Fusion

    PubMed Central

    Watkins, Robert; Watkins, Robert; Hanna, Robert

    2014-01-01

    Abstract Retrospective radiographic analysis. To determine the fusion rate of stand-alone lateral lumbar interbody fusion (LLIF). Biomechanical studies have indicated that LLIF may be more stable than anterior or transforaminal lumbar interbody fusion. Early clinical reports of stand-alone LLIF have shown success in obtaining fusion and indirectly decompressing nerve roots. A consecutive case series of stand-alone LLIF was analyzed with chart and radiographic review. Non-union was determined by symptomatology consistent with non-union and absence of bridging bone on the CT scan. Thirty-nine levels of stand alone LLIF were performed in 23 patients. Eleven patients received 1-level surgery, 7 patients received 2-level surgery, 3 patients received 3-level surgery, and 1 patient received 4-level surgery. Excluding 1 infected case, we analyzed 37 levels of stand alone LLIF in 22 patients. Non-union incidence was 7 levels in 6 patients. Non-union rate was 7/37 (19%) per level and 6/22 (27%) per patient. While our study population was relatively low, a non-union rate of 19% to 27% is concerning for modern spine surgery. Currently in our practice, we occasionally still perform stand-alone LLIF utilizing 22 mm wide grafts in low-demand levels in non-smoking and non-osteoporotic patients. However, in a majority of patients, we provide supplemental fixation: bilateral pedicle screws in most patients and unilateral pedicle screws or spinous process plates in some patients. PMID:25546670

  9. Performance evaluation of stand alone hybrid PV-wind generator

    NASA Astrophysics Data System (ADS)

    Nasir, M. N. M.; Saharuddin, N. Z.; Sulaima, M. F.; Jali, Mohd Hafiz; Bukhari, W. M.; Bohari, Z. H.; Yahaya, M. S.

    2015-05-01

    This paper presents the performance evaluation of standalone hybrid system on Photovoltaic (PV)-Wind generator at Faculty of Electrical Engineering (FKE), UTeM. The hybrid PV-Wind in UTeM system is combining wind turbine system with the solar system and the energy capacity of this hybrid system can generate up to charge the battery and supply the LED street lighting load. The purpose of this project is to evaluate the performance of PV-Wind hybrid generator. Solar radiation meter has been used to measure the solar radiation and anemometer has been used to measure the wind speed. The effectiveness of the PV-Wind system is based on the various data that has been collected and compared between them. The result shows that hybrid system has greater reliability. Based on the solar result, the correlation coefficient shows strong relationship between the two variables of radiation and current. The reading output current followed by fluctuate of solar radiation. However, the correlation coefficient is shows moderate relationship between the two variables of wind speed and voltage. Hence, the wind turbine system in FKE show does not operate consistently to produce energy source for this hybrid system compare to PV system. When the wind system does not fully operate due to inconsistent energy source, the other system which is PV will operate and supply the load for equilibrate the extra load demand.

  10. Performance evaluation of stand alone hybrid PV-wind generator

    SciTech Connect

    Nasir, M. N. M.; Saharuddin, N. Z.; Sulaima, M. F.; Jali, Mohd Hafiz; Bukhari, W. M.; Bohari, Z. H.; Yahaya, M. S.

    2015-05-15

    This paper presents the performance evaluation of standalone hybrid system on Photovoltaic (PV)-Wind generator at Faculty of Electrical Engineering (FKE), UTeM. The hybrid PV-Wind in UTeM system is combining wind turbine system with the solar system and the energy capacity of this hybrid system can generate up to charge the battery and supply the LED street lighting load. The purpose of this project is to evaluate the performance of PV-Wind hybrid generator. Solar radiation meter has been used to measure the solar radiation and anemometer has been used to measure the wind speed. The effectiveness of the PV-Wind system is based on the various data that has been collected and compared between them. The result shows that hybrid system has greater reliability. Based on the solar result, the correlation coefficient shows strong relationship between the two variables of radiation and current. The reading output current followed by fluctuate of solar radiation. However, the correlation coefficient is shows moderate relationship between the two variables of wind speed and voltage. Hence, the wind turbine system in FKE show does not operate consistently to produce energy source for this hybrid system compare to PV system. When the wind system does not fully operate due to inconsistent energy source, the other system which is PV will operate and supply the load for equilibrate the extra load demand.

  11. Stand-Alone and Hybrid Positioning Using Asynchronous Pseudolites

    PubMed Central

    Gioia, Ciro; Borio, Daniele

    2015-01-01

    global navigation satellite system (GNSS) receivers are usually unable to achieve satisfactory performance in difficult environments, such as open-pit mines, urban canyons and indoors. Pseudolites have the potential to extend GNSS usage and significantly improve receiver performance in such environments by providing additional navigation signals. This also applies to asynchronous pseudolite systems, where different pseudolites operate in an independent way. Asynchronous pseudolite systems require, however, dedicated strategies in order to properly integrate GNSS and pseudolite measurements. In this paper, several asynchronous pseudolite/GNSS integration strategies are considered: loosely- and tightly-coupled approaches are developed and combined with pseudolite proximity and receiver signal strength (RSS)-based positioning. The performance of the approaches proposed has been tested in different scenarios, including static and kinematic conditions. The tests performed demonstrate that the methods developed are effective techniques for integrating heterogeneous measurements from different sources, such as asynchronous pseudolites and GNSS. PMID:25609041

  12. Stand-alone and hybrid positioning using asynchronous pseudolites.

    PubMed

    Gioia, Ciro; Borio, Daniele

    2015-01-01

    global navigation satellite system (GNSS) receivers are usually unable to achieve satisfactory performance in difficult environments, such as open-pit mines, urban canyons and indoors. Pseudolites have the potential to extend GNSS usage and significantly improve receiver performance in such environments by providing additional navigation signals. This also applies to asynchronous pseudolite systems, where different pseudolites operate in an independent way. Asynchronous pseudolite systems require, however, dedicated strategies in order to properly integrate GNSS and pseudolite measurements. In this paper, several asynchronous pseudolite/GNSS integration strategies are considered: loosely- and tightly-coupled approaches are developed and combined with pseudolite proximity and receiver signal strength (RSS)-based positioning. The performance of the approaches proposed has been tested in different scenarios, including static and kinematic conditions. The tests performed demonstrate that the methods developed are effective techniques for integrating heterogeneous measurements from different sources, such as asynchronous pseudolites and GNSS. PMID:25609041

  13. Stand-alone solar residence and solar electric auto

    SciTech Connect

    Reuyl, J.S.

    1980-01-01

    In a system design recently patented (US Patent No. 4,182,960, Integrated Residential and Automotive (Solar) Energy System, issued January 8, 1980). a passive solar residence first is equipped with photovoltaic arrays to charge both the residence and an electric auto. Then, a liquid-fueled engine/generator on board the auto both (1) extends the range of the electric auto and (2) enables the auto with its engine/generator to serve as a backup source of heat and electricity for the residence.

  14. Array structure design handbook for stand alone photovoltaic applications

    NASA Technical Reports Server (NTRS)

    Didelot, R. C.

    1980-01-01

    This handbook will permit the user to design a low-cost structure for a variety of photovoltaic system applications under 10 kW. Any presently commercially available photovoltaic modules may be used. Design alternatives are provided for different generic structure types, structural materials, and electric interfaces. The use of a hand-held calculator is sufficient to perform the necessary calculations for the array designs.

  15. An Intelligent Stand-Alone Ultrasonic Device for Monitoring Local Damage Growth in Civil Structures

    NASA Astrophysics Data System (ADS)

    Pertsch, Alexander T.; Kim, Jin-Yeon; Wang, Yang; Jacobs, Laurence J.

    2010-02-01

    For aged, in-service civil structures, continuous structural health monitoring is vital to avoid catastrophic failure. This includes monitoring local damage growth at points crucial to the structure's stability. While traditional ultrasonic devices are well-established for scheduled local human inspections, they are ineligible for continuous monitoring. The objective of this research is to develop a stand-alone, self-contained, compact ultrasonic device for continuous structural health monitoring of civil structures. The battery powered device integrates small ultrasonic transducers with a compact high speed data acquisition and processing unit and a wireless communication device. Rayleigh surface waves, generated by the device, will be used to detect and assess surface cracks. This study, documenting the ongoing development, presents a concept for the functional layout of the ultrasonic device. It also examines a method for the assessment of surface breaking damage using Rayleigh waves in a simulated environment. The examination is under the limitations on power levels that can be supplied by batteries. The ultrasonic device may later be combined with global approaches, like analysis of vibration signals, to increase the sensitivity of damage detection in order to avoid catastrophic failures.

  16. NOY: a neutrino observatory network project based on stand alone air shower detector arrays

    NASA Astrophysics Data System (ADS)

    Montanet, F.; Lebrun, D.; Chauvin, J.; Lagorio, E.; Stassi, P.

    2011-09-01

    We have developed a self powered stand alone particle detector array dedicated to the observation of horizontal tau air showers induced by high energy neutrinos interacting in mountain rock. Air shower particle detection reaches a 100% duty cycle and is practically free of background when compared to Cherenkov light or radio techniques. It is thus better suited for rare neutrino event search. An appropriate mountain to valley topological configuration has been identified and the first array will be deployed on an inclined slope at an elevation of 1500 m facing Southern Alps near the city of Grenoble (France). A full simulation has been performed. A neutrino energy dependent mountain tomography chart is obtained using a neutrino and tau propagation code together with a detailed cartography and elevation map of the region. The array acceptance is then evaluated between 1 PeV and 100 EeV by simulating decaying tau air showers across the valley. The effective detection surface is determined by the shower lateral extension at array location and is hence much larger than the array geometrical area. The array exposure will be 1014 cm2 sr s at 100 PeV. Several independent arrays can be deployed with the aim of constituting a large distributed observatory. Some other sites are already under study. At last, special care is dedicated to the educational and outreach aspects of such a cosmic ray detector.

  17. An intelligent stand-alone ultrasonic device for monitoring local structural damage: implementation and preliminary experiments

    NASA Astrophysics Data System (ADS)

    Pertsch, Alexander; Kim, Jin-Yeon; Wang, Yang; Jacobs, Laurence J.

    2011-01-01

    Continuous structural health monitoring has the potential to significantly improve the safety management of aged, in-service civil structures. In particular, monitoring of local damage growth at hot-spot areas can help to prevent disastrous structural failures. Although ultrasonic nondestructive evaluation (NDE) has proved to be effective in monitoring local damage growth, conventional equipment and devices are usually bulky and only suitable for scheduled human inspections. The objective of this research is to harness the latest developments in embedded hardware and wireless communication for developing a stand-alone, compact ultrasonic device. The device is directed at the continuous structural health monitoring of civil structures. Relying on battery power, the device possesses the functionalities of high-speed actuation, sensing, signal processing, and wireless communication. Integrated with contact ultrasonic transducers, the device can generate 1 MHz Rayleigh surface waves in a steel specimen and measure response waves. An envelope detection algorithm based on the Hilbert transform is presented for efficiently determining the peak values of the response signals, from which small surface cracks are successfully identified.

  18. Performance Analysis of a Stand-Alone Permanent-Magnet Induction Generator with Single-Phase Output

    NASA Astrophysics Data System (ADS)

    Tsuda, Toshihiro; Fukami, Tadashi; Kanamaru, Yasunori; Miyamoto, Toshio

    The performance of a stand-alone permanent-magnet induction generator (PMIG) with single-phase output is analyzed using the method of symmetrical components and is compared to that of the same-sized conventional induction generator (IG). Experimental results conducted on a 2.2-kW testing machine are also provided to justify the theoretical analysis. Calculation and experimental results show that containing a permanent-magnet (PM) rotor generates electric power without fail and contributes to the improvement of efficiency and frequency variation.

  19. A Stand-Alone Induction Generator with Improved Stator Flux Oriented Control

    NASA Astrophysics Data System (ADS)

    Vukadinović, Dinko; Bašić, Mateo

    2011-03-01

    This paper presents an improved stator flux oriented (SFO) control system for a stand-alone induction generator. The induction generator supplies a variable resistive dc load. In order to provide an essentially constant terminal voltage, the product of the rotor speed and the stator flux reference should remain constant. However, in this case the control system is not able to function properly at different loads and dc-link voltages. In this paper, we introduce a new algorithm in which this product is constant at certain dc-load and dc-link voltage references. The dependence of the stator flux reference on the dc load and dc voltage reference is mapped using an artificial neural network (ANN). We also present an analysis of the efficiency of the SFO control system, as well as its performance during transients, over a wide range of both dc-link voltage references and loads. The validity of the proposed approach is verified by realistic simulation in a Matlab-Simulink environment.

  20. Setup of the Mössbauer spectrometer based on stand-alone instruments - A case study

    NASA Astrophysics Data System (ADS)

    Kouřil, Lukáš; Kohout, Pavel; Novák, Petr; Navařík, Jakub; Pechoušek, Jiří

    2014-10-01

    In this study, an optional assembling of a Mössbauer spectrometer based on stand-alone instruments (an Agilent 33521A function generator and an Agilent DSO-X 2002A digital oscilloscope) is presented. The main goal is to identify the possible functional limits of selected instruments used as standard and cheap laboratory equipment in comparison to the special and expensive devices. For communication with the instruments and to perform all measurement tasks, an application was created in the LabVIEW{trade mark, serif} 2013 (National Instruments), a graphical programming environment. In addition to the instruments, the standard ORTEC NIM system was used in the gamma-ray detection part of the system. Development of the control application to accumulate Mössbauer spectra with synchronization of the reference signal generation and detectors signal processing is presented. Despite the fact that the setup of the spectrometer was correct and usable for daily research, some disadvantages were found. The sources of high measurement dead time value were identified mainly in the oscilloscope usage. Possible solutions to additionally increase the performance of the proposed system are discussed in details.

  1. Integrated versus stand-alone second generation ethanol production from sugarcane bagasse and trash.

    PubMed

    Dias, Marina O S; Junqueira, Tassia L; Cavalett, Otávio; Cunha, Marcelo P; Jesus, Charles D F; Rossell, Carlos E V; Maciel Filho, Rubens; Bonomi, Antonio

    2012-01-01

    Ethanol production from lignocellulosic materials is often conceived considering independent, stand-alone production plants; in the Brazilian scenario, where part of the potential feedstock (sugarcane bagasse) for second generation ethanol production is already available at conventional first generation production plants, an integrated first and second generation production process seems to be the most obvious option. In this study stand-alone second generation ethanol production from surplus sugarcane bagasse and trash is compared with conventional first generation ethanol production from sugarcane and with integrated first and second generation; simulations were developed to represent the different technological scenarios, which provided data for economic and environmental analysis. Results show that the integrated first and second generation ethanol production process from sugarcane leads to better economic results when compared with the stand-alone plant, especially when advanced hydrolysis technologies and pentoses fermentation are included. PMID:22019267

  2. A fast, programmable, stand-alone pulse generator emulating spectroscopy nuclear events

    SciTech Connect

    Imperiale, C.

    1996-10-01

    The design of a fast, programmable, stand-alone pulse generator emulating spectroscopy nuclear events is described. The generator is one unit in a system aiming to test the validity of the simulation and theoretical work relating to the shaping, acquisition, and processing of spectroscopy signals in different experimental situations arising from different technical and scientific fields. The generator output, which also includes piled-up shapes, can be used in many different ways. For example, it can be used: (1) as an input to a charge sensitive preamplifier and shaping amplifier system; (2) as an input to a module for real-time digital shaping of spectroscopy pulses; and (3) it can generate a digital sequence emulating a digitally sampled analog pulse. The signals that it can emulate include those from simple charge sensitive preamplifiers, from more refined analog shapers, and the signals generated directly from scintillation detectors. The main element of the generator is the Analog Devices 21060, a fast and flexible digital signal processor (DSP). This paper considers various generator configurations arising from the need to reach a compromise among generator speed, shape resolution, and memory requirements. It is possible to program both the emulated average counting rate and the time interval between two consecutive samples (tns) using a predetermined pulse shape. The minimum tns value is equal to 10 ns in parallel configurations.

  3. CloneAssistant 1.0: a stand-alone software for automated cloning primer design.

    PubMed

    Shao, Chaogang; Meng, Yijun; Lv, Shaolei; Zhong, Wei; Wang, Zheyu; Chen, Ming

    2010-11-01

    "CloneAssistant 1.0" is a stand-alone software compatible with the current Windows operating systems, which can automatically design cloning primers with full consideration of the sequence information of vectors and genes, cloning strategies, the principles of primer design, reading frames, position effects, and enzymatic reaction conditions for users. Five internal XML (extensible markup language) databases [restriction enzymes, plasmids, universal buffers, PCR (polymerase chain reaction) protection bases, and an MCS (multiple cloning site) double digest interference database] were established to serve as the basic support for "CloneAssistant 1.0". The primer pairs designed are sorted according to the difficulty of the follow-up experiments. Once a primer pair is selected by the user, detailed experimental guidance for this primer pair will be provided. In addition, "CloneAssistant 1.0" can be used for restriction map analysis, ORF (open reading frame) finding, sequence alignment and complementary analysis, translation, restriction enzyme and universal buffer queries, and isocaudamer analysis. "CloneAssistant 1.0" makes gene clone design much easier, and it can be freely downloaded from http://bis.zju.edu.cn/clone. PMID:20887760

  4. Grid parity analysis of stand-alone hybrid microgrids: A comparative study of Germany, Pakistan, South Africa and the United States

    NASA Astrophysics Data System (ADS)

    Siddiqui, Jawad M.

    Grid parity for alternative energy resources occurs when the cost of electricity generated from the source is lower than or equal to the purchasing price of power from the electricity grid. This thesis aims to quantitatively analyze the evolution of hybrid stand-alone microgrids in the US, Germany, Pakistan and South Africa to determine grid parity for a solar PV/Diesel/Battery hybrid system. The Energy System Model (ESM) and NREL's Hybrid Optimization of Multiple Energy Resources (HOMER) software are used to simulate the microgrid operation and determine a Levelized Cost of Electricity (LCOE) figure for each location. This cost per kWh is then compared with two distinct estimates of future retail electricity prices at each location to determine grid parity points. Analysis results reveal that future estimates of LCOE for such hybrid stand-alone microgrids range within the 35-55 cents/kWh over the 25 year study period. Grid parity occurs earlier in locations with higher power prices or unreliable grids. For Pakistan grid parity is already here, while Germany hits parity between the years 2023-2029. Results for South Africa suggest a parity time range of the years 2040-2045. In the US, places with low grid prices do not hit parity during the study period. Sensitivity analysis results reveal the significant impact of financing and the cost of capital on these grid parity points, particularly in developing markets of Pakistan and South Africa. Overall, the study helps conclude that variations in energy markets may determine the fate of emerging energy technologies like microgrids. However, policy interventions have a significant impact on the final outcome, such as the grid parity in this case. Measures such as eliminating uncertainty in policies and improving financing can help these grids overcome barriers in developing economies, where they may find a greater use much earlier in time.

  5. Adoption and Usage of Stand-Alone Electronic Prescribing in a Health Plan–Sponsored Initiative

    PubMed Central

    Pevnick, Joshua M.; Asch, Steven M.; Adams, John L.; Mattke, Soeren; Patel, Mihir H.; Ettner, Susan L.; Bell, Douglas S.

    2016-01-01

    Objective We sought to quantify rates of stand-alone e-prescribing (SEP) adoption and usage among primary care physicians (PCPs) participating in an SEP initiative, and to determine which physician and patient-panel characteristics were associated with higher rates of each. Background Health Information Technology (HIT) holds promise for improving care, but its use among physicians practicing in smaller groups has been limited by cost and implementation barriers. SEP is an entry-level technology that may minimize these barriers. Design Using records from in an insurer-led SEP initiative, we compared the characteristics of 297 PCPs who adopted SEP through the initiative with the characteristics of 1892 eligible PCPs who did not. Among the 297 adopters, we studied the extent of SEP usage. Measurements Dependent variables were each physician’s adoption of SEP and their e-prescribing usage ratio (the ratio of electronic prescriptions to pharmacy claims in the same time period). Independent variables included characteristics of PCPs (specialty, practice size, and prescribing volume) and their patients (patient age, gender, income, race, and ethnicity). Results Solo practitioners, pediatricians, and physicians with more patients from predominantly African-American zip codes were under-represented among SEP adopters. The mean e-prescribing usage ratio among adopters was 0.23 (SD 0.28); 20% of physicians maintained usage ratios above 0.50. Available physician characteristics explained little of the variance in usage, but physicians in smaller practices had greater usage (p = 0.02). Conclusion Certain categories of physicians may need more tailored incentives to adopt SEP. On average, adopters only used the SEP system for about one quarter of their prescriptions. Some adopters achieved high levels of SEP usage, though, and further research is needed to elucidate the factors that enabled this. PMID:20225913

  6. Stand-alone minimally invasive lateral lumbar interbody fusion: multicenter clinical outcomes.

    PubMed

    Ahmadian, Amir; Bach, Konrad; Bolinger, Bryan; Malham, Gregory M; Okonkwo, David O; Kanter, Adam S; Uribe, Juan S

    2015-04-01

    Stand-alone minimally invasive lateral transpsoas interbody fusion (MIS-LIF), without posterior instrumentation, is feasible because the technique does not necessitate the disruption of the stabilizing elements. The objectives of this study are to evaluate the efficacy and clinical outcomes of patients who underwent stand-alone lateral interbody fusion. A multicenter chart review was conducted to identify patients who underwent stand-alone MIS-LIF between 2008 and 2012. Patients were classified by spinal pathology (degenerative disc disease [DDD], spondylolisthesis [SL] and adult degenerative scoliosis [ADS]). Routine clinical follow-up was scheduled at 3, 6, and12 months. Outcome measures included hospital length of stay, fusion rates, neurologic complications, integrity of construct and clinical outcome questionnaires (Visual Analog Scale [VAS] and Oswestry Disability Index [ODI]). A total of 59 patients met the inclusion criteria. The average age was 60 years (range 31-86 years). Spinal pathologies treated were DDD in 37 (63%), SL in four (7%) and ADS in 18 (30%) patients. Fusion rate was 93% of patients (95% of levels) at 12 months. Two patients required re-operation. Mean hospital stay and follow-up were 3.3days (range 1-10) and 14.6 months, respectively. The mean preoperative VAS and ODI were 69.1 and 51.8, respectively. VAS improved to 37.8 (p<0.0005). ODI improved to 31.8 (p<0.0005). Seventy percent of patients had grade 0 subsidence while 30% had grade I and grade II subsidence. Stand-alone MIS-LIF is viable option in a carefully selected patient population for both single and multilevel disease and shows significant improvement in health related quality of life. PMID:25684343

  7. 49 CFR 1109.4 - Mandatory mediation in rate cases to be considered under the stand-alone cost methodology.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... will not affect the procedural schedule in stand alone cost rate cases set forth at 49 CFR 1111.8(a). ...-binding mediation of its dispute with the railroad upon filing a formal complaint under 49 CFR part 1111... under the stand-alone cost methodology. 1109.4 Section 1109.4 Transportation Other Regulations...

  8. Stand Alone Pressure Measurement Device (SAPMD) for the space shuttle Orbiter, part 1

    NASA Technical Reports Server (NTRS)

    Tomlinson, Bill

    1989-01-01

    The specifications for the Stand Alone Pressure Measurement Device (SAPMD) are as follows: the SAPMD shall measure ambient pressure at the surface of the Orbiter TPS in the range of 0 to 15 pounds per square inch absolute (PSIA). Measurement will begin at solid rocket booster (SRB) ignition as sensed by appropriate vibration sensing elements in the SAPMD. Pressure and corresponding real-time data are to be recorded every one tenth second for 140 seconds and at the end of the recording period, the operation will be discontinued with the data preserved for interrogation subsequent to Orbiter re-entry and landing. The type and size of the battery shall be such as to allow the vibration sensing elements and a real-time clock to be initialized a minimum of 30 day prior to launch and still provide power as necessary to perform the 140 second data recording period after SRB ignition. Battery installation shall be in such a manner as to allow battery replacement without removing the SAPMD from its position or removing more than one TPS tile. The SAPMD must be mounted in specific locations under tile of the TPS. To accommodate such mounting, the absolute maximum physical dimensions much not exceed 6.0 inches in length, 1.5 inches in width, and 0.4 inches in height, and the device shall be of such configuration that it can be bonded to the Orbiter skin at the joint line of two TPS tiles with the pressure sensing port at the surface of the tile. The SAPMD must remain operational in the temperature range of -40 to +85 C and survive storage temperature of -55 to +125 C. The pressure port must withstand 934 C without causing damage to the TPS during entry and must remain functional at 262 C during ascent. The accuracy of the pressure measurement must be plus or minus one-half PSIA over a temperature range of 0 to +36 C. All the specifications were met and verified by prototype testing and documented in the enclosed test data. Four flight-qualified models were fabricated and of these, two were delivered and successfully flown in the cargo bay of STS-26.

  9. [Online retrieval of patient information by asynchronous communication between a general purpose computer and a stand-alone personal computer].

    PubMed

    Tsutsumi, R; Takahashi, K; Sato, T; Komatani, A; Yamaguchi, K

    1988-03-01

    Asynchronous communication was made between host (FACOM M-340) and personal computer (OLIBETTIE S-2250) to get patient's information required for RIA test registration. The retrieval system consists of a keyboard input of six numeric codes, patient's ID, and a real time reply containing six parameters for the patient. Their identified parameters are patient's name, sex, date of birth (include area), department, and out- or inpatient. Linking this program to RIA registration program for individual patient, then, operator can input name of RIA test requested. Our simple retrieval program made a useful data network between different types of host and stand-alone personal computers, and enabled us accurate and labor-saving registration for RIA test. PMID:3387606

  10. SADIST (the SAndia Data Index STructure): a stand-alone data base for computer-aided design and general use

    SciTech Connect

    Stauffer, J D

    1980-11-01

    A file structure has been designed that fills the needs of multilevel hierarchical design of integrated circuits (ICs). Since the structure is actualized by a stand-alone FORTRAN program, it is applicable to general-purpose use in situations where the structure of the data modeled is similar to that of IC data. Though the structure itself is a FORTRAN direct-access file, its interface with user programs is a small sequential subfile accessible to FORTRAN, PASCAL, and most other languages. This ability facilitates linkup to systems already in use and requires minimal recoding. Backup, restore, and other data base recovery and integrity operations are automatic, but may be initiated by the user if desired. 3 figures.

  11. Sleeve Gastrectomy as a Stand-alone Bariatric Operation for Severe, Morbid, and Super Obesity

    PubMed Central

    Bellatorre, Anna; Bellatorre, Nina

    2013-01-01

    Background: The laparoscopic sleeve gastrectomy (LSG) is emerging as an effective bariatric operation and is especially attractive in high-risk populations. In this study we examine the efficacy of LSG as a stand-alone operation in the veteran population. Methods: This is a retrospective review of consecutive patients who underwent LSG as a stand-alone procedure at the Palo Alto Veterans Affairs medical center with a minimum 12-month follow-up. Results: Of 205 patients undergoing bariatric surgery, 71 patients had a sleeve gastrectomy, 40 of whom had the operation performed at least 12 months previously. Thirty-six (90%) were available for 1-year follow-up, with a mean follow-up duration of 22 months (range: 12–42), a mean body mass index of 48.3 kg/m2, and an 83% male population. Mean percent excess weight loss was 61% at an average of 22 months, with no significant difference between severely obese, morbidly obese, and super obese cohorts. Diabetes remission was seen in 56% of patients, hypertension remission in 51.6%, and obstructive sleep apnea remission in 46.4%, and gastroesophageal reflux disease improved or did not change in 83%. Medication use significantly decreased after surgery. Conclusion: LSG is safe and effective as a stand-alone bariatric operation in the high-risk veteran population. It is effective in severely obese, morbidly obese, and super obese patients. LSG induces remission or improvement in comorbidities of nearly all patients, translating to a decrease in medication use. PMID:23743373

  12. Improvements and applications of COBRA-TF for stand-alone and coupled LWR safety analyses

    SciTech Connect

    Avramova, M.; Cuervo, D.

    2006-07-01

    The advanced thermal-hydraulic subchannel code COBRA-TF has been recently improved and applied for stand-alone and coupled LWR core calculations at the Pennsylvania State Univ. in cooperation with AREVA NP GmbH (Germany)) and the Technical Univ. of Madrid. To enable COBRA-TF for academic and industrial applications including safety margins evaluations and LWR core design analyses, the code programming, numerics, and basic models were revised and substantially improved. The code has undergone through an extensive validation, verification, and qualification program. (authors)

  13. Myelography as a stand-alone diagnostic procedure for degenerative spine disease in developing nations.

    PubMed

    Park, Bert Edward; Kitya, David

    2010-04-01

    The use of "stand-alone" contrast myelography (i.e., without computed tomography) has a proven track record in developing nations where few patients have access to magnetic resonance imaging, whether on the basis of prohibitive cost or the absence of such a modality altogether. To substantiate the author's 12-year experience with more than 300 myelograms performed in 16 different countries (plus some 1500 studies during 30 years of practice in the United States), a prospective pilot study was undertaken over 1 month in a community-based neurosurgical setting in western Kenya. Forty patients underwent cervical or lumbar myelography at Tenwek Hospital under the auspices of the Neurosurgery Training Program for East, Central, and South Africa (NSTP-ECSA) following failure of conservative measures to treat spine-related pathology. Thirty-five of the forty patients (88%) came to definitive surgery on the basis of a positive study that correlated with their clinical history and physical examination. There were no significant complications from the procedures, and no false-positive studies, with virtually all patients returning to normal activity and/or gainful employment within 3 weeks of their surgery. Myelography as a stand-alone diagnostic procedure is a sensitive, specific, and cost-effective means of diagnosing symptomatic degenerative spine disorders. Accordingly, its use should be encouraged at every NSTP-ECSA training site to address such ubiquitous pathology. PMID:20849779

  14. Design, construction and evaluation of two large photovoltaic power systems

    SciTech Connect

    Solman, F.J.; Nichols, B.E.

    1980-01-01

    A description and comparison of two large photovoltaic electric power systems is presented. The smaller system is designed for economic viability in the near future and provides 70 to 90 percent of the electric requirements for its prime load, a daytime AM radio station. The second system is a stand-alone power system suitable for a remote residential and light industrial community. No electric utility grid is present at this location so the management of a backup Diesel generator is also required.

  15. Continuous monitoring bed-level dynamics on an intertidal flat: introducing novel stand-alone high-resolution SED-sensors

    NASA Astrophysics Data System (ADS)

    Hu, Zhan; Lenting, Walther; van der Wal, Daphne; Bouma, Tjeerd

    2015-04-01

    Tidal flat morphology is continuously shaped by hydrodynamic force, resulting in highly dynamic bed elevations. The knowledge of short-term bed-level changes is important both for understanding sediment transport processes as well as for assessing critical ecological processes such as e.g. vegetation recruitment chances on tidal flats. Due to the labour involved, manual discontinuous measurements lack the ability to continuously monitor bed-elevation changes. Existing methods for automated continuous monitoring of bed-level changes lack vertical accuracy (e.g., Photo-Electronic Erosion Pin sensor and resistive rod) or limited in spatial application by using expensive technology (e.g., acoustic bed level sensors). A method provides sufficient accuracy with a reasonable cost is needed. In light of this, a high-accuracy sensor (2 mm) for continuously measuring short-term Surface-Elevation Dynamics (SED-sensor) was developed. This SED-sensor makes use of photovoltaic cells and operates stand-alone using internal power supply and data logging system. The unit cost and the labour in deployments is therefore reduced, which facilitates monitoring with a number of units. In this study, the performance of a group of SED-sensors is tested against data obtained with precise manual measurements using traditional Sediment Erosion Bars (SEB). An excellent agreement between the two methods was obtained, indicating the accuracy and precision of the SED-sensors. Furthermore, to demonstrate how the SED-sensors can be used for measuring short-term bed-level dynamics, two SED-sensors were deployed for 1 month at two sites with contrasting wave exposure conditions. Daily bed-level changes were obtained including a severe storm erosion event. The difference in observed bed-level dynamics at both sites was statistically explained by their different hydrodynamic conditions. Thus, the stand-alone SED-sensor can be applied to monitor sediment surface dynamics with high vertical and temporal resolutions, which provides opportunities to pinpoint morphological responses to various forces in a number of environments (e.g. tidal flats, beaches, rivers and dunes).

  16. CEPH accreditation of stand-alone baccalaureate programs: a preliminary mapping exercise.

    PubMed

    Figueroa, Jorge L; Birch, David A; Rasar King, Laura; Cottrell, Randall R

    2015-01-01

    The purpose of this article is to provide a brief background of quality assurance efforts in health education, provide a brief overview of the new Council on Education for Public Health (CEPH) accreditation process for stand-alone baccalaureate public health programs that prepare health education specialists, and describe the experience of two academic programs in reviewing their curricula for coverage of the newly approved CEPH requirements. The University of Alabama and the University of North Carolina Wilmington undertook a curriculum mapping exercise identifying which courses in their programs Introduced, Reinforced, and/or Covered each of the Critical Components Elements identified by CEPH. The mapping process is described, and recommendations for other programs considering accreditation under the newly adopted CEPH standards are provided. PMID:24898243

  17. High Angular Sensitivity, Absolute Rotary Encoding Device with Polygonal Mirror and Stand-Alone Diffraction Gratings

    NASA Technical Reports Server (NTRS)

    Leviton, Douglas B. (Inventor)

    1996-01-01

    A device for position encoding of a rotating shaft in which a polygonal mirror having a number of facets is mounted to the shaft and a monochromatic light beam is directed towards the facets. The facets of the polygonal mirror direct the light beam to a stand-alone low line density diffraction grating to diffract the monochromatic light beam into a number of diffracted light beams such that a number of light spots are created on a linear array detector. An analog-to-digital converter is connected to the linear array detector for reading the position of the spots on the linear array detector means. A microprocessor with memory is connected to the analog-to-digital converter to hold and manipulate the data provided by the analog-to-digital converter on the position of the spots and to compute the position of the shaft based upon the data from the analog-lo-digital converter.

  18. Adverse selection and the challenges to stand-alone prescription drug insurance.

    PubMed

    Pauly, Mark V; Zeng, Yuhui

    2004-01-01

    This paper investigates a possible predictor of adverse selection problems in unsubsidized stand-alone prescription drug insurance: the persistence of an individual's high spending over multiple years. Using Medstat claims data and data from the Medicare Survey of Current Beneficiaries, we find that persistence is much higher for outpatient drug expenses than for other categories of medical expenses. We then use these estimates to develop a simple and intuitive model of adverse selection in competitive insurance markets and show that this high relative persistence makes it unlikely that unsubsidized drug insurance can be offered for sale, even with premiums partially risk adjusted, without a probable adverse selection death spiral. We show that this outcome can be avoided if drug coverage is bundled with other coverage, and we briefly discuss the need either for comprehensive coverage or generous subsidies if adverse selection is to be avoided in private and Medicare insurance markets. PMID:15612335

  19. A Meta-Analytic Review of Stand-Alone Interventions to Improve Body Image

    PubMed Central

    Alleva, Jessica M.; Sheeran, Paschal; Webb, Thomas L.; Martijn, Carolien; Miles, Eleanor

    2015-01-01

    Objective Numerous stand-alone interventions to improve body image have been developed. The present review used meta-analysis to estimate the effectiveness of such interventions, and to identify the specific change techniques that lead to improvement in body image. Methods The inclusion criteria were that (a) the intervention was stand-alone (i.e., solely focused on improving body image), (b) a control group was used, (c) participants were randomly assigned to conditions, and (d) at least one pretest and one posttest measure of body image was taken. Effect sizes were meta-analysed and moderator analyses were conducted. A taxonomy of 48 change techniques used in interventions targeted at body image was developed; all interventions were coded using this taxonomy. Results The literature search identified 62 tests of interventions (N = 3,846). Interventions produced a small-to-medium improvement in body image (d+ = 0.38), a small-to-medium reduction in beauty ideal internalisation (d+ = -0.37), and a large reduction in social comparison tendencies (d+ = -0.72). However, the effect size for body image was inflated by bias both within and across studies, and was reliable but of small magnitude once corrections for bias were applied. Effect sizes for the other outcomes were no longer reliable once corrections for bias were applied. Several features of the sample, intervention, and methodology moderated intervention effects. Twelve change techniques were associated with improvements in body image, and three techniques were contra-indicated. Conclusions The findings show that interventions engender only small improvements in body image, and underline the need for large-scale, high-quality trials in this area. The review identifies effective techniques that could be deployed in future interventions. PMID:26418470

  20. Stand-alone PC-based fast readout electronics and software for 2D-gaseous detectors

    NASA Astrophysics Data System (ADS)

    Popov, Vladimir; Hirschhorn, Shimon; Roich, Alexander; Frumkin, Igor

    1994-12-01

    A novel readout system based on time signals processing and digitization for 2-D gaseous radiation detectors is presented. It is comprised of fast amplifiers, constant fraction discriminators, a dedicated 486 PC/AT-born time-to-digital converter and data acquisition boards and software. Its software package runs under Windows 3.1. The system allows for fast real-time data acquisition as well as for on-line and off-line data processing and image analysis. At event rates reaching 3 kHz this readout system provides an efficient and convenient tool for laboratory tests. It can operate at higher rates, exceeding 0.5 MHz under DOS. The entire system is stand-alone and does not require any additional electronics. It can operate under both external and self-triggering modes. The novel system is versatile and may be applied for the readout of a large variety of gaseous imaging detectors. Images acquired by X-ray and β imaging avalanche gas detectors equipped with this electronic system and using the software package are presented.

  1. Are integrated HIV services less stigmatizing than stand-alone models of care? A comparative case study from Swaziland

    PubMed Central

    Church, Kathryn; Wringe, Alison; Fakudze, Phelele; Kikuvi, Joshua; Simelane, Dudu; Mayhew, Susannah H

    2013-01-01

    Introduction Integrating HIV with primary health services has the potential to reduce HIV-related stigma through delivering care in settings disassociated with HIV. This study investigated the relationship between integrated care and felt stigma. The study design was a comparative case study of four models of HIV care in Swaziland, ranging from fully integrated to fully stand-alone HIV care. Methods An exit survey (N=602) measured differences in felt stigma across model of care; the primary outcome “perception of HIV status exposure through clinic attendance” was analyzed using multivariable logistic regression. In-depth interviews (N=22) explored whether and how measured differences in stigma experiences were related to service integration. Results There were significant differences in perceived status exposure across models of care. After adjustment for potential confounding between sites, those at a partially integrated site and a partially stand-alone site had greater odds of perceived status exposure than those at the fully stand-alone site (aOR 3.33, 95% CI 1.98–5.60; and aOR 11.84, 95% CI 6.89–20.36, respectively). There was no difference between the fully stand-alone and the fully integrated clinic. Qualitative data suggested that many clients at HIV-only sites felt greater confidentiality knowing that those around them were positive, and support was gained from other HIV care clients. Confidentiality was maintained in various ways, even in stand-alone sites, through separate waiting areas for HIV testing and HIV treatment, and careful clinic and room labelling. Conclusions The relationship between model of care and stigma was complex, and the hypothesis that stigma is higher at stand-alone sites did not hold true in this high prevalence setting. Policy-makers should ensure that service integration does not increase stigma, in particular within partially integrated models of care. PMID:23336726

  2. SAPT units turn-on in an interference-dominant environment. [Stand Alone Pressure Transducer

    NASA Technical Reports Server (NTRS)

    Peng, W.-C.; Yang, C.-C.; Lichtenberg, C.

    1990-01-01

    A stand alone pressure transducer (SAPT) is a credit-card-sized smart pressure sensor inserted between the tile and the aluminum skin of a space shuttle. Reliably initiating the SAPT units via RF signals in a prelaunch environment is a challenging problem. Multiple-source interference may exist if more than one GSE (ground support equipment) antenna is turned on at the same time to meet the simultaneity requirement of 10 ms. A polygon model for orbiter, external tank, solid rocket booster, and tail service masts is used to simulate the prelaunch environment. Geometric optics is then applied to identify the coverage areas and the areas which are vulnerable to multipath and/or multiple-source interference. Simulation results show that the underside areas of an orbiter have incidence angles exceeding 80 deg. For multipath interference, both sides of the cargo bay areas are found to be vulnerable to a worst-case multipath loss exceeding 20 dB. Multiple-source interference areas are also identified. Mitigation methods for the coverage and interference problem are described. It is shown that multiple-source interference can be eliminated (or controlled) using the time-division-multiplexing method or the time-stamp approach.

  3. Power Systems Integration Laboratory (Fact Sheet)

    SciTech Connect

    Not Available

    2011-10-01

    This fact sheet describes the purpose, lab specifications, applications scenarios, and information on how to partner with NREL's Power Systems Integration Laboratory at the Energy Systems Integration Facility. At NREL's Power Systems Integration Laboratory in the Energy Systems Integration Facility (ESIF), research focuses on developing and testing large-scale distributed energy systems for grid-connected, stand-alone, and microgrid applications. The laboratory can accommodate large power system components such as inverters for photovoltaic (PV) and wind systems, diesel and natural gas generators, battery packs, microgrid interconnection switchgear, and vehicles. Closely coupled with the research electrical distribution bus at the ESIF, the Power Systems Integration Laboratory will offer power testing capability of megawatt-scale DC and AC power systems, as well as advanced hardware-in-the-loop and model-in-the-loop simulation capabilities. Thermal heating and cooling loops and fuel also allow testing of combined heating/cooling and power systems (CHP).

  4. Review of stand-alone photovoltaic application projects sponsored by US DOE and US AID

    NASA Astrophysics Data System (ADS)

    Bifano, W. J.

    Experience with dc photovoltaic systems (without backup power) and ranging in output from 23 to 3,500 peak watts, in a wide range of environmental conditions and with a wide range of insolation, is described. Cooperation of NASA with other government agencies resulted in the installation of an air pollution monitor in New Jersey, a seismic sensor in Hawaii, power for lookout towers in national forests in California, an electric power system for a Papago Indian village in Arizona, and a power system for a grain mill and water pump in Tangaye, Upper Volta. Significant operational results are discussed and system reliability is assessed for the 20 experimental systems installed since 1976. Additional systems to be installed overseas are highlighted, and economic factors are considered.

  5. Review of stand-alone photovoltaic application projects sponsored by US DOE and US AID

    NASA Technical Reports Server (NTRS)

    Bifano, W. J.

    1981-01-01

    Experience with dc photovoltaic systems (without backup power) and ranging in output from 23 to 3,500 peak watts, in a wide range of environmental conditions and with a wide range of insolation, is described. Cooperation of NASA with other government agencies resulted in the installation of an air pollution monitor in New Jersey, a seismic sensor in Hawaii, power for lookout towers in national forests in California, an electric power system for a Papago Indian village in Arizona, and a power system for a grain mill and water pump in Tangaye, Upper Volta. Significant operational results are discussed and system reliability is assessed for the 20 experimental systems installed since 1976. Additional systems to be installed overseas are highlighted, and economic factors are considered.

  6. Porous silicon with embedded tritium as a stand-alone prime power source for optoelectronic applications

    DOEpatents

    Tam, Shiu-Wing

    1997-01-01

    An illumination source comprising a porous silicon having a source of electrons on the surface and/or interticies thereof having a total porosity in the range of from about 50 v/o to about 90 v/o. Also disclosed are a tritiated porous silicon and a photovoltaic device and an illumination source of tritiated porous silicon.

  7. Porous silicon with embedded tritium as a stand-alone prime power source for optoelectronic applications

    DOEpatents

    Tam, Shiu-Wing

    1998-01-01

    An illumination source comprising a porous silicon having a source of electrons on the surface and/or interticies thereof having a total porosity in the range of from about 50 v/o to about 90 v/o. Also disclosed are a tritiated porous silicon and a photovoltaic device and an illumination source of tritiated porous silicon.

  8. Porous silicon with embedded tritium as a stand-alone prime power source for optoelectronic applications

    DOEpatents

    Tam, S.W.

    1997-02-25

    Disclosed is an illumination source comprising a porous silicon having a source of electrons on the surface and/or interstices thereof having a total porosity in the range of from about 50 v/o to about 90 v/o. Also disclosed are a tritiated porous silicon and a photovoltaic device and an illumination source of tritiated porous silicon. 1 fig.

  9. Porous silicon with embedded tritium as a stand-alone prime power source for optoelectronic applications

    DOEpatents

    Tam, S.W.

    1998-06-16

    An illumination source is disclosed comprising a porous silicon having a source of electrons on the surface and/or interstices thereof having a total porosity in the range of from about 50 v/o to about 90 v/o. Also disclosed are a tritiated porous silicon and a photovoltaic device and an illumination source of tritiated porous silicon. 1 fig.

  10. EVALUATION AND USE OF STAND-ALONE COMMERCIAL PHOTOLYTIC CONVERTERS FOR CONVERSION OF NO2 AND NO

    EPA Science Inventory

    Two types of stand-alone photolytic converters of nitrogen dioxide (NO2) to nitric oxide (NO) are now commercially available for use with NO, ozone (O3) chemiluminescence detector (CLD) monitors for the measurement of NO2. Both units have been tested for interferences resulting...

  11. Water Wisdom: 23 Stand-Alone Activities on Water Supply and Water Conservation for High School Students. 2nd Edition.

    ERIC Educational Resources Information Center

    Massachusetts State Water Resources Authority, Boston.

