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Sample records for conventional high power

  1. High power microwave system based on power combining and pulse compression of conventional klystrons

    CERN Document Server

    Xiong, Zheng-Feng; Cheng, Cheng; Ning, Hui; Tang, Chuan-Xiang

    2015-01-01

    A high power microwave system based on power combining and pulse compression of conventional klystrons is introduced in this paper. This system mainly consists of pulse modulator, power combiner, driving source of klystrons and pulse compressor. A solid state induction modulator and pulse transformer were used to drive two 50 MW S-band klystrons with pulse widths 4 {\\mu}s in parallel, after power combining and pulse compression, the tested peak power had reached about 210 MW with pulse widths nearly 400 ns at 25 Hz, while the experimental maximum output power was just limited by the power capacity of loads. This type of high power microwave system has widely application prospect in RF system of large scale particle accelerators, high power radar transmitters and high level electromagnetic environment generators.

  2. First Aspect of Conventional Power System Assessment for High Wind Power Plants Penetration

    Directory of Open Access Journals (Sweden)

    A Merzic

    2012-11-01

    Full Text Available Most power systems in underdeveloped and developing countries are based on conventional power plants, mainly "slow-response" thermal power plants and a certain number of hydro power plants; characterized by inflexible generating portfolios and traditionally designed to meet own electricity needs. Taking into account operational capabilities of conventional power systems, their development planning will face problems with integration of notable amounts of installed capacities in wind power plants (WPP. This is what highlights the purpose of this work and in that sense, here, possible variations of simulated output power from WPP in the 10 minute and hourly time interval, which need to be balanced, are investigated, presented and discussed. Comparative calculations for the amount of installed power in WPP that can be integrated into a certain power system, according to available secondary balancing power amounts, in case of concentrated and dispersed future WPP are given. The stated has been done using a part of the power system of Bosnia and Herzegovina. In the considered example, by planned geographically distributed WPP construction, even up to cca. 74% more in installed power of WPP can be integrated into the power system than in case of geographically concentrated WPP construction, for the same available amount of (secondary balancing power. These calculations have shown a significant benefit of planned, geographically distributed WPP construction, as an important recommendation for the development planning of conventional power systems, with limited balancing options. Keywords: balancing reserves,  geographical dispersion, output power  variations

  3. A non-conventional ERL configuration for high-power EUV FELs

    Energy Technology Data Exchange (ETDEWEB)

    Venturini, M., E-mail: mventurini@lbl.gov; Penn, G.

    2015-09-21

    We show that a standard Linac configuration (consisting of accelerating sections, linearizing section, and magnetic chicane compressor) currently used in drivers for single-pass EUV/x-ray FELs is compatible with energy recovery, provided that certain timing constraints are met. By circulating the spent, rather than the fresh beam as in a conventional high-power ERL FEL design, the beam brightness can be more easily preserved thus facilitating lasing at short wavelength. As in a conventional ERL, the proposed design allows for energy-spread compression, enabling low-energy beam dumping and high energy-recovery efficiency. Results from numerical simulations presented in this paper show that this configuration could, in principle, support the generation of multi-kW average radiation power required for high-volume production EUV lithography.

  4. Comparison of Bond Strength of Metal and Ceramic Brackets Bonded with Conventional and High-Power LED Light Curing Units

    Science.gov (United States)

    Chalipa, Javad; Jalali, Yasamin Farajzadeh; Gorjizadeh, Fatemeh; Baghaeian, Pedram; Hoseini, Mohammad Hashem

    2016-01-01

    Objectives: The aim of this study was to evaluate the effect of conventional and high-power light emitting diode (LED) light curing units on shear bond strength (SBS) of metal and ceramic brackets to tooth surface. Materials and Methods: Forty sound bovine maxillary central incisors were used for the study. The teeth were divided into four groups (n=10). Teeth surfaces were etched with 37% phosphoric acid for 20 seconds. After applying a uniform layer of adhesive primer on the etched enamel, composite was placed on the base of brackets. The samples were light cured according to the manufacturer’s instructions and thermocycled. The SBS was measured. The failure mode was scored using the adhesive remnant index (ARI). Results: The mean SBS of samples in groups A (high-power LED, metal bracket), B (high-power LED, ceramic bracket), C (conventional LED, metal bracket) and D (conventional LED, ceramic bracket) was 23.1±3.69, 10.7±2.06, 24.92±6.37 and 10.74±3.18MPa, respectively. The interaction effect of type of LED unit (high-power/conventional) and bracket type on SBS was not statistically significant (P=0.483). In general, type of LED unit did not affect SBS. Type of bracket significantly affected SBS (P<0.001). The ARI score was not significantly influenced by the interaction between the type of LED unit and bracket. Conclusions: The obtained SBS is the same for both bracket types by use of high-power and conventional LED light curing units. Regardless of the type of LED unit, SBS of ceramic brackets was significantly lower than that of metal brackets.

  5. High power microwaves

    CERN Document Server

    Benford, James; Schamiloglu, Edl

    2016-01-01

    Following in the footsteps of its popular predecessors, High Power Microwaves, Third Edition continues to provide a wide-angle, integrated view of the field of high power microwaves (HPMs). This third edition includes significant updates in every chapter as well as a new chapter on beamless systems that covers nonlinear transmission lines. Written by an experimentalist, a theorist, and an applied theorist, respectively, the book offers complementary perspectives on different source types. The authors address: * How HPM relates historically and technically to the conventional microwave field * The possible applications for HPM and the key criteria that HPM devices have to meet in order to be applied * How high power sources work, including their performance capabilities and limitations * The broad fundamental issues to be addressed in the future for a wide variety of source types The book is accessible to several audiences. Researchers currently in the field can widen their understanding of HPM. Present or pot...

  6. A Study of Conventional and Unconventional RADIAC Power Sources.

    Science.gov (United States)

    Feasible substitutes for RADIAC power sources are identified and evaluated. The experimental methods and the results are described. Cautions that...should be observed in the selection of RADIAC power sources are described. Cost comparisons are made of power sources considered to be suitable D-cell...substitutes and conventional D-cells. Recommendations are made for RADIAC power sources and for further study topics. (Author)

  7. Second law analysis of a conventional steam power plant

    Science.gov (United States)

    Liu, Geng; Turner, Robert H.; Cengel, Yunus A.

    1993-01-01

    A numerical investigation of exergy destroyed by operation of a conventional steam power plant is computed via an exergy cascade. An order of magnitude analysis shows that exergy destruction is dominated by combustion and heat transfer across temperature differences inside the boiler, and conversion of energy entering the turbine/generator sets from thermal to electrical. Combustion and heat transfer inside the boiler accounts for 53.83 percent of the total exergy destruction. Converting thermal energy into electrical energy is responsible for 41.34 percent of the total exergy destruction. Heat transfer across the condenser accounts for 2.89 percent of the total exergy destruction. Fluid flow with friction is responsible for 0.50 percent of the total exergy destruction. The boiler feed pump turbine accounts for 0.25 percent of the total exergy destruction. Fluid flow mixing is responsible for 0.23 percent of the total exergy destruction. Other equipment including gland steam condenser, drain cooler, deaerator and heat exchangers are, in the aggregate, responsible for less than one percent of the total exergy destruction. An energy analysis is also given for comparison of exergy cascade to energy cascade. Efficiencies based on both the first law and second law of thermodynamics are calculated for a number of components and for the plant. The results show that high first law efficiency does not mean high second law efficiency. Therefore, the second law analysis has been proven to be a more powerful tool in pinpointing real losses. The procedure used to determine total exergy destruction and second law efficiency can be used in a conceptual design and parametric study to evaluate the performance of other steam power plants and other thermal systems.

  8. Second law analysis of a conventional steam power plant

    Science.gov (United States)

    Liu, Geng; Turner, Robert H.; Cengel, Yunus A.

    1993-11-01

    A numerical investigation of exergy destroyed by operation of a conventional steam power plant is computed via an exergy cascade. An order of magnitude analysis shows that exergy destruction is dominated by combustion and heat transfer across temperature differences inside the boiler, and conversion of energy entering the turbine/generator sets from thermal to electrical. Combustion and heat transfer inside the boiler accounts for 53.83 percent of the total exergy destruction. Converting thermal energy into electrical energy is responsible for 41.34 percent of the total exergy destruction. Heat transfer across the condenser accounts for 2.89 percent of the total exergy destruction. Fluid flow with friction is responsible for 0.50 percent of the total exergy destruction. The boiler feed pump turbine accounts for 0.25 percent of the total exergy destruction. Fluid flow mixing is responsible for 0.23 percent of the total exergy destruction. Other equipment including gland steam condenser, drain cooler, deaerator and heat exchangers are, in the aggregate, responsible for less than one percent of the total exergy destruction. An energy analysis is also given for comparison of exergy cascade to energy cascade. Efficiencies based on both the first law and second law of thermodynamics are calculated for a number of components and for the plant. The results show that high first law efficiency does not mean high second law efficiency. Therefore, the second law analysis has been proven to be a more powerful tool in pinpointing real losses. The procedure used to determine total exergy destruction and second law efficiency can be used in a conceptual design and parametric study to evaluate the performance of other steam power plants and other thermal systems.

  9. Frequency control in power systems with high wind power penetration

    Energy Technology Data Exchange (ETDEWEB)

    Tarnowski, German Claudio [Technical Univ. of Denmark (Denmark). Centre for Electric Technology; Vestas Wind Systems A/S, Alsve (Denmark); Kjaer, Philip Carne [Vestas Wind Systems A/S, Alsve (Denmark); Oestergaard, Jacob [Technical Univ. of Denmark (Denmark). Centre for Electric Technology; Soerensen, Poul E. [Risoe National Laboratory for Sustainable Energy, Roskilde (Denmark). Wind Energy Dept.

    2010-07-01

    The fluctuating nature of wind power introduces several challenges to reliable operation of power system. With high wind power penetration, conventional power plants are displaced and wind speed fluctuations introduce large power imbalances which lead to power system frequency control and operational problems. This paper analysis the impact of wind power in the frequency control of power systems for different amount of controllable variable speed wind turbines. Real measurements from short term wind power penetration tests in a power system are shown and used to study the amount of total regulating power needed from conventional power plants. Dynamic simulations with validated model of the power system support the studies. The paper also presents control concepts for wind power plants necessary to achieve characteristic of frequency response and active power balancing similarly to conventional power plants, therefore allowing higher wind power penetration. As the power system dependency on wind power increases, wind power generation has to contribute with dynamic response and control actions similarly to conventional power plants. (orig.)

  10. Optimizing efficiency on conventional transformer based low power AC/DC standby power supplies

    DEFF Research Database (Denmark)

    Nielsen, Nils

    2004-01-01

    This article describes the research results for simple and cheap methods to reduce the idle- and load-losses in very low power conventional transformer based power supplies intended for standby usage. In this case "very low power" means 50 Hz/230 V-AC to 5 V-DC@1 W. The efficiency is measured...... on two common power supply topologies designed for this power level. The two described topologies uses either a series (or linear) or a buck regulation approach. Common to the test power supplies is they either are using a standard cheap off-the-shelf transformer, or one, which are loss optimized by very...

  11. High Power Factor Power Design

    Directory of Open Access Journals (Sweden)

    Zhang Jing-yi

    2013-07-01

    Full Text Available The PFC circuit takes UCC28019 made by TI Company as the core of system control, realize the power factor correction circuit functions, and the circuit power factor can be measured. Through a variety of detection circuit, with the support SCM control. And 30V~36V output voltage regulator can be set; with over-current protection circuits function, and be able to automatically back. Output current, voltage, and little significant value are displayed by display modules.

  12. High power fiber lasers

    Institute of Scientific and Technical Information of China (English)

    LOU Qi-hong; ZHOU Jun

    2007-01-01

    In this review article, the development of the double cladding optical fiber for high power fiber lasers is reviewed. The main technology for high power fiber lasers, including laser diode beam shaping, fiber laser pumping techniques, and amplification systems, are discussed in de-tail. 1050 W CW output and 133 W pulsed output are ob-tained in Shanghai Institute of Optics and Fine Mechanics, China. Finally, the applications of fiber lasers in industry are also reviewed.

  13. Resonant High Power Combiners

    CERN Document Server

    Langlois, Michel; Peillex-Delphe, Guy

    2005-01-01

    Particle accelerators need radio frequency sources. Above 300 MHz, the amplifiers mostly used high power klystrons developed for this sole purpose. As for military equipment, users are drawn to buy "off the shelf" components rather than dedicated devices. IOTs have replaced most klystrons in TV transmitters and find their way in particle accelerators. They are less bulky, easier to replace, more efficient at reduced power. They are also far less powerful. What is the benefit of very compact sources if huge 3 dB couplers are needed to combine the power? To alleviate this drawback, we investigated a resonant combiner, operating in TM010 mode, able to combine 3 to 5 IOTs. Our IOTs being able to deliver 80 kW C.W. apiece, combined power would reach 400 kW minus the minor insertion loss. Values for matching and insertion loss are given. The behavior of the system in case of IOT failure is analyzed.

  14. Switching power converters medium and high power

    CERN Document Server

    Neacsu, Dorin O

    2013-01-01

    An examination of all of the multidisciplinary aspects of medium- and high-power converter systems, including basic power electronics, digital control and hardware, sensors, analog preprocessing of signals, protection devices and fault management, and pulse-width-modulation (PWM) algorithms, Switching Power Converters: Medium and High Power, Second Edition discusses the actual use of industrial technology and its related subassemblies and components, covering facets of implementation otherwise overlooked by theoretical textbooks. The updated Second Edition contains many new figures, as well as

  15. Life-cycle cost analysis of conventional and fuel cell/battery powered urban passenger vehicles

    Science.gov (United States)

    1992-11-01

    This Final Report summarizes the work on the life cycle cost (LCC) analysis of conventional and fuel cell/battery powered urban passenger vehicles. The purpose of the work is to support the Division in making sound economic comparisons between conventional and fuel cell/battery powered buses, passenger vans, and cars for strategic analysis of programmatic R&D goals. The LCC analysis can indicate whether paying a relatively high initial capital cost for advanced technology with low operating and/or environmental costs is advantageous over paying a lower initial cost for conventional technology with higher operating and/or environmental costs. While minimizing life cycle cost is an important consideration, it does not always result in technology penetration in the marketplace. The LCC analysis model developed under this contract facilitates consideration of all perspectives. Over 100 studies have been acquired and analyzed for their applicability. Drawing on prior work by JPL and Los Alamos National Laboratory as primary sources, specific analytical relationships and cost/performance data relevant to fuel cell/battery and intemal combustion engine (ICE) powered vehicles were selected for development of an LCC analysis model. The completed LCC model is structured around twelve integrated modules. Comparative analysis is made between conventional gasoline and diesel vehicles and fuel cell/battery vehicles using either phosphoric acid fuel cells or proton-exchange membrane fuel cells. In all, seven base vehicle configuration cases with a total of 21 vehicle class/powertrain/fuel combinations are analyzed. The LCC model represents a significant advance in comparative economic analysis of conventional and fuel cell/battery powered vehicle technologies embodying several unique features which were not included in prior models.

  16. High Power Cryogenic Targets

    Energy Technology Data Exchange (ETDEWEB)

    Gregory Smith

    2011-08-01

    The development of high power cryogenic targets for use in parity violating electron scattering has been a crucial ingredient in the success of those experiments. As we chase the precision frontier, the demands and requirements for these targets have grown accordingly. We discuss the state of the art, and describe recent developments and strategies in the design of the next generation of these targets.

  17. High temperature, high power piezoelectric composite transducers.

    Science.gov (United States)

    Lee, Hyeong Jae; Zhang, Shujun; Bar-Cohen, Yoseph; Sherrit, Stewart

    2014-08-08

    Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have led to the improvement of overall transducer performance, such as transducer sensitivity and bandwidth, resulting in rapid implementation of piezoelectric composites in medical imaging ultrasounds and other acoustic transducers. Recently, new piezoelectric composite transducers have been developed with optimized composite components that have improved thermal stability and mechanical quality factors, making them promising candidates for high temperature, high power transducer applications, such as therapeutic ultrasound, high power ultrasonic wirebonding, high temperature non-destructive testing, and downhole energy harvesting. This paper will present recent developments of piezoelectric composite technology for high temperature and high power applications. The concerns and limitations of using piezoelectric composites will also be discussed, and the expected future research directions will be outlined.

  18. High Temperature, High Power Piezoelectric Composite Transducers

    Directory of Open Access Journals (Sweden)

    Hyeong Jae Lee

    2014-08-01

    Full Text Available Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have led to the improvement of overall transducer performance, such as transducer sensitivity and bandwidth, resulting in rapid implementation of piezoelectric composites in medical imaging ultrasounds and other acoustic transducers. Recently, new piezoelectric composite transducers have been developed with optimized composite components that have improved thermal stability and mechanical quality factors, making them promising candidates for high temperature, high power transducer applications, such as therapeutic ultrasound, high power ultrasonic wirebonding, high temperature non-destructive testing, and downhole energy harvesting. This paper will present recent developments of piezoelectric composite technology for high temperature and high power applications. The concerns and limitations of using piezoelectric composites will also be discussed, and the expected future research directions will be outlined.

  19. Multi-Threshold NULL Convention Logic (MTNCL: An Ultra-Low Power Asynchronous Circuit Design Methodology

    Directory of Open Access Journals (Sweden)

    Liang Zhou

    2015-05-01

    Full Text Available This paper develops an ultra-low power asynchronous circuit design methodology, called Multi-Threshold NULL Convention Logic (MTNCL, also known as Sleep Convention Logic (SCL, which combines Multi-Threshold CMOS (MTCMOS with NULL Convention Logic (NCL, to yield significant power reduction without any of the drawbacks of applying MTCMOS to synchronous circuits. In contrast to other power reduction techniques that usually result in large area overhead, MTNCL circuits are actually smaller than their original NCL versions. MTNCL utilizes high-Vt transistors to gate power and ground of a low-Vt logic block to provide for both fast switching and very low leakage power when idle. To demonstrate the advantages of MTNCL, a number of 32-bit IEEE single-precision floating-point co-processors were designed for comparison using the 1.2 V IBM 8RF-LM 130 nm CMOS process: original NCL, MTNCL with just combinational logic (C/L slept, Bit-Wise MTNCL (BWMTNCL, MTNCL with C/L and completion logic slept, MTNCL with C/L, completion logic, and registers slept, MTNCL with Safe Sleep architecture, and synchronous MTCMOS. These designs are compared in terms of throughput, area, dynamic energy, and idle power, showing the tradeoffs between the various MTNCL architectures, and that the best MTNCL design is much better than the original NCL design in all aspects, and much better than the synchronous MTCMOS design in terms of area, energy per operation, and idle power, although the synchronous design can operate faster.

  20. World Engineer’s Convention 2011: Engineers Power the World

    CERN Multimedia

    Yi Ling Hwong (Knowledge Transfer) and Katarina Anthony

    2011-01-01

    Can the increasing global energy consumption be met without intensifying global warming? Do the necessary technical solutions exist, and is the switch to a low-carbon energy supply feasible and financially viable? These crucial questions and many others were dealt with at the 2011World Engineer’s Convention (WEC). CERN was invited to participate in the event, highlighting its significant contribution to global engineering with an exhibition space devoted to the LHC on the convention floor and a keynote speech delivered by CERN’s Director-General.   From 4 – 9 September 2011, more than 2000 engineers and researchers, as well as politicians and business representatives from about 100 countries gathered at the 2011World Engineer’s Convention (WEC). Held in Geneva, Switzerland, they met to discuss solutions for a sustainable energy future. Discussions looked at the development of engineering solutions through a variety of approaches, with ...

  1. High Power Switching Transistor

    Science.gov (United States)

    Hower, P. L.; Kao, Y. C.; Carnahan, D. C.

    1983-01-01

    Improved switching transistors handle 400-A peak currents and up to 1,200 V. Using large diameter silicon wafers with twice effective area as D60T, form basis for D7 family of power switching transistors. Package includes npn wafer, emitter preform, and base-contact insert. Applications are: 25to 50-kilowatt high-frequency dc/dc inverters, VSCF converters, and motor controllers for electrical vehicles.

  2. High-power electronics

    CERN Document Server

    Kapitsa, Petr Leonidovich

    1966-01-01

    High-Power Electronics, Volume 2 presents the electronic processes in devices of the magnetron type and electromagnetic oscillations in different systems. This book explores the problems of electronic energetics.Organized into 11 chapters, this volume begins with an overview of the motion of electrons in a flat model of the magnetron, taking into account the in-phase wave and the reverse wave. This text then examines the processes of transmission of electromagnetic waves of various polarization and the wave reflection from grids made of periodically distributed infinite metal conductors. Other

  3. High Power Dye Lasers

    Science.gov (United States)

    1975-09-30

    art capabilities for developmental models of hydrogen thyratrons and solid state thyristors. Table II-l is a list of switches that have been... thyratron Table II-l Switch Ignitron GE, GL - 37207 Hydrogen Thyratron High Power Switches Peak Cur. (kA) RMS Cm. (A) 300 120 Max. Rep Rate...for 2 usec Pulse Cli„) 8 1. EG&G HY-5 2. EW. GHT9 3. EG&G Develop- mental model Thyristors 5 7.5 15 125 335 350 300 1000 300 RCA

  4. Dynamic Analysis & Characterization of Conventional Hydraulic Power Supply Units

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Liedhegener, Michael; Bech, Michael Møller

    2016-01-01

    Hydraulic power units operated as constant supply pres-sure systems remain to be widely used in the industry, to supply valve controlled hydraulic drives etc., where the hydraulic power units are constituted by variable pumps with mechanical outlet pressure control, driven by induction motors...... and drives will reduce the flow-to-pressure gain of the supply system, and hence increase the time constant of the sup-ply pressure dynamics. A consequence of this may be large vari-ations in the supply pressure, hence large variations in the pump shaft torque, and thereby the induction motor load torque......, with possible excitation of the induction motor dynamics as a result. In such cases, the coupled dynamics of the pressure controlled pump and induction motor may influence the supply pressure sig-nificantly, possibly affecting the dynamics of the supplied drives, especially in cases where pilot operated valves...

  5. High power coaxial ubitron

    Science.gov (United States)

    Balkcum, Adam J.

    In the ubitron, also known as the free electron laser, high power coherent radiation is generated from the interaction of an undulating electron beam with an electromagnetic signal and a static periodic magnetic wiggler field. These devices have experimentally produced high power spanning the microwave to x-ray regimes. Potential applications range from microwave radar to the study of solid state material properties. In this dissertation, the efficient production of high power microwaves (HPM) is investigated for a ubitron employing a coaxial circuit and wiggler. Designs for the particular applications of an advanced high gradient linear accelerator driver and a directed energy source are presented. The coaxial ubitron is inherently suited for the production of HPM. It utilizes an annular electron beam to drive the low loss, RF breakdown resistant TE01 mode of a large coaxial circuit. The device's large cross-sectional area greatly reduces RF wall heat loading and the current density loading at the cathode required to produce the moderate energy (500 keV) but high current (1-10 kA) annular electron beam. Focusing and wiggling of the beam is achieved using coaxial annular periodic permanent magnet (PPM) stacks without a solenoidal guide magnetic field. This wiggler configuration is compact, efficient and can propagate the multi-kiloampere electron beams required for many HPM applications. The coaxial PPM ubitron in a traveling wave amplifier, cavity oscillator and klystron configuration is investigated using linear theory and simulation codes. A condition for the dc electron beam stability in the coaxial wiggler is derived and verified using the 2-1/2 dimensional particle-in-cell code, MAGIC. New linear theories for the cavity start-oscillation current and gain in a klystron are derived. A self-consistent nonlinear theory for the ubitron-TWT and a new nonlinear theory for the ubitron oscillator are presented. These form the basis for simulation codes which, along

  6. Electric and magnetic properties measurement and analysis of a conventional and a superconducting power transformer

    Science.gov (United States)

    Figueira, P.; Pronto, A. G.; Vilhena, N.; Pina, J. M.

    2014-05-01

    Power transformers based on High Temperature Superconductors (HTS) technology have revealed potential for several practical applications, offering economic, environmental and operational benefits. In this work, two 650 VA single-phase transformers prototypes were developed, tested and characterized: a conventional one, using copper windings, and another with the same primary copper winding, but with a secondary winding made of HTS BSCCO tape. The two prototypes were compared regarding magnetic properties, losses, electric parameters and efficiency, and the results are presented and interpreted. Also, several measures to determine AC critical current of the HTS tape were made. The results are compared with DC critical current for the same tape.

  7. High power beam analysis

    Science.gov (United States)

    Aharon, Oren

    2014-02-01

    In various modern scientific and industrial laser applications, beam-shaping optics manipulates the laser spot size and its intensity distribution. However the designed laser spot frequently deviates from the design goal due to real life imperfections and effects, such as: input laser distortions, optical distortion, heating, overall instabilities, and non-linear effects. Lasers provide the ability to accurately deliver large amounts of energy to a target area with very high accuracy. Thus monitoring beam size power and beam location is of high importance for high quality results and repeatability. Depending on the combination of wavelength, beam size and pulse duration , laser energy is absorbed by the material surface, yielding into processes such as cutting, welding, surface treatment, brazing and many other applications. This article will cover the aspect of laser beam measurements, especially at the focal point where it matters the most. A brief introduction to the material processing interactions will be covered, followed by fundamentals of laser beam propagation, novel measurement techniques, actual measurement and brief conclusions.

  8. Investigation of switching mechanism in HfOx-ReRAM under low power and conventional operation modes

    Science.gov (United States)

    Feng, Wei; Shima, Hisashi; Ohmori, Kenji; Akinaga, Hiroyuki

    2016-12-01

    Low-power resistive random access memory (LP-ReRAM) devices have attracted increasing attention owing to their advantages of low operation power. In this study, a vertical-type LP-ReRAM consisting of TiN/Ti/HfO2/TiN structure was fabricated. The switching mechanism for LP-ReRAM was elucidated as the conductive filament mechanism for conventional mode, and an interface-type switching mechanism for low power mode was proposed. The analysis of low frequency noise shows that power spectral density (PSD) is approximately proportional to 1/f for conventional operation mode. Nevertheless, for low power mode, the PSD of low resistance state (LRS) is proportional to 1/f, while that of high resistance state (HRS) is clear proportional to 1/f2. The envelope of multiple Lorentzian spectra of 1/f2 characteristics due to different traps reveals the characteristics of 1/f. For HRS of low power mode, a limited number of traps results in a characteristic of 1/f2. During the set process, the number of oxygen vacancies increases for LRS. Therefore, the PSD value is proportional to 1/f. Owing to the increase in the number of traps when the operation mode changes to conventional mode, the PSD value is proportional to 1/f. To the best of our knowledge, this is the first study that reveals the different noise characteristics in the low power operation mode from that in the conventional operation mode.

  9. Parameter optimization of multimachine power system conventional stabilizers using CDCARLA method

    Energy Technology Data Exchange (ETDEWEB)

    Kashki, M. [Electrical and Computer Engineering Faculty, KN Toosi University of Technology, Tehran (Iran); Abdel-Magid, Y.L. [Electrical Engineering Program, The Petroleum Institue, P.O. Box 2533, Abu Dhabi (United Arab Emirates); Abido, M.A. [Electrical Engineering Department, King Fahd University of Petroleum and Minerals, KFUPM Box 183, Dhahran 31261 (Saudi Arabia)

    2010-06-15

    In this paper, a novel Combinatorial Discrete and Continuous Action Reinforcement Learning Automata (CDCARLA) based approach for optimal design of multimachine power system stabilizers (PSSs) is presented. The proposed CDCARLA based design approach is a combined procedure of two optimization stages in discrete and continuous spaces for fast convergence and high optimization efficiency. The potential of the proposed approach in seeking the optimal settings of the widely used conventional lead-lag PSSs' parameters is investigated and assessed in multimachine power systems. The performance and robustness of the proposed CDCARLA based PSS is evaluated under different power system disturbances. The performance of the proposed stabilizer is also compared with other stabilizers reported in the literature including the multi-band PSSs for a two-area four-machine power system. Simulation results show the effectiveness and robustness of the proposed CDCARLA PSS in damping local and inter area oscillation modes under various disturbances, and confirm its superiority in comparison with other types of PSSs. (author)

  10. High power evaluation of X-band high power loads

    CERN Document Server

    Matsumoto, Shuji; Syratchev, Igor; Riddone, Germana; Wuensch, Walter

    2010-01-01

    Several types of X-band high power loads developed for several tens of MW range were designed, fabricated and used for high power tests at X-band facility of KEK. Some of them have been used for many years and few units showed possible deterioration of RF performance. Recently revised-design loads were made by CERN and the high power evaluation was performed at KEK. In this paper, the main requirements are recalled, together with the design features. The high power test results are analysed and presented

  11. High Efficiency Power Converter for Low Voltage High Power Applications

    DEFF Research Database (Denmark)

    Nymand, Morten

    , and remote power generation for light towers, camper vans, boats, beacons, and buoys etc. A review of current state-of-the-art is presented. The best performing converters achieve moderately high peak efficiencies at high input voltage and medium power level. However, system dimensioning and cost are often......The topic of this thesis is the design of high efficiency power electronic dc-to-dc converters for high-power, low-input-voltage to high-output-voltage applications. These converters are increasingly required for emerging sustainable energy systems such as fuel cell, battery or photo voltaic based...... determined by the performance at the system worst case operating point which is usually at minimum input voltage and maximum power. Except for the non-regulating V6 converters, all published solutions exhibit a very significant drop in conversion efficiency at minimum input voltage and maximum output power...

  12. High Efficiency Power Converter for Low Voltage High Power Applications

    DEFF Research Database (Denmark)

    Nymand, Morten

    , and remote power generation for light towers, camper vans, boats, beacons, and buoys etc. In chapter 2, a review of current state-of-the-art is presented. The best performing converters achieve moderately high peak efficiencies at high input voltage and medium power level. However, system dimensioning...

  13. Technical Feasibility Study of Thermal Energy Storage Integration into the Conventional Power Plant Cycle

    Directory of Open Access Journals (Sweden)

    Jacek D. Wojcik

    2017-02-01

    Full Text Available The current load balance in the grid is managed mainly through peaking fossil-fuelled power plants that respond passively to the load changes. Intermittency, which comes from renewable energy sources, imposes additional requirements for even more flexible and faster responses from conventional power plants. A major challenge is to keep conventional generation running closest to the design condition with higher load factors and to avoid switching off periods if possible. Thermal energy storage (TES integration into the power plant process cycle is considered as a possible solution for this issue. In this article, a technical feasibility study of TES integration into a 375-MW subcritical oil-fired conventional power plant is presented. Retrofitting is considered in order to avoid major changes in the power plant process cycle. The concept is tested based on the complete power plant model implemented in the ProTRAX software environment. Steam and water parameters are assessed for different TES integration scenarios as a function of the plant load level. The best candidate points for heat extraction in the TES charging and discharging processes are evaluated. The results demonstrate that the integration of TES with power plant cycle is feasible and provide a provisional guidance for the design of the TES system that will result in the minimal influence on the power plant cycle.

  14. Effects of feeding high protein or conventional canola meal on dry cured and conventionally cured bacon.

    Science.gov (United States)

    Little, K L; Bohrer, B M; Stein, H H; Boler, D D

    2015-05-01

    Objectives were to compare belly, bacon processing, bacon slice, and sensory characteristics from pigs fed high protein canola meal (CM-HP) or conventional canola meal (CM-CV). Soybean meal was replaced with 0 (control), 33, 66, or 100% of both types of canola meal. Left side bellies from 70 carcasses were randomly assigned to conventional or dry cure treatment and matching right side bellies were assigned the opposite treatment. Secondary objectives were to test the existence of bilateral symmetry on fresh belly characteristics and fatty acid profiles of right and left side bellies originating from the same carcass. Bellies from pigs fed CM-HP were slightly lighter and thinner than bellies from pigs fed CM-CV, yet bacon processing, bacon slice, and sensory characteristics were unaffected by dietary treatment and did not differ from the control. Furthermore, testing the existence of bilateral symmetry on fresh belly characteristics revealed that bellies originating from the right side of the carcasses were slightly (P≤0.05) wider, thicker, heavier and firmer than bellies from the left side of the carcass.

  15. Participation of non-conventional energy resources in power system frequency control

    Science.gov (United States)

    Aghazadeh Tabrizi, Mehriar

    Frequency control is one of the key issues in designing, planning and reliably operating a power system and is becoming more challenging as new complexities and uncertainties are introduced into the modern power systems. Traditionally, power system frequency has been controlled using conventional generation units' capabilities namely inertial, primary and secondary frequency responses. Limited fossil-based fuel resources, ever-increasing energy consumption and rising public awareness for environmental protection have created growing interest in use of non-conventional energy resources such as Wind Generation Resources (WGRs) and Solar Generation Resources (SGRs) which have unfavorable characteristics in comparison with conventional generation units such as lack of frequency response. The more conventional generation units are replaced by these resources, the more challenges power system operators will face in terms of power system frequency control. These challenges are further compounded due to less system inertia during off-peak hours or within small power systems. This dissertation mainly focuses on participation of SGRs and Interior Permanent Magnet Synchronous Generator (IPMSG) based WGRs in power system frequency control. Detailed information regarding dynamic modeling of power system including conventional generation units, SGRs and IPMSG based WGRs is provided. The frequency response of conventional generation units is compared with that of SGRs and IPMSG based WGRs. The control systems associated with IPMSG based WGR and SGR are modified in order to improve their frequency response capabilities. The effectiveness of the proposed control strategies is evaluated and confirmed via MATLAB based time-domain simulations for different scenarios. Moreover, application of Battery Energy Storage Systems (BESSs) in power system frequency regulation is discussed. The detailed dynamic model of BESSs is utilized to develop a simplified model suitable for Automatic

  16. High average power supercontinuum sources

    Indian Academy of Sciences (India)

    J C Travers

    2010-11-01

    The physical mechanisms and basic experimental techniques for the creation of high average spectral power supercontinuum sources is briefly reviewed. We focus on the use of high-power ytterbium-doped fibre lasers as pump sources, and the use of highly nonlinear photonic crystal fibres as the nonlinear medium. The most common experimental arrangements are described, including both continuous wave fibre laser systems with over 100 W pump power, and picosecond mode-locked, master oscillator power fibre amplifier systems, with over 10 kW peak pump power. These systems can produce broadband supercontinua with over 50 and 1 mW/nm average spectral power, respectively. Techniques for numerical modelling of the supercontinuum sources are presented and used to illustrate some supercontinuum dynamics. Some recent experimental results are presented.

  17. Correlative analysis of MRI-evident abductor hip muscle degeneration and power after minimally invasive versus conventional unilateral cementless THA.

    Science.gov (United States)

    Vasilakis, Ioannis; Solomou, Ekaterini; Vitsas, Vasilis; Fennema, Peter; Korovessis, Panagiotis; Siamblis, Dimitrios K

    2012-12-01

    The 2 main null hypotheses of this study were: (1) the 4-year surgical trauma-related degeneration within the hip abductor muscles after a minimally invasive approach to total hip arthroplasty would be similar to that following a conventional approach; and (2) no differences in perioperative blood loss or postoperative hip pain would be observed between the minimally invasive and conventional approaches.In 40 consecutive randomly selected adult patients with unilateral primary hip osteoarthritis, a cementless Zweymüller-Plus THA (Smith & Nephew Orthopaedics, Baar, Switzerland) was implanted by a single surgeon in 1 institution during the same period. Twenty patients underwent a minimally invasive approach (group A), and 20 patients underwent a conventional anterolateral approach (group B). Four years postoperatively, the operated and contralateral nonoperated hips of 37 available patients from both groups were examined with magnetic resonance imaging to show any changes in the gluteus medius and tensor fascia latae. Simultaneously, hip abductor power was measured bilaterally in both groups. Anthropometric data, blood loss, Short Form 36 self-assessment questionnaire, visual analog pain score, and walking distance were also analyzed.The reliability of magnetic resonance imaging and hip abductor power measurements was high. No difference was found in hip abductor power on the operated side between the 2 groups, whereas hip abductor power on the nonoperated side was significantly higher in both groups. This study revealed no mechanical and functional benefits in favor of patients undergoing minimally invasive vs conventional total hip arthroplasty.

  18. Modular VSC converter based HVDC power transmission from offshore wind power plant: Compared to the conventional HVAC system

    DEFF Research Database (Denmark)

    Sharma, Ranjan; Rasmussen, Tonny Wederberg; Jensen, Kim Høj;

    2010-01-01

    power transmission options with HVDC systems are under consideration. In this paper, a comparison between a conventional HVAC transmission system and a HVDC system equipped with modular voltage source converters is provided. The comparison is based on the total energy transmission capability...

  19. High-powered manoeuvres

    CERN Multimedia

    Anaïs Schaeffer

    2013-01-01

    This week, CERN received the latest new transformers for the SPS. Stored in pairs in 24-tonne steel containers, these transformers will replace the old models, which have been in place since 1981.     The transformers arrive at SPS's access point 4 (BA 4). During LS1, the TE-EPC Group will be replacing all of the transformers for the main converters of the SPS. This renewal campaign is being carried out as part of the accelerator consolidation programme, which began at the start of April and will come to an end in November. It involves 80 transformers: 64 with a power of 2.6 megavolt-amperes (MVA) for the dipole magnets, and 16 with 1.9 MVA for the quadrupoles. These new transformers were manufactured by an Italian company and are being installed outside the six access points of the SPS by the EN-HE Group, using CERN's 220-tonne crane. They will contribute to the upgrade of the SPS, which should thus continue to operate as the injector for the LHC until 2040....

  20. Cognitive Targeting: A Coercive Air Power Theory for Conventional Escalation Control Against Nuclear Armed Adversaries

    Science.gov (United States)

    2016-06-01

    COGNITIVE TARGETING: A COERCIVE AIR POWER THEORY FOR CONVENTIONAL ESCALATION CONTROL AGAINST NUCLEAR- ARMED ADVERSARIES BY PAUL A. GOOSSEN, MAJ...process with both critical analysis and with encouragement. Most importantly, I want to express my most sincere appreciation to my family. Their love...regional powers such as North Korea, the post-Cold War geo-political environment characterized by U.S. hegemony is fading away. In the emerging

  1. An Evolutionary Transition of conventional n MOS VLSI to CMOS considering Scaling, Low Power and Higher Mobility

    Directory of Open Access Journals (Sweden)

    Md Mobarok Hossain Rubel

    2016-07-01

    Full Text Available This paper emphasizes on the gradual revolution of CMOS scaling by delivering the modern concepts of newly explored device structures and new materials. After analyzing the improvements in sources, performance of CMOS technology regarding conventional semiconductor devices has been thoroughly discussed. This has been done by considering the significant semiconductor evolution devices like metal gate electrode, double gate FET, FinFET, high dielectric constant (high k and strained silicon FET. Considering the power level while scaling, the paper showed how nMOS VLSI chips have been gradually replaced by CMOS aiming for the reduction in the growing power of VLSI systems.

  2. High Average Power Optical FEL Amplifiers

    CERN Document Server

    Ben-Zvi, I; Litvinenko, V

    2005-01-01

    Historically, the first demonstration of the FEL was in an amplifier configuration at Stanford University. There were other notable instances of amplifying a seed laser, such as the LLNL amplifier and the BNL ATF High-Gain Harmonic Generation FEL. However, for the most part FELs are operated as oscillators or self amplified spontaneous emission devices. Yet, in wavelength regimes where a conventional laser seed can be used, the FEL can be used as an amplifier. One promising application is for very high average power generation, for instance a 100 kW average power FEL. The high electron beam power, high brightness and high efficiency that can be achieved with photoinjectors and superconducting energy recovery linacs combine well with the high-gain FEL amplifier to produce unprecedented average power FELs with some advantages. In addition to the general features of the high average power FEL amplifier, we will look at a 100 kW class FEL amplifier is being designed to operate on the 0.5 ampere Energy Recovery Li...

  3. Service Power Rate and Electricity-Saving in Conventional Thermal Power Plants

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Since reforming and opening to the outside world, the power construction in China has been expanding by leaps and bounds. As of the end of 2005, the nationwide generation installed capacity made a breakthrough of 500 GW, of which thermal power units represented three-fourths.Relevant predictions indicate that the installed capacity will reach 680-730 GW in 2010 and it will exceed 1000 GW in 2020 as expected. The present situation of service power rate of thermal power units and how to make it approach and come up to world level are questions to be discussed in this paper.

  4. TRANSISTOR HIGH VOLTAGE POWER SUPPLY

    Science.gov (United States)

    Driver, G.E.

    1958-07-15

    High voltage, direct current power supplies are described for use with battery powered nuclear detection equipment. The particular advantages of the power supply described, are increased efficiency and reduced size and welght brought about by the use of transistors in the circuit. An important feature resides tn the employment of a pair of transistors in an alternatefiring oscillator circuit having a coupling transformer and other circuit components which are used for interconnecting the various electrodes of the transistors.

  5. Assessing Mothers' and Children's Perceptions of Power through Personal, Conventional, and Prudential Conflict Situations

    Science.gov (United States)

    Porta, Sandra Della; Howe, Nina

    2012-01-01

    Mothers' and school-aged children's perceptions of types of power executed (coercive, reward, legitimate, information, negotiation, and sneaky) in three domains of conflict (personal, conventional, and prudential) were investigated. Participants included 41 children ranging from 7 to 12 years (M = 10.12, SD = 1.42) and their mothers. Perceptions…

  6. Assessing Mothers' and Children's Perceptions of Power through Personal, Conventional, and Prudential Conflict Situations

    Science.gov (United States)

    Porta, Sandra Della; Howe, Nina

    2012-01-01

    Mothers' and school-aged children's perceptions of types of power executed (coercive, reward, legitimate, information, negotiation, and sneaky) in three domains of conflict (personal, conventional, and prudential) were investigated. Participants included 41 children ranging from 7 to 12 years (M = 10.12, SD = 1.42) and their mothers. Perceptions…

  7. Modular High Voltage Power Supply

    Energy Technology Data Exchange (ETDEWEB)

    Newell, Matthew R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-18

    The goal of this project is to develop a modular high voltage power supply that will meet the needs of safeguards applications and provide a modular plug and play supply for use with standard electronic racks.

  8. High Power Betavoltaic Technology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation will dramatically improve the performance of tritium-powered betavoltaic batteries through the development of a high-aspect ratio, expanded...

  9. Fuzzy and conventional control of high-frequency ventilation.

    Science.gov (United States)

    Noshiro, M; Matsunami, T; Takakuda, K; Ryumae, S; Kagawa, T; Shimizu, M; Fujino, T

    1994-07-01

    A high-frequency ventilator was developed, consisting of a single-phase induction motor, an unbalanced mass and a mechanical vibration system. Intermittent positive pressure respiration was combined with high-frequency ventilation to measure end-tidal pCO2. Hysteresis was observed between the rotational frequency of the high-frequency ventilator and end-tidal pCO2. A fuzzy proportional plus integral control system, designed on the basis of the static characteristics of the controlled system and a knowledge of respiratory physiology, successfully regulated end-tidal pCO2. The characteristics of gas exchange under high-frequency ventilation was approximated by a first-order linear model. A conventional PI control system, designed on the basis of the approximated model, regulated end-tidal pCO2 with a performance similar to that of the fuzzy PI control system. The design of the fuzzy control system required less knowledge about the controlled system than that of the conventional control system.

  10. EURISOL High Power Targets

    CERN Document Server

    Kadi, Y; Lindroos, M; Ridikas, D; Stora, T; Tecchio, L; CERN. Geneva. BE Department

    2009-01-01

    Modern Nuclear Physics requires access to higher yields of rare isotopes, that relies on further development of the In-flight and Isotope Separation On-Line (ISOL) production methods. The limits of the In-Flight method will be applied via the next generation facilities FAIR in Germany, RIKEN in Japan and RIBF in the USA. The ISOL method will be explored at facilities including ISAC-TRIUMF in Canada, SPIRAL-2 in France, SPES in Italy, ISOLDE at CERN and eventually at the very ambitious multi-MW EURISOL facility. ISOL and in-flight facilities are complementary entities. While in-flight facilities excel in the production of very short lived radioisotopes independently of their chemical nature, ISOL facilities provide high Radioisotope Beam (RIB) intensities and excellent beam quality for 70 elements. Both production schemes are opening vast and rich fields of nuclear physics research. In this article we will introduce the targets planned for the EURISOL facility and highlight some of the technical and safety cha...

  11. High Aspect-Ratio Neural Probes using Conventional Blade Dicing

    Science.gov (United States)

    Goncalves, S. B.; Ribeiro, J. F.; Silva, A. F.; Correia, J. H.

    2016-10-01

    Exploring deep neural circuits has triggered the development of long penetrating neural probes. Moreover, driven by brain displacement, the long neural probes require also a high aspect-ratio shafts design. In this paper, a simple and reproducible method of manufacturing long-shafts neural probes using blade dicing technology is presented. Results shows shafts up to 8 mm long and 200 µm wide, features competitive to the current state-of-art, being its outline simply accomplished by a single blade dicing program. Therefore, conventional blade dicing presents itself as a viable option to manufacture long neural probes.

  12. Study on electrical power output of floating photovoltaic and conventional photovoltaic

    Science.gov (United States)

    Azmi, Mohd Syahriman Mohd; Othman, Mohd Yusof Hj.; Ruslan, Mohd Hafidz Hj.; Sopian, Kamaruzzaman; Majid, Zafri Azran Abdul

    2013-11-01

    In this paper, several attempt were made to investigate the best electrical performance of a floating photovoltaic (FPV). In photovoltaic (PV) system, the electrical efficiency of the system decreases rapidly as the PV module temperature increases. Therefore, in order to achieve higher electrical efficiency, the PV module have to be cooled by removing the heat in some way. This paper presents study on a conventional photovoltaic (PV) module and floating photovoltaic (FPV) system. The objective of the study is to compare the performance of conventional PV module and FPV. At FPV, an absorber comprises of aluminum flat-box housing was attached to the back of the PV module to absorb heat. Water is used to cool the PV module by passing it under the bottom surface of the module. The system was tested under simulated solar intensity of 417 W/m2, 667 W/m2 and 834 W/m2. Current (I) - voltage (V) curves and power (P) - voltage (V) curves of the results were analyzed. The study found that the FPV has higher efficiency and total power gain than the conventional PV module. The average PV temperature in a FPV might be lower than that for a conventional PV module, thereby increasing its electrical power output. The simplicity of the system structure and aluminum as the chosen material enabled it to reduce the installation costs for a larger scale. Applicable as heat sink, this FPV system is convenient to place on lakes, ponds or rivers.

  13. High power ferrite microwave switch

    Science.gov (United States)

    Bardash, I.; Roschak, N. K.

    1975-01-01

    A high power ferrite microwave switch was developed along with associated electronic driver circuits for operation in a spaceborne high power microwave transmitter in geostationary orbit. Three units were built and tested in a space environment to demonstrate conformance to the required performance characteristics. Each unit consisted of an input magic-tee hybrid, two non-reciprocal latching ferrite phase shifters, an out short-slot 3 db quadrature coupler, a dual driver electronic circuit, and input logic interface circuitry. The basic mode of operation of the high power ferrite microwave switch is identical to that of a four-port, differential phase shift, switchable circulator. By appropriately designing the phase shifters and electronic driver circuits to operate in the flux-transfer magnetization mode, power and temperature insensitive operation was achieved. A list of the realized characteristics of the developed units is given.

  14. High Power Amplifier and Power Supply

    Science.gov (United States)

    Duong, Johnny; Stride, Scot; Harvey, Wayne; Haque, Inam; Packard, Newton; Ng, Quintin; Ispirian, Julie Y.; Waian, Christopher; Janes, Drew

    2008-01-01

    A document discusses the creation of a high-voltage power supply (HVPS) that is able to contain voltages up to -20 kV, keep electrical field strengths to below 200 V/mil (approximately equal to 7.87 kV/mm), and can provide a 200-nanosecond rise/fall time focus modulator swinging between cathode potential of 16.3 kV and -19.3 kV. This HVPS can protect the 95-GHz, pulsed extended interaction klystron (EIK) from arcs/discharges from all sources, including those from within the EIK fs vacuum envelope. This innovation has a multi-winding pulse transformer design, which uses new winding techniques to provide the same delays and rise/fall times (less than 10 nanoseconds) at different potential levels ranging from -20 kV to -16 kV. Another feature involves a high-voltage printed-wiring board that was corona-free at -20 kV DC with a 3- kV AC swing. The corona-free multilayer high-voltage board is used to simulate fields of less than 200 V/mil (approximately equal to 7.87 kV/mm) at 20 kV DC. Drive techniques for the modulator FETs (field-effect transistors) (four to 10 in a series) were created to change states (3,000-V swing) without abrupt steps, while still maintaining required delays and transition times. The packing scheme includes a potting mold to house a ten-stage modulator in the space that, in the past, only housed a four-stage modulator. Problems keeping heat down were solved using aluminum oxide substrate in the high-voltage section to limit temperature rise to less than 10 while withstanding -20 kV DC voltage and remaining corona-free.

  15. High-power microwave development in Russia

    Science.gov (United States)

    Gauthier, Sylvain

    1995-03-01

    This is a survey of Russian research and development in high-power microwave (HPM) sources. It emphasizes those sources of nanoseconds pulse duration time which have potential weapon as well as radar applications. It does not cover the whole range of Russian HPM research and development but concentrates on those aspects which may lead to military applications. Russian investigators have achieved many world firsts in HPM generation; for example, a multiwave Cerenkov generator with a peak output power of 15 gigawatts. Their successes are based on their impressive capability in pulsed power technology which has yielded high-current generators of terawatt peak power. They have transformed the energy of these currents into microwave radiation using tubes of both conventional and novel designs exploiting relativistic electron beams. Recently, the development of high-current mini-accelerators has moved relativistic electron-beam (REB) HPM generation out of the laboratory and enabled the development of deployable military systems with peak powers in the gigawatt range. As a result, they now see development of a REB-based radar systems as one of the most promising directions in radar systems. Details of such a system are described and the implications for HPM weapons are considered.

  16. From Power Projection To Power Protection: Revitalizing Conventional Deterrence In NATO

    Science.gov (United States)

    2016-06-01

    thin and power projection would have to provide forces on demand. To demonstrate resolve despite the force cuts, 1969 saw the first REFORGER...target airborne threats at up to 400 km, and allegedly 1. Rick Gladstone , “Air Force...Press, 2013), 225. 7. Gladstone , “Russian Missile Defense.” 8. President Barack Obama, “Remarks by President Obama to the People of Estonia

  17. Numerical simulation and comparison of conventional and sloped solar chimney power plants: the case for Lanzhou.

    Science.gov (United States)

    Cao, Fei; Li, Huashan; Zhang, Yang; Zhao, Liang

    2013-01-01

    The solar chimney power plant (SCPP) generates updraft wind through the green house effect. In this paper, the performances of two SCPP styles, that is, the conventional solar chimney power plant (CSCPP) and the sloped solar chimney power plant (SSCPP), are compared through a numerical simulation. A simplified Computational Fluid Dynamics (CFD) model is built to predict the performances of the SCPP. The model is validated through a comparison with the reported results from the Manzanares prototype. The annual performances of the CSCPP and the SSCPP are compared by taking Lanzhou as a case study. Numerical results indicate that the SSCPP holds a higher efficiency and generates smoother power than those of the CSCPP, and the effective pressure in the SSCPP is relevant to both the chimney and the collector heights.

