WorldWideScience

Sample records for watt power range

  1. Thermal Design for 5 Watt Power LED

    Institute of Scientific and Technical Information of China (English)

    WANG Cai-feng; NIU Ping-juan; GAO Tie-cheng; YANG Guang-hua; FU Xian-song

    2009-01-01

    With the consideration of the thermal management and heat sink requirements, a cooling device is designed and the thermal resistance of this device is calculated with a single 5 W power LED. The thermal design of a single 5 W power LED is reasonable, effective and the result has been simulated. This design also instruct other power LEDs' thermal design. Provided is a reliable and effective method for the design of power LED illumination lamps and lanterns.

  2. ONE WATT 30-DAY PLUS POWER SOURCES.

    Science.gov (United States)

    Four alternative power sources are considered as replacements for the mercury cells which are currently used. Of these, silver-zinc batteries can...percent. Hydrogen-air and hydrogen-oxygen fuel cells offer no advantage over present power sources . Solar cell-battery power systems are advisable for some applications. (Author)

  3. 300-Watt Power Source Development at the Jet Propulsion Laboratory

    Science.gov (United States)

    Valdez, Thomas I.

    2005-01-01

    This viewgraph presentation reviews the JPL program to develop a 300 Watt direct methanol fuel cell. The immediate use of the fuel cell is to power test instrumentation on armored vehicles. It reviews the challenges, the system design and the system demonstration.

  4. 500 Watt Diesel Fueled TPV Portable Power Supply

    Science.gov (United States)

    Horne, W. E.; Morgan, M. D.; Sundaram, V. S.; Butcher, T.

    2003-01-01

    A test-bed 500 watt diesel fueled thermophotovoltaic (TPV) portable power supply is described. The goal of the design is a compact, rugged field portable unit weighing less than 15 pounds without fuel. The conversion efficiency goal is set at 15% fuel energy to electric energy delivered to an external load at 24 volts. A burner/recuperator system has been developed to meet the objectives of high combustion air preheat temperatures with a compact heat exchanger, low excess air operation, and high convective heat transfer rates to the silicon carbide emitter surface. The burner incorporates a air blast atomizer with 100% of the combustion air passing through the nozzle. Designed firing rate of 2900 watts at 0.07 gallons of oil per hour. This incorporates a single air supply dc motor/fan set and avoids the need for a system air compressor. The recuperator consists of three annular, concentric laminar flow passages. Heat from the combustion of the diesel fuel is both radiantly and convectively coupled to the inside wall of a cylindrical silicon carbide emitter. The outer wall of the emitter then radiates blackbody energy at the design temperature of 1400°C. The cylindrical emitter is enclosed in a quartz envelope that separates it from the photovoltaic (PV) cells. Spectral control is accomplished by a resonant mesh IR band-pass filter placed between the emitter and the PV array. The narrow band of energy transmitted by the filter is intercepted and converted to electricity by an array of GaSb PV cells. The array consists of 216 1-cm × 1-cm GaSb cells arranged into series and parallel arrays. An array of heat pipes couple the PV cell arrays to a heat exchanger which is cooled by forced air convection. A brief status of the key TPV technologies is presented followed by data characterizing the performance of the 500 watt TPV system.

  5. Microcombustor-thermoelectric power generator for 10-50 watt applications

    Science.gov (United States)

    Marshall, Daniel S.; Cho, Steve T.

    2010-04-01

    Fuel-based portable power systems, including combustion and fuel cell systems, take advantage of the 80x higher energy density of fuel over lithium battery technologies and offer the potential for much higher energy density power sources - especially for long-duration applications, such as unattended sensors. Miniaturization of fuel-based systems poses significant challenges, including processing of fuel in small channels, catalyst poisoning, and coke and soot formation. Recent advances in micro-miniature combustors in the 200Watt thermal range have enabled the development of small power sources that use the chemical energy of heavy fuel to drive thermal-to-electric converters for portable applications. CUBE Technology has developed compact Micro-Furnace combustors that efficiently deliver high-quality heat to optimized thermal-to-electric power converters, such as advanced thermoelectric power modules and Stirling motors, for portable power generation at the 10-50Watt scale. Key innovations include a compact gas-gas recuperator, innovative heavy fuel processing, coke- & soot-free operation, and combustor optimization for low balance-of-plant power use while operating at full throttle. This combustor enables the development of robust, high energy density, miniature power sources for portable applications.

  6. A 1-Watt Ku-Band Power Amplifier MMIC Using Cost-Effective Organic SMD Package

    NARCIS (Netherlands)

    Bessemoulin, A.; Parisot, M.; Quentin, P.; Saboureau, C.; Heijningen, M. van; Priday, J.

    2004-01-01

    This paper presents the design and performance of a compact 1-Watt Ku-band power amplifier MMIC implemented in a novel microwave organic power package, compatible with SMD assembly lines. Due to the use of simple materials, like RO4003 substrate and copper, it allows significant cost reduction for

  7. A 1-Watt Ku-Band Power Amplifier MMIC Using Cost-Effective Organic SMD Package

    NARCIS (Netherlands)

    Bessemoulin, A.; Parisot, M.; Quentin, P.; Saboureau, C.; Heijningen, M. van; Priday, J.

    2004-01-01

    This paper presents the design and performance of a compact 1-Watt Ku-band power amplifier MMIC implemented in a novel microwave organic power package, compatible with SMD assembly lines. Due to the use of simple materials, like RO4003 substrate and copper, it allows significant cost reduction for R

  8. 5 Watt GaN HEMT Power Amplifier for LTE

    Directory of Open Access Journals (Sweden)

    K. Niotaki

    2014-04-01

    Full Text Available This work presents the design and implementation of a stand-alone linear power amplifier at 2.4 GHz with high output power. A GaN HEMT transistor is selected for the design and implementation of the power amplifier. The device exhibits a gain of 11.7 dB and a drain efficiency of 39% for an output power of 36.7 dBm at 2.4 GHz for an input power of 25dBm. The carrier to intermodulation ratio is better than 25 dB for a two tone input signal of 25 dBm of total power and a spacing of 5 MHz. The fabricated device is also tested with LTE input signals of different bandwidths (5MHz to 20MHz.

  9. Low-cost high-efficient 10-Watt X-band high-power amplifier

    NARCIS (Netherlands)

    Bent, G. van der; Hek, A.P. de; Bessemoulin, A.; Vliet, F.E. van

    2009-01-01

    A high power X-band amplifier with an output power over 10 Watts and a Power Added Efficiency (PAE) in excess of 40 percent has been developed. The design was fabricated in a 0.25 μm pHEMT GaAs process (WIN Semiconductor PP25-01). The small die area in combination with a 6-inch wafer technology prov

  10. Design of multihundred-watt dynamic isotope power system for robotic space missions

    Science.gov (United States)

    Bents, D. J.; Geng, S. M.; Schreiber, J. G.; Withrow, C. A.; Schmitz, P. C.; McComas, T. J.

    The design of a multihundred-watt dynamic isotope power system (DIPS) based on the US Department of Energy (DOE) general-purpose heat source (GPHS) and small (multihundred-watt) free-piston Stirling engine (FPSE) is described as a potential lower cost alternative to radioisotope thermoelectric generators (RTGs). The design is targeted at the power needs of future unmanned deep space and planetary surface exploration missions. Since the competitive potential of FPSE as an isotope convertor was first identified, work has focused on the feasibility of directly integrating GPHS with the Stirling heater head. Thermal modeling of various radiatively coupled heat source/heater head geometries has been performed using data furnished by the developers of FPSE and GPHS. The analysis indicates that, for the 1050 K heater head configurations considered, GPHS fuel clad temperatures remain safe operating limits under all conditions including shutdown of one engine on a twin engine unit. Based on these results, preliminary characterizations of multihundred-watt units have been established. They indicate that, per electrical watt, the GPHS/small Stirling DIPS will be roughly equivalent to MOD RTG in size and mass but will require about a third the amount of isotope fuel.

  11. Quantum transport with long-range steps on Watts-Strogatz networks

    Science.gov (United States)

    Wang, Yan; Xu, Xin-Jian

    2016-07-01

    We study transport dynamics of quantum systems with long-range steps on the Watts-Strogatz network (WSN) which is generated by rewiring links of the regular ring. First, we probe physical systems modeled by the discrete nonlinear schrödinger (DNLS) equation. Using the localized initial condition, we compute the time-averaged occupation probability of the initial site, which is related to the nonlinearity, the long-range steps and rewiring links. Self-trapping transitions occur at large (small) nonlinear parameters for coupling ɛ=-1 (1), as long-range interactions are intensified. The structure disorder induced by random rewiring, however, has dual effects for ɛ=-1 and inhibits the self-trapping behavior for ɛ=1. Second, we investigate continuous-time quantum walks (CTQW) on the regular ring ruled by the discrete linear schrödinger (DLS) equation. It is found that only the presence of the long-range steps does not affect the efficiency of the coherent exciton transport, while only the allowance of random rewiring enhances the partial localization. If both factors are considered simultaneously, localization is greatly strengthened, and the transport becomes worse.

  12. Design of a 300-Watt Isolated Power Supply with Minimized Circuit Input-to-Output Parasitic Capacitance

    DEFF Research Database (Denmark)

    Nguyen-Duy, Khiem; Petersen, Lars Press; Knott, Arnold;

    2014-01-01

    This paper presents the design of a 300-Watt isolated power supply for MOS gate driver circuit in medium and high voltage applications. The key feature of the developed power supply is having a very low circuit input-to-output parasitic capacitance, thus maximizing its noise immunity. This makes ...

  13. Time Delay and Long-Range Connection Induced Synchronization Transitions in Newman-Watts Small-World Neuronal Networks

    Science.gov (United States)

    Qian, Yu

    2014-01-01

    The synchronization transitions in Newman-Watts small-world neuronal networks (SWNNs) induced by time delay and long-range connection (LRC) probability have been investigated by synchronization parameter and space-time plots. Four distinct parameter regions, that is, asynchronous region, transition region, synchronous region, and oscillatory region have been discovered at certain LRC probability as time delay is increased. Interestingly, desynchronization is observed in oscillatory region. More importantly, we consider the spatiotemporal patterns obtained in delayed Newman-Watts SWNNs are the competition results between long-range drivings (LRDs) and neighboring interactions. In addition, for moderate time delay, the synchronization of neuronal network can be enhanced remarkably by increasing LRC probability. Furthermore, lag synchronization has been found between weak synchronization and complete synchronization as LRC probability is a little less than 1.0. Finally, the two necessary conditions, moderate time delay and large numbers of LRCs, are exposed explicitly for synchronization in delayed Newman-Watts SWNNs. PMID:24810595

  14. Time delay and long-range connection induced synchronization transitions in Newman-Watts small-world neuronal networks.

    Science.gov (United States)

    Qian, Yu

    2014-01-01

    The synchronization transitions in Newman-Watts small-world neuronal networks (SWNNs) induced by time delay τ and long-range connection (LRC) probability P have been investigated by synchronization parameter and space-time plots. Four distinct parameter regions, that is, asynchronous region, transition region, synchronous region, and oscillatory region have been discovered at certain LRC probability P = 1.0 as time delay is increased. Interestingly, desynchronization is observed in oscillatory region. More importantly, we consider the spatiotemporal patterns obtained in delayed Newman-Watts SWNNs are the competition results between long-range drivings (LRDs) and neighboring interactions. In addition, for moderate time delay, the synchronization of neuronal network can be enhanced remarkably by increasing LRC probability. Furthermore, lag synchronization has been found between weak synchronization and complete synchronization as LRC probability P is a little less than 1.0. Finally, the two necessary conditions, moderate time delay and large numbers of LRCs, are exposed explicitly for synchronization in delayed Newman-Watts SWNNs.

  15. Design of a 300-Watt Isolated Power Supply for Ultra-Fast Tracking Converters

    DEFF Research Database (Denmark)

    Nguyen-Duy, Khiem; Ouyang, Ziwei; Petersen, Lars Press;

    2015-01-01

    that an overall circuit input-to-output parasitic capacitance of 10 pF in a 300 W prototype can be achieved. The circuit input-to-output capacitance per watt is therefore 30 times lower than that of existing approaches. A mathematical model of the inter-winding capacitance of the proposed transformer, circuit......This paper presents the design of a medium-powerrating isolated power supply for ultra-fast tracking converters and MOS-gate driver circuits in medium and high voltage applications. The key feature of the design is its very low circuit input-to-output parasitic capacitance, which maximizes its...... noise immunity from noise due to fast changes in voltage. The converter is a voltage-controlled current source, utilizing a transformer with extremely low inter-winding parasitic capacitance, which is achieved by separating the windings by a significant distance. Experimental measurements show...

  16. A compact broadband high efficient X-band 9-watt PHEMT MMIC high-power amplifier for phased array radar applications

    NARCIS (Netherlands)

    Hek, A.P. de; Hunneman, P.A.H.; Demmler, M.; Hulsmann, A.

    1999-01-01

    ln this paper the development and measurement results of a compact broadband 9-Watt high efficient X-band high-power amplifier are discussed. The described amplifier has the following state-of-the art performance: an average ouput power of 9 Watt, a gain of 20 dB and an average Power Added

  17. A compact broadband high efficient X-band 9-watt PHEMT MMIC high-power amplifier for phased array radar applications

    NARCIS (Netherlands)

    Hek, A.P. de; Hunneman, P.A.H.; Demmler, M.; Hulsmann, A.

    1999-01-01

    ln this paper the development and measurement results of a compact broadband 9-Watt high efficient X-band high-power amplifier are discussed. The described amplifier has the following state-of-the art performance: an average ouput power of 9 Watt, a gain of 20 dB and an average Power Added Efficienc

  18. Conceptual Design of 500 watt portable thermophotovoltaic power supply using JP-8 fuel

    Science.gov (United States)

    DeBellis, Crispin L.; Scotto, Mark V.; Scoles, Stephen W.; Fraas, Lewis

    1997-03-01

    Babcock & Wilcox (B&W) and JX Crystals (JXC) have developed an innovative design for a compact, 500 watt net electric (We), 24-VDC thermophotovoltaic (TPV) power supply using JP-8 fuel. As currently envisioned, the TPV generator will be approximately 20 cm (8 inches) in diameter and 50 cm (20 inches) high, not including a fuel tank and controls. The total system may weigh as little as 7.5 kg (16.5 lb) without fuel. This system will achieve high efficiency and high power density relative to its size through the use of low bandgap gallium antimonide (GaSb) PV cells and a matched emitter. A thermally integrated fuel vaporizer and recuperator will boost system efficiency by transferring the unused energy in the exhaust stream to the incoming fuel and combustion air. At rated conditions and 500 We output, the system is expected to have an overall efficiency of 8% to 10%. This paper examines the trade-offs between system efficiency, power density, and weight required in the selection and configuration of the major system components.

  19. Component development for 500 watt diesel fueled portable thermophotovoltaic (TPV) power supply

    Science.gov (United States)

    DeBellis, Crispin L.; Scotto, Mark V.; Fraas, Lewis; Samaras, John; Watson, Ron C.; Scoles, Stephen W.

    1999-03-01

    McDermott Technology, Inc. (MTI) and JX Crystals have developed an innovative design for a compact, 500-watt, thermophotovoltaic (TPV) power supply using diesel fuel. Under a contract with the Defense Advanced Research Projects Agency (DARPA) and managed by the U.S. Army Communications-Electronics Command (CECOM), this design is being reduced to hardware. Prototypes of the two main subsystems, the power converter assembly (PCA) and the burner/emitter/recuperator (BER), have been designed, fabricated, and tested. The PCA uses low-band-gap gallium antimonide (GaSb) photovoltaic (PV) cells for high efficiency and power density. The prototype PCA will be air cooled for system simplicity and portability. However, initial testing was performed on a water-cooled PCA. The BER uses a thermal vaporizer to produce a stable, high-intensity, low-emissions combustion zone inside an impervious emitter. A thermally integrated recuperator is utilized to boost system efficiency by transferring the unused energy in the exhaust stream to the incoming fuel and combustion air. This paper describes the design, testing and performance of the first-generation PCA and BER along with model predictions used for design and evaluation.

  20. Narrow linewidth picosecond UV pulsed laser with mega-watt peak power.

    Science.gov (United States)

    Huang, Chunning; Deibele, Craig; Liu, Yun

    2013-04-08

    We demonstrate a master oscillator power amplifier (MOPA) burst mode laser system that generates 66 ps/402.5 MHz pulses with mega-watt peak power at 355 nm. The seed laser consists of a single frequency fiber laser (linewidth picosecond pulse generator, and a fiber based preamplifier. A very high extinction ratio (45 dB) has been achieved by using an adaptive bias control of the EOM. The multi-stage Nd:YAG amplifier system allows a uniformly temporal shaping of the macropulse with a tunable pulse duration. The light output from the amplifier is converted to 355 nm, and over 1 MW peak power is obtained when the laser is operating in a 5-μs/10-Hz macropulse mode. The laser output has a transform-limited spectrum with a very narrow linewidth of individual longitudinal modes. The immediate application of the laser system is the laser-assisted hydrogen ion beam stripping for the Spallation Neutron Source (SNS).

  1. Development and Demonstration of a 25 Watt Thermophotovoltaic Power Source for a Hybrid Power System

    Science.gov (United States)

    Doyle, Edward; Shukla, Kailash; Metcalfe, Christopher

    2001-01-01

    The development of a propane-fueled, 25 W thermophotovoltaic (TPV) power source for use in a hybrid power system is described. The TPV power source uses a platinum emitting surface with an anti-reflective coating to radiate to gallium antimonide photocells, which converts the radiation to electric power. The development program started with the design and fabrication of an engineering prototype system. This was used as a component development vehicle to develop the technologies for the various components. A 25 W demonstration prototype was then designed and fabricated using the most advanced component approaches. The designs and test results from this development program are discussed.

  2. A new Cu(TiBN x ) alloy film for boosting the per-watt illuminance of high power LEDs

    Science.gov (United States)

    Lin, Chon-Hsin

    2017-01-01

    In this study, a new Cu(TiBN x ) alloy film has been explored and utilized as a flexible heat dissipation layer for the substrate of high power LEDs to boost their per-watt illuminance by reducing the thermal resistance and increasing the thermal conductivity of the substrate. The new film is a Cu-alloy seed layer fabricated by co-sputtering Cu and TiB in an N2 atmosphere on a Ta/polyimide (Ta/PI) substrate. The film was then annealed at 340 °C for 1 h without noticeable Cu oxide formation around the film-substrate interface. The new film exhibits low resistivity, high thermal conductivity and low thermal resistance, rendering a substantially higher per-watt illuminance for LEDs that utilize the film as their additional heat dissipation layer. The experimental results gained in the study appear to confirm the new Cu(TiBN x ) film as a good candidate material, at least, for boosting the per-watt illuminance of high power LEDs.

  3. Multi-Watt femtosecond optical parametric master oscillator power amplifier at 43 MHz.

    Science.gov (United States)

    Mörz, Florian; Steinle, Tobias; Steinmann, Andy; Giessen, Harald

    2015-09-07

    We present a high repetition rate mid-infrared optical parametric master oscillator power amplifier (MOPA) scheme, which is tunable from 1370 to 4120nm. Up to 4.3W average output power are generated at 1370nm, corresponding to a photon conversion efficiency of 78%. Bandwidths of 6 to 12nm with pulse durations between 250 and 400fs have been measured. Strong conversion saturation over the whole signal range is observed, resulting in excellent power stability. The system consists of a fiber-feedback optical parametric oscillator that seeds an optical parametric power amplifier. Both systems are pumped by the same Yb:KGW femtosecond oscillator.

  4. Difference between the maximum empirical and field measured peak Watt values of thermal power system under highly sufficient solar conditions

    Science.gov (United States)

    Elhussain, O. A.; Abdel-Magid, T. I. M.

    2016-08-01

    Mono-Crystalline solar cell module is experimentally conducted in Khartoum, Sudan to study the difference between maximum empirical value of peak Watt and maximum value of thermal power produced in field under highly sufficient solar conditions. Field measurements are recorded for incident solar radiation, produced voltage, current and temperature at several time intervals during sun shine period. The thermal power system has been calculated using fundamental principles of heat transfer. The study shows that solar power for considered module could not attain the empirical peak power irrespective to maximum value of direct incident solar radiation and maximum temperature gained. A loss of about 6% of power can be considered as the difference between field measurements and the manufacturer's indicated empirical value. Solar cell exhibits 94% efficiency in comparison with manufacturer's provided data, and is 3'% more efficient in thermal energy production than in electrical power extraction for hot-dry climate conditions.

  5. On-chip power-combining techniques for watt-level linear power amplifiers in 0.18 μm CMOS

    Science.gov (United States)

    Zhixiong, Ren; Kefeng, Zhang; Lanqi, Liu; Cong, Li; Xiaofei, Chen; Dongsheng, Liu; Zhenglin, Liu; Xuecheng, Zou

    2015-09-01

    Three linear CMOS power amplifiers (PAs) with high output power (more than watt-level output power) for high data-rate mobile applications are introduced. To realize watt-level output power, there are two 2.4 GHz PAs using an on-chip parallel combining transformer (PCT) and one 1.95 GHz PA using an on-chip series combining transformer (SCT) to combine output signals of multiple power stages. Furthermore, some linearization techniques including adaptive bias, diode linearizer, multi-gated transistors (MGTR) and the second harmonic control are applied in these PAs. Using the proposed power combiner, these three PAs are designed and fabricated in TSMC 0.18 μm RFCMOS process. According to the measurement results, the proposed two linear 2.4 GHz PAs achieve a gain of 33.2 dB and 34.3 dB, a maximum output power of 30.7 dBm and 29.4 dBm, with 29% and 31.3% of peak PAE, respectively. According to the simulation results, the presented linear 1.95 GHz PA achieves a gain of 37.5 dB, a maximum output power of 34.3 dBm with 36.3% of peak PAE. Project supported by the National Natural Science Foundation of China (No. 61076030).

  6. Watt and joule balances

    Science.gov (United States)

    Robinson, Ian A.

    2014-04-01

    time of the weighing and at the centre of gravity of the mass. The paper by Liard and his co-authors at NRC describes how they have made this essential measurement. The accuracy of the watt balance may also depend on the alignment of the apparatus. Two papers deal with this important issue. The first, by Sanchez and his co-authors at NRC, shows that their balance is insensitive to a range of alignments and concentrates on the essential alignments that contribute directly to the overall uncertainty of the apparatus. Thomas and his co-authors at LNE describe their technique for reducing uncertainties in their watt balance by aligning its coil in the field of the magnet to minimize both horizontal forces and torques about horizontal axes. The search for discrepancies between the results from watt balances has encouraged researchers to consider possible error mechanisms arising from the secondary electrical interactions between the coil of a watt balance and other parts of the apparatus. Researchers from INRIM have two such papers: one considering magnetic interactions and the other considering electrostatic interactions. It is essential that such investigations are carried out: both to prove that the problems are understood and for the guidance of those building the next generation of watt and joule balances. The next four papers describe aspects of the construction of watt balances. The BIPM watt balance group describe the principles behind their simultaneous measurement scheme for a watt balance. The balance that they are constructing can also be used in the conventional two-phase mode and their paper describes the relative advantages and disadvantages of the two modes of operation. In a watt balance there are some advantages to precise vertical movement of the coil. The METAS group describe the two mechanisms that they have tested to achieve such motion and give the reasons for the choice of mechanism for use in the balance that they are constructing. The KRISS watt

  7. Powering a Home with Just 25 Watts of Solar PV. Super-Efficient Appliances Can Enable Expanded Off-Grid Energy Service Using Small Solar Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Phadke, Amol A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Jacobson, Arne [Schatz Energy Research Center, Arcata, CA (United States); Park, Won Young [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lee, Ga Rick [Schatz Energy Research Center, Arcata, CA (United States); Alstone, Peter [Univ. of California, Berkeley, CA (United States); Khare, Amit [Schatz Energy Research Center, Arcata, CA (United States)

    2015-04-01

    Highly efficient direct current (DC) appliances have the potential to dramatically increase the affordability of off-grid solar power systems used for rural electrification in developing countries by reducing the size of the systems required. For example, the combined power requirement of a highly efficient color TV, four DC light emitting diode (LED) lamps, a mobile phone charger, and a radio is approximately 18 watts and can be supported by a small solar power system (at 27 watts peak, Wp). Price declines and efficiency advances in LED technology are already enabling rapidly increased use of small off-grid lighting systems in Africa and Asia. Similar progress is also possible for larger household-scale solar home systems that power appliances such as lights, TVs, fans, radios, and mobile phones. When super-efficient appliances are used, the total cost of solar home systems and their associated appliances can be reduced by as much as 50%. The results vary according to the appliances used with the system. These findings have critical relevance for efforts to provide modern energy services to the 1.2 billion people worldwide without access to the electrical grid and one billion more with unreliable access. However, policy and market support are needed to realize rapid adoption of super-efficient appliances.

  8. Preliminary systems-interaction results from the Digraph Matrix Analysis of the Watts Bar Nuclear Power Plant safety-injection systems

    Energy Technology Data Exchange (ETDEWEB)

    Sacks, I.J.; Ashmore, B.C.; Champney, J.M.; Alesso, H.P.

    1983-06-01

    This report provides preliminary results generated by a Digraph Matrix Analysis (DMA) for a Systems Interaction analysis performed on the Safety Injection System of the Tennessee Valley Authority Watts Bar Nuclear Power Plant. An overview of DMA is provided along with a brief description of the computer codes used in DMA.

  9. Preliminary systems-interaction results from the Digraph Matrix Analysis of the Watts Bar Nuclear Power Plant safety-injection systems

    Energy Technology Data Exchange (ETDEWEB)

    Sacks, I.J.; Ashmore, B.C.; Champney, J.M.; Alesso, H.P.

    1983-06-01

    This report provides preliminary results generated by a Digraph Matrix Analysis (DMA) for a Systems Interaction analysis performed on the Safety Injection System of the Tennessee Valley Authority Watts Bar Nuclear Power Plant. An overview of DMA is provided along with a brief description of the computer codes used in DMA.

  10. Researching new EUV pellicle films for source powers beyond 250 watts

    Science.gov (United States)

    Nasalevich, Maxim; van Zwol, Pieter Jan; Abegg, Erik; Voorthuijzen, Pim; Vles, David; Péter, Mária; van der Zande, Wim; Vermeulen, Hans

    2016-10-01

    In order to deploy EUV lithography as a high volume manufacturing technology an extreme control of reticle defectivity is required. Systematic defect printing is unaffordable. A potential solution being investigated for meeting the EUV reticle contamination control requirements is to utilize a suspended thin membrane (pellicle) mounted at a fixed distance in front of the reticle as a physical barrier against particles. Pellicles of the aspect ratios relevant for the scanner ( 11x14 cm2, 50 nm) that are based on polycrystalline silicon were produced and successful imaging runs were carried out. Investigations of pellicles using different materials continue to ensure having membranes capable of withstanding future high EUV source powers and to ensure larger EUV transmission values. The ideal requirements of the pellicle are: (i) maximum EUV transmission ideally above 90% single pass, (ii) chemical stability and (iii) thermo-mechanical resistance under EUV/H2. Since fulfilling all the requirements in one single layer is a challenge, different layer film architectures are proposed. This paper discusses such architectures, both silicon- and carbon-based. The base materials are complemented by nanometre thin coatings that increase IR absorption and thus enhance emissivity and that prevents oxidation of the base material occurring in high power EUV systems.

  11. A Liquid Hydrogen Cooler with a Cooling Capacity of 20 Watts Project

    Data.gov (United States)

    National Aeronautics and Space Administration — For the future spaceport and long-term storage of liquid hydrogen NASA requires cryocoolers that can provide cooling power in the range of 20 watts at 20 K. The...

  12. Large-Mode-Area Double-Cladding Photonic Crystal Fiber Laser in the Watt Range at 980 nm

    Institute of Scientific and Technical Information of China (English)

    LI Ping-Xue; ZHANG Xue-Xia; LIU Zhi; CHI Jun-Jie

    2011-01-01

    @@ We report on a quasi-three-level large-mode-area double-clad Yb-doped fiber laser that adopts a linear cavity consisting of a 0°fiber end and a cavity mirror.Two kinds of Yb-doped photonic crystal fiber(PCF) with different inner-clads (170 μm and 200μm) and absorption coefficients (4.5 dB/m and 3 dB/m) are used as the gain media.By optimizing the structure and elements of the cavity, maximum output powers of 1.24 W and 1.1 W were yielded with optical conversion efficiencies of 7.8% and 6.8% when the fiber lengths were 25 cm and 40 cm with 170μm and 200 μm inner-claddings, respectively.

  13. Analysis of Passive RF-DC Power Rectification and Harvesting Wireless RF Energy for Micro-watt Sensors

    Directory of Open Access Journals (Sweden)

    Antwi Nimo

    2015-04-01

    Full Text Available In this paper, analytical modeling of passive rectifying circuits and the harvesting of electromagnetic (EM power from intentionally generated as well as from ubiquitous sources are presented. The presented model is based on the linearization of rectifying circuits. The model provides an accurate method of determining the output characteristics of rectifying circuits. The model was verified with Advance Design System (ADS Harmonic balance (HB simulations and measurements. The results from the presented model were in agreement with simulations and measurements. Consequently design considerations and trade-off of radio frequency (RF harvesters are discussed. To verify the exploitation of ambient RF power sources for operation of sensors, a dual-band antenna with a size of ~λ/4 at 900MHz and a passive dual-band rectifier that is able to power a commercial Thermo-Hygrometer requiring ~1.3V and 0.5MΩ from a global system for mobile communications (GSM base station is demonstrated. The RF power delivered by the receiving dual-band antenna at a distance of about 110 m from the GSM base station ranges from -27 dBm to -50 dBm from the various GSM frequency bands. Additionally, wireless range measurements of the RF harvesters in the industrial, scientific and medical (ISM band 868MHz is presented at indoor conditions.

  14. Duration-tunable picosecond source at 560  nm with watt-level average power.

    Science.gov (United States)

    Runcorn, T H; Murray, R T; Kelleher, E J R; Popov, S V; Taylor, J R

    2015-07-01

    A pulse source at 560 nm that is tunable in duration between 50 ps and 2.7 ns with >1  W of average power and near diffraction-limited beam quality is demonstrated. The source is based on efficient (up to 50%) second-harmonic generation in a periodically poled lithium tantalate crystal of a linearly polarized fiber-integrated Raman amplifier operating at 1120 nm. A duration-tunable ytterbium master-oscillator power-fiber amplifier is used to pulse-pump the Raman amplifier, which is seeded by a continuous-wave distributed-feedback laser diode at 1120 nm. The performance of the system using two different master oscillator schemes is compared. A pulse energy of up to 765 nJ is achieved with a conversion efficiency of 25% from the ytterbium fiber pump, demonstrating a compact and turn-key architecture for obtaining high peak-power radiation at 560 nm.

  15. 10 Watts Double-Cladding Fiber Laser

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Considering the wavelength characteristics of the pump high-power laser diode, a modified Fabry-Perot fiber laser resonator is designed. And a fiber laser with more than 10Watts output, near diffraction-limited and operating in the 1110nm region is developed.

  16. Makahiki+WattDepot

    DEFF Research Database (Denmark)

    Johnson, Philip M.; Xu, Yongwen; Brewer, Robert S.;

    2013-01-01

    Satisfying the radically different requirements and operating assumptions of the next generation smart grid requires new kinds of software that enable research and experimentation into the ways that electrical energy production and consumption can be collected, analyzed, visualized, and provided...... to consumers. Since 2009, we have been designing, implementing, and evaluating an open source software "stack" to facilitate this research. This software stack consists of two custom systems called WattDepot and Makahiki, along with the open source components they rely upon (Java, Restlet, Postgres, Python...

  17. 基于TCC081C的多功能单相载波电能表%Multifunction Single-phase Power Line Carrier Watt-hour Meter Based on TCC081C

    Institute of Scientific and Technical Information of China (English)

    陈斯; 杨增汪; 戴新宇

    2012-01-01

    A low power, low cost single-phase power line carrier watt-hour meter was designed based on the special power line carrier chip TCC081C. Energy measurement part adopts RN8209 anti-steal special energy measurement chip, micro controller using NEC u,78F0525 and peripheral circuits. The designed watt-hour meter can realize timesharing accounting, need quantity measurement, anti-steal and power line carrier communication and other functions. Test results show that the design of watt-hour meter in accuracy reaches national standard 0.5s level standard requirements,current power consumption is 10u,A,when system is power down, electrostatic discharge immunity is 16kV.%基于专用的载波通信芯片TCC081C设计了一种低功耗、低成本单相载波电能表.计量部分采用RN8209防窃电专用电能计量芯片,微控制器采用NEC μ78F0525及其外围电路,实现分时计费、需量计量、防窃电、载波通讯等多种功能.测试结果显示所设计的电能表在精度上达到国标0.Ss级标准的要求,掉电工作时电流消耗10μA,静电放电抗扰度达到16kV.

  18. 30-Hz-linewidth Watt output power 1.65-$\\mu$m continuous-wave singly resonant optical parametric oscillator

    CERN Document Server

    LY, Aliou; Bretenaker, Fabien

    2016-01-01

    We build a 1-Watt cw singly resonant optical parametric oscillator operating at an idler wavelength of 1.65-$\\mu$m for application to quantum interfaces. The non resonant idler is frequency stabilized by side-fringe locking on a relatively high-finesse Fabry-Perot cavity, and the influence of intensity noise is carefully analyzed. A relative linewidth down to the sub-kHz level (about 30 Hz over 2 s) is achieved. A very good long term stability is obtained for both frequency and intensity.

  19. Wide Output Range Power Processing Unit for Electric Propulsion Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A power supply concept capable of operation over 25:1 and 64:1 impedance ranges at full power has been successfully demonstrated in our Phase I effort at...

  20. Microwave beam power transmission at an arbitrary range

    Science.gov (United States)

    Pinero, L. R.; Christian, J. L., Jr.; Acosta, R. J.

    1992-01-01

    The power transfer efficiency between two circular apertures at an arbitrary range is obtained numerically. The apertures can have generally different sizes and arbitrary taper illuminations. The effects of distance and taper illumination on the transmission efficiency are investigated for equal size apertures. The result shows that microwave beam power is more effective at close ranges, namely distances less than 2D(exp 2)/lambda. Also shown was the power transfer efficiency increase with taper illumination for close range distances. A computer program was developed for calculating the power transfer efficiency at an arbitrary range.

  1. Twenty-watt average output power, picosecond thin-rod Yb:YAG regenerative chirped pulse amplifier with 200 mJ pulse energy

    OpenAIRE

    MATSUBARA, Shinichi; TANAKA, Motoharu; TAKAMA, Masaki; KAWATO, Sakae; Kobayashi, Takao

    2008-01-01

    A high-average power, laser-diode-pumped, picosecond-pulse regenerative chirpedpulse amplifier was developed by using the thin-rod Yb:YAG laser architecture. An averageoutput power of 20 W was achieved at a repetition rate of 100 kHz with an output pulse width of 2ps.

  2. Coil motion effects in watt balances: a theoretical check

    Science.gov (United States)

    Li, Shisong; Schlamminger, Stephan; Haddad, Darine; Seifert, Frank; Chao, Leon; Pratt, Jon R.

    2016-04-01

    A watt balance is a precision apparatus for the measurement of the Planck constant that has been proposed as a primary method for realizing the unit of mass in a revised International System of Units. In contrast to an ampere balance, which was historically used to realize the unit of current in terms of the kilogram, the watt balance relates electrical and mechanical units through a virtual power measurement and has far greater precision. However, because the virtual power measurement requires the execution of a prescribed motion of a coil in a fixed magnetic field, systematic errors introduced by horizontal and rotational deviations of the coil from its prescribed path will compromise the accuracy. We model these potential errors using an analysis that accounts for the fringing field in the magnet, creating a framework for assessing the impact of this class of errors on the uncertainty of watt balance results.

  3. One watt gallium arsenide class-E power amplifier with a thin-film bulk acoustic resonator filter embedded in the output network

    Directory of Open Access Journals (Sweden)

    Kyle Holzer

    2015-05-01

    Full Text Available Integration of a class-E power amplifier (PA and a thin-film bulk acoustic wave resonator (FBAR filter is shown to provide high power added efficiency in addition to superior out-of-band spectrum suppression. A discrete gallium arsenide pseudomorphic high-electron-mobility transistor is implemented to operate as a class-E amplifier from 2496 to 2690 MHz. The ACPF7041 compact bandpass FBAR filter is incorporated to replace the resonant LC tank in a traditional class-E PA. To reduce drain voltage stress, the supply choke is replaced by a finite inductance. The fabricated PA provides up to 1 W of output power with a peak power added efficiency (PAE of 58%. The improved out-of-band spectrum filtering is compared to a traditional class-E with discrete LC resonant filtering. Such PAs can be combined with linearisation techniques to reduce out-of-band emissions.

  4. Wide Output Range Power Processing Unit for Electric Propulsion Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Hall thrusters can be operated over a wide range of specific impulse while maintaining high efficiency. However S/C power system constraints on electric propulsion...

  5. Recent progress in mid-range wireless power transfer

    OpenAIRE

    Lee, CK; Hui, RSY; Zhong, W

    2012-01-01

    This is a review paper describing recent progress of mid-range applications of wireless power transfer. Starting from Tesla's principles of wireless power transfer a century ago, it outlines magneto-inductive research activities in the last decade on wireless power transfer with the transmission distance in the order of or greater than the coil dimension. It covers the basic characteristics of 2-coil systems, 4-coil systems, systems with relay resonators and the wireless domino-resonator syst...

  6. Designing Intervention Studies: Selected Populations, Range Restrictions, and Statistical Power

    Science.gov (United States)

    Miciak, Jeremy; Taylor, W. Pat; Stuebing, Karla K.; Fletcher, Jack M.; Vaughn, Sharon

    2016-01-01

    An appropriate estimate of statistical power is critical for the design of intervention studies. Although the inclusion of a pretest covariate in the test of the primary outcome can increase statistical power, samples selected on the basis of pretest performance may demonstrate range restriction on the selection measure and other correlated…

  7. Middle range wireless power transfer systems with multiple resonators

    Institute of Scientific and Technical Information of China (English)

    陈新; 张桂香

    2015-01-01

    The equivalent two-port network model of a middle range wireless power transfer (WPT) system was presented based on strongly coupled multiple resonators. The key parameters of the WPT system include self-inductance, resistance, parasitic capacitance, mutual inductance and S-parameters of coils & resonators were analyzed. The impedance matching method was used to optimize load power and transmission efficiency of the multi-resonator WPT system, and the impedance matching method was realized through adjusting the distances between the coils and resonators. Experiments show that the impedance matching method can effectively improve load power and transmission efficiency for middle range wireless power transfer systems with multiple resonators, at distances up to 3 times the coil radius with efficiency more than 70% and load power also close to 3.5 W.

  8. Ultra-low-power short-range radios

    CERN Document Server

    Chandrakasan, Anantha

    2015-01-01

    This book explores the design of ultra-low-power radio-frequency integrated circuits (RFICs), with communication distances ranging from a few centimeters to a few meters. Such radios have unique challenges compared to longer-range, higher-powered systems. As a result, many different applications are covered, ranging from body-area networks to transcutaneous implant communications and Internet-of-Things devices. A mix of introductory and cutting-edge design techniques and architectures which facilitate each of these applications are discussed in detail. Specifically, this book covers:.

  9. Systems interaction results from the digraph matrix analysis of the Watts Bar Nuclear Power Plant high pressure safety injection systems. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Sacks, I.J.; Ashmore, B.C.; Alesso, H.P.

    1983-07-01

    Spatial and functional coupling (including human actions) of nuclear power plant systems that lead to interdependencies are called Systems Interactions. At present, the US Nuclear Regulatory Commission (NRC) is investigating ways of integrating a systems interactions study with existing Probabilistic Risk Assessment efforts. One approach is based on graph-theoretic methods utilizing matrix representations of logic diagrams called Digraph Matrix Analysis (DMA). The objective in this report is to demonstrate the capabilities of Digraph Matrix Analysis to model an accident sequence (including front-line systems, support systems and human actions) as a continuous, well-integrated logic model in order to identify and evaluate functional systems interactions. The selected accident sequence, loss of high pressure safety injection during a LOCA, was modeled and qualitative and quantitative comparisons were made to the Reactor Safety Study (WASH 1400) and other studies.

  10. Systems interaction results from the digraph matrix analysis of the Watts Bar Nuclear Power Plant high pressure safety injection systems. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Sacks, I.J.; Ashmore, B.C.; Alesso, H.P.

    1983-07-01

    Spatial and functional coupling of nuclear power plant systems that lead to interdependencies are called Systems Interactions. At present, the US Nuclear Regulatory Commission (NRC) is investigating ways of integrating a systems interactions study with existing Probabilistic Risk Assessment efforts. One approach is based on graph-theoretic methods utilizing matrix representations of logic diagrams called Digraph Matrix Analysis (DMA). The objective in this report is to demonstrate the capabilities of Digraph Matrix Analysis to model an accident sequence (including front line systems, support systems and human actions) as a continuous, well-integrated logic model in order to identify and evaluate functional systems interactions. The selected accident sequence, loss of high pressure safety injection during an S1 LOCA, was modeled and qualitative and quantitative comparisons were made to WASH 1400 aand other studies.

  11. Magnetic metamaterial superlens for increased range wireless power transfer.

    Science.gov (United States)

    Lipworth, Guy; Ensworth, Joshua; Seetharam, Kushal; Huang, Da; Lee, Jae Seung; Schmalenberg, Paul; Nomura, Tsuyoshi; Reynolds, Matthew S; Smith, David R; Urzhumov, Yaroslav

    2014-01-10

    The ability to wirelessly power electrical devices is becoming of greater urgency as a component of energy conservation and sustainability efforts. Due to health and safety concerns, most wireless power transfer (WPT) schemes utilize very low frequency, quasi-static, magnetic fields; power transfer occurs via magneto-inductive (MI) coupling between conducting loops serving as transmitter and receiver. At the "long range" regime - referring to distances larger than the diameter of the largest loop - WPT efficiency in free space falls off as (1/d)(6); power loss quickly approaches 100% and limits practical implementations of WPT to relatively tight distances between power source and device. A "superlens", however, can concentrate the magnetic near fields of a source. Here, we demonstrate the impact of a magnetic metamaterial (MM) superlens on long-range near-field WPT, quantitatively confirming in simulation and measurement at 13-16 MHz the conditions under which the superlens can enhance power transfer efficiency compared to the lens-less free-space system.

  12. Scaling range of power laws that originate from fluctuation analysis.

    Science.gov (United States)

    Grech, Dariusz; Mazur, Zygmunt

    2013-05-01

    We extend our previous study of scaling range properties performed for detrended fluctuation analysis (DFA) [Physica A 392, 2384 (2013)] to other techniques of fluctuation analysis (FA). The new technique, called modified detrended moving average analysis (MDMA), is introduced, and its scaling range properties are examined and compared with those of detrended moving average analysis (DMA) and DFA. It is shown that contrary to DFA, DMA and MDMA techniques exhibit power law dependence of the scaling range with respect to the length of the searched signal and with respect to the accuracy R^{2} of the fit to the considered scaling law imposed by DMA or MDMA methods. This power law dependence is satisfied for both uncorrelated and autocorrelated data. We find also a simple generalization of this power law relation for series with a different level of autocorrelations measured in terms of the Hurst exponent. Basic relations between scaling ranges for different techniques are also discussed. Our findings should be particularly useful for local FA in, e.g., econophysics, finances, or physiology, where the huge number of short time series has to be examined at once and wherever the preliminary check of the scaling range regime for each of the series separately is neither effective nor possible.

  13. Low Power, Wide Dynamic Range Carbon Nanotube Vacuum Gauges

    Science.gov (United States)

    Kaul, Anupama B.; Manohara, Harish M.

    2008-01-01

    This slide presentation presents carbon nanotube vacuum pressure sensor gauges that operate at low power and exhibit a wide-dynamic range based on microelectromechanical systems (MEMS) technology. The fabrication facility, and the formation process are shown. Pressure sensitivity was found to increase rapidly as the bias power was increased. In addition, by etching part of the thermal SiO2 beneath the tubes and minimizing heat conduction through the substrate, pressure sensitivity was extended toward lower pressures. Results are compared to a conventional thin film meander resistor, which was fabricated and whose pressure response was also measured for comparative purposes.

  14. Reflections: Michael Watts interviewed by Murat Arsel

    NARCIS (Netherlands)

    M. Arsel (Murat)

    2009-01-01

    textabstractMichael Watts is ‘Class of 1963’ Chair in Undergraduate Studies and Chancellor’s Professor of Geography at the University of California, Berkeley. Born and raised in rural southwest England, Watts studied at University College London and completed his PhD in 1979 at the University of Mic

  15. Distant and wide range wireless power transfer from metamedia

    Science.gov (United States)

    Zhu, Lin; Luo, Xudong; Ma, Hongru

    2016-07-01

    Based on electromagnetic scattering theory, a model of superscatterer enhanced distant wireless power transfer (WPT) device has designed and analyzed with the concept of transformation optics. The numerical results obtained through a series expansion method reveal that a properly designed ss-WPT has high efficiency for long transfer distances as well as a wide transfer range. The transfer distance can be further enlarged by fine tuning of the design. These effects can be explained qualitatively through the study of magnetic flux.

  16. Two-watt, 4-Kelvin closed cycle refrigerator performance

    Science.gov (United States)

    Britcliffe, M.

    1987-01-01

    A 2-watt, 4-K helium refrigerator using the Gifford-McMahon/Joule Thomson cycle is described. The unit features a removable displacer cylinder and high-efficiency, low-pressure drop heat exchangers. These improvements result in a 100 percent increase in cooling power over the existing Deep Space Network system. The effects of the heat exchanger efficiency and Gifford-McMahon expander performance on refrigerator capacity are also discussed.

  17. Construction of a new watt balance with the goal to realize the kilogram in the US

    Science.gov (United States)

    Schlamminger, Stephan; Haddad, Darine; Seifert, Frank; Chao, Leon; Newell, David; Pratt, Jon

    2015-04-01

    A watt balance is a mechanical device that compares mechanical power to electrical power. Since electrical power is measured using quantum physics by employing the Josephson effect and the Quantum Hall effect, electrical power can be measured as a product of a known factor, two frequencies, and the Planck constant h. Mechanical power is given by mgv , where m is the mass of a weight, g the local acceleration, and v the velocity. Hence, the watt balance provides a link between mass and Planck's constant. Currently several watt balances worldwide are employed to measure h. A redefinition of the international system of units (SI) is currently in discussion and may become reality as early as 2018. In the new SI, the numerical value of the Planck constant will be fixed and the watt balance is a means to realize the unit of mass. Researchers at NIST are preparing for a new SI and we have started in 2011 with plans to design a new watt balance capable of realizing the kilogram with relative uncertainties of a few parts in 108. Construction of the new watt balance has started in 2014. In my talk, I will show some of the latest results achieved with this apparatus.

  18. James Watt making the world anew

    CERN Document Server

    Russell, Ben

    2014-01-01

    Scottish inventor and mechanical engineer James Watt (1736-1819) is best known for his pioneering work on the steam engine that became fundamental to the incredible changes and developments wrought by the Industrial Revolution. But in this new biography, Ben Russell tells a much bigger, richer story, peering over Watt's shoulder to more fully explore the processes he used and how his ephemeral ideas were transformed into tangible artifacts. Over the course of the book, Russell reveals as much about the life of James Watt as he does a history of Britain's early industrial transformation and the

  19. Modelling major failures in power grids in the whole range

    CERN Document Server

    Prieto, Faustino; Sáez, Antonio José

    2013-01-01

    Empirical research with electricity transmission networks reliability data shows that the size of major failures - in terms of energy not supplied (ENS), total loss of power (TLP) or restoration time (RT) - appear to follow a power law behaviour in the upper tail of the distribution. However, this pattern - also known as Pareto distribution - is not valid in the whole range of those major events. We aimed to find a probability distribution that we could use to model them, and hypothesized that there is a two-parameter model that fits the pattern of those data well in the entire domain. We considered the major failures produced between 2002 and 2009 in the European power grid; analyzed those reliability indicators: ENS, TLP and RT; fitted six alternative models: Pareto II, Fisk, Lognormal, Pareto, Weibull and Gamma distributions, to the data by maximum likelihood; compared these models by the Bayesian information criterion; tested the goodness-of-fit of those models by a Kolmogorov-Smirnov test method based on...

  20. Power regulating range broadening of the WWER-type reactor power units

    Energy Technology Data Exchange (ETDEWEB)

    Dement' ev, B.A.; Petrov, V.A.; Proskuryakov, A.G.; Puchkov, V.V. (Moskovskij Ehnergeticheskij Inst. (USSR))

    1984-02-01

    Calculational studies on the use of sliding pressure (SP) regime to expand the regulating range of the WWER-440 reactor power units are presented. Two operation regimes of a power unit have been considered: according to weekly and daily load swings in electrical grids. The conclusion is made that the use of SP regime in the secondary circuit improves manoeuvable characterstics of the power unit in the second half of operating cycle. T of the reactor (0.6 power regulating range broadening of the reactor. Besides, the use of SP regime during power unit operation with decreased loadings is the more efficient the smaller is the load. The range of operating cycle 0.8 <= T <= 1 makes the greatest contribution to regulating range broadening as a result of SP regime use. Conclusions of the calculational studies can be also applied to WWER reactors of other types as well as to RBMK reactors.

  1. Fuel economy and range estimates for fuel cell powered automobiles

    Energy Technology Data Exchange (ETDEWEB)

    Steinbugler, M.; Ogden, J. [Princeton Univ., NJ (United States)

    1996-12-31

    While a number of automotive fuel cell applications have been demonstrated, including a golf cart, buses, and a van, these systems and others that have been proposed have utilized differing configurations ranging from direct hydrogen fuel cell-only power plants to fuel cell/battery hybrids operating on reformed methanol. To date there is no clear consensus on which configuration, from among the possible combinations of fuel cell, peaking device, and fuel type, is the most likely to be successfully commercialized. System simplicity favors direct hydrogen fuel cell vehicles, but infrastructure is lacking. Infrastructure favors a system using a liquid fuel with a fuel processor, but system integration and performance issues remain. A number of studies have analyzed particular configurations on either a system or vehicle scale. The objective of this work is to estimate, within a consistent framework, fuel economies and ranges for a variety of configurations using flexible models with the goal of identifying the most promising configurations and the most important areas for further research and development.

  2. 百瓦级高亮度光纤耦合半导体激光模块的研制%Reaearch on High Brightness Fiber Coupled Diode Laser Module with Hundred Watts Class Output Power

    Institute of Scientific and Technical Information of China (English)

    郝明明; 朱洪波; 秦莉; 宁永强; 刘云; 张志军; 王立军

    2012-01-01

    Three 976 nm diode laser short bars were used as submodule to manufacture high brightness fiber coupled module with CW hundred watts class output power. First, beam transform systems were employed to shape beams emitted from each submodlue; Second, the three beams were stacked in direction of lower beam parameter product by means of spatial multiplexing technology; Finally, the laser was focused into a mullimode fiber with 200 \\xm core diameter and NA =0. 22 by optimized Ien9. Experiment result showed that divergence angle of the focused laser beam was 24. 8° and its beam waist diameter was 175. 2 |xm; laser output from fiber could reach to 107 W, equalizing brightness of 2.23 MW/(cm2 ? Sr) , which is a higher level in China. Furthermore, the wall plug efficiency is 43. 1 % when driving current is 52.5 A, which is far higher than that of solid state laser. Finally the thermal resistance was computed by means of measuring spectrum with different current and the result is 1. 29 K/W which indicates favorable heat dissipation of the module. All of theresult showed that the module can be used in the field of pumping fiber lasers, medical, material processing and so on.%用3只976 nm半导体激光短列阵作为子模块,研制出连续工作的百瓦级高亮度光纤耦合模块.首先,利用光束转换器将每个半导体激光短列阵进行光束整形;然后采用空间复用技术将3个半导体激光短列阵在光参数积小的方向上叠加,并利用倒置伽利略望远镜作为扩束器进一步压缩发散角;最后利用优化结构的透镜组将激光聚焦到芯径200μm,数值孔径为0.22的光纤中.测量结果显示:聚焦后激光的发散角为24.8°,焦平面的光斑尺寸为175.2 μm;耦合后测量光纤出光功率可达107W,对应亮度为2.23 MW/( cm2·sr),达到了国内利用列阵进行光纤耦合的领先水平;在工作电流为52.5 A时,电光转换效率为43.1%,远高于全固态等激光器;最后测量本模块

  3. An Experiment to Measure Range, Range Straggling, Stopping Power, and Energy Straggling of Alpha Particles in Air

    Science.gov (United States)

    Ouseph, P. J.; Mostovych, Andrew

    1978-01-01

    Experiments to measure range, range straggling, stopping power, and energy straggling of alpha particles are discussed in this article. Commercially available equipment with simple modifications is used for these measurements. (Author/GA)

  4. 100 watts in a confetti; 100 watts dans un confetti

    Energy Technology Data Exchange (ETDEWEB)

    Guezel, J.Ch.

    2002-03-01

    Technologies transferred from microelectronics will allow to build miniature power generators for portable applications. This short article gives an overview of some techniques under study: the free-piston engine of the Honeywell Technology Center, the micro-combustion system with Seebeck effect of South Carolina Univ., the hydrogen micro-turbine of the MIT, the Wankel gas micro-engine of Berkeley univ. (J.S.)

  5. Watt-Lite; Energy Statistics Made Tangible

    DEFF Research Database (Denmark)

    Jönsson, Li; Broms, Loove; Katzeff, Cecilia

    2011-01-01

    in the physical environments of its employees. The design of Watt-Lite is meant to explore ways of representing, understanding and interacting with electricity in industrial workspaces. We discuss three design inquiries and their implications for the design of Watt-Lite: the use of tangible statistics......Increasing our knowledge of how design affects behaviour in the workplace has a large potential for reducing electricity consumption. This would be beneficial for the environment as well as for industry and society at large. In Western society energy use is hidden and for the great mass...... of consumers its consequences are poorly understood. In order to better understand how we can use design to increase awareness of electricity consumption in everyday life, we will discuss the design of Watt-Lite, a set of three oversized torches projecting real time energy statistics of a factory...

  6. Ion Stopping Powers and Ranges Whenever You Need Them

    DEFF Research Database (Denmark)

    Bassler, Niels; Christensen, Casper; Tørresø, Jesper Rosholm

    A new app "Electronic Stopping Power" for Android mobile phones and tablets, looks up stopping powers using the ICRU 49 (protons and alphas) and the revised ICRU 73 (lithium and heavier ions) tables. In addition, also MSTAR and an implementation of the Bethe equation expanded to low energies...

  7. Stopping Powers and Ranges of Electrons and Positions,

    Science.gov (United States)

    2) use of the general formulation of Sternheimer and Peierls for the density-effect correcting to the collision stopping power; and (3) use of theoretical bremsstrahlung cross sections of Tseng and Pratt. (Author)

  8. Very High Power THz Radiation Sources

    OpenAIRE

    Carr, G.L.; Martin, M. C.; McKinney, W.R.; Jordan, K.; Neil, G. R.; Williams, G. P.

    2003-01-01

    We report the production of high power (20watts average, ∼ 1 Megawatt peak) broadbandTHz light based on coherent emission fromrelativistic electrons. Such sources areideal for imaging, for high power damagestudies and for studies of non-linearphenomena in this spectral range. Wedescribe the source, presenting theoreticalcalculations and their experimentalverification. For clarity we compare thissource with one based on ultrafast lasertechniques.

  9. Computer Aided Design of Ka-Band Waveguide Power Combining Architectures for Interplanetary Spacecraft

    Science.gov (United States)

    Vaden, Karl R.

    2006-01-01

    Communication systems for future NASA interplanetary spacecraft require transmitter power ranging from several hundred watts to kilowatts. Several hybrid junctions are considered as elements within a corporate combining architecture for high power Ka-band space traveling-wave tube amplifiers (TWTAs). This report presents the simulated transmission characteristics of several hybrid junctions designed for a low loss, high power waveguide based power combiner.

  10. Low Power High Dynamic Range A/D Conversion Channel

    DEFF Research Database (Denmark)

    Marker-Villumsen, Niels; Rombach, Pirmin

    on this knowledge, a new method is proposed for the reduction of the transient glitches, based on linear extrapolation of the channel output signal. The design of a low power continuous-time (CT) Delta-Sigma (∆Σ) ADC for use in the adaptive A/D conversion channel is also presented. When designing a CT ∆Σ ADC......, the choice of e.g. integrator topology, feedback waveform, feedback type, noise transfer function, and quantization levels, results in a large design space, both at the modulator and circuit level. A new optimization method is presented, that seeks to minimize the current consumption of the ADC. Based...... on an analysis of the modulator circuits and loopfilter, the optimization method determines a theoretical minimum current solution based on a set of performance requirements. Furthermore the use of current mode feedback in combination with active-RC integrators in the CT ∆Σ ADC is investigated as a method...

  11. Toolkits for Automatic Service Generation: WATT and Kill-A-WATT

    Science.gov (United States)

    Qu, Y.; Bollig, E. F.; Erlebacher, G.

    2007-12-01

    As part of the NSF funded VLab consortium [1], we have been involved in the automatic generation of visualization web services using the Web Automation and Translation Toolkit (WATT) compiler. The WATT compiler converts VTK Tcl input scripts into equivalent yet more efficient C++ web services by interpreting code structure, translating and then integrating bindings to the gSOAP library. WATT seeks to completely automate code distribution, integration of transport protocols and interface generation. Ideally, developers should concentrate on writing core applications, and let WATT transform them into web services in the background. Currently, the WATT compiler is limited to converting known Tcl commands and types to C++. For VTK a simple one to one mapping between Tcl and C++ is enforced, but Tcl commands without direct mappings slow the compilation process and require new mappings to be created. Loops and conditional statements are not yet implemented. In an effort to move forward with automation and not get caught up in the details of cross-language compilation, we developed a new application: Kill-A-WATT (KWATT). KWATT is a C++ application that utilizes the C++/Tcl library [2] to evaluate Tcl input scripts using the official Tcl interpreter. During evaluation of the input script, KWATT interprets code structure, integrating communication details via a Tcl-specific SOAP library [3]. Since KWATT drives the Tcl interpreter, the application has access to the full Tcl command base plus the ability to load new commands from other packages. KWATT is not a compiler; instead, it is a stand-alone application that is itself a web service. When KWATT consumes Tcl input, the generated web methods extend the list of previously available commands. This implies that C++ web methods statically defined in KWATT provide a set of standard methods available to every service. Also, since KWATT uses the Tcl interpreter, it has the potential to accept additional Tcl at any time while

  12. Stopping-Power and Range Tables for Electrons, Protons, and Helium Ions

    Science.gov (United States)

    SRD 124 Stopping-Power and Range Tables for Electrons, Protons, and Helium Ions (Web, free access)   The databases ESTAR, PSTAR, and ASTAR calculate stopping-power and range tables for electrons, protons, or helium ions. Stopping-power and range tables can be calculated for electrons in any user-specified material and for protons and helium ions in 74 materials.

  13. Compact sources for the generation of high-peak power wavelength-stabilized laser pulses in the picoseconds and nanoseconds ranges

    Science.gov (United States)

    Wenzel, H.; Klehr, A.; Schwertfeger, S.; Liero, A.; Hoffmann, Th.; Brox, O.; Thomas, M.; Erbert, G.; Tränkle, G.

    2012-03-01

    Diode lasers are ideally suited for the generation of optical pulses in the nanoseconds and picoseconds ranges by gainswitching, Q-switching or mode-locking. We have developed diode-laser based light sources where the pulses are spectrally stabilized and nearly-diffraction limited as required by many applications. Diffraction limited emission is achieved by a several microns wide ridge waveguide (RW), so that only the fundamental lateral mode should lase. Spectral stabilization is realized with a Bragg grating integrated into the semiconductor chip, resulting in distributed feedback (DFB) or distributed Bragg reflector (DBR) lasers. We obtained a peak power of 3.8W for 4ns long pulses using a gain-switched DFB laser and a peak power of more than 4W for 65ps long pulses using a three-section DBR laser. Higher peak powers of several tens of Watts can be reached by an amplification of the pulses with semiconductor optical amplifiers, which can be either monolithically or hybrid integrated with the master oscillators. We developed compact modules with a footprint of 4×5cm2 combining master oscillator, tapered power amplifier, beam-shaping optical elements and high-frequency electronics. In order to diminish the generation of amplified spontaneous emission between the pulses, the amplifier is modulated with short-pulses of high amplitude, too. Beyond the amplifier, we obtained a peak power of more than 10W for 4ns long pulses, a peak power of about 35W for 80ps long pulses and a peak power of 70W for 10ps long pulses at emission wavelengths around 1064nm.