    This water conservation education program for high schools consists of both stand-alone activities and teacher support materials. Lessons are divided into six broad categories: (1) The Water Cycle; (2) Water and Society; (3) Keeping Water Pure; (4) Visualizing Volumes; (5) The Economics of Water Use; and (6) Domestic Water Conservation. The…

  12. Stand-Alone Ethics, Social Responsibility, and Sustainability Course Requirements: A Snapshot from Australia and New Zealand

    ERIC Educational Resources Information Center

    Rundle-Thiele, Sharyn R.; Wymer, Walter

    2010-01-01

    This article analyzes the extent to which Australian and New Zealand marketing educators use dedicated or stand-alone courses to equip students with alternative views of business. A census of marketing programs in degree-granting universities was conducted. Program brochures were obtained via the Internet and were content analyzed. This study…

  13. 49 CFR 1109.4 - Mandatory mediation in rate cases to be considered under the stand-alone cost methodology.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... complaint under 49 CFR Part 1111. (b) Within 10 business days after the shipper files its formal complaint... cases, set forth at 49 CFR 1111.8(a). ... under the stand-alone cost methodology. 1109.4 Section 1109.4 Transportation Other Regulations...

  14. 49 CFR 1109.4 - Mandatory mediation in rate cases to be considered under the stand-alone cost methodology.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...-binding mediation of its dispute with the railroad upon filing a formal complaint under 49 CFR part 1111... will not affect the procedural schedule in stand alone cost rate cases set forth at 49 CFR 1111.8(a). ... mediator(s) or the opposing party before the Board or in any other forum without the consent of the...

  15. 77 FR 14006 - Proposed Development of the Alaska Stand Alone Gas Pipeline Project (ASAP), From the North Slope...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-08

    ... Department of the Army, Corps of Engineers Proposed Development of the Alaska Stand Alone Gas Pipeline Project (ASAP), From the North Slope to South Central Alaska, Draft Environmental Impact Statement (DEIS... January 20, 2012, issue of the Federal Register (77 FR No. 13), the U.S. Army Corps of Engineers...

  16. Stand-Alone Lateral Interbody Fusion for the Treatment of Low-Grade Degenerative Spondylolisthesis

    PubMed Central

    Marchi, Luis; Abdala, Nitamar; Oliveira, Leonardo; Amaral, Rodrigo; Coutinho, Etevaldo; Pimenta, Luiz

    2012-01-01

    The purpose of this paper was to investigate the stand-alone lateral interbody fusion as a minimally invasive option for the treatment of low-grade degenerative spondylolisthesis with a minimum 24-month followup. Prospective nonrandomized observational single-center study. 52 consecutive patients (67.6 ± 10 y/o; 73.1% female; 27.4 ± 3.4 BMI) with single-level grade I/II single-level degenerative spondylolisthesis without significant spine instability were included. Fusion procedures were performed as retroperitoneal lateral transpsoas interbody fusions without screw supplementation. The procedures were performed in average 73.2 minutes and with less than 50cc blood loss. VAS and Oswestry scores showed lasting improvements in clinical outcomes (60% and 54.5% change, resp.). The vertebral slippage was reduced in 90.4% of cases from mean values of 15.1% preoperatively to 7.4% at 6-week followup (P < 0.001) and was maintained through 24 months (7.1%, P < 0.001). Segmental lordosis (P < 0.001) and disc height (P < 0.001) were improved in postop evaluations. Cage subsidence occurred in 9/52 cases (17%) and 7/52 cases (13%) spine levels needed revision surgery. At the 24-month evaluation, solid fusion was observed in 86.5% of the levels treated. The minimally invasive lateral approach has been shown to be a safe and reproducible technique to treat low-grade degenerative spondylolisthesis. PMID:22545019

  17. "Candidatus Fokinia solitaria", a Novel "Stand-Alone" Symbiotic Lineage of Midichloriaceae (Rickettsiales).

    PubMed

    Szokoli, Franziska; Sabaneyeva, Elena; Castelli, Michele; Krenek, Sascha; Schrallhammer, Martina; Soares, Carlos A G; da Silva-Neto, Inacio D; Berendonk, Thomas U; Petroni, Giulio

    2016-01-01

    Recently, the family Midichloriaceae has been described within the bacterial order Rickettsiales. It includes a variety of bacterial endosymbionts detected in different metazoan host species belonging to Placozoa, Cnidaria, Arthropoda and Vertebrata. Representatives of Midichloriaceae are also considered possible etiological agents of certain animal diseases. Midichloriaceae have been found also in protists like ciliates and amoebae. The present work describes a new bacterial endosymbiont, "Candidatus Fokinia solitaria", retrieved from three different strains of a novel Paramecium species isolated from a wastewater treatment plant in Rio de Janeiro (Brazil). Symbionts were characterized through the full-cycle rRNA approach: SSU rRNA gene sequencing and fluorescence in situ hybridization (FISH) with three species-specific oligonucleotide probes. In electron micrographs, the tiny rod-shaped endosymbionts (1.2 x 0.25-0.35 μm in size) were not surrounded by a symbiontophorous vacuole and were located in the peripheral host cytoplasm, stratified in the host cortex in between the trichocysts or just below them. Frequently, they occurred inside autolysosomes. Phylogenetic analyses of Midichloriaceae apparently show different evolutionary pathways within the family. Some genera, such as "Ca. Midichloria" and "Ca. Lariskella", have been retrieved frequently and independently in different hosts and environmental surveys. On the contrary, others, such as Lyticum, "Ca. Anadelfobacter", "Ca. Defluviella" and the presently described "Ca. Fokinia solitaria", have been found only occasionally and associated to specific host species. These last are the only representatives in their own branches thus far. Present data do not allow to infer whether these genera, which we named "stand-alone lineages", are an indication of poorly sampled organisms, thus underrepresented in GenBank, or represent fast evolving, highly adapted evolutionary lineages. PMID:26731731

  18. Automated gas-phase purification for accurate, multiplexed quantification on a stand-alone ion trap mass spectrometer

    PubMed Central

    Vincent, Catherine E.; Rensvold, Jarred W.; Westphall, Michael S.; Pagliarini, David J.; Coon, Joshua J.

    2012-01-01

    Isobaric tagging enables the acquisition of highly-multiplexed proteome quantification but is hindered by the pervasive problem of precursor interference. The elimination of co-isolated contaminants prior to reporter tag generation can be achieved through the use of gas-phase purification via proton transfer ion/ion reactions (QuantMode); however, the original QuantMode technique was implemented on the high resolution linear ion trap-Orbitrap hybrid mass spectrometer enabled with electron transfer dissociation (ETD). Here we extend this technology to stand-alone linear ion trap systems (trapQuantMode). Facilitated by the use of inlet beam-type activation (i.e., trapHCD) for production and observation of the low mass-to-charge reporter region, this scan sequence comprises three separate events to maximize peptide identifications, minimize duty cycle requirements, and increase quantitative accuracy, precision, and dynamic range. Significant improvements in quantitative accuracy were attained over standard methods when using trapQuantMode (trapQM) to analyze an interference model system comprising tryptic peptides of yeast that we contaminated with human peptides. Finally, we demonstrate practical benefits of this method by analysis of the proteomic changes that occur during mouse skeletal muscle myoblast differentiation. While trapQM’s reduced duty cycle led to the identification of fewer proteins than conventional operation (4,050 vs. 2,964), trapQM identified more significant differences (>1.5 fold, 1,362 vs 1,132, respectively; P<0.05) between the proteomes of undifferentiated myoblasts and differentiated myotubes and nearly ten-fold more differences with changes greater than 5-fold (96 vs. 12). We further show that our trapQM dataset is superior for identifying changes in protein abundance that are consistent with the metabolic and structural changes known to accompany myotube formation. PMID:23046161

  19. Analysis of regional high spatial resolution sounding products: demonstration of MODIS and AIRS stand-alone and synergistic processing approaches

    NASA Astrophysics Data System (ADS)

    Guan, Li; Huang, Hung-Lung A.; Gao, Wei; Weisz, Elisabeth; Li, Jun

    2004-10-01

    In this paper we present regional high spatial resolution sounding products from MODIS and AIRS data processed by both stand-alone and synergistic retrieval approaches. These unique regional high spatial resolution (at sensor"s single field of view) atmospheric sounding products such as temperature, total precipitable water and surface temperature can provide valuable information for regional near-real time weather monitoring and meso-scale synoptic analysis, and other local environmental applications. Performance comparison between stand-alone and fusion products will assist validation effort and lead to the refinement of processing algorithms. Synergistic utilization of MODIS and AIRS data will also demonstrate the complementary information content provided by two different sensors and will pave the way for future optimal amalgamation of imaging and sounding data.

  20. prfectBLAST: a platform-independent portable front end for the command terminal BLAST+ stand-alone suite.

    PubMed

    Santiago-Sotelo, Perfecto; Ramirez-Prado, Jorge Humberto

    2012-11-01

    prfectBLAST is a multiplatform graphical user interface (GUI) for the stand-alone BLAST+ suite of applications. It allows researchers to do nucleotide or amino acid sequence similarity searches against public (or user-customized) databases that are locally stored. It does not require any dependencies or installation and can be used from a portable flash drive. prfectBLAST is implemented in Java version 6 (SUN) and runs on all platforms that support Java and for which National Center for Biotechnology Information has made available stand-alone BLAST executables, including MS Windows, Mac OS X, and Linux. It is free and open source software, made available under the GNU General Public License version 3 (GPLv3) and can be downloaded at www.cicy.mx/sitios/jramirez or http://code.google.com/p/prfectblast/. PMID:23148880

  1. Comparison of Operating Time between Stand-alone Cage and a Standard Method for a Single Level Cervical Disc Disease

    PubMed Central

    Kim, Chang Hyoun; Chung, Chun Kee; Jahng, Tae-Ahn

    2012-01-01

    Objective Autologous bone graft with anterior plating had been a standard method for anterior cervical discectomy and fusion (ACDF). Drawbacks of a standard method were donor site problem and problem associated with anterior plate. The stand-alone cage was introduced to reduce such problems. However, problems associated with subsidence and local kyphosis at the index level (segmental kyphosis) still persist with stand-alone cage and a standard method would be required in some cases. It seems that harvest of autologous bone and anterior plating procedure is time consuming, but this has not been verified. The aim of this study was to compare the operating time between patients operated on with stand-alone cage versus a standard method for single-level cervical disc disease. Methods Consecutive 29 patients (M:F=18:11; mean age, 58.4±12.4 years), who had undergone ACDF for single-level disc disease by a single surgeon from incision to closure during 2009-2011, were selected for this retrospective study. Seventeen patients were operated with stand-alone cage (Group I), and twelve patients were with a standard method (Group II). Operating time (from incision to closure), estimated blood loss, clinical and radiological outcomes were compared. Follow-up period was 11.4±6.3 months. Results Operating time was not different between groups longer; Group I (96.1±28.7 minutes) and Group II (112.4±31.7 minutes) (p=0.13). There was no surgery related complication. Excellent or good outcome was achieved in 11 and 10 patients of group I and II, respectively. Bony fusion was achieved in 15 and 10 patients of group I and II respectively, while one subsidence occurred in each group. Postoperative segmental angle at the index level and cervical curvature was not different between groups. No patient complained donor site pain at the last follow-up. Conclusions ACDF with a standard method for single-level cervical disc disease was not a time-consuming procedure comparing stand-alone cage. PMID:25983782

  2. Stand-Alone Personalized Normative Feedback for College Student Drinkers: A Meta-Analytic Review, 2004 to 2014

    PubMed Central

    Dotson, Keri B.

    2015-01-01

    Background Norms clarification has been identified as an effective component of college student drinking interventions, prompting research on norms clarification as a single-component intervention known as Personalized Normative Feedback (PNF). Previous reviews have examined PNF in combination with other components but not as a stand-alone intervention. Objectives To investigate the degree to which computer-delivered stand-alone personalized normative feedback interventions reduce alcohol consumption and alcohol-related harms among college students and to compare gender-neutral and gender-specific PNF. Data Sources Electronic databases were searched systematically through November 2014. Reference lists were reviewed manually and forward and backward searches were conducted. Selection Criteria Outcome studies that compared computer-delivered, stand-alone PNF intervention with an assessment only, attention-matched, or active treatment control and reported alcohol use and harms among college students. Methods Between-group effect sizes were calculated as the standardized mean difference in change scores between treatment and control groups divided by pooled standard deviation. Within-group effect sizes were calculated as the raw mean difference between baseline and follow-up divided by pooled within-groups standard deviation. Results Eight studies (13 interventions) with a total of 2,050 participants were included. Compared to control participants, students who received gender-neutral (dbetween = 0.291, 95% CI [0.159, 0.423]) and gender-specific PNF (dbetween = 0.284, 95% CI [0.117, 0.451]) reported greater reductions in drinking from baseline to follow-up. Students who received gender-neutral PNF reported 3.027 (95% CI [2.171, 3.882]) fewer drinks per week at first follow-up and gender-specific PNF reported 3.089 (95% CI [0.992, 5.186]) fewer drinks. Intervention effects were small for harms (dbetween = 0.157, 95% CI [0.037, 0.278]). Conclusions Computer-delivered PNF is an effective stand-alone approach for reducing college student drinking and has a small impact on alcohol-related harms. Effects are small but clinically relevant when considered from a public health perspective. Additional research is needed to examine computer-delivered, stand-alone PNF as a population-level prevention program. PMID:26447792

  3. A simple mathematical description of an off-grid hybrid solar-wind power generating system

    NASA Astrophysics Data System (ADS)

    Blasone, M.; Dell'Anno, F.; De Luca, R.; Torre, G.

    2013-05-01

    We give a detailed description of the energy balance equation for a stand-alone hybrid solar-wind power generating system. The dimensions of the power generator and the energy capacity of a buffer battery (used as an energy storage system) are chosen to suit a known consumer's profile. Future applications of the mathematical model developed and analogies with a similar hydrodynamic problem are discussed.

  4. Performance of a stand-alone wind-electric ice maker for remote villages

    SciTech Connect

    Davis, H.C.; Brandemuehl, M.J.; Bergey, M.L.S.

    1995-01-01

    Two ice makers in the 1.1 metric tons per 24 hours (1.2 tons per day) size range were tested to determine their performance when directly coupled to a variable-frequency wind turbine generator. Initial tests were conducted using a dynamometer to simulate to wind to evaluate whether previously determined potential problems were significant and to define basic performance parameters. Field testing in Norman, Oklahoma, was completed to determine the performance of one of the ice makers under real wind conditions. As expected, the ice makers produced more ice at a higher speed than rated, and less ice at a lower speed. Due to the large start-up torque requirement of reciprocating compressors, the ice making system experienced a large start-up current and corresponding voltage drop which required a larger wind turbine that expected to provide the necessary current and voltage. Performance curves for ice production and power consumption are presented. A spreadsheet model was constructed to predict ice production at a user-defined site given the wind conditions for that location. Future work should include long-term performance tests and research on reducing the large start-up currents the system experiences when first coming on line.

  5. Human microRNA target analysis and gene ontology clustering by GOmir, a novel stand-alone application

    PubMed Central

    Roubelakis, Maria G; Zotos, Pantelis; Papachristoudis, Georgios; Michalopoulos, Ioannis; Pappa, Kalliopi I; Anagnou, Nicholas P; Kossida, Sophia

    2009-01-01

    Background microRNAs (miRNAs) are single-stranded RNA molecules of about 20–23 nucleotides length found in a wide variety of organisms. miRNAs regulate gene expression, by interacting with target mRNAs at specific sites in order to induce cleavage of the message or inhibit translation. Predicting or verifying mRNA targets of specific miRNAs is a difficult process of great importance. Results GOmir is a novel stand-alone application consisting of two separate tools: JTarget and TAGGO. JTarget integrates miRNA target prediction and functional analysis by combining the predicted target genes from TargetScan, miRanda, RNAhybrid and PicTar computational tools as well as the experimentally supported targets from TarBase and also providing a full gene description and functional analysis for each target gene. On the other hand, TAGGO application is designed to automatically group gene ontology annotations, taking advantage of the Gene Ontology (GO), in order to extract the main attributes of sets of proteins. GOmir represents a new tool incorporating two separate Java applications integrated into one stand-alone Java application. Conclusion GOmir (by using up to five different databases) introduces miRNA predicted targets accompanied by (a) full gene description, (b) functional analysis and (c) detailed gene ontology clustering. Additionally, a reverse search initiated by a potential target can also be conducted. GOmir can freely be downloaded BRFAA. PMID:19534746

  6. Clinical outcome of stand-alone ALIF compared to posterior instrumentation for degenerative disc disease: A pilot study and a literature review.

    PubMed

    Udby, Peter M; Bech-Azeddine, Rachid

    2015-06-01

    The objective of the article was to: a) present results from a case cohort pilot study comparing stand-alone ALIF and TLIF and, b) review the literature on studies comparing the clinical outcome of stand-alone ALIF with posterior instrumentation including TLIF or PLIF, in patients with disabling low back pain resulting from degenerative disc disease. ALIF surgery has previously been linked with certain high risk complications and unfavorable long term fusion results. Newer studies suggest that stand-alone ALIF can possibly be advantageous compared to other types of posterior instrumented interbody fusion for a selected group of DDD patients. The methods and material consisted of a cohort pilot study of patients, with DDD treated with stand-alone ALIF or TLIF followed by a literature review conducted through a comprehensive PubMed database search of the English literature. Studies comparing stand-alone ALIF with posterior instrumented interbody fusion were selected and reviewed. Results from the pilot study, n = 21, showed a reduced perioperative blood loss, shorter operative time and a trend towards better pain reduction and decreased use of opioid analgesics in patients undergoing stand-alone ALIF compared to posterior instrumented fusion with TLIF. The literature review included three studies, n = 630. All three studies were retrospective cohort studies. The average patient follow-up was 2-years but with heterogeneous selected outcomes. Two of three articles documented significant advantages when using stand-alone ALIF on outcomes such as ODI, VAS, surgical time, blood loss and patient satisfaction. No study found stand-alone ALIF inferior in chosen outcomes including fusion. In conclusion the pilot study and the literature review, finds similar clinical outcomes and fusion rates after stand-alone ALIF and posterior interbody fusion. Stand-alone ALIF was associated with a shorter duration of surgery, less perioperative blood loss and a faster improvement post-operatively. Therefore stand-alone ALIF is a viable and important surgical option, which could be considered first choice as surgical treatment. PMID:25855474

  7. Design and fabrication of a photovoltaic power system for the Papago Indian village of Schuchuli (Gunsight), Arizona

    NASA Technical Reports Server (NTRS)

    Bifano, W. J.; Ratajczak, A. F.; Ice, W. J.

    1978-01-01

    A stand alone photovoltaic power system for installation in the Papago Indian village of Schuchuli is being designed and fabricated to provide electricity for village water pumping and basic domestic needs. The system will consist of a 3.5 kW (peak) photovoltaic array; controls, instrumentations, and storage batteries located in an electrical equipment building and a 120 volt dc village distribution network. The system will power a 2 HP dc electric motor.

  8. Can Network Characteristics Detect Spam Effectively in a Stand-Alone Enterprise?

    NASA Astrophysics Data System (ADS)

    Ouyang, Tu; Ray, Soumya; Rabinovich, Michael; Allman, Mark

    Previous work has shown that the network dynamics experienced by both the initial packet and an entire connection carrying an email can be leveraged to classify the email as spam or ham. In the case of packet properties, the prior work has investigated their efficacy based on models of traffic collected from around the world. In this paper, we first revisit the techniques when only using information from a single enterprise's vantage point and find packet properties to be less useful. We also show that adding flow characteristics to a model of packet features adds modest discriminating power, and some flow features' information is captured by packet features.

  9. Biomechanical comparison of three stand-alone lumbar cages — a three-dimensional finite element analysis

    PubMed Central

    2013-01-01

    Background For anterior lumbar interbody fusion (ALIF), stand-alone cages can be supplemented with vertebral plate, locking screws, or threaded cylinder to avoid the use of posterior fixation. Intuitively, the plate, screw, and cylinder aim to be embedded into the vertebral bodies to effectively immobilize the cage itself. The kinematic and mechanical effects of these integrated components on the lumbar construct have not been extensively studied. A nonlinearly lumbar finite-element model was developed and validated to investigate the biomechanical differences between three stand-alone (Latero, SynFix, and Stabilis) and SynCage-Open plus transpedicular fixation. All four cages were instrumented at the L3-4 level. Methods The lumbar models were subjected to the follower load along the lumbar column and the moment at the lumbar top to produce flexion (FL), extension (EX), left/right lateral bending (LLB, RLB), and left/right axial rotation (LAR, RAR). A 10 Nm moment was applied to obtain the six physiological motions in all models. The comparison indices included disc range of motion (ROM), facet contact force, and stresses of the annulus and implants. Results At the surgical level, the SynCage-open model supplemented with transpedicular fixation decreased ROM (>76%) greatly; while the SynFix model decreased ROM 56-72%, the Latero model decreased ROM 36-91%, in all motions as compared with the INT model. However, the Stabilis model decreased ROM slightly in extension (11%), lateral bending (21%), and axial rotation (34%). At the adjacent levels, there were no obvious differences in ROM and annulus stress among all instrumented models. Conclusions ALIF instrumentation with the Latero or SynFix cage provides an acceptable stability for clinical use without the requirement of additional posterior fixation. However, the Stabilis cage is not favored in extension and lateral bending because of insufficient stabilization. PMID:24088294

  10. Alignment of the CMS silicon strip tracker during stand-alone commissioning

    SciTech Connect

    Adam, W.; et al.

    2009-07-01

    The results of the CMS tracker alignment analysis are presented using the data from cosmic tracks, optical survey information, and the laser alignment system at the Tracker Integration Facility at CERN. During several months of operation in the spring and summer of 2007, about five million cosmic track events were collected with a partially active CMS Tracker. This allowed us to perform first alignment of the active silicon modules with the cosmic tracks using three different statistical approaches; validate the survey and laser alignment system performance; and test the stability of Tracker structures under various stresses and temperatures ranging from +15C to -15C. Comparison with simulation shows that the achieved alignment precision in the barrel part of the tracker leads to residual distributions similar to those obtained with a random misalignment of 50 (80) microns in the outer (inner) part of the barrel.

  11. COMPARING UTILITY CONNECTED TO STAND ALONE MICRO-GRIDS: FROM THE VIEWPOINT OF A UTILITY ENGINEER

    SciTech Connect

    Hoffman, Michael G.; Russo, Bryan J.

    2011-06-23

    Project examples of grid connected micro grid & example of grid isolated micro grid: drivers – economic, environmental and financial tools to plan/design modeling software resource options, tools to plan/design generation types, fuel options and services to provide smooth transitions required equipment and software controls minimal expense to maximum functionality, real time operational interfaces, getting it built real world complications and advice. This paper is an attempt to present a broad overview of micro grids, project examples, modeling tools, technology options, practical and business insights to enable those interested in micro-grids to quickly come up to speed on the basics and potentially move forward on their own projects with the tools and resources presented. Knowledge and experience with electrical distribution systems will make such an effort easier.

  12. Continuous stand-alone controllable aerosol/cloud droplet dryer for atmospheric sampling

    NASA Astrophysics Data System (ADS)

    Sjogren, S.; Frank, G. P.; Berghof, M. I. A.; Martinsson, B. G.

    2013-02-01

    We describe a general-purpose dryer designed for continuous sampling of atmospheric aerosol, where a specified relative humidity (RH) of the sample flow (lower than the atmospheric humidity) is required. It is often prescribed to measure the properties of dried aerosol, for instance for monitoring networks. The specific purpose of our dryer is to dry cloud droplets (maximum diameter approximately 25 μm, highly charged, up to 5 × 102 charges). One criterion is to minimise losses from the droplet size distribution entering the dryer as well as on the residual dry particle size distribution exiting the dryer. This is achieved by using a straight vertical downwards path from the aerosol inlet mounted above the dryer, and removing humidity to a dry, closed loop airflow on the other side of a semi-permeable GORE-TEX membrane (total area 0.134 m2). The water vapour transfer coefficient, k, was measured to be 4.6 × 10-7 kg m-2 s-1% RH-1 in the laboratory (temperature 294 K) and is used for design purposes. A net water vapour transfer rate of up to 1.2 × 10-6 kg s-1 was achieved in the field. This corresponds to drying a 5.7 L min-1 (0.35 m3 h-1) aerosol sample flow from 100% RH to 27% RH at 293 K (with a drying air total flow of 8.7 L min-1). The system was used outdoors from 9 May until 20 October 2010, on the mountain Brocken (51.80° N, 10.67° E, 1142 m a.s.l.) in the Harz region in central Germany. Sample air relative humidity of less than 30% was obtained 72% of the time period. The total availability of the measurement system was >94% during these five months.

  13. APT - NASA ENHANCED VERSION OF AUTOMATICALLY PROGRAMMED TOOL SOFTWARE - STAND-ALONE VERSION

    NASA Technical Reports Server (NTRS)

    Premo, D. A.

    1994-01-01

    The APT code is one of the most widely used software tools for complex numerically controlled (N/C) machining. APT is an acronym for Automatically Programmed Tools and is used to denote both a language and the computer software that processes that language. Development of the APT language and software system was begun over twenty years ago as a U. S. government sponsored industry and university research effort. APT is a "problem oriented" language that was developed for the explicit purpose of aiding the N/C machine tools. Machine-tool instructions and geometry definitions are written in the APT language to constitute a "part program." The APT part program is processed by the APT software to produce a cutter location (CL) file. This CL file may then be processed by user supplied post processors to convert the CL data into a form suitable for a particular N/C machine tool. This June, 1989 offering of the APT system represents an adaptation, with enhancements, of the public domain version of APT IV/SSX8 to the DEC VAX-11/780 for use by the Engineering Services Division of the NASA Goddard Space Flight Center. Enhancements include the super pocket feature which allows concave and convex polygon shapes of up to 40 points including shapes that overlap, that leave islands of material within the pocket, and that have one or more arcs as part of the pocket boundary. Recent modifications to APT include a rework of the POCKET subroutine and correction of an error that prevented the use within a macro of a macro variable cutter move statement combined with macro variable double check surfaces. Former modifications included the expansion of array and buffer sizes to accommodate larger part programs, and the insertion of a few user friendly error messages. The APT system software on the DEC VAX-11/780 is organized into two separate programs: the load complex and the APT processor. The load complex handles the table initiation phase and is usually only run when changes to the APT processor capabilities are made. This phase initializes character recognition and syntax tables for the APT processor by creating FORTRAN block data programs. The APT processor consists of four components: the translator, the execution complex, the subroutine library, and the CL editor. The translator examines each APT statement in the part program for recognizable structure and generates a new statement, or series of statements, in an intermediate language. The execution complex processes all of the definition, motion, and related statements to generate cutter location coordinates. The subroutine library contains routines defining the algorithms required to process the sequenced list of intermediate language commands generated by the translator. The CL editor re-processes the cutter location coordinates according to user supplied commands to generate a final CL file. A sample post processor is also included which translates a CL file into a form for use with a Wales Strippit Fabramatic Model 30/30 sheet metal punch. The user should be able to readily develop post processors for other N/C machine tools. The APT language is a statement oriented, sequence dependent language. With the exception of such programming techniques as looping and macros, statements in an APT program are executed in a strict first-to-last sequence. In order to provide programming capability for the broadest possible range of parts and of machine tools, APT input (and output) is generalized, as represented by 3-dimensional geometry and tools, and arbitrarily uniform, as represented by the moving tool concept and output data in absolute coordinates. A command procedure allows the user to select the desired part program, ask for a graphics file of cutter motions in IGES format, and submit the procedure as a batch job, if desired. The APT system software is written in FORTRAN 77 for batch and interactive execution and has been implemented on a DEC VAX series computer under VMS 4.4. The enhancements for this version of APT were last updated in June, 1989. The NASA adaptation, with enhancements, of the public domain version of the APT IV/SSX8 software to the DEC VAX-11/780 is available by license for a period of ten (10) years to approved licensees. The licensed program product delivered includes the APT IV/SSX8 system source code, object code, executable images, and command procedures and one set of supporting documentation. Additional copies of the supporting documentation may be purchased at any time at the price indicated below.

  14. Dynamical downscaling of historical climate over CORDEX East Asia domain: A comparison of regional ocean-atmosphere coupled model to stand-alone RCM simulations

    NASA Astrophysics Data System (ADS)

    Zou, Liwei; Zhou, Tianjun; Peng, Dongdong

    2016-02-01

    The FROALS (flexible regional ocean-atmosphere-land system) model, a regional ocean-atmosphere coupled model, has been applied to the Coordinated Regional Downscaling Experiment (CORDEX) East Asia domain. Driven by historical simulations from a global climate system model, dynamical downscaling for the period from 1980 to 2005 has been conducted at a uniform horizontal resolution of 50 km. The impacts of regional air-sea couplings on the simulations of East Asian summer monsoon rainfall have been investigated, and comparisons have been made to corresponding simulations performed using a stand-alone regional climate model (RCM). The added value of the FROALS model with respect to the driving global climate model was evident in terms of both climatology and the interannual variability of summer rainfall over East China by the contributions of both the high horizontal resolution and the reasonably simulated convergence of the moisture fluxes. Compared with the stand-alone RCM simulations, the spatial pattern of the simulated low-level monsoon flow over East Asia and the western North Pacific was improved in the FROALS model due to its inclusion of regional air-sea coupling. The results indicated that the simulated sea surface temperature (SSTs) resulting from the regional air-sea coupling were lower than those derived directly from the driving global model over the western North Pacific north of 15°N. These colder SSTs had both positive and negative effects. On the one hand, they strengthened the western Pacific subtropical high, which improved the simulation of the summer monsoon circulation over East Asia. On the other hand, the colder SSTs suppressed surface evaporation and favored weaker local interannual variability in the SST, which led to less summer rainfall and weaker interannual rainfall variability over the Korean Peninsula and Japan. Overall, the reference simulation performed using the FROALS model is reasonable in terms of rainfall over the land area of East Asia and will become the basis for the generation of climate change scenarios for the CORDEX East Asia domain that will be described in future reports.

  15. An explosively driven high-power microwave pulsed power system

    NASA Astrophysics Data System (ADS)

    Elsayed, M. A.; Neuber, A. A.; Dickens, J. C.; Walter, J. W.; Kristiansen, M.; Altgilbers, L. L.

    2012-02-01

    The increased popularity of high power microwave systems and the various sources to drive them is the motivation behind the work to be presented. A stand-alone, self-contained explosively driven high power microwave pulsed power system has been designed, built, and tested at Texas Tech University's Center for Pulsed Power and Power Electronics. The system integrates four different sub-units that are composed of a battery driven prime power source utilizing capacitive energy storage, a dual stage helical flux compression generator as the main energy amplification device, an integrated power conditioning system with inductive energy storage including a fast opening electro-explosive switch, and a triode reflex geometry virtual cathode oscillator as the microwave radiating source. This system has displayed a measured electrical source power level of over 5 GW and peak radiated microwaves of about 200 MW. It is contained within a 15 cm diameter housing and measures 2 m in length, giving a housing volume of slightly less than 39 l. The system and its sub-components have been extensively studied, both as integrated and individual units, to further expand on components behavior and operation physics. This report will serve as a detailed design overview of each of the four subcomponents and provide detailed analysis of the overall system performance and benchmarks.

  16. Standing Alone in Judgment

    ERIC Educational Resources Information Center

    Freado, Mark D.; Bath, Howard I.

    2014-01-01

    In this article, Mark Freado and Howard Bath present the case of an 11 year boy who had been arrested and charged with the murder of his two-year-old cousin. Because of the severity of the criminal charge against this boy, and despite his age, a transfer hearing was set to determine whether he would be tried as a juvenile or an adult. Such…

  17. Standing Alone in Judgment

    ERIC Educational Resources Information Center

    Freado, Mark D.; Bath, Howard I.

    2014-01-01

    In this article, Mark Freado and Howard Bath present the case of an 11 year boy who had been arrested and charged with the murder of his two-year-old cousin. Because of the severity of the criminal charge against this boy, and despite his age, a transfer hearing was set to determine whether he would be tried as a juvenile or an adult. Such

  18. CRionScan: A stand-alone real time controller designed to perform ion beam imaging, dose controlled irradiation and proton beam writing

    NASA Astrophysics Data System (ADS)

    Daudin, L.; Barberet, Ph.; Serani, L.; Moretto, Ph.

    2013-07-01

    High resolution ion microbeams, usually used to perform elemental mapping, low dose targeted irradiation or ion beam lithography needs a very flexible beam control system. For this purpose, we have developed a dedicated system (called “CRionScan”), on the AIFIRA facility (Applications Interdisciplinaires des Faisceaux d'Ions en Région Aquitaine). It consists of a stand-alone real-time scanning and imaging instrument based on a Compact Reconfigurable Input/Output (Compact RIO) device from National Instruments™. It is based on a real-time controller, a Field Programmable Gate Array (FPGA), input/output modules and Ethernet connectivity. We have implemented a fast and deterministic beam scanning system interfaced with our commercial data acquisition system without any hardware development. CRionScan is built under LabVIEW™ and has been used on AIFIRA's nanobeam line since 2009 (Barberet et al., 2009, 2011) [1,2]. A Graphical User Interface (GUI) embedded in the Compact RIO as a web page is used to control the scanning parameters. In addition, a fast electrostatic beam blanking trigger has been included in the FPGA and high speed counters (15 MHz) have been implemented to perform dose controlled irradiation and on-line images on the GUI. Analog to Digital converters are used for the beam current measurement and in the near future for secondary electrons imaging. Other functionalities have been integrated in this controller like LED lighting using Pulse Width Modulation and a “NIM Wilkinson ADC” data acquisition.

  19. Emerging technologies: polymer-free phospholipid encapsulated sirolimus nanocarriers for the controlled release of drug from a stent-plus-balloon or a stand-alone balloon catheter.

    PubMed

    Lemos, Pedro A; Farooq, Vasim; Takimura, Celso K; Gutierrez, Paulo S; Virmani, Renu; Kolodgie, Frank; Christians, Uwe; Kharlamov, Alexander; Doshi, Manish; Sojitra, Prakash; van Beusekom, Heleen M M; Serruys, Patrick W

    2013-05-20

    Drug-eluting stents have proven to be effective in reducing the risk of late restenosis. In order to achieve a controlled and prolonged release of the antiproliferative agent, current drug-eluting stents utilise various biodegradable as well as non-erodible polymeric blends to coat the stent surface and to serve as drug carriers. The utilisation of polymeric compounds in current drug-eluting stents may eventually limit their performance as well as their clinical applicability due to the potential induction of undesirable local reactions. The development of alternative, polymer-free drug carriers has the potential to overcome some of the limitations of current drug-eluting stent formulations. Moreover, improvements in drug carriers may also result in an expansion of the technological possibilities for other intravascular drug delivery systems, such as metal-free or even implant-free solutions. This article describes the structure and the preclinical validation profile of a novel phospholipid encapsulated sirolimus nanocarrier, used as a coating in two formulations: a coronary stent-plus-balloon system and a stand-alone balloon catheter. The nanoparticles provided a stable, even and homogenous coating to the devices in both formulations. Dose-finding studies allowed the most appropriate identification of the best nanoparticle structure associated with an extremely efficient transfer of drug to all layers of the vessel wall, achieving high tissue concentrations that persisted days after the application, with low systemic drug leaks. PMID:23685303

  20. Numerical Study of Cerebroarterial Hemodynamic Changes Following Carotid Artery Operation: A Comparison Between Multiscale Modeling and Stand-Alone Three-Dimensional Modeling.

    PubMed

    Liang, Fuyou; Oshima, Marie; Huang, Huaxiong; Liu, Hao; Takagi, Shu

    2015-10-01

    Free outflow boundary conditions have been widely adopted in hemodynamic model studies, they, however, intrinsically lack the ability to account for the regulatory mechanisms of systemic hemodynamics and hence carry a risk of producing incorrect results when applied to vascular segments with multiple outlets. In the present study, we developed a multiscale model capable of incorporating global cardiovascular properties into the simulation of blood flows in local vascular segments. The multiscale model was constructed by coupling a three-dimensional (3D) model of local arterial segments with a zero-one-dimensional (0-1-D) model of the cardiovascular system. Numerical validation based on an idealized model demonstrated the ability of the multiscale model to preserve reasonable pressure/flow wave transmission among different models. The multiscale model was further calibrated with clinical data to simulate cerebroarterial hemodynamics in a patient undergoing carotid artery operation. The results showed pronounced hemodynamic changes in the cerebral circulation following the operation. Additional numerical experiments revealed that a stand-alone 3D model with free outflow conditions failed to reproduce the results obtained by the multiscale model. These results demonstrated the potential advantage of multiscale modeling over single-scale modeling in patient-specific hemodynamic studies. Due to the fact that the present study was limited to a single patient, studies on more patients would be required to further confirm the findings. PMID:26343584

  1. Application of a stand-alone anchored spacer in noncontiguous anterior cervical arthrodesis with radiologic analysis of the intermediate segment.

    PubMed

    Shi, Sheng; Liu, Zu-De; You, Wen-Jie; Ouyang, Yue-Ping; Li, Xin-Feng; Qian, Lie; Zhong, Gui-Bin

    2016-03-01

    The purpose of this study was to describe the clinical features of noncontiguous cervical degenerative disc disease (cDDD), investigate the efficacy and complications of a stand-alone anchored spacer (SAAS) for patients with noncontiguous cDDD, and present radiologic analysis of the intermediate segment (IS) after skip-level fusion. Nineteen consecutive patients with noncontiguous cDDD who underwent skip-level anterior cervical discectomy and fusion (ACDF) with SAAS from January 2010 to December 2012 were enrolled in this study. Clinical outcomes were assessed preoperatively and at 24months postoperatively using the Japanese Orthopaedic Association score, Neck Disability Index, and Visual Analog Scale. Overall cervical alignment (OCA) of the cervical spine, and the range of motion (ROM), intervertebral disc height (IDH), disc signal intensity and disc protrusion of IS were measured and compared before and after surgery. Clinical outcomes significantly improved compared to preoperative scores. The OCA was corrected and maintained at 24months postoperatively compared with preoperative values (p<0.05). There were no significant differences in the ROM and IDH of the IS at each follow-up (p>0.05). However, decreased signal intensity on T2-weighted MRI was evidenced in three mobile IS at final follow-up (20.0%). Skip-level ACDF with SAAS may be an efficacious option for the treatment of noncontiguous cDDD. PMID:26597607

  2. IntellCAD: Software to enhance CAD and database management systems for power system operations. Final report

    SciTech Connect

    1995-05-01

    IntellCAD for PC Windows has been designed and developed specially for electric power utilities to view and navigate existing utility drawings and databases easily. It is a stand-alone system and runs outside AutoCAD. IntellCAD is designed for use by electric utility personnel without any special knowledge of CAD systems. It provides Open System Architecture and offers Open Data Base Connectivity (ODBC), the industry standard for linking database files. IntellCAD can be used as an open platform for integrating power system analytical tools, such as power flow, short circuit and fault location calculation.

  3. Bimode uninterruptible power supply compatibility in renewable hybrid energy systems

    SciTech Connect

    Bower, W. ); O'Sullivan, G. )

    1990-08-01

    Inverters installed in renewable hybrid energy systems are typically used in a stand-alone mode to supply ac power to loads from battery storage when the engine-generator is not being used. Similarities in topology and in the performance requirements of the standby uninterruptible power supply (UPS) system and the hybrid system suggest the UPS could be used in hybrid energy systems. Another alternative to inverters with add-on charging circuits or standby UPS hardware is the Bimode UPS. The bimode UPS uses common circuitry and power components for dc to ac inversion and battery charging. It also provides an automatic and nearly instantaneous ac power transfer function when the engine-generator is started or stopped. The measured operating and transfer characteristics of a bimode UPS in a utility system and in a hybrid system are presented. The applicability of the bimode UPS to hybrid systems and its compatibility in a PV/engine-generator hybrid system are given.

  4. Adult Degenerative Scoliosis with Spinal Stenosis Treated with Stand-Alone Cage via an Extreme Lateral Transpsoas Approach; a Case Report and Literature Review

    PubMed Central

    von Keudell, Arvind; Alimi, Marjan; Gebhard, Harry; Härtl, Roger

    2015-01-01

    We report the case of a 73-year-old female with severe degenerative scoliosis and back and leg pain that was successfully treated with stand- alone cages via an extreme lateral transpsoas approach. This patient had declined open surgery and instrumentation due to her advanced age concerns about potential side effects. PMID:26110180

  5. Estuary Data Mapper: A Stand-Alone Tool for Geospatial Data Access, Visualization and Download for Estuaries and Coastal Watersheds of the United States

    EPA Science Inventory

    The US EPA Estuary Data Mapper (EDM; http://badger.epa.gov/rsig/edm/index.html) has been designed as a free stand-alone tool for geospatial data discovery, visualization, and data download for estuaries and their associated watersheds in the conterminous United States. EDM requi...

  6. Estuary Data Mapper: A Stand-Alone Tool for Geospatial Data Access, Visualization and Download for Estuaries and Coastal Watersheds of the United States. (UNH)

    EPA Science Inventory

    The US EPA Estuary Data Mapper (EDM; http://badger.epa.gov/rsig/edm/index.html) has been designed as a free stand-alone tool for geospatial data discovery, visualization, and data download for estuaries and their associated watersheds in the conterminous United States. EDM requi...

  7. Preparing Teachers to Integrate Technology into K-12 Instruction: Comparing a Stand-Alone Technology Course with a Technology-Infused Approach

    ERIC Educational Resources Information Center

    Buss, Ray R.; Wetzel, Keith; Foulger, Teresa S.; Lindsey, LeeAnn

    2015-01-01

    We compared the effectiveness of learning technological, pedagogical, and content knowledge (TPACK) domain knowledge in a new technology-infused approach for teaching technology to teacher candidates with a more traditional, stand-alone course. In the new approach, learning to use technology is infused into program methods courses. Candidates all…

  8. Preparing Teachers to Integrate Technology into K-12 Instruction: Comparing a Stand-Alone Technology Course with a Technology-Infused Approach

    ERIC Educational Resources Information Center

    Buss, Ray R.; Wetzel, Keith; Foulger, Teresa S.; Lindsey, LeeAnn

    2015-01-01

    We compared the effectiveness of learning technological, pedagogical, and content knowledge (TPACK) domain knowledge in a new technology-infused approach for teaching technology to teacher candidates with a more traditional, stand-alone course. In the new approach, learning to use technology is infused into program methods courses. Candidates all

  9. Leadership in Dental Hygiene Degree Completion Programs: A Pilot Study Comparing Stand-Alone Leadership Courses and Leadership-Infused Curricula.

    PubMed

    Smith, Michelle L; Gurenlian, JoAnn R; Freudenthal, Jacqueline J; Farnsworth, Tracy J

    2016-05-01

    The aim of this study was to define the extent to which leadership and leadership skills are taught in dental hygiene degree completion programs by comparing stand-alone leadership courses/hybrid programs with programs that infuse leadership skills throughout the curricula. The study involved a mixed-methods approach using qualitative and quantitative data. Semi-structured interviews were conducted with program directors and faculty members who teach a stand-alone leadership course, a hybrid program, or leadership-infused courses in these programs. A quantitative comparison of course syllabi determined differences in the extent of leadership content and experiences between stand-alone leadership courses and leadership-infused curricula. Of the 53 U.S. dental hygiene programs that offer degree completion programs, 49 met the inclusion criteria, and 19 programs provided course syllabi. Of the program directors and faculty members who teach a stand-alone leadership course or leadership-infused curriculum, 16 participated in the interview portion of the study. The results suggested that competencies related to leadership were not clearly defined or measurable in current teaching. Reported barriers to incorporating a stand-alone leadership course included overcrowded curricula, limited qualified faculty, and lack of resources. The findings of this study provide a synopsis of leadership content and gaps in leadership education for degree completion programs. Suggested changes included defining a need for leadership competencies and providing additional resources to educators such as courses provided by the American Dental Education Association and the American Dental Hygienists' Association. PMID:27139211

  10. Subtask 3.12 - Small Power Systems

    SciTech Connect

    Sprynczynatyk, C.; Schmidt, L.; Kurz, M.D.; Mann, M.D.; Kjelden, M.

    1997-08-01

    The programmatic goal in advanced power systems is to develop small integrated waste treatment, water purification, and power systems in the range of 20 kW to 20 MW in cooperation with commercial vendors. These systems will be designed to incorporate the advanced technical capabilities of the Energy and Environmental Research Center (EERC) with the latest advancements in vendor-offered hardware and software. The primary objective for the work to be performed under this subtask is to develop a commercialization plan for small power systems, evaluate alternative design concepts, and select practical and economical designs for targeted development in upcoming years. A leading objective for the EERC will be to continue to form strong business partnerships with equipment manufacturers who can commercialize the selected power system and treatment design(s). FY95 activities were focused on collecting information from vendors and evaluating alternative design concepts. This year's activities began with the process of selecting one design for targeted development. A case study was performed to determine if the combination of water and waste treatment with power generation could improve the economics over a stand-alone power generation system.

  11. Design description of the Schuchuli Village photovoltaic power system

    NASA Astrophysics Data System (ADS)

    Ratajczak, A. F.; Vasicek, R. W.; Delombard, R.

    1981-05-01

    A stand alone photovoltaic (PV) power system for the village of Schuchuli (Gunsight), Arizona, on the Papago Indian Reservation is a limited energy, all 120 V (d.c.) system to which loads cannot be arbitrarily added and consists of a 3.5 kW (peak) PV array, 2380 ampere-hours of battery storage, an electrical equipment building, a 120 V (d.c.) electrical distribution network, and equipment and automatic controls to provide control power for pumping water into an existing water system; operating 15 refrigerators, a clothes washing machine, a sewing machine, and lights for each of the homes and communal buildings. A solar hot water heater supplies hot water for the washing machine and communal laundry. Automatic control systems provide voltage control by limiting the number of PV strings supplying power during system operation and battery charging, and load management for operating high priority at the expense of low priority loads as the main battery becomes depleted.

  12. Design description of the Schuchuli Village photovoltaic power system

    NASA Technical Reports Server (NTRS)

    Ratajczak, A. F.; Vasicek, R. W.; Delombard, R.