  18. The study and performance of a modified conventional refrigerator to serve as a PV powered one

    Energy Technology Data Exchange (ETDEWEB)

    Kaplanis, Socrates; Papanastasiou, Nikolaos

    2006-05-15

    This paper describes the design and development stages to convert a conventional refrigerator to a solar powered one. The development of such a system was effected and the results of this work to provide a cost effective version are given. A conventional refrigerator was chosen and some changes were introduced to reduce the cooling load and consequently the power required. Tests were carried out to study the performance of the refrigerator components and especially the compressor's, as well as the refrigerator as a whole. The latter tests are the well-known pull down tests. The cost effective final product was searched via a PV sizing package developed for the purpose of this project incorporating the LCC analysis. (author)

  19. Multiaxial fatigue behavior of conventional and highly crosslinked UHMWPE during cyclic small punch testing.

    Science.gov (United States)

    Villarraga, M L; Kurtz, S M; Herr, M P; Edidin, A A

    2003-08-01

    Previous observations of reduced uniaxial elongation, fracture resistance, and crack propagation resistance of highly crosslinked ultrahigh molecular weight polyethylene (UHMWPE) have contributed to concern that the technology may not be appropriate for systems undergoing cyclic fatigue loading. Using a "total life" approach, we examined the influence of radiation crosslinking on the fatigue response of UHMWPE under cyclic loading via the small punch test. Our goal in this study was to evaluate the suitability of the small punch test for conducting miniature-specimen, cyclic loading, and fatigue experiments of conventional and highly crosslinked UHMWPE. We subjected four types of conventional and highly crosslinked UHMWPE to cyclic loading at 200 N/s and at body temperature in a small punch test apparatus. After failure, the fracture surfaces were characterized with the use of field emission scanning electron microscopy to evaluate the fatigue mechanisms. Cyclic small punch testing under load control was found to be an effective and repeatable method for relative assessment of the fatigue resistance of conventional and highly crosslinked UHMWPE specimens under multiaxial loading conditions. For each of the four conventional and highly crosslinked UHMWPE materials evaluated in this study, fatigue failures were consistently produced according to a power law relationship in the low cycle regimen, corresponding to failures below 10000 cycles. The fatigue failures were all found to be consistent with a single source of initiation and propagation to failure. Our long-term goal in this research is to develop miniature-specimen fatigue testing techniques for characterization of retrieved UHMWPE inserts.

  20. High-Average Power Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Dowell, David H.; /SLAC; Power, John G.; /Argonne

    2012-09-05

    There has been significant progress in the development of high-power facilities in recent years yet major challenges remain. The task of WG4 was to identify which facilities were capable of addressing the outstanding R&D issues presently preventing high-power operation. To this end, information from each of the facilities represented at the workshop was tabulated and the results are presented herein. A brief description of the major challenges is given, but the detailed elaboration can be found in the other three working group summaries.

  1. Exergy and Environmental Impact Assessment between Solar Powered Gas Turbine and Conventional Gas Turbine Power Plant

    Directory of Open Access Journals (Sweden)

    Ali Rajaei

    2016-01-01

    Full Text Available Recuperator is a heat exchanger that is used in gas turbine power plants to recover energy from outlet hot gases to heat up the air entering the combustion chamber. Similarly, the combustion chamber inlet air can be heated up to temperatures up to 1000 (°C by solar power tower (SPT as a renewable and environmentally benign energy source. In this study, comprehensive comparison between these two systems in terms of energy, exergy, and environmental impacts is carried out. Thermodynamic simulation of both cycles is conducted using a developed program in MATLAB environment. Exergetic performances of both cycles and their emissions are compared and parametric study is carried out. A new parameter (renewable factor is proposed to evaluate resources quality and measure how green an exergy loss or destruction or a system as a whole is. Nonrenewable exergy destruction and loss are reduced compared to GT with recuperator cycle by 34.89% and 47.41%, respectively. Reductions in CO2, NOx, and CO compared to GT with recuperator cycle by 49.92%, 66.14%, and 39.77%, respectively, are in line with renewable factor value of around 55.7 which proves the ability of the proposed green measure to evaluate and compare the cycles performances.

  2. The renewable energy targets of the Maghreb countries: Impact on electricity supply and conventional power markets

    Energy Technology Data Exchange (ETDEWEB)

    Brand, Bernhard, E-mail: brandb@uni-koeln.de [Institute of Energy Economics at the University of Cologne, Vogelsanger Strasse 321, 50827 Cologne (Germany); Zingerle, Jonas [Institute of Energy Economics at the University of Cologne, Vogelsanger Strasse 321, 50827 Cologne (Germany)

    2011-08-15

    Morocco, Algeria and Tunisia, the three countries of the North African Maghreb region, are showing increased efforts to integrate renewable electricity into their power markets. Like many other countries, they have pronounced renewable energy targets, defining future shares of 'green' electricity in their national generation mixes. The individual national targets are relatively varied, reflecting the different availability of renewable resources in each country, but also the different political ambitions for renewable electricity in the Maghreb states. Open questions remain regarding the targets' economic impact on the power markets. Our article addresses this issue by applying a linear electricity market optimization model to the North African countries. Assuming a competitive, regional electricity market in the Maghreb, the model minimizes dispatch and investment costs and simulates the impact of the renewable energy targets on the conventional generation system until 2025. Special emphasis is put on investment decisions and overall system costs. - Research Highlights: >Market simulation shows impact of RES-E penetration on the conventional power system of Morocco, Algeria and Tunisia. >Noticeable effects on dispatch and investments in fossil power plants. >Reduced utilization of base-load plants - stronger investments in flexible capacities. >Overall system costs can be decreased by optimizing the RES-E goals.

  3. High power neutron production targets

    Energy Technology Data Exchange (ETDEWEB)

    Wender, S. [Los Alamos National Lab., NM (United States)

    1996-06-01

    The author describes issues of concern in the design of targets and associated systems for high power neutron production facilities. The facilities include uses for neutron scattering, accelerator driven transmutation, accelerator production of tritium, short pulse spallation sources, and long pulse spallation sources. Each of these applications requires a source with different design needs and consequently different implementation in practise.

  4. The role of co-located storage for wind power producers in conventional electricity markets

    KAUST Repository

    Bitar, E.

    2011-06-01

    In this paper we study the problem of optimizing contract offerings for an independent wind power producer (WPP) participating in conventional day-ahead forward electricity markets for energy. As wind power is an inherently variable source of energy and is difficult to predict, we explore the extent to which co-located energy storage can be used to improve expected profit and mitigate the the financial risk associated with shorting on the offered contracts. Using a simple stochastic model for wind power production and a model for the electricity market, we show that the problem of determining optimal contract offerings for a WPP with co-located energy storage can be solved using convex programming.

  5. Primary reserve studies for high wind power penetrated systems

    DEFF Research Database (Denmark)

    Das, Kaushik; Altin, Müfit; Hansen, Anca Daniela;

    2015-01-01

    With high penetration of non-synchronous wind generations replacing conventional generators, the inertia of power system will reduce. A large disturbance in such a power system can cause faster frequency change in this power system and might invoke emergency defence strategies like underfrequency....... This paper further explores the capabilities of wind turbines to provide support during underfrequency to prevent load shedding. Maximum wind penetration possible without causing load shedding following a large disturbance is also investigated....

  6. High Power VCSEL Device with Periodic Gain Active Region

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    High power vertical cavity surface emitting lasers(VCSEKLs) with large aperture have been fabricated through improving passivation, lateral oxidation and heat dissipation techniques. Different from conventional three quantum well structures, a periodic gain active region with nine quantum wells was incorporated into the VCSEL structure, with which high efficiency and high power operation were expected. The nine quantum wells were divided into three groups with each of them located at the antinodes of the ca...

  7. Models for the transient stability of conventional power generating stations connected to low inertia systems

    Science.gov (United States)

    Zarifakis, Marios; Coffey, William T.; Kalmykov, Yuri P.; Titov, Sergei V.

    2017-06-01

    An ever-increasing requirement to integrate greater amounts of electrical energy from renewable sources especially from wind turbines and solar photo-voltaic installations exists and recent experience in the island of Ireland demonstrates that this requirement influences the behaviour of conventional generating stations. One observation is the change in the electrical power output of synchronous generators following a transient disturbance especially their oscillatory behaviour accompanied by similar oscillatory behaviour of the grid frequency, both becoming more pronounced with reducing grid inertia. This behaviour cannot be reproduced with existing mathematical models indicating that an understanding of the behaviour of synchronous generators, subjected to various disturbances especially in a system with low inertia requires a new modelling technique. Thus two models of a generating station based on a double pendulum described by a system of coupled nonlinear differential equations and suitable for analysis of its stability corresponding to infinite or finite grid inertia are presented. Formal analytic solutions of the equations of motion are given and compared with numerical solutions. In particular the new finite grid model will allow one to identify limitations to the operational range of the synchronous generators used in conventional power generation and also to identify limits, such as the allowable Rate of Change of Frequency which is currently set to ± 0.5 Hz/s and is a major factor in describing the volatility of a grid as well as identifying requirements to the total inertia necessary, which is currently provided by conventional power generators only, thus allowing one to maximise the usage of grid connected non-synchronous generators, e.g., wind turbines and solar photo-voltaic installations.

  8. Synergistic mercury removal by conventional pollutant control strategies for coal-fired power plants in China.

    Science.gov (United States)

    Wang, Shuxiao; Zhang, Lei; Wu, Ye; Ancora, Maria Pia; Zhao, Yu; Hao, Jiming

    2010-06-01

    China's 11th 5-yr plan has regulated total sulfur dioxide (SO2) emissions by installing flue gas desulfurization (FGD) devices and shutting down small thermal power units. These control measures will not only significantly reduce the emission of conventional pollutants but also benefit the reduction of mercury emissions from coal-fired power plants. This paper uses the emission factor method to estimate the efficiencies of these measures on mercury emission abatement. From 2005 to 2010, coal consumption in power plants will increase by 59%; however, the mercury emission will only rise from 141 to 155 t, with an increase of 10%. The average emission rate of mercury from coal burning will decrease from 126 mg Hg/t of coal to 87 mg Hg/t of coal. The effects of the three desulfurization measures were assessed and show that wet FGD will play an important role in mercury removal. Mercury emissions in 2015 and 2020 are also projected under different policy scenarios. Under the most probable scenario, the total mercury emission in coal-fired power plants in China will decrease to 130 t by 2020, which will benefit from the rapid installation of fabric filters and selective catalytic reduction.

  9. Transmission grating stretcher for contrast enhancement of high power lasers.

    Science.gov (United States)

    Tang, Yunxin; Hooker, Chris; Chekhlov, Oleg; Hawkes, Steve; Collier, John; Rajeev, P P

    2014-12-01

    We propose, for the first time, a transmission grating stretcher for high power lasers and demonstrate its superiority over conventional, reflective gold grating stretchers in terms of pulse temporal quality. We show that, compared to a conventional stretcher with the same stretching factor, the transmission-grating based stretcher yields more than an order of magnitude improvement in the contrast pedestal. We have also quantitatively characterized the roughness of the grating surfaces and estimated its impact on the contrast pedestal.

  10. High power, high beam quality regenerative amplifier

    Science.gov (United States)

    Hackel, L.A.; Dane, C.B.

    1993-08-24

    A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

  11. High-power pulsed lasers

    Energy Technology Data Exchange (ETDEWEB)

    Holzrichter, J.F.

    1980-04-02

    The ideas that led to the successful construction and operation of large multibeam fusion lasers at the Lawrence Livermore Laboratory are reviewed. These lasers are based on the use of Nd:glass laser materials. However, most of the concepts are applicable to any laser being designed for fusion experimentation. This report is a summary of lectures given by the author at the 20th Scottish University Summer School in Physics, on Laser Plasma Interaction. This report includes basic concepts of the laser plasma system, a discussion of lasers that are useful for short-pulse, high-power operation, laser design constraints, optical diagnostics, and system organization.

  12. Development of High-Power Hall Thruster Power Processing Units at NASA GRC

    Science.gov (United States)

    Pinero, Luis R.; Bozak, Karin E.; Santiago, Walter; Scheidegger, Robert J.; Birchenough, Arthur G.

    2015-01-01

    NASA GRC successfully designed, built and tested four different power processor concepts for high power Hall thrusters. Each design satisfies unique goals including the evaluation of a novel silicon carbide semiconductor technology, validation of innovative circuits to overcome the problems with high input voltage converter design, development of a direct-drive unit to demonstrate potential benefits, or simply identification of lessonslearned from the development of a PPU using a conventional design approach. Any of these designs could be developed further to satisfy NASA's needs for high power electric propulsion in the near future.

  13. Debugging on High-voltage Power Supply,Focusing Power Supply and Magnetic Field Power Supply

    Institute of Scientific and Technical Information of China (English)

    TU; Rui

    2015-01-01

    High-voltage power supply,focusing power supply and magnetic field power supply are the main parts of the power supply system of the EMIS(Electro-Magnetic Isotope Separator)supplying the ion source.In 2015,a high-voltage power supply,power supply for focusing and

  14. High-power LEDs for plant cultivation

    Science.gov (United States)

    Tamulaitis, Gintautas; Duchovskis, Pavelas; Bliznikas, Zenius; Breive, Kestutis; Ulinskaite, Raimonda; Brazaityte, Ausra; Novickovas, Algirdas; Zukauskas, Arturas; Shur, Michael S.

    2004-10-01

    We report on high-power solid-state lighting facility for cultivation of greenhouse vegetables and on the results of the study of control of photosynthetic activity and growth morphology of radish and lettuce imposed by variation of the spectral composition of illumination. Experimental lighting modules (useful area of 0.22 m2) were designed based on 4 types of high-power light-emitting diodes (LEDs) with emission peaked in red at the wavelengths of 660 nm and 640 nm (predominantly absorbed by chlorophyll a and b for photosynthesis, respectively), in blue at 455 nm (phototropic function), and in far-red at 735 nm (important for photomorphology). Morphological characteristics, chlorophyll and phytohormone concentrations in radish and lettuce grown in phytotron chambers under lighting with different spectral composition of the LED-based illuminator and under illumination by high pressure sodium lamps with an equivalent photosynthetic photon flux density were compared. A well-balanced solid-state lighting was found to enhance production of green mass and to ensure healthy morphogenesis of plants compared to those grown using conventional lighting. We observed that the plant morphology and concentrations of morphologically active phytohormones is strongly affected by the spectral composition of light in the red region. Commercial application of the LED-based illumination for large-scale plant cultivation is discussed. This technology is favorable from the point of view of energy consumption, controllable growth, and food safety but is hindered by high cost of the LEDs. Large scale manufacturing of high-power red AlInGaP-based LEDs emitting at 650 nm and a further decrease of the photon price for the LEDs emitting in the vicinity of the absorption peak of chlorophylls have to be achieved to promote horticulture applications.

  15. Design concept and performance considerations for fast high power semiconductor switching for high repetition rate and high power excimer laser

    Science.gov (United States)

    Goto, Tatsumi; Kakizaki, Kouji; Takagi, Shigeyuki; Satoh, Saburoh; Shinohe, Takashi; Ohashi, Hiromichi; Endo, Fumihiko; Okamura, Katsuya; Ishii, Akira; Teranishi, Tsuneharu; Yasuoka, Koichi

    1997-07-01

    A semiconductor switching power supply has been developed, in which a novel structure semiconductor device, metal-oxide-semiconductor assisted gate-triggered thyristor (MAGT) was incorporated with a single stage magnetic pulse compression circuit (MPC). The MAGT was specially designed to directly replace thyratrons in a power supply for a high repetition rate laser. Compared with conventional high power semiconductor switching devices, it was designed to enable a fast switching, retaining a high blocking voltage and to extremely reduce the transient turn-on power losses, enduring a higher peak current. A maximum peak current density of 32 kA/cm2 and a current density risetime rate di/dt of 142 kA/(cm2×μs) were obtained at the chip area with an applied anode voltage of 1.5 kV. A MAGT switching unit connecting 32 MAGTs in series was capable of switching on more than 25 kV-300 A at a repetition rate of 5 kHz, which, coupled with the MPC, was equivalent to the capability of a high power thyratron. A high repetition rate and high power XeCl excimer laser was excited by the power supply. The results confirmed the stable laser operation of a repetition rate of up to 5 kHz, the world record to our knowledge. An average output power of 0.56 kW was obtained at 5 kHz where the shortage of the total discharge current was subjoined by a conventional power supply with seven parallel switching thyratrons, simultaneously working, for the MAGT power supply could not switch a greater current than that switched by one thyratron. It was confirmed by those excitations that the MAGT unit with the MPC could replace a high power commercial thyratron directly for excimer lasers. The switching stability was significantly superior to that of the thyratron in a high repetition rate region, judging from the discharge current wave forms. It should be possible for the MAGT unit, in the future, to directly switch the discharge current within a rise time of 0.1 μs with a magnetic assist.

  16. The acute effects of conventional, complex, and contrast protocols on lower-body power.

    Science.gov (United States)

    Talpey, Scott W; Young, Warren B; Saunders, Natalie

    2014-02-01

    This study compared conventional, complex, and contrast protocols on peak power (PP) output. Static vs. dynamic contractions were also manipulated to determine the effect of these confounding variables. Eighteen recreationally trained men [age, 21.1 ± 3.3 years; body mass, 81.7 ± 15.9 kg; height, 182.8 ± 6.2 cm; 5 repetition maximum (5RM) half back squat, 119.2 ± 25.4 kg; 5RM/BW, 1.5 ± 0.2 kg] involved in sports including Australian Rules football, basketball, soccer, and rugby participated in this investigation. Five protocols were executed in a randomized order, a conventional protocol in which 3 sets of 4 countermovement jumps (CMJs) were performed 2 minutes apart. Contrast protocols using a heavy resistance conditioning action of either 4 repetitions with a 5RM load or a 5-second static back squat were alternated with sets of 4 CMJs. Complex conditions with 3 sets of 4 repetitions of a 5RM back squat or a 5-second static back squat were performed before the 3 sets of CMJs. In all conditions, 4 minutes of rest followed sets of heavy resistance exercises and 2 minutes of rest followed each set of CMJs. Individual set means and a total session mean were calculated from each CMJ performed during the session. Results showed that the conventional protocol produced significantly greater PP than all conditions except for the dynamic complex and the static contrast. Results suggest that the use of the complex and contrast protocols used in this investigation should not be used for acute increases in lower-body PP in recreationally trained individuals.

  17. Use of EPICS for High-Level Control of SNS Conventional Facilities

    CERN Document Server

    Munro, J K; Williams, E L; Nypaver, D J; Kasemir, K U; Meyer, R D

    2001-01-01

    The SNS Project intends to integrate Conventional Facility Controls with its EPICS-based Accelerator and Target Control Systems. EPICS will therefore be used to provide distributed high-level access to all subsystems of the SNS conventional facilities, including cooling water towers, chilled water, de-ionized water, HVAC, waste processing, and power monitoring. EPICS will provide operator displays and high-level control for more than 1000 process variables. EPICS support will be provided by four IOCs using PowerPC-based VMEbus controllers . Low-level control will be provided by Allen-Bradley ControlLogix PLCs that will communicate among themselves using ControlNet and with EPICS using EtherNet/IP [2]. Both the PLC layer and the EPICS layer will be implemented by an industrial supplier. File server support will be Linux-based and Concurrent Versions System (CVS) will be used to manage version control, both for EPICS and for PLC program and configuration files. All system process variable names, hardware, softw...

  18. High power parallel ultrashort pulse laser processing

    Science.gov (United States)

    Gillner, Arnold; Gretzki, Patrick; Büsing, Lasse

    2016-03-01

    The class of ultra-short-pulse (USP) laser sources are used, whenever high precession and high quality material processing is demanded. These laser sources deliver pulse duration in the range of ps to fs and are characterized with high peak intensities leading to a direct vaporization of the material with a minimum thermal damage. With the availability of industrial laser source with an average power of up to 1000W, the main challenge consist of the effective energy distribution and disposition. Using lasers with high repetition rates in the MHz region can cause thermal issues like overheating, melt production and low ablation quality. In this paper, we will discuss different approaches for multibeam processing for utilization of high pulse energies. The combination of diffractive optics and conventional galvometer scanner can be used for high throughput laser ablation, but are limited in the optical qualities. We will show which applications can benefit from this hybrid optic and which improvements in productivity are expected. In addition, the optical limitations of the system will be compiled, in order to evaluate the suitability of this approach for any given application.

  19. Fibrous zinc anodes for high power batteries

    Science.gov (United States)

    Zhang, X. Gregory

    This paper introduces newly developed solid zinc anodes using fibrous material for high power applications in alkaline and large size zinc-air battery systems. The improved performance of the anodes in these two battery systems is demonstrated. The possibilities for control of electrode porosity and for anode/battery design using fibrous materials are discussed in light of experimental data. Because of its mechanical integrity and connectivity, the fibrous solid anode has good electrical conductivity, mechanical stability, and design flexibility for controlling mass distribution, porosity and effective surface area. Experimental data indicated that alkaline cells made of such anodes can have a larger capacity at high discharging currents than commercially available cells. It showed even greater improvement over commercial cells with a non-conventional cell design. Large capacity anodes for a zinc-air battery have also been made and have shown excellent material utilization at various discharge rates. The zinc-air battery was used to power an electric bicycle and demonstrated good results.

  20. Optics assembly for high power laser tools

    Science.gov (United States)

    Fraze, Jason D.; Faircloth, Brian O.; Zediker, Mark S.

    2016-06-07

    There is provided a high power laser rotational optical assembly for use with, or in high power laser tools for performing high power laser operations. In particular, the optical assembly finds applications in performing high power laser operations on, and in, remote and difficult to access locations. The optical assembly has rotational seals and bearing configurations to avoid contamination of the laser beam path and optics.

  1. Optics assembly for high power laser tools

    Energy Technology Data Exchange (ETDEWEB)

    Fraze, Jason D.; Faircloth, Brian O.; Zediker, Mark S.

    2016-06-07

    There is provided a high power laser rotational optical assembly for use with, or in high power laser tools for performing high power laser operations. In particular, the optical assembly finds applications in performing high power laser operations on, and in, remote and difficult to access locations. The optical assembly has rotational seals and bearing configurations to avoid contamination of the laser beam path and optics.

  2. Review of Power System Stability with High Wind Power Penetration

    DEFF Research Database (Denmark)

    Hu, Rui; Hu, Weihao; Chen, Zhe

    2015-01-01

    analyzing methods and stability improvement approaches. With increasing wind power penetration, system balancing and the reduced inertia may cause a big threaten for stable operation of power systems. To mitigate or eliminate the wind impacts for high wind penetration systems, although the practical......This paper presents an overview of researches on power system stability with high wind power penetration including analyzing methods and improvement approaches. Power system stability issues can be classified diversely according to different considerations. Each classified issue has special...... and reliable choices currently are the strong outside connections or sufficient reserve capacity constructions, many novel theories and approaches are invented to investigate the stability issues, looking forward to an extra-high penetration or totally renewable resource based power systems. These analyzing...

  3. Impacts of the Minamata Convention for Mercury Emissions from Coal-fired Power Generation in Asia

    Science.gov (United States)

    Giang, A.; Stokes, L. C.; Streets, D. G.; Corbitt, E. S.; Selin, N. E.

    2014-12-01

    We explore the potential implications of the recently signed United Nations Minamata Convention on Mercury for emissions from coal-fired power generation in Asia, and the impacts of these emissions changes on deposition of mercury worldwide by 2050. We use qualitative interviews, document analysis, and engineering analysis to create plausible technology scenarios consistent with the Convention, taking into account both technological and political factors. We translate these scenarios into possible emissions inventories for 2050, based on IPCC development scenarios, and then use the GEOS-Chem global transport model to evaluate the effect of these different technology choices on mercury deposition over geographic regions and oceans. We find that China is most likely to address mercury control through co-benefits from technologies for SO2, NOx, and particulate matter (PM) capture that will be required to attain its existing air quality goals. In contrast, India is likely to focus on improvements to plant efficiency such as upgrading boilers, and coal washing. Compared to current technologies, we project that these changes will result in emissions decreases of approximately 140 and 190 Mg/yr for China and India respectively in 2050, under an A1B development scenario. With these emissions reductions, simulated average gross deposition over India and China are reduced by approximately 10 and 3 μg/m2/yr respectively, and the global average concentration of total gaseous mercury (TGM) is reduced by approximately 10% in the Northern hemisphere. Stricter, but technologically feasible, requirements for mercury control in both countries could lead to an additional 200 Mg/yr of emissions reductions. Modeled differences in concentration and deposition patterns between technology suites are due to differences in both the mercury removal efficiency of technologies and their resulting stack speciation.

  4. A high-power switch-mode dc power supply for dynamic loads

    Energy Technology Data Exchange (ETDEWEB)

    Shimer, D.W.; Lange, A.C. [Lawrence Livermore National Lab., CA (United States); Bombay, J.N. [Kaiser Engineers, Oakland, CA (United States)

    1994-06-23

    High-voltage dc power supplies are often required to operate with highly dynamic loads, such as arcs. A switch-mode dc power supply can offer significant advantages over conventional thyristor-based dc power supplies under such conditions. It can quickly turn off the supply to extinguish the arc, and it can quickly recover after the arc. It has a relatively small output filter capacitance, which results in small stored energy available to the arc. A 400-kW, 50-kV switch-mode dc power supply for an electron-beam gun that exploits these advantages was designed and tested. It uses four 100-kW, current-source-type dc-dc converters with inputs in parallel and outputs in series. The dc-dc converters operate at 20 kHz in the voltage regulator part and 10 kHz in the inverter, transformer, and output rectifier part of the circuit. Insulated gate bipolar transistors (IGBTs) are used as the power switches. Special techniques are used to protect the power supply and load against arcs and hard shorts. The power supply has an efficiency of 93%, an output voltage ripple of 1%, and fast dynamic response. In addition, it is nearly one-third the size of conventional power supplies.

  5. ULTRA HIGH POWER TRANSMISSION LINE TECHNIQUES

    Science.gov (United States)

    The ultra-high power transmission line techniques including both failure mechanisms and component design are discussed. Failures resulting from...a waveguide. In view of the many advantages of the low loss mode in circular waveguide for ultra-high power levels, a mode transducer and a two...percent of the peak power of a standard rectangular wave guide. Water cooling is provided for high average power operation. Analysis of mode sup pression

  6. Optimization study of large-scale low-grade energy recovery from conventional Rankine cycle power plants

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, K.M.; Bettle, M.C.; Gerber, A.G.; Hall, J.W. [University of New Brunswick, Fredericton, NB (Canada). Dept. of Mechanical Engineering

    2010-10-10

    This study evaluates large-scale low-grade energy recovery (LS-LGER) from a conventional coal-fired Rankine cycle (RC) as a 'green' option to offsetting the cost of treating pollution. An energy and exergy analysis of a reference-generating station isolates the key areas for investigation into LS-LGER. This is followed by a second law analysis and a detailed optimization study for a revised RC configuration, which provides a conservative estimate of the possible energy recovery. Cycle optimization based on specific power output, and including compact heat exchanger designs, indicates plant efficiency improvements (with high-capacity equipment) of approximately 2 percentage points with reduced environmental impact.

  7. Electronic DC transformer with high power density

    NARCIS (Netherlands)

    Pavlovský, M.

    2006-01-01

    This thesis is concerned with the possibilities of increasing the power density of high-power dc-dc converters with galvanic isolation. Three cornerstones for reaching high power densities are identified as: size reduction of passive components, reduction of losses particularly in active components

  8. Quantitative comparison of tumor vascularity of HCC after intravenous contrast Agent: Conventional versus harmonic power Doppler US

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seong Ho; Kim, Tae Kyoung; Lee, Kyoung Ho; Kim, Ah Young; Han, Joon Koo; Choi, Byung Ihn [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1999-09-15

    For the quantitative comparison of the degree of enhancement in nodular hepatocellular carcinoma (HCC) at conventional and harmonic Power Doppler (PD) ultrasound (US). The average of %PDA of ten nodules gradually increased until 60 seconds after contrast injection and then gradually decreased. The average %PDA on conventional and harmonic PD US at 60 seconds were 34.9% and 19.5%, respectively. The average %PDA were significantly higher on conventional PD US than those on harmonic PD US at all times except at 20 seconds. The ratio of average %pda on conventional PD US to those on harmonic PD US became gradually larger after 120 seconds. Although contrast-enhanced harmonic PD US can be an effective method in evaluating the tumor vascularity of HCC because of less PD artifacts, the duration of effective enhancement was shorter and degree of enhancement is less than that of conventional PD US.

  9. High Temperature, High Power Piezoelectric Composite Transducers

    OpenAIRE

    Hyeong Jae Lee; Shujun Zhang; Yoseph Bar-Cohen; Stewart Sherrit

    2014-01-01

    Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have le...

  10. High Power Fiber Laser Test Bed

    Data.gov (United States)

    Federal Laboratory Consortium — This facility, unique within DoD, power-combines numerous cutting-edge fiber-coupled laser diode modules (FCLDM) to integrate pumping of high power rare earth-doped...

  11. High power RF solid state power amplifier system

    Science.gov (United States)

    Sims, III, William Herbert (Inventor); Chavers, Donald Gregory (Inventor); Richeson, James J. (Inventor)

    2011-01-01

    A high power, high frequency, solid state power amplifier system includes a plurality of input multiple port splitters for receiving a high-frequency input and for dividing the input into a plurality of outputs and a plurality of solid state amplifier units. Each amplifier unit includes a plurality of amplifiers, and each amplifier is individually connected to one of the outputs of multiport splitters and produces a corresponding amplified output. A plurality of multiport combiners combine the amplified outputs of the amplifiers of each of the amplifier units to a combined output. Automatic level control protection circuitry protects the amplifiers and maintains a substantial constant amplifier power output.

  12. High Power Performance of Rod Fiber Amplifiers

    DEFF Research Database (Denmark)

    Johansen, Mette Marie; Michieletto, Mattia; Kristensen, Torben

    2015-01-01

    An improved version of the DMF rod fiber is tested in a high power setup delivering 360W of stable signal power. Multiple testing degrades the fiber and transverse modal instability threshold from >360W to ~290W.......An improved version of the DMF rod fiber is tested in a high power setup delivering 360W of stable signal power. Multiple testing degrades the fiber and transverse modal instability threshold from >360W to ~290W....

  13. High-speed Power Line Communications

    Directory of Open Access Journals (Sweden)

    Matthew N. O. Sadiku,

    2015-11-01

    Full Text Available This is the idea of using existing power lines for communication purposes. Power line communications (PLC enables network communication of voice, data, and video over direct power lines. High-speed PLC involves data rates in excess of 10 Mbps. PLC has attracted a lot of attention and has become an interesting subject of research lately.

  14. Coordination Between Wind Power, Hydro Storage Facility and Conventional Generating Units According to the Annual Growth Load

    Directory of Open Access Journals (Sweden)

    Shahrokh Shojaeean

    2013-04-01

    Full Text Available Considering the growing trend of the consumption of the electric power and the global tendency to substitute new renewable sources of energy, this paper proposes a Monte Carlo based method to determine an optimal level of this change. Considering the limitation of the wind farms in continuous supply of electric power, hydrostatic power storage facilities are used beside wind farms so that the electric power could be stored and fed in a continuous flow into power systems. Due to the gradual exclusion of conventional generators and 5 percent annual load increments, LOLE index was used in order to calculate the amount of the wind power and the capacity of the necessary power storage facility. To this end, LOLE index was calculated for the first year as the reference index for the estimation of the amount of wind power and the capacity of the storage facility in consequent years. For the upcoming years, calculations have been made to account for the gradual exclusion of conventional generators in proportion to load increments. The proposed method has been implemented and simulated on IEEE-RTS test system.

  15. Controlled Compact High Voltage Power Lines

    Directory of Open Access Journals (Sweden)

    Postolati V.

    2016-04-01

    Full Text Available Nowadays modern overhead transmission lines (OHL constructions having several significant differences from conventional ones are being used in power grids more and more widely. Implementation of compact overhead lines equipped with FACTS devices, including phase angle regulator settings (compact controlled OHL, appears to be one of the most effective ways of power grid development. Compact controlled AC HV OHL represent a new generation of power transmission lines embodying recent advanced achievements in design solutions, including towers and insulation, together with interconnection schemes and control systems. Results of comprehensive research and development in relation to 110–500kV compact controlled power transmission lines together with theoretical basis, substantiation, and methodological approaches to their practical application are presented in the present paper.

  16. High Average Power Yb:YAG Laser

    Energy Technology Data Exchange (ETDEWEB)

    Zapata, L E; Beach, R J; Payne, S A

    2001-05-23

    We are working on a composite thin-disk laser design that can be scaled as a source of high brightness laser power for tactical engagement and other high average power applications. The key component is a diffusion-bonded composite comprising a thin gain-medium and thicker cladding that is strikingly robust and resolves prior difficulties with high average power pumping/cooling and the rejection of amplified spontaneous emission (ASE). In contrast to high power rods or slabs, the one-dimensional nature of the cooling geometry and the edge-pump geometry scale gracefully to very high average power. The crucial design ideas have been verified experimentally. Progress this last year included: extraction with high beam quality using a telescopic resonator, a heterogeneous thin film coating prescription that meets the unusual requirements demanded by this laser architecture, thermal management with our first generation cooler. Progress was also made in design of a second-generation laser.

  17. High Power/High Temperature Battery Development

    Science.gov (United States)

    1992-09-01

    dcruit stand The bipolar conliguration permits cello be closely packed, share cell walls, and combine the functions of wall and intercell connector. The...LUthco Symp. on Lithium Chem., Ed. R. Bach , John Wiley and Sons, N.Y. M. Wliams, st. al., Proc. 32nd Power Sources Conf., p 658 If (1986). C.D...on Electron Devices ATTN: Documents 2011 Crystal Drive, Suite 307 002 Adington, VA 22202 Page 43 Plop 2 O nlPage Elstronlo Technooyand DvcsLaomtory

  18. 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.

  19. Packaging of high power semiconductor lasers

    CERN Document Server

    Liu, Xingsheng; Xiong, Lingling; Liu, Hui

    2014-01-01

    This book introduces high power semiconductor laser packaging design. The characteristics and challenges of the design and various packaging, processing, and testing techniques are detailed by the authors. New technologies, in particular thermal technologies, current applications, and trends in high power semiconductor laser packaging are described at length and assessed.

  20. High power laser perforating tools and systems

    Science.gov (United States)

    Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

    2014-04-22

    ystems devices and methods for the transmission of 1 kW or more of laser energy deep into the earth and for the suppression of associated nonlinear phenomena. Systems, devices and methods for the laser perforation of a borehole in the earth. These systems can deliver high power laser energy down a deep borehole, while maintaining the high power to perforate such boreholes.

  1. Integration of high capacity materials into interdigitated mesostructured electrodes for high energy and high power density primary microbatteries

    Science.gov (United States)

    Pikul, James H.; Liu, Jinyun; Braun, Paul V.; King, William P.

    2016-05-01

    Microbatteries are increasingly important for powering electronic systems, however, the volumetric energy density of microbatteries lags behind that of conventional format batteries. This paper reports a primary microbattery with energy density 45.5 μWh cm-2 μm-1 and peak power 5300 μW cm-2 μm-1, enabled by the integration of large volume fractions of high capacity anode and cathode chemistry into porous micro-architectures. The interdigitated battery electrodes consist of a lithium metal anode and a mesoporous manganese oxide cathode. The key enabler of the high energy and power density is the integration of the high capacity manganese oxide conversion chemistry into a mesostructured high power interdigitated bicontinuous cathode architecture and an electrodeposited dense lithium metal anode. The resultant energy density is greater than previously reported three-dimensional microbatteries and is comparable to commercial conventional format lithium-based batteries.

  2. Evolution of Very High Frequency Power Supplies

    DEFF Research Database (Denmark)

    Knott, Arnold; Andersen, Toke Meyer; Kamby, Peter

    2013-01-01

    in radio frequency transmission equipment helps to overcome those. However those circuits were not designed to meet the same requirements as power converters. This paper summarizes the contributions in recent years in application of very high frequency (VHF) technologies in power electronics, shows results......The ongoing demand for smaller and lighter power supplies is driving the motivation to increase the switching frequencies of power converters. Drastic increases however come along with new challenges, namely the increase of switching losses in all components. The application of power circuits used...

  3. High-power optics lasers and applications

    CERN Document Server

    Apollonov, Victor V

    2015-01-01

    This book covers the basics, realization and materials for high power laser systems and high power radiation interaction with  matter. The physical and technical fundamentals of high intensity laser optics and adaptive optics and the related physical processes in high intensity laser systems are explained. A main question discussed is: What is power optics? In what way is it different from ordinary optics widely used in cameras, motion-picture projectors, i.e., for everyday use? An undesirable consequence of the thermal deformation of optical elements and surfaces was discovered during studies of the interaction with powerful incident laser radiation. The requirements to the fabrication, performance and quality of optical elements employed within systems for most practical applications are also covered. The high-power laser performance is generally governed by the following: (i) the absorption of incident optical radiation (governed primarily by various absorption mechanisms), (ii) followed by a temperature ...

  4. High-Efficiency Helical Coil Electromagnetic Launcher and High Power Hall-Effect Switch

    Science.gov (United States)

    2008-02-29

    Expressions for electromagnetic force, efficiency, back-voltage, and kinetic power are derived and given in terms of electrical circuit parameters. Launcher...helical electromagnetic launcher which is subsequently compared to a one-turn augmented railgun and a conventional railgun operating at comparable scale...Efficiency Helical Coil Electromagnetic Launcher and High Power Hall-Effect Switch by T.G. Engel, W.C. Nunnally, and J.M. Gahl Center for Energy Conversion

  5. High temperature power electronics for space

    Science.gov (United States)

    Hammoud, Ahmad N.; Baumann, Eric D.; Myers, Ira T.; Overton, Eric

    1991-01-01

    A high temperature electronics program at NASA Lewis Research Center focuses on dielectric and insulating materials research, development and testing of high temperature power components, and integration of the developed components and devices into a demonstrable 200 C power system, such as inverter. An overview of the program and a description of the in-house high temperature facilities along with experimental data obtained on high temperature materials are presented.

  6. Performance of improved magnetostrictive vibrational power generator, simple and high power output for practical applications

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, Toshiyuki, E-mail: ueno@ec.t.kanazawa-u.ac.jp [Kanazawa University, Kakuma-machi, Kanazawa-city, Ishikawa 920-1192 (Japan)

    2015-05-07

    Vibration based power generation technology is utilized effectively in various fields. Author has invented novel vibrational power generation device using magnetostrictive material. The device is based on parallel beam structure consisting of a rod of iron-gallium alloy wound with coil and yoke accompanied with permanent magnet. When bending force is applied on the tip of the device, the magnetization inside the rod varies with induced stress due to the inverse magnetostrictive effect. In vibration, the time variation of the magnetization generates voltage on the wound coil. The magnetostrictive type is advantageous over conventional such using piezoelectric or moving magnet types in high efficiency and high robustness, and low electrical impedance. Here, author has established device configuration, simple, rigid, and high power output endurable for practical applications. In addition, the improved device is lower cost using less volume of Fe-Ga and permanent magnet compared to our conventional, and its assembly by soldering is easy and fast suitable for mass production. Average power of 3 mW/cm{sup 3} under resonant vibration of 212 Hz and 1.2 G was obtained in miniature prototype using Fe-Ga rod of 2 × 0.5× 7 mm{sup 3}. Furthermore, the damping effect was observed, which demonstrates high energy conversion of the generator.

  7. Powering the High-Luminosity Triplets

    CERN Document Server

    Ballarino, A

    2015-01-01

    The powering of the magnets in the LHC High-Luminosity Triplets requires production and transfer of more than 150 kA of DC current. High precision power converters will be adopted, and novel High Temperature Superconducting (HTS) current leads and MgB2 based transfer lines will provide the electrical link between the power converters and the magnets. This chapter gives an overview of the systems conceived in the framework of the LHC High-Luminosity upgrade for feeding the superconducting magnet circuits. The focus is on requirements, challenges and novel developments.

  8. High power solid state switches

    Science.gov (United States)

    Gundersen, Martin

    1991-11-01

    We have successfully produced an optically triggered thyristor based in Gallium Arsenide, developed a model for breakdown, and are developing two related devices, including a Gallium Arsenide based static inductor thyristor. We are getting at the basic limitations of Gallium Arsenide for these applications, and are developing models for the physical processes that will determine device limitations. The previously supported gas phase work - resulting in the back-lighted thyratron (BLT) - has actually resulted in a very changed view of how switching can be accomplished, and this is impacting the design of important machines. The BLT is being studied internationally: in Japan for laser fusion and laser isotope separation. ITT has built a BLT that has switched 30 kA at 60 kV in testing at NSWC Dahlgren and the device is being commercialized by another American company. Versions of the switch are now being tested for excimer laser and other applications. Basically, the switch, which arose from pulse power physics studies at USC, can switch more current faster (higher di/dt), with less housekeeping, and with other advantageous properties. There are a large number of other new applications, include kinetic energy weapons, pulsed microwave sources and R.F. accelerators.

  9. High-Temperature Passive Power Electronics

    Science.gov (United States)

    1997-01-01

    In many future NASA missions - such as deep-space exploration, the National AeroSpace Plane, minisatellites, integrated engine electronics, and ion or arcjet thrusters - high-power electrical components and systems must operate reliably and efficiently in high-temperature environments. The high-temperature power electronics program at the NASA Lewis Research Center focuses on dielectric and insulating material research, the development and characterization of high-temperature components, and the integration of the developed components into a demonstrable 200 C power system - such as an inverter. NASA Lewis has developed high-temperature power components through collaborative efforts with the Air Force Wright Laboratory, Northrop Grumman, and the University of Wisconsin. Ceramic and film capacitors, molypermalloy powder inductors, and a coaxially wound transformer were designed, developed, and evaluated for high-temperature operation.

  10. Low Power Design with High-Level Power Estimation and Power-Aware Synthesis

    CERN Document Server

    Ahuja, Sumit; Shukla, Sandeep Kumar

    2012-01-01

    Low-power ASIC/FPGA based designs are important due to the need for extended battery life, reduced form factor, and lower packaging and cooling costs for electronic devices. These products require fast turnaround time because of the increasing demand for handheld electronic devices such as cell-phones, PDAs and high performance machines for data centers. To achieve short time to market, design flows must facilitate a much shortened time-to-product requirement. High-level modeling, architectural exploration and direct synthesis of design from high level description enable this design process. This book presents novel research techniques, algorithms,methodologies and experimental results for high level power estimation and power aware high-level synthesis. Readers will learn to apply such techniques to enable design flows resulting in shorter time to market and successful low power ASIC/FPGA design. Integrates power estimation and reduction for high level synthesis, with low-power, high-level design; Shows spec...

  11. High Power Picosecond Laser Pulse Recirculation

    Energy Technology Data Exchange (ETDEWEB)

    Shverdin, M Y; Jovanovic, I; Semenov, V A; Betts, S M; Brown, C; Gibson, D J; Shuttlesworth, R M; Hartemann, F V; Siders, C W; Barty, C P

    2010-04-12

    We demonstrate a nonlinear crystal-based short pulse recirculation cavity for trapping the second harmonic of an incident high power laser pulse. This scheme aims to increase the efficiency and flux of Compton-scattering based light sources. We demonstrate up to 36x average power enhancement of frequency doubled sub-millijoule picosecond pulses, and 17x average power enhancement of 177 mJ, 10 ps, 10 Hz pulses.

  12. High-power picosecond laser pulse recirculation.

    Science.gov (United States)

    Shverdin, M Y; Jovanovic, I; Semenov, V A; Betts, S M; Brown, C; Gibson, D J; Shuttlesworth, R M; Hartemann, F V; Siders, C W; Barty, C P J

    2010-07-01

    We demonstrate a nonlinear crystal-based short pulse recirculation cavity for trapping the second harmonic of an incident high-power laser pulse. This scheme aims to increase the efficiency and flux of Compton-scattering-based light sources. We demonstrate up to 40x average power enhancement of frequency-doubled submillijoule picosecond pulses, and 17x average power enhancement of 177 mJ, 10 ps, 10 Hz pulses.

  13. Numerical Analysis on Key Structure of Super High Pressure Hydraulic Bolt Stretcher for Conventional Island of Nuclear Power%核电常规岛用超高液压螺栓拉伸器关键结构的数值分析

    Institute of Scientific and Technical Information of China (English)

    张澄东; 浦琪琦; 张江涛; 李萍

    2014-01-01

    针对核电常规岛用螺栓拉伸器具有超高压、超小空间作业工况的特性,提出一种基于数值分析与实验相接合的设计方法,运用ANSYS软件对螺栓拉伸器关键结构---缸体与螺帽进行有限元校核,并与测定的应变实验数据进行对比;同时分析参数Rm、D对螺帽结构的优化特性。研究结果表明:初设的缸体强度和刚度满足材料的要求,但螺帽在“L型”截面拐点处出现“负”安全系数;优化螺帽结构尺寸,当Rm =8 mm,D=60 mm时与初设参数相比应力减小了121.2%,应变减小了58%,安全系数得到极大提高,这为该设备的可靠性和安全性提供了设计依据。%Aiming at the characteristics that the bolt stretcher for conventional island of nuclear power has the ultra high pres-sure,ultra small space operation conditions,a design method based on numerical analysis and experiment was presented,the ANSYS software was used to check the cylinder block and blind nut,and the analysis results were compared with the experimental strain data. The optimization characteristices of the parameters Rm ,D on the blind nut were analyzed. The results show that:the strength and stiff-ness of first set of cylinder block can meet the material requirements,but the blind nut has“negative”safety factor in the inflection point of“L”section;optimizing the blind nut structure size,when Rm and D are equal to 8 mm and 60 mm respectively,the stress de-creases by 121.2% and the strain decreases by 58% comparing with initial parameters,the safety coefficient is heightened,which pro-vides design basis for the reliability and safety of the equipment.

  14. High Power Co-Axial Coupler

    Energy Technology Data Exchange (ETDEWEB)

    Neubauer, M. [Muons, Inc.; Dudas, A. [Muons, Inc.; Rimmer, Robert A. [JLAB; Guo, Jiquan [JLAB; Williams, R. Scott [JLAB

    2013-12-01

    A very high power Coax RF Coupler (MW-Level) is very desirable for a number of accelerator and commercial applications. For example, the development of such a coupler operating at 1.5 GHz may permit the construction of a higher-luminosity version of the Electron-Ion Collider (EIC) being planned at JLab. Muons, Inc. is currently funded by a DOE STTR grant to develop a 1.5-GHz high-power doublewindowcoax coupler with JLab (about 150 kW). Excellent progress has been made on this R&D project, so we propose an extension of this development to build a very high power coax coupler (MW level peak power and a max duty factor of about 4%). The dimensions of the current coax coupler will be scaled up to provide higher power capability.

  15. High-power atomic xenon laser

    NARCIS (Netherlands)

    Witteman, W.J.; Peters, P.J.M.; Botma, H.; Botma, H.; Tskhai, S.N.; Udalov, Yu.B.; Mei, Q.C.; Mei, Qi-Chu; Ochkin, V.N.

    1995-01-01

    The high pressure atomic xenon laser is becoming the most promising light source in the wavelength region of a few microns. The merits are high efficiency (so far up to 8 percent), high output energies (15 J/liter at 9 bar), high continuous output power (more than 200 W/liter), no gas dissociation a

  16. High average-power induction linacs

    Energy Technology Data Exchange (ETDEWEB)

    Prono, D.S.; Barrett, D.; Bowles, E.; Caporaso, G.J.; Chen, Yu-Jiuan; Clark, J.C.; Coffield, F.; Newton, M.A.; Nexsen, W.; Ravenscroft, D.

    1989-03-15

    Induction linear accelerators (LIAs) are inherently capable of accelerating several thousand amperes of /approximately/ 50-ns duration pulses to > 100 MeV. In this paper we report progress and status in the areas of duty factor and stray power management. These technologies are vital if LIAs are to attain high average power operation. 13 figs.

  17. A Survey of Non-conventional Techniques for Low-voltage Low-power Analog Circuit Design

    Directory of Open Access Journals (Sweden)

    F. Khateb

    2013-06-01

    Full Text Available Designing integrated circuits able to work under low-voltage (LV low-power (LP condition is currently undergoing a very considerable boom. Reducing voltage supply and power consumption of integrated circuits is crucial factor since in general it ensures the device reliability, prevents overheating of the circuits and in particular prolongs the operation period for battery powered devices. Recently, non-conventional techniques i.e. bulk-driven (BD, floating-gate (FG and quasi-floating-gate (QFG techniques have been proposed as powerful ways to reduce the design complexity and push the voltage supply towards threshold voltage of the MOS transistors (MOST. Therefore, this paper presents the operation principle, the advantages and disadvantages of each of these techniques, enabling circuit designers to choose the proper design technique based on application requirements. As an example of application three operational transconductance amplifiers (OTA base on these non-conventional techniques are presented, the voltage supply is only ±0.4 V and the power consumption is 23.5 µW. PSpice simulation results using the 0.18 µm CMOS technology from TSMC are included to verify the design functionality and correspondence with theory.

  18. HTR-Based Power Plants’ Performance Analysis Applied on Conventional Combined Cycles

    Directory of Open Access Journals (Sweden)

    José Carbia Carril

    2015-01-01

    Full Text Available In high temperature reactors including gas cooled fast reactors and gas turbine modular helium reactors (GT-MHR specifically designed to operate as power plant heat sources, efficiency enhancement at effective cost under safe conditions can be achieved. Mentioned improvements concern the implementation of two cycle structures: (a, a stand alone Brayton operating with helium and a stand alone Rankine cycle (RC with regeneration, operating with carbon dioxide at ultrasupercritical pressure as working fluid (WF, where condensation is carried out at quasicritical conditions, and (b, a combined cycle (CC, in which the topping closed Brayton cycle (CBC operates with helium as WF, while the bottoming RC is operated with one of the following WFs: carbon dioxide, xenon, ethane, ammonia, or water. In both cases, an intermediate heat exchanger (IHE is proposed to provide thermal energy to the closed Brayton or to the Rankine cycles. The results of the case study show that the thermal efficiency, through the use of a CC, is slightly improved (from 45.79% for BC and from 50.17% for RC to 53.63 for the proposed CC with He-H2O operating under safety standards.

  19. 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...

  20. Advances in Very High Frequency Power Conversion

    DEFF Research Database (Denmark)

    Kovacevic, Milovan

    . Excellent performance and small size of magnetic components and capacitors at very high frequencies, along with constant advances in performance of power semiconductor devices, suggests a sizable shift in consumer power supplies market into this area in the near future. To operate dc-dc converter power...... to be applied, especially at low power levels where gating loss becomes a significant percentage of the total loss budget. Various resonant gate drive methods have been proposed to address this design challenge, with varying size, cost, and complexity. This dissertation presents a self-oscillating resonant gate...

  1. Highly-efficient high-power pumps for fiber lasers

    Science.gov (United States)

    Gapontsev, V.; Moshegov, N.; Berezin, I.; Komissarov, A.; Trubenko, P.; Miftakhutdinov, D.; Berishev, I.; Chuyanov, V.; Raisky, O.; Ovtchinnikov, A.

    2017-02-01

    We report on high efficiency multimode pumps that enable ultra-high efficiency high power ECO Fiber Lasers. We discuss chip and packaged pump design and performance. Peak out-of-fiber power efficiency of ECO Fiber Laser pumps was reported to be as high as 68% and was achieved with passive cooling. For applications that do not require Fiber Lasers with ultimate power efficiency, we have developed passively cooled pumps with out-of-fiber power efficiency greater than 50%, maintained at operating current up to 22A. We report on approaches to diode chip and packaged pump design that possess such performance.

  2. High power density carbonate fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Yuh, C.; Johnsen, R.; Doyon, J.; Allen, J. [Energy Research Corp., Danbury, CT (United States)

    1996-12-31

    Carbonate fuel cell is a highly efficient and environmentally clean source of power generation. Many organizations worldwide are actively pursuing the development of the technology. Field demonstration of multi-MW size power plant has been initiated in 1996, a step toward commercialization before the turn of the century, Energy Research Corporation (ERC) is planning to introduce a 2.85MW commercial fuel cell power plant with an efficiency of 58%, which is quite attractive for distributed power generation. However, to further expand competitive edge over alternative systems and to achieve wider market penetration, ERC is exploring advanced carbonate fuel cells having significantly higher power densities. A more compact power plant would also stimulate interest in new markets such as ships and submarines where space limitations exist. The activities focused on reducing cell polarization and internal resistance as well as on advanced thin cell components.

  3. High Power Density Power Electronic Converters for Large Wind Turbines

    DEFF Research Database (Denmark)

    Senturk, Osman Selcuk

    In large wind turbines (in MW and multi-MW ranges), which are extensively utilized in wind power plants, full-scale medium voltage (MV) multi-level (ML) voltage source converters (VSCs) are being more preferably employed nowadays for interfacing these wind turbines with electricity grids...... assessments of these specific VSCs so that their power densities and reliabilities are quantitatively determined, which requires extensive utilization of the electro-thermal models of the VSCs under investigation. In this thesis, the three-level neutral-point-clamped VSCs (3L-NPC-VSCs), which are classified......-HB-VSCs). As the switch technology for realizing these 3L-VSCs, press-pack IGBTs are chosen to ensure high power density and reliability. Based on the selected 3L-VSCs and switch technology, the converter electro-thermal models are developed comprehensively, implemented practically, and validated via a full-scale 3L...