  14. Recent progress on the BIPM watt balance

    Directory of Open Access Journals (Sweden)

    Fang Hao

    2014-01-01

    Full Text Available We present the recent progress on the BIPM (Bureau International des Poids et Mesures watt balance. The existing apparatus was transferred to the dedicated new laboratory with better thermal and vibrational conditions. The apparatus is fully operational in air. An improvement by a factor of three was achieved on the S/N ratio of both the voltage-to-velocity and force-to-current ratios. The fabrication of the parts of the new magnet is completed and its assembly is finished.

  15. Watts Bar Unit 2 Startup Results with VERA

    Energy Technology Data Exchange (ETDEWEB)

    Godfrey, Andrew T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Collins, Benjamin S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gentry, Cole A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Stimpson, Shane G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ritchie, John A. [Tennessee Valley Authority (TVA), Knoxville, TN (United States)

    2017-03-01

    CASL members TVA, Westinghouse, and Oak Ridge National Laboratory have successfully completed a detailed simulation of the initial startup of Watts Bar Nuclear Unit 2 (WBN2) using the advanced reactor simulation tools known as VERA. WBN2 is the first commercial power reactor to join the nation’s electrical grid in over two decades, and the modern core design and availability of data make it an excellent benchmark for CASL. Calculations were performed three months prior to the startup, and in the first blind application of VERA to a new reactor, predicted criticality and physics parameters very close to those later measured by TVA. Subsequent calculations with the latest version of VERA and using exact measurement conditions improved the results even further.

  16. 47 CFR 22.627 - Effective radiated power limits.

    Science.gov (United States)

    2010-10-01

    ... radiated power limits. The effective radiated power (ERP) of transmitters operating on the channels listed in § 22.621 must not exceed the limits in this section. (a) Maximum ERP. The ERP must not exceed the applicable limits in this paragraph under any circumstances. Frequency range (MHz) Maximum ERP (watts)...

  17. Optimizing performance per watt on GPUs in High Performance Computing: temperature, frequency and voltage effects

    CERN Document Server

    Price, D C; Barsdell, B R; Babich, R; Greenhill, L J

    2014-01-01

    The magnitude of the real-time digital signal processing challenge attached to large radio astronomical antenna arrays motivates use of high performance computing (HPC) systems. The need for high power efficiency (performance per watt) at remote observatory sites parallels that in HPC broadly, where efficiency is an emerging critical metric. We investigate how the performance per watt of graphics processing units (GPUs) is affected by temperature, core clock frequency and voltage. Our results highlight how the underlying physical processes that govern transistor operation affect power efficiency. In particular, we show experimentally that GPU power consumption grows non-linearly with both temperature and supply voltage, as predicted by physical transistor models. We show lowering GPU supply voltage and increasing clock frequency while maintaining a low die temperature increases the power efficiency of an NVIDIA K20 GPU by up to 37-48% over default settings when running xGPU, a compute-bound code used in radio...

  18. Low Power Penalty Operation of a Wide Input Dynamic Range Cross-Phase Modulation Wavelength Converter

    Institute of Scientific and Technical Information of China (English)

    Jun; Endo; Akira; Ohki; Rieko; Sato; Toshio; Ito; Yuichi; Tohmori; Yasuhiro; Suzuki

    2003-01-01

    We successfully demonstrated low power penalty operation of a cross-phase modulated (XPM) wavelength converter using a semiconductor optical amplifier (SOA) power equalizer. We also clarified the SOA equalizing level for more adaptive wavelength conversion and achieved a power penalty of less than 1 dB over the wide input dynamic range of 15 dB.

  19. A 20 GHz, 70 watt, 48 percent efficient space communications TWT

    Science.gov (United States)

    McDermott, M. A.; Tamashiro, R. N.

    A space qualifiable helix traveling wave tube capable of producing saturated output power levels above 70 watts at 48 percent total efficiency has been developed for 20 GHz satellite communications systems. The design approach stresses high reliability consistent with high power and efficiency. Advanced construction features incorporated into the design are a five stage collector, an M-type dispenser cathode, and a dynamic velocity tapered (DVT) helix.

  20. A critical review of recent progress in mid-range wireless power transfer

    OpenAIRE

    2013-01-01

    Starting from Tesla’s principles of wireless power transfer a century ago, this critical review outlines recent magneto-inductive research activities on wireless power transfer with the transmission distance greater than the transmitter coil dimension. It summarizes the operating principles of a range of wireless power research into (i) the maximum power transfer and (ii) the maximum energy efficiency principles. The differences and the implications of these two approaches are explained in te...

  1. ORNL Trusted Corridors Project: Watts Bar Dam Inland Waterway Project

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Randy M [ORNL; Gross, Ian G [ORNL; Smith, Cyrus M [ORNL; Hill, David E [ORNL

    2011-11-01

    Radiation has existed everywhere in the environment since the Earth's formation - in rocks, soil, water, and plants. The mining and processing of naturally occurring radioactive materials for use in medicine, power generation, consumer products, and industry inevitably generate emissions and waste. Radiological measuring devices have been used by industry for years to measure for radiation in undesired locations or simply identify radioactive materials. Since the terrorist attacks on the United States on 9-11-01 these radiation measuring devices have proliferated in many places in our nation's commerce system. DOE, TVA, the Army Corps and ORNL collaborated to test the usefulness of these devices in our nation's waterway system on this project. The purpose of the Watts Bar Dam ORNL Trusted Corridors project was to investigate the security, safety and enforcement needs of local, state and federal government entities for state-of-the-art sensor monitoring in regards to illegal cargo including utilization of the existing infrastructure. TVA's inland waterways lock system is a recognized and accepted infrastructure by the commercial carrier industry. Safety Monitoring activities included tow boat operators, commercial barges and vessels, recreational watercraft and their cargo, identification of unsafe vessels and carriers, and, monitoring of domestic and foreign commercial vessels and cargo identification. Safety Enforcement activities included cargo safety, tracking, identification of hazardous materials, waterway safety regulations, and hazardous materials regulations. Homeland Security and Law Enforcement Applications included Radiological Dispersive Devices (RDD) identification, identification of unsafe or illicit transport of hazardous materials including chemicals and radiological materials, and screening for shipments of illicit drugs. In the Fall of 2005 the SensorNet funding for the project expired. After several unsuccessful attempts to

  2. Modular Power Electronic Converters in the Power Range 1 to 10 kW

    DEFF Research Database (Denmark)

    Klimczak, Pawel

    of SES based plants , like hydro-, geothermal-, biofuel-plants, use synchronous generators directly connected to the grid. But some other SES technologies, like fuel cell or photovoltaic, require a power electronic converter between the energy source and the load or the grid. Work presented...... in this thesis concentrates on dc-dc non-isolated converters suitable for high voltage gain applications, like uninterruptible power supply (UPS) and some of sustainable energy sources. A special attention is on reduction of power losses and efficiency improvements in non-isolated dc-dc step-up converters......-pull-boost and a non-isolated two-inductor-boost converters are the best candidates for applications requiring a high voltage gain. Design of a high efficiency converter requires a detailed knowledge and accurate prediction of power losses. For this purpose average steady-state models of selected topologies...

  3. Self-Biased Differential Rectifier with Enhanced Dynamic Range for Wireless Powering

    KAUST Repository

    Ouda, Mahmoud H.

    2016-08-29

    A self-biased, cross-coupled, differential rectifier is proposed with enhanced power-conversion efficiency over an extended range of input power. A prototype is designed for UHF 433MHz RF power-harvesting applications and is implemented using 0.18μm CMOS technology. The proposed rectifier architecture is compared to the conventional cross-coupled rectifier. It demonstrates an improvement of more than 40% in the rectifier power conversion efficiency (PCE) and an input power range extension of more than 50% relative to the conventional crosscoupled rectifier. A sensitivity of -15.2dBm (30μW) input power for 1V output voltage and a peak power-conversion efficiency of 65% are achieved for a 50kω load. © 2004-2012 IEEE.

  4. Registration error study of digital watt-hour meters under distorted conditions

    Science.gov (United States)

    Reta-Hernandez, Manuel

    The increasing application of non-linear loads based on the use of converters, uninterruptible power supplies, and other solid-state switching devices has increased the harmonic content in voltage and current at metering points. One of many problems caused by the voltage and current distortion is the effect on the watt-hour meter performance. The digital watt-hour meter is replacing the old induction meter for measuring electric energy, obtaining additional flexibility and functionality. However, the digital meter performance can be deeply affected when a dc current component is added to the distorted conditions. This dissertation presents a study of the digital watt-hour meter's performance under different nonsinusoidal conditions, including a dc current component. The work is divided into two sections: experimental and analytical. The experimental section consists of accuracy testing on several models of digital meters, both single-phase and three-phase units, subjected to computer-controlled distortion. The system setup used for the measurements was designed by using 12-bits data acquisition hardware (DAQ) and virtual-instrument software (VI) installed in a personal computer. Additional testing on electromechanical watt-hour meters is included for comparison purposes.

  5. Multi-Watt Small Radioisotope Thermoelectric Generator Conceptual Design Study

    Science.gov (United States)

    Determan, William R.; Otting, William; Frye, Patrick; Abelson, Robert; Ewell, Richard; Miyake, Bob; Synder, Jeff

    2007-01-01

    A need has been identified for a small, light-weight, reliable power source using a radioisotope heat source, to power the next generation of NASA's small surface rovers and exploration probes. Unit performance, development costs, and technical risk are key criteria to be used to select the best design approach. Because safety can be a major program cost and schedule driver, RTG designs should utilize the DOE radioisotope safety program's data base to the maximum extent possible. Other aspects important to the conceptual design include: 1) a multi-mission capable design for atmospheric and vacuum environments, 2) a module size based on one GPHS Step 2 module, 3) use of flight proven thermoelectric converter technologies, 4) a long service lifetime of up to 14 years, 5) maximize unit specific power consistent with all other requirements, and 6) be ready by 2013. Another critical aspect of the design is the thermal integration of the RTG with the rover or probe's heat rejection subsystem and the descent vehicle's heat rejection subsystem. This paper describes two multi-watt RTG design concepts and their integration with a MER-class rover.

  6. 47 CFR 95.855 - Transmitter effective radiated power limitation.

    Science.gov (United States)

    2010-10-01

    ... Transmitter effective radiated power limitation. The effective radiated power (ERP) of each CTS and RTU shall... with an ERP exceeding 20 watts. No mobile RTU may transmit with an ERP exceeding 4 watts....

  7. Power System Stabilizer Based on Robust H∞ Controller for Low Frequency Operating Range

    Directory of Open Access Journals (Sweden)

    Ali Mohamed Yousef

    2012-05-01

    Full Text Available The aim of study is designed of Power System Stabilizer (PSS based on H4 approach for power system stabilization. The uncertainties in power system modeling and operations are considered at designing of H∞ PSS. The bounds of power system parameters are determined over a wide range of low frequency operating conditions. These bounds are used to design a robust H∞ PSS. A sample power system composed a synchronous generator connected to infinite bus through transmission line is simulated. The digital H∞ PSS can achieve good performance over a wide range of operating conditions. A comparison between power system responses at variety of operating conditions using the proposed H∞ PSS and Linear Quadratic Regulator LQR control have been done. H2 PSS is designed and compared with the proposed controller.

  8. Stopping power and CSDA range calculations for incident electrons and positrons in breast and brain tissues.

    Science.gov (United States)

    Tufan, Mustafa Çağatay; Namdar, Tuba; Gümüş, Hasan

    2013-05-01

    The stopping power in some biological compounds for electrons and positrons was calculated over the energy range from 100 eV to 1 GeV. Total stopping power was obtained by summing the electronic (collisional) and radiative stopping power of the target materials and then employing the continuous slowing down approximation (CSDA) to calculate the path length of incident particles in the target. An effective charge approximation was used for the calculation of collisional stopping power, and an analytical expression for the radiation length was applied to obtain the radiative stopping power. Calculations of stopping power and CSDA range were based mostly on analytical expressions, to allow for an easy calculation of these parameters. The results were tabulated and compared with available data.

  9. Militarized Thermoelectric Power Sources.

    Science.gov (United States)

    1979-07-01

    Thermoelectric power sources are being developed to provide multifuel, silent, maintenance free tactical power generators for forward area...applications. Recent technology improvements, state of development, and performance characteristics of the 100-Watt and 500-Watt Thermoelectric Power Sources are presented. (Author)

  10. Development Of Multi-users Multi-function Watt-hour Meter Based On ATT7022B

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>According to the feature of city’s apartment building in China,a kind of Multi-users Watt-hour Meter based on ATT7022B has been developed in this paper.The master-slave MCU control model and the principles of Time Sharing Multiplex are adopted in this Watt-hour Meter,its function includes the measurement of current, voltage,power,power factor and the overload protection.It supports remote reading,pre-payment,multi-rate and etc. The practice shows that this meter has high accuracy,runs stable.It has wide prospect in the future market.

  11. Wide Symmetrical Dynamic Range PWM Neuron Circuit with Power Efficient Architecture

    Institute of Scientific and Technical Information of China (English)

    陈继伟; 石秉学

    2002-01-01

    A novel pulse stream neuron circuit is presented whose output pulse width facilitates sigmoid activation to activate the function of neurons. The wide symmetrical dynamic range of this neuron ensures high noise immunity. The pulsed activation strategy provides a power efficient architecture, so the circuit has very low power dissipation. The simplicity of the circuit ensures its suitability for large-scale integration.

  12. Power Inverter Topologies for Photovoltaic Modules - A Review

    DEFF Research Database (Denmark)

    Kjær, Søren Bækhøj; Pedersen, John Kim; Blaabjerg, Frede

    2002-01-01

    This review-paper focuses on the latest development of inverters for photovoltaic AC-Modules. The power range for these inverters is usually within 90 Watt to 500 Watt, which covers the most commercial photovoltaic-modules. Self-commutated inverters have replaced the grid-commutated ones. The same...... is true for the bulky low-frequency transformers versus the high-frequency transformers, which are used to adapt the voltage level. The AC-Module provides a modular design and a flexible behaviour in various grid conditions. It hereby opens the market for photovoltaic-power for everyone at a low cost due...

  13. Monolithic watt-level millimeter-wave diode-grid frequency tripler array

    Science.gov (United States)

    Hwu, R. J.; Luhmann, N. C., Jr.; Rutledge, D. B.; Hancock, B.; Lieneweg, U.

    1988-01-01

    In order to provide watt-level CW output power throughout the millimeter and submillimeter wave region, thousands of solid-state diodes have been monolithically integrated using a metal grid to produce a highly efficient frequency multiplier. Devices considered include GaAs Schottky diodes, thin MOS diodes, and GaAs Barrier-Intrinsic-N(+)diodes. The performance of the present compact low-cost device has been theoretically and experimentally validated.

  14. The distribution of the electric current in a watt-balance coil

    CERN Document Server

    Sasso, Carlo Paolo; Mana, Giovanni

    2013-01-01

    In the watt balance experiment, separate measurements of the Lorentz and electromotive forces in a coil in a radial magnetic field enable a virtual comparison between mechanical and electric powers to be carried out, which lead to an accurate measurement of the Planck constant. This paper investigates the effect of a spatially inhomogeneous distribution of the electric current in the coil due to the higher or lower resistance of the outer or inner paths.

  15. On the scaling range of power-laws originated from fluctuation analysis

    CERN Document Server

    Dariusz, Grech

    2012-01-01

    We extend our previous study of scaling range properties done for detrended fluctuation analysis (DFA) \\cite{former_paper} to other techniques of fluctuation analysis (FA). The new technique called Modified Detrended Moving Average Analysis (MDMA) is introduced and its scaling range properties are examined and compared with those of detrended moving average analysis (DMA) and DFA. It is shown that contrary to DFA, DMA and MDMA techniques exhibit power law dependence of the scaling range with respect to the length of the searched signal and with respect to the accuracy $R^2$ of the fit to the considered scaling law imposed by DMA or MDMA schemes. This power law dependence is satisfied for both uncorrelated and autocorrelated data. We find also a simple generalization of this power law relation for series with different level of autocorrelations measured in terms of the Hurst exponent. Basic relations between scaling ranges for different techniques are also discussed. Our findings should be particularly useful ...

  16. 47 CFR 22.727 - Power limits for conventional rural radiotelephone transmitters.

    Science.gov (United States)

    2010-10-01

    ... this section. (a) Maximum ERP. The effective radiated power (ERP) of central office and rural... circumstances. Frequency range (MHz) Maximum ERP (watts) 152-153 1400 157-159 150 454-455 3500 459-460 150 (b) Basic power limit. Except as provided in paragraph (d) of this section, the ERP of central...

  17. Harvesting Ambient Vibration Energy over a Wide Frequency Range for Self-Powered Electronics.

    Science.gov (United States)

    Wang, Xiaofeng; Niu, Simiao; Yi, Fang; Yin, Yajiang; Hao, Chenglong; Dai, Keren; Zhang, Yue; You, Zheng; Wang, Zhong Lin

    2017-02-28

    Vibration is one of the most common energy sources in ambient environment. Harvesting vibration energy is a promising route to sustainably drive small electronics. This work introduces an approach to scavenge vibrational energy over a wide frequency range as an exclusive power source for continuous operation of electronics. An elastic multiunit triboelectric nanogenerator (TENG) is rationally designed to efficiently harvest low-frequency vibration energy, which can provide a maximum instantaneous output power density of 102 W·m(-3) at as low as 7 Hz and maintain its stable current outputs from 5 to 25 Hz. A self-charging power unit (SCPU) combining the TENG and a 10 mF supercapacitor gives a continuous direct current (DC) power delivery of 1.14 mW at a power management efficiency of 45.6% at 20 Hz. The performance of the SCPU can be further enhanced by a specially designed power management circuit, with a continuous DC power of 2 mW and power management efficiency of 60% at 7 Hz. Electronics such as a thermometer, hygrometer, and speedometer can be sustainably powered solely by the harvested vibration energy from a machine or riding bicycle. This approach has potential applications in self-powered systems for environment monitoring, machine safety, and transportation.

  18. Simulation of Watts Bar Unit 1 Initial Startup Tests with Continuous Energy Monte Carlo Methods

    Energy Technology Data Exchange (ETDEWEB)

    Godfrey, Andrew T [ORNL; Gehin, Jess C [ORNL; Bekar, Kursat B [ORNL; Celik, Cihangir [ORNL

    2014-01-01

    The Consortium for Advanced Simulation of Light Water Reactors* is developing a collection of methods and software products known as VERA, the Virtual Environment for Reactor Applications. One component of the testing and validation plan for VERA is comparison of neutronics results to a set of continuous energy Monte Carlo solutions for a range of pressurized water reactor geometries using the SCALE component KENO-VI developed by Oak Ridge National Laboratory. Recent improvements in data, methods, and parallelism have enabled KENO, previously utilized predominately as a criticality safety code, to demonstrate excellent capability and performance for reactor physics applications. The highly detailed and rigorous KENO solutions provide a reliable nu-meric reference for VERAneutronics and also demonstrate the most accurate predictions achievable by modeling and simulations tools for comparison to operating plant data. This paper demonstrates the performance of KENO-VI for the Watts Bar Unit 1 Cycle 1 zero power physics tests, including reactor criticality, control rod worths, and isothermal temperature coefficients.

  19. An Energy-Efficient Link with Adaptive Transmit Power Control for Long Range Networks

    DEFF Research Database (Denmark)

    Blaszczyk, Tomasz; Lynggaard, Per

    2016-01-01

    — A considerable amount of research is carried out to develop a reliable smart sensor system with high energy efficiency for battery operated wireless IoT devices in the agriculture sector. However, only a limited amount of research has covered automatic transmission power adjustment schemes...... and algorithms which are essential for deployment of wireless IoT nodes. This paper presents an adaptive link algorithm for farm applications with emphasis on power adjustment for long range communication networks....

  20. An Energy-Efficient Link with Adaptive Transmit Power Control for Long Range Networks

    DEFF Research Database (Denmark)

    Lynggaard, P.; Blaszczyk, Tomasz

    2016-01-01

    A considerable amount of research is carried out to develop a reliable smart sensor system with high energy efficiency for battery operated wireless IoT devices in the agriculture sector. However, only a limited amount of research has covered automatic transmission power adjustment schemes...... and algorithms which are essential for deployment of wireless IoT nodes. This paper presents an adaptive link algorithm for farm applications with emphasis on power adjustment for long range communication networks....

  1. An Energy-Efficient Link with Adaptive Transmit Power Control for Long Range Networks

    DEFF Research Database (Denmark)

    Lynggaard, P.; Blaszczyk, Tomasz

    2016-01-01

    A considerable amount of research is carried out to develop a reliable smart sensor system with high energy efficiency for battery operated wireless IoT devices in the agriculture sector. However, only a limited amount of research has covered automatic transmission power adjustment schemes...... and algorithms which are essential for deployment of wireless IoT nodes. This paper presents an adaptive link algorithm for farm applications with emphasis on power adjustment for long range communication networks....

  2. Wide-Range Adaptive RF-to-DC Power Converter for UHF RFIDs

    KAUST Repository

    Ouda, Mahmoud H.

    2016-07-27

    A wide-range, differential, cross-coupled rectifier is proposed with an extended dynamic range of input RF power that enables wireless powering from varying distances. The proposed architecture mitigates the reverse-leakage problem in conven- tional, cross-coupled rectifiers without degrading sensitivity. A prototype is designed for UHF RFID applications, and is imple- mented using 0.18 μ m CMOS technology. On-chip measurements demonstrate a sensitivity of − 18 dBm for 1 V output over a 100 k Ω load and a peak RF-to-DC power conversion efficiency of 65%. A conventional, fully cross-coupled rectifier is fabricated along- side for comparison and the proposed rectifier shows more than 2 × increase in dynamic range and a 25% boosting in output voltage than the conventional rectifier

  3. Wide Operational Range Processor Power Delivery Design for Both Super-Threshold Voltage and Near-Threshold Voltage Computing

    Institute of Scientific and Technical Information of China (English)

    Xin He; Gui-Hai Yan; Yin-He Han; Xiao-Wei Li

    2016-01-01

    The load power range of modern processors is greatly enlarged because many advanced power management techniques are employed, such as dynamic voltage frequency scaling, Turbo Boosting, and near-threshold voltage (NTV) technologies. However, because the efficiency of power delivery varies greatly with different load conditions, conventional power delivery designs cannot maintain high efficiency over the entire voltage spectrum, and the gained power saving may be offset by power loss in power delivery. We propose SuperRange, a wide operational range power delivery unit. SuperRange complements the power delivery capability of on-chip voltage regulator and off-chip voltage regulator. On top of SuperRange, we analyze its power conversion characteristics and propose a voltage regulator (VR) aware power management algorithm. Moreover, as more and more cores have been integrated on a singe chip, multiple SuperRange units can serve as basic building blocks to build, in a highly scalable way, more powerful power delivery subsystem with larger power capacity. Experimental results show SuperRange unit offers 1x and 1.3x higher power conversion efficiency (PCE) than other two conventional power delivery schemes at NTV region and exhibits an average 70%PCE over entire operational range. It also exhibits superior resilience to power-constrained systems.

  4. 47 CFR 22.535 - Effective radiated power limits.

    Science.gov (United States)

    2010-10-01

    ... limits. The effective radiated power (ERP) of transmitters operating on the channels listed in § 22.531 must not exceed the limits in this section. (a) Maximum ERP. The ERP must not exceed the applicable limits in this paragraph under any circumstances. Frequency range (MHz) Maximum ERP (Watts) 35-36 600...

  5. The European Legislation Applicable to Medium-Range Inductive Wireless Power Transmission Systems

    Directory of Open Access Journals (Sweden)

    Frédéric Broydé

    2014-01-01

    Full Text Available Medium-range inductive wireless power transmission systems allow a sufficient power transfer without requiring close proximity between a primary coil and a secondary coil. We briefly investigate the range of a typical system and its radiated emission, from the perspectives of electromagnetic compatibility (EMC and human exposure requirements. We then discuss the applicable legislation in the European Union, the main question being the applicability of the R&TTE or radio equipment directives. Our conclusion is that this applicability depends on multiple parameters, among which is the presence of a self-tuning capability or of a transmitter control based on telemetry.

  6. Wide-Range Highly-Efficient Wireless Power Receivers for Implantable Biomedical Sensors

    KAUST Repository

    Ouda, Mahmoud

    2016-11-01

    Wireless power transfer (WPT) is the key enabler for a myriad of applications, from low-power RFIDs, and wireless sensors, to wirelessly charged electric vehicles, and even massive power transmission from space solar cells. One of the major challenges in designing implantable biomedical devices is the size and lifetime of the battery. Thus, replacing the battery with a miniaturized wireless power receiver (WPRx) facilitates designing sustainable biomedical implants in smaller volumes for sentient medical applications. In the first part of this dissertation, we propose a miniaturized, fully integrated, wirelessly powered implantable sensor with on-chip antenna, designed and implemented in a standard 0.18μm CMOS process. As a batteryless device, it can be implanted once inside the body with no need for further invasive surgeries to replace batteries. The proposed single-chip solution is designed for intraocular pressure monitoring (IOPM), and can serve as a sustainable platform for implantable devices or IoT nodes. A custom setup is developed to test the chip in a saline solution with electrical properties similar to those of the aqueous humor of the eye. The proposed chip, in this eye-like setup, is wirelessly charged to 1V from a 5W transmitter 3cm away from the chip. In the second part, we propose a self-biased, differential rectifier with enhanced efficiency over an extended range of input power. A prototype is designed for the medical implant communication service (MICS) band at 433MHz. It demonstrates an efficiency improvement of more than 40% in the rectifier power conversion efficiency (PCE) and a dynamic range extension of more than 50% relative to the conventional cross-coupled rectifier. A sensitivity of -15.2dBm input power for 1V output voltage and a peak PCE of 65% are achieved for a 50k load. In the third part, we propose a wide-range, differential RF-to-DC power converter using an adaptive, self-biasing technique. The proposed architecture doubles

  7. Stream-power incision model in non-steady-state mountain ranges: An empirical approach

    Institute of Scientific and Technical Information of China (English)

    CHEN Yen-Chieh; SUNG Quocheng; CHEN Chao-Nan

    2006-01-01

    Stream-power incision model has always been applied to detecting the steady-state situation of ranges. Oblique arc-continent collision occurring during the period of Penglai Orogeny caused the Taiwan mountain belt to develop landscape of three evolution stages, namely stages of pre-steady-state (growing ranges in southern Taiwan), steady-state (ranges in central Taiwan) and post-steady-state (decaying ranges in northern Taiwan). In the analysis on streams of the Taiwan mountain belt made by exploring the relationship between the slope of bedrock channel (S) and the catchment area (A), the topographic features of the ranges at these three stages are acquired. The S-A plot of the steady-state ranges is in a linear form, revealing that the riverbed height of bedrock channel does not change over time (dz/dt =0). The slope and intercept of the straight line S-A are related to evolution time of steady-state topography and tectonic uplift rate respectively. The S-A plots of the southern and northern ranges of Taiwan mountain belt appear to be in convex and concave forms respectively, implying that the riverbed height of bedrock channel at the two ranges rises (dz/dt>0)and falls (dz/dt<0) over time respectively. Their tangent intercept can still reflect the tectonic uplift rate.This study develops an empirical stream-power eresion model of pre-steady-state and post-steady-state topography.

  8. Range based power control for multi-radio multi-channel wireless mesh networks

    CSIR Research Space (South Africa)

    Olwal, TO

    2009-08-01

    Full Text Available . This information is piggy-backed in the “ps-Ack” message to the originating NICs and sent via feedback path using probing power level. (iii) Upon receiving the ps-Ack messages, each sending NIC independently computes the connectivity range, queue state, energy...

  9. Towards ten-watt-level 3-5 µm Raman lasers using tellurite fiber.

    Science.gov (United States)

    Zhu, Gongwen; Geng, Lixiang; Zhu, Xiushan; Li, Li; Chen, Qian; Norwood, R A; Manzur, T; Peyghambarian, N

    2015-03-23

    Raman lasers based on mid-infrared fibers operating at 3-5 µm atmospheric transparency window are attractive sources for several applications. Compared to fluoride and chalcogenide fibers, tellurite fibers are more advantageous for high power Raman fiber laser sources at 3-5 µm because of their broader Raman gain bandwidth, much larger Raman shift and better physical and chemical properties. Here we report on our simulations for the development of 10-watt-level 3-5 µm Raman lasers using tellurite fibers as the nonlinear gain medium and readily available continuous-wave (cw) and Q-switched erbium-doped fluoride fiber lasers at 2.8 µm as the pump sources. Our results show that a watt-level or even ten-watt-level fiber laser source in the 3-5 µm atmospheric transparency window can be achieved by utilizing the 1st- and 2nd-order Raman scattering in the tellurite fiber. The presented numerical study provides valuable guidance for future 3-5 um Raman fiber laser development.

  10. Low-power wide-locking-range injection-locked frequency divider for OFDM UWB systems

    Energy Technology Data Exchange (ETDEWEB)

    Yin Jiangwei; Li Ning; Zheng Renliang; Li Wei; Ren Junyan, E-mail: lining@fudan.edu.c [State Key Laboratory of ASIC and System, Fudan University, Shanghai 201203 (China)

    2009-05-01

    This paper describes a divide-by-two injection-locked frequency divider (ILFD) for frequency synthesizers as used in multiband orthogonal frequency division multiplexing (OFDM) ultra-wideband (UWB) systems. By means of dual-injection technique and other conventional tuning techniques, such as DCCA and varactor tuning, the divider demonstrates a wide locking range while consuming much less power. The chip was fabricated in the Jazz 0.18 mum RF CMOS process. The measurement results show that the divider achieves a locking range of 4.85 GHz (6.23 to 11.08 GHz) at an input power of 8 dBm. The core circuit without the test buffer consumes only 3.7 mA from a 1.8 V power supply and has a die area of 0.38 x 0.28 mm{sup 2}. The wide locking range combined with low power consumption makes the ILFD suitable for its application in UWB systems.

  11. Venus Surface Power and Cooling System Design

    Science.gov (United States)

    Landis, Geoffrey A.; Mellott, Kenneth D.

    2004-01-01

    A radioisotope power and cooling system is designed to provide electrical power for the a probe operating on the surface of Venus. Most foreseeable electronics devices and sensors simply cannot operate at the 450 C ambient surface temperature of Venus. Because the mission duration is substantially long and the use of thermal mass to maintain an operable temperature range is likely impractical, some type of active refrigeration may be required to keep certain components at a temperature below ambient. The fundamental cooling requirements are comprised of the cold sink temperature, the hot sink temperature, and the amount of heat to be removed. In this instance, it is anticipated that electronics would have a nominal operating temperature of 300 C. Due to the highly thermal convective nature of the high-density atmosphere, the hot sink temperature was assumed to be 50 C, which provided a 500 C temperature of the cooler's heat rejecter to the ambient atmosphere. The majority of the heat load on the cooler is from the high temperature ambient surface environment on Venus. Assuming 5 cm radial thickness of ceramic blanket insulation, the ambient heat load was estimated at approximately 77 watts. With an estimated quantity of 10 watts of heat generation from electronics and sensors, and to accommodate some level of uncertainty, the total heat load requirement was rounded up to an even 100 watts. For the radioisotope Stirling power converter configuration designed, the Sage model predicts a thermodynamic power output capacity of 478.1 watts, which slightly exceeds the required 469.1 watts. The hot sink temperature is 1200 C, and the cold sink temperature is 500 C. The required heat input is 1740 watts. This gives a thermodynamic efficiency of 27.48 %. The maximum theoretically obtainable efficiency is 47.52 %. It is estimated that the mechanical efficiency of the power converter design is on the order of 85 %, based on experimental measurements taken from 500 watt power

  12. Gas Turbine Energy Conversion Systems for Nuclear Power Plants Applicable to LiFTR Liquid Fluoride Thorium Reactor Technology

    Science.gov (United States)

    Juhasz, Albert J.

    2014-01-01

    This panel plans to cover thermal energy and electric power production issues facing our nation and the world over the next decades, with relevant technologies ranging from near term to mid-and far term.Although the main focus will be on ground based plants to provide baseload electric power, energy conversion systems (ECS) for space are also included, with solar- or nuclear energy sources for output power levels ranging tens of Watts to kilo-Watts for unmanned spacecraft, and eventual mega-Watts for lunar outposts and planetary surface colonies. Implications of these technologies on future terrestrial energy systems, combined with advanced fracking, are touched upon.Thorium based reactors, and nuclear fusion along with suitable gas turbine energy conversion systems (ECS) will also be considered by the panelists. The characteristics of the above mentioned ECS will be described, both in terms of their overall energy utilization effectiveness and also with regard to climactic effects due to exhaust emissions.

  13. 5 Watt, Solid State, EHF Transmitter.

    Science.gov (United States)

    2014-09-26

    satellite-communication ground terminals. This state-of- the- art transmitter demonstrates efficient and cost-effective RF power generation at EHF for...are relatively little or no spectrum allocation problems, is that the state-of-the- art in RF power generation is far below the required levels for...accomplished using E-H hybrid magic tees of reduced height waveguide with good balance and isolation characteristics. Modulation and other signal

  14. A High-Voltage class-D power amplifier with switching frequency regulation for improved high-efficiency output power range

    NARCIS (Netherlands)

    Ma, Haifeng; Zee, van der Ronan; Nauta, Bram

    2015-01-01

    This paper describes the power dissipation analysis and the design of an efficiency-improved high-voltage class-D power amplifier. The amplifier adaptively regulates its switching frequency for optimal power efficiency across the full output power range. This is based on detecting the switching outp

  15. Survey and selection of Energy Storage System for Low Power Embedded System

    OpenAIRE

    Meenu Nair; Chandan Maity

    2012-01-01

    Energy storage for portable low power Embedded System is one of the biggest challenges for a long time operation in present research and application. These systems are designed to operate the lowest possible energy at micro-watt or Milli-Watt range and the power is supplied from a small primary or secondary cell. In this paper an extensive study and latest survey has been shown to estimate and select the right suitable energy storage device in theoretical aspects and also commercially availab...

  16. Power-Performance Tradeoffs in Wide Dynamic Range Image Sensors with Multiple Reset Approach

    Directory of Open Access Journals (Sweden)

    Arthur Spivak

    2011-03-01

    Full Text Available A variety of solutions for widening the dynamic range (DR of CMOS image sensors have been proposed throughout the years. These solutions can be categorized into different groups according to the principle used for DR widening. One of the methods, which is based on autonomous control over the integration time, was implemented by our group. We proposed the multiple resets algorithm, which was successfully implemented in three generations of WDR image sensors. While achieving the same goal of widening the DR of the sensor, each of the implemented imagers had a different architecture, and therefore presented different performance and power figures. This paper reviews designs of the aforementioned sensors and presents a comprehensive analysis of their power consumption. Power-performance tradeoffs are also discussed. Advantages and disadvantages of each sensor are presented.

  17. An Energy-Efficient Link with Adaptive Transmit Power Control for Long Range Networks

    DEFF Research Database (Denmark)

    Lynggaard, Per; Blaszczyk, tomasz

    2016-01-01

    — A considerable amount of research is carried out to develop a reliable smart sensor system with high energy efficiency for battery operated wireless IoT devices in the agriculture sector. However, only a limited amount of research has covered automatic transmission power adjustment schemes and ...... and algorithms which are essential for deployment of wireless IoT nodes. This paper presents an adaptive link algorithm for farm applications with emphasis on power adjustment for long range communication networks.......— A considerable amount of research is carried out to develop a reliable smart sensor system with high energy efficiency for battery operated wireless IoT devices in the agriculture sector. However, only a limited amount of research has covered automatic transmission power adjustment schemes...

  18. High-power laser delocalization in plasmas leading to long-range beam merging

    Energy Technology Data Exchange (ETDEWEB)

    Nakatsutsumi, M.; Marques, J.R.; Antici, P.; Bourgeois, N.; Romagnani, L.; Audebert, P.; Fuchs, J. [UPMC, CEA, CNRS, LULI, Ecole Polytech, F-91128 Palaiseau (France); Nakatsutsumi, M.; Kodama, R. [Osaka Univ, Grad Sch Engn, Suita, Osaka 5650871 (Japan); Antici, P. [Univ Roma La Sapienza, Dipartimento SBAI, I-00161 Rome (Italy); Feugeas, J.L.; Nicolai, P. [Univ Bordeaux 1, CNRS, CEA, Ctr Lasers Intenses and Applicat, F-33405 Talence (France); Lin, T. [Fox Chase Canc Ctr, Philadelphia, PA 19111 (United States)

    2010-07-01

    Attraction and fusion between co-propagating light beams, mutually coherent or not, can take place in nonlinear media as a result of the beam power modifying the refractive index of the medium. In the context of high-power light beams, induced modifications of the beam patterns could potentially impact many topics, including long-range laser propagation, the study of astrophysical colliding blast waves and inertial confinement fusion. Here, through experiments and simulations, we show that in a fully ionized plasma, which is a nonlinear medium, beam merging can take place for high-power and mutually incoherent beams that are initially separated by several beam diameters. This is in contrast to the usual assumption that this type of interaction is limited to beams separated by only one beam diameter. This effect, which is orders of magnitude more significant than Kerr-like nonlinearity in gases, demonstrates the importance of potential cross-talk amongst multiple beams in plasma. (authors)

  19. Method for enhancing the resolving power of ion mobility separations over a limited mobility range

    Science.gov (United States)

    Shvartsburg, Alexandre A; Tang, Keqi; Smith, Richard D

    2014-09-23

    A method for raising the resolving power, specificity, and peak capacity of conventional ion mobility spectrometry is disclosed. Ions are separated in a dynamic electric field comprising an oscillatory field wave and opposing static field, or at least two counter propagating waves with different parameters (amplitude, profile, frequency, or speed). As the functional dependencies of mean drift velocity on the ion mobility in a wave and static field or in unequal waves differ, only single species is equilibrated while others drift in either direction and are mobility-separated. An ion mobility spectrum over a limited range is then acquired by measuring ion drift times through a fixed distance inside the gas-filled enclosure. The resolving power in the vicinity of equilibrium mobility substantially exceeds that for known traveling-wave or drift-tube IMS separations, with spectra over wider ranges obtainable by stitching multiple segments. The approach also enables low-cutoff, high-cutoff, and bandpass ion mobility filters.

  20. Comparison of Stopping Power and Range Databases for Radiation Transport Study

    Science.gov (United States)

    Tai, H.; Bichsel, Hans; Wilson, John W.; Shinn, Judy L.; Cucinotta, Francis A.; Badavi, Francis F.

    1997-01-01

    The codes used to calculate stopping power and range for the space radiation shielding program at the Langley Research Center are based on the work of Ziegler but with modifications. As more experience is gained from experiments at heavy ion accelerators, prudence dictates a reevaluation of the current databases. Numerical values of stopping power and range calculated from four different codes currently in use are presented for selected ions and materials in the energy domain suitable for space radiation transport. This study of radiation transport has found that for most collision systems and for intermediate particle energies, agreement is less than 1 percent, in general, among all the codes. However, greater discrepancies are seen for heavy systems, especially at low particle energies.

  1. On the Percolation BCFT and the Crossing Probability of Watts

    CERN Document Server

    Ridout, David

    2008-01-01

    The logarithmic conformal field theory describing critical percolation is further explored using Watts' determination of the probability that there exists a cluster connecting both horizontal and vertical edges. The boundary condition changing operator which governs Watts' computation is identified with a primary field which does not fit naturally within the extended Kac table. Instead a ``shifted'' extended Kac table is shown to be relevant. Augmenting the previously known logarithmic theory based on Cardy's crossing probability by this field, a larger theory is obtained, in which new classes of indecomposable rank-2 modules are present. No rank-3 Jordan cells are yet observed. A highly non-trivial check of the identification of Watts' field is that no Gurarie-Ludwig-type inconsistencies are observed in this augmentation. The article concludes with an extended discussion of various topics related to extending these results including projectivity, boundary sectors and inconsistency loopholes.

  2. Stopping power for electrons in pyrimidine in the energy range 20-3000 eV.

    Science.gov (United States)

    Colmenares, R; Sanz, A G; Fuss, M C; Blanco, F; García, G

    2014-01-01

    In this work, we present new experimental electron energy loss distribution functions for pyrimidine (C4H4N2) measured for the incident energy range 30-2000 eV. Theoretical total and elastic cross sections for electron scattering from pyrimidine were calculated using the screening-corrected additivity rule (IAM-SCAR) method. Based on the mean energy loss observed in the experiment and the theoretical integral inelastic cross section, the stopping power for electrons in pyrimidine is calculated in the energy range 20-3000 eV.

  3. Pulsed Laser Centre (CLPU). The Salamanca peta watt laser; Centro de Laseres Pulsados (CLPU). El laser de Petavatio de Salamanca

    Energy Technology Data Exchange (ETDEWEB)

    Franco, L. R.

    2016-08-01

    With pulses lasting 30 photo seconds, the CLPU VEGA laser is capable of generating a peak power level of one peta watt, this making it one of the worlds most powerful lasers. When focussed it can reach extreme intensities. The way in which a pulse of this nature interacts with an atom or what its applications might be are among the questions answered by this article. (Author)

  4. Biosonar resolving power: Echo-acoustic perception of surface structures in the submillimeter range

    Directory of Open Access Journals (Sweden)

    Ralph eSimon

    2014-02-01

    Full Text Available The minimum distance for which two points still can be separated from each other defines the resolving power of a visual system. In an echo-acoustic context, the resolving power is usually measured as the smallest perceivable distance of two reflecting surfaces on the range axis and is found to be around half a millimetre for bats employing frequency modulated echolocation calls. Only few studies measured such thresholds with physical objects, most often bats were trained on virtual echoes i.e. echoes generated and played back by a computer; moreover, bats were sitting while they received the stimuli. In these studies differences in structure depth between 200 µm and 340 µm were found. However, these low thresholds were never verified for free-flying bats and real physical objects. Here, we show behavioural evidence that the echo-acoustic resolving power for surface structures in fact can be as low as measured for computer generated echoes and even lower, sometimes below 100 µm. We found this exceptional fine discrimination ability only when one of the targets showed spectral interferences in the frequency range of the bats' echolocation call while the other target did not. This result indicates that surface structure is likely to be perceived as a spectral quality rather than being perceived strictly in the time domain. Further, it points out that sonar resolving power directly depends on the highest frequency/shortest wavelength of the signal employed.

  5. Analysis of Multipath MANET Routing Protocols under Variable Range Transmission Power

    Directory of Open Access Journals (Sweden)

    V.Lalitha

    2013-03-01

    Full Text Available A Mobile Ad Hoc Network is a collection of mobile wireless nodes connected together to form a dynamic network without the need for any fixed infrastructure. This dynamic and unpredictable nature of MANETs requires multi-path routing. In multipath routing multiple paths are established between a source and destination pair of nodes. Multi-path routing provides several benefits such as fault-tolerance, load balancing etc. Transmission power of nodes plays an important role in MANET communication. Now, let us assume that each node can dynamically control the transmission power it uses independently of other nodes. The objective of this work is to study the behavior and performance of the two multi-path MANET routing protocols with respect to different transmission range/power of individual nodes of the network. We have selected Ad Hoc On-Demand Multi-path Distance Vector (AOMDV Routing Protocol and Multi-path Dynamic Address Routing (MDART Protocol for this study. We will analyze the impact of increase in transmission range/power of individual nodes on the performance of these multi-path MANET routing protocols.

  6. A Wirelessly Powered Smart Contact Lens with Reconfigurable Wide Range and Tunable Sensitivity Sensor Readout Circuitry.

    Science.gov (United States)

    Chiou, Jin-Chern; Hsu, Shun-Hsi; Huang, Yu-Chieh; Yeh, Guan-Ting; Liou, Wei-Ting; Kuei, Cheng-Kai

    2017-01-07

    This study presented a wireless smart contact lens system that was composed of a reconfigurable capacitive sensor interface circuitry and wirelessly powered radio-frequency identification (RFID) addressable system for sensor control and data communication. In order to improve compliance and reduce user discomfort, a capacitive sensor was embedded on a soft contact lens of 200 μm thickness using commercially available bio-compatible lens material and a standard manufacturing process. The results indicated that the reconfigurable sensor interface achieved sensitivity and baseline tuning up to 120 pF while consuming only 110 μW power. The range and sensitivity tuning of the readout circuitry ensured a reliable operation with respect to sensor fabrication variations and independent calibration of the sensor baseline for individuals. The on-chip voltage scaling allowed the further extension of the detection range and prevented the implementation of large on-chip elements. The on-lens system enabled the detection of capacitive variation caused by pressure changes in the range of 2.25 to 30 mmHg and hydration level variation from a distance of 1 cm using incident power from an RFID reader at 26.5 dBm.

  7. JENOPTIK diode lasers and bars optimized for high-power applications in the NIR range

    Science.gov (United States)

    Zorn, M.; Hülsewede, R.; Schulze, H.; Sebastian, J.; Hennig, P.; Schröder, D.

    2010-02-01

    Laser diodes and laser bars for the high-volume wavelength ranges at 808 nm and 940 nm are available in optimized design and high quality. However, a lot of other wavelengths in the NIR are needed for specialized applications also requiring high stability, reliability and a good efficiency with a good beam quality. An efficient adaptation of the laser diode design to optimize the laser performance at the customized wavelength is highly desirable. At JENOPTIK Diode Lab (JDL) we therefore focus on a flexible and competitive laser diode design resulting in a high output power and a high efficiency at reasonable production costs. Starting from excellent laser bars at 808 nm and 940 nm laser bars with emission wavelengths around 790 nm, 830 nm, 880nm (cw) and 940 nm (pulsed operation) are developed. For 792 nm a maximum output power of 90 W and an efficiency of 55 % has been achieved with an expected lifetime of more than 15000 hours. At 825 nm a maximum efficiency of 60 % and 60 W output power for more than 20.000 h with a high degree of polarization can be presented. Changing the quantum well material for 885 nm the output power reaches 125W with 63% efficiency also for more than 25.000 hours. Laser bars for pulsed applications (quasi-cw) at 940 nm result in an output power of 500 W with an efficiency of 60 %.

  8. Caracterización y control del regulador de WATT

    OpenAIRE

    Carrillo Salagre, Isabel

    2011-01-01

    El propósito de este proyecto es hacer un análisis detallado del regulador de Watt. Desde un punto de vista didáctico, se plantea fabricar un modelo del regulador de Watt. En la actualidad, los alumnos que realizan prácticas de control manejan los controladores mediante un software determinado, dónde modifican unos parámetros y obtienen unos resultados, de esta forma eléctrica no acaban de comprender su funcionamiento. El objetivo de la construcción del regulador es mostrar físicamente en...

  9. Particle Swarm Optimization with Watts-Strogatz Model

    Science.gov (United States)

    Zhu, Zhuanghua

    Particle swarm optimization (PSO) is a popular swarm intelligent methodology by simulating the animal social behaviors. Recent study shows that this type of social behaviors is a complex system, however, for most variants of PSO, all individuals lie in a fixed topology, and conflict this natural phenomenon. Therefore, in this paper, a new variant of PSO combined with Watts-Strogatz small-world topology model, called WSPSO, is proposed. In WSPSO, the topology is changed according to Watts-Strogatz rules within the whole evolutionary process. Simulation results show the proposed algorithm is effective and efficient.

  10. A high dynamic range linear RF power detector with a preceding LNA

    Science.gov (United States)

    Yingbo, Dai; Kefeng, Han; Na, Yan; Xi, Tan

    2012-01-01

    A design of high dynamic range linear radio frequency power detector (PD), aimed for transmitter carrier leakage suppression is presented in this paper. Based on the logarithmic amplifier principle, this detector utilizes the successive detection method to achieve a high dynamic range in the radio frequency band. In order to increase sensitivity, a low noise amplifier (LNA) is placed in the front of this detector. DC coupling is adopted in this architecture to reduce parasitics and save area, but this will unavoidably cause DC offsets in the circuit which are detrimental to the dynamic range. So a DC offset cancelling (DCOC) technique is proposed to solve the problem. Finally, this detector was fabricated in the SMIC 0.13 μm CMOS process. The measured results show that it achieves a wide dynamic range of 50 dB/40 dB with log errors in ±1 dB at 900 MHz/2 GHz, while draws 16 mA from a 1.5 V power supply. The active chip area is 0.27 × 0.67 mm2.

  11. CMOS Amperometric ADC With High Sensitivity, Dynamic Range and Power Efficiency for Air Quality Monitoring.

    Science.gov (United States)

    Li, Haitao; Boling, C Sam; Mason, Andrew J

    2016-08-01

    Airborne pollutants are a leading cause of illness and mortality globally. Electrochemical gas sensors show great promise for personal air quality monitoring to address this worldwide health crisis. However, implementing miniaturized arrays of such sensors demands high performance instrumentation circuits that simultaneously meet challenging power, area, sensitivity, noise and dynamic range goals. This paper presents a new multi-channel CMOS amperometric ADC featuring pixel-level architecture for gas sensor arrays. The circuit combines digital modulation of input currents and an incremental Σ∆ ADC to achieve wide dynamic range and high sensitivity with very high power efficiency and compact size. Fabricated in 0.5 [Formula: see text] CMOS, the circuit was measured to have 164 dB cross-scale dynamic range, 100 fA sensitivity while consuming only 241 [Formula: see text] and 0.157 [Formula: see text] active area per channel. Electrochemical experiments with liquid and gas targets demonstrate the circuit's real-time response to a wide range of analyte concentrations.

  12. Stream power framework for predicting geomorphic change: The 2013 Colorado Front Range flood

    Science.gov (United States)

    Yochum, Steven E.; Sholtes, Joel S.; Scott, Julian A.; Bledsoe, Brian P.

    2017-09-01

    The Colorado Front Range flood of September 2013 induced a diverse range of geomorphic changes along numerous stream corridors, providing an opportunity to assess responses to a large flood in a semiarid landscape. We defined six classes of geomorphic change related to peak unit stream power and valley confinement for 531 stream reaches over 226 km, spanning a gradient of channel scales and slope. Geomorphic change was generally driven by erosion of channel margins in confined reaches and by a combination of deposition and erosion in unconfined reaches. The magnitude of geomorphic change typically increased with unit stream power (ω), with greater responses observed in unconfined channels. Cumulative logit modeling indicated that total stream power or unit stream power, unit stream power gradient, and valley confinement are significant predictors of geomorphic response for this flood event. Based on this dataset, thresholds for geomorphic adjustment were defined. For channel slopes 230 W/m2 (16 lb/ft-s; at least 10% of the investigated sites experienced substantial channel widening) and a credible potential for avulsions, braiding, and loss of adjacent road embankments associated with ω > 480 W/m2 (33 lb/ft-s; at least 10% of the investigated sites experienced such geomorphic change). Infrequent to numerous eroded banks were very likely with ω > 700 W/m2 (48 lb/ft-s), with substantial channel widening or major geomorphic change shifting from credible to likely. Importantly, in reaches where there were large reductions in ω as the valley form shifted from confined to relatively unconfined, large amounts of deposition-induced, reach-scale geomorphic change occurred in some locations at relatively low ω. Additionally, alluvial channels with slopes > 3% had greater resistance to geomorphic change, likely caused by armoring by larger bed material and increased flow resistance from enhanced bedforms. Finally, we describe how these results can potentially be used by

  13. Energy, Power and Thermal Research Overview

    Science.gov (United States)

    2010-09-01

    and space force. 4 AFRL’s Core Areas of Expertise Space Vehicles Materials Directed Energy Munitions Propulsion Human Effectiveness Information...model ionic/electronic transport in a “ Phthalocyanine Complex” • Results validated through synthesis processes SOFC Stack Development - increased power...Watt power generation • Magnetic materials • Thermoelectric power generation • Mega-Watt power generation ‒ Superconducting and conventional

  14. Swisswoodhouse -a building for the 2000-Watt Society; Swisswoodhouse - ein Gebaeude fuer die 2000-Watt-Gesellschaft - Synthesebericht

    Energy Technology Data Exchange (ETDEWEB)

    Menz, T.; Wallbaum, H.; Hardziewski, R.; Graf, S.; Trachsel-Gerber, N.; Koschenz, M.; Guentert, P.

    2009-05-15

    This report deals with a building conceived to meet the requirements of the Swiss '2000-Watt Society' concept. The aims of the project are discussed which feature the demonstration of a forward-looking architectural layout, comfortable and healthy living, environmentally compatible and low resource consumption, standardisation and cost reduction. The report contains seven sections: Basics of the '2000-Watt Society' concept, optimisation of the whole building system, investor-orientated rating, use-oriented monitoring system, the development of the building, standardised building technology and, finally, a description of this pilot project.

  15. Acoustic emission monitoring of hot functional testing: Watts Bar Unit 1 Nuclear Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hutton, P.H.; Dawson, J.F.; Friesel, M.A.; Harris, J.C.; Pappas, R.A.

    1984-06-01

    Acoustic emission (AE) monitoring of selected pressure boundary areas at TVA's Watts Bar, Unit 1 Nuclear Power Plant during hot functional preservice testing is described in this report. The report deals with background, methodology, and results. The work discussed here is a major milestone in a program supported by NRC to develop and demonstrate application of AE monitoring for continuous surveillance of reactor pressure boundaries to detect and evaluate growing flaws. The subject work demonstrated that anticipated problem areas can be overcome. Work is continuing toward AE monitoring during reactor operation.

  16. A Simple Watt Balance for the Absolute Determination of Mass

    Science.gov (United States)

    Quinn, Terry; Quinn, Lucas; Davis, Richard

    2013-01-01

    A watt balance is an electromechanical device that allows a mass to be determined in terms of measurable electrical and mechanical quantities, themselves traceable to the fundamental constants of physics. International plans are well advanced to redefine the unit of mass, the kilogram, in terms of a fixed numerical value for the Planck constant. A…

  17. A Simple Watt Balance for the Absolute Determination of Mass

    Science.gov (United States)

    Quinn, Terry; Quinn, Lucas; Davis, Richard

    2013-01-01

    A watt balance is an electromechanical device that allows a mass to be determined in terms of measurable electrical and mechanical quantities, themselves traceable to the fundamental constants of physics. International plans are well advanced to redefine the unit of mass, the kilogram, in terms of a fixed numerical value for the Planck constant. A…

  18. Stray capacitances in the watt balance operation: electrostatic forces

    CERN Document Server

    Quagliotti, Danilo

    2014-01-01

    In a watt balance, stray capacitances exist between the coil and the magnet. Since the electric current flowing in the coil originates a difference between the coil and magnet electric-potentials, their electrostatic interactions must be taken into account. This paper reports the results of a finite element analysis of the forces acting on the coil.

  19. Stray capacitances in the watt balance operation: electrostatic forces

    DEFF Research Database (Denmark)

    Quagliotti, Danilo; Mana, G.

    2014-01-01

    In a watt balance, stray capacitances exist between the coil and the magnet. Since the electric current flowing in the coil creates a difference in electric potentials between the coil and magnet, their electrostatic interactions must be taken into account. This paper reports the results of a fin...

  20. Theology and psychology – the interdisciplinary work of Fraser Watts

    Directory of Open Access Journals (Sweden)

    Willem J. Smith

    2005-10-01

    Full Text Available In the preface to his book, Theology and Psychology, Fraser Watts, a lecturer in Theology and Natural Science at the University of Cambridge, states that he approaches “… the interface between theology and psychology by looking at each discipline from the perspective of the other. This includes a religious perspective on several current hot topics in psychology, such as evolution, neuroscience, and computer intelligence. I also consider theological topics like divine action, salvation history and eschatology, in each case using the psychological perspective in a different way”. By taking an interdisciplinary approach, Watts aims at proposing a psychology of religious experience. He considers theology to be the rational reflection on the Christian tradition. When exponents of this tradition are in dialogue with exponents of psychology, the focus falls on human nature. Watts admits that a certain lack of competence in one of the two disciplines can be a problem when working in an interdisciplinary way. However, he is willing to take the risk. Watts worked in psychology for 25 years and was also involved with a medical research council, before taking up a position at the Faculty of Divinity, University of Cambridge.

  1. Mr.Knott and Mr.Watt

    Institute of Scientific and Technical Information of China (English)

    许涛

    2004-01-01

    Mr. Knott has a job in a factory far from his home. So he was usually quite tired when he got home. At nine o'clock one evening, when he was in bed, the telephone bell rang in the living room of his house. He went downstairs loathly, picked up the telephone and said, "This is Washington Street 165. Who's speaking, please?"

  2. Sizing Power Components of an Electrically Driven Tail Cone Thruster and a Range Extender

    Science.gov (United States)

    Jansen, Ralph H.; Bowman, Cheryl; Jankovsky, Amy

    2016-01-01

    The aeronautics industry has been challenged on many fronts to increase efficiency, reduce emissions, and decrease dependency on carbon-based fuels. This paper provides an overview of the turboelectric and hybrid electric technologies being developed under NASA's Advanced Air Transportation Technology (AATT) Project and discusses how these technologies can impact vehicle design. The discussion includes an overview of key hybrid electric studies and technology investments, the approach to making informed investment decisions based on key performance parameters and mission studies, and the power system architectures for two candidate aircraft. Finally, the power components for a single-aisle turboelectric aircraft with an electrically driven tail cone thruster and for a hybrid-electric nine-passenger aircraft with a range extender are parametrically sized, and the sensitivity of these components to key parameters is presented.

  3. Analog Circuit Design Low Voltage Low Power; Short Range Wireless Front-Ends; Power Management and DC-DC

    CERN Document Server

    Roermund, Arthur; Baschirotto, Andrea

    2012-01-01

    The book contains the contribution of 18 tutorials of the 20th workshop on Advances in Analog Circuit Design.  Each part discusses a specific to-date topic on new and valuable design ideas in the area of analog circuit design. Each part is presented by six experts in that field and state of the art information is shared and overviewed. This book is number 20 in this successful series of Analog Circuit Design, providing valuable information and excellent overviews of Low-Voltage Low-Power Data Converters - Chaired by Prof. Anderea Baschirotto, University of Milan-Bicocca Short Range Wireless Front-Ends - Chaired by Prof. Arthur van Roermund, Eindhoven University of Technology Power management and DC-DC - Chaired by Prof. M. Steyaert, Katholieke University Leuven Analog Circuit Design is an essential reference source for analog circuit designers and researchers wishing to keep abreast with the latest development in the field. The tutorial coverage also makes it suitable for use in an advanced design.

  4. Next generation cooled long range thermal sights with minimum size, weight, and power

    Science.gov (United States)

    Breiter, R.; Ihle, T.; Wendler, J.; Rühlich, 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 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.

  5. Apparent Power Law Scaling of Variable Range Hopping Conduction in Carbonized Polymer Nanofibers

    Science.gov (United States)

    Kim, Kyung Ho; Lara-Avila, Samuel; Kang, Hojin; He, Hans; Eklӧf, Johnas; Hong, Sung Ju; Park, Min; Moth-Poulsen, Kasper; Matsushita, Satoshi; Akagi, Kazuo; Kubatkin, Sergey; Park, Yung Woo

    2016-11-01

    We induce dramatic changes in the structure of conducting polymer nanofibers by carbonization at 800 °C and compare charge transport properties between carbonized and pristine nanofibers. Despite the profound structural differences, both types of systems display power law dependence of current with voltage and temperature, and all measurements can be scaled into a single universal curve. We analyze our experimental data in the framework of variable range hopping and argue that this mechanism can explain transport properties of pristine polymer nanofibers as well.

  6. A programmable log-linear amplifier for wide range nuclear power measuring channels

    Science.gov (United States)

    Khaleeq, M. Tahir; Alam, Mahmood; Ghumman, Iftikhar Ahmad

    2002-12-01

    A programmable log-linear amplifier has been developed for nuclear channels. The amplifier can be programmed for logarithmic, linear or log-linear mode of operation. In the log-linear mode, the amplifier operates partially in log mode and automatically switches to linear mode at any preset point. The log-linear mode is used for wide range operation of nuclear channels and, hence, the amplifier will improve the fault finding capabilities of the nuclear channels used in power range. The amplifier is tested at nuclear reactor and the results are found in very good agreement with the designed specifications. This article presents design and construction of the amplifier and field test results.