    1981-01-01

    A stand alone photovoltaic (PV) power system for the village of Schuchuli (Gunsight), Arizona, on the Papago Indian Reservation is a limited energy, all 120 V (d.c.) system to which loads cannot be arbitrarily added and consists of a 3.5 kW (peak) PV array, 2380 ampere-hours of battery storage, an electrical equipment building, a 120 V (d.c.) electrical distribution network, and equipment and automatic controls to provide control power for pumping water into an existing water system; operating 15 refrigerators, a clothes washing machine, a sewing machine, and lights for each of the homes and communal buildings. A solar hot water heater supplies hot water for the washing machine and communal laundry. Automatic control systems provide voltage control by limiting the number of PV strings supplying power during system operation and battery charging, and load management for operating high priority at the expense of low priority loads as the main battery becomes depleted.

  13. A PC-PCL-based control system for the high-voltage pulsed-power operation of the Intense Diagnostic Neutral Beam (IDNB) Experiment

    SciTech Connect

    Gribble, R.

    1993-06-01

    A stand-alone, semiautomated control system for the high-voltage pulsed-power energy sources on the Intense Diagnostic Neutral Beam Experiment at Los Alamos National Laboratory using personal computer (PC) and programmable logic controller (PLC) technology has been developed and implemented. The control system, consisting of a PC with the graphic operator interface, the network connecting the PC to the PLC, the PLC, the PLC I/O modules, fiber-optic interfaces and software, is described.

  14. Prospective Randomized Controlled Trial of The Stabilis Stand Alone Cage (SAC) Versus Bagby and Kuslich (BAK) Implants for Anterior Lumbar Interbody Fusion

    PubMed Central

    Lavelle, William; McLain, Robert F.; Rufo-Smith, Candace; Gurd, David P.

    2014-01-01

    Background Degenerative disc disease is common and debilitating for many patients. If conservative extensive care fails, anterior lumbar interbody fusion has proven to be an alternative form of surgical management. The Stabilis Stand Alone Cage(SAC) was introduced as a method to obtain stability and fusion. The purpose of this study was to determine whether the Stabilis Stand Alone Cage (SAC) is comparable in safety and efficacy to the Bagby and Kuslich (BAK) device. Methods As part of a prospective, randomized, controlled FDA trial, 73 patients underwent anterior interbody fusion using either the SAC(56%) or the BAK device (44%). Results Background characteristics were similar between the two groups. There was no significant difference between the SAC and BAK groups in mean operative time or mean blood loss during surgery. Adverse event rates did not differ between the groups. Assessment of plain radiographs could not confirm solid fusion in 63% of control and 71% of study patients. Functional scores from Owestry and SF-36 improved in both groups by the two-year follow-up. There were no significant differences between the SAC and BAK patients with respect to outcome. Conclusions Both the Stabilis Stand Alone Cage and the BAK Cage provided satisfactory improvement in function and pain relief, despite less than expected radiographic fusion rates. The apparent incongruency between fusion rates and functional outcomes suggests that either radiographs underestimate the true incidence of fusion, or that patients are obtaining good pain relief and improved function despite a lower rate of fusion than previously reported. This was a Level III study. PMID:25694930

  15. Biomechanical comparison of anterior lumbar interbody fusion: stand-alone interbody cage versus interbody cage with pedicle screw fixation - a finite element analysis

    PubMed Central

    2013-01-01

    Background Anterior lumbar interbody fusion (ALIF) followed by pedicle screw fixation (PSF) is used to restore the height of the intervertebral disc and provide stability. Recently, stand-alone interbody cage with anterior fixation has been introduced, which eliminates the need for posterior surgery. We compared the biomechanics of the stand-alone interbody cage to that of the interbody cage with additional PSF in ALIF. Methods A three-dimensional, non-linear finite element model (FEM) of the L2-5 segment was modified to simulate ALIF in L3-4. The models were tested under the following conditions: (1) intact spine, (2) destabilized spine, (3) with the interbody cage alone (type 1), (4) with the stand-alone cage with anterior fixation (SynFix-LR®; type 2), and (5) with type 1 in addition to PSF (type 3). Range of motion (ROM) and the stiffness of the operated level, ROM of the adjacent segments, load sharing distribution, facet load, and vertebral body stress were quantified with external loading. Results The implanted models had decreased ROM and increased stiffness compared to those of the destabilized spine. The type 2 had differences in ROM limitation of 8%, 10%, 4%, and 6% in flexion, extension, axial rotation, and lateral bending, respectively, compared to those of type 3. Type 2 had decreased ROM of the upper and lower adjacent segments by 3-11% and 3-6%, respectively, compared to those of type 3. The greatest reduction in facet load at the operated level was observed in type 3 (71%), followed by type 2 (31%) and type 1 (23%). An increase in facet load at the adjacent level was highest in type 3, followed by type 2 and type 1. The distribution of load sharing in type 2 (anterior:posterior, 95:5) was similar to that of the intact spine (89:11), while type 3 migrated posterior (75:25) to the normal. Type 2 reduced about 15% of the stress on the lower vertebral endplate compared to that in type 1. The stress of type 2 increased two-fold compared to the stress of type 3, especially in extension. Conclusions The stand-alone interbody cage can provide sufficient stability, reduce stress in adjacent levels, and share the loading distribution in a manner similar to an intact spine. PMID:23890389

  16. Photovoltaic Power System and Power Distribution Demonstration for the Desert RATS Program

    NASA Technical Reports Server (NTRS)

    Colozza, Anthony; Jakupca, Ian; Mintz, Toby; Herlacher, Mike; Hussey, Sam

    2012-01-01

    A stand alone, mobile photovoltaic power system along with a cable deployment system was designed and constructed to take part in the Desert Research And Technology Studies (RATS) lunar surface human interaction evaluation program at Cinder Lake, Arizona. The power system consisted of a photovoltaic array/battery system. It is capable of providing 1 kW of electrical power. The system outputs were 48 V DC, 110 V AC, and 220 V AC. A cable reel with 200 m of power cable was used to provide power from the trailer to a remote location. The cable reel was installed on a small trailer. The reel was powered to provide low to no tension deployment of the cable. The cable was connected to the 220 V AC output of the power system trailer. The power was then converted back to 110 V AC on the cable deployment trailer for use at the remote site. The Scout lunar rover demonstration vehicle was used to tow the cable trailer and deploy the power cable. This deployment was performed under a number of operational scenarios, manned operation, remote operation and tele-robotically. Once deployed, the cable was used to provide power, from the power system trailer, to run various operational tasks at the remote location.

  17. Power system

    DOEpatents

    Hickam, Christopher Dale

    2008-03-18

    A power system includes a prime mover, a transmission, and a fluid coupler having a selectively engageable lockup clutch. The fluid coupler may be drivingly connected between the prime mover and the transmission. Additionally, the power system may include a motor/generator drivingly connected to at least one of the prime mover and the transmission. The power-system may also include power-system controls configured to execute a control method. The control method may include selecting one of a plurality of modes of operation of the power system. Additionally, the control method may include controlling the operating state of the lockup clutch dependent upon the mode of operation selected. The control method may also include controlling the operating state of the motor/generator dependent upon the mode of operation selected.

  18. Expression, purification, crystallization and preliminary crystallographic analysis of a stand-alone RAM domain with hydrolytic activity from the hyperthermophile Pyrococcus furiosus

    SciTech Connect

    Agapay, Ramelito C.; Savvides, Savvas N.; Van Driessche, Gonzalez; Devreese, Bart; Van Beeumen, Jozef; Jongejan, Jaap A. Hagen, Wilfred R.

    2005-10-01

    A P. furiosus stand-alone RAM domain with hydrolytic activity has been cloned and expressed in E. coli. The purified protein was crystallized alone and with EPNP and PMSF, producing crystals that yield diffraction data to resolutions of 2.8, 2.2 and 2.8 Å, respectively. The RAM domain is one of several ligand-binding modules present in prokaryotes that are presumed to regulate the transcription of specific genes. To date, no hydrolytic activity has been reported for such modules. Curiously, a stand-alone RAM domain in Pyrococcus furiosus was isolated during a screen for hydrolytic activity against chromogenic esters. The gene encoding this protein was cloned and expressed in Escherichia coli and crystallized after a single purification step. X-ray diffraction data from the crystals were obtained to a resolution of 2.8 Å using a conventional X-ray source. The cocrystallization of the recombinant protein with 1,2-epoxy-3-(4-nitrophenoxy)propane (EPNP) and phenylmethylsulfonyl fluoride (PMSF) produced crystals that yielded data to 2.2 and 2.8 Å, respectively, using synchrotron radiation. Both the untreated and EPNP-treated crystals crystallize isomorphously in space group C2 and contain three dimers in the asymmetric unit. The PMSF-treated crystals also belong to this space group and have almost identical packing density, but show dramatically different unit-cell parameters.

  19. Adaptive wide area protection of power systems

    NASA Astrophysics Data System (ADS)

    Huang, Jiang

    Studies of major blackouts reveal that power system protection devices have contributed to a majority of system disturbances. This leads to efforts of improving protection philosophy. Analysis shows that conventional protection relies on coordination among stand-alone relays to obtain a dependability-biased component-protection scheme. Whereas it is more desirable and also feasible nowadays for an integrated approach to both component and system protection, provided modern relays possessing the ability of sharing information and applying intelligence in decision-making. This dissertation proposes the adaptive protection concept for wide area systems. The scope of the research includes identifying and developing the desired architecture, intelligent algorithms and communication needs that facilitate the protection system to avoid and reduce the impact of system emergencies. The purpose of this research work is to conceptualize and nurture adaptive protection concept for wide area systems, and to conduct feasibility studies to make this concept practically viable. Several case studies are conducted to show the effectiveness of the proposed adaptive protection scheme. In addition, voltage stability, which is a classic wide area problem, can be alleviated with the proposed concept. Steady state and transient simulation studies provided encouraging results. The detailed decision-making algorithms are simulated in several examples for validation of the concept.

  20. Power Systems Development Facility. Environmental Assessment

    SciTech Connect

    Not Available

    1993-06-01

    The objective of the PSDF would be to provide a modular facility which would support the development of advanced, pilot-scale, coal-based power systems and hot gas clean-up components. These pilot-scale components would be designed to be large enough so that the results can be related and projected to commercial systems. The facility would use a modular approach to enhance the flexibility and capability for testing; consequently, overall capital and operating costs when compared with stand-alone facilities would be reduced by sharing resources common to different modules. The facility would identify and resolve technical barrier, as well as-provide a structure for long-term testing and performance assessment. It is also intended that the facility would evaluate the operational and performance characteristics of the advanced power systems with both bituminous and subbituminous coals. Five technology-based experimental modules are proposed for the PSDF: (1) an advanced gasifier module, (2) a fuel cell test module, (3) a PFBC module, (4) a combustion gas turbine module, and (5) a module comprised of five hot gas cleanup particulate control devices. The final module, the PCD, would capture coal-derived ash and particles from both the PFBC and advanced gasifier gas streams to provide for overall particulate emission control, as well as to protect the combustion turbine and the fuel cell.

  1. Market assessment of photovoltaic power systems for agricultural applications in Nigeria

    SciTech Connect

    Staples, D.; Steingass, H.; Nolfi, J.

    1981-10-01

    The results of a month-long study in Nigeria conducted in February 1981 are detailed. The study was aimed at assessing in the 1981 to 1986 market potential for stand-alone photovoltaic systems in agriculture. Information on technically and economically feasible applications, and assessments of business, government and financial climate for photovoltaic sales are provided. The study concluded that the market for stand-alone photovoltaic power systems will be large, the primary reasons being the availability of capital and the high premium placed on high reliability, low maintenance power systems. A market exists for such agricultural/rural applications as: micro-irrigation, veterinary units, grain grinding, dryers, produce coolers, ice makers, water/boreholes, and health, education and extension services. Other markets with high PV sales potential include: remote local government centers, public and private communication systems, TV battery chargers, domestic power supply and cathodic protection. The potential market for photovoltaics in the 1981 to 1986 time frame is estimated at about 1.9 to 4.7 MW. The major purchaser in the near-term would be the federal and state governments.

  2. Description of photovoltaic village power systems in the United States and Africa

    NASA Technical Reports Server (NTRS)

    Ratajczak, A. F.; Bifano, W. J.

    1979-01-01

    The paper describes the designs, hardware, and installations of NASA photovoltaic power systems in the village of Schuchuli in Arizona and Tangaye in Upper Volta, Africa. The projects were designed to demonstrate that current photovoltaic system technology can provide electrical power for domestic services for small, remote communities. The Schuchuli system has a 3.5 kW peak solar array which provides power for water pumping, a refrigerator for each family, lights, and community washing and sewing machines. The 1.8 kW Tangaye system provides power for pumping, flour milling, and lights in the milling building. Both are stand-alone systems operated by local personnel, and they are monitored by NASA to measure design adequacy and refine future designs.

  3. Lumbar Interspinous Process Fixation and Fusion with Stand-Alone Interlaminar Lumbar Instrumented Fusion Implant in Patients with Degenerative Spondylolisthesis Undergoing Decompression for Spinal Stenosis

    PubMed Central

    Postacchini, Franco; Menchetti, Pier Paolo Maria; Sessa, Pasquale; Paolino, Michela; Cinotti, Gianluca

    2016-01-01

    Study Design Prospective cohort study. Purpose To assess the ability of a stand-alone lumbar interspinous implant (interspinous/interlaminar lumbar instrumented fusion, ILIF) associated with bone grafting to promote posterior spine fusion in degenerative spondylolisthesis (DS) with vertebral instability. Overview of Literature A few studies, using bilateral laminotomy (BL) or bilateral decompression by unilateral laminotomy (BDUL), found satisfactory results in stenotic patients with decompression alone, but others reported increased olisthesis, or subsequent need for fusion in DS with or without dynamic instability. Methods Twenty-five patients with Grade I DS, leg pain and chronic low back pain underwent BL or BDUL and ILIF implant. Olisthesis was 13% to 21%. Follow-up evaluations were performed at 4 to 12 months up to 25 to 44 months (mean, 34.4). Outcome measures were numerical rating scale (NRS) for back and leg pain, Oswestry disability index (ODI) and short-form 36 health survey (SF-36) of body pain and function. Results Fusion occurred in 21 patients (84%). None had increased olisthesis or instability postoperatively. Four types of fusion were identified. In Type I, the posterior part of the spinous processes were fused. In Type II, fusion extended to the base of the processes. In Type III, bone was present also around the polyetheretherketone plate of ILIF. In Type IV, even the facet joints were fused. The mean NRS score for back and leg pain decreased by 64% and 80%, respectively. The mean ODI score was decreased by 52%. SF-36 bodily pain and physical function mean scores increased by 53% and 58%, respectively. Computed tomography revealed failed fusion in four patients, all of whom still had vertebral instability postoperatively. Conclusions Stand-alone ILIF with interspinous bone grafting promotes vertebral fusion in most patients with lumbar stenosis and unstable Grade I DS undergoing BL or BDUL. PMID:26949455

  4. Sensing Technologies in Ubiquitous Network Environment: From Stand-alone Intelligent Sensing to Knowledge-Shared Network Sensing

    NASA Astrophysics Data System (ADS)

    Ando, Shigeru

    Real world consists of various kinds of natural and man-made objects, which are changing, moving, and interacting with each other dynamically. Capturing all these objects widely, continuously, and accurately is the rapidly growing subjects in the sensing technology. In order to use those vast information in the computerized network environment as precious resources, and make the best use of the corresponding physical objects as sustainable resources, we will show in this article how the ubiquitous sensing and networkin systems can be developed based on a tight coupling of sensing and wireless communication technologies, and based on a tight coupling of objects in the real world and information in somewhere in the network via a ubiquitous, automatic identification tag system.

  5. Field detection of bacillus spore aerosols with stand-alone pyrolysis-gas chromatography and ion mobility spectrometry

    NASA Astrophysics Data System (ADS)

    Snyder, A.; Maswadeh, Waleed M.; Parsons, John A.; Tripathi, Ashish; Meuzelaar, Henk L. C.; Dworzanski, Jacek P.; Kim, Man-Goo

    1999-12-01

    A commercially available, hand-held chemical vapor detector was modified to detect Gram-positive Bacillus subtilis var. globigii spores (BG) in outdoor field scenarios. An Airborne Vapor Monitor (AVM) ion mobility spectrometry (IMS) vapor detector was interfaced to a biological sample processing and transfer introduction system. The biological sample processing was accomplished by quartz tube pyrolysis (Py), and the resultant vapor was transferred by gas chromatography (GC) to the IMS detector. The Py-GC/IMS system can be described as a hyphenated device where two analytical dimensions, in series, allow the separation and isolation of individual components from the pyrolytic decomposition of biological analytes. Gram positive spores such as BG contain 5 - 15% by weight of dipicolinic acid (DPA), and picolinic acid is a pyrolysis product of DPA. Picolinic acid has a high proton affinity, and it is detected in a sensitive fashion by the atmospheric pressure-based IMS device. Picolinic acid occupies a unique region in the GC/IMS data domain with respect to other bacterial pyrolysis products. A 1000 to 1, air-to-air, aerosol concentrator was interfaced to the Py-GC/IMS instrument, and the system was placed in an open-air, Western United States desert environment. The system was tested with BG spore aerosol releases, and the instrument was remotely operated during a trial. A Met-One aerosol particle counter was placed next to the Py-GC/IMS so as to obtain a real-time record of the ambient and bacterial aerosol challenges. The presence/absence of an aerosol event, determined by an aerosol particle counter and a slit sampler-agar plate system, was compared to the presence/absence of a picolinic acid response in a GC/IMS data window at selected times in a trial with respect to a BG challenge. In the 21 BG trials, the Py-GC/IMS instrument experienced two true negatives, no false positives, and the instrument developed a software failure in one trial. The remaining 18 trials were true positive determinations for the presence of BG aerosol, and a limit of detection for the Py-GC/IMS instrument was estimated at approximately 3300 BG spore-containing particles.

  6. Applications of ultraviolet germicidal irradiation disinfection in health care facilities: effective adjunct, but not stand-alone technology.

    PubMed

    Memarzadeh, Farhad; Olmsted, Russell N; Bartley, Judene M

    2010-06-01

    This review evaluates the applicability and relative contribution of ultraviolet germicidal irradiation (UVGI) to disinfection of air in health care facilities. A section addressing the use of UVGI for environmental surfaces is also included. The germicidal susceptibility of biologic agents is addressed, but with emphasis on application in health care facilities. The balance of scientific evidence indicates that UVGI should be considered as a disinfection application in a health care setting only in conjunction with other well-established elements, such as appropriate heating, ventilating, and air-conditioning (HVAC) systems; dynamic removal of contaminants from the air; and preventive maintenance in combination with through cleaning of the care environment. We conclude that although UVGI is microbiocidal, it is not "ready for prime time" as a primary intervention to kill or inactivate infectious microorganisms; rather, it should be considered an adjunct. Other factors, such as careful design of the built environment, installation and effective operation of the HVAC system, and a high level of attention to traditional cleaning and disinfection, must be assessed before a health care facility can decide to rely solely on UVGI to meet indoor air quality requirements for health care facilities. More targeted and multiparameter studies are needed to evaluate the efficacy, safety, and incremental benefit of UVGI for mitigating reservoirs of microorganisms and ultimately preventing cross-transmission of pathogens that lead to health care-associated infections. PMID:20569852

  7. 49 CFR 232.609 - Handling of defective equipment with ECP brake systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... pneumatic brakes shall not operate with freight cars equipped with stand-alone ECP brake systems unless: (1... initial terminal with freight cars that are equipped with stand-alone ECP brake systems provided all of... operative brakes when including the freight cars equipped with stand-alone ECP brake systems; and (3)...

  8. The Hardware Helper: Taking the Guesswork out of Multimedia Systems.

    ERIC Educational Resources Information Center

    Jacso, Peter

    1996-01-01

    A computer expert describes two stand-alone, multimedia CD-ROM computer systems suitable for school and public libraries: a budget version for less than $2000 and a power version for about $3000. Recommends specific personal computer models, monitors, operating systems, processors, RAM (random access memory), hard drives, video subsystems, CD-ROM…

  9. Determining the optimum solar water pumping system for domestic use, livestock water, or irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For several years we have field tested many different types of solar powered water pumping systems. In this paper, several steps are given to select a solar-PV water pumping system. The steps for selection of stand-alone water pumping system were: deciding whether a wind or solar water pumping sys...

  10. Anterior Cervical Discectomy and Fusion with Stand-Alone Trabecular Metal Cages as a Surgical Treatment for Cervical Radiculopathy: Mid-Term Outcomes

    PubMed Central

    ElAbed, Khaldoun; Shawky, Ahmad; Ainscow, Donald

    2016-01-01

    Study Design Retrospective case cohort study done between 2002 and 2012. Purpose To assess the mid-term clinical and radiological outcomes of 1-level and 2-level anterior cervical discectomy and fusion (ACDF) with stand-alone trabecular metal cages. Overview of Literature ACDF is the gold standard surgical treatment for cervical degenerative disease. The usual surgical practice is to use an anteriorly placed fusion plate with or without interdiscal cages. Methods Patients between 36 and 64 years of age diagnosed with cervical radiculopathy who underwent ACDF using stand-alone trabecular metal cages with at least 3 years follow-up were included in this study. Recorded clinical outcomes included residual axial neck pain, radicular arm pain, upper extremity weakness, and upper extremity altered sensation. Visual Analogue scores were also recorded. Fusion was assessed by lateral radiographs looking for bone breaching and radiolucent lines around the device at the latest follow-up. Results Ninety patients were included in the study. Fifty-one patients underwent 2-level surgery and 39 patients underwent 1-level surgery. Mean age was 44±10.4 years and mean follow-up time was 4.5±2.6 years. Patients reported excellent or good outcomes (90%), as well as improvements in axial neck pain (80%), radicular arm pain (95%), upper extremity weakness (85%), and upper extremity altered sensation (90%). Most patients (90%) progressed to fusion at the 1-year follow-up. The reoperation rate was 3.6%. There was no reported persistent dysphagia, voice complaints, dural tear, or tracheal or oesophageal perforation in any of the patients. One patient developed a deep methicillin-resistant Staphylococcus aureus infectious infarction of the spinal cord, which was treated with antibiotics. Recovery was complete at the 1-year follow up. Conclusions Mid-term results show that surgical treatment with ACDF with trabecular metal cages is a safe and effective treatment of single and 2-level cervical disc radiculopathy and neck pain. PMID:27114764

  11. QmRLFS-finder: a model, web server and stand-alone tool for prediction and analysis of R-loop forming sequences

    PubMed Central

    Jenjaroenpun, Piroon; Wongsurawat, Thidathip; Yenamandra, Surya Pavan; Kuznetsov, Vladimir A.

    2015-01-01

    The possible formation of three-stranded RNA and DNA hybrid structures (R-loops) in thousands of functionally important guanine-rich genic and inter-genic regions could suggest their involvement in transcriptional regulation and even development of diseases. Here, we introduce the first freely available R-loop prediction program called Quantitative Model of R-loop Forming Sequence (RLFS) finder (QmRLFS-finder), which predicts RLFSs in nucleic acid sequences based on experimentally supported structural models of RLFSs. QmRLFS-finder operates via a web server or a stand-alone command line tool. This tool identifies and visualizes RLFS coordinates from any natural or artificial DNA or RNA input sequences and creates standards-compliant output files for further annotation and analysis. QmRLFS-finder demonstrates highly accurate predictions of the detected RLFSs, proposing new perspective to further discoveries in R-loop biology, biotechnology and molecular therapy. QmRLFS-finder is freely available at http://rloop.bii.a-star.edu.sg/?pg=qmrlfs-finder. PMID:25883153

  12. Graphical contig analyzer for all sequencing platforms (G4ALL): a new stand-alone tool for finishing and draft generation of bacterial genomes

    PubMed Central

    Ramos, Rommel Thiago Juc; Carneiro, Adriana R; Caracciolo, Pablo H; Azevedo, Vasco; Schneider, Maria Paula C; Barh, Debmalya; Silva, Artur

    2013-01-01

    Genome assembly has always been complicated due to the inherent difficulties of sequencing technologies, as well the computational methods used to process sequences. Although many of the problems for the generation of contigs from reads are well known, especially those involving short reads, the orientation and ordination of contigs in the finishing stages is still very challenging and time consuming, as it requires the manual curation of the contigs to guarantee correct identification them and prevent misassembly. Due to the large numbers of sequences that are produced, especially from the reads produced by next generation sequencers, this process demands considerable manual effort, and there are few software options available to facilitate the process. To address this problem, we have developed the Graphic Contig Analyzer for All Sequencing Platforms (G4ALL): a stand-alone multi-user tool that facilitates the editing of the contigs produced in the assembly process. Besides providing information on the gene products contained in each contig, obtained through a search of the available biological databases, G4ALL produces a scaffold of the genome, based on the overlap of the contigs after curation. Availability The software is available at: http://www.genoma.ufpa.br/rramos/softwares/g4all.xhtml PMID:23888102

  13. QmRLFS-finder: a model, web server and stand-alone tool for prediction and analysis of R-loop forming sequences.

    PubMed

    Jenjaroenpun, Piroon; Wongsurawat, Thidathip; Yenamandra, Surya Pavan; Kuznetsov, Vladimir A

    2015-07-01

    The possible formation of three-stranded RNA and DNA hybrid structures (R-loops) in thousands of functionally important guanine-rich genic and inter-genic regions could suggest their involvement in transcriptional regulation and even development of diseases. Here, we introduce the first freely available R-loop prediction program called Quantitative Model of R-loop Forming Sequence (RLFS) finder (QmRLFS-finder), which predicts RLFSs in nucleic acid sequences based on experimentally supported structural models of RLFSs. QmRLFS-finder operates via a web server or a stand-alone command line tool. This tool identifies and visualizes RLFS coordinates from any natural or artificial DNA or RNA input sequences and creates standards-compliant output files for further annotation and analysis. QmRLFS-finder demonstrates highly accurate predictions of the detected RLFSs, proposing new perspective to further discoveries in R-loop biology, biotechnology and molecular therapy. QmRLFS-finder is freely available at http://rloop.bii.a-star.edu.sg/?pg=qmrlfs-finder. PMID:25883153

  14. Low-frequency switching voltage regulators for terrestrial photovoltaic systems

    NASA Technical Reports Server (NTRS)

    Delombard, R.

    1984-01-01

    The photovoltaic technology project and the stand alone applications project are discussed. Two types of low frequency switching type regulators were investigated. The design, operating characteristics and field application of these regulators is described. The regulators are small in size, low in cost, very low in power dissipation, reliable and allow considerable flexibility in system design.

  15. Integrating an Embedded System within a Microwave Moisture Meter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this paper, the conversion of a PC or laptop-controlled microwave moisture meter to a stand-alone meter hosting its own embedded system is discussed. The moisture meter uses low-power microwaves to measure the attenuation and phase shift of the sample, from which the dielectric properties are cal...

  16. Integrating an embedded system in a microwave moisture meter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The conversion of a PC- or laptop-controlled microwave moisture meter to a stand-alone meter hosting its own embedded system is discussed. The moisture meter measures the attenuation and phase shift of low power microwaves traversing the sample, from which the dielectric properties are calculated. T...

  17. Survivorship and clinical outcomes after multi-level anterior lumbar reconstruction with stand-alone anterior lumbar interbody fusion or hybrid construct.

    PubMed

    Chen, Benjamin; Akpolat, Yusuf T; Williams, Paul; Bergey, Darren; Cheng, Wayne K

    2016-06-01

    In multilevel disc disease, there is still uncertainty regarding whether multiple total disc replacement is more effective and safer than fusion. Our objective was to measure and compare the clinical outcome of multilevel hybrid constructs with stand-alone anterior lumbar interbody fusion (ALIF) using a retrospective analysis. Sixty-four patients with chronic low back pain determined to be from two or three-level degenerative disc disease were included. Thirty-three patients were treated with hybrid fusion and 31 with ALIF. Several parameters were retrospectively reviewed, including blood loss, operation time, hospital stay, Visual Analog Scale (VAS) score, Oswestry Disability Index (ODI), and survivorship without the need for revision surgery. Telephone follow-ups were conducted to ascertain survivorship, clinical outcomes (VAS, ODI) and patient satisfaction. Operation time was longer in the hybrid group (p=0.021). The hybrid group showed a significant improvement in VAS and ODI with 52.2% and 50.0% improvement versus 28.3% and 25.5% in the ALIF group (p<0.05). At the telephone follow-up for patient satisfaction, 95.7% (n=22) of the hybrid group were satisfied and 95.2% (n=21) of the ALIF group were satisfied. Seventy-four percent (n=17) in the hybrid group and 85.7% (n=18) in the ALIF group would choose to do the initial surgery again. Kaplan-Meier analysis showed 80.5% survivorship for hybrids and 75.9% for ALIF at 5years. With our clinical outcomes in VAS and ODI scores, these results, when taken together, indicate that hybrid fusion is a valid and viable alternative to ALIF fusion, with at least equal if not better clinical outcomes in terms of survivorship, back pain, and disability scores. PMID:26896904

  18. Size-exclusion chromatography as a stand-alone methodology identifies novel markers in mass spectrometry analyses of plasma-derived vesicles from healthy individuals

    PubMed Central

    de Menezes-Neto, Armando; Sáez, María José Fidalgo; Lozano-Ramos, Inés; Segui-Barber, Joan; Martin-Jaular, Lorena; Ullate, Josep M. Estanyol; Fernandez-Becerra, Carmen; Borrás, Francesc E.; del Portillo, Hernando A.

    2015-01-01

    Plasma-derived vesicles hold a promising potential for use in biomedical applications. Two major challenges, however, hinder their implementation into translational tools: (a) the incomplete characterization of the protein composition of plasma-derived vesicles, in the size range of exosomes, as mass spectrometric analysis of plasma sub-components is recognizably troublesome and (b) the limited reach of vesicle-based studies in settings where the infrastructural demand of ultracentrifugation, the most widely used isolation/purification methodology, is not available. In this study, we have addressed both challenges by carrying-out mass spectrometry (MS) analyses of plasma-derived vesicles, in the size range of exosomes, from healthy donors obtained by 2 alternative methodologies: size-exclusion chromatography (SEC) on sepharose columns and Exo-Spin™. No exosome markers, as opposed to the most abundant plasma proteins, were detected by Exo-Spin™. In contrast, exosomal markers were present in the early fractions of SEC where the most abundant plasma proteins have been largely excluded. Noticeably, after a cross-comparative analysis of all published studies using MS to characterize plasma-derived exosomes from healthy individuals, we also observed a paucity of “classical exosome markers.” Independent of the isolation method, however, we consistently identified 2 proteins, CD5 antigen-like (CD5L) and galectin-3-binding protein (LGALS3BP), whose presence was validated by a bead-exosome FACS assay. Altogether, our results support the use of SEC as a stand-alone methodology to obtain preparations of extracellular vesicles, in the size range of exosomes, from plasma and suggest the use of CD5L and LGALS3BP as more suitable markers of plasma-derived vesicles in MS. PMID:26154623

  19. How Does Drug Treatment for Diabetes Compare between Medicare Advantage Prescription Drug Plans (MAPDs) and Stand-Alone Prescription Drug Plans (PDPs)?

    PubMed Central

    Erten, Mujde Z; Stuart, Bruce; Davidoff, Amy J; Shoemaker, J Samantha; Bryant-Comstock, Lynda; Shenolikar, Rahul

    2013-01-01

    Objective To compare the use of guideline-recommended prescription medications for diabetes among Medicare beneficiaries enrolled in stand-alone prescription drug plans (PDPs) with Medicare Advantage prescription drug plans (MAPDs) in the presence of potential selection bias. Data Sources/Study Setting Centers for Medicare and Medicaid Services' Chronic Condition Data Warehouse (2006, 2007). Study Design Retrospective cross-sectional comparison of drug use and proportion of days covered (PDC) for oral-antidiabetics, ACE-inhibitors/ARBs, and antihyperlipidemics among PDP and MAPD enrollees with diabetes. We estimated “naïve” regression models assuming exogenous plan choice and two-stage residual inclusion (2SRI) models to study endogeneity in choice of Part D plan type. Data Collection/Extraction Methods We identified 111,290 diabetics based on ICD-9 codes in Medicare claims from a random 5 percent sample of Medicare beneficiaries in 2005 excluding dual eligibles. Principal Findings The naïve regression models indicated lower probability of drug use for oral-antidiabetics (−4 percent; p < .001) and ACE-inhibitors/ARBS (−2 percent; p = .004) among PDP enrollees, but their PDC was higher (3–5 percent) for all drug classes (p < .001). 2SRI models produced no significant differences in any-use equations, but significantly higher PDC values for PDP enrollees for oral-antidiabetics and ACE-inhibitors/ARBs. Conclusions We found similar overall use of recommended drugs in diabetes treatment and no consistent evidence of favorable or adverse selection into PDPs and MAPDs. PMID:23205568

  20. Independent trajectory determination system

    NASA Technical Reports Server (NTRS)

    Armstrong, M. G.; Tomaszewski, I. B.

    1977-01-01

    Stand-alone subsystem calculates flight data analytically or numerically. System is orbit ephemeris generation program and is subsystem of comprehensive Goddard Trajectory Determination System (GTDS).

  1. Design description of the Tangaye Village photovoltaic power system

    NASA Technical Reports Server (NTRS)

    Martz, J. E.; Ratajczak, A. F.

    1982-01-01

    The engineering design of a stand alone photovoltaic (PV) powered grain mill and water pump for the village of Tangaye, Upper Volta is described. The socioeconomic effects of reducing the time required by women in rural areas for drawing water and grinding grain were studied. The suitability of photovoltaic technology for use in rural areas by people of limited technical training was demonstrated. The PV system consists of a 1.8-kW (peak) solar cell array, 540 ampere hours of battery storage, instrumentation, automatic controls, and a data collection and storage system. The PV system is situated near an improved village well and supplies d.c. power to a grain mill and a water pump. The array is located in a fenced area and the mill, battery, instruments, controls, and data system are in a mill building. A water storage tank is located near the well. The system employs automatic controls which provide battery charge regulation and system over and under voltage protection. This report includes descriptions of the engineering design of the system and of the load that it serves; a discussion of PV array and battery sizing methodology; descriptions of the mechanical and electrical designs including the array, battery, controls, and instrumentation; and a discussion of the safety features. The system became operational on March 1, 1979.

  2. Design description of the Tangaye Village photovoltaic power system

    NASA Astrophysics Data System (ADS)

    Martz, J. E.; Ratajczak, A. F.

    1982-06-01

    The engineering design of a stand alone photovoltaic (PV) powered grain mill and water pump for the village of Tangaye, Upper Volta is described. The socioeconomic effects of reducing the time required by women in rural areas for drawing water and grinding grain were studied. The suitability of photovoltaic technology for use in rural areas by people of limited technical training was demonstrated. The PV system consists of a 1.8-kW (peak) solar cell array, 540 ampere hours of battery storage, instrumentation, automatic controls, and a data collection and storage system. The PV system is situated near an improved village well and supplies d.c. power to a grain mill and a water pump. The array is located in a fenced area and the mill, battery, instruments, controls, and data system are in a mill building. A water storage tank is located near the well. The system employs automatic controls which provide battery charge regulation and system over and under voltage protection. This report includes descriptions of the engineering design of the system and of the load that it serves; a discussion of PV array and battery sizing methodology; descriptions of the mechanical and electrical designs including the array, battery, controls, and instrumentation; and a discussion of the safety features. The system became operational on March 1, 1979.

  3. Market assessment of photovoltaic power systems for agricultural applications worldwide

    NASA Astrophysics Data System (ADS)

    Cabraal, A.; Delasanta, D.; Rosen, J.; Nolfi, J.; Ulmer, R.

    1981-11-01

    Agricultural sector PV market assessments conducted in the Phillippines, Nigeria, Mexico, Morocco, and Colombia are extrapolated worldwide. The types of applications evaluated are those requiring less than 15 kW of power and operate in a stand alone mode. The major conclusions were as follows: PV will be competitive in applications requiring 2 to 3 kW of power prior to 1983; by 1986 PV system competitiveness will extend to applications requiring 4 to 6 kW of power, due to capital constraints, the private sector market may be restricted to applications requiring less than about 2 kW of power; the ultimate purchase of larger systems will be governments, either through direct purchase or loans from development banks. Though fragmented, a significant agriculture sector market for PV exists; however, the market for PV in telecommunications, signalling, rural services, and TV will be larger. Major market related factors influencing the potential for U.S. PV Sales are: lack of awareness; high first costs; shortage of long term capital; competition from German, French and Japanese companies who have government support; and low fuel prices in capital surplus countries. Strategies that may aid in overcoming some of these problems are: setting up of a trade association aimed at overcoming problems due to lack of awareness, innovative financing schemes such as lease arrangements, and designing products to match current user needs as opposed to attempting to change consumer behavior.

  4. Market assessment of photovoltaic power systems for agricultural applications worldwide

    NASA Technical Reports Server (NTRS)

    Cabraal, A.; Delasanta, D.; Rosen, J.; Nolfi, J.; Ulmer, R.

    1981-01-01

    Agricultural sector PV market assessments conducted in the Phillippines, Nigeria, Mexico, Morocco, and Colombia are extrapolated worldwide. The types of applications evaluated are those requiring less than 15 kW of power and operate in a stand alone mode. The major conclusions were as follows: PV will be competitive in applications requiring 2 to 3 kW of power prior to 1983; by 1986 PV system competitiveness will extend to applications requiring 4 to 6 kW of power, due to capital constraints, the private sector market may be restricted to applications requiring less than about 2 kW of power; the ultimate purchase of larger systems will be governments, either through direct purchase or loans from development banks. Though fragmented, a significant agriculture sector market for PV exists; however, the market for PV in telecommunications, signalling, rural services, and TV will be larger. Major market related factors influencing the potential for U.S. PV Sales are: lack of awareness; high first costs; shortage of long term capital; competition from German, French and Japanese companies who have government support; and low fuel prices in capital surplus countries. Strategies that may aid in overcoming some of these problems are: setting up of a trade association aimed at overcoming problems due to lack of awareness, innovative financing schemes such as lease arrangements, and designing products to match current user needs as opposed to attempting to change consumer behavior.

  5. Market assessment of photovoltaic power systems for agricultural applications in the Philippines

    NASA Technical Reports Server (NTRS)

    Cabraal, R. A.; Delasanta, D.; Burrill, G.

    1981-01-01

    The market potential in the Philippines for stand alone photovoltaic (P/V) systems in agriculture was assessed. Applications include: irrigation, postharvest operation, food and fiber processing and storage, and livestock and fisheries operations. Power and energy use profiles for many applications as well as assessments of business, government and financial climate for P/V sales are described. Many characteristics of the Philippine agriculture and energy sector favorably influence the use of P/V systems. However, serious and significant barriers prevent achieving the technically feasible, cost competitive market for P/V systems in the agricultural sector. The reason for the small market is the limited availability capital for financing P/V systems. It is suggested that innovative financing schemes and promotional campaigns should be devised.

  6. Power management system

    DOEpatents

    Algrain, Marcelo C.; Johnson, Kris W.; Akasam, Sivaprasad; Hoff, Brian D.

    2007-10-02

    A method of managing power resources for an electrical system of a vehicle may include identifying enabled power sources from among a plurality of power sources in electrical communication with the electrical system and calculating a threshold power value for the enabled power sources. A total power load placed on the electrical system by one or more power consumers may be measured. If the total power load exceeds the threshold power value, then a determination may be made as to whether one or more additional power sources is available from among the plurality of power sources. At least one of the one or more additional power sources may be enabled, if available.

  7. System and Battery Charge Control for PV-Powered AC Lighting Systems

    SciTech Connect

    Kern, G.

    1999-04-01

    This report reviews a number of issues specific to stand-alone AC lighting systems. A review of AC lighting technology is presented, which discusses the advantages and disadvantages of various lamps. The best lamps for small lighting systems are compact fluorescent. The best lamps for intermediate-size systems are high- or low-pressure sodium. Specifications for battery charging and load control are provided with the goal of achieving lamp lifetimes on the order of 16,000 to 24,000 hours and battery lifetimes of 4 to 5 years. A rough estimate of the potential domestic and global markets for stand-alone AC lighting systems is presented. DC current injection tests were performed on high-pressure sodium lamps and the test results are presented. Finally, a prototype system was designed and a prototype system controller (with battery charger and DC/AC inverter) was developed and built.

  8. Performance characteristics of solar-photovoltaic flywheel-storage systems

    SciTech Connect

    Jarvinen, P. O.; Brench, B. L.; Rasmussen, N. E.

    1981-01-01

    A solar photovoltaic energy flywheel storage and conversion system for residential applications was designed, built and tested. Performance and efficiency measurements were conducted on the system, which utilizes low-loss magnetic bearings, maximum-power-point tracking of the photovoltaic array, integrated permanent magnet motor-generator, and output power-conditioning sections of either the stand-alone cycloconverter or utility interactive inverter type. The overall in-out electrical storage efficiency of the flywheel system was measured along with the power transfer efficiencies of the individual components and the system spin-down tare losses. A round-trip storage efficiency of 82% in the utility interactive mode and 74% in the stand-alone mode was found. This compares favorably with systems involving batteries and an inverter, which typically exhibit a round trip efficiency less than 70%.

  9. Description of photovoltaic village power systems in the United States and Africa

    NASA Technical Reports Server (NTRS)

    Ratajczak, A. F.; Bifano, W. J.

    1979-01-01

    Photovoltaic power systems in remote villages in the United States and Africa are described. These projects were undertaken to demonstrate that existing photovoltaic system technology is capable of providing electrical power for basic domestic services for the millions of small, remote communities in both developed and developing countries. One system is located in the Papago Indian Village of Schuchuli in southwest Arizona (U. S.) and became operational 16 December 1978. The other system is located in Tangaye, a rural village in Upper Volta, Africa. It became operational 1 March 1979. The Schuchuli system has a 3.5 kW (peak) solar array which provides electric power for village water pumping, a refrigerator for each family, lights in the village buildings, and a community washing machine and sewing machine. The 1.8 kW (peak) Tangaye system provides power for community water pumping, flour milling and lights in the milling building. These are both stand-alone systems (i.e., no back-up power source) which are being operated and maintained by local personnel. Both systems are instrumented. Systems operations are being monitored by NASA to measure design adequacy and to refine designs for future systems.

  10. Phase 1 of the First Solar Small Power System Experiment (experimental System No. 1). Volume 1: Technical Studies for Solar Point-focusing, Distributed Collector System, with Energy Conversion at the Collector, Category C

    NASA Technical Reports Server (NTRS)

    Clark, T. B. (Editor)

    1979-01-01

    The technical and economic feasibility of a solar electric power plant for a small community is evaluated and specific system designs for development and demonstration are selected. All systems investigated are defined as point focusing, distributed receiver concepts, with energy conversion at the collector. The preferred system is comprised of multiple parabolic dish concentrators employing Stirling cycle engines for power conversion. The engine, AC generator, cavity receiver, and integral sodium pool boiler/heat transport system are combined in a single package and mounted at the focus of each concentrator. The output of each concentrator is collected by a conventional electrical distribution system which permits grid-connected or stand-alone operation, depending on the storage system selected.

  11. Surgical Outcome of a Zero-profile Device Comparing with Stand-alone Cage and Anterior Cervical Plate with Iliac Bone Graft in the Anterior Cervical Discectomy and Fusion

    PubMed Central

    Shin, Jae Sik; Cho, Pyoung Goo

    2014-01-01

    Objective A Zero-profile device is a cervical stand-alone cage with integrated segmental fixation device. We characteristically evaluated the radiological changes as well as clinical outcomes in the application of Zero-profile devices compared with stand-alone cages and anterior cervical plates with iliac bone grafts for the cervical disease. Methods Retrospectively, total 60 patients at least more than one year follow-up were enrolled. Twenty patients were treated with Zero-profile devices (Group A), twenty patients with stand-alone cages (Group B) and twenty patients with anterior cervical plates and iliac bone grafts (Group C) for a single level cervical disease. The clinical outcomes were evaluated by Odom's criteria and Bazaz-Yoo dysphagia index. The radiologic parameters were by subsidence and the changes of the midpoint interbody height (IBH), the segmental kyphotic angle (SKA), the overall kyphotic angle (OKA) in index level. Results Although there was no significant clinical difference according to the Odom's criteria among them(p=0.766), post-operative dysphagia was significantly decreased in the Group A and B compared with the Group C (p=0.04). From the immediate postoperative to the last follow-up time, the mean change of IBH decrement and SKA increment were significant in the Group B compared with the Group A (p=0.025, p=0.033) and the Group C (p=0.001, p=0.000). The subsidence rate was not significant among all groups (p=0.338). Conclusion This Zero-profile device is a valuable alternative to the anterior cervical discectomy and fusion with a low incidence of postoperative dysphagia and without segmental kyphotic change. PMID:25346764

  12. Power system restoration issues

    SciTech Connect

    Adibi, M.M. ); Kafka, R.J. )

    1991-04-01

    This article describes some of the problems encountered in the three phases of power system restoration (PSR). The three phases of PSR are: Planning for restart and reintegration of the bulk power supply; Actions during system degradation for saving and retaining critical sources of power; Restoration when the power system has stabilized at some degraded level.

  13. Design, Fabrication and Certification of Advanced Modular PV Power Systems

    NASA Astrophysics Data System (ADS)

    Minyard, Glen E.; Lambarski, Timothy J.