  4. High Power Helicon Plasma Propulsion Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed work seeks to develop and optimize an electrode-less plasma propulsion system that is based on a high power helicon (HPH) that is being developed...

  5. High Power Helicon Plasma Propulsion Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A new thruster has been conceived and tested that is based on a high power helicon (HPH) plasma wave. In this new method of propulsion, an antenna generates and...

  6. Drivers for High Power Laser Diodes

    Institute of Scientific and Technical Information of China (English)

    Yankov P; Todorov D; Saramov E

    2006-01-01

    During the last year the high power laser diodes jumped over the 1 kW level of CW power for a stack,and the commercial 1 cm bars reached 100 W output optical power at the standard wavelengths around 800 nm and 980 nm. The prices are reaching the industry acceptable levels. All Nd:YAG and fiber industrial lasers manufacturers have developed kW prototypes. Those achievements have set new requirements for the power supplies manufactuers-high and stable output current, and possibilities for fast control of the driving current, keeping safe the expensive laser diode. The fast switching frequencies also allow long range free space communications and optical range finding. The high frequencies allow the design of a 3D laser radar with high resolution and other military applications. The prospects for direct laser diode micro machining are also attractive.

  7. Coupling output of multichannel high power microwaves

    Science.gov (United States)

    Li, Guolin; Shu, Ting; Yuan, Chengwei; Zhang, Jun; Yang, Jianhua; Jin, Zhenxing; Yin, Yi; Wu, Dapeng; Zhu, Jun; Ren, Heming; Yang, Jie

    2010-12-01

    The coupling output of multichannel high power microwaves is a promising technique for the development of high power microwave technologies, as it can enhance the output capacities of presently studied devices. According to the investigations on the spatial filtering method and waveguide filtering method, the hybrid filtering method is proposed for the coupling output of multichannel high power microwaves. As an example, a specific structure is designed for the coupling output of S/X/X band three-channel high power microwaves and investigated with the hybrid filtering method. In the experiments, a pulse of 4 GW X band beat waves and a pulse of 1.8 GW S band microwave are obtained.

  8. High power regenerative laser amplifier

    Science.gov (United States)

    Miller, J.L.; Hackel, L.A.; Dane, C.B.; Zapata, L.E.

    1994-02-08

    A regenerative amplifier design capable of operating at high energy per pulse, for instance, from 20-100 Joules, at moderate repetition rates, for instance from 5-20 Hertz is provided. The laser amplifier comprises a gain medium and source of pump energy coupled with the gain medium; a Pockels cell, which rotates an incident beam in response to application of a control signal; an optical relay system defining a first relay plane near the gain medium and a second relay plane near the rotator; and a plurality of reflectors configured to define an optical path through the gain medium, optical relay and Pockels cell, such that each transit of the optical path includes at least one pass through the gain medium and only one pass through the Pockels cell. An input coupler, and an output coupler are provided, implemented by a single polarizer. A control circuit coupled to the Pockels cell generates the control signal in timed relationship with the input pulse so that the input pulse is captured by the input coupler and proceeds through at least one transit of the optical path, and then the control signal is applied to cause rotation of the pulse to a polarization reflected by the polarizer, after which the captured pulse passes through the gain medium at least once more and is reflected out of the optical path by the polarizer before passing through the rotator again to provide an amplified pulse. 7 figures.

  9. High Voltage Power Transmission for Wind Energy

    Science.gov (United States)

    Kim, Young il

    The high wind speeds and wide available area at sea have recently increased the interests on offshore wind farms in the U.S.A. As offshore wind farms become larger and are placed further from the shore, the power transmission to the onshore grid becomes a key feature. Power transmission of the offshore wind farm, in which good wind conditions and a larger installation area than an onshore site are available, requires the use of submarine cable systems. Therefore, an underground power cable system requires unique design and installation challenges not found in the overhead power cable environment. This paper presents analysis about the benefit and drawbacks of three different transmission solutions: HVAC, LCC/VSC HVDC in the grid connecting offshore wind farms and also analyzed the electrical characteristics of underground cables. In particular, loss of HV (High Voltage) subsea power of the transmission cables was evaluated by the Brakelmann's theory, taking into account the distributions of current and temperature.

  10. High Power Short Wavelength Laser Development

    Science.gov (United States)

    1977-11-01

    Unlimited güä^äsjäsiiiüüü X NRTC-77-43R P I High Power Short Wavelength Laser Development November 1977 D. B. Cohn and W. B. Lacina...NO NRTC-77-43R, «. TITLE fana »uetjjitj BEFORE COMPLETING FORM CIPIENT’S CATALOO NUMBER KIGH.POWER SHORT WAVELENGTH LASER DEVELOPMENT , 7...fWhtn Data Enterte NRTC-77-43R HIGH POWER SHORT WAVELENGTH LASER DEVELOPMENT ARPA Order Number: Program Code Number: Contract Number: Principal

  11. A Comparative Study of the Flow Field of High Viscosity Media in Conventional/Rotary Hydrocyclones

    Institute of Scientific and Technical Information of China (English)

    Ren Liancheng; Liang Zheng; Zhong Gongxiang; Wu Shihui

    2007-01-01

    The flow fields inside conventional and rotary hydrocyclones were simulated respectively. In these simulations,water only and oil-water mixture,with distinctly different viscosities,were used as continuous phases. Simulation results agreed well with the experimental measurements. Simulation results showed that the conventional hydrocyclone could effectively separate sand from water,but could not separate sand from high viscosity water/oil emulsion. This showed that the viscosity of continuous phases influenced greatly both the separation efficiency and the flow field distribution in the conventional hydrocyclone. For high viscosity oil/water sand dispersion (mixture),the rotary hydrocyclone has better separation performance than the conventional one,with a more favorable flow field distribution.

  12. Evaluation of conventional power systems. [emphasizing fossil fuels and nuclear energy

    Science.gov (United States)

    Smith, K. R.; Weyant, J.; Holdren, J. P.

    1975-01-01

    The technical, economic, and environmental characteristics of (thermal, nonsolar) electric power plants are reviewed. The fuel cycle, from extraction of new fuel to final waste management, is included. Emphasis is placed on the fossil fuel and nuclear technologies.

  13. Small high cooling power space cooler

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, T. V.; Raab, J.; Durand, D.; Tward, E. [Northrop Grumman Aerospace Systems Redondo Beach, Ca, 90278 (United States)

    2014-01-29

    The small High Efficiency pulse tube Cooler (HEC) cooler, that has been produced and flown on a number of space infrared instruments, was originally designed to provide cooling of 10 W @ 95 K. It achieved its goal with >50% margin when limited by the 180 W output ac power of its flight electronics. It has also been produced in 2 stage configurations, typically for simultaneously cooling of focal planes to temperatures as low as 35 K and optics at higher temperatures. The need for even higher cooling power in such a low mass cryocooler is motivated by the advent of large focal plane arrays. With the current availability at NGAS of much larger power cryocooler flight electronics, reliable long term operation in space with much larger cooling powers is now possible with the flight proven 4 kg HEC mechanical cooler. Even though the single stage cooler design can be re-qualified for those larger input powers without design change, we redesigned both the linear and coaxial version passive pulse tube cold heads to re-optimize them for high power cooling at temperatures above 130 K while rejecting heat to 300 K. Small changes to the regenerator packing, the re-optimization of the tuned inertance and no change to the compressor resulted in the increased performance at 150 K. The cooler operating at 290 W input power achieves 35 W@ 150 K corresponding to a specific cooling power at 150 K of 8.25 W/W and a very high specific power of 72.5 W/Kg. At these powers the cooler still maintains large stroke, thermal and current margins. In this paper we will present the measured data and the changes to this flight proven cooler that were made to achieve this increased performance.

  14. Advances in high power semiconductor diode lasers

    Science.gov (United States)

    Ma, Xiaoyu; Zhong, Li

    2008-03-01

    High power semiconductor lasers have broad applications in the fields of military and industry. Recent advances in high power semiconductor lasers are reviewed mainly in two aspects: improvements of diode lasers performance and optimization of packaging architectures of diode laser bars. Factors which determine the performance of diode lasers, such as power conversion efficiency, temperature of operation, reliability, wavelength stabilization etc., result from a combination of new semiconductor materials, new diode structures, careful material processing of bars. The latest progress of today's high-power diode lasers at home and abroad is briefly discussed and typical data are presented. The packaging process is of decisive importance for the applicability of high-power diode laser bars, not only technically but also economically. The packaging techniques include the material choosing and the structure optimizing of heat-sinks, the bonding between the array and the heat-sink, the cooling and the fiber coupling, etc. The status of packaging techniques is stressed. There are basically three different diode package architectural options according to the integration grade. Since the package design is dominated by the cooling aspect, different effective cooling techniques are promoted by different package architectures and specific demands. The benefit and utility of each package are strongly dependent upon the fundamental optoelectronic properties of the individual diode laser bars. Factors which influence these properties are outlined and comparisons of packaging approaches for these materials are made. Modularity of package for special application requirements is an important developing tendency for high power diode lasers.

  15. Silver based batteries for high power applications

    Science.gov (United States)

    Karpinski, A. P.; Russell, S. J.; Serenyi, J. R.; Murphy, J. P.

    The present status of silver oxide-zinc technology and applications has been described by Karpinski et al. [A.P. Karpinski, B. Makovetski, S.J. Russell, J.R. Serenyi, D.C. Williams, Silver-Zinc: status of technology and applications, Journal of Power Sources, 80 (1999) 53-60], where the silver-zinc couple is still the preferred choice where high specific energy/energy density, coupled with high specific power/power density are important for high-rate, weight or size/configuration sensitive applications. Perhaps the silver oxide cathode can be considered one of the most versatile electrode materials. When coupled with other anodes and corresponding electrolyte management system, the silver electrode provides for a wide array of electrochemical systems that can be tailored to meet the most demanding, high power requirements. Besides zinc, the most notable include cadmium, iron, metal hydride, and hydrogen electrode for secondary systems, while primary systems include lithium and aluminum. Alloys including silver are also available, such as silver chloride, which when coupled with magnesium or aluminum are primarily used in many seawater applications. The selection and use of these couples is normally the result of a trade-off of many factors. These include performance, safety, risk, reliability, and cost. When high power is required, silver oxide-zinc, silver oxide-aluminum, and silver oxide-lithium are the most energetic. For moderate performance (i.e., lower power), silver oxide-zinc or silver-cadmium would be the system of choice. This paper summarizes the suitability of the silver-based couples, with an emphasis on the silver-zinc system, as primary or rechargeable power sources for high energy/power applications.

  16. Can high resolution manometry parameters for achalasia be obtained by conventional manometry?

    Institute of Scientific and Technical Information of China (English)

    Fernando; AM; Herbella; Marco; G; Patti

    2015-01-01

    High resolution manometry(HRM) is a new technology that made important contributions to the field of gastrointestinal physiology. HRM showed clear advan-tages over conventional manometry and it allowed the creation of different manometric parameters. On the other side, conventional manometry is still wild available. It must be better studied if the new technology made possible the creation and study of these parameters or if they were always there but the colorful intuitive panoramic view of the peristalsis from the pharynx to the stomach HRM allowed the human eyes to distinguish subtle parameters unknown or uncomprehend so far and if HRM parameters can be reliably obtained by conventional manometry and data from conventional manometry still can be accepted in achalasia studies. Conventional manometry relied solely on the residual pressure to evaluate lower esophageal sphincter(LES) relaxation while HRM can obtain the Integrated Relaxation Pressure. Esophageal body HRM parameters defines achalasia subtypes, the Chicago classification, based on esophageal pressurization after swallows. The characterization of each subtype is very intuitive by HRM but also easy by conventional manometry since only wave amplitudes need to be measured. In conclusion, conventional manometry is still valuable to classify achalasia according to the Chicago classification. HRM permits a better study of the LES.

  17. Protection Related to High-power Targets

    CERN Document Server

    Plum, M.A.

    2016-01-01

    Target protection is an important part of machine protection. The beam power in high-intensity accelerators is high enough that a single wayward pulse can cause serious damage. Today's high-power targets operate at the limit of available technology, and are designed for a very narrow range of beam parameters. If the beam pulse is too far off centre, or if the beam size is not correct, or if the beam density is too high, the target can be seriously damaged. We will start with a brief introduction to high-power targets and then move to a discussion of what can go wrong, and what are the risks. Next we will discuss how to control the beam-related risk, followed by examples from a few different accelerator facilities. We will finish with a detailed example of the Oak Ridge Spallation Neutron Source target tune up and target protection.

  18. 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.

  19. High Power Test for Klystron Stability

    Energy Technology Data Exchange (ETDEWEB)

    Seol, Kyung-Tae; Kim, Seong-Gu; Kwon, Hyeok-Jung; Kim, Han-Sung; Cho, Yong-Sub [Korea Atomic Energy Research Institute, Gyeongju (Korea, Republic of)

    2015-10-15

    The 100-MeV linac consists of a 50-keV proton injector based on a microwave ion source, a 3-MeV RFQ with a four-vane structure, and a 100-MeV DTL. Nine sets of 1MW klystrons have been operated for the 100-MeV proton linac. The klystron filament heating time was approximately 5700 hours in 2014. During the high power operation of the klystron, unstable RF waveforms appeared at the klystron output, and we have checked and performed cavity frequency adjustments, magnet and heater current, reflection from a circulator, klystron test without a circulator, and the frequency spectrum measurement. The problems may be from harmonic power stay between the klystron and the circulator. A harmonic filter of waveguide type is designed to eliminate the harmonic power. Nine sets of the klystrons have been operated for the KOMAC 100-MeV proton linac. Some klystrons have unstable RF waveforms at specific power level. We have checked and tested the cavity frequency adjustment, reflection from a circulator, high power test without a circulator, and frequency spectrum at the unstable RF. The unstable RF may be from harmonic power stay between the klystron and the circulator. To eliminate the harmonic power, a harmonic filter of waveguide type is designed.

  20. Evaluation of conventional electric power generating industry quality assurance and reliability practices

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, R.T.; Lauffenburger, H.A.

    1981-03-01

    The techniques and practices utilized in an allied industry (electric power generation) that might serve as a baseline for formulating Quality Assurance and Reliability (QA and R) procedures for photovoltaic solar energy systems were studied. The study results provide direct near-term input for establishing validation methods as part of the SERI performance criteria and test standards development task.

  1. Diagnostics for High Power Targets and Dumps

    CERN Document Server

    Gschwendtner, E

    2012-01-01

    High power targets are generally used for neutrino, antiproton, neutron and secondary beam production whereas dumps are needed in beam waste management. In order to guarantee an optimized and safe use of these targets and dumps, reliable instrumentation is needed; the diagnostics in high power beams around targets and dumps is reviewed. The suite of beam diagnostics devices used in such extreme environments is discussed, including their role in commissioning and operation. The handling and maintenance of the instrumentation components in high radiation areas is also addressed.

  2. Advanced High Voltage Power Device Concepts

    CERN Document Server

    Baliga, B Jayant

    2012-01-01

    Advanced High Voltage Power Device Concepts describes devices utilized in power transmission and distribution equipment, and for very high power motor control in electric trains and steel-mills. Since these devices must be capable of supporting more than 5000-volts in the blocking mode, this books covers operation of devices rated at 5,000-V, 10,000-V and 20,000-V. Advanced concepts (the MCT, the BRT, and the EST) that enable MOS-gated control of power thyristor structures are described and analyzed in detail. In addition, detailed analyses of the silicon IGBT, as well as the silicon carbide MOSFET and IGBT, are provided for comparison purposes. Throughout the book, analytical models are generated to give a better understanding of the physics of operation for all the structures. This book provides readers with: The first comprehensive treatment of high voltage (over 5000-volts) power devices suitable for the power distribution, traction, and motor-control markets;  Analytical formulations for all the device ...

  3. Advances in industrial high-power lasers

    Science.gov (United States)

    Schlueter, Holger

    2005-03-01

    Four major types of laser sources are used for material processing. Excluding Excimer lasers, this paper focuses on advances in High Power CO2 lasers, Solid State Lasers and Diode Lasers. Because of their unrivaled cost to brightness relationship the fast axial flow CO2 laser remains unrivaled for flat-sheet laser cutting. Adding approximately a kW of output power ever four years, this laser type has been propelling the entire sheet metal fabrication industry for the last two decades. Very robust, diffusion cooled annular discharge CO2 lasers with 2kW output power have enabled robot mounted lasers for 3D applications. Solid State Lasers are chosen mainly because of the option of fiber delivery. Industrial applications still rely on lamp-pumped Nd:YAG lasers with guaranteed output powers of 4.5 kW at the workpiece. The introduction of the diode pumped Thin Disc Laser 4.5 kW laser enables new applications such as the Programmable Focus Optics. Pumping the Thin Disc Laser requires highly reliable High Power Diode Lasers. The necessary reliability can only be achieved in a modern, automated semiconductor manufacturing facility. For Diode Lasers, electro-optical efficiencies above 65% are as important as the passivation of the facets to avoid Burn-In power degradation.

  4. High power infrared QCLs: advances and applications

    Science.gov (United States)

    Patel, C. Kumar N.

    2012-01-01

    QCLs are becoming the most important sources of laser radiation in the midwave infrared (MWIR) and longwave infrared (LWIR) regions because of their size, weight, power and reliability advantages over other laser sources in the same spectral regions. The availability of multiwatt RT operation QCLs from 3.5 μm to >16 μm with wall plug efficiency of 10% or higher is hastening the replacement of traditional sources such as OPOs and OPSELs in many applications. QCLs can replace CO2 lasers in many low power applications. Of the two leading groups in improvements in QCL performance, Pranalytica is the commercial organization that has been supplying the highest performance QCLs to various customers for over four year. Using a new QCL design concept, the non-resonant extraction [1], we have achieved CW/RT power of >4.7 W and WPE of >17% in the 4.4 μm - 5.0 μm region. In the LWIR region, we have recently demonstrated QCLs with CW/RT power exceeding 1 W with WPE of nearly 10 % in the 7.0 μm-10.0 μm region. In general, the high power CW/RT operation requires use of TECs to maintain QCLs at appropriate operating temperatures. However, TECs consume additional electrical power, which is not desirable for handheld, battery-operated applications, where system power conversion efficiency is more important than just the QCL chip level power conversion efficiency. In high duty cycle pulsed (quasi-CW) mode, the QCLs can be operated without TECs and have produced nearly the same average power as that available in CW mode with TECs. Multiwatt average powers are obtained even in ambient T>70°C, with true efficiency of electrical power-to-optical power conversion being above 10%. Because of the availability of QCLs with multiwatt power outputs and wavelength range covering a spectral region from ~3.5 μm to >16 μm, the QCLs have found instantaneous acceptance for insertion into multitude of defense and homeland security applications, including laser sources for infrared

  5. The Jefferson Lab High Power Light Source

    Energy Technology Data Exchange (ETDEWEB)

    James R. Boyce

    2006-01-01

    Jefferson Lab has designed, built and operated two high average power free-electron lasers (FEL) using superconducting RF (SRF) technology and energy recovery techniques. Between 1999-2001 Jefferson Lab operated the IR Demo FEL. This device produced over 2 kW in the mid-infrared, in addition to producing world record average powers in the visible (50 W), ultraviolet (10 W) and terahertz range (50 W) for tunable, short-pulse (< ps) light. This FEL was the first high power demonstration of an accelerator configuration that is being exploited for a number of new accelerator-driven light source facilities that are currently under design or construction. The driver accelerator for the IR Demo FEL uses an Energy Recovered Linac (ERL) configuration that improves the energy efficiency and lowers both the capital and operating cost of such devices by recovering most of the power in the spent electron beam after optical power is extracted from the beam. The IR Demo FEL was de-commissioned in late 2001 for an upgraded FEL for extending the IR power to over 10 kW and the ultraviolet power to over 1 kW. The FEL Upgrade achieved 10 kW of average power in the mid-IR (6 microns) in July of 2004, and its IR operation currently is being extended down to 1 micron. In addition, we have demonstrated the capability of on/off cycling and recovering over a megawatt of electron beam power without diminishing machine performance. A complementary UV FEL will come on-line within the next year. This paper presents a summary of the FEL characteristics, user community accomplishments with the IR Demo, and planned user experiments.

  6. Mode-evolution-based coupler for high saturation power Ge-on-Si photodetectors.

    Science.gov (United States)

    Byrd, Matthew J; Timurdogan, Erman; Su, Zhan; Poulton, Christopher V; Fahrenkopf, Nicholas M; Leake, Gerald; Coolbaugh, Douglas D; Watts, Michael R

    2017-02-15

    We propose a mode-evolution-based coupler for high saturation power germanium-on-silicon photodetectors. This coupler uniformly illuminates the intrinsic germanium region of the detector, decreasing saturation effects, such as carrier screening, observed at high input powers. We demonstrate 70% more photocurrent generation (9.1-15.5 mA) and more than 40 times higher opto-electrical bandwidth (0.7-31 GHz) than conventional butt-coupled detectors under high-power illumination. The high-power and high-speed performance of the device, combined with the compactness of the coupling method, will enable new applications for integrated silicon photonics systems.

  7. High Power Diode Lasers Technology and Applications

    CERN Document Server

    Bachmann, Friedrich; Poprawe, Reinhart

    2007-01-01

    In a very comprehensive way this book covers all aspects of high power diode laser technology for materials processing. Basics as well as new application oriented results obtained in a government funded national German research project are described in detail. Along the technological chain after a short introduction in the second chapter diode laser bar technology is discussed regarding structure, manufacturing technology and metrology. The third chapter illuminates all aspects of mounting and cooling, whereas chapter four gives wide spanning details on beam forming, beam guiding and beam combination, which are essential topics for incoherently coupled multi-emitter based high power diode lasers. Metrology, standards and safety aspects are the theme of chapter five. As an outcome of all the knowledge from chapter two to four various system configurations of high power diode lasers are described in chapter six; not only systems focussed on best available beam quality but especially also so called "modular" set...

  8. High power density yeast catalyzed microbial fuel cells

    Science.gov (United States)

    Ganguli, Rahul

    Microbial fuel cells leverage whole cell biocatalysis to convert the energy stored in energy-rich renewable biomolecules such as sugar, directly to electrical energy at high efficiencies. Advantages of the process include ambient temperature operation, operation in natural streams such as wastewater without the need to clean electrodes, minimal balance-of-plant requirements compared to conventional fuel cells, and environmentally friendly operation. These make the technology very attractive as portable power sources and waste-to-energy converters. The principal problem facing the technology is the low power densities compared to other conventional portable power sources such as batteries and traditional fuel cells. In this work we examined the yeast catalyzed microbial fuel cell and developed methods to increase the power density from such fuel cells. A combination of cyclic voltammetry and optical absorption measurements were used to establish significant adsorption of electron mediators by the microbes. Mediator adsorption was demonstrated to be an important limitation in achieving high power densities in yeast-catalyzed microbial fuel cells. Specifically, the power densities are low for the length of time mediator adsorption continues to occur. Once the mediator adsorption stops, the power densities increase. Rotating disk chronoamperometry was used to extract reaction rate information, and a simple kinetic expression was developed for the current observed in the anodic half-cell. Since the rate expression showed that the current was directly related to microbe concentration close to the electrode, methods to increase cell mass attached to the anode was investigated. Electrically biased electrodes were demonstrated to develop biofilm-like layers of the Baker's yeast with a high concentration of cells directly connected to the electrode. The increased cell mass did increase the power density 2 times compared to a non biofilm fuel cell, but the power density

  9. E3000 High Power SADM development

    Science.gov (United States)

    Bamford, Steve G.; McMahon, Paul

    2003-09-01

    Astrium UK has been actively involved in the study, design, development, manufacture and test of Solar Array Drive Mechanisms (SADMs) and Bearing and Power Transfer Assemblies (BAPTAs) since the early 1970s having delivered 105 of these mechanisms to 22 spacecraft programs. As a result Astrium UK has accumulated in excess of 700 years of failure free SADM operation in-orbit. During that period power transfer requirements have grown steadily from below 1kW to 9.9kW and beyond. With this increase in power handling capability comes the associated problem of handling and dissipating the heat being generated within the SADM. The Eurostar 2000 family of SADMs were designed to handle up to 5.6kW for the E2000 family of spacecraft but the High Power SADM was conceived to meet the needs of the much bigger Eurostar 3000 family of spacecraft that could potentially grow to 15kW.

  10. Technology development for high power induction accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Birx, D.L.; Reginato, L.L.

    1985-06-11

    The marriage of Induction Linac technology with Nonlinear Magnetic Modulators has produced some unique capabilities. It appears possible to produce electron beams with average currents measured in amperes, at gradients exceeding 1 MeV/meter, and with power efficiencies approaching 50%. A 2 MeV, 5 kA electron accelerator has been constructed at the Lawrence Livermore National Laboratory (LLNL) to demonstrate these concepts and to provide a test facility for high brightness sources. The pulse drive for the accelerator is based on state-of-the-art magnetic pulse compressors with very high peak power capability, repetition rates exceeding a kilohertz and excellent reliability.

  11. Compact high-power terahertz radiation source

    Directory of Open Access Journals (Sweden)

    G. A. Krafft

    2004-06-01

    Full Text Available In this paper a new type of THz radiation source, based on recirculating an electron beam through a high gradient superconducting radio frequency cavity, and using this beam to drive a standard electromagnetic undulator on the return leg, is discussed. Because the beam is recirculated and not stored, short bunches may be produced that radiate coherently in the undulator, yielding exceptionally high average THz power for relatively low average beam power. Deceleration from the coherent emission, and the detuning it causes, limits the charge-per-bunch possible in such a device.

  12. Operation of Power Grids with High Penetration of Wind Power

    Science.gov (United States)

    Al-Awami, Ali Taleb

    The integration of wind power into the power grid poses many challenges due to its highly uncertain nature. This dissertation involves two main components related to the operation of power grids with high penetration of wind energy: wind-thermal stochastic dispatch and wind-thermal coordinated bidding in short-term electricity markets. In the first part, a stochastic dispatch (SD) algorithm is proposed that takes into account the stochastic nature of the wind power output. The uncertainty associated with wind power output given the forecast is characterized using conditional probability density functions (CPDF). Several functions are examined to characterize wind uncertainty including Beta, Weibull, Extreme Value, Generalized Extreme Value, and Mixed Gaussian distributions. The unique characteristics of the Mixed Gaussian distribution are then utilized to facilitate the speed of convergence of the SD algorithm. A case study is carried out to evaluate the effectiveness of the proposed algorithm. Then, the SD algorithm is extended to simultaneously optimize the system operating costs and emissions. A modified multi-objective particle swarm optimization algorithm is suggested to identify the Pareto-optimal solutions defined by the two conflicting objectives. A sensitivity analysis is carried out to study the effect of changing load level and imbalance cost factors on the Pareto front. In the second part of this dissertation, coordinated trading of wind and thermal energy is proposed to mitigate risks due to those uncertainties. The problem of wind-thermal coordinated trading is formulated as a mixed-integer stochastic linear program. The objective is to obtain the optimal tradeoff bidding strategy that maximizes the total expected profits while controlling trading risks. For risk control, a weighted term of the conditional value at risk (CVaR) is included in the objective function. The CVaR aims to maximize the expected profits of the least profitable scenarios, thus

  13. Conventional P-ω/Q-V Droop Control in Highly Resistive Line of Low-Voltage Converter-Based AC Microgrid

    DEFF Research Database (Denmark)

    Hou, Xiaochao; Sun, Yao; Yuan, Wenbin

    2016-01-01

    In low-voltage converter-based alternating current (AC) microgrids with resistive distribution lines, the P-V droop with Q-f boost (VPD/FQB) is the most common method for load sharing. However, it cannot achieve the active power sharing proportionally. To overcome this drawback, the conventional P......-ω/Q-V droop control is adopted in the low-voltage AC microgrid. As a result, the active power sharing among the distributed generators (DGs) is easily obtained without communication. More importantly, this study clears up the previous misunderstanding that conventional P-ω/Q-V droop control is only applicable...... to microgrids with highly inductive lines, and lays a foundation for the application of conventional droop control under different line impedances. Moreover, in order to guarantee the accurate reactive power sharing, a guide for designing Q-V droop gains is given, and virtual resistance is adopted to shape...

  14. Spatial and Spectral Brightness Enhancement of High Power Semiconductor Lasers

    Science.gov (United States)

    Leidner, Jordan Palmer

    The performance of high-power broad-area diode lasers is inhibited by beam filamentation induced by free-carrier-based self-focusing. The resulting beam degradation limits their usage in high-brightness, high-power applications such as pumping fiber lasers, and laser cutting, welding, or marking. Finite-difference propagation method simulations via RSoft's BeamPROP commercial simulation suite and a custom-built MATLAB code were used for the study and design of laser cavities that suppress or avoid filamentation. BeamPROP was used to design a tapered, passive, multi-mode interference cavity for the creation of a self-phase-locking laser array, which is comprised of many single-mode gain elements coupled to a wide output coupler to avoid damage from local high optical intensities. MATLAB simulations were used to study the effects of longitudinal and lateral cavity confinement on lateral beam quality in conventional broad-area lasers. This simulation was expanded to design a laser with lateral gain and index prescription that is predicted to operate at or above state-of-the-art powers while being efficiently coupled to conventional telecom single-mode optical fibers. Experimentally, a commercial broad-area laser was coupled in the far-field to a single-mode fiber Bragg grating to provide grating-stabilized single-mode laser feedback resulting in measured spectral narrowing for efficient pump absorption. Additionally a 19 GHz-span, spatially resolved, self-heterodyne measurement was made of a broad-area laser to study the evolution/devolution of the mode content of the emitted laser beam with increasing power levels.

  15. Convention between Romania and the Great Powers on the 12th of September 1944

    Directory of Open Access Journals (Sweden)

    Stefan GHEORGHE

    2005-10-01

    Full Text Available The formula for the “unconditional surrender” adopted in Casablanca on the 24th of January 1943 was meant to acquaint the governmentsof the states at war with the United Nations with the treatment and the terms of their countries would have to take, no matter when or why they mightwithdraw. As far as Romania was concerned, the terms of surrender included, among others, demobilisation and disarmament, handing over warmaterials, amends etc, all of which were to be imposed on by the three great powers and had been thought mainly to secure safety and to carrying onthe warfare against Germany. These objectives were considered to have deep political implications.

  16. All-metal metamaterial slow-wave structure for high-power sources with high efficiency

    Science.gov (United States)

    Wang, Yanshuai; Duan, Zhaoyun; Tang, Xianfeng; Wang, Zhanliang; Zhang, Yabin; Feng, Jinjun; Gong, Yubin

    2015-10-01

    In this paper, we have proposed a metamaterial (MTM) which is suitable for the compact high-power vacuum electron devices. For example, an S-band slow-wave structure (SWS) based on the all-metal MTMs has been studied by both simulation and experiment. The results show that this MTM SWS is very helpful to miniaturize the high-power vacuum electron devices and largely improve the output power and the electronic efficiency. The simulation model of an S-band MTM backward wave oscillator (BWO) is built, and the particle-in-cell simulated results are presented here: a 2.454 GHz signal is generated and its peak output power is 4.0 MW with a higher electronic efficiency of 31.5% relative to the conventional BWOs.

  17. All-metal metamaterial slow-wave structure for high-power sources with high efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yanshuai; Duan, Zhaoyun, E-mail: zhyduan@uestc.edu.cn; Tang, Xianfeng; Wang, Zhanliang; Zhang, Yabin; Gong, Yubin [National Key Laboratory of Science and Technology on Vacuum Electronics in Chengdu, School of Physical Electronics, University of Electronic Science and Technology of China, No. 4, Section 2, North Jianshe Road, Chengdu 610054 (China); Feng, Jinjun [National Key Laboratory of Science and Technology on Vacuum Electronics in Beijing, Beijing Vacuum Electronics Research Institute, Beijing 100015 (China)

    2015-10-12

    In this paper, we have proposed a metamaterial (MTM) which is suitable for the compact high-power vacuum electron devices. For example, an S-band slow-wave structure (SWS) based on the all-metal MTMs has been studied by both simulation and experiment. The results show that this MTM SWS is very helpful to miniaturize the high-power vacuum electron devices and largely improve the output power and the electronic efficiency. The simulation model of an S-band MTM backward wave oscillator (BWO) is built, and the particle-in-cell simulated results are presented here: a 2.454 GHz signal is generated and its peak output power is 4.0 MW with a higher electronic efficiency of 31.5% relative to the conventional BWOs.

  18. An Evolutionary Transition of conventional n MOS VLSI to CMOS considering Scaling, Low Power and Higher Mobility

    OpenAIRE

    2016-01-01

    This paper emphasizes on the gradual revolution of CMOS scaling by delivering the modern concepts of newly explored device structures and new materials. After analyzing the improvements in sources, performance of CMOS technology regarding conventional semiconductor devices has been thoroughly discussed. This has been done by considering the significant semiconductor evolution devices like metal gate electrode, double gate FET, FinFET, high dielectric constant (high k) and strained silicon FET...

  19. High impact data visualization with Power View, Power Map, and Power BI

    CERN Document Server

    Aspin, Adam

    2014-01-01

    High Impact Data Visualization with Power View, Power Map, and Power BI helps you take business intelligence delivery to a new level that is interactive, engaging, even fun, all while driving commercial success through sound decision-making. Learn to harness the power of Microsoft's flagship, self-service business intelligence suite to deliver compelling and interactive insight with remarkable ease. Learn the essential techniques needed to enhance the look and feel of reports and dashboards so that you can seize your audience's attention and provide them with clear and accurate information. Al

  20. Generating power at high efficiency combined cycle technology for sustainable energy production

    CERN Document Server

    Jeffs, E

    2008-01-01

    Combined cycle technology is used to generate power at one of the highest levels of efficiency of conventional power plants. It does this through primary generation from a gas turbine coupled with secondary generation from a steam turbine powered by primary exhaust heat. Generating power at high efficiency thoroughly charts the development and implementation of this technology in power plants and looks to the future of the technology, noting the advantages of the most important technical features - including gas turbines, steam generator, combined heat and power and integrated gasification com

  1. High power collimated diode laser stack

    Institute of Scientific and Technical Information of China (English)

    LIU Yuan-yuan; FANG Gao-zhan; MA Xiao-yu; LIU Su-ping; FENG Xiao-ming

    2006-01-01

    A high power collimated diode laser stack is carried out based on fast-axis collimation and stack packaging techniques.The module includes ten typical continuous wave (cw) bars and the total output power can be up to 368W at 48.6A.Using a cylindrical lens as the collimation elements,we can make the fast-axis divergence and the slow-axis divergence are 0.926 40 and 8.2060 respectively.The light emitting area is limited in a square area of 18.3 mm×11 mm.The module has the advantage of high power density and offers a wide potential applications in pumping and material processing.

  2. High Power Disk Loaded Guide Load

    Energy Technology Data Exchange (ETDEWEB)

    Farkas, Z.D.; /SLAC

    2006-02-22

    A method to design a matching section from a smooth guide to a disk-loaded guide, using a variation of broadband matching, [1, 2] is described. Using this method, we show how to design high power loads. The load consists of a disk-loaded coaxial guide operating in the TE{sub 01}-mode. We use this mode because it has no electric field terminating on a conductor, has no axial currents, and has no current at the cylinder-disk interface. A high power load design that has -35 dB reflection and a 200 MHz, -20 dB bandwidth, is presented. It is expected that it will carry the 600 MW output peak power of the pulse compression network. We use coaxial geometry and stainless steel material to increase the attenuation per cell.

  3. Modulation of Exciton Generation in Organic Active Planar pn Heterojunction: Toward Low Driving Voltage and High-Efficiency OLEDs Employing Conventional and Thermally Activated Delayed Fluorescent Emitters.

    Science.gov (United States)

    Chen, Dongcheng; Liu, Kunkun; Gan, Lin; Liu, Ming; Gao, Kuo; Xie, Gaozhan; Ma, Yuguang; Cao, Yong; Su, Shi-Jian

    2016-08-01

    Organic light-emitting diodes (OLEDs) combining low driving voltage and high efficiency are designed by employing conventional and thermally activated delayed fluorescence emitters through modulation of excitons generated at the planar p-n heterojunction region. To date, this approach enables the highest power efficiency for yellow-green emitting fluorescent OLEDs with a simplified structure.

  4. Next High Performance and Low Power Flash Memory Package Structure

    Institute of Scientific and Technical Information of China (English)

    Jung-Hoon Lee

    2007-01-01

    In general, SAND flash memory has advantages in low power consumption, storage capacity, and fast erase/write performance in contrast to NOR flash. But, main drawback of the SAND flash memory is the slow access time for random read operations. Therefore, we proposed the new SAND flash memory package for overcoming this major drawback. We present a high performance and low power SAND flash memory system with a dual cache memory. The proposed SAND flash package consists of two parts, i.e., an SAND flash memory module, and a dual cache module. The new SAND flash memory system can achieve dramatically higher performance and lower power consumption compared with any conventional NAND-type flash memory module. Our results show that the proposed system can reduce about 78% of write operations into the flash memory cell and about 70% of read operations from the flash memory cell by using only additional 3KB cache space. This value represents high potential to achieve low power consumption and high performance gain.

  5. Materials for high average power lasers

    Energy Technology Data Exchange (ETDEWEB)

    Marion, J.E.; Pertica, A.J.

    1989-01-01

    Unique materials properties requirements for solid state high average power (HAP) lasers dictate a materials development research program. A review of the desirable laser, optical and thermo-mechanical properties for HAP lasers precedes an assessment of the development status for crystalline and glass hosts optimized for HAP lasers. 24 refs., 7 figs., 1 tab.

  6. High power Ka band TWT amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Golkowski, C.; Ivers, J.D.; Nation, J.A.; Wang, P.; Schachter, L.

    1999-07-01

    Two high power 35 GHz TWT amplifiers driven by a relativistic pencil, 850 kV, 200A electron beam have been assembled and tested. The first had a dielectric slow wave structure and was primarily used to develop diagnostics, and to gain experience in working with high power systems in Ka band. The source of the input power for the amplifier was a magnetron producing a 30 kW, 200ns long pulse of which 10 kW as delivered to the experiment. The 30 cm long dielectric (Teflon) amplifier produced output power levels of about 1 MW with a gain of about 23 dB. These results are consistent with expectations from PIC code simulations for this arrangement. The second amplifier, which is a single stage disk loaded slow wave structure, has been designed. It consists of one hundred uniform cells with two sets of ten tapered calls at the ends to lower the reflection coefficient. The phase advance per cell is {pi}/2. The amplifier passband extends from 28 to 40 GHz. It is designed to increase the output power to about 20 MW. The amplifier is in construction and will be tested in the near future. Details of the design of both systems will be provided and initial results from the new amplifier presented.

  7. High speed InAs electron avalanche photodiodes overcome the conventional gain-bandwidth product limit.

    Science.gov (United States)

    Marshall, Andrew R J; Ker, Pin Jern; Krysa, Andrey; David, John P R; Tan, Chee Hing

    2011-11-07

    High bandwidth, uncooled, Indium Arsenide (InAs) electron avalanche photodiodes (e-APDs) with unique and highly desirable characteristics are reported. The e-APDs exhibit a 3dB bandwidth of 3.5 GHz which, unlike that of conventional APDs, is shown not to reduce with increasing avalanche gain. Hence these InAs e-APDs demonstrate a characteristic of theoretically ideal electron only APDs, the absence of a gain-bandwidth product limit. This is important because gain-bandwidth products restrict the maximum exploitable gain in all conventional high bandwidth APDs. Non-limiting gain-bandwidth products up to 580 GHz have been measured on these first high bandwidth e-APDs.

  8. Iloprost drug delivery during infant conventional and high-frequency oscillatory ventilation.

    Science.gov (United States)

    DiBlasi, Robert M; Crotwell, Dave N; Shen, Shuijie; Zheng, Jiang; Fink, James B; Yung, Delphine

    2016-03-01

    Iloprost is a selective pulmonary vasodilator approved for inhalation by the Food and Drug Administration. Iloprost has been increasingly used in the management of critically ill neonates with hypoxic lung disease. This in vitro study was designed to test the hypothesis that aerosol drug delivery could be effectively administered to infants with both conventional ventilation and high-frequency oscillatory ventilation (HFOV). A neonatal test lung model configured with newborn lung mechanics was ventilated with a conventional ventilator and an HFOV with standard settings. A vibrating-mesh nebulizer was placed (1) proximal to the patient airway in the inspiratory limb between the humidifier probe and patient wye (conventional) as well as between the vent circuit and the endotracheal tube (ETT) for HFOV and (2) between the ventilator and humidifier (distal). Iloprost was nebulized in three separate runs using three new nebulizers in each of the circuit locations. A collecting filter was placed at the distal end of the ETT for each trial. Iloprost was quantified using high-performance liquid chromatography. The percentage of nominal dose delivered was greater with the nebulizer placed proximal to the airway for conventional ventilation (10.74% ± 2%) and HFOV (29% ± 2%) than with it placed in the distal position (2.96% ± 0.2% vs. 0.96% ± 0.8%, respectively; P < 0.05). Drug delivery in proximal position was nearly threefold greater during HFOV than during conventional ventilation. In conclusion, iloprost drug delivery was best achieved when the nebulizer was placed proximal to the patient airway during neonatal mechanical ventilation. Drug delivery appears to be more efficient during HFOV than during conventional ventilation.

  9. High Efficiency Microwave Power Amplifier (HEMPA) Design

    Science.gov (United States)

    Sims, W. Herbert

    2004-01-01

    This paper will focus on developing an exotic switching technique that enhances the DC-to-RF conversion efficiency of microwave power amplifiers. For years, switching techniques implemented in the 10 kHz to 30 MHz region have resulted in DC-to-RF conversion efficiencies of 90-95-percent. Currently amplifier conversion efficiency, in the 2-3 GHz region approaches, 10-20-percent. Using a combination of analytical modeling and hardware testing, a High Efficiency Microwave Power Amplifier was built that demonstrated conversion efficiencies four to five times higher than current state of the art.

  10. Generation Expansion Planning with High Penetration of Wind Power

    Science.gov (United States)

    Sharan, Ishan; Balasubramanian, R.

    2016-08-01

    Worldwide thrust is being provided in generation of electricity from wind. Planning for the developmental needs of wind based power has to be consistent with the objective and basic framework of overall resource planning. The operational issues associated with the integration of wind power must be addressed at the planning stage. Lack of co-ordinated planning of wind turbine generators, conventional generating units and expansion of the transmission system may lead to curtailment of wind power due to transmission inadequacy or operational constraints. This paper presents a generation expansion planning model taking into account fuel transportation and power transmission constraints, while addressing the operational issues associated with the high penetration of wind power. For analyzing the operational issues, security constrained unit commitment algorithm is embedded in the integrated generation and transmission expansion planning model. The integrated generation and transmission expansion planning problem has been formulated as a mixed integer linear problem involving both binary and continuous variables in GAMS. The model has been applied to the expansion planning of a real system to illustrate the proposed approach.

  11. Conventional Audiometry, Extended High-Frequency Audiometry, and DPOAE for Early Diagnosis of NIHL

    OpenAIRE

    Mehrparvar, Amir Houshang; Mirmohammadi, Seyyed Jalil; Davari, Mohammad Hossein; MOSTAGHACI, Mehrdad; Mollasadeghi, Abolfazl; Bahaloo, Maryam; Hashemi, Seyyed Hesam

    2014-01-01

    Background: Noise most frequently affects hearing system, as it may typically cause a bilateral, progressive sensorineural hearing loss at high frequencies. Objectives: This study was designed to compare three different methods to evaluate noise-induced hearing loss (conventional audiometry, high-frequency audiometry, and distortion product otoacoustic emission). Material and Methods: This was a cross-sectional study. Data was analyzed by SPSS (ver. 19) using chi square, T test and repeated m...

  12. High Power Experiments in VX-10

    Science.gov (United States)

    Squire, Jared; Chang-Diaz, Franklin; Araya-Chacon, Gonzalo; Jacobson, Verlin; Glover, Tim; McCaskill, Greg; Vera, Jerry; Baity, Wally; Carter, Mark; Goulding, Rick

    2004-11-01

    In the Advanced Space Propulsion Laboratory VASIMR experiment (VX-10) we have measured a plasma flux to input gas rate ratio near 100power levels up to 10 kW. The plasma source is being developed to supply a dense target with a high degree of ionization for ICRF acceleration of the flow in an expanding magnetic field. An upgrade to 20 kW helicon operations is underway. Recent results at Oak Ridge National Laboratory show enhanced efficiency operation with a high power density, over 5 kW in a 5 cm diameter tube. Our helicon is presently 9 cm in diameter, so comparable power densities will be achieved in VX-10. We have operated with a Boswell double-saddle antenna design with a magnetic cusp just upstream of the antenna. Recently we have converted to a double-helix half-turn antenna. ICRF experiments have been performed as 1.5 kW that show significant plasma flow acceleration, doubling the flow velocity. A 10 kW ICRF upgrade is underway. Results from high total power ( ˜ 30 kW) experiments with this new helicon antenna and ICRF acceleration are presented.

  13. A high-average-power FEL for industrial applications

    Energy Technology Data Exchange (ETDEWEB)

    Dylla, H.F.; Benson, S.; Bisognano, J.

    1995-12-31

    CEBAF has developed a comprehensive conceptual design of an industrial user facility based on a kilowatt UV (150-1000 nm) and IR (2-25 micron) FEL driven by a recirculating, energy-recovering 200 MeV superconducting radio-frequency (SRF) accelerator. FEL users{endash}CEBAF`s partners in the Laser Processing Consortium, including AT&T, DuPont, IBM, Northrop-Grumman, 3M, and Xerox{endash}plan to develop applications such as polymer surface processing, metals and ceramics micromachining, and metal surface processing, with the overall effort leading to later scale-up to industrial systems at 50-100 kW. Representative applications are described. The proposed high-average-power FEL overcomes limitations of conventional laser sources in available power, cost-effectiveness, tunability and pulse structure. 4 refs., 3 figs., 2 tabs.

  14. Intraoral fluoride levels after use of conventional and high-fluoride dentifrices.

    Science.gov (United States)

    Pessan, Juliano P; Conceição, Juliana M; Grizzo, Larissa T; Székely, Melinda; Fazakas, Zita; Buzalaf, Marília Ar

    2015-05-01

    This study aimed to evaluate saliva and plaque as indicators of intraoral fluoride (F) levels after the use of conventional and high-fluoride dentifrices. Subjects were randomly assigned to brush their teeth with conventional (1000 ppm F), high-fluoride (5000 ppm F), and placebo dentifrices (fluoride free) for 10 days, following a double-blind, crossover protocol. Saliva and plaque samples were collected on the morning of the 5(th) and 10th days, respectively at 1 and 12 h after brushing, and analyzed with an ion-selective electrode after HMDS-facilitated diffusion. Data were analyzed by two-way repeated measures ANOVA, Tukey's test and Spearman's correlation coefficient (p dentifrices when compared to values obtained for placebo, except plaque 12 h after the use of conventional dentifrice. A positive and significant correlation was found between fluoride concentrations in plaque and saliva for both times of sample collection. Both indicators assessed were able to detect significant differences among treatments and between times after brushing. The use of a high-fluoride dentifrice is able to significantly increase intraoral fluoride levels throughout the day, being therefore a useful therapy for patients at high caries risk. A dentifrice with high fluoride concentration could be regarded as a useful therapy of F delivery for high caries-risk patients, since intraoral F levels were sustained throughout most of the day after using this formulation.

  15. Coal-fired high performance power generating system. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-31

    As a result of the investigations carried out during Phase 1 of the Engineering Development of Coal-Fired High-Performance Power Generation Systems (Combustion 2000), the UTRC-led Combustion 2000 Team is recommending the development of an advanced high performance power generation system (HIPPS) whose high efficiency and minimal pollutant emissions will enable the US to use its abundant coal resources to satisfy current and future demand for electric power. The high efficiency of the power plant, which is the key to minimizing the environmental impact of coal, can only be achieved using a modern gas turbine system. Minimization of emissions can be achieved by combustor design, and advanced air pollution control devices. The commercial plant design described herein is a combined cycle using either a frame-type gas turbine or an intercooled aeroderivative with clean air as the working fluid. The air is heated by a coal-fired high temperature advanced furnace (HITAF). The best performance from the cycle is achieved by using a modern aeroderivative gas turbine, such as the intercooled FT4000. A simplified schematic is shown. In the UTRC HIPPS, the conversion efficiency for the heavy frame gas turbine version will be 47.4% (HHV) compared to the approximately 35% that is achieved in conventional coal-fired plants. This cycle is based on a gas turbine operating at turbine inlet temperatures approaching 2,500 F. Using an aeroderivative type gas turbine, efficiencies of over 49% could be realized in advanced cycle configuration (Humid Air Turbine, or HAT). Performance of these power plants is given in a table.

  16. New Power Estimation Methods for Highly Overloaded Synchronous CDMA Systems

    CERN Document Server

    Nashtaali, Damoun; Pad, Pedram; Moghadasi, Seyed Reza; Marvasti, Farokh

    2011-01-01

    In CDMA systems, the received user powers vary due to moving distance of users. Thus, the CDMA receivers consist of two stages. The first stage is the power estimator and the second one is a Multi-User Detector (MUD). Conventional methods for estimating the user powers are suitable for underor fully-loaded cases (when the number of users is less than or equal to the spreading gain). These methods fail to work for overloaded CDMA systems because of high interference among the users. Since the bandwidth is becoming more and more valuable, it is worth considering overloaded CDMA systems. In this paper, an optimum user power estimation for over-loaded CDMA systems with Gaussian inputs is proposed. We also introduce a suboptimum method with lower complexity whose performance is very close to the optimum one. We shall show that the proposed methods work for highly over-loaded systems (up to m(m + 1) =2 users for a system with only m chips). The performance of the proposed methods is demonstrated by simulations. In ...

  17. Wideband high efficiency CMOS envelope amplifiers for 4G LTE handset envelope tracking RF power amplifiers

    OpenAIRE

    Hassan, Muhammad

    2012-01-01

    Fourth generation cellular networks offer performance similar to cable modems while allowing wide mobility. Although the use of orthogonal frequency division multiplexing in fourth generation increases its spectral efficiency but it also increases the peak-to-average power ratio of the transmitted signal. If a conventional power amplifier is used to transmit a high peak-to-average power ratio signal, then to meet the stringent linearity requirements, it will be operating 6 to 10 dB back-off f...

  18. Long-Term Reserve Expansion of Power Systems With High Wind Power Penetration Using Universal Generating Function Methods

    DEFF Research Database (Denmark)

    DING, YI; Wang, Peng; Goel, Lalit

    2010-01-01

    In a power system with high wind power penetration, reliability based reserve expansion is a major problem of system planning and operation due to the uncertainty and fast fluctuation of wind speeds. This paper studied the impact of high wind power penetration on the system reserve and reliabilit...... is proposed to determine the conventional reserve required for power systems with high wind power penetration. The IEEE-RTS has been modified to illustrate the applications of the proposed method.......In a power system with high wind power penetration, reliability based reserve expansion is a major problem of system planning and operation due to the uncertainty and fast fluctuation of wind speeds. This paper studied the impact of high wind power penetration on the system reserve and reliability...... reliabilities. The effect of transmission network on customer reliabilities is also considered in the system UGF. The power output models of wind turbine generators in a wind farm considering wind speed correlation and un-correlation are developed, respectively. A reliability-based reserve expansion method...