  7. Global earth systems : from waste to watts

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, M.

    2006-04-01

    As sanitary landfills reach capacity in North America, many municipal jurisdictions are searching for alternative environmental solutions. Global Earth Systems is a company that develops treatment technologies for solid and liquid organic materials to serve the nutrient and waste management needs of agricultural, industrial and municipal interests. Their accelerated composting system provides a practical alternative energy source of recoverable thermal energy and the generation of green electrical energy for use on site or for commercial resale. The company was initially formed to investigate aerobic composting to reduce the overall environmental impact of liquid swine manure. In 2003, an innovative technology was developed to recapture heat generated from the natural organic decomposition process. The technology extracts heat from the organic mass in a controlled system environment that enhances the thermophilic reaction in the composting material. Some systems made by the company can recover thermal energy in the medium of hot water for reuse in a variety of applications. A new system designed by the company can convert thermal energy recaptured from the decomposing mass into electricity for on-site use or resale to the power grid. The proprietary process uses a patented organic fluid in an electrical generator which operates continuously. The company has also developed a biomass energy system which processes unwanted and nuisance organic waste materials into organic fertilizer products. 5 figs.

  8. A low-power high dynamic range front-end ASIC for imaging calorimeters

    CERN Document Server

    Bagliesi, M G; Marrocchesi, P S; Meucci, M; Millucci, V; Morsani, F; Paoletti, R; Pilo, F; Scribano, A; Turini, N; Valle, G D

    2002-01-01

    High granularity calorimeters with shower imaging capabilities require dedicated front-end electronics. The ICON 4CH and VA4 PMT chip-set is suitable for very high dynamic range systems with strict noise requirements. The ICON 4CH is a 4 channel input, 12 channel output ASIC designed for use in a multi-anode photomultiplier system with very large dynamic range and low-noise requirements. Each of the four input signals to the ASIC is split equally into three branches by a current conveyor. Each of the three branches is scaled differently: 1:1, 1:8 and 1:80. The signal is read out by a 12 channel low noise/low power high dynamic range charge sensitive preamplifier-shaper circuit (VA4-PMT chip), with simultaneous sample- and-hold, multiplexed analog read-out, calibration facilities. Tests performed in our lab with a PMT are reported in terms of linearity, dynamic range and cross-talk of the system. (5 refs).

  9. IC design of low power, wide tuning range VCO in 90 nm CMOS technology

    Science.gov (United States)

    Zhu, Li; Zhigong, Wang; Zhiqun, Li; Qin, Li; Faen, Liu

    2014-12-01

    A low power VCO with a wide tuning range and low phase noise has been designed and realized in a standard 90 nm CMOS technology. A newly proposed current-reuse cross-connected pair is utilized as a negative conductance generator to compensate the energy loss of the resonator. The supply current is reduced by half compared to that of the conventional LC-VCO. An improved inversion-mode MOSFET (IMOS) varactor is introduced to extend the capacitance tuning range from 32.8% to 66%. A detailed analysis of the proposed varactor is provided. The VCO achieves a tuning range of 27-32.5 GHz, exhibiting a frequency tuning range (FTR) of 18.4% and a phase noise of -101.38 dBc/Hz at 1 MHz offset from a 30 GHz carrier, and shows an excellent FOM of -185 dBc/Hz. With the voltage supply of 1.5 V, the core circuit of VCO draws only 2.1 mA DC current.

  10. Communication Range Dynamics and Performance Analysis for a Self-Adaptive Transmission Power Controller.

    Science.gov (United States)

    Lucas Martínez, Néstor; Martínez Ortega, José-Fernán; Hernández Díaz, Vicente; Del Toro Matamoros, Raúl M

    2016-05-12

    The deployment of the nodes in a Wireless Sensor and Actuator Network (WSAN) is typically restricted by the sensing and acting coverage. This implies that the locations of the nodes may be, and usually are, not optimal from the point of view of the radio communication. Additionally, when the transmission power is tuned for those locations, there are other unpredictable factors that can cause connectivity failures, like interferences, signal fading due to passing objects and, of course, radio irregularities. A control-based self-adaptive system is a typical solution to improve the energy consumption while keeping good connectivity. In this paper, we explore how the communication range for each node evolves along the iterations of an energy saving self-adaptive transmission power controller when using different parameter sets in an outdoor scenario, providing a WSAN that automatically adapts to surrounding changes keeping good connectivity. The results obtained in this paper show how the parameters with the best performance keep a k-connected network, where k is in the range of the desired node degree plus or minus a specified tolerance value.

  11. Communication Range Dynamics and Performance Analysis for a Self-Adaptive Transmission Power Controller †

    Science.gov (United States)

    Lucas Martínez, Néstor; Martínez Ortega, José-Fernán; Hernández Díaz, Vicente; del Toro Matamoros, Raúl M.

    2016-01-01

    The deployment of the nodes in a Wireless Sensor and Actuator Network (WSAN) is typically restricted by the sensing and acting coverage. This implies that the locations of the nodes may be, and usually are, not optimal from the point of view of the radio communication. Additionally, when the transmission power is tuned for those locations, there are other unpredictable factors that can cause connectivity failures, like interferences, signal fading due to passing objects and, of course, radio irregularities. A control-based self-adaptive system is a typical solution to improve the energy consumption while keeping good connectivity. In this paper, we explore how the communication range for each node evolves along the iterations of an energy saving self-adaptive transmission power controller when using different parameter sets in an outdoor scenario, providing a WSAN that automatically adapts to surrounding changes keeping good connectivity. The results obtained in this paper show how the parameters with the best performance keep a k-connected network, where k is in the range of the desired node degree plus or minus a specified tolerance value. PMID:27187397

  12. Communication Range Dynamics and Performance Analysis for a Self-Adaptive Transmission Power Controller

    Directory of Open Access Journals (Sweden)

    Néstor Lucas Martínez

    2016-05-01

    Full Text Available The deployment of the nodes in a Wireless Sensor and Actuator Network (WSAN is typically restricted by the sensing and acting coverage. This implies that the locations of the nodes may be, and usually are, not optimal from the point of view of the radio communication. Additionally, when the transmission power is tuned for those locations, there are other unpredictable factors that can cause connectivity failures, like interferences, signal fading due to passing objects and, of course, radio irregularities. A control-based self-adaptive system is a typical solution to improve the energy consumption while keeping good connectivity. In this paper, we explore how the communication range for each node evolves along the iterations of an energy saving self-adaptive transmission power controller when using different parameter sets in an outdoor scenario, providing a WSAN that automatically adapts to surrounding changes keeping good connectivity. The results obtained in this paper show how the parameters with the best performance keep a k-connected network, where k is in the range of the desired node degree plus or minus a specified tolerance value.

  13. Measurement of fast electrons spectra generated by interaction between solid target and peta watt laser

    Energy Technology Data Exchange (ETDEWEB)

    Tanimoto, T; Habara, H; Tanaka, K A; Kodama, R [Graduate School of Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan); Nakatsutsumi, M [Laboratoire pour l' Utilisation des Laser Intenses (LULI), CNRS, Ecole Polytechnique, Route de Saclay, 91128 Palaiseau, Cedex F 91128 (France); Lancaster, K L; Green, J S; Scott, R H H; Sherlock, M; Norreys, P A [STFC Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom); Evans, R G; Haines, M G [Department of Physics, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2BZ (United Kingdom); Kar, S; Zepf, M [Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, University Road, Belfast BT7 1NN (United Kingdom); King, J; Ma, T; Wei, M S; Yabuuchi, T; Beg, F N [Department of Mechanical and Aerospace Engineering, UC San Diego, 9500 Gillman Drive 0411, La Jolla, California 92093-0411, United States of America (United States); Key, M H, E-mail: tanimoto@ile.osaka-u.ac.j [Lawrence Livermore National Laboratory, PO Box 808, Livermore, California 94550, United States of America (United States)

    2010-08-01

    Fast electron energy spectra have been measured for a range of intensities between 10{sup 18} Wcm{sup -2} and 10{sup 21} Wcm{sup -2} and for different target materials using electron spectrometers. Several experimental campaigns were conducted on peta watt laser facilities at the Rutherford Appleton Laboratory and Osaka University. In these experimental campaigns, the pulse duration was varied from 0.5 ps to 5 ps. The laser incident angle was also changed from normal incidence to 40{sup 0} in p-polarized. The results show a reduction from the ponderomotive scaling on fast electrons over 10{sup 20} Wcm{sup -2}.

  14. HEPS4Power - Extended-range Hydrometeorological Ensemble Predictions for Improved Hydropower Operations and Revenues

    Science.gov (United States)

    Bogner, Konrad; Monhart, Samuel; Liniger, Mark; Spririg, Christoph; Jordan, Fred; Zappa, Massimiliano

    2015-04-01

    In recent years large progresses have been achieved in the operational prediction of floods and hydrological drought with up to ten days lead time. Both the public and the private sectors are currently using probabilistic runoff forecast in order to monitoring water resources and take actions when critical conditions are to be expected. The use of extended-range predictions with lead times exceeding 10 days is not yet established. The hydropower sector in particular might have large benefits from using hydro meteorological forecasts for the next 15 to 60 days in order to optimize the operations and the revenues from their watersheds, dams, captions, turbines and pumps. The new Swiss Competence Centers in Energy Research (SCCER) targets at boosting research related to energy issues in Switzerland. The objective of HEPS4POWER is to demonstrate that operational extended-range hydro meteorological forecasts have the potential to become very valuable tools for fine tuning the production of energy from hydropower systems. The project team covers a specific system-oriented value chain starting from the collection and forecast of meteorological data (MeteoSwiss), leading to the operational application of state-of-the-art hydrological models (WSL) and terminating with the experience in data presentation and power production forecasts for end-users (e-dric.ch). The first task of the HEPS4POWER will be the downscaling and post-processing of ensemble extended-range meteorological forecasts (EPS). The goal is to provide well-tailored forecasts of probabilistic nature that should be reliable in statistical and localized at catchment or even station level. The hydrology related task will consist in feeding the post-processed meteorological forecasts into a HEPS using a multi-model approach by implementing models with different complexity. Also in the case of the hydrological ensemble predictions, post-processing techniques need to be tested in order to improve the quality of the

  15. Small Stirling dynamic isotope power system for robotic space missions

    Science.gov (United States)

    Bents, D. J.

    1992-08-01

    The design of a multihundred-watt Dynamic Isotope Power System (DIPS), based on the U.S. Department of Energy (DOE) General Purpose Heat Source (GPHS) and small (multihundred-watt) free-piston Stirling engine (FPSE), is being pursued as a potential lower cost alternative to radioisotope thermoelectric generators (RTG's). The design is targeted at the power needs of future unmanned deep space and planetary surface exploration missions ranging from scientific probes to Space Exploration Initiative precursor missions. Power level for these missions is less than a kilowatt. The incentive for any dynamic system is that it can save fuel and reduce costs and radiological hazard. Unlike DIPS based on turbomachinery conversion (e.g. Brayton), this small Stirling DIPS can be advantageously scaled to multihundred-watt unit size while preserving size and mass competitiveness with RTG's. Stirling conversion extends the competitive range for dynamic systems down to a few hundred watts--a power level not previously considered for dynamic systems. The challenge for Stirling conversion will be to demonstrate reliability and life similar to RTG experience. Since the competitive potential of FPSE as an isotope converter was first identified, work has focused on feasibility of directly integrating GPHS with the Stirling heater head. Thermal modeling of various radiatively coupled heat source/heater head geometries has been performed using data furnished by the developers of FPSE and GPHS. The analysis indicates that, for the 1050 K heater head configurations considered, GPHS fuel clad temperatures remain within acceptable operating limits. Based on these results, preliminary characterizations of multihundred-watt units have been established.

  16. Alignment of the magnetic circuit of the BIPM watt balance

    Science.gov (United States)

    Bielsa, F.; Lu, Y. F.; Lavergne, T.; Kiss, A.; Fang, H.; Stock, M.

    2015-12-01

    The International Bureau of Weights and Measures (BIPM) is developing a watt balance for the forthcoming redefinition of the kilogram. An improved version of the apparatus, based on a new closed magnetic circuit is now being assembled. The new apparatus will significantly reduce the type B uncertainty due to misalignment of the magnetic circuit as this work demonstrates. We present two techniques recently developed to accurately align the magnetic field of the circuit perpendicular to the direction defined by the local acceleration of gravity. Uncertainty below 30 μrad was achieved for both techniques which fulfils the requirements for the BIPM watt balance to enable a Planck constant determination at the 1  ×  10-8 level.

  17. A Study of LoRa: Long Range & Low Power Networks for the Internet of Things.

    Science.gov (United States)

    Augustin, Aloÿs; Yi, Jiazi; Clausen, Thomas; Townsley, William Mark

    2016-09-09

    LoRa is a long-range, low-power, low-bitrate, wireless telecommunications system, promoted as an infrastructure solution for the Internet of Things: end-devices use LoRa across a single wireless hop to communicate to gateway(s), connected to the Internet and which act as transparent bridges and relay messages between these end-devices and a central network server. This paper provides an overview of LoRa and an in-depth analysis of its functional components. The physical and data link layer performance is evaluated by field tests and simulations. Based on the analysis and evaluations, some possible solutions for performance enhancements are proposed.

  18. A Study of LoRa: Long Range & Low Power Networks for the Internet of Things

    Science.gov (United States)

    Augustin, Aloÿs; Yi, Jiazi; Clausen, Thomas; Townsley, William Mark

    2016-01-01

    LoRa is a long-range, low-power, low-bitrate, wireless telecommunications system, promoted as an infrastructure solution for the Internet of Things: end-devices use LoRa across a single wireless hop to communicate to gateway(s), connected to the Internet and which act as transparent bridges and relay messages between these end-devices and a central network server. This paper provides an overview of LoRa and an in-depth analysis of its functional components. The physical and data link layer performance is evaluated by field tests and simulations. Based on the analysis and evaluations, some possible solutions for performance enhancements are proposed. PMID:27618064

  19. Paralleling power MOSFETs in their active region: Extended range of passively forced current sharing

    Science.gov (United States)

    Niedra, Janis M.

    1989-01-01

    A simple passive circuit that improves current balance in parallelled power MOSFETs that are not precisely matched and that are operated in their active region from a common gate drive are exhibited. A nonlinear circuit consisting of diodes and resistors generates the differential gate potential required to correct for unbalance while maintaining low losses over a range of current. Also application of a thin tape wound magnetic core to effect dynamic current balance is reviewed, and a simple theory is presented showing that for operation in the active region the branch currents tend to revert to their normal unbalanced values even if the core is not driven into saturation. Results of several comparative experiments are given.

  20. A Study of LoRa: Long Range & Low Power Networks for the Internet of Things

    Directory of Open Access Journals (Sweden)

    Aloÿs Augustin

    2016-09-01

    Full Text Available LoRa is a long-range, low-power, low-bitrate, wireless telecommunications system, promoted as an infrastructure solution for the Internet of Things: end-devices use LoRa across a single wireless hop to communicate to gateway(s, connected to the Internet and which act as transparent bridges and relay messages between these end-devices and a central network server. This paper provides an overview of LoRa and an in-depth analysis of its functional components. The physical and data link layer performance is evaluated by field tests and simulations. Based on the analysis and evaluations, some possible solutions for performance enhancements are proposed.

  1. Cooperative Downlink Listening for Low-Power Long-Range Wide-Area Network

    Directory of Open Access Journals (Sweden)

    Byoungwook Kim

    2017-04-01

    Full Text Available Recently, the development of the Internet of Things (IoT applications has become more active with the emergence of low-power wide-area network (LPWAN, which has the advantages of low-power and long communication distance. Among the various LPWAN technologies, long-range wide-area network (LoRaWAN, or LoRa is considered as the most mature technology. However, since LoRa performs uplink-oriented communication to increase energy efficiency, there is a restriction on the downlink function from the network server to the end devices. In this paper, we propose cooperative downlink listening to solve the fundamental problem of LoRa. In particular, the proposed scheme can be extended to various communication models such as groupcasting and geocasting by combining with the data-centric model. Experiments also show that the proposed technology not only significantly reduces network traffic compared to the LoRa standard, but also guarantees maximum energy efficiency of the LoRa.

  2. THE EFFECTS OF COLD WHIRLPOOL ON POWER, SPEED, AGILITY, AND RANGE OF MOTION

    Directory of Open Access Journals (Sweden)

    Stephen M. Patterson

    2008-09-01

    Full Text Available The purpose was to determine if cold whirlpool treatment decreases functional performance equally regardless of gender. A secondary aim was to determine if there is a gradual increase in functional performance across time. Twenty-one college-aged subjects volunteered to participate in this study and were required to perform four measures of functional performance including: counter movement vertical jump, T-test, 36.58-meter dash (40-yard, and active range of motion of the ankle. Participants were treated with a 20 minute, 10 degree Celsius cold whirlpool following the pre-test of a given functional performance measure. Participants demonstrated significant decreases in counter movement vertical jump, T-test, and 40-yard dash performance immediately following treatment. Vertical jump performance remained impaired for at least 32 minutes. While both the T-test and 40-yard dash were affected for 7 and 22 minutes post- treatment, respectively. Participants also demonstrated significant decreases in peak power and average power immediately after and for 32 minutes post-treatment. Dorsiflexion was significantly decreased 7 and 12 minutes following treatment. There were no differences for plantar flexion, inversion, or eversion. These data suggest functional performance was affected immediately following and for up to 32 minutes after cold whirlpool treatment. It was also evident that there is a gradual performance increase for each measure of functional performance across time. Therefore, the consequences should be carefully considered before returning athletes to activity following cold whirlpool treatment

  3. Snow Cover, Snowmelt Timing and Stream Power in the Wind River Range, Wyoming

    Science.gov (United States)

    Hall, Dorothy K.; Foster, James L.; DiGirolamo, Nicolo E.; Riggs, George A.

    2011-01-01

    Earlier onset of springtime weather, including earlier snowmelt, has been documented in the western United States over at least the last 50 years. Because the majority (is greater than 70%) of the water supply in the western U.S. comes from snowmelt, analysis of the declining spring snowpack (and shrinking glaciers) has important implications for the management of streamflow. The amount of water in a snowpack influences stream discharge which can also influence erosion and sediment transport by changing stream power, or the rate at which a stream can do work, such as move sediment and erode the stream bed. The focus of this work is the Wind River Range (WRR) in west-central Wyoming. Ten years of Moderate-Resolution Imaging Spectroradiometer (MODIS) snow-cover, cloud-gap-filled (CGF) map products and 30 years of discharge and meteorological station data are studied. Streamflow data from streams in WRR drainage basins show lower annual discharge and earlier snowmelt in the decade of the 2000s than in the previous three decades, though no trend of either lower streamflow or earlier snowmelt was observed within the decade of the 2000s. Results show a statistically-significant trend at the 95% confidence level (or higher) of increasing weekly maximum air temperature (for three out of the five meteorological stations studied) in the decade of the 1970s, and also for the 40-year study period as a whole. The extent of snow-cover (percent of basin covered) derived from the lowest elevation zone (2500-3000 m) of the WRR, using MODIS CGF snow-cover maps, is strongly correlated with maximum monthly discharge on 30 April, where Spearman's Rank correlation, rs,=0.89 for the decade of the 2000s. We also investigated stream power for Bull Lake Creek above Bull Lake; and found a trend (significant at the 90% confidence level) toward reduced stream power from 1970 to 2009. Observed changes in streamflow and stream power may be related to increasing weekly maximum air temperature

  4. Short Range Photoassociation of Rb2 by a high power fiber laser

    Science.gov (United States)

    Passagem, Henry; Rodriguez, Ricardo; Ventura, Paulo; Bouloufa, Nadia; Dulieu, Olivier; Marcassa, Luis

    2016-05-01

    Photoassociation has been studied using cold trapped atomic samples for the last 20 years. Due to poor Franck-Condon overlap, a free-to-bound transition followed by spontaneous decay results in a small production of electronic ground state molecules. If the photoassociation is done at short range, deeply bound ground state molecules can be formed. Optical pumping schemes can be used to populate a single state. In our experiment, we have performed trap loss spectroscopy on trapped 85 Rb atoms in a MOT using a high power fiber laser. Our single mode fiber laser (linewidth < 1 MHz) produces about 50 W, which can be tuned in the 1060-1070 nm range. Two vibrational bound states of the 0u+ potential were observed (ν = 137 and 138). The frequency positions as well as the rotational constants of these states are in good agreement with theoretical predictions. We have also measured the lifetime of a crossed optical dipole trap using such fiber laser. The lifetime on resonance is shorter than off resonance as expected. A simple theoretical model indicates that the molecules decay to deeply bound vibrational levels in the ground state. This work was supported by Fapesp and INCT-IQ.

  5. Application of power transformation and moments in time based UWB ranging

    Science.gov (United States)

    Liu, Wenyan; Huang, Xiaotao

    2016-04-01

    For ultra-wideband (UWB) ranging, TOA estimation with the energy detection (ED) receiver is to detect the energy sample that contains the first path (FP) signal in dense multipath. Threshold crossing (TC) is used frequently. However, it is difficult to determine the threshold. Some threshold setting methods are based on constant false alarm rate (CFAR) and the chi-squared distribution. However, the distribution is complicated. Moreover, it depends on the degree of freedom (DOF). If the DOF used is wrong, it will degrade the detection performance. The study bypasses the distribution. We first examine the distribution of the output of the ED receiver after power transformation. Based on the new characteristics of the transformed data and approximate distributions, we propose some practical TOA estimation methods. Similarly, the moments of the output of the ED receiver, such as the second or one-third order moments, are also analysed and used. The proposed methods are easy to implement and can achieve about the same ranging performance with methods based on the chi-squared distribution. We provide both theoretical and simulation results to prove their effectiveness.

  6. Hundred-Watt-Level, All-Fiber-Integrated Supercontinuum Generation from Photonic Crystal Fiber

    Science.gov (United States)

    Chen, Hongwei; Chen, Zilun; Chen, Shengping; Hou, Jing; Lu, Qisheng

    2013-03-01

    A photonic crystal fiber (PCF) based supercontinuum source with hundred-watt-level average power output is presented in this paper. The output delivery fiber of a 120 W picosecond master-oscillator power-amplifier (MOPA) laser with a 15 µm fiber core is directly spliced with a 2.6-m-long PCF to form the all-fiber-integrated SC source. Using the controlled air-hole collapse technique to expand the core diameter of the PCF, a super-low splice loss (˜0.2 dB) between the delivery fiber and the PCF has been demonstrated. A 92.5 W SC spanning from about 700 nm to beyond 1700 nm is obtained.

  7. Radioisotope Power Supply Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Between 1998 and 2003, Hi-Z Technology developed and built a 40 mW radioisotope power supply (RPS) that used a 1 watt radioisotope heater unit (RHU) as the energy...

  8. The watt balance: determination of the Planck constant and redefinition of the kilogram.

    Science.gov (United States)

    Stock, M

    2011-10-28

    Since 1889, the international prototype of the kilogram has served as the definition of the unit of mass in the International System of Units (SI). It is the last material artefact to define a base unit of the SI, and it influences several other base units. This situation is no longer acceptable in a time of ever-increasing measurement precision. It is therefore planned to redefine the unit of mass by fixing the numerical value of the Planck constant. At the same time three other base units, the ampere, the kelvin and the mole, will be redefined. As a first step, the kilogram redefinition requires a highly accurate determination of the Planck constant in the present SI system, with a relative uncertainty of the order of 1 part in 10(8). The most promising experiment for this purpose, and for the future realization of the kilogram, is the watt balance. It compares mechanical and electrical power and makes use of two macroscopic quantum effects, thus creating a relationship between a macroscopic mass and the Planck constant. In this paper, the operating principle of watt balance experiments is explained and the existing experiments are reviewed. An overview is given of all available experimental determinations of the Planck constant, and it is shown that further investigation is needed before the redefinition of the kilogram can take place. Independent of this requirement, a consensus has been reached on the form that future definitions of the SI base units will take.

  9. Feasibility study of a 110 watt per kilogram lightweight solar array system

    Science.gov (United States)

    Shepard, N. F.; Stahle, C. V.; Schneider, A.; Hanson, K. L.

    1972-01-01

    An investigation of the feasibility of a solar array panel subsystem which will produce 10,000 watts of electrical output at 1 A.U. with an overall beginning-of-life power-to-weight ratio of at least 110 watt/kg is reported. A description of the current baseline configuration which meets these requirements is presented. A parametric analysis of the single boom, two blanket planar solar array system was performed to arrive at the optimum system aspect ratio. A novel concept for the stiffening of a lightweight solar array by canting the solar cell blankets at a small angle to take advantage of the inherent in-plane stiffness to increase the symmetric out-of-plane frequency is introduced along with a preliminary analysis of the stiffening effect. A comparison of welded and soldered solar cell interconnections leads to the conclusion that welding is required on this ultralightweight solar array. The use of a boron/aluminum composite material in a BI-STEM type deployable boom is investigated as a possible advancement in the state-of-the-art.

  10. One-Watt level mid-IR output, singly resonant, continuous-wave optical parametric oscillator pumped by a monolithic diode laser

    NARCIS (Netherlands)

    Nieuwenhuis, Albert F.; Lee, Christopher James; Sumpf, Bernd; van der Slot, Petrus J.M.; Erbert, Götz; Boller, Klaus J.

    2010-01-01

    We report more than 1.1 Watt of idler power at 3373 nm in a singly resonant optical parametric oscillator (SRO), directly pumped by a single-frequency monolithic tapered diode laser. The SRO is based on a periodically poled MgO:LiNbO3 crystal in a four mirror cavity and is excited by 8.05 W of 1062

  11. Short Range Wireless Power Transfer (WPT) for UAV/UAS Battery Charging - Phase 1

    Science.gov (United States)

    2014-12-01

    Power Satellites and Microwave Power Trans- mission in Japan,” IEEE Microwave Magazine , December 2002, pp. 36-45. [6] C. Balanis, Antenna Theory...numerous advantages of wireless power transfer (WPT) for many remote energy source and battery charging applications. The approach was first proposed for...antennas rather than coils, and the energy is transferred by a propagating wave, as depicted in Figure 3. The received power at antenna separation d is

  12. Image simulation and a model of noise power spectra across a range of mammographic beam qualities

    Energy Technology Data Exchange (ETDEWEB)

    Mackenzie, Alistair, E-mail: alistairmackenzie@nhs.net; Dance, David R.; Young, Kenneth C. [National Coordinating Centre for the Physics of Mammography, Royal Surrey County Hospital, Guildford GU2 7XX, United Kingdom and Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Diaz, Oliver [Centre for Vision, Speech and Signal Processing, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom and Computer Vision and Robotics Research Institute, University of Girona, Girona 17071 (Spain)

    2014-12-15

    Purpose: The aim of this work is to create a model to predict the noise power spectra (NPS) for a range of mammographic radiographic factors. The noise model was necessary to degrade images acquired on one system to match the image quality of different systems for a range of beam qualities. Methods: Five detectors and x-ray systems [Hologic Selenia (ASEh), Carestream computed radiography CR900 (CRc), GE Essential (CSI), Carestream NIP (NIPc), and Siemens Inspiration (ASEs)] were characterized for this study. The signal transfer property was measured as the pixel value against absorbed energy per unit area (E) at a reference beam quality of 28 kV, Mo/Mo or 29 kV, W/Rh with 45 mm polymethyl methacrylate (PMMA) at the tube head. The contributions of the three noise sources (electronic, quantum, and structure) to the NPS were calculated by fitting a quadratic at each spatial frequency of the NPS against E. A quantum noise correction factor which was dependent on beam quality was quantified using a set of images acquired over a range of radiographic factors with different thicknesses of PMMA. The noise model was tested for images acquired at 26 kV, Mo/Mo with 20 mm PMMA and 34 kV, Mo/Rh with 70 mm PMMA for three detectors (ASEh, CRc, and CSI) over a range of exposures. The NPS were modeled with and without the noise correction factor and compared with the measured NPS. A previous method for adapting an image to appear as if acquired on a different system was modified to allow the reference beam quality to be different from the beam quality of the image. The method was validated by adapting the ASEh flat field images with two thicknesses of PMMA (20 and 70 mm) to appear with the imaging characteristics of the CSI and CRc systems. Results: The quantum noise correction factor rises with higher beam qualities, except for CR systems at high spatial frequencies, where a flat response was found against mean photon energy. This is due to the dominance of secondary quantum noise

  13. Characterization of flexure hinges for the French watt balance experiment

    Directory of Open Access Journals (Sweden)

    Pinot Patrick

    2014-01-01

    Full Text Available In the French watt balance experiment, the translation and rotation functions must have no backlash, no friction, nor the need for lubricants. In addition errors in position and movement must be below 100 nm. Flexure hinges can meet all of these criteria. Different materials, profile shapes and machining techniques have been studied. The flexure pivots have been characterized using three techniques: 1 an optical microscope and, if necessary, a SEM to observe the surface inhomogeneities; 2 a mass comparator to determine the bending stiffness of unloaded pivots; 3 a loaded beam oscillating freely under vacuum to study the dynamic behavior of loaded pivots.

  14. High Throughput 600 Watt Hall Effect Thruster for Space Exploration

    Science.gov (United States)

    Szabo, James; Pote, Bruce; Tedrake, Rachel; Paintal, Surjeet; Byrne, Lawrence; Hruby, Vlad; Kamhawi, Hani; Smith, Tim

    2016-01-01

    A nominal 600-Watt Hall Effect Thruster was developed to propel unmanned space vehicles. Both xenon and iodine compatible versions were demonstrated. With xenon, peak measured thruster efficiency is 46-48% at 600-W, with specific impulse from 1400 s to 1700 s. Evolution of the thruster channel due to ion erosion was predicted through numerical models and calibrated with experimental measurements. Estimated xenon throughput is greater than 100 kg. The thruster is well sized for satellite station keeping and orbit maneuvering, either by itself or within a cluster.

  15. Characterization of flexure hinges for the French watt balance experiment

    Science.gov (United States)

    Pinot, Patrick; Genevès, Gérard

    2014-08-01

    In the French watt balance experiment, the translation and rotation functions must have no backlash, no friction, nor the need for lubricants. In addition errors in position and movement must be below 100 nm. Flexure hinges can meet all of these criteria. Different materials, profile shapes and machining techniques have been studied. The flexure pivots have been characterized using three techniques: 1) an optical microscope and, if necessary, a SEM to observe the surface inhomogeneities; 2) a mass comparator to determine the bending stiffness of unloaded pivots; 3) a loaded beam oscillating freely under vacuum to study the dynamic behavior of loaded pivots.

  16. Analytical model for ion stopping power and range in the therapeutic energy interval for beams of hydrogen and heavier ions

    Science.gov (United States)

    Donahue, William; Newhauser, Wayne D.; Ziegler, James F.

    2016-09-01

    Many different approaches exist to calculate stopping power and range of protons and heavy charged particles. These methods may be broadly categorized as physically complete theories (widely applicable and complex) or semi-empirical approaches (narrowly applicable and simple). However, little attention has been paid in the literature to approaches that are both widely applicable and simple. We developed simple analytical models of stopping power and range for ions of hydrogen, carbon, iron, and uranium that spanned intervals of ion energy from 351 keV u-1 to 450 MeV u-1 or wider. The analytical models typically reproduced the best-available evaluated stopping powers within 1% and ranges within 0.1 mm. The computational speed of the analytical stopping power model was 28% faster than a full-theoretical approach. The calculation of range using the analytic range model was 945 times faster than a widely-used numerical integration technique. The results of this study revealed that the new, simple analytical models are accurate, fast, and broadly applicable. The new models require just 6 parameters to calculate stopping power and range for a given ion and absorber. The proposed model may be useful as an alternative to traditional approaches, especially in applications that demand fast computation speed, small memory footprint, and simplicity.

  17. Analytical model for ion stopping power and range in the therapeutic energy interval for beams of hydrogen and heavier ions.

    Science.gov (United States)

    Donahue, William; Newhauser, Wayne D; Ziegler, James F

    2016-09-01

    Many different approaches exist to calculate stopping power and range of protons and heavy charged particles. These methods may be broadly categorized as physically complete theories (widely applicable and complex) or semi-empirical approaches (narrowly applicable and simple). However, little attention has been paid in the literature to approaches that are both widely applicable and simple. We developed simple analytical models of stopping power and range for ions of hydrogen, carbon, iron, and uranium that spanned intervals of ion energy from 351 keV u(-1) to 450 MeV u(-1) or wider. The analytical models typically reproduced the best-available evaluated stopping powers within 1% and ranges within 0.1 mm. The computational speed of the analytical stopping power model was 28% faster than a full-theoretical approach. The calculation of range using the analytic range model was 945 times faster than a widely-used numerical integration technique. The results of this study revealed that the new, simple analytical models are accurate, fast, and broadly applicable. The new models require just 6 parameters to calculate stopping power and range for a given ion and absorber. The proposed model may be useful as an alternative to traditional approaches, especially in applications that demand fast computation speed, small memory footprint, and simplicity.

  18. Spin-chirality decoupling in the one-dimensional Heisenberg spin glass with long-range power-law interactions.

    Science.gov (United States)

    Viet, Dao Xuan; Kawamura, Hikaru

    2010-08-27

    We study the issue of the spin-chirality decoupling or coupling in the ordering of the Heisenberg spin glass by performing large-scale Monte Carlo simulations on a one-dimensional Heisenberg spin-glass model with a long-range power-law interaction up to large system sizes. We find that the spin-chirality decoupling occurs for an intermediate range of the power-law exponent. Implications to the corresponding d-dimensional short-range model are discussed.

  19. Portable fuel cell power sources for various applications

    Energy Technology Data Exchange (ETDEWEB)

    Daugherty, Mark; Kenyon, Ken; Jackson, Greg [Enable Fuel Cell Corporation, Middleton, WI 53562 (US)] (and others)

    2001-07-01

    The Enable Fuel Cell Corporation is developing proton exchange membrane (PEM) fuel cells ranging in size from a fraction of a Watt to several kilowatts. Our goal is to develop efficient, reliable and cost effective fuel cells, suitable for meeting the day-to-day needs of users in the industrial and consumer power markets. In this paper we present results of testing and initial field deployment of several different fuel cell systems. (author)

  20. Shortening start-up and an extension of the power unit load range

    Directory of Open Access Journals (Sweden)

    Taler Jan

    2017-01-01

    Full Text Available A power plant with additional water pressure tanks was proposed. The maximum rise in the block electric power resulting from the shut-off of low-pressure regenerative heaters was determined. At that time, the boiler is fed with hot water from water pressure tanks acting as heat accumulators. Accumulation of hot water in water tanks is also proposed in the periods of the power unit small load. In order to lower the plant electric power in the off-peak night hours, water heated to the nominal temperature in low-pressure regenerative heaters is directed from the feed water tank to pressure tanks. The water accumulated during the night is used to feed the boiler during the period of peak demand for electricity. Pressure accumulators are proposed to be used for the rapid start-up of the boiler from a cold state. The evaporator of the boiler is filled at the beginning of start-up with hot water from the accumulators. Drops in the power block electric power were determined for different capacities of the tanks and periods when they are charged. The tanks may also be used to ensure a sudden increase in the electric power of the unit that is operating in the automatic system of frequency and power control (in Polish: ARCM.

  1. Simulation of power – current characteristics of high-power semiconductor lasers emitting in the range 1.5 – 1.55 μm

    Energy Technology Data Exchange (ETDEWEB)

    Gorlachuk, P V; Ivanov, A V; Kurnosov, V D; Kurnosov, K V; Romantsevich, V I; Simakov, V A; Chernov, R V [Open Joint-Stock Company M.F. Stel' makh Polyus Research Institute, Moscow (Russian Federation)

    2014-02-28

    We report the simulation of power – current characteristics of high-power semiconductor lasers emitting in the range 1.5 – 1.55 μm. A technique is described which allows one to determine the thermal resistance and characteristic temperatures of a laser diode. The radiative and nonradiative carrier recombination rates are evaluated. Simulation results are shown to agree well with experimental data. (lasers)

  2. High Resolving Power Volume Diffractive Gratings for 400-2700 nm Spectral Range Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this NASA SBIR Phase I proposal is to develop a novel type of high resolving power diffraction gratings based on volume Bragg gratings technology. The...

  3. High Resolving Power Volume Diffractive Gratings for 400-2700 nm Spectral Range Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The main purpose of this NASA SBIR Phase II proposal is development of a novel type of high resolving power diffraction gratings based on volume Bragg gratings...

  4. Heterojunction Bipolar Transistor Power Amplifiers for Long-Range X-band Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this SBIR Phase I project, Vega Wave Systems, Inc. will develop and demonstrate a novel InGaP-GaAs heterojunction bipolar transistor power amplifier for...

  5. An Envelope Soliton in a Nonlinear Chain with the Power-Law Dependence of Long-Range Interaction

    Institute of Scientific and Technical Information of China (English)

    王登龙; 颜晓红; 唐翌

    2003-01-01

    We study the Fermi-Pasta-Ulam lattice model in the presence ora power-law dependence of long-range interaction by virtue of the method of multiple scales. Our results show that an envelope soliton still appears, but it is of different property for the group velocity compared with that of the soliton in the model when long-range interaction is absent.

  6. Evolutionary Games on Weighted Newman-Watts Small-World Networks

    Institute of Scientific and Technical Information of China (English)

    DU Wen-Bo; CAO Xian-Bin; ZHAO Lin; ZHOU Hong

    2009-01-01

    We investigate the evolutionary prisoner's dilemma game (PDG) on weighted Newman-Watts (NW) networks. In weighted NW networks, the link weight wij is assigned to the link between the nodes i and j as: wij = (ki · kj)β,where ki(kj) is the degree of node i(j) and β represents the strength of the correlations. Obviously, the link weight can be tuned by only one parameter β. We focus on the cooperative behavior and wealth distribution in the system. Simulation results show that the cooperator frequency is promoted by a large range of β and there is a minimal cooperation frequency around β = - 1. Moreover, we also employ the Gini coefficient to study the wealth distribution in the population. Numerical results show that the Gini coefficient reaches its minimum when β≈ -1. Our work may be helpful in understanding the emergence of cooperation and unequal wealth distribution in society.

  7. Wide-range structurally optimized channel for monitoring the certified power of small-core reactors

    Energy Technology Data Exchange (ETDEWEB)

    Koshelev, A. S., E-mail: alexsander.coshelev@yandex.ru; Kovshov, K. N.; Ovchinnikov, M. A.; Pikulina, G. N.; Sokolov, A. B. [Russian Federal Nuclear Center—All-Russian Scientific Research Institute of Experimental Physics (Russian Federation)

    2016-12-15

    The results of tests of a prototype version of a channel for monitoring the certified power of small-core reactors performed at the BR-K1 reactor at the All-Russian Scientific Research Institute of Experimental Physics are reported. An SNM-11 counter and commercial KNK-4 and KNK-3 compensated ion chambers were used as neutron detectors in the tested channel, and certified NCMM and CCMM measurement modules controlled by a PC with specialized software were used as measuring instruments. The specifics of metrological assurance of calibration of the channel in the framework of reactor power monitoring are discussed.

  8. Low-Voltage, Low-Power, and Wide-Tuning-Range Ring-VCO for Frequency ΔΣ Modulator

    DEFF Research Database (Denmark)

    Tuan Vu, Cao; Wisland, Dag T.; Lande, Tor Sverre

    A low-voltage, low-power, and wide-tuning-range VCO which converts an analog input voltage to phase information for a frequency ΔΣ modulator is proposed in this paper. The VCO is based on a differential ring oscillator, which is improved with modified symmetric load and a positive feedback in the...

  9. Low-Voltage, Low-Power, and Wide-Tuning-Range Ring-VCO for Frequency ΔΣ Modulator

    DEFF Research Database (Denmark)

    Tuan Vu, Cao; Wisland, Dag T.; Lande, Tor Sverre

    A low-voltage, low-power, and wide-tuning-range VCO which converts an analog input voltage to phase information for a frequency ΔΣ modulator is proposed in this paper. The VCO is based on a differential ring oscillator, which is improved with modified symmetric load and a positive feedback...... in the differential delay cells, a new bias circuit and a full-swing amplifier. The proposed VCO operating with two stages at a power supply voltage of 0.6 V can achieve wide tuning-range and low power consumption of 176.892 uW. The new VCO has a good linearity reducing harmonic distortion for frequency ΔΣ modulator...

  10. Electronic power regulator C02 laser emission

    OpenAIRE

    V. M. Pipka

    1986-01-01

    Proposed power control laser ILGN-705 on the electronic key (GI-30), a control pulse with a variable duty cycle, designed for industrial applications. The limits of the power adjustment 0.06 ... 3 watts.

  11. Electronic power regulator C02 laser emission

    Directory of Open Access Journals (Sweden)

    V. M. Pipka

    1986-04-01

    Full Text Available Proposed power control laser ILGN-705 on the electronic key (GI-30, a control pulse with a variable duty cycle, designed for industrial applications. The limits of the power adjustment 0.06 ... 3 watts.

  12. On a Finite Range Decomposition of the Resolvent of a Fractional Power of the Laplacian

    Science.gov (United States)

    Mitter, P. K.

    2016-06-01

    We prove the existence as well as regularity of a finite range decomposition for the resolvent G_{α } (x-y,m^2) = ((-Δ )^{α over 2} + m2)^{-1} (x-y) , for 0<α <2 and all real m, in the lattice {Z}d as well as in the continuum {R}d for dimension d≥ 2. This resolvent occurs as the covariance of the Gaussian measure underlying weakly self- avoiding walks with long range jumps (stable Lévy walks) as well as continuous spin ferromagnets with long range interactions in the long wavelength or field theoretic approximation. The finite range decomposition should be useful for the rigorous analysis of both critical and off-critical renormalisation group trajectories. The decomposition for the special case m=0 was known and used earlier in the renormalisation group analysis of critical trajectories for the above models below the critical dimension d_c =2α.

  13. 78 FR 53494 - Dam Safety Modifications at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams

    Science.gov (United States)

    2013-08-29

    ... Dam Safety Modifications at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams AGENCY: Tennessee... preferred alternative in its final environmental impact statement (EIS) for the dam safety modifications at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams. The notice of availability (NOA) of the...

  14. The Frequency-Watt Function: Simulation and Testing for the Hawaiian Electric Companies

    Energy Technology Data Exchange (ETDEWEB)

    Hoke, Anderson F. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Nelson, Austin A. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Tan, Jin [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Mahmud, Rasel [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gevorgian, Vahan [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Elkhatib, Mohamed [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Antonio, Chris [Hawaiian Electric Companies, Honolulu, HI (United States); Arakawa, Dean [Hawaiian Electric Companies, Honolulu, HI (United States); Fong, Ken [Hawaiian Electric Companies, Honolulu, HI (United States)

    2017-07-25

    This interim report describes research related to frequency-watt control of solar photovoltaic (PV) inverters conducted under the U.S. Department of Energy's Grid Modernization Laboratory Consortium (GMLC) by a regional partnership for Hawaii. The purpose of this report is to inform an ongoing discussion around frequency-watt control activation in Hawaii.

  15. A comparative investigation of three PM-less MW power range wind generator topologies

    DEFF Research Database (Denmark)

    Bratiloveanu, Catalin-Rauti; Traian Cosmin Anghelus, Dumitru; Boldea, I.

    2012-01-01

    heteropolar-rotor (standard) synchronous generators, especially for direct drives (very low speed) and multibrid (with single stage transmission (5/1-8/1 ratio)), new topologies have to be investigated to reduce initial costs and weights for high enough efficiency and energy annual yield. The present paper......, with sensitivity design inquires, the claw pole synchronous generator topology for a multibrid wind generator of 3 MW ,75rpm generator for a 15 rpm wind turbine with above 94 % efficiency for unity power factor (diode rectified output) for around 10 tons of copper and iron core materials. Though the case studies...... refer to large wind generators the same topologies are believed worth considering for powers less than 1 MW and even less than 100 kW. Similar topologies may be applied to micro-hydro generators. The results are promising but further in depth modeling, design and control studies of such novel PM...

  16. Diode lasers with asymmetric barriers for 850 nm spectral range: experimental studies of power characteristics

    OpenAIRE

    Zubov, F. I.; Zhukov, A. E.; Shernyakov, Yu. M.; M. V. Maximov; Semenova, Elizaveta; Asryan, L. V.

    2015-01-01

    It is demonstrated that the use of asymmetric barrier layers in a waveguide of a diode laser suppress non-linearity of light-current characteristic and thus improve its power characteristics under high current injection. The results are presented for 850-nm AlGaAs/GaAs broad-area lasers with GaInP and AlInGaAs asymmetric barriers.

  17. Low-power short-range transceivers for sensor network applications (Keynote Address)

    Science.gov (United States)

    Lopez-Villegas, J. M.

    2005-06-01

    Emerging technologies like ZigBee or Ultra Wide Band (UWB) Radio, based on the new standards of the IEEE 802.15 family, will, in a near future, compete with and/or complement Bluetooth technology in the development of Wireless Personal Area Networks (WPAN"s), capable to satisfy the increasing demand of high bit rate data transfer links as well as low power and small size constrains. Nowadays coexistence and interconnectivity of Wireless Local Area Networks (WLAN"s), WPAN"s and mobile phones is just the first step towards the implementation of the so called Ambient Intelligence. The main characteristics of this new paradigm are: ubiquity, transparency, and intelligence. In this context, sensor networks are the first front of the communication chain. Thus, most of the wireless data transfers will take place at very short distances and most of the information flow will be performed at very low rates. To implement the RF transceiver devices constituting sensor networks in an Ambient Intelligence environment, several challenges still need to be solved, among them: packaging (SoP vs. SoC approaches), powering (low power, batteryless systems, energy scavenging) and system architecture (new simplified direct conversion approaches). All these matters will be considered in this work.

  18. Request for One-Time Shipment of 32 Watt PU-328 Source in 9968 Packaging

    Energy Technology Data Exchange (ETDEWEB)

    Massey, W.M.

    1998-11-25

    The 9968 package is designed for surface shipment of fissile and other radioactive materials where a high degree of double containment is required. The use of the 9968 radioactive material package for a one time shipment of a 32 watt heat source versus the SARP approved maximum 30 watt heat source is addressed in this report. The analyses show that the small increase in heat load from 30 watts to 32 watts does not substantially increase internal temperatures or pressures that would approach limits for the package. Also, the weight of the content is within the current 9968 package limits. It is concluded that the 32-watt heat source can be safely shipped in the 9968 package and therefore a waiver to ship the source is justified.

  19. An Efficiency-Optimized Isolated Bidirectional DC-DC Converter with Extended Power Range for Energy Storage Systems in Microgrids

    Directory of Open Access Journals (Sweden)

    Xiaolong Shi

    2012-12-01

    Full Text Available This paper proposes a novel extended-single-phase shift (ESPS control strategy of isolated bidirectional full-bridge DC-DC converters (IBDCs which are a promising alternative as a power electronic interface in microgrids with an additional function of galvanic isolation. Based on the mathematical models of ESPS control under steady-state conditions, detailed theoretical and experimental analyses of IBDC under ESPS control are presented. Compared with conventional single-phase-shift (CSPS control, ESPS control can greatly improve the efficiency of IBDCs in microgrids through decreasing current stress and backflow power considerably over a wide input and output voltage range under light and medium loads. In addition, ESPS control only needs to adjust one single phase-shift angel to control transmission power, thus it retains implementation simplicity in comparison with dual-phase-shift (DPS control for microgrid applications. Furthermore, an efficiency-optimized modulation scheme based on ESPS and CSPS control is developed in the whole power range of IBDC for power distribution in microgrids. A 10 kW IBDC prototype is constructed and the experimental results validate the effectiveness of the proposed control strategy, showing that the proposed strategy can enhance the overall efficiency up to 30%.

  20. Effect of Modeling Range on Structural Analysis for Powerhouse of Hydroelectric Power Plant by FEM

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qiling; WU Hegao; YANG Huaquan

    2009-01-01

    In this paper, three different modeling ranges were selected in the structural analysis for a hydropower house. The analysis was carried out using ABAQUS 6.6. The modeling range has a remarkable effect on finite ele-ment method(FEM)calculation result at the middle position of typical cross-sections where the concrete is rela-tively thin, and at the region close to turbine floor. If the ventilation barrel, floor slabs and columns above turbine floor are excluded from FEM model, the maximum rise difference of pedestal structure increases by about 24% compared with that of the whole model. It is indicated that different modeling ranges indeed affect FEM calculation result, and the structure above turbine floor in the FEM model should be included.

  1. Testing of ground fault relay response during the energisation of megawatt range electric boilers in thermal power plants

    DEFF Research Database (Denmark)

    Silva, Filipe Miguel Faria da; Bak, Claus Leth; Davidsen, Troels

    2015-01-01

    , during the energisation of a boiler. A special case for concern was the presence of an electric arc between the electrodes of the boiler and the water in the boiler during approximately 2s at the energisation, which can in theory be seen as a ground fault by the relay. The voltage and current transient......Large controllable loads may support power systems with an increased penetration of fluctuating renewable energy, by providing a rapid response to a change in the power production. Megawatt range electric boilers are an example of such controllable loads, capable of change rapidly...

  2. Anisotropic metamaterial for efficiency enhancement of mid-range wireless power transfer under coil misalignment

    Science.gov (United States)

    Ranaweera, A. L. A. K.; Arriola Moscoso, Carlos; Lee, Jong-Wook

    2015-11-01

    In a wireless power transfer (WPT) system, misalignment between transmitter and receiver coils is one of the key factors affecting efficiency. Recently, metamaterials have shown great potential to enhance electromagnetic propagation in various environments. In this work, we apply a metamaterial to enhance the WPT in a more general environment where misalignment is considered. Using an anisotropic metamaterial, we obtain a significant efficiency enhancement. Therefore, we propose that the metamaterial is an effective means to mitigate the decreased efficiency caused by misalignment. In addition, we investigate the effect of coil misalignment on the threshold distance beyond which the metamaterial enhances the performance of WPT.

  3. Improvement of the Power Control Unit for Ion Thruster to Cope with Milli-Newton Range RIT

    Science.gov (United States)

    Ceruti, Luca; Polli, Aldo; Galantini, Paolo

    2014-08-01

    The recent development and testing activities of a miniaturized Radio-Frequency Ion Thruster, with relevant ancillary elements, in the range of 10 to 100 micro-Newtons, joined with past flight heritage in the milli-Newton range (RIT-10 for Artemis), shows an appealing capability of such an electrical propulsion technology to support thrust in a wide range of space applications from very fine attitude control up to deorbiting of small-medium satellites. As expectable, this implies that the mentioned ancillary elements (mainly Radio-Frequency Generator and Power Control Unit) require adaptation to the different requirements imposed to different missions and thrust ranges. Regarding the Power Control Unit different power levels, both the controllability requirements and the spacecraft interfaces impose non negligible adaptation leading to significant increase of development activities and associated cost (nonrecurring) increase. From that and with the main purpose to minimize such impacts and provide reliable equipments, Selex ES since a few years is devoting maximum attention in the incremental innovation of the existing design in order to maximize their reuse.

  4. Results of Performance Tests Performed on the John Watts WW Casing Connection on 7" Pipe

    Energy Technology Data Exchange (ETDEWEB)

    John D. Watts

    2000-02-01

    Stress Engineering Services (SES) was contracted by Mr. John Watts to test his ''WW'' threaded connection developed for oilfield oil and gas service. This work was a continuation of testing performed by SES as reported in August of 1999. The connection design tested was identified as ''WW''. The samples were all integral (no coupled connections) and contained a wedge thread form with 90{sup o} flank angles relative to the pipe centerline. The wedge thread form is a variable width thread that primarily engages on the flanks. This thread form provides very high torque capacity and good stabbing ability and makeup. The test procedure selected for one of the samples was the newly written ISO 13679 procedure for full scale testing of casing and tubing connections, which is currently going through the ISO acceptance process. The ISO procedure requires a variety of tests that includes makeup/breakout testing, internal gas sealability/external water sealability testing with axial tension, axial compression, bending, internal gas thermal cycle tests and limit load (failure) tests. This test procedure was performed with one sample. Four samples were tested to failure. Table 1 contains a summary of the tasks performed by SES. The project started with the delivery of test samples by Mr. Watts. Pipe from the previous round of tests was used for the new samples. Figure 1 shows the structural and sealing results relative to the pipe body. Sample 1 was used to determine the torque capacity of the connection. Torque was applied to the capacity of SES's equipment which was 28,424 ft-lbs. From this, an initial recommended torque range of 7,200 to 8,800 ft-lbs. was selected. The sample was disassembled and while there was no galling observed in the threads, the end of the pin had collapsed inward. Sample 2 received three makeups. Breakouts 1 and 2 also had collapsing of the pin end, with no thread galling. From these make/breaks, it was

  5. Results of Performance Tests Performed on the John Watts WW Casing Connection on 7" Pipe

    Energy Technology Data Exchange (ETDEWEB)

    John D. Watts

    2000-02-01

    Stress Engineering Services (SES) was contracted by Mr. John Watts to test his ''WW'' threaded connection developed for oilfield oil and gas service. This work was a continuation of testing performed by SES as reported in August of 1999. The connection design tested was identified as ''WW''. The samples were all integral (no coupled connections) and contained a wedge thread form with 90{sup o} flank angles relative to the pipe centerline. The wedge thread form is a variable width thread that primarily engages on the flanks. This thread form provides very high torque capacity and good stabbing ability and makeup. The test procedure selected for one of the samples was the newly written ISO 13679 procedure for full scale testing of casing and tubing connections, which is currently going through the ISO acceptance process. The ISO procedure requires a variety of tests that includes makeup/breakout testing, internal gas sealability/external water sealability testing with axial tension, axial compression, bending, internal gas thermal cycle tests and limit load (failure) tests. This test procedure was performed with one sample. Four samples were tested to failure. Table 1 contains a summary of the tasks performed by SES. The project started with the delivery of test samples by Mr. Watts. Pipe from the previous round of tests was used for the new samples. Figure 1 shows the structural and sealing results relative to the pipe body. Sample 1 was used to determine the torque capacity of the connection. Torque was applied to the capacity of SES's equipment which was 28,424 ft-lbs. From this, an initial recommended torque range of 7,200 to 8,800 ft-lbs. was selected. The sample was disassembled and while there was no galling observed in the threads, the end of the pin had collapsed inward. Sample 2 received three makeups. Breakouts 1 and 2 also had collapsing of the pin end, with no thread galling. From these make/breaks, it was

  6. Winding Schemes for Wide Constant Power Range of Double Stator Transverse Flux Machine

    Energy Technology Data Exchange (ETDEWEB)

    Husain, Tausif; Hassan, Iftekhar; Sozer, Yilmaz; Husain, Iqbal; Muljadi, Eduard

    2015-05-01

    Different ring winding schemes for double sided transverse flux machines are investigated in this paper for wide speed operation. The windings under investigation are based on two inverters used in parallel. At higher power applications this arrangement improves the drive efficiency. The new winding structure through manipulation of the end connection splits individual sets into two and connects the partitioned turns from individual stator sets in series. This configuration offers the flexibility of torque profiling and a greater flux weakening region. At low speeds and low torque only one winding set is capable of providing the required torque thus providing greater fault tolerance. At higher speeds one set is dedicated to torque production and the other for flux control. The proposed method improves the machine efficiency and allows better flux weakening which is desirable for traction applications.

  7. Internal combustion engine system having a power turbine with a broad efficiency range

    Science.gov (United States)

    Whiting, Todd Mathew; Vuk, Carl Thomas

    2010-04-13

    An engine system incorporating an air breathing, reciprocating internal combustion engine having an inlet for air and an exhaust for products of combustion. A centripetal turbine receives products of the combustion and has a housing in which a turbine wheel is rotatable. The housing has first and second passages leading from the inlet to discrete, approximately 180.degree., portions of the circumference of the turbine wheel. The passages have fixed vanes adjacent the periphery of the turbine wheel and the angle of the vanes in one of the passages is different than those in the other so as to accommodate different power levels providing optimum approach angles between the gases passing the vanes and the blades of the turbine wheel. Flow through the passages is controlled by a flapper valve to direct it to one or the other or both passages depending upon the load factor for the engine.

  8. A High Dynamic Range and Low Power Consumption Audio Delta-Sigma Modulator with Opamp Sharing Technique among Three Integrators

    Science.gov (United States)

    Kanemoto, Daisuke; Ido, Toru; Taniguchi, Kenji

    A low power and high performance with third order delta-sigma modulator for audio applications, fabricated in a 0.18µm CMOS process, is presented. The modulator utilizes a third order noise shaping with only one opamp by using an opamp sharing technique. The opamp sharing among three integrator stages is achieved through the optimal operation timing, which makes use of the load capacitance differences between the three integrator stages. The designed modulator achieves 101.1dB signal-to-noise ratio (A-weighted) and 101.5dB dynamic range (A-weighted) with 7.5mW power consumption from a 3.3V supply. The die area is 1.27mm2. The fabricated delta-sigma modulator achieves the highest figure-of-merit among published high performance low power audio delta-sigma modulators.

  9. BEGA Starter/Alternator—Vector Control Implementation and Performance for Wide Speed Range at Unity Power Factor Operation

    DEFF Research Database (Denmark)

    Boldea, Ion; Coroban-Schramel, Vasile; Andreescu, Gheorghe-Daniel

    2010-01-01

    The Biaxial Excitation Generator for Automobiles (BEGA) is proposed as a solution for integrated starter/alternator systems used in hybrid electric vehicles. This paper demonstrates through experiments and simulations that BEGA has a very large constant power speed range. A vector control structure...... is proposed for BEGA operation during motoring and generating, at unity power factor with zero d-axis current (id) and zero q-axis flux (Ψq) control. In such conditions, BEGA behaves like a separately excited dc brush(commutator) machine, in the sense that no stator inductance voltage drop occurs...... in such constraint control conditions. A high iq current is required in order to cancel the q-axis flux, during unity power factor operation. This engages higher copper losses in the machine under light load. In order to minimize the copper losses, for lower load levels, a current referencer is proposed. Due...

  10. Determining the bounds of skilful forecast range for probabilistic prediction of system-wide wind power generation

    Directory of Open Access Journals (Sweden)

    Dirk Cannon

    2017-06-01

    Full Text Available State-of-the-art wind power forecasts beyond a few hours ahead rely on global numerical weather prediction models to forecast the future large-scale atmospheric state. Often they provide initial and boundary conditions for nested high resolution simulations. In this paper, both upper and lower bounds on forecast range are identified within which global ensemble forecasts provide skilful information for system-wide wind power applications. An upper bound on forecast range is associated with the limit of predictability, beyond which forecasts have no more skill than predictions based on climatological statistics. A lower bound is defined at the lead time beyond which the resolved uncertainty associated with estimating the future large-scale atmospheric state is larger than the unresolved uncertainty associated with estimating the system-wide wind power response to a given large-scale state.The bounds of skilful ensemble forecast range are quantified for three leading global forecast systems. The power system of Great Britain (GB is used as an example because independent verifying data is available from National Grid. The upper bound defined by forecasts of GB-total wind power generation at a specific point in time is found to be 6–8 days. The lower bound is found to be 1.4–2.4 days. Both bounds depend on the global forecast system and vary seasonally. In addition, forecasts of the probability of an extreme power ramp event were found to possess a shorter limit of predictability (4.5–5.5 days. The upper bound on this forecast range can only be extended by improving the global forecast system (outside the control of most users or by changing the metric used in the probability forecast. Improved downscaling and microscale modelling of the wind farm response may act to decrease the lower bound. The potential gain from such improvements have diminishing returns beyond the short-range (out to around 2 days.

  11. 47 CFR 22.659 - Effective radiated power limits.

    Science.gov (United States)

    2010-10-01

    ... radiated power limits. The purpose of the rules in this section, which limit effective radiated power (ERP... subsequently relocated. (a) Maximum ERP. The ERP of base transmitters must not exceed 100 Watts under any circumstances. The ERP of mobile transmitters must not exceed 60 Watts under any circumstances. (b)...