    1997-02-01

    The Design, Fabrication and Certification of Advanced Modular PV Power Systems contract is a Photovoltaic Manufacturing Technology (PVMaT) cost-shared contract under Phase 4A1 for Product Driven Systems and Component Technologies. Phase 4A1 has the goals to improve the cost-effectiveness and manufacturing efficiency of PV end-products, optimize manufacturing and packaging methods, and generally improve balance-of-system performance, integration and manufacturing. This contract has the specific goal to reduce the installed PV system life cycle costs to the customer with the ultimate goal of increasing PV system marketability and customer acceptance. The specific objectives of the project are to develop certified, standardized, modular, pre-engineered products lines of our main stand-alone systems, the Modular Autonomous PV Power Supply (MAPPS) and PV-Generator Hybrid System (Photogenset). To date, we have designed a 200 W MAPPS and a 1 kW Photogenset and are in the process of having the MAPPS certified by Underwriters Laboratories (UL Listed) and approved for hazardous locations by Factory Mutual (FM). We have also developed a manufacturing plan for product line expansion for the MAPPS. The Photogenset will be fabricated in February 1997 and will also be UL Listed. Functionality testing will be performed at NREL and Sandia with the intentions of providing verification of performance and reliability and of developing test-based performance specifications. In addition to an expansion on the goals, objectives and status of the project, specific accomplishments and benefits are also presented in this paper.

  14. Market assessment of photovoltaic power systems for agricultural applications worldwide

    SciTech Connect

    Cabraal, A.; Delasanta, D.; Rosen, J.; Nolfi, J.; Ulmer, R.

    1981-11-01

    This report integrates and extrapolates worldwide the results of the agricultural sector PV market assessments conducted in the Philippines, Nigeria, Mexico, Morocco, and Colombia. The types of applications evaluated are those requiring less than 15 kW of power and operate in a stand-alone mode. The study focused on the needs of low- and middle-income countries. The major conclusions derived from the studies were as follows: PV will be competitive in applications requiring 2 - 3 kW of power prior to 1983; by 1986 PV system competitiveness will extend to applications requiring 4 - 6 kW of power, due to capital constraints, the private sector market may be restricted to applications requiring less than about 2 kW of power; the ultimate purchase of larger systems will be governments, either through direct purchase or loans from development banks. Though fragmented, significant agriculture sector market for PV exists; however the market for PV in telecommunications, signalling, rural services, and TV will be larger. Major market-related factors influencing the potential for US PV sales are: lack of awareness; high first costs; shortage of long-term capital; competition from German, French and Japanese companies who have their governments support; and low fuel prices in capital surplus countries. Strategies that may aid in overcoming some of these problems are: setting up of a trade association aimed at overcoming problems due to lack of awareness, innovative financing schemes such as lease arrangements, and designing products to match current user needs as opposed to attempting to change consumer behavior.

  15. An overview of power electronics applications in fuel cell systems: DC and AC converters.

    PubMed

    Ali, M S; Kamarudin, S K; Masdar, M S; Mohamed, A

    2014-01-01

    Power electronics and fuel cell technologies play an important role in the field of renewable energy. The demand for fuel cells will increase as fuel cells become the main power source for portable applications. In this application, a high-efficiency converter is an essential requirement and a key parameter of the overall system. This is because the size, cost, efficiency, and reliability of the overall system for portable applications primarily depend on the converter. Therefore, the selection of an appropriate converter topology is an important and fundamental aspect of designing a fuel cell system for portable applications as the converter alone plays a major role in determining the overall performance of the system. This paper presents a review of power electronics applications in fuel cell systems, which include various topology combinations of DC converters and AC inverters and which are primarily used in fuel cell systems for portable or stand-alone applications. This paper also reviews the switching techniques used in power conditioning for fuel cell systems. Finally, this paper addresses the current problem encountered with DC converters and AC inverter. PMID:25478581

  16. An Overview of Power Electronics Applications in Fuel Cell Systems: DC and AC Converters

    PubMed Central

    Ali, M. S.; Kamarudin, S. K.; Masdar, M. S.; Mohamed, A.

    2014-01-01

    Power electronics and fuel cell technologies play an important role in the field of renewable energy. The demand for fuel cells will increase as fuel cells become the main power source for portable applications. In this application, a high-efficiency converter is an essential requirement and a key parameter of the overall system. This is because the size, cost, efficiency, and reliability of the overall system for portable applications primarily depend on the converter. Therefore, the selection of an appropriate converter topology is an important and fundamental aspect of designing a fuel cell system for portable applications as the converter alone plays a major role in determining the overall performance of the system. This paper presents a review of power electronics applications in fuel cell systems, which include various topology combinations of DC converters and AC inverters and which are primarily used in fuel cell systems for portable or stand-alone applications. This paper also reviews the switching techniques used in power conditioning for fuel cell systems. Finally, this paper addresses the current problem encountered with DC converters and AC inverter. PMID:25478581

  17. Modeling, analysis and control of fuel cell hybrid power systems

    NASA Astrophysics Data System (ADS)

    Suh, Kyung Won

    Transient performance is a key characteristic of fuel cells, that is sometimes more critical than efficiency, due to the importance of accepting unpredictable electric loads. To fulfill the transient requirement in vehicle propulsion and portable fuel cell applications, a fuel cell stack is typically coupled with a battery through a DC/DC converter to form a hybrid power system. Although many power management strategies already exist, they all rely on low level controllers that realize the power split. In this dissertation we design controllers that realize various power split strategies by directly manipulating physical actuators (low level commands). We maintain the causality of the electric dynamics (voltage and current) and investigate how the electric architecture affects the hybridization level and the power management. We first establish the performance limitations associated with a stand-alone and power-autonomous fuel cell system that is not supplemented by an additional energy storage and powers all its auxiliary components by itself. Specifically, we examine the transient performance in fuel cell power delivery as it is limited by the air supplied by a compressor driven by the fuel cell itself. The performance limitations arise from the intrinsic coupling in the fluid and electrical domain between the compressor and the fuel cell stack. Feedforward and feedback control strategies are used to demonstrate these limitations analytically and with simulations. Experimental tests on a small commercial fuel cell auxiliary power unit (APU) confirm the dynamics and the identified limitations. The dynamics associated with the integration of a fuel cell system and a DC/DC converter is then investigated. Decentralized and fully centralized (using linear quadratic techniques) controllers are designed to regulate the power system voltage and to prevent fuel cell oxygen starvation. Regulating these two performance variables is a difficult task and requires a compromise due to the conflicting objectives. The compromise can be mitigated by augmenting the fuel cell power system with an energy buffer such as a battery. We consider two different and popular ways of connecting the battery and the fuel cell to the load and we refer to them as electric architectures. Various controller gains are used to span the fuel cell operation from load-following to load-leveling, and hence, to determine adequate fuel cell-battery sizing (hybridization level) and the associated trends in the system efficiency.

  18. Development of a Multi-bus, Multi-source Reconfigurable Stirling Radioisotope Power System Test Bed

    NASA Technical Reports Server (NTRS)

    Coleman, Anthony S.

    2004-01-01

    The National Aeronautics and Space Administration (NASA) has typically used Radioisotope Thermoelectric Generators (RTG) as their source of electric power for deep space missions. A more efficient and potentially more cost effective alternative to the RTG, the high efficiency 110 watt Stirling Radioisotope Generator 110 (SRG110) is being developed by the Department of Energy (DOE), Lockheed Martin (LM), Stirling Technology Company (STC) and NASA Glenn Research Center (GRC). The SRG110 consists of two Stirling convertors (Stirling Engine and Linear Alternator) in a dual-opposed configuration, and two General Purpose Heat Source (GPHS) modules. Although Stirling convertors have been successfully operated as a power source for the utility grid and as a stand-alone portable generator, demonstration of the technology required to interconnect two Stirling convertors for a spacecraft power system has not been attempted. NASA GRC is developing a Power System Test Bed (PSTB) to evaluate the performance of a Stirling convertor in an integrated electrical power system application. This paper will describe the status of the PSTB and on-going activities pertaining to the PSTB in the NASA Thermal-Energy Conversion Branch of the Power and On-Board Propulsion Technology Division.

  19. Space nuclear power systems

    NASA Technical Reports Server (NTRS)

    Carpenter, R. T.

    1972-01-01

    Space nuclear power systems are considered for use in those particular spacecraft applications for which nuclear power systems offer unique advantages over solar and/or chemical space power systems. Both isotopic and reactor heated space electrical power units are described in an attempt to illustrate their operating characteristics, spacecraft integration aspects, and factory-to-end of mission operational considerations. The status of technology developments in nuclear power systems is presented. Some projections of those technologies are made to form a basis for the applications of space nuclear power systems to be expected over the next 10-15 years.

  20. Photovoltaic power system applications

    SciTech Connect

    Hasti, D.E.

    1994-04-01

    This article is an overview of Photovoltaic Power System applications. Photovoltaic power system range in size from watts to megawatts. They are the most modular of all electric power generating systems. PV systems produce electricity for a wide variety of applications. They can be placed in almost any location in the world, and beyond when space applications are included. When PV power for watches, calculators, and similar consumer electronic products is included in the definition of PV power system, system sizes are even smaller and applications more numerous.

  1. Power Plant Systems Analysis

    NASA Technical Reports Server (NTRS)

    Williams, J. R.; Yang, Y. Y.

    1973-01-01

    Three basic thermodynamic cycles of advanced nuclear MHD power plant systems are studied. The effect of reactor exit temperature and space radiator temperature on the overall thermal efficiency of a regenerative turbine compressor power plant system is shown. The effect of MHD pressure ratio on plant efficiency is also described, along with the dependence of MHD power output, compressor power requirement, turbine power output, mass flow rate of H2, and overall plant efficiency on the reactor exit temperature for a specific configuration.

  2. Development of Standardized Power Electronic Components, Subsystems, and Systems for Increased Modularity and Scalability

    SciTech Connect

    Chakraborty, S.; Pink, C.; Price, J.; Kroposki, B.; Kern, G.

    2007-11-01

    Power electronics devices hold substantial promise for making distributed energy applications more efficient and cost effective. This project is motivated towards developing and testing inverters that will allow distributed energy systems to provide ancillary services such as voltage and VAR regulation, and increased grid reliability by seamlessly transitioning between grid-tied and stand-alone operation modes. The objectives of this project are to identify system integration and optimization issues and technologies and to provide solutions through research, analysis, and testing of power electronic interfaces for distributed energy applications that are cost-competitive and have substantially faster response times than conventional technologies. In addition, the testing of power electronics interfaces will develop a technical basis for performance assessment for distributed energy systems, subsystems, and components that will finally create a foundation for standardized measurements and test procedures. The ultimate goal for this research is to advance the potential benefits of distributed energy to provide ancillary services, enhance power system reliability, and allow customer choice.

  3. Joint U.S./Brazilian hybrid power system (wind-PV-diesel) on Marajo Island

    SciTech Connect

    Leboeuf, C.; Taylor, R.W.; Corbus, D.; Moszkowicz, M.; Lima, J.; Ribeiro, C.

    1995-09-01

    A cooperative renewable energy project is underway between the U.S. Department of Energy (through the National Renewable Energy Laboratory, NREL), and the Federal Republic of Brazil (through the Centro de Pesquisas de Energia Eletrica, CEPEL). The objectives of this joint US/Brazilian program are to establish technical, institutional, and economic confidence in using renewable energy systems to meet the needs of the people of rural Brazil, to build ongoing partnerships beneficial to both countries, and to demonstrate the potential for large-scale rural electrification through the use of renewable energy systems. Phase 1 of this program resulted in the deployment of more than 700 photovoltaic (PV) electric lighting systems in the Brazilian states of Pernambuco and Ceara. Phase 2 of the program extends the pilot project into six additional Brazilian states and demonstrates a wider variety of stand-alone end uses, including the use of wind electric power generation for selected sites and applications. Additionally, Phase 2 also includes the development of two hybrid village power systems, including one comprising PV, wind, battery, and diesel power sources. This paper focuses on this hybrid system, which is located in the Amazon River delta.

  4. Space station power system

    NASA Technical Reports Server (NTRS)

    Baraona, Cosmo R.

    1987-01-01

    The major requirements and guidelines that affect the space station configuration and power system are explained. The evolution of the space station power system from the NASA program development-feasibility phase through the current preliminary design phase is described. Several early station concepts are described and linked to the present concept. Trade study selections of photovoltaic system technologies are described in detail. A summary of present solar dynamic and power management and distribution systems is also given.

  5. Do Trunk Muscles Affect the Lumbar Interbody Fusion Rate?: Correlation of Trunk Muscle Cross Sectional Area and Fusion Rates after Posterior Lumbar Interbody Fusion Using Stand-Alone Cage

    PubMed Central

    Choi, Man Kyu; Park, Bong Jin; Park, Chang Kyu; Kim, Sung Min

    2016-01-01

    Objective Although trunk muscles in the lumbar spine preserve spinal stability and motility, little is known about the relationship between trunk muscles and spinal fusion rate. The aim of the present study is to evaluate the correlation between trunk muscles cross sectional area (MCSA) and fusion rate after posterior lumbar interbody fusion (PLIF) using stand-alone cages. Methods A total of 89 adult patients with degenerative lumbar disease who were performed PLIF using stand-alone cages at L4–5 were included in this study. The cross-sectional area of the psoas major (PS), erector spinae (ES), and multifidus (MF) muscles were quantitatively evaluated by preoperative lumbar magnetic resonance imaging at the L3–4, L4–5, and L5–S1 segments, and bone union was evaluated by dynamic lumbar X-rays. Results Of the 89 patients, 68 had bone union and 21 did not. The MCSAs at all segments in both groups were significantly different (p<0.05) for the PS muscle, those at L3–4 and L4–5 segments between groups were significantly different (p=0.048, 0.021) for the ES and MF muscles. In the multivariate analysis, differences in the PS MCSA at the L4–5 and L5–S1 segments remained significant (p=0.048, 0.043 and odds ratio=1.098, 1.169). In comparison analysis between male and female patients, most MCSAs of male patients were larger than female's. Fusion rates of male patients (80.7%) were higher than female's (68.8%), too. Conclusion For PLIF surgery, PS muscle function appears to be an important factor for bone union and preventing back muscle injury is essential for better fusion rate. PMID:27226860

  6. Development of a Low-Cost, Stand-Alone Microterminal for Support of Testing and Instruction. Final Report for Period January 1977-February 1978.

    ERIC Educational Resources Information Center

    Steffen, Dale A.; And Others

    A study was undertaken to develop a microterminal for use in a computer-based instructional system. Objectives were to use new microprocessor technology to produce one terminal that is more effective and efficient than either the management terminal or the plasma type interactive terminal presently in use by the Air Force Advanced Instructional…

  7. Economical space power systems

    NASA Technical Reports Server (NTRS)

    Burkholder, J. H.

    1980-01-01

    A commercial approach to design and fabrication of an economical space power system is investigated. Cost projections are based on a 2 kW space power system conceptual design taking into consideration the capability for serviceability, constraints of operation in space, and commercial production engineering approaches. A breakdown of the system design, documentation, fabrication, and reliability and quality assurance estimated costs are detailed.

  8. Power system commonality study

    NASA Astrophysics Data System (ADS)

    Littman, Franklin D.

    1992-07-01

    A limited top level study was completed to determine the commonality of power system/subsystem concepts within potential lunar and Mars surface power system architectures. A list of power system concepts with high commonality was developed which can be used to synthesize power system architectures which minimize development cost. Examples of potential high commonality power system architectures are given in this report along with a mass comparison. Other criteria such as life cycle cost (which includes transportation cost), reliability, safety, risk, and operability should be used in future, more detailed studies to select optimum power system architectures. Nineteen potential power system concepts were identified and evaluated for planetary surface applications including photovoltaic arrays with energy storage, isotope, and nuclear power systems. A top level environmental factors study was completed to assess environmental impacts on the identified power system concepts for both lunar and Mars applications. Potential power system design solutions for commonality between Mars and lunar applications were identified. Isotope, photovoltaic array (PVA), regenerative fuel cell (RFC), stainless steel liquid-metal cooled reactors (less than 1033 K maximum) with dynamic converters, and in-core thermionic reactor systems were found suitable for both lunar and Mars environments. The use of SP-100 thermoelectric (TE) and SP-100 dynamic power systems in a vacuum enclosure may also be possible for Mars applications although several issues need to be investigated further (potential single point failure of enclosure, mass penalty of enclosure and active pumping system, additional installation time and complexity). There are also technical issues involved with development of thermionic reactors (life, serviceability, and adaptability to other power conversion units). Additional studies are required to determine the optimum reactor concept for Mars applications. Various screening criteria (availability, environmental compatibility, mass competitiveness of energy storage, safety, and practicality for the application) were used to define concept applicability for each lunar and Mars application. A screening study resulted in 13 power systems for lunar applications and 15 for Mars applications. A commonality analysis showed several power systems with potentially high commonality (across both lunar and Mars applications). These high commonality systems include d PVA/RFC, dynamic isotope (1033 K Stirling, 1133 K Brayton, and 1300 K Brayton PCU's), SP-100 TE and dynamic derivatives (Mars systems required vacuum enclosure), in-core thermionic reactor, and liquid metal cooled reactor/Stirling cycle (1033 K). The generic commonality results were used to synthesize 3 high commonality power system architectures: (1) predominantly PV (limited nuclear and isotope), (2) predominantly in-core thermionic reactor/DIPS, and (3) predominantly SP-100 reactor/DIPS. The in-core thermionic reactor/DIPS power system architecture had the lowest total mass. Specific outputs from this study included lists of power system requirements, power system candidates, a power system application matrix, power system characteristics (mass), power system commonality ratings, example high commonality power system architectures, architecture masses, and issues/design solutions for lunar/Mars commonality.

  9. Future summer precipitation changes over CORDEX-East Asia domain downscaled by a regional ocean-atmosphere coupled model: A comparison to the stand-alone RCM

    NASA Astrophysics Data System (ADS)

    Zou, Liwei; Zhou, Tianjun

    2016-03-01

    Climate changes under the RCP8.5 scenario over the Coordinated Regional Downscaling Experiment (CORDEX)-East Asia domain downscaled by a regional ocean-atmosphere coupled model Flexible Regional Ocean-Atmosphere Land System (FROALS) are compared to those downscaled by the corresponding atmosphere-only regional climate model driven by a global climate system model. Changes in the mean and interannual variability of summer rainfall were discussed for the period of 2051-2070 with respect to the present-day period of 1986-2005. Followed by an enhanced western North Pacific subtropical high and an intensified East Asian summer monsoon, an increase in total rainfall over north China, the Korean Peninsula, and Japan but a decrease in total rainfall over southern China are observed in the FROALS projection. Homogeneous increases of extreme rainfall amounts were found over the CORDEX-East Asia domain. A predominant increase in the interannual variability was evident for both total rainfall and the extreme rainfall amount. The spatial patterns of the projected rainfall changes by FROALS were generally consistent with those from the driving global model at a broad scale due to similar projected circulation changes. In both models, the enhanced southerlies over east China increased the moisture divergences over southern China and enhanced the moisture advection over north China. However, the atmosphere-only regional climate model (RCM) exhibited responses to the underlying sea surface temperature (SST) warming anomalies that were too strong, which induced an anomalous cyclone over the north South China Sea, followed by increases (decreases) of total and extreme rainfall over southern China (central China). The differences of the projected changes in both rainfall and circulation between FROALS and the atmosphere-only RCM were partly affected by the differences in the projected SST changes. The results recommend the employment of a regional ocean-atmosphere coupled model in the dynamical downscaling of climate change over the CORDEX-East Asian domain.

  10. Space Nuclear Power Systems

    NASA Technical Reports Server (NTRS)

    Houts, Michael G.

    2012-01-01

    Fission power and propulsion systems can enable exciting space exploration missions. These include bases on the moon and Mars; and the exploration, development, and utilization of the solar system. In the near-term, fission surface power systems could provide abundant, constant, cost-effective power anywhere on the surface of the Moon or Mars, independent of available sunlight. Affordable access to Mars, the asteroid belt, or other destinations could be provided by nuclear thermal rockets. In the further term, high performance fission power supplies could enable both extremely high power levels on planetary surfaces and fission electric propulsion vehicles for rapid, efficient cargo and crew transfer. Advanced fission propulsion systems could eventually allow routine access to the entire solar system. Fission systems could also enable the utilization of resources within the solar system.

  11. Electrical power generating system

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (inventor)

    1983-01-01

    A power generating system for adjusting coupling an induction motor, as a generator, to an A.C. power line wherein the motor and power line are connected through a triac is described. The triac is regulated to normally turn on at a relatively late point in each half cycle of its operation, whereby at less than operating speed, and thus when the induction motor functions as a motor rather than as a generator, power consumption from the line is substantially reduced.

  12. Design, fabrication, and certification of advanced modular PV power systems. Final technical progress report

    SciTech Connect

    Lambarski, T.; Minyard, G.

    1998-10-01

    Solar Electric Specialties Company (SES) has completed a two and a half year effort under the auspices of the US Department of Energy (DOE) PVMaT (Photovoltaic Manufacturing Technology) project. Under Phase 4A1 of the project for Product Driven System and Component Technology, the SES contract ``Design, Fabrication and Certification of Advanced Modular PV Power Systems`` had the goal to reduce installed system life cycle costs through development of certified (Underwriters Laboratories or other listing) and standardized prototype products for two of the product lines, MAPPS{trademark} (Modular Autonomous PV Power Supply) and Photogensets{trademark}. MAPPS are small DC systems consisting of Photovoltaic modules, batteries and a charge controller and producing up to about a thousand watt-hours per day. Photogensets are stand-alone AC systems incorporating a generator as backup for the PV in addition to a DC-AC inverter and battery charger. The program tasks for the two-year contract consisted of designing and fabricating prototypes of both a MAPPS and a Photogenset to meet agency listing requirements using modular concepts that would support development of families of products, submitting the prototypes for listing, and performing functionality testing at Sandia and NREL. Both prototypes were candidates for UL (Underwriters Laboratories) listing. The MAPPS was also a candidate for FM (Factory Mutual) approval for hazardous (incendiary gases) locations.

  13. Power systems integration

    SciTech Connect

    Brantley, L.W.

    1982-06-01

    Power systems integration in large flexible space structures is discussed with emphasis upon body control. A solar array is discussed as a typical example of spacecraft configuration problems. Information on how electric batteries dominate life-cycle costs is presented in chart form. Information is given on liquid metal droplet generators and collectors, hot spot analysis, power dissipation in solar arrays, solar array protection optimization, and electromagnetic compatibility for a power system platform.

  14. Exhibits Enhanced by Stand-Alone Computers.

    ERIC Educational Resources Information Center

    Van Rennes, Eve C.

    Both the development and evaluation of one of a set of computer programs designed for use by visitors as adjuncts to museum exhibits are described. Museum displays used were (1) a static, behind-glass exhibit on evolution; (2) a hands-on primitive stone age tools exhibit; and (3) a Foucault pendulum. A computer placed next to each exhibit served…

  15. A Stand-Alone Interactive Physics Showcase

    ERIC Educational Resources Information Center

    Pfaff, Daniel; Hagelgans, Anja; Weidemuller, Matthias; Bretzer, Klaus

    2012-01-01

    We present a showcase with interactive exhibits of basic physical experiments that constitutes a complementary method for teaching physics and interesting students in physical phenomena. Our interactive physics showcase, shown in Fig. 1, stimulates interest for science by letting the students experience, firsthand, surprising phenomena and…

  16. TROPIX Power System Architecture

    NASA Technical Reports Server (NTRS)

    Manner, David B.; Hickman, J. Mark

    1995-01-01

    This document contains results obtained in the process of performing a power system definition study of the TROPIX power management and distribution system (PMAD). Requirements derived from the PMADs interaction with other spacecraft systems are discussed first. Since the design is dependent on the performance of the photovoltaics, there is a comprehensive discussion of the appropriate models for cells and arrays. A trade study of the array operating voltage and its effect on array bus mass is also presented. A system architecture is developed which makes use of a combination of high efficiency switching power convertors and analog regulators. Mass and volume estimates are presented for all subsystems.

  17. Autonomous power expert system

    NASA Technical Reports Server (NTRS)

    Ringer, Mark J.; Quinn, Todd M.

    1990-01-01

    The goal of the Autonomous Power System (APS) program is to develop and apply intelligent problem solving and control technologies to the Space Station Freedom Electrical Power Systems (SSF/EPS). The objectives of the program are to establish artificial intelligence/expert system technology paths, to create knowledge based tools with advanced human-operator interfaces, and to integrate and interface knowledge-based and conventional control schemes. This program is being developed at the NASA-Lewis. The APS Brassboard represents a subset of a 20 KHz Space Station Power Management And Distribution (PMAD) testbed. A distributed control scheme is used to manage multiple levels of computers and switchgear. The brassboard is comprised of a set of intelligent switchgear used to effectively switch power from the sources to the loads. The Autonomous Power Expert System (APEX) portion of the APS program integrates a knowledge based fault diagnostic system, a power resource scheduler, and an interface to the APS Brassboard. The system includes knowledge bases for system diagnostics, fault detection and isolation, and recommended actions. The scheduler autonomously assigns start times to the attached loads based on temporal and power constraints. The scheduler is able to work in a near real time environment for both scheduling an dynamic replanning.

  18. Autonomous power expert system

    NASA Technical Reports Server (NTRS)

    Ringer, Mark J.; Quinn, Todd M.

    1990-01-01

    The goal of the Autonomous Power System (APS) program is to develop and apply intelligent problem solving and control technologies to the Space Station Freedom Electrical Power Systems (SSF/EPS). The objectives of the program are to establish artificial intelligence/expert system technology paths, to create knowledge based tools with advanced human-operator interfaces, and to integrate and interface knowledge-based and conventional control schemes. This program is being developed at the NASA-Lewis. The APS Brassboard represents a subset of a 20 KHz Space Station Power Management And Distribution (PMAD) testbed. A distributed control scheme is used to manage multiple levels of computers and switchgear. The brassboard is comprised of a set of intelligent switchgear used to effectively switch power from the sources to the loads. The Autonomous Power Expert System (APEX) portion of the APS program integrates a knowledge based fault diagnostic system, a power resource scheduler, and an interface to the APS Brassboard. The system includes knowledge bases for system diagnostics, fault detection and isolation, and recommended actions. The scheduler autonomously assigns start times to the attached loads based on temporal and power constraints. The scheduler is able to work in a near real time environment for both scheduling and dynamic replanning.

  19. 49 CFR 236.1015 - PTC Safety Plan content requirements and PTC System Certification.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... maintenance, inspections, tests, adjustments, repairs, or replacements, and the system's resulting conditions... abbreviated as that term is used in subpart H of this part. (3) Stand-alone. A PTC system proposed on a newly...) Mixed systems. If a PTC system combining overlay, stand-alone, vital, or non-vital characteristics...

  20. Effect of Initial Powder Morphology and Thermal and Mechanical Properties of Stand-Alone Plasma-Sprayed 7 wt%Y2O3-ZrO2 Coatings

    SciTech Connect

    Ercan, Batur; Bowman, Keith; Trice, Rodney; Wang, Hsin; Porter, Wallace D

    2006-01-01

    The effects of starting powder morphology on the thermal and mechanical properties of stand-alone plasma-sprayed 7 wt.% Y{sub 2}O{sub 3}-ZrO{sub 2}(YSZ) coatings were studied. Two powder morphologies were investigated: an agglomerated and sintered powder (referred to presently as 'AS') and a powder manufactured using plasma spheroidization to create hollow spheres (referred to presently as 'HS'). Coatings made from AS powders contained 0.21 wt.% SiO{sub 2} impurity, twice as much as observed in coatings made from HS powders. Properties of coatings made from each powder type were compared in the as-sprayed state and after 50 h heat treatments at temperatures ranging from 1000 to 1400 C. SEM microstructural investigations revealed significant differences in the porosity and distribution of pores in the coatings. In coatings made with AS powders the majority of the high aspect ratio pores were located between lamella (interlamellar porosity). In addition to interlamellar pores, coatings made with HS powders demonstrated 1.5 times more spherical-shaped globular pores by number located within lamella. Globular pores were shown to still exist in coatings made with HS powders after 50 h heat treatments at 1400 C. Archimedes porosity measurements showed that coatings made with AS powders typically contained 4-5% less total porosity than coatings made with HS powders. Thermal conductivity experiments using laser flash showed that there was no difference in the thermal conductivity of coatings made from either powder type in the as-sprayed state despite higher porosity in the coatings made from HS powders. After a 50 h heat treatment at 1000 and 1200 C, coatings made from both powder types still demonstrated statistically similar thermal conductivities. However, after a 50 h heat treatment at 1400 C the thermal conductivity of coatings made from AS powders was found to be 0.3 W/m/K higher than coatings made from HS powders. Microstructural differences in the coatings made from the two powder types that affected sintering rates, including the increased level of SiO{sub 2} impurities and fewer globular pores, were used to explain variations in properties. In uniaxial compression tests on stand-alone samples at 1000, 1100, and 1200 C, coatings made from AS powders typically relaxed more stress than coatings made from HS powders. Differences in coating relaxation became more apparent as the test temperature increased through 1200 C. The higher percentage of impurity SiO{sub 2} in the AS coatings is believed to contribute to increased relaxation via formation of a glassy phase at the grain boundaries which assists grain boundary sliding during elevated temperature deformation.

  1. Market assessment of photovoltaic power systems for agricultural applications in Mexico

    SciTech Connect

    Steigelman, W.; Asmon, I.

    1981-07-01

    A month-long study in Mexico was aimed at assessing the market potential for stand-alone photovoltaic systems in agriculture. The types of applications considered are those requiring less than 15 kw of power. The applications include irrigation, cattle watering, refrigeration, crop processing and animal raising. Descriptions are provided of power and energy use profiles for many applications as well as assessments of business environment, government and private sector attitudes towards photovoltaics, and financing. The Mexican market presents both advantages and disadvantages for American PV manufacturers. The principal advantages are recognition of the technical superiority of American photovoltaics and the favorable reputation of several American PV firms already active in the Mexican market. Major disadvantages include lack of government incentives for PV use, cheap domestic energy sources, extensive electric grid, high first cost of PV, competition from Mexican and other non-US PV companies, and lack of financing. Given these parameters the market for PV in the Mexican agricultural sector during the period 1981 to 1986, will be relatively small, about 605 kwp. However, other sectors where the market for PV is likely to be more favorable than for agriculture include: rural services, telecommunications and cathodic protection. The primary market appears to be in the public (i.e., government) rather than private sector, due to financing constraints and the high price of PV relative to conventional power sources available to the private sector.

  2. Market assessment of photovoltaic power systems for agricultural applications in Morocco

    SciTech Connect

    Steingass, H.; Asmon, I.

    1981-09-01

    A month-long study in Morocco was aimed at assessing the market potential for stand-alone photovoltaic systems in agriculture and rural service applications. The types of applications considered are those requiring less than 15 kw of power. The applications include irrigation, cattle watering, refrigeration, crop processing, potable water and educational TV. Telecommunications and transportation signalling applications were also considered in the course of the study. Power and energy use profiles are described for many applications as well assessments of business environment, government and private sector attitudes towards photovoltaics, and financing. The Moroccan market presents both advantages and disadvantages for American PV manufacturers. The principle advantages are a limited grid, interest in and present use of PV in communications applications, attractive investment incentives and a stated policy favoring American investment. Major disadvantages include lack of government incentives for PV use, general unfamiliarity with PV technology, high first cost of PV, a well-established market network for diesel generators, and difficulty with financing. Given these parameters the market for PV in Morocco during the period of 1981 to 1986, will be relatively small, about 340 kwp. Sectors where the market for PV is likely to be more favorable than for agriculture include: telecommunications, transport signalling and some rural services. The primary market appears to be in the public (i.e., government) rather than private sector, due to financial constraints and the high price of PV relative to conventional power sector.

  3. Market assessment of photovoltaic power systems for agricultural applications in Morocco

    NASA Technical Reports Server (NTRS)

    Steingass, H.; Asmon, I.

    1981-01-01

    Results of a month-long study in Morocco aimed at assessing the market potential for stand-alone photovoltaic systems in agriculture and rural service applications are presented. The following applications, requiring less than 15 kW of power, are described: irrigation, cattle watering, refrigeration, crop processing, potable water and educational TV. Telecommunications and transportation signalling applications, descriptions of power and energy use profiles, assessments of business environment, government and private sector attitudes towards photovoltaics, and financing were also considered. The Moroccan market presents both advantages and disadvantages for American PV manufacturers. The principle advantages of the Moroccan market are: a limited grid, interest in and present use of PV in communications applications, attractive investment incentives, and a stated policy favoring American investment. Disadvantages include: lack of government incentives for PV use, general unfamiliarity with PV technology, high first cost of PV, a well-established market network for diesel generators, and difficulty with financing. The market for PV in Morocco (1981-1986), will be relatively small, about 340 kwp. The market for PV is likely to be more favorable in telecommunications, transport signalling and some rural services. The primary market appears to be in the public (i.e., government) rather than private sector, due to financial constraints and the high price of PV relative to conventional power sector.

  4. Dynamic power systems for power generation

    SciTech Connect

    English, R.E.

    1984-04-01

    The characteristics of dynamic power systems have considerable potential value, especially for the space station. The base of technology that makes these dynamic power systems practical is reviewed. The following types of power-generating systems are examined herein: organic Rankine cycle, potassium Rankine cycle, Brayton cycle, and Stirling cycle.

  5. AC power system breadboard

    NASA Technical Reports Server (NTRS)

    Wappes, Loran J.; Sundberg, R.; Mildice, J.; Peterson, D.; Hushing, S.

    1987-01-01

    The object of this program was to design, build, test, and deliver a high-frequency (20-kHz) Power System Breadboard which would electrically approximate a pair of dual redundant power channels of an IOC Space Station. This report describes that program, including the technical background, and discusses the results, showing that the major assumptions about the characteristics of this class of hardware (size, mass, efficiency, control, etc.) were substantially correct. This testbed equipment has been completed and delivered to LeRC, where it is operating as a part of the Space Station Power System Test Facility.

  6. Wind power generating system

    SciTech Connect

    Schachle, Ch.; Schachle, E. C.; Schachle, J. R.; Schachle, P. J.

    1985-03-12

    Normally feathered propeller blades of a wind power generating system unfeather in response to the actuation of a power cylinder that responds to actuating signals. Once operational, the propellers generate power over a large range of wind velocities. A maximum power generation design point signals a feather response of the propellers so that once the design point is reached no increase in power results, but the system still generates power. At wind speeds below this maximum point, propeller speed and power output optimize to preset values. The propellers drive a positive displacement pump that in turn drives a positive displacement motor of the swash plate type. The displacement of the motor varies depending on the load on the system, with increasing displacement resulting in increasing propeller speeds, and the converse. In the event of dangerous but not clandestine problems developing in the system, a control circuit dumps hydraulic pressure from the unfeathering cylinder resulting in a predetermined, lower operating pressure produced by the pump. In the event that a problem of potentially cladestine consequence arises, the propeller unfeathering cylinder immediately unloads. Upon startup, a bypass around the motor is blocked, applying a pressure across the motor. The motor drives the generator until the generator reaches a predetermined speed whereupon the generator is placed in circuit with a utility grid and permitted to motor up to synchronous speed.

  7. Solar Powered Refrigeration System

    NASA Technical Reports Server (NTRS)

    Ewert, Michael K. (Inventor); Bergeron, David J., III (Inventor)

    2002-01-01

    A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

  8. Power Systems Development Facility

    SciTech Connect

    Southern Company Services

    2009-01-31

    In support of technology development to utilize coal for efficient, affordable, and environmentally clean power generation, the Power Systems Development Facility (PSDF), located in Wilsonville, Alabama, has routinely demonstrated gasification technologies using various types of coals. The PSDF is an engineering scale demonstration of key features of advanced coal-fired power systems, including a Transport Gasifier, a hot gas particulate control device, advanced syngas cleanup systems, and high-pressure solids handling systems. This final report summarizes the results of the technology development work conducted at the PSDF through January 31, 2009. Twenty-one major gasification test campaigns were completed, for a total of more than 11,000 hours of gasification operation. This operational experience has led to significant advancements in gasification technologies.

  9. Residential photovoltaic flywheel storage system performance and cost

    SciTech Connect

    Hay, R.D.; Millner, A.R.; Jarvinen, P.O.

    1980-01-01

    A subscale prototype of a flywheel energy storage and conversion system for use with photovoltaic power systems of residential and intermediate load-center size has been designed, built and tested by MIT Lincoln Laboratory. System design, including details of such key components as magnetic bearings, motor generator, and power-conditioning electronics, are described. Performance results of prototype testing are given and indicate that this system is the equal of or superior to battery and inverter systems for the same application. Results of cost and user-worth analysis show that residential systems are economically feasible in stand-alone and in utility-interactive applications.

  10. Autonomous power system brassboard

    NASA Astrophysics Data System (ADS)

    Merolla, Anthony

    1992-10-01

    The Autonomous Power System (APS) brassboard is a 20 kHz power distribution system which has been developed at NASA Lewis Research Center, Cleveland, Ohio. The brassboard exists to provide a realistic hardware platform capable of testing artificially intelligent (AI) software. The brassboard's power circuit topology is based upon a Power Distribution Control Unit (PDCU), which is a subset of an advanced development 20 kHz electrical power system (EPS) testbed, originally designed for Space Station Freedom (SSF). The APS program is designed to demonstrate the application of intelligent software as a fault detection, isolation, and recovery methodology for space power systems. This report discusses both the hardware and software elements used to construct the present configuration of the brassboard. The brassboard power components are described. These include the solid-state switches (herein referred to as switchgear), transformers, sources, and loads. Closely linked to this power portion of the brassboard is the first level of embedded control. Hardware used to implement this control and its associated software is discussed. An Ada software program, developed by Lewis Research Center's Space Station Freedom Directorate for their 20 kHz testbed, is used to control the brassboard's switchgear, as well as monitor key brassboard parameters through sensors located within these switches. The Ada code is downloaded from a PC/AT, and is resident within the 8086 microprocessor-based embedded controllers. The PC/AT is also used for smart terminal emulation, capable of controlling the switchgear as well as displaying data from them. Intelligent control is provided through use of a T1 Explorer and the Autonomous Power Expert (APEX) LISP software. Real-time load scheduling is implemented through use of a 'C' program-based scheduling engine. The methods of communication between these computers and the brassboard are explored. In order to evaluate the features of both the brassboard hardware and intelligent controlling software, fault circuits have been developed and integrated as part of the brassboard. A description of these fault circuits and their function is included. The brassboard has become an extremely useful test facility, promoting artificial intelligence (AI) applications for power distribution systems. system performance. &Modifications and enhancements to improve the brassboard's operation are discussed.

  11. Autonomous power system brassboard

    NASA Technical Reports Server (NTRS)

    Merolla, Anthony

    1992-01-01

    The Autonomous Power System (APS) brassboard is a 20 kHz power distribution system which has been developed at NASA Lewis Research Center, Cleveland, Ohio. The brassboard exists to provide a realistic hardware platform capable of testing artificially intelligent (AI) software. The brassboard's power circuit topology is based upon a Power Distribution Control Unit (PDCU), which is a subset of an advanced development 20 kHz electrical power system (EPS) testbed, originally designed for Space Station Freedom (SSF). The APS program is designed to demonstrate the application of intelligent software as a fault detection, isolation, and recovery methodology for space power systems. This report discusses both the hardware and software elements used to construct the present configuration of the brassboard. The brassboard power components are described. These include the solid-state switches (herein referred to as switchgear), transformers, sources, and loads. Closely linked to this power portion of the brassboard is the first level of embedded control. Hardware used to implement this control and its associated software is discussed. An Ada software program, developed by Lewis Research Center's Space Station Freedom Directorate for their 20 kHz testbed, is used to control the brassboard's switchgear, as well as monitor key brassboard parameters through sensors located within these switches. The Ada code is downloaded from a PC/AT, and is resident within the 8086 microprocessor-based embedded controllers. The PC/AT is also used for smart terminal emulation, capable of controlling the switchgear as well as displaying data from them. Intelligent control is provided through use of a T1 Explorer and the Autonomous Power Expert (APEX) LISP software. Real-time load scheduling is implemented through use of a 'C' program-based scheduling engine. The methods of communication between these computers and the brassboard are explored. In order to evaluate the features of both the brassboard hardware and intelligent controlling software, fault circuits have been developed and integrated as part of the brassboard. A description of these fault circuits and their function is included. The brassboard has become an extremely useful test facility, promoting artificial intelligence (AI) applications for power distribution systems. However, there are elements of the brassboard which could be enhanced, thus improving system performance. Modifications and enhancements to improve the brassboard's operation are discussed.

  12. Laser satellite power systems

    SciTech Connect

    Walbridge, E.W.

    1980-01-01

    A laser satellite power system (SPS) converts solar power captured by earth-orbiting satellites into electrical power on the earth's surface, the satellite-to-ground transmission of power being effected by laser beam. The laser SPS may be an alternative to the microwave SPS. Microwaves easily penetrate clouds while laser radiation does not. Although there is this major disadvantage to a laser SPS, that system has four important advantages over the microwave alternative: (1) land requirements are much less, (2) radiation levels are low outside the laser ground stations, (3) laser beam sidelobes are not expected to interfere with electromagnetic systems, and (4) the laser system lends itself to small-scale demonstration. After describing lasers and how they work, the report discusses the five lasers that are candidates for application in a laser SPS: electric discharge lasers, direct and indirect solar pumped lasers, free electron lasers, and closed-cycle chemical lasers. The Lockheed laser SPS is examined in some detail. To determine whether a laser SPS will be worthy of future deployment, its capabilities need to be better understood and its attractiveness relative to other electric power options better assessed. First priority should be given to potential program stoppers, e.g., beam attenuation by clouds. If investigation shows these potential program stoppers to be resolvable, further research should investigate lasers that are particularly promising for SPS application.

  13. Integrated power system

    SciTech Connect

    Waddington, C.

    1987-10-13

    An integrated power system is described for transmitting power from a gas turbine engine, including a gas producer and a free turbine engine, to the driving elements of a vehicle comprising: a pair of independent output shafts; a pair of combining planetary gear systems, each being drivingly coupled to an associated one of the output shafts; a variable speed transmission drivingly coupled to the free power turbine; drive means operatively connecting the transmission and each of the combining planetary gear systems; steering means operatively coupled to each of the combining planetary gear systems for selectively driving at least one of the combining planetary gear systems; the steering means including a variable displacement hydraulic motor in driving engagement with the planetary gear systems and an hydraulic pump in driving engagement with the transmission for supplying fluid under pressure to the hydraulic motor to thereby effect steering of the vehicle; a fuel control for controlling the power output of the gas turbine engine; and an adjustable relief valve operatively interposed between the hydraulic motor and the hydraulic pump, the valve being responsive to the fuel control to establish a maximum fluid pressure imparted by the hydraulic pump to the hydraulic motor.

  14. Windmill power system

    SciTech Connect

    Siegel, E.A.

    1985-01-01

    The present invention relates to a windmill power system, particularly a passive solar powered windmill. Specifically, the present invention is directed to a windmill in which a solar chamber and a stack produce an upwardly flowing natural convection draft which is utilized to turn the blades of a horizontally positioned windmill. A conventional vertical windmill may also be used in conjunction with the horizontal windmill. The invention can also be used in a cogeneration system or with any heat source, with waste heat being used to heat the air in the solar chamber.

  15. Automated Power-Distribution System

    NASA Technical Reports Server (NTRS)

    Ashworth, Barry; Riedesel, Joel; Myers, Chris; Miller, William; Jones, Ellen F.; Freeman, Kenneth; Walsh, Richard; Walls, Bryan K.; Weeks, David J.; Bechtel, Robert T.

    1992-01-01

    Autonomous power-distribution system includes power-control equipment and automation equipment. System automatically schedules connection of power to loads and reconfigures itself when it detects fault. Potential terrestrial applications include optimization of consumption of power in homes, power supplies for autonomous land vehicles and vessels, and power supplies for automated industrial processes.

  16. Power line detection system

    DOEpatents

    Latorre, Victor R.; Watwood, Donald B.

    1994-01-01

    A short-range, radio frequency (RF) transmitting-receiving system that provides both visual and audio warnings to the pilot of a helicopter or light aircraft of an up-coming power transmission line complex. Small, milliwatt-level narrowband transmitters, powered by the transmission line itself, are installed on top of selected transmission line support towers or within existing warning balls, and provide a continuous RF signal to approaching aircraft. The on-board receiver can be either a separate unit or a portion of the existing avionics, and can also share an existing antenna with another airborne system. Upon receipt of a warning signal, the receiver will trigger a visual and an audio alarm to alert the pilot to the potential power line hazard.

  17. Power line detection system

    DOEpatents

    Latorre, V.R.; Watwood, D.B.

    1994-09-27

    A short-range, radio frequency (RF) transmitting-receiving system that provides both visual and audio warnings to the pilot of a helicopter or light aircraft of an up-coming power transmission line complex. Small, milliwatt-level narrowband transmitters, powered by the transmission line itself, are installed on top of selected transmission line support towers or within existing warning balls, and provide a continuous RF signal to approaching aircraft. The on-board receiver can be either a separate unit or a portion of the existing avionics, and can also share an existing antenna with another airborne system. Upon receipt of a warning signal, the receiver will trigger a visual and an audio alarm to alert the pilot to the potential power line hazard. 4 figs.

  18. Laboratory evaluation of a pilot cell battery protection system for photovoltaic applications

    NASA Technical Reports Server (NTRS)

    Cataldo, R. L.; Thomas, R. D.

    1981-01-01

    An energy storage method for the 3.5 kW battery power system was investigated. The Pilot Cell Battery Protection System was tested for use in photovoltaic power systems and results show that this is a viable method of storage battery control. The method of limiting battery depth of discharge has the following advantages: (1) temperature sensitivity; (2) rate sensitivity; and (3) state of charge indication. The pilot cell concept is of interest in remote stand alone photovoltaic power systems. The battery can be protected from damaging overdischarge by using the proper ratio of pilot cell capacities to main battery capacity.