  19. Comparison of Wear and Oxidation in Retrieved Conventional and Highly Cross-Linked UHMWPE Tibial Inserts.

    Science.gov (United States)

    Currier, Barbara H; Currier, John H; Franklin, Katherine J; Mayor, Michael B; Reinitz, Steven D; Van Citters, Douglas W

    2015-12-01

    Two groups of retrieved tibial inserts from one manufacturer's knee system were analyzed to evaluate the effect of a highly cross-linked bearing surface on wear and in vivo oxidation. The two groups ((1) conventional gamma-inert sterilized and (2) highly cross-linked, coupled with the same rough (Ra=0.25) Ti-6Al-4V tray) were matched with statistically similar in vivo duration and patient variables. The retrieved inserts were analyzed for ketone oxidation and wear in the form of dimensional change. The difference in oxidation rate between highly cross-linked and conventional gamma-inert sterilized inserts did not reach statistical significance. Observations suggest that the majority of wear can be accounted for by the backside interface with the rough Ti-6Al-4V tray; however, wear measured by thickness-change rate was statistically indistinguishable between the two bearing materials.

  20. Vascularity of hepatic VX2 tumors of rabbits: Assessment with conventional power Doppler US and contrast enhanced harmonic power Doppler US

    Institute of Scientific and Technical Information of China (English)

    Wen-Hua Du; Wei-Xiao Yang; Xiang Wang; Xiu-Qin Xiong; Yi Zhou; Tao Li

    2003-01-01

    AIM: To investigate the characteristics of the vascularity ofhepatic metastasis.METHODS: Six New Zealand rabbits, weighing averagely2.7±0.4 kg, were selected and operated to establish hepaticVX2 tumor carrier model. Hepatic VX2 tumors were thenimaged with conventional B mode US, second harmonicimaging (SHI), color Doppler flow imaging (CDFI), powerDoppler imaging (PDI) and harmonic PDI by a transducerS8 connected to HP-5 500 ultrasound system. A kind of selfmade echo contrast agent was intravenously injected at adose of 0.01 mL/kg through ear vein, and then the venouspassage was cleaned with sterilized saline.RESULTS: Totally, 6 hypoechoic lesions and 3 hyperechoiclesions were found in the six carrier rabbits with a mean sizeabout 2.1±0.4 cm under conventional B mode ultrasound, theywere oval or round in shape with a dear outline or a hypoechoichalo at the margin of the lesions. Contrast agent could notchange the echogenicity of the lesions under conventional Bmode and SHI, however, it could greatly increase the flowsensitivity of the lesions under PDI and harmonic PDI. Nutrientartery of these metastatic lesions might also be well depictedunder contrast enhanced PDI and harmonic PDI.CONCLUSION: Our result suggested that contrast enhancedPDI, especially harmonic PDI, was a promised method inthe detection of vascularity of hepatic tumor nodules.

  1. High efficiency WCDMA power amplifier with Pulsed Load Modulation (PLM) technique

    Science.gov (United States)

    Liao, Shu-Hsien

    In wireless communication, high data rate complex modulation is used for spectral efficiency. However, power efficiency of power amplifier degrades when complex modulation is applied. Therefore, efficiency enhancement is necessary to maintain the performance. However, conventional efficiency enhancement schemes are nonlinear and performance improvement can only be optimized over a small range of power level. In order to preserve linearity and power efficiency, we propose a new digital power amplification technique "Pulsed Load Modulation (PLM)" for high efficiency and linear amplification. The PLM technique realizes load impedance modulation in digital fashion which is insensitive to device nonlinearity. Furthermore, the optimum power efficiency can be maintained over a wide range of output power. In this work, a PLM power amplifier module has been fabricated and to demonstrate the ability of PLM to provide high efficiency and linear amplification.

  2. High-Power, High-Thrust Ion Thruster (HPHTion)

    Science.gov (United States)

    Peterson, Peter Y.

    2015-01-01

    Advances in high-power photovoltaic technology have enabled the possibility of reasonably sized, high-specific power solar arrays. At high specific powers, power levels ranging from 50 to several hundred kilowatts are feasible. Ion thrusters offer long life and overall high efficiency (typically greater than 70 percent efficiency). In Phase I, the team at ElectroDynamic Applications, Inc., built a 25-kW, 50-cm ion thruster discharge chamber and fabricated a laboratory model. This was in response to the need for a single, high-powered engine to fill the gulf between the 7-kW NASA's Evolutionary Xenon Thruster (NEXT) system and a notional 25-kW engine. The Phase II project matured the laboratory model into a protoengineering model ion thruster. This involved the evolution of the discharge chamber to a high-performance thruster by performance testing and characterization via simulated and full beam extraction testing. Through such testing, the team optimized the design and built a protoengineering model thruster. Coupled with gridded ion thruster technology, this technology can enable a wide range of missions, including ambitious near-Earth NASA missions, Department of Defense missions, and commercial satellite activities.

  3. Reduced filamentation in high power semiconductor lasers

    DEFF Research Database (Denmark)

    Skovgaard, Peter M. W.; McInerney, John; O'Brien, Peter

    1999-01-01

    High brightness semiconductor lasers have applications in fields ranging from material processing to medicine. The main difficulty associated with high brightness is that high optical power densities cause damage to the laser facet and thus require large apertures. This, in turn, results in spatio...... in the optical field causes spatial hole-burning and thus filamentation. To reduce filamentation we propose a new, relatively simple design based on inhomogeneous pumping in which the injected current has a gradual transverse profile. We confirm the improved laser performance theoretically and experimentally...

  4. High Power UV LED Industrial Curing Systems

    Energy Technology Data Exchange (ETDEWEB)

    Karlicek, Robert, F., Jr; Sargent, Robert

    2012-05-14

    UV curing is a green technology that is largely underutilized because UV radiation sources like Hg Lamps are unreliable and difficult to use. High Power UV LEDs are now efficient enough to replace Hg Lamps, and offer significantly improved performance relative to Hg Lamps. In this study, a modular, scalable high power UV LED curing system was designed and tested, performing well in industrial coating evaluations. In order to achieve mechanical form factors similar to commercial Hg Lamp systems, a new patent pending design was employed enabling high irradiance at long working distances. While high power UV LEDs are currently only available at longer UVA wavelengths, rapid progress on UVC LEDs and the development of new formulations designed specifically for use with UV LED sources will converge to drive more rapid adoption of UV curing technology. An assessment of the environmental impact of replacing Hg Lamp systems with UV LED systems was performed. Since UV curing is used in only a small portion of the industrial printing, painting and coating markets, the ease of use of UV LED systems should increase the use of UV curing technology. Even a small penetration of the significant number of industrial applications still using oven curing and drying will lead to significant reductions in energy consumption and reductions in the emission of green house gases and solvent emissions.

  5. Website Design Guidelines: High Power Distance and High Context Culture

    Directory of Open Access Journals (Sweden)

    Tanveer Ahmed

    2009-06-01

    Full Text Available This paper aims to address the question of offering a culturally adapted website for a local audience. So far, in the website design arena the vast majority of studies examined mainly Western and the American (low power distance and low context culture disregarding possible cultural discrepancies. This study fills this gap and explores the key cultural parameters that are likely to have an impact on local website design for Asian-Eastern culture high power distance and high context correlating with both Hofstede’s and Hall’s cultural dimensions. It also reviews how website localisation may be accomplished more effectively by extracting the guidelines from two different yet compatible cultural dimensions: high power distance and high context.

  6. Power Supplies for High Energy Particle Accelerators

    Science.gov (United States)

    Dey, Pranab Kumar

    2016-06-01

    The on-going research and the development projects with Large Hadron Collider at CERN, Geneva, Switzerland has generated enormous enthusiasm and interest amongst all to know about the ultimate findings on `God's Particle'. This paper has made an attempt to unfold the power supply requirements and the methodology adopted to provide the stringent demand of such high energy particle accelerators during the initial stages of the search for the ultimate particles. An attempt has also been made to highlight the present status on the requirement of power supplies in some high energy accelerators with a view that, precautionary measures can be drawn during design and development from earlier experience which will be of help for the proposed third generation synchrotron to be installed in India at a huge cost.

  7. High-Power Wind Turbine: Performance Calculation

    Directory of Open Access Journals (Sweden)

    Goldaev Sergey V.

    2015-01-01

    Full Text Available The paper is devoted to high-power wind turbine performance calculation using Pearson’s chi-squared test the statistical hypothesis on distribution of general totality of air velocities by Weibull-Gnedenko. The distribution parameters are found by numerical solution of transcendental equation with the definition of the gamma function interpolation formula. Values of the operating characteristic of the incomplete gamma function are defined by numerical integration using Weddle’s rule. The comparison of the calculated results using the proposed methodology with those obtained by other authors found significant differences in the values of the sample variance and empirical Pearson. The analysis of the initial and maximum wind speed influence on performance of the high-power wind turbine is done

  8. High power/large area PV systems

    Science.gov (United States)

    Wise, Joseph; Baraona, Cosmo

    1987-01-01

    The major photovoltaic power system technology drivers for a wide variety of mission types were ranked. Each technology driver was ranked on a scale of high, medium, or low in terms of importance to each particular mission type. The rankings were then compiled to determine the overall importance of each driver over the entire range of space missions. In each case cost was ranked the highest.

  9. 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.

  10. Conceptual and feasibility study on lab-scale series power generation by carbon-air and conventional solid oxide fuel cells

    Science.gov (United States)

    Duan, Nan-Qi; Cao, Yong; Chi, Bo; Pu, Jian; Li, Jian

    2016-10-01

    To take the advantage chemical-looping combustion (CLC) process for CO2 sequestration, carbon-air fuel cell (CAFC) and conventional solid oxide fuel cell (SOFC) are prepared for high-efficiency series power generation. The tubular CAFC (Cell-I) consisting of Sb anode, (Y2O3)0.08(ZrO2)0.92 (YSZ) electrolyte and La0.6Sr0.4Co0.2Fe0.8O3-δ-Gd0.1Ce0.9O3-δ (LSCF-GDC) cathode has achieved peak power densities of 117, 186 and 295 mW cm-2 at 700, 750 and 800 °C, respectively. Fueled by repeatedly added 3 g of coconut-derived activated charcoal, Cell-I has operated stably at 800 °C for 21 h under the condition of 0.4 A cm-2 and 0.502 V, with an electrical efficiency of 30.8%. The tubular conventional SOFC (Cell-II) is designed with Ni-YSZ as anode, YSZ electrolyte as electrolyte and (La0.8Sr0.2)0.95MnO3-δ-YSZ (LSM-YSZ) as cathode. The anode exhaust gas of Cell-I, which is operated at temperatures from 750 to 850 °C, contains CO and CO2. Using this exhaust gas as fuel, Cell-II has demonstrated peak power densities between 87 and 133 mW cm-2 at 750 °C, and performed stably for 6 h at 0.1 A cm-2 and 0.720 V during which 69.6% of CO in the exhaust gas is consumed. Cell-II has achieved an extra electrical efficiency of 11.0%, giving a total electrical efficiency of 41.8% for the series power generation.

  11. Iloprost drug delivery during infant conventional and high-frequency oscillatory ventilation

    OpenAIRE

    Robert M. DiBlasi; Crotwell, Dave N.; Shen, Shuijie; Zheng, Jiang; Fink, James B.; Yung, Delphine

    2016-01-01

    Iloprost is a selective pulmonary vasodilator approved for inhalation by the Food and Drug Administration. Iloprost has been increasingly used in the management of critically ill neonates with hypoxic lung disease. This in vitro study was designed to test the hypothesis that aerosol drug delivery could be effectively administered to infants with both conventional ventilation and high-frequency oscillatory ventilation (HFOV). A neonatal test lung model configured with newborn lung mechanics wa...

  12. Automatic high voltage conditioning of the electrostatic LEP separators without conventional programming

    CERN Document Server

    Balhan, B; Carlier, E; Dieperink, J H; Mertens, V

    1995-01-01

    The TS Tool Kit is a generic, fully data-driven, and user-configurable software system developed at CERN for supervisory, control, and data acquisition applications. It provides a comprehensive framework to solve fairly complex process control problems requiring response times of the order of a second, without any need for conventional programming. The characteristics and benefits of this approach are discussed at the example of the new high voltage conditioning process for the electrostatic LEP separators.

  13. The future of high power laser techniques

    Science.gov (United States)

    Poprawe, Reinhart; Loosen, Peter; Hoffmann, Hans-Dieter

    2007-05-01

    High Power Lasers have been used for years in corresponding applications. Constantly new areas and new processes have been demonstrated, developed and transferred to fruitful use in industry. With the advent of diode pumped solid state lasers in the multi-kW-power regime at beam qualities not far away from the diffraction limit, a new area of applicability has opened. In welding applications speeds could be increased and systems could be developed with higher efficiently leading also to new perspectives for increased productivity, e.g. in combined processing. Quality control is increasingly demanded by the applying industries, however applications still are rare. Higher resolution of coaxial process control systems in time and space combined with new strategies in signal processing could give rise to new applications. The general approach described in this paper emphasizes the fact, that laser applications can be developed more efficiently, more precisely and with higher quality, if the laser radiation is tailored properly to the corresponding application. In applying laser sources, the parameter ranges applicable are by far wider and more flexible compared to heat, mechanical or even electrical energy. The time frame ranges from several fs to continuous wave and this spans approximately 15 orders of magnitude. Spacewise, the foci range from several µm to cm and the resulting intensities suitable for materials processing span eight orders of magnitude from 10 3 to 10 11 W/cm2. In addition to space (power, intensity) and time (pulse) the wavelength can be chosen as a further parameter of optimization. As a consequence, the resulting new applications are vast and can be utilized in almost every market segment of our global economy (Fig. 1). In the past and only partly today, however, this flexibility of laser technology is not exploited in full in materials processing, basically because in the high power regime the lasers with tailored beam properties are not

  14. Use of dominant harmonic active filters in high power applications

    Science.gov (United States)

    Cheng, Po-Tai

    The application of power electronics equipment is increasing rapidly. It is estimated that 60% of electrical power will be processed by power electronics equipment by year 2000. These equipments typically require rectifiers for AC-DC power conversion. Due to their nonlinear nature, most rectifiers draw harmonic current from the utility grid. The harmonic current causes higher energy losses, and may excite resonance conditions in the utility grid. Harmonic standards such as IEEE 519 and IEC 1000-3-2 have been proposed to regulate the harmonic current and voltage levels. This work is to develop a dominant harmonic active filter (DHAF) to realize a cost-effective active filtering solution for nonlinear loads in the range of megawatt and above. The DHAF system achieves harmonic isolation at dominant harmonic frequencies, e.g. the 5th and 7th. This approach allows use of low switching frequency and small rating active filter inverters (1%--2% of the load MVA rating) for implementation. Review of conventional passive filters and various active filters based on high bandwidth PWM inverters is provided. The control theory of the DHAF system is presented. Comparison of the DHAF system and other dominant harmonic filtering approach is provided. Simulation results and laboratory prototype test results are presented to validate the effectiveness of the proposed DHAF system.

  15. Industrial Applications of High Average Power FELS

    CERN Document Server

    Shinn, Michelle D

    2005-01-01

    The use of lasers for material processing continues to expand, and the annual sales of such lasers exceeds $1 B (US). Large scale (many m2) processing of materials require the economical production of laser powers of the tens of kilowatts, and therefore are not yet commercial processes, although they have been demonstrated. The development of FELs based on superconducting RF (SRF) linac technology provides a scaleable path to laser outputs above 50 kW in the IR, rendering these applications economically viable, since the cost/photon drops as the output power increases. This approach also enables high average power ~ 1 kW output in the UV spectrum. Such FELs will provide quasi-cw (PRFs in the tens of MHz), of ultrafast (pulsewidth ~ 1 ps) output with very high beam quality. This talk will provide an overview of applications tests by our facility's users such as pulsed laser deposition, laser ablation, and laser surface modification, as well as present plans that will be tested with our upgraded FELs. These upg...

  16. High-power LED package requirements

    Science.gov (United States)

    Wall, Frank; Martin, Paul S.; Harbers, Gerard

    2004-01-01

    Power LEDs have evolved from simple indicators into illumination devices. For general lighting applications, where the objective is to light up an area, white LED arrays have been utilized to serve that function. Cost constraints will soon drive the industry to provide a discrete lighting solution. Early on, that will mean increasing the power densities while quantum efficiencies are addressed. For applications such as automotive headlamps & projection, where light needs to be tightly collimated, or controlled, arrays of die or LEDs will not be able to satisfy the requirements & limitations defined by etendue. Ultimately, whether a luminaire requires a small source with high luminance, or light spread over a general area, economics will force the evolution of the illumination LED into a compact discrete high power package. How the customer interfaces with this new package should be an important element considered early on in the design cycle. If an LED footprint of adequate size is not provided, it may prove impossible for the customer, or end user, to get rid of the heat in a manner sufficient to prevent premature LED light output degradation. Therefore it is critical, for maintaining expected LED lifetime & light output, that thermal performance parameters be defined, by design, at the system level, which includes heat sinking methods & interface materials or methdology.

  17. A high power impulse magnetron sputtering model to explain high deposition rate magnetic field configurations

    Science.gov (United States)

    Raman, Priya; Weberski, Justin; Cheng, Matthew; Shchelkanov, Ivan; Ruzic, David N.

    2016-10-01

    High Power Impulse Magnetron Sputtering (HiPIMS) is one of the recent developments in the field of magnetron sputtering technology that is capable of producing high performance, high quality thin films. Commercial implementation of HiPIMS technology has been a huge challenge due to its lower deposition rates compared to direct current Magnetron Sputtering. The cylindrically symmetric "TriPack" magnet pack for a 10 cm sputter magnetron that was developed at the Center for Plasma Material Interactions was able to produce higher deposition rates in HiPIMS compared to conventional pack HiPIMS for the same average power. The "TriPack" magnet pack in HiPIMS produces superior substrate uniformity without the need of substrate rotation in addition to producing higher metal ion fraction to the substrate when compared to the conventional pack HiPIMS [Raman et al., Surf. Coat. Technol. 293, 10 (2016)]. The films that are deposited using the "TriPack" magnet pack have much smaller grains compared to conventional pack DC and HiPIMS films. In this paper, the reasons behind the observed increase in HiPIMS deposition rates from the TriPack magnet pack along with a modified particle flux model is discussed.

  18. Laser welding of polymers using high-power diode lasers

    Science.gov (United States)

    Bachmann, Friedrich G.; Russek, Ulrich A.

    2003-09-01

    Laser welding of polymers using high power diode lasers offers specific process advantages over conventional technologies, such as short process times while providing optically and qualitatively valuable weld seams, contactless yielding of the joining energy, absence of process induced vibrations, imposing minimal thermal stress and avoiding particle generation. Furthermore this method exhibits high integration capabilities and automatization potential. Moreover, because of the current favorable cost development within the high power diode laser market laser welding of polymers has become more and more an industrially accepted joining method. This novel technology permits both, reliable high quality joining of mechanically and electronically highly sensitive micro components and hermetic sealing of macro components. There are different welding strategies available, which are adaptable to the current application. Within the frame of this discourse scientific and also application oriented results concerning laser transmission welding of polymers using preferably diode lasers are presented. Besides the used laser systems the fundamental process strategies as well as decisive process parameters are illustrated. The importance of optical, thermal and mechanical properties is discussed. Applications at real technical components will be presented, demonstrating the industrial implementation capability and the advantages of a novel technology.

  19. The JLab high power ERL light source

    Energy Technology Data Exchange (ETDEWEB)

    G.R. Neil; C. Behre; S.V. Benson; M. Bevins; G. Biallas; J. Boyce; J. Coleman; L.A. Dillon-Townes; D. Douglas; H.F. Dylla; R. Evans; A. Grippo; D. Gruber; J. Gubeli; D. Hardy; C. Hernandez-Garcia; K. Jordan; M.J. Kelley; L. Merminga; J. Mammosser; W. Moore; N. Nishimori; E. Pozdeyev; J. Preble; R. Rimmer; Michelle D. Shinn; T. Siggins; C. Tennant; R. Walker; G.P. Williams and S. Zhang

    2005-03-19

    A new THz/IR/UV photon source at Jefferson Lab is the first of a new generation of light sources based on an Energy-Recovered, (superconducting) Linac (ERL). The machine has a 160 MeV electron beam and an average current of 10 mA in 75 MHz repetition rate hundred femtosecond bunches. These electron bunches pass through a magnetic chicane and therefore emit synchrotron radiation. For wavelengths longer than the electron bunch the electrons radiate coherently a broadband THz {approx} half cycle pulse whose average brightness is > 5 orders of magnitude higher than synchrotron IR sources. Previous measurements showed 20 W of average power extracted[1]. The new facility offers simultaneous synchrotron light from the visible through the FIR along with broadband THz production of 100 fs pulses with >200 W of average power. The FELs also provide record-breaking laser power [2]: up to 10 kW of average power in the IR from 1 to 14 microns in 400 fs pulses at up to 74.85 MHz repetition rates and soon will produce similar pulses of 300-1000 nm light at up to 3 kW of average power from the UV FEL. These ultrashort pulses are ideal for maximizing the interaction with material surfaces. The optical beams are Gaussian with nearly perfect beam quality. See www.jlab.org/FEL for details of the operating characteristics; a wide variety of pulse train configurations are feasible from 10 microseconds long at high repetition rates to continuous operation. The THz and IR system has been commissioned. The UV system is to follow in 2005. The light is transported to user laboratories for basic and applied research. Additional lasers synchronized to the FEL are also available. Past activities have included production of carbon nanotubes, studies of vibrational relaxation of interstitial hydrogen in silicon, pulsed laser deposition and ablation, nitriding of metals, and energy flow in proteins. This paper will present the status of the system and discuss some of the discoveries we have made

  20. Volatile Organic Compounds (VOCs in Conventional and High Performance School Buildings in the U.S.

    Directory of Open Access Journals (Sweden)

    Lexuan Zhong

    2017-01-01

    Full Text Available Exposure to volatile organic compounds (VOCs has been an indoor environmental quality (IEQ concern in schools and other buildings for many years. Newer designs, construction practices and building materials for “green” buildings and the use of “environmentally friendly” products have the promise of lowering chemical exposure. This study examines VOCs and IEQ parameters in 144 classrooms in 37 conventional and high performance elementary schools in the U.S. with the objectives of providing a comprehensive analysis and updating the literature. Tested schools were built or renovated in the past 15 years, and included comparable numbers of conventional, Energy Star, and Leadership in Energy and Environmental Design (LEED-certified buildings. Indoor and outdoor VOC samples were collected and analyzed by thermal desorption, gas chromatography and mass spectroscopy for 94 compounds. Aromatics, alkanes and terpenes were the major compound groups detected. Most VOCs had mean concentrations below 5 µg/m3, and most indoor/outdoor concentration ratios ranged from one to 10. For 16 VOCs, the within-school variance of concentrations exceeded that between schools and, overall, no major differences in VOC concentrations were found between conventional and high performance buildings. While VOC concentrations have declined from levels measured in earlier decades, opportunities remain to improve indoor air quality (IAQ by limiting emissions from building-related sources and by increasing ventilation rates.

  1. Volatile Organic Compounds (VOCs) in Conventional and High Performance School Buildings in the U.S.

    Science.gov (United States)

    Zhong, Lexuan; Su, Feng-Chiao; Batterman, Stuart

    2017-01-01

    Exposure to volatile organic compounds (VOCs) has been an indoor environmental quality (IEQ) concern in schools and other buildings for many years. Newer designs, construction practices and building materials for “green” buildings and the use of “environmentally friendly” products have the promise of lowering chemical exposure. This study examines VOCs and IEQ parameters in 144 classrooms in 37 conventional and high performance elementary schools in the U.S. with the objectives of providing a comprehensive analysis and updating the literature. Tested schools were built or renovated in the past 15 years, and included comparable numbers of conventional, Energy Star, and Leadership in Energy and Environmental Design (LEED)-certified buildings. Indoor and outdoor VOC samples were collected and analyzed by thermal desorption, gas chromatography and mass spectroscopy for 94 compounds. Aromatics, alkanes and terpenes were the major compound groups detected. Most VOCs had mean concentrations below 5 µg/m3, and most indoor/outdoor concentration ratios ranged from one to 10. For 16 VOCs, the within-school variance of concentrations exceeded that between schools and, overall, no major differences in VOC concentrations were found between conventional and high performance buildings. While VOC concentrations have declined from levels measured in earlier decades, opportunities remain to improve indoor air quality (IAQ) by limiting emissions from building-related sources and by increasing ventilation rates. PMID:28117727

  2. Microstructured fibers for high power applications

    Science.gov (United States)

    Baggett, J. C.; Petrovich, M. N.; Hayes, J. R.; Finazzi, V.; Poletti, F.; Amezcua, R.; Broderick, N. G. R.; Richardson, D. J.; Monro, T. M.; Salter, P. L.; Proudley, G.; O'Driscoll, E. J.

    2005-10-01

    Fiber delivery of intense laser radiation is important for a broad range of application sectors, from medicine through to industrial laser processing of materials, and offers many practical system design and usage benefits relative to free space solutions. Optical fibers for high power transmission applications need to offer low optical nonlinearity and high damage thresholds. Single-mode guidance is also often a fundamental requirement for the many applications in which good beam quality is critical. In recent years, microstructured fiber technology has revolutionized the dynamic field of optical fibers, bringing with them a wide range of novel optical properties. These fibers, in which the cladding region is peppered with many small air holes, are separated into two distinct categories, defined by the way in which they guide light: (1) index-guiding holey fibers (HFs), in which the core is solid and light is guided by a modified form of total internal reflection, and (2) photonic band-gap fibers (PBGFs) in which guidance in a hollow core can be achieved via photonic band-gap effects. Both of these microstructured fiber types offer attractive qualities for beam delivery applications. For example, using HF technology, large-mode-area, pure silica fibers with robust single-mode guidance over broad wavelength ranges can be routinely fabricated. In addition, the ability to guide light in an air-core within PBGFs presents obvious power handling advantages. In this paper we review the fundamentals and current status of high power, high brightness, beam delivery in HFs and PBGFs, and speculate as to future prospects.

  3. Conventional Exergetic and Exergoeconomic Analyses of a Power Plant with Chemical Looping Combustion for CO2 Capture

    Directory of Open Access Journals (Sweden)

    Tatiana Morosuk

    2010-09-01

    Full Text Available

    Exergy-based methods can be used as a tool for examining, comparing and assessing thermodynamic systems. In this paper, an exergoeconomic analysis is used to evaluate a power plant with chemical looping combustion (CLC for CO2 capture. This oxy-fuel plant is compared, from an exergetic and an economic perspective, to a conventional, reference power plant without CO2 capture. The exergetic analysis shows decreased exergy destruction in the CLC reactors, compared to the exergy destruction in the conventional combustion chamber of the reference case; thus, the irreversibilities caused by combustion in the CLC are reduced. However, due to the addition of the CO2 compression unit, the overall exergetic efficiency of the plant with CLC is lower than that of the reference plant by approximately 5 percentage points. The economic analysis confirms a significant increase in the investment cost of the CO2 capture plant, due to the addition of the units for CO2 compression and CLC. Thus, the cost of electricity is 24% higher for this plant in comparison to that of the reference case. Nevertheless, when compared to the reference plant with CO2 capture with monoethanolamine, the plant with CLC was found to be a more economical option. Since CO2 abatement must be realized in the future, given expected environmental or tax measures, CLC provides relatively low cost carbon dioxide capture and it, therefore, appears to be a promising option for

  4. Transportable high-energy high-power generator.

    Science.gov (United States)

    Novac, B M; Smith, I R; Senior, P; Parker, M; Louverdis, G

    2010-05-01

    High-power applications sometimes require a transportable, simple, and robust gigawatt pulsed power generator, and an analysis of various possible approaches shows that one based on a twin exploding wire array is extremely advantageous. A generator based on this technology and used with a high-energy capacitor bank has recently been developed at Loughborough University. An H-configuration circuit is used, with one pair of diagonally opposite arms each comprising a high-voltage ballast inductor and the other pair exploding wire arrays capable of generating voltages up to 300 kV. The two center points of the H configuration provide the output to the load, which is coupled through a high-voltage self-breakdown spark gap, with the entire autonomous source being housed in a metallic container. Experimentally, a load resistance of a few tens of Ohms is provided with an impulse of more than 300 kV, having a rise time of about 140 ns and a peak power of over 1.7 GW. Details of the experimental arrangement and typical results are presented and diagnostic measurements of the current and voltage output are shown to compare well with theoretical predictions based on detailed numerical modeling. Finally, the next stage toward developing a more powerful and energetic transportable source is outlined.

  5. Performance evaluation of a high power DC-DC boost converter for PV applications using SiC power devices

    Science.gov (United States)

    Almasoudi, Fahad M.; Alatawi, Khaled S.; Matin, Mohammad

    2016-09-01

    The development of Wide band gap (WBG) power devices has been attracted by many commercial companies to be available in the market because of their enormous advantages over the traditional Si power devices. An example of WBG material is SiC, which offers a number of advantages over Si material. For example, SiC has the ability of blocking higher voltages, reducing switching and conduction losses and supports high switching frequency. Consequently, SiC power devices have become the affordable choice for high frequency and power application. The goal of this paper is to study the performance of 4.5 kW, 200 kHz, 600V DC-DC boost converter operating in continuous conduction mode (CCM) for PV applications. The switching behavior and turn on and turn off losses of different switching power devices such as SiC MOSFET, SiC normally ON JFET and Si MOSFET are investigated and analyzed. Moreover, a detailed comparison is provided to show the overall efficiency of the DC-DC boost converter with different switching power devices. It is found that the efficiency of SiC power switching devices are higher than the efficiency of Si-based switching devices due to low switching and conduction losses when operating at high frequencies. According to the result, the performance of SiC switching power devices dominate the conventional Si power devices in terms of low losses, high efficiency and high power density. Accordingly, SiC power switching devices are more appropriate for PV applications where a converter of smaller size with high efficiency, and cost effective is required.

  6. High Efficiency Reversible Fuel Cell Power Converter

    DEFF Research Database (Denmark)

    Pittini, Riccardo

    The large scale integration of renewable energy sources requires suitable energy storage systems to balance energy production and demand in the electrical grid. Bidirectional fuel cells are an attractive technology for energy storage systems due to the high energy density of fuel. Compared...... entitled "High Efficiency Reversible Fuel Cell Power Converter" and it presents the design of a high efficiency dc-dc converter developed and optimized for bidirectional fuel cell applications. First, a brief overview of fuel cell and energy storage technologies is presented. Different system topologies...... to traditional unidirectional fuel cell, bidirectional fuel cells have increased operating voltage and current ranges. These characteristics increase the stresses on dc-dc and dc-ac converters in the electrical system, which require proper design and advanced optimization. This work is part of the PhD project...

  7. Hybrid high power femtosecond laser system

    Science.gov (United States)

    Trunov, V. I.; Petrov, V. V.; Pestryakov, E. V.; Kirpichnikov, A. V.

    2006-01-01

    Design of a high-power femtosecond laser system based on hybrid chirped pulse amplification (CPA) technique developed by us is presented. The goal of the hybrid principle is the use of the parametric and laser amplification methods in chirped pulse amplifiers. It makes it possible to amplify the low-cycle pulses with a duration of <= fs to terawatt power with a high contrast and high conversion efficiency of the pump radiation. In a created system the Ti:Sapphire laser with 10 fs pulses at 810 nm and output energy about 1-3 nJ will be used like seed source. The oscillator pulses were stretched to duration of about 500 ps by an all-reflective grating stretcher. Then the stretched pulses are injected into a nondegenerate noncollinear optical parametric amplifier (NOPA) on the two BBO crystals. After amplification in NOPA the residual pump was used in a bow-tie four pass amplifier with hybrid active medium (based on Al II0 3:Ti 3+ and BeAl IIO 4:Ti 3+ crystals). The final stage of the amplification system consists of two channels, namely NIR (820 nm) and short-VIS (410 nm). Numerical simulation has shown that the terawatt level of output power can be achieved also in a short-VIS channel at the pumping of the double-crystal BBO NOPA by the radiation of the fourth harmonic of the Nd:YAG laser at 266 nm. Experimentally parametric amplification in BBO crystals of 30-50 fs pulses were investigated and optimized using SPIDER technique and single-shot autocomelator for the realization of shortest duration 40 fs.

  8. Photovoltaics for high capacity space power systems

    Science.gov (United States)

    Flood, Dennis J.

    1988-01-01

    The anticipated energy requirements of future space missions will grow by factors approaching 100 or more, particularly as a permanent manned presence is established in space. The advances that can be expected in solar array performance and lifetime, when coupled with advanced, high energy density storage batteries and/or fuel cells, will continue to make photovoltaic energy conversion a viable power generating option for the large systems of the future. The specific technologies required to satisfy any particular set of power requirements will vary from mission to mission. Nonetheless, in almost all cases the technology push will be toward lighter weight and higher efficiency, whether of solar arrays of storage devices. This paper will describe the content and direction of the current NASA program in space photovoltaic technology. The paper will also discuss projected system level capabilities of photovoltaic power systems in the context of some of the new mission opportunities under study by NASA, such as a manned lunar base, and a manned visit to Mars.

  9. Computing High Accuracy Power Spectra with Pico

    CERN Document Server

    Fendt, William A

    2007-01-01

    This paper presents the second release of Pico (Parameters for the Impatient COsmologist). Pico is a general purpose machine learning code which we have applied to computing the CMB power spectra and the WMAP likelihood. For this release, we have made improvements to the algorithm as well as the data sets used to train Pico, leading to a significant improvement in accuracy. For the 9 parameter nonflat case presented here Pico can on average compute the TT, TE and EE spectra to better than 1% of cosmic standard deviation for nearly all $\\ell$ values over a large region of parameter space. Performing a cosmological parameter analysis of current CMB and large scale structure data, we show that these power spectra give very accurate 1 and 2 dimensional parameter posteriors. We have extended Pico to allow computation of the tensor power spectrum and the matter transfer function. Pico runs about 1500 times faster than CAMB at the default accuracy and about 250,000 times faster at high accuracy. Training Pico can be...

  10. High-power converters and AC drives

    CERN Document Server

    Wu, Bin

    2017-01-01

    This new edition reflects the recent technological advancements in the MV drive industry, such as advanced multilevel converters and drive configurations. It includes three new chapters, Control of Synchronous Motor Drives, Transformerless MV Drives, and Matrix Converter Fed Drives. In addition, there are extensively revised chapters on Multilevel Voltage Source Inverters and Voltage Source Inverter-Fed Drives. This book includes a systematic analysis on a variety of high-power multilevel converters, illustrates important concepts with simulations and experiments, introduces various megawatt drives produced by world leading drive manufacturers, and addresses practical problems and their mitigations methods.

  11. Analysis of Highly Wind Power Integrated Power System model performance during Critical Weather conditions

    DEFF Research Database (Denmark)

    Basit, Abdul; Hansen, Anca Daniela; Sørensen, Poul Ejnar

    2014-01-01

    . For this purpose, the power system model has been developed that represents the relevant dynamic features of power plants and compensates for power imbalances caused by the forecasting error during critical weather conditions. The regulating power plan, as an input time series for the developed power system model......Secure power system operation of a highly wind power integrated power system is always at risk during critical weather conditions, e.g. in extreme high winds. The risk is even higher when 50% of the total electricity consumption has to be supplied by wind power, as the case for the future Danish...... power system in 2020. This paper analyses and compares the performance of the future Danish power system during extreme wind speeds, where wind power plants are either controlled through a traditional High Wind Shut Down storm controller or a new High Wind Extended Production storm controller...

  12. NULL Convention Floating Point Multiplier

    OpenAIRE

    Anitha Juliette Albert; Seshasayanan Ramachandran

    2015-01-01

    Floating point multiplication is a critical part in high dynamic range and computational intensive digital signal processing applications which require high precision and low power. This paper presents the design of an IEEE 754 single precision floating point multiplier using asynchronous NULL convention logic paradigm. Rounding has not been implemented to suit high precision applications. The novelty of the research is that it is the first ever NULL convention logic multiplier, designed to p...

  13. Optimal Operation of Plug-In Electric Vehicles in Power Systems with High Wind Power Penetrations

    DEFF Research Database (Denmark)

    Hu, Weihao; Su, Chi; Chen, Zhe

    2013-01-01

    The Danish power system has a large penetration of wind power. The wind fluctuation causes a high variation in the power generation, which must be balanced by other sources. The battery storage based Plug-In Electric Vehicles (PEV) may be a possible solution to balance the wind power variations...... in the power systems with high wind power penetrations. In this paper, the integration of plug-in electric vehicles in the power systems with high wind power penetrations is proposed and discussed. Optimal operation strategies of PEV in the spot market are proposed in order to decrease the energy cost for PEV...

  14. Scale Law of the High Power Free Electron Laser

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The scale law and design procedure of the high power FEL are discussed. It is pointed out that theextraction efficiency, which is the critical factor of the output power besides the power of the electron

  15. Improved cooling design for high power waveguide system

    Science.gov (United States)

    Chen, W. C. J.; Hartop, R.

    1981-06-01

    Testing of X band high power components in a traveling wave resonator indicates that this improved cooling design reduces temperature in the waveguide and flange. The waveguide power handling capability and power transmission reliability is increased substantially.

  16. Digitally Controlled High Availability Power Supply

    Energy Technology Data Exchange (ETDEWEB)

    MacNair, David; /SLAC

    2009-05-07

    This paper will report on the test results of a prototype 1320 watt power module for a high availability power supply. The module will allow parallel operation for N+1 redundancy with hot swap capability. The two quadrant output of each module allows pairs of modules to provide a 4 quadrant (bipolar) operation. Each module employs a novel 4 FET buck regulator arranged in a bridge configuration. Each side of the bridge alternately conducts through a small saturable ferrite that limits the reverse current in the FET body diode during turn off. This allows hard switching of the FETs with low switching losses. The module is designed with over-rated components to provide high reliability and better then 97% efficiency at full load. The modules use a Microchip DSP for control, monitoring, and fault detection. The switching FETS are driven by PWM modules in the DSP at 60 KHz. A Dual CAN bus interface provides for low cost redundant control paths. The DSP will also provide current sharing between modules, synchronized switching, and soft start up for hot swapping. The input and output of each module have low resistance FETs to allow hot swapping and isolation of faulted units.

  17. Design and characterization of a novel power over fiber system integrating a high power diode laser

    Science.gov (United States)

    Perales, Mico; Yang, Mei-huan; Wu, Cheng-liang; Hsu, Chin-wei; Chao, Wei-sheng; Chen, Kun-hsein; Zahuranec, Terry

    2017-02-01

    High power 9xx nm diode lasers along with MH GoPower's (MHGP's) flexible line of Photovoltaic Power Converters (PPCs) are spurring high power applications for power over fiber (PoF), including applications for powering remote sensors and sensors monitoring high voltage equipment, powering high voltage IGBT gate drivers, converters used in RF over Fiber (RFoF) systems, and system power applications, including powering UAVs. In PoF, laser power is transmitted over fiber, and is converted to electricity by photovoltaic cells (packaged into Photovoltaic Power Converters, or PPCs) which efficiently convert the laser light. In this research, we design a high power multi-channel PoF system, incorporating a high power 976 nm diode laser, a cabling system with fiber break detection, and a multichannel PPC-module. We then characterizes system features such as its response time to system commands, the PPC module's electrical output stability, the PPC-module's thermal response, the fiber break detection system response, and the diode laser optical output stability. The high power PoF system and this research will serve as a scalable model for those interested in researching, developing, or deploying a high power, voltage isolated, and optically driven power source for high reliability utility, communications, defense, and scientific applications.

  18. One-step synthesis of highly reduced graphene hydrogels for high power supercapacitor applications

    Science.gov (United States)

    Banda, Harish; Aradilla, David; Benayad, Anass; Chenavier, Yves; Daffos, Barbara; Dubois, Lionel; Duclairoir, Florence

    2017-08-01

    Graphene hydrogels with high electrical conductivity were prepared by a one-step process using hydrazine hydrate as gel assembly agent (GH-HD). Conventional two-step process of gel formation and further reduction to prepare highly conducting gels was replaced by a single step involving equivalent amount of hydrazine. Optimized graphene oxide concentration was established to facilitate such monolith formation. Extensive characterization and control studies enabled understanding of the material properties and gel formation mechanism. The synthesized gel shows a high electrical conductivity of 1141 S/m. The supercapacitor based on GH-HD delivers a high specific capacitance of 190 F/g at a current density of 0.5 A/g and 123 F/g at very high current density of 100 A/g. Furthermore, excellent power capability and cyclic stability were also observed. 3D macroporous morphology of GH-HD makes it ideal for high rate supercapacitor applications.

  19. Series-Tuned High Efficiency RF-Power Amplifiers

    DEFF Research Database (Denmark)

    Vidkjær, Jens

    2008-01-01

    An approach to high efficiency RF-power amplifier design is presented. It addresses simultaneously efficiency optimization and peak voltage limitations when transistors are pushed towards their power limits.......An approach to high efficiency RF-power amplifier design is presented. It addresses simultaneously efficiency optimization and peak voltage limitations when transistors are pushed towards their power limits....

  20. K-band high power latching switch

    Science.gov (United States)

    Mlinar, M. J.; Piotrowski, W. S.; Raue, J. E.

    1980-12-01

    A 19 GHz waveguide latching switch with a bandwidth of 1400 MHz and an exceptionally low insertion loss of 0.25 dB was demonstrated. The RF and driver ferrites are separate structures and can be optimized individually. This analysis for each structure is separately detailed. Basically, the RF section features a dual turnstile junction. The circulator consists of a dielectric tube which contains two ferrite rods, and a dielectric spacer separating the ferrite parts along the center of symmetry of the waveguide to form two turnstiles. This subassembly is indexed and locked in the center of symmetry of a uniform junction of three waveguides by the metallic transformers installed in the top and bottom walls of the housing. The switching junction and its actuating circuitry met all RF performance objectives and all shock and vibration requirements with no physical damage or performance degradation. It exceeds thermal requirements by operating over a 100 C temperature range (-44 C to +56 C) and has a high power handling capability allowing up to 100 W of CW input power.

  1. High Energy High Power Battery Exceeding PHEV40 Requirements

    Energy Technology Data Exchange (ETDEWEB)

    Rempel, Jane [TIAX LLC, Lexington, MA (United States)

    2016-03-31

    TIAX has developed long-life lithium-ion cells that can meet and exceed the energy and power targets (200Wh/kg and 800W/kg pulse power) set out by DOE for PHEV40 batteries. To achieve these targets, we selected and scaled-up a high capacity version of our proprietary high energy and high power CAM-7® cathode material. We paired the cathode with a blended anode containing Si-based anode material capable of delivering high capacity and long life. Furthermore, we optimized the anode blend composition, cathode and anode electrode design, and selected binder and electrolyte compositions to achieve not only the best performance, but also long life. By implementing CAM-7 with a Si-based blended anode, we built and tested prototype 18650 cells that delivered measured specific energy of 198Wh/kg total energy and 845W/kg at 10% SOC (projected to 220Wh/kg in state-of-the-art 18650 cell hardware and 250Wh/kg in 15Ah pouch cells). These program demonstration cells achieved 90% capacity retention after 500 cycles in on-going cycle life testing. Moreover, we also tested the baseline CAM-7/graphite system in 18650 cells showing that 70% capacity retention can be achieved after ~4000 cycles (20 months of on-going testing). Ultimately, by simultaneously meeting the PHEV40 power and energy targets and providing long life, we have developed a Li-ion battery system that is smaller, lighter, and less expensive than current state-of-the-art Li-ion batteries.

  2. Non-Thermionic Cathode for High Power Long Pulse, Long Lifetime Magnetrons

    Science.gov (United States)

    2010-11-18

    switched with an SCR. The coil produces a 3 kG magnetic field with a 20mS critically damped waveform. This is sufficient to allow flux penetration...that the conventional thermionic cathode doses not provide acceptable electron emission for operation in the HPM power levels (> 100Mw). In this work...TECHNICAL REPORT AFOSR CONTRACT: FA9550-09-C-0127 “Non- Thermionic Cathode for High Power Long Pulse, Long Lifetime Magnetrons” Miles Collins Clark

  3. Finite-Element Simulation of Conventional and High-Speed Peripheral Milling of Hardened Mold Steel

    Science.gov (United States)

    Tang, D. W.; Wang, C. Y.; Hu, Y. N.; Song, Y. X.

    2009-12-01

    A finite-element model (FEM) with the flow stress and typical fracture is used to simulate a hard machining process, which before this work could not adequately represent the constitutive behavior of workpiece material that is usually heat treated to hardness levels above 50 Rockwell C hardness (HRC). Thus, a flow stress equation with a variation in hardness is used in the computer simulation of hard machining. In this article, the influence of the milling speed on the cutting force, chip morphology, effective stress, and cutting temperature in the deformation zones of both conventional and high-speed peripheral milling hardened mold steel is systematically studied by finite-element analysis (FEA). By taking into consideration the importance of material characteristics during the milling process, the similar Johnson-Cook’s constitutive equation with hardened mold steel is introduced to the FEM to investigate the peripheral milling of hardened mold steel. In comparison with the experimental data of the cutting force at various cutting speeds, the simulation result is identical with the measured data. The results indicate that the model can be used to accurately predict the behavior of hardened mold steel in both conventional and high-speed milling.

  4. Low-Power, High-Speed Transceivers for Network-on-Chip Communication

    NARCIS (Netherlands)

    Schinkel, Daniel; Mensink, E.; Klumperink, Eric A.M.; van Tuijl, Adrianus Johannes Maria; Nauta, Bram

    Networks on chips (NoCs) are becoming popular as they provide a solution for the interconnection problems on large integrated circuits (ICs). But even in a NoC, link-power can become unacceptably high and data rates are limited when conventional data transceivers are used. In this paper, we present

  5. Low-Power, High-Speed Transceivers for Network-on-Chip Communication

    NARCIS (Netherlands)

    Schinkel, Daniel; Mensink, E.; Klumperink, Eric A.M.; van Tuijl, Adrianus Johannes Maria; Nauta, Bram

    2009-01-01

    Networks on chips (NoCs) are becoming popular as they provide a solution for the interconnection problems on large integrated circuits (ICs). But even in a NoC, link-power can become unacceptably high and data rates are limited when conventional data transceivers are used. In this paper, we present

  6. Short-Term and Medium-Term Reliability Evaluation for Power Systems With High Penetration of Wind Power

    DEFF Research Database (Denmark)

    Ding, Yi; Singh, Chanan; Goel, Lalit;

    2014-01-01

    The expanding share of the fluctuating and less predictable wind power generation can introduce complexities in power system reliability evaluation and management. This entails a need for the system operator to assess the system status more accurately for securing real-time balancing. The existing...... a useful tool for the system operator to evaluate the reliability and arrange reserve for maintaining secure system operation in the short- as well as medium-terms....... an approximation of the time-varying behavior of power systems with high penetration of wind power. This paper proposes a time-varying reliability assessment technique. Time-varying reliability models for wind farms, conventional generating units, and rapid start-up generating units are developed and represented...

  7. Innovations in high power fiber laser applications

    Science.gov (United States)

    Beyer, Eckhard; Mahrle, Achim; Lütke, Matthias; Standfuss, Jens; Brückner, Frank

    2012-02-01

    Diffraction-limited high power lasers represent a new generation of lasers for materials processing, characteristic traits of which are: smaller, cost-effective and processing "on the fly". Of utmost importance is the high beam quality of fiber lasers which enables us to reduce the size of the focusing head incl. scanning mirrors. The excellent beam quality of the fiber laser offers a lot of new applications. In the field of remote cutting and welding the beam quality is the key parameter. By reducing the size of the focusing head including the scanning mirrors we can reach scanning frequencies up to 1.5 kHz and in special configurations up to 4 kHz. By using these frequencies very thin and deep welding seams can be generated experienced so far with electron beam welding only. The excellent beam quality of the fiber laser offers a high potential for developing new applications from deep penetration welding to high speed cutting. Highly dynamic cutting systems with maximum speeds up to 300 m/min and accelerations up to 4 g reduce the cutting time for cutting complex 2D parts. However, due to the inertia of such systems the effective cutting speed is reduced in real applications. This is especially true if complex shapes or contours are cut. With the introduction of scanner-based remote cutting systems in the kilowatt range, the effective cutting speed on the contour can be dramatically increased. The presentation explains remote cutting of metal foils and sheets using high brightness single mode fiber lasers. The presentation will also show the effect of optical feedback during cutting and welding with the fiber laser, how those feedbacks could be reduced and how they have to be used to optimize the cutting or welding process.

  8. High power solid state laser modulator

    Science.gov (United States)

    Birx, Daniel L.; Ball, Don G.; Cook, Edward G.

    2004-04-27

    A multi-stage magnetic modulator provides a pulse train of .+-.40 kV electrical pulses at a 5-7 kHz repetition rate to a metal vapor laser. A fractional turn transformer steps up the voltage by a factor of 80 to 1 and magnetic pulse compression is used to reduce the pulse width of the pulse train. The transformer is fabricated utilizing a rod and plate stack type of construction to achieve a high packing factor. The pulses are controlled by an SCR stack where a plurality of SCRs are electrically connected in parallel, each SCR electrically connected to a saturable inductor, all saturable inductors being wound on the same core of magnetic material for enhanced power handling characteristics.

  9. High power coherent polarization locked laser diode.

    Science.gov (United States)

    Purnawirman; Phua, P B

    2011-03-14

    We have coherently combined a broad area laser diode array to obtain high power single-lobed output by using coherent polarization locking. The single-lobed coherent beam is achieved by spatially combining four diode emitters using walk-off crystals and waveplates while their phases are passively locked via polarization discrimination. While our previous work focused on coherent polarization locking of diode in Gaussian beams, we demonstrate in this paper, the feasibility of the same polarization discrimination for locking multimode beams from broad area diode lasers. The resonator is designed to mitigate the loss from smile effect by using retro-reflection feedback in the cavity. In a 980 nm diode array, we produced 7.2 W coherent output with M2 of 1.5x11.5. The brightness of the diode is improved by more than an order of magnitude.

  10. Splitting of high power, cw proton beams

    CERN Document Server

    Facco, Alberto; Berkovits, Dan; Yamane, Isao

    2007-01-01

    A simple method for splitting a high power, continuous wave (cw) proton beam in two or more branches with low losses has been developed in the framework of the EURISOL (European Isotope Separation On-Line adioactive Ion Beam Facility) design study. The aim of the system is to deliver up to 4 MW of H beam to the main radioactive ion beam production target, and up to 100 kWof proton beams to three more targets, simultaneously. A three-step method is used, which includes magnetic neutralization of a fractionof the main H- beam, magnetic splitting of H- and H0, and stripping of H0 to H+. The method allowsslow raising and individual fine adjustment of the beam intensity in each branch.

  11. Advanced Materials for High Temperature, High Performance, Wide Bandgap Power Modules

    Science.gov (United States)

    O'Neal, Chad B.; McGee, Brad; McPherson, Brice; Stabach, Jennifer; Lollar, Richard; Liederbach, Ross; Passmore, Brandon

    2016-01-01

    Advanced packaging materials must be utilized to take full advantage of the benefits of the superior electrical and thermal properties of wide bandgap power devices in the development of next generation power electronics systems. In this manuscript, the use of advanced materials for key packaging processes and components in multi-chip power modules will be discussed. For example, to date, there has been significant development in silver sintering paste as a high temperature die attach material replacement for conventional solder-based attach due to the improved thermal and mechanical characteristics as well as lower processing temperatures. In order to evaluate the bond quality and performance of this material, shear strength, thermal characteristics, and void quality for a number of silver sintering paste materials were analyzed as a die attach alternative to solder. In addition, as high voltage wide bandgap devices shift from engineering samples to commercial components, passivation materials become key in preventing premature breakdown in power modules. High temperature, high dielectric strength potting materials were investigated to be used to encapsulate and passivate components internal to a power module. The breakdown voltage up to 30 kV and corresponding leakage current for these materials as a function of temperature is also presented. Lastly, high temperature plastic housing materials are important for not only discrete devices but also for power modules. As the operational temperature of the device and/or ambient temperature increases, the mechanical strength and dielectric properties are dramatically reduced. Therefore, the electrical characteristics such as breakdown voltage and leakage current as a function of temperature for housing materials are presented.