  12. Design Issues for Low Power Integrated Thermal Flow Sensors with Ultra-Wide Dynamic Range and Low Insertion Loss

    Directory of Open Access Journals (Sweden)

    Paolo Bruschi

    2012-04-01

    Full Text Available Flow sensors are the key elements in most systems for monitoring and controlling fluid flows. With the introduction of MEMS thermal flow sensors, unprecedented performances, such as ultra wide measurement ranges, low power consumptions and extreme miniaturization, have been achieved, although several critical issues have still to be solved. In this work, a systematic approach to the design of integrated thermal flow sensors, with specification of resolution, dynamic range, power consumption and pressure insertion loss is proposed. All the critical components of the sensors, namely thermal microstructure, package and read-out interface are examined, showing their impact on the sensor performance and indicating effective optimization strategies. The proposed design procedures are supported by experiments performed using a recently developed test chip,including several different sensing structures and a flexible electronic interface.

  13. High-power pulsed laser diodes emitting in the range 1.5 – 1.6 μm

    Energy Technology Data Exchange (ETDEWEB)

    Gorlachuk, P V; Ryaboshtan, Yu L; Ladugin, M A; Padalitsa, A A; Marmalyuk, A A; Kurnosov, V D; Kurnosov, K V; Zhuravleva, O V; Romantsevich, V I; Chernov, R V; Ivanov, A V; Simakov, V A [Open Joint-Stock Company M.F. Stel' makh Polyus Research Institute, Moscow (Russian Federation)

    2013-09-30

    This paper examines approaches for increasing the output pulse power of laser diodes based on MOVPE InGaAs/AlGaInAs/InP heterostructures and emitting in the range 1.5 – 1.6 μm. We demonstrate that optimising waveguide layer parameters may ensure an increase in the quantum efficiency of the laser diodes and a reduction in their internal optical loss. Characterisation results are presented for laser diodes based on the proposed heterostructures. (lasers)

  14. Wide Input Range Power Converters Using a Variable Turns Ratio Transformer

    DEFF Research Database (Denmark)

    Ouyang, Ziwei; Andersen, Michael A. E.

    2016-01-01

    A new integrated transformer with variable turns ratio is proposed to enable dc-dc converters operating over a wide input voltage range. The integrated transformer employs a new geometry of magnetic core with “four legs”, two primary windings with orthogonal arrangement, and “8” shape connection...... of diagonal secondary windings, in order to make the transformer turns ratio adjustable by controlling the phase between the two current excitations subjected to the two primary windings. Full-bridge boost dc-dc converter is employed with the proposed transformer to demonstrate the feasibility of the variable...

  15. Safety evaluation report related to the operation of Watts Bar Nuclear Plant, Units 1 and 2 (Docket Nos. 50-390 and 50-391). Supplement No. 17

    Energy Technology Data Exchange (ETDEWEB)

    Tam, P.S.

    1995-10-01

    This report supplements the Safety Evaluation Report (SER), NUREG-0847 (June 1982), Supplement No. 1 (September 1982), Supplement No. 2 (January 1984), Supplement No. 3 (January 1985), Supplement No. 4 (March 1985), Supplement No. 5 (November 1990), Supplement No. 6 (April 1991), Supplement No. 7 (September 1991), 1991), Supplement No. 8 (January 1992), Supplement No. 9 (June 1992), Supplement No. 10 (October 1992), Supplement No. 11 (April.1993), Supplement No. 12 (October 1993), Supplement No. 13 (April 1994), Supplement No. 14 (December 1994), Supplement No. 15 (June 1995), and Supplement No. 16 (September 1995) issued by the Office of Nuclear Reactor Regulation of the US Nuclear Regulatory Commission with respect to the application filed by the Tennessee Valley Authority, as applicant and owner, for licenses to operate the Watts Bar Nuclear Plant, Units 1 and 2 (Docket Nos. 50--390 and 50--391). The facility is located in Rhea county, Tennessee, near the Watts Bar Dam on the Tennessee River. In this supplement, NRC examines the significant problems of construction quality and quality assurance effectiveness that led TVA to withdraw its certification in 1985 that Watts Bar Unit I was ready to load fuel. Also discussed are the extensive corrective actions performed by TVA according to its nuclear performance plans and other supplemental programs, and NRC`s extensive oversight to determine whether the Watts Bar Unit 1 construction quality and TVA`s operational readiness and quality assurance effectiveness are adequate for a low-power operating license to be issued. SSER 17 does not address Watts Bar Unit 2, except for the systems which are necessary to support Unit 1 operation.

  16. Lightweight Innovative Solar Array (LISA): Providing Higher Power to Small Spacecraft

    Science.gov (United States)

    Johnson, Les; Carr, John; Fabisinski, Leo; Russell,Tiffany; Smith, Leigh

    2015-01-01

    Affordable and convenient access to electrical power is essential for all spacecraft and is a critical design driver for the next generation of smallsats, including cubesats, which are currently extremely power limited. The Lightweight Innovative Solar Array (LISA), a concept designed, prototyped, and tested at the NASA Marshall Space Flight Center (MSFC) in Huntsville, Alabama provides an affordable, lightweight, scalable, and easily manufactured approach for power generation in space. This flexible technology has many wide-ranging applications from serving small satellites to providing abundant power to large spacecraft in GEO and beyond. By using very thin, ultra-flexible solar arrays adhered to an inflatable structure, a large area (and thus large amount of power) can be folded and packaged into a relatively small volume. The LISA array comprises a launch-stowed, orbit-deployed structure on which lightweight photovoltaic devices and, potentially, transceiver elements are embedded. The system will provide a 2.5 to 5 fold increase in specific power generation (Watts/kilogram) coupled with a >2x enhancement of stowed volume (Watts/cubic-meter) and a decrease in cost (dollars/Watt) when compared to state-of-the-art solar arrays.

  17. Muscle coordination limits efficiency and power output of human limb movement under a wide range of mechanical demands.

    Science.gov (United States)

    Blake, Ollie M; Wakeling, James M

    2015-12-01

    This study investigated the influence of cycle frequency and workload on muscle coordination and the ensuing relationship with mechanical efficiency and power output of human limb movement. Eleven trained cyclists completed an array of cycle frequency (cadence)-power output conditions while excitation from 10 leg muscles and power output were recorded. Mechanical efficiency was maximized at increasing cadences for increasing power outputs and corresponded to muscle coordination and muscle fiber type recruitment that minimized both the total muscle excitation across all muscles and the ineffective pedal forces. Also, maximum efficiency was characterized by muscle coordination at the top and bottom of the pedal cycle and progressive excitation through the uniarticulate knee, hip, and ankle muscles. Inefficiencies were characterized by excessive excitation of biarticulate muscles and larger duty cycles. Power output and efficiency were limited by the duration of muscle excitation beyond a critical cadence (120-140 rpm), with larger duty cycles and disproportionate increases in muscle excitation suggesting deteriorating muscle coordination and limitations of the activation-deactivation capabilities. Most muscles displayed systematic phase shifts of the muscle excitation relative to the pedal cycle that were dependent on cadence and, to a lesser extent, power output. Phase shifts were different for each muscle, thereby altering their mechanical contribution to the pedaling action. This study shows that muscle coordination is a key determinant of mechanical efficiency and power output of limb movement across a wide range of mechanical demands and that the excitation and coordination of the muscles is limited at very high cycle frequencies. Copyright © 2015 the American Physiological Society.

  18. On the extent of size range and power law scaling for particles of natural carbonate fault cores

    Science.gov (United States)

    Billi, Andrea

    2007-09-01

    To determine the size range and both type and extent of the scaling laws for particles of loose natural carbonate fault rocks, six granular fault cores from Mesozoic carbonate strata of central Italy were sampled. Particle size distributions of twelve samples were determined by combining sieving and sedimentation methods. Results show that, regardless of the fault geometry, kinematics, and tectonic history, the size of fault rock particles respects a power law distribution across approximately four orders of magnitude. The fractal dimension ( D) of the particle size distribution in the analysed samples ranges between ˜2.0 and ˜3.5. A lower bound to the power law trend is evident in all samples except in those with the highest D-values; in these samples, the smallest analysed particles (˜0.0005 mm in diameter) were also included in the power law interval, meaning that the lower size limit of the power law distribution decreases for increasing D-values and that smallest particles start to be comminuted with increasing strain (i.e. increasing fault displacement and D-values). For increasing D-values, also the largest particles tends to decrease in number, but this evidence may be affected by a censoring bias connected with the sample size. Stick-slip behaviour is suggested for the studied faults on the basis of the inferred particle size evolutions. Although further analyses are necessary to make the results of this study more generalizable, the preliminary definition of the scaling rules for fault rock particles may serve as a tool for predicting a large scale of fault rock particles once a limited range is known. In particular, data from this study may result useful as input numbers in numerical models addressing the packing of fault rock particles for frictional and hydraulic purposes.

  19. High-power coherent GaAs-based monolithic semiconductor lasers

    Science.gov (United States)

    Botez, Dan

    2001-11-01

    Stable-beam operation to high coherent powers from large aperture devices can only be obtained from active-photonic- lattice (APL) structures of large built-in index step. Resonant phase-locked arrays of antiguides, so called ROW array, have provided 1.6W CW coherent power from 200micrometers - wide apertures. Two-dimensional surface-emitting APLs combining ROW arrays and DFB-DBR structures with central (pi) phase-shift are capable of providing coherent powers in the multi-watt range. ARROW-type devices, simpler APL structures, hold the potential for emitting 1W single-mode CW power reliability in stable beam patterns.

  20. High-power Bessel beams with orbital angular momentum in the terahertz range

    Science.gov (United States)

    Choporova, Yu. Yu.; Knyazev, B. A.; Kulipanov, G. N.; Pavelyev, V. S.; Scheglov, M. A.; Vinokurov, N. A.; Volodkin, B. O.; Zhabin, V. N.

    2017-08-01

    In this paper, we have performed experimental, analytical, and numerical studies of beams with topological charges of ±1 and ±2 formed by silicon binary phase axicons (BPAs) with spiral zone structures. The axicons were illuminated with the Novosibirsk free electron laser radiation (a continuous stream of 100-ps pulses at f =5.6 MHz). The cw power of the beams produced reached 30 W and can by doubled via antireflection coating of the axicons. The intensity distribution in the beam cross sections was in good agreement with the Bessel functions and was kept constant within a distance of about L /r ≈190 and 100, where the first ring radii of the beams r were 0.9 and 1.5 mm for the Bessel beams of the first and second orders, respectively. Although the characteristics of the beams (Bessel cross section, "diffraction-free" propagation, self-recovery after passing obstacles, and randomly inhomogeneous media) corresponded to the properties of ideal Bessel beams, their spatial Fourier spectrum (the image in the focal plane of the lens) was, instead of an ideal ring, intertwined segments of arcs with phases shifted by π , the number of which was equal to the double value of the topological charge. This feature can be used, for example, in a demultiplexing unit of a free vortex-wave communication system or for identification of beam topological charge. We also revisited Young's double-slit diffraction and rotation of beams obstructed by a half-plane, previously applied to Laguerre-Gaussian beam characterization, in the case of the Bessel beams. The Young diffraction pattern demonstrated in this case a complicated intensity-phase distribution. It was shown that the Bessel beams formed by BPAs have two important advantages, which can be used in applications, in comparison with other methods of generation, e.g., a combination of an axicon lens with a spiral phase plate. Although the phase jumps of the axicons are designed for a determined wavelength (141 μ m in our case

  1. Incident particle range dependence of radiation damage in a power bipolar junction transistor

    Science.gov (United States)

    Liu, Chao-Ming; Li, Xing-Ji; Geng, Hong-Bin; Rui, Er-Ming; Guo, Li-Xin; Yang, Jian-Qun

    2012-10-01

    The characteristic degradations in silicon NPN bipolar junction transistors (BJTs) of type 3DD155 are examined under the irradiations of 25-MeV carbon (C), 40-MeV silicon (Si), and 40-MeV chlorine (Cl) ions respectively. Different electrical parameters are measured in-situ during the exposure of heavy ions. The experimental data shows that the changes in the reciprocal of the gain variation (Δ(1/β)) of 3DD155 transistors irradiated respectively by 25-MeV C, 40-MeV Si, and 40-MeV Cl ions each present a nonlinear behaviour at a low fluence and a linear response at a high fluence. The Δ(1/β) of 3DD155 BJT irradiated by 25-MeV C ions is greatest at a given fluence, a little smaller when the device is irradiated by 40-MeV Si ions, and smallest in the case of the 40-MeV Cl ions irradiation. The measured and calculated results clearly show that the range of heavy ions in the base region of BJT affects the level of radiation damage.

  2. Incident particle range dependence of radiation damage in a power bipolar junction transistor

    Institute of Scientific and Technical Information of China (English)

    Liu Chao-Ming; Li Xing-Ji; Geng Hong-Bin; Rui Er-Ming; Guo Li-Xin; Yang Jian-Qun

    2012-01-01

    The characteristic degradations in silicon NPN bipolar junction transistors (BJTs) of type 3DD155 are examined under the irradiations of 25-MeV carbon (C),40-MeV silicon (Si),and 40-MeV chlorine (C1) ions respectively.Different electrical parameters are measured in-situ during the exposure of heavy ions.The experimental data shows that the changes in the reciprocal of the gain variation (△(1/β)) of 3DD155 transistors irradiated respectively by 25-MeV C,40-MeV Si,and 40-MeV C1 ions each present a nonlinear behaviour at a low fluence and a linear response at a high fluence.The △(1/β) of 3DDl55 BJT irradiated by 25-MeV C ions is greatest at a given fluence,a little smaller when the device is irradiated by 40-MeV Si ions,and smallest in the case of the 40-MeV C1 ions irradiation.The measured and calculated results clearly show that the range of heavy ions in the base region of BJT affects the level of radiation damage.

  3. Power System for Venus Surface Exploration

    Science.gov (United States)

    Landis, Geoffrey A.; Mellott, Kenneth

    2002-01-01

    A radioisotope power and cooling system is designed to provide electrical power for a probe operating on the surface of Venus. Most foreseeable electronics devices and sensors cannot operate at the 450 C ambient surface temperature of Venus. Because the mission duration is substantially long and the use of thermal mass to maintain an operable temperature range is likely impractical, some type of active refrigeration may be required to keep electronic components at a temperature below ambient. The fundamental cooling parameters are the cold sink temperature, the hot sink temperature, and the amount of heat to be removed. In this instance, it is anticipated that electronics would have a nominal operating temperature of 300 C. Due to the highly thermal convective nature of the high-density (90 bar CO2) atmosphere, the hot sink temperature was assumed to be 50 C, which provided a 500 C temperature of the cooler's heat rejecter to the ambient atmosphere. The majority of the heat load on the cooler is from the high temperature ambient surface environment on Venus, with a small contribution of heat generation from electronics and sensors. Both thermoelectric (RTG) and dynamic power conversion systems were analyzed, based on use of a standard isotope (General-purpose heat source, or GPHS) brick. For the radioisotope Stirling power converter configuration designed, the Sage model predicts a thermodynamic power output capacity of 478.1 watts, which slightly exceeds the required 469.1 watts. The hot sink temperature is 1200 C, and the cold sink temperature is 500 C. The required heat input is 1740 watts. This gives a thermodynamic efficiency of 27.48 %. It is estimated that the mechanical efficiency of the power converter design is on the order of 85 %, based on experimental measurements taken from 500-watt power class, laboratory-tested Stirling engines. The overall efficiency is calculated to be 23.36 %. The mass of the power converter is estimated at approximately 21.6 kg

  4. Considerations on fatigue stress range calculations in nuclear power plants using on-line monitoring systems and the ASME Code

    Energy Technology Data Exchange (ETDEWEB)

    Cicero, R., E-mail: ciceror@unican.e [INESCO INGENIEROS S.L., Santander (Spain); Departamento de Ciencia e Ingenieria del Terreno y los Materiales, Universidad de Cantabria, Santander (Spain); Cicero, S. [Departamento de Ciencia e Ingenieria del Terreno y los Materiales, Universidad de Cantabria, Santander (Spain); Gorrochategui, I. [Centro Tecnologico de Componentes, Santander (Spain); Lacalle, R. [INESCO INGENIEROS S.L., Santander (Spain); Departamento de Ciencia e Ingenieria del Terreno y los Materiales, Universidad de Cantabria, Santander (Spain)

    2010-01-15

    Nuclear power plants are generally designed and inspected according to the ASME Code. This code indicates stress intensity (S{sub INT}) as the parameter to be used in the stress analysis of components. One of the particularities of S{sub INT} is that it always takes positive values, independently of the nature of the stress (tensile or compressive). This circumstance is relevant in the Fatigue Monitoring Systems used in nuclear power plants, due to the manner in which the different variable stresses are combined in order to obtain the final total stress range. This paper describes some situations derived from the application of the ASME Code, shows different ways of dealing with them and illustrates their influence on the evaluation of the fatigue usage factor through a case study.

  5. The Watts-Strogatz network model developed by including degree distribution: theory and computer simulation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y W [Surface Physics Laboratory and Department of Physics, Fudan University, Shanghai 200433 (China); Zhang, L F [Surface Physics Laboratory and Department of Physics, Fudan University, Shanghai 200433 (China); Huang, J P [Surface Physics Laboratory and Department of Physics, Fudan University, Shanghai 200433 (China)

    2007-07-20

    By using theoretical analysis and computer simulations, we develop the Watts-Strogatz network model by including degree distribution, in an attempt to improve the comparison between characteristic path lengths and clustering coefficients predicted by the original Watts-Strogatz network model and those of the real networks with the small-world property. Good agreement between the predictions of the theoretical analysis and those of the computer simulations has been shown. It is found that the developed Watts-Strogatz network model can fit the real small-world networks more satisfactorily. Some other interesting results are also reported by adjusting the parameters in a model degree-distribution function. The developed Watts-Strogatz network model is expected to help in the future analysis of various social problems as well as financial markets with the small-world property.

  6. First measurements of the flux integral with the NIST-4 watt balance

    CERN Document Server

    Haddad, D; Chao, L S; Cao, A; Sineriz, G; Pratt, J R; Newell, D B; Schlamminger, S

    2015-01-01

    In early 2014, construction of a new watt balance, named NIST-4, has started at the National Institute of Standards and Technology (NIST). In a watt balance, the gravitational force of an unknown mass is compensated by an electromagnetic force produced by a coil in a magnet system. The electromagnetic force depends on the current in the coil and the magnetic flux integral. Most watt balances feature an additional calibration mode, referred to as velocity mode, which allows one to measure the magnetic flux integral to high precision. In this article we describe first measurements of the flux integral in the new watt balance. We introduce measurement and data analysis techniques to assess the quality of the measurements and the adverse effects of vibrations on the instrument.

  7. U.S. Department of Energy Space and Defense Power Systems Program Ten-Year Strategic Plan, Volume 1 and Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Dwight, Carla

    2013-06-01

    The Department of Energy's Space and Defense Power Systems program provides a unique capability for supplying power systems that function in remote or hostile environments. This capability has been functioning since the early 1960s and counts the National Aeronautics and Space Administration as one of its most prominent customers. This enabling technology has assisted the exploration of our solar system including the planets Jupiter, Saturn, Mars, Neptune, and soon Pluto. This capability is one-of-kind in the world in terms of its experience (over five decades), breadth of power systems flown (over two dozen to date) and range of power levels (watts to hundreds of watts). This document describes the various components of that infrastructure, work scope, funding needs, and its strategic plans going forward.

  8. From single photons to milliwatt radiant power-electron storage rings as radiation sources with a high dynamic range

    Energy Technology Data Exchange (ETDEWEB)

    Klein, R.; Thornagel, R.; Ulm, G. [Physikalisch-Technische Bundesanstalt, Berlin (Germany)

    2010-10-15

    The spectral radiant intensity of synchrotron radiation from electron storage rings can be calculated from basic electrodynamic relations (Schwinger equation) and it is directly proportional to the stored electron beam current, i.e. the number of stored electrons. With the necessary equipment installed to measure and control the electron beam current over a wide dynamic range, the radiant intensity of the synchrotron radiation can be adjusted accordingly without changing the spectrum. This is done, e.g., at the Metrology Light Source (MLS), the dedicated electron storage ring of the Physikalisch-Technische Bundesanstalt. The MLS is operated as a primary radiation source standard from the near IR up to the soft x-ray region and its operational parameters can be adjusted and accurately measured in a wide range: the electron beam current can be varied from 1 pA (one stored electron) up to 200 mA and thus the radiant intensity can be changed by more than 11 decades. The photon flux or radiant power for typical angular acceptances can thus be varied from single photons to milliwatts. This is a very powerful tool, e.g., for the characterization of the linearity of the response of radiation detectors or for the calibration of photon counting detectors. In this article we present an overview of past, current and possible future activities exploiting this feature. (authors)

  9. 47 CFR 22.867 - Effective radiated power limits.

    Science.gov (United States)

    2010-10-01

    ... Effective radiated power limits. The effective radiated power (ERP) of ground and airborne stations... peak ERP of airborne mobile station transmitters must not exceed 12 Watts. (b) The peak ERP of...

  10. Analog Encoding Voltage—A Key to Ultra-Wide Dynamic Range and Low Power CMOS Image Sensor

    Directory of Open Access Journals (Sweden)

    Orly Yadid-Pecht

    2013-03-01

    Full Text Available Usually Wide Dynamic Range (WDR sensors that autonomously adjust their integration time to fit intra-scene illumination levels use a separate digital memory unit. This memory contains the data needed for the dynamic range. Motivated by the demands for low power and chip area reduction, we propose a different implementation of the aforementioned WDR algorithm by replacing the external digital memory with an analog in-pixel memory. This memory holds the effective integration time represented by analog encoding voltage (AEV. In addition, we present a “ranging” scheme of configuring the pixel integration time in which the effective integration time is configured at the first half of the frame. This enables a substantial simplification of the pixel control during the rest of the frame and thus allows for a significantly more remarkable DR extension. Furthermore, we present the implementation of “ranging” and AEV concepts on two different designs, which are targeted to reach five and eight decades of DR, respectively. We describe in detail the operation of both systems and provide the post-layout simulation results for the second solution. The simulations show that the second design reaches DR up to 170 dBs. We also provide a comparative analysis in terms of the number of operations per pixel required by our solution and by other widespread WDR algorithms. Based on the calculated results, we conclude that the proposed two designs, using “ranging” and AEV concepts, are attractive, since they obtain a wide dynamic range at high operation speed and low power consumption.

  11. Comprehensive analysis of proton range uncertainties related to patient stopping-power-ratio estimation using the stoichiometric calibration.

    Science.gov (United States)

    Yang, Ming; Zhu, X Ronald; Park, Peter C; Titt, Uwe; Mohan, Radhe; Virshup, Gary; Clayton, James E; Dong, Lei

    2012-07-07

    The purpose of this study was to analyze factors affecting proton stopping-power-ratio (SPR) estimations and range uncertainties in proton therapy planning using the standard stoichiometric calibration. The SPR uncertainties were grouped into five categories according to their origins and then estimated based on previously published reports or measurements. For the first time, the impact of tissue composition variations on SPR estimation was assessed and the uncertainty estimates of each category were determined for low-density (lung), soft, and high-density (bone) tissues. A composite, 95th percentile water-equivalent-thickness uncertainty was calculated from multiple beam directions in 15 patients with various types of cancer undergoing proton therapy. The SPR uncertainties (1σ) were quite different (ranging from 1.6% to 5.0%) in different tissue groups, although the final combined uncertainty (95th percentile) for different treatment sites was fairly consistent at 3.0-3.4%, primarily because soft tissue is the dominant tissue type in the human body. The dominant contributing factor for uncertainties in soft tissues was the degeneracy of Hounsfield numbers in the presence of tissue composition variations. To reduce the overall uncertainties in SPR estimation, the use of dual-energy computed tomography is suggested. The values recommended in this study based on typical treatment sites and a small group of patients roughly agree with the commonly referenced value (3.5%) used for margin design. By using tissue-specific range uncertainties, one could estimate the beam-specific range margin by accounting for different types and amounts of tissues along a beam, which may allow for customization of range uncertainty for each beam direction.

  12. Wind speed and wind power short and medium range predictions for complex terrain using artificial neural networks and ensemble calibration

    Science.gov (United States)

    Schicker, Irene; Papazek, Petrina; Kann, Alexander; Wang, Yong

    2017-04-01

    Reliable predictions of wind speed and wind power are vital for balancing the electricity network. Within the last two decades the amount of energy stemming from renewable sources increased substantially relying heavily on the prevailing synoptic conditions. Especially for regions with complex terrain and forested surfaces providing reliable predictions is a challenging task. Forecasts in the nowcasting as well as in the (two) day-ahead range are thus essential for the network balancing. Predictions of wind speed and wind power from the nowcasting to the +72-hour forecast range using NWP models in regions with complex terrain need a suitable horizontal, vertical and temporal resolution (e.g. 10 - 15 minute forecasts for the Nowcasting range) requiring high performance computing. To be able to provide sub-hourly to hourly forecasts different approaches such as model output statistics (MOS) or artificial neural networks (ANN) - including feed forward recurrent neural networks, fuzzy logic, particle swarm optimizations - are needed as computational costs are too high. To represent the forecast uncertainties additional probabilistic ensemble predictions are required increasing the computational needs. Ensemble prediction systems account for errors and uncertainties in the initial and boundary conditions, parameterizations, numeric, etc. Due to the underestimation of model and sampling errors ensemble predictions tend to be underdispersive and biased. They lack, too, sharpness and reliability. These shortcomings can be accounted for using statistical post-processing methods such as the non-homogeneous Gaussian regression (NGR) to calibrate an ensemble. These calibrated ensembles provide forecasts in the medium range for any arbitrary location where observations are available. In this study an ANN is used to provide forecasts for the nowcasting and medium-range with sub-hourly to hourly predictions for different Austrian sites, including high alpine sites as well as low

  13. On a Finite Range Decomposition of the Resolvent of a Fractional Power of the Laplacian II. The Torus

    Science.gov (United States)

    Mitter, P. K.

    2017-09-01

    In previous papers, Mitter (J Stat Phys 163:1235-1246, 2016; Erratum: J Stat Phys 166:453-455, 2017; On a finite range decomposition of the resolvent of a fractional power of the Laplacian, http://arxiv.org/abs/1512.02877), we proved the existence as well as regularity of a finite range decomposition for the resolvent G_{α } (x-y,m^2) = ((-Δ )^{α \\over 2} + m2)^{-1} (x-y) , for 0<α <2 and all real m, in the lattice Zd for dimension d≥ 2. In this paper, which is a continuation of the previous one, we extend those results by proving the existence as well as regularity of a finite range decomposition for the same resolvent but now on the lattice torus Zd/L^{N+1}Zd for d≥ 2 provided m≠ 0 and 0<α <2. We also prove differentiability and uniform continuity properties with respect to the resolvent parameter m2. Here L is any odd positive integer and N≥ 2 is any positive integer.

  14. Extended femtosecond laser wavelength range to 330 nm in a high power LBO based optical parametric oscillator.

    Science.gov (United States)

    Fan, Jintao; Gu, Chenglin; Wang, Chingyue; Hu, Minglie

    2016-06-13

    We experimentally demonstrate a compact tunable, high average power femtosecond laser source in the ultraviolet (UV) regime. The laser source is based on intra-cavity frequency doubling of a temperature-tuned lithium tribotate (LBO) optical parametric oscillator (OPO), synchronously pumped at 520 nm by a frequency-doubled, Yb-fiber femtosecond laser amplifier system. By adjusting crystal temperature, the OPO can provide tunable visible to near-infrared (NIR) signal pulse, which have a wide spectral tuning range from 660 to 884 nm. Using a β-barium borate (BBO) crystal for intra-cavity frequency doubling, tunable femtosecond UV pulse are generated across 330~442 nm with up to 364 mW at 402 nm.

  15. Surface-emitting terahertz quantum cascade lasers with continuous-wave power in the tens of milliwatt range

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Gangyi, E-mail: gangyi.xu@mail.sitp.ac.cn [Institut d' Electronique Fondamentale, Univ. Paris Sud, UMR8622 CNRS, 91405 Orsay (France); Key Laboratory of Infrared Imaging Materials and Detectors, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China); Li, Lianhe; Giles Davies, A.; Linfield, Edmund H. [School of Electronic and Electrical Engineering, University of Leeds, Leeds LS9 2JT (United Kingdom); Isac, Nathalie; Halioua, Yacine; Colombelli, Raffaele, E-mail: raffaele.colombelli@u-psud.fr [Institut d' Electronique Fondamentale, Univ. Paris Sud, UMR8622 CNRS, 91405 Orsay (France)

    2014-03-03

    We demonstrate efficient surface-emitting terahertz frequency quantum cascade lasers with continuous wave output powers of 20–25 mW at 15 K and maximum operating temperatures of 80–85 K. The devices employ a resonant-phonon depopulation active region design with injector, and surface emission is realized using resonators based on graded photonic heterostructures (GPHs). GPHs can be regarded as energy wells for photons and have recently been implemented through grading the period of the photonic structure. In this paper, we show that it is possible to keep the period constant and grade instead the lateral metal coverage across the GPH. This strategy ensures spectrally single-mode operation across the whole laser dynamic range and represents an additional degree of freedom in the design of confining potentials for photons.

  16. Thermal control of power supplies with electronic packaging techniques. [using low cost heat pipes

    Science.gov (United States)

    1977-01-01

    The integration of low-cost commercial heat pipes in the design of a NASA candidate standard modular power supply with a 350 watt output resulted in a 44% weight reduction. Part temperatures were also appreciably reduced, increasing the environmental capability of the unit. A complete 350- watt modular power converter was built and tested to evaluate thermal performance of the redesigned supply.

  17. Ultralow-power and ultrafast all-optical tunable plasmon-induced transparency in metamaterials at optical communication range.

    Science.gov (United States)

    Zhu, Yu; Hu, Xiaoyong; Fu, Yulan; Yang, Hong; Gong, Qihuang

    2013-01-01

    Actively all-optical tunable plasmon-induced transparency in metamaterials paves the way for achieving ultrahigh-speed quantum information processing chips. Unfortunately, up to now, very small experimental progress has been made for all-optical tunable plasmon-induced transparency in metamaterials in the visible and near-infrared range because of small third-order optical nonlinearity of conventional materials. The achieved operating pump intensity was as high as several GW/cm(2) order. Here, we report an ultralow-power and ultrafast all-optical tunable plasmon-induced transparency in metamaterials coated on polycrystalline indium-tin oxide layer at the optical communication range. Compared with previous reports, the threshold pump intensity is reduced by four orders of magnitude, while an ultrafast response time of picoseconds order is maintained. This work not only offers a way to constructing photonic materials with large nonlinearity and ultrafast response, but also opens up the possibility for realizing quantum solid chips and ultrafast integrated photonic devices based on metamaterials.

  18. Comprehensive analysis of proton range uncertainties related to stopping-power-ratio estimation using dual-energy CT imaging

    Science.gov (United States)

    Li, B.; Lee, H. C.; Duan, X.; Shen, C.; Zhou, L.; Jia, X.; Yang, M.

    2017-09-01

    The dual-energy CT-based (DECT) approach holds promise in reducing the overall uncertainty in proton stopping-power-ratio (SPR) estimation as compared to the conventional stoichiometric calibration approach. The objective of this study was to analyze the factors contributing to uncertainty in SPR estimation using the DECT-based approach and to derive a comprehensive estimate of the range uncertainty associated with SPR estimation in treatment planning. Two state-of-the-art DECT-based methods were selected and implemented on a Siemens SOMATOM Force DECT scanner. The uncertainties were first divided into five independent categories. The uncertainty associated with each category was estimated for lung, soft and bone tissues separately. A single composite uncertainty estimate was eventually determined for three tumor sites (lung, prostate and head-and-neck) by weighting the relative proportion of each tissue group for that specific site. The uncertainties associated with the two selected DECT methods were found to be similar, therefore the following results applied to both methods. The overall uncertainty (1σ) in SPR estimation with the DECT-based approach was estimated to be 3.8%, 1.2% and 2.0% for lung, soft and bone tissues, respectively. The dominant factor contributing to uncertainty in the DECT approach was the imaging uncertainties, followed by the DECT modeling uncertainties. Our study showed that the DECT approach can reduce the overall range uncertainty to approximately 2.2% (2σ) in clinical scenarios, in contrast to the previously reported 1%.

  19. Ultra-low-power and ultra-low-cost short-range wireless receivers in nanoscale CMOS

    CERN Document Server

    Lin, Zhicheng; Martins, Rui Paulo

    2016-01-01

    This book provides readers with a description of state-of-the-art techniques to be used for ultra-low-power (ULP) and ultra-low-cost (ULC), short-range wireless receivers. Readers will learn what is required to deploy these receivers in short-range wireless sensor networks, which are proliferating widely to serve the internet of things (IoT) for “smart cities.” The authors address key challenges involved with the technology and the typical tradeoffs between ULP and ULC. Three design examples with advanced circuit techniques are described in order to address these trade-offs, which specially focus on cost minimization. These three techniques enable respectively, cascading of radio frequency (RF) and baseband (BB) circuits under an ultra-low-voltage (ULV) supply, cascoding of RF and BB circuits in current domain for current reuse, and a novel function-reuse receiver architecture, suitable for ULV and multi-band ULP applications such as the sub-GHz ZigBee. ·         Summarizes the state-of-the-art i...

  20. The '2000-Watt per person'- industrial society - Utopia, vision or necessity?; Die '2000 Watt pro Kopf'-Industriegesellschaft - Utopie, Vision oder Notwendigkeit?

    Energy Technology Data Exchange (ETDEWEB)

    Jochem, E

    2006-07-01

    This short article takes a look at the '2000-Watt per person' concept initially developed at the Swiss Federal Institute of Technology (ETH) in Zurich, Switzerland, in 1998. The author is of the opinion that the concept is not utopian but a vision that can be realised - providing it is accepted socially and that politics can implement it. Further work on the concept done at the ETH over the years is listed and commented on. A diagram provides an overview of energy resources, energy transformation and energy flows to final energy consumption. The question as to if the realisation of such a '2000-Watt'-society is actually necessary is posed.

  1. A discussion of $Bl$ conservation on a two dimensional magnetic field plane in watt balances

    CERN Document Server

    Li, Shisong; Huang, Songling

    2015-01-01

    The watt balance is an experiment being pursued in national metrology institutes for precision determination of the Planck constant $h$. In watt balances, the $1/r$ magnetic field, expected to generate a geometrical factor $Bl$ independent to any coil horizontal displacement, can be created by a strict two dimensional, symmetric (horizontal $r$ and vertical $z$) construction of the magnet system. In this paper, we present an analytical understanding of magnetic field distribution when the $r$ symmetry of the magnet is broken and the establishment of the $Bl$ conservation is shown. By using either Gauss's law on magnetism with monopoles or conformal transformations, we extend the $Bl$ conservation to arbitrary two dimensional magnetic planes where the vertical magnetic field component equals zero. The generalized $Bl$ conservation allows a relaxed physical alignment criteria for watt balance magnet systems.

  2. A LEGO Watt balance: An apparatus to determine a mass based on the new SI

    Science.gov (United States)

    Chao, L. S.; Schlamminger, S.; Newell, D. B.; Pratt, J. R.; Seifert, F.; Zhang, X.; Sineriz, G.; Liu, M.; Haddad, D.

    2015-11-01

    A global effort to redefine our International System of Units (SI) is underway, and the change to the new system is expected to occur in 2018. Within the newly redefined SI, the present base units will still exist but be derived from fixed numerical values of seven reference constants. In particular, the unit of mass (the kilogram) will be realized through a fixed value of the Planck constant h. A so-called watt balance, for example, can then be used to realize the kilogram unit of mass within a few parts in 108. Such a balance has been designed and constructed at the National Institute of Standards and Technology. For educational outreach and to demonstrate the principle, we have constructed a LEGO tabletop watt balance capable of measuring a gram-level masses to 1% relative uncertainty. This article presents the design, construction, and performance of the LEGO watt balance and its ability to determine h.

  3. Life test result of Ricor K529N 1watt linear cryocooler

    Science.gov (United States)

    Nachman, Ilan; Veprik, Alexander; Pundak, Nachman

    2007-04-01

    The authors summarize the results of the accelerated life testing of the Ricor type K529N 1 Watt linear split Stirling cooler. The test was conducted in the period 2003-2006, during which the cooler accumulated in excess of 27,500 working hours at an elevated ambient temperature, which is equivalent to 45,000 hours at normal ambient conditions, and performed about 7,500 operational cycles including cooldown and steady-state phases. The cryocooler performances were assessed through the cooldown time and power consumption; no visible degradation in performances was observed. After the cooler failure and the compressor disassembling, an electrical short was discovered in the driving coil. The analysis has shown that the wire insulating varnish was not suitable for such elevated temperatures. It is important to note that the cooler under test was taken from the earliest engineering series; in the later manufacturing line military grade wire with high temperature insulation was used, no customer complaints have been recorded in this instance Special attention was paid to the thorough examination of the technical condition of the critical components of the cooler interior. In particular, dynamic piston-cylinder seal, flying leads, internal O-rings and driving coil were examined in the compressor. As to the cold head, we focused on studying the conditions of the dynamic bushing-plunger seal, O-rings and displacer-regenerator. In addition, a leak test was performed to assess the condition of the metallic crushed seals. From the analysis, the authors draw the conclusion that the cooler design is adequate for long life performance (in excess of 20,000 working hours) applications.

  4. Assessment of Pellet-Clad Interaction Indicators in Watts Bar Unit 1 using the VERA Framework

    Energy Technology Data Exchange (ETDEWEB)

    Stimpson, Shane G [ORNL; Powers, Jeffrey J [ORNL; Clarno, Kevin T [ORNL; Pawlowski, Roger [Sandia National Laboratory (SNL); Bratton, Ryan [Pennsylvania State University

    2015-01-01

    The Consortium for Advanced Simulation of Light Water Reactors (CASL) aims to provide high-fidelity, multiphysics simulations of light water reactors (LWRs) by coupling a variety of codes within the Virtual Environment for Reactor Analysis (VERA). One of the primary goals of CASL is to predict local cladding failure through pellet-clad interaction (PCI). This capability is currently being pursued through several different approaches, such as with Tiamat, which is a simulation tool within VERA that more tightly couples the MPACT neutron transport solver, the CTF thermal hydraulics solver, and the MOOSE-based Bison-CASL fuel performance code. However, the process in this paper focuses on running fuel performance calculations with Bison-CASL to predict PCI using the multicycle output data from coupled neutron transport/thermal hydraulics simulations. In recent work within CASL, Watts Bar Unit 1 has been simulated over 12 cycles using the VERA core simulator capability based on MPACT and CTF. Using the output from these simulations, Bison-CASL results can be obtained without rerunning all 12 cycles, while providing some insight into PCI indicators. Multi-cycle Bison-CASL results are presented and compared against results from the FRAPCON fuel performance code. There are several quantities of interest in considering PCI and subsequent fuel rod failures, such as the clad hoop stress and maximum centerline fuel temperature, particularly as a function of time. Bison-CASL performs single-rod simulations using representative power and temperature distributions, providing high-resolution results for these and a number of other quantities. This will assist in identifying fuels rods as potential failure locations for use in further analyses.

  5. The Mars Hopper: a radioisotope powered, impulse driven, long-range, long-lived mobile platform for exploration of Mars

    Energy Technology Data Exchange (ETDEWEB)

    Steven D. Howe; Robert C. O' Brien; William Taitano; Doug Crawford; Nathan Jerred; Spencer Cooley; John Crapeau; Steve Hansen; Andrew Klein; James Werner

    2011-02-01

    Planetary exploration mission requirements are becoming more demanding. Due to the increasing cost, the missions that provide mobile platforms that can acquire data at multiple locations are becoming more attractive. Wheeled vehicles such as the MER rovers have proven extremely capable but have very limited range and cannot traverse rugged terrain. Flying vehicles such as balloons and airplanes have been proposed but are problematic due to the very thin atmospheric pressure and the strong, dusty winds present on Mars. The Center for Space Nuclear Research has designed an instrumented platform that can acquire detailed data at hundreds of locations during its lifetime - a Mars Hopper. The Mars Hopper concept utilizes energy from radioisotopic decay in a manner different from any existing radioisotopic power sources—as a thermal capacitor. By accumulating the heat from radioisotopic decay for long periods, the power of the source can be dramatically increased for short periods. The platform will be able to "hop" from one location to the next every 5-7 days with a separation of 5-10 km per hop. Preliminary designs show a platform that weighs around 52 kgs unfueled which is the condition at deployment. Consequently, several platforms may be deployed on a single launch from Earth. With sufficient lifetime, the entire surface of Mars can be mapped in detail by a couple dozen platforms. In addition, Hoppers can collect samples from all over the planet, including gorges, mountains and crevasses, and deliver them to a central location for eventual pick-up by a Mars Sample Return mission. The status of the Mars Hopper development project at the CSNR is discussed.

  6. Random walk in degree space and the time-dependent Watts-Strogatz model

    CERN Document Server

    Grande, H L Casa; Hase, M O

    2016-01-01

    In this work, we propose a scheme that provides an analytical estimate for the time-dependent degree distribution of some networks. This scheme maps the problem into a random walk in degree space, and then we choose the paths that are responsible for the dominant contributions. The method is illustrated on the dynamical versions of the Erd\\"os-R\\'enyi and Watts-Strogatz graphs, which were introduced as static models in the original formulation. We have succeeded in obtaining an analytical form for the dynamics Watts-Strogatz model, which is asymptotically exact for some regimes.

  7. Evolutionary snowdrift game on heterogeneous Newman-Watts small-world network

    Institute of Scientific and Technical Information of China (English)

    Yang Han-Xin; Gao Kun; Han Xiao-Pu; Wang Bing-Hong

    2008-01-01

    We study the evolutionary snowdrift game in a heterogeneous Newman-Watts small-world network. The hetero-geneity of the network is controlled by the number of hubs. It is found that the moderate heterogeneity of the network can promote the cooperation best. Besides, we study how the hubs affect the evolution of cooperative behaviours of the heterogeneous Newman-Watts small-world network. Simulation results show that both the initial states of hubs and the connections between hubs can play an important role. Our work gives a further insight into the effect of hubs on the heterogeneous networks.

  8. Subsea thermoelectric generators. 1- 10-watt peltier effect prototypes - a step towards autonomous electrical control units at subsea wellheads

    Energy Technology Data Exchange (ETDEWEB)

    Weid, J.P. von der; Silva, J.A.P. da; Gama, A.L.; Sant' Anna, A.C.

    1994-05-01

    Offshore oil production activities require the operation of underwater hydraulic or electric equipment. The high cost of acquisition and installation of umbilical cables to supply power is leading to the development of independently powered cableless equipment, connected to the surface by the transmission and reception of control signals through the water. As a first step toward these autonomous wellhead control systems, the authors designed and successfully tested in laboratory conditions a thermoelectric generator able to supply at least 10 watts of electric power, extracting it from the temperature difference between the oil and the surrounding water. Hydraulic pumps and pressure accumulators, control electronics, and valve actuators for wellhead control units are all technically solved problems, even for seafloors as deep as 1,000 meters. However, an autonomous underwater wellhead control unit can only be conceived if an energy source is available at the seafloor. The development of a reliable and compact power source is indeed a fundamental step towards autonomous wet Christmas tree valve actuators.

  9. 175-W continuous-wave master oscillator power amplifier structure ytterbium-doped all-fiber laser

    Institute of Scientific and Technical Information of China (English)

    Ping Yan; Shupeng Yin; Mali Gong

    2008-01-01

    We report on hundred watts range ytterbium-doped all-fiber laser assembly based on the master oscillator power amplifier structure. It consisted of an oscillator and an amplifier with all-fiber components. And fiber fusion splice made the laser be an integrated fiber system. It generated up to 175.5 W of continuouswave (CW) output power at 1085 nm with more than 75% extraction efficiency in the amplifier when the total coupled pump power into the double clad fiber was 270 W.

  10. Laser cutting - from 200 Watt to 12 Kilowatt

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove; Nielsen, Jakob Skov

    2004-01-01

    Laser cutting is the most widespread industrial application of high power lasers. The development of this process was initiated around 1970, when scientists at TWI first demonstrated laser cutting with coaxial gas assistance. 10 years later, the polarisation problem was solved and the technology...... got its breakthrough. Since then some 30,000 laser cutting systems have been installed worldwide, making the laser an important cutting tool in modern industry....

  11. Laser cutting - from 200 Watt to 12 Kilowatt

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove; Nielsen, Jakob Skov

    2004-01-01

    Laser cutting is the most widespread industrial application of high power lasers. The development of this process was initiated around 1970, when scientists at TWI first demonstrated laser cutting with coaxial gas assistance. 10 years later, the polarisation problem was solved and the technology...... got its breakthrough. Since then some 30,000 laser cutting systems have been installed worldwide, making the laser an important cutting tool in modern industry....

  12. De Novo Transcriptome Sequencing of Oryza officinalis Wall ex Watt to Identify Disease-Resistance Genes

    Directory of Open Access Journals (Sweden)

    Bin He

    2015-12-01

    Full Text Available Oryza officinalis Wall ex Watt is one of the most important wild relatives of cultivated rice and exhibits high resistance to many diseases. It has been used as a source of genes for introgression into cultivated rice. However, there are limited genomic resources and little genetic information publicly reported for this species. To better understand the pathways and factors involved in disease resistance and accelerating the process of rice breeding, we carried out a de novo transcriptome sequencing of O. officinalis. In this research, 137,229 contigs were obtained ranging from 200 to 19,214 bp with an N50 of 2331 bp through de novo assembly of leaves, stems and roots in O. officinalis using an Illumina HiSeq 2000 platform. Based on sequence similarity searches against a non-redundant protein database, a total of 88,249 contigs were annotated with gene descriptions and 75,589 transcripts were further assigned to GO terms. Candidate genes for plant–pathogen interaction and plant hormones regulation pathways involved in disease-resistance were identified. Further analyses of gene expression profiles showed that the majority of genes related to disease resistance were all expressed in the three tissues. In addition, there are two kinds of rice bacterial blight-resistant genes in O. officinalis, including two Xa1 genes and three Xa26 genes. All 2 Xa1 genes showed the highest expression level in stem, whereas one of Xa26 was expressed dominantly in leaf and other 2 Xa26 genes displayed low expression level in all three tissues. This transcriptomic database provides an opportunity for identifying the genes involved in disease-resistance and will provide a basis for studying functional genomics of O. officinalis and genetic improvement of cultivated rice in the future.

  13. A low-power tool for measuring acceleration, pressure, and temperature (APT) with wide dynamic range and bandwidth

    Science.gov (United States)

    Heesemann, Martin; Davis, Earl E.; Paros, Jerome; Johnson, Greg; Meldrum, Robert; Scherwath, Martin; Mihaly, Steven

    2017-04-01

    We present a new tool that facilitates the study of inter-related geodetic, geodynamic, seismic, and oceanographic phenomena. It incorporates a temperature compensated tri-axial accelerometer developed by Quartz Seismic Sensors, Inc., a pressure sensor built by Paroscientific Inc., and a low-power, high-precision frequency counter developed by Bennest Enterprises Ltd. and built by RBR, Ltd. The sensors are housed in a 7 cm o.d. titanium pressure case designed for use to full ocean depths (withstands more than 20 km of water pressure). Sampling intervals are programmable from 0.08 s to 1 hr; standard memory can store up to 130 million samples; total power consumption is roughly 115 mW when operating continuously and proportionately lower when operating intermittently (e.g., 2 mW average at 1 sample per min). Serial and USB communications protocols allow a variety of autonomous and cable-connection options. Measurement precision of the order of 10-8 of full scale (e.g., pressure equivalent to 4000 m water depth, acceleration = +/- 3 g) allows observations of pressure and acceleration variations of 0.4 Pa and 0.3 μm s-2. Long-term variations in vertical acceleration are sensitive to displacement through the gravity gradient down to a level of roughly 2 cm, and variations in horizontal acceleration are sensitive to tilt down to a level of 0.03 μrad. With the large dynamic ranges, high sensitivities and broad bandwidth (6 Hz to DC), ground motion associated with microseisms, strong and weak seismic ground motion, tidal loading, and slow and rapid geodynamic deformation - all normally studied using disparate instruments - can be observed with a single tool. Installation in the marine environment is accomplished by pushing the tool roughly 1 m vertically below the seafloor with a submersible or remotely operated vehicle, with no profile remaining above the seafloor to cause current-induced noise. The weight of the tool is designed to match the sediment it displaces to

  14. Texture and microstructure evolution in nickel electrodeposited from an additive-free Watts electrolyte

    DEFF Research Database (Denmark)

    Alimadadi, Hossein; da Silva Fanta, Alice Bastos; Kasama, Takeshi;

    2016-01-01

    Nickel layers with 〈100〉, 〈210〉, 〈110〉 and 〈211〉 fiber textures were electrodeposited from additive-free Watts type electrolytes by adjusting both the pH and the applied current density. Quantitative crystallographic texture analysis by XRD was supplemented by micro-texture analysis applying EBSD...

  15. Results of metallographical diagnostic examination of Navy half-watt thermoelectric converters degraded by accelerated tests

    Science.gov (United States)

    Rosell, F. E., Jr.; Rouklove, P. G.

    1977-01-01

    To verify the 15-year reliability of the Navy half-watt radioisotope thermoelectric generator (RTG), bismuth-telluride thermoelectric converters were submitted to testing at high temperatures which accelerated the degradation and caused failure of the converters. Metallographic diagnostic examination of failed units verified failure mechanisms. Results of diagnostic examinations are presented.

  16. Rock the Watt: An Energy Conservation Campaign at Pacific Northwest National Lab

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-01-01

    Case study describes Pacific Northwest National Laboratory's (PNNL) three-month Rock the Watt campaign to reduce energy use at its main campus in Richland, Washington. The campaign objectives were to educate PNNL employees about energy conservation opportunities in their workplace and to motivate them to help PNNL save energy and costs and to reduce greenhouse gas emissions.

  17. Method of defining isolation parameters in 1000 Watt symmetric electricity network

    Directory of Open Access Journals (Sweden)

    Samat Amurgaliev

    2009-10-01

    Full Text Available The authors define parameters for isolation three-phase electric network to provide safety conditions for personnel working at open-operated coal deposits. The authors conclude the technique provides satisfactory accuracy of the parameters’ defining, as well as simplicity and safety of coal mining works with electric network having pressure up to 1000 Watt.

  18. 76 FR 34799 - Permanent Dam Safety Modification at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams, TN

    Science.gov (United States)

    2011-06-14

    ... Permanent Dam Safety Modification at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams, TN AGENCY... various alternatives for permanent modifications to the existing dam facilities at Cherokee, Fort Loudoun, Tellico, and Watts Bar dams in Tennessee. The level of review will be determined after the public...

  19. Multi-watt 589nm fiber laser source

    Energy Technology Data Exchange (ETDEWEB)

    DAWSON, J W; DROBSHOFF, A D; BEACH, R J; MESSERLY, M J; PAYNE, S A; BROWN, A; PENNINGTON, D M; BAMFORD, D J; SHARPE, S J; COOK, D J

    2006-01-19

    We have demonstrated 3.5W of 589nm light from a fiber laser using periodically poled stoichiometric Lithium Tantalate (PPSLT) as the frequency conversion crystal. The system employs 938nm and 1583nm fiber lasers, which were sum-frequency mixed in PPSLT to generate 589nm light. The 938nm fiber laser consists of a single frequency diode laser master oscillator (200mW), which was amplified in two stages to >15W using cladding pumped Nd{sup 3+} fiber amplifiers. The fiber amplifiers operate at 938nm and minimize amplified spontaneous emission at 1088nm by employing a specialty fiber design, which maximizes the core size relative to the cladding diameter. This design allows the 3-level laser system to operate at high inversion, thus making it competitive with the competing 1088nm 4-level laser transition. At 15W, the 938nm laser has an M{sup 2} of 1.1 and good polarization (correctable with a quarter and half wave plate to >15:1). The 1583nm fiber laser consists of a Koheras 1583nm fiber DFB laser that is pre-amplified to 100mW, phase modulated and then amplified to 14W in a commercial IPG fiber amplifier. As a part of our research efforts we are also investigating pulsed laser formats and power scaling of the 589nm system. We will discuss the fiber laser design and operation as well as our results in power scaling at 589nm.

  20. A 20 GHz, 75 watt, helix TWT for space communications

    Science.gov (United States)

    Heney, J. F.; Tamashiro, R. N.

    A space-qualified, helix-type traveling wave tube is being developed for satellite communication systems in the frequency band of 17.7 to 21.2 GHz. The design approach stresses very high efficiency operation, but with very low distortion. The tube provides multi-mode operation, permitting CW saturated power output levels of 75, 40, and 7.5 W. Operation is also anticipated at 5 dB below these saturation levels to achieve the required low distortion levels. Advanced construction features include a five-stage depressed collector, a diamond supported helix slow-wave circuit, and a type M dispenser cathode. High reliability and long life (10 yr) are objectives of the tube design. Preliminary test results on early developmental models of this tube are very encouraging. An output power of 75 to 90 W has been achieved over the full bandwidth with about 40 dB of saturated gain. More importantly, the basic electronic efficiency of the interaction process has been increased from about 7.5-11 percent by the use of the diamond helix support compared to earlier tubes using BeO support rods. This effort is supported by NASA Lewis Research Center and is aimed toward application in the NASA Advanced Communications Satellite Technology Program.

  1. Watt-level passively Q-switched double-cladding fiber laser based on graphene oxide saturable absorber.

    Science.gov (United States)

    Yu, Zhenhua; Song, Yanrong; Dong, Xinzheng; Li, Yanlin; Tian, Jinrong; Wang, Yonggang

    2013-10-10

    A watt-level passively Q-switched ytterbium-doped double-cladding fiber laser with a graphene oxide (GO) absorber was demonstrated. The structure of the GO saturable absorber mirror (GO-SAM) was of the sandwich type. A maximum output power of 1.8 W was obtained around a wavelength of 1044 nm. To the best of our knowledge, this is the highest output power in Q-switched fiber lasers based on a GO saturable absorber. The pure GO was protected from the oxygen in the air so that the damage threshold of the GO-SAM was effectively raised. The gain fiber was a D-shaped ytterbium-doped double-cladding fiber. The pulse repetition rates were tuned from 120 to 215 kHz with pump powers from 3.89 to 7.8 W. The maximum pulse energy was 8.37 μJ at a pulse width of 1.7 μs.

  2. Beta-range cortical motor spectral power and corticomuscular coherence as a mechanism for effective corticospinal interaction during steady-state motor output.

    Science.gov (United States)

    Kristeva, Rumyana; Patino, Luis; Omlor, Wolfgang

    2007-07-01

    The steady-state motor output, occurring during static force, is characterized by synchronization between oscillatory cortical motor and muscle activity confined to the beta frequency range (15-30 Hz). The functional significance of this beta-range coherence remains unclear. We hypothesized that if the beta-range coherence had a functional role, it would have a behavioral correlate; specifically, it would be related to the precision of the steady-state motor output. To test this hypothesis, we investigated the corticomuscular (EEG-EMG) coherence in eight healthy subjects during steady-state motor output in a visuomotor task, in which the subjects exerted a static force with their right index finger to keep a visual cursor within a target zone. We show that the beta-range EEG-EMG coherence is related to the behavioral performance, i.e. the error signal between target and exerted force. Furthermore, we show that the amplitude of the cortical spectral power is also related to the performance. Moreover, we provide evidence that the EEG-EMG coherence and the cortical spectral power are not completely independent phenomena. Together, our findings indicate that higher beta-range cortical spectral power and increased corticospinal coherence in the beta-range improve motor performance during steady-state motor output. This suggests that the beta-range cortical motor spectral power and corticomuscular coherence may promote effective corticospinal interaction.

  3. Tuning range and output power optimization of an external-cavity GaN diode laser at 455  nm.

    Science.gov (United States)

    Chi, Mingjun; Jensen, Ole Bjarlin; Petersen, Paul Michael

    2016-03-20

    In this paper we discuss how different feedback gratings affect the tuning range and the output power of external feedback diode laser systems. A tunable high-power narrow-spectrum external-cavity diode laser system around 455 nm is investigated. The laser system is based on a high-power GaN diode laser in a Littrow external-cavity. Both a holographic diffraction grating and a ruled diffraction grating are used as feedback elements in the external cavity. The output power, spectral bandwidth, and tunable range of the external cavity diode laser system are measured and compared with the two gratings at different injected currents. When the holographic grating is used, the laser system can be tuned over a range of 1.4 nm with an output power around 530 mW. When the ruled grating is used, the laser system can be tuned over a range of 6.0 nm with an output power around 80 mW. The results can be used as a guide for selecting gratings for external-cavity diode lasers for different requirements.

  4. A Fully Digital AGC System with 100MHz Bandwidth and 35dB Dynamic Range Power Detectors for DVB-S2 Application

    Science.gov (United States)

    Pu, Younggun; Lee, Kang-Yoon

    This paper presents a fully digital gain control system with a new high bandwidth and wide dynamic range power detector for DVB-S2 application. Because the peak-to-average power ratio (PAPR) of DVB-S2 system is so high and the settling time requirement is so stringent, the conventional closed-loop analog gain control scheme cannot be used. The digital gain control is necessary for the robust gain control and the direct digital interface with the baseband modem. Also, it has several advantages over the analog gain control in terms of the settling time and insensitivity to the process, voltage and temperature variation. In order to have a wide gain range with fine step resolution, a new AGC system is proposed. The system is composed of high-bandwidth digital VGAs, wide dynamic range power detectors with RMS detector, low power SAR type ADC, and a digital gain controller. To reduce the power consumption and chip area, only one SAR type ADC is used, and its input is time-interleaved based on four power detectors. Simulation and measurement results show that the new AGC system converges with gain error less than 0.25dB to the desired level within 10µs. It is implemented in a 0.18µm CMOS process. The measurement results of the proposed IF AGC system exhibit 80-dB gain range with 0.25-dB resolution, 8nV/\\\\!\\\\sqrt{Hz} input referred noise, and 5-dBm IIP3 at 60-mW power consumption. The power detector shows the 35dB dynamic range for 100MHz input.

  5. 279 Watt Metal-Wrap-Through module using industrial processes

    Energy Technology Data Exchange (ETDEWEB)

    Guillevin, N.; Heurtault, B.; Geerligs, L.J.; Anker, J.; Van Aken, B.B.; Bennett, I.J.; Jansen, M.J.; Berkeveld, L.D.; Weeber, A.W.; Bultman, J.H. [ECN Solar Energy, PO Box 1, 1755 ZG Petten (Netherlands); Wenchao, Zhao; Jianming, Wang; Ziqian, Wang; Yingle, Chen; Yanlong, Shen; Zhiyan, Hu; Gaofei, Li; Jianhui, Chen; Bo, Yu; Shuquan, Tian; Jingfeng, Xiong [Yingli Solar, 3399 Chaoyang North Street, Baoding (China)

    2012-09-15

    This paper describes results of metal wrap through (MWT) cells produced from n-type Czochralski silicon wafers, and modules produced from those cells. The use of n-type silicon as base material allows for high efficiencies: for front emitter contacted industrial cells, efficiencies up to 20% have been reported. MWT cells allow even higher cell efficiency due to reduced front metal coverage, and additionally full back-contacting of the MWT cells in a module results in reduced cell to module (CTM) fill factor losses. MWT cells were produced by industrial process technologies. The efficiency of the MWT cells reproducibly exceeds the efficiency of front contact cells based on the same technology by about 0.2-0.3%, and routes for further improvement are analyzed. 60-cell modules were produced from both types of cells (MWT and H-pattern front emitter). In a direct module performance comparison, the MWT module, based on integrated backfoil, produced 3% higher power output than the comparable tabbed front emitter contact module. CTM current differences arise from the higher packing density, and in this experiment from a lower reflectance of the backfoil, in MWT modules. CTM FF differences are related to resistive losses in copper circuitry on the backfoil versus tabs. The CTM FF loss of the MWT module was reduced by 2.2%abs compared to the tabbed front emitter contact module. Finally, simple process optimizations were tested to improve the n-type MWT cell and module efficiency. A module made using MWT cells of 19.6% average efficiency resulted in a power output of 279W. The cell and module results are analyzed and routes for improvements are discussed.