  19. Modeling and sizing optimization of hybrid photovoltaic/wind power generation system

    NASA Astrophysics Data System (ADS)

    Yazdanpanah, Mohammad-Ali

    2014-03-01

    The rapid industrialization and growth of world's human population have resulted in the unprecedented increase in the demand for energy and in particular electricity. Depletion of fossil fuels and impacts of global warming caused widespread attention using renewable energy sources, especially wind and solar energies. Energy security under varying weather conditions and the corresponding system cost are the two major issues in designing hybrid power generation systems. In this paper, the match evaluation method (MEM) is developed based on renewable energy supply/demand match evaluation criteria to size the proposed system in lowest cost. This work is undertaken with triple objective function: inequality coefficient, correlation coefficient, and annualized cost of system. It provides optimum capacity of as many numbers of supplies as required to match with a load demand in lowest investment, so it can handle large-scale design problems. Meteorological data were collected from the city of Zabol, located in south-east of Iran, as a case study. Six types of wind turbine and also six types of PV modules, with different output powers and costs, are considered for this optimization procedure. A battery storage system is used to even out irregularities in meteorological data. A multi-objective particle swarm optimization algorithm has been used for the prediction of an optimized set of design based on the MEM technique. The results of this study are valuable for evaluating the performance of future stand-alone hybrid power system. It is worth mentioning that the proposed methodology can be effectively employed for any composition of hybrid energy systems in any locations taking into account the meteorological data and the consumer's demand.

  20. Power systems testing

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Space Station Freedom (SSF) will give the U.S. a permanent manned presence in space in 1999. The SSF underwent its final design concept in 1991. Launches of hardware will begin in late 1995, and the SSF will become operational in the man tended configuration in 1997. Additional Space Shuttle flights between 1997 and 1999 will complete the SSF. Along with international partners, a crew of four astronauts will conduct long-term experimentation in the microgravity environment of the orbiting spacecraft. Lewis Research Center, along with its prime contractor, will provide the electrical power system (EPS) for SSF. Two major testing facilities at the Lewis Research Center will support the Lewis EPS. The Power Systems Facility provides test beds for life testing the station batteries and the power management distribution system testbed. This testbed simulates two channels of the EPS. The Space Power Facility at the Lewis Plum Brook Station is the largest vacuum chamber in the world. Within this chamber, a simulated space environment, testing of full-size EPS components will occur.

  1. Heatpipe power system development

    SciTech Connect

    Houts, M.G.; Poston, D.I.

    1998-12-31

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of the project was to develop a design approach that could enable the development of near-term, low-cost, space fission-power systems. Sixteen desired attributes were identified for such systems and detailed analyses were performed to verify that they are feasible. Preliminary design work was performed on one concept, the Heatpipe Power system (HPS). As a direct result of this project, funding was obtained from the National Aeronautics and Space Administration to build and test an HPS module. The module tests went well, and they now have funding to build a bimodal module.

  2. Wireless power transfer system

    DOEpatents

    Wu, Hunter; Sealy, Kylee; Gilchrist, Aaron

    2016-02-23

    A system includes a first stage of an inductive power transfer system with an LCL load resonant converter with a switching section, an LCL tuning circuit, and a primary receiver pad. The IPT system includes a second stage with a secondary receiver pad, a secondary resonant circuit, a secondary rectification circuit, and a secondary decoupling converter. The secondary receiver pad connects to the secondary resonant circuit. The secondary resonant circuit connects to the secondary rectification circuit. The secondary rectification circuit connects to the secondary decoupling converter. The second stage connects to a load. The load includes an energy storage element. The second stage and load are located on a vehicle and the first stage is located at a fixed location. The primary receiver pad wirelessly transfers power to the secondary receiver pad across a gap when the vehicle positions the secondary receiver pad with respect to the primary receiver pad.

  3. High power connection system

    DOEpatents

    Schaefer, Christopher E.; Beer, Robert C.; McCall, Mark D.

    2000-01-01

    A high power connection system adapted for automotive environments which provides environmental and EMI shielding includes a female connector, a male connector, and a panel mount. The female connector includes a female connector base and a snap fitted female connector cover. The male connector includes a male connector base and a snap fitted male connector cover. The female connector base has at least one female power terminal cavity for seatably receiving a respective female power terminal. The male connector base has at least one male power terminal cavity for seatably receiving a respective male power terminal. The female connector is covered by a cover seal and a conductive shroud. A pair of lock arms protrude outward from the front end of the male connector base, pass through the panel mount and interface with a lever of a lever rotatably connected to the shroud to thereby mechanically assist mating of the male and female connectors. Safety terminals in the male and female connectors provide a last-to-connect-first-to-break connection with an HVIL circuit.

  4. Advanced Solar Power Systems

    NASA Technical Reports Server (NTRS)

    Atkinson, J. H.; Hobgood, J. M.

    1984-01-01

    The Advanced Solar Power System (ASPS) concentrator uses a technically sophisticated design and extensive tooling to produce very efficient (80 to 90%) and versatile energy supply equipment which is inexpensive to manufacture and requires little maintenance. The advanced optical design has two 10th order, generalized aspheric surfaces in a Cassegrainian configuration which gives outstanding performance and is relatively insensitive to temperature changes and wind loading. Manufacturing tolerances also have been achieved. The key to the ASPS is the direct absorption of concentrated sunlight in the working fluid by radiative transfers in a black body cavity. The basic ASPS design concepts, efficiency, optical system, and tracking and focusing controls are described.

  5. Advanced solar power systems

    NASA Astrophysics Data System (ADS)

    Atkinson, J. H.; Hobgood, J. M.

    1984-03-01

    The Advanced Solar Power System (ASPS) concentrator uses a technically sophisticated design and extensive tooling to produce very efficient (80 to 90%) and versatile energy supply equipment which is inexpensive to manufacture and requires little maintenance. The advanced optical design has two 10th order, generalized aspheric surfaces in a Cassegrainian configuration which gives outstanding performance and is relatively insensitive to temperature changes and wind loading. Manufacturing tolerances also have been achieved. The key to the ASPS is the direct absorption of concentrated sunlight in the working fluid by radiative transfers in a black body cavity. The basic ASPS design concepts, efficiency, optical system, and tracking and focusing controls are described.

  6. Evolution of a Medical School Library Circulation System from a Batch to an Online System

    PubMed Central

    Larson, Robert H.

    1982-01-01

    The circulation system at the Health Sciences Library, George Washington University Medical Center has evolved from a stand alone batch process to an online system which is integrated into an automated library system called HAL (Himmelfarb Automated Library-System).

  7. Lunar power systems

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The findings of a study on the feasibility of several methods of providing electrical power for a permanently manned lunar base are provided. Two fundamentally different methods for lunar electrical power generation are considered. One is the use of a small nuclear reactor and the other is the conversion of solar energy to electricity. The baseline goal was to initially provide 300 kW of power with growth capability to one megawatt and eventually to 10 megawatts. A detailed, day by day scenario for the establishment, build-up, and operational activity of the lunar base is presented. Also presented is a conceptual approach to a supporting transportation system which identifies the number, type, and deployment of transportation vehicles required to support the base. An approach to the use of solar cells in the lunar environment was developed. There are a number of heat engines which are applicable to solar/electric conversions, and these are examined. Several approaches to energy storage which were used by the electric power utilities were examined and those which could be used at a lunar base were identified.

  8. TOPEX electrical power system

    NASA Astrophysics Data System (ADS)

    Chetty, P. R. K.; Roufberg, Lew; Costogue, Ernest

    The TOPEX mission requirements which impact the power requirements and analyses are presented. A description of the electrical power system (EPS), including energy management and battery charging methods that were conceived and developed to meet the identified satellite requirements, is included. Analysis of the TOPEX EPS confirms that all of its electrical performance and reliability requirements have been met. The TOPEX EPS employs the flight-proven modular power system (MPS) which is part of the Multimission Modular Spacecraft and provides high reliability, abbreviated development effort and schedule, and low cost. An energy balance equation, unique to TOPEX, has been derived to confirm that the batteries will be completely recharged following each eclipse, under worst-case conditions. TOPEX uses three NASA Standard 50AH Ni-Cd batteries, each with 22 cells in series. The MPS contains battery charge control and protection based on measurements of battery currents, voltages, temperatures, and computed depth-of-discharge. In case of impending battery depletion, the MPS automatically implements load shedding.

  9. TOPEX electrical power system

    NASA Technical Reports Server (NTRS)

    Chetty, P. R. K.; Roufberg, Lew; Costogue, Ernest

    1991-01-01

    The TOPEX mission requirements which impact the power requirements and analyses are presented. A description of the electrical power system (EPS), including energy management and battery charging methods that were conceived and developed to meet the identified satellite requirements, is included. Analysis of the TOPEX EPS confirms that all of its electrical performance and reliability requirements have been met. The TOPEX EPS employs the flight-proven modular power system (MPS) which is part of the Multimission Modular Spacecraft and provides high reliability, abbreviated development effort and schedule, and low cost. An energy balance equation, unique to TOPEX, has been derived to confirm that the batteries will be completely recharged following each eclipse, under worst-case conditions. TOPEX uses three NASA Standard 50AH Ni-Cd batteries, each with 22 cells in series. The MPS contains battery charge control and protection based on measurements of battery currents, voltages, temperatures, and computed depth-of-discharge. In case of impending battery depletion, the MPS automatically implements load shedding.

  10. Financial study of commercialization of solar central receiver power systems

    NASA Astrophysics Data System (ADS)

    1981-03-01

    Commercialization requires that central receiver (CR) systems meet the economic criteria used by industry to select systems for capital ventures. Quantitative estimates are given of the investment required by government, utilities, and the manufacturing sector to meet the energy displacement goals for central receiver technology. Initial solar repowering and stand-alone electric utility plants will not have economic comparability with competitive energy sources. A major factor for this is that initial (first of a kind) heliostat costs will be high. As heliostat costs are reduced due to automated manufacturing economies, learning, and high volume production, central receiver technology will become more competitive. Under this task, several scenarios (0.1, 0.5, and 1.0 quad/y) were evaluated to determine the effect on commercial attractiveness and to determine the cost to government to bring about commercialization of solar central receivers.

  11. Power control system and method

    DOEpatents

    Steigerwald, Robert Louis [Burnt Hills, NY; Anderson, Todd Alan [Niskayuna, NY

    2008-02-19

    A power system includes an energy harvesting device, a battery coupled to the energy harvesting device, and a circuit coupled to the energy harvesting device and the battery. The circuit is adapted to deliver power to a load by providing power generated by the energy harvesting device to the load without delivering excess power to the battery and to supplement the power generated by the energy harvesting device with power from the battery if the power generated by the energy harvesting device is insufficient to fully power the load. A method of operating the power system is also provided.

  12. Power control system and method

    DOEpatents

    Steigerwald, Robert Louis; Anderson, Todd Alan

    2006-11-07

    A power system includes an energy harvesting device, a battery coupled to the energy harvesting device, and a circuit coupled to the energy harvesting device and the battery. The circuit is adapted to deliver power to a load by providing power generated by the energy harvesting device to the load without delivering excess power to the battery and to supplement the power generated by the energy harvesting device with power from the battery if the power generated by the energy harvesting device is insufficient to fully power the load. A method of operating the power system is also provided.

  13. Automated Power-Distribution System

    NASA Technical Reports Server (NTRS)

    Thomason, Cindy; Anderson, Paul M.; Martin, James A.

    1990-01-01

    Automated power-distribution system monitors and controls electrical power to modules in network. Handles both 208-V, 20-kHz single-phase alternating current and 120- to 150-V direct current. Power distributed to load modules from power-distribution control units (PDCU's) via subsystem distributors. Ring busses carry power to PDCU's from power source. Needs minimal attention. Detects faults and also protects against them. Potential applications include autonomous land vehicles and automated industrial process systems.

  14. Power Systems Development Facility

    SciTech Connect

    2003-07-01

    This report discusses Test Campaign TC12 of the Kellogg Brown & Root, Inc. (KBR) Transport Gasifier train with a Siemens Westinghouse Power Corporation (SW) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The Transport Gasifier is an advanced circulating fluidized-bed reactor designed to operate as either a combustor or a gasifier using a particulate control device (PCD). While operating as a gasifier, either air or oxygen can be used as the oxidant. Test run TC12 began on May 16, 2003, with the startup of the main air compressor and the lighting of the gasifier start-up burner. The Transport Gasifier operated until May 24, 2003, when a scheduled outage occurred to allow maintenance crews to install the fuel cell test unit and modify the gas clean-up system. On June 18, 2003, the test run resumed when operations relit the start-up burner, and testing continued until the scheduled end of the run on July 14, 2003. TC12 had a total of 733 hours using Powder River Basin (PRB) subbituminous coal. Over the course of the entire test run, gasifier temperatures varied between 1,675 and 1,850 F at pressures from 130 to 210 psig.

  15. Power plant feedwater system

    SciTech Connect

    Silvestri, G.

    1985-12-31

    A feedwater heater system for a steam turbine power plant is provided which incorporates a liquid-to-liquid heat exchanger in addition to a plurality of vapor-to-liquid feedwater heaters. The advantage of this configuration is that the potential magnitude of entrained impurities within the feedwater stream is reduced without a significant increase in the overall heat rate of the steam turbine power plant. A preferred embodiment of the present invention incorporates three low pressure feedwater heaters and two high pressure feedwater heaters in conjunction with a drain cooler which is connected serially between the low and high pressure feedwater heaters. An alternative embodiment of the present invention incorporates a liquid-to-liquid heat exchanger connected hydraulically in parallel with the low pressure feedwater heaters. In both embodiments of the present invention, the liquid-to-liquid heat exchanger of the present invention receives the drain water from a reheater, such as a moisture separator-reheater, and exhausts this liquid to a condenser of the steam turbine power plant.

  16. Solar total energy project at Shenandoah, Georgia system design

    NASA Astrophysics Data System (ADS)

    Poche, A. J.

    1980-05-01

    The solar total energy system (STES) was to provide 50% of the total electrical and thermal energy requirements of the 25,000 sq ft Bleyle of America knitwear plant located at the Shenandoah Site. The system will provide 400 kilowatts electrical and 3 megawatts of thermal energy. The STES has a classical, cascaded total energy system configuration. It utilizes one hundred twenty (120), parabolic dish collectors, high temperature (750 F) trickle oil thermal energy storage and a steam turbine generator. The electrical load shaving system was designed for interconnected operation with the Georgia Power system and for operation in a stand alone mode.

  17. Power Systems Development Facility

    SciTech Connect

    Southern Company Services

    2004-04-30

    This report discusses Test Campaign TC15 of the Kellogg Brown & Root, Inc. (KBR) Transport Gasifier train with a Siemens Power Generation, Inc. (SPG) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The Transport Gasifier is an advanced circulating fluidized-bed reactor designed to operate as either a combustor or gasifier using a particulate control device (PCD). While operating as a gasifier, either air or oxygen can be used as the oxidant. Test run TC15 began on April 19, 2004, with the startup of the main air compressor and the lighting of the gasifier startup burner. The Transport Gasifier was shutdown on April 29, 2004, accumulating 200 hours of operation using Powder River Basin (PRB) subbituminous coal. About 91 hours of the test run occurred during oxygen-blown operations. Another 6 hours of the test run was in enriched-air mode. The remainder of the test run, approximately 103 hours, took place during air-blown operations. The highest operating temperature in the gasifier mixing zone mostly varied from 1,800 to 1,850 F. The gasifier exit pressure ran between 200 and 230 psig during air-blown operations and between 110 and 150 psig in oxygen-enhanced air operations.

  18. Mission Benefits of Gridded Ion and Hall Thruster Hybrid Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Dankanich, John W.; Polsgrove, Tara

    2006-01-01

    The NASA In-Space Propulsion Technology (ISPT) Project Office has been developing the NEXT gridded ion thruster system and is planning to procure a low power Hall system. The new ion propulsion systems will join NSTAR as NASA's primary electric propulsion system options. Studies have been performed to show mission benefits of each of the stand alone systems. A hybrid ion propulsion system (IPS) can have the advantage of reduced cost, decreased flight time and greater science payload delivery over comparable homogeneous systems. This paper explores possible advantages of combining various thruster options for a single mission.

  19. POWER SYSTEMS DEVELOPMENT FACILITY

    SciTech Connect

    Unknown

    2002-11-01

    This report discusses test campaign GCT4 of the Kellogg Brown & Root, Inc. (KBR) transport reactor train with a Siemens Westinghouse Power Corporation (Siemens Westinghouse) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The transport reactor is an advanced circulating fluidized-bed reactor designed to operate as either a combustor or a gasifier using one of two possible particulate control devices (PCDs). The transport reactor was operated as a pressurized gasifier during GCT4. GCT4 was planned as a 250-hour test run to continue characterization of the transport reactor using a blend of several Powder River Basin (PRB) coals and Bucyrus limestone from Ohio. The primary test objectives were: Operational Stability--Characterize reactor loop and PCD operations with short-term tests by varying coal-feed rate, air/coal ratio, riser velocity, solids-circulation rate, system pressure, and air distribution. Secondary objectives included the following: Reactor Operations--Study the devolatilization and tar cracking effects from transient conditions during transition from start-up burner to coal. Evaluate the effect of process operations on heat release, heat transfer, and accelerated fuel particle heat-up rates. Study the effect of changes in reactor conditions on transient temperature profiles, pressure balance, and product gas composition. Effects of Reactor Conditions on Synthesis Gas Composition--Evaluate the effect of air distribution, steam/coal ratio, solids-circulation rate, and reactor temperature on CO/CO{sub 2} ratio, synthesis gas Lower Heating Value (LHV), carbon conversion, and cold and hot gas efficiencies. Research Triangle Institute (RTI) Direct Sulfur Recovery Process (DSRP) Testing--Provide syngas in support of the DSRP commissioning. Loop Seal Operations--Optimize loop seal operations and investigate increases to previously achieved maximum solids-circulation rate.

  20. Solar thermal power system

    DOEpatents

    Bennett, Charles L.

    2010-06-15

    A solar thermal power generator includes an inclined elongated boiler tube positioned in the focus of a solar concentrator for generating steam from water. The boiler tube is connected at one end to receive water from a pressure vessel as well as connected at an opposite end to return steam back to the vessel in a fluidic circuit arrangement that stores energy in the form of heated water in the pressure vessel. An expander, condenser, and reservoir are also connected in series to respectively produce work using the steam passed either directly (above a water line in the vessel) or indirectly (below a water line in the vessel) through the pressure vessel, condense the expanded steam, and collect the condensed water. The reservoir also supplies the collected water back to the pressure vessel at the end of a diurnal cycle when the vessel is sufficiently depressurized, so that the system is reset to repeat the cycle the following day. The circuital arrangement of the boiler tube and the pressure vessel operates to dampen flow instabilities in the boiler tube, damp out the effects of solar transients, and provide thermal energy storage which enables time shifting of power generation to better align with the higher demand for energy during peak energy usage periods.

  1. Satellite Power System (SPS)

    NASA Technical Reports Server (NTRS)

    Edler, H. G.

    1978-01-01

    Potential organizational options for a solar power satellite system (SPS) were investigated. Selection and evaluation criteria were determined to include timeliness, reliability, and adequacy to contribute meaningfully to the U.S. supply; political feasibility (both national and international); and cost effectiveness (including environmental and other external costs). Based on these criteria, four organizational alternatives appeared to offer reasonable promise as potential options for SPS. A large number of key issues emerged as being factors which would influence the final selection process. Among these issues were a variety having to do with international law, international institutions, environmental controls, economics, operational flexibility, congressional policies, commercial-vs-governmental ownership, national dedication, and national and operational stategic issues.

  2. Automated Power Systems Management (APSM)

    NASA Technical Reports Server (NTRS)

    Bridgeforth, A. O.

    1981-01-01

    A breadboard power system incorporating autonomous functions of monitoring, fault detection and recovery, command and control was developed, tested and evaluated to demonstrate technology feasibility. Autonomous functions including switching of redundant power processing elements, individual load fault removal, and battery charge/discharge control were implemented by means of a distributed microcomputer system within the power subsystem. Three local microcomputers provide the monitoring, control and command function interfaces between the central power subsystem microcomputer and the power sources, power processing and power distribution elements. The central microcomputer is the interface between the local microcomputers and the spacecraft central computer or ground test equipment.

  3. Power Transfer in Physical Systems.

    ERIC Educational Resources Information Center

    Kaeck, Jack A.

    1990-01-01

    Explores the power transfer using (1) a simple electric circuit consisting of a power source with internal resistance; (2) two different mechanical systems (gravity driven and constant force driven); (3) ecological examples; and (4) a linear motor. (YP)

  4. Switching power pulse system

    DOEpatents

    Aaland, K.

    1983-08-09

    A switching system for delivering pulses of power from a source to a load using a storage capacitor charged through a rectifier, and maintained charged to a reference voltage level by a transistor switch and voltage comparator. A thyristor is triggered to discharge the storage capacitor through a saturable reactor and fractional turn saturable transformer having a secondary to primary turn ratio N of n:l/n = n[sup 2]. The saturable reactor functions as a soaker'' while the thyristor reaches saturation, and then switches to a low impedance state. The saturable transformer functions as a switching transformer with high impedance while a load coupling capacitor charges, and then switches to a low impedance state to dump the charge of the storage capacitor into the load through the coupling capacitor. The transformer is comprised of a multilayer core having two secondary windings tightly wound and connected in parallel to add their output voltage and reduce output inductance, and a number of single turn windings connected in parallel at nodes for the primary winding, each single turn winding linking a different one of the layers of the multilayer core. The load may be comprised of a resistive beampipe for a linear particle accelerator and capacitance of a pulse forming network. To hold off discharge of the capacitance until it is fully charged, a saturable core is provided around the resistive beampipe to isolate the beampipe from the capacitance until it is fully charged. 5 figs.

  5. Pluto Express power system architecture

    SciTech Connect

    Carr, G.A.

    1996-12-31

    The Pluto Express power system must answer the challenge of the next generation spacecraft by reducing its power, mass and volume envelopes. Technology developed by the New Millennium Program will enable the power system to meet the stringent requirements for the Pluto Express mission without exceeding the spacecraft mass and volume budgets. Traditionally, there has been an increasing trend of the percentage of mass of the power system electronics with respect to the total spacecraft mass. With all of the previous technology focus on high density digital packaging, the power system electronics have not been keeping pace forcing the spacecraft to absorb a relative increase in the power system mass. The increasing trend can be reversed by using mixed signal ASICs and high density multi-chip-module (MCM) packaging techniques validated by the New Millennium Program. As the size of the spacecraft shrinks, the power system electronics must become tightly integrated with the spacecraft loads. The power system architecture needs the flexibility to accommodate the specific load requirements without sacrificing the capability for growth or reduction as the spacecraft requirements change throughout the development. Modularity is a key requirement that will reduce the overall power system cost. Although the focus has been on shrinking the power system volume and mass, the efficiency and functionality cannot be ignored. Increased efficiency and functionality will only enhance the power systems capability to reduce spacecraft power requirements. The combination of the New Millennium packaging technologies with the Pluto Express power system architecture will produce a product with the capability to meet a wide range of mission profiles while reducing system development costs.

  6. Solar probe power systems concepts

    NASA Technical Reports Server (NTRS)

    Nesmith, Bill J.

    1992-01-01

    Some of the design options under consideration for providing on-board electric power for the Solar Probe Mission are discussed. Five spacecraft configurations were evaluated with slightly different power demands and volumetric constraints on the power system. This resulted in three different baseline power system designs to satisfy the five spacecraft configurations. These three current baseline power system designs use modified general-purpose heat source (GPHS) radioisotope thermoelectric generators (RTGs) similar to those launched on the Galileo and Ulysses spacecraft. The modular RTG currently under development and testing is a potential advanced alternative to the current baseline GPHS-RTG technology design.

  7. Solar probe power systems concepts

    SciTech Connect

    Nesmith, B.J. )

    1992-01-01

    Some of the design options under consideration for providing on-board electric power for the Solar Probe Mission are discussed. Five spacecraft configurations were evaluated with slightly different power demands and volumetric constraints on the power system. This resulted in three different baseline power system designs to satisfy the five spacecraft configurations. These three current baseline power system designs use modified general-purpose heat source (GPHS) radioisotope thermoelectric generators (RTGs) similar to those launched on the Galileo and Ulysses spacecraft. The modular RTG currently under development and testing is a potential advanced alternative to the current baseline GPHS-RTG technology design. 8 refs.

  8. Unitized electrolysis propulsion and fuel cell power for selected satellite missions

    SciTech Connect

    McElroy, J.F.; Humble, R.; Groot, W.A. de; Oleson, S.R.; Mitlitsky, R.; Weisberg, A.H.; Myers, B.; Carter, P.H. II

    1998-07-01

    An integrated modular propulsion and regenerative electro-energy storage system for propulsion and power functions on board spacecraft is described. The system is based on electrolysis and fuel cell principles integrated in a single unit. With water as the working fluid for both the power and propulsion systems, a clean, safe, low cost and low weight solution for many spacecraft missions is assured. The system can be designed for stand-alone propulsion, or integrated with the power system. Representative missions for two different size spacecraft are given. Both missions show a significant weight savings when electrolysis propulsion systems are used. The weight savings are augmented when the power system is unified with the propulsion system.

  9. POWER SYSTEMS DEVELOPMENT FACILITY

    SciTech Connect

    Unknown

    2002-05-01

    This report discusses test campaign GCT3 of the Halliburton KBR transport reactor train with a Siemens Westinghouse Power Corporation (Siemens Westinghouse) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The transport reactor is an advanced circulating fluidized-bed reactor designed to operate as either a combustor or a gasifier using one of two possible particulate control devices (PCDs). The transport reactor was operated as a pressurized gasifier during GCT3. GCT3 was planned as a 250-hour test run to commission the loop seal and continue the characterization of the limits of operational parameter variations using a blend of several Powder River Basin coals and Bucyrus limestone from Ohio. The primary test objectives were: (1) Loop Seal Commissioning--Evaluate the operational stability of the loop seal with sand and limestone as a bed material at different solids circulation rates and establish a maximum solids circulation rate through the loop seal with the inert bed. (2) Loop Seal Operations--Evaluate the loop seal operational stability during coal feed operations and establish maximum solids circulation rate. Secondary objectives included the continuation of reactor characterization, including: (1) Operational Stability--Characterize the reactor loop and PCD operations with short-term tests by varying coal feed, air/coal ratio, riser velocity, solids circulation rate, system pressure, and air distribution. (2) Reactor Operations--Study the devolatilization and tar cracking effects from transient conditions during transition from start-up burner to coal. Evaluate the effect of process operations on heat release, heat transfer, and accelerated fuel particle heat-up rates. Study the effect of changes in reactor conditions on transient temperature profiles, pressure balance, and product gas composition. (3) Effects of Reactor Conditions on Syngas Composition--Evaluate the effect of air distribution, steam/coal ratio, solids circulation rate, and reactor temperature on CO/CO{sub 2} ratio, H{sub 2}/converted carbon ratio, gasification rates, carbon conversion, and cold and hot gas efficiencies. Test run GCT3 was started on December 1, 2000, with the startup of the thermal oxidizer fan, and was completed on February 1, 2001. This test was conducted in two parts; the loop seal was commissioned during the first part of this test run from December 1 through 15, which consisted of hot inert solids circulation testing. These initial tests provided preliminary data necessary to understand different parameters associated with the operation and performance of the loop seal. The loop seal was tested with coal feed during the second part of the test run and additional data was gathered to analyze reactor operations and to identify necessary modifications to improve equipment and process performance. In the second part of GCT3, the gasification portion of the test, from January 20 to February 1, 2001, the mixing zone and riser temperatures were varied between 1,675 and 1,825 F at pressures ranging from 200 to 240 psig. There were 306 hours of solid circulation and 184 hours of coal feed attained in GCT3.

  10. Uniform power plant identification system

    SciTech Connect

    Christiansen, W. ); Pannenbacker, K. ); Popp, H. ); Seltmann, A. )

    1990-01-01

    In the seventies in the Federal Republic of Germany a uniform power plant identification system (Kraftwerks-Kennzeichen-System, KKS) was developed and introduced. It allows to keep the identification by all engineering disciplines from planning to waste management for any type of power plant. The paper explains the historical development, the structure and the application of this system.

  11. High power communication satellites power systems study

    NASA Astrophysics Data System (ADS)

    Josloff, Allan T.; Peterson, Jerry R.

    1995-01-01

    This paper discusses a planned study to evaluate the commercial attractiveness of high power communication satellites and assesses the attributes of both conventional photovoltaic and reactor power systems. These high power satellites can play a vital role in assuring availability of universally accessible, wide bandwidth communications, for high definition TV, super computer networks and other services. Satellites are ideally suited to provide the wide bandwidths and data rates required and are unique in the ability to provide services directly to the users. As new or relocated markets arise, satellites offer a flexibility that conventional distribution services cannot match, and it is no longer necessary to be near population centers to take advantage of the telecommunication revolution. The geopolitical implications of these substantially enhanced communications capabilities can be significant.

  12. Switching power pulse system

    DOEpatents

    Aaland, Kristian

    1983-01-01

    A switching system for delivering pulses of power from a source (10) to a load (20) using a storage capacitor (C3) charged through a rectifier (D1, D2), and maintained charged to a reference voltage level by a transistor switch (Q1) and voltage comparator (12). A thyristor (22) is triggered to discharge the storage capacitor through a saturable reactor (18) and fractional turn saturable transformer (16) having a secondary to primary turn ratio N of n:l/n=n.sup.2. The saturable reactor (18) functions as a "soaker" while the thyristor reaches saturation, and then switches to a low impedance state. The saturable transformer functions as a switching transformer with high impedance while a load coupling capacitor (C4) charges, and then switches to a low impedance state to dump the charge of the storage capacitor (C3) into the load through the coupling capacitor (C4). The transformer is comprised of a multilayer core (26) having two secondary windings (28, 30) tightly wound and connected in parallel to add their output voltage and reduce output inductance, and a number of single turn windings connected in parallel at nodes (32, 34) for the primary winding, each single turn winding linking a different one of the layers of the multilayer core. The load may be comprised of a resistive beampipe (40) for a linear particle accelerator and capacitance of a pulse forming network (42). To hold off discharge of the capacitance until it is fully charged, a saturable core (44) is provided around the resistive beampipe (40) to isolate the beampipe from the capacitance (42) until it is fully charged.

  13. US electric power system reliability

    NASA Astrophysics Data System (ADS)

    Electric energy supply, transmission and distribution systems are investigated in order to determine priorities for legislation. The status and the outlook for electric power reliability are discussed.

  14. Modeling of gas turbine - solid oxide fuel cell systems for combined propulsion and power on aircraft

    NASA Astrophysics Data System (ADS)

    Waters, Daniel Francis

    This dissertation investigates the use of gas turbine (GT) engine integrated solid oxide fuel cells (SOFCs) to reduce fuel burn in aircraft with large electrical loads like sensor-laden unmanned air vehicles (UAVs). The concept offers a number of advantages: the GT absorbs many SOFC balance of plant functions (supplying fuel, air, and heat to the fuel cell) thereby reducing the number of components in the system; the GT supplies fuel and pressurized air that significantly increases SOFC performance; heat and unreacted fuel from the SOFC are recaptured by the GT cycle offsetting system-level losses; good transient response of the GT cycle compensates for poor transient response of the SOFC. The net result is a system that can supply more electrical power more efficiently than comparable engine-generator systems with only modest (<10%) decrease in power density. Thermodynamic models of SOFCs, catalytic partial oxidation (CPOx) reactors, and three GT engine types (turbojet, combined exhaust turbofan, separate exhaust turbofan) are developed that account for equilibrium gas phase and electrochemical reaction, pressure losses, and heat losses in ways that capture `down-the-channel' effects (a level of fidelity necessary for making meaningful performance, mass, and volume estimates). Models are created in a NASA-developed environment called Numerical Propulsion System Simulation (NPSS). A sensitivity analysis identifies important design parameters and translates uncertainties in model parameters into uncertainties in overall performance. GT-SOFC integrations reduce fuel burn 3-4% in 50 kW systems on 35 kN rated engines (all types) with overall uncertainty <1%. Reductions of 15-20% are possible at the 200 kW power level. GT-SOFCs are also able to provide more electric power (factors >3 in some cases) than generator-based systems before encountering turbine inlet temperature limits. Aerodynamic drag effects of engine-airframe integration are by far the most important limiter of the combined propulsion/electrical generation concept. However, up to 100-200 kW can be produced in a bypass ratio = 8, overall pressure ratio = 40 turbofan with little or no drag penalty. This study shows that it is possible to create cooperatively integrated GT-SOFC systems for combined propulsion and power with better overall performance than stand-alone components.

  15. Nanosatellite Power System Considerations

    NASA Technical Reports Server (NTRS)

    Robyn, M.; Thaller, L.; Scott, D.

    1995-01-01

    The capability to build complex electronic functions into compact packages is opening the path to miniature satellites on the order of 1 kg mass, 10 cm across, packed with the computing processors, motion controllers, measurement sensors, and communications hardware necessary for operation. Power generation will be from short strings of silicon or gallium arsenide-based solar photovoltaic cells with the array power maximized by a peak power tracker (PPT). Energy storage will utilize a low voltage battery with nickel cadmium or lithium ion cells as the most likely selections for rechargeables and lithium (MnO2-Li) primary batteries for one shot short missions.

  16. The space station power system

    NASA Technical Reports Server (NTRS)

    Baraona, C. R.

    1986-01-01

    The manned space station is the next major NASA program. It presents many challenges to the power system designers. The power system in turn is a major driver on the overall configuration. In this paper, the major requirements and guidelines that affect the station configuration and the power system are explained. The evolution of the space station power system from the NASA program development-feasibility phase through the current preliminary design phase is described. Several early station concepts, both fanciful and feasible, are described and linked to the present concept. The recently completed Phase B trade study selections of photovoltaic system technologies are described in detail. A summary of the present solar dynamic and power management and distribution systems is also given for completeness.

  17. Advanced Power System Analysis Capabilities

    NASA Technical Reports Server (NTRS)

    1997-01-01

    As a continuing effort to assist in the design and characterization of space power systems, the NASA Lewis Research Center's Power and Propulsion Office developed a powerful computerized analysis tool called System Power Analysis for Capability Evaluation (SPACE). This year, SPACE was used extensively in analyzing detailed operational timelines for the International Space Station (ISS) program. SPACE was developed to analyze the performance of space-based photovoltaic power systems such as that being developed for the ISS. It is a highly integrated tool that combines numerous factors in a single analysis, providing a comprehensive assessment of the power system's capability. Factors particularly critical to the ISS include the orientation of the solar arrays toward the Sun and the shadowing of the arrays by other portions of the station.

  18. Space station electrical power system

    NASA Technical Reports Server (NTRS)

    Labus, Thomas L.; Cochran, Thomas H.

    1987-01-01

    The purpose of this paper is to describe the design of the Space Station Electrical Power System. This includes the Photovoltaic and Solar Dynamic Power Modules as well as the Power Management and Distribution System (PMAD). In addition, two programmatic options for developing the Electrical Power System will be presented. One approach is defined as the Enhanced Configuration and represents the results of the Phase B studies conducted by the NASA Lewis Research Center over the last two years. Another option, the Phased Program, represents a more measured approach to reaching about the same capability as the Enhanced Configuration.

  19. Photovoltaic power system reliability considerations

    NASA Technical Reports Server (NTRS)

    Lalli, V. R.

    1980-01-01

    An example of how modern engineering and safety techniques can be used to assure the reliable and safe operation of photovoltaic power systems is presented. This particular application is for a solar cell power system demonstration project designed to provide electric power requirements for remote villages. The techniques utilized involve a definition of the power system natural and operating environment, use of design criteria and analysis techniques, an awareness of potential problems via the inherent reliability and FMEA methods, and use of fail-safe and planned spare parts engineering philosophy.

  20. 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.

  1. The space station power system

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The requirements for electrical power by the proposed Space Station Freedom are discussed. The options currently under consideration are examined. The three power options are photovoltaic, solar dynamic, and a hybrid system. Advantages and disadvantages of each system are tabulated. Drawings and artist concepts of the Space Station configuration are provided.

  2. Power quality load management for large spacecraft electrical power systems

    NASA Technical Reports Server (NTRS)

    Lollar, Louis F.

    1988-01-01

    In December, 1986, a Center Director's Discretionary Fund (CDDF) proposal was granted to study power system control techniques in large space electrical power systems. Presented are the accomplishments in the area of power system control by power quality load management. In addition, information concerning the distortion problems in a 20 kHz ac power system is presented.

  3. Wind Energy System Time-domain (WEST) analyzers using hybrid simulation techniques

    NASA Technical Reports Server (NTRS)

    Hoffman, J. A.

    1979-01-01

    Two stand-alone analyzers constructed for real time simulation of the complex dynamic characteristics of horizontal-axis wind energy systems are described. Mathematical models for an aeroelastic rotor, including nonlinear aerodynamic and elastic loads, are implemented with high speed digital and analog circuitry. Models for elastic supports, a power train, a control system, and a rotor gimbal system are also included. Limited correlation efforts show good comparisons between results produced by the analyzers and results produced by a large digital simulation. The digital simulation results correlate well with test data.

  4. Power system requirements

    NASA Technical Reports Server (NTRS)

    Conway, Edmund J.

    1992-01-01

    An overview of electrical power requirements for each mission of a baseline and alternate plan for space activities in the 1990-2035 timeframe is presented. The specific missions included low earth orbit (LEO), geosynchronous earth orbit (GEO), lunar, Mars, and asteroid related projects.

  5. Reactive Power Compensating System.

    DOEpatents

    Williams, Timothy J.; El-Sharkawi, Mohamed A.; Venkata, Subrahmanyam S.

    1985-01-04

    The circuit was designed for the specific application of wind-driven induction generators. It has great potential for application in any situation where a varying reactive power load is present, such as with induction motors or generators, or for transmission network compensation.

  6. Reactive power compensating system

    DOEpatents

    Williams, Timothy J.; El-Sharkawi, Mohamed A.; Venkata, Subrahmanyam S.

    1987-01-01

    The reactive power of an induction machine is compensated by providing fixed capacitors on each phase line for the minimum compensation required, sensing the current on one line at the time its voltage crosses zero to determine the actual compensation required for each phase, and selecting switched capacitors on each line to provide the balance of the compensation required.

  7. Electrical power systems for Mars

    NASA Astrophysics Data System (ADS)

    Giudici, Robert J.

    1986-05-01

    Electrical power system options for Mars Manned Modules and Mars Surface Bases were evaluated for both near-term and advanced performance potential. The power system options investigated for the Mission Modules include photovoltaics, solar thermal, nuclear reactor, and isotope power systems. Options discussed for Mars Bases include the above options with the addition of a brief discussion of open loop energy conversion of Mars resources, including utilization of wind, subsurface thermal gradients, and super oxides. Electrical power requirements for Mission Modules were estimated for three basic approaches: as a function of crew size; as a function of electric propulsion; and as a function of transmission of power from an orbiter to the surface of Mars via laser or radio frequency. Mars Base power requirements were assumed to be determined by production facilities that make resources available for follow-on missions leading to the establishment of a permanently manned Base. Requirements include the production of buffer gas and propellant production plants.

  8. Electrical power systems for Mars

    NASA Technical Reports Server (NTRS)

    Giudici, Robert J.

    1986-01-01

    Electrical power system options for Mars Manned Modules and Mars Surface Bases were evaluated for both near-term and advanced performance potential. The power system options investigated for the Mission Modules include photovoltaics, solar thermal, nuclear reactor, and isotope power systems. Options discussed for Mars Bases include the above options with the addition of a brief discussion of open loop energy conversion of Mars resources, including utilization of wind, subsurface thermal gradients, and super oxides. Electrical power requirements for Mission Modules were estimated for three basic approaches: as a function of crew size; as a function of electric propulsion; and as a function of transmission of power from an orbiter to the surface of Mars via laser or radio frequency. Mars Base power requirements were assumed to be determined by production facilities that make resources available for follow-on missions leading to the establishment of a permanently manned Base. Requirements include the production of buffer gas and propellant production plants.

  9. Space power systems technology

    NASA Technical Reports Server (NTRS)

    Coulman, George A.

    1994-01-01

    Reported here is a series of studies which examine several potential catalysts and electrodes for some fuel cell systems, some materials for space applications, and mathematical modeling and performance predictions for some solid oxide fuel cells and electrolyzers. The fuel cell systems have a potential for terrestrial applications in addition to solar energy conversion in space applications. Catalysts and electrodes for phosphoric acid fuel cell systems and for polymer electrolyte membrane (PEM) fuel cell and electrolyzer systems were examined.

  10. Development of a multiplane multispeed balancing system for turbine systems

    NASA Technical Reports Server (NTRS)

    Martin, M. R.

    1984-01-01

    A prototype high speed balancing system was developed for assembled gas turbine engine modules. The system permits fully assembled gas turbine modules to be operated and balanced at selected speeds up to full turbine speed. The balancing system is a complete stand-alone system providing all necesary lubrication and support hardware for full speed operation. A variable speed motor provides the drive power. A drive belt and gearbox provide rotational speeds up to 21,000 rpm inside a vacuum chamber. The heart of the system is a dedicated minicomputer with attendant data acquisition, storage and I/O devices. The computer is programmed to be completely interactive with the operator. The system was installed at CCAD and evaluated by testing 20 T55 power turbines and 20 T53 power turbines. Engine test results verified the performance of the high speed balanced turbines.

  11. Electrical power system WP-04

    NASA Technical Reports Server (NTRS)

    Nored, Donald L.

    1990-01-01

    Viewgraphs on Space Station Freedom Electrical Power System (EPS) WP-40 are presented. Topics covered include: key EPS technical requirements; photovoltaic power module systems; solar array assembly; blanket containment box and box positioning subassemblies; solar cell; bypass diode assembly; Kapton with atomic oxygen resistant coating; sequential shunt unit; gimbal assembly; energy storage subsystem; thermal control subsystem; direct current switching unit; integrated equipment assembly; PV cargo element; PMAD system; and PMC and AC architecture.

  12. Autonomously managed high power systems

    NASA Technical Reports Server (NTRS)

    Weeks, D. J.; Bechtel, R. T.

    1985-01-01

    The need for autonomous power management capabilities will increase as the power levels of spacecraft increase into the multi-100 kW range. The quantity of labor intensive ground and crew support consumed by the 9 kW Skylab cannot be afforded in support of a 75-300 kW Space Station or high power earth orbital and interplanetary spacecraft. Marshall Space Flight Center is managing a program to develop necessary technologies for high power system autonomous management. To date a reference electrical power system and automation approaches have been defined. A test facility for evaluation and verification of management algorithms and hardware has been designed with the first of the three power channel capability nearing completion.

  13. Shunt regulation electric power system

    NASA Technical Reports Server (NTRS)

    Wright, W. H.; Bless, J. J. (Inventor)

    1971-01-01

    A regulated electric power system having load and return bus lines is described. A plurality of solar cells interconnected in a power supplying relationship and having a power shunt tap point electrically spaced from the bus lines is provided. A power dissipator is connected to the shunt tap point and provides for a controllable dissipation of excess energy supplied by the solar cells. A dissipation driver is coupled to the power dissipator and controls its conductance and dissipation and is also connected to the solar cells in a power taping relationship to derive operating power therefrom. An error signal generator is coupled to the load bus and to a reference signal generator to provide an error output signal which is representative of the difference between the electric parameters existing at the load bus and the reference signal generator. An error amplifier is coupled to the error signal generator and the dissipation driver to provide the driver with controlling signals.

  14. Balloon Fuel Cell Power System

    NASA Technical Reports Server (NTRS)

    1997-01-01

    NASA Lewis Research Center's Electrochemical Technology Branch has teamed with the NASA Wallops Flight Facility to demonstrate the operation of a hydrogen-oxygen proton exchange membrane (PEM) fuel cell for application in the upper atmosphere. NASA Wallops' Balloon Programs Branch has a requirement for a high-power, long-duration power system for use on a scientific balloon platform. The current power system will not meet these needs. The objective of this program is to deliver a 200-W (minimum) fuel cell system that can deliver approximately 10 kWh of electrical energy.

  15. Photovoltaic power system reliability considerations

    NASA Technical Reports Server (NTRS)

    Lalli, V. R.

    1980-01-01

    This paper describes an example of how modern engineering and safety techniques can be used to assure the reliable and safe operation of photovoltaic power systems. This particular application was for a solar cell power system demonstration project in Tangaye, Upper Volta, Africa. The techniques involve a definition of the power system natural and operating environment, use of design criteria and analysis techniques, an awareness of potential problems via the inherent reliability and FMEA methods, and use of a fail-safe and planned spare parts engineering philosophy.

  16. Power systems for future missions

    NASA Technical Reports Server (NTRS)

    Gill, S. P.; Frye, P. E.; Littman, Franklin D.; Meisl, C. J.

    1994-01-01

    A comprehensive scenario of future missions was developed and applicability of different power technologies to these missions was assessed. Detailed technology development roadmaps for selected power technologies were generated. A simple methodology to evaluate economic benefits of current and future power system technologies by comparing Life Cycle Costs of potential missions was developed. The methodology was demonstrated by comparing Life Cycle Costs for different implementation strategies of DIPS/CBC technology to a selected set of missions.

  17. Power generation systems and methods

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor); Chao, Yi (Inventor)

    2011-01-01

    A power generation system includes a plurality of submerged mechanical devices. Each device includes a pump that can be powered, in operation, by mechanical energy to output a pressurized output liquid flow in a conduit. Main output conduits are connected with the device conduits to combine pressurized output flows output from the submerged mechanical devices into a lower number of pressurized flows. These flows are delivered to a location remote of the submerged mechanical devices for power generation.