  12. Search for high-Tc conventional superconductivity at megabar pressures in the lithium-sulfur system

    Science.gov (United States)

    Kokail, Christian; Heil, Christoph; Boeri, Lilia

    2016-08-01

    Motivated by the recent report of superconductivity above 200 K in ultra-dense hydrogen sulfide, we search for high-TC conventional superconductivity in the phase diagram of the binary Li-S system, using ab initio methods for crystal structure prediction and linear response calculations for the electron-phonon coupling. We find that at pressures higher than 20 GPa, several new compositions, besides the known Li2S , are stabilized; many exhibit electride-like interstitial charge localization observed in other alkali-metal compounds. Of all predicted phases, only an fcc phase of Li3S , metastable before 640 GPa, exhibits a sizable TC, in contrast to what is observed in sulfur and phosphorus hydrides, where several stoichiometries lead to high TC. We attribute this difference to 2 s -2 p hybridization and avoided core overlap, and predict similar behavior for other alkali-metal compounds.

  13. High-temperature alloys for high-power thermionic systems

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Kwang S.; Jacobson, D.L.; D' cruz, L.; Luo, Anhua; Chen, Bor-Ling.

    1990-08-01

    The need for structural materials with useful strength above 1600 k has stimulated interest in refractory-metal alloys. Tungsten possesses an extreme high modulus of elasticity as well as the highest melting temperature among metals, and hence is being considered as one of the most promising candidate materials for high temperature structural applications such as space nuclear power systems. This report is divided into three chapters covering the following: (1) the processing of tungsten base alloys; (2) the tensile properties of tungsten base alloys; and (3) creep behavior of tungsten base alloys. Separate abstracts were prepared for each chapter. (SC)

  14. HIGH POWER APPLICATIONS OF ELECTROMAGNETIC DEVICES

    Directory of Open Access Journals (Sweden)

    VASILE DOBREF

    2016-06-01

    Full Text Available For the next generation, conventional weapon will touch the best performance limits and will became more and more what in what more an important part plans of improvement systems of weapon to the future. Physical laws that govern electromagnetic propulsion of guns, enabling them higher speeds than those of conventional arms projectiles. This is substantially benefit electromagnetic weapons - using electricity as energy for an lectromagnetic weapons.

  15. High Power High Efficiency Ka-Band Power Combiners for Solid-State Devices

    Science.gov (United States)

    Freeman, Jon C.; Wintucky, Edwin G.; Chevalier, Christine T.

    2006-01-01

    Wide-band power combining units for Ka-band are simulated for use as MMIC amplifier applications. Short-slot couplers as well as magic-tees are the basic elements for the combiners. Wide bandwidth (5 GHz) and low insertion (approx.0.2 dB) and high combining efficiencies (approx.90 percent) are obtained.

  16. Conventional P-ω/Q-V Droop Control in Highly Resistive Line of Low-Voltage Converter-Based AC Microgrid

    Directory of Open Access Journals (Sweden)

    Xiaochao Hou

    2016-11-01

    Full Text Available In low-voltage converter-based alternating current (AC microgrids with resistive distribution lines, the P-V droop with Q-f boost (VPD/FQB is the most common method for load sharing. However, it cannot achieve the active power sharing proportionally. To overcome this drawback, the conventional P-ω/Q-V droop control is adopted in the low-voltage AC microgrid. As a result, the active power sharing among the distributed generators (DGs is easily obtained without communication. More importantly, this study clears up the previous misunderstanding that conventional P-ω/Q-V droop control is only applicable to microgrids with highly inductive lines, and lays a foundation for the application of conventional droop control under different line impedances. Moreover, in order to guarantee the accurate reactive power sharing, a guide for designing Q-V droop gains is given, and virtual resistance is adopted to shape the desired output impedance. Finally, the effects of power sharing and transient response are verified through simulations and experiments in converter-based AC Microgrid.

  17. Method and apparatus for improved high power impulse magnetron sputtering

    Science.gov (United States)

    Anders, Andre

    2013-11-05

    A high power impulse magnetron sputtering apparatus and method using a vacuum chamber with a magnetron target and a substrate positioned in the vacuum chamber. A field coil being positioned between the magnetron target and substrate, and a pulsed power supply and/or a coil bias power supply connected to the field coil. The pulsed power supply connected to the field coil, and the pulsed power supply outputting power pulse widths of greater that 100 .mu.s.

  18. High Power Piezoelectric Characterization for Piezoelectric Transformer Development

    Science.gov (United States)

    Ural, Seyit O.

    The major goal was to develop characterization techniques to identify and define guidelines to manufacture high power density actuators. We particularly aim at improving the strengths of piezoelectric transformers, namely the high efficiency, ease of manufacturing, low electromagnetic noise, and high power to weight ratio resulting in an adaptor application by identifying material limitations, geometrical limitations and offer guidelines to counter drawbacks limiting the power density. There are 3 losses present in piezoelectrics. Namely dielectric, elastic and piezoelectric losses. These losses can be calculated using mechanical quality factors of the resonating piezoelectric actuator. But in order to calculate all three losses, the mechanical quality factor for resonance and anti resonance need to be measured. Although the mechanical quality factor for resonance is conventionally measured, measurements in antiresonance have been ignored. Since there was no unique measurement technique to address antiresonance and resonance Q in one single sweep, in this study constant vibration velocity method was developed. During the constant vibration velocity measurement, the input electrical energy is monitored and significant differences between resonance and antiresonance drives are observed. For the same output work (identical vibration velocity) significant differences in the losses were observed. Thermographic images have shown increasing temperature differences for resonance and antiresonance nodal point temperatures, with higher vibration velocities. The theoretical evaluation identified the difference observed in the mechanical quality factors at resonance and antiresonance to stem from the piezoelectric loss. In order to investigate losses in the absence of thermal effects a transient characterization technique was adopted. The burst technique, originally developed for characterization of the mechanical quality factor at resonance, has been modified with a switch

  19. High Power Combiner/Divider Design for Dual Band RF Power Amplifiers

    OpenAIRE

    Flattery, Kyle; Amin, Shoaib; Rönnow, Daniel; Mahamat, Yaya; Eroglu, Abdullah

    2015-01-01

    Design of low loss with an enhanced thermal profile power divider/combiner for high power dual-band Radio Frequency (RF) power amplifier applications is given. The practical implementation, low loss and substrate characteristics make this type of combiner ideal for high power microwave applications.  The combiner operational frequencies are chosen to operate at 900 MHz and 2.14 GHz, which are common frequencies for concurrent dual band RF power amplifiers. The analytical results are verified ...

  20. Diagnostic imaging of gout: comparison of high-resolution US versus conventional X-ray

    Energy Technology Data Exchange (ETDEWEB)

    Rettenbacher, Thomas; Ennemoser, Sybille; Weirich, Harald [Innsbruck Medical University, Department of Radiology, Innsbruck (Austria); Ulmer, Hanno [Innsbruck Medical University, Department of Medical Statistics, Informatics, and Health Economics, Innsbruck (Austria); Hartig, Frank; Klotz, Werner; Herold, Manfred [Innsbruck Medical University, Department of Internal Medicine, Innsbruck (Austria)

    2008-03-15

    The aim was to compare X-ray and ultrasound (US) in diagnosing gout. In a prospective study, 105 consecutive patients with clinical suspicion of gout underwent conventional X-ray und high-resolution US in order to help in arriving at a definite diagnosis. X-ray findings suggestive of gout included soft-tissue opacifications with densities between soft tissue and bone, articular and periarticular bone erosions, and osteophytes at the margins of opacifications or erosions. US findings suggestive of gout included bright stippled foci and hyperechoic soft-tissue areas. Fifty-five patients had a definite diagnosis of gout (102 involved sites), 31 patients were diagnosed as having another disease (59 involved sites), and 19 patients were excluded from the study because a definite diagnosis could not be established. X-ray suggested gout with a sensitivity of 31% (32/102) and a specificity of 93% (55/59), whereas US suggested gout with a sensitivity of 96% (98/102) and a specificity of 73% (43/59). US was much more sensitive than conventional X-ray but less specific. Our data show that US often provided additional diagnostic information in patients with clinical suspicion of gout when laboratory findings and X-ray results were negative or inconclusive and should therefore be used in these cases. (orig.)

  1. Separation of Aliphatic and Aromatic Carboxylic Acids by Conventional and Ultra High Performance Ion Exclusion Chromatography.

    Science.gov (United States)

    Mansour, Fotouh R; Kirkpatrick, Christine L; Danielson, Neil D

    2013-06-01

    An ion exclusion chromatography (IELC) comparison between a conventional ion exchange column and an ultra-high performance liquid chromatography (UHPLC) dynamically surfactant modified C18 column for the separation of an aliphatic carboxylic acid and two aromatic carboxylic acids is presented. Professional software is used to optimize the conventional IELC separation conditions for acetylsalicylic acid and the hydrolysis products: salicylic acid and acetic acid. Four different variables are simultaneously optimized including H2SO4 concentration, pH, flow rate, and sample injection volume. Thirty different runs are suggested by the software. The resolutions and the time of each run are calculated and feed back to the software to predict the optimum conditions. Derringer's desirability functions are used to evaluate the test conditions and those with the highest desirability value are utilized to separate acetylsalicylic acid, salicylic acid, and acetic acid. These conditions include using a 0.35 mM H2SO4 (pH 3.93) eluent at a flow rate of 1 mL min(-1) and an injection volume of 72 μL. To decrease the run time and improve the performance, a UHPLC C18 column is used after dynamic modification with sodium dodecyl sulfate. Using pure water as a mobile phase, a shorter analysis time and better resolution are achieved. In addition, the elution order is different from the IELC method which indicates the contribution of the reversed-phase mode to the separation mechanism.

  2. Prediction of multiaxial mechanical behavior for conventional and highly crosslinked UHMWPE using a hybrid constitutive model.

    Science.gov (United States)

    Bergström, J S; Rimnac, C M; Kurtz, S M

    2003-04-01

    The development of theoretical failure, fatigue, and wear models for ultra-high molecular weight polyethylene (UHMWPE) used in joint replacements has been hindered by the lack of a validated constitutive model that can accurately predict large deformation mechanical behavior under clinically relevant, multiaxial loading conditions. Recently, a new Hybrid constitutive model for unirradiated UHMWPE was developed Bergström et al., (Biomaterials 23 (2002) 2329) based on a physics-motivated framework which incorporates the governing micro-mechanisms of polymers into an effective and accurate continuum representation. The goal of the present study was to compare the predictive capability of the new Hybrid model with the J(2)-plasticity model for four conventional and highly crosslinked UHMWPE materials during multiaxial loading. After calibration under uniaxial loading, the predictive capabilities of the J(2)-plasticity and Hybrid model were tested by comparing the load-displacement curves from experimental multiaxial (small punch) tests with simulated load-displacement curves calculated using a finite element model of the experimental apparatus. The quality of the model predictions was quantified using the coefficient of determination (r(2)). The results of the study demonstrate that the Hybrid model outperforms the J(2)-plasticity model both for combined uniaxial tension and compression predictions and for simulating multiaxial large deformation mechanical behavior produced by the small punch test. The results further suggest that the parameters of the HM may be generalizable for a wide range of conventional, highly crosslinked, and thermally treated UHMWPE materials, based on the characterization of four material properties related to the elastic modulus, yield stress, rate of strain hardening, and locking stretch of the polymer chains. Most importantly, from a practical perspective, these four key material properties for the Hybrid constitutive model can be measured

  3. Enabling high grayscale resolution displays and accurate response time measurements on conventional computers.

    Science.gov (United States)

    Li, Xiangrui; Lu, Zhong-Lin

    2012-02-29

    Display systems based on conventional computer graphics cards are capable of generating images with 8-bit gray level resolution. However, most experiments in vision research require displays with more than 12 bits of luminance resolution. Several solutions are available. Bit++ (1) and DataPixx (2) use the Digital Visual Interface (DVI) output from graphics cards and high resolution (14 or 16-bit) digital-to-analog converters to drive analog display devices. The VideoSwitcher (3) described here combines analog video signals from the red and blue channels of graphics cards with different weights using a passive resister network (4) and an active circuit to deliver identical video signals to the three channels of color monitors. The method provides an inexpensive way to enable high-resolution monochromatic displays using conventional graphics cards and analog monitors. It can also provide trigger signals that can be used to mark stimulus onsets, making it easy to synchronize visual displays with physiological recordings or response time measurements. Although computer keyboards and mice are frequently used in measuring response times (RT), the accuracy of these measurements is quite low. The RTbox is a specialized hardware and software solution for accurate RT measurements. Connected to the host computer through a USB connection, the driver of the RTbox is compatible with all conventional operating systems. It uses a microprocessor and high-resolution clock to record the identities and timing of button events, which are buffered until the host computer retrieves them. The recorded button events are not affected by potential timing uncertainties or biases associated with data transmission and processing in the host computer. The asynchronous storage greatly simplifies the design of user programs. Several methods are available to synchronize the clocks of the RTbox and the host computer. The RTbox can also receive external triggers and be used to measure RT with respect

  4. High power ring methods and accelerator driven subcritical reactor application

    Energy Technology Data Exchange (ETDEWEB)

    Tahar, Malek Haj [Univ. of Grenoble (France)

    2016-08-07

    transverse beam dynamics. The results obtained allow to develop a correction scheme to minimize the tune variations of the FFAG. This is the cornerstone of a new fixed tune non-scaling FFAG that represents a potential candidate for high power applications. As part of the developments towards high power at the KURRI FFAG, beam dynamics studies have to account for space charge effects. In that framework, models have been installed in the tracking code ZGOUBI to account for the self-interaction of the particles in the accelerator. Application to the FFAG studies is shown. Finally, one focused on the ADSR concept as a candidate to solve the problem of nuclear waste. In order to establish the accelerator requirements, one compared the performance of ADSR with other conventional critical reactors by means of the levelized cost of energy. A general comparison between the different accelerator technologies that can satisfy these requirements is finally presented. In summary, the main drawback of the ADSR technology is the high Levelized Cost Of Energy compared to other advanced reactor concepts that do not employ an accelerator. Nowadays, this is a show-stopper for any industrial application aiming at producing energy (without dealing with the waste problem). Besides, the reactor is not intrinsically safer than critical reactor concepts, given the complexity of managing the target interface between the accelerator and the reactor core.

  5. Fast Decoupled Power Flow for Power System with High Voltage Direct Current Transmission Line System

    Directory of Open Access Journals (Sweden)

    Prechanon Kumkratug

    2010-01-01

    Full Text Available Problem statement: High voltage direct current transmission line system has been widely applied for control power flow in power system. The power flow analysis was the one of powerful tools by which the power system equipped was analyzed both for planning and operation strategies. Approach: This study presented the method to analyze power flow of power system consisted of HVDC system. HVDC was modeled as the complex power injections. The presented complex power injected was incorporated into the existing power flow program based on fast decoupled method. The presented method was tested on the multimachine power system. Results: The transmission line loss of the system with and without HVDC was compared. Conclusion: From the simulation results, the HVDC can reduce transmission line loss of power system.

  6. Self-biased circulators for high power applications

    Science.gov (United States)

    Sokolov, Alexander S.

    Self-biased circulators exploit the properties of high anisotropy magnetic field in hexagonal ferrites, thus allowing operation without biasing magnets and a significant size and weight reduction. Although first self-biased circulators were demonstrated more than 20 years ago, all the prototypes constructed so far are unsuitable for practical applications. An attempt to design a self-biased circulator from scratch was made. Novel exceptionally low dielectric loss and high heat conductivity ceramic materials were developed and innovative substrate synthesis techniques were employed. Low temperature cofiring of green body ferrite compacts and dielectric ceramic slurries were mastered, resulting in solid composite substrates. Original device design was developed. Key features (including wide coupling angles, wide microstriplines, thick substrate, and absence of impedance transformers) enable low insertion loss, broadband operation, high power handling, and compact size. Fabrication and testing of Ka band Y-junction self-biased circulator are reported herein. Furthermore, design approach and fabrication techniques developed here can be readily applied for the construction of X-band self-biased circulators, provided that suitable ferrite materials are available. Low temperature cofiring of ferrite and dielectric materials is especially beneficial for various RF and high-frequency applications. Multiple devices can be readily fabricated on a single wafer using conventional lithographic techniques, resulting in true microwave monolithic integrated circuit.

  7. Analysis of RNA folding and ligand binding by conventional and high-throughput calorimetry.

    Science.gov (United States)

    Sokoloski, Joshua E; Bevilacqua, Philip C

    2012-01-01

    Noncoding RNAs serve myriad functions in the cell, but their biophysical properties are not well understood. Calorimetry offers direct and label-free means for characterizing the ligand-binding and thermostability properties of these RNA. We apply two main types of calorimetry--isothermal titration calorimetry (ITC) and differential scanning calorimetry (DSC)--to the characterization of these functional RNA molecules. ITC can describe ligand binding in terms of stoichiometry, affinity, and heat (enthalpy), while DSC can provide RNA stability in terms of heat capacity, melting temperature, and folding enthalpy. Here, we offer detailed experimental protocols for studying such RNA systems with commercially available conventional and high-throughput ITC and DSC instruments.

  8. Design of Ultra-High-Power-Density Machine Optimized for Future Aircraft

    Science.gov (United States)

    Choi, Benjamin B.

    2004-01-01

    The NASA Glenn Research Center's Structural Mechanics and Dynamics Branch is developing a compact, nonpolluting, bearingless electric machine with electric power supplied by fuel cells for future "more-electric" aircraft with specific power in the projected range of 50 hp/lb, whereas conventional electric machines generate usually 0.2 hp/lb. The use of such electric drives for propulsive fans or propellers depends on the successful development of ultra-high-power-density machines. One possible candidate for such ultra-high-power-density machines, a round-rotor synchronous machine with an engineering current density as high as 20,000 A/sq cm, was selected to investigate how much torque and power can be produced.

  9. Conventional superconductivity at 203 kelvin at high pressures in the sulfur hydride system.

    Science.gov (United States)

    Drozdov, A P; Eremets, M I; Troyan, I A; Ksenofontov, V; Shylin, S I

    2015-09-03

    A superconductor is a material that can conduct electricity without resistance below a superconducting transition temperature, Tc. The highest Tc that has been achieved to date is in the copper oxide system: 133 kelvin at ambient pressure and 164 kelvin at high pressures. As the nature of superconductivity in these materials is still not fully understood (they are not conventional superconductors), the prospects for achieving still higher transition temperatures by this route are not clear. In contrast, the Bardeen-Cooper-Schrieffer theory of conventional superconductivity gives a guide for achieving high Tc with no theoretical upper bound--all that is needed is a favourable combination of high-frequency phonons, strong electron-phonon coupling, and a high density of states. These conditions can in principle be fulfilled for metallic hydrogen and covalent compounds dominated by hydrogen, as hydrogen atoms provide the necessary high-frequency phonon modes as well as the strong electron-phonon coupling. Numerous calculations support this idea and have predicted transition temperatures in the range 50-235 kelvin for many hydrides, but only a moderate Tc of 17 kelvin has been observed experimentally. Here we investigate sulfur hydride, where a Tc of 80 kelvin has been predicted. We find that this system transforms to a metal at a pressure of approximately 90 gigapascals. On cooling, we see signatures of superconductivity: a sharp drop of the resistivity to zero and a decrease of the transition temperature with magnetic field, with magnetic susceptibility measurements confirming a Tc of 203 kelvin. Moreover, a pronounced isotope shift of Tc in sulfur deuteride is suggestive of an electron-phonon mechanism of superconductivity that is consistent with the Bardeen-Cooper-Schrieffer scenario. We argue that the phase responsible for high-Tc superconductivity in this system is likely to be H3S, formed from H2S by decomposition under pressure. These findings raise hope for the

  10. Design of A Novel High Speed Dynamic Comparator with Low Power Dissipation for High Speed ADCs

    Directory of Open Access Journals (Sweden)

    Sougata Ghosh

    2013-01-01

    Full Text Available A new CMOS dynamic comparator using dual input single output differential amplifier as latch stage suitable for high speed analog-to-digital converters with High Speed, low power dissipation and immune to noise than the previous reported work is proposed. Back to-back inverter in the latch stage is replaced with dual-input single output differential amplifier. This topology completely removes the noise that is present in the input. The structure shows lower power dissipation and higher speed than the conventional comparators. The circuit is simulated with 1V DC supply voltage and 250 MHz clock frequency. The proposed topology is based on two cross coupled differential pairs positive feedback and switchable current sources, has a lower power dissipation, higher speed, less area, and it is shown to be very robust against transistor mismatch, noise immunity. Previous reported comparators are designed and simulated their DC response and Transient response in Cadence®Virtuoso Analog Design Environment using GPDK 90nm technology. Layouts of the proposed comparator have been done in Cadence® Virtuoso Layout XL Design Environment. DRC and LVS has been checked and compared with the corresponding circuits and RC extracted diagram has been generated. After that post layout simulation with 1V supply voltage has been done and compared the speed, power dissipation, Area, delay with the results before layout and the superior features of the proposed comparator are established

  11. Potential power sources for high-temperature geothermal applications

    Energy Technology Data Exchange (ETDEWEB)

    Guidotti, R.A.; Dobranich, D

    1996-05-01

    The thermal response under geothermal-borehole conditions of a conventional thermal battery was evaluated for various designs by numerical simulations using a finite-element thermal model. This technology, which is based on molten salts, may be suitable as a power source for geothermal borehole applications for data logging. Several promising candidate electrolytes were identified for further study.

  12. Fuel element concept for long life high power nuclear reactors

    Science.gov (United States)

    Mcdonald, G. E.; Rom, F. E.

    1969-01-01

    Nuclear reactor fuel elements have burnups that are an order of magnitude higher than can currently be achieved by conventional design practice. Elements have greater time integrated power producing capacity per unit volume. Element design concept capitalizes on known design principles and observed behavior of nuclear fuel.

  13. Laboratory Astrophysics on High Power Lasers and Pulsed Power Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Remington, B A

    2002-02-05

    Over the past decade a new genre of laboratory astrophysics has emerged, made possible by the new high energy density (HED) experimental facilities, such as large lasers, z-pinch generators, and high current particle accelerators. (Remington, 1999; 2000; Drake, 1998; Takabe, 2001) On these facilities, macroscopic collections of matter can be created in astrophysically relevant conditions, and its collective properties measured. Examples of processes and issues that can be experimentally addressed include compressible hydrodynamic mixing, strong shock phenomena, radiative shocks, radiation flow, high Mach-number jets, complex opacities, photoionized plasmas, equations of state of highly compressed matter, and relativistic plasmas. These processes are relevant to a wide range of astrophysical phenomena, such as supernovae and supernova remnants, astrophysical jets, radiatively driven molecular clouds, accreting black holes, planetary interiors, and gamma-ray bursts. These phenomena will be discussed in the context of laboratory astrophysics experiments possible on existing and future HED facilities.

  14. The SPES High Power ISOL production target

    Science.gov (United States)

    Andrighetto, A.; Corradetti, S.; Ballan, M.; Borgna, F.; Manzolaro, M.; Scarpa, D.; Monetti, A.; Rossignoli, M.; Silingardi, R.; Mozzi, A.; Vivian, G.; Boratto, E.; De Ruvo, L.; Sattin, N.; Meneghetti, G.; Oboe, R.; Guerzoni, M.; Margotti, A.; Ferrari, M.; Zenoni, A.; Prete, G.

    2016-11-01

    SPES (Selective Production of Exotic Species) is a facility under construction at INFN-LNL (Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Legnaro), aimed to produce intense neutron-rich radioactive ion beams (RIBs). These will be obtained using the ISOL (Isotope Separation On-Line) method, bombarding a uranium carbide target with a proton beam of 40MeV energy and currents up to 200μA. The target configuration was designed to obtain a high number of fissions, up to 1013 per second, low power deposition and fast release of the produced isotopes. The exotic isotopes generated in the target are ionized, mass separated and re-accelerated by the ALPI superconducting LINAC at energies of 10AMeV and higher, for masses in the region of A = 130 amu , with an expected rate on the secondary target up to 109 particles per second. In this work, recent results on the R&D activities regarding the SPES RIB production target-ion source system are reported.

  15. Test of a High Power Target Design

    CERN Multimedia

    2002-01-01

    %IS343 :\\\\ \\\\ A high power tantalum disc-foil target (RIST) has been developed for the proposed radioactive beam facility, SIRIUS, at the Rutherford Appleton Laboratory. The yield and release characteristics of the RIST target design have been measured at ISOLDE. The results indicate that the yields are at least as good as the best ISOLDE roll-foil targets and that the release curves are significantly faster in most cases. Both targets use 20 -25 $\\mu$m thick foils, but in a different internal geometry.\\\\ \\\\Investigations have continued at ISOLDE with targets having different foil thickness and internal geometries in an attempt to understand the release mechanisms and in particular to maximise the yield of short lived isotopes. A theoretical model has been developed which fits the release curves and gives physical values of the diffusion constants.\\\\ \\\\The latest target is constructed from 2 $\\mu$m thick tantalum foils (mass only 10 mg) and shows very short release times. The yield of $^{11}$Li (half-life of ...

  16. High Precision Current Measurement for Power Converters

    CERN Document Server

    Cerqueira Bastos, M

    2015-01-01

    The accurate measurement of power converter currents is essential to controlling and delivering stable and repeatable currents to magnets in particle accelerators. This paper reviews the most commonly used devices for the measurement of power converter currents and discusses test and calibration methods.

  17. High intensity exercise or conventional exercise for patients with rheumatoid arthritis?: outcome expectations of patients, rheumatologists, and physiotherapists.

    NARCIS (Netherlands)

    Munneke, M.; Jong, Z. de; Zwinderman, A.H.; Ronday, H.K.; Ende, C.H.M. van den; Vliet Vlieland, T.P.M.; Hazes, J.M.W.

    2004-01-01

    OBJECTIVE: To examine the outcome expectations of RA patients, rheumatologists, and physiotherapists regarding high intensity exercise programmes compared with conventional exercise programmes. METHODS: An exercise outcome expectations questionnaire was administered to 807 RA patients, 153 rheumatol

  18. High intensity exercise or conventional exercise for patients with rheumatoid arthritis?: outcome expectations of patients, rheumatologists, and physiotherapists.

    NARCIS (Netherlands)

    Munneke, M.; Jong, Z. de; Zwinderman, A.H.; Ronday, H.K.; Ende, C.H.M. van den; Vliet Vlieland, T.P.M.; Hazes, J.M.W.

    2004-01-01

    OBJECTIVE: To examine the outcome expectations of RA patients, rheumatologists, and physiotherapists regarding high intensity exercise programmes compared with conventional exercise programmes. METHODS: An exercise outcome expectations questionnaire was administered to 807 RA patients, 153

  19. Cytotoxicity evaluation of a new fast set highly viscous conventional glass ionomer cement with L929 fibroblast cell line

    Directory of Open Access Journals (Sweden)

    Hany Mohamed Aly Ahmed

    2011-01-01

    Conclusions : This new fast set highly viscous conventional GIC showed low cytotoxicity to mouse fibroblast cells, and it can be suggested as a substitute for dental cements exhibiting a long setting time.

  20. High-power converters for space applications

    Science.gov (United States)

    Park, J. N.; Cooper, Randy

    1991-06-01

    Phase 1 was a concept definition effort to extend space-type dc/dc converter technology to the megawatt level with a weight of less than 0.1 kg/kW (220 lb./MW). Two system designs were evaluated in Phase 1. Each design operates from a 5 kV stacked fuel cell source and provides a voltage step-up to 100 kV at 10 A for charging capacitors (100 pps at a duty cycle of 17 min on, 17 min off). Both designs use an MCT-based, full-bridge inverter, gaseous hydrogen cooling, and crowbar fault protection. The GE-CRD system uses an advanced high-voltage transformer/rectifier filter is series with a resonant tank circuit, driven by an inverter operating at 20 to 50 kHz. Output voltage is controlled through frequency and phase shift control. Fast transient response and stability is ensured via optimal control. Super-resonant operation employing MCTs provides the advantages of lossless snubbing, no turn-on switching loss, use of medium-speed diodes, and intrinsic current limiting under load-fault conditions. Estimated weight of the GE-CRD system is 88 kg (1.5 cu ft.). Efficiency of 94.4 percent and total system loss is 55.711 kW operating at 1 MW load power. The Maxwell system is based on a resonance transformer approach using a cascade of five LC resonant sections at 100 kHz. The 5 kV bus is converted to a square wave, stepped-up to a 100 kV sine wave by the LC sections, rectified, and filtered. Output voltage is controlled with a special series regulator circuit. Estimated weight of the Maxwell system is 83.8 kg (4.0 cu ft.). Efficiency is 87.2 percent and total system loss is 146.411 kW operating at 1 MW load power.

  1. Advanced Gunn diode as high power terahertz source for a millimetre wave high power multiplier

    Science.gov (United States)

    Amir, F.; Mitchell, C.; Farrington, N.; Missous, M.

    2009-09-01

    An advanced step-graded Gunn diode is reported, which has been developed through joint modelling-experimental work. The ~ 200 GHz fundamental frequency devices have been realized to test GaAs based Gunn oscillators at sub-millimetre wave for use as a high power (multi mW) Terahertz source in conjunction with a mm-wave multiplier, with novel Schottky diodes. The epitaxial growth of both the Gunn diode and Schottky diode wafers were performed using an industrial scale Molecular Beam Epitaxy (V100+) reactor. The Gunn diodes were then manufactured and packaged by e2v Technologies (UK) Plc. Physical models of the high power Gunn diode sources, presented here, are developed in SILVACO.

  2. HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER

    Energy Technology Data Exchange (ETDEWEB)

    BROWN,LC; BESENBRUCH,GE; LENTSCH,RD; SCHULTZ,KR; FUNK,JF; PICKARD,PS; MARSHALL,AC; SHOWALTER,SK

    2003-06-01

    OAK B202 HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER. Combustion of fossil fuels, used to power transportation, generate electricity, heat homes and fuel industry provides 86% of the world's energy. Drawbacks to fossil fuel utilization include limited supply, pollution, and carbon dioxide emissions. Carbon dioxide emissions, thought to be responsible for global warming, are now the subject of international treaties. Together, these drawbacks argue for the replacement of fossil fuels with a less-polluting potentially renewable primary energy such as nuclear energy. Conventional nuclear plants readily generate electric power but fossil fuels are firmly entrenched in the transportation sector. Hydrogen is an environmentally attractive transportation fuel that has the potential to displace fossil fuels. Hydrogen will be particularly advantageous when coupled with fuel cells. Fuel cells have higher efficiency than conventional battery/internal combustion engine combinations and do not produce nitrogen oxides during low-temperature operation. Contemporary hydrogen production is primarily based on fossil fuels and most specifically on natural gas. When hydrogen is produced using energy derived from fossil fuels, there is little or no environmental advantage. There is currently no large scale, cost-effective, environmentally attractive hydrogen production process available for commercialization, nor has such a process been identified. The objective of this work is to find an economically feasible process for the production of hydrogen, by nuclear means, using an advanced high-temperature nuclear reactor as the primary energy source. Hydrogen production by thermochemical water-splitting (Appendix A), a chemical process that accomplishes the decomposition of water into hydrogen and oxygen using only heat or, in the case of a hybrid thermochemical process, by a combination of heat and electrolysis, could meet these goals. Hydrogen produced from

  3. The relevance of the high frequency audiometry in tinnitus patients with normal hearing in conventional pure-tone audiometry

    OpenAIRE

    Veronika Vielsmeier; Astrid Lehner; Jürgen Strutz; Thomas Steffens; Kreuzer, Peter M; Martin Schecklmann; Michael Landgrebe; Berthold Langguth; Tobias Kleinjung

    2015-01-01

    Objective. The majority of tinnitus patients suffer from hearing loss. But a subgroup of tinnitus patients show normal hearing thresholds in the conventional pure-tone audiometry (125 Hz–8 kHz). Here we explored whether the results of the high frequency audiometry (>8 kHz) provide relevant additional information in tinnitus patients with normal conventional audiometry by comparing those with normal and pathological high frequency audiometry with respect to their demographic and clinical chara...

  4. High power electronics package: from modeling to implementation

    NARCIS (Netherlands)

    Yuan, C.A.; Kregting, R.; Ye, H.; Driel, W. van; Gielen, A.W.J.; Zhang, G.Q.

    2011-01-01

    Power electronics, such as high power RF components and high power LEDs, requires the combination of robust and reliable package structures, materials, and processes to guarantee their functional performance and lifetime. We started with the thermal and thermal-mechanical modeling of such component

  5. High-power FDML laser for swept source-OCT at 1060 nm

    DEFF Research Database (Denmark)

    Marschall, Sebastian; Klein, Thomas; Wieser, Wolfgang;

    2010-01-01

    We present a novel frequency-swept light source working at 1060nm that utilizes a tapered amplifier as gain medium. These devices feature significantly higher saturation power than conventional semiconductor optical amplifiers and can thus improve the limited output power of swept sources...... in this wavelength range. We demonstrate that a tapered amplifier can be integrated into a fiber-based swept source and allows for high-speed FDML operation. The developed light source operates at a sweep rate of 116kHz with an effective average output power in excess of 30mW. With a total sweep range of 70 nm...

  6. The high intensity solar cell: Key to low cost photovoltaic power

    Science.gov (United States)

    Sater, B. L.; Goradia, C.

    1975-01-01

    The design considerations and performance characteristics of the 'high intensity' (HI) solar cell are presented. A high intensity solar system was analyzed to determine its cost effectiveness and to assess the benefits of further improving HI cell efficiency. It is shown that residential sized systems can be produced at less than $1000/kW peak electric power. Due to their superior high intensity performance characteristics compared to the conventional and VMJ cells, HI cells and light concentrators may be the key to low cost photovoltaic power.

  7. Unique Power Dense, Configurable, Robust, High-Voltage Power Supplies Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Princeton Power will develop and deliver three small, lightweight 50 W high-voltage power supplies that have a configurable output voltage range from 500 to 50 kVDC....

  8. High Power Photonic Crystal Fibre Raman Laser

    Institute of Scientific and Technical Information of China (English)

    YAN Pei-Guang; RUAN Shuang-Chen; YU Yong-Qin; GUO Chun-Yu; GUO Yuan; LIU Cheng-Xiang

    2006-01-01

    A cw Raman laser based on a 100-m photonic crystal fibre is demonstrated with up to 3.8 W output power at the incident pump power of 12 W, corresponding to an optical-to-optical efficiency of about 31.6%. The second order Stokes light, which is firstly reported in a cw photonic crystal fibre Raman laser, is obtained at 1183nm with an output power of 1.6 W and a slope efficiency of about 45.7%.

  9. Thermoelectric Powered High Temperature Wireless Sensing

    Science.gov (United States)

    Kucukkomurler, Ahmet

    This study describes use of a thermoelectric power converter to transform waste heat into electrical energy to power an RF receiver and transmitter, for use in harsh environment wireless temperature sensing and telemetry. The sensing and transmitting module employs a DS-1820 low power digital temperature sensor to perform temperature to voltage conversion, an ATX-34 RF transmitter, an ARX-34 RF receiver module, and a PIC16f84A microcontroller to synchronize data communication between them. The unit has been tested in a laboratory environment, and promising results have been obtained for an actual automotive wireless under hood temperature sensing and telemetry implementation.

  10. Neuromuscular contributions to the age-related reduction in muscle power: Mechanisms and potential role of high velocity power training.

    Science.gov (United States)

    McKinnon, Neal B; Connelly, Denise M; Rice, Charles L; Hunter, Susan W; Doherty, Timothy J

    2017-05-01

    Although much of the literature on neuromuscular changes with aging has focused on loss of muscle mass and isometric strength, deficits in muscle power are more pronounced with aging and may be a more sensitive measure of neuromuscular degeneration. This review aims to identify the adaptations to the neuromuscular system with aging, with specific emphasis on changes that result in decreased muscle power. We discuss how these changes in neuromuscular performance can affect mobility, and ultimately contribute to an increased risk for falls in older adults. Finally, we evaluate the literature regarding high-velocity muscle power training (PT), and its potential advantages over conventional strength training for improving functional performance and mitigating fall risk in older adults. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Advanced Capacitors for High-Power Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — As the consumer and industrial requirements for compact, high-power-density, electrical power systems grow substantially over the next decade; there will be a...

  12. Molecular chain stretch is a multiaxial failure criterion for conventional and highly crosslinked UHMWPE.

    Science.gov (United States)

    Bergström, J S; Rimnac, C M; Kurtz, S M

    2005-03-01

    The development of accurate theoretical failure, fatigue, and wear models for ultra-high molecular weight polyethylene (UHMWPE) is an important step towards better understanding the micromechanisms of the surface damage that occur in load bearing orthopaedic components and improving the lifetime of joint arthoplasties. Previous attempts to analytically predict the clinically observed damage, wear, and fatigue failure modes have met with limited success due to the complicated interaction between microstructural deformations and continuum level stresses. In this work, we examined monotonic uniaxial and multiaxial loading to failure of UHMWPE using eight failure criteria (maximum principal stress, Mises stress, Tresca stress, hydrostatic stress, Coulomb stress, maximum principal strain, Mises strain, and chain stretch). The quality of the predictions of the different models was assessed by comparing uniaxial tension and small punch test data at different rates with the failure model predictions. The experimental data were obtained for two conventional (unirradiated and gamma radiation sterilized in nitrogen) and two highly crosslinked (150kGy, remelted and annealed) UHMWPE materials. Of the different failures models examined, the chain stretch failure model was found to capture uniaxial and multiaxial failure data most accurately for all of the UHMWPE materials. In addition, the chain stretch failure criterion can readily be calculated for contemporary UHMWPE materials based on available uniaxial tension data. These results lay the foundation for future developments of damage and wear models capable of predicting multiaxial failure under cyclic loading conditions.

  13. High Intensity Tactical Power Sources for the 1990 Army.

    Science.gov (United States)

    conceptual or physical study which may become feasible as high intensity power sources . These considerations include present state of the art of...requirements, energy and power output capabilities, and fixed costs. From these tables, it may be seen that a variety of electrical power sources would be...required to satisfy diverse requirements, but an attempt is made to categorize possible high intensity power sources into their areas of optimum

  14. High output power reluctance electric motors with bulk high-temperature superconductor elements

    Science.gov (United States)

    Kovalev, L. K.; Ilushin, K. V.; Penkin, V. T.; Kovalev, K. L.; Larionoff, A. E.; M-A Koneev, S.; Modestov, K. A.; Larionoff, S. A.; Poltavets, V. N.; Akimov, I. I.; Alexandrov, V. V.; Gawalek, W.; Oswald, B.; Krabbes, G.

    2002-05-01

    We present new types of electric machines with the rotors containing bulk high-temperature superconductor (HTS) - YBCO and Bi-Ag - elements. We discuss different schematics of hysteresis, reluctance, 'trapped field' and composed synchronous HTS machines. The two-dimensional mathematical models describing the processes in such types of HTS machines were developed on the basis of the theoretical analysis of the electrodynamic and hysteresis processes in the single-domain and polycrystal YBCO ceramic samples and plate shape Bi-Ag elements. We give the test results of the series of hysteresis, reluctance, 'trapped field' and composed with permanent magnets HTS motors with an output power rating of 0.1-18 kW and current frequencies 50 Hz and 400 Hz. These results show that in the media of liquid nitrogen the specific output power per one unit weight of the HTS motor is four to seven times better than for conventional electric machines. A comparison of the theoretical and experimental characteristics of the developed HTS motors show that they are in good agreement. We discuss the test results for a liquid nitrogen cryogenic pump system with a hysteresis 500 W HTS motor. We describe several designs of new HTS motors operating in the media of liquid nitrogen with an output power 125 kW (and more) and a power factor of more than 0.8. We discuss future applications of new types of HTS motors for aerospace technology, on-land industry and transport systems.

  15. Combination of comprehensive geophysical measurements and conventional soil sampling for high resolution soil mapping

    Science.gov (United States)

    Werban, U.; Nuesch, A.; Vienken, T.; Dietrich, P.; Behrens, T.

    2010-12-01

    The focus of the FP7-EU project iSOIL “Interactions between soil related sciences - Linking geophysics, soil science and digital soil mapping” is to develop new and to improve existing strategies and innovative methods for generating accurate, high-resolution soil property maps. Thus we will develop, validate, and evaluate concepts and strategies for transferring measured physical parameter distributions into soil property, soil function and soil threat maps of different scales. The resulting soil property maps can be used for agriculture applications and soil degradation threats studies, e.g. erosion, compaction and soil organic matter decline. A fast and cost efficient way to detect physical parameters of soils at large areas is the application of mobile geophysical platforms. An advantage of these platforms is the flexibility since different kind of instruments can be mounted and combined. Following instruments are used on platforms within iSOIL project: EMI, GPR, gamma-spectrometry and magnetics. Since geophysical methods provide only physical parameters it is essential to combine them with conventional soil sampling methods for ground truthing. Physical parameters have to be converted into soil parameters via (site specific) transfer functions. One focus of the project was the development of measuring designs for the evaluation and combination of different geophysical methods. The application of a hierarchical approach is one way to combine different scales and parameters. The implementation of this approach will be presented and can be summarized as follows: - The first step is a survey of the total area with EMI and gamma-spectrometry. The distance between two lines is 10 - 20 meters. - By means of the geophysical data and a digital elevation model, representative soil sampling points are chosen, via a weighted conditioned latin hypercube sampling scheme (wLHS) based on conditioned latin hypercube sampling (cLHS). - All soil sampling points are probed

  16. Probabilistic modeling of wind energy sources integrated in a conventional power system; Modelagem probabilistica de fontes eolicas de energia integradas em sistema de potencia convencional

    Energy Technology Data Exchange (ETDEWEB)

    Dalence, G.W.H.

    1990-06-15

    This work describes a model capable of including non-conventional energy sources into a stochastic energy production model for conventional power sources. A wind energy system is initially considered as statistically independent of the hourly demand. The correlation between two wind systems is then considered by means of a joint wind speed distribution. The joint wind system is thereafter submitted to the stochastic energy production model considering independence between demand and wind speed. Finally the correlation wind systems and the hourly demand is studied. (author). 29 figs, 31 tabs

  17. 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.

  18. Systematic Approach for Design of Broadband, High Efficiency, High Power RF Amplifiers

    National Research Council Canada - National Science Library

    Mohadeskasaei, Seyed Alireza; An, Jianwei; Chen, Yueyun; Li, Zhi; Abdullahi, Sani Umar; Sun, Tie

    2017-01-01

    ...‐AB RF amplifiers with high gain flatness. It is usually difficult to simultaneously achieve a high gain flatness and high efficiency in a broadband RF power amplifier, especially in a high power design...

  19. Design of Plasma Generator Driven by High-frequency High-voltage Power Supply

    Directory of Open Access Journals (Sweden)

    C. Yong-Nong

    2013-03-01

    Full Text Available In this research, a high-frequency high-voltage power supply designed for plasma generator is presented. The powersupply mainly consists of a series resonant converter with a high-frequency high-voltage boost transformer. Due to theindispensable high-voltage inheritance in the operation of plasma generator, the analysis of transformer needconsidering not only winding resistance, leakage inductance, magnetizing inductance, and core-loss resistance, butalso parasitic capacitance resulted from the insulation wrappings on the high-voltage side. This research exhibits asimple approach to measuring equivalent circuit parameters of the high-frequency, high-voltage transformer with straycapacitance being introduced into the conventional modeling. The proposed modeling scheme provides not only aprecise measurement procedure but also effective design information for series-load resonant converter. The plasmadischarging plate is designed as part of the electric circuit in the series load-resonant converter and the circuit modelof the plasma discharging plate is also conducted as well. Thus, the overall model of the high-voltage plasmagenerator is built and the designing procedures for appropriate selections of the corresponding resonant-circuitparameters can be established. Finally, a high-voltage plasma generator with 220V, 60Hz, and 1kW input, along witha 22 kHz and over 8kV output, is realized and implemented.

  20. High power densities from high-temperature material interactions

    Energy Technology Data Exchange (ETDEWEB)

    Morris, J.F.

    1981-01-01

    Thermionic energy conversion (TEC) and metallic-fluid heat pipes (MFHPs) offer important and unique advantages in terrestrial and space energy processing. And they are well suited to serve together synergistically. TEC and MFHPs operate through working-fluid vaporization, condensation cycles that accept great thermal power densities at high temperatures. TEC and MFHPs have apparently simple, isolated performance mechanisms that are somewhat similar. And they also have obviously difficult, complected material problems that again are somewhat similar. Intensive investigation reveals that aspects of their operating cycles and material problems tend to merge: high-temperature material effects determine the level and lifetime of performance. Simplified equations verify the preceding statement for TEC and MFHPs. Material properties and interactions exert primary influences on operational effectiveness. And thermophysicochemical stabilities dictate operating temperatures which regulate the thermoemissive currents of TEC and the vaporization flow rates of MFHPs. Major high-temperature material problems of TEC and MFHPs have been solved. These solutions lead to productive, cost-effective applications of current TEC and MFHPs - and point to significant improvements with anticipated technological gains.

  1. Development of highly reliable power and communication system for essential instruments under severe accidents in NPP

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Bo Hwan; Jang, Gi Chan; Shin, Sung Min; Kang, Hyun Gook; Rim, Chun Taek [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Lee, Soo Ill [I and C Group, Korea Hydro and Nuclear Power Co., Ltd, Central Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    This article proposes a highly reliable power and communication system that guarantees the protection of essential instruments in a nuclear power plant under a severe accident. Both power and communication lines are established with not only conventional wired channels, but also the proposed wireless channels for emergency reserve. An inductive power transfer system is selected due to its robust power transfer characteristics under high temperature, high pressure, and highly humid environments with a large amount of scattered debris after a severe accident. A thermal insulation box and a glass-fiber reinforced plastic box are proposed to protect the essential instruments, including vulnerable electronic circuits, from extremely high temperatures of up to 627 .deg. C and pressure of up to 5 bar. The proposed wireless power and communication system is experimentally verified by an inductive power transfer system prototype having a dipole coil structure and prototype Zigbee modules over a 7-m distance, where both the thermal insulation box and the glass-fiber reinforced plastic box are fabricated and tested using a high-temperature chamber. Moreover, an experiment on the effects of a high radiation environment on various electronic devices is conducted based on the radiation test having a maximum accumulated dose of 27 Mrad.

  2. COMPARISON OF HIGH-FREQUENCY OSCILLATION VENTILATION WITH CONVENTIONAL MANDATORY VENTILATION IN ANIMAL ARDS MODEL

    Institute of Scientific and Technical Information of China (English)

    SHI Guo-chao; HUANG Shao-guang; LI Min; DENG Wei-wu; WAN Huan-ying

    2005-01-01

    Objective To compare effect of high-frequency oscillation ventilation (HFOV) and conventional mandatory ventilation (CMV) on lung injury development in rabbit with acute respiratory distress syndrome (ARDS). Methods Animals that underwent saline lung lavage to produce lung injury were randomized to one of the two treatment groups (HFOV or CMV, n=6). PaCO2 was maintained between 35-45mmHg and arterial oxygen saturation (SaO2) was maintain >88% by adjusting corresponding ventilator parameters. Ventilation period was 6h. Lung fluids were aspirated before and at the end of ventilation for cell analysis. Then the animals were euthanized, lung tissue was removed for wet/dry weight measurement, light and electron microscopic examination.Results The difference of artery blood gas analyses(pH, PaO2, PaCO2) between HFOV and CMV was insignificant. The difference between HFOV and CMV in cytological examination of lung fluids, wet/dry weight measurement was also insignificant. But compared with CMV,HFOV not only reduced the area of lung injury, but also reduced lung injury score in light and electron microscopic examination. Conclusion When same artery blood gas analysis was obtained, HFOV significantly reduced lung injury development in ARDS animal than CMV. As a lung protection strategy, HFOV can be used in the treatment of ARDS.

  3. Comparison of high frequency chest compression and conventional chest physiotherapy in hospitalized patients with cystic fibrosis.

    Science.gov (United States)

    Arens, R; Gozal, D; Omlin, K J; Vega, J; Boyd, K P; Keens, T G; Woo, M S

    1994-10-01

    Clearance of bronchial secretions is essential in the management of cystic fibrosis (CF) patients admitted for acute pulmonary exacerbation. Conventional physiotherapy (CPT) is labor-intensive, time-consuming, expensive, and may not be available as frequently as desired during hospitalization. High frequency chest compression (HFCC), which uses an inflatable vest linked to an air-pulse delivery system, may offer an attractive alternative. To study this, we prospectively studied 50 CF patients admitted for acute pulmonary exacerbation who were randomly allocated to receive either HFCC or CPT three times a day. On admission, clinical status and pulmonary function tests (PFT) in the HFCC group were not significantly different from those measured in the CPT group. Significant improvements in clinical status and PFT were observed after 7 and 14 d of treatment, and were similar in the two study groups, leading to patient discharge after similar periods of hospitalization. We conclude that HFCC and CPT are equally safe and effective when used during acute pulmonary exacerbations in CF patients. We speculate that HFCC may provide an adequate alternative in management of CF patients in a hospital setting.

  4. Efficacy of intradermal mesotherapy in cellulite reduction - Conventional and high-frequency ultrasound monitoring results.

    Science.gov (United States)

    Sylwia, Malinowska; Krzysztof, Mlosek Robert

    2017-10-01

    Cellulite affects the majority of women and is an unacceptable cosmetic defect. Therefore, effective methods for cellulite reduction are being sought. Intradermal mesotherapy is one of such methods. The aim of the study was to assess the efficacy of intradermal mesotherapy in cellulite reduction, using conventional and high-frequency ultrasound. Twenty-one women with cellulite underwent a series of intradermal mesotherapy procedures. The following parameters were assessed: thickness of epidermis, dermis and hypodermis, echogenicity of dermis and the surface area of serrated hypodermis-dermis junction. Furthermore, the thigh circumference was measured; body mass index and cellulite severity were assessed based on photographs using Nürnberger-Müller's scale. Intradermal mesotherapy reduced severity of cellulite. The surface area of serrated hypodermis-dermis junction and hypodermis thickness decreased significantly as compared to baseline. Cellulite reduction was also confirmed by palpation, decreased thigh circumference and the Nürnberger-Müller's grade. There were no statistically significant changes in epidermis or dermis thickness, body weight and the BMI. Intradermal mesotherapy offers effective cellulite reduction. It is a simple and safe treatment, which makes it popular. Further research in mesotherapy is essential due to a limited number of published studies. Ultrasound is a useful method to monitor intradermal mesotherapy and assess its efficacy.

  5. Cyanobacteria and Cyanotoxins Occurrence and Removal from Five High-Risk Conventional Treatment Drinking Water Plants

    Directory of Open Access Journals (Sweden)

    David C. Szlag

    2015-06-01

    Full Text Available An environmental protection agency EPA expert workshop prioritized three cyanotoxins, microcystins, anatoxin-a, and cylindrospermopsin (MAC, as being important in freshwaters of the United States. This study evaluated the prevalence of potentially toxin producing cyanobacteria cell numbers relative to the presence and quantity of the MAC toxins in the context of this framework. Total and potential toxin producing cyanobacteria cell counts were conducted on weekly raw and finished water samples from utilities located in five US states. An Enzyme-Linked Immunosorbant Assay (ELISA was used to screen the raw and finished water samples for microcystins. High-pressure liquid chromatography with a photodiode array detector (HPLC/PDA verified microcystin concentrations and quantified anatoxin-a and cylindrospermopsin concentrations. Four of the five utilities experienced cyanobacterial blooms in their raw water. Raw water samples from three utilities showed detectable levels of microcystins and a fourth utility had detectable levels of both microcystin and cylindrospermopsin. No utilities had detectable concentrations of anatoxin-a. These conventional plants effectively removed the cyanobacterial cells and all finished water samples showed MAC levels below the detection limit by ELISA and HPLC/PDA.

  6. Cyanobacteria and Cyanotoxins Occurrence and Removal from Five High-Risk Conventional Treatment Drinking Water Plants

    Science.gov (United States)

    Szlag, David C.; Sinclair, James L.; Southwell, Benjamin; Westrick, Judy A.