  6. Electric Propulsion of a Different Class: The Challenges of Testing for MegaWatt Missions

    Science.gov (United States)

    2012-08-01

    ALTA , Italy, IV1047 20 ft diameter, 33 ft long 710,000 1.96E-04 Dry, oil free: scroll, turbo and cryopumps JUMBO, Giessen, Germany48 10 ft...2) a high-power testing phase at NASA GRC’s VF5. Table 2 below summarizes the power ranges for each of the test campaigns: Table 2. X3 Test Plan ...Facility Power Range PEPL LVTF 2-65 kW GRC VF5 2-200 kW The logic underlying the test plan is based on a stepped approach to testing the highest

  7. Stopping power of liquid water for carbon ions in the energy range between 1 MeV and 6 MeV.

    Science.gov (United States)

    Rahm, J M; Baek, W Y; Rabus, H; Hofsäss, H

    2014-07-21

    The stopping power of liquid water was measured for the first time for carbon ions in the energy range between 1 and 6 MeV using the inverted Doppler shift attenuation method. The feasibility study carried out within the scope of the present work shows that this method is well suited for the quantification of the controversial condensed phased effect in the stopping power for heavy ions in the intermediate energy range. The preliminary results of this work indicate that the stopping power of water for carbon ions with energies prevailing in the Bragg-peak region is significantly lower than that of water vapor. In view of the relatively high uncertainty of the present results, a new experiment with uncertainties less than the predicted difference between the stopping powers of both water phases is planned.

  8. Ultra-Low-Power MEMS Selective Gas Sensors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — KWJ offers this proposal for a very low power but very practical "nano-watt" MEMS sensor platform for NASA requirements. The proposed nano-sensor platform is ultra...

  9. Design and Thermal Analysis of a 300 Watt BLDC motor

    Directory of Open Access Journals (Sweden)

    Ali Jabbari

    2009-12-01

    Full Text Available This paper presents the mechanical design and transient thermal analysis of a permanent magnet Brushless DC motor to be replaced with an induction motor and its gearbox for a propulsion application requiring 300 W and 220 RPM. This work presents a suitable method for direct motor drive design. The critical design criterion is based on magnet demagnetization. The motor has magnets inset into the surface of the rotor to give a maximum field-weakening range. A prototype model is fabricated based on the presented method. Analytically based lumped circuit method for thermal analysis has been used to simulate the motor. Simulation results are compared with practical measurements. The comparison of the results shows that the presented method has a high efficiency in design and thermal analysis of BLDC motors.

  10. Low Voltage Power Efficient Tunable Shaper Circuit With Rail-To-Rail Output Range for the HYDE Detector at FAIR

    Science.gov (United States)

    Galán, J.; López-Ahumada, R.; Sánchez-Rodríguez, T.; Torralba, A.; Carvajal, R. G.; Martel, I.

    2014-04-01

    This paper presents a low voltage, low power readout front-end system implemented in 130 nm CMOS technology. A conventional architecture that consists of charge sensitive amplifier, pole/zero cancellation and shaper has been used. The work focuses on the design of novel circuit topologies in low voltage environment minimizing the power consumption in modern deep submicron CMOS technologies. An operational amplifier with rail-to-rail output swing that uses a gain boosting technique and class-AB output stage without extra power consumption has been used for the shaper. The circuit combines excellent performances with simplicity of design and suitability for low voltage operation. The system is intended to work with silicon detectors for nuclear physics applications and is optimized to match an input capacitance of 10 pF. The system features a peaking time of 500 ns, a power dissipation of 1.57 mW/channel and an equivalent noise charge of 201 e-.

  11. Present and future of the power electronics (II). Middle and low-power applications; Presente y future de la electronica de potencia (II). Aplicaciones de mediana y pequena potencia

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Garcia, S. A.; Dede-Garcia, E. J.; Campo-Rodriguez, J. C.; Bradleym, P. J.; Rueda-Boldo, P.; Monteso-Fernandez, S.; Cagigal-Olauy, C.; Vela-Garcia, R.

    2010-07-01

    In the previous paper, published last month, the generated aspects of Power Electronics and the high power ranger applications were reviewed. The many existing applications throughout industry, transport, public buildings, communications, computing, home automation and electro-medical devices, mainly in the role of feeding power to equipment and systems, were presented. As shown, the power range is very wide, covering from over five thousand megawatts in High Voltage DC Transmission to a few tenths of a watt in micro-power converters for mobile telephones and electro-medical devices. In this second and las paper the medium and low power range applications, normally with important weight and size restrictions, are reviewed. (Author) 20 refs.

  12. BEGA Starter/Alternator - Vector Control Implementation and Performance for Wide Speed Range at Unity Power Factor Operation

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Boldea, Ion; Coroban-Schramel, Vasile

    2008-01-01

    to infinite. A vector control structure is proposed for BEGA operation during motoring and generating, at unity power factor with zero d-axis current (id) and zero q-axis flux (Ψq) control. In such conditions BEGA behaves like a truly dc. brush machine (with zero reactance in steady state !). A high iq...... current is required in order to cancel the q-axis flux, during unity power factor operation. This engages higher copper losses in the machine. In order to minimize the copper losses, for lower load levels, a current referencer is proposed. Due to higher dc field excitation time constant, the dc field...

  13. The procedure used to assess the long range generation and transmission resources in the Mid-Continent Area Power Pool

    Energy Technology Data Exchange (ETDEWEB)

    Head, W.J. (Mid-Continent Area Power Pool, Minneapolis, MN (USA)); Nguyen, H.V. (Montana-Dakota Utilities Co., Bismarck, ND (USA)); Kahle, R.L. (Lincoln Electric System, NE (USA)); Bachman, P.A. (Northwestern Public Service Co., Huron, SD (USA)); Jensen, A.A. (Iowa Power and Light Co., Des Moines, IA (USA)); Watry, S.J. (Minnesota Power and Light Co., Duluth, MN (USA))

    1990-11-01

    Regional generation expansion planning has traditionally been viewed as merely a compilation of individual utility expansion plans. A study, undertaken by the Mid-Continent Area Power Pool, examines future power supply options from a regional perspective. The pool is modeled as a single utility, without regard to particular economic or operating characteristics of any individual utility or group of utilities. While the dynamic programming method is commonly used in most capacity planning studies, this study makes extensive use of the generalized benders decomposition algorithm in the EPRI's EGEAS computer program to model poolwide optimization of capacity additions.

  14. Optimization of solar cell contacts by system cost-per-watt minimization

    Science.gov (United States)

    Redfield, D.

    1977-01-01

    New, and considerably altered, optimum dimensions for solar-cell metallization patterns are found using the recently developed procedure whose optimization criterion is the minimum cost-per-watt effect on the entire photovoltaic system. It is also found that the optimum shadow fraction by the fine grid is independent of metal cost and resistivity as well as cell size. The optimum thickness of the fine grid metal depends on all these factors, and in familiar cases it should be appreciably greater than that found by less complete analyses. The optimum bus bar thickness is much greater than those generally used. The cost-per-watt penalty due to the need for increased amounts of metal per unit area on larger cells is determined quantitatively and thereby provides a criterion for the minimum benefits that must be obtained in other process steps to make larger cells cost effective.

  15. Fractional watt Vuillemier cryogenic refrigerator program engineering notebook. Volume 2: Stress analysis

    Science.gov (United States)

    Miller, W. S.

    1974-01-01

    A structural analysis performed on the 1/4-watt cryogenic refrigerator. The analysis covered the complete assembly except for the cooling jacket and mounting brackets. Maximum stresses, margin of safety, and natural frequencies were calculated for structurally loaded refrigerator components shown in assembly drawings. The stress analysis indicates that the design is satisfactory for the specified vibration environment, and the proof, burst, and normal operating loads.

  16. Improvement of input power dynamic range for 20 Gbit/s optical WDM switch nodes using an integrated Michelson wavelength converter

    DEFF Research Database (Denmark)

    Danielsen, Søren Lykke; Hansen, Peter Bukhave; Jørgensen, Carsten

    1997-01-01

    be improved compared to switch blocks without IWCs. This is especially important at high bit rates where the cascadability of the SOA gates decreases. Here, more than 15 dB improvement of the input power dynamic range is achieved at 20 Gbit/s using a high-speed Michelson interferometer wavelength converter...

  17. An analytical algorithm for 3D magnetic field mapping of a watt balance magnet

    CERN Document Server

    Fu, Zhuang; Li, Zhengkun; Zhao, Wei; Han, Bing; Lu, Yunfeng; Li, Shisong

    2015-01-01

    A yoke-based permanent magnet, which has been employed in many watt balances at national metrology institutes, is supposed to generate strong and uniform magnetic field in an air gap in the radial direction. However, in reality the fringe effect due to the finite height of the air gap will introduce an undesired vertical magnetic component to the air gap, which should either be measured or modeled towards some optimizations of the watt balance. A recent publication, i.e., {\\it Metrologia} 52(4) 445 [1], presented a full field mapping method, which in theory will supply useful information for profile characterization and misalignment analysis. This article is an additional material of [1], which develops a different analytical algorithm to represent the 3D magnetic field of a watt balance magnet based on only one measurement for the radial magnetic flux density along the vertical direction, $B_r(z)$. The new algorithm is based on the electromagnetic nature of the magnet, which has a much better accuracy.

  18. Power

    DEFF Research Database (Denmark)

    Elmholdt, Claus Westergård; Fogsgaard, Morten

    2016-01-01

    In this chapter, we will explore the dynamics of power in processes of creativity, and show its paradoxical nature as both a bridge and a barrier to creativity in organisations. Recent social psychological experimental research (Slighte, de Dreu & Nijstad, 2011) on the relation between power...... and creativity suggests that when managers give people the opportunity to gain power and explicate that there is reason to be more creative, people will show a boost in creative behaviour. Moreover, this process works best in unstable power hierarchies, which implies that power is treated as a negotiable...... and floating source for empowering people in the organisation. We will explore and discuss here the potentials, challenges and pitfalls of power in relation to creativity in the life of organisations today. The aim is to demonstrate that power struggles may be utilised as constructive sources of creativity...

  19. A wide range ultra-low power Phase-Locked Loop with automatic frequency setting in 130 nm CMOS technology for data serialisation

    Science.gov (United States)

    Firlej, M.; Fiutowski, T.; Idzik, M.; Moroń, J.; Świentek, K.

    2015-12-01

    The design and measurements results of a wide frequency range ultra-low power Phase-Locked Loop (PLL) for applications in readout systems of particle physics detectors are presented. The PLL was fabricated in a 130 nm CMOS technology. To allow the implementation of different data serialisation schemes multiple division factors (6, 8, 10, 16) were implemented in the PLL feedback loop. The main PLL block—VCO works in 16 frequency ranges/modes, switched either manually or automatically. A dedicated automatic frequency mode switching circuit was developed to allow simple frequency tuning. Although the PLL was designed and simulated for a frequency range of 30 MHz-3 GHz, due to the SLVS interface limits, the measurements were done only up to 1.3 GHz. The full PLL functionality was experimentally verified, confirming a very low and frequency scalable power consumption (0.7 mW at 1 GHz).

  20. 67.9  W high-power white supercontinuum all-fiber laser source.

    Science.gov (United States)

    Sun, Chang; Ge, Tingwu; Li, Siyuan; An, Na; Wang, Zhiyong

    2016-05-10

    We present a high-power white supercontinuum (SC) all-fiber laser source with average power of 67.9 W, spectrum ranging from 500 to 1700 nm, and spectral width exceeding 1000 nm for spectrum with flatness below 10 dB (except pump wavelength). Also, the visible waveband power (below 850 nm) occupies about 21% of the total SC power. A 145 W high-power picosecond pulse fiber laser is specially designed with high repetition frequency of 656 MHz to reduce nonlinear effects. Meanwhile, a homemade high-power mode field adaptor that can operate stably at hundreds of watts of pulse power has high coupling efficiency of 82%. To our knowledge, the 67.9 W white SC fiber laser source we achieved is the highest reported with such a wide and flat optical spectrum.

  1. Intermediate steps towards the 2000-Watt society in Switzerland: an energy-economic scenario analysis[Dissertation 17314

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, T. F

    2007-07-01

    In this dissertation by Thorsten Frank Schulz the intermediate steps necessary to realise the 2000-Watt Society in Switzerland are examined. An analysis of an energy-economic scenario shows that the 2000-Watt Society should be seen as a long-term goal. According to the author, the major changes required to allow the implementation of this project concern energy-transformation and energy-demand technologies. Electricity will, according to the author, play an important role in a service-oriented society in the future. In such a transformation even intermediate steps are associated with considerable expense. The aims of the 2000-Watt Society project are listed. Energy and CO{sub 2} balances for the domestic and transport sectors are presented and discussed. Complementary analyses are presented concerning fuel cells and wood-based fuel technologies. Finally, the implications of the 2000-Watt society and the effects of technological change are summarised and an outlook is presented.

  2. F-band, High-Efficiency GaN Power Amplifier for the Scanning Microwave Limb Sounder and SOFIA Project

    Data.gov (United States)

    National Aeronautics and Space Administration — QuinStar Technology proposes to develop a 4-watt Solid-State Power Amplifier (SSPA) operating at F-band (106-114 GHz) with a power-added efficiency (PAE) of greater...

  3. Fast Robust Gate-Drivers with Easy Adjustable Voltage Ranges for Driving Normally-On Wide-Bandgap Power Transistors

    OpenAIRE

    Jacqmaer, Pieter; Everts, Jordi; Gelagaev, Ratmir; Tant, Peter; Driesen, Johan

    2010-01-01

    Wide-bandgap (WBG) semiconductors, such as gallium nitride (GaN), are more and more being used in switching power devices. An AlGaN/GaN/AlGaN Double Heterojunction Field Effect transistor (DHFET) was developed in previous work and needed to be tested. The used test circuit was a buck converter. This type of converter, in addition with the normally-on switching behaviour of the GaN-based transistors, requires dedicated gate drive circuitry, resulting in the development of three types of gate-d...

  4. 基于CS5464计量芯片的智能电能表设计与实现%Design and Implementation of Intelligent Watt-hour Meter Based on the CS5464

    Institute of Scientific and Technical Information of China (English)

    田晔非

    2013-01-01

    Electricity information acquisition in smart grid plays an important role, and the intelligent Watt-hour meter is the important carrier of it. This paper introduces a design of intelligent Watt-hour meter based on CS5464. The in-telligent Watt-hour meter has power real-time information acquisition, strong anti-interference ability, low power con-sumption, etc. Through our testing and functional verification, it reflects the good reliability and stability. This design scheme using the popularization and application, has good practical value.%电能信息采集在智能电网的运用中起着非常重要的作用,智能电能表是电能信息采集的重要载体。本文介绍了一种基于CS5464计量芯片的智能电能表设计方案,所设计的智能电能表具有电能信息采集实时、抗干扰能力强、低功耗等优点,通过测试和功能验证,体现出了很好的可靠性和稳定性。该设计方案具有较好的实用价值。

  5. Low-power cryocooler survey

    NARCIS (Netherlands)

    Brake, ter H.J.M.; Wiegerinck, G.F.M.

    2002-01-01

    A cryocooler survey has been performed on data of 235 cryocoolers, with cooling powers below some tens of watts and operating between 4 and 120 K. The state-of-the-art is discussed and trends are investigated on cooling performance, mass and size, cost, lifetime and reliability. The data were compar

  6. Watt-level red-emitting diode lasers and modules for display applications

    Science.gov (United States)

    Paschke, Katrin; Blume, Gunnar; Feise, David; Pohl, Johannes; Sumpf, Bernd

    2016-02-01

    Red-emitting lasers for display applications require high output powers and a high visibility. We demonstrate diode lasers and modules in the red spectral range based on AlGaInP with optical output powers up to 1 W and a nearly diffraction limited beam. These high-luminance light sources based on tapered lasers are well suited for laser TVs and projectors for virtual reality simulators based on the flying spot technology. Additionally, we developed diode lasers with internal distributed Bragg reflector (DBR) surface gratings. These DBR tapered lasers and master-oscillator power-amplifiers based on DBR ridge-waveguide lasers and tapered amplifiers feature high power, single mode emission with coherence lengths up to several meters, which are suitable for the next-generation 3D displays based on holography.

  7. Test of hybrid power system for electrical vehicles using a lithium-ion battery pack and a reformed methanol fuel cell range extender

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Ashworth, Leanne; Sahlin, Simon Lennart

    2014-01-01

    monoxide, the HTPEM fuel cell system can efficiently use a liquid methanol/water mixture of 60%/40% by volume, as fuel instead of compressed hydrogen, enabling potentially a higher volumetric energy density. In order to test the performance of such a system, the experimental validation conducted uses......This work presents the proof-of-concept of an electric traction power system with a high temperature polymer electrolyte membrane fuel cell range extender, usable for automotive class electrical vehicles. The hybrid system concept examined, consists of a power system where the primary power...... is delivered by a lithium ion battery pack. In order to increase the run time of the application connected to this battery pack, a high temperature PEM (HTPEM) fuel cell stack acts as an on-board charger able to charge a vehicle during operation as a series hybrid. Because of the high tolerance to carbon...

  8. A Low-Power Single-Bit Continuous-Time ΔΣ Converter with 92.5 dB Dynamic Range for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Vishal Saxena

    2012-07-01

    Full Text Available A third-order single-bit CT-ΔΣ modulator for generic biomedical applications is implemented in a 0.15 µm FDSOI CMOS process. The overall power efficiency is attained by employing a single-bit ΔΣ and a subthreshold FDSOI process. The loop-filter coefficients are determined using a systematic design centering approach by accounting for the integrator non-idealities. The single-bit CT-ΔΣ modulator consumes 110 µW power from a 1.5 V power supply when clocked at 6.144 MHz. The simulation results for the modulator exhibit a dynamic range of 94.4 dB and peak SNDR of 92.4 dB for 6 kHz signal bandwidth. The figure of merit (FoM for the third-order, single-bit CT-ΔΣ modulator is 0.271 pJ/level.

  9. Comparative efficiency and driving range of light- and heavy-duty vehicles powered with biomass energy stored in liquid fuels or batteries.

    Science.gov (United States)

    Laser, Mark; Lynd, Lee R

    2014-03-04

    This study addresses the question, "When using cellulosic biomass for vehicular transportation, which field-to-wheels pathway is more efficient: that using biofuels or that using bioelectricity?" In considering the question, the level of assumed technological maturity significantly affects the comparison, as does the intended transportation application. Results from the analysis indicate that for light-duty vehicles, over ranges typical in the United States today (e.g., 560-820 miles), field-to-wheels performance is similar, with some scenarios showing biofuel to be more efficient, and others indicating the two pathways to be essentially the same. Over the current range of heavy-duty vehicles, the field-to-wheels efficiency is higher for biofuels than for electrically powered vehicles. Accounting for technological advances and range, there is little basis to expect mature bioelectricity-powered vehicles to have greater field-to-wheels efficiency (e.g., kilometers per gigajoule biomass or per hectare) compared with mature biofuel-powered vehicles.

  10. First Season QUIET Observations: Measurements of CMB Polarization Power Spectra at 43 GHz in the Multipole Range 25 <= ell <= 475

    CERN Document Server

    Bischoff, C; Buder, I; Chinone, Y; Cleary, K; Dumoulin, R N; Kusaka, A; Monsalve, R; Næss, S K; Newburgh, L B; Reeves, R; Smith, K M; Wehus, I K; Zuntz, J A; Zwart, J T L; Bronfman, L; Bustos, R; Church, S E; Dickinson, C; Eriksen, H K; Ferreira, P G; Gaier, T; Gundersen, J O; Hasegawa, M; Hazumi, M; Huffenberger, K M; Jones, M E; Kangaslahti, P; Kapner, D J; Lawrence, C R; Limon, M; May, J; McMahon, J J; Miller, A D; Nguyen, H; Nixon, G W; Pearson, T J; Piccirillo, L; Radford, S J E; Readhead, A C S; Richards, J L; Samtleben, D; Seiffert, M; Shepherd, M C; Staggs, S T; Tajima, O; Thompson, K L; Vanderlinde, K; Williamson, R; Winstein, B

    2010-01-01

    The Q/U Imaging ExperimenT (QUIET) employs coherent receivers at 43GHz and 95GHz, operating on the Chajnantor plateau in the Atacama Desert in Chile, to measure the anisotropy in the polarization of the CMB. QUIET primarily targets the B modes from primordial gravitational waves. The combination of these frequencies gives sensitivity to foreground contributions from diffuse Galactic synchrotron radiation. Between 2008 October and 2010 December, >10,000hours of data were collected, first with the 19-element 43GHz array (3458hours) and then with the 90-element 95GHz array. Each array observes the same four fields, selected for low foregrounds, together covering ~1000deg^2. This paper reports initial results from the 43GHz receiver which has an array sensitivity to CMB fluctuations of 69uK sqrt(s). The data were extensively studied with a large suite of null tests before the power spectra, determined with two independent pipelines, were examined. Analysis choices, including data selection, were modified until th...

  11. A miniature powerplant for very small, very long range autonomous aircraft. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Tad McGeer

    1999-09-29

    The authors have developed a new piston engine offering unprecedented efficiency for a new generation of miniature robotic aircraft. Following Phase 1 preliminary design in 1996--97, they have gone forward in Phase 2 to complete detail design, and are nearing completion of a first batch of ten engines. A small-engine dynamometer facility has been built in preparation for the test program. Provisions have been included for supercharging, which will allow operation at ceilings in the 10,000 m range. Component tests and detailed analysis indicate that the engine will achieve brake-specific fuel consumption well below 300 gm/kWh at power levels of several hundred watts. This level of performance opens the door to development of tabletop-sized aircraft having transpacific range and multi-day endurance, which will offer extraordinary new capabilities for meteorology, geomagnetic, and a variety of applications in environmental monitoring and military operations.

  12. A miniature powerplant for very small, very long range autonomous aircraft. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Tad McGeer

    1999-09-29

    The authors have developed a new piston engine offering unprecedented efficiency for a new generation of miniature robotic aircraft. Following Phase 1 preliminary design in 1996--97, they have gone forward in Phase 2 to complete detail design, and are nearing completion of a first batch of ten engines. A small-engine dynamometer facility has been built in preparation for the test program. Provisions have been included for supercharging, which will allow operation at ceilings in the 10,000 m range. Component tests and detailed analysis indicate that the engine will achieve brake-specific fuel consumption well below 300 gm/kWh at power levels of several hundred watts. This level of performance opens the door to development of tabletop-sized aircraft having transpacific range and multi-day endurance, which will offer extraordinary new capabilities for meteorology, geomagnetic, and a variety of applications in environmental monitoring and military operations.

  13. Lumen Maintenance Testing of the Philips 60-Watt Replacement Lamp L Prize Entry

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, Kelly L.; Hafen, Ryan P.; Hathaway, John E.; McCullough, Jeffrey J.

    2012-09-01

    This paper describes testing conducted to evaluate the Philips' L Prize award winning 60-watt LED replacement product's ability to meet the lifetime/lumen maintenance requirement of the competition, which was: "having 70 percent of the lumen value under subparagraph (A) [producing a luminous flux greater than 900 lumens] exceeding 25,000 hours under typical conditions expected in residential use." A custom test apparatus was designed and constructed for this testing and a statistical approach was developed for use in evaluating the test results. This will be the only publicly available, third-party data set of long-term LED product operation.

  14. Design of New Long-Distance Intelligent Watt-Hour Meter

    Institute of Scientific and Technical Information of China (English)

    Zhao Wenlei; Xue Yanbing

    2005-01-01

    The design scheme for a new kind of long-distance intelligent watt-hour meter is presented. In the system, the control computer communicates with the bank's host computer by the X. 25 network; the built-in embeded secure access module (FSAM) can verify data by commutation with the intelligent nodes that enhance the security of the data. IC TSS721 is adopted to collect data remotely,and the CPU IC card is used to ensure the the bargaining security and reliability. In addition, the software of the system is introduced.

  15. Chaos in complex motor networks induced byNewman-Watts small-world connections

    Institute of Scientific and Technical Information of China (English)

    WeiDu-Qu; Luo Xiao-Shu; Zhang Bo

    2011-01-01

    We investigate how dynamical behaviours of complex motor networks depend on the Newman-Watts small-world (NWSW) connections.Network elements are described by the permanent magnet synchronous motor (PMSM) with the values of parameters at which each individual PMSM is stable.It is found that with the increase of connection probability p,the motor in networks becomes periodic and falls into chaotic motion as p further increases.These phenomena imply that NWSW connections can induce and enhance chaos in motor networks.The possible mechanism behind the action of NWSW connections is addressed based on stability theory.

  16. Dynamics of a periodic Watt-type predator-prey system with impulsive effect

    Energy Technology Data Exchange (ETDEWEB)

    Wang Xiaoqin [Faculty of Science, Shaanxi University of Science and Technology, Xianyang, Shaanxi 712081 (China)], E-mail: wangxiaoqin@sust.edu.cn; Wang Weiming [School of Mathematics and Information Science, Wenzhou University, Wenzhou, Zhejiang 325035 (China)], E-mail: weimingwang2003@163.com; Lin Xiaolin [Faculty of Science, Shaanxi University of Science and Technology, Xianyang, Shaanxi 712081 (China)

    2009-02-15

    In this paper, an impulsive periodic predator-prey system with Watt-type functional response is investigated. By using the Floquet theory of linear periodic impulsive equation, the stability conditions for the prey-eradication positive periodic solution are given, and the boundedness of the system is proved. By the method of coincidence degree, the sufficient conditions for the existence of at least one strictly positive periodic solution are obtained. Furthermore, we give numerical analysis to confirm our theoretical results. It will be useful for ecosystem control.

  17. 3-D model of a radial flow sub-watt methanol fuel processor

    Energy Technology Data Exchange (ETDEWEB)

    Holladay, J. D.; Wang, Y.

    2015-10-01

    A 3-D model is presented for a novel sub-watt packed bed reactor. The reactor uses an annular inlet flow combined with a radial flow packed bed reactor. The baseline reactor is compared to a reactor with multiple outlets and a reactor with 3 internal fins. Increasing the outlets from 1 to 4 did improve the flow distribution, but did not increase the performance in the simulation. However, inserting fins allowed a decrease in temperature with same inlet flow of approximately 35K. Or the inlet flow rate could be increased by a factor of 2.8x while maintaining >99% conversion.

  18. Comment on 'Critical materials assessment program' (S. A. Smith and R. Watts, Battelle Memorial Institute)

    Energy Technology Data Exchange (ETDEWEB)

    Zweibel, K.; Jackson, B.; Hermann, A.

    1986-01-15

    In the article ''Critical materials assessment program'' (1984) Smith and Watts examine the availability of indium for use in CuInSe/sub 2//CdS solar cells and conclude that indium's use should be ''decreased or eliminated''. Our response to this article is an update of the status of indium usage in CuInSe/sub 2/ cells. It will be shown that the use of indium is being significantly reduced and that pressures on the world indium supply can be minimal. Our conclusion is that the CdS/CuInSe/sub 2/ solar cell technology is viable, not limited by indium availability or cost.

  19. Synchronization of Coupled Oscillators on Newman-Watts Small-World Networks

    Institute of Scientific and Technical Information of China (English)

    GUAN Jian-Yue; XU Xin-Jian; WU Zhi-Xi; WANG Ying-Hai

    2006-01-01

    We investigate the collection behaviour of coupled phase oscillators on Newman- Watts small-world networks in one and two dimensions. Each component of the network is assumed as an oscillator and each interacts with the others following the Kuramoto model. We then study the onset of global synchronization of phases and frequencies based on dynamic simulations and finite-size scah'ng. Both the phase and frequency synchronization are observed to emerge in the presence of a tiny fraction of shortcuts and enhanced with the increases of nearest neighbours and lattice dimensions.

  20. Nanopositioning and nanomeasuring machine NPMM-200—a new powerful tool for large-range micro- and nanotechnology

    Science.gov (United States)

    Jäger, G.; Manske, E.; Hausotte, T.; Müller, A.; Balzer, F.

    2016-09-01

    High-precision metrology has emerged as an enabling technology for modern key technologies. Therefore, at the Technische Universität Ilmenau, a new nanopositioning and nanomeasuring machine NPMM-200 with a measuring range of 200 mm × 200 mm × 25 mm, and a resolution of 0.02 nm was developed. The machine represents the great improvement of the extended three-dimensional Abbe comparator principle to achieve nanometre accuracy. All six degrees of freedom of the mirror plate with the measuring object are measured by fibre-coupled laser interferometers, the signals of which are then used together with the probe system signals for a high-precision position and orientation control and surface and coordinate measurements. This paper presents the metrological concept, the realized design as well as the metrological parameters.

  1. Remedial investigation/feasibility study report for Lower Watts Bar Reservoir Operable Unit

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-03-01

    This document is the combined Remedial Investigation and Feasibility Study Report for the lower Watts Bar Reservoir (LWBR) Operable Unit (OU). The LWBR is located in Roane, Rhea, and Meigs counties, Tennessee, and consists of Watts Bar Reservoir downstream of the Clinch river. This area has received hazardous substances released over a period of 50 years from the US Department of Energy`s Oak Ridge Reservation (ORR), a National Priority List site established under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). As required by this law, the ORR and all off-site areas that have received contaminants, including LWBR, must be investigated to determine the risk to human health and the environment resulting from these releases, the need for any remedial action to reduce these risks, and the remedial actions that are most feasible for implementation in this OU. Contaminants from the ORR are primarily transported to the LWBR via the Clinch River. There is little data regarding the quantities of most contaminants potentially released from the ORR to the Clinch River, particularly for the early years of ORR operations. Estimates of the quantities released during this period are available for most radionuclides and some inorganic contaminants, indicating that releases 30 to 50 years ago were much higher than today. Since the early 1970s, the release of potential contaminants has been monitored for compliance with environmental law and reported in the annual environmental monitoring reports for the ORR.

  2. Effects of choline chloride on electrodeposited Ni coating from a Watts-type bath

    Science.gov (United States)

    Wang, Yurong; Yang, Caihong; He, Jiawei; Wang, Wenchang; Mitsuzak, Naotoshi; Chen, Zhidong

    2016-05-01

    Electrodeposition of bright nickel (Ni) was carried out in a Watts-type bath. Choline chloride (ChCl) was applied as a multifunctional additive and substitute for nickel chloride (NiCl2) in a Watts-type bath. The function of ChCl was investigated through conductivity tests, anodic polarization, and cathodic polarization experiments. The studies revealed that ChCl performed well as a conducting salt, anodic activator, and cathodic inhibitor. The effects of ChCl on deposition rate, preferred orientation, grain size, surface morphology, and microhardness of Ni coatings were also studied. The deposition rate reached a maximum value of greater than 27 μm h-1 when 20 g L-1 ChCl was introduced to the bath. Using X-ray diffraction, it was confirmed that progressive addition of ChCl promoted the preferred crystal orientation modification from (2 0 0) and (2 2 0) to (1 1 1), refined grain size, and enhanced microhardness. The presence of ChCl lowered the roughness of the coating.

  3. A five-watt G-M/J-T refrigerator for LHe target at BNL

    Science.gov (United States)

    Jia, L. X.; Wang, L.; Addessi, L.; Miglionico, G.; Martin, D.; Leskowicz, J.; McNeill, M.; Yatauro, B.; Tallerico, T.

    2002-05-01

    A five-watts G-M/J-T refrigerator was built and installed for the high-energy physics research at Brookhaven National Laboratory in 2001. A liquid helium target of 8.25 liters was required for an experiment in the proton beam line at the Alternating Gradient Synchrotron (AGS) of BNL. The large radiation heat load towards the target requires a five-watts refrigerator at 4.2 K to support a liquid helium flask of 0.2 meter in diameter and 0.3 meter in length, which is made of Mylar film of 0.35 mm in thickness. The liquid helium flask is thermally exposed to the vacuum windows that are also made of 0.35 mm thickness Mylar film at room temperature. The refrigerator uses a two-stage Gifford-McMahon cryocooler for precooling the Joule-Thomson circuit that consists of five Linde-type heat exchangers. A mass flow rate of 0.8˜1.0 grams per second at 17.7 atm is applied to the refrigerator cold box. The two-phase helium flows between the liquid target and liquid/gas separator by means of a thermosyphon. This paper presents the system design as well as the test results including the control of the thermal oscillation.

  4. Reconciling Planck constant determinations via watt balance and enriched-silicon measurements at NRC Canada

    Science.gov (United States)

    Steele, A. G.; Meija, J.; Sanchez, C. A.; Yang, L.; Wood, B. M.; Sturgeon, R. E.; Mester, Z.; Inglis, A. D.

    2012-02-01

    The next revision to the International System of Units will emphasize the relationship between the base units (kilogram, metre, second, ampere, kelvin, candela and mole) and fundamental constants of nature (the speed of light, c, the Planck constant, h, the elementary charge, e, the Boltzmann constant, kB, the Avogadro constant, NA, etc). The redefinition cannot proceed without consistency between two complementary metrological approaches to measuring h: a 'physics' approach, using watt balances and the equivalence principle between electrical and mechanical force, and a 'chemistry' approach that can be viewed as determining the mass of a single atom of silicon. We report the first high precision physics and chemistry results that agree within 12 parts per billion: h (watt balance) = 6.626 070 63(43) × 10-34 J s and h(silicon) = 6.626 070 55(21) × 10-34 J s. When combined with values determined by other metrology laboratories, this work helps to constrain our knowledge of h to 20 parts per billion, moving us closer to a redefinition of the metric system used around the world.

  5. Field representation of a watt balance magnet by partial profile measurements

    CERN Document Server

    Li, Shisong; Zhao, Wei; Huang, Songling

    2015-01-01

    Permanent magnets with high-permeability yokes have been widely used in watt balances for supplying a robust and strong magnetic field at the coil position. Subjected to the mechanical realization, only several $B_r(z)$ (radial magnetic field along the vertical direction) profiles can be measured by coils for field characterization. In this article, we present an algorithm that can construct the global magnetic field of the air gap based on $N(N\\geq1)$ additional measurements of $B_r(z)$ profiles. The proposed algorithm is realized by polynomially estimating the $B_z(r)$ function with analysis of basic relations between two magnetic components in air gap, i.e., $B_r(r,z)$ and $B_z(r,z)$, following the Maxwell's equations. The algorithm, verified by FEM simulations, can characterize the three-dimensional contribution of the magnetic field for a watt balance magnet with acceptable accuracy, which would supply basic field parameters for alignment and misalignment corrections.

  6. 一种考虑风电随机性的电力系统电压运行区间计算方法%Voltage operating range calculation method for electric power system considering wind power randomness

    Institute of Scientific and Technical Information of China (English)

    李苗; 邓长虹; 游佳斌; 周沁

    2016-01-01

    针对风电场出力的波动性使风电接入地区电网的随机性增强,并网点电压波动的频率和幅度变大,造成的电压稳定问题,以实际风电场的运行数据为基础,通过统计学方法分析风电场输出功率的波动特性,得到风功率波动率在不同时间尺度内的分布参数以及95%置信区间,并分析不同风电水平下的电压波动特性,在此基础上提出使用t location⁃scale分布函数对电压波动率的概率分布进行拟合,进而得出一种基于风功率波动特性以及仿射区间潮流算法的电压运行区间计算方法,通过该方法计算得到的电压运行区间反映了在风功率波动条件下未来一段时间内电力系统电压的运行区间,对风电接入系统的运行、控制及规划工作具有重要的指导意义。%The fluctuation of wind power plant can enhance the power grid randomness of wind power access region,and in⁃crease the frequency and amplitude of the voltage fluctuation at the connection point,which may cause the voltage stability problem. On the basis of the operating data of practical wind power plant,the statistical method is used to analyze the fluctuation charac⁃teristic of the wind power plant output power,so as to obtain the distribution parameters and 95% confidence interval of wind power fluctuation in different time scales,and analyze the voltage fluctuation characteristic under different wind power levels. On this basis,the t location⁃scale distribution function is used to fit the probability distribution of voltage fluctuation rate,and the voltage operating range calculation method based on wind power fluctuation characteristic and affine interval power flow algo⁃rithm is obtained. The voltage operating range calculated by this method reflects the possible operating voltage range of the electric power system within a period of time in the future under the condition of wind power fluctuation,and has an

  7. Power distribution of a co-axial dual-mechanical-port flux-switching permanent magnet machine for fuel-based extended range electric vehicles

    Science.gov (United States)

    Zhou, Lingkang; Hua, Wei; Zhang, Gan

    2017-05-01

    In this paper, power distribution between the inner and outer machines of a co-axial dual-mechanical-port flux-switching permanent magnet (CADMP-FSPM) machine is investigated for fuel-based extended range electric vehicle (ER-EV). Firstly, the topology and operation principle of the CADMP-FSPM machine are introduced, which consist of an inner FSPM machine used for high-speed, an outer FSPM machine for low-speed, and a magnetic isolation ring between them. Then, the magnetic field coupling of the inner and outer FSPM machines is analyzed with more attention paid to the optimization of the isolation ring thickness. Thirdly, the power-dimension (PD) equations of the inner and outer FSPM machines are derived, respectively, and thereafter, the PD equation of the whole CADMP-FSPM machine can be given. Finally, the PD equations are validated by finite element analysis, which supplies the guidance on the design of this type of machines.

  8. Future Photovoltaic Power Generation for Space-Based Power Utilities

    Science.gov (United States)

    Bailey, S.; Landis, G.; Raffaelle, R.; Hepp, A.

    2002-01-01

    dictate a more complicated trade space. Until recently the focus in space cells has been on efficiency rather than cost. In a several billion-dollar spacecraft the cell cost is relatively small at even a thousand dollars per watt, which is approximately the current array cost. This has primarily been true for spacecraft with power needs from a few hundred watts to tens of kilowatts. However, deployment of a large earth orbiting space power system will require major advances in the photovoltaic array weight, stability in the space environment, efficiency, and ultimately the cost of production and deployment of such arrays. The development of large space power systems, and a host of other proposed space missions, will require the development of viable thin film arrays. The specific power required is almost 40 times what is presently available in commercial arrays. While high efficiency ultra lightweight arrays are not likely to become commercially available anytime soon, advances in thin film photovoltaics may still impact other space technologies (i.e., thin film integrated power supplies) and thus support a broad range of missions in the next decade. Mission examples include micro- air vehicles, ultra-long duration balloons (e.g. Olympus), deep space solar electric propulsion (SEP) "Tug" Array, Mars SEP Array, and Mars surface power outpost. A discussion of the state of the art of thin film cells and their characteristics will be included, particularly focused on their applicability to the space environment. This survey of thin film cells will also include a discussion of inorganic/organic solar cells and their adaptability to the space environment. Enhancements to the efficiency of thin film cells, such as intermediate band quantum dots will be discussed and results presented for current cell configurations.

  9. A LEGO Watt Balance: An apparatus to demonstrate the definition of mass based on the new SI

    CERN Document Server

    Chao, L S; Newell, D B; Pratt, J R; Sineriz, G; Seifert, F; Cao, A; Haddad, D; Zhang, X

    2014-01-01

    A global effort to redefine our International System of Units (SI) is underway and the change to the new system is expected to occur in 2018. Within the newly redefined SI, the present base units will still exist but be derived from fixed numerical values of seven reference constants. More specifically, the unit of mass, the kilogram, will be realized through a fixed value of the Planck constant $h$. For instance, a watt balance can be used to realize the kilogram unit of mass within a few parts in $10^8$. Such a balance has been designed and constructed at the National Institute of Standards and Technology. For educational outreach and to demonstrate the principle, we have constructed a LEGO tabletop watt balance capable of measuring a gram size mass to 1 % relative uncertainty. This article presents the design, construction, and performance of the LEGO watt balance and its ability to determine $h$

  10. Development of high power quantum well lasers at RRCAT

    CERN Document Server

    Sharma, T K; Dixit, V K; Singh, S D; Pal, S; Porwal, S; Kumar, Ravi; Khakha, Alexander; Jangir, R; Kheraj, V; Rawat, P; Nath, A K

    2014-01-01

    We at RRCAT have recently developed high power laser diodes in the wavelength range of 740 to 1000 nm. A typical semiconductor laser structure is consisted of about 10 epilayers with different composition, thickness and doping values. For example, a laser diode operating at 0.8 micron has either GaAs or GaAsP quantum well as an active layer. The quantum well is sandwiched between AlGaAs wider bandgap waveguide and cladding layers. The complete laser structure is grown by metal organic vapour phase epitaxy technique and devices are fabricated through standard procedure using photolithography. We recently achieved about 5.3 Watt peak power at 853 nm. These laser diodes were tested under pulsed operation at room temperature for 500 nanosecond pulse duration with a duty cycle of 1:1000. Laser diode arrays consisting of 6-10 elements were also developed and tested for operation in pulsed mode at room temperature.

  11. Sampled grating tunable twin-guide laser diodes with wide tuning range (40 nm) and large output power (10 mW)

    Science.gov (United States)

    Todt, R.; Jacke, T.; Meyer, R.; Adler, J.; Laroy, R.; Morthier, G.; Amann, M.-C.

    2006-03-01

    The sampled grating tunable twin-guide (SG-TTG) laser diode is a DFB-like tunable laser that employs Vernier-effect tuning to achieve wide wavelength tuning. In contrast to most other monolithic widely tunable lasers (which are usually DBR-type lasers), a phase tuning section is not needed and, hence, the SG-TTG laser requires at least one tuning current less than comparable devices.The devices provide full wavelength coverage over a 40 nm-broad tuning range that is centered at 1.54 μm. Its tuning behavior is quasi-continuous with up to 8.2 nm broad continuous tuning regions. High side-mode suppression (SMSR 35 dB) as well as large output power (P 10 mW) are obtained over the whole wavelength range from 1520.5 to 1561.5 nm.

  12. Design of a Sub-Picosecond Jitter with Adjustable-Range CMOS Delay-Locked Loop for High-Speed and Low-Power Applications

    Directory of Open Access Journals (Sweden)

    Bilal I. Abdulrazzaq

    2016-09-01

    Full Text Available A Delay-Locked Loop (DLL with a modified charge pump circuit is proposed for generating high-resolution linear delay steps with sub-picosecond jitter performance and adjustable delay range. The small-signal model of the modified charge pump circuit is analyzed to bring forth the relationship between the DLL’s internal control voltage and output time delay. Circuit post-layout simulation shows that a 0.97 ps delay step within a 69 ps delay range with 0.26 ps Root-Mean Square (RMS jitter performance is achievable using a standard 0.13 µm Complementary Metal-Oxide Semiconductor (CMOS process. The post-layout simulation results show that the power consumption of the proposed DLL architecture’s circuit is 0.1 mW when the DLL is operated at 2 GHz.

  13. Design of a Sub-Picosecond Jitter with Adjustable-Range CMOS Delay-Locked Loop for High-Speed and Low-Power Applications.

    Science.gov (United States)

    Abdulrazzaq, Bilal I; Ibrahim, Omar J; Kawahito, Shoji; Sidek, Roslina M; Shafie, Suhaidi; Yunus, Nurul Amziah Md; Lee, Lini; Halin, Izhal Abdul

    2016-09-28

    A Delay-Locked Loop (DLL) with a modified charge pump circuit is proposed for generating high-resolution linear delay steps with sub-picosecond jitter performance and adjustable delay range. The small-signal model of the modified charge pump circuit is analyzed to bring forth the relationship between the DLL's internal control voltage and output time delay. Circuit post-layout simulation shows that a 0.97 ps delay step within a 69 ps delay range with 0.26 ps Root-Mean Square (RMS) jitter performance is achievable using a standard 0.13 µm Complementary Metal-Oxide Semiconductor (CMOS) process. The post-layout simulation results show that the power consumption of the proposed DLL architecture's circuit is 0.1 mW when the DLL is operated at 2 GHz.

  14. [Effects of low power laser radiation of blue, green and red ranges on free radical processes in rat blood in endotoxic shock].

    Science.gov (United States)

    Machneva, T V; Kosmacheva, N V; Vladimirov, Iu A; Osipov, A N

    2013-01-01

    This study was performed to investigate the effects of low power laser radiation in blue (441.2 nm), green (532.5 nm) and red (632.8 nm) wavelength ranges on free radical processes in experimental endotoxic shock in rats. The experimental model was produced by intraperitoneal injection of lipopolysacharide B (25 mg/kg) (LPS). The following parameters were assayed in the study: the chemiluminescent assay (to evaluate the free radical production by blood leukocytes), nitro blue tetrazolium assay (to monitor the superoxide dismutase activity of plasma) and cis-parinaric acid fluorescence (to estimate the intensity of lipid peroxidation in erythrocyte membranes). It was found that the low power laser radiation significantly influenced all investigated processes, in animals both treated and untreated without LPS injection. The most pronounced effects were observed in all groups of animals subjected to the low power laser radiation: at the dose of 0.75 J/cm2 green laser was most effective and at the dose of 1.5 J/cm2 green and red lasers provided maximal effects. The mechanisms of the observed phenomena are discussed.

  15. Design and evaluation of wide-range and low-power analog front-end enabling body-implanted devices to monitor charge injection properties

    Science.gov (United States)

    Ito, Keita; Uno, Shoma; Goto, Tatsuya; Takezawa, Yoshiki; Harashima, Takuya; Morikawa, Takumi; Nishino, Satoru; Kino, Hisashi; Kiyoyama, Koji; Tanaka, Tetsu

    2017-04-01

    For safe electrical stimulation with body-implanted devices, the degradation of stimulus electrodes must be considered because it causes the unexpected electrolysis of water and the destruction of tissues. To monitor the charge injection property (CIP) of stimulus electrodes while these devices are implanted, we have proposed a charge injection monitoring system (CIMS). CIMS can safely read out voltages produced by a biphasic current pulse to a stimulus electrode and CIP is calculated from waveforms of the acquired voltages. In this paper, we describe a wide-range and low-power analog front-end (AFE) for CIMS that has variable gain-frequency characteristics and low-power analog-to-digital (A/D) conversion to adjust to the degradation of stimulus electrodes. The designed AFE was fabricated with 0.18 µm CMOS technology and achieved a valuable gain of 20-60 dB, an upper cutoff frequency of 0.2-10 kHz, and low-power interleaving A/D conversion. In addition, we successfully measured the CIP of stimulus electrodes for body-implanted devices using CIMS.

  16. A Ku-band wide-tuning-range high-output-power VCO in InGaP/GaAs HBT technology

    Science.gov (United States)

    Jincan, Zhang; Yuming, Zhang; Hongliang, Lü; Yimen, Zhang; Bo, Liu; Leiming, Zhang; Fei, Xiang

    2015-06-01

    A fully integrated Ku-band voltage controlled oscillator (VCO) is presented in an InGaP/GaAs heterojunction bipolar transistor (HBT) technology. To achieve the wide tuning range (TR), the VCO employs a Colpitts configuration, and the VCO simultaneously achieves high output power. The implemented VCO demonstrates an oscillation frequency range from 12.82 to 14.97 GHz, a frequency TR of 15.47%, an output power from 0.31 to 6.46 dBm, and a phase noise of -94.9 dBc/Hz at 1 MHz offset from 13.9 GHz center frequency. The VCO consumes 52.75 mW from 5 V supply and occupies an area of 0.81 × 0.78 mm2. Finally, the figures-of-merit for VCOs is discussed. Project supported by the National Basic Research Program of China (No. 2010CBxxxx05), the Advance Research Project of China (No. 51308xxxx06), the Advance Research Foundation of China (No. 9140A08xxxx11DZ111), and Doctoral Scientific Research Foundation of Henan University of Science and Technology (No. 400613480011), and the Foundation of He'nan Educational Commettee (No. 15A510001).

  17. How James Watt invented the copier forgotten inventions of our great scientists

    CERN Document Server

    Schils, René

    2012-01-01

    Features 25 different scientists and the ideas which may not have made them famous, but made history… Typically, we remember our greatest scientists from one single invention, one new formula or one incredible breakthrough. This narrow perspective does not give justice to the versatility of many scientists who also earned a reputation in other areas of science. James Watt, for instance, is known for inventing the steam engine, yet most people do not know that he also invented the copier. Alexander Graham Bell of course invented the telephone, but only few know that he invented artificial breathing equipment, a prototype of the ‘iron lung’. Edmond Halley, whose name is associated with the comet that visits Earth every 75 years, produced the first mortality tables, used for life insurances. This entertaining book is aimed at anyone who enjoys reading about inventions and discoveries by the most creative minds. Detailed illustrations of the forgotten designs and ideas enrich the work throughout.

  18. Autaptic self-feedback-induced synchronization transitions in Newman-Watts neuronal network with time delays

    Science.gov (United States)

    Wang, Qi; Gong, Yubing; Wu, Yanan

    2015-04-01

    Autapse is a special synapse that connects a neuron to itself. In this work, we numerically study the effect of chemical autapse on the synchronization of Newman-Watts Hodgkin-Huxley neuron network with time delays. It is found that the neurons exhibit synchronization transitions as autaptic self-feedback delay is varied, and the phenomenon enhances when autaptic self-feedback strength increases. Moreover, this phenomenon becomes strongest when network time delay or coupling strength is optimal. It is also found that the synchronization transitions by network time delay can be enhanced by autaptic activity and become strongest when autaptic delay is optimal. These results show that autaptic delayed self-feedback activity can intermittently enhance and reduce the synchronization of the neuronal network and hence plays an important role in regulating the synchronization of the neurons. These findings could find potential implications for the information processing and transmission in neural systems.

  19. Optimization of Watt's Six-bar Linkage to Generate Straight and Parallel Leg Motion

    Directory of Open Access Journals (Sweden)

    Saeed Akbarnejad

    2008-11-01

    Full Text Available This paper considers optimal synthesis of a special type of four-bar linkages. Combination of this optimal four-bar linkage with on of it's cognates and elimination of two redundant cognates will result in a Watt's six-bar mechanism, which generates straight and parallel motion. This mechanism can be utilized for legged machines. The advantage of this mechanism is that the leg remains straight during it's contact period and because of it's parallel motion, the legs can be as wide as desired to increase contact area and decrease the number of legs required to keep body's stability statically and dynamically. "Genetic algorithm" optimization method is used to find optimal lengths. It is especially useful for problems like the coupler curve equation which are completely nonlinear or extremely difficult to solve.

  20. Autaptic activity-induced synchronization transitions in Newman-Watts network of Hodgkin-Huxley neurons

    Science.gov (United States)

    Wu, Yanan; Gong, Yubing; Wang, Qi

    2015-04-01

    In this paper, we numerically study the effect of autapse on the synchronization of Newman-Watts small-world Hodgkin-Huxley neuron network. It is found that the neurons exhibit synchronization transitions as autaptic self-feedback delay is varied, and the phenomenon becomes strongest when autaptic self-feedback strength is optimal. This phenomenon also changes with the change of coupling strength and network randomness and become strongest when they are optimal. There are similar synchronization transitions for electrical and chemical autapse, but the synchronization transitions for chemical autapse occur more frequently and are stronger than those for electrical synapse. The underlying mechanisms are briefly discussed in quality. These results show that autaptic activity plays a subtle role in the synchronization of the neuronal network. These findings may find potential implications of autapse for the information processing and transmission in neural systems.

  1. First Passage Percolation on the Newman-Watts Small World Model

    Science.gov (United States)

    Komjáthy, Júlia; Vadon, Viktória

    2016-02-01

    The Newman-Watts model is given by taking a cycle graph of n vertices and then adding each possible edge (i,j), |i-j|≠ 1 mod n with probability ρ /n for some ρ >0 constant. In this paper we add i.i.d. exponential edge weights to this graph, and investigate typical distances in the corresponding random metric space given by the least weight paths between vertices. We show that typical distances grow as 1/λ log n for a λ >0 and determine the distribution of smaller order terms in terms of limits of branching process random variables. We prove that the number of edges along the shortest weight path follows a Central Limit Theorem, and show that in a corresponding epidemic spread model the fraction of infected vertices follows a deterministic curve with a random shift.

  2. Wide-frequency range, dynamic matching network and power system for the "Shoelace" radio frequency antenna on the Alcator C-Mod tokamak

    Science.gov (United States)

    Golfinopoulos, Theodore; LaBombard, Brian; Burke, William; Parker, Ronald R.; Parkin, William; Woskov, Paul

    2014-04-01

    A wide-frequency range (50-300 kHz) power system has been implemented for use with a new RF antenna - the "Shoelace" antenna - built to drive coherent plasma fluctuations in the edge of the Alcator C-Mod tokamak. A custom, dynamically tunable matching network allows two commercial 1 kW, 50-Ω RF amplifiers to drive the low-impedance, inductive load presented by the antenna. This is accomplished by a discretely variable L-match network, with 81 independently selected steps available for each of the series and parallel legs of the matching configuration. A compact programmable logic device provides a control system that measures the frequency with better than 1 kHz accuracy and transitions to the correct tuning state in less than 1 ms. At least 85% of source power is dissipated in the antenna across the operational frequency range, with a minimum frequency slew rate of 1 MHz/s; the best performance is achieved in the narrower band from 80 to 150 kHz which is of interest in typical experiments. The RF frequency can be run with open-loop control, following a pre-programmed analog waveform, or phase-locked to track a plasma fluctuation diagnostic signal in real time with programmable phase delay; the amplitude control is always open-loop. The control waveforms and phase delay are programmed remotely. These tools have enabled first-of-a-kind measurements of the tokamak edge plasma system response in the frequency range and at the wave number at which coherent fluctuations regulate heat and particle transport through the plasma boundary.

  3. Wide-frequency range, dynamic matching network and power system for the "Shoelace" radio frequency antenna on the Alcator C-Mod tokamak.

    Science.gov (United States)

    Golfinopoulos, Theodore; LaBombard, Brian; Burke, William; Parker, Ronald R; Parkin, William; Woskov, Paul

    2014-04-01

    A wide-frequency range (50-300 kHz) power system has been implemented for use with a new RF antenna - the "Shoelace" antenna - built to drive coherent plasma fluctuations in the edge of the Alcator C-Mod tokamak. A custom, dynamically tunable matching network allows two commercial 1 kW, 50-Ω RF amplifiers to drive the low-impedance, inductive load presented by the antenna. This is accomplished by a discretely variable L-match network, with 81 independently selected steps available for each of the series and parallel legs of the matching configuration. A compact programmable logic device provides a control system that measures the frequency with better than 1 kHz accuracy and transitions to the correct tuning state in less than 1 ms. At least 85% of source power is dissipated in the antenna across the operational frequency range, with a minimum frequency slew rate of 1 MHz/s; the best performance is achieved in the narrower band from 80 to 150 kHz which is of interest in typical experiments. The RF frequency can be run with open-loop control, following a pre-programmed analog waveform, or phase-locked to track a plasma fluctuation diagnostic signal in real time with programmable phase delay; the amplitude control is always open-loop. The control waveforms and phase delay are programmed remotely. These tools have enabled first-of-a-kind measurements of the tokamak edge plasma system response in the frequency range and at the wave number at which coherent fluctuations regulate heat and particle transport through the plasma boundary.

  4. Wide-frequency range, dynamic matching network and power system for the “Shoelace” radio frequency antenna on the Alcator C-Mod tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Golfinopoulos, Theodore, E-mail: golfit@mit.edu; LaBombard, Brian; Burke, William; Parker, Ronald R.; Parkin, William; Woskov, Paul [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139 (United States)

    2014-04-15

    A wide-frequency range (50–300 kHz) power system has been implemented for use with a new RF antenna – the “Shoelace” antenna – built to drive coherent plasma fluctuations in the edge of the Alcator C-Mod tokamak. A custom, dynamically tunable matching network allows two commercial 1 kW, 50-Ω RF amplifiers to drive the low-impedance, inductive load presented by the antenna. This is accomplished by a discretely variable L-match network, with 81 independently selected steps available for each of the series and parallel legs of the matching configuration. A compact programmable logic device provides a control system that measures the frequency with better than 1 kHz accuracy and transitions to the correct tuning state in less than 1 ms. At least 85% of source power is dissipated in the antenna across the operational frequency range, with a minimum frequency slew rate of 1 MHz/s; the best performance is achieved in the narrower band from 80 to 150 kHz which is of interest in typical experiments. The RF frequency can be run with open-loop control, following a pre-programmed analog waveform, or phase-locked to track a plasma fluctuation diagnostic signal in real time with programmable phase delay; the amplitude control is always open-loop. The control waveforms and phase delay are programmed remotely. These tools have enabled first-of-a-kind measurements of the tokamak edge plasma system response in the frequency range and at the wave number at which coherent fluctuations regulate heat and particle transport through the plasma boundary.

  5. Thermal control of power supplies with electronic packaging techniques

    Science.gov (United States)

    1975-01-01

    The analysis, design, and development work to reduce the weight and size of a standard modular power supply with a 350 watt output was summarized. By integrating low cost commercial heat pipes in the redesign of this power supply, weight was reduced by 30% from that of the previous design. The temperature was also appreciably reduced, increasing the environmental capability of the unit. A demonstration unit with a 100 watt output and a 15 volt regulator module, plus simulated output modules, was built and tested to evaluate the thermal performance of the redesigned power supply.

  6. Watt loss in three-phase transformers with circular and hexagonal forming contours of twisted spatial magnetic core rods

    Directory of Open Access Journals (Sweden)

    E.A. Avdieieva

    2014-04-01

    Full Text Available For spatial three-phase axial electromagnetic systems with circular and hexagonal cross-section configurations of twisted butt-end magnetic core rods, analytical dependences for optimal geometrical relations determination over the transformer minimum watt loss criterion are obtained, comparative analysis of the systems energy efficiency made.

  7. 75 FR 80731 - Request for Exclusion of 120 Volt, 100 Watt R20 Short Incandescent Reflector Lamps

    Science.gov (United States)

    2010-12-23

    ... of energy conservation standards for incandescent reflector lamps a 120 volt, 100 watt R20 short lamp....gov . SUPPLEMENTARY INFORMATION: The Administrative Procedure Act (APA), 5 U.S.C. 551 et seq... APA, NEMA petitioned the Department of Energy for the issuance of a new rule, as set forth below....

  8. 76 FR 70169 - Draft Supplement 2 to Final Environmental Statement Related to the Operation of Watts Bar Nuclear...

    Science.gov (United States)

    2011-11-10

    ...The U.S. Nuclear Regulatory Commission (NRC) is requesting comments on NUREG-0498, ``Final Environmental Statement, Supplement 2, Related to the Operation of Watts Bar Nuclear Plant [WBN], Unit 2-- Draft Report for Comment'' (draft SFES). The NRC will hold a public meeting on the draft SFES on December 8,...

  9. Multichannel low power time-to-digital converter card with 21 ps precision and full scale range up to 10 μs

    Energy Technology Data Exchange (ETDEWEB)

    Tamborini, D., E-mail: davide.tamborini@polimi.it; Portaluppi, D.; Villa, F.; Tosi, A. [Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Piazza Leonardo Da Vinci 32, 20133 Milano (Italy); Tisa, S. [Micro Photon Devices, via Stradivari 4, 39100 Bolzano (Italy)

    2014-11-15

    We present a Time-to-Digital Converter (TDC) card with a compact form factor, suitable for multichannel timing instruments or for integration into more complex systems. The TDC Card provides 10 ps timing resolution over the whole measurement range, which is selectable from 160 ns up to 10 μs, reaching 21 ps rms precision, 1.25% LSB rms differential nonlinearity, up to 3 Mconversion/s with 400 mW power consumption. The I/O edge card connector provides timing data readout through either a parallel bus or a 100 MHz serial interface and further measurement information like input signal rate and valid conversion rate (typically useful for time-correlated single-photon counting application) through an independent serial link.

  10. Stopping power and mean free path for low-energy electrons in ten scintillators over energy range of 20-20,000 eV.

    Science.gov (United States)

    Tan, Zhenyu; Xia, Yueyuan

    2012-01-01

    Systematic calculations of the stopping powers (SP) and inelastic mean free paths (IMFP) for 20-20,000eV electrons in a group of 10 important scintillators have been carried out. The calculations are based on the dielectric model including the Born-Ochkur exchange correction and the optical energy loss functions (OELFs) are empirically evaluated because of the lack of available experimental optical data for the scintillators under consideration. The evaluated OELFs are examined by both the f-sum rule and the calculation of mean ionization potential. The SP and IMFP data presented here are the first results for the 10 scintillators over the energy range of 20-20,000eV, and are of key importance for the investigation of liquid scintillation counting.

  11. Power distribution of a co-axial dual-mechanical-port flux-switching permanent magnet machine for fuel-based extended range electric vehicles

    Directory of Open Access Journals (Sweden)

    Lingkang Zhou

    2017-05-01

    Full Text Available In this paper, power distribution between the inner and outer machines of a co-axial dual-mechanical-port flux-switching permanent magnet (CADMP-FSPM machine is investigated for fuel-based extended range electric vehicle (ER-EV. Firstly, the topology and operation principle of the CADMP-FSPM machine are introduced, which consist of an inner FSPM machine used for high-speed, an outer FSPM machine for low-speed, and a magnetic isolation ring between them. Then, the magnetic field coupling of the inner and outer FSPM machines is analyzed with more attention paid to the optimization of the isolation ring thickness. Thirdly, the power-dimension (PD equations of the inner and outer FSPM machines are derived, respectively, and thereafter, the PD equation of the whole CADMP-FSPM machine can be given. Finally, the PD equations are validated by finite element analysis, which supplies the guidance on the design of this type of machines.