  18. Power turbine ventilation system

    NASA Technical Reports Server (NTRS)

    Wakeman, Thomas G. (Inventor); Brown, Richard W. (Inventor)

    1991-01-01

    Air control mechanism within a power turbine section of a gas turbine engine. The power turbine section includes a rotor and at least one variable pitch propulsor blade. The propulsor blade is coupled to and extends radially outwardly of the rotor. A first annular fairing is rotatable with the propulsor blade and interposed between the propulsor blade and the rotor. A second fairing is located longitudinally adjacent to the first fairing. The first fairing and the second fairing are differentially rotatable. The air control mechanism includes a platform fixedly coupled to a radially inner end of the propulsor blade. The platform is generally positioned in a first opening and a first fairing. The platform and the first fairing define an outer space. In a first position corresponding with a first propulsor blade pitch, the platform is substantially conformal with the first fairing. In a second position corresponding with the second propulsor blade pitch, an edge portion of the platform is displaced radially outwardly from the first fairing. When the blades are in the second position and rotating about the engine axis, the displacement of the edge portion with respect to the first fairing allows air to flow from the outer space to the annular cavity.

  19. Operational performance of the photovoltaic-powered grain mill and water pump at Tangaye, Upper Volta

    NASA Technical Reports Server (NTRS)

    Martz, J. E.; Ratajczak, A. F.; Delombard, R.

    1982-01-01

    The first two years of operation of a stand alone photovoltaic (PV) power system for the village of Tangaye, Upper Volta in West Africa are described. The purpose of the experiment was to demonstrate that PV systems could provide reliable electrical power for multiple use applications in remote areas where local technical expertise is limited. The 1.8 kW (peak) power system supplies 120-V (d.c.) electrical power to operate a grain mill, a water pump, and mill building lights for the village. The system was initially sized to pump a part of the village water requirements from an existing improved well, and to meet a portion of the village grain grinding requirements. The data, observations, experiences, and conclusions developed during the first two years of operation are discussed. Reports of tests of the mills used in the project are included.

  20. Electric-Power System Simulator

    NASA Technical Reports Server (NTRS)

    Caldwell, R. W.; Grumm, R. L.; Biedebach, B. L.

    1984-01-01

    Shows different combinations of generation, storage, and load components: display, video monitor with keyboard input to microprocessor, and video monitor for display of load curves and power generation. Planning tool for electric utilities, regulatory agencies, and laymen in understanding basics of electric-power systems operation.

  1. Navigation-aid power systems

    NASA Technical Reports Server (NTRS)

    Goltz, G. L.; Kaiser, L. M.; Weiner, H.

    1979-01-01

    Design synthesis and performance analysis (DSPA) program package is collection of subroutines used for computation of design and performance characteristics of viable solar-array-charged battery powered system for flashing-lamp buoys employed as maritime aids to navigation.

  2. 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.

  3. Simulation of the performance of a 100-kW-peak photovoltaic system

    SciTech Connect

    Grossman, B.L.; Brench, B.L.; Bucciarelli, L.L.; Solman, F.J.

    1980-01-01

    MIT Lincoln Laboratory designed and is currently constructing a 100-kW-peak photovoltaic (PV) power system for the Natural Bridges National Monument (NBNM). NBNM is located in a remote part of southeastern Utah and the PV system will operate in a stand-alone mode (i.e., no tie-in with a utility grid). Backup power will be supplied by an existing diesel-powered generator. The PV system and its individual components are being analyzed through the use of a computer simulation. Useful relationships have been found for system operating characteristics, array output, generator power usage, generator control strategy, storage losses and battery charge/discharge cycles. The system operating voltage can be set to extract maximum power from the array during the winter when that power is needed most. The generator operating strategy can be designed to minimize adverse effects on the batteries. Losses due to storage are offset by surplus array energy and by generator power.

  4. Power Systems Advanced Research

    SciTech Connect

    California Institute of Technology

    2007-03-31

    In the 17 quarters of the project, we have accomplished the following milestones - first, construction of the three multiwavelength laser scattering machines for different light scattering study purposes; second, build up of simulation software package for simulation of field and laboratory particulates matters data; third, carried out field online test on exhaust from combustion engines with our laser scatter system. This report gives a summary of the results and achievements during the project's 16 quarters period. During the 16 quarters of this project, we constructed three multiwavelength scattering instruments for PM2.5 particulates. We build up a simulation software package that could automate the simulation of light scattering for different combinations of particulate matters. At the field test site with our partner, Alturdyne, Inc., we collected light scattering data for a small gas turbine engine. We also included the experimental data feedback function to the simulation software to match simulation with real field data. The PM scattering instruments developed in this project involve the development of some core hardware technologies, including fast gated CCD system, accurately triggered Passively Q-Switched diode pumped lasers, and multiwavelength beam combination system. To calibrate the scattering results for liquid samples, we also developed the calibration system which includes liquid PM generator and size sorting instrument, i.e. MOUDI. In this report, we give the concise summary report on each of these subsystems development results.

  5. The ac power system testbed

    NASA Technical Reports Server (NTRS)

    Mildice, J.; Sundberg, R.

    1987-01-01

    The object of this program was to design, build, test, and deliver a high frequency (20 kHz) Power System Testbed which would electrically approximate a single, separable power channel of an IOC Space Station. That program is described, including the technical background, and the results are discussed showing that the major assumptions about the characteristics of this class of hardware (size, mass, efficiency, control, etc.) were substantially correct. This testbed equipment was completed and delivered and is being operated as part of the Space Station Power System Test Facility.

  6. Improved thermophotovoltaic power system

    NASA Technical Reports Server (NTRS)

    Horne, W. E.; Day, A. C.; Crabtree, L.

    1982-01-01

    Improvements in thermophotovoltaic (TPV) system design to ease the geometry and performance requirements are discussed. A TPV system usually consists of a receiver cavity lined with reflective materials and Si solar cells. A suspended central absorber/radiator converter absorbs solar energy and heats to an equilibrium temperature of 2000-23,000 K. Radiant heat at that temperature is well matched to Si solar cell low energy excitation. An elliptical geometry cavity is described which bypasses normal cell mounting problems by having the cells fixed to a plate positioned between the loci of the cavity. Incoming concentrated solar flux is absorbed by the absorber/radiator, which emits the radiation for reflection from the cavity walls to eventually pass through the solar cell wall. Dielectric stack coatings can be used on the walls. A theoretical model was developed for the performance and verified with a laboratory apparatus. Efficiencies of nearly 30% were found practical with existing materials and technologies.

  7. The Ames Power Monitoring System

    NASA Technical Reports Server (NTRS)

    Osetinsky, Leonid; Wang, David

    2003-01-01

    The Ames Power Monitoring System (APMS) is a centralized system of power meters, computer hardware, and specialpurpose software that collects and stores electrical power data by various facilities at Ames Research Center (ARC). This system is needed because of the large and varying nature of the overall ARC power demand, which has been observed to range from 20 to 200 MW. Large portions of peak demand can be attributed to only three wind tunnels (60, 180, and 100 MW, respectively). The APMS helps ARC avoid or minimize costly demand charges by enabling wind-tunnel operators, test engineers, and the power manager to monitor total demand for center in real time. These persons receive the information they need to manage and schedule energy-intensive research in advance and to adjust loads in real time to ensure that the overall maximum allowable demand is not exceeded. The APMS (see figure) includes a server computer running the Windows NT operating system and can, in principle, include an unlimited number of power meters and client computers. As configured at the time of reporting the information for this article, the APMS includes more than 40 power meters monitoring all the major research facilities, plus 15 Windows-based client personal computers that display real-time and historical data to users via graphical user interfaces (GUIs). The power meters and client computers communicate with the server using Transmission Control Protocol/Internet Protocol (TCP/IP) on Ethernet networks, variously, through dedicated fiber-optic cables or through the pre-existing ARC local-area network (ARCLAN). The APMS has enabled ARC to achieve significant savings ($1.2 million in 2001) in the cost of power and electric energy by helping personnel to maintain total demand below monthly allowable levels, to manage the overall power factor to avoid low power factor penalties, and to use historical system data to identify opportunities for additional energy savings. The APMS also provides power engineers and electricians with the information they need to plan modifications in advance and perform day-to-day maintenance of the ARC electric-power distribution system.

  8. Manned spacecraft electrical power systems

    SciTech Connect

    Simon, W.E.; Nored, D.L.

    1987-03-01

    A brief history of the development of electrical power systems from the earliest manned space flights illustrates a natural trend toward growth of electrical power requirements and operational lifetimes with each succeeding space program. A review of the design philosophy and development experience associated with the Space Shuttle Orbiter electrical power system is presented, beginning with the state of technology at the conclusion of the Apollo Program. A discussion of prototype, verification, and qualification hardware is included, and several design improvements following the first Orbiter flight are described. The problems encountered, the scientific and engineering approaches used to meet the technological challenges, and the results obtained are stressed. Major technology barriers and their solutions are discussed, and a brief Orbiter flight experience summary of early Space Shuttle missions is included. A description of projected Space Station power requirements and candidate system concepts which could satisfy these anticipated needs is presented.

  9. Dynamic Isotope Surface Power Systems

    NASA Technical Reports Server (NTRS)

    Hunt, Maribeth E.; Rovang, Richard D.; Cataldo, Robert

    1991-01-01

    The Dynamic Isotope Power Systems (DIPS) demonstration program, sponsored by the U.S. Department of Energy (DOE) with support funding from the National Aeronautics and Space Administration (NASA), is currently focused on the development of a standardized 2.5 kWe portable generator for multiple applications on the lunar or Martian surface. A variety of potential remote and mobile applications has been identified by NASA including surface rovers for both short and extended duration missions, remote power to science packages, and backup to central base power. Recent work focused on refining the 2.5 kWe design including assessing compatibility with the Martian environment to assure the design is suitable while imposing only a minor mass penalty on lunar operations. Additional work included a study performed to compare the DIPS with regenerative fuel cell systems for lunar mobile and remote power systems. Power requirements were reviewed and a modular system chosen for the comparison. Finally, a plan and cycle schematic were generated for an early demonstration of a prototypic isotope power Brayton system using the Antarctic as the test bed.

  10. Power system interface and umbilical system study

    NASA Technical Reports Server (NTRS)

    1980-01-01

    System requirements and basic design criteria were defined for berthing or docking a payload to the 25 kW power module which will provide electrical power and attitude control, cooling, data transfer, and communication services to free-flying and Orbiter sortie payloads. The selected umbilical system concept consists of four assemblies and command and display equipment to be installed at the Orbiter payload specialist station: (1) a movable platen assembly which is attached to the power system with EVA operable devices; (2) a slave platen assembly which is attached to the payload with EVA operable devices; (3) a fixed secondary platen permanently installed in the power system; and (4) a fixed secondary platen permanently installed on the payload. Operating modes and sequences are described.

  11. Solar-Powered Refrigeration System

    NASA Technical Reports Server (NTRS)

    Ewert, Michael K. (Inventor); Bergeron, David J., III (Inventor)

    2001-01-01

    A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure. and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

  12. Solar-Powered Refrigeration System

    NASA Technical Reports Server (NTRS)

    Ewert, Michael K. (Inventor); Bergeron, David J., III (Inventor)

    2002-01-01

    A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

  13. Controlling power systems during emergencies

    SciTech Connect

    Kirschen, D.S.; Wollenberg, B.F.; Irisarri, G.D.; Bann, J.J.; Miller, B.N.

    1989-04-01

    Economic and social factors in many parts of the world now require power systems to be operated at less generation reserve and closer to transmission flow and contingency voltage limits than formerly practiced. The result has been an increase in the complexity of power systems operations. The installation of computerized Energy Management Systems (EMS) has helped alleviate some of these difficulties: Supervisory Control And Data-Acquisition (SCADA) systems have made possible the centralization of the decision-making process. Advanced applications such as optimal power flow and security analysis have helped operators maintain the system in a secure and optimal state. Expert system technology is now being implemented in EMS installations to provide operators with the tools necessary to meet the needs just described. This article explores some applications of expert systems to power system control and shows how they can be used to alleviate the burden on the operators during emergency periods. To this end, the design and implementation of two applications are presented: An intelligent alarm processor (IAP); and A program for the diagnosis of system faults (DSF).

  14. Solar-powered cooling system

    DOEpatents

    Farmer, Joseph C

    2013-12-24

    A solar-powered adsorption-desorption refrigeration and air conditioning system uses nanostructural materials made of high specific surface area adsorption aerogel as the adsorptive media. Refrigerant molecules are adsorbed on the high surface area of the nanostructural material. A circulation system circulates refrigerant from the nanostructural material to a cooling unit.

  15. Power systems for space exploration

    NASA Astrophysics Data System (ADS)

    Shipbaugh, Calvin; Solomon, Kenneth A.

    The Outreach Program was designed to solicit creative ideas from academia, research institutions, private enterprises, and the general public and is intended to be helpful in defining promising technical areas and program paths for more detailed study. To the Outreach Program, a number of power system concepts were proposed. In conclusion, there are a number of advanced concepts for space power and propulsion sources that deserve study if we want to expand our ability to not only explore space, but to utilize it. Advanced nuclear concepts and power beaming concepts are two areas worthy of detailed assessments.

  16. Power systems for space exploration

    SciTech Connect

    Shipbaugh, C.; Solomon, K.A.

    1992-01-01

    The Outreach Program was designed to solicit creative ideas from academia, research institutions, private enterprises, and the general public and is intended to be helpful in defining promising technical areas and program paths for more detailed study. To the Outreach Program, a number of power system concepts were proposed. In conclusion, there are a number of advanced concepts for space power and propulsion sources that deserve study if we want to expand our ability to not only explore space, but to utilize it. Advanced nuclear concepts and power beaming concepts are two areas worthy of detailed assessments.

  17. Ignitor Electrical Power Supply System

    NASA Astrophysics Data System (ADS)

    Coletti, Alberto; Coletti, Roberto; Costa, Pietro; Maffia, Giuseppe; Ramogida, Giuseppe; Roccella, Massimo; Santinelli, Maurizio; Starace, Fabio

    2004-11-01

    An iterative optimization process to reduce the total installed electrical power required for Ignitor has been performed, bringing its value down to about 70% of that estimated originally. Ignitor is planned to be installed within the 400 kV Station of Rondissone (near Turin). The required electrical power (1000 MVA / 320 MVAr, including 480 MVAr locally compensated through static system, SVC) has been demonstrated by the technical authority GRTN to be compatible with the Grid capability. The magnet systems of Ignitor are supplied by means of a set of 14, 12 pulse, current regulated, sequentially or internal freewheeling controlled, fully static power amplifier units which are installed inside standard, outdoor-kind containers, located near to the related step-down transformers. Each container can house up to 100 MW, 2x12 pulse power amplifier units. The connection between the power amplifiers and the machine is performed by means of coaxial, outdoor-kind, segregated bus-bars. These choices make the whole power supply system as flexible as possible in terms of the overall layout of the Ignitor plant.

  18. Hybrid Power Management System and Method

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J. (Inventor)

    2008-01-01

    A system and method for hybrid power management. The system includes photovoltaic cells, ultracapacitors, and pulse generators. In one embodiment, the hybrid power management system is used to provide power for a highway safety flasher.

  19. Hybrid power management system and method

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J. (Inventor)

    2007-01-01

    A system and method for hybrid power management. The system includes photovoltaic cells, ultracapacitors, and pulse generators. In one embodiment, the hybrid power management system is used to provide power for a highway safety flasher.

  20. Solar power satellite microwave power transmission system description executive summary

    NASA Astrophysics Data System (ADS)

    Woodcock, G. R.

    1980-12-01

    The history of the concept of microwave power beaming to Earth is reviewed with emphasis on transmission frequency selection. Constraints on the system power level results from (1) required rejection of waste heat resulting from inefficiencies in the cover conversion of dc electric power to microwave power; (2) the rf power intensity in the ionosphere; and (3) the effect of sidelobe level on aperture illumination factors. Transmitter arrangement, the power distribution system, attitude control, subarrays, waveguides, and alignment are discussed.

  1. Nanosat Intelligent Power System Development

    NASA Technical Reports Server (NTRS)

    Johnson, Michael A.; Beaman, Robert G.; Mica, Joseph A.; Truszkowski, Walter F.; Rilee, Michael L.; Simm, David E.

    1999-01-01

    NASA Goddard Space Flight Center is developing a class of satellites called nano-satellites. The technologies developed for these satellites will enable a class of constellation missions for the NASA Space Science Sun-Earth Connections theme and will be of great benefit to other NASA enterprises. A major challenge for these missions is meeting significant scientific- objectives with limited onboard and ground-based resources. Total spacecraft power is limited by the small satellite size. Additionally, it is highly desirable to minimize operational costs by limiting the ground support required to manage the constellation. This paper will describe how these challenges are met in the design of the nanosat power system. We will address the factors considered and tradeoffs made in deriving the nanosat power system architecture. We will discuss how incorporating onboard fault detection and correction capability yields a robust spacecraft power bus without the mass and volume penalties incurred from redundant systems and describe how power system efficiency is maximized throughout the mission duration.

  2. ADVANCED POWER SYSTEMS ASH BEHAVIOR IN POWER SYSTEMS

    SciTech Connect

    CHRISTOPHER J. ZYGARLICKE; DONALD P. MCCOLLOR; JOHN P. KAY; MICHAEL L. SWANSON

    1998-09-01

    The overall goal of this initiative is to develop fundamental knowledge of ash behavior in power systems for the purpose of increasing power production efficiency, reducing operation and maintenance costs, and reducing greenhouse gas emissions into the atmosphere. The specific objectives of this initiative focus primarily on ash behavior related to advanced power systems and include the following: � Determine the current status of the fundamental ash interactions and deposition formation mechanisms as already reported through previous or ongoing projects at the EERC or in the literature. � Determine sintering mechanisms for temperatures and particle compositions that are less well known and remain for the most part undetermined. � Identify the relationship between the temperature of critical viscosity (Tcv ) as measured in a viscometer and the crystallization occurring in the melt. � Perform a literature search on the use of heated-stage microscopy (HSM) for examining in situ ash-sintering phenomena and then validate the use of HSM in the determination of viscosity in spherical ash particles. � Ascertain the formation and stability of specific mineral or amorphous phases in deposits typical of advanced power systems. � Evaluate corrosion for alloys being used in supercritical combustion systems.

  3. Models for multimegawatt space power systems

    SciTech Connect

    Edenburn, M.W.

    1990-06-01

    This report describes models for multimegawatt, space power systems which Sandia's Advanced Power Systems Division has constructed to help evaluate space power systems for SDI's Space Power Office. Five system models and models for associated components are presented for both open (power system waste products are exhausted into space) and closed (no waste products) systems: open, burst mode, hydrogen cooled nuclear reactor -- turboalternator system; open, hydrogen-oxygen combustion turboalternator system; closed, nuclear reactor powered Brayton cycle system; closed, liquid metal Rankine cycle system; and closed, in-core, reactor therminonic system. The models estimate performance and mass for the components in each of these systems. 17 refs., 8 figs., 15 tabs.

  4. TPX power systems design overview

    SciTech Connect

    Neumeyer, C.; Bronner, G.; Lu, E.; Ramakrishnan, S.; Jackson, M.

    1993-11-01

    The power systems for the Tokamak Physics Experiment (TPX) supply the Toroidal Field (TF). Poloidal Field (PF), Field Error Correction (FEC), and Fast Vertical Position Control (FVPC) coil systems, the Neutral Beam (NB), Ion Cyclotron (IC), Lower Hybrid (LH) and Electron Cyclotron (EC) heating and current drive systems, and all balance of plant loads. Existing equipment from the Tokamak Fusion Test Reactor (TFTR), including the motor-generator (MG) sets and the rectifiers, can be adapted for the supply of the TPX PF systems. A new TF power supply is required. A new substation is required for the heating and current drive systems (NB, IC, LH, and EC). The baseline TPX load can be taken directly from the grid without special provision, whereas if all upgrade options are undertaken, a modest amount of reactive compensation will be required. This paper describes the conceptual design of the power systems, with emphasis on the AC, TF, and PF Systems, and the quench protection of the superconducting coils.

  5. NASA's Radioisotope Power Systems - Plans

    NASA Technical Reports Server (NTRS)

    Hamley, John A.; Mccallum, Peter W.; Sandifer, Carl E., II; Sutliff, Thomas J.; Zakrajsek, June F.

    2015-01-01

    NASA's Radioisotope Power Systems (RPS) Program continues to plan and implement content to enable planetary exploration where such systems could be needed, and to prepare more advanced RPS technology for possible infusion into future power systems. The 2014-2015 period saw significant changes, and strong progress. Achievements of near-term objectives have enabled definition of a clear path forward in which payoffs from research investments and other sustaining efforts can be applied. The future implementation path is expected to yield a higher-performing thermoelectric generator design, a more isotope-fuel efficient system concept design, and a robust RPS infrastructure maintained effectively within both NASA and the Department of Energy. This paper describes recent work with an eye towards the future plans that result from these achievements.

  6. Homopolar generator power supply system

    SciTech Connect

    Weldon, W. F.; Gully, J. H.

    1985-10-01

    A high-energy, high-current homopolar generator pulsed power supply system that is compact and field portable. The power supply system includes a homopolar generator (HPG), an auxiliary supply and drive system, both mounted on a skid frame, and a control system coupled to the HPG and drive system. The homopolar generator has a split rotor with insulation between the halves and a recess in the periphery. A stator ring and field coil, for producing a magnetic field through which the rotor halves make two simultaneous voltage-generating passes, are disposed within the recess in the rotor. Air-actuated brush mechanisms inside and outside the recess contact surfaces of the rotor and collect discharge current. The auxiliary supply and drive system includes a motoring system comprising hydraulic motors for driving the HPG to speed, a bearing lubrication system, a generator for energizing the field coil, and a brush actuator air supply system, all of which are driven by a prime mover. The control system comprises a logic controller for executing a prescribed sequence of steps including turning on the prime mover, initiating motoring of the HPG, energizing the field coil, and initiating the discharge of electrical current.

  7. Space station power system requirements

    NASA Technical Reports Server (NTRS)

    Dunning, John W., Jr.

    1988-01-01

    Presented is an overview of the requirements on which the Space Station Electric Power System is based as well as a summary of the design itself. The current design, which is based on silicon photovoltaic arrays, NiH2 batteries, and 20 kHz distribution technology, meets all of the requirements.

  8. Modeling of power electronic systems with EMTP

    NASA Technical Reports Server (NTRS)

    Tam, Kwa-Sur; Dravid, Narayan V.

    1989-01-01

    In view of the potential impact of power electronics on power systems, there is need for a computer modeling/analysis tool to perform simulation studies on power systems with power electronic components as well as to educate engineering students about such systems. The modeling of the major power electronic components of the NASA Space Station Freedom Electric Power System is described along with ElectroMagnetic Transients Program (EMTP) and it is demonstrated that EMTP can serve as a very useful tool for teaching, design, analysis, and research in the area of power systems with power electronic components. EMTP modeling of power electronic circuits is described and simulation results are presented.

  9. Bonneville, Power Administration Timing System

    NASA Technical Reports Server (NTRS)

    Martin, Kenneth E.

    1996-01-01

    Time is an integral part of the Bonneville Power Administration's (BPA) operational systems. Generation and power transfers are planned in advance. Utilities coordinate with each other by making these adjustments on a timed schedule. Price varies with demand, so billing is based on time. Outages for maintenance are scheduled to assure they do not interrupt reliable power delivery. Disturbance records are aligned with recorded timetags for analysis and comparison with related information. Advanced applications like traveling wave fault location and real-time phase measurement require continuous timing with high precision. Most of BPA is served by a Central Time System (CTS) at the Dittmer Control Center near Portland, OR. This system keeps time locally and supplies time to both the control center systems and field locations via a microwave signal. It is kept synchronized to national standard time and coordinated with interconnected utilities. It is the official BPA time. Powwer system control and operation is described, followed by a description of BPA timing systems including CTS, the Fault Location Acquisition Reporter, time dissemination, and phasor measurements. References are provided for further reading.

  10. Molecular Mechanics and Dynamics Characterization of an "in silico" Mutated Protein: A Stand-Alone Lab Module or Support Activity for "in vivo" and "in vitro" Analyses of Targeted Proteins

    ERIC Educational Resources Information Center

    Chiang, Harry; Robinson, Lucy C.; Brame, Cynthia J.; Messina, Troy C.

    2013-01-01

    Over the past 20 years, the biological sciences have increasingly incorporated chemistry, physics, computer science, and mathematics to aid in the development and use of mathematical models. Such combined approaches have been used to address problems from protein structure-function relationships to the workings of complex biological systems.

  11. Molecular Mechanics and Dynamics Characterization of an "in silico" Mutated Protein: A Stand-Alone Lab Module or Support Activity for "in vivo" and "in vitro" Analyses of Targeted Proteins

    ERIC Educational Resources Information Center

    Chiang, Harry; Robinson, Lucy C.; Brame, Cynthia J.; Messina, Troy C.

    2013-01-01

    Over the past 20 years, the biological sciences have increasingly incorporated chemistry, physics, computer science, and mathematics to aid in the development and use of mathematical models. Such combined approaches have been used to address problems from protein structure-function relationships to the workings of complex biological systems.…

  12. Manned spacecraft electrical power systems

    NASA Technical Reports Server (NTRS)

    Simon, William E.; Nored, Donald L.

    1987-01-01

    A brief history of the development of electrical power systems from the earliest manned space flights illustrates a natural trend toward a growth of electrical power requirements and operational lifetimes with each succeeding space program. A review of the design philosophy and development experience associated with the Space Shuttle Orbiter electrical power system is presented, beginning with the state of technology at the conclusion of the Apollo Program. A discussion of prototype, verification, and qualification hardware is included, and several design improvements following the first Orbiter flight are described. The problems encountered, the scientific and engineering approaches used to meet the technological challenges, and the results obtained are stressed. Major technology barriers and their solutions are discussed, and a brief Orbiter flight experience summary of early Space Shuttle missions is included. A description of projected Space Station power requirements and candidate system concepts which could satisfy these anticipated needs is presented. Significant challenges different from Space Shuttle, innovative concepts and ideas, and station growth considerations are discussed. The Phase B Advanced Development hardware program is summarized and a status of Phase B preliminary tradeoff studies is presented.

  13. Power system applications for PASC converter systems

    SciTech Connect

    Donnelly, M.K.; Johnson, R.M.

    1994-04-01

    This paper shows, using computer EMTP simulations, some preliminary results of applying pulse amplitude synthesis and control (PASC) technology to single-source level voltage converter system. The method can be applied to any single terminal pair source with appropriate modifications in power extraction interface and computer control program to match source and load impedance characteristics. The PASC realization as discussed here employs banks of transformers, one bank per phase, in which the primaries are connected in parallel through a switch matrix to the dc source. Two opposite polarity primaries per transformer are pulsed alternatively in time to produce an oscillatory sinusoidal output waveform. PASC conversion system capabilities to produce both leading and lagging power factor power output in single-phase and three-phase {Delta} or Y configurations are illustrated. EMTP simulations are used to demonstrate the converter capabilities. Also included are discussions regarding harmonics and potential control strategies to adapt the converter to an application or to minimize harmonics.

  14. Power System Optimization Codes Modified

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.

    1999-01-01

    A major modification of and addition to existing Closed Brayton Cycle (CBC) space power system optimization codes was completed. These modifications relate to the global minimum mass search driver programs containing three nested iteration loops comprising iterations on cycle temperature ratio, and three separate pressure ratio iteration loops--one loop for maximizing thermodynamic efficiency, one for minimizing radiator area, and a final loop for minimizing overall power system mass. Using the method of steepest ascent, the code sweeps through the pressure ratio space repeatedly, each time with smaller iteration step sizes, so that the three optimum pressure ratios can be obtained to any desired accuracy for each of the objective functions referred to above (i.e., maximum thermodynamic efficiency, minimum radiator area, and minimum system mass). Two separate options for the power system heat source are available: 1. A nuclear fission reactor can be used. It is provided with a radiation shield 1. (composed of a lithium hydride (LiH) neutron shield and tungsten (W) gamma shield). Suboptions can be used to select the type of reactor (i.e., fast spectrum liquid metal cooled or epithermal high-temperature gas reactor (HTGR)). 2. A solar heat source can be used. This option includes a parabolic concentrator and heat receiver for raising the temperature of the recirculating working fluid. A useful feature of the code modifications is that key cycle parameters are displayed, including the overall system specific mass in kilograms per kilowatt and the system specific power in watts per kilogram, as the results for each temperature ratio are computed. As the minimum mass temperature ratio is encountered, a message is printed out. Several levels of detailed information on cycle state points, subsystem mass results, and radiator temperature profiles are stored for this temperature ratio condition and can be displayed or printed by users.

  15. Dynamic Isotope Power System, Integrated System Test

    NASA Astrophysics Data System (ADS)

    Otting, William D.; Hunt, Maribeth E.; Ashe, Thomas L.

    1994-07-01

    The Dynamic Isotope Power System (DIPS) can supply three to four times more electrical power than Radioisotope Thermoelectric Generators (RTGs) for the same amount of Pu-238 fuel. The available electrical power can be used to drive propellant-efficient electric thrusters, which would enable and/or significantly enhance the capabilities of interplanetary missions. Because of this, the DIPS program has been reviewing the application of DIPS technology to the interplanetary missions in the 500 We to 1.0 kWe power range. Such a DIPS program would focus on completing an Integrated System Test (IST) of the DIPS in a simulated space environment. The DIPS IST would fully demonstrate DIPS integrated operation, long-term containment boundary integrity, and, most importantly, DIPS flight readiness. To reduce cost, schedule, and risk of the DIPS development, the design would use the DOE-developed Brayton Isotope Power System (BIPS) turboalternator compressor (TAC), which is currently being refurbished for use in the NASA-LeRC Solar Dynamic Ground Test Demonstration (SD GTD) Program. The DIPS IST, which would follow the SD GTD testing, would make use of common elements with the SD GTD wherever practical to reduce the IST cost and schedule. The components demonstrated in the IST would be flight prototypical except that full flight qualification would not be performed. For future interplanetary applications, the DIPS system would employ the identical TAC design demonstrated in the IST for all applications. Power level scalability would be achieved by scaling other loop components in a straightforward manner without technology development or requalification. This will significantly reduce costs while providing only a small scalability performance penalty.

  16. Automated power distribution system hardware. [for space station power supplies

    NASA Technical Reports Server (NTRS)

    Anderson, Paul M.; Martin, James A.; Thomason, Cindy

    1989-01-01

    An automated power distribution system testbed for the space station common modules has been developed. It incorporates automated control and monitoring of a utility-type power system. Automated power system switchgear, control and sensor hardware requirements, hardware design, test results, and potential applications are discussed. The system is designed so that the automated control and monitoring of the power system is compatible with both a 208-V, 20-kHz single-phase AC system and a high-voltage (120 to 150 V) DC system.

  17. Radioisotope Power System Pool Concept

    NASA Technical Reports Server (NTRS)

    Rusick, Jeffrey J.; Bolotin, Gary S.

    2015-01-01

    Advanced Radioisotope Power Systems (RPS) for NASA deep space science missions have historically used static thermoelectric-based designs because they are highly reliable, and their radioisotope heat sources can be passively cooled throughout the mission life cycle. Recently, a significant effort to develop a dynamic RPS, the Advanced Stirling Radioisotope Generator (ASRG), was conducted by NASA and the Department of Energy, because Stirling based designs offer energy conversion efficiencies four times higher than heritage thermoelectric designs; and the efficiency would proportionately reduce the amount of radioisotope fuel needed for the same power output. However, the long term reliability of a Stirling based design is a concern compared to thermoelectric designs, because for certain Stirling system architectures the radioisotope heat sources must be actively cooled via the dynamic operation of Stirling converters throughout the mission life cycle. To address this reliability concern, a new dynamic Stirling cycle RPS architecture is proposed called the RPS Pool Concept.

  18. Thruster models for NEP system analysis

    NASA Technical Reports Server (NTRS)

    Gilland, Jim

    1993-01-01

    There are currently no thruster modeling codes that can be integrated with power system codes for full propulsion system modeling. Most existing thruster models were written from a 'stand alone' viewpoint, assuming the user is performing analyses on thruster performance alone. The goal of the present modeling effort is to develop thruster codes that model performance and scaling as a function of mission and system inputs, rather than in terms of more elemental physical parameters. System level parameters of interest are as follows: performance, such as specific impulse and efficency; terminal characteristics, such as voltage or current; and mass. Specific impulse and efficiency couple with mission analyses, while terminal characteristics allow integration with power systems. Additional information on lifetime and operation may be required for detailed designs.

  19. Assessing the Usefulness of AIRS Radiance Observations in a 4D-Var Assimilation Scheme Using the Penn State/NCAR Mesoscale Model Version 5 (MM5) and a Stand Alone Radiative Transfer Algorithm (SARTA)

    NASA Technical Reports Server (NTRS)

    Carrier, M.; Zou, X.; Lapenta, W. M.; Jedlovec, G.

    2004-01-01

    Short-term precipitation forecast skill remains poor despite further advances in numerical modeling and data analysis. Utilizing indirect observations, such as the radiance observations obtained from the Atmospheric Infrared Sounder (AIRS), in a 4D-Var assimilation scheme may lead to a rapid improvement in the skill of 12-h QPF. In order to investigate the usefulness of AIRS observations, the adjoint code of a radiative transfer model (SARTA) is developed and linked to MM5 4D-Var system. A statistical comparison of the AIRS radiances with those calculated using the linked MMS-SARTA model is carried out to assess errors in the radiative transfer model, MM5 and AIRS data, and to develop a quality control scheme. Outliers and any bias that may exist in radiative transfer model, MM5 and AIRS data are identified. An adjoint sensitivity study, utilizing the SARTA adjoint model, is then done to identify the relative sensitivities of each spectral channel to such parameters as atmospheric temperature, pressure, and mixing ratio. Another sensitivity study is done using the MM5 alone to determine the sensitivity of the 12-h QPF to model parameters such as atmospheric temperature, pressure, and mixing ratio under various weather regimes (i.e. summertime convection, winter snowfall). Results from these two types of adjoint sensitivity studies are used to determine which AIRS channels contribute most to 12-h QPF under differing weather regimes. This information is useful when conducting 4D-Var experiments using a subset of the 2378 AIRS spectral channels. Finally, 4D-Var experiments are done to analyze the impact of the AIRS observations on the quality of the 12-h QPF results. This project falls under the data assimilation general session topic as specified by the conference organizers.

  20. Estimating the incidence, prevalence and true cost of asthma in the UK: secondary analysis of national stand-alone and linked databases in England, Northern Ireland, Scotland and Wales—a study protocol

    PubMed Central

    Mukherjee, Mome; Gupta, Ramyani; Farr, Angela; Heaven, Martin; Stoddart, Andrew; Nwaru, Bright I; Fitzsimmons, Deborah; Chamberlain, George; Bandyopadhyay, Amrita; Fischbacher, Colin; Dibben, Christopher; Shields, Michael; Phillips, Ceri; Strachan, David; Davies, Gwyneth; McKinstry, Brian; Sheikh, Aziz

    2014-01-01

    Introduction Asthma is now one of the most common long-term conditions in the UK. It is therefore important to develop a comprehensive appreciation of the healthcare and societal costs in order to inform decisions on care provision and planning. We plan to build on our earlier estimates of national prevalence and costs from asthma by filling the data gaps previously identified in relation to healthcare and broadening the field of enquiry to include societal costs. This work will provide the first UK-wide estimates of the costs of asthma. In the context of asthma for the UK and its member countries (ie, England, Northern Ireland, Scotland and Wales), we seek to: (1) produce a detailed overview of estimates of incidence, prevalence and healthcare utilisation; (2) estimate health and societal costs; (3) identify any remaining information gaps and explore the feasibility of filling these and (4) provide insights into future research that has the potential to inform changes in policy leading to the provision of more cost-effective care. Methods and analysis Secondary analyses of data from national health surveys, primary care, prescribing, emergency care, hospital, mortality and administrative data sources will be undertaken to estimate prevalence, healthcare utilisation and outcomes from asthma. Data linkages and economic modelling will be undertaken in an attempt to populate data gaps and estimate costs. Separate prevalence and cost estimates will be calculated for each of the UK-member countries and these will then be aggregated to generate UK-wide estimates. Ethics and dissemination Approvals have been obtained from the NHS Scotland Information Services Division's Privacy Advisory Committee, the Secure Anonymised Information Linkage Collaboration Review System, the NHS South-East Scotland Research Ethics Service and The University of Edinburgh's Centre for Population Health Sciences Research Ethics Committee. We will produce a report for Asthma-UK, submit papers to peer-reviewed journals and construct an interactive map. PMID:25371419

  1. Analysis methods for wind turbine control and electrical system dynamics

    NASA Technical Reports Server (NTRS)

    Hinrichsen, E. N.

    1995-01-01

    The integration of new energy technologies into electric power systems requires methods which recognize the full range of dynamic events in both the new generating unit and the power system. Since new energy technologies are initially perceived as small contributors to large systems, little attention is generally paid to system integration, i.e. dynamic events in the power system are ignored. As a result, most new energy sources are only capable of base-load operation, i.e. they have no load following or cycling capability. Wind turbines are no exception. Greater awareness of this implicit (and often unnecessary) limitation is needed. Analysis methods are recommended which include very low penetration (infinite bus) as well as very high penetration (stand-alone) scenarios.

  2. Photovoltaic System Performance

    Energy Science and Technology Software Center (ESTSC)

    1989-09-25

    PVFORM4.0 is used to design a photovoltaic (PV) system using a set of design parameters which optimize the system's economic potential for the proposed location and the expected operating conditions. PVFORM3.3 has been used to determine PV system size and optimum mounting configuration. The anticipated electrical load determines the system size and the weather and the mounting configuration affect the system output. PVFORM4.0 uses program-supplied default values or their user-supplied equivalents for each of amore » large number of parameters describing the system and time-series data describing the environment to perform a series of hourly calculations to simulate the physical (photovoltaic) performance of a PV system for a one-year period. These iterative calculations sample the performance of the PV system throughout a simulated 365-day year of system operation. Within any simulated day on which system performance is sampled, the calculations are done hourly. The number of days sampled and the interval between them is determined by an input parameter. The results of these calculations are summarized on a monthly basis in output tables and an optional plot file. The program is applicable to grid interactive or stand-alone flat-plate systems. The grid interactive system is assumed to use power purchased from a local utility to supply that portion of the load not met by the simulated PV array. If the array produces more energy than can be consumed by the load, the excess energy is assumed to be sold back to the utility at a constant energy sellback price. If a stand-alone system is being modeled, the program assumes that all energy produced by the simulated PV array is first applied to the external load, and any excess is then used to charge the battery bank. Energy not consumed by the load or the batteries is considered to be wasted.« less

  3. Advanced Radioisotope Power Systems Segmented Thermoelectric Research

    NASA Technical Reports Server (NTRS)

    Caillat, Thierry

    2004-01-01

    Flight times are long; - Need power systems with >15 years life. Mass is at an absolute premium; - Need power systems with high specific power and scalability. 3 orders of magnitude reduction in solar irradiance from Earth to Pluto. Nuclear power sources preferable. The Overall objective is to develop low mass, high efficiency, low-cost Advanced Radioisotope Power System with double the Specific Power and Efficiency over state-of-the-art Radioisotope Thermoelectric Generators (RTGs).

  4. Modeling Power Systems as Complex Adaptive Systems

    SciTech Connect

    Chassin, David P.; Malard, Joel M.; Posse, Christian; Gangopadhyaya, Asim; Lu, Ning; Katipamula, Srinivas; Mallow, J V.

    2004-12-30

    Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today's most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This report explores the state-of-the-art physical analogs for understanding the behavior of some econophysical systems and deriving stable and robust control strategies for using them. We review and discuss applications of some analytic methods based on a thermodynamic metaphor, according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood. We apply these methods to the question of how power markets can be expected to behave under a variety of conditions.

  5. Power system design of ESMO

    NASA Astrophysics Data System (ADS)

    Ulrich, Steve; Veilleux, Jean-François; Landry Corbin, François

    2009-01-01

    The European Student Moon Orbiter (ESMO) spacecraft is a student-built mini satellite being designed for a mission to the Moon. Designing and launching mini satellites are becoming a current trend in the space sector since they provide an economic way to perform innovative scientific experiments and in-flight demonstration of novel space technologies. The generation, storage, control, and distribution of the electrical power in a mini satellite represents unique challenges to the power engineer since the mass and volume restrictions are very stringent. Regardless of these problems, every subsystem and payload equipment must be operated within their specified voltage band whenever they required to be turned on. This paper presents the preliminary design of a lightweight, compact, and reliable power system for ESMO that can generate 720 W. Some of the key components of the EPS include ultra triple-junction (UTJ) GaAs solar cells controlled by maximum power point trackers, and high efficiency Li-ion secondary batteries recharged in parallel.

  6. MEMS Rotary Engine Power System

    NASA Astrophysics Data System (ADS)

    Fernandez-Pello, A. Carlos; Pisano, Albert P.; Fu, Kelvin; Walther, David C.; Knobloch, Aaron; Martinez, Fabian; Senesky, Matt; Stoldt, Conrad; Maboudian, Roya; Sanders, Seth; Liepmann, Dorian

    This work presents a project overview and recent research results for the MEMS Rotary Engine Power System project at the Berkeley Sensor & Actuator Center of the University of California at Berkeley. The research motivation for the project is the high specific energy density of hydrocarbon fuels. When compared with the energy density of batteries, hydrocarbon fuels may have as much as 20x more energy. However, the technical challenge is the conversion of hydrocarbon fuel to electricity in an efficient and clean micro engine. A 12.9 mm diameter Wankel engine will be shown that has already generated 4 Watts of power at 9300rpm. In addition, the 1mm and 2.4 mm Wankel engines that BSAC is developing for power generation at the microscale will be discussed. The project goal is to develop electrical power output of 90milliwatts from the 2.4 mm engine. Prototype engine components have already been fabricated and these will be described. The integrated generator design concept utilizes a nickel-iron alloy electroplated in the engine rotor poles, so that the engine rotor also serves as the generator rotor.

  7. Advanced secondary power system for transport aircraft

    NASA Technical Reports Server (NTRS)

    Hoffman, A. C.; Hansen, I. G.; Beach, R. F.; Plencner, R. M.; Dengler, R. P.; Jefferies, K. S.; Frye, R. J.

    1985-01-01

    A concept for an advanced aircraft power system was identified that uses 20-kHz, 440-V, sin-wave power distribution. This system was integrated with an electrically powered flight control system and with other aircraft systems requiring secondary power. The resulting all-electric secondary power configuration reduced the empty weight of a modern 200-passenger, twin-engine transport by 10 percent and the mission fuel by 9 percent.

  8. Study on photovoltaic power system on ships

    SciTech Connect

    Katagi, Takeshi; Fujii, Yoshimi; Nishikawa, Eiichi; Hashimoto, Takeshi

    1995-11-01

    This paper presents the application of photovoltaic power systems to ships. Two types of leisure or fishing boats powered by photovoltaics are designed. The boats described are single hull and catamaran type with twin hulls. The design of a new electric power system using a photovoltaic power system in a harbor ship having 20 tons is also proposed. The results of this study show that the photovoltaic power system can apply to small ships.

  9. A Novel 500kW High-Speed Turbine PM Synchronous Generator Set for Distributed Power Generation

    NASA Astrophysics Data System (ADS)

    Wendt, Sven; Benecke, Frank; Güldner, Henry

    The paper presents a power generation system based on the cogeneration of heat and electricity with a novel high speed turbogenerator. The machine consists of a single stage steam turbine and a directly coupled permanent magnet synchronous generator in one constructional unit. A PWM IGBT rectifier is the load to the generator and a PWM IGBT three-phase four-wire inverter feeds the power into the low voltage mains. In order to increase the turbine efficiency at light load, variable speed operation of the turbogenerator is realized. Different control schemes for mains parallel operation and stand alone operation are presented. The control schemes allow for the use of a lookup table based control with a speed-power-characteristic or for the use of a maximum power point tracker. Measurement results from the successfully tested turbogenerator set are presented.

  10. Stand-Alone versus Integrated Critical Thinking Courses

    ERIC Educational Resources Information Center

    Hatcher, Donald L.

    2006-01-01

    For well over 25 years, critical thinking has been declared an educational ideal. However, though institutions are committed to teaching "critical thinking" (CT), there are numerous important questions that need careful treatment if this goal is to be met. First, the faculties must arrive at a shared understanding of what they mean by the phrase…

  11. Developing a Stand Alone Sun Photometer for Ships and Buoys

    NASA Technical Reports Server (NTRS)

    Porter, John N.

    1997-01-01

    During November and December 1995 the first Aerosol Characterization Experiment (ACE 1) was carried to characterize the aerosol physical and optical properties in the clean marine atmosphere near Tasmania in the South Pacific. As part of this effort, and with funding from this proposal, we installed a sun photometer on the R/V Discoverer and a spectro-photometer on the NOAA C-130 aircraft.

  12. A One-Term Stand Alone General Chemistry Laboratory Course.

    ERIC Educational Resources Information Center

    Rasmussen, Paul G.; And Others

    1980-01-01

    Evaluated and described is an innovative freshman chemistry one-semester laboratory, relating changes in the course to objectives in decreasing lab expenditures, increasing learning, increasing quality, improving attitudes, and producing materials for widespread use. Lists topics for experiments, videotape presentation, and computer simulation.…

  13. Automatic calorimetry system monitors RF power

    NASA Technical Reports Server (NTRS)

    Harness, B. W.; Heiberger, E. C.

    1969-01-01

    Calorimetry system monitors the average power dissipated in a high power RF transmitter. Sensors measure the change in temperature and the flow rate of the coolant, while a multiplier computes the power dissipated in the RF load.

  14. System analysis of global space power problem

    NASA Astrophysics Data System (ADS)

    Latyshev, Leonid

    A brief discussion of Space Power System development problems is presented. Topics covered include the following: solar energy utilization; solar energy concentrators and receivers; solar electric power plants; thermonuclear electric power plants; energy transmission; and lunar bases.