    2015-01-01

    An environmental protection agency EPA expert workshop prioritized three cyanotoxins, microcystins, anatoxin-a, and cylindrospermopsin (MAC), as being important in freshwaters of the United States. This study evaluated the prevalence of potentially toxin producing cyanobacteria cell numbers relative to the presence and quantity of the MAC toxins in the context of this framework. Total and potential toxin producing cyanobacteria cell counts were conducted on weekly raw and finished water samples from utilities located in five US states. An Enzyme-Linked Immunosorbant Assay (ELISA) was used to screen the raw and finished water samples for microcystins. High-pressure liquid chromatography with a photodiode array detector (HPLC/PDA) verified microcystin concentrations and quantified anatoxin-a and cylindrospermopsin concentrations. Four of the five utilities experienced cyanobacterial blooms in their raw water. Raw water samples from three utilities showed detectable levels of microcystins and a fourth utility had detectable levels of both microcystin and cylindrospermopsin. No utilities had detectable concentrations of anatoxin-a. These conventional plants effectively removed the cyanobacterial cells and all finished water samples showed MAC levels below the detection limit by ELISA and HPLC/PDA. PMID:26075379

  7. Cyanobacteria and Cyanotoxins Occurrence and Removal from Five High-Risk Conventional Treatment Drinking Water Plants.

    Science.gov (United States)

    Szlag, David C; Sinclair, James L; Southwell, Benjamin; Westrick, Judy A

    2015-06-12

    An environmental protection agency EPA expert workshop prioritized three cyanotoxins, microcystins, anatoxin-a, and cylindrospermopsin (MAC), as being important in freshwaters of the United States. This study evaluated the prevalence of potentially toxin producing cyanobacteria cell numbers relative to the presence and quantity of the MAC toxins in the context of this framework. Total and potential toxin producing cyanobacteria cell counts were conducted on weekly raw and finished water samples from utilities located in five US states. An Enzyme-Linked Immunosorbant Assay (ELISA) was used to screen the raw and finished water samples for microcystins. High-pressure liquid chromatography with a photodiode array detector (HPLC/PDA) verified microcystin concentrations and quantified anatoxin-a and cylindrospermopsin concentrations. Four of the five utilities experienced cyanobacterial blooms in their raw water. Raw water samples from three utilities showed detectable levels of microcystins and a fourth utility had detectable levels of both microcystin and cylindrospermopsin. No utilities had detectable concentrations of anatoxin-a. These conventional plants effectively removed the cyanobacterial cells and all finished water samples showed MAC levels below the detection limit by ELISA and HPLC/PDA.

  8. Innovations in papermaking: an LCA of printing and writing paper from conventional and high yield pulp.

    Science.gov (United States)

    Manda, B M Krishna; Blok, Kornelis; Patel, Martin K

    2012-11-15

    Pulp and paper industry is facing challenges such as resource scarcity and greenhouse gas (GHG) emissions. The objective of this research is to investigate whether the use of new coatings (micro or nano TiO(2)) and different pulp types could bring savings in wood, energy, GHG emissions and other environmental impacts in comparison with conventional printing and writing paper. We studied three types of pulp, namely i) unbleached virgin kraft pulp, ii) recovered fiber, and iii) high yield virgin chemithermo-mechanical pulp (CTMP). A life cycle assessment (LCA) was conducted from cradle to grave. Applying attributional modeling, we found that wood savings amount to 60% for the nanoparticle coated recovered fiber paper and 35% for the micro TiO(2) coated CTMP paper. According to the ReCiPe single score impact assessment method, the new product configurations allow the reduction of the environmental impacts by 10-35% compared to conventional kraft paper. Applying consequential modeling, we found larger energy and GHG emission savings compared to attributional modeling because the saved wood is used for producing energy, thereby replacing fossil fuels. The nanoparticle coated recovered fiber paper offered savings of non-renewable energy use (NREU) by 100% (13GJ/ton paper) and GHG emission reduction by 75% (0.6 tonCO(2)eq./ton paper). Micro TiO(2) coated CTMP paper offered NREU savings by 25% (3GJ/ton paper) and savings of GHG emissions by 10% (0.1 tonCO(2)eq./ton paper). The taking into account of all environmental impacts with the ReCiPe single score method leads to comparable results as that of attributional modeling. We conclude that the nanoparticle coated recovered fiber paper offered the highest savings and lowest environmental impacts. However, human toxicity and ecotoxicity impacts of the nanoparticles were not included in this analysis and need further research. If this leads to the conclusion that the toxicity impacts of the nanoparticles are serious, then the

  9. Innovations in papermaking: An LCA of printing and writing paper from conventional and high yield pulp

    Energy Technology Data Exchange (ETDEWEB)

    Manda, B.M. Krishna, E-mail: b.m.k.manda@uu.nl; Blok, Kornelis, E-mail: K.Blok@uu.nl; Patel, Martin K., E-mail: m.k.patel@uu.nl

    2012-11-15

    Pulp and paper industry is facing challenges such as resource scarcity and greenhouse gas (GHG) emissions. The objective of this research is to investigate whether the use of new coatings (micro or nano TiO{sub 2}) and different pulp types could bring savings in wood, energy, GHG emissions and other environmental impacts in comparison with conventional printing and writing paper. We studied three types of pulp, namely i) unbleached virgin kraft pulp, ii) recovered fiber, and iii) high yield virgin chemithermo-mechanical pulp (CTMP). A life cycle assessment (LCA) was conducted from cradle to grave. Applying attributional modeling, we found that wood savings amount to 60% for the nanoparticle coated recovered fiber paper and 35% for the micro TiO{sub 2} coated CTMP paper. According to the ReCiPe single score impact assessment method, the new product configurations allow the reduction of the environmental impacts by 10-35% compared to conventional kraft paper. Applying consequential modeling, we found larger energy and GHG emission savings compared to attributional modeling because the saved wood is used for producing energy, thereby replacing fossil fuels. The nanoparticle coated recovered fiber paper offered savings of non-renewable energy use (NREU) by 100% (13 GJ/ton paper) and GHG emission reduction by 75% (0.6 ton CO{sub 2} eq./ton paper). Micro TiO{sub 2} coated CTMP paper offered NREU savings by 25% (3 GJ/ton paper) and savings of GHG emissions by 10% (0.1 ton CO{sub 2} eq./ton paper). The taking into account of all environmental impacts with the ReCiPe single score method leads to comparable results as that of attributional modeling. We conclude that the nanoparticle coated recovered fiber paper offered the highest savings and lowest environmental impacts. However, human toxicity and ecotoxicity impacts of the nanoparticles were not included in this analysis and need further research. If this leads to the conclusion that the toxicity impacts of the

  10. 157 W all-fiber high-power picosecond laser.

    Science.gov (United States)

    Song, Rui; Hou, Jing; Chen, Shengping; Yang, Weiqiang; Lu, Qisheng

    2012-05-01

    An all-fiber high-power picosecond laser is constructed in a master oscillator power amplifier configuration. The self-constructed fiber laser seed is passively mode locked by a semiconductor saturable absorber mirror. Average output power of 157 W is obtained after three stages of amplification at a fundamental repetition rate of 60 MHz. A short length of ytterbium double-clad fiber with a high doping level is used to suppress nonlinear effects. However, a stimulated Raman scattering (SRS) effect occurs owing to the 78 kW high peak power. A self-made all-fiber repetition rate increasing system is used to octuple the repetition rate and decrease the high peak power. Average output power of 156.6 W is obtained without SRS under the same pump power at a 480 MHz repetition rate with 0.6 nm line width.

  11. High brilliance and high efficiency: optimized high power diode laser bars

    Science.gov (United States)

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

    2008-02-01

    The strong increasing laser market has ongoing demands to reduce the costs of diode laser pumped systems. For that reason JENOPTIK Diode Lab GmbH (JDL) optimized the bar brilliance (small vertical far field divergence) and bar efficiency (higher optical power operation) with respect to the pump applications. High efficiency reduces the costs for mounting and cooling and high brilliance increases the coupling efficiency. Both are carefully adjusted in the 9xx nm - high power diode laser bars for pump applications in disc- and fiber lasers. Based on low loss waveguide structures high brilliance bars with 19° fast axis beam divergence (FWHM) with 58 % maximum efficiency and 27° fast axis beam divergence (FWHM) with 62 % maximum efficiency are developed. Mounted on conductive cooled heat sinks high power operation with lifetime > 20.000 hours at 120 W output power level (50 % filling factor bars) and 80W (20 % filling factor bars) is demonstrated. 808nm bars used as pump sources for Nd:YAG solid state lasers are still dominating in the market. With respect to the demands on high reliability at high power operation current results of a 100 W high power life time test are showing more than 9000 hour operation time for passively cooled packaged high efficiency 50 % filling factor bars. Measurement of the COMD-level after this hard pulse life time test demonstrates very high power levels with no significant droop in COMD-power level. This confirms the high facet stability of JDL's facet technology. New high power diode laser bars with wavelength of 825 nm and 885 nm are still under development and first results are presented.

  12. Optimal Design and Tradeoff Analysis of Planar Transformer in High-Power DC–DC Converters

    DEFF Research Database (Denmark)

    Ouyang, Ziwei; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2012-01-01

    The trend toward high power density, high operating frequency, and low profile in power converters has exposed a number of limitations in the use of conventional wire-wound magnetic component structures. A planar magnetic is a low-profile transformer or inductor utilizing planar windings, instead...... of the traditional windings made of Cu wires. In this paper, the most important factors for planar transformer (PT) design including winding loss, core loss, leakage inductance, and stray capacitance have individually been investigated. The tradeoffs among these factors have to be analyzed in order to achieve...

  13. High-power LEDs influence on germination rate of tomato seeds

    Science.gov (United States)

    Tudora, Cătălina; Ristici, M.; Ristici, Esofina

    2007-08-01

    Artificial lighting for plants cultivation is an important factor that can determine the nutritional quality of vegetables. The improvement of quality is determined by the emission spectrum of LED, suitable for vegetables. This spectrum values must be inside the solar ones. So, by using red high-power LEDs we can supplement the conventional lighting (ex. HPS) and we can enrich the red light from the emission light. We have used a special device that has 200 high-power red LEDs, having emission wavelength in 640-670 nm range, which is presented below. Using red LEDs on tomato seeds, we can observe that the germination rate significantly increased.

  14. Analysis of Valve Requirements for High-Efficiency Digital Displacement Fluid Power Motors

    DEFF Research Database (Denmark)

    Rømer, Daniel; Johansen, Per; Pedersen, Henrik C.

    2013-01-01

    Digital displacement fluid power motors have been shown to enable high-efficiency operation in a wide operation range, including the part load range where conventional fluid power motors suffers from poor efficiencies. The use of these digital displacement motors set new requirements for the valve...... technology, as very fast switching and low pressure loss is needed to obtain high-efficient motor operation. Two central parameters describing the valve operation are the valve switching time and the flow-pressure coefficient. These requirements are important inputs for the mechatronic valve design process...

  15. Simulation of High Power Lasers (Preprint)

    Science.gov (United States)

    2010-06-01

    product of laser power. 5. References 1 Wilcox, D. C, Turbulence Modeling for CFD, DCW Industries, Inc. pp. 185-193, July 1998. 2 Menter, F. L...Modeling for CFD, DCW Industries, Inc. pp. 294-296, July 1998. 4 Perram, G. P, .Int. J. Chem. Kinet. 27, 817-28 (1995). 5 Madden, T. J. and Solomon

  16. Coordinated Frequency Control of Wind Turbines in Power Systems with High Wind Power Penetration

    DEFF Research Database (Denmark)

    Tarnowski, Germán Claudio

    particular views. These models were developed and verified during this work, basedaround a particular manufacturer’s wind turbine and on said isolated power system withwind power. The capability of variable speed wind turbines for providing Inertial Response is analysed. To perform this assessment, a control...... and the dynamic stability of the grid frequency under large disturbances would be compromised. The aim of this study is to investigate the integration of large scale wind power generation in power systems and its active power control.Novel methods and solutions dealing specifically with the electric frequency...... stability and high wind power penetration or in islanding situations are addressed. The review of relevant theoretical concepts is supported by measurements carried out on an isolated power system characterized by high wind power penetration. Different mathematical and simulation models are used in several...

  17. Air-insufflated high-definition dacryoendoscopy yields significantly better image quality than conventional dacryoendoscopy.

    Science.gov (United States)

    Sasaki, Tsugihisa; Sounou, Tsutomu; Tsuji, Hideki; Sugiyama, Kazuhisa

    2017-01-01

    To facilitate the analysis of lacrimal conditions, we utilized high-definition dacryoendoscopy (HDD) and undertook observations with a pressure-controlled air-insufflation system. We report the safety and performance of HDD. In this retrospective, non-randomized clinical trial, 46 patients (14 males and 32 females; age range 39-91 years; mean age ± SD 70.3±12.0 years) who had lacrimal disorders were examined with HDD and conventional dacryoendoscopy (CD). The high-definition dacryoendoscope had 15,000 picture element image fibers and an advanced objective lens. Its outer diameter was 0.9-1.2 mm. Air insufflation was controlled at 0-20 kPa with a digital manometer-based pressure-controlled air-insufflation system to evaluate the quality of the image. The HDD had an air/saline irrigation channel between the outer sheath (outer diameter =1.2 mm) and the metal inner sheath of the endoscope. We used it and the CD in air, saline, and diluted milk saline with and without manual irrigation to quantitatively evaluate the effect of air pressure and saline irrigation on image quality. In vivo, the most significant improvement in image quality was demonstrated with air-insufflated (5-15 kPa) HDD, as compared with saline-irrigated HDD and saline-irrigated CD. No emphysema or damage was noted under observation with HDD. In vitro, no significant difference was demonstrated between air-insufflated HDD and saline-irrigated HDD. In vitro, the image quality of air-insufflated HDD was significantly improved as compared with that of saline-irrigated CD. Pressure-controlled (5-15 kPa) air-insufflated HDD is safe, and yields significantly better image quality than CD and saline-irrigated HDD.

  18. Atmospheric Propagation and Combining of High-Power Lasers

    Science.gov (United States)

    2015-09-08

    Naval Research Laboratory Washington, DC 20375-5320 NRL/MR/6703--15-9646 Atmospheric Propagation and Combining of High-Power Lasers W. NelsoN...ABSTRACT c. THIS PAGE 18. NUMBER OF PAGES 17. LIMITATION OF ABSTRACT Atmospheric Propagation and Combining of High-Power Lasers W. Nelson,* P. Sprangle...Turbulence Beam combining In this paper we analyze the beam combining and atmospheric propagation of high-power lasers for directed-energy (DE

  19. High Temperature Power Converters for Military Hybrid Electric Vehicles

    Science.gov (United States)

    2011-08-09

    M) MINI-SYMPOSIUM AUGUST 9-11 DEARBORN, MICHIGAN HIGH TEMPERATURE POWER CONVERTERS FOR MILITARY HYBRID ELECTRIC VEHICLES ABSTRACT...SUBTITLE High Temperature Power Converters for Military Hybrid Electric Vehicles 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...public release High Temperature Power Converters for Military Hybrid Electric Vehicles Page 2 of 8 I. INTRODUCTION Today, wide bandgap devices

  20. High-Speed Low Power Design in CMOS

    DEFF Research Database (Denmark)

    Ghani, Arfan; Usmani, S. H.; Stassen, Flemming

    2004-01-01

    Static CMOS design displays benefits such as low power consumption, dominated by dynamic power consumption. In contrast, MOS Current Mode Logic (MCML) displays static rather than dynamic power consumption. High-speed low-power design is one of the many application areas in VLSI that require...... the appropriate domains of performance and power requirements in which MCML presents benefits over standard CMOS. An optimized cell library is designed and implemented in both CMOS and MCML in order to make a comparison with reference to speed and power. Much more time is spent in order to nderstand...

  1. Design and Construction of Low Cost High Voltage dc Power Supply for Constant Power Operation

    Science.gov (United States)

    Kumar, N. S.; Jayasankar, V.

    2013-06-01

    Pulsed load applications like laser based systems need high voltage dc power supplies with better regulation characteristics. This paper presents the design, construction and testing of dc power supply with 1 kV output at 300 W power level. The designed converter has half bridge switched mode power supply (SMPS) configuration with 20 kHz switching. The paper covers the design of half bridge inverter, closed loop control, High frequency transformer and other related electronics. The designed power supply incorporates a low cost OPAMP based feedback controller which is designed using small signal modelling of the converter. The designed converter was constructed and found to work satisfactorily as per the specifications.

  2. Modelling aluminium wire bond reliability in high power OMP devices

    NARCIS (Netherlands)

    Kregting, R.; Yuan, C.A.; Xiao, A.; Bruijn, F. de

    2011-01-01

    In a RF power application such as the OMP, the wires are subjected to high current (because of the high power) and high temperature (because of the heat from IC and joule-heating from the wire itself). Moreover, the wire shape is essential to the RF performance. Hence, the aluminium wire is preferre

  3. Multidisciplinary Modelling Tools for Power Electronic Circuits:with Focus on High Power Modules

    OpenAIRE

    Bahman, Amir Sajjad

    2015-01-01

    This thesis presents multidisciplinary modelling techniques in a Design For Reliability (DFR) approach for power electronic circuits. With increasing penetration of renewable energy systems, the demand for reliable power conversion systems is becoming critical. Since a large part of electricity is processed through power electronics, highly efficient, sustainable, reliable and cost-effective power electronic devices are needed. Reliability of a product is defined as the ability to perform wit...

  4. Measurement of H!gh Power Current-Stabilized Power Supply with High Stability

    Institute of Scientific and Technical Information of China (English)

    YanHuaihai; FengXiuming; BaiZhen; ZhouZhongzu

    2003-01-01

    The DC power supply system of HIRFL has been upgraded since 1999, these new power supplies are used mainly as high frequency ZVS soft-switching converters or thyristor phase-controlled rectifiers. Each power supply is strictly tested before being put into operation, especially for long-term current stability, current ripple, efficiency, repeatability, EMI and so on. The tested results indicated that performances of power supplies satisfy requirement of HIRFL.

  5. High specific power flexible integrated IMM photovoltaic blanket Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Originally designed for space applications, multi-junction solar cells have a high overall power conversion efficiency (>30%) which compares favorably to...

  6. High Efficiency Hall Thruster Discharge Power Converter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek leveraged previous, internally sponsored, high power, Hall thruster discharge converter development which allowed it to design, build, and test new printed...

  7. Temperature Stabilized Characterization of High Voltage Power Supplies

    CERN Document Server

    Krarup, Ole

    2017-01-01

    High precision measurements of the masses of nuclear ions in the ISOLTRAP experiment relies on an MR-ToF. A major source of noise and drift is the instability of the high voltage power supplies employed. Electrical noise and temperature changes can broaden peaks in time-of-flight spectra and shift the position of peaks between runs. In this report we investigate how the noise and drift of high-voltage power supplies can be characterized. Results indicate that analog power supplies generally have better relative stability than digitally controlled ones, and that the high temperature coefficients of all power supplies merit efforts to stabilize them.

  8. Thermo economic comparison of conventional micro combined heat and power systems with solid oxide fuel cell systems for small scale applications

    DEFF Research Database (Denmark)

    Batens, Ellen; Cuellar, Rafael; Marissal, Matthieu

    2013-01-01

    Fuel cells have the potential to reduce domestic energy consumption by providing both heat and electricity at the point of use. However, the cost of installing the fuel cell must be sufficiently competitive to be recovered by the savings made over its lifetime. The goal of this paper is to carry...... out a thermo economic comparison of a conventional micro combined heat and power systems with solid oxide fuel cell systems. A model to estimate the savings and cost targets for solid oxide fuel cell systems is presented. A comparison between fuel cell technologies in the danish market with “state...... of the art” traditional heat and power generation technologies currently used in Denmark is considered. The conventional method of covering electrical, heating (e.g. hot water) and cooling (e.g. space cooling) load demands is by purchasing electricity from the electricity network grid and with a fossil fuel...

  9. Safety aspects of high power targets for European spallation sources

    Energy Technology Data Exchange (ETDEWEB)

    Moormann, Rainer; Bongardt, Klaus; Chiriki, Suresh [Forschungszentrum Juelich, D 52425 Juelich (Germany)

    2008-07-01

    An overview on the safety of options for future European high power targets is given. More detailed the safety features of a mercury target are presented. The radio-toxic inventory is comparable to that of a research reactor. The conventional mercury toxicity of the whole target cannot be neglected in relation to its radiotoxicity but. As most relevant nuclides for safety considerations Iodine-isotopes, Sr-90, Gd-148 and Hg-194 were identified. Formation of HgI{sub 2} and FeI{sub 2} during operation reduces the volatility of Iodine. For waste disposal several very long-lived nuclides have to be considered, too. Because Hg-194 cannot be separated, the whole target has to disposed. This requires mercury solidification, because liquids are not permitted in a repository. Experimental and theoretical work on mercury disposal is shortly discussed. Mercury sulphide was found to be a suitable solid compound for disposal. Its formation from target mercury by a wet process is identified as a procedure, which can be reasonably handled under hot cell conditions. (authors)

  10. Output beam analysis of high power COIL

    Institute of Scientific and Technical Information of China (English)

    Deli Yu(于德利); Fengting Sang(桑凤亭); Yuqi Jin(金玉奇); Yizhu Sun(孙以珠)

    2003-01-01

    As the output power of a chemical oxygen iodine laser (COIL) increases, the output laser beam instabilityappears as the far-field beam spot drift and deformation for the large Fresnel number unstable resonator.In order to interpret this phenomenon, an output beam mode simulation code was developed with the fastFourier transform method. The calculation results show that the presence of the nonuniform gain in COILproduces a skewed output intensity distribution, which causes the mirror tilt and bulge due to the thermalexpansion. With the output power of COIL increases, the mirror surfaces, especially the back surface ofthe scraper mirror, absorb more and more heat, which causes the drift and deformation of far field beamspot seriously. The initial misalignment direction is an important factor for the far field beam spot driftingand deformation.

  11. NULL Convention Floating Point Multiplier

    Directory of Open Access Journals (Sweden)

    Anitha Juliette Albert

    2015-01-01

    Full Text Available Floating point multiplication is a critical part in high dynamic range and computational intensive digital signal processing applications which require high precision and low power. This paper presents the design of an IEEE 754 single precision floating point multiplier using asynchronous NULL convention logic paradigm. Rounding has not been implemented to suit high precision applications. The novelty of the research is that it is the first ever NULL convention logic multiplier, designed to perform floating point multiplication. The proposed multiplier offers substantial decrease in power consumption when compared with its synchronous version. Performance attributes of the NULL convention logic floating point multiplier, obtained from Xilinx simulation and Cadence, are compared with its equivalent synchronous implementation.

  12. NULL convention floating point multiplier.

    Science.gov (United States)

    Albert, Anitha Juliette; Ramachandran, Seshasayanan

    2015-01-01

    Floating point multiplication is a critical part in high dynamic range and computational intensive digital signal processing applications which require high precision and low power. This paper presents the design of an IEEE 754 single precision floating point multiplier using asynchronous NULL convention logic paradigm. Rounding has not been implemented to suit high precision applications. The novelty of the research is that it is the first ever NULL convention logic multiplier, designed to perform floating point multiplication. The proposed multiplier offers substantial decrease in power consumption when compared with its synchronous version. Performance attributes of the NULL convention logic floating point multiplier, obtained from Xilinx simulation and Cadence, are compared with its equivalent synchronous implementation.

  13. High-power CSI-fed induction motor drive with optimal power distribution based control

    Science.gov (United States)

    Kwak, S.-S.

    2011-11-01

    In this article, a current source inverter (CSI) fed induction motor drive with an optimal power distribution control is proposed for high-power applications. The CSI-fed drive is configured with a six-step CSI along with a pulsewidth modulated voltage source inverter (PWM-VSI) and capacitors. Due to the PWM-VSI and the capacitor, sinusoidal motor currents and voltages with high quality as well as natural commutation of the six-step CSI can be obtained. Since this CSI-fed drive can deliver required output power through both the six-step CSI and PWM-VSI, this article shows that the kVA ratings of both the inverters can be reduced by proper real power distribution. The optimal power distribution under load requirements, based on power flow modelling of the CSI-fed drive, is proposed to not only minimise the PWM-VSI rating but also reduce the six-step CSI rating. The dc-link current control of the six-step CSI is developed to realise the optimal power distribution. Furthermore, a vector controlled drive for high-power induction motors is proposed based on the optimal power distribution. Experimental results verify the high-power CSI-fed drive with the optimal power distribution control.

  14. The Seductive Power of an Innovation: Enrolling Non-Conventional Actors in a Drip Irrigation Community in Morocco

    Science.gov (United States)

    Benouniche, Maya; Errahj, Mostafa; Kuper, Marcel

    2016-01-01

    Purpose: The aim of this study was to analyze the motivations of non-conventional innovation actors to engage in innovation processes, how their involvement changed the technology and their own social-professional status, and to analyze their role in the diffusion of the innovation. Design/methodology/approach: We studied the innovation process of…

  15. High Energy Density Capacitors for Pulsed Power Applications

    Science.gov (United States)

    2009-07-01

    high energy density energy storage capacitors. High efficency capacitors are available with energy densities as high as 3 J/cc for 1000 shots or...GENERAL ATOMICS ENERGY PRODUCTS Engineering Bulletin HIGH ENERGY DENSITY CAPACITORS FOR PULSED POWER APPLICATIONS Fred MacDougall, Joel...00-2009 4. TITLE AND SUBTITLE High Energy Density Capacitors for Pulsed Power Applications 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM

  16. Investigation on Satellite-borne High-power Solid-state Power Amplifier Technology and Experiment

    OpenAIRE

    Wu Xiao-po; Zhao Hai-yang; Xi Song-tao

    2014-01-01

    Based on the research and development efforts of satellite-borne lumped solid-state transmitters, the design of a satellite-borne high-power microwave amplifier module is introduced. Focusing on satellite-borne applications, aspects of the high-power density thermal design, multipactor proof design, EMC design and so on, which are critical technologies for a solid-state power amplifier, are discussed. Subsequently, experiments are used to verify the concept.

  17. Investigation on Satellite-borne High-power Solid-state Power Amplifier Technology and Experiment

    Directory of Open Access Journals (Sweden)

    Wu Xiao-po

    2014-06-01

    Full Text Available Based on the research and development efforts of satellite-borne lumped solid-state transmitters, the design of a satellite-borne high-power microwave amplifier module is introduced. Focusing on satellite-borne applications, aspects of the high-power density thermal design, multipactor proof design, EMC design and so on, which are critical technologies for a solid-state power amplifier, are discussed. Subsequently, experiments are used to verify the concept.

  18. High power telecommunication-compatible photoconductive terahertz emitters based on plasmonic nano-antenna arrays

    Science.gov (United States)

    Yardimci, Nezih Tolga; Lu, Hong; Jarrahi, Mona

    2016-11-01

    We present a high-power and broadband photoconductive terahertz emitter operating at telecommunication optical wavelengths, at which compact and high-performance fiber lasers are commercially available. The presented terahertz emitter utilizes an ErAs:InGaAs substrate to achieve high resistivity and short carrier lifetime characteristics required for robust operation at telecommunication optical wavelengths. It also uses a two-dimensional array of plasmonic nano-antennas to offer significantly higher optical-to-terahertz conversion efficiencies compared to the conventional photoconductive emitters, while maintaining broad operation bandwidths. We experimentally demonstrate pulsed terahertz radiation over 0.1-5 THz frequency range with the power levels as high as 300 μW. This is the highest-reported terahertz radiation power from a photoconductive emitter operating at telecommunication optical wavelengths.

  19. High power telecommunication-compatible photoconductive terahertz emitters based on plasmonic nano-antenna arrays.

    Science.gov (United States)

    Yardimci, Nezih Tolga; Lu, Hong; Jarrahi, Mona

    2016-11-07

    We present a high-power and broadband photoconductive terahertz emitter operating at telecommunication optical wavelengths, at which compact and high-performance fiber lasers are commercially available. The presented terahertz emitter utilizes an ErAs:InGaAs substrate to achieve high resistivity and short carrier lifetime characteristics required for robust operation at telecommunication optical wavelengths. It also uses a two-dimensional array of plasmonic nano-antennas to offer significantly higher optical-to-terahertz conversion efficiencies compared to the conventional photoconductive emitters, while maintaining broad operation bandwidths. We experimentally demonstrate pulsed terahertz radiation over 0.1-5 THz frequency range with the power levels as high as 300 μW. This is the highest-reported terahertz radiation power from a photoconductive emitter operating at telecommunication optical wavelengths.

  20. High-power CMUTs: design and experimental verification.

    Science.gov (United States)

    Yamaner, F Yalçin; Olçum, Selim; Oğuz, H Kağan; Bozkurt, Ayhan; Köymen, Hayrettin; Atalar, Abdullah

    2012-06-01

    Capacitive micromachined ultrasonic transducers (CMUTs) have great potential to compete with piezoelectric transducers in high-power applications. As the output pressures increase, nonlinearity of CMUT must be reconsidered and optimization is required to reduce harmonic distortions. In this paper, we describe a design approach in which uncollapsed CMUT array elements are sized so as to operate at the maximum radiation impedance and have gap heights such that the generated electrostatic force can sustain a plate displacement with full swing at the given drive amplitude. The proposed design enables high output pressures and low harmonic distortions at the output. An equivalent circuit model of the array is used that accurately simulates the uncollapsed mode of operation. The model facilities the design of CMUT parameters for high-pressure output, without the intensive need for computationally involved FEM tools. The optimized design requires a relatively thick plate compared with a conventional CMUT plate. Thus, we used a silicon wafer as the CMUT plate. The fabrication process involves an anodic bonding process for bonding the silicon plate with the glass substrate. To eliminate the bias voltage, which may cause charging problems, the CMUT array is driven with large continuous wave signals at half of the resonant frequency. The fabricated arrays are tested in an oil tank by applying a 125-V peak 5-cycle burst sinusoidal signal at 1.44 MHz. The applied voltage is increased until the plate is about to touch the bottom electrode to get the maximum peak displacement. The observed pressure is about 1.8 MPa with -28 dBc second harmonic at the surface of the array.

  1. Self-commutating converters for high power applications

    CERN Document Server

    Arrillaga, Jos; Watson, Neville R; Murray, Nicholas J

    2010-01-01

    For very high voltage or very high current applications, the power industry still relies on thyristor-based Line Commutated Conversion (LCC), which limits the power controllability to two quadrant operation. However, the ratings of self-commutating switches such as the Insulated-Gate Bipolar Transistor (IGBT) and Integrated Gate-Commutated Thyristor (IGCT), are reaching levels that make the technology possible for very high power applications. This unique book reviews the present state and future prospects of self-commutating static power converters for applications requiring either ultr

  2. Design of High Power Density Amplifiers: Application to Ka Band

    Science.gov (United States)

    Passi, Davide; Leggieri, Alberto; Di Paolo, Franco; Bartocci, Marco; Tafuto, Antonio

    2017-06-01

    Recent developments in the design of high-power-high-frequency amplifiers are assessed in this paper by the analysis and measurements of a high power density amplifier operating in the Ka Band. Design procedure is presented and a technical investigation is reported. The proposed device has shown over 23% of useful frequency bandwidth. It is an ensemble of 16 monolithic solid state power amplifiers that employees mixed technologies as spatial and planar combiners. Test performed have given maximum delivered power of 47.2 dBm.

  3. High-power MUTC photodetectors for RF photonic links

    Science.gov (United States)

    Estrella, Steven; Johansson, Leif A.; Mashanovitch, Milan L.; Beling, Andreas

    2016-02-01

    High power photodiodes are needed for a range of applications. The high available power conversion efficiency makes these ideal for antenna remoting applications, including high power, low duty-cycle RF pulse generation. The compact footprint and fiber optic input allow densely packed RF aperture arrays with low cross-talk for phased high directionality emitters. Other applications include linear RF photonic links and other high dynamic range optical systems. Freedom Photonics has developed packaged modified uni-traveling carrier (MUTC) photodetectors for high-power applications. Both single and balanced photodetector pairs are mounted on a ceramic carrier, and packaged in a compact module optimized for high power operation. Representative results include greater than 100 mA photocurrent, >100m W generated RF power and >20 GHz bandwidth. In this paper, we evaluate the saturation and bandwidth of these single ended and balanced photodetectors for detector diameter in the 16 μm to 34 μm range. Packaged performance is compared to chip performance. Further new development towards the realization of <100GHz packaged photodetector modules with optimized high power performance is described. Finally, incorporation of these photodetector structures in novel photonic integrated circuits (PICs) for high optical power application areas is outlined.

  4. High power couplers for Project X

    Energy Technology Data Exchange (ETDEWEB)

    Kazakov, S.; Champion, M.S.; Yakovlev, V.P.; Kramp, M.; Pronitchev, O.; Orlov, Y.; /Fermilab

    2011-03-01

    Project X, a multi-megawatt proton source under development at Fermi National Accelerator Laboratory. The key element of the project is a superconducting (SC) 3GV continuous wave (CW) proton linac. The linac includes 5 types of SC accelerating cavities of two frequencies.(325 and 650MHz) The cavities consume up to 30 kW average RF power and need proper main couplers. Requirements and approach to the coupler design are discussed in the report. New cost effective schemes are described. Results of electrodynamics and thermal simulations are presented.

  5. Compressive Creep Performance and High Temperature Dimensional Stability of Conventional Silica Refractories

    Energy Technology Data Exchange (ETDEWEB)

    Karakus, M.; Kirkland, T.P.; Liu, K.C.; Moore, R.E.; Pint, B.A.; Wereszczak, A.A.

    1999-03-01

    Furnace designers and refractory engineers recognize that optimized furnace superstructure design and refractory selection are needed as glass production furnaces are continually striving toward greater output and efficiencies. Harsher operating conditions test refractories to the limit, while changing production technology (such as the conversion to oxy-fuel from traditional air-fuel firing) can alter the way the materials perform. Refractories for both oxy- and air-fuel fired furnace superstructures are subjected to high temperatures during service that may cause them to excessively creep or subside if the refractory material is not creep resistant, or if it is subjected to high stress, or both. Furnace designers can ensure that superstructure structural integrity is maintained if the creep behavior of the refractory material is well understood and well represented by appropriate engineering creep models. Several issues limit the abilities of furnace designers to (1) choose the optimum refractory for their applications, (2) optimize the engineering design, or (3) predict the service mechanical integrity of their furnace superstructures. Published engineering creep data are essentially non-existent for almost all commercially available refractories used for glass furnace superstructures. The limited data that do exist are supplied by the various refractory suppliers. Unfortunately, these suppliers generally have different ways of conducting their mechanical testing and they also interpret and report their data differently; this makes it hard for furnace designers to draw fair comparisons between competing grades of candidate refractories. Furthermore, the refractory supplier's data are often not available in a form that can be readily used for furnace design and for the prediction and design of long-term structural integrity of furnace superstructures. With the aim of providing such comparable data, the US DOE's Office of Industrial Technology and its

  6. The power processor of a high temperature superconducting energy storage system

    Energy Technology Data Exchange (ETDEWEB)

    Ollila, J. [Power Electronics, Tampere University of Technology, Tampere (Finland)

    1997-12-31

    This report introduces the structure and properties of a power processor unit for a high temperature superconducting magnetic energy storage system which is bused in an UPS demonstration application. The operation is first demonstrated using simulations. The software based operating and control system utilising combined Delta-Sigma and Sliding-Mode control is described shortly. Preliminary test results using a conventional NbTi superconducting energy y storage magnet operating at 4.2 K is shown. (orig.)

  7. Adequacy of Frequency Reserves for High Wind Power Generation

    DEFF Research Database (Denmark)

    Das, Kaushik; Litong-Palima, Marisciel; Maule, Petr

    2016-01-01

    In this article, a new methodology is developed to assess the adequacy of frequency reserves to handle power imbalances caused by wind power forecast errors. The goal of this methodology is to estimate the adequate volume and speed of activation of frequency reserves required to handle power...... imbalances caused due to high penetration of wind power. An algorithm is proposed and developed to estimate the power imbalances due to wind power forecast error following activation of different operating reserves. Frequency containment reserve requirements for mitigating these power imbalances...... are developed through this methodology. Furthermore, the probability of reducing this frequency containment reserve requirement is investigated through this methodology with activation of different volumes and speed of frequency restoration reserve. Wind power generation for 2020 and 2030 scenarios...

  8. High density operation for reactor-relevant power exhaust

    Science.gov (United States)

    Wischmeier, M.

    2015-08-01

    With increasing size of a tokamak device and associated fusion power gain an increasing power flux density towards the divertor needs to be handled. A solution for handling this power flux is crucial for a safe and economic operation. Using purely geometric arguments in an ITER-like divertor this power flux can be reduced by approximately a factor 100. Based on a conservative extrapolation of current technology for an integrated engineering approach to remove power deposited on plasma facing components a further reduction of the power flux density via volumetric processes in the plasma by up to a factor of 50 is required. Our current ability to interpret existing power exhaust scenarios using numerical transport codes is analyzed and an operational scenario as a potential solution for ITER like divertors under high density and highly radiating reactor-relevant conditions is presented. Alternative concepts for risk mitigation as well as strategies for moving forward are outlined.

  9. High performance magnet power supply optimization

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, L.T.

    1988-01-01

    The power supply system for the joint LBL--SLAC proposed accelerator PEP provides the opportunity to take a fresh look at the current techniques employed for controlling large amounts of dc power and the possibility of using a new one. A basic requirement of +- 100 ppM regulation is placed on the guide field of the bending magnets and quadrupoles placed around the 2200 meter circumference of the accelerator. The optimization questions to be answered by this paper are threefold: Can a firing circuit be designed to reduce the combined effects of the harmonics and line voltage combined effects of the harmonics and line voltage unbalance to less than 100 ppM in the magnet field. Given the ambiguity of the previous statement, is the addition of a transistor bank to a nominal SCR controlled system the way to go or should one opt for an SCR chopper system running at 1 KHz where multiple supplies are fed from one large dc bus and the cost--performance evaluation of the three possible systems.

  10. Low reflectance high power RF load

    Energy Technology Data Exchange (ETDEWEB)

    Ives, R. Lawrence; Mizuhara, Yosuke M.

    2016-02-02

    A load for traveling microwave energy has an absorptive volume defined by cylindrical body enclosed by a first end cap and a second end cap. The first end cap has an aperture for the passage of an input waveguide with a rotating part that is coupled to a reflective mirror. The inner surfaces of the absorptive volume consist of a resistive material or are coated with a coating which absorbs a fraction of incident RF energy, and the remainder of the RF energy reflects. The angle of the reflector and end caps is selected such that reflected RF energy dissipates an increasing percentage of the remaining RF energy at each reflection, and the reflected RF energy which returns to the rotating mirror is directed to the back surface of the rotating reflector, and is not coupled to the input waveguide. Additionally, the reflector may have a surface which generates a more uniform power distribution function axially and laterally, to increase the power handling capability of the RF load. The input waveguide may be corrugated for HE11 mode input energy.

  11. 3-D Printed High Power Microwave Magnetrons

    Science.gov (United States)

    Jordan, Nicholas; Greening, Geoffrey; Exelby, Steven; Gilgenbach, Ronald; Lau, Y. Y.; Hoff, Brad

    2015-11-01

    The size, weight, and power requirements of HPM systems are critical constraints on their viability, and can potentially be improved through the use of additive manufacturing techniques, which are rapidly increasing in capability and affordability. Recent experiments on the UM Recirculating Planar Magnetron (RPM), have explored the use of 3-D printed components in a HPM system. The system was driven by MELBA-C, a Marx-Abramyan system which delivers a -300 kV voltage pulse for 0.3-1.0 us, with a 0.15-0.3 T axial magnetic field applied by a pair of electromagnets. Anode blocks were printed from Water Shed XC 11122 photopolymer using a stereolithography process, and prepared with either a spray-coated or electroplated finish. Both manufacturing processes were compared against baseline data for a machined aluminum anode, noting any differences in power output, oscillation frequency, and mode stability. Evolution and durability of the 3-D printed structures were noted both visually and by tracking vacuum inventories via a residual gas analyzer. Research supported by AFOSR (grant #FA9550-15-1-0097) and AFRL.

  12. High power, ultra-broadband supercontinuum source based on highly GeO2 doped silica fiber

    DEFF Research Database (Denmark)

    Jain, Deepak; Sidharthan, Raghuraman; Moselund, Peter M.

    2017-01-01

    We demonstrate a 74 mol % GeO2 doped fiber for mid-infrared supercontinuum generation. Experiments ensure a highest output power for a broadest spectrum from 700nm to 3200nm from this fiber, while being pumped by a broadband 4 stage Erbium fiber based MOPA. The effect of repetition rate of pump...... source and length of Germania-doped fiber has also been investigated. Further, Germania doped fiber has been pumped by conventional Silica based photonic crystal fiber supercontinuum source. At low power, a considerable broadening of 200-300nm was observed. Further broadening of spectrum was limited due...... to limited power of pump source. Our investigations reveal the unexploited potential of Germania doped fiber for mid-infrared supercontinuum generation. This measurement ensures a possibility of Germania based photonic crystal fiber or a step-index fiber supercontinuum source for high power ultra-broad band...

  13. Power Constrained High-Level Synthesis of Battery Powered Digital Systems

    DEFF Research Database (Denmark)

    Nielsen, Sune Fallgaard; Madsen, Jan

    2003-01-01

    We present a high-level synthesis algorithm solving the combined scheduling, allocation and binding problem minimizing area under both latency and maximum power per clock-cycle constraints. Our approach eliminates the large power spikes, resulting in an increased battery lifetime, a property...... of utmost importance for battery powered embedded systems. Our approach extends the partial-clique partitioning algorithm by introducing power awareness through a heuristic algorithm which bounds the design space to those of power feasible schedules. We have applied our algorithm on a set of dataflow graphs...

  14. Improved cutting performance in high power laser cutting

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove

    2003-01-01

    Recent results in high power laser cutting especially with focus on cutting of mild grade steel types for shipbuilding are described.......Recent results in high power laser cutting especially with focus on cutting of mild grade steel types for shipbuilding are described....

  15. In-volume heating using high-power laser diodes

    NARCIS (Netherlands)

    Denisenkov, V.S.; Kiyko, V.V.; Vdovin, G.V.

    2015-01-01

    High-power lasers are useful instruments suitable for applications in various fields; the most common industrial applications include cutting and welding. We propose a new application of high-power laser diodes as in-bulk heating source for food industry. Current heating processes use surface

  16. Linear and nonlinear filters under high power microwave conditions

    Directory of Open Access Journals (Sweden)

    F. Brauer

    2009-05-01

    Full Text Available The development of protection circuits against a variety of electromagnetic disturbances is important to assure the immunity of an electronic system. In this paper the behavior of linear and nonlinear filters is measured and simulated with high power microwave (HPM signals to achieve a comprehensive protection against different high power electromagnetic (HPEM threats.

  17. Improved cutting performance in high power laser cutting

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove

    2003-01-01

    Recent results in high power laser cutting especially with focus on cutting of mild grade steel types for shipbuilding are described.......Recent results in high power laser cutting especially with focus on cutting of mild grade steel types for shipbuilding are described....

  18. In-volume heating using high-power laser diodes

    NARCIS (Netherlands)

    Denisenkov, V.S.; Kiyko, V.V.; Vdovin, G.V.

    2015-01-01

    High-power lasers are useful instruments suitable for applications in various fields; the most common industrial applications include cutting and welding. We propose a new application of high-power laser diodes as in-bulk heating source for food industry. Current heating processes use surface heatin

  19. Atmospheric propagation and combining of high power lasers: comment.

    Science.gov (United States)

    Goodno, Gregory D; Rothenberg, Joshua E

    2016-10-10

    Nelson et al. [Appl. Opt.55, 1757 (2016)APOPAI0003-693510.1364/AO.55.001757] recently concluded that coherent beam combining and remote phase locking of high-power lasers are fundamentally limited by the laser source linewidth. These conclusions are incorrect and not relevant to practical high-power coherently combined laser architectures.

  20. Phase noise measurement of high-power fiber amplifiers

    Institute of Scientific and Technical Information of China (English)

    Hu Xiao; Xiaolin Wang; Yanxing Ma; Bing He; Pu Zhou; Jun Zhou; Xiaojun Xu

    2011-01-01

    We measure the phase fluctuation in a high-power fiber amplifier using a multi-dithering technique. Its fluctuation property is qualitatively analyzed by the power spectral density and integrated spectral density.Low frequency fluctuations caused by the environment are dominant in the phase fluctuations in an amplifier, whereas the high frequency components related to laser power affect the control bandwidth. The bandwidth requirement of the active phase-locking is calculated to be 300 Hz, 670 Hz, 1.6 kHz, and 3.9 kHz under the output power of 25,55, 125, and 180W, respectively. The approximately linear relationship between the control bandwidth and laser power needs to be further investigated.%@@ We measure the phase fluctuation in a high-power fiber amplifier using a multi-dithering technique.Its fluctuation property is qualitatively analyzed by the power spectral density and integrated spectral density.Low frequency fluctuations caused by the environment are dominant in the phase fluctuations in an am-plifier, whereas the high frequency components related to laser power affect the control bandwidth.The bandwidth requirement of the active phase-locking is calculated to be 300 Hz, 670 Hz, 1.6 kHz, and 3.9kHz under the output power of 25, 55, 125, and 180 W, respectively.The approximately linear relationship between the control bandwidth and laser power needs to be further investigated.

  1. 1.55 Micron High Peak Power Fiber Amplifier Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this proposal, we propose to demonstrate and build a 1.55 micron single frequency high energy and high peak power fiber amplifier by developing an innovative...

  2. 1.55 Micron High Peak Power Fiber Amplifier Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this proposal, we propose to demonstrate and build a 1.55 micron single frequency high energy and high peak power fiber amplifier by developing an innovative...

  3. On the Ongoing Evolution of Very High Frequency Power Supplies

    DEFF Research Database (Denmark)

    Knott, Arnold; Andersen, Toke Meyer; Kamby, Peter

    2013-01-01

    in radio frequency transmission equipment helps to overcome those. However those circuits were not designed to meet the same requirements as power converters. This paper summarizes the contributions in recent years in application of very high frequency (VHF) technologies in power electronics, describes......The ongoing demand for smaller and lighter power supplies is driving the motivation to increase the switching frequencies of power converters. Drastic increases however come along with new challenges, namely the increase of switching losses in all components. The application of power circuits used...

  4. 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.

  5. Antipsychotic-induced extrapyramidal syndromes - Risperidone compared with low- and high-potency conventional antipsychotic drugs

    NARCIS (Netherlands)

    Schillevoort, [No Value; de Boer, A; Herings, RMC; Roos, RAC; Jansen, PAF; Leufkens, HGM

    2001-01-01

    Aim: To compare the risk of extrapyramidal syndromes (EPS) between patients using risperidone and those using low-potency conventional antipsychotic drugs (APDs) in outpatient clinical practice, as measured by the use of anticholinergic medication. We tried to replicate results from previous clinica

  6. SOLAR POWERING OF HIGH EFFICIENCY ABSORPTION CHILLER

    Energy Technology Data Exchange (ETDEWEB)

    Randy C. Gee

    2004-11-15

    This is the Final Report for two solar cooling projects under this Cooperative Agreement. The first solar cooling project is a roof-integrated solar cooling and heating system, called the Power Roof{trademark}, which began operation in Raleigh, North Carolina in late July 2002. This system provides 176 kW (50 ton) of solar-driven space cooling using a unique nonimaging concentrating solar collector. The measured performance of the system during its first months of operation is reported here, along with a description of the design and operation of this system. The second solar cooling system, with a 20-ton capacity, is being retrofit to a commercial office building in Charleston, South Carolina but has not yet been completed.

  7. High power UV and VUV pulsed excilamps

    Science.gov (United States)

    Tarasenko, V.; Erofeev, M.; Lomaev, M.; Rybka, D.

    2008-07-01

    Emission characteristics of a nanosecond discharge in inert gases and its halogenides without preionization of the gap from an auxiliary source have been investigated. A volume discharge, initiated by an avalanche electron beam (VDIAEB) was realized at pressures up to 12 atm. In xenon at pressure of 1.2 atm, the energy of spontaneous radiation in the full solid angle was sim 45 mJ/cm^3, and the FWHM of a radiation pulse was sim 110 ns. The spontaneous radiation power rise in xenon was observed at pressures up to 12 atm. Pulsed radiant exitance of inert gases halogenides excited by VDIAEB was sim 4.5 kW/cm^2 at efficiency up to 5.5 %.

  8. High-Power-Density Organic Radical Batteries.

    Science.gov (United States)

    Friebe, Christian; Schubert, Ulrich S

    2017-02-01

    Batteries that are based on organic radical compounds possess superior charging times and discharging power capability in comparison to established electrochemical energy-storage technologies. They do not rely on metals and, hence, feature a favorable environmental impact. They furthermore offer the possibility of roll-to-roll processing through the use of different printing techniques, which enables the cost-efficient fabrication of mechanically flexible devices. In this review, organic radical batteries are presented with the focus on the hitherto developed materials and the key properties thereof, e.g., voltage, capacity, and cycle life. Furthermore, basic information, such as significant characteristics, housing approaches, and applied additives, are presented and discussed in the context of organic radical batteries.

  9. Laser Cooled High-Power Fiber Amplifier

    CERN Document Server

    Nemova, Galina

    2009-01-01

    A theoretical model for laser cooled continuous-wave fiber amplifier is presented. The amplification process takes place in the Tm3+-doped core of the fluoride ZBLAN (ZrF4-BaF2-LaF3-AlF3-NaF) glass fiber. The cooling process takes place in the Yb3+:ZBLAN fiber cladding. It is shown that for each value of the pump power and the amplified signal there is a distribution of the concentration of the Tm3+ along the length of the fiber amplifier, which provides its athermal operation. The influence of a small deviation in the value of the amplified signal on the temperature of the fiber with the fixed distribution of the Tm3+ions in the fiber cladding is investigated.

  10. Designing high efficient solar powered lighting systems

    DEFF Research Database (Denmark)

    Poulsen, Peter Behrensdorff; Thorsteinsson, Sune; Lindén, Johannes;

    2016-01-01

    Some major challenges in the development of L2L products is the lack of efficient converter electronics, modelling tools for dimensioning and furthermore, characterization facilities to support the successful development of the products. We report the development of 2 Three-Port-Converters respec......Some major challenges in the development of L2L products is the lack of efficient converter electronics, modelling tools for dimensioning and furthermore, characterization facilities to support the successful development of the products. We report the development of 2 Three......-Port-Converters respectively for 1-10Wp and 10-50 Wp with a peak efficiency of 97% at 1.8 W of PV power for the 10 Wp version. Furthermore, a modelling tool for L2L products has been developed and a laboratory for feeding in component data not available in the datasheets to the model is described....

  11. Eighth CW and High Average Power RF Workshop

    CERN Document Server

    2014-01-01

    We are pleased to announce the next Continuous Wave and High Average RF Power Workshop, CWRF2014, to take place at Hotel NH Trieste, Trieste, Italy from 13 to 16 May, 2014. This is the eighth in the CWRF workshop series and will be hosted by Elettra - Sincrotrone Trieste S.C.p.A. (www.elettra.eu). CWRF2014 will provide an opportunity for designers and users of CW and high average power RF systems to meet and interact in a convivial environment to share experiences and ideas on applications which utilize high-power klystrons, gridded tubes, combined solid-state architectures, high-voltage power supplies, high-voltage modulators, high-power combiners, circulators, cavities, power couplers and tuners. New ideas for high-power RF system upgrades and novel ways of RF power generation and distribution will also be discussed. CWRF2014 sessions will start on Tuesday morning and will conclude on Friday lunchtime. A visit to Elettra and FERMI will be organized during the workshop. ORGANIZING COMMITTEE (OC): Al...

  12. High-frequency high-voltage high-power DC-to-DC converters

    Science.gov (United States)

    Wilson, T. G.; Owen, H. A.; Wilson, P. M.

    1982-01-01

    A simple analysis of the current and voltage waveshapes associated with the power transistor and the power diode in an example current-or-voltage step-up (buck-boost) converter is presented. The purpose of the analysis is to provide an overview of the problems and design trade-offs which must be addressed as high-power high-voltage converters are operated at switching frequencies in the range of 100 kHz and beyond. Although the analysis focuses on the current-or-voltage step-up converter as the vehicle for discussion, the basic principles presented are applicable to other converter topologies as well.

  13. High Input Voltage, Silicon Carbide Power Processing Unit Performance Demonstration

    Science.gov (United States)

    Bozak, Karin E.; Pinero, Luis R.; Scheidegger, Robert J.; Aulisio, Michael V.; Gonzalez, Marcelo C.; Birchenough, Arthur G.