  12. Unmanned Aerial Vehicle (UAV) Dynamic-Tracking Directional Wireless Antennas for Low Powered Applications that Require Reliable Extended Range Operations in Time Critical Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Scott G. Bauer; Matthew O. Anderson; James R. Hanneman

    2005-10-01

    The proven value of DOD Unmanned Aerial Vehicles (UAVs) will ultimately transition to National and Homeland Security missions that require real-time aerial surveillance, situation awareness, force protection, and sensor placement. Public services first responders who routinely risk personal safety to assess and report a situation for emergency actions will likely be the first to benefit from these new unmanned technologies. ‘Packable’ or ‘Portable’ small class UAVs will be particularly useful to the first responder. They require the least amount of training, no fixed infrastructure, and are capable of being launched and recovered from the point of emergency. All UAVs require wireless communication technologies for real- time applications. Typically on a small UAV, a low bandwidth telemetry link is required for command and control (C2), and systems health monitoring. If the UAV is equipped with a real-time Electro-Optical or Infrared (EO/Ir) video camera payload, a dedicated high bandwidth analog/digital link is usually required for reliable high-resolution imagery. In most cases, both the wireless telemetry and real-time video links will be integrated into the UAV with unity gain omni-directional antennas. With limited on-board power and payload capacity, a small UAV will be limited with the amount of radio-frequency (RF) energy it transmits to the users. Therefore, ‘packable’ and ‘portable’ UAVs will have limited useful operational ranges for first responders. This paper will discuss the limitations of small UAV wireless communications. The discussion will present an approach of utilizing a dynamic ground based real-time tracking high gain directional antenna to provide extend range stand-off operation, potential RF channel reuse, and assured telemetry and data communications from low-powered UAV deployed wireless assets.

  13. Power dissipation by Higher Order Modes

    CERN Document Server

    Schuh, M

    2010-01-01

    The additional power loss due to HOMs in cavities and HOM couplers is estimated as function of the damping with analytic and beam dynamics simulation based models. Based on these results,HOM damping requirements for the Superconducting Proton Linac (SPL) can be defined to limit the additional heat load to the watt level.

  14. A Tariff for Reactive Power

    Energy Technology Data Exchange (ETDEWEB)

    Kueck, John D [ORNL; Kirby, Brendan J [ORNL; Li, Fangxing [ORNL; Tufon, Christopher [Pacific Gas and Electric Company; Isemonger, Alan [California Independent System Operator

    2008-07-01

    Two kinds of power are required to operate an electric power system: real power, measured in watts, and reactive power, measured in volt-amperes reactive or VARs. Reactive power supply is one of a class of power system reliability services collectively known as ancillary services, and is essential for the reliable operation of the bulk power system. Reactive power flows when current leads or lags behind voltage. Typically, the current in a distribution system lags behind voltage because of inductive loads such as motors. Reactive power flow wastes energy and capacity and causes voltage droop. To correct lagging power flow, leading reactive power (current leading voltage) is supplied to bring the current into phase with voltage. When the current is in phase with voltage, there is a reduction in system losses, an increase in system capacity, and a rise in voltage. Reactive power can be supplied from either static or dynamic VAR sources. Static sources are typically transmission and distribution equipment, such as capacitors at substations, and their cost has historically been included in the revenue requirement of the transmission operator (TO), and recovered through cost-of-service rates. By contrast, dynamic sources are typically generators capable of producing variable levels of reactive power by automatically controlling the generator to regulate voltage. Transmission system devices such as synchronous condensers can also provide dynamic reactive power. A class of solid state devices (called flexible AC transmission system devices or FACTs) can provide dynamic reactive power. One specific device has the unfortunate name of static VAR compensator (SVC), where 'static' refers to the solid state nature of the device (it does not include rotating equipment) and not to the production of static reactive power. Dynamic sources at the distribution level, while more costly would be very useful in helping to regulate local voltage. Local voltage regulation would

  15. Relationship Between Satellite-Derived Snow Cover and Snowmelt-Runoff Timing and Stream Power in the Wind River Range, Wyoming

    Science.gov (United States)

    Hall, Dorothy K.; Foster, James L.; DiGirolamo, Nicolo E.; Riggs, George A.

    2010-01-01

    Earlier onset of springtime weather including earlier snowmelt has been documented in the western United States over at least the last 50 years. Because the majority (>70%) of the water supply in the western U.S. comes from snowmelt, analysis of the declining spring snowpack (and shrinking glaciers) has important implications for streamflow management. The amount of water in a snowpack influences stream discharge which can also influence erosion and sediment transport by changing stream power, or the rate at which a stream can do work such as move sediment and erode the stream bed. The focus of this work is the Wind River Range (WRR) in west-central Wyoming. Ten years of Moderate-Resolution Imaging Spectroradiometer (MODIS) snow-cover, cloud- gap-filled (CGF) map products and 30 years of discharge and meteorological station data are studied. Streamflow data from six streams in the WRR drainage basins show lower annual discharge and earlier snowmelt in the decade of the 2000s than in the previous three decades, though no trend of either lower streamflow or earlier snowmelt was observed using MODIS snow-cover maps within the decade of the 2000s. Results show a statistically-significant trend at the 95% confidence level (or higher) of increasing weekly maximum air temperature (for three out of the five meteorological stations studied) in the decade of the 1970s, and also for the 40-year study period. MODIS-derived snow cover (percent of basin covered) measured on 30 April explains over 89% of the variance in discharge for maximum monthly streamflow in the decade of the 2000s using Spearman rank correlation analysis. We also investigated stream power for Bull Lake Creek Above Bull Lake from 1970 to 2009; a statistically-significant end toward reduced stream power was found (significant at the 90% confidence level). Observed changes in streamflow and stream power may be related to increasing weekly maximum air temperature measured during the 40-year study period. The

  16. Investigations on the minimization of climatic impacts on the range of electric-powered vehicles; Untersuchungen zur Minimierung der Klimaeinfluesse auf die Reichweite von Elektrofahrzeugen

    Energy Technology Data Exchange (ETDEWEB)

    Rauh, Hubert; Hofmann, Maximilian; Maerz, Martin [Fraunhofer Institut fuer Integrierte Systeme und Bauelementetechnologie, Erlangen (Germany)

    2012-11-01

    Efficient drives and power electronics are key components for the realisation of drive trains in electric vehicles. A low energy density of the battery and little thermal loss in the electric drive train - in comparison with a combustion engine - requires efforts to acclimatise the vehicle in a way which minimises its impact on the vehicle's cruising range. Using equivalent thermal networks, Fraunhofer IISB thus develops simulation tools of passenger compartment, components of the acclimatisation system and the electric drive train. With these tools the heat flow in the passenger compartment as well as in the components of the electric drive train can be calculated. Furthermore, it is possible to compare different acclimatisation strategies as well as different topologies of the acclimatisation system. To minimize the electrical energy consumption of acclimatisation, the thermal energy needed in this process is provided by a heat pump. By preconditioning cabin, cooling circuit and drive train components while charging the battery, the energy consumption at the beginning of a drive can be further reduced, whereby the maximal cruising range at different ambient temperatures increases. (orig.)

  17. Reconfigurable Resonant Regulating Rectifier With Primary Equalization for Extended Coupling- and Loading-Range in Bio-Implant Wireless Power Transfer.

    Science.gov (United States)

    Li, Xing; Meng, Xiaodong; Tsui, Chi-Ying; Ki, Wing-Hung

    2015-12-01

    Wireless power transfer using reconfigurable resonant regulating (R(3)) rectification suffers from limited range in accommodating varying coupling and loading conditions. A primary-assisted regulation principle is proposed to mitigate these limitations, of which the amplitude of the rectifier input voltage on the secondary side is regulated by accordingly adjusting the voltage amplitude Veq on the primary side. A novel current-sensing method and calibration scheme track Veq on the primary side. A ramp generator simultaneously provides three clock signals for different modules. Both the primary equalizer and the R(3) rectifier are implemented as custom integrated circuits fabricated in a 0.35 μm CMOS process, with the global control implemented in FPGA. Measurements show that with the primary equalizer, the workable coupling and loading ranges are extended by 250% at 120 mW load and 300% at 1.2 cm coil distance compared to the same system without the primary equalizer. A maximum rectifier efficiency of 92.5% and a total system efficiency of 62.4% are demonstrated.

  18. A study of the laser power online detecting

    Science.gov (United States)

    Zhang, Qiue; Zhang, Rong; Li, Yongzheng

    2008-12-01

    This article introduced a fundamental of new intelligent instruments. It can be used in laser power online detecting. Based in this theory, we have made a new intelligent mini-power meter. The device adopt SPCE061A MPU to control and process the all detected data, Its CPU core is used 16-bits MPU, it is a perfect unit in industry field. It can process complicated digital signals. Its detecting parts adopt high-speed responding and high-sensitive photoelectric dynatron 3DU13 to detecting the beam's output. It respond spectrum is from 0.4 to 1.1µm, can detect any other laser source's online detecting. Which locate in this spectrum range, optical design is made up of 45 degrees high reflect device and dark body scattering structure. The detector receive a little scatter light, use on-chip ADC to sampling the detector's output. By subsection, insert value linearity, proportion calculate to beam's output powers. And then real-time to displaying by LCD. It can communicate to PC by RS232. By communicate to upper instrument and others, the users can use detected data to achieve laser power's closed-loop control, to control laser source's real time output correctly and calibrating by itself. This mini-power meter need use standard power meter to calibrate in installing, after this process, the device can detect laser power's output from 1 to 200 watts correctly. It error is less than 5 percent.

  19. Quantification of degeneracy in Hodgkin-Huxley neurons on Newman-Watts small world network.

    Science.gov (United States)

    Man, Menghua; Zhang, Ya; Ma, Guilei; Friston, Karl; Liu, Shanghe

    2016-08-07

    Degeneracy is a fundamental source of biological robustness, complexity and evolvability in many biological systems. However, degeneracy is often confused with redundancy. Furthermore, the quantification of degeneracy has not been addressed for realistic neuronal networks. The objective of this paper is to characterize degeneracy in neuronal network models via quantitative mathematic measures. Firstly, we establish Hodgkin-Huxley neuronal networks with Newman-Watts small world network architectures. Secondly, in order to calculate the degeneracy, redundancy and complexity in the ensuing networks, we use information entropy to quantify the information a neuronal response carries about the stimulus - and mutual information to measure the contribution of each subset of the neuronal network. Finally, we analyze the interdependency of degeneracy, redundancy and complexity - and how these three measures depend upon network architectures. Our results suggest that degeneracy can be applied to any neuronal network as a formal measure, and degeneracy is distinct from redundancy. Qualitatively degeneracy and complexity are more highly correlated over different network architectures, in comparison to redundancy. Quantitatively, the relationship between both degeneracy and redundancy depends on network coupling strength: both degeneracy and redundancy increase with complexity for small coupling strengths; however, as coupling strength increases, redundancy decreases with complexity (in contrast to degeneracy, which is relatively invariant). These results suggest that the degeneracy is a general topologic characteristic of neuronal networks, which could be applied quantitatively in neuroscience and connectomics.

  20. Stochastic resonance on Newman-Watts networks of Hodgkin-Huxley neurons with local periodic driving

    Energy Technology Data Exchange (ETDEWEB)

    Ozer, Mahmut [Zonguldak Karaelmas University, Engineering Faculty, Department of Electrical and Electronics Engineering, 67100 Zonguldak (Turkey)], E-mail: mahmutozer2002@yahoo.com; Perc, Matjaz [University of Maribor, Faculty of Natural Sciences and Mathematics, Department of Physics, Koroska cesta 160, SI-2000 Maribor (Slovenia); Uzuntarla, Muhammet [Zonguldak Karaelmas University, Engineering Faculty, Department of Electrical and Electronics Engineering, 67100 Zonguldak (Turkey)

    2009-03-02

    We study the phenomenon of stochastic resonance on Newman-Watts small-world networks consisting of biophysically realistic Hodgkin-Huxley neurons with a tunable intensity of intrinsic noise via voltage-gated ion channels embedded in neuronal membranes. Importantly thereby, the subthreshold periodic driving is introduced to a single neuron of the network, thus acting as a pacemaker trying to impose its rhythm on the whole ensemble. We show that there exists an optimal intensity of intrinsic ion channel noise by which the outreach of the pacemaker extends optimally across the whole network. This stochastic resonance phenomenon can be further amplified via fine-tuning of the small-world network structure, and depends significantly also on the coupling strength among neurons and the driving frequency of the pacemaker. In particular, we demonstrate that the noise-induced transmission of weak localized rhythmic activity peaks when the pacemaker frequency matches the intrinsic frequency of subthreshold oscillations. The implications of our findings for weak signal detection and information propagation across neural networks are discussed.

  1. A nonlinearity in permanent-magnet systems used in watt balances

    CERN Document Server

    Li, Shisong; Pratt, Jon

    2014-01-01

    Watt balances are used to measure the Planck constant and will be used in the future to realize mass at the kilogram level. They increasingly rely on permanent magnet systems to generate the magnetic flux. It has been known that the weighing current might effect the magnetization state of the permanent magnetic system used in these systems causing a systematic bias that can lead to an error in the result if not accounted for. In this article a simple model explaining the effect of the weighing current on the yoke of the magnet is developed. This model leads to a nonlinear dependence of the magnetic flux density in the gap that is proportional to the squared value of the coil current. The effect arises from changing the reluctance of the yoke by the additional field produced by the coil. Our analysis shows that the effect depends on the width of the air gap, the magnetic flux density in the air gap, and the $BH$ curve of the yoke material. Suggestions to reduce the nonlinear effect are discussed.

  2. Design and development of Stirling engines for stationary power generation applications in the 500 to 3000 horsepower range. Volume 1. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    ,

    1980-09-15

    This project was Phase I of a multiphased program for the design and development of Stirling engines for stationary power generation applications in the 500 to 3000 horsepower range. Phase I comprised the conceptual design and associated cost estimates of a stationary Stirling engine capable of being fueled by a variety of heat sources, with emphasis on coal firing, followed by the preparation of a plan for implementing the design, fabrication and testing of a demonstration engine by 1985. The development and evaluation of conceptual designs have been separated into two broad categories: the A designs which represent the present state-of-the-art and which are demonstrable by 1985 with minimum technical risk; and the B designs which involve advanced technology and therefore would require significant research and development prior to demonstration and commercialization, but which may ultimately offer advantages in terms of lower cost, better performance, or higher reliability. The majority of the effort in Phase I was devoted to the A designs.

  3. WattJournals: Towards an Economic and Lightweight Search Tool Alternative for Libraries To Help Their Students and Researchers Keep Up-To-Date

    Directory of Open Access Journals (Sweden)

    Santiago Chumbe

    2010-12-01

    Full Text Available Learn how Heriot-Watt University Library's WattJournals could be just the search tool your patrons need to efficiently find the content that your library subscribes to. Built on top of a RESTful search API created by the JISC-sponsored JournalTOCs Project, WattJournals is a toolkit for connecting fulltext articles to the people who need them. This article provides a technical overview of the system, showing how it uses citation data pulled from the JournalTOCs table of contents awareness service to provide access to just your library's subscriptions.

  4. High power diode lasers for solid-state laser pumps

    Science.gov (United States)

    Linden, Kurt J.; McDonnell, Patrick N.

    1994-02-01

    The development and commercial application of high power diode laser arrays for use as solid-state laser pumps is described. Such solid-state laser pumps are significantly more efficient and reliable than conventional flash-lamps. This paper describes the design and fabrication of diode lasers emitting in the 780 - 900 nm spectral region, and discusses their performance and reliability. Typical measured performance parameters include electrical-to-optical power conversion efficiencies of 50 percent, narrow-band spectral emission of 2 to 3 nm FWHM, pulsed output power levels of 50 watts/bar with reliability values of over 2 billion shots to date (tests to be terminated after 10 billion shots), and reliable operation to pulse lengths of 1 ms. Pulse lengths up to 5 ms have been demonstrated at derated power levels, and CW performance at various power levels has been evaluated in a 'bar-in-groove' laser package. These high-power 1-cm stacked-bar arrays are now being manufactured for OEM use. Individual diode laser bars, ready for package-mounting by OEM customers, are being sold as commodity items. Commercial and medical applications of these laser arrays include solid-state laser pumping for metal-working, cutting, industrial measurement and control, ranging, wind-shear/atmospheric turbulence detection, X-ray generation, materials surface cleaning, microsurgery, ophthalmology, dermatology, and dental procedures.

  5. Long range prospect of the electric power demand in FY 2,000. Total demand: 8. 38 trillion KWh, annual average increase: 2. 3%

    Energy Technology Data Exchange (ETDEWEB)

    1988-01-05

    The Agency of Natural Resources and Energy, the Ministry of International Trade and Industry held meetings of the Committee on Demand and Supply of the Electric Utility Industrial Council in October, 1987. This article is the Committee's interim report and establishes the prospect of the electric power supply and demand in Japan in FY 1995 and FY 2000. Total power demand in FY 1995 is about 7.38 trillion KWh and in FY 2000, about 8.38 trillion KWh. Average annual growth is about 2.6% during the period of FY 1995 through FY 2000. Among the above, the public demand will increase and occupy 50.2% of the total power demand in the year of 2000. The industrial demand will increase about 1.4% in terms of annual rate during the period of FY 1995 through FY 2000 due to the demand increase by new industries, etc. against continued rationalization of power utilization. The maximum electric power demand is around 163 million KW in FY 2000. The target of electric power supply in FY 2000 is 53 million KW from atomic power generation, 23 million KW from coal burning thermal power generation, 43 million KW from LNG, 21 million KW from hydro power generation and 52 million KW from oil and LPG. Hereafter, electric load leveling, more efficient electric power supply and strengthening of the basis of electric power utilization are necessary. (1 photo, 3 tabs)

  6. Comparison of the Danish step test and the watt-max test for estimation of maximal oxygen uptake

    DEFF Research Database (Denmark)

    Aadahl, Mette; Zacho, Morten; Linneberg, Allan René

    2013-01-01

    test may be a feasible alternative for estimation of VO(2max.)Aim: To compare a simple fitness test, the Danish step test, to an indirect maximal test, the watt-max test, for estimation of VO(2max.)Methods: In the population-based Health2008 study, 2218 men and women aged 30-60 years were invited....... Altogether, 795 eligible participants (response rate 35.8%) performed the watt max and the Danish step test. Correlation and agreement between the two VO(2max) test results was explored by Pearson's rho, Bland-Altman plots, Kappa(w), and gamma coefficients.Results: The correlation between VO(2max) (ml....../kg/min) estimated by the two tests was moderate to high (men: r = 0.69, p test slightly overestimated VO(2max )compared to the watt-max test, more so in women than in men. Agreement between the two tests when VO(2max) was classified in five levels was gamma = 0...

  7. High power continuous-wave GaSb-based superluminescent diodes as gain chips for widely tunable laser spectroscopy in the 1.95-2.45 μm wavelength range

    Science.gov (United States)

    Vizbaras, K.; Dvinelis, E.; ŠimonytÄ--, I.; TrinkÅ«nas, A.; Greibus, M.; Songaila, R.; Žukauskas, T.; Kaušylas, M.; Vizbaras, A.

    2015-07-01

    We present high-power single-spatial mode electrically pumped GaSb-based superluminescent diodes (SLDs) operating in the 1.95 to 2.45 μm wavelength range in continuous-wave (CW). MBE grown GaSb-based heterostructures were fabricated into single-angled facet ridge-waveguide devices that demonstrate more than 40 mW CW output power at 2.05 μm, to >5 mW at 2.40 μm at room-temperature. We integrated these SLDs into an external cavity (Littrow configuration) as gain chips and achieved single-mode CW lasing with maximum output powers exceeding 18 mW. An extremely wide tuning range of 120 nm per chip with side-mode-suppression-ratios >25 dB was demonstrated while maintaining optical output power level above 3 mW across the entire tuning range.

  8. Standalone BISON Fuel Performance Results for Watts Bar Unit 1, Cycles 1-3

    Energy Technology Data Exchange (ETDEWEB)

    Clarno, Kevin T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pawlowski, Roger [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stimpson, Shane [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Powers, Jeffrey [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-03-07

    The Consortium for Advanced Simulation of Light Water Reactors (CASL) is moving forward with more complex multiphysics simulations and increased focus on incorporating fuel performance analysis methods. The coupled neutronics/thermal-hydraulics capabilities within the Virtual Environment for Reactor Applications Core Simulator (VERA-CS) have become relatively stable, and major advances have been made in analysis efforts, including the simulation of twelve cycles of Watts Bar Nuclear Unit 1 (WBN1) operation. While this is a major achievement, the VERA-CS approaches for treating fuel pin heat transfer have well-known limitations that could be eliminated through better integration with the BISON fuel performance code. Several approaches are being implemented to consider fuel performance, including a more direct multiway coupling with Tiamat, as well as a more loosely coupled one-way approach with standalone BISON cases. Fuel performance typically undergoes an independent analysis using a standalone fuel performance code with manually specified input defined from an independent core simulator solution or set of assumptions. This report summarizes the improvements made since the initial milestone to execute BISON from VERA-CS output. Many of these improvements were prompted through tighter collaboration with the BISON development team at Idaho National Laboratory (INL). A brief description of WBN1 and some of the VERA-CS data used to simulate it are presented. Data from a small mesh sensitivity study are shown, which helps justify the mesh parameters used in this work. The multi-cycle results are presented, followed by the results for the first three cycles of WBN1 operation, particularly the parameters of interest to pellet-clad interaction (PCI) screening (fuel-clad gap closure, maximum centerline fuel temperature, maximum/minimum clad hoop stress, and cumulative damage index). Once the mechanics of this capability are functioning, future work will target cycles with

  9. Effects of coal fly ash on tree swallow reproduction in Watts Bar Reservoir, Tennessee.

    Science.gov (United States)

    Walls, Suzanne J; Meyer, Carolyn B; Iannuzzi, Jacqueline; Schlekat, Tamar H

    2015-01-01

    Coal-fly ash was released in unprecedented amounts (4.1 × 10(6) m(3) ) into the Emory River from the Tennessee Valley Authority Kingston Fossil Plant on Watts Bar Reservoir in Tennessee. Tree swallows were exposed to ash-related constituents at the ash release via their diet of emergent aquatic insects, whose larval forms can accumulate constituents from submerged river sediments. Reproduction of tree swallow colonies was assessed over a 2-year period by evaluating whether 1) ash constituent concentrations were elevated in egg, eggshell, and nestling tissues at colonies near ash-impacted river reaches compared to reference colonies, 2) production of fledglings per nesting female was significantly lower in ash-impacted colonies versus reference colonies, and 3) ash constituent concentrations or diet concentrations were correlated with nest productivity measures (clutch size, hatching success, and nestling survival, and fledglings produced per nest). Of the 26 ash constituents evaluated, 4 (Se, Sr, Cu, and Hg) were significantly elevated in tissues potentially from the ash, and 3 (Se, Sr, and Cu) in tissues or in swallow diet items were weakly correlated to at least one nest-productivity measure or egg weight. Tree swallow hatching success was significantly reduced by 12%, but fledgling production per nest was unaffected due to larger clutch sizes in the impacted than reference colonies. Bioconcentration from the ash to insects in the diet to tree swallow eggs appears to be low. Overall, adverse impacts of the ash on tree swallow reproduction were not observed, but monitoring is continuing to further ensure Se from the residual ash does not adversely affect tree swallow reproduction over time. Integr Environ Assess Manag 2015;11:56-66. © 2014 SETAC.

  10. Measuring laser power as a force: a new paradigm to accurately monitor optical power during laser-based machining operations

    Science.gov (United States)

    Williams, Paul; Simonds, Brian; Sowards, Jeffrey; Hadler, Joshua

    2016-03-01

    In laser manufacturing operations, accurate measurement of laser power is important for product quality, operational repeatability, and process validation. Accurate real-time measurement of high-power lasers, however, is difficult. Typical thermal power meters must absorb all the laser power in order to measure it. This constrains power meters to be large, slow and exclusive (that is, the laser cannot be used for its intended purpose during the measurement). To address these limitations, we have developed a different paradigm in laser power measurement where the power is not measured according to its thermal equivalent but rather by measuring the laser beam's momentum (radiation pressure). Very simply, light reflecting from a mirror imparts a small force perpendicular to the mirror which is proportional to the optical power. By mounting a high-reflectivity mirror on a high-sensitivity force transducer (scale), we are able to measure laser power in the range of tens of watts up to ~ 100 kW. The critical parameters for such a device are mirror reflectivity, angle of incidence, and scale sensitivity and accuracy. We will describe our experimental characterization of a radiation-pressure-based optical power meter. We have tested it for modulated and CW laser powers up to 92 kW in the laboratory and up to 20 kW in an experimental laser welding booth. We will describe present accuracy, temporal response, sources of measurement uncertainty, and hurdles which must be overcome to have an accurate power meter capable of routine operation as a turning mirror within a laser delivery head.

  11. Miniaturized radioisotope solid state power sources

    Science.gov (United States)

    Fleurial, J.-P.; Snyder, G. J.; Patel, J.; Herman, J. A.; Caillat, T.; Nesmith, B.; Kolawa, E. A.

    2000-01-01

    Electrical power requirements for the next generation of deep space missions cover a wide range from the kilowatt to the milliwatt. Several of these missions call for the development of compact, low weight, long life, rugged power sources capable of delivering a few milliwatts up to a couple of watts while operating in harsh environments. Advanced solid state thermoelectric microdevices combined with radioisotope heat sources and energy storage devices such as capacitors are ideally suited for these applications. By making use of macroscopic film technology, microgenrators operating across relatively small temperature differences can be conceptualized for a variety of high heat flux or low heat flux heat source configurations. Moreover, by shrinking the size of the thermoelements and increasing their number to several thousands in a single structure, these devices can generate high voltages even at low power outputs that are more compatible with electronic components. Because the miniaturization of state-of-the-art thermoelectric module technology based on Bi2Te3 alloys is limited due to mechanical and manufacturing constraints, we are developing novel microdevices using integrated-circuit type fabrication processes, electrochemical deposition techniques and high thermal conductivity substrate materials. One power source concept is based on several thermoelectric microgenerator modules that are tightly integrated with a 1.1W Radioisotope Heater Unit. Such a system could deliver up to 50mW of electrical power in a small lightweight package of approximately 50 to 60g and 30cm3. An even higher degree of miniaturization and high specific power values (mW/mm3) can be obtained when considering the potential use of radioisotope materials for an alpha-voltaic or a hybrid thermoelectric/alpha-voltaic power source. Some of the technical challenges associated with these concepts are discussed in this paper. .

  12. Results of Performance Tests Performed on the John Watts Casing Connection on 7" Pipe

    Energy Technology Data Exchange (ETDEWEB)

    John D. Watts

    1999-08-01

    Stress Engineering Services (SES) was contracted by Mr. John Watts to test his threaded connection developed for oilfield oil and gas service. This particular test required the application of a variety of loads including axial tension and compression, internal pressure (gas), external pressure (water), bending and both low and elevated temperature. These loads were used to determine the sealing and structural limits of the connection. The connection design tested had tapered threads with 10 threads per inch. A square thread form and a round thread form were tested. The square thread form had a 2{sup o} load flank and 15{sup o} stab flank. The round thread had a 0{sup o} load flank and 20{sup o} stab flank. Most of the testing was performed on the round thread form. Both a coupled connection design and an integral connection design were tested. The coupling was a pin by pin (male) thread, with the pipe having a box (female) thread. Both designs have outside and inside diameters that are flush with the pipe body. Both designs also contain a small external shoulder. The test procedure selected for this evaluation was the newly written ISO 13679 procedure for full scale testing of casing and tubing connections. The ISO procedure requires a variety of tests that includes makeup/breakout testing, internal gas sealability/external water sealability testing with axial tension, axial compression, bending, internal gas thermal cycle tests and limit load (failure) tests. This test was performed with four coupled samples and included most of these loads. Two integral samples were also included for limit load testing ISO makeup/breakout tests are divided into three types--initial makeup, IML1, repeated makeup within the same sample, MBL, and repeated makeup using several samples called round robin, RR. IMU and MBL were performed in this project. The ISO sealing and structural procedure is divided into four primary tests and identified as Series A, B, C and Limit Load (failure

  13. Results of Performance Tests Performed on the John Watts Casing Connection on 7" Pipe

    Energy Technology Data Exchange (ETDEWEB)

    John D. Watts

    1999-08-01

    Stress Engineering Services (SES) was contracted by Mr. John Watts to test his threaded connection developed for oilfield oil and gas service. This particular test required the application of a variety of loads including axial tension and compression, internal pressure (gas), external pressure (water), bending and both low and elevated temperature. These loads were used to determine the sealing and structural limits of the connection. The connection design tested had tapered threads with 10 threads per inch. A square thread form and a round thread form were tested. The square thread form had a 2{sup o} load flank and 15{sup o} stab flank. The round thread had a 0{sup o} load flank and 20{sup o} stab flank. Most of the testing was performed on the round thread form. Both a coupled connection design and an integral connection design were tested. The coupling was a pin by pin (male) thread, with the pipe having a box (female) thread. Both designs have outside and inside diameters that are flush with the pipe body. Both designs also contain a small external shoulder. The test procedure selected for this evaluation was the newly written ISO 13679 procedure for full scale testing of casing and tubing connections. The ISO procedure requires a variety of tests that includes makeup/breakout testing, internal gas sealability/external water sealability testing with axial tension, axial compression, bending, internal gas thermal cycle tests and limit load (failure) tests. This test was performed with four coupled samples and included most of these loads. Two integral samples were also included for limit load testing ISO makeup/breakout tests are divided into three types--initial makeup, IML1, repeated makeup within the same sample, MBL, and repeated makeup using several samples called round robin, RR. IMU and MBL were performed in this project. The ISO sealing and structural procedure is divided into four primary tests and identified as Series A, B, C and Limit Load (failure

  14. An improved high-power battery with increased thermal operating range: C-LiFePO4//C-Li4Ti5O12

    Science.gov (United States)

    Zaghib, K.; Dontigny, M.; Guerfi, A.; Trottier, J.; Hamel-Paquet, J.; Gariepy, V.; Galoutov, K.; Hovington, P.; Mauger, A.; Groult, H.; Julien, C. M.

    2012-10-01

    The carbon-coated LiFePO4 and C-Li4Ti5O12 particles of 90 nm in diameter have been tested as active elements of electrodes of Li-ion batteries. The 18650-size cell using the usual electrolyte 1 mol L-1 LiPF6 in ethylene carbonate (EC) and diethylene carbonate (DEC) displays a charge capacity of 650 mAh at low C-rate and retains more than 80% of rated capacity at 60C charge rate (1 min). 2032-size coin cells have been tested with different electrolytes: 1.5 mol L-1 lithium tetrafluoroborate LiBF4 in EC+ γ-butyrolactone (GBL), and 0.5 mol L-1 lithium bis(trifluoromethanesulfonyl)imide (LiN(CF3SO2)2, LiTFSI) + 1 mol L-1 LiBF4 in EC + GBL, aiming to replace the less stable LiPF6 salt. The LiTFSI-based electrolyte can be used owing to the low operating voltage that avoids the corrosion of the aluminum of the collector. This electrolyte shows the best results as the performance is even higher at 60 °C. The infrared images show that the temperature of the cell never reaches this temperature during cycling, making this battery a high-power battery with remarkable thermal stability. The maximum temperature reached by the cell is 34 °C at 40C-rate and 40 °C at 60C. The free EC-based electrolytes even operate at 80 °C by using 1 mol L-1 lithium bis(fluorosulfonyl)imide (LiFSI) in GBL or 1 mol L-1 LiFSI in PC + GBL, thus increasing importantly the operating temperature range for the battery. The carbon coated on LTO depresses the evolution of gases during charge discharge.

  15. High-Efficiency, High-Power Ka-Band Elliptic-Beam Traveling-Wave-Tube Amplifier for Long-Range Space RF Telecommunications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Space telecommunications require amplifiers that are efficient, high-power, wideband, small, lightweight, and highly reliable. Currently, helix traveling wave tube...

  16. Doppler-free intermodulated fluorescence spectroscopy of $^4He$ $2^3P-3^{1,3}D$ transitions at 588 nm with a one-watt compact laser system

    CERN Document Server

    Luo, Pei-Ling; Feng, Yan; Wang, Li-Bang; Shy, Jow-Tsong

    2015-01-01

    We have demonstrated Doppler-free intermodulated fluorescence spectroscopy of helium $2^3P-3^{1,3}D$ transitions in an rf discharged sealed-off cell using a compact laser system at 588 nm. An external cavity diode laser at 1176 nm was constructed to seed a Raman fiber amplifier. Laser power of more than one watt at 588 nm was produced by frequency doubling of the fiber amplifier output using a MgO:PPLN crystal. A doubling efficiency of 23 % was achieved. The power-dependent spectra of the $2^3P-3^3D$ transitions were investigated. Furthermore, the Doppler-free spectrum of the spin-forbidden $2^3P-3^1D$ transitions was observed for the first time. Our results are crucial towards precision test of QED atomic calculations, especially for improving the determination of the helium $3^1D-3^3D$ separation.

  17. A 10kWatt 36GHz Solid-State Power Amplifier using GaN-on-Diamond Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase-II SBIR proposal proposes for the first time ever, the use of a new class of materials - Gallium Nitride-on-diamond - in the manufacture of very high...

  18. A 10kWatt 36GHz Solid-State Power Amplifier using GaN-on-Diamond Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase-I SBIR proposal proposes for the first time ever, the use of a new class of materials - Gallium Nitride-on-diamond - in the manufacture of very high...

  19. Recent development on high-power tandem-pumped fiber laser

    Science.gov (United States)

    Zhou, Pu; Xiao, Hu; Leng, Jinyong; Zhang, Hanwei; Xu, Jiangmin; Wu, Jian

    2016-11-01

    High power fiber laser is attracting more and more attention due to its advantage in excellent beam quality, high electricto- optical conversion efficiency and compact system configuration. Power scaling of fiber laser is challenged by the brightness of pump source, nonlinear effect, modal instability and so on. Pumping active fiber by using high-brightness fiber laser instead of common laser diode may be the solution for the brightness limitation. In this paper, we will present the recent development of various kinds of high power fiber laser based on tandem pumping scheme. According to the absorption property of Ytterbium-doped fiber, Thulium-doped fiber and Holmium-doped fiber, we have theoretically studied the fiber lasers that operate at 1018 nm, 1178 nm and 1150 nm, respectively in detail. Consequently, according to the numerical results we have optimized the fiber laser system design, and we have achieved (1) 500 watt level 1018nm Ytterbium-doped fiber laser (2) 100 watt level 1150 nm fiber laser and 100 watt level random fiber laser (3) 30 watt 1178 nm Ytterbium-doped fiber laser, 200 watt-level random fiber laser. All of the above-mentioned are the record power for the corresponded type of fiber laser to the best of our knowledge. By using the high-brightness fiber laser operate at 1018 nm, 1178 nm and 1150 nm that we have developed, we have achieved the following high power fiber laser (1) 3.5 kW 1090 nm Ytterbium-doped fiber amplifier (2) 100 watt level Thulium-doped fiber laser and (3) 50 watt level Holmium -doped fiber laser.

  20. Novel wave power analysis linking pressure-flow waves, wave potential, and the forward and backward components of hydraulic power.

    Science.gov (United States)

    Mynard, Jonathan P; Smolich, Joseph J

    2016-04-15

    Wave intensity analysis provides detailed insights into factors influencing hemodynamics. However, wave intensity is not a conserved quantity, so it is sensitive to diameter variations and is not distributed among branches of a junction. Moreover, the fundamental relation between waves and hydraulic power is unclear. We, therefore, propose an alternative to wave intensity called "wave power," calculated via incremental changes in pressure and flow (dPdQ) and a novel time-domain separation of hydraulic pressure power and kinetic power into forward and backward wave-related components (ΠP±and ΠQ±). Wave power has several useful properties:1) it is obtained directly from flow measurements, without requiring further calculation of velocity;2) it is a quasi-conserved quantity that may be used to study the relative distribution of waves at junctions; and3) it has the units of power (Watts). We also uncover a simple relationship between wave power and changes in ΠP±and show that wave reflection reduces transmitted power. Absolute values of ΠP±represent wave potential, a recently introduced concept that unifies steady and pulsatile aspects of hemodynamics. We show that wave potential represents the hydraulic energy potential stored in a compliant pressurized vessel, with spatial gradients producing waves that transfer this energy. These techniques and principles are verified numerically and also experimentally with pressure/flow measurements in all branches of a central bifurcation in sheep, under a wide range of hemodynamic conditions. The proposed "wave power analysis," encompassing wave power, wave potential, and wave separation of hydraulic power provides a potent time-domain approach for analyzing hemodynamics.

  1. Nuclear power systems for the First Lunar Outpost

    Science.gov (United States)

    Mason, Lee S.; Cataldo, Robert L.

    1993-01-01

    A recent study effort at NASA has developed a preliminary reference mission description for a human return to the Moon by the end of this decade. The First Lunar Outpost (FLO) would provide the framework for establishing a permanent human presence on the Moon and a necessary step toward eventual piloted trips to Mars. The primary objectives of FLO are to sustain a crew of four on the lunar surface for 45 days during which local roving, surface science, and demonstration-level resource extraction would be accomplished. Power systems capable of meeting the diverse requirements of FLO are a significant engineering challenge. Power requirements range from 10's of watts for small science packages to 10's of kilowatts for the crew habitat. The guidelines imposed on power systems include that they be lightweight, easily deployable, and cost efficient. Nuclear systems such as radioisotope thermoelectric generators (RTGs), dynamic isotope power systems (DIPS), and small reactor power systems offer distinct advantages over solar and electrochemical alternatives. Concepts for modular RTGs and DIPS, and deployable reactor systems relevant to the FLO mission and its evolution are described and compared.

  2. Improvements in the percent range. Machine learning improves accuracy of forecasting for wind power generation; Verbesserungen im Prozentbereich. Maschinelles Lernen steigert Prognosegenauigkeit bei Windkrafterzeugung

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2011-07-01

    The more accurate the availability of wind power can be predicted, the more better electricity can be placed on the market and the less control energy is required. Machine learning methods allow a further increase in the accuracy of forecasting. However, this requires enormous computational resources. Researchers at the Centre on Research of Solar Energy and Hydrogen (Stuttgart, Federal Republic of Germany) use powerful graphics processors. Project partner EWC Weather Consult GmbH (Karlsruhe, Federal Republic of Germany) combines various weather models to the best possible prediction by means of machine learning. This new offer takes particular interest to producers who want to go into the direct marketing of wind power.

  3. Solar Panel Maximum Power Point Tracker for Power Utilities

    Directory of Open Access Journals (Sweden)

    Sandeep Banik,

    2014-01-01

    Full Text Available ―Solar Panel Maximum Power Point Tracker For power utilities‖ As the name implied, it is a photovoltaic system that uses the photovoltaic array as a source of electrical power supply and since every photovoltaic (PV array has an optimum operating point, called the maximum power point, which varies depending on the insolation level and array voltage. A maximum power point tracker (MPPT is needed to operate the PV array at its maximum power point. The objective of this thesis project is to build a photovoltaic (PV array Of 121.6V DC Voltage(6 cell each 20V, 100watt And convert the DC voltage to Single phase 120v,50Hz AC voltage by switch mode power converter‘s and inverter‘s.

  4. CSDA range, stopping power and mean penetration depth energy relationships in some hydrocarbons and biologic materials for 10 eV to 100 MeV with the modified Rohrlich-Carlson model

    Energy Technology Data Exchange (ETDEWEB)

    Guemues, Hasan [Ondokuz Mayis University, Department of Physics, Faculty of Sciences and Arts, Samsun (Turkey); Bentabet, Abdelouahab [Bordj Bou Arreridj University, LCVRN, SNVSTU Faculty, El Anasser (Algeria)

    2017-05-15

    In this study, for some hydrocarbons and biological compounds, stopping power formula are presented, being valid for low and intermediate electron energies. In addition, calculation of the continuous slowing down approximation range (CSDA range) from the stopping power is also made. Calculation of the CSDA range for some hydrocarbons: C{sub 2}H{sub 6} (ethane), C{sub 4}H{sub 10} (butane), C{sub 6}H{sub 14} (hexane) C{sub 8}H{sub 18} (octane), C{sub 5}H{sub 5}N{sub 5} (adenine) and C{sub 5}H{sub 5}N{sub 5}O (guanine) have been introduced for incident electrons in the energy range 30 eV to 1 MeV. The range of electrons has been calculated within the continuous slowing down approximation (CSDA) using modified Rohrlich and Carlson formula of stopping power. Besides, we have calculated the mean penetration depths using a spherical geometric model developed by Bentabet (Vacuum 86:1855-1859, 35). The results have been compared with the other theoretical results, Monte Carlo code such as PENELOPE predictions and semi-empirical results. The calculated results of CSDA ranges for electrons in the energy range from 20 eV to 100 MeV are found to be in good agreement to within 10% with available date. (orig.)

  5. High Power Diode Lasers with External Feedback: Overview and Prospects

    DEFF Research Database (Denmark)

    Chi, Mingjun; Petersen, Paul Michael

    2012-01-01

    In summary, different external-cavity feedback techniques to improve the spatial beam quality and narrow the linewidth of the output beam from both BALs and TDLs are presented. Broad-area diode laser system with external-cavity feedback around 800 nm can produce several Watts of output power...

  6. Module-Level Power Converters For Parallel Connected Photovoltaic Arrays

    Science.gov (United States)

    2012-01-01

    Secondary Bare Wire Area Rs Secondary Resistance Ps Secondary Copper Loss Pcu Total Copper Loss W/kg Watts Per Kilogram Pfe Core Loss PΣ Total...material properties of the chosen core [30]. The calculated core loss power density was was 17.2712 W/kg. The core loss, Pfe , was calculated

  7. 47 CFR 90.1321 - Power and antenna limits.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Power and antenna limits. 90.1321 Section 90... and antenna limits. (a) Base and fixed stations are limited to 25 watts/25 MHz equivalent... receiver. (2) If the transmitter employs an antenna system that emits multiple directional beams but...

  8. 抽油机电动机合理负载率的研究%Reasonable Range of Electrical Motor Power Utilization Ratio of Pumping Units

    Institute of Scientific and Technical Information of China (English)

    宋扬; 姜雪; 张德实; 王新民

    2012-01-01

    The load characteristic of pumping units is a cyclicity loading. In order to startup and run the pumping units normally, the electrical motor theory installed power of pumping unit was usually higher than running power for requirement of the motor margin, which makes the electric power lost. The reasonable upper limit of electrical motor power utilization ratio by theorical check of the motor heating conditions, overload capacity and startup character and the lower limit by characteristic curve of electrical motor were made. It had been checked by experimental study. Declining electrical motor of pumping units installed power reasonably not only can raise electrical motor power utilization ratio and decrease inirial investment, but also can make importance for energy saving of oilfield.%游梁式抽油机的负载属于一种周期性交变载荷,为了满足抽油机正常启动、运行,所用电动机装机功率普遍高于理论装机功率,使电动机长期处于低负荷运行,造成能耗浪费.通过对电动机发热条件、过载能力及启动性能的理论校验与分析,确定了电动机负载率的合理上限,根据电动机工作特性曲线确定了负载率的合理下限,并利用试验研究进行了验证,合理地降低抽油机所用电动机的装机功率,不仅可以提高油井电动机负载率,降低初期投入,而且对油田生产节能降耗意义重大.

  9. Design of a miniature wind turbine for powering wireless sensors

    Science.gov (United States)

    Xu, F. J.; Yuan, F. G.; Hu, J. Z.; Qiu, Y. P.

    2010-04-01

    In this paper, a miniature wind turbine (MWT) system composed of commercially available off-the-shelf components was designed and tested for harvesting energy from ambient airflow to power wireless sensors. To make MWT operate at very low air flow rates, a 7.6 cm thorgren plastic Propeller blade was adopted as the wind turbine blade. A sub watt brushless DC motor was used as generator. To predict the performance of the MWT, an equivalent circuit model was employed for analyzing the output power and the net efficiency of the MWT system. In theory, the maximum net efficiency 14.8% of the MWT system was predicted. Experimental output power of the MWT versus resistive loads ranging from 5 ohms to 500 ohms under wind speeds from 3 m/s to 4.5 m/s correlates well with those from the predicted model, which means that the equivalent circuit model provides a guideline for optimizing the performance of the MWT and can be used for fulfilling the design requirements by selecting specific components for powering wireless sensors.

  10. DC power flow control for radial offshore multi-terminal HVDC transmission system by considering steady-state DC voltage operation range

    DEFF Research Database (Denmark)

    Irnawan, Roni; Silva, Filipe Miguel Faria da; Bak, Claus Leth

    2017-01-01

    of this MTDC system due to the inherited limit from point-to-point (PtP) configuration. An analytic method is proposed in order to estimate the steady-state DC voltage operational points of this MTDC system. The proposed method has been confirmed with a conventional DC power flow study result....

  11. Korea's 1-watt plan ''Standby Korea 2010''

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yungrae

    2010-09-15

    Korea announced standby power of all electronics shall be reduced to below 1W by 2010. Ministry of Knowledge Economy (MKE, Korean government) and Korea Energy Management Corporation (KEMCO) established ''Standby Korea 2010'' which is a roadmap to limit standby power below 1W by 2010. Korea implemented mandatory program over a relatively short period of time, incorporating the better elements from the more established national program and adding new initiatives, such as the threat of using mandatory warning label for products that fail to meet standby power targets.

  12. Short Tm3+-doped fiber lasers with watt-level output near 2 μm

    Institute of Scientific and Technical Information of China (English)

    Yulong Tang; Yong Yang; Xiaojin Cheng; Jianqiu Xu

    2008-01-01

    High-power operation of diode-pumped fiber lasers at wavelength near 2μm are demonstrated with short length of heavily Tm3+-doped silica glass fibers. With 7-cm long fiber, a laser at near 2 μm is obtained with the threshold of 135 mW, maximum output power of 1.09 W, and slope efficiency of 9.6% with respect to the launched power from a laser diode at 790 nm. The output stability of this fiber laser is within 5%.The dependence of the performance of fiber lasers on the operation temperature and cavity configuration parameters is also investigated.

  13. Korea's 1-watt plan ''Standby Korea 2010''

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yungrae

    2010-09-15

    Korea announced standby power of all electronics shall be reduced to below 1W by 2010. Ministry of Knowledge Economy (MKE, Korean government) and Korea Energy Management Corporation (KEMCO) established ''Standby Korea 2010'' which is a roadmap to limit standby power below 1W by 2010. Korea implemented mandatory program over a relatively short period of time, incorporating the better elements from the more established national program and adding new initiatives, such as the threat of using mandatory warning label for products that fail to meet standby power targets.

  14. Watt-level, all-fiber, ultrafast Er/Yb-codoped double-clad fiber laser mode-locked by reduced graphene oxide interacting with a weak evanescent field

    CERN Document Server

    Gao, Lei; Li, Yujia

    2015-01-01

    We propose a Watt-level, all-fiber, ultrafast Er/Yb-codoped double-clad fiber laser passively mode-locked by reduced graphene oxide (rGO) interacting with a weak evanescent field of photonic crystal fiber (PCF). The rGO solution is filled into the cladding holes of the PCF based on total reflection, and after evaporation, the rGO flakes bear only 1/107 of the total energy in laser system, which enhances the thermal damage threshold and decreases the accumulated nonlinearity. By incorporating the saturable absorber into an Er/Yb-codoped fiber ring cavity, stable conventional soliton with a duration of 573 fs is generated, and a average output power up to 1.14 W is obtained.

  15. 三相四线有功电能表错误接线分析与判断%Analysis and Judgment of the Wrong Wiring of the 3-Phase and 4-Wire Watt-Hour Meter

    Institute of Scientific and Technical Information of China (English)

    王洪莲; 何伟; 陈虎

    2016-01-01

    通过分析接线图、相量图、功率及更正系数,介绍三相四线有功电能表常见的错误接线方式,提出检查三相四线有功电能表错误接线的简单方法,并介绍退补电量的计算方法。%By analyzing the wiring diagram,the vector diagram,the power and the adjusted coefficient,this paper in-troduces the common wrong wiring modes of the 3-phase and 4-wire watt-hour meter,presents simple checking methods,and describes the method of calculation for electricity return and compensation.

  16. Parametric design study of ``power stick'' and its derivatives

    Science.gov (United States)

    Schock, Alfred; Or, Chuen T.

    1995-01-01

    The paper addresses some major concerns about the Power Stick concept proposed by Jet Propulsion Laboratory (JPL) personnel, and describes parametric studies of derivative designs to determine to what extent those concerns can be alleviated. The Power Stick and its derivatives are based on the use of the 1-watt(t) Radioisotope Heater Unit (RHU) to power a thermoelectric multicouple. Our study concludes that: (a) while the RHU has been safety-qualified as a low-temperature heater, additional reentry analyses and test would be needed to qualify it as a higher temperature heat source for the Power Stick, (b) even after parametric design optimization, the efficiency of the Power Stick and its derivatives is only 2.2%, and, (c) all generators based on the 1-watt heat source require a thermoelectric multicouple with a large number of extremely thin legs, of very doubtful fabricability.

  17. Computer Control of the Spectral Composition of the Powerful Laser System Irradiation with a Wide Range of Laser Transitions on Metal Vapors

    Directory of Open Access Journals (Sweden)

    Soldatov Anatoly

    2016-01-01

    Full Text Available The results of the experimental study cycle of the multiwave metal vapor laser system on the basis of the original configuration of the multimedia laser emitter. The spectral parameters of the setup have been controlled using a personal computer (PC. This allows carrying out their independent optimization according to excitation conditions, and, therefore, promptly allocating the output set of oscillating wavelengths and their relative distribution in power, which makes the system attractive for scientific and technological application.

  18. Electric-bicycle propulsion power

    Energy Technology Data Exchange (ETDEWEB)

    Oman, H.; Morchin, W.C. [Electro-Bicycle, Inc., Auburn, WA (United States); Jamerson, F.E. [Electric Battery Bicycle Co., Naples, FL (United States)

    1995-12-31

    In a human-powered hybrid electric vehicle (HPHEV) the travel distance available from a single battery charge can be lengthened with power from another source, the cyclist`s leg muscles. In a battery-powered electric bicycle the propulsion power goes mostly into overcoming aerodynamic drag. For example, at 18 km per hour (11 miles per hour) this drag represents 200 watts at the tire-to-road interface for a typical cyclist`s shape and clothing. Today`s typical electrical bicycle is propelled by a high-speed dc motor which is powered from a lead-acid battery. The combined efficiency of the motor and its speed-reducing gears is 50 to 65 percent. In this paper we calculate available travel distances, as a function of speed, grade, and the battery energy-content as measured in watt-hours per kg. We show the effect of battery cost and charge/discharge cycle-life on travel cost in terms of cents per kilometer travelled. Designs used in today`s electric bicycles are illustrated.

  19. Characterization of high performance silicon-based VMJ PV cells for laser power transmission applications

    Science.gov (United States)

    Perales, Mico; Yang, Mei-huan; Wu, Cheng-liang; Hsu, Chin-wei; Chao, Wei-sheng; Chen, Kun-hsien; Zahuranec, Terry

    2016-03-01

    Continuing improvements in the cost and power of laser diodes have been critical in launching the emerging fields of power over fiber (PoF), and laser power beaming. Laser power is transmitted either over fiber (for PoF), or through free space (power beaming), and is converted to electricity by photovoltaic cells designed to efficiently convert the laser light. MH GoPower's vertical multi-junction (VMJ) PV cell, designed for high intensity photovoltaic applications, is fueling the emergence of this market, by enabling unparalleled photovoltaic receiver flexibility in voltage, cell size, and power output. Our research examined the use of the VMJ PV cell for laser power transmission applications. We fully characterized the performance of the VMJ PV cell under various laser conditions, including multiple near IR wavelengths and light intensities up to tens of watts per cm2. Results indicated VMJ PV cell efficiency over 40% for 9xx nm wavelengths, at laser power densities near 30 W/cm2. We also investigated the impact of the physical dimensions (length, width, and height) of the VMJ PV cell on its performance, showing similarly high performance across a wide range of cell dimensions. We then evaluated the VMJ PV cell performance within the power over fiber application, examining the cell's effectiveness in receiver packages that deliver target voltage, intensity, and power levels. By designing and characterizing multiple receivers, we illustrated techniques for packaging the VMJ PV cell for achieving high performance (> 30%), high power (> 185 W), and target voltages for power over fiber applications.

  20. Design of a Sub-Picosecond Jitter with Adjustable-Range CMOS Delay-Locked Loop for High-Speed and Low-Power Applications

    OpenAIRE

    Abdulrazzaq, Bilal I.; Omar J. Ibrahim; Shoji Kawahito; Sidek, Roslina M.; Suhaidi Shafie; Nurul Amziah Md. Yunus; Lini Lee; Izhal Abdul Halin

    2016-01-01

    A Delay-Locked Loop (DLL) with a modified charge pump circuit is proposed for generating high-resolution linear delay steps with sub-picosecond jitter performance and adjustable delay range. The small-signal model of the modified charge pump circuit is analyzed to bring forth the relationship between the DLL’s internal control voltage and output time delay. Circuit post-layout simulation shows that a 0.97 ps delay step within a 69 ps delay range with 0.26 ps Root-Mean Square (RMS) jitter perf...

  1. Performance characteristics of the 12 GHz, 200 watt transmitter experiment package for CTS

    Science.gov (United States)

    Miller, E. F.; Fiala, J. L.; Hansen, I. G.

    1975-01-01

    The experiment package consists of a 200 W output stage tube (OST) powered by a power processing system (PPS). Descriptions of both the PPS and OST are given. The PPS provides the necessary voltages with a measured dc/dc conversion efficiency of 89 percent. The OST, a traveling wave tube with multiple collectors, has a saturated rf output power of 224 W and operates at an overall efficiency exceeding 40 percent over an 85 MHz bandwidth at 12 GHz. OST performance given includes frequency response, saturation characteristics, group delay, AM to PM conversion, inter-modulation distortion, and two channel gain suppression. Single and dual channel FM video performance is presented. It was determined that for 12 MHz peak to peak frequency deviation on each channel, dual channel FM television signals can be transmitted through the TEP at 60 W, each channel, with 40 MHz channel spacing (center to center).

  2. SPIKE-2: A practical Stirling engine for kilowatt level solar power

    Science.gov (United States)

    Beale, W. T.

    1984-03-01

    Recent advances in the art of free piston Stirling engine design make possible the production of 1-10kW free piston Stirling linear alternator engine, hermetically sealed, efficient, durable and simple in construction and operation. Power output is in the form of single or three phase 60 Hz. AC, or DC. The three phase capability is available from single machines without need of external conditioning. Engine voltage control regains set voltage within 5 cycles in response to any load change. The existing SPIKE-2 design has an engine alternator efficiency of 25% at 650 C heater wall temperature and a service life of over three years in solar service. The same system can be scaled over a range of at least 100 watts to 25kW.

  3. Nano-watt fueling from a micro-scale microbial fuel cell using black tea waste

    KAUST Repository

    Rojas, Jhonathan Prieto

    2016-02-03

    In this report, we show the rapid assessment of black tea as potential fuel to power up nanopower systems using a microsized, simplistic and sustainable air-cathode microbial fuel cell. It was found that tea produced more power compared with traditional sodium acetate media due in part to its acidophilic pH and its higher organics content. Although high internal resistance remains a big concern, this simple, curiosity-driven experiment gave us the preliminary results to say that energy could be extracted from the reuse of waste resources such the collection of our afternoon-tea\\'s leftovers.

  4. Vacuum Testing of a Miniaturized Switch Mode Amplifier Powering an Electrothermal Plasma Micro-Thruster

    Directory of Open Access Journals (Sweden)

    Christine Charles

    2017-08-01

    Full Text Available A structurally supportive miniaturized low-weight (≤150 g radiofrequency switch mode amplifier developed to power the small diameter Pocket Rocket electrothermal plasma micro-thruster called MiniPR is tested in vacuum conditions representative of space to demonstrate its suitability for use on nano-satellites such as “CubeSats.” Argon plasma characterization is carried out by measuring the optical emission signal seen through the plenum window vs. frequency (12.8–13.8 MHz and the plenum cavity pressure increase (indicative of thrust generation from volumetric gas heating in the plasma cavity vs. power (1–15 Watts with the amplifier operating at atmospheric pressure and a constant flow rate of 20 sccm. Vacuum testing is subsequently performed by measuring the operational frequency range of the amplifier as a function of gas flow rate. The switch mode amplifier design is finely tuned to the input impedance of the thruster (~16 pF to provide a power efficiency of 88% at the resonant frequency and a direct feed to a low-loss (~10 % impedance matching network. This system provides successful plasma coupling at 1.54 Watts for all investigated flow rates (10–130 sccm for cryogenic pumping speeds of the order of 6,000 l.s−1 and a vacuum pressure of the order of ~2 × 10−5 Torr during operation. Interestingly, the frequency bandwidth for which a plasma can be coupled increases from 0.04 to 0.4 MHz when the gas flow rate is increased, probably as a result of changes in the plasma impedance.

  5. Power management system for a 2.5 W remote sensor powered by a sediment microbial fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Donovan, Conrad; Peng, Huan; Heo, Deukhyoun [School of Electrical Engineering and Computer Science, Washington State University, Pullman, WA 99163-2710 (United States); Dewan, Alim; Beyenal, Haluk [Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Center for Environmental, Sediment and Aquatic Research, Washington State University, Pullman, WA 99163-2710 (United States)

    2011-02-01

    One of the challenges in using wireless sensors that require high power to monitor the environment is finding a renewable power source that can produce enough power. Sediment microbial fuel cells (SMFCs) are considered an alternative renewable power source for remote monitoring, but current research on SMFCs has demonstrated that they can only produce several to tens of mW of continuous power. This limits the use of SMFCs as an alternative renewable remote power source to mW-level power. Such low power is only enough to operate a low-power sensors. However, there are many remote sensors that require higher power, on the order of watts. Current technology using a SMFC to power a remote sensor requiring watts-level intermittent power is limited because of limitations of power management technology. Our goal was to develop a power management system (PMS) that enables a SMFC to operate a remote sensor consuming 2.5 W of power. We designed a custom PMS to store microbial energy in capacitors and use the stored energy in short bursts. Our results demonstrate that SMFCs can be a viable alternative renewable power source for remote sensors requiring high power. (author)

  6. A new calculation on the stopping power and mean free path for low energy electrons in toluene over energy range of 20-10000 eV.

    Science.gov (United States)

    Tan, Zhenyu; Xia, Yueyuan; Liu, Xiangdong; Zhao, Mingwen; Zhang, Liming

    2009-04-01

    A new calculation of the stopping powers (SP) and inelastic mean free paths (IMFP) for electrons in toluene at energies below 10 keV has been presented. The calculation is based on the dielectric model and on an empirical evaluation approach of optical energy loss function (OELF). The reliability for the evaluated OELFs of several hydrocarbons with available experimental optical data has been systematically checked. For toluene, using the empirical OELF, the evaluated mean ionization potential, is compared with that given by Bragg's rule, and the calculated SP at 10 keV is also compared with the Bethe-Bloch prediction. The present results for SP and IMFP provide an alternative basic data for the study on the energy deposition of low-energy electrons transport through toluene, and also show that the method used in this work may be a good one for evaluating the SP and IMFP for hydrocarbons.

  7. On-chip power delivery and management

    CERN Document Server

    Vaisband, Inna P; Popovich, Mikhail; Mezhiba, Andrey V; Köse, Selçuk; Friedman, Eby G

    2016-01-01

    This book describes methods for distributing power in high speed, high complexity integrated circuits with power levels exceeding many tens of watts and power supplies below a volt. It provides a broad and cohesive treatment of power delivery and management systems and related design problems, including both circuit network models and design techniques for on-chip decoupling capacitors, providing insight and intuition into the behavior and design of on-chip power distribution systems. Organized into subareas to provide a more intuitive flow to the reader, this fourth edition adds more than a hundred pages of new content, including inductance models for interdigitated structures, design strategies for multi-layer power grids, advanced methods for efficient power grid design and analysis, and methodologies for simultaneously placing on-chip multiple power supplies and decoupling capacitors. The emphasis of this additional material is on managing the complexity of on-chip power distribution networks.