  15. Electrical power generating system. [for windpowered generation

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1981-01-01

    An alternating current power generation system adopted to inject power in an already powered power line is discussed. The power generating system solves to adjustably coup an induction motor, as a generator, to an ac power line wherein the motor and power line are connected through a triac. The triac is regulated to normally turn on at a relatively late point in each half cycle of its operation, whereby at less than operating speed, and thus when the induction motor functions as a motor rather than as a generator, power consumption from the line is substantially reduced. The principal application will be for windmill powered generation.

  16. Uninterruptible power supply (UPS) systems

    SciTech Connect

    1997-04-01

    Use of this purchase specification is not mandatory. User should review the document and determine if it meets the user`s purpose. This document contains a fill-in-the-blanks guide specification for the procurement of uninterruptible power supply (UPS) systems greater than 10 kVA, organized as follows: Parts 1 through 7--technical requirements; Appendix A--technical requirements to be included in the proposal; Appendix B--UPS system data sheets to be completed by each bidder (Seller) and submitted with the proposal; Appendix C--general guidelines giving the specifier parameters for selecting a UPS system; it should be read before preparing an actual specification, and is not attached to the specification; Attachment 1--sketches prepared by the purchaser (Owner); Attachment 2--sample title page.

  17. Distributed generation with photovoltaic systems: A utility perspective

    SciTech Connect

    Vigotti, R.

    1998-07-01

    Today PV power systems are already cost-effective and commonly employed in a wide range of remote applications such as electricity supply to isolated users and small communities; water pumping and desalination; powering of service equipment such as radio repeaters; pipelines and well-heads cathodic protection. PV systems can easily cover a broad range of power requirements, allowing them to take advantage of new niche markets as they develop. Besides such applications a ``non-power'', low performance, consumer market also exists (watches, calculators, gadgets) that has already reached a stable growth condition. In the last decade, an increase has been experienced of about three times in the amount of module shipments (103 MW expected in 1997), a more balanced regional manufacturer share has developed, crystalline technology has maintained its lead, and a more market-oriented application share has appeared (at present most applications are for stand-alone).

  18. System and method for advanced power management

    DOEpatents

    Atcitty, Stanley; Symons, Philip C.; Butler, Paul C.; Corey, Garth P.

    2009-07-28

    A power management system is provided that includes a power supply means comprising a plurality of power supply strings, a testing means operably connected to said plurality of power supply strings for evaluating performance characteristics of said plurality of power supply strings, and a control means for monitoring power requirements and comprising a switching means for controlling switching of said plurality of power supply strings to said testing means.

  19. Artificial Intelligence and Spacecraft Power Systems

    NASA Technical Reports Server (NTRS)

    Dugel-Whitehead, Norma R.

    1997-01-01

    This talk will present the work which has been done at NASA Marshall Space Flight Center involving the use of Artificial Intelligence to control the power system in a spacecraft. The presentation will include a brief history of power system automation, and some basic definitions of the types of artificial intelligence which have been investigated at MSFC for power system automation. A video tape of one of our autonomous power systems using co-operating expert systems, and advanced hardware will be presented.

  20. Costing the satellite power system

    NASA Technical Reports Server (NTRS)

    Hazelrigg, G. A., Jr.

    1978-01-01

    The paper presents a methodology for satellite power system costing, places approximate limits on the accuracy possible in cost estimates made at this time, and outlines the use of probabilistic cost information in support of the decision-making process. Reasons for using probabilistic costing or risk analysis procedures instead of standard deterministic costing procedures are considered. Components of cost, costing estimating relationships, grass roots costing, and risk analysis are discussed. Risk analysis using a Monte Carlo simulation model is used to estimate future costs.

  1. Autonomous power system intelligent diagnosis and control

    NASA Technical Reports Server (NTRS)

    Ringer, Mark J.; Quinn, Todd M.; Merolla, Anthony

    1991-01-01

    The Autonomous Power System (APS) project at NASA Lewis Research Center is designed to demonstrate the abilities of integrated intelligent diagnosis, control, and scheduling techniques to space power distribution hardware. Knowledge-based software provides a robust method of control for highly complex space-based power systems that conventional methods do not allow. The project consists of three elements: the Autonomous Power Expert System (APEX) for fault diagnosis and control, the Autonomous Intelligent Power Scheduler (AIPS) to determine system configuration, and power hardware (Brassboard) to simulate a space based power system. The operation of the Autonomous Power System as a whole is described and the responsibilities of the three elements - APEX, AIPS, and Brassboard - are characterized. A discussion of the methodologies used in each element is provided. Future plans are discussed for the growth of the Autonomous Power System.

  2. A Nonlinear Digital Control Solution for a DC/DC Power Converter

    NASA Technical Reports Server (NTRS)

    Zhu, Minshao

    2002-01-01

    A digital Nonlinear Proportional-Integral-Derivative (NPID) control algorithm was proposed to control a 1-kW, PWM, DC/DC, switching power converter. The NPID methodology is introduced and a practical hardware control solution is obtained. The design of the controller was completed using Matlab (trademark) Simulink, while the hardware-in-the-loop testing was performed using both the dSPACE (trademark) rapid prototyping system, and a stand-alone Texas Instruments (trademark) Digital Signal Processor (DSP)-based system. The final Nonlinear digital control algorithm was implemented and tested using the ED408043-1 Westinghouse DC-DC switching power converter. The NPID test results are discussed and compared to the results of a standard Proportional-Integral (PI) controller.

  3. A Nonlinear Digital Control Solution for a DC/DC Power Converter

    NASA Astrophysics Data System (ADS)

    Zhu, Minshao

    2002-02-01

    A digital Nonlinear Proportional-Integral-Derivative (NPID) control algorithm was proposed to control a 1-kW, PWM, DC/DC, switching power converter. The NPID methodology is introduced and a practical hardware control solution is obtained. The design of the controller was completed using Matlab (trademark) Simulink, while the hardware-in-the-loop testing was performed using both the dSPACE (trademark) rapid prototyping system, and a stand-alone Texas Instruments (trademark) Digital Signal Processor (DSP)-based system. The final Nonlinear digital control algorithm was implemented and tested using the ED408043-1 Westinghouse DC-DC switching power converter. The NPID test results are discussed and compared to the results of a standard Proportional-Integral (PI) controller.

  4. Computer Center: CIBE Systems.

    ERIC Educational Resources Information Center

    Crovello, Theodore J.

    1982-01-01

    Differentiates between computer systems and Computers in Biological Education (CIBE) systems (computer system intended for use in biological education). Describes several CIBE stand alone systems: single-user microcomputer; single-user microcomputer/video-disc; multiuser microcomputers; multiuser maxicomputer; and local and long distance computer…

  5. Aircraft Fuel Cell Power Systems

    NASA Technical Reports Server (NTRS)

    Needham, Robert

    2004-01-01

    In recent years, fuel cells have been explored for use in aircraft. While the weight and size of fuel cells allows only the smallest of aircraft to use fuel cells for their primary engines, fuel cells have showed promise for use as auxiliary power units (APUs), which power aircraft accessories and serve as an electrical backup in case of an engine failure. Fuel cell MUS are both more efficient and emit fewer pollutants. However, sea-level fuel cells need modifications to be properly used in aircraft applications. At high altitudes, the ambient air has a much lower pressure than at sea level, which makes it much more difficult to get air into the fuel cell to react and produce electricity. Compressors can be used to pressurize the air, but this leads to added weight, volume, and power usage, all of which are undesirable things. Another problem is that fuel cells require hydrogen to create electricity, and ever since the Hindenburg burst into flames, aircraft carrying large quantities of hydrogen have not been in high demand. However, jet fuel is a hydrocarbon, so it is possible to reform it into hydrogen. Since jet fuel is already used to power conventional APUs, it is very convenient to use this to generate the hydrogen for fuel-cell-based APUs. Fuel cells also tend to get large and heavy when used for applications that require a large amount of power. Reducing the size and weight becomes especially beneficial when it comes to fuel cells for aircraft. My goal this summer is to work on several aspects of Aircraft Fuel Cell Power System project. My first goal is to perform checks on a newly built injector rig designed to test different catalysts to determine the best setup for reforming Jet-A fuel into hydrogen. These checks include testing various thermocouples, transmitters, and transducers, as well making sure that the rig was actually built to the design specifications. These checks will help to ensure that the rig will operate properly and give correct results when it is finally ready for testing. Another of my goals is to test new membranes for use in proton-exchange membrane fuel cells, in the hope that these membranes can increase the electricity that is produced by he1 cells. Producing more electricity means that fewer fuel cells are needed, thus reducing the weight and volume of an APU based on fuel cells, making such an APU much more viable.

  6. Space commercialization and power system technology

    NASA Technical Reports Server (NTRS)

    Brandhorst, H., Jr.; Faymon, K. A.

    1987-01-01

    The development and application of power and energy technologies important to the commercialization of space is discussed, stressing the significance of these technologies to space transportation systems, on-orbit services and on-orbit commercial production and processing ventures. Energy conversion systems examined include solar photovoltaic systems, solar thermal dynamic power systems, and nuclear power systems. Energy storage systems include electrochemical systems, inertial storage systems, and magnetic energy storage systems. In addition, power management and distribution systems used in space commercialization and NASA programs for the commercial development of space are discussed.

  7. Large autonomous spacecraft electrical power system (LASEPS)

    NASA Technical Reports Server (NTRS)

    Dugal-Whitehead, Norma R.; Johnson, Yvette B.

    1992-01-01

    NASA - Marshall Space Flight Center is creating a large high voltage electrical power system testbed called LASEPS. This testbed is being developed to simulate an end-to-end power system from power generation and source to loads. When the system is completed it will have several power configurations, which will include several battery configurations. These configurations are: two 120 V batteries, one or two 150 V batteries, and one 250 to 270 V battery. This breadboard encompasses varying levels of autonomy from remote power converters to conventional software control to expert system control of the power system elements. In this paper, the construction and provisions of this breadboard are discussed.

  8. Solar-powered cooling system

    SciTech Connect

    Farmer, Joseph C.

    2015-07-28

    A solar-powered adsorption-desorption refrigeration and air conditioning system that uses nanostructural materials such as aerogels, zeolites, and sol gels as the adsorptive media. Refrigerant molecules are adsorbed on the high surface area of the nanostructural material while the material is at a relatively low temperature, perhaps at night. During daylight hours, when the nanostructural materials is heated by the sun, the refrigerant are thermally desorbed from the surface of the aerogel, thereby creating a pressurized gas phase in the vessel that contains the aerogel. This solar-driven pressurization forces the heated gaseous refrigerant through a condenser, followed by an expansion valve. In the condenser, heat is removed from the refrigerant, first by circulating air or water. Eventually, the cooled gaseous refrigerant expands isenthalpically through a throttle valve into an evaporator, in a fashion similar to that in more conventional vapor recompression systems.

  9. ELECTRICAL POWER SYSTEM DESCRIPTION DOCUMENT

    SciTech Connect

    M. Maniyar

    2004-06-22

    The purpose of this revision of the System Description Document (SDD) is to establish requirements that drive the design of the electrical power system and their bases to allow the design effort to proceed to License Application. This SDD is a living document that will be revised at strategic points as the design matures over time. This SDD identifies the requirements and describes the system design as they exist at this time, with emphasis on those attributes of the design provided to meet the requirements. This SDD has been developed to be an engineering tool for design control. Accordingly, the primary audience are design engineers. This type of SDD leads and follows the design process. It leads the design process with regard to the flow down of upper tier requirements onto the system. Knowledge of these requirements is essential to performing the design process. This SDD follows the design with regard to the description of the system. The description provided in the SDD is a reflection of the results of the design process to date. Functional and operational requirements applicable to this system are obtained from ''Project Functional and Operational Requirements'' (F&OR) (Siddoway, 2003). Other requirements to support the design process have been taken from higher level requirements documents such as ''Project Design Criteria Document'' (PDC) (Doraswamy 2004), the fire hazards analyses, and the preclosure safety analysis. The above mentioned low-level documents address ''Project Requirements Document'' (PRD) (Canori and Leitner 2003) requirements. This SDD includes several appendices with supporting information. Appendix B lists key system charts, diagrams, drawings, and lists; and Appendix C is a list of system procedures.

  10. Captive Water Current Power System

    SciTech Connect

    Wuenscher, H. F.; Wuenscher, H. A.

    1984-01-31

    Current energy is converted into shaft power in two stages; First, buoyant power units with stationary hydrofoil wings reach faster than the current speed by sweeping out a captive path. Second, turbines at said power units convert the fast relative local current into shaft power. Power units sweeping along the water surface, using cycloidal turbine methods, as well as power units sweeping on a submerged path, using axial flow turbine methods, are described.

  11. SITE ELECTRICAL POWER SYSTEM DESCRIPTION DOCUMENT

    SciTech Connect

    E.P. McCann

    1999-04-16

    The Site Electrical Power System receives and distributes utility power to all North Portal site users. The major North Portal users are the Protected Area including the subsurface facility and Balance of Plant areas. The system is remotely monitored and controlled from the Surface Operations Monitoring and Control System. The system monitors power quality and provides the capability to transfer between Off-Site Utility and standby power (including dedicated safeguards and security power). Standby power is only distributed to selected loads for personnel safety and essential operations. Security power is only distributed to essential security operations. The standby safeguards and security power is independent from all other site power. The system also provides surface lighting, grounding grid, and lightning protection for the North Portal. The system distributes power during construction, operation, caretaker, and closure phases of the repository. The system consists of substation equipment (disconnect switches, breakers, transformers and grounding equipment) and power distribution cabling from substation to the north portal switch gear building. Additionally, the system includes subsurface facility substation (located on surface), switch-gear, standby diesel generators, underground duct banks, power cables and conduits, switch-gear building and associated distribution equipment for power distribution. Each area substation distributes power to the electrical loads and includes the site grounding, site lighting and lightning protection equipment. The site electrical power system distributes power of sufficient quantity and quality to meet users demands. The Site Electrical Power System interfaces with the North Portal surface systems requiring electrical power. The system interfaces with the Subsurface Electrical Distribution System which will supply power to the underground facilities from the North Portal. Power required for the South Portal and development side activities of the subsurface facility will be provided at the South Portal by the Subsurface Electrical Distribution System. The Site Electrical Power System interfaces with the Off-Site Utility System for the receipt of power. The System interfaces with the Surface Operations Monitoring and Control System for monitoring and control. The System interfaces with MGR Site Layout System for the physical location of equipment and power distribution.

  12. Solar powered automobile cooling system

    SciTech Connect

    Shum, S.

    1987-04-21

    A cooling system is described for the passenger compartment of an automobile, the automobile including a ventilation duct extending between a front portion of the automobile and passenger compartment for admitting external air to the compartment, the system comprising: an evaporative cooler including a water reservoir, an evaporative mesh pad, a pump for circulating water from the reservoir to the pad and a fan for blowing air over the pad and into the passenger compartment, the pad positioned in the ventilation duct in a path of the external air, the fan being positioned in the ventilation duct between the front portion and the pad for blowing air through the pad when the automobile is motionless, the water reservoir comprising a refillable enclosed tank positioned externally of the ventilation duct and the pump being located in the reservoir and connected to the pad by tubing for pumping water from the reservoir to the pad; a solar energy system for converting solar energy to electrical power including solar conversion units mounted externally of the automobile, units connected in an array to provide electrical current at a predetermined voltage; and a thermostatic switch positioned within the automobile, the switch being connected in a series circuit between the solar system and the evaporative cooler.

  13. Options for Affordable Fission Surface Power Systems

    NASA Technical Reports Server (NTRS)

    Houts, Mike; Gaddis, Steve; Porter, Ron; VanDyke, Melissa; Martin Jim; Godfroy, Tom; Bragg-Sitton, Shannon; Garber, Anne; Pearson, Boise

    2006-01-01

    Fission surface power systems could provide abundant power anywhere on free surface of the moon or Mars. Locations could include permanently shaded regions on the moon and high latitudes on Mars. To be fully utilized; however, fission surface power systems must be safe, have adequate performance, and be affordable. This paper discusses options for the design and development of such systems.

  14. X2000 power system electronics development

    NASA Technical Reports Server (NTRS)

    Carr, Greg; Deligiannis, Frank; Franco, Lauro; Jones, Loren; Lam, Barbara; Nelson, Ron; Pantaleon, Jose; Ruiz, Ian; Treichler, John; Wester, Gene; Sauers, Jim; Giampoli, Paul; Haskell, Russ; Mulvey, Jim; Repp, John

    2005-01-01

    The X2000 Power System Electronics (PSE) is a Jet Propulsion Laboratory (JPL) task to develop a new generation of power system building blocks for potential use on future deep space missions. The effort includes the development of electronic components and modules that can be used as building blocks in the design of generic spacecraft power systems.

  15. Options for Affordable Fission Surface Power Systems

    SciTech Connect

    Houts, Mike; Gaddis, Steve; Porter, Ron; Van Dyke, Melissa; Martin, Jim; Godfroy, Tom; Bragg-Sitton, Shannon; Garber, Anne; Pearson, Boise

    2006-07-01

    Fission surface power systems could provide abundant power anywhere on the surface of the moon or Mars. Locations could include permanently shaded regions on the moon and high latitudes on Mars. To be fully utilized, however, fission surface power systems must be safe, have adequate performance, and be affordable. This paper discusses options for the design and development of such systems. (authors)

  16. 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.

  17. Emergency Power For Critical Items

    NASA Astrophysics Data System (ADS)

    Young, William R.

    2009-07-01

    Natural disasters, such as hurricanes, floods, tornados, and tsunami, are becoming a greater problem as climate change impacts our environment. Disasters, whether natural or man made, destroy lives, homes, businesses and the natural environment. Such disasters can happen with little or no warning, leaving hundreds or even thousands of people without medical services, potable water, sanitation, communications and electrical services for up to several weeks. In our modern world, the need for electricity has become a necessity. Modern building codes and new disaster resistant building practices are reducing the damage to homes and businesses. Emergency gasoline and diesel generators are becoming common place for power outages. Generators need fuel, which may not be available after a disaster, but Photovoltaic (solar-electric) systems supply electricity without petroleum fuel as they are powered by the sun. Photovoltaic (PV) systems can provide electrical power for a home or business. PV systems can operate as utility interactive or stand-alone with battery backup. Determining your critical load items and sizing the photovoltaic system for those critical items, guarantees their operation in a disaster.

  18. Automated load management for spacecraft power systems

    NASA Technical Reports Server (NTRS)

    Lollar, Louis F.

    1987-01-01

    An account is given of the results of a study undertaken by NASA's Marshall Space Flight Center to design and implement the load management techniques for autonomous spacecraft power systems, such as the Autonomously Managed Power System Test Facility. Attention is given to four load-management criteria, which encompass power bus balancing on multichannel power systems, energy balancing in such systems, power quality matching of loads to buses, and contingency load shedding/adding. Full implementation of these criteria calls for the addition of a second power channel.

  19. EMERY BIOMASS GASIFICATION POWER SYSTEM

    SciTech Connect

    Benjamin Phillips; Scott Hassett; Harry Gatley

    2002-11-27

    Emery Recycling Corporation (now Emery Energy Company, LLC) evaluated the technical and economical feasibility of the Emery Biomass Gasification Power System (EBGPS). The gasifier technology is owned and being developed by Emery. The Emery Gasifier for this project was an oxygen-blown, pressurized, non-slagging gasification process that novelly integrates both fixed-bed and entrained-flow gasification processes into a single vessel. This unique internal geometry of the gasifier vessel will allow for tar and oil destruction within the gasifier. Additionally, the use of novel syngas cleaning processes using sorbents is proposed with the potential to displace traditional amine-based and other syngas cleaning processes. The work scope within this project included: one-dimensional gasifier modeling, overall plant process modeling (ASPEN), feedstock assessment, additional analyses on the proposed syngas cleaning process, plant cost estimating, and, market analysis to determine overall feasibility and applicability of the technology for further development and commercial deployment opportunities. Additionally, the project included the development of a detailed technology development roadmap necessary to commercialize the Emery Gasification technology. Process modeling was used to evaluate both combined cycle and solid oxide fuel cell power configurations. Ten (10) cases were evaluated in an ASPEN model wherein nine (9) cases were IGCC configurations with fuel-to-electricity efficiencies ranging from 38-42% and one (1) case was an IGFC solid oxide case where 53.5% overall plant efficiency was projected. The cost of electricity was determined to be very competitive at scales from 35-71 MWe. Market analysis of feedstock availability showed numerous market opportunities for commercial deployment of the technology with modular capabilities for various plant sizes based on feedstock availability and power demand.

  20. Reliability of emergency ac power systems at nuclear power plants

    SciTech Connect

    Battle, R E; Campbell, D J

    1983-07-01

    Reliability of emergency onsite ac power systems at nuclear power plants has been questioned within the Nuclear Regulatory Commission (NRC) because of the number of diesel generator failures reported by nuclear plant licensees and the reactor core damage that could result from diesel failure during an emergency. This report contains the results of a reliability analysis of the onsite ac power system, and it uses the results of a separate analysis of offsite power systems to calculate the expected frequency of station blackout. Included is a design and operating experience review. Eighteen plants representative of typical onsite ac power systems and ten generic designs were selected to be modeled by fault trees. Operating experience data were collected from the NRC files and from nuclear plant licensee responses to a questionnaire sent out for this project.

  1. POWER GRID DYNAMICS: ENHANCING POWER SYSTEM OPERATION THROUGH PRONY ANALYSIS

    SciTech Connect

    Ray, C.; Huang, Z.

    2007-01-01

    Prony Analysis is a technique used to decompose a signal into a series consisting of weighted complex exponentials and promises to be an effi cient way of recognizing sensitive lines during faults in power systems such as the U.S. Power grid. Positive Sequence Load Flow (PSLF) was used to simulate the performance of a simple two-area-four-generator system and the reaction of the system during a line fault. The Dynamic System Identifi cation (DSI) Toolbox was used to perform Prony analysis and use modal information to identify key transmission lines for power fl ow adjustment to improve system damping. The success of the application of Prony analysis methods to the data obtained from PSLF is reported, and the key transmission line for adjustment is identifi ed. Future work will focus on larger systems and improving the current algorithms to deal with networks such as large portions of the Western Electricity Coordinating Council (WECC) power grid.

  2. Grid-Tied Photovoltaic Power System

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J.

    2011-01-01

    A grid-tied photovoltaic (PV) power system is connected directly to the utility distribution grid. Facility power can be obtained from the utility system as normal. The PV system is synchronized with the utility system to provide power for the facility, and excess power is provided to the utility. Operating costs of a PV power system are low compared to conventional power technologies. This method can displace the highest-cost electricity during times of peak demand in most climatic regions, and thus reduce grid loading. Net metering is often used, in which independent power producers such as PV power systems are connected to the utility grid via the customers main service panels and meters. When the PV power system is generating more power than required at that location, the excess power is provided to the utility grid. The customer pays the net of the power purchased when the on-site power demand is greater than the onsite power production, and the excess power is returned to the utility grid. Power generated by the PV system reduces utility demand, and the surplus power aids the community. Modern PV panels are readily available, reliable, efficient, and economical, with a life expectancy of at least 25 years. Modern electronics have been the enabling technology behind grid-tied power systems, making them safe, reliable, efficient, and economical with a life expectancy equal to the modern PV panels. The grid-tied PV power system was successfully designed and developed, and this served to validate the basic principles developed, and the theoretical work that was performed. Grid-tied PV power systems are reliable, maintenance- free, long-life power systems, and are of significant value to NASA and the community. Of particular value are the analytical tools and capabilities that have been successfully developed. Performance predictions can be made confidently for grid-tied PV systems of various scales. The work was done under the NASA Hybrid Power Management (HPM) Program, which is the integration of diverse power devices in an optimal configuration for space and terrestrial applications.

  3. The physics of power systems operation

    NASA Astrophysics Data System (ADS)

    Ohler, C.

    2015-08-01

    The article explains the operation of power systems from the point of view of physics. Physicists imagine things, rather than in terms of impedances and circuits, in terms of fields and energy conversions. The account is concrete and simple. The use of alternating current entails the issue of reactive power. Reactive power consists of energy that oscillates between electrical and magnetic fields, it flows on top of the active power which carries the useful energy. The control of active and reactive power is essential for the power system's reliable operation. The frequency of a power system is the same everywhere. The stability of the frequency indicates that generation and demand of active power are equal, a decline in frequency indicates a lack of generation relative to the demand. Adapting the electrical power injected into the system is the way of frequency control. Because of the parasitic inductances and capacitances of overhead lines, cables, and transformers, the voltage at different locations of the power system depends on the load. The voltage is regulated by the combined action of generator excitation, transformer tap changers and series compensation in order to provide consumers with a stable voltage supply. The integration of solar cells and wind turbines into the power system poses some challenges. But the power system is able to accommodate large amounts of fluctuating renewable power generation if the right complementary measures are taken.

  4. Environmental Control and Life Support Systems and Power Systems ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Environmental Control and Life Support Systems and Power Systems - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  5. Multi-Mission Power Analysis Tool (MMPAT) Version 3

    NASA Technical Reports Server (NTRS)

    Wood, Eric G.; Chang, George W.; Chen, Fannie C.

    2012-01-01

    The Multi-Mission Power Analysis Tool (MMPAT) simulates a spacecraft power subsystem including the power source (solar array and/or radioisotope thermoelectric generator), bus-voltage control, secondary battery (lithium-ion or nickel-hydrogen), thermostatic heaters, and power-consuming equipment. It handles multiple mission types including heliocentric orbiters, planetary orbiters, and surface operations. Being parametrically driven along with its user-programmable features can reduce or even eliminate any need for software modifications when configuring it for a particular spacecraft. It provides multiple levels of fidelity, thereby fulfilling the vast majority of a project s power simulation needs throughout the lifecycle. It can operate in a stand-alone mode with a graphical user interface, in batch mode, or as a library linked with other tools. This software can simulate all major aspects of a spacecraft power subsystem. It is parametrically driven to reduce or eliminate the need for a programmer. Added flexibility is provided through user-designed state models and table-driven parameters. MMPAT is designed to be used by a variety of users, such as power subsystem engineers for sizing power subsystem components; mission planners for adjusting mission scenarios using power profiles generated by the model; system engineers for performing system- level trade studies using the results of the model during the early design phases of a spacecraft; and operations personnel for high-fidelity modeling of the essential power aspect of the planning picture.

  6. Power system extreme event screening using graphpartitioning

    SciTech Connect

    Lesieutre, Bernard C.; Roy, Sandip; Donde, Vaibhav; Pinar, Ali

    2006-09-06

    We propose a partitioning problem in a power system contextthat weighs the two objectives of minimizing cuts between partitions andmaximizing the power imbalance between partitions. We then pose theproblem in a purely graph theoretic sense. We offer an approximatesolution through relaxation of the integer problem and suggest refinementusing stochastic methods. Results are presented for the IEEE 30-bus and118-bus electric power systems.

  7. Hubble Space Telescope electrical power system model

    NASA Technical Reports Server (NTRS)

    Baggett, Randy; Miller, Jim; Leisgang, Tom

    1988-01-01

    This paper describes one of the most comprehensive models ever developed for a spacecraft electrical power system (EPS). The model was developed for the Hubble Space Telescope (HST) to evaluate vehicle power system performance and to assist in scheduling maintenance and refurbishment missions by providing data needed to forecast EPS power and energy margins for the mission phases being planned. The EPS model requires a specific mission phase description as the input driver and uses a high granularity database to produce a multi-orbit power system performance report. The EPS model accurately predicts the power system response to various mission timelines over the entire operational life of the spacecraft.

  8. Realistic Specific Power Expectations for Advanced Radioisotope Power Systems

    NASA Technical Reports Server (NTRS)

    Mason, Lee S.

    2006-01-01

    Radioisotope Power Systems (RPS) are being considered for a wide range of future NASA space science and exploration missions. Generally, RPS offer the advantages of high reliability, long life, and predictable power production regardless of operating environment. Previous RPS, in the form of Radioisotope Thermoelectric Generators (RTG), have been used successfully on many NASA missions including Apollo, Viking, Voyager, and Galileo. NASA is currently evaluating design options for the next generation of RPS. Of particular interest is the use of advanced, higher efficiency power conversion to replace the previous thermoelectric devices. Higher efficiency reduces the quantity of radioisotope fuel and potentially improves the RPS specific power (watts per kilogram). Power conversion options include Segmented Thermoelectric (STE), Stirling, Brayton, and Thermophotovoltaic (TPV). This paper offers an analysis of the advanced 100 watt-class RPS options and provides credible projections for specific power. Based on the analysis presented, RPS specific power values greater than 10 W/kg appear unlikely.

  9. Fault analysis of multichannel spacecraft power systems

    NASA Technical Reports Server (NTRS)

    Dugal-Whitehead, Norma R.; Lollar, Louis F.

    1990-01-01

    The NASA Marshall Space Flight Center proposes to implement computer-controlled fault injection into an electrical power system breadboard to study the reactions of the various control elements of this breadboard. Elements under study include the remote power controllers, the algorithms in the control computers, and the artificially intelligent control programs resident in this breadboard. To this end, a study of electrical power system faults is being performed to yield a list of the most common power system faults. The results of this study will be applied to a multichannel high-voltage DC spacecraft power system called the large autonomous spacecraft electrical power system (LASEPS) breadboard. The results of the power system fault study and the planned implementation of these faults into the LASEPS breadboard are described.

  10. New Generation Power System for Space Applications

    NASA Technical Reports Server (NTRS)

    Jones, Loren; Carr, Greg; Deligiannis, Frank; Lam, Barbara; Nelson, Ron; Pantaleon, Jose; Ruiz, Ian; Treicler, John; Wester, Gene; Sauers, Jim; Giampoli, Paul; Haskell, Russ; Mulvey, Jim; Repp, John

    2004-01-01

    The Deep Space Avionics (DSA) Project is developing a new generation of power system building blocks. Using application specific integrated circuits (ASICs) and power switching modules a scalable power system can be constructed for use on multiple deep space missions including future missions to Mars, comets, Jupiter and its moons. The key developments of the DSA power system effort are five power ASICs and a mod ule for power switching. These components enable a modular and scalab le design approach, which can result in a wide variety of power syste m architectures to meet diverse mission requirements and environments . Each component is radiation hardened to one megarad) total dose. The power switching module can be used for power distribution to regular spacecraft loads, to propulsion valves and actuation of pyrotechnic devices. The number of switching elements per load, pyrotechnic firin gs and valve drivers can be scaled depending on mission needs. Teleme try data is available from the switch module via an I2C data bus. The DSA power system components enable power management and distribution for a variety of power buses and power system architectures employing different types of energy storage and power sources. This paper will describe each power ASIC#s key performance characteristics as well a s recent prototype test results. The power switching module test results will be discussed and will demonstrate its versatility as a multip urpose switch. Finally, the combination of these components will illu strate some of the possible power system architectures achievable fro m small single string systems to large fully redundant systems.

  11. A nuclear powered space based multimegawatt MHD disc power system

    NASA Astrophysics Data System (ADS)

    Holman, Robert R.; Lance, Joseph R.; Vanbibber, Lawrence E.; Louis, Jean F.

    A very compact space based magnetohydrodynamic (MHD) power system capable of meeting space platform burst power needs is examined. An open cycle MHD disc generator concept has been incorporated in a nuclear power system arrangement. Thermal energy for the system is provided by a NERVA derivative nuclear reactor and the MHD disc generator is used for thermal to electric energy conversion. Study results show to date that the NERVA derivative reactor coupled with the MHD disc generator provides a low total system launch mass and a very high energy extraction of greater than 20 MJ/kg in power operation. This energy extraction is much higher than the less than 2.5 MJ/kg values of linear MHD generator systems studied previously.

  12. SystemSketch Poster

    EPA Science Inventory

    SystemSketch is a dynamic, graphic visualization tool to help stakeholders better understand system context and access information resources. It is constructed using the Driver-Pressure-State-Impact-Response framework, and functions both as a stand-alone tool and as a component ...

  13. SystemSketch Poster

    EPA Science Inventory

    SystemSketch is a dynamic, graphic visualization tool to help stakeholders better understand system context and access information resources.  It is constructed using the Driver-Pressure-State-Impact-Response framework, and functions both as a stand-alone tool and as a component ...

  14. Status of space station power system

    NASA Technical Reports Server (NTRS)

    Baraona, Cosmo R.; Sheibley, Dean W.

    1987-01-01

    The major requirements and guidelines that affect the manned space station configuration and the power systems are explained. The evolution of the space station power system from the NASA program development feasibility phase through the current preliminary design phase is described. Several early station concepts are described and linked to the present concept. The recently completed phase B tradeoff study selections of photovoltaic system technologies are described. The present solar dynamic and power management and distribution systems are also summarized for completeness.

  15. Feasibility study of wireless power transmission systems

    NASA Technical Reports Server (NTRS)

    Robinson, W. J., Jr.

    1968-01-01

    Wireless microwave or laser energy transfers power from a manned earth-orbiting central station to unmanned astronomical substations. More efficient systems are required for the microwave power transmission.

  16. Modular Solar Electric Power (MSEP) Systems (Presentation)

    SciTech Connect

    Hassani, V.

    2000-06-18

    This presentation discusses the development and deployment of Modular Solar Electric Power (MSEP) systems, the feasibility of application of existing binary power cycles to solar trough technology, and identification of next action items.

  17. Power system with an integrated lubrication circuit

    DOEpatents

    Hoff, Brian D.; Akasam, Sivaprasad; Algrain, Marcelo C.; Johnson, Kris W.; Lane, William H.

    2009-11-10

    A power system includes an engine having a first lubrication circuit and at least one auxiliary power unit having a second lubrication circuit. The first lubrication circuit is in fluid communication with the second lubrication circuit.

  18. Unfulfilled technology needs in space power systems

    NASA Technical Reports Server (NTRS)

    Slifer, L. W., Jr.

    1980-01-01

    The paper defines the major space power system technology development needs related to the solution of currently existing problems. A major portion of the present review derives from the deliberations of the Power Subsystems Panel at the NASA Flight Technology Improvement Workshop, July 31 to August 2, 1979. The Panel led to 10 primary recommendations for power technology research and development to overcome past and current problems in spacecraft power and experiment/instrument power supplies.

  19. Power Management and Distribution System Developed for Thermionic Power Converters

    NASA Technical Reports Server (NTRS)

    Baez, Anastacio N.

    1998-01-01

    A spacecraft solar, bimodal system combines propulsion and power generation into a single integrated system. An Integrated Solar Upper Stage (ISUS) provides orbital transfer capabilities, power generation for payloads, and onboard propulsion to the spacecraft. A key benefit of a bimodal system is a greater payload-to-spacecraft mass ratio resulting in lower launch vehicle requirements. Scaling down to smaller launch vehicles increases space access by reducing overall mission cost. NASA has joined efforts with the Air Force Phillips Laboratory to develop enabling technologies for such a system. The NASA/Air Force bimodal concept uses solar concentrators to focus energy into an integrated power plant. This power plant consists of a graphite core that stores thermal energy within a cavity. An array of thermionic converters encircles the graphite cavity and provides electrical energy conversion functions. During the power generation phase of the bimodal system, the thermionic converters are exposed to the heated cavity and convert the thermal energy to electricity. Near-term efforts of the ISUS bimodal program are focused on a ground demonstration of key technologies in order to proceed to a full space flight test. Thermionic power generation is one key technology of the bimodal concept. Thermionic power converters impose unique operating requirements upon a power management and distribution (PMAD) system design. Single thermionic converters supply large currents at very low voltages. Operating voltages can vary over a range of up to 3 to 1 as a function of operating temperature. Most spacecraft loads require regulated 28-volts direct-current (Vdc) power. A combination of series-connected converters and powerprocessing boosters is required to deliver power to the spacecraft's payloads at this level.

  20. Lessons learned from the autonomous power system

    SciTech Connect

    Ringer, M.J.; Quinn, T.M.; Merolla, A. . NASA Lewis Research Center Group)

    1993-01-01

    The Autonomous Power System (APS) project at the NASA Lewis Research Center is designed to demonstrate the applications of integrated intelligent diagnosis, control and scheduling techniques to space power distribution systems. The project consists of three elements: the Autonomous Power Expert System (APEX) for Fault Detection, Isolation, and Recovery (FDIR); the Autonomous Intelligent Power Scheduler (AIPS) to efficiently assign activities start times and resources; and power hardware (Brassboard) to emulate a space-based power system. The APS project has been through one design iteration. Each of the three elements of the APS project has been designed, tested, and integrated into a complete working system. After these three portions were completed, an evaluation period was initiated. Each piece of the system was critiqued based on individual performance as well as ability to interact with the other portions of the APS project. These critiques were then used to determine guidelines for new and improved components of the APS system.

  1. Lessons learned from the Autonomous Power System

    NASA Technical Reports Server (NTRS)

    Ringer, Mark J.; Quinn, Todd M.; Merolla, Anthony

    1992-01-01

    The Autonomous Power System (APS) project at the NASA Lewis Research Center is designed to demonstrate the applications of integrated intelligent diagnosis, control and scheduling techniques to space power distribution systems. The project consists of three elements: the Autonomous Power Expert System (APEX) for Fault Diagnosis, Isolation, and Recovery (FDIR); the Autonomous Intelligent Power Scheduler (AIPS) to efficiently assign activities start times and resources; and power hardware (Brassboard) to emulate a space-based power system. The APS project had been through one design iteration. Each of the three elements of the APS project has been designed, tested, and integrated into a complete working system. After these three portions were completed, an evaluation period was initiated. Each piece of the system was critiqued based on individual performance as well as the ability to interact with the other portions of the APS project. These critiques were then used to determine guidelines for new and improved components of the APS system.

  2. Power Coupling Alternatives for the NEP Thermionic Power System

    NASA Technical Reports Server (NTRS)

    Manda, M. L.; Britt, E. J.; Fitzpatrick, G. O.

    1978-01-01

    Three output power coupling methods which can eliminate the high temperature insulator from the Nuclear Electric Propulsion (NEP) power system are described and estimates of their effects on the NEP system masses and cooling requirements are presented. Nominal 400 kWe power systems using push-pull and flux reset inductive output coupling are shown to have specific masses of 22.2 kg/kWe and 18.8 kg/kWe, respectively. Series connected heat pipe systems, which use the heat pipe-to-heat pipe resistance to isolate converters on adjacent heat pipes, are shown to have specific masses 0.5 to 1.4 kg/kWe lower than the NEP baseline system. Increasing the number and temperature of the heat pipes in the system without changing the electric output reduces the calculated system specific mass only slightly, whereas increasing the output power significantly reduces the specific mass. Estimates of cooling requirements indicate that 11-45 sq m of power conditioning radiator are needed. A possible location for the power conditioning radiator may be in the present location of the kapton sputter shield.

  3. Advanced power conditioning for maglev systems

    NASA Astrophysics Data System (ADS)

    Nerem, A.; Bowles, E. E.; Chapelle, S.; Callanan, R. J.

    1992-08-01

    The final report contains parametric scaling data and computer models of power conditioning equipment applicable to the design of an advanced maglev system. The power conditioning topologies were selected based on data from a literature search, on characteristics of present power semiconductor technology devices, and on actual performance characterization of designs using a circuit analysis program. The analyses show that GTO's are the best switches for traction drives, input power conditioning equipment, and the braking chopper. At lower power levels, as required for auxiliary power and superconducting coil power conditioning, the IGBT appeared to be the best switch.

  4. Combustion powered thermophotovoltaic emitter system

    SciTech Connect

    McHenry, R.S.; Harper, M.J.; Lindler, K.W.

    1995-12-31

    The United States Naval Academy, under interagency agreement with the Department of Energy (DOE), has recently completed an engineering design project for a high temperature thermophotovoltaic (TPV) photon emitter. The design was constrained by the physical geometry and photovoltaic cell type of the DOE TPV generator so that a cylindrical emitter at 1,756 K (2,700 F) was dictated. The final apparatus was to be portable, completely self contained, and was to incorporate cycle efficiency optimization such as exhaust stream recuperation. Through computer modeling and prototype experimentation, a methane fueled emitter system was designed from structural ceramic materials to fulfill the DOE requirements. This paper outlines the engineering design process, discusses obstacles and solutions encountered, and presents the final design. The concept of thermophotovoltaic energy conversion dates to the 1960s and has been the subject of broad research effort. This is a direct energy conversion process that converts thermal energy into electricity with only photonic coupling. The process offers high theoretical efficiency, versatile application as a primary or secondary power cycle, and a number of operational advantages resulting from the lack of a working substance or moving parts.

  5. High efficiency power generating system

    SciTech Connect

    Cook, A.; Rice, J.N.; Hitt, D.H.

    1990-10-16

    This patent describes a power generating system. It comprises: a converter for producing an AC output including a fundamental and at least one harmonic of the fundamental in response to applied control signals; a frequency analyzer, having at least one input coupled to the AC output, for providing an analysis of a frequency spectrum of the AC output; a processor, coupled to the frequency analyzer, for calculating a least one switching frequency, each switching frequency being used for transforming a different harmonic within the AC output of the fundamental; a controller, responsive to the at least one calculated switching frequency, for producing control signals at the at least one calculated switching frequency for transforming the at least one harmonic back to the fundamental and control signals for the converter for producing the AC output; a separating filter, coupled to the AC output, for separating the AC output into the fundamental and the at least one harmonic; at least one additional converter, coupled to the at least one harmonic from the converter and to the controller, each converter being switched by control signals from the controller which have a calculated switching frequency for transforming one of the at least one harmonics to the fundamental; and outputs from the at least one converter being combined with the fundamental from the separating filter.

  6. Wave activated power generation system

    SciTech Connect

    Ono, Y.

    1983-08-09

    A wave activated power generation system of the float type is disclosed, comprising at least one piston-cylinder device having an anchored cylinder and a piston slidable in the cylinder and cooperating with the cylinder to form a pumping chamber above the piston and a low pressure chamber below the piston. The cylinder has an intake port and an exhaust port both formed at an upper port thereof to communicate with the pumping chamber and each provided with a check valve. A float is connected through a cable to the piston of the piston- cylinder device. A pair of fluid storages are connected to the intake port and the exhaust port of the pumping chamber, respectively. A waterwheel generator is driven by the fluid flowing from one of the fluid storages to another. A pressure regulating device is connected to the low pressure chamber so as to maintain the low pressure chamber at a pressure lower than the pressure in the pumping chamber, the difference in pressure ceaselessly applying a downward force on the piston to keep the cable in a tensed condition.

  7. Technologies for Lunar Surface Power Systems Power Beaming and Transfer

    NASA Astrophysics Data System (ADS)

    Marzwell, Neville; Pogorzelski, Ronald J.; Chang, Kai; Little, Frank

    2008-01-01

    Wireless power transmission within a given working area is required or enabling for many NASA Exploration Systems. Fields of application include robotics, habitats, autonomous rendezvous and docking, life support, EVA, and many others. In robotics applications, for example, the robots must move in the working area without being hampered by power cables and, meanwhile, obtain a continuous and constant power from a power transmitter. The development of modern technology for transmitting electric power over free space has been studied for several decades, but its use in a system has been mainly limited to low power, 1-2 Vdc output voltage at a transmission distance of few meters for which relatively less than 0.5 mW/cm2 is required (e.g., Radio frequency identification RFID). Most of the rectenna conversion efficiency research to date has concentrated in low GHz frequency range of 2.45 to 10 GHz, with some work at 35 GHz. However, for space application, atmospheric adsorbtion is irrelevant and higher frequency systems with smaller transmit and receive apertures may be appropriate. For high power, most of the work on rectennas has concentrated on optimizing the conversion efficiency of the microwave rectifier element; the highest power demonstrated was 35 kW of power over a distance of 1.5 km. The objective of this paper is to establish the manner in which a very large number of very low power microwave devices can be synchronized to provide a beam of microwaves that can be used to efficiently and safely transport a significant amount of power to a remote location where it can be converted to dc (or ac) power by a ``rectenna.'' The proposed system is based on spatial power combining of the outputs of a large number of devices synchronized by mutual injection locking. We have demonstrated at JPL that such power could be achieved by combining 25 sources in a configuration that allows for convenient steering of the resulting beam of microwaves. Retrodirective beam steering for microwave power transmission (the ability to accurately track a moving receiver) has been demonstrated at Texas A&M. It is proposed that the next step in development of this concept is a modest scale up from 25 elements to 435 followed by a further scale up using such 435 element arrays as subarrays for a still larger retrodirective system. Ultimately, transmit antenna sizes on the order of 100 meters are envisioned permitting transfer levels on the order of 30 kW to aerial vehicles up to 20 km.

  8. Smart Power Supply for Battery-Powered Systems

    NASA Technical Reports Server (NTRS)

    Krasowski, Michael J.; Greer, Lawrence; Prokop, Norman F.; Flatico, Joseph M.

    2010-01-01

    A power supply for battery-powered systems has been designed with an embedded controller that is capable of monitoring and maintaining batteries, charging hardware, while maintaining output power. The power supply is primarily designed for rovers and other remote science and engineering vehicles, but it can be used in any battery alone, or battery and charging source applications. The supply can function autonomously, or can be connected to a host processor through a serial communications link. It can be programmed a priori or on the fly to return current and voltage readings to a host. It has two output power busses: a constant 24-V direct current nominal bus, and a programmable bus for output from approximately 24 up to approximately 50 V. The programmable bus voltage level, and its output power limit, can be changed on the fly as well. The power supply also offers options to reduce the programmable bus to 24 V when the set power limit is reached, limiting output power in the case of a system fault detected in the system. The smart power supply is based on an embedded 8051-type single-chip microcontroller. This choice was made in that a credible progression to flight (radiation hard, high reliability) can be assumed as many 8051 processors or gate arrays capable of accepting 8051-type core presently exist and will continue to do so for some time. To solve the problem of centralized control, this innovation moves an embedded microcontroller to the power supply and assigns it the task of overseeing the operation and charging of the power supply assets. This embedded processor is connected to the application central processor via a serial data link such that the central processor can request updates of various parameters within the supply, such as battery current, bus voltage, remaining power in battery estimations, etc. This supply has a direct connection to the battery bus for common (quiescent) power application. Because components from multiple vendors may have differing power needs, this supply also has a secondary power bus, which can be programmed a priori or on-the-fly to boost the primary battery voltage level from 24 to 50 V to accommodate various loads as they are brought on line. Through voltage and current monitoring, the device can also shield the charging source from overloads, keep it within safe operating modes, and can meter available power to the application and maintain safe operations.