    2015-01-01

    A silicon carbide brassboard power processing unit has been developed by the NASA Glenn Research Center in Cleveland, Ohio. The power processing unit operates from two sources: a nominal 300 Volt high voltage input bus and a nominal 28 Volt low voltage input bus. The design of the power processing unit includes four low voltage, low power auxiliary supplies, and two parallel 7.5 kilowatt (kW) discharge power supplies that are capable of providing up to 15 kilowatts of total power at 300 to 500 Volts (V) to the thruster. Additionally, the unit contains a housekeeping supply, high voltage input filter, low voltage input filter, and master control board, such that the complete brassboard unit is capable of operating a 12.5 kilowatt Hall effect thruster. The performance of the unit was characterized under both ambient and thermal vacuum test conditions, and the results demonstrate exceptional performance with full power efficiencies exceeding 97%. The unit was also tested with a 12.5kW Hall effect thruster to verify compatibility and output filter specifications. With space-qualified silicon carbide or similar high voltage, high efficiency power devices, this would provide a design solution to address the need for high power electric propulsion systems.

  14. Development of Highly Survivable Power and Communication System for NPP Instruments under Severe Accident

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Seung J.; Gu, Beom W.; Nguyen, Duy T.; Choi, Bo H.; Rim, Chun T. [KAIST, Daejeon (Korea, Republic of); Lee, So I. [KHNP CRI, Daejeon (Korea, Republic of)

    2014-10-15

    According to the detail report from the Fukushima nuclear accident, the failure of conventional instruments is mainly due to the following reasons. 1) Insufficient backup battery capacity after the station black out (SBO) 2) The malfunction or damage of instruments due to the extremely harsh ambient condition after the severe accident 3) The cut-off of power and communication cable due to the physical shocks of hydrogen explosion after the severe accident Since the current equipment qualification (EQ) for the NPP instruments is based on the design basis accident such as loss of coolant accident (LOCA), conventional instruments, which are examined under EQ condition, cannot guarantee their normal operation during the severe accident. A 7m-long-distance wireless power transfer and a radio frequency (RF) communication were introduced with conventional wired system to increase a redundancy. A heat isolation box and a harness are adopted to provide a protection from the expected physical shocks such as missiles and drastic increase of ambient temperature and pressure. A detail design principle of the highly survivable power and communication system, which has 4 sub-systems of a DCRS wireless power transfer, a Zigbee wireless communication, a GFRP harness, and a passive type router with a fly back regulator, has been presented in this paper. Each sub-system has been designed to have a robust operation characteristic regardless of the estimated physical shocks after the severe accident.

  15. Overview on the high power excimer laser technology

    Science.gov (United States)

    Liu, Jingru

    2013-05-01

    High power excimer laser has essential applications in the fields of high energy density physics, inertial fusion energy and industry owing to its advantages such as short wavelength, high gain, wide bandwidth, energy scalable and repetition operating ability. This overview is aimed at an introduction and evaluation of enormous endeavor of the international high power excimer laser community in the last 30 years. The main technologies of high power excimer laser are reviewed, which include the pumping source technology, angular multiplexing and pulse compressing, beam-smoothing and homogenous irradiation, high efficiency and repetitive operation et al. A high power XeCl laser system developed in NINT of China is described in detail.

  16. Feasibility Study on High Concentrating Photovoltaic Power Towers

    Science.gov (United States)

    Frohberger, Dirk; Jaus, Joachim; Wiesenfarth, Maike; Schramek, Philipp; Bett, Andreas W.

    2010-10-01

    This paper presents an analysis on the concept of high concentrating PV power towers. A feasibility study is conducted in order to evaluate the future potential of this technology. Objective of the analysis is to provide an improved basis for establishing research and development priorities for the PV power tower concept. Performance assessments and cost calculations for a 1 MW prototype PV tower power are derived. Based on the assumption of a highly homogeneously illuminated receiver, levelized costs of electricity of 0.29 €/kWh have been calculated for a prototype PV tower power.

  17. A Novel DFIG Damping Control for Power System with High Wind Power Penetration

    Directory of Open Access Journals (Sweden)

    Aiguo Tan

    2016-07-01

    Full Text Available Aiming at the fact that large-scale penetration of wind power will to some extent weaken the small signal stability of power systems, in this paper, the dynamic model of a doubly fed induction generator (DFIG is established firstly, to analyze the impact of wind generation on power oscillation damping. Then, based on the conventional maximum power point tracking control of variable speed wind turbine, a supplementary control scheme is proposed to increase the damping of power system. To achieve best performance, parameters of the damping control are tuned by using a genetic algorithm. Results of eigenvalue analysis and simulations demonstrate the effectiveness of supplementary damping control with fixed wind speed. At last, due to the problem that fluctuation of output power of wind generators would cause the unstable performance of the DFIG damping controller above, a new algorithm that adapts to the wind variation is added to the supplementary damping control scheme. Results of the simulation show that an improved damping control scheme can stably enhance system damping under various wind speeds and has higher practical value.

  18. High figure-of-merit SOI power LDMOS for power integrated circuits

    Directory of Open Access Journals (Sweden)

    Yashvir Singh

    2015-06-01

    Full Text Available The structural modifications in the conventional power laterally diffused metal-oxide-semiconductor field-effect transistor (LDMOS are carried out to improve the breakdown voltage, on-resistance, gate-charge and figure-of-merits of the device with reduced cell pitch. The modified device has planer structure implemented on silicon-on-insulator which is suitable for low to medium voltage power integrated circuits. The proposed LDMOS consists of two gate electrodes placed vertically in two separate trenches build in the drift region and single source and drain contacts are taken on the top. The trench structure reduces the electric field inside the drift region and allow increased drift layer doping concentration leading to higher breakdown voltage, lower specific on-resistance, reduced gate-drain charge, and substantial improvement in the figure-of-merits. Using two-dimensional simulations, the performance of the proposed LDMOS is optimized and results are compared with the conventional LDMOS. Our simulation results show that the proposed device exhibits 110% higher breakdown voltage, 40% reduction in cell pitch, 19% lower specific on-resistance, 30% lower gate-to-drain charge leading to 5.5 times improvement in Baliga's figure-of-merit and 43% reduction in dynamic figure-of-merit over the conventional device.

  19. The Relevance of the High Frequency Audiometry in Tinnitus Patients with Normal Hearing in Conventional Pure-Tone Audiometry.

    Science.gov (United States)

    Vielsmeier, Veronika; Lehner, Astrid; Strutz, Jürgen; Steffens, Thomas; Kreuzer, Peter M; Schecklmann, Martin; Landgrebe, Michael; Langguth, Berthold; Kleinjung, Tobias

    2015-01-01

    The majority of tinnitus patients suffer from hearing loss. But a subgroup of tinnitus patients show normal hearing thresholds in the conventional pure-tone audiometry (125 Hz-8 kHz). Here we explored whether the results of the high frequency audiometry (>8 kHz) provide relevant additional information in tinnitus patients with normal conventional audiometry by comparing those with normal and pathological high frequency audiometry with respect to their demographic and clinical characteristics. From the database of the Tinnitus Clinic at Regensburg we identified 75 patients with normal hearing thresholds in the conventional pure-tone audiometry. We contrasted these patients with normal and pathological high-frequency audiogram and compared them with respect to gender, age, tinnitus severity, pitch, laterality and duration, comorbid symptoms and triggers for tinnitus onset. Patients with pathological high frequency audiometry were significantly older and had higher scores on the tinnitus questionnaires in comparison to patients with normal high frequency audiometry. Furthermore, there was an association of high frequency audiometry with the laterality of tinnitus. In tinnitus patients with normal pure-tone audiometry the high frequency audiometry provides useful additional information. The association between tinnitus laterality and asymmetry of the high frequency audiometry suggests a potential causal role for the high frequency hearing loss in tinnitus etiopathogenesis.

  20. The Relevance of the High Frequency Audiometry in Tinnitus Patients with Normal Hearing in Conventional Pure-Tone Audiometry

    Directory of Open Access Journals (Sweden)

    Veronika Vielsmeier

    2015-01-01

    Full Text Available Objective. The majority of tinnitus patients suffer from hearing loss. But a subgroup of tinnitus patients show normal hearing thresholds in the conventional pure-tone audiometry (125 Hz–8 kHz. Here we explored whether the results of the high frequency audiometry (>8 kHz provide relevant additional information in tinnitus patients with normal conventional audiometry by comparing those with normal and pathological high frequency audiometry with respect to their demographic and clinical characteristics. Subjects and Methods. From the database of the Tinnitus Clinic at Regensburg we identified 75 patients with normal hearing thresholds in the conventional pure-tone audiometry. We contrasted these patients with normal and pathological high-frequency audiogram and compared them with respect to gender, age, tinnitus severity, pitch, laterality and duration, comorbid symptoms and triggers for tinnitus onset. Results. Patients with pathological high frequency audiometry were significantly older and had higher scores on the tinnitus questionnaires in comparison to patients with normal high frequency audiometry. Furthermore, there was an association of high frequency audiometry with the laterality of tinnitus. Conclusion. In tinnitus patients with normal pure-tone audiometry the high frequency audiometry provides useful additional information. The association between tinnitus laterality and asymmetry of the high frequency audiometry suggests a potential causal role for the high frequency hearing loss in tinnitus etiopathogenesis.

  1. A high-power target experiment

    CERN Document Server

    Kirk, H G; Ludewig, H; Palmer, Robert; Samulyak, V; Simos, N; Tsang, Thomas; Bradshaw, T W; Drumm, Paul V; Edgecock, T R; Ivanyushenkov, Yury; Bennett, Roger; Efthymiopoulos, Ilias; Fabich, Adrian; Haseroth, H; Haug, F; Lettry, Jacques; Hayato, Y; Yoshimura, Koji; Gabriel, Tony A; Graves, Van; Spampinato, P; Haines, John; McDonald, Kirk T

    2005-01-01

    We describe an experiment designed as a proof-of-principle test for a target system capable of converting a 4 MW proton beam into a high-intensity muon beam suitable for incorporation into either a neutrino factory complex or a muon collider. The target system is based on exposing a free mercury jet to an intense proton beam in the presence of a high strength solenoidal field.

  2. A battery-powered high-current power supply for superconductors

    CERN Document Server

    Wake, M; Suda, K

    2002-01-01

    Since superconductors do not require voltages, a high-current power supply could run with low power if the voltage is sufficiently reduced. Even a battery-powered power supply could give as much as 2,000A for a superconductor. To demonstrate this hypothesis, a battery-powered 2,000A power supply was constructed. It uses an IGBT chopper and Schottky diode together with a specially arranged transformer to produce a high current with low voltage. Testing of 2,000A operation was performed for about 1.5 hr using 10 car batteries. Charging time for this operation was 8 hr. Ramping control was smooth and caused no trouble. Although the IGBT frequency ripple of 16.6 kHz was easily removed using a passive filter, spike noise remained in the output voltage. This ripple did not cause any trouble in operating a pancake-type inductive superconducting load. (author)

  3. Active Photonic crystal fibers for high power applications

    DEFF Research Database (Denmark)

    Olausson, Christina Bjarnal Thulin

    . This plays an important role in high power lasers and ampliers with respect to efficiency, packaging, and thermal handling. The third part of the work has involved developing tools for characterizing the mode quality and stability of large core bers. Stable, single-mode bers with larger cores are essential......The photonic crystal ber technology provides means to realize bers optimized for high power operation, due to the large single-mode cores and the unique design exibility of the microstructure. The work presented in this thesis focuses on improving the properties of active photonic crystal bers...... for high power ber lasers and ampliers, and on adding new functionality to the fibers - all with the purpose of pushing the technology towards high powers. The first part of the work has been to investigate photo darkening, the mitigation of which is crucial in the quest for higher powers. The work has...

  4. High Efficiency, High Temperature Foam Core Heat Exchanger for Fission Surface Power Systems, Phase II Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Fission-based power systems with power levels of 30 to ≥100 kWe will be needed for planetary surface bases. Development of high temperature, high efficiency...

  5. High-frequency oscillatory ventilation is not superior to conventional mechanical ventilation in surfactant-treated rabbits with lung injury

    NARCIS (Netherlands)

    D.A.M.P.J. Gommers (Diederik); A. Hartog (Anneke); R. Schnabel; A. de Jaegere (Anne); B.F. Lachmann (Burkhard)

    1999-01-01

    textabstractThe aim of this study was to compare high-frequency oscillatory ventilation (HFOV) with conventional mechanical ventilation (CMV) with and without surfactant in the treatment of surfactant-deficient rabbits. A previously described saline lung lavage model of

  6. Conventional Gymnasium vs. Geodesic Field House. A Comparative Study of High School Physical Education and Assembly Facilities.

    Science.gov (United States)

    Educational Facilities Labs., Inc., New York, NY.

    A description is presented of the design features of a high school's geodesic dome field house. Following consideration of various design features and criteria for the physical education facility, a comprehensive analysis is given of comparative costs of a geodesic dome field house and conventional gymnasium. On the basis of the study it would…

  7. Three Types of Programed Learning and the Conventional Teaching of the Nuclear Chemistry Portion of the High School Chemistry Course.

    Science.gov (United States)

    Darnowski, Vincent S.

    Compared was the learning and retention of facts and principles of nuclear chemistry in the high school chemistry course using three forms of programed materials, and the conventional lecture-demonstration method of teaching. Groups using the programs gained significantly more than the control group, and among the three forms of programs, the…

  8. Real-time power measurement and control for high power diode laser

    Science.gov (United States)

    Qin, Wen-bin; Liu, You-qiang; Cao, Yin-hua; Wang, Zhi-yong

    2011-06-01

    As the continual improvement of technology and beam quality, diode laser, with poor beam quality, no longer just apply to pump solid-state laser. As a kind of implement of laser materials processing, high-power diode laser has been used in manufacture, as a brand new means of laser processing. Due to the influence of inevitable unstable factors, for example, the temperature of water-cooler, the current of power supply, etc, the output power of diode laser will be unstable. And laser output power, as an important parameter, frequently affects the performance of the laser beam and the experimental results of processing, especially in the laser materials processing. Therefore, researching the real-time power measurement and control of high power diode laser has great significance, and for diode laser, it would improve performance of itself. To achieve the purpose of real-time detection, traditional measuring method, placing a power sensor behind the total-reflection mirror of laser resonant cavity, is mainly applied in the system of gas laser and solid-state laser. However, Owing to the high integration level of diode laser, traditional measuring method can't be adopted. A technique for real-time measure output power of high power diode laser is developed to improve quality of the laser in this paper. A lens placed at an angle of 45° in the system was used to sample output light of laser, and a piece of ground glass was used to uniform the beam power density, then the photoelectric detector received an optic signal and converted it into electric signal. This feeble signal was processed by amplification circuit with a filter. Finally, this detected electric signal was applied to accomplish the closed-loop control of power. The performance of power measurement and control system was tested with the 300W diode laser, and the measuring inaccuracy achieved was less than +/-1%.

  9. High Power Silicon Carbide (SiC) Power Processing Unit Development

    Science.gov (United States)

    Scheidegger, Robert J.; Santiago, Walter; Bozak, Karin E.; Pinero, Luis R.; Birchenough, Arthur G.

    2015-01-01

    NASA GRC successfully designed, built and tested a technology-push power processing unit for electric propulsion applications that utilizes high voltage silicon carbide (SiC) technology. The development specifically addresses the need for high power electronics to enable electric propulsion systems in the 100s of kilowatts. This unit demonstrated how high voltage combined with superior semiconductor components resulted in exceptional converter performance.

  10. Recidive tumor and excessive cerebral angiofibrosis 28 years after high-dose conventional prolactinom-radiation

    Energy Technology Data Exchange (ETDEWEB)

    Peiffer, J.; Wowra, B.; Geissler, D.

    1983-09-01

    A fatal recurrence developed 28 years after conventional X-ray therapy of a hypophyseal adenoma with a focal dose of 10340 R. An organic psychosyndrome of many years preceded the recurrence. The immunocytologic examination of the recurrent tumor showed a prolactinoma. As radiogenic fibroses without primary parenchyma necrosis, massive angiofibroses within tumor, hypothalamus, and neostriatum and less massive angiofibroses in the cerebrum and cortex of cerebrum are opposed to the classical late radiation damage with plasmatic infiltration necrosis.

  11. High-power random distributed feedback fiber laser: From science to application

    Energy Technology Data Exchange (ETDEWEB)

    Du, Xueyuan [College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China); Naval Academy of Armament, Beijing 100161 (China); Zhang, Hanwei; Xiao, Hu; Ma, Pengfei; Wang, Xiaolin; Zhou, Pu; Liu, Zejin [College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

    2016-10-15

    A fiber laser based on random distributed feedback has attracted increasing attention in recent years, as it has become an important photonic device and has found wide applications in fiber communications or sensing. In this article, recent advances in high-power random distributed feedback fiber laser are reviewed, including the theoretical analyses, experimental approaches, discussion on the practical applications and outlook. It is found that a random distributed feedback fiber laser can not only act as an information photonics device, but also has the feasibility for high-efficiency/high-power generation, which makes it competitive with conventional high-power laser sources. In addition, high-power random distributed feedback fiber laser has been successfully applied for midinfrared lasing, frequency doubling to the visible and high-quality imaging. It is believed that the high-power random distributed feedback fiber laser could become a promising light source with simple and economic configurations. (copyright 2016 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Overview of space power electronic's technology under the CSTI High Capacity Power Program

    Science.gov (United States)

    Schwarze, Gene E.

    The Civilian Space Technology Initiative (CSTI) is a NASA Program targeted at the development of specific technologies in the areas of transportation, operations and science. Each of these three areas consists of major elements and one of the operation's elements is the High Capacity Power element. The goal of this element is to develop the technology base needed to meet the long duration, high capacity power requirements for future NASA initiatives. The High Capacity Power element is broken down into several subelements that includes energy conversion in the areas of the free piston Stirling power converter and thermoelectrics, thermal management, power management, system diagnostics, and environmental compatibility and system's lifetime. A recent overview of the CSTI High capacity Power element and a description of each of the program's subelements is given by Winter (1989). The goals of the Power Management subelement are twofold. The first is to develop, test, and demonstrate high temperature, radiation-resistant power and control components and circuits that will be needed in the Power Conditioning, Control and Transmission (PCCT) subsystem of a space nuclear power system. The results obtained under this goal will also be applicable to the instrumentation and control subsystem of a space nuclear reactor. These components and circuits must perform reliably for lifetimes of 7-10 years. The second goal is to develop analytical models for use in computer simulations of candidate PCCT subsystems. Circuits which will be required for a specific PCCT subsystem will be designed and built to demonstrate their performance and, also, to validate the analytical models and simulations. The tasks under the Power Management subelement will now be described in terms of objectives, approach and present status of work.

  13. Overview of space power electronic's technology under the CSTI High Capacity Power Program

    Science.gov (United States)

    Schwarze, Gene E.

    1994-01-01

    The Civilian Space Technology Initiative (CSTI) is a NASA Program targeted at the development of specific technologies in the areas of transportation, operations and science. Each of these three areas consists of major elements and one of the operation's elements is the High Capacity Power element. The goal of this element is to develop the technology base needed to meet the long duration, high capacity power requirements for future NASA initiatives. The High Capacity Power element is broken down into several subelements that includes energy conversion in the areas of the free piston Stirling power converter and thermoelectrics, thermal management, power management, system diagnostics, and environmental compatibility and system's lifetime. A recent overview of the CSTI High capacity Power element and a description of each of the program's subelements is given by Winter (1989). The goals of the Power Management subelement are twofold. The first is to develop, test, and demonstrate high temperature, radiation-resistant power and control components and circuits that will be needed in the Power Conditioning, Control and Transmission (PCCT) subsystem of a space nuclear power system. The results obtained under this goal will also be applicable to the instrumentation and control subsystem of a space nuclear reactor. These components and circuits must perform reliably for lifetimes of 7-10 years. The second goal is to develop analytical models for use in computer simulations of candidate PCCT subsystems. Circuits which will be required for a specific PCCT subsystem will be designed and built to demonstrate their performance and, also, to validate the analytical models and simulations. The tasks under the Power Management subelement will now be described in terms of objectives, approach and present status of work.

  14. Social power and recognition of emotional prosody: High power is associated with lower recognition accuracy than low power.

    Science.gov (United States)

    Uskul, Ayse K; Paulmann, Silke; Weick, Mario

    2016-02-01

    Listeners have to pay close attention to a speaker's tone of voice (prosody) during daily conversations. This is particularly important when trying to infer the emotional state of the speaker. Although a growing body of research has explored how emotions are processed from speech in general, little is known about how psychosocial factors such as social power can shape the perception of vocal emotional attributes. Thus, the present studies explored how social power affects emotional prosody recognition. In a correlational study (Study 1) and an experimental study (Study 2), we show that high power is associated with lower accuracy in emotional prosody recognition than low power. These results, for the first time, suggest that individuals experiencing high or low power perceive emotional tone of voice differently.

  15. High-Power Considerations in Metamaterial Antennas

    Science.gov (United States)

    2014-07-08

    adding the lens. Z. H. Jiang, M. D. Gregory, and D. H. Werner, "Experimental Demonstration of a Broadband Transformation Optics Lens for Highly...Directive Multibeam Emission," Phys. Rev. B, 84, 165111 (2011). 5.50 GHz 0 5 10 15 20 25 30 35 Maximum Field Enhancement Factor 5.00 GHz 4.50 GHz 4.00

  16. Modular high voltage power supply for chemical analysis

    Science.gov (United States)

    Stamps, James F.; Yee, Daniel D.

    2008-07-15

    A high voltage power supply for use in a system such as a microfluidics system, uses a DC-DC converter in parallel with a voltage-controlled resistor. A feedback circuit provides a control signal for the DC-DC converter and voltage-controlled resistor so as to regulate the output voltage of the high voltage power supply, as well as, to sink or source current from the high voltage supply.

  17. A new high-power klystron for the DSN

    Science.gov (United States)

    Goldfinger, A.; Gregg, M. A.; Hartop, R.

    1982-06-01

    A very high reliability 100 kW klystron for the Deep Space Network (DSN) high power transmitters in support of spacecrafts to the distant planets was studied. The last phases included electron gun fabrication and beam analyzer evaluation and klystron prototype fabrication, mechanical and electrical design improvements resulted in the delivery of a prototype klystron meeting all requirements. It is concluded that the development of a new high power klystron for the DSN was very successful as demonstrated by the prototype results.

  18. Silicon-Carbide Power MOSFET Performance in High Efficiency Boost Power Processing Unit for Extreme Environments

    Science.gov (United States)

    Ikpe, Stanley A.; Lauenstein, Jean-Marie; Carr, Gregory A.; Hunter, Don; Ludwig, Lawrence L.; Wood, William; Del Castillo, Linda Y.; Fitzpatrick, Fred; Chen, Yuan

    2016-01-01

    Silicon-Carbide device technology has generated much interest in recent years. With superior thermal performance, power ratings and potential switching frequencies over its Silicon counterpart, Silicon-Carbide offers a greater possibility for high powered switching applications in extreme environment. In particular, Silicon-Carbide Metal-Oxide- Semiconductor Field-Effect Transistors' (MOSFETs) maturing process technology has produced a plethora of commercially available power dense, low on-state resistance devices capable of switching at high frequencies. A novel hard-switched power processing unit (PPU) is implemented utilizing Silicon-Carbide power devices. Accelerated life data is captured and assessed in conjunction with a damage accumulation model of gate oxide and drain-source junction lifetime to evaluate potential system performance at high temperature environments.

  19. GaN High-Electron-Mobility Transistor with WN x /Cu Gate for High-Power Applications

    Science.gov (United States)

    Hsieh, Ting-En; Lin, Yueh-Chin; Li, Fang-Ming; Shi, Wang-Cheng; Huang, Yu-Xiang; Lan, Wei-Cheng; Chin, Ping-Chieh; Chang, Edward Yi

    2015-12-01

    A GaN high-electron-mobility transistor (HEMT) with WN x /Cu gate for high-power applications has been investigated. The direct-current (DC) characteristics of the device are comparable to those of conventional Ni/Au-gated GaN HEMTs. The results of high-voltage stress testing indicate that the device is stable after application of 200 V stress for 42 h. The WN x /Cu-gated GaN HEMT exhibited no obvious changes in the DC characteristics or Schottky barrier height before and after annealing at 250°C for 1 h. These results demonstrate that the WN x /Cu gate structure can be used in a GaN HEMT for high-power applications with good thermal stability.

  20. Control of high power IGBT modules in the active region for fast pulsed power converters

    CERN Document Server

    Cravero, J M; Garcia Retegui, R; Maestri, S; Uicich, G

    2014-01-01

    At CERN, fast pulsed power converters are used to supply trapezoidal current in different magnet loads. These converters perform output current regulation by using a high power IGBT module in its ohmic region. This paper presents a new strategy for pulsed current control applications using a specifically designed IGBT driver.

  1. Electric Vehicles for Improved Operation of Power Systems with High Wind Power Penetration

    DEFF Research Database (Denmark)

    Larsen, Esben; Chandrashekhara, Divya K; Østergaard, Jacob

    2008-01-01

    In a power system with a high share of wind energy the wind fluctuation causes a variation in the power generation, which must be compensated from other sources. The situation in Denmark with a penetration of more than 20% wind in yearly average is presented. The introduction of electric drive ve...

  2. High-Power Electron Accelerators for Space (and other) Applications

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Dinh Cong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lewellen, John W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-23

    This is a presentation on high-power electron accelerators for space and other applications. The main points covered are: electron beams for space applications, new designs of RF accelerators, high-power high-electron mobility transistors (HEMT) testing, and Li-ion battery design. In summary, the authors have considered a concept of 1-MeV electron accelerator that can operate up to several seconds. This concept can be extended to higher energy to produce higher beam power. Going to higher beam energy requires adding more cavities and solid-state HEMT RF power devices. The commercial HEMT have been tested for frequency response and RF output power (up to 420 W). Finally, the authors are testing these HEMT into a resonant load and planning for an electron beam test in FY17.

  3. High-power lead-acid batteries for different applications

    Science.gov (United States)

    Wagner, Rainer

    High-power lead-acid batteries have been used for a rather long time in various applications, especially for uninterruptible power supplies (UPSs) and starting of automobiles. Future automotive service requires, in addition to cold-cranking performance, the combination of high-power capability, a very good charge-acceptance, and an excellent cycle-life. Such applications include stop-start, regenerative braking, and soft, mild and full hybrid vehicles. For UPS, there has been a clear tendency to shorter discharge times and higher discharge rates. During the past decades, the specific power of lead-acid batteries has been raised steadily and there is still, room for further improvement. This paper gives an overview of the progress made in the development of high-power lead-acid batteries and focuses on stationary and automotive applications.

  4. Development of a 500 MHz high power RF test stand

    Institute of Scientific and Technical Information of China (English)

    PAN Wei-Min; SHA Peng; HUANG Tong-Ming; MA Qiang; WANG Guang-Wei; LIN Hai-Ying; ZHAO Guang-Yuan; SUN Yi; XU Bo; WANG Qun-Yao

    2012-01-01

    A flexible high power RF test stand has been designed and constructed at IHEP to test a variety of 500 MHz superconducting RF components for the upgrade project of the Beijing Electron Positron Collider (BEPC Ⅱ ),such as the input coupler,the higher order modes (HOMs) absorber and so on.A high power input coupler has been conditioned and tested with the RF power up to 250 kW in continuous wave (CW),traveling wave (TW) mode and 150 kW CW in standing wave (SW) mode.A prototype of the HOMs absorber has been tested to absorb power of 4.4 kW.An introduction of the test stand design,construction and high power tests is presented in this paper.

  5. Cryogenic cooling for high power laser amplifiers

    Directory of Open Access Journals (Sweden)

    Perin J.P.

    2013-11-01

    Full Text Available Using DPSSL (Diode Pumped Solid State Lasers as pumping technology, PW-class lasers with enhanced repetition rates are developed. Each of the Yb YAG amplifiers will be diode-pumped at a wavelength of 940 nm. This is a prerequisite for achieving high repetition rates (light amplification duration 1 millisecond and repetition rate 10 Hz. The efficiency of DPSSL is inversely proportional to the temperature, for this reason the slab amplifier have to be cooled at a temperature in the range of 100 K–170 K with a heat flux of 1 MW*m−2. This paper describes the thermo-mechanical analysis for the design of the amplification laser head, presents a preliminary proposal for the required cryogenic cooling system and finally outlines the gain of cryogenic operation for the efficiency of high pulsed laser.

  6. A High Power Density Integrated Charger for Electric Vehicles with Active Ripple Compensation

    Directory of Open Access Journals (Sweden)

    Liwen Pan

    2015-01-01

    Full Text Available This paper suggests a high power density on-board integrated charger with active ripple compensation circuit for electric vehicles. To obtain a high power density and high efficiency, silicon carbide devices are reported to meet the requirement of high-switching-frequency operation. An integrated bidirectional converter is proposed to function as AC/DC battery charger and to transfer energy between battery pack and motor drive of the traction system. In addition, the conventional H-bridge circuit suffers from ripple power pulsating at second-order line frequency, and a scheme of active ripple compensation circuit has been explored to solve this second-order ripple problem, in which a pair of power switches shared traction mode, a ripple energy storage capacitor, and an energy transfer inductor. Simulation results in MATLAB/Simulink validated the eligibility of the proposed topology. The integrated charger can work as a 70 kW motor drive circuit or a converter with an active ripple compensation circuit for 3 kW charging the battery. The impact of the proposed topology and control strategy on the integrated charger power losses, efficiency, power density, and thermal performance has also been analysed and simulated.

  7. High Temperature Magnetics for Power Conversion

    Science.gov (United States)

    2005-06-01

    complex zig zag cutout shown earlier. On the secondary, 3 layers at a time were folded. Folds alternated in direction to even out overall foil...ingredients were mixed in a high-shear blender, calcined at 900°C in air, and ground in a stirred ball mill for 2 hours to an average particle size of...approximately 1 micron. Various organic binders and dispersants were added at the milling step to enhance particle size reduction and improve pressing

  8. High performance protection circuit for power electronics applications

    Science.gov (United States)

    Tudoran, Cristian D.; Dǎdârlat, Dorin N.; Toşa, Nicoleta; Mişan, Ioan

    2015-12-01

    In this paper we present a high performance protection circuit designed for the power electronics applications where the load currents can increase rapidly and exceed the maximum allowed values, like in the case of high frequency induction heating inverters or high frequency plasma generators. The protection circuit is based on a microcontroller and can be adapted for use on single-phase or three-phase power systems. Its versatility comes from the fact that the circuit can communicate with the protected system, having the role of a "sensor" or it can interrupt the power supply for protection, in this case functioning as an external, independent protection circuit.

  9. High power CO lasers and their application potential

    Science.gov (United States)

    Maisenhaelder, F.

    1989-06-01

    Industrial applications of high-power CO lasers are examined. The characteristics specific to CO lasers are briefly reviewed, and applications where the CO laser seems to promise wavelength-related advantages over other lasers are examined. Experimentally demonstrated applications in the drilling and cutting of metals, isotope separation and photochemistry, and laser medicine are addressed, Developments in the high power range in Japan, Soviet Union, and Germany are described, and a comparison is made between high power CO and CO2 gas lasers for civil applications.

  10. High performance protection circuit for power electronics applications

    Energy Technology Data Exchange (ETDEWEB)

    Tudoran, Cristian D., E-mail: cristian.tudoran@itim-cj.ro; Dădârlat, Dorin N.; Toşa, Nicoleta; Mişan, Ioan [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, PO 5 Box 700, 400293 Cluj-Napoca (Romania)

    2015-12-23

    In this paper we present a high performance protection circuit designed for the power electronics applications where the load currents can increase rapidly and exceed the maximum allowed values, like in the case of high frequency induction heating inverters or high frequency plasma generators. The protection circuit is based on a microcontroller and can be adapted for use on single-phase or three-phase power systems. Its versatility comes from the fact that the circuit can communicate with the protected system, having the role of a “sensor” or it can interrupt the power supply for protection, in this case functioning as an external, independent protection circuit.

  11. High power density reactors based on direct cooled particle beds

    Science.gov (United States)

    Powell, J. R.; Horn, F. L.

    Reactors based on direct cooled High Temperature Gas Cooled Reactor (HTGR) type particle fuel are described. The small diameter particle fuel is packed between concentric porous cylinders to make annular fuel elements, with the inlet coolant gas flowing inwards. Hot exit gas flows out along the central channel of each element. Because of the very large heat transfer area in the packed beds, power densities in particle bed reactors (PBRs) are extremely high resulting in compact, lightweight systems. Coolant exit temperatures are high, because of the ceramic fuel temperature capabilities, and the reactors can be ramped to full power and temperature very rapidly. PBR systems can generate very high burst power levels using open cycle hydrogen coolant, or high continuous powers using closed cycle helium coolant. PBR technology is described and development requirements assessed.

  12. Novel Polymers for High Efficiency Renewable and Portable Power Applications

    Science.gov (United States)

    2015-07-30

    systems with frontier orbital levels (HOMOs and LUMOs) and morphologies systematically investigated and optimized for high efficiency photoelectric and...of polymer-dye covalently linked systems that could efficiently convert light/heat into electrical power. Therefore, frontier orbital matching...force between the polymer and dye would result in weaker PL quenching and optoelectronic device power conversion efficiency , this experimentally

  13. Intense neutron source: high-voltage power supply specifications

    Energy Technology Data Exchange (ETDEWEB)

    Riedel, A.A.

    1980-08-01

    This report explains the need for and sets forth the electrical, mechanical and safety specifications for a high-voltage power supply to be used with the intense neutron source. It contains sufficient information for a supplier to bid on such a power supply.

  14. Development of Compact Ozonizer with High Ozone Output by Pulsed Power

    Science.gov (United States)

    Tanaka, Fumiaki; Ueda, Satoru; Kouno, Kanako; Sakugawa, Takashi; Akiyama, Hidenori; Kinoshita, Youhei

    Conventional ozonizer with a high ozone output using silent or surface discharges needs a cooling system and a dielectric barrier, and therefore becomes a large machine. A compact ozonizer without the cooling system and the dielectric barrier has been developed by using a pulsed power generated discharge. The wire to plane electrodes made of metal have been used. However, the ozone output was low. Here, a compact and high repetition rate pulsed power generator is used as an electric source of a compact ozonizer. The ozone output of 6.1 g/h and the ozone yield of 86 g/kWh are achieved at 500 pulses per second, input average power of 280 W and an air flow rate of 20 L/min.

  15. Concentric Parallel Combining Balun for Millimeter-Wave Power Amplifier in Low-Power CMOS with High-Power Density

    Science.gov (United States)

    Han, Jiang-An; Kong, Zhi-Hui; Ma, Kaixue; Yeo, Kiat Seng; Lim, Wei Meng

    2016-11-01

    This paper presents a novel balun for a millimeter-wave power amplifier (PA) design to achieve high-power density in a 65-nm low-power (LP) CMOS process. By using a concentric winding technique, the proposed parallel combining balun with compact size accomplishes power combining and unbalance-balance conversion concurrently. For calculating its power combination efficiency in the condition of various amplitude and phase wave components, a method basing on S-parameters is derived. Based on the proposed parallel combining balun, a fabricated 60-GHz industrial, scientific, and medical (ISM) band PA with single-ended I/O achieves an 18.9-dB gain and an 8.8-dBm output power at 1-dB compression and 14.3-dBm saturated output power ( P sat) at 62 GHz. This PA occupying only a 0.10-mm2 core area has demonstrated a high-power density of 269.15 mW/mm2 in 65 nm LP CMOS.

  16. Advanced ceramics sintering using high-power millimeter-wave radiation

    Energy Technology Data Exchange (ETDEWEB)

    Setsuhara, Y.; Kamai, M.; Kinoshita, S.; Abe, N.; Miyake, S. [Osaka Univ. (Japan). Welding Research Inst.; Saji, T. [Fujidempa Kogyo Co., Ltd., Ibaraki (Japan)

    1996-12-31

    The results of ceramics sintering experiments using high-power millimeter-wave radiation are reported. Sintering of silicon nitride with 5% Al{sub 2}O{sub 3} and 5% Y{sub 2}O{sub 3} was performed in a multi-mode applicator using a 10-kW 28-GHz gyrotron in CW operation. It was found that the silicon nitride samples sintered with 28 GHz radiation at 1,650 C for 30 min reached to as high as theoretical density (TD), while the conventionally sintered samples at 1700 C for 60 min resulted in the density as low as 90% TD. Focusing experiments of millimeter-wave radiation from the high-power pulsed 60-GHz gyrotron have been performed using a quasi-optical antenna system (two-dimensional ellipso-parabolic focusing antenna system) to demonstrate the feasibility of the power density of as high as 100 kW/cm{sup 2}. Typical heating characteristics using the focused beam were made clear for this system. It was found that the densification of yttria-stabilized zirconia (ZrO{sub 2}-8mol%Y{sub 2}O{sub 3}) samples to as high as 97% TD was obtained from the sintering with focused 60 GHz beam in pulse operation with a 10-ms pulse duration at a 0.5Hz repetition. The densification temperature for the zirconia could be lowered by 200 C than that expected conventionally.

  17. Single phase forced convection cooling of high power leds

    NARCIS (Netherlands)

    Ozdemir, M.Z.; Chestakov, D.; Frijns, A.J.H.

    2011-01-01

    LEDs are strong candidates for future illumination applications dueto their much lower consumption of energy compared to conventional lighting options. One of key problems in development of LEDs is successful thermal management during illumination. Therefore, current research ongoing related to high

  18. On-Chip Power-Combining for High-Power Schottky Diode-Based Frequency Multipliers

    Science.gov (United States)

    Chattopadhyay, Goutam; Mehdi, Imran; Schlecht, Erich T.; Lee, Choonsup; Siles, Jose V.; Maestrini, Alain E.; Thomas, Bertrand; Jung, Cecile D.

    2013-01-01

    A 1.6-THz power-combined Schottky frequency tripler was designed to handle approximately 30 mW input power. The design of Schottky-based triplers at this frequency range is mainly constrained by the shrinkage of the waveguide dimensions with frequency and the minimum diode mesa sizes, which limits the maximum number of diodes that can be placed on the chip to no more than two. Hence, multiple-chip power-combined schemes become necessary to increase the power-handling capabilities of high-frequency multipliers. The design presented here overcomes difficulties by performing the power-combining directly on-chip. Four E-probes are located at a single input waveguide in order to equally pump four multiplying structures (featuring two diodes each). The produced output power is then recombined at the output using the same concept.

  19. 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.

  20. High-Speed Low Power Design in CMOS

    DEFF Research Database (Denmark)

    Ghani, Arfan; Usmani, S. H.; Stassen, Flemming

    2004-01-01

    Static CMOS design displays benefits such as low power consumption, dominated by dynamic power consumption. In contrast, MOS Current Mode Logic (MCML) displays static rather than dynamic power consumption. High-speed low-power design is one of the many application areas in VLSI that require...... the theorethical description of MOS Current Mode Logic, and it is found that it is more difficult to model and simulate the circuit with compare to standard CMOS because of the differential inputs and low voltage swing....

  1. The Quest for Ultimate Broadband High Power Microwaves

    CERN Document Server

    Podgorski, Andrew S

    2014-01-01

    Paper describes High Power Microwave research of combining GW peak power to achieve MV/m and GV/m radiated fields in 1 to 500 GHz band. To achieve such fields multiple independently triggered broadband GW sources, supplying power to multiple spatially distributed broadband radiators/antennas are used. Single TW array is used as an ultimate microwave weapon in 1 to 5 GHz range while multiple TW arrays provide GV/m radiating field at plasma frequencies in 300 GHz range leading to fusion power.

  2. A High Power Test Method for Pattern Magnet Power Supplies with Capacitor Banks

    Science.gov (United States)

    Kurimoto, Yoshinori; Morita, Yuichi; Sagawa, Ryu; Shimogawa, Tetsushi; Miura, Kazuki

    In the J-PARC Main Ring (MR), we plan to increase the beam intensity from 230 to 750 kW. To achieve this, the synchrotron repetition period must be shortened from 2.48 s to approximately 1 s using new power supplies for the main magnets. We are currently researching and developing new power supplies with large capacitor banks. Such banks are needed to reduce the power variation at the main grid in the J-PARC site for future operations with shorter repetition periods. However, it is very difficult to test the new power supplies at their rated power before installation. This is because the power handled by the power supplies used for the J-PARC MR main magnets is too high to be tested in factories or laboratories. To overcome this problem, we suggest a test method involving the use of two capacitor banks. In this method, two power supplies and a small inductive load are connected between two capacitor banks. By controlling the energy flow between the two capacitor banks in this setup, the received power and inductive load can be kept very small. This article describes the details of the control method and the results of the test experiment using a mini-model power supply.

  3. The Feasibility of TOFD Detection in Nuclear Power Conventional Island Pipeline Weld%超声衍射时差法用于核电站常规岛管道焊缝检测的可行性

    Institute of Scientific and Technical Information of China (English)

    惠维山; 钟华; 穆晓忠

    2016-01-01

    根据核电站常规岛管道焊缝施工特点,设计制作了带有人工缺陷的试块,对试块进行了超声衍射时差法(TOFD)、射线及超声检测,并对检测结果从检出率、缺陷定位、缺陷定量及缺陷评级等方面进行了对比分析。结果表明,TOFD方法在管道检测方面具有较高的可靠性。通过在工程现场进行TOFD和射线检测试验,表明TOFD方法在核电站常规岛中的应用是可行的。%According to the construction features of conventional island of nuclear power plant,test blocks with artificial defects were designed and manufactured.The TOFD,X-ray and conventional ultrasonic detection on the test block were performed.The detection results from the detection rate,defect location and quantification of defects and defect rating were compared and analyzed.Results show that the TOFD technique in pipeline detection is of high detection reliability.By means of TOFD and radiographic testing in engineering,the application of TOFD technology in conventional island of nuclear power plant is feasible.

  4. A high-power versatile wireless power transfer for biomedical implants.

    Science.gov (United States)

    Jiang, Hao; Zhang, Jun Min; Liou, Shy Shenq; Fechter, Richard; Hirose, Shinjiro; Harrison, Michael; Roy, Shuvo

    2010-01-01

    Implantable biomedical actuators are highly desired in modern medicine. However, how to power up these biomedical implants remains a challenge since most of them need more than several hundreds mW of power. The air-core based radio-frequency transformer (two face-to-face inductive coils) has been the only non-toxic and non-invasive power source for implants for the last three decades [1]. For various technical constraints, the maximum delivered power is limited by this approach. The highest delivered power reported is 275 mW over 1 cm distance [2]. Also, the delivered power is highly vulnerable to the coils' geometrical arrangement and the electrical property of the medium around them. In this paper, a novel rotating-magnets based wireless power transfer that can deliver ∼10 W over 1 cm is demonstrated. The delivered power is significantly higher than the existing start-of-art. Further, the new method is versatile since there is no need to have the impedance matching networks that are highly susceptible to the operating frequency, the coil arrangement and the environment.

  5. Beyond blue pico laser: development of high power blue and low power direct green

    Science.gov (United States)

    Vierheilig, Clemens; Eichler, Christoph; Tautz, Sönke; Lell, Alfred; Müller, Jens; Kopp, Fabian; Stojetz, Bernhard; Hager, Thomas; Brüderl, Georg; Avramescu, Adrian; Lermer, Teresa; Ristic, Jelena; Strauss, Uwe

    2012-03-01

    There is a big need on R&D concerning visible lasers for projection applications. The pico-size mobile projection on the one hand awaits the direct green lasers with sufficiently long lifetimes at optical powers above 50mW. In this paper we demonstrate R&D-samples emitting at 519nm with lifetimes up to 10.000 hours. The business projection on the other hand requires high power operation and already uses blue lasers and phosphor conversion, but there is a strong demand for higher power levels. We investigate the power limits of R&D laser structures. In continuous wave operation, the power is limited by thermal roll-over. With an excellent power conversion efficiency of up to 29% the thermal roll-over is as high as 2.5W for a single emitter in TO56 can. We do not observe significant leakage at high currents. Driven in short pulse operation to prevent the laser from self heating, linear laser characteristics of optical power versus electrical current are observed up to almost 8W of optical power.

  6. High-power lasers for directed-energy applications.

    Science.gov (United States)

    Sprangle, Phillip; Hafizi, Bahman; Ting, Antonio; Fischer, Richard

    2015-11-01

    In this article, we review and discuss the research programs at the Naval Research Laboratory (NRL) on high-power lasers for directed-energy (DE) applications in the atmosphere. Physical processes affecting propagation include absorption/scattering, turbulence, and thermal blooming. The power levels needed for DE applications require combining a number of lasers. In atmospheric turbulence, there is a maximum intensity that can be placed on a target that is independent of the initial beam spot size and laser beam quality. By combining a number of kW-class fiber lasers, scientists at the NRL have successfully demonstrated high-power laser propagation in a turbulent atmosphere and wireless recharging. In the NRL experiments, four incoherently combined fiber lasers having a total power of 5 kW were propagated to a target 3.2 km away. These successful high-power experiments in a realistic atmosphere formed the basis of the Navy's Laser Weapon System. We compare the propagation characteristics of coherently and incoherently combined beams without adaptive optics. There is little difference in the energy on target between coherently and incoherently combined laser beams for multi-km propagation ranges and moderate to high levels of turbulence. Unlike incoherent combining, coherent combining places severe constraints on the individual lasers. These include the requirement of narrow power spectral linewidths in order to have long coherence times as well as polarization alignment of all the lasers. These requirements are extremely difficult for high-power lasers.

  7. Atmospheric propagation and combining of high-power lasers.

    Science.gov (United States)

    Nelson, W; Sprangle, P; Davis, C C

    2016-03-01

    In this paper, we analyze beam combining and atmospheric propagation of high-power lasers for directed-energy (DE) applications. The large linewidths inherent in high-power fiber and slab lasers cause random phase and intensity fluctuations that occur on subnanosecond time scales. Coherently combining these high-power lasers would involve instruments capable of precise phase control and operation at rates greater than ∼10  GHz. To the best of our knowledge, this technology does not currently exist. This presents a challenging problem when attempting to phase lock high-power lasers that is not encountered when phase locking low-power lasers, for example, at milliwatt power levels. Regardless, we demonstrate that even if instruments are developed that can precisely control the phase of high-power lasers, coherent combining is problematic for DE applications. The dephasing effects of atmospheric turbulence typically encountered in DE applications will degrade the coherent properties of the beam before it reaches the target. Through simulations, we find that coherent beam combining in moderate turbulence and over multikilometer propagation distances has little advantage over incoherent combining. Additionally, in cases of strong turbulence and multikilometer propagation ranges, we find nearly indistinguishable intensity profiles and virtually no difference in the energy on the target between coherently and incoherently combined laser beams. Consequently, we find that coherent beam combining at the transmitter plane is ineffective under typical atmospheric conditions.

  8. Benefits of Nanostructuring Electrodes for High-Energy and High-Power Lithium Batteries

    Institute of Scientific and Technical Information of China (English)

    Joachim; Maier

    2007-01-01

    1 Results One of the greatest challenges for our society is providing powerful electrochemical energy storage devices with both high energy and high power densities. Rechargeable lithium-based batteries are amongst the most promising candidates in terms of energy density,the achievement of high power density is hindered by kinetic problems of the electrode materials.This contribution that emphasizes the power of nanostructuring for electrodes in lithium-based batteries,deals with several nanostructured ...

  9. High Power Room Temperature Terahertz Local Oscillator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to build a high-power, room temperature compact continuous wave terahertz local oscillator for driving heterodyne receivers in the 1-5 THz frequency...

  10. Mn based olivine electrode material with high power and energy.

    Science.gov (United States)

    Kim, Jongsoon; Seo, Dong-Hwa; Kim, Sung-Wook; Park, Young-Uk; Kang, Kisuk

    2010-02-28

    We report the Mn based olivine electrode material with high power and energy. Easier and more frequent nucleation by Fe and Co in Mn-based olivines significantly enhanced the rate capability as evidenced by the electrochemical results.

  11. High Power Uplink Amplifier for Deep Space Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Critical to the success of delivering on the promise of deep space optical communications is the creation of a stable and reliable high power multichannel optical...

  12. High Power Room Temperature Terahertz Local Oscillator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The motivation of the proposed SBIR is to develop, demonstrate and commercialize a compact, low-mass, high output power (1-10 milliwatt), tunable source of CW THz...

  13. High Power Uplink Amplifier for Deep Space Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Critical to the success of delivering on the promise of deep space optical communications is the creation of a stable and reliable high power multichannel optical...

  14. Very High Frequency Switch-Mode Power Supplies

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre

    The importance of technology and electronics in our daily life is constantly increasing. At the same time portability and energy efficiency are currently some of the hottest topics. This creates a huge need for power converters in a compact form factor and with high efficiency, which can supply...... these electronic devices. This calls for new technologies in order to miniaturize the power electronics of today. One way to do this is by increasing the switching frequency dramatically and develop very high frequency switch mode power supplies. If these converters can be designed to operate efficiently, a huge...... of technologies for very high frequency switch mode power supplies. At these highly elevated frequencies normal bulky magnetics with heavy cores consisting of rare earth materials, can be replaced by air core inductors embedded in the printed circuit board. This is investigated thoroughly and both spirals...

  15. High power laser-matter interaction

    CERN Document Server

    Mulser, Peter

    2010-01-01

    This book intended as a guide for scientists and students who have just discovered the field as a new and attractive area of research, and for scientists who have worked in another field and want to join now the subject of laser plasmas. In the first chapter the plasma dynamics is described phenomenologically by a two fluid model and similarity relations from dimensional analysis. Chapter 2 is devoted to plasma optics and collisional absorption in the dielectric and ballistic model. Linear resonance absorption at the plasma frequency and its mild nonlinearities as well as the self-quenching of high amplitude electron plasma waves by wave breaking are discussed in Chapter 3. With increasing laser intensity the plasma dynamics is dominated by radiation pressure, at resonance producing all kinds of parametric instabilities and out of resonance leading to density steps, self-focusing and filamentation, described in Chapters 4 and 5. A self-contained treatment of field ionization of atoms and related phenomena ar...

  16. Quantum-limit linkage of ‘strange’ and conventional metal states of high-T{sub c} superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Krusin-Elbaum, L., E-mail: krusin@sci.ccny.cuny.edu [Department of Physics, The City College of New York, NY 10031 (United States); Shibauchi, T. [Department of Physics, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); Kasahara, Y. [Quantum-Phase Electronics Center, University of Tokyo, Tokyo 113-8656 (Japan); Department of Physics, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); Okazaki, R.; Matsuda, Y. [Department of Physics, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); McDonald, R.D.; Mielke, C.H. [NHMFL, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Hasegawa, M. [Department of Materials Science and Engineering, Nagoya University, Chikusa-ku, Nagoya 464-8603 (Japan)

    2013-10-15

    Highlights: • High magnetic field transport in high-Tc cuprate superconductors. • Field-temperature-doping map of the pseudogap state. • Crossover from non-Fermi-liquid to the conventional Fermi liquid in the overdoped regime. • Strange metal regime and magnetic field dependent quantum critical point. -- Abstract: The key to the nature of superconducting pairing in high-T{sub c} cuprates lies in understanding the transition to a conventional behavior when they are heavily doped. By using high magnetic fields, we show that the pseudogapped Tl{sub 2}Ba{sub 2}CuO{sub 6+x} becomes a conventional metal at heavy doping in a quantum phase transition, where the pseudogap boundary develops a thermodynamic divergence corresponding to a zero entropy jump. The critical doping point downshifts with magnetic field in unison with the suppression of T{sub c}. This implies that quantum critical fluctuations and magnetic degrees that destabilize the pseudogap are linked to the superconductivity with high T{sub c}.