  8. Spike-timing-dependent plasticity enhanced synchronization transitions induced by autapses in adaptive Newman-Watts neuronal networks.

    Science.gov (United States)

    Gong, Yubing; Wang, Baoying; Xie, Huijuan

    2016-12-01

    In this paper, we numerically study the effect of spike-timing-dependent plasticity (STDP) on synchronization transitions induced by autaptic activity in adaptive Newman-Watts Hodgkin-Huxley neuron networks. It is found that synchronization transitions induced by autaptic delay vary with the adjusting rate Ap of STDP and become strongest at a certain Ap value, and the Ap value increases when network randomness or network size increases. It is also found that the synchronization transitions induced by autaptic delay become strongest at a certain network randomness and network size, and the values increase and related synchronization transitions are enhanced when Ap increases. These results show that there is optimal STDP that can enhance the synchronization transitions induced by autaptic delay in the adaptive neuronal networks. These findings provide a new insight into the roles of STDP and autapses for the information transmission in neural systems. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Effect of Autaptic Activity on Intrinsic Coherence Resonance in Newman-Watts Networks of Stochastic Hodgkin-Huxley Neurons

    Science.gov (United States)

    Wang, Qi; Gong, Yubing

    2016-06-01

    In this paper, we study the effect of autaptic activity on intrinsic coherence resonance (CR) induced by channel noise in Newman-Watts (NW) networks of stochastic Hodgkin-Huxley (HH) neurons. It is found that autaptic strength and autaptic delay have a big effect on the intrinsic CR. As autaptic strength increases, there is optimal autaptic strength by which the intrinsic CR is most highly enhanced. Autaptic delay can enhance, reduce, or destroy the intrinsic CR, depending on the delay length. Moreover, there are optimal coupling strength and network randomness by which autaptic activity can most highly enhance the intrinsic CR. These results show that autaptic activity has different effects on the intrinsic CR in the neuronal networks, and it can most highly enhance the intrinsic CR at optimal coupling strength and network randomness. These findings could find potential implications of channel noise and autaptic activity for the information processing and transmission in neural systems.

  10. Optimization of Intrinsic Stochastic Resonance in Adaptive Newman-Watts Network of Channel Blocked Hodgkin-Huxley Neurons

    Science.gov (United States)

    Wang, Qi; Gong, Yubing; Wu, Yanan

    2014-08-01

    In this paper, we study stochastic resonance (SR) induced by channel noise in adaptive weighted Newman-Watts networks of Hodgkin-Huxley neurons with channel blocking (CB). It is found that the intrinsic SR is dependent on adaptive coupling and is strongly enhanced when the changing rate of adaptive coupling is optimal, and this phenomenon is independent of sodium and potassium CB levels. As CB increases, the channel noise for SR decreases, but the strength of intrinsic SR nearly does not change in the presence of adaptive coupling, which is different from the case for fixed coupling. These results show that intrinsic SR can be enhanced and optimized by adaptive coupling, and CB's effect on the intrinsic SR can be reduced by adaptive coupling. This implies that adaptive coupling could more efficiently improve the time precision of information processing in neural systems.

  11. Waste to Watts and Water: Enabling Self-Contained Facilities Using Microbial Fuel Cells

    Science.gov (United States)

    2008-05-01

    Logan et al., "Microbial Fuel Cells: Methodology and Technology," Environmental Science & Technology 40, no. 17 (2006): 5189. 60 M. A. Rodrigo et al...348. 67 Bruce Logan et al., "Graphite Fiber Brush Anodes for Increased Power Production in Air-Cathode Microbial Fuel Cells," Environmental Science & Technology 41...34Diversifying Biological Fuel Cell Designs by Use of Nanoporous Filters," Environmental Science & Technology 41, no. 4 (2007). 76 Eliza M. Tsui and

  12. Highly-efficient multi-watt Yb:CaLnAlO4 microchip lasers

    Science.gov (United States)

    Loiko, Pavel; Serres, Josep Maria; Mateos, Xavier; Xu, Xiaodong; Xu, Jun; Yumashev, Konstantin; Griebner, Uwe; Petrov, Valentin; Aguiló, Magdalena; Díaz, Francesc; Major, Arkady

    2017-02-01

    Tetragonal rare-earth calcium aluminates, CaLnAlO4 where Ln = Gd or Y (CALGO and CALYO, respectively), are attractive laser crystal hosts due to their locally disordered structure and high thermal conductivity. In the present work, we report on highly-efficient power-scalable microchip lasers based on 8 at.% Yb:CALGO and 3 at.% Yb:CALYO crystals grown by the Czochralski method. Pumped by an InGaAs laser diode at 978 nm, the 6 mm-long Yb:CALGO microchip laser generated 7.79 W at 1057-1065 nm with a slope efficiency of η = 84% (with respect to the absorbed pump power) and an optical-to-optical efficiency of ηopt = 49%. The 3 mm-long Yb:CALYO microchip laser generated 5.06 W at 1048-1056 nm corresponding to η = 91% and ηopt = 32%. Both lasers produced linearly polarized output (σ- polarization) with an almost circular beam profile and beam quality factors M2 x,y <1.1. The output performance of the developed lasers was modeled yielding a loss coefficient as low as 0.004-0.007 cm-1. The results indicate that the Yb3+- doped calcium aluminates are very promising candidates for high-peak-power passively Q-switched microchip lasers.

  13. On-orbit performance of the 12 GHz, 200 watt transmitter experiment package for CTS

    Science.gov (United States)

    Alexovich, R. E.

    1977-01-01

    Performance characteristics from on-orbit tests of the Transmitter Experiment Package (TEP) for the Communications Technology Satellite (CTS) are presented. The TEP consists of a Power Processing System (PPS), an Output Stage Tube (OST), and a Variable Conductance Heat Pipe System (VCHPS), all of which are described. The OST is a coupled-cavity traveling-wave tube with a multistage depressed collector and a stepped velocity-tapered slow-wave structure for efficiency enhancement. It has an RF output power of 240 W and an overall efficiency of 51.5% at a center band frequency of 12.080 GHz. The PPS provides the required operating voltages, regulation, control, and protection for the OST. It has a measured dc-dc conversion efficiency of 86.5% to 88.5%. The VCHPS consists of a fin radiator and three dual-artery stainless steel heat pipes using methanol and a mixture of inert gases. Test results presented include efficiencies, RF output power, frequency response, and performance with single and multiple (two) carriers frequency-modulated by video signals.

  14. Wireless power transfer via strongly coupled magnetic resonances.

    Science.gov (United States)

    Kurs, André; Karalis, Aristeidis; Moffatt, Robert; Joannopoulos, J D; Fisher, Peter; Soljacic, Marin

    2007-07-06

    Using self-resonant coils in a strongly coupled regime, we experimentally demonstrated efficient nonradiative power transfer over distances up to 8 times the radius of the coils. We were able to transfer 60 watts with approximately 40% efficiency over distances in excess of 2 meters. We present a quantitative model describing the power transfer, which matches the experimental results to within 5%. We discuss the practical applicability of this system and suggest directions for further study.

  15. RF-MEMS Switched Varactors for Medium Power Applications

    CERN Document Server

    Maury, F; Crunteanu, A; Conseil, F; Blondy, P

    2008-01-01

    In RF (Radio Frequency) domain, one of the limitations of using MEMS (Micro Electromechanical Systems) switching devices for medium power applications is RF power. Failure phenomena appear even for 500 mW. A design of MEMS switched capacitors with an enhanced topology is presented in this paper to prevent it. This kind of device and its promising performances will serve to fabricate a MEMS based phase shifter able to work under several watts.

  16. Biological effects of implanted nuclear energy sources for artificial heart devices. Progress report, September 1, 1975--August 31, 1976. [Heat dissipation from /sup 238/Pu power sources implanted in dogs

    Energy Technology Data Exchange (ETDEWEB)

    Kallfelz, F.A.; Wentworth, R.A.; Cady, K.B.

    1976-01-01

    A total of sixty dogs were implanted with radioisotope-powered artificial heart systems producing radiation fluxes similar to that of plutonium-238, but having no associated heat, at levels of from one to seventy times the radiation flux expected from a 30-watt plutonium-238 source. Results from studies lasting up to 6 years after implantation indicate that these animals, and by inference human beings, may be able to tolerate the radiation flux from 30-watt /sup 238/Pu power sources. Results of heat dissipation studies in calves indicate that it may be possible to induce a vascularized connective tissue capsule sufficient to dissipate 30 watts of additional heat from a surface area of approximately 500 cm sq., allowing a heat flux of 0.06 watts per cm sq.

  17. REMOVAL OF CHEMICAL AND MICROBIAL CONTAMINANTS IN DRINKING WATER - WATTS PREMIER M-2400 POINT-OF-ENTRY REVERSE OSMOSIS DRINKINGWATER TREATMENT SYSTEM

    Science.gov (United States)

    The Watts Premier M-2400 POE RO Drinking Water Treatment System was tested at the NSF Drinking Water Treatment Systems Laboratory for removal of the viruses fr and MS2, the bacteria Brevundimonas diminuta, and chemicals aldicarb, benzene, cadmium, carbofuran, cesium, chl...

  18. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, REMOVAL OF ARSENIC IN DRINKING WATER: WATTS PREMIER M-SERIES M-15,000 REVERSE OSMOSIS TREATMENT SYSTEM

    Science.gov (United States)

    Verification testing of the Watts Premier M-Series M-15,000 RO Treatment System was conducted over a 31-day period from April 26, 2004, through May 26, 2004. This test was conducted at the Coachella Valley Water District (CVWD) Well 7802 in Thermal, California. The source water...

  19. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, REMOVAL OF ARSENIC IN DRINKING WATER: WATTS PREMIER M-SERIES M-15,000 REVERSE OSMOSIS TREATMENT SYSTEM

    Science.gov (United States)

    Verification testing of the Watts Premier M-Series M-15,000 RO Treatment System was conducted over a 31-day period from April 26, 2004, through May 26, 2004. This test was conducted at the Coachella Valley Water District (CVWD) Well 7802 in Thermal, California. The source water...

  20. REMOVAL OF CHEMICAL AND MICROBIAL CONTAMINANTS IN DRINKING WATER - WATTS PREMIER M-2400 POINT-OF-ENTRY REVERSE OSMOSIS DRINKINGWATER TREATMENT SYSTEM

    Science.gov (United States)

    The Watts Premier M-2400 POE RO Drinking Water Treatment System was tested at the NSF Drinking Water Treatment Systems Laboratory for removal of the viruses fr and MS2, the bacteria Brevundimonas diminuta, and chemicals aldicarb, benzene, cadmium, carbofuran, cesium, chl...

  1. E-Learning for Power Quality

    Science.gov (United States)

    Bauer, Pavol; Nagy, Istvan

    E-learning with pre-solved animations can provide a better understanding of the status and different network options, compared to complex simulation or a set of equations. In this paper, examples of such animations for e-learning for power quality are presented. Different network options in a centralized or distributed power system and power electronics based compensators are introduced in the form of a new web-based, software learning tool. Power flow congestion and the impact of power electronic compensators on the system, including detailed operations of power electronic based compensators are presented. These compensators include SVCs, Statcom and UPFC presented in this paper. Using these animated tools, both system level and component level operation of these devices are presented. Further the frequent solutions of power factor correction (PFC) applied on low power level of several hundred watts are treated in the paper.

  2. Highly efficient high power single-mode fiber amplifier utilizing the distributed mode filtering bandgap rod fiber

    DEFF Research Database (Denmark)

    Laurila, Marko; Alkeskjold, Thomas T.; Jørgensen, Mette Marie

    2012-01-01

    We report on an ytterbium doped single mode distributed mode filtering rod fiber in an amplifier configuration delivering high average output power, up to 292 watts, using a mode-locked 30ps source at 1032nm with good power conversion efficiency. We study the modal stability of the output beam...

  3. Application range affected by software failures in safety relevant instrumentation and control systems of nuclear power plants; Auswirkungsbereiche von Softwarefehlern in sicherheitstechnisch wichtigen Einrichtungen von Kernkraftwerken

    Energy Technology Data Exchange (ETDEWEB)

    Jopen, Manuela; Mbonjo, Herve; Sommer, Dagmar; Ulrich, Birte

    2017-03-15

    This report presents results that have been developed within a BMUB-funded research project (Promotion Code 3614R01304). The overall objective of this project was to broaden the knowledge base of GRS regarding software failures and their impact in software-based instrumentation and control (I and C) systems. To this end, relevant definitions and terms in standards and publications (DIN, IEEE standards, IAEA standards, NUREG publications) as well as in the German safety requirements for nuclear power plants were analyzed first. In particular, it was found that the term ''software fault'' is defined differently and partly contradictory in the considered literature sources. For this reason, a definition of software fault was developed on the basis of the software life cycle of software-based I and C systems within the framework of this project, which takes into account the various aspects relevant to software faults and their related effects. It turns out that software failures result from latent faults in a software-based control system, which can lead to a non-compliant behavior of a software-based I and C system. Hereby a distinction should be made between programming faults and specification faults. In a further step, operational experience with software failures in software-based I and C systems in nuclear facilities and in nonnuclear sector was investigated. The identified events were analyzed with regard to their cause and impacts and the analysis results were summarized. Based on the developed definition of software failure and on the COMPSIS-classification scheme for events related to software based I and C systems, the COCS-classification scheme was developed to classify events from operating experience with software failures, in which the events are classified according to the criteria ''cause'', ''affected system'', ''impact'' and ''CCF potential''. This

  4. Generation of picosecond laser pulses at 1030 nm with gigahertz range continuously tunable repetition rate.

    Science.gov (United States)

    Aubourg, Adrien; Lhermite, Jérôme; Hocquet, Steve; Cormier, Eric; Santarelli, Giorgio

    2015-12-01

    We report on a watt range laser system generating picosecond pulses using electro-optical modulation of a 1030 nm single frequency low noise laser diode. Its repetition rate is continuously tunable between 11 and 18 GHz. Over this range, output spectra and pulse characteristics are measured and compared with a numerical simulation. Finally, amplitude and residual phase noise measurements of the source are also presented.

  5. Injector power supplies reliability improvements at the Advanced Photon Source.

    Energy Technology Data Exchange (ETDEWEB)

    Hillman, A.; Pasky, S.; Sereno, N.; Soliday, R.; Wang, J.

    2006-01-01

    Operational goals for the Advanced Photon Source (APS) facility include 97% availability and a mean time between unscheduled beam losses (faults) of 70 hours, with more than 5000 user hours of scheduled beam per year. To meet this objective, our focus has been maximizing the mean time between faults (MTBF). We have made various hardware and software improvements to better operate and monitor the injector power supply systems. These improvements have been challenging to design and implement in light of the facility operating requirements but are critical to maintaining maximum reliability and availability of beam for user operations. This paper presents actions taken as well as future plans to continue improving injector power supply hardware and software to meet APS user operation goals. The Advanced Photon Source (APS) has two major components. The storage ring (SR) accelerator is the primary accelerator that delivers X-ray beams to users and uses over 1,400 power supplies. The injector accelerators provide beam to the SR and use 361 different supplies. The control system ranges from the standard VME-IOC and Allen Bradley to GESPAC with additional mini-PLCs for monitoring. Injector power supplies range from {approx}30 watts DC to a ramped peak of 4.6 megawatts in 250 ms. Finally, all accelerators use pulsed supplies, and some of them deliver peak power in megawatts. In the SR, each multipole and corrector magnet is separately powered, with only the main dipole magnets on a common bus. Independent power supplies provide increased flexibility, but place additional demands on power supply reliability. The APS reliability goals are 97% availability and 70 hours mean time to unscheduled beam loss. There are 5,129 user hours scheduled per year, 1,315 hours used for machine studies, and the remaining 2,316 hours used for maintenance. The present annual operating schedule provides for three user runs (typically 10 to 12 weeks long), and three machine shutdowns (typically

  6. Measurement of the stopping power of water for carbon ions in the energy range of 1 MeV-6 MeV using the inverted Doppler-shift attenuation method

    Energy Technology Data Exchange (ETDEWEB)

    Rahm, Johannes Martin

    2016-10-31

    Cancer therapy using carbon ions has gained increasing interest in the last decade due to its advantageous dose distributions. For the dosimetry and treatment planning, the accurate knowledge of the stopping power of water for carbon ions is of crucial importance. In the high energy region, the stopping power can be calculated rather accurately by means of the Bethe-Bloch formula. In the case of projectile velocities comparable to those of the valence electrons of the target, these calculations are subject to large uncertainties. There exist no experimental data for the stopping power of water for projectile energies prevailing in the so-called Bragg peak region. The currently available stopping power data for water are derived from measurements in water vapour or D{sub 2}O ice and, hence, neglect the dependence on the state of aggregation. The stopping power of water for charged particles is of high interest not only for practical applications but also to consider how physical and chemical state of the target influence the collisional energy transfer. For the measurement of the stopping power of water, the inverted Doppler-shift attenuation method was used in this work. This method has the advantage that the projectile itself is not needed to be detected and can be slowed down entirely in the target. In this method, the stopping power is determined from the Doppler-shift of the gamma-quanta emitted by projectiles during their slow down. This experiment can be performed at atmospheric pressure and consequently, the stopping power of water can be measured in its real physiological condition. In this work, the stopping power of water for carbon ions was measured for the first time in the energy range between 1 MeV and 6 MeV covering the kinetic energies of carbon ions in the Bragg peak region. The experimental method is presented in detail along with the design of the apparatus and of the data acquisition system. A comprehensive analysis of instrumental effects

  7. Traveling Wave Tube (TVT) RF Power Combining Demonstration for use in the Jupiter Icy Moons Orbiter (JIMO)

    Science.gov (United States)

    Downey, Joseph A.

    2004-01-01

    The Jupiter Icy Moons Orbiter (JIMO) is set to launch between the years 2012 and 2015. It will possibly utilize a nuclear reactor power source and ion engines as it travels to the moons of Jupiter. The nuclear reactor will produce hundreds of kilowatts of power for propulsion, communication and various scientific instruments. Hence, the RF amplification devices aboard will be able to operate at a higher power level and data rate. The initial plan for the communications system is for an output of 1000 watts of RF power, a data rate of at least 10 megabits a second, and a frequency of 32 GHz. A higher data rate would be ideal to fully utilize the instruments aboard JIMO. At NASA Glenn, one of our roles in the JIMO project is to demonstrate RF power combining using multiple traveling wave tubes (TWT). In order for the power of separate TWT s to be combined, the RF output waves from each must be in-phase and have the same amplitude. Since different tubes act differently, we had to characterize each tube using a Network Analyzer. We took frequency sweeps and power sweeps to characterize each tube to ensure that they will behave similarly under the same conditions. The 200 watt Dornier tubes had been optimized to run at a lower power level (120 watts) for their extensive use in the ACTS program, so we also had to experiment with adjusting the voltage settings on several internal components (helix, anode, collector) of the tubes to reach the full 200 watt potential. from the ACTS program. Phase shifters and power attenuators were placed in the waveguide circuit at the inputs to the tubes so that adjustments could be made individually to match them exactly. A magic tee was used to route and combine the amplified electromagnetic RF waves on the tube output side. The demonstration of 200 watts of combined power was successful with efficiencies greater than 90% over a 500 MHz bandwidth. The next step will be to demonstrate the use of three amplifiers using two magic tees by

  8. Design of Automatic Switch Device of the Auxiliary Power Supply to a High-Reliability System in Shooting Range%靶场某高可靠系统备用电源自投装置设计

    Institute of Scientific and Technical Information of China (English)

    何吉祥; 李晓波; 张昊

    2012-01-01

    In order to improve the reliability of the power supply and to ensure uninterrupted power supply of shooting range equipment,an automatic switch device of the auxiliary power supply is developed.Firstly,its composition structure and working principles are introduced;the general design thoughts and hardware design methods of the device are described in detail,mainly about the design of power plug-ins,master controller plug-ins,human-computer interaction plug-ins,current and voltage acquisition plug-ins,relay plug-in and human-machine interface plug-ins.Meanwhile software design method of the automatic switch device of the auxiliary power supply is researched;rapid and reliable power supply switching and a concise human-machine interface are realized.At last,the reliability of this device is discussed.%为了提高电源的可靠性,保证靶场设备的不间断供电,研究了一种备用电源自投装置。在介绍其组成结构和工作原理的基础上,对装置的总体设计思想和硬件设计方法进行了详细的描述,主要包括电源插件、主控制器插件、电流和电压采集插件、继电器插件、人机交互插件等关键环节的设计。同时对备用电源自投装置的软件设计方法做了研究,实现了主备电源的快速、可靠切换和简洁的人机界面。最后对该装置的可靠性问题进行了探讨。

  9. High Efficiency Microwave Power Amplifier: From the Lab to Industry

    Science.gov (United States)

    Sims, William Herbert, III; Bell, Joseph L. (Technical Monitor)

    2001-01-01

    Since the beginnings of space travel, various microwave power amplifier designs have been employed. These included Class-A, -B, and -C bias arrangements. However, shared limitation of these topologies is the inherent high total consumption of input power associated with the generation of radio frequency (RF)/microwave power. The power amplifier has always been the largest drain for the limited available power on the spacecraft. Typically, the conversion efficiency of a microwave power amplifier is 10 to 20%. For a typical microwave power amplifier of 20 watts, input DC power of at least 100 watts is required. Such a large demand for input power suggests that a better method of RF/microwave power generation is required. The price paid for using a linear amplifier where high linearity is unnecessary includes higher initial and operating costs, lower DC-to-RF conversion efficiency, high power consumption, higher power dissipation and the accompanying need for higher capacity heat removal means, and an amplifier that is more prone to parasitic oscillation. The first use of a higher efficiency mode of power generation was described by Baxandall in 1959. This higher efficiency mode, Class-D, is achieved through distinct switching techniques to reduce the power losses associated with switching, conduction, and gate drive losses of a given transistor.

  10. Development of 3 kW at 325 MHz solid-state RF power amplifier using four power amplifier modules

    Energy Technology Data Exchange (ETDEWEB)

    Ramarao, B.V., E-mail: bvram@barc.gov.in [Ion Accelerator Development Division, Bhabha Atomic Research Center, Mumbai 400085 (India); Sonal, S.; Mishra, J.K.; Pande, M.; Singh, P. [Ion Accelerator Development Division, Bhabha Atomic Research Center, Mumbai 400085 (India); Kumar, G.; Mukherjee, J. [Indian Institute of Technology, Powai, Mumbai 400076 (India)

    2014-01-21

    A high power solid-state RF power amplifier of 3 kW at 325 MHz has been developed using only four RF power amplifier modules of 850 W power output each. The design and characterization of RF power modules have been presented. A four way Wilkinson power combiner adds the output of four power amplifier modules with a total transmission loss of less than 6%. The combined power amplifier has a power gain of 20.2 dB at 1-dB compression point, and the corresponding output power is 2.8 kW at 325 MHz. The drain efficiency of the power amplifier is 65.3% at 3 kW. All the harmonics of this amplifier are below −40 dBc. The amplifier has better characteristics like fewer numbers of active devices per kilo watt, high efficiency, high gain, and ruggedness etc for RF accelerator applications. -- Highlights: • High gain power amplifier, power gain at 20 dB. • High efficiency amplifier, efficiency >65%. • Minimum number of modules per kilo watt power output. • Heat sink with modules on both side, high density.

  11. Range Tracing

    OpenAIRE

    Jenke, Philipp; Huhle, Benjamin

    2010-01-01

    In this report, we tackle the problem of merging an arbitrary number of range scans (depth images) into a single surface mesh. The mesh-based representation is superior to point-based approaches since it contains important connectivity information. Most previous mesh-based merge methods, however, lose surface details by using simplifying intermediate surface representations (e.g.\\ implicit functions). Such details are essential for further processing steps, especially for feature-preserving r...

  12. Experimental studies for improvement of thermal effects in a high-power fiber-coupled diode laser module operating at 808 nm

    Science.gov (United States)

    El-Sherif, Ashraf F.; Hussein, Khalid; Hassan, Mahmoud F.; Talat, Mahmoud M.

    2012-03-01

    High power diode laser module operating at 808 nm is required for different applications, such as developing an efficient high power Nd3+-doped solid state laser and Tm3+ -doped silica fiber laser, industrial, medical and military applications. Optical and thermal images characterization for a fiber-coupled high power diode laser module is presented experimentally for 6.6 Watt output optical power .An external temperature controller system was designed, which stabilizes the central wavelength at 808 nm at 25°C over a wide range of diode laser driving current from 1A to 6 A. without this cooling system, the wavelength changes by 0.35nm/°C for temperature changes from 20°C to 40°C at the same range of the driving current. In this paper we have present a methodology for temperature reduction of a 808 nm high power diode laser module, based on dynamically thermal control, which is known as dynamic thermal management. Stabilization of the output wavelength has been done by using proportional speed control (PSC) of a CPU cooling fan with certain scheme of straight fins heat sink. Two electronic circuits based on pulse width modulation (PWM) in microcontroller and comparators IC have been used. This technique can be considered as an effective mechanism for reducing temperature and power dissipation to make stabilization of the diode laser output wavelength by preventing heat accumulation from the thermo electric cooling (TEC) inside the diode laser module confirmed by thermal images.

  13. High-coherent-power, two-dimensional grating surface-emitting (GSE) semiconductor lasers

    Science.gov (United States)

    Li, Shuang

    High-power semiconductor lasers, with coherent radiation, are attractive sources for many applications. However, achieving stable, coherent radiation to watt-range power from monolithic semiconductor lasers has been a challenge. This work covers the study and development of high power coherent semiconductor lasers employing novel-types of both surface-emitting and edge-emitting structures. Surface-emitting (SE) semiconductor lasers are preferred over edge-emitting lasers due to their inherent reliability, scalability, and packaging advantages. Horizontal-cavity, grating SE semiconductor lasers are promising candidates for high-power coherent sources. Here we present the design and analysis of a two-dimensional (2D) horizontal-cavity GSE laser (so called ROW-SEDFB laser), for which 2nd-order, distributed feedback/distributed Bragg reflector (DFB/DBR) gratings with central pi phaseshift are preferentially placed in the element regions of a resonant-optical-waveguide (ROW) structure. We find that beside their usual functions (feedback and outcoupling), the gratings act as an effective array-mode selector. The in-phase mode is strongly favored to lase around its resonance due both to better field overlap with the active-grating (i.e., DFB) and to lower interelement loss than the other array modes. For 20-element arrays with 700/600mum-long DFB/DBR gratings, and of 100mum-wide lateral dimension, high intermodal discrimination is obtained. The primary mechanisms behind this discrimination are found to be: absorption losses for the interelement field to the metal contact and to a semiconductor/metal grating layer, and the longitudinal guided-field overlap with the DFB region. The discrimination can be further enhanced by introducing free-carrier absorption in the interelement regions. The device has relatively uniform guided-field profiles in both lateral and longitudinal directions and a strong built-in index profile in the lateral direction. These features make the ROW

  14. A Distributed Multi-agent Control System for Power Consumption in Buildings

    DEFF Research Database (Denmark)

    Kosek, Anna Magdalena; Gehrke, Oliver

    2012-01-01

    This paper presents a distributed controller for adjusting the electrical consumption of a residential building in response to an external power setpoint in Watts. The controller is based on a multi-agent system and has been implemented in JCSP. It is modularly built, capable of self...

  15. Novel organic SMD package for high-power millimeter wave MMICs

    NARCIS (Netherlands)

    Heijningen, M. van; Friday, J.

    2004-01-01

    In this paper a novel low-cost SMD package for high-power MMICs is presented. Due to the special design this package has a very low thermal resistance and low parasitic ground inductance. 3D EM simulations of a packaged through-line correspond well with measurements. Measurement results of a 1 Watt

  16. Novel organic SMD package for high-power millimeter wave MMICs

    NARCIS (Netherlands)

    Heijningen, M. van; Friday, J.

    2004-01-01

    In this paper a novel low-cost SMD package for high-power MMICs is presented. Due to the special design this package has a very low thermal resistance and low parasitic ground inductance. 3D EM simulations of a packaged through-line correspond well with measurements. Measurement results of a 1 Watt

  17. Reverse electrodialysis : Comparison of six commercial membrane pairs on the thermodynamic efficiency and power density

    NARCIS (Netherlands)

    Veerman, J.; de Jong, R. M.; Saakes, M.; Metz, S. J.; Harmsen, G. J.

    2009-01-01

    Reverse electrodialysis (RED) generates electricity through the entropy increase from the mixing of sea and river water. Two important RED process parameters were investigated: power density (in Watts per square meter membrane) and the thermodynamic efficiency Beside this, we quantified losses in a

  18. Novel Organic SMD Package for High-Power Millimeter Wave MMICs

    NARCIS (Netherlands)

    Heijningen, M. van; Priday, J.

    2004-01-01

    In this paper a novel low-cost SMD package for high-power MMICs is presented. Due to the special design this package has a very low thermal resistance and low parasitic ground inductance. 3D EM simulations of a packaged through-line correspond well with measurements. Measurement results of a 1 Watt

  19. Impact of Partial Time Delay on Temporal Dynamics of Watts-Strogatz Small-World Neuronal Networks

    Science.gov (United States)

    Yan, Hao; Sun, Xiaojuan

    2017-06-01

    In this paper, we mainly discuss effects of partial time delay on temporal dynamics of Watts-Strogatz (WS) small-world neuronal networks by controlling two parameters. One is the time delay τ and the other is the probability of partial time delay pdelay. Temporal dynamics of WS small-world neuronal networks are discussed with the aid of temporal coherence and mean firing rate. With the obtained simulation results, it is revealed that for small time delay τ, the probability pdelay could weaken temporal coherence and increase mean firing rate of neuronal networks, which indicates that it could improve neuronal firings of the neuronal networks while destroying firing regularity. For large time delay τ, temporal coherence and mean firing rate do not have great changes with respect to pdelay. Time delay τ always has great influence on both temporal coherence and mean firing rate no matter what is the value of pdelay. Moreover, with the analysis of spike trains and histograms of interspike intervals of neurons inside neuronal networks, it is found that the effects of partial time delays on temporal coherence and mean firing rate could be the result of locking between the period of neuronal firing activities and the value of time delay τ. In brief, partial time delay could have great influence on temporal dynamics of the neuronal networks.

  20. A summary of the Planck constant measurements using a watt balance with a superconducting solenoid at NIST

    CERN Document Server

    Schlamminger, S; Haddad, D; Newell, D B; Seifert, F; Chao, L S; Liu, R; Williams, E R; Pratt, J R

    2015-01-01

    Researchers at the National Institute of Standards and Technology have been using a watt balance, NIST-3, to measure the Planck constant $h$ for over ten years. Two recently published values disagree by more than one standard uncertainty. The motivation for the present manuscript is twofold. First, we correct the latest published number to take into account a recently discovered systematic error in mass dissemination at the Bureau International des Poids et Mesures (BIPM). Second, we provide guidance on how to combine the two numbers into one final result. In order to adequately reflect the discrepancy, we added an additional systematic uncertainty to the published uncertainty budgets. The final value of $h$ measured with NIST-3 is $h = 6.626\\,069\\,36(37)\\times 10^{-34}\\,\\mbox{J\\,s}$. This result is $77(57) \\times 10^{-9}$ fractionally higher than $h_{\\mathrm{90}}$. Each number in parentheses gives the value of the standard uncertainty in the last two digits of the respective value and $h_{\\mathrm{90}}$ is th...

  1. Periodic coupling strength-dependent multiple coherence resonance by time delay in Newman-Watts neuronal networks.

    Science.gov (United States)

    Wu, Yanan; Gong, Yubing; Xu, Bo

    2013-12-01

    Recently, multiple coherence resonance induced by time delay has been observed in neuronal networks with constant coupling strength. In this paper, by employing Newman-Watts Hodgkin-Huxley neuron networks with time-periodic coupling strength, we study how the temporal coherence of spiking behavior and coherence resonance by time delay change when the frequency of periodic coupling strength is varied. It is found that delay induced coherence resonance is dependent on periodic coupling strength and increases when the frequency of periodic coupling strength increases. Periodic coupling strength can also induce multiple coherence resonance, and the coherence resonance occurs when the frequency of periodic coupling strength is approximately multiple of the spiking frequency. These results show that for periodic coupling strength time delay can more frequently optimize the temporal coherence of spiking activity, and periodic coupling strength can repetitively optimize the temporal coherence of spiking activity as well. Frequency locking may be the mechanism for multiple coherence resonance induced by periodic coupling strength. These findings imply that periodic coupling strength is more efficient for enhancing the temporal coherence of spiking activity of neuronal networks, and thus it could play a more important role in improving the time precision of information processing and transmission in neural networks.

  2. Bubbler---A Novel Ultra High Power Density Energy Harvesting Method Based on Reverse Electrowetting

    Science.gov (United States)

    Hsu, Tsung-Hsing

    A novel approach to direct conversion of mechanical energy into electrical energy has been proposed and experimentally and theoretically investigated. The method combines previously demonstrated reverse electrowetting on dielectric (REWOD) phenomenon with the fast self-oscillating process of bubble growth and collapse inside a conductive liquid placed in contact with a dielectric-covered electrode. Fast bubble dynamics, used in conjunction with REWOD, can enable extremely high power densities, in excess of 10 kW/m2. The method can be scaled in power from microwatts to tens of watts, and can enable direct coupling to a wide range of mechanical energy sources, which make it particularly attractive for energy harvesting applications. We believe that this approach can enable extraction of useful energy from various non-traditional sources including thermal expansion of buildings, human motion, and vehicle and machinery movement. Also, this makes the fabrication of small light-weight energy harvesting devices capable of producing a wide range of power outputs feasible.

  3. Development and Short-Range Testing of a 100 kW Side-Illuminated Millimeter-Wave Thermal Rocket

    Science.gov (United States)

    Bruccoleri, Alexander; Eilers, James A.; Lambot, Thomas; Parkin, Kevin

    2015-01-01

    The objective of the phase described here of the Millimeter-Wave Thermal Launch System (MTLS) Project was to launch a small thermal rocket into the air using millimeter waves. The preliminary results of the first MTLS flight vehicle launches are presented in this work. The design and construction of a small thermal rocket with a planar ceramic heat exchanger mounted along the axis of the rocket is described. The heat exchanger was illuminated from the side by a millimeter-wave beam and fed propellant from above via a small tank containing high pressure argon or nitrogen. Short-range tests where the rocket was launched, tracked, and heated with the beam are described. The rockets were approximately 1.5 meters in length and 65 millimeters in diameter, with a liftoff mass of 1.8 kilograms. The rocket airframes were coated in aluminum and had a parachute recovery system activated via a timer and Pyrodex. At the rocket heat exchanger, the beam distance was 40 meters with a peak power intensity of 77 watts per square centimeter. and a total power of 32 kilowatts in a 30 centimeter diameter circle. An altitude of approximately 10 meters was achieved. Recommendations for improvements are discussed.

  4. Normative Power

    DEFF Research Database (Denmark)

    The social sciences have many different understandings of ‘normative power', but in European Union (EU) studies normative power has three particular meanings. The first meaning of normative power is its emphasis on normative theory, that is, how we judge and justify truth claims in social science....... The second meaning of normative power is as a form of power that is ideational rather than material or physical. The third meaning of normative power is as a characterisation of an ideal type of international actor. Empirical studies of normative forms of power have analysed both the causal and constitutive...... effects of EU relations with the world in areas ranging from inter-regional relations, through traditional diplomacy, to environmental politics. Research areas of particular interest include the study of the interplay between physical, material and normative forms of power, as well as the constitutive...

  5. High-Power Amplifier Compatible Internally Sensed Optical Phased Array for Space Debris Tracking and Maneuvering

    Science.gov (United States)

    Roberts, L.; Francis, S.; Sibley, P.; Ward, R.; Smith, C.; McClelland, D.; Shaddock, D.

    2016-09-01

    Optical phased arrays (OPAs) provide a way to scale optical power beyond the capabilities of conventional CW lasers via coherent beam combination. By stabilising the relative output phase of multiple spatially separate lasers, OPAs form a coherent optical wavefront in the far field. Since the phase of each laser can be controlled independently, OPAs also have the ability to manipulate the distribution of optical power in the far field, and therefore may provide the capability to compensate for atmospheric turbulence. Combined with their inherent scalability and high power handling capabilities, OPAs are a promising technology for CW space debris ranging and manoeuvring. The OPA presented here is unique in its ability to sense the phase of each laser internally, without requiring any external sampling optics between it and the telescope. This allows the internally sensed OPA to be constructed entirely within fibre, utilising high-power fiber amplifiers to scale optical power beyond the limits of any conventional single lasers. The total power that can be delivered by each emitter in the OPA is limited only by the onset of stimulated Brillouin scattering, a non-linear effect that clamps the amount of power that can be delivered through a fiber waveguide. A three element internally sensed OPA developed at the Australian National University has been demonstrated to coherently combine three commercial 15 Watt fiber amplifiers with an output phase stability of one 200th of a wavelength. We have also demonstrated the ability to dynamically manipulate the distribution of optical power in the far-field at a bandwidth of up to 10 kHz. Since the OPA's control system is implemented using field-programmable gate-array technology, the system may be scaled beyond 100 emitters, potentially reaching the kilowatt level optical powers required to perturb the orbit of space debris.

  6. Development of 3 kW at 325 MHz solid-state RF power amplifier using four power amplifier modules

    Science.gov (United States)

    Ramarao, B. V.; Sonal, S.; Mishra, J. K.; Pande, M.; Singh, P.; Kumar, G.; Mukherjee, J.

    2014-01-01

    A high power solid-state RF power amplifier of 3 kW at 325 MHz has been developed using only four RF power amplifier modules of 850 W power output each. The design and characterization of RF power modules have been presented. A four way Wilkinson power combiner adds the output of four power amplifier modules with a total transmission loss of less than 6%. The combined power amplifier has a power gain of 20.2 dB at 1-dB compression point, and the corresponding output power is 2.8 kW at 325 MHz. The drain efficiency of the power amplifier is 65.3% at 3 kW. All the harmonics of this amplifier are below -40 dBc. The amplifier has better characteristics like fewer numbers of active devices per kilo watt, high efficiency, high gain, and ruggedness etc for RF accelerator applications.

  7. 新能源并网三电平逆变器中低功率区间效率优化%Efficiency Optimization in Low and Medium Power Range of New Energy Grid-connected Three-level Inverter

    Institute of Scientific and Technical Information of China (English)

    王菲; 王勇; 傅旻帆

    2014-01-01

    三电平逆变器因为电压应力只有两电平逆变器的一半,并且具有损耗小、谐波含量低的特点,所以在风能、太阳能等新能源发电系统中得到了越来越多的应用和研究。文中从新能源的功率随机波动特点出发,首先,评估了应用于新能源系统的传统三电平逆变器拓扑的损耗特点,然后,针对应用于光伏发电系统的三电平并网逆变器提出了硬件和控制策略上的改进,最后,利用一台样机验证了所提出的改进措施。试验证明,所提改进措施能够有效改善和提高三电平逆变器的效率,尤其是在中低功率范围内的效率。%By virtue of its remarkably low voltage stress,low harmonics and low power loss,the three-level inverter is increasingly applied in renewable energy systems such as the solar and wind power system.Anyway,the manifest feature of the new energy generating system is power fluctuation.Proceeding from the stochastic power fluctuation,the conventional three-level inverter is evaluated in terms of its topological power loss first.Then,some new schemes of hardware and control strategies are proposed for a three-level inverter applied in a solar inverter. Finally, a prototype is built to verify the improvement.Test results show the proposed schemes can improve the efficiency of the three-level inverter,especially the efficiency in the low and medium power range.

  8. Wireless Power Transfer in 3D Space

    Directory of Open Access Journals (Sweden)

    C.Bhuvaneshvari

    2014-06-01

    Full Text Available The main objective of this project is to develop a system of wireless power transfer in 3D space. This concept based on low frequency to high frequency conversion. High frequency power is transmit between air-core and inductor. This work presents an experiment for wireless energy transfer by using the Inductive resonant coupling (also known as resonant energy transfer phenomenon. The basic principles will be presented about this physical phenomenon, the experiment design, and the results obtained for the measurements performed on the system. The parameters measured were the efficiency of the power transfer, and the angle between emitter and receiver. We can achieve wireless power transfer up to 10watts in 3D space using high frequency through tuned circuit. The wireless power supply is motivated by simple and comfortable use of many small electric appliances with low power input.

  9. 2.1 μm high-power laser diode beam combining(Conference Presentation)

    Science.gov (United States)

    Berrou, Antoine P. C.; Elder, Ian F.; Lamb, Robert A.; Esser, M. J. Daniel

    2016-10-01

    Laser power and brightness scaling, in "eye safe" atmospheric transmission windows, is driving laser system research and development. High power lasers with good beam quality, at wavelength around 2.1 µm, are necessary for optical countermeasure applications. For such applications, focusing on efficiency and compactness of the system is mandatory. In order to cope with these requirements, one must consider the use of laser diodes which emit directly in the desired spectral region. The challenge for these diodes is to maintain a good beam quality factor as the output power increases. 2 µm diodes with excellent beam quality in both axes are available with output powers of 100 mW. Therefore, in order to reach multi-watt of average output power, broad-area single emitters and beam combining becomes relevant. Different solutions have been implemented in the 1.9 to 2 µm wavelength range, one of which is to stack multiple emitter bars reaching more than one hundred watt, while another is a fibre coupled diode module. The beam propagation factor of these systems is too high for long atmospheric propagation applications. Here we describe preliminary results on non-coherent beam combining of 2.1 µm high power Fabry-Perot GaSb laser diodes supplied by Brolis Semiconductors Ltd. First we evaluated single mode diodes (143 mW) with good beam quality (M2 beam consisted of two symmetric lobes with a total full width at half maximum (FWHM) divergence angle of 25 degrees, corresponding to a calculated beam quality factor of M2 = 25. The fast axis divergence was specified to be 44 degrees, with an expected beam quality factor close to the diffraction limit, which informed our selection of collimation lenses used in the experiment. We evaluated two broadband (1.8 - 3 µm) AR coated Geltech aspheric lenses with focal lengths of 1.87 mm and 4 mm, with numerical apertures of 0.85 and 0.56, respectively, as an initial collimation lens, followed by an additional cylindrical lens of

  10. High Power Local Oscillator Sources for 1-2 THz

    Science.gov (United States)

    Mehdi, Imran; Thomas, Bertrand; Lin, Robert; Maestrini, Alain; Ward, John; Schlecht, Erich; Gill, John; Lee, Choonsup; Chattopadhyay, Goutam; Maiwald, Frank

    2010-01-01

    Recent results from the Heterodyne Instrument for Far-Infrared (HIFI) on the Herschel Space Telescope have confirmed the usefulness of high resolution spectroscopic data for a better understanding of our Universe. This paper will explore the current status of tunable local oscillator sources beyond HIFI and provide demonstration of how power combining of GaAs Schottky diodes can be used to increase both power and upper operating frequency for heterodyne receivers. Availability of power levels greater than 1 watt in the W-band now makes it possible to design a 1900 GHz source with more than 100 microwatts of expected output power.

  11. Australian Marsh Beetles (Coleoptera: Scirtidae). 8. The new genera Cygnocyphon, Eximiocyphon, Paracyphon, Leptocyphon, Tectocyphon, and additions to Contacyphon de Gozis, Nanocyphon Zwick and Eurycyphon Watts.

    Science.gov (United States)

    Zwick, Peter

    2015-07-07

    New monotypic genera proposed are: Cygnocyphon ibex n. gen., n. sp., Eximiocyphon excisus n. gen., n. sp., and Paracyphon avicularis n. gen., n. sp. Also proposed are the new genera Leptocyphon n. gen., with L. furcalonga, n. sp. and L. quadricornutus, n. sp., Tectocyphon n. gen., with T. microphallus n. sp., T. hirsutus n. sp., and T. victoriae n. sp. The diagnosis of genus Eurycyphon Watts is amended, E. fulvus Watts and E. aquilus Watts are partly redescribed. New species are: Eurycyphon barringtoni n. sp., E. castaneus n. sp., E. falcatus n. sp., E. parvus n. sp., E. perlatus n. sp., E. thunguttii, n. sp., E. tomweiri n. sp., and E. tricornis n. sp. Species of Nanocyphon are discussed and N. tasmanicus n. sp. is described. Contacyphon forcipatus n. sp. is described and an apparently introduced population of the European Contacyphon putonii Gozis is reported from West Australia. For comparison with some of the new taxa the redescription of Pseudomicrocara orientalis Armstrong, type species of the genus, is supplemented.

  12. Mechanical power efficiency of modified turbine blades

    Science.gov (United States)

    Mahmud, Syahir; Sampebatu, Limbran; Kwang, Suendy Ciayadi

    2017-01-01

    Abstract-The problem of energy crisis has become one of the unsolved issues until today. Indonesia has a lot of non-conventional energy sources that does not utilized effectively yet. For that the available resources must utilized efficiently due to the energy crisis and the growing energy needs. Among the abundant resources of energy, one potential source of energy is hydroelectric energy. This research compares the mechanical power efficiency generated by the Darrieus turbine, Savonius turbine and the Darrieus-Savonius turbine. The comparation of the mechanical power amongst the three turbine starts from the measurement of the water flow rate, water temperature, turbine rotation and force on the shaft on each type of turbine. The comparison will show the mechanical power efficiency of each turbine to find the most efficient turbine that can work optimally. The results show that with 0.637m/s flow velocity and 44.827 Watt of water flow power, the Darrieus-Savonius turbine can generate power equal to 29.927 Watt and shaft force around by 17 N. The Darrieus-Savonius turbine provides around 66.76% efficiency betwen the three turbines; Darrieus turbine, Savonius turbine and the Darrieus-Savonius turbine. Overall, the Darrieus Savonius turbine has the ability to work optimally at the research location.

  13. Reliability and Characterization of High Voltage Power Capacitors

    Science.gov (United States)

    2014-03-01

    ix LIST OF FIGURES Figure 1.   System level overview of IPC EVCS (from [3]). ..............................................2   Figure 2...permittivity EVCS electric vehicle charging system GPIB general-purpose interface bus GW giga-watt HVST high voltage stress test IV current voltage...Power Converter (IPC). This converter is being used for the Electric Vehicle Charging Station ( EVCS ), currently being investigated and installed in

  14. AMTEC radioisotope power system design and analysis for Pluto Express Fly-By

    Energy Technology Data Exchange (ETDEWEB)

    Hendricks, T.J.; Huang, C.; Sievers, R.K. [Advanced Modular Power Systems, Inc., Ann Arbor, MI (United States)

    1997-12-31

    The Pluto Express Fly-By program requires a Radioisotope Power System (RPS) to supply spacecraft power for various internal functions and mission instruments and experiments. AMTEC (Alkali-Metal Thermal-Electric Conversion) power conversion is the DOE-selected technology for an advanced, high-efficiency RPS to power the Pluto Express Fly-By spacecraft. An AMTEC-based RPS using the General Purpose Heat Source (GPHS) has been conceptually designed to satisfy the Pluto Express power requirements. Integrated AMTEC cell and system thermal/electrical design analyses, structural design analyses, and mass analyses were performed to define an optimum system design. Using fresh radioisotope fuel at beginning of mission, the RPS produces 102 watts of power, has a mass of 8.35 kg (specific power density = 12.2 watts/kg), with a system conversion efficiency of 20.3%. Mass/power scale-up estimates have also been generated, indicating that a 150-watt version of this RPS would weigh approximately 11.3 kg. This paper presents and discusses the key features of this RPS design, the design and analysis methodology, and the numerous system and AMTEC cell tradeoff studies establishing the optimum AMTEC-based RPS.

  15. James Watt: a trajetória que levou ao desenvolvimento da máquina a vapor vista por seus biógrafos e homens de ciências

    OpenAIRE

    Tavares, Luiz Alberto

    2008-01-01

    Esta dissertação tem por objetivo a abordagem do trabalho do escocês James Watt no aperfeiçoamento da máquina a vapor. Este levantamento foi feito a partir de estudos de historiadores do século XIX contemporâneos a Watt e historiadores do século XX que vêem Watt de forma mais crítica. Abordamos também o relacionamento de Watt com seus parceiros, tanto na Universidade de Glasgow, como na Lunar Society, além de sua parceria com Thomas Boulton estabelecida para a comercialização da máquina. A...

  16. Twitter, King Lear, and the Freedom of Speech, by John Curtis, and Judicial Allusion as Ornament: A Response to John Curtis’s, ‘Twitter, King Lear, and the Freedom of Speech’ by Professor Gary Watt

    Directory of Open Access Journals (Sweden)

    John Curtis

    2014-03-01

    Full Text Available On 27 July 2012, in his judgment following ‘The Twitter Joke Trial’, the Lord Chief Justice of England & Wales quoted from King Lear (Folio.  The trial was the first time a British Court had considered the use of Twitter in the context of a bomb hoax.  The judgment was hailed as ‘a victory for common sense’, reversing decisions of two lower courts.  It now provides authority against similar prosecutions.  This paper argues that the use of a four-hundred-year-old Shakespearean text in negotiating modern legal principles is of considerable cultural significance – both through using the familiar to respond to the new – and by invoking Shakespeare’s voice within the powerful social mechanism of the law courts.  It also considers the advantages and disadvantages of literary allusions within legal proceedings, contrasting these two widely reported judgments.This piece is adapted from a transcript of: King Lear, Twitter and the Da Vinci Code given as part of the Sidelights on Shakespeare lecture series at University of Warwick on 29 November 2013.Professor Gary Watt provides a response to Curtis's critical reflection, considering judicial allusion as logic or ornament. Image: Cordelia in the Court of King Lear, Sir John Gilbert (1873

  17. Frequency doubled high-power disk lasers in pulsed and continuous-wave operation

    Science.gov (United States)

    Weiler, Sascha; Hangst, Alexander; Stolzenburg, Christian; Zawischa, Ivo; Sutter, Dirk; Killi, Alexander; Kalfhues, Steffen; Kriegshaeuser, Uwe; Holzer, Marco; Havrilla, David

    2012-03-01

    The disk laser with multi-kW output power in infrared cw operation is widely used in today's manufacturing, primarily in the automotive industry. The disk technology combines high power (average and/or peak power), excellent beam quality, high efficiency and high reliability with low investment and operating costs. Additionally, the disk laser is ideally suited for frequency conversion due to its polarized output with negligible depolarization losses. Laser light in the green spectral range (~515 nm) can be created with a nonlinear crystal. Pulsed disk lasers with green output of well above 50 W (extracavity doubling) in the ps regime and several hundreds of Watts in the ns regime with intracavity doubling are already commercially available whereas intracavity doubled disk lasers in continuous wave operation with greater than 250 W output are in test phase. In both operating modes (pulsed and cw) the frequency doubled disk laser offers advantages in existing and new applications. Copper welding for example is said to show much higher process reliability with green laser light due to its higher absorption in comparison to the infrared. This improvement has the potential to be very beneficial for the automotive industry's move to electrical vehicles which requires reliable high-volume welding of copper as a major task for electro motors, batteries, etc.

  18. The Circuit Theory Behind Coupled-Mode Magnetic Resonance-Based Wireless Power Transmission.

    Science.gov (United States)

    Kiani, Mehdi; Ghovanloo, Maysam

    2012-09-01

    Inductive coupling is a viable scheme to wirelessly energize devices with a wide range of power requirements from nanowatts in radio frequency identification tags to milliwatts in implantable microelectronic devices, watts in mobile electronics, and kilowatts in electric cars. Several analytical methods for estimating the power transfer efficiency (PTE) across inductive power transmission links have been devised based on circuit and electromagnetic theories by electrical engineers and physicists, respectively. However, a direct side-by-side comparison between these two approaches is lacking. Here, we have analyzed the PTE of a pair of capacitively loaded inductors via reflected load theory (RLT) and compared it with a method known as coupled-mode theory (CMT). We have also derived PTE equations for multiple capacitively loaded inductors based on both RLT and CMT. We have proven that both methods basically result in the same set of equations in steady state and either method can be applied for short- or midrange coupling conditions. We have verified the accuracy of both methods through measurements, and also analyzed the transient response of a pair of capacitively loaded inductors. Our analysis shows that the CMT is only applicable to coils with high quality factor (Q) and large coupling distance. It simplifies the analysis by reducing the order of the differential equations by half compared to the circuit theory.

  19. Continuation Power Flow Method based Assessment of Static Voltage Stability considering the Power System Contingencies

    Directory of Open Access Journals (Sweden)

    Khan Aafreen

    2014-11-01

    Full Text Available Power system security is recognized as one of the major problems in many power systems throughout the world. Power system insecurity such as transmission lines being overloaded causes transmission elements cascade outages, which may lead to complete blackout. In accordance with these reasons, the prediction and recognition of voltage instability in power system has particular importance and it makes the network security stronger. This work, by considering the power system contingencies based on the effects of them on Mega Watt Margin (MWM and maximum loading point (MLP is focused to analyse the voltage stability using continuation power flow method. The study has been carried out on IEEE 30-Bus Test System using MATLAB and PSAT softwares and results are presented.

  20. Powering light boats

    Energy Technology Data Exchange (ETDEWEB)

    Affolter, J.-F.

    1999-07-01

    This short paper reports on a workshop held in Horw, Switzerland, on the application potential of low-temperature fuel cells. It looks at the increasing interest in small, electrically-driven boats in Europe and, in particular, at the option of powering them with fuel cells. A prototype implementation of a test boat is described. Powered by a 300-watt portable PEFC fuel cell constructed by the Paul Scherrer Institute (PSI) and the University of Applied Science in Solothurn, Switzerland, the boat is part of a project to study the technical feasibility of such drive systems for leisure craft and small boats. The paper addresses hydrogen security questions, energy-efficient drives and controllers, maintenance questions and discusses if a combination of fuel cells and photovoltaics would be viable. Also, the design of the boat's hull and the propellers that are used are looked at critically. The economic viability of fuel-cell powered boats is examined. The authors state that they are convinced that such fuel cell drives could be commercially interesting for larger passenger boats, too.

  1. Regenerative Fuel Cells for Space Power and Energy Conversion (NaBH4/H2O2 Fuel Cell Development)

    Science.gov (United States)

    Valdez, Thomas I.; Miley, George H.; Luo, Nie; Burton, Rodney; Mather, Joseph; Hawkins, Glenn; Byrd, Ethan; Gu, Lifeng; Shrestha, Prajakti Joshi

    2006-01-01

    A viewgraph presentation describing hydrogen peroxide and sodium borohydride development is shown. The topics include: 1) Motivation; 2) The Sodium Borohydride Fuel Cell; 3) Fuel Cell Comparisons; 4) MEA Optimization; 5) 500-Watt Stack Testing; 6) System Modeling: Fuel Cell Power Source for Lunar Rovers; and 7) Conclusions

  2. 部分时滞诱发Watts-Strogatz小世界神经元网络产生随机多共振∗%Sto chastic multi-resonance induced by partial time delay in a Watts-Strogatz small-world neuronal network

    Institute of Scientific and Technical Information of China (English)

    孙晓娟; 李国芳

    2016-01-01

    In a neuronal system, propagation speed of neuronal information is mainly determined by the length, the diameter, and the kind of the axons between the neurons. Thus, some communications between neurons are not instantaneous, and others are instantaneous or with some negligible delay. In the past years, effects of time delay on neuronal dynamics, such as synchronization, stochastic resonance, firing regularity, etc., have been investigated. For stochastic resonance, it has been reported recently that stochastic multi-resonance in a neuronal system can be induced by time delay. However, in these studies, time delay has been introduced to every connection of the neuronal system. As mentioned in the beginning, in a real neuronal system, communication between some neurons can be instantaneous or with some negligible delays. Thus, considering the effect of partial time delay (time delay is called as partial time delay if only part of connections are delayed) on neuronal dynamics could be more meaningful. In this paper, we focus on discussing effect of partial time delay on response amplitude of a Watts-Strogatz neuronal network which is locally modeled by Rulkov map. With the numerically obtained results, we can see that partial time delay can induce a stochastic multi-resonance which is indicated by the multi-peak characteristics in the variation of response amplitude with partial time delay. Namely, partial time delay could also induce stochastic multi-resonance in a neuronal system. Moreover, we also find that optimal response amplitude can be reached in much wider range of the partial time delay value when delayed connections are less (i.e., the partial time delay probability is small). This is different from the case in which all connections are delayed, where response amplitude become optimal only when time delay is nearly the multiples of external signal’s period. But the range of the partial time delay value becomes narrower and narrower with the increasing of

  3. The relationship between critical power and the onset of blood lactate accumulation.

    Science.gov (United States)

    Housh, T J; Devries, H A; Housh, D J; Tichy, M W; Smyth, K D; Tichy, A M

    1991-03-01

    The purpose of this investigation was to determine the contribution of the onset of blood lactate accumulation (OBLA), the heartrate-workload slope (HR-WL) and the efficiency of electrical activity (EEA = slope of IEMG vs. workload) of the leg extensor muscles to Critical Power (CP). Twelve adult males (mean age +/- SD = 24.5 +/- 2.8 yrs) volunteered as subjects for this study. Zero-order correlations indicated that OBLA was significantly (p less than 0.05) related to CP (r = 0.616) and EEA (r = -0.577). Stepwise multiple regression resulted in a one variable model with OBLA the only significant (p less than 0.05) predictor of CP. Furthermore, a related t-test resulted in a significant difference between the means of the power out-put at CP (mean +/- SD = 230.0 +/- 22.1 watts) and OBLA (179.6 +/- 31.8 watts). The results of this study indicated that the two threshold parameters, CP and OBLA, were significantly related and therefore it is likely that the physiological factors responsible for OBLA also influence CP. However, the significant mean differences indicated that the mechanisms which underly CP and OBLA were not identical. Furthermore, the HR-WL slope (mean +/- SD = 0.343 +/- 0.071 beats per watt) and EEA (0.969 +/- 0.572 microvolts per watt) were not potent predictors of CP.

  4. Time and Power Optimizations in FPGA-Based Architectures for Polyphase Channelizers

    DEFF Research Database (Denmark)

    Awan, Mehmood-Ur-Rehman; Harris, Fred; Koch, Peter

    2012-01-01

    This paper presents the time and power optimization considerations for Field Programmable Gate Array (FPGA) based architectures for a polyphase filter bank channelizer with an embedded square root shaping filter in its polyphase engine. This configuration performs two different re-sampling tasks......% slice register resources of a Xilinx Virtex-5 FPGA, operating at 400 and 480 MHz, and consuming 1.9 and 2.6 Watts of dynamic power, respectively....

  5. Power consumption and lumber yields for reduced-kerf circular saws cutting hardwoods

    Science.gov (United States)

    Donald G. Cuppett

    1982-01-01

    Two 50-inch diameter headsaws were used for sawing (a) hardwood cants into boards, and (b) hardwood bolts into pallet parts. One saw had a 9x10 gage plate with 114-inch kerf teeth, and the other had a 7x8 gage plate with 9/32-inch kerf teeth. Power consumption for the two saws was determined with a watt-hour meter, measuring power used for paired cuts in 6-inch thick...

  6. Pulsed operation of high power light emitting diodes for flow velocimetry

    OpenAIRE

    Willert, Christian; Mößner, Steffen; Klinner, Joachim

    2009-01-01

    High powered light emitting diodes (LED) are investigated for possible uses as light sources in flow diagnostics, in particular, as an alternative to laser-based illumination in particle imaging flow velocimetry. Recent developments in solid state illumination resulted in mass-produced LEDs that provide average radiant power in excess of 10 Watt. By operating these LEDs with short duration, pulsed currents that are considerably beyond their continuous current damage th...

  7. Contingency management of power system with Interline Power Flow Controller using Real Power Performance Index and Line Stability Index

    Directory of Open Access Journals (Sweden)

    Akanksha Mishra

    2016-03-01

    Full Text Available As a result of privatization of the electrical industry the power transmission lines have to transfer power at their maximum transmission limits because of the competitive scenario of the electrical market. Hence, secured operation of power system has become one of the most important issues of modern era. In this paper, a probability of severity based placement strategy for Interline Power Flow Controller (IPFC has been proposed based on Composite Severity Index (CSI. The composite severity index provides an exact measure of stress in the line in terms of mega watt overloading and voltage instability. IPFC is placed on the line which has the highest probability of severity during the occurrence of different outages. The IPFC has been tuned for a multi-objective function using Differential Evolution (DE and the results have been compared with genetic Algorithm (GA. To verify the proposed method, it has been tested and implemented on IEEE 14 and 57 bus systems.