  9. Device system and method for miniaturized radiation spectrometer

    NASA Technical Reports Server (NTRS)

    Stassinopoulos, Epaminondas G. (Inventor)

    2008-01-01

    A device/system for radiation sensing is configured to detect high and low LET radiation. The radiation sensing system may include a high LET detector and a low LET detector coupled to the high LET detector by a CPU, wherein the high LET detector and the low LET detector are assembled within a single unit. The device/system may also include a high LET and low LET detector that may be coupled together without an internal CPU. Overall, the device/system may be a stand-alone system and/or coupled to an external processing device. The device/system may also be approximately 6.times.6.times.2 cm.sup.3 in size, making it hand portable and may weigh less or equal to approximately ninety (90) grams, and operate on less than or approximately 0.25 watts of power.

  10. TPV Power Source Using Infrared-Sensitive Cells with Commercially Available Radiant Tube Burner

    NASA Astrophysics Data System (ADS)

    Fraas, Lewis; Minkin, Leonid; Hui, She; Avery, James; Howells, Christopher

    2004-11-01

    Over the last several years, JX Crystals has invented and systematically developed the key components for thermophotovoltaic systems. These key components include GaSb infrared sensitive cells, high power density shingle circuits, dielectric filters, and hydrocarbon-fueled radiant tube burners. Most recently, we invented and demonstrated an antireflection (AR)-coated tungsten IR emitter which when integrated with the other key components should make TPV systems with efficiencies over 10% practical. However, the use of the AR tungsten emitter requires an oxygen-free hermetic seal enclosure. During a 2003 Small Business Innovative Research (SBIR) Phase I contract, we integrated a tungsten emitter foil and a commercial SiC radiant tube burner within an emitter thermos and successfully demonstrated its operation at high temperature. We also designed a complete stand alone 500 W TPV generator. During the upcoming SBIR Phase II, we plan to implement this design in hardware.

  11. ADVANCED POWER SYSTEMS ANALYSIS TOOLS

    SciTech Connect

    Robert R. Jensen; Steven A. Benson; Jason D. Laumb

    2001-08-31

    The use of Energy and Environmental Research Center (EERC) modeling tools and improved analytical methods has provided key information in optimizing advanced power system design and operating conditions for efficiency, producing minimal air pollutant emissions and utilizing a wide range of fossil fuel properties. This project was divided into four tasks: the demonstration of the ash transformation model, upgrading spreadsheet tools, enhancements to analytical capabilities using the scanning electron microscopy (SEM), and improvements to the slag viscosity model. The ash transformation model, Atran, was used to predict the size and composition of ash particles, which has a major impact on the fate of the combustion system. To optimize Atran key factors such as mineral fragmentation and coalescence, the heterogeneous and homogeneous interaction of the organically associated elements must be considered as they are applied to the operating conditions. The resulting model's ash composition compares favorably to measured results. Enhancements to existing EERC spreadsheet application included upgrading interactive spreadsheets to calculate the thermodynamic properties for fuels, reactants, products, and steam with Newton Raphson algorithms to perform calculations on mass, energy, and elemental balances, isentropic expansion of steam, and gasifier equilibrium conditions. Derivative calculations can be performed to estimate fuel heating values, adiabatic flame temperatures, emission factors, comparative fuel costs, and per-unit carbon taxes from fuel analyses. Using state-of-the-art computer-controlled scanning electron microscopes and associated microanalysis systems, a method to determine viscosity using the incorporation of grey-scale binning acquired by the SEM image was developed. The image analysis capabilities of a backscattered electron image can be subdivided into various grey-scale ranges that can be analyzed separately. Since the grey scale's intensity is dependent on the chemistry of the particle, it is possible to map chemically similar areas which can also be related to the viscosity of that compound at temperature. A second method was also developed to determine the elements associated with the organic matrix of the coals, which is currently determined by chemical fractionation. Mineral compositions and mineral densities can be determined for both included and excluded minerals, as well as the fraction of the ash that will be represented by that mineral on a frame-by-frame basis. The slag viscosity model was improved to provide improved predictions of slag viscosity and temperature of critical viscosity for representative Powder River Basin subbituminous and lignite coals.

  12. The Failure Analysis in Traction Power System

    NASA Astrophysics Data System (ADS)

    Kim, Hyungchul; Heo, Guk-bum; Lee, Hyungwoo; Kim, Dong Jin; Kim, Jin O.

    2008-10-01

    This paper presents a failure analysis of traction power systems. The electric railway consists of traction power systems, various vehicles, operating equipment, track, overhead line and electric equipment. It is a fundamental function of traction power systems that they supply customers with acceptable reliability and high quality power. Perhaps the most commonly used reliability assessment for railway systems has been the failure analysis of the traction signal system. The reliability assessment of traction power systems has also been an indispensable issue for reliability assessment. This paper deals with the classification of railway accidents caused by electrification problems, the estimation of failure rate in power equipments and failure analysis using fault trees. In study cases, the fault tree method for failure analysis is applied to railway substations in South Korea.

  13. Modular, Intelligent Power Systems for Space Exploration

    NASA Technical Reports Server (NTRS)

    Button, Robert

    2006-01-01

    NASA's new Space Exploration Initiative demands that vehicles, habitats, and rovers achieve unprecedented levels of reliability, safety, effectiveness, and affordability. Modular and intelligent electrical power systems are critical to achieving those goals. Modular electrical power systems naturally increase reliability and safety through built-in fault tolerance. These modular systems also enable standardization across a multitude of systems, thereby greatly increasing affordability of the programs. Various technologies being developed to support this new paradigm for space power systems will be presented. Examples include the use of digital control in power electronics to enable better performance and advanced modularity functions such as distributed, master-less control and series input power conversion. Also, digital control and robust communication enables new levels of power system control, stability, fault detection, and health management. Summary results from recent development efforts are presented along with expected future technology development needs required to support NASA's ambitious space exploration goals.

  14. Small fission power systems for NEP

    NASA Astrophysics Data System (ADS)

    Lipinski, Ronald J.; Wright, Steven A.; Sherman, Martin P.; Lenard, Roger X.; Marshall, Albert C.; Talandis, Regina A.; Poston, David I.; Kapernick, Richard; Guffee, Ray; Reid, Robert; Elson, Jay; Lee, James

    2002-01-01

    Two nuclear electric propulsion (NEP) power system configurations are presented, each with an output power of 50 kWe and a system mass of about 2500 kg. Both consist of a reactor coupled to a recuperated Brayton power conversion system with a fixed conical radiator driven by loop heat pipes. In one system the reactor is gas-cooled with the gas directly driving the Brayton power conversion system. In the other the reactor is heatpipe-cooled with a heat exchanger between the reactor and the Brayton system. Two variations are described briefly with powers of 100 k We and 150 kWe. The mass scales approximately with the square root of the power. .

  15. Artificial intelligence and space power systems automation

    NASA Technical Reports Server (NTRS)

    Weeks, David J.

    1987-01-01

    Various applications of artificial intelligence to space electrical power systems are discussed. An overview is given of completed, on-going, and planned knowledge-based system activities. These applications include the Nickel-Cadmium Battery Expert System (NICBES) (the expert system interfaced with the Hubble Space Telescope electrical power system test bed); the early work with the Space Station Experiment Scheduler (SSES); the three expert systems under development in the space station advanced development effort in the core module power management and distribution system test bed; planned cooperation of expert systems in the Core Module Power Management and Distribution (CM/PMAD) system breadboard with expert systems for the space station at other research centers; and the intelligent data reduction expert system under development.

  16. Power Management in Regenerative Life Support Systems

    NASA Technical Reports Server (NTRS)

    Crawford, Sekou; Pawlowski, Christopher; Finn, Cory; Mead, Susan C. (Technical Monitor)

    1999-01-01

    Effective management of power can reduce the cost of launch and operation of regenerative life support systems. Variations in power may be quite severe and may manifest as surges or spikes, While the power plant may have some ability to deal with these variations, with batteries for example, over-capacity is expensive and does nothing to address the fundamental issue of excessive demand. Because the power unit must be sized to accommodate the largest demand, avoiding power spikes has the potential to reduce the required size of the power plant while at the same time increasing the dependability of the system. Scheduling of processors can help to reduce potential power spikes. However, not all power-consuming equipment is easily scheduled. Therefore, active power management is needed to further decrease the risk of surges or spikes. We investigate the use of a hierarchical scheme to actively manage power for a model of a regenerative life support system. Local level controllers individually determine subsystem power usage. A higher level controller monitors overall system power and detects surges or spikes. When a surge condition is detected, the higher level controller conducts an 'auction' and describes subsystem power usage to re-allocate power. The result is an overall reduction in total power during a power surge. The auction involves each subsystem making a 'bid' to buy or sell power based on local needs. However, this re-allocation cannot come at the expense of life support function. To this end, participation in the auction is restricted to those processes meeting certain tolerance constraints. These tolerances represent acceptable limits within which system processes can be operated. We present a simulation model and discuss some of our results.

  17. Solar Thermal Power Systems parabolic dish project

    NASA Technical Reports Server (NTRS)

    Truscello, V. C.

    1981-01-01

    The status of the Solar Thermal Power Systems Project for FY 1980 is summarized. Included is: a discussion of the project's goals, program structure, and progress in parabolic dish technology. Analyses and test results of concentrators, receivers, and power converters are discussed. Progress toward the objectives of technology feasibility, technology readiness, system feasibility, and system readiness are covered.

  18. Critical areas: Satellite power systems concepts

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Critical Areas are defined and discussed in the various areas pertinent to satellite power systems. The presentation is grouped into five areas (General, Space Systems, Solar Energy Conversion, Microwave Systems, and Environment/Ecology) with a sixth area (Power Relay) considered separately in an appendix. Areas for Future Consideration as critical areas are discussed in a second appendix.

  19. Flexibility in 21st Century Power Systems

    SciTech Connect

    Cochran, J.; Miller, M.; Zinaman, O.; Milligan, M.; Arent, D.; Palmintier, B.; O'Malley, M.; Mueller, S.; Lannoye, E.; Tuohy, A.; Kujala, B.; Sommer, M.; Holttinen, H.; Kiviluoma, J.; Soonee, S. K.

    2014-05-01

    Flexibility of operation--the ability of a power system to respond to change in demand and supply--is a characteristic of all power systems. Flexibility is especially prized in twenty-first century power systems, with higher levels of grid-connected variable renewable energy (primarily, wind and solar). This paper summarizes the analytic frameworks that have emerged to measure this characteristic and distills key principles of flexibility for policy makers.

  20. Space-to-earth power transmission system

    NASA Technical Reports Server (NTRS)

    Stevens, G. H.; Schuh, R.

    1976-01-01

    A preliminary analysis was conducted to establish the requirements of a space-to-earth microwave power transmission system. The need for accurate phase control on the transmitter was established and methods for assessing the impact of power density and thermal constraints on system performance were demonstrated. Potential radio frequency interference was considered. The sensitivity of transmission system scale to variations in power source, transportation and orbital fabrication and assembly costs was also determined.

  1. Power system applications of fiber optics

    NASA Technical Reports Server (NTRS)

    Kirkham, H.; Johnston, A.; Lutes, G.; Daud, T.; Hyland, S.

    1984-01-01

    Power system applications of optical systems, primarily using fiber optics, are reviewed. The first section reviews fibers as components of communication systems. The second section deals with fiber sensors for power systems, reviewing the many ways light sources and fibers can be combined to make measurements. Methods of measuring electric field gradient are discussed. Optical data processing is the subject of the third section, which begins by reviewing some widely different examples and concludes by outlining some potential applications in power systems: fault location in transformers, optical switching for light fired thyristors and fault detection based on the inherent symmetry of most power apparatus. The fourth and final section is concerned with using optical fibers to transmit power to electric equipment in a high voltage situation, potentially replacing expensive high voltage low power transformers. JPL has designed small photodiodes specifically for this purpose, and fabricated and tested several samples. This work is described.

  2. Acceptance test report: Backup power system

    SciTech Connect

    Cole, D.B.

    1996-01-26

    Acceptance Test Report for construction functional testing of Project W-030 Backup Power System. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. Backup power includes a single 125 KW diesel generator, three 10-kva uninterruptible power supply units, and all necessary control.

  3. Switching System for Redundant Power Supplies

    NASA Technical Reports Server (NTRS)

    Bradford, M.; Grant, R.; Parkinson, G.

    1986-01-01

    Load-transfer unit connects airborne computer to standby power supply in case primary supply fails. Concept adaptable to systems in which power interruptions cannot be tolerated; for example, computers with volatile memories, safety equipment, and precise timers. Load-transfer unit monitors voltages and load current. Microprocessor controls transistor switches that connect load to whichever power supply has highest priority and correct voltage.

  4. Nuclear power for space based systems

    NASA Astrophysics Data System (ADS)

    Livingston, J. M.; Ivanenok, Joseph F., III

    1991-09-01

    A 100 kWe closed Brayton cycle power conversion system utilizing a recuperator coupled to a NERVA derivative reactor for a lunar power plant is presented. Power plant mass versus recuperator effectiveness, compressor inlet temperature, and turbine pressure ratio are described.

  5. Solar power satellite system definition study

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A synopsis of the study plan for the solar power satellite system is presented. Descriptions of early task progress is reported for the following areas: (1) laser annealing, (2) solid state power amplifiers, (3) rectenna option, (4) construction of an independent electric orbit transfer vehicle, and (5) construction of a 2.5 GW solar power satellite.

  6. Space Shuttle Upgrades Advanced Hydraulic Power System

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Three Auxiliary Power Units (APU) on the Space Shuttle Orbiter each provide 145 hp shaft power to a hydraulic pump which outputs 3000 psi hydraulic fluid to 41 hydraulic actuators. A hydrazine fuel powered APU utilized throughout the Shuttle program has undergone many improvements, but concerns remain with flight safety, operational cost, critical failure modes, and hydrazine related hazards. The advanced hydraulic power system (AHPS), also known as the electric APU, is being evaluated as an upgrade to replace the hydrazine APU. The AHPS replaces the high-speed turbine and hydrazine fuel supply system with a battery power supply and electric motor/pump that converts 300 volt electrical power to 3000 psi hydraulic power. AHPS upgrade benefits include elimination of toxic hydrazine propellant to improve flight safety, reduction in hazardous ground processing operations, and improved reliability. Development of this upgrade provides many interesting challenges and includes development of four hardware elements that comprise the AHPS system: Battery - The battery provides a high voltage supply of power using lithium ion cells. This is a large battery that must provide 28 kilowatt hours of energy over 99 minutes of operation at 300 volts with a peak power of 130 kilowatts for three seconds. High Voltage Power Distribution and Control (PD&C) - The PD&C distributes electric power from the battery to the EHDU. This 300 volt system includes wiring and components necessary to distribute power and provide fault current protection. Electro-Hydraulic Drive Unit (EHDU) - The EHDU converts electric input power to hydraulic output power. The EHDU must provide over 90 kilowatts of stable, output hydraulic power at 3000 psi with high efficiency and rapid response time. Cooling System - The cooling system provides thermal control of the Orbiter hydraulic fluid and EHDU electronic components. Symposium presentation will provide an overview of the AHPS upgrade, descriptions of the four hardware elements, and a summary of development results to date.

  7. Power line monitoring system using fiber optic power supply

    NASA Astrophysics Data System (ADS)

    Tanaka, Yosuke; Shioda, Tatsutoshi; Kurokawa, Takashi; Oka, Junji; Ueta, Kazuyuki; Fukuoka, Toshiharu

    2009-05-01

    We propose a novel power-line-monitoring system using optical fibers for transmitting power as well as signal. The principle is experimentally confirmed with a system composed of a monitoring side with a 1.5-μm laser diode, transmission line of a single mode fiber, and a sensing side having an efficient photovoltaic (PV) cell, electrical junction sensor, and low power liquid crystal optical modulator (LCOM). The PV cell generates the electrical power in the sensing side with a conversion efficiency of 20%. The LCOM is driven with low power of less than 50 μW, modulates the laser light with a signal indicating the power line condition, and transmits the optical signal. The developed sensing unit produces an optical signal having an extinction ratio of 15 dB with low optical power of 1.8 mW. Five systems were in operation for two years, faithfully monitoring the oil pressure in electrical cables every 20 min without incident.

  8. 25 kW solar photovoltaic flat panel power supply for an electrodialysis water desalination unit in New Mexico. Final report, 1 October 1978-31 May 1979

    SciTech Connect

    Wood, J.R.; Crutcher, J.L.

    1980-06-01

    The stand-alone system designed by Mobil Tyco Solar Energy Corporation consists of a 25 kW flat panel array employing silicon ribbon solar cells, used in conjunction with a lead-acid battery bank to provide the complete power requirements of an electrodialysis water desalination unit. The Mobil Tyco system design is intended to be prototypical of part of the drinking water supply for a remote village. The specific task which this system will perform during Phase III is to aid in the restoration of an aquifer following a uranium leaching operation by the Energy Minerals Division of Mobil Oil Corporation at a site which is approximately four miles from the township of Crownpoint in northwestern New Mexico. System design is described, and a detailed description of a mathematical model and computerized simulation of the system is included. (WHK)

  9. Water reactive hydrogen fuel cell power system

    DOEpatents

    Wallace, Andrew P; Melack, John M; Lefenfeld, Michael

    2014-11-25

    A water reactive hydrogen fueled power system includes devices and methods to combine reactant fuel materials and aqueous solutions to generate hydrogen. The generated hydrogen is converted in a fuel cell to provide electricity. The water reactive hydrogen fueled power system includes a fuel cell, a water feed tray, and a fuel cartridge to generate power for portable power electronics. The removable fuel cartridge is encompassed by the water feed tray and fuel cell. The water feed tray is refillable with water by a user. The water is then transferred from the water feed tray into the fuel cartridge to generate hydrogen for the fuel cell which then produces power for the user.

  10. Water reactive hydrogen fuel cell power system

    DOEpatents

    Wallace, Andrew P; Melack, John M; Lefenfeld, Michael

    2014-01-21

    A water reactive hydrogen fueled power system includes devices and methods to combine reactant fuel materials and aqueous solutions to generate hydrogen. The generated hydrogen is converted in a fuel cell to provide electricity. The water reactive hydrogen fueled power system includes a fuel cell, a water feed tray, and a fuel cartridge to generate power for portable power electronics. The removable fuel cartridge is encompassed by the water feed tray and fuel cell. The water feed tray is refillable with water by a user. The water is then transferred from the water feed tray into a fuel cartridge to generate hydrogen for the fuel cell which then produces power for the user.

  11. Continuously charged flywheel type power delivery system

    SciTech Connect

    Frank, A.A.; Omitsu, T.

    1986-04-22

    In a method of controlling the operation of a flywheel-type power delivery system having an energy-storing flywheel, an internal combustion engine is described operatively coupled to the flywheel for delivering power to the flywheel, and a continuously variable ratio transmission operatively coupled to the flywheel for delivering power to an output shaft. The improvement described here consists of: predetermining a desired maximum output shaft speed limit; and adjusting the working displacement of the engine in proportion to the output shaft speed limit, whereby the efficient power output of the engine is tailored to the power requirements of the system.

  12. A new bipolar Qtrim power supply system

    SciTech Connect

    Mi, C.; Bruno, D.; Drozd, J.; Nolan, T.; Orsatti, F.; Heppener, G.; Di Lieto, A.; Schultheiss, C.; Samms, T.; Zapasek, R.; Sandberg, J.

    2015-05-03

    This year marks the 15th run of RHIC (Relativistic Heavy Ion Collider) operations. The reliability of superconducting magnet power supplies is one of the essential factors in the entire accelerator complex. Besides maintaining existing power supplies and their associated equipment, newly designed systems are also required based on the physicist’s latest requirements. A bipolar power supply was required for this year’s main quadruple trim power supply. This paper will explain the design, prototype, testing, installation and operation of this recently installed power supply system.

  13. Standardized sensitivity coefficients for power system networks

    SciTech Connect

    Barcelo, W.R.; Lemmon, W.W. )

    1988-11-01

    A simple mathematical transformation for converting power system network sensitivity coefficients from one reference frame to another is derived using a generalized power center concept. The generalized power center consists of a swing power center and an angle center. A standard power center is presented wherein the swing power and angle centers are set equal to the load center. The resulting standardized sensitivity coefficients are independent of the swing bus. Solving a Lagrangian formulation of the economic dispatch problem results in the direct calculation of true system incremental cost only when standardized sensitivity coefficients are used. Results are presented for several practical cases involving the Jacobian and DC load flow matrices and several different power centers. The importance of the swing power sensitivity vector is identified and other key network relationships are developed.

  14. Photovoltaic power without batteries for continuous cathodic protection and an alternate photovoltaic/ultracapacitor combined power source

    SciTech Connect

    Muehl, W.W. Sr.

    1995-12-31

    The Coastal Systems Station (COASTSYSTA) designed, installed, and started up on 20 January 1990, a state-of-the-art stand-alone photovoltaic powered impressed current cathodic protection system (PVCPSYS) not requiring any backup power for steel and iron submerged structures. The PVCPSYS, installed on a 775-foot steel sheet piling of a Navy dock bulkhead, provides complete, continuous corrosion protection. The PVCPSYS has been in operation for more than five years, has not required any repair or maintenance, and is environmentally clean. Initial cost savings of the PVCPSYS versus conventional cathodic protection system was $46,000. A second PVCPSYS was installed on another 800-foot bulkhead on 21 May 1993. It is also providing complete corrosion protection without backup power. Performance is well documented. Other potential applications are moth-balled ships, locks, dams, bridges, pipelines, and similar structures. These systems are considered a major advance by Sandia and the Department of Defense (DOD) Photovoltaic Review Committee. An ultracapacitor, a recent hi-tech development that is environmentally clean, will be incorporated in the PVCPSYS when required to enhance the system`s capability. A photovoltaic/ultracapacitor (or equivalent) combined power source operating under adverse conditions, and/or to satisfy or meet regulations will assure cathodic protection, including pipelines carrying combustibles or other products that could otherwise create environmental problems. Patents are pending on this PVCPSYS and the photovoltaic/ ultracapacitor powered systems.

  15. Modeling of DC spacecraft power systems

    NASA Technical Reports Server (NTRS)

    Berry, F. C.

    1995-01-01

    Future spacecraft power systems must be capable of supplying power to various loads. This delivery of power may necessitate the use of high-voltage, high-power dc distribution systems to transmit power from the source to the loads. Using state-of-the-art power conditioning electronics such as dc-dc converters, complex series and parallel configurations may be required at the interface between the source and the distribution system and between the loads and the distribution system. This research will use state-variables to model and simulate a dc spacecraft power system. Each component of the dc power system will be treated as a multiport network, and a state model will be written with the port voltages as the inputs. The state model of a component will be solved independently from the other components using its state transition matrix. A state-space averaging method is developed first in general for any dc-dc switching converter, and then demonstrated in detail for the particular case of the boost power stage. General equations for both steady-state (dc) and dynamic effects (ac) are obtained, from which important transfer functions are derived and applied to a special case of the boost power stage.

  16. Modeling of DC spacecraft power systems

    NASA Astrophysics Data System (ADS)

    Berry, F. C.

    1995-07-01

    Future spacecraft power systems must be capable of supplying power to various loads. This delivery of power may necessitate the use of high-voltage, high-power dc distribution systems to transmit power from the source to the loads. Using state-of-the-art power conditioning electronics such as dc-dc converters, complex series and parallel configurations may be required at the interface between the source and the distribution system and between the loads and the distribution system. This research will use state-variables to model and simulate a dc spacecraft power system. Each component of the dc power system will be treated as a multiport network, and a state model will be written with the port voltages as the inputs. The state model of a component will be solved independently from the other components using its state transition matrix. A state-space averaging method is developed first in general for any dc-dc switching converter, and then demonstrated in detail for the particular case of the boost power stage. General equations for both steady-state (dc) and dynamic effects (ac) are obtained, from which important transfer functions are derived and applied to a special case of the boost power stage.

  17. Power System Information Delivering System Based on Distributed Object

    NASA Astrophysics Data System (ADS)

    Tanaka, Tatsuji; Tsuchiya, Takehiko; Tamura, Setsuo; Seki, Tomomichi; Kubota, Kenji

    In recent years, improvement in computer performance and development of computer network technology or the distributed information processing technology has a remarkable thing. Moreover, the deregulation is starting and will be spreading in the electric power industry in Japan. Consequently, power suppliers are required to supply low cost power with high quality services to customers. Corresponding to these movements the authors have been proposed SCOPE (System Configuration Of PowEr control system) architecture for distributed EMS/SCADA (Energy Management Systems / Supervisory Control and Data Acquisition) system based on distributed object technology, which offers the flexibility and expandability adapting those movements. In this paper, the authors introduce a prototype of the power system information delivering system, which was developed based on SCOPE architecture. This paper describes the architecture and the evaluation results of this prototype system. The power system information delivering system supplies useful power systems information such as electric power failures to the customers using Internet and distributed object technology. This system is new type of SCADA system which monitors failure of power transmission system and power distribution system with geographic information integrated way.

  18. 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.

  19. High-power VCSEL systems and applications

    NASA Astrophysics Data System (ADS)

    Moench, Holger; Conrads, Ralf; Deppe, Carsten; Derra, Guenther; Gronenborn, Stephan; Gu, Xi; Heusler, Gero; Kolb, Johanna; Miller, Michael; Pekarski, Pavel; Pollmann-Retsch, Jens; Pruijmboom, Armand; Weichmann, Ulrich

    2015-03-01

    Easy system design, compactness and a uniform power distribution define the basic advantages of high power VCSEL systems. Full addressability in space and time add new dimensions for optimization and enable "digital photonic production". Many thermal processes benefit from the improved control i.e. heat is applied exactly where and when it is needed. The compact VCSEL systems can be integrated into most manufacturing equipment, replacing batch processes using large furnaces and reducing energy consumption. This paper will present how recent technological development of high power VCSEL systems will extend efficiency and flexibility of thermal processes and replace not only laser systems, lamps and furnaces but enable new ways of production. High power VCSEL systems are made from many VCSEL chips, each comprising thousands of low power VCSELs. Systems scalable in power from watts to multiple ten kilowatts and with various form factors utilize a common modular building block concept. Designs for reliable high power VCSEL arrays and systems can be developed and tested on each building block level and benefit from the low power density and excellent reliability of the VCSELs. Furthermore advanced assembly concepts aim to reduce the number of individual processes and components and make the whole system even more simple and reliable.

  20. Solar dynamic power system definition study

    NASA Technical Reports Server (NTRS)

    Wallin, Wayne E.; Friefeld, Jerry M.

    1988-01-01

    The solar dynamic power system design and analysis study compared Brayton, alkali-metal Rankine, and free-piston Stirling cycles with silicon planar and GaAs concentrator photovoltaic power systems for application to missions beyond the Phase 2 Space Station level of technology for all power systems. Conceptual designs for Brayton and Stirling power systems were developed for 35 kWe and 7 kWe power levels. All power systems were designed for 7-year end-of-life conditions in low Earth orbit. LiF was selected for thermal energy storage for the solar dynamic systems. Results indicate that the Stirling cycle systems have the highest performance (lowest weight and area) followed by the Brayton cycle, with photovoltaic systems considerably lower in performance. For example, based on the performance assumptions used, the planar silicon power system weight was 55 to 75 percent higher than for the Stirling system. A technology program was developed to address areas wherein significant performance improvements could be realized relative to the current state-of-the-art as represented by Space Station. In addition, a preliminary evaluation of hardenability potential found that solar dynamic systems can be hardened beyond the hardness inherent in the conceptual designs of this study.

  1. Automated diagnostics for aerospace power management systems

    SciTech Connect

    Granieri, M.N.; Darty, M.

    1995-12-31

    Due to safety and mission criticality, aerospace power management systems require built in fault tolerance. Existing systems focus on hardware redundancy and lack the characteristics needed to provide rapid fault diagnostics and reconfiguration of power flow to critical users. Solid state power control (SSPC) electronics can provide faster switching times than electromechanical devices and when this technology is coupled with advanced software for diagnostics, a fault tolerant system design can be implemented. This paper describes a new project to integrate advanced SSPC electronics with newly available, knowledge-based diagnostic software in order to demonstrate the ability to detect, isolate and implement corrective action within a short period of time consistent with requirements for uninterrupted power. A fast embedded microprocessor will be used to run the diagnostic software and control power electronics. This project seeks to demonstrate the technology needed to enable a power management and distribution system to automatically compensate for faults in real time.

  2. Thermal power systems small power systems applications project. Volume 2: Detailed report

    NASA Technical Reports Server (NTRS)

    Marriott, A. T.

    1979-01-01

    Small power system technology as applied to power plants up to 10 MW in size was considered. Markets for small power systems were characterized and cost goals were established for the project. Candidate power plant system design concepts were selected for evaluation and preliminary performance and cost assessments were made. Breakeven capital costs were determined for leading contenders among the candidate systems. The potential use of small power systems in providing part of the demand for pumping power by the extensive aqueduct system of California, was studied. Criteria and methodologies were developed for the ranking of candidate power plant system design concepts. Experimental power plant concepts of 1 MW rating were studied to define a power plant configuration for subsequent detail design construction, testing and evaluation. Site selection criteria and ground rules were developed.

  3. Propulsion element requirements using electrical power system unscheduled power

    NASA Technical Reports Server (NTRS)

    Zimmermann, Frank; Hodge, Kathy

    1989-01-01

    The suitability of using the electrical energy from the Space Station's Electrical Power System (EPS) during the periods of peak solar insolation which is currently not specifically allocated (unscheduled power) to produce propulsion propellants, gaseous hydrogen, and oxygen by electrolyzing water is investigated. Reboost propellant requirements are emphasized, but the results are more generally relevant because the balance of recurring propellant requirements are an order of magnitude smaller and the nonrecurring requirements are not significant on an average basis.

  4. High power RF solid state power amplifier system

    NASA Technical Reports Server (NTRS)

    Sims, III, William Herbert (Inventor); Chavers, Donald Gregory (Inventor); Richeson, James J. (Inventor)

    2011-01-01

    A high power, high frequency, solid state power amplifier system includes a plurality of input multiple port splitters for receiving a high-frequency input and for dividing the input into a plurality of outputs and a plurality of solid state amplifier units. Each amplifier unit includes a plurality of amplifiers, and each amplifier is individually connected to one of the outputs of multiport splitters and produces a corresponding amplified output. A plurality of multiport combiners combine the amplified outputs of the amplifiers of each of the amplifier units to a combined output. Automatic level control protection circuitry protects the amplifiers and maintains a substantial constant amplifier power output.

  5. Automated System Tests High-Power MOSFET's

    NASA Technical Reports Server (NTRS)

    Huston, Steven W.; Wendt, Isabel O.

    1994-01-01

    Computer-controlled system tests metal-oxide/semiconductor field-effect transistors (MOSFET's) at high voltages and currents. Measures seven parameters characterizing performance of MOSFET, with view toward obtaining early indication MOSFET defective. Use of test system prior to installation of power MOSFET in high-power circuit saves time and money.

  6. High power laser perforating tools and systems

    DOEpatents

    Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

    2014-04-22

    ystems devices and methods for the transmission of 1 kW or more of laser energy deep into the earth and for the suppression of associated nonlinear phenomena. Systems, devices and methods for the laser perforation of a borehole in the earth. These systems can deliver high power laser energy down a deep borehole, while maintaining the high power to perforate such boreholes.

  7. International Space Station Power System Model Validated

    NASA Technical Reports Server (NTRS)

    Hojnicki, Jeffrey S.; Delleur, Ann M.

    2002-01-01

    System Power Analysis for Capability Evaluation (SPACE) is a computer model of the International Space Station's (ISS) Electric Power System (EPS) developed at the NASA Glenn Research Center. This uniquely integrated, detailed model can predict EPS capability, assess EPS performance during a given mission with a specified load demand, conduct what-if studies, and support on-orbit anomaly resolution.

  8. Expert System Detects Power-Distribution Faults

    NASA Technical Reports Server (NTRS)

    Walters, Jerry L.; Quinn, Todd M.

    1994-01-01

    Autonomous Power Expert (APEX) computer program is prototype expert-system program detecting faults in electrical-power-distribution system. Assists human operators in diagnosing faults and deciding what adjustments or repairs needed for immediate recovery from faults or for maintenance to correct initially nonthreatening conditions that could develop into faults. Written in Lisp.

  9. Concentrators Enhance Solar Power Systems

    NASA Technical Reports Server (NTRS)

    2013-01-01

    "Right now, solar electric propulsion is being looked at very seriously," says Michael Piszczor, chief of the photovoltaic and power technologies branch at Glen Research Center. The reason, he explains, originates with a unique NASA mission from the late 1990s. In 1998, the Deep Space 1 spacecraft launched from Kennedy Space Center to test a dozen different space technologies, including SCARLET, or the Solar Concentrator Array with Refractive Linear Element Technology. As a solar array that focused sunlight on a smaller solar cell to generate electric power, SCARLET not only powered Deep Space 1 s instruments but also powered its ion engine, which propelled the spacecraft throughout its journey. Deep Space 1 was the first spacecraft powered by a refractive concentrator design like SCARLET, and also utilized multi-junction solar cells, or cells made of multiple layers of different materials. For the duration of its 38-month mission, SCARLET performed flawlessly, even as Deep Space 1 flew by Comet Borrelly and Asteroid Braille. "Everyone remembers the ion engine on Deep Space 1, but they tend to forget that the SCARLET array powered it," says Piszczor. "Not only did both technologies work as designed, but the synergy between the two, solar power and propulsion together, is really the important aspect of this technology demonstration mission. It was the first successful use of solar electric propulsion for primary propulsion." More than a decade later, NASA is keenly interested in using solar electric propulsion (SEP) for future space missions. A key issue is cost, and SEP has the potential to substantially reduce cost compared to conventional chemical propulsion technology. "SEP allows you to use spacecraft that are smaller, lighter, and less costly," says Piszczor. "Even though it might take longer to get somewhere using SEP, if you are willing to trade time for cost and smaller vehicles, it s a good trade." Potentially, SEP could be used on future science missions in orbit around the Earth or Moon, to planets or asteroids, on deep space science missions, and even on exploration missions. In fact, electric propulsion is already being used on Earth-orbiting satellites for positioning.

  10. Next generation cooled long range thermal sights with minimum size, weight, and power

    NASA Astrophysics Data System (ADS)

    Breiter, R.; Ihle, T.; Wendler, J.; Rhlich, I.; Ziegler, J.

    2013-06-01

    Situational awareness and precise targeting at day, night and severe weather conditions are key elements for mission success in asymmetric warfare. To support these capabilities for the dismounted soldier, AIM has developed a family of stand-alone thermal weapon sights based on high performance cooled IR-modules which are used e.g. in the infantryman of the future program of the German army (IdZ). The design driver for these sights is a long ID range <1500m for the NATO standard target to cover the operational range of a platoon with the engagement range of .50 cal rifles, 40mm AGLs or for reconnaissance tasks. The most recent sight WBZG has just entered into serial production for the IdZ enhanced system of the German army with additional capabilities like a wireless data link to the soldier backbone computer. Minimum size, weight and power (SWaP) are most critical requirements for the dismounted soldiers' equipment and sometimes push a decision towards uncooled equipment with marginal performance referring to the outstanding challenges in current asymmetric warfare, e.g. the capability to distinguish between combatants and non-combatants in adequate ranges. To provide the uncompromised e/o performance with SWaP parameters close to uncooled, AIM has developed a new thermal weapon sight based on high operating temperature (HOT) MCT MWIR FPAs together with a new low power single piston stirling cooler. In basic operation the sight is used as a clip-on in front of the rifle scope. An additional eyepiece for stand-alone targeting with e.g. AGLs or a biocular version for relaxed surveillance will be available. The paper will present details of the technologies applied for such long range cooled sights with size, weight and power close to uncooled.

  11. Power electronics in electric utilities: HVDC power transmission systems

    SciTech Connect

    Nozari, F.; Patel, H.S.

    1988-04-01

    High Voltage Direct Current (HVDC) power transmission systems constitute an important application of power electronics technology. This paper reviews salient aspects of this growing industry. The paper summarizes the history of HVDC transmission and discusses the economic and technical reasons responsible for development of HVDC systems. The paper also describes terminal design and basic configurations of HVDC systems, as well as major equipments of HVDC transmission system. In this regard, the state-of-the-art technology in the equipments constructions are discussed. Finally, the paper reviews future developments in the HVDC transmission systems, including promising technologies, such as multiterminal configurations, Gate Turn-Off (GTO) devices, forced commutation converters, and new advances in control electronics.

  12. TOPEX/Poseidon electrical power system -- Performance

    SciTech Connect

    Sherwood, R.; Deligiannis, F.

    1996-12-31

    This paper shows that the power system performance (batteries, solar array, power regulator) on-board the TOPEX/Poseidon satellite has met or exceeded pre-launch predictions, and has successfully managed the performance of NiCd batteries which had shown anomalous performance on other missions such as UARS and GRO. The battery performance is addressed through the following parameters: end-of-discharge voltage, peak charge current, charge to discharge ratio, and voltage differential. The solar array performance discussion includes voltage, current and power. There is also a discussion of the power regulator efficiency and the satellite load power history.

  13. TFTR neutral-beam power system

    SciTech Connect

    Winje, R.A.

    1982-10-01

    The TFTR Neutral Beam Power System (NBPS) consists of the accelerator grid power supply and the auxiliary power supplies required to operate the TFTR 120-keV ion sources. The current configuration of the NBPS including the 11-MVA accelerator grid power supply and the Arc and Filament power supplies isolated for operation at accelerator grid voltages up to 120 kV, is described. The prototype NBPS has been assembled at the Princeton Plasma Physics Laboratory and has been operated. The results of the initial operation and the description and resolution of some of the technical problems encountered during the commissioning tests are presented.

  14. Heatpipe space power and propulsion systems

    SciTech Connect

    Houts, M.G.; Poston, D.I.; Ranken, W.A.

    1995-07-01

    Safe, reliable, low-mass space power and propulsion systems could have numerous civilian and military applications. This paper discusses two fission-powered concepts: the Heatpipe Power System (HPS) that provides power only, and the Heatpipe Bimodal System (HBS) that provides both power and thermal propulsion. Both concepts have 10 important features. First, only existing technology and recently tested fuel forms are used. Second, fuel can be removed whenever desired, greatly facilitating system fabrication and handling. Third, full electrically heated system testing is possible, with minimal operations required to replace the heaters with fuel and ready the system for launch. Fourth, the systems are passively subcritical during launch accidents. Fifth, a modular approach is used, and most technical issues can be resolved with inexpensive module tests. Sixth, bonds between dissimilar metals are minimized. Seventh, there are no single point failures during power mode operation. Eighth, fuel burnup rate is quite low to help ensure greater than 10-year system life. Ninth, there are no pumped coolant loops, and the systems can be shut down and restarted without coolant freeze/thaw concerns. Finally, a full ground nuclear test is not needed, and development costs will be low. The baseline HPS uses SNAP-10A-style thermoelectric power converters to produce 5 kWe at a system mass of about 500 kg. The unicouple thermoelectric converters have a hot shoe temperature of 1275 K and reject waste heat at 775 K. This type of thermoelectric converter has been used extensively by the space program, demonstrating an operational lifetime of decades. At higher thermal power, the same core can produce over 10 kWe using thermoelectric converters, and over 50 kWe using advanced power conversion systems.

  15. Heatpipe space power and propulsion systems

    NASA Astrophysics Data System (ADS)

    Houts, M. G.; Poston, D. I.; Ranken, W. A.

    1995-04-01

    Safe, reliable, low-mass space power and propulsion systems could have numerous civilian and military applications. This paper discusses two fission-powered concepts: the Heatpipe Power System (HPS) that provides power only, and the Heatpipe Bimodal System (HBS) that provides both power and thermal propulsion. Both concepts have 10 important features. First, only existing technology and recently tested fuel forms are used. Second, fuel can be removed whenever desired, greatly facilitating system fabrication and handling. Third, full electrically heated system testing is possible, with minimal operations required to replace the heaters with fuel and ready the system for launch. Fourth, the systems are passively subcritical during launch accidents. Fifth, a modular approach is used, and most technical issues can be resolved with inexpensive module tests. Sixth, bonds between dissimilar metals are minimized. Seventh, there are no single point failures during power mode operation. Eighth, fuel burnup rate is quite low to help ensure greater than 10-year system life. Ninth, there are no pumped coolant loops, and the systems can be shut down and restarted without coolant freeze/thaw concerns. Finally, a full ground nuclear test is not needed, and development costs will be low. The baseline HPS uses SNAP-10A-style thermoelectric power converters to produce 5 kWe at a system mass of about 500 kg. The unicouple thermoelectric converters have a hot shoe temperature of 1275 K and reject waste heat at 775 K. This type of thermoelectric converter has been used extensively by the space program, demonstrating an operational lifetime of decades. At higher thermal power, the same core can produce over 10 kWe using thermoelectric converters, and over 50 kWe using advanced power conversion systems.

  16. High frequency power distribution system

    NASA Technical Reports Server (NTRS)

    Patel, Mikund R.

    1986-01-01

    The objective of this project was to provide the technology of high frequency, high power transmission lines to the 100 kW power range at 20 kHz frequency. In addition to the necessary design studies, a 150 m long, 600 V, 60 A transmission line was built, tested and delivered for full vacuum tests. The configuration analysis on five alternative configurations resulted in the final selection of the three parallel Litz straps configuration, which gave a virtually concentric design in the electromagnetic sense. Low inductance, low EMI and flexibility in handling are the key features of this configuration. The final design was made after a parametric study to minimize the losses, weight and inductance. The construction of the cable was completed with no major difficulties. The R,L,C parameters measured on the cable agreed well with the calculated values. The corona tests on insulation samples showed a safety factor of 3.

  17. Power limits for wind energy concentrator systems

    NASA Astrophysics Data System (ADS)

    Dick, E.

    Momentum theory, in the classical sense of Betz, is applied to wind energy concentrator systems in order to determine their theoretical power limits. It is shown that the power coefficient based on frontal area for any concentrator system can be written in a form which is very similar to the form of a free turbine. The difference lies in the different functional relationships between the wind velocity at the rotor disk and the wind velocity behind the system. This functional relationship is called the system function. Due to the different system functions, the maxima of the power coefficients are different. It is shown that the system function is favorable for the diffuser augmented concentrator system and that it is unfavorable for the tipvane system and the tornado system.

  18. Prony Analysis for Power System Transient Harmonics

    NASA Astrophysics Data System (ADS)

    Qi, Li; Qian, Lewei; Woodruff, Stephen; Cartes, David

    2007-12-01

    Proliferation of nonlinear loads in power systems has increased harmonic pollution and deteriorated power quality. Not required to have prior knowledge of existing harmonics, Prony analysis detects frequencies, magnitudes, phases, and especially damping factors of exponential decaying or growing transient harmonics. In this paper, Prony analysis is implemented to supervise power system transient harmonics, or time-varying harmonics. Further, to improve power quality when transient harmonics appear, the dominant harmonics identified from Prony analysis are used as the harmonic reference for harmonic selective active filters. Simulation results of two test systems during transformer energizing and induction motor starting confirm the effectiveness of the Prony analysis in supervising and canceling power system transient harmonics.

  19. Hybrid power systems for autonomous MEMS

    NASA Astrophysics Data System (ADS)

    Bennett, Daniel M.; Selfridge, Richard H.; Humble, Paul; Harb, John N.

    2001-08-01

    This paper describes the design of a hybrid power system for use with autonomous MEMS and other microdevices. This hybrid power system includes energy conversion and storage along with an electronic system for managing the collection and distribution of power. It offers flexibility and longevity in a compact package. The hybrid power system couples a silicon solar cell with a microbattery specially designed for MEMS applications. We have designed a control/interface charging circuit to be compatible with a MEMS duty cycle. The design permits short pulses of 'high' power while taking care to avoid excessive charging or discharging of the battery. Charging is carefully controlled to provide a balance between acceptably small charging times and a charging profile that extends battery life. Our report describes the charging of our Ni/Zn microbatteries using solar cells. To date we have demonstrated thousands of charge/discharge cycles of a simulated MEMS duty cycle.

  20. Nuclear power propulsion system for spacecraft

    NASA Astrophysics Data System (ADS)

    Koroteev, A. S.; Oshev, Yu. A.; Popov, S. A.; Karevsky, A. V.; Solodukhin, A. Ye.; Zakharenkov, L. E.; Semenkin, A. V.

    2015-12-01

    The proposed designs of high-power space tugs that utilize solar or nuclear energy to power an electric jet engine are reviewed. The conceptual design of a nuclear power propulsion system (NPPS) is described; its structural diagram, gas circuit, and electric diagram are discussed. The NPPS incorporates a nuclear reactor, a thermal-to-electric energy conversion system, a system for the conversion and distribution of electric energy, and an electric propulsion system. Two criterion parameters were chosen in the considered NPPS design: the temperature of gaseous working medium at the nuclear reactor outlet and the rotor speed of turboalternators. The maintenance of these parameters at a given level guarantees that the needed electric voltage is generated and allows for power mode control. The processes of startup/shutdown and increasing/reducing the power, the principles of distribution of electric energy over loads, and the probable emergencies for the proposed NPPS design are discussed.