  8. Properties of the relaxation time distribution underlying the Kohlrausch-Williams-Watts photoionization of the DX centers in Cd{sub 1-x}Mn{sub x}Te mixed crystals

    Energy Technology Data Exchange (ETDEWEB)

    Trzmiel, J; Weron, K; Placzek-Popko, E [Institute of Physics, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland); Janczura, J [Hugo Steinhaus Center for Stochastic Methods and Institute of Mathematics and Computer Science, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland)

    2009-08-26

    In this paper we clarify the relationship between the relaxation rate and relaxation time distributions underlying the Kohlrausch-Williams-Watts (KWW) photoconductivity build-ups in indium- and gallium-doped Cd{sub 1-x}Mn{sub x}Te mixed crystals. We discuss the role of asymptotic properties of the corresponding probability density functions. We show that the relaxation rate distribution, as a completely asymmetric alpha-stable distribution, leads to an infinite mean value of the effective relaxation rate. In contrast, the relaxation time distribution related to it leads to a finite mean value of the effective relaxation time. It follows from the experimental data analysis that for all the investigated samples the KWW exponent alpha decreases linearly with increasing photon flux in the range of (0.6-0.99) and its values are more spread in the case of gallium-doped material. We also observe a linear dependence of the mean relaxation time on the characteristic material time constant, which is consistent with the theoretical model.

  9. Testing of Liquid Metal Components for Nuclear Surface Power Systems

    Science.gov (United States)

    Polzin, K. A.; Pearson, J. B.; Godfroy, T. J.; Schoenfeld, M.; Webster, K.; Briggs, M. H.; Geng, S. M.; Adkins, H. E.; Werner, J. E.

    2010-01-01

    The capability to perform testing at both the module/component level and in near prototypic reactor configurations using a non-nuclear test methodology allowed for evaluation of two components critical to the development of a potential nuclear fission power system for the lunar surface. A pair of 1 kW Stirling power convertors, similar to the type that would be used in a reactor system to convert heat to electricity, were integrated into a reactor simulator system to determine their performance using pumped NaK as the hot side working fluid. The performance in the pumped-NaK system met or exceed the baseline performance measurements where the converters were electrically heated. At the maximum hot-side temperature of 550 C the maximum output power was 2375 watts. A specially-designed test apparatus was fabricated and used to quantify the performance of an annular linear induction pump that is similar to the type that could be used to circulate liquid metal through the core of a space reactor system. The errors on the measurements were generally much smaller than the magnitude of the measurements, permitting accurate performance evaluation over a wide range of operating conditions. The pump produced flow rates spanning roughly 0.16 to 5.7 l/s (2.5 to 90 GPM), and delta p levels from less than 1 kPa to 90 kPa (greater than 0.145 psi to roughly 13 psi). At the nominal FSP system operating temperature of 525 C the maximum efficiency was just over 4%.

  10. Design of 1+ Ion Source Coupling First Design of the Resonant Ionization Laser Ion Source For the Multi-Mega Watt Target Station

    CERN Document Server

    A. Olivier, F. Le Blanc, C. Lau

    The realisation of next-generation ion sources suitable for the EURISOL multi-mega-watt (MMW) target station needs exhaustive studies and developments. An exhaustive review was carried out to evaluate the capability of the ion-sources to operate under the irradiation conditions of the MMW target station. In addition, selectivity must be taken into account to avoid the spread of unwanted radioactivity out of the target-ion-source system (TIS).These studies led to consider RILIS (Resonance Ionization Laser Ion Source) as the reference ion source for this target station.

  11. Power Generator with Thermo-Differential Modules

    Science.gov (United States)

    Saiz, John R.; Nguyen, James

    2010-01-01

    A thermoelectric power generator consists of an oven box and a solar cooker/solar reflector unit. The solar reflector concentrates sunlight into heat and transfers the heat into the oven box via a heat pipe. The oven box unit is surrounded by five thermoelectric modules and is located at the bottom end of the solar reflector. When the heat is pumped into one side of the thermoelectric module and ejected from the opposite side at ambient temperatures, an electrical current is produced. Typical temperature accumulation in the solar reflector is approximately 200 C (392 F). The heat pipe then transfers heat into the oven box with a loss of about 40 percent. At the ambient temperature of about 20 C (68 F), the temperature differential is about 100 C (180 F) apart. Each thermoelectric module, generates about 6 watts of power. One oven box with five thermoelectric modules produces about 30 watts. The system provides power for unattended instruments in remote areas, such as space colonies and space vehicles, and in polar and other remote regions on Earth.

  12. 高功率大动态范围的双极性电调衰减器的设计%Design of High Power and High Attenuation Range Bipolar Electronic-controlled Attenuator

    Institute of Scientific and Technical Information of China (English)

    李毅; 赵治华; 唐健; 潘启军

    2011-01-01

    首先分析了由PIN二极管组成的桥式双极性电调衰减器的工作原理.然后讨论了其关键参数:插损、最大衰减、阻抗匹配、平衡点电流和驱动电路等的设计方法.最后,给出了研制的短波波段的电调衰减器的性能曲线.结果表明,研制的电调衰减器输入功率大,衰减的动态范围大,插入损耗小,阻抗匹配好,控制电压与电调的电压传输系数基本呈线性关系.%The principle of a bipolar bridge electronic-controlled attenuator composed of PIN diodes is first analyzed. Then its key parameters are discussed in detail. These parameters include insertion loss, maximum attenuation, impedance matching, the balance electrity current and the drive circuit. Finally, the performance of the made attenuator has been given. The attenuator has been used in shortwave band. The results show that input power of the attenuator is high,and the attenuator has a high attenuation range and low insertion loss,and its impedance matching is good,and its contolled voltage and voltage transmission coefficient is approximately linear.

  13. Effect of resistive load on the inspiratory work and power of breathing during exertion.

    Directory of Open Access Journals (Sweden)

    Thomas Powell

    Full Text Available The resistive work of breathing against an external load during inspiration (WR(I was measured at the mouth, during sub-maximal exercise in healthy participants. This measure (which excludes the elastic work component allows the relationship between resistive work and power, ventilation and exercise modality to be explored. A total of 45 adult participants with healthy lung function took part in a series of exercise protocols, in which the relationship between WR(I, power of breathing, PR(I and minute ventilation, [Formula: see text] were assessed during rest, while treadmill walking or ergometer cycling, over a range of exercise intensities (up to 150 Watts and ventilation rates (up to 48 L min(-1 with applied constant resistive loads of 0.75 and 1.5 kPa.L.sec(-1. Resting WR(I was 0.12 JL(-1 and PR(I was 0.9 W. At each resistive load, independent of the breathing pattern or exercise mode, the WR(I increased in a linear fashion at 20 mJ per litre of [Formula: see text], while PR(I increased exponentially. With increasing resistive load the work and power at any given [Formula: see text] increased exponentially. Calculation of the power to work ratio during loaded breathing suggests that loads above 1.5 kPa.L.sec(-1 make the work of resistive breathing become inhibitive at even a moderate [Formula: see text] (>30 L sec(-1. The relationship between work done and power generated while breathing against resistive loads is independent of the exercise mode (cycling or walking and that ventilation is limited by the work required to breathe, rather than an inability to maintain or generate power.

  14. A Low-Power and Low-Voltage Power Management Strategy for On-Chip Micro Solar Cells

    Directory of Open Access Journals (Sweden)

    Ismail Cevik

    2015-01-01

    Full Text Available Fundamental characteristics of on-chip micro solar cell (MSC structures were investigated in this study. Several MSC structures using different layers in three different CMOS processes were designed and fabricated. Effects of PN junction structure and process technology on solar cell performance were measured. Parameters for low-power and low-voltage implementation of power management strategy and boost converter based circuits utilizing fractional voltage maximum power point tracking (FVMPPT algorithm were determined. The FVMPPT algorithm works based on the fraction between the maximum power point operation voltage and the open circuit voltage of the solar cell structure. This ratio is typically between 0.72 and 0.78 for commercially available poly crystalline silicon solar cells that produce several watts of power under typical daylight illumination. Measurements showed that the fractional voltage ratio is much higher and fairly constant between 0.82 and 0.85 for on-chip mono crystalline silicon micro solar cell structures that produce micro watts of power. Mono crystalline silicon solar cell structures were observed to result in better power fill factor (PFF that is higher than 74% indicating a higher energy harvesting efficiency.

  15. Safety evaluation report related to the operation of Watts Bar Nuclear Plant, Units 1 and 2 (Docket Nos. 50-390 and 50-391). Supplement No. 15

    Energy Technology Data Exchange (ETDEWEB)

    Tam, P.S.

    1995-06-01

    This report supplements the Safety Evaluation Report (SER), NUREG-0847 (June 1982), Supplement No. 1 (September 1982), Supplement No. 2 (January 1984), Supplement No. 3 (January 1985), Supplement No. 4 (March 1985), Supplement No. 5 (November 1990), Supplement No. 6 (April 1991), Supplement No. 7 (September 1991), Supplement No. 8 (January 1992), Supplement No. 9 (June 1992), Supplement No. 10 (October 1992), Supplement No. 11 (April 1993), Supplement No. 12 (October 1993), Supplement No. 13 (April 1994), and Supplement No. 14 (December 1994) issued by the Office of Nuclear Reactor Regulation of the US Nuclear Regulatory Commission with respect to the application filed by the Tennessee Valley Authority, as applicant and owner, for licenses to operate the Watts Bar Nuclear Plant, Units 1 and 2 (Docket Nos. 50-390 and 50-391). The facility is located in Rhea County, Tennessee, near the Watts Bar Dam on the Tennessee River. This supplement provides recent information regarding resolution of some of the outstanding and confirmatory items, and proposed license conditions identified in the SER.

  16. "Watts per person" paradigm to design net zero energy buildings: Examining technology interventions and integrating occupant feedback to reduce plug loads in a commercial building

    Science.gov (United States)

    Yagi Kim, Mika

    As building envelopes have improved due to more restrictive energy codes, internal loads have increased largely due to the proliferation of computers, electronics, appliances, imaging and audio visual equipment that continues to grow in commercial buildings. As the dependency on the internet for information and data transfer increases, the electricity demand will pose a challenge to design and operate Net Zero Energy Buildings (NZEBs). Plug Loads (PLs) as a proportion of the building load has become the largest non-regulated building energy load and represents the third highest electricity end-use in California's commercial office buildings, accounting for 23% of the total building electricity consumption (Ecova 2011,2). In the Annual Energy Outlook 2008 (AEO2008), prepared by the Energy Information Administration (EIA) that presents long-term projections of energy supply and demand through 2030 states that office equipment and personal computers are the "fastest growing electrical end uses" in the commercial sector. This thesis entitled "Watts Per Person" Paradigm to Design Net Zero Energy Buildings, measures the implementation of advanced controls and behavioral interventions to study the reduction of PL energy use in the commercial sector. By integrating real world data extracted from an energy efficient commercial building of its energy use, the results produce a new methodology on estimating PL energy use by calculating based on "Watts Per Person" and analyzes computational simulation methods to design NZEBs.

  17. A High Efficiency 1kWatt GaN Amplifier for P-Band Pulsed Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An improved efficiency amplifier for high power pulse applications at P-Band will be investigated that will support space based RADAR systems. Current P-Band pulsed...

  18. A High Efficiency 1kWatt GaN amplifier for P-Band pulsed applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An improved efficiency amplifier for high power pulse applications at P-Band will be investigated that will support space based RADAR systems. Current P-Band pulsed...

  19. Power electronics for low power arcjets

    Science.gov (United States)

    Hamley, John A.; Hill, Gerald M.

    1991-01-01

    In anticipation of the needs of future light-weight low-power spacecraft, arcjet power electronics in the 100- to 400-W operating range were developed. Power topologies similar to those in the higher 2-kW and 5- to 30-kW power range were implemented, including a four-transistor bridge-switching circuit, current-mode pulse-width modulated control, and an output current averaging inductor with an integral pulse generation winding. Reduction of switching transients was accomplished using a low inductance power distribution network, and no passive snubber circuits were necessary for power switch protection. Phase shift control of the power bridge was accomplished using an improved pulse width modulation to phase shift converter circuit. These features, along with conservative magnetics designs, allowed power conversion efficiencies of greater than 92.5 percent to be achieved into resistive loads over the entire operating range of the converter.

  20. Laser and Pulsed Power Electron Density Imaging Through Talbot-Lau X-ray Deflectometry

    Science.gov (United States)

    Valdivia Leiva, Maria Pia; Stutman, Dan; Stoeckl, Christian; Mileham, Chad; Begischev, Ildar; Theobald, Wolfgang; Bromage, Jake; Regan, Sean; Klein, Salee; Muñoz-Cordovez, Gonzalo; Vescovi, Milenko; Valenzuela-Villaseca, Vicente; Veloso, Felipe

    2016-10-01

    A Talbot-Lau X-ray Deflectometer was deployed using laser driven and x-pinch x-ray backlighters. The Talbot-Lau X-ray Deflectometer is an ideal electron density diagnostic for High Energy Density plasmas with the potential to simultaneously deliver x-ray refraction, attenuation, elemental composition, and scatter information from a single image with source limited resolution. Grating survival and electron density mapping was demonstrated for 10-29 J, 8-30 ps laser pulses using Cu foil targets at the Multi-TeraWatt facility. An areal electron density of 0.050 g/cm2 was obtained at the center of a fluoro-nylon fiber of 300 mm diameter with a source FWHM of 80 µm and resolution of 50 µm. Grating survival and Moiré pattern formation was demonstrated using a Cu x-pinch plasma of FWHM 27 µm, driven by the 350 kA, 350 ns Llampudken pulsed power generator. These results closely match simulations and laboratory results. It was demonstrated that the technique can detect both sharp and smooth density gradients in the range of 2x1023 to 2x1025 cm-3, thus allowing implementation of the electron density technique as a HED plasma diagnostic in both laser and pulsed power experiments U.S. DoE/NNSA and DE-NA0002955.

  1. Ultra-low power HOT MCT grown by MOVPE for handheld applications

    Science.gov (United States)

    Pillans, Luke; Baker, Ian; McEwen, R. Kennedy

    2014-06-01

    In 2012 Selex ES demonstrated High Operating Temperature (HOT) MCT detectors with 5μm cut-off wavelength and f/4 aperture operating at temperatures above 200K. These detectors are grown by Metal Organic Vapour Phase Epitaxy (MOVPE) which enables fine control over the photo-diode structure. Since 2012 Selex has created two further generations of MOVPE HOT MCT, progressively improving operability and yield. This paper presents performance data for Selex's third generation of HOT MCT technology and describes the improvements to the diode design and materials processing that have enabled these advances. A parallel program has developed miniature Dewars with lower heatload and reduced manufacturing costs. When integrated with the latest generation of miniature linear cryo-engines the required cooler power is reduced to the region of 1W at temperatures of 200K. This paper will present example imagery from a detector operating with <1 Watt cooler input power. The combination of third generation HOT MCT, high efficiency Dewars and miniature linear coolers will allow a drastic reduction in SWAP-C for long range hand-held thermal imagers.

  2. Accurate Engineering Model of PV Module and Voltage Range at Maximum Power Point of Grid-Connected PV Inverter%光伏组件精确工程模型及MPP电压范围研究

    Institute of Scientific and Technical Information of China (English)

    王冰清; 曾国宏; 童亦斌; 张勇波

    2013-01-01

    The research on output characteristics of photovoltaic (PV) module is the foundation to determine the voltage range at maximum power point (MPP) of grid-connected PV inverter. The mathematical model of PV module is of high accuracy, however considering such disadvantages of the mathematical model such as concerning in transcendental equation, complex solving process and too much input parameters, it is not suitable for engineering design; the calculation of simplified model of PV module is simple, however by which the output characteristics of PV module under low light condition cannot be accurately described. Based on contrastive analysis on the mathematical model and simplified model, an accurate engineering model of PV module, which is benchmarked in the mathematical model, is proposed. The compensation parameters of the simplified model is fitted and modified, meanwhile both accuracy and complexity of engineering model are taken into account. The MathCad program is utilized to built the simulation model of PV module, and the output results of the simulation model is contrasted with the output of the mathematical model to verify the accuracy of accurate engineering model. Based on the proposed engineering model, through analyzing the impacts of external conditions such as illumination, temperature and so on, the voltage range traced at MPP of grid-connected PV inverter can be accurately determined, and the correctness of this conclusion is validated by experimental results.%光伏并网变流器最大功率点(maximum power point, MPP)电压范围的确定是以组件的输出特性研究为基础的。组件的数学模型精确度较高,但涉及到超越方程,求解复杂且输入参数多,不适用于工程设计。简化模型计算过程简单但不能准确表述弱光条件下的组件输出特性。基于对数学模型及简化模型的对比分析,提出了一种精确的工程模型,该模型以数学模型为基准,对简化模型的

  3. High-power monolithic single-mode diode lasers employing active photonic lattices

    Science.gov (United States)

    Botez, Dan

    2003-06-01

    Photonic-lattice structures with modulated gain, that is active photonic lattices (APLs), of large index steps and gain preferentially enhanced on the low-index lattice sites have been used, as early as 1988, for effective lateral-mode control range in large-aperture (100-200 microns) high-power coherent devices. Photonic-bandpass (PBP) structures relying on long-range resonant leaky-wave coupling, so called ROW arrays, have allowed stable, near-diffraction-limited beam operation to powers as high as 1.6W CW and 10W peak pulsed. Photonic-bandgap (PBG) structures with a built-in lattice defect, so called ARROW lasers, have provided up to 0.5W peak-pulsed stable, single-mode power and hold the potential for 1W CW reliable single-mode operation from apertures 8-10 microns wide. The solution for high-efficiency surface emission, from 2nd-order DFB/DBR lasers, in an orthonormal, single-lobe beam pattern was found in 2000. Recently, single-lobe and single-mode operation in a diffraction-limited beam orthonormal to the chip surface was demonstrated from 1.5mm-long DFB/DBR ridge-guide lasers. That opens the way for the realization of 2-D surface-emitting,2nd-order APLs for the stable generation of watts of CW single-lobe, single-mode power from large 2-D apertures, as well as scalability of such devices at the wafer level.

  4. Using high-power light emitting diodes for photoacoustic imaging

    DEFF Research Database (Denmark)

    Hansen, René Skov

    The preliminary result of using a high-power light emitting diode, LED, for photoacoustic imaging is presented. The pulsed light source is created by a 1Watt red Luxeon LED. The LED delivers light pulses with 25W peak power when supplied by 40A peak, 60ns wide current pulses. The phantom used...... for the experiment consists of a 3mm high x 5mm wide slice of green colored gelatine overlaid by a 3cm layer of colorless gelatine. The light pulses from the LED is focused on the green gelatine. The photoacoustic response from the green gelatine is detected by a single transducer on the opposite (top) surface...

  5. Advanced Grid Support Functionality Testing for Florida Power and Light

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Austin [National Renewable Energy Lab. (NREL), Golden, CO (United States); Martin, Gregory [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hurtt, James [Florida Power and Light, Juno Beach, FL (United States)

    2017-03-21

    This report describes the results of laboratory testing of advanced photovoltaic (PV) inverter testing undertaken by the National Renewable Energy Laboratory (NREL) on behalf of the Florida Power and Light Company (FPL). FPL recently commissioned a 1.1 MW-AC PV installation on a solar carport at the Daytona International Speedway in Daytona Beach, Florida. In addition to providing a source of clean energy production, the site serves as a live test bed with 36 different PV inverters from eight different manufacturers. Each inverter type has varied support for advanced grid support functions (GSFs) that are becoming increasingly commonplace, and are being required through revised interconnection standards such as UL1741, IEEE1547, and California (CA) Rule 21. FPL is interested in evaluating the trade-offs between different GSFs, their compliance to emerging standards, and their effects on efficiency and reliability. NREL has provided a controlled laboratory environment to undertake such a study. This work covered nine different classes of tests to compare inverter capabilities and performance for four different inverters that were selected by FPL. The test inverters were all three-phase models rated between 24-36 kW, and containing multiple PV input power point trackers. Advanced grid support functions were tested for functional behavior, and included fixed power factor operation, voltage-ride through, frequency ride-through, volt-var control, and frequency-Watt control. Response to abnormal grid conditions with GSFs enabled was studied through anti-islanding, fault, and load rejection overvoltage tests. Finally, efficiency was evaluated across a range of operating conditions that included power factor, output power, and input voltage variations. Test procedures were derived from requirements of a draft revision of UL741, CA Rule 21, and/or previous studies at NREL. This reports summarizes the results of each test case, providing a comparative performance analysis

  6. 20-kHz watt-level green laser with LGS crystal electro-optic Q-switch

    Institute of Scientific and Technical Information of China (English)

    Hao Tang; Xiaolei Zhu; Junqing Meng; Huaguo Zang

    2009-01-01

    A diode-end-pumped electro-optic(EO)Q-switched green laser operating at the repetition rate of 20 kHz is reported.A block of La3Ga5SiO14(LGS)single crystal is used as a Q-switch and the type I phasematching LiB3O5(LBO)is used as the nonlinear crystal in the second harmonic generation.The 2.3-W average power of 532-nm green laser is obtained at the repetition rate of 20 kHz with the pulse width as short as 10 ns.When the output power is about 1.5 W,the measured power fluctuation is less than 1.4% (root-mean-square,RMS)with the beam quality factor of M2 < 2 in both orthogonal directions.

  7. Future directions in 980-nm pump lasers: submarine deployment to low-cost watt-class terrestrial pumps

    Science.gov (United States)

    Gulgazov, Vadim N.; Jackson, Gordon S.; Lascola, Kevin M.; Major, Jo S.; Parke, Ross; Richard, Tim; Rossin, Victor V.; Zhang, Kai

    1999-09-01

    The demands of global bandwidth and distribution are rising rapidly as Internet usage grows. This fundamentally means that more photons are flowing within optical cables. While transmitting sources launches some optical power, the majority of the optical power that is present within modern telecommunication systems originates from optical amplifiers. In addition, modern optical amplifiers offer flat optical gain over broad wavelength bands, thus making possible dense wavelength de-multiplexing (DWDM) systems. Optical amplifier performance, and by extension the performance of the laser pumps that drive them, is central to the future growth of both optical transmission and distribution systems. Erbium-doped amplifiers currently dominate optical amplifier usage. These amplifiers absorb pump light at 980 nm and/or 1480 nm, and achieve gain at wavelengths around 1550 nm. 980 nm pumps achieve better noise figures and are therefore used for the amplification of small signals. Due to the quantum defect, 1480 nm lasers deliver more signal photon per incident photon. In addition, 1480 nm lasers are less expensive than 980 nm lasers. Thus, 1480 nm pump lasers are used for amplification in situations where noise is not critical. The combination of these traits leads to the situation where many amplifiers contain 980 nm lasers to pump the input section of the Er- doped fiber with 1480 nm lasers being used to pump the latter section of Er fiber. This can be thought of as using 980 nm lasers to power an optical pre-amplifier with the power amplification function being pump with 1480 nm radiation. This paper will focus on 980 nm pump lasers and the impact that advances in 980 nm pump technology will have on optical amplification systems. Currently, 980 nm technology is rapidly advancing in two areas, power and reliability. Improving reliability is becoming increasingly important as amplifiers move towards employing more pump lasers and using these pump lasers without redundancy

  8. Multi-watt Q-switched Nd:YVO4 laser with GaAs output coupler

    Institute of Scientific and Technical Information of China (English)

    Ping Li(李平); Qingpu Wang(王青圃); Shichen Li(李世忱); Jie Lian(连结); Baomin Ma(马宝民); Jingliang He(何京良)

    2003-01-01

    A passively Q-switched operation of a diode-pumped Nd:YVO4 laser is demonstrated, in which a GaAs film is used as the saturable absorber as well as the output coupler. At the pump power of 10 W, a stable fundamental-mode average power output of 2.11 W was obtained with a pulse duration of 140 ns, pulse energy of 76 μJ and pulse repetition rate of 28 kHz. A theoretical analysis that describes the passive Q-switching dynamics of GaAs is presented.

  9. Fuel-Cell Power Source Based on Onboard Rocket Propellants

    Science.gov (United States)

    Ganapathi, Gani; Narayan, Sri

    2010-01-01

    The use of onboard rocket propellants (dense liquids at room temperature) in place of conventional cryogenic fuel-cell reactants (hydrogen and oxygen) eliminates the mass penalties associated with cryocooling and boil-off. The high energy content and density of the rocket propellants will also require no additional chemical processing. For a 30-day mission on the Moon that requires a continuous 100 watts of power, the reactant mass and volume would be reduced by 15 and 50 percent, respectively, even without accounting for boiloff losses. The savings increase further with increasing transit times. A high-temperature, solid oxide, electrolyte-based fuel-cell configuration, that can rapidly combine rocket propellants - both monopropellant system with hydrazine and bi-propellant systems such as monomethyl hydrazine/ unsymmetrical dimethyl hydrazine (MMH/UDMH) and nitrogen tetroxide (NTO) to produce electrical energy - overcomes the severe drawbacks of earlier attempts in 1963-1967 of using fuel reforming and aqueous media. The electrical energy available from such a fuel cell operating at 60-percent efficiency is estimated to be 1,500 Wh/kg of reactants. The proposed use of zirconia-based oxide electrolyte at 800-1,000 C will permit continuous operation, very high power densities, and substantially increased efficiency of conversion over any of the earlier attempts. The solid oxide fuel cell is also tolerant to a wide range of environmental temperatures. Such a system is built for easy refueling for exploration missions and for the ability to turn on after several years of transit. Specific examples of future missions are in-situ landers on Europa and Titan that will face extreme radiation and temperature environments, flyby missions to Saturn, and landed missions on the Moon with 14 day/night cycles.

  10. Quasistatic Cavity Resonance for Ubiquitous Wireless Power Transfer.

    Science.gov (United States)

    Chabalko, Matthew J; Shahmohammadi, Mohsen; Sample, Alanson P

    2017-01-01

    Wireless power delivery has the potential to seamlessly power our electrical devices as easily as data is transmitted through the air. However, existing solutions are limited to near contact distances and do not provide the geometric freedom to enable automatic and un-aided charging. We introduce quasistatic cavity resonance (QSCR), which can enable purpose-built structures, such as cabinets, rooms, and warehouses, to generate quasistatic magnetic fields that safely deliver kilowatts of power to mobile receivers contained nearly anywhere within. A theoretical model of a quasistatic cavity resonator is derived, and field distributions along with power transfer efficiency are validated against measured results. An experimental demonstration shows that a 54 m3 QSCR room can deliver power to small coil receivers in nearly any position with 40% to 95% efficiency. Finally, a detailed safety analysis shows that up to 1900 watts can be transmitted to a coil receiver enabling safe and ubiquitous wireless power.

  11. Quasistatic Cavity Resonance for Ubiquitous Wireless Power Transfer

    Science.gov (United States)

    Shahmohammadi, Mohsen; Sample, Alanson P.

    2017-01-01

    Wireless power delivery has the potential to seamlessly power our electrical devices as easily as data is transmitted through the air. However, existing solutions are limited to near contact distances and do not provide the geometric freedom to enable automatic and un-aided charging. We introduce quasistatic cavity resonance (QSCR), which can enable purpose-built structures, such as cabinets, rooms, and warehouses, to generate quasistatic magnetic fields that safely deliver kilowatts of power to mobile receivers contained nearly anywhere within. A theoretical model of a quasistatic cavity resonator is derived, and field distributions along with power transfer efficiency are validated against measured results. An experimental demonstration shows that a 54 m3 QSCR room can deliver power to small coil receivers in nearly any position with 40% to 95% efficiency. Finally, a detailed safety analysis shows that up to 1900 watts can be transmitted to a coil receiver enabling safe and ubiquitous wireless power. PMID:28199321

  12. A new complete model of switch-mode plasma cutting power supply

    Institute of Scientific and Technical Information of China (English)

    Abdolreza Esmaeli; SUN Li(孙力); NIE Jian-hong(聂剑红)

    2004-01-01

    A complete model of switch-mode plasma cutting power supply and its simulation are developed. The full bridge isolated pulse width modulation (PWM) buck converter in continuous conduction mode (CCM) for high watt plasma power supply is approached. Reduced ripple current and improved power factor are achieved in the plasma power supply. With a PID control strategy, circuit responses become more stable and faster with low overshoot during load and current changing. The converter achieved high efficiency under 3 to 15kW load conditions.

  13. Optimal Power Flow Pursuit

    Energy Technology Data Exchange (ETDEWEB)

    Dall' Anese, Emiliano

    2016-08-01

    Past works that focused on addressing power-quality and reliability concerns related to renewable energy resources (RESs) operating with business-as-usual practices have looked at the design of Volt/VAr and Volt/Watt strategies to regulate real or reactive powers based on local voltage measurements, so that terminal voltages are within acceptable levels. These control strategies have the potential of operating at the same time scale of distribution-system dynamics, and can therefore mitigate disturbances precipitated fast time-varying loads and ambient conditions; however, they do not necessarily guarantee system-level optimality, and stability claims are mainly based on empirical evidences. On a different time scale, centralized and distributed optimal power flow (OPF) algorithms have been proposed to compute optimal steady-state inverter setpoints, so that power losses and voltage deviations are minimized and economic benefits to end-users providing ancillary services are maximized. However, traditional OPF schemes may offer decision making capabilities that do not match the dynamics of distribution systems. Particularly, during the time required to collect data from all the nodes of the network (e.g., loads), solve the OPF, and subsequently dispatch setpoints, the underlying load, ambient, and network conditions may have already changed; in this case, the DER output powers would be consistently regulated around outdated setpoints, leading to suboptimal system operation and violation of relevant electrical limits. The present work focuses on the synthesis of distributed RES-inverter controllers that leverage the opportunities for fast feedback offered by power-electronics interfaced RESs. The overarching objective is to bridge the temporal gap between long-term system optimization and real-time control, to enable seamless RES integration in large scale with stability and efficiency guarantees, while congruently pursuing system-level optimization objectives. The

  14. Power theories for improved power quality

    CERN Document Server

    Pasko, Marian

    2012-01-01

    Power quality describes a set of parameters of electric power and the load’s ability to function properly under specific conditions. It is estimated that problems relating to power quality costs the European industry hundreds of billions of Euros annually. In contrast, financing for the prevention of these problems amount to fragments of these costs. Power Theories for Improved Power Quality addresses this imbalance by presenting and assessing a range of methods and problems related to improving the quality of electric power supply. Focusing particularly on active compensators and the DSP based control algorithms, Power Theories for Improved Power Quality introduces the fundamental problems of electrical power. This introduction is followed by chapters which discuss: •‘Power theories’ including their historical development and application to practical problems, •operational principles of active compensator’s DSP control based algorithms using examples and results from laboratory research, and •t...

  15. Control of Vibratory Energy Harvesters in the Presence of Nonlinearities and Power-Flow Constraints

    Science.gov (United States)

    Cassidy, Ian L.

    Over the past decade, a significant amount of research activity has been devoted to developing electromechanical systems that can convert ambient mechanical vibrations into usable electric power. Such systems, referred to as vibratory energy harvesters, have a number of useful of applications, ranging in scale from self-powered wireless sensors for structural health monitoring in bridges and buildings to energy harvesting from ocean waves. One of the most challenging aspects of this technology concerns the efficient extraction and transmission of power from transducer to storage. Maximizing the rate of power extraction from vibratory energy harvesters is further complicated by the stochastic nature of the disturbance. The primary purpose of this dissertation is to develop feedback control algorithms which optimize the average power generated from stochastically-excited vibratory energy harvesters. This dissertation will illustrate the performance of various controllers using two vibratory energy harvesting systems: an electromagnetic transducer embedded within a flexible structure, and a piezoelectric bimorph cantilever beam. Compared with piezoelectric systems, large-scale electromagnetic systems have received much less attention in the literature despite their ability to generate power at the watt--kilowatt scale. Motivated by this observation, the first part of this dissertation focuses on developing an experimentally validated predictive model of an actively controlled electromagnetic transducer. Following this experimental analysis, linear-quadratic-Gaussian control theory is used to compute unconstrained state feedback controllers for two ideal vibratory energy harvesting systems. This theory is then augmented to account for competing objectives, nonlinearities in the harvester dynamics, and non-quadratic transmission loss models in the electronics. In many vibratory energy harvesting applications, employing a bi-directional power electronic drive to actively

  16. An ultra short pulse reconstruction software applied to the GEMINI high power laser system

    Energy Technology Data Exchange (ETDEWEB)

    Galletti, Mario, E-mail: mario.gall22@gmail.com [INFN – LNF, Via Enrico Fermi 40, 00044 Frascati (Italy); Galimberti, Marco [Central Laser Facility, Rutherford Appleton Laboratory, Didcot (United Kingdom); Hooker, Chris [Central Laser Facility, Rutherford Appleton Laboratory, Didcot (United Kingdom); University of Oxford, Oxford (United Kingdom); Chekhlov, Oleg; Tang, Yunxin [Central Laser Facility, Rutherford Appleton Laboratory, Didcot (United Kingdom); Bisesto, Fabrizio Giuseppe [INFN – LNF, Via Enrico Fermi 40, 00044 Frascati (Italy); Curcio, Alessandro [INFN – LNF, Via Enrico Fermi 40, 00044 Frascati (Italy); Sapienza – University of Rome, P.le Aldo Moro, 2, 00185 Rome (Italy); Anania, Maria Pia [INFN – LNF, Via Enrico Fermi 40, 00044 Frascati (Italy); Giulietti, Danilo [Physics Department of the University and INFN, Pisa (Italy)

    2016-09-01

    The GRENOUILLE traces of Gemini pulses (15 J, 30 fs, PW, shot per 20 s) were acquired in the Gemini Target Area PetaWatt at the Central Laser Facility (CLF), Rutherford Appleton Laboratory (RAL). A comparison between the characterizations of the laser pulse parameters made using two different types of algorithms: Video Frog and GRenouille/FrOG (GROG), was made. The temporal and spectral parameters came out to be in great agreement for the two kinds of algorithms. In this experimental campaign it has been showed how GROG, the developed algorithm, works as well as VideoFrog algorithm with the PetaWatt pulse class. - Highlights: • Integration of the diagnostic tool on high power laser. • Validation of the GROG algorithm in comparison to a well-known commercial available software. • Complete characterization of the GEMINI ultra-short high power laser pulse.

  17. Power management systems for sediment microbial fuel cells in high power and continuous power applications

    Science.gov (United States)

    Donovan, Conrad Koble

    The objective of this dissertation was to develop power management systems (PMS) for sediment microbial fuel cells (SFMCs) for high power and continuous applications. The first part of this dissertation covers a new method for testing the performance of SMFCs. This device called the microbial fuel cell tester was developed to automatically test power generation of PMS. The second part focuses on a PMS capable of delivering high power in burst mode. This means that for a small amount of time a large amount of power up to 2.5 Watts can be delivered from a SMFC only generating mW level power. The third part is aimed at developing a multi-potentiostat laboratory tool that measures the performance at fixed cell potentials of microbial fuel cells so that I can optimize them for use with the PMS. This tool is capable of controlling the anode potential or cathode potential and measuring current of six separate SMFCs simultaneously. By operating multiple potentiostats, I was able to run experiments that find ideal operating conditions for the sediment microbial fuel cells, and also I can optimize the power management system for these conditions. The fourth part of the dissertation is targeting a PMS that was able to operate a sensor continuously which was powered by an SMFC. In pervious applications involving SMFCs, the PMS operated in batch mode. In this PMS, the firmware on the submersible ultrasonic receiver (SUR) was modified for use with my PMS. This integration of PMS and SUR allowed for the continuous operation of the SUR without using a battery. Finally, the last part of the dissertation recommends a scale-up power management system to overcome the linearity scale up issue of SMFCs as future work. Concluding remarks are also added to summarize the goal and focus of this dissertation.

  18. Safety evaluation report related to the operation of Watts Bar Nuclear Plant, Units 1 and 2 (Docket Nos. 50-390 and 50-391). Supplement No. 18

    Energy Technology Data Exchange (ETDEWEB)

    Tam, P.S.

    1995-10-01

    In June 1982, the Nuclear Regulatory Commission staff (NRC staff or staff) issued a Safety Evaluation Report, NUREG-0847, regarding the application by the Tennessee Valley Authority (TVA or the applicant) for licenses to operate the Watts Bar Nuclear Plant, Units 1 and 2. Each of the following sections and appendices of this supplement is numbered the same as the section or appendix of the SER that is being updated, and the discussions are supplementary to, and not in lieu of, the discussion in the SER, unless otherwise noted. Accordingly, Appendix A continues the chronology of the safety review. Appendix E lists principal contributors to this supplement. Appendix FF is added in this supplement. The other appendices are not changed by this supplement.

  19. Watts-level super-compact narrow-linewidth Tm-doped silica all-fiber laser near 1707 nm with fiber Bragg gratings

    Science.gov (United States)

    Xiao, X. S.; Guo, H. T.; Lu, M.; Yan, Z. J.; Wang, H. S.; Wang, Y. S.; Xu, Y. T.; Gao, C. X.; Cui, X. X.; Guo, Q.; Peng, B.

    2016-11-01

    Watts-level ultra-short wavelength operation of a Tm-doped all fiber laser was developed by using a 1550 nm Er-doped fiber laser pump source and a pair of fiber Bragg gratings (FBGs). The laser yielded 1.28 W of continuous-wave output at 1707.01 nm with a narrow linewidth of ~44 pm by means of a 20 cm Tm-doped fiber. The dependencies of the slope efficiencies and pump threshold of the Tm-doped fiber laser versus the length of active fiber and reflectivity of the output mirror (FBG) were investigated in detail, in which the maximum average slope efficiency was 36.1%. There is no doubt that this all fiber laser will be a perfect pump source for mid-IR laser output.

  20. Determination of the Planck constant using a watt balance with a superconducting magnet system at the National Institute of Standards and Technology

    CERN Document Server

    Schlamminger, Stephan; Seifert, Frank; Chao, Leon S; Newell, David B; Liu, Ruimin; Steiner, Richard L; Pratt, Jon R

    2014-01-01

    For the past two years, measurements have been performed with a watt balance at the National Institute of Standards and Technology (NIST) to determine the Planck constant. A detailed analysis of these measurements and their uncertainties has led to the value $h=6.626\\,069\\,79(30)\\times 10^{-34}\\,$J$\\,$s. The relative standard uncertainty is $ 45\\times 10^{-9}$. This result is $141\\times 10^{-9}$ fractionally higher than $h_{90}$. Here $h_{90}$ is the conventional value of the Planck constant given by $h_{90}\\equiv 4 /( K_{\\mathrm{J-90}}^2R_{\\mathrm{K-90}})$, where $K_{\\mathrm{J-90}}$ and $R_{\\mathrm{K-90}}$ denote the conventional values of the Josephson and von Klitzing constants, respectively.

  1. Watt-level erbium-doped all-fiber laser at 3.44 μm.

    Science.gov (United States)

    Fortin, Vincent; Maes, Frédéric; Bernier, Martin; Bah, Souleymane Toubou; D'Auteuil, Marc; Vallée, Réal

    2016-02-01

    We demonstrate a 3.44 μm all-fiber laser emitting a maximum of 1.5 W at room temperature, the highest continuous power ever generated from a mid-IR fiber oscillator clearly beyond 3 μm. The laser operates on the 4F(9/2)→4I(9/2) transition of erbium-doped fluoride glasses and relies on a dual pumping scheme at 974 and 1976 nm. By combining a dichroic mirror deposited on the input fiber tip and a fiber Bragg grating as an output coupler, a stable laser emission is produced with a FWHM bandwidth of less than 0.6 nm. The laser cavity has an efficiency of 19% with respect to the launched pump power at 1976 nm and no saturation is observed provided 974 nm co-pumping is sufficient. The joint effect of the two pumps is also investigated.

  2. Sustainable development - billions of watts under the seas - Marine current turbines play simple - Technological waves; Developpement durable - Des milliards de watts sous les mers - Les hydroliennes jouent la simplicite - Vagues technologiques

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, Th.

    2011-10-27

    The author evokes the opportunities of power generation by the development of sea current or tidal stream turbines. Some developments are already tested by Norwegian, French, Danish, British and American companies. Some specific turbines are briefly presented. In order to reduce the cost of the electricity production from sea currents, manufacturers are using simple and robust technologies, and exploit the experience gained on wind turbines. Some designs and prototypes are evoked for the production of electricity by sea waves (Pelamis and Oyster projects). Principles, strengths and production projects are briefly indicated. The challenge of maintenance in sea environment is outlined for these projects

  3. Linearization and efficiency enhancement of power amplifiers using digital predistortion

    Energy Technology Data Exchange (ETDEWEB)

    Safari, Nima

    2008-07-01

    Today, demand of higher spectral efficiency forces wireless communication systems to employ non-constant envelope modulation schemes such as Quadrature Amplitude Modulations (QAM), Code Division Multiple Access (CDMA) and Orthogonal Frequency-Division Multiplexing (OFDM) schemes. These modulation techniques generate signals with wide range of envelope fluctuation. This property makes these schemes sensitive to nonlinear amplifications. Nonlinearities introduced by Power Amplifiers (PA) cause both a distortion of the signal and an increased out of band output spectrum, which leads to a rise in adjacent channel interference. Thus, in order to ensure a high spectral efficiency and to avoid spectral regrowth, a linearization technique is required. Among all the linearization techniques, basedband Digital Predistortion (DPD) is one of the commonly used linearization techniques, which is characterized by robust operation, low implementation cost and high accuracy. In the first chapter of this thesis, an introduction on the motivation and necessity of using PA linearization techniques is presented. Digital Predistortion as a popular linearization technique aims to improve the efficiency and linearity of RF power amplifiers. The scope of the thesis, the goals to be achieved and the contributions are also discussed in chapter one. Chapter two, mainly discusses sample-by-sample updating algorithm in Digital Predistorters to adaptively linearize the PA memoryless nonlinearities. Look-up Table (LUT) and polynomial approaches are studied and implemented in Hardware using a test-bed provided by Nera Research. The experimental results together with a discussion are then given. A new DPD algorithm based on block estimation is proposed in chapter three to avoid realtime signal processing, reduce the complexity and also avoid the bad performance during the slow adaptation of adaptive the Adjacent Channel Power Ratio (ACPR) and the Error Vector Magnitude (EVM) requirements. In

  4. Wind-powered asynchronous AC/DC/AC converter system. [for electric power supply regulation

    Science.gov (United States)

    Reitan, D. K.

    1973-01-01

    Two asynchronous ac/dc/ac systems are modelled that utilize wind power to drive a variable or constant hertz alternator. The first system employs a high power 60-hertz inverter tie to the large backup supply of the power company to either supplement them from wind energy, storage, or from a combination of both at a preset desired current; rectifier and inverter are identical and operate in either mode depending on the silicon control rectifier firing angle. The second system employs the same rectification but from a 60-hertz alternator arrangement; it provides mainly dc output, some sinusoidal 60-hertz from the wind bus and some high harmonic content 60-hertz from an 800-watt inverter.

  5. Millimeterwave Space Power Grid architecture development 2012

    Science.gov (United States)

    Komerath, Narayanan; Dessanti, Brendan; Shah, Shaan

    This is an update of the Space Power Grid architecture for space-based solar power with an improved design of the collector/converter link, the primary heater and the radiator of the active thermal control system. The Space Power Grid offers an evolutionary approach towards TeraWatt-level Space-based solar power. The use of millimeter wave frequencies (around 220GHz) and Low-Mid Earth Orbits shrinks the size of the space and ground infrastructure to manageable levels. In prior work we showed that using Brayton cycle conversion of solar power allows large economies of scale compared to the linear mass-power relationship of photovoltaic conversion. With high-temperature materials permitting 3600 K temperature in the primary heater, over 80 percent cycle efficiency was shown with a closed helium cycle for the 1GW converter satellite which formed the core element of the architecture. Work done since the last IEEE conference has shown that the use of waveguides incorporated into lighter-than-air antenna platforms, can overcome the difficulties in transmitting millimeter wave power through the moist, dense lower atmosphere. A graphene-based radiator design conservatively meets the mass budget for the waste heat rejection system needed for the compressor inlet temperature. Placing the ultralight Mirasol collectors in lower orbits overcomes the solar beam spot size problem of high-orbit collection. The architecture begins by establishing a power exchange with terrestrial renewable energy plants, creating an early revenue generation approach with low investment. The approach allows for technology development and demonstration of high power millimeter wave technology. A multinational experiment using the International Space Station and another power exchange satellite is proposed to gather required data and experience, thus reducing the technical and policy risks. The full-scale architecture deploys pairs of Mirasol sunlight collectors and Girasol 1 GW converter satellites t

  6. 1.34 µm picosecond self-mode-locked Nd:GdVO4 watt-level laser

    Science.gov (United States)

    Han, Ming; Peng, Jiying; Li, Zuohan; Cao, Qiuyuan; Yuan, Ruixia

    2017-01-01

    With a simple linear configuration, a diode-pumped, self-mode-locked Nd:GdVO4 laser at 1.34 µm is experimentally demonstrated for the first time. Based on the aberrationless theory of self-focusing and thermal lensing effect, through designing and optimizing the resonator, a pulse width as short as 9.1 ps is generated at a repetition rate of 2.0 GHz and the average output power is 2.51 W. The optical conversion efficiency and the slope efficiency for the stable mode-locked operation are approximately 16.7% and 19.2%, respectively.

  7. Wind power systems in the MW range. Part 2. Digital control of a double-fed asynchronous generator without position control; Windkraftanlagen fuer den Megawatt-Bereich. Teil 2. Digitale Steuerung eines doppelt gespeisten Asynchrongenerators ohne Lagegeber

    Energy Technology Data Exchange (ETDEWEB)

    Ehrenberg, J. [sci-worx GmbH, Braunschweig (Germany); Andresen, B.; Rebsdorf, A.V. [Vestas Wind Systems A/S (Denmark)

    2001-09-18

    While the first part investigated the characteristics of synchronous and asynchronous generators for wind power system development and presented theoretical fundamentals, part 2 discusses practical problems of synchronisation with the network and interpretation of measurements as illustrated by a prototype 2 MW wind power plant. [German] Nach einem Vergleich der Eignung von Synchron- und Asynchrongeneratoren fuer die Konzeption von Windkraftanlagen und einer Darstellung der Theoretischen Grundlagen im Teil 1 widmet sich der zweite Teil des Beitrages den praktischen Fragen der Synchronisation zum Netz und der Interpretation der Messergebnisse an dem Prototyp einer 2-MW-Windkraftanlage. (org.)

  8. JV Task 46 - Development and Testing of a Thermally Integrated SOFC-Gasification System for Biomass Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Phillip Hutton; Nikhil Patel; Kyle Martin; Devinder Singh

    2008-02-01

    The Energy & Environmental Research Center has designed a biomass power system using a solid oxide fuel cell (SOFC) thermally integrated with a downdraft gasifier. In this system, the high-temperature effluent from the SOFC enables the operation of a substoichiometric air downdraft gasifier at an elevated temperature (1000 C). At this temperature, moisture in the biomass acts as an essential carbon-gasifying medium, reducing the equivalence ratio at which the gasifier can operate with complete carbon conversion. Calculations show gross conversion efficiencies up to 45% (higher heating value) for biomass moisture levels up to 40% (wt basis). Experimental work on a bench-scale gasifier demonstrated increased tar cracking within the gasifier and increased energy density of the resultant syngas. A series of experiments on wood chips demonstrated tar output in the range of 9.9 and 234 mg/m{sup 3}. Both button cells and a 100-watt stack was tested on syngas from the gasifier. Both achieved steady-state operation with a 22% and 15% drop in performance, respectively, relative to pure hydrogen. In addition, tar tolerance testing on button cells demonstrated an upper limit of tar tolerance of approximately 1%, well above the tar output of the gasifier. The predicted system efficiency was revised down to 33% gross and 27% net system efficiency because of the results of the gasifier and fuel cell experiments. These results demonstrate the feasibility and benefits of thermally integrating a gasifier and a high-temperature fuel cell in small distributed power systems.

  9. Solid state RF power: The route to 1W per euro cent

    Energy Technology Data Exchange (ETDEWEB)

    Heid, Oliver [Siemens AG, Mozartstrasse 57, Erlangen (Germany)

    2013-04-19

    In most particle accelerators RF power is a decisive design constraint due to high costs and relative inflexibility of current electron beam based RF sources, i.e. Klystrons, Magnetrons, Tetrodes etc. At VHF/UHF frequencies the transition to solid state devices promises to fundamentally change the situation. Recent progress brings 1 Watt per Euro cent installed cost within reach. We present a Silicon Carbide semiconductor solution utilising the Solid State Direct Drive technology at unprecedented efficiency, power levels and power densities. The proposed solution allows retrofitting of existing RF accelerators and opens the route to novel particle accelerator concepts.

  10. Thin-Film Thermoelectric Module for Power Generator Applications Using a Screen-Printing Method

    Science.gov (United States)

    Lee, Heon-Bok; Yang, Hyun Jeong; We, Ju Hyung; Kim, Kukjoo; Choi, Kyung Cheol; Cho, Byung Jin

    2011-05-01

    A new process for fabricating a low-cost thermoelectric module using a screen-printing method has been developed. Thermoelectric properties of screen-printed ZnSb films were investigated in an effort to develop a thermoelectric module with low cost per watt. The screen-printed Zn x Sb1- x films showed a low carrier concentration and high Seebeck coefficient when x was in the range of 0.5 to 0.57 and the annealing temperature was kept below 550°C. When the annealing temperature was higher than 550°C, the carrier concentration of the Zn x Sb1- x films reached that of a metal, leading to a decrease of the Seebeck coefficient. In the present experiment, the optimized carrier concentration of screen-printed ZnSb was 7 × 1018/cm3. The output voltage and power density of the ZnSb film were 10 mV and 0.17 mW/cm2, respectively, at Δ T = 50 K. A thermoelectric module was produced using the proposed screen-printing approach with ZnSb and CoSb3 as p-type and n-type thermoelectric materials, respectively, and copper as the pad metal.

  11. Navigation on Power-Law Small World Network with Incomplete Information

    Institute of Scientific and Technical Information of China (English)

    CHEN Jian-Zhen; ZHU Jian-Yang

    2007-01-01

    We investigate the navigation process on a variant of the Watts-Strogatz small-world network model with local information. In the network construction, each vertex of an N × N square lattice sends out a long-range link with probability p. The other end of the link falls on a randomly chosen vertex with probability proportional to r-α, where r is the lattice distance between the two vertices, and α ≥ 0. The average actual path length,i.e. the expected number of steps for passing messages between randomly chosen vertex pairs, is found to scale as a power-law function of the network size Nβ, except when α is close to a specific value αmin, which gives the highest efficiency of message navigation. For a finite network, the exponent β depends on both α and p, and αmin drops to zero at a critical value of p which depends on N. When the network size goes to infinity,β depends only on α, and αmin is equal to the network dimensionality.

  12. Range Distribution Parameters and Electronic Stopping Power for 19F+ Ions in SnO2, Indium-Tin Oxide, AgGaSe2 and AgGaS2:Comparison Between Theory and Experiment

    Institute of Scientific and Technical Information of China (English)

    XIA Hui-Hao; LIU Xiang-Dong

    2004-01-01

    @@ Range distributions of fluorine for 19F+- implantation into SnO2, indium-tin oxide, AgGaS2 and AgGaSe2 are measured by using the 1gF(p,αγ)16O resonant nuclear reactions. The electronic stopping cross sections for 19F ions in these materials are derived from the measured range distributions. These experimental results are compared with those obtained from the newest version of stopping and range computer code, SRIM2003. The values of projected range predicted by the SRIM2003 agree well with the measured values for AgGaS2 and AgGaSe2 substrates. However, the values given by the SRIM2003 substantially deviate from the experimental values for the oxide materials SnO2 and ITO.

  13. Wind power systems of the MW range. Digital control of a double-fed asynchronous generator without position indicator; Windkraftanlagen fuer den Megawatt-Bereich. Teil 1. Digitale Steuerung eines doppelt gespeisten Asynchrongenerators ohne Lagegeber

    Energy Technology Data Exchange (ETDEWEB)

    Ehrenberg, J. [sci-worx GmbH, Braunschweig (Germany); Andresen, B.; Rebsdorf, A.V. [Vestas Wind Systems A/S (Denmark). R and D Dept.

    2001-09-04

    The marketing chances of wind power systems are getting better as fossil fuels are getting shorter. Vestas Wind Systems A/S relies on sci-worx GmbH for the development of control systems for their new generation of wind power plants. [German] Ausgeloest durch die Oelkrise und angesichts der begrenzten Ressourcen der fossilen Energietraeger begann man vor gut zehn Jahren, vermehrt ueber den moeglichen Einsatz von regenerativen Energiequellen zur Stromerzeugung nachzudenken. Vor allem der Windenergie kommt dabei eine grosse Bedeutung zu, weil sie mit relativ hohem Wirkungsgrad in elektrische Energie umgewandelt werden kann. Im Rahmen dieses Trends beauftragte die Vestas Wind Systems A/S, als Hersteller von Windkraftanlagen, die sci-worx GmbH mit der Entwicklung von Regelung und Steuergeraet fuer ihre neueste Anlagengeneration. (orig.)

  14. Performance/Power Space Exploration for Binary64 Division Units

    DEFF Research Database (Denmark)

    Nannarelli, Alberto

    2016-01-01

    The digit-recurrence division algorithm is used in several high-performance processors because it provides good tradeoffs in terms of latency, area and power dissipation. In this work we develop a minimally redundant radix-8 divider for binary64 (double-precision) aiming at obtaining better energ...... efficiency in the performance-per-watt space. The results show that the radix-8 divider, when compared to radix-4 and radix-16 units, requires less energy to complete a division for high clock rates....

  15. Development of a solar charged laboratory bench power supply

    Science.gov (United States)

    Ayara, W. A.; Omotosho, T. V.; Usikalu, M. R.; Singh, M. S. J.; Suparta, W.

    2017-05-01

    This product is an improvement on available DC laboratory bench power supply. It is capable of delivering low voltage Alternating Current (AC) and Direct Current (DC) to carry out basic laboratory experiment for both secondary schools and also at higher education institutions. The power supply is capable of delivering fixed DC voltages of 5V, 9V, 12V, variable voltage of between 1.25-30V and a 12V AC voltage. Also Incorporated is a USB port that allows for charging cell phones and other mobile devices, and a dedicated 12V DC output to power 5-7 Watt LED bulb to provide illumination in the laboratory for the instructor who may need to work at night in the absence of utility power.

  16. Solid state radioisotopic energy converter for space nuclear power

    Energy Technology Data Exchange (ETDEWEB)

    Brown, P.M. (IsoGen Radioisotopic Research Laboratory, 315 S. McLoughlin Blvd., Oregon City, Oregon 97045 (United States))

    1993-01-10

    Recent developments in materials technology now make it possible to fabricate nonthermal thin-film radioisotopic energy converters (REC) with a specific power of 24 W/kg and a 10 year working life at 5 to 10 watts. This creates applications never before possible, such as placing the power supply directly on integrated circuit chips. The efficiency of the REC is about 25% which is two to three times greater than the 6 to 8% capabilities of current thermoelectric systems. Radioisotopic energy converters have the potential to meet many future space power requirements for a wide variety of applications with less mass, better efficiency, and less total area than other power conversion options. These benefits result in significant dollar savings over the projected mission lifetime.

  17. Improving Advanced Inverter Control Convergence in Distribution Power Flow

    Energy Technology Data Exchange (ETDEWEB)

    Nagarajan, Adarsh; Palmintier, Bryan; Ding, Fei; Mather, Barry; Baggu, Murali

    2016-11-21

    Simulation of modern distribution system powerflow increasingly requires capturing the impact of advanced PV inverter voltage regulation on powerflow. With Volt/var control, the inverter adjusts its reactive power flow as a function of the point of common coupling (PCC) voltage. Similarly, Volt/watt control curtails active power production as a function of PCC voltage. However, with larger systems and higher penetrations of PV, this active/reactive power flow itself can cause significant changes to the PCC voltage potentially introducing oscillations that slow the convergence of system simulations. Improper treatment of these advanced inverter functions could potentially lead to incorrect results. This paper explores a simple approach to speed such convergence by blending in the previous iteration's reactive power estimate to dampen these oscillations. Results with a single large (5MW) PV system and with multiple 500kW advanced inverters show dramatic improvements using this approach.

  18. Design and evaluation of laser diodes with distributed bragg reflectors and diffracted waves amplifiers bound to their association into a powerful coherent source; Conception et Evaluation de Diodes Laser a Reflecteurs de Bragg Distribues et d`amplificateurs a onde Diffractee et vue de leur Association en une Source Coherente de Puissance

    Energy Technology Data Exchange (ETDEWEB)

    Dagens, B.

    1995-09-29

    This work is concerned with the evaluation of AlGaAs/GaAs MOPAs (Master Oscillator Power Amplifier) based on the association of a distributed Bragg reflector (DBR) quantum well laser diode with an optical power amplifier. For any given structure and incident wave, the software SIMLAS allows to describe the behaviour of a travelling wave amplifier and to obtain its working characteristics including the output power, the amplified spontaneous emission and the quality of the output beam. This model takes into account the nonlinear interaction between the wave, the injected carriers distribution and the complex index of the structure. The application of the software to a flared non-guided amplified shows that the output power associated with a good beam quality is limited to a range less than one watt. Then a new design is proposed to greatly improve this performance. The modelling software of the DBR laser takes into account wave propagation in a second-order grating structure and the gain and absorption properties in the quantum well. Thus, the output optical power, efficiency, threshold current and model discrimination of the device can be predicted. The model has been used to establish the definition of design criteria in order to promote edge emission relative to surface emission. Finally the fabrication of each device is established. Special attention is paid to the design of the grating region. The fabrication process is validated by the prototypes performance. (author) refs.

  19. The Inertial Stellar Compass (ISC): A Multifunction, Low Power, Attitude Determination Technology Breakthrough

    Science.gov (United States)

    Bauer, Frank H. (Technical Monitor); Dennehy, Neil; Gambino, Joel; Maynard, Andrew; Brady, T.; Buckley, S.; Zinchuk, J.

    2003-01-01

    The Inertial Stellar Compass (ISC) is a miniature, low power, stellar inertial attitude determination system with an accuracy of better than 0.1 degree (1 sigma) in three axes. The ISC consumes only 3.5 Watts of power and is contained in a 2.5 kg package. With its embedded on-board processor, the ISC provides attitude quaternion information and has Lost-in-Space (LIS) initialization capability. The attitude accuracy and LIS capability are provided by combining a wide field of view Active Pixel Sensor (APS) star camera and Micro- ElectroMechanical System (MEMS) inertial sensor information in an integrated sensor system. The performance and small form factor make the ISC a useful sensor for a wide range of missions. In particular, the ISC represents an enabling, fully integrated, micro-satellite attitude determination system. Other applications include using the ISC as a single sensor solution for attitude determination on medium performance spacecraft and as a bolt on independent safe-hold sensor or coarse acquisition sensor for many other spacecraft. NASA's New Millennium Program (NMP) has selected the ISC technology for a Space Technology 6 (ST6) flight validation experiment scheduled for 2004. NMP missions, such a s ST6, are intended to validate advanced technologies that have not flown in space in order to reduce the risk associated with their infusion into future NASA missions. This paper describes the design, operation, and performance of the ISC and outlines the technology validation plan. A number of mission applications for the ISC technology are highlighted, both for the baseline ST6 ISC configuration and more ambitious applications where ISC hardware and software modifications would be required. These applications demonstrate the wide range of Space and Earth Science missions that would benefit from infusion of the ISC technology.

  20. Electric power systems

    CERN Document Server

    Weedy, B M; Jenkins, N; Ekanayake, J B; Strbac, G

    2012-01-01

    The definitive textbook for Power Systems students, providing a grounding in essential power system theory while also focusing on practical power engineering applications. Electric Power Systems has been an essential book in power systems engineering for over thirty years. Bringing the content firmly up-to-date whilst still retaining the flavour of Weedy's extremely popular original, this Fifth Edition has been revised by experts Nick Jenkins, Janaka Ekanayake and Goran Strbac. This wide-ranging text still covers all of the fundamental power systems subjects but is now e