  17. High power transient characteristics and capability of NSRR

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Takehiko; Kashima, Yoichi; Yachi, Shigeyasu; Yoshinaga, Makio; Terakado, Yoshibumi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Katanishi, Shoji [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

    2002-03-01

    In order to study fuel behavior under abnormal transients and accidents, the control system of the Nuclear Safety Research Reactor (NSRR) of the Japan Atomic Energy Research Institute (JAERI) was modified to achieve high power transients. With this new operational mode, called Shaped Pulse (SP), transients at the maximum power of 10 MW can be conducted for a few seconds. This new operational mode supplements the previous Natural Pulse (NP) operation at the maximum power of 23 GW for milliseconds. For high power transient operation, a simulator using a point kinetic model was developed, and characteristics of the NSRR in the new operational mode were examined through tests and calculations. With the new operational mode, new types of fuel irradiation tests simulating power oscillations of boiling water reactors (BWRs) can be conducted in the NSRR. Reactor characteristics and capability, such as control rod worth, feedback reactivity, and operational limits of the NSRR for SP operations are discussed. (author)

  18. High-Power Electron Accelerators for Space (and other) Applications

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Dinh Cong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lewellen, John W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-23

    This is a presentation on high-power electron accelerators for space and other applications. The main points covered are: electron beams for space applications, new designs of RF accelerators, high-power HEMT testing, and battery design. In summary, we have considered a concept of 1-MeV electron accelerator that can operate up to several seconds. This concept can be extended to higher energy to produce higher beam power. Going to higher beam energy requires adding more cavities and solid-state HEMT RF power devices. The commercial HEMT have been tested for frequency response and RF output power (up to 420 W). And finally, we are testing these HEMT into a resonant load and planning for an electron beam test in FY17.

  19. A Switched Capacitor Based AC/DC Resonant Converter for High Frequency AC Power Generation

    Directory of Open Access Journals (Sweden)

    Cuidong Xu

    2015-09-01

    Full Text Available A switched capacitor based AC-DC resonant power converter is proposed for high frequency power generation output conversion. This converter is suitable for small scale, high frequency wind power generation. It has a high conversion ratio to provide a step down from high voltage to low voltage for easy use. The voltage conversion ratio of conventional switched capacitor power converters is fixed to n, 1/n or −1/n (n is the switched capacitor cell. In this paper, A circuit which can provide n, 1/n and 2n/m of the voltage conversion ratio is presented (n is stepping up the switched capacitor cell, m is stepping down the switching capacitor cell. The conversion ratio can be changed greatly by using only two switches. A resonant tank is used to assist in zero current switching, and hence the current spike, which usually exists in a classical switching switched capacitor converter, can be eliminated. Both easy operation and efficiency are possible. Principles of operation, computer simulations and experimental results of the proposed circuit are presented. General analysis and design methods are given. The experimental result verifies the theoretical analysis of high frequency AC power generation.

  20. High power, fast, microwave components based on beam generated plasmas

    Science.gov (United States)

    Manheimer, W. M.; Fernsler, R. F.; Gitlin, M. S.

    1998-10-01

    It is shown that the agile mirror plasma, under development as a device to simply and cheaply give electronic steering to microwave beams, also has application as a fast, electronically controlled, high power reflector, or phase shifter. In a radar system, this can lead to such applications as pulse to pulse polarization agility and electronic control of antenna gain, as well as to innovative approaches to high power millimeter wave circulators. The basic theory of the enhanced glow plasma is also developed.

  1. Thermally induced nonlinear mode coupling in high power fiber amplifiers

    DEFF Research Database (Denmark)

    Johansen, Mette Marie; Hansen, Kristian Rymann; Alkeskjold, Thomas T.;

    2013-01-01

    Thermally induced nonlinear mode coupling leads to transverse mode instability (TMI) in high power fiber amplifiers. A numerical model including altering mode profiles from thermal effects and waveguide perturbations predicts a TMI threshold of ~200W.......Thermally induced nonlinear mode coupling leads to transverse mode instability (TMI) in high power fiber amplifiers. A numerical model including altering mode profiles from thermal effects and waveguide perturbations predicts a TMI threshold of ~200W....

  2. High power laser downhole cutting tools and systems

    Energy Technology Data Exchange (ETDEWEB)

    Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

    2015-01-20

    Downhole cutting systems, devices and methods for utilizing 10 kW or more laser energy transmitted deep into the earth with the suppression of associated nonlinear phenomena. Systems and devices for the laser cutting operations within a borehole in the earth. These systems and devices can deliver high power laser energy down a deep borehole, while maintaining the high power to perform cutting operations in such boreholes deep within the earth.

  3. High power laser workover and completion tools and systems

    Science.gov (United States)

    Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

    2014-10-28

    Workover and completion systems, devices and methods for utilizing 10 kW or more laser energy transmitted deep into the earth with the suppression of associated nonlinear phenomena. Systems and devices for the laser workover and completion of a borehole in the earth. These systems and devices can deliver high power laser energy down a deep borehole, while maintaining the high power to perform laser workover and completion operations in such boreholes deep within the earth.

  4. Apparatus for advancing a wellbore using high power laser energy

    Science.gov (United States)

    Zediker, Mark S.; Land, Mark S.; Rinzler, Charles C.; Faircloth, Brian O.; Koblick, Yeshaya; Moxley, Joel F.

    2014-09-02

    Delivering high power laser energy to form a borehole deep into the earth using laser energy. Down hole laser tools, laser systems and laser delivery techniques for advancement, workover and completion activities. A laser bottom hole assembly (LBHA) for the delivery of high power laser energy to the surfaces of a borehole, which assembly may have laser optics, a fluid path for debris removal and a mechanical means to remove earth.

  5. High Thrust-to-Power Annular Engine Technology

    Science.gov (United States)

    Patterson, Michael J.; Thomas, Robert E.; Crofton, Mark W.; Young, Jason A.; Foster, John E.

    2015-01-01

    Gridded ion engines have the highest efficiency and total impulse of any mature electric propulsion technology, and have been successfully implemented for primary propulsion in both geocentric and heliocentric environments with excellent ground/in-space correlation of performance. However, they have not been optimized to maximize thrust-to-power, an important parameter for Earth orbit transfer applications. This publication discusses technology development work intended to maximize this parameter. These activities include investigating the capabilities of a non-conventional design approach, the annular engine, which has the potential of exceeding the thrust-to-power of other EP technologies. This publication discusses the status of this work, including the fabrication and initial tests of a large-area annular engine. This work is being conducted in collaboration among NASA Glenn Research Center, The Aerospace Corporation, and the University of Michigan.

  6. Modeling, fabrication and high power optical characterization of plasmonic waveguides

    DEFF Research Database (Denmark)

    Lavrinenko, Andrei; Lysenko, Oleg

    2015-01-01

    This paper describes modeling, fabrication and high power optical characterization of thin gold films embedded in silicon dioxide. The propagation vector of surface plasmon polaritons has been calculated by the effective index method for the wavelength range of 750-1700 nm and film thickness of 15......, 30 and 45 nm. The fabrication process of such plasmonic waveguides with width in the range of 1-100 μm and their quality inspection are described. The results of optical characterization of plasmonic waveguides using a high power laser with the peak power wavelength 1064 nm show significant deviation...

  7. High Temperature Superconductors for the Electric Power Grid

    Science.gov (United States)

    Malozemoff, Alexis P.

    2011-03-01

    High Temperature Superconductor power equipment is positioned to play a key role in addressing our national and global energy challenges. While the most obvious benefit is efficiency by using the superconductor's lossless current flow to cut the 10% power lost in the grid, other benefits are likely to be even more impactful. These benefits arise from the high current density of superconductor wire which enables design of highly power-dense and compact equipment including high capacity cables and rotating machinery -- generators and motors. Vast and dense urban areas are becoming home to an increasingly large proportion of world population, and high capacity ac superconductor cables offer a non-interfering and easily installed solution to increasing urban power needs. Longer term, the ultra-low loss of long-distance dc superconductor cables offers strengthened links and power sharing across wide geographical areas. Compact superconductor generators are the key to high power off-shore wind turbines, a major source of renewable energy. Some of these applications have reached a sophisticated level of demonstration, initiating commercial use.

  8. Development of Discrete Power Supply with Charge Pump Method for High Powered Sonar System

    Directory of Open Access Journals (Sweden)

    Kristian Ismail

    2012-07-01

    Full Text Available Power supply is one of the electronic devices that can provide electric energy for electronic systems or other systems. There are several types of power supplies that can be applied depend on the requirement and functions. One example is the use of power supply for sonar systems. Sonar system is a device which can be used to detect a target under water. The sonar system is an electronic circuit that requires a power supply with specific characteristics when the sonar functions as a transmitter and a receiver in the specific span time (when on and the specific lag time (when off. This paper discusses the design of power supply for high-powered sonar systems with discrete methods in which high power supply is only applied when the acoustic waves radiated under water. Charge pump was used to get the appropriate output voltage from lower input voltage. Charge pump utilized a combination of series and parallel connections of capacitors. The working mode of this power supply used the lag time as the calculation of time to charge charge pump capacitors in parallel while the span time was used for the calculation of discharging the charge pump capacitors in series.

  9. High Efficiency, High Linearity, Switch Mode Power Amplifiers for Varying envelop Signal Applications

    DEFF Research Database (Denmark)

    Tong, Tian; Sira, Daniel; Nielsen, Michael;

    2009-01-01

    using switch-mode power amplifier aided by various linearization techniques can present a feasible way to achieve both high linearity and high power efficiency. In this paper two different implementations of the switch-mode power amplifier a re p resented for varying envelop applications: the RF pulse...

  10. High-power laser source evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Back, C. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Decker, C. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Davis, J. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dixit, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Grun, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Managan, R. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Serduke, F. J. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Simonson, G. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Suter, L. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wuest, C. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ze, F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    1998-07-01

    Robust Nuclear-Weapons-Effects Testing (NWET) capability will be needed for the foreseeable future to ensure the performance and reliability, in nuclear environments, of the evolving U.S. stockpile of weapons and other assets. Ongoing research on the use of high-energy lasers to generate environments of utility in nuclear weapon radiation effects simulations is addressed in the work described in this report. Laser-driven hohlraums and a variety of other targets have been considered in an effort to develop NWET capability of the highest possible fidelity in above-ground experiments. The envelope of large-system test needs is shown as the gray region in fig. 1. It does not represent the spectrum of any device; it is just the envelope of the spectral region of outputs from a number of possible devices. It is a goal of our laser-only and ignition-capsule source development work to generate x rays that fall somewhere in this envelope. One of the earlier appearances of this envelope is in ref. 1. The Defense Special Weapons Agency provided important support for the work described herein. A total of $520K was provided in the 1997 IACROs 97-3022 for Source Development and 97-3048 for Facilitization. The period of performance specified in the Statement of Work ran from 28 February 1997 until 30 November 1997. This period was extended, by agreement with DSWA, for two reasons: 1) despite the stated period of performance, funds were not available at LLNL to begin this work until somewhat later in the fiscal year, and 2) we agreed to stretch the current resources until follow-on funds were in hand, to minimize effects of ramping down and up again. The tasks addressed in this report are the following: 1) Non-ignition-source model benchmarking and design. This involves analysis of existing and new data on laser-only sources to benchmark LASNEX predictions 2) Non-ignition-source development experiments 3) Ignition capsule design to improve total x-ray output and simplify target

  11. High-power laser source evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Back, C. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Decker, C. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Davis, J. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dixit, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Grun, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Managan, R. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Serduke, F. J. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Simonson, G. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Suter, L. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wuest, C. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ze, F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    1998-07-01

    Robust Nuclear-Weapons-Effects Testing (NWET) capability will be needed for the foreseeable future to ensure the performance and reliability, in nuclear environments, of the evolving U.S. stockpile of weapons and other assets. Ongoing research on the use of high-energy lasers to generate environments of utility in nuclear weapon radiation effects simulations is addressed in the work described in this report. Laser-driven hohlraums and a variety of other targets have been considered in an effort to develop NWET capability of the highest possible fidelity in above-ground experiments. The envelope of large-system test needs is shown as the gray region in fig. 1. It does not represent the spectrum of any device; it is just the envelope of the spectral region of outputs from a number of possible devices. It is a goal of our laser-only and ignition-capsule source development work to generate x rays that fall somewhere in this envelope. One of the earlier appearances of this envelope is in ref. 1. The Defense Special Weapons Agency provided important support for the work described herein. A total of $520K was provided in the 1997 IACROs 97-3022 for Source Development and 97-3048 for Facilitization. The period of performance specified in the Statement of Work ran from 28 February 1997 until 30 November 1997. This period was extended, by agreement with DSWA, for two reasons: 1) despite the stated period of performance, funds were not available at LLNL to begin this work until somewhat later in the fiscal year, and 2) we agreed to stretch the current resources until follow-on funds were in hand, to minimize effects of ramping down and up again. The tasks addressed in this report are the following: 1) Non-ignition-source model benchmarking and design. This involves analysis of existing and new data on laser-only sources to benchmark LASNEX predictions 2) Non-ignition-source development experiments 3) Ignition capsule design to improve total x-ray output and simplify target

  12. High-power diode-end-pumped Tm:YLF slab laser delivering 189 W at 1890 nm

    CSIR Research Space (South Africa)

    Koen, W

    2010-09-01

    Full Text Available The authors present a high-power Tm:YLF slab laser double-end-pumped by two 300 W laser diode stacks. The resonator was designed such that the laser emitted at 1890 nm instead of the conventional operating wavelength of 1912 nm. At full incident...

  13. The mechanical properties of high carbon steel wires drawn in conventional and hydrodynamic dies

    Directory of Open Access Journals (Sweden)

    M. Suliga

    2013-01-01

    Full Text Available In the paper the influence of the hydrodynamic die on mechanical properties has been assessed. The drawing process of φ 5,5 mm wires to the final wire of φ 2,5 mm was conducted in 7 passes, in industrial conditions, by means of a modern Koch multi-die drawing machine. The drawing speed in the last passes was 8,2 m/s. On the basis of numerical analyses wire drawing process, the redundant strain of wires has been determined. In the case of the wires drawn with hydrodynamic dies the increase of plasticity properties have been noted. It has been shown that the increase of strength properties in wires drawn with conventional die is related to the occurrence in their bigger redundant strain.

  14. Productivity, Profitability and Resource Use Efficiency: A Comparative Analysis between Conventional and High Yielding Rice in Rajbari District, Bangladesh

    Directory of Open Access Journals (Sweden)

    Md. Yahia Bapari

    2016-10-01

    Full Text Available The study was analyzed the determinants, costs and benefits and resources allocation of both conventional and high yielding rice cultivation over the Rajbari district of Bangladesh. Data were accumulated from 300 regular rice growers of conventional and high yielding varieties and random sampling technique was applied for selecting the respondents from the study area from which information was collected through pre-tested questionnaire. Cobb – Douglas production function and gross margin were mainly used to determine the productivities and profits of both rice and the marginal value of the product was highly recommended to derive the optimal use of the resources. Results obtained by applying ordinary least square method showed that the most important factors of production in the study area were irrigation, labor, fertilizer and insecticide costs whose elasticities were 0.904, 0.048, 0.045 and 0.044 respectively and insignificant factors were seed and ploughing costs whose elasticities were – 0.009 and 0.030 respectively for high yielding rice. On the other hand, irrigation, insecticide, seed and ploughing costs of elasticities 0.880, 0.589, 0.116 and – 0.127 respectively were the important factors and minor role playing factors were labor and fertilizer costs whose elasticities were 0.098 and 0.077 respectively for conventional yielding rice. The core message from productivity analysis was that the irrigation was key variable which played a positive and vital role in producing rice of both varieties. All variables (resources were economically misallocated in the production activities of both varieties along the study area but high yielding rice was more profitable than conventional one. Results also showed that the farmers of the study area produced rice of both varieties in the inefficient range of production. Continuous supply of electricity, flexible credit and improving the existing resources were the prime policy recommendations of

  15. High-resolution MR imaging of triangular fibrocartilage complex (TFCC): comparison of microscopy coils and a conventional small surface coil

    Energy Technology Data Exchange (ETDEWEB)

    Yoshioka, Hiroshi [Department of Radiology, University of Tsukuba, Tsukuba (Japan); Department of Radiology, Brigham and Women' s Hospital, 75 Francis Street, 02115, Boston, MA (United States); Ueno, Teruko; Itai, Yuji [Department of Radiology, University of Tsukuba, Tsukuba (Japan); Tanaka, Toshikazu [Department of Orthopedic Surgery, Tsukuba Kinen Hospital, Tsukuba (Japan); Shindo, Masashi [Tsukuba University Hospital, Tsukuba (Japan)

    2003-10-01

    To compare MR images of the triangular fibrocartilage complex (TFCC) using microscopy coils with those using a conventional surface coil qualitatively and quantitatively. Proton density-weighted images and T2*-weighted images of the TFCC from ten normal volunteers were obtained with a conventional surface coil (C4 coil; 80 mm in diameter), a 47-mm microscopy surface coil and a 23-mm microscopy surface coil at 1.5 T. Qualitative image analysis of MR images with three coils was performed by two radiologists who assigned one of five numerical scores (0, nonvisualization; 1, poor; 2, average; 3, good; 4, excellent) for five TFCC components, which were disc proper, triangular ligament, meniscus homologue, ulnotriquetral and ulnolunate ligament. Quantitative analysis included the signal-to-noise ratio (S/N) of the disc proper of TFCC, the lunate cartilage, the lunate bone and the contrast-noise-ratio (C/N) between articular cartilage and disc proper or bone marrow were measured. All structures show higher scores qualitatively on MR with microscopy coils than those with a C4 coil, and the difference was significant with the exception of the ulnolunate ligament. MR with microscopy coils showed significantly higher S/N values than those with a conventional surface coil (P<0.05 to P<0.001). T2*-weighted images using microscopy coils showed significantly higher cartilage-disc proper C/N and cartilage-bone marrow C/N (P<0.01 to P<0.001). On proton density-weighted images, the C/N between cartilage and disc proper with two microscopy coils was significantly higher (P<0.01) than that with a conventional coil. High-resolution MR images of the normal wrist using microscopy coils were superior to those using a conventional surface coil qualitatively and quantitatively. High-resolution MR imaging with a microscopy coil would be a promising method to diagnose TFCC lesions. (orig.)

  16. Uppsala High Power Test Stand for ESS Spoke Cavities

    CERN Document Server

    Yogi, RA; Dancila, D; Gajewski, K; Hermansson, L; Noor, M; Wedberg, R; Santiago-Kern, R; Ekelöf, T; Lofnes, T; Ziemann, V; Goryashko, V; Ruber, R

    2013-01-01

    The European Spallation Source (ESS) is one of the world’s most powerful neutron source. The ESS linac will accelerate 50mA pulse current of protons to 2.5GeV in 2.86 ms long pulses at a repetition rate of 14 Hz. It produces a beam with 5MW average power and 125MW peak power. ESS Spoke Linac consist of 28 superconducting spoke cavities, which will be developed by IPN Orsay, France. These Spoke Cavities will be tested at low power at IPN Orsay and high power testing will be performed in a high power test stand at Uppsala University. The test stand consists of tetrode based RF amplifier chain (352MHz, 350 kW) power and related RF distribution. Outputs of two tetrodes shall be combined with the hybrid coupler to produce 350 kW power. Preamplifier for a tetrode shall be solid state amplifier. As the spoke cavities are superconducting, the test stand also includes horizontal cryostat, Helium liquefier, test bunker etc. The paper describes features of the test stand in details.

  17. Advanced, High Power, Next Scale, Wave Energy Conversion Device

    Energy Technology Data Exchange (ETDEWEB)

    Mekhiche, Mike [Principal Investigator; Dufera, Hiz [Project Manager; Montagna, Deb [Business Point of Contact

    2012-10-29

    The project conducted under DOE contract DE‐EE0002649 is defined as the Advanced, High Power, Next Scale, Wave Energy Converter. The overall project is split into a seven‐stage, gated development program. The work conducted under the DOE contract is OPT Stage Gate III work and a portion of Stage Gate IV work of the seven stage product development process. The project effort includes Full Concept Design & Prototype Assembly Testing building on our existing PowerBuoy technology to deliver a device with much increased power delivery. Scaling‐up from 150kW to 500kW power generating capacity required changes in the PowerBuoy design that addressed cost reduction and mass manufacturing by implementing a Design for Manufacturing (DFM) approach. The design changes also focused on reducing PowerBuoy Installation, Operation and Maintenance (IO&M) costs which are essential to reducing the overall cost of energy. In this design, changes to the core PowerBuoy technology were implemented to increase capability and reduce both CAPEX and OPEX costs. OPT conceptually envisaged moving from a floating structure to a seabed structure. The design change from a floating structure to seabed structure would provide the implementation of stroke‐ unlimited Power Take‐Off (PTO) which has a potential to provide significant power delivery improvement and transform the wave energy industry if proven feasible.

  18. Design Challenges in High Power Free-Electron Laser Oscillators

    CERN Document Server

    Benson, S V

    2005-01-01

    Several FELs have now demonstrated high power lasing and several projects are under construction to deliver higher power or shorter wavelengths. This presentation will summarize progress in upgrading FEL oscillators towards higher power and will discuss some of the challenges these projects face. The challenges fall into three categories: 1. energy recovery with large exhaust energy spread, 2. output coupling and maintaining mirror figure in the presence of high intracavity power loading, and 3. high current operation in an energy recovery linac (ERL). Progress in all three of these areas has been made in the last year. Energy recovery of over 12% of exhaust energy spread has been demonstrated and designs capable of accepting even larger energy spreads have been proposed. Cryogenic transmissive output couplers for narrow band operation and both hole and scraper output coupling have been developed. Investigation of short Rayleigh range operation has started as well. Energy recovery of over 20 mA CW has been de...

  19. Water Vapour Propulsion Powered by a High-Power Laser-Diode

    Science.gov (United States)

    Minami, Y.; Uchida, S.

    Most of the laser propulsion schemes now being proposed and developed assume neither power supplies nor on-board laser devices and therefore are bound to remote laser stations like a kite via a laser beam “string”. This is a fatal disadvantage for a space vehicle that flies freely though it is often said that no need of installing an energy source is an advantage of a laser propulsion scheme. The possibility of an independent laser propulsion space vehicle that carries a laser source and a power supply on board is discussed. This is mainly due to the latest development of high power laser diode (LD) technology. Both high specific impulse-low thrust mode and high thrust-low specific impulse mode can be selected by controlling the laser output by using vapour or water as a propellant. This mode change can be performed by switching between a high power continuous wave (cw), LD engine for high thrust with a low specific impulse mode and high power LD pumping Q-switched Nd:YAG laser engine for low thrust with the high specific impulse mode. This paper describes an Orbital Transfer Vehicle equipped with the above-mentioned laser engine system and fuel cell that flies to the Moon from a space platform or space hotel in Earth orbit, with cargo shipment from lunar orbit to the surface of the Moon, including the possibility of a sightseeing trip.

  20. High Efficiency, High Temperature Foam Core Heat Exchanger for Fission Surface Power Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Fission-based power systems are anticipated for various planetary surface human base applications with power levels of 30?100+ kWe. The development of high...

  1. High Performance Plasma Channel Insulators for High Power Hall Thrusters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA missions for planetary exploration require high power, long-life Hall thrusters. However, thruster power and lifetime are limited by the erosion of plasma...

  2. High Performance Plasma Channel Insulators for High Power Hall Thrusters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA missions for planetary exploration require high power, long-life Hall thrusters. However, thruster power and lifetime are limited by the erosion of plasma...

  3. Waveguide Power Combiner Demonstration for Multiple High Power Millimeter Wave TWTAs

    Science.gov (United States)

    Wintucky, Edwin G.; Simons, Rainee N.; Lesny, Gary G.; Glass, Jeffrey L.

    2004-01-01

    NASA is presently developing nuclear reactor technologies, under Project Prometheus, which will provide spacecraft with greatly increased levels of sustained onboard power and thereby dramatically enhance the capability for future deep space exploration. The first mission planned for use of this high power technology is the Jupiter Icy Moons Orbiter (JIMO). In addition to electric propulsion and science, there will also be unprecedented onboard power available for deep space communications. A 32 GHz transmitter with 1 kW of RF output power is being considered to enable the required very high data transmission rates. One approach to achieving the 1 kW RF power, now being investigated at NASA GRC, is the possible power combining of a number of 100-1 50 W TWTs now under development. The work presented here is the results of a proof-of-concept demonstration of the power combining Ka-band waveguide circuit design and test procedure using two Ka- band TWTAs (Varian model VZA6902V3 and Logimetrics model A440/KA-1066), both of which were previously employed in data uplink evaluation terminals at 29.36 GHz for the NASA Advanced Communications Technology Satellite (ACTS) program. The characterization of the individual TWTAs and power combining demonstration were done over a 500 MHz bandwidth from 29.1 to 29.6 GHz to simulate the Deep Space Network (DSN) bandwidth of 3 1.8 to 32.3 GHz. Figures 1-3 show some of the power transfer and gain measurements of the TWTAs using a swept signal generator (Agilent 83640b) for the RF input. The input and output powers were corrected for circuit insertion losses due to the waveguide components. The RF saturated powers of both ACTS TWTAs were on the order of 120 W, which is comparable to the expected output powers of the 32 GHz TWTs. Additional results for the individual TWTAs will be presented (AM/AM, AM/PM conversion and gain compression), some of which were obtained from swept frequency and power measurements using a vector network

  4. High output power electric motors with bulk HTS elements

    Science.gov (United States)

    Kovalev, L. K.; Ilushin, K. V.; Kovalev, K. L.; Penkin, V. T.; Poltavets, V. N.; Koneev, S. M.-A.; Akimov, I. I.; Gawalek, W.; Oswald, B.; Krabbes, G.

    2003-04-01

    New types of electric machines with the rotors containing bulk HTS (YBCO and Bi-Ag) elements are presented. Different schematics of hysteresis, reluctance, “trapped field” and composed synchronous HTS machines are discussed. The two-dimensional mathematical models describing the processes in such types of HTS machines were developed on the basis of the theoretical analysis of the electrodynamic and hysteresis processes in the single-domain and polycrystal YBCO ceramic samples and plate shape Bi-Ag elements. The test results of the series of hysteresis, reluctance, “trapped field” and composed with permanent magnets HTS motors with output power rating 0.1-18 kW and current frequency 50 and 400 Hz are given. These results show that in the media of liquid nitrogen the specific output power per one weight unit of HTS motors is 4-7 times better than for conventional electric machines. Comparison of the theoretical and experimental characteristics of the developed HTS motors show that they are in good agreement. The test results for liquid nitrogen cryogenic pump system with hysteresis 500 W HTS motor are discussed. The designs and first test results of HTS motor operating in the media of liquid nitrogen with output power 100 kW and power factor more than 0.8 are given. Future development and applications of new types of HTS motors for aerospace technology, on-land industry and transport systems are discussed.

  5. Design of measurement equipment for high power laser beam shapes

    DEFF Research Database (Denmark)

    Hansen, K. S.; Olsen, F. O.; Kristiansen, Morten

    2013-01-01

    To analyse advanced high power beam patterns, a method, which is capable of analysing the intensity distribution in 3D is needed. Further a measuring of scattered light in the same system is preferred. This requires a high signal to noise ratio. Such a system can be realised by a CCD-chip impleme......To analyse advanced high power beam patterns, a method, which is capable of analysing the intensity distribution in 3D is needed. Further a measuring of scattered light in the same system is preferred. This requires a high signal to noise ratio. Such a system can be realised by a CCD...

  6. Influence of load by high power on the optical coupler

    Science.gov (United States)

    Bednarek, Lukas; Poboril, Radek; Vanderka, Ales; Hajek, Lukas; Nedoma, Jan; Vasinek, Vladimir

    2016-12-01

    Nowadays, aging of the optical components is a very current topic. Therefore, some investigations are focused on this area, so that the aging of the optical components is accelerated by thermal, high power and gamma load. This paper deals by findings of the influence of the load by laser with high optical power on the transmission parameters of the optical coupler. The investigated coupler has one input and eight outputs (1x8). Load by laser with high optical power is realized using a fiber laser with a cascade configuration EDFA amplifiers. The output power of the amplifier is approximately 250 mW. Duration of the load is moving from 104 hours to 139 hours. After each load, input power and output powers of all branches are measured. Following parameters of the optical coupler are calculated using formulas: the insertion losses of the individual branches, split ratio, total losses, homogeneity of the losses and cross-talk between different branches. All measurements are performed at wavelengths 1310 nm and 1550 nm. Individual optical powers are measured 20 times, due to the exclusion of statistical error of the measurement. After measuring, the coupler is connected to the amplifier for next cycle of the load. The paper contains an evaluation of the results of the coupler before and after four cycles of the burden.

  7. Progress at SLAC on high-power rf pulse compression

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, P.B.; Farkas, Z.D.; Lavine, T.L.; Menegat, A.; Nantista, C.; Ruth, R.D. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Kroll, N.M. [Stanford Linear Accelerator Center, Menlo Park, CA (United States)]|[California Univ., San Diego, La Jolla, CA (United States). Dept. of Physics

    1992-06-01

    Rf pulse compression is a technique for augmenting the peak power output of a klystron (typically 50--100 MW) to obtain the high peak power required to drive a linear collider at a high accelerating gradient (typically 200 MW/m is required for a gradient of 100 MV/m). The SLED pulse compression system, with a power gain of about 2.6, has been operational on the SLAC linac for more than a decade. Recently, a binary pulse-compression system with a power gain of about 5.2 has been tested up to an output power of 120 MW. Further high-power tests are in progress. Our current effort is focused on prototyping a so-called SLED-II pulse-compression system with a power gain of four. Over-moded TE{sub 01}-mode circular waveguide components, some with novel technical features, are used to reduce losses at the 11.4-GHz operating frequency.

  8. Progress at SLAC on high-power rf pulse compression

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, P.B.; Farkas, Z.D.; Lavine, T.L.; Menegat, A.; Nantista, C.; Ruth, R.D. (Stanford Linear Accelerator Center, Menlo Park, CA (United States)); Kroll, N.M. (Stanford Linear Accelerator Center, Menlo Park, CA (United States) California Univ., San Diego, La Jolla, CA (United States). Dept. of Physics)

    1992-06-01

    Rf pulse compression is a technique for augmenting the peak power output of a klystron (typically 50--100 MW) to obtain the high peak power required to drive a linear collider at a high accelerating gradient (typically 200 MW/m is required for a gradient of 100 MV/m). The SLED pulse compression system, with a power gain of about 2.6, has been operational on the SLAC linac for more than a decade. Recently, a binary pulse-compression system with a power gain of about 5.2 has been tested up to an output power of 120 MW. Further high-power tests are in progress. Our current effort is focused on prototyping a so-called SLED-II pulse-compression system with a power gain of four. Over-moded TE[sub 01]-mode circular waveguide components, some with novel technical features, are used to reduce losses at the 11.4-GHz operating frequency.

  9. High Rhine power plant Rheinfelden and hydroelectric power in Germany; Hochrheinkraftwerk Rheinfelden und Wasserkraft in Deutschland

    Energy Technology Data Exchange (ETDEWEB)

    Mazurkiewicz, Jacek [EnBW Energie Baden-Wuerttemberg AG, Karlsruhe (Germany)

    2011-10-15

    In Germany, electric energy had been generated from water power since 1880; in the beginning, it was a dominating factor along with energy generation from coal, but it lost its importance as from 1950 when crude oil, natural gas and nuclear power became dominant. Since 1991, however, many small hydroelectric power plants have again been put into operation, or have been newly built, as a consequence of the government aids granted. In the Hochrhein (High Rhine) region, the German-Swiss power plant Rheinfelden was reconstructed, and other major hydroelectric power plants are being modernized. Technically, a much greater potential could be used, but this is currently not practicable for economical and ecological reasons. (orig.)

  10. Evaluation of purity with its uncertainty value in high purity lead stick by conventional and electro-gravimetric methods

    OpenAIRE

    Singh, Nahar; SINGH, Niranjan; Tripathy, S Swarupa; Soni, Daya; Singh, Khem; GUPTA Prabhat K

    2013-01-01

    Background A conventional gravimetry and electro-gravimetry study has been carried out for the precise and accurate purity determination of lead (Pb) in high purity lead stick and for preparation of reference standard. Reference materials are standards containing a known amount of an analyte and provide a reference value to determine unknown concentrations or to calibrate analytical instruments. A stock solution of approximate 2 kg has been prepared after dissolving approximate 2 g of Pb stic...

  11. High-Efficiency Ka-Band Waveguide Two-Way Asymmetric Power Combiner

    Science.gov (United States)

    Wintucky, E. G.; Simons, R. N.; Freeman, J. C.; Chevalier, C. T.

    2011-01-01

    NASA is planning a number of Space Exploration, Earth Observation and Space Science missions where Ka-band solid-state power amplifiers (SSPAs) could have a role. Monolithic microwave integrated circuit (MMIC) based SSPAs with output powers on the order of 10 W at Ka-band frequencies would be adequate to satisfy the data transmission rate requirements at the distances involved. MMICs are a type of integrated circuit fabricated on a GaAs wafer, which operates at micro wave frequencies and performs the function of signal amplification. The highest power Ka-band (31.8 to 32.3 GHz) SSPA to have flown in space had an output power of 2.6 W with an overall efficiency of 14.3 percent. This SSPA was built around discrete GaAs pHEMT (high electron mobility transistor) devices and flew aboard the Deep Space One spacecraft. State-of-the-art GaAs pHEMT-based MMIC power amplifiers (PAs) can deliver RF power at Ka-band frequencies anywhere from 3 W with a power added efficiency (PAE) of 32 percent to 6 W with a PAE of 26 percent. However, to achieve power levels higher than 6 W, the output of several MMIC PAs would need to be combined using a high-efficiency power combiner. Conventional binary waveguide power combiners, based on short-slot and magic-T circuits, require MMIC PAs with identical amplitude and phase characteristics for high combining efficiency. However, due to manufacturing process variations, the output powers of the MMIC PAs tend to be unequal, and hence the need to develop unequal power combiners. A two-way asymmetric magic-T based power combiner for MMIC power amplifiers, which can take in unequal inputs, has been successfully designed, fabricated, and characterized over NASA s Deep Space Network (DSN) frequency range of 31.8 to 32.3 GHz. The figure is a transparent view of the a sym - metric combiner that shows the 4-port configuration and the internal structure. The rod, post, and iris are positioned by design to achieve the desired asymmetric power ratio

  12. Toxicological properties of emission particles from heavy duty engines powered by conventional and bio-based diesel fuels and compressed natural gas

    Science.gov (United States)

    2012-01-01

    Background One of the major areas for increasing the use of renewable energy is in traffic fuels e.g. bio-based fuels in diesel engines especially in commuter traffic. Exhaust emissions from fossil diesel fuelled engines are known to cause adverse effects on human health, but there is very limited information available on how the new renewable fuels may change the harmfulness of the emissions, especially particles (PM). We evaluated the PM emissions from a heavy-duty EURO IV diesel engine powered by three different fuels; the toxicological properties of the emitted PM were investigated. Conventional diesel fuel (EN590) and two biodiesels were used − rapeseed methyl ester (RME, EN14214) and hydrotreated vegetable oil (HVO) either as such or as 30% blends with EN590. EN590 and 100% HVO were also operated with or without an oxidative catalyst (DOC + POC). A bus powered by compressed natural gas (CNG) was included for comparison with the liquid fuels. However, the results from CNG powered bus cannot be directly compared to the other situations in this study. Results High volume PM samples were collected on PTFE filters from a constant volume dilution tunnel. The PM mass emission with HVO was smaller and with RME larger than that with EN590, but both biofuels produced lower PAH contents in emission PM. The DOC + POC catalyst greatly reduced the PM emission and PAH content in PM with both HVO and EN590. Dose-dependent TNFα and MIP-2 responses to all PM samples were mostly at the low or moderate level after 24-hour exposure in a mouse macrophage cell line RAW 264.7. Emission PM from situations with the smallest mass emissions (HVO + cat and CNG) displayed the strongest potency in MIP-2 production. The catalyst slightly decreased the PM-induced TNFα responses and somewhat increased the MIP-2 responses with HVO fuel. Emission PM with EN590 and with 30% HVO blended in EN590 induced the strongest genotoxic responses, which were significantly greater than

  13. Toxicological properties of emission particles from heavy duty engines powered by conventional and bio-based diesel fuels and compressed natural gas.

    Science.gov (United States)

    Jalava, Pasi I; Aakko-Saksa, Päivi; Murtonen, Timo; Happo, Mikko S; Markkanen, Ari; Yli-Pirilä, Pasi; Hakulinen, Pasi; Hillamo, Risto; Mäki-Paakkanen, Jorma; Salonen, Raimo O; Jokiniemi, Jorma; Hirvonen, Maija-Riitta

    2012-09-29

    One of the major areas for increasing the use of renewable energy is in traffic fuels e.g. bio-based fuels in diesel engines especially in commuter traffic. Exhaust emissions from fossil diesel fuelled engines are known to cause adverse effects on human health, but there is very limited information available on how the new renewable fuels may change the harmfulness of the emissions, especially particles (PM). We evaluated the PM emissions from a heavy-duty EURO IV diesel engine powered by three different fuels; the toxicological properties of the emitted PM were investigated. Conventional diesel fuel (EN590) and two biodiesels were used - rapeseed methyl ester (RME, EN14214) and hydrotreated vegetable oil (HVO) either as such or as 30% blends with EN590. EN590 and 100% HVO were also operated with or without an oxidative catalyst (DOC + POC). A bus powered by compressed natural gas (CNG) was included for comparison with the liquid fuels. However, the results from CNG powered bus cannot be directly compared to the other situations in this study. High volume PM samples were collected on PTFE filters from a constant volume dilution tunnel. The PM mass emission with HVO was smaller and with RME larger than that with EN590, but both biofuels produced lower PAH contents in emission PM. The DOC + POC catalyst greatly reduced the PM emission and PAH content in PM with both HVO and EN590. Dose-dependent TNFα and MIP-2 responses to all PM samples were mostly at the low or moderate level after 24-hour exposure in a mouse macrophage cell line RAW 264.7. Emission PM from situations with the smallest mass emissions (HVO + cat and CNG) displayed the strongest potency in MIP-2 production. The catalyst slightly decreased the PM-induced TNFα responses and somewhat increased the MIP-2 responses with HVO fuel. Emission PM with EN590 and with 30% HVO blended in EN590 induced the strongest genotoxic responses, which were significantly greater than those with EN590

  14. Toxicological properties of emission particles from heavy duty engines powered by conventional and bio-based diesel fuels and compressed natural gas

    Directory of Open Access Journals (Sweden)

    Jalava Pasi I

    2012-09-01

    Full Text Available Abstract Background One of the major areas for increasing the use of renewable energy is in traffic fuels e.g. bio-based fuels in diesel engines especially in commuter traffic. Exhaust emissions from fossil diesel fuelled engines are known to cause adverse effects on human health, but there is very limited information available on how the new renewable fuels may change the harmfulness of the emissions, especially particles (PM. We evaluated the PM emissions from a heavy-duty EURO IV diesel engine powered by three different fuels; the toxicological properties of the emitted PM were investigated. Conventional diesel fuel (EN590 and two biodiesels were used − rapeseed methyl ester (RME, EN14214 and hydrotreated vegetable oil (HVO either as such or as 30% blends with EN590. EN590 and 100% HVO were also operated with or without an oxidative catalyst (DOC + POC. A bus powered by compressed natural gas (CNG was included for comparison with the liquid fuels. However, the results from CNG powered bus cannot be directly compared to the other situations in this study. Results High volume PM samples were collected on PTFE filters from a constant volume dilution tunnel. The PM mass emission with HVO was smaller and with RME larger than that with EN590, but both biofuels produced lower PAH contents in emission PM. The DOC + POC catalyst greatly reduced the PM emission and PAH content in PM with both HVO and EN590. Dose-dependent TNFα and MIP-2 responses to all PM samples were mostly at the low or moderate level after 24-hour exposure in a mouse macrophage cell line RAW 264.7. Emission PM from situations with the smallest mass emissions (HVO + cat and CNG displayed the strongest potency in MIP-2 production. The catalyst slightly decreased the PM-induced TNFα responses and somewhat increased the MIP-2 responses with HVO fuel. Emission PM with EN590 and with 30% HVO blended in EN590 induced the strongest genotoxic responses, which were

  15. Effect of Additives on Magnetic Properties of High Frequency MnZn Power Ferrite

    Institute of Scientific and Technical Information of China (English)

    YU Zhong; LAN Zhongwen; WANG Jingmei; ZHANG Yidong; WANG Haocai

    2004-01-01

    The effect of additives,such as CaO and V2O5 on the magnetic properties of high frequency MnZn power ferrite is studied by the conventional ceramic process.As a result,the grain boundary resistivity increases and the power loss declines with the addition of CaO enriched at the grain boundary.By adding an optimum amount of V2O5 which acts indirectly via liquid phase formation and influences the microstructural development during sintering,the crystalline grain of ferrite was refined,the porosity decreases,the amount of grain boundary and the grain boundary resistivity increased,so the power loss is suppressed.

  16. Applications of high power lasers. [using reflection holograms for machining and surface treatment

    Science.gov (United States)

    Angus, J. C.

    1979-01-01

    The use of computer generated, reflection holograms in conjunction with high power lasers for precision machining of metals and ceramics was investigated. The Reflection holograms which were developed and made to work at both optical wavelength (He-Ne, 6328 A) and infrared (CO2, 10.6) meet the primary practical requirement of ruggedness and are relatively economical and simple to fabricate. The technology is sufficiently advanced now so that reflection holography could indeed be used as a practical manufacturing device in certain applications requiring low power densities. However, the present holograms are energy inefficient and much of the laser power is lost in the zero order spot and higher diffraction orders. Improvements of laser machining over conventional methods are discussed and addition applications are listed. Possible uses in the electronics industry include drilling holes in printed circuit boards making soldered connections, and resistor trimming.

  17. Integration of electric drive vehicles in the Danish electricity network with high wind power penetration

    DEFF Research Database (Denmark)

    Chandrashekhara, Divya K; Østergaard, Jacob; Larsen, Esben

    2010-01-01

    /conventional) which are likely to fuel these cars. The study was carried out considering the Danish electricity network state around 2025, when the EDV penetration levels would be significant enough to have an impact on the power system. Some of the interesting findings of this study are - EDV have the potential......This paper presents the results of a study carried out to examine the feasibility of integrating electric drive vehicles (EDV) in the Danish electricity network which is characterised by high wind power penetration. One of the main aims of this study was to examine the effect of electric drive...... vehicles on the Danish electricity network, wind power penetration and electricity market. In particular the study examined the effect of electric drive vehicles on the generation capacity constraints, load curve, cross border transmission capacity and the type of generating sources (renewable...

  18. Improving Switching Performance of Power MOSFETs Used in High Rep-Rate, Short Pulse, High-Power Pulsers

    Energy Technology Data Exchange (ETDEWEB)

    Cook, E G

    2006-09-19

    As their switching and power handling characteristics improve, solid-state devices are finding new applications in pulsed power. This is particularly true of applications that require fast trains of short duration pulses. High voltage (600-1200V) MOSFETs are especially well suited for use in these systems, as they can switch at significant peak power levels and are easily gated on and off very quickly. MOSFET operation at the shortest pulse durations is not constrained by the intrinsic capabilities of the MOSFET, but rather by the capabilities of the gate drive circuit and the system physical layout. This project sought to improve MOSFET operation in a pulsed power context by addressing these issues. The primary goal of this project is to improve the switching performance of power MOSFETs for use in high rep-rate, short pulse, high-power applications by improving the design of the gate drive circuits and the circuit layouts used in these systems. This requires evaluation of new commercial gate drive circuits and upgrading the designs of LLNL-developed circuits. In addition, these circuits must be tested with the fastest available high-voltage power MOSFETs.

  19. HIGH EFFICIENCY FOSSIL POWER PLANT (HEFPP) CONCEPTUALIZATION PROGRAM

    Energy Technology Data Exchange (ETDEWEB)

    J.L. Justice

    1999-03-25

    This study confirms the feasibility of a natural gas fueled, 20 MW M-C Power integrated pressurized molten carbonate fuel cell combined in a topping cycle with a gas turbine generator plant. The high efficiency fossil power plant (HEFPP) concept has a 70% efficiency on a LHV basis. The study confirms the HEFPP has a cost advantage on a cost of electricity basis over the gas turbine based combined cycle plants in the 20 MW size range. The study also identifies the areas of further development required for the fuel cell, gas turbine generator, cathode blower, inverter, and power module vessel. The HEFPP concept offers an environmentally friendly power plant with minuscule emission levels when compared with the combined cycle power plant.

  20. High voltage direct current modelling in optimal power flows

    Energy Technology Data Exchange (ETDEWEB)

    Ambriz-Perez, H. [Comision Federal de Electricidad, Mexico, Unidad de Ingenieria Especializada, Rio Rodano No. 14 - Piso 10, Sala 1002, Col. Cuauhtemoc, C.P. 06598, Mexico, D.F. (Mexico); Acha, E. [Department of Electronics and Electrical Engineering, University of Glasgow, Glasgow G128LT, Scotland (United Kingdom); Fuerte-Esquivel, C.R. [Faculty of Electrical Engineering, Universidad Michoacana de San Nicolas de Hidalgo, Morelia 58030, Michoacan (Mexico)

    2008-03-15

    Two-terminal high voltage direct current (HVDC) transmission links are in operation throughout the world. They are key elements in electrical power networks; their representation is oversimplified or ignored in most power system studies. This is particularly the case in Optima Power Flow (OPF) studies. Hence, an OPF program has been extended to incorporate HVDC links, taking due account of overlapping and power transfer control characteristics. This is a new development in Newton Optimal Power Flows, where the converter equations are included directly in the matrix W. The method is indeed a unified one since the solution vector is extended to accommodate the DC variables. The HVDC link model correctly takes into account the relevant DC limit variables. The impact of HVDC links on OPF studies is illustrated by numeric examples, which includes a 5-node system, the AEP 14-node and a 166-node system. (author)

  1. High Power High Thrust Ion Thruster (HPHTion): 50 CM Ion Thruster for Near-Earth Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advances in high power, photovoltaic technology has enabled the possibility of reasonably sized, high specific power, high power, solar arrays. At high specific...

  2. Reviews of a Diode-Pumped Alkali Laser (DPAL): a potential high powered light source

    Science.gov (United States)

    Cai, He; Wang, You; Han, Juhong; An, Guofei; Zhang, Wei; Xue, Liangping; Wang, Hongyuan; Zhou, Jie; Gao, Ming; Jiang, Zhigang

    2015-03-01

    Diode pumped alkali vapor lasers (DPALs) were first developed by in W. F. Krupke at the beginning of the 21th century. In the recent years, DPALs have been rapidly developed because of their high Stokes efficiency, good beam quality, compact size and near-infrared emission wavelengths. The Stokes efficiency of a DPAL can achieve a miraculous level as high as 95.3% for cesium (Cs), 98.1% for rubidium (Rb), and 99.6% for potassium (K), respectively. The thermal effect of a DPAL is theoretically smaller than that of a normal diode-pumped solid-state laser (DPSSL). Additionally, generated heat of a DPAL can be removed by circulating the gases inside a sealed system. Therefore, the thermal management would be relatively simple for realization of a high-powered DPAL. In the meantime, DPALs combine the advantages of both DPSSLs and normal gas lasers but evade the disadvantages of them. Generally, the collisionally broadened cross sections of both the D1 and the D2 lines for a DPAL are much larger than those for the most conventional solid-state, fiber and gas lasers. Thus, DPALs provide an outstanding potentiality for realization of high-powered laser systems. It has been shown that a DPAL is now becoming one of the most promising candidates for simultaneously achieving good beam quality and high output power. With a lot of marvelous merits, a DPAL becomes one of the most hopeful high-powered laser sources of next generation.

  3. Development of a two arm, high energy, high power laser for plasma research in India

    Science.gov (United States)

    Joshi, A. S.; Kamath, M. P.; Sharma, A. K.; Raghuramaiah, M. R.; Patidar, R. K.; Ansari, M. S.; Sreedhar, N.; Chandra, R.; Navathe, C. P.; Naik, P. A.; Gupta, P. D.

    2013-11-01

    We report here work done towards development of a two arm, high energy, high power Nd:phosphate glass laser system. One arm of the laser is proposed to be operated in a long pulse (˜1.5ns pulse duration) with an energy of ˜400 J. Presently, this arm of the laser is operating at energy of ˜100 J after a disc amplifier that amplifies the laser beam of diameter ˜94 mm. After the addition of two more disc amplifiers which are nearing completion, the laser beam will have energy of ˜400 J, with a beam diameter 140 mm, at an intensity of ˜2 GW/cm2. This beam will be converted to its second harmonic using a 2 × 2 array KDP crystals. The second arm, under development, will operate with a hybrid amplification scheme using optical parametric chirped pulse amplification (OPCPA) and conventional amplification using the existing Nd:glass amplifiers to produce 50 TW, 25 J, 500 fs pulse. A tiled triangular pulse compressor is under development for compressing the stretched pulse.

  4. Toward High-Power Klystrons With RF Power Conversion Efficiency on the Order of 90%

    CERN Document Server

    Baikov, Andrey Yu; Syratchev, Igor

    2015-01-01

    The increase in efficiency of RF power generation for future large accelerators is considered a high priority issue. The vast majority of the existing commercial high-power RF klystrons operates in the electronic efficiency range between 40% and 55%. Only a few klystrons available on the market are capable of operating with 65% efficiency or above. In this paper, a new method to achieve 90% RF power conversion efficiency in a klystron amplifier is presented. The essential part of this method is a new bunching technique - bunching with bunch core oscillations. Computer simulations confirm that the RF production efficiency above 90% can be reached with this new bunching method. The results of a preliminary study of an L-band, 20-MW peak RF power multibeam klystron for Compact Linear Collider with the efficiency above 85% are presented.

  5. An Insight on Right of Way and its Cost for Power Transmission Cable and Conventional Overhead Transmission Lines

    Science.gov (United States)

    Khandelwal, P.; Pachori, A.; Khandelwal, T.

    2013-12-01

    This paper provides the complete information related to Right of Way (RoW) for the construction of new power transmission line (TL) in terms of present cost for overhead transmission line and underground XLPE transmission cable. The former part of the paper describes the general procedure and rules for acquisition of land for RoW by transmission asset owner (TAO) while in the later part the cost associated to acquire RoW and its impact on the cost of adjacent land have been detailed. It also discusses the actual dismantling cost including the cost of waste metal what TAO get after completion of lifecycle of TL due to increase in metal prices. In this paper cost of RoW after completion of lifecycle of TL is also highlighted. This paper compares the cost of RoW for overhead transmission line and underground XLPE transmission cable for construction of new TL. Also for old transmission infrastructure cost of RoW for change from overhead transmission line to underground XLPE transmission cable is detailed by application of replacement model.

  6. EVALUATION OF POWER SPECTRAL DENSITY OF PASSIVE INTERMODULATION DISTORTION IN HIGH-POWER COMMUNICATION SATELLITE SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Zhang Shiquan; Ge Debiao

    2005-01-01

    In order to analyze the deleterious effects of Passive InterModulation (PIM) on high power communication satellite systems, the basic concept of PIM is introduced, and an equation for the power spectral density of the n-th order PIM distortion insuch systems is derived by applying flat signal-power spectrum assumption and Fourier transform method. It is indicated that PIM level generally decreases with order and the lowest frequency receive channel in the receive band is the channel of most affected by PIM interference.

  7. Thermal Impact Analysis of Circulating Current in High Power Modular Online Uninterruptible Power Supplies Application

    DEFF Research Database (Denmark)

    Zhang, Chi; Guerrero, Josep M.; Quintero, Juan Carlos Vasquez

    2017-01-01

    In modular uninterruptible power supplies (UPSs), several DC/AC modules are required to work in parallel. This structure allows the system to be more reliable and flexible. These DC/AC modules share the same DC bus and AC critical bus. Module differences, such as filter inductor, filter capacitor......, control parameters, and so on, will make it possible for the potential zero sequence current to flow among the modules. This undesired type of circulating current will bring extra losses to the power semiconductor devices in the system, which should be paid special attention in high power application...

  8. High-quality Wind Power Scenario Forecasts for Decision-making Under Uncertainty in Power Systems

    DEFF Research Database (Denmark)

    Delikaraoglou, Stefanos; Pinson, Pierre

    2014-01-01

    The large scale integration of wind generation in existing power systems requires novel operational strategies and market clearing mechanisms to account for the variable nature of this energy source. An efficient method to cope with this uncertainty is stochastic optimization which however requires...... high-quality forecasts in the form of scenarios. The main goal of this work is to release a public dataset of wind power forecasts to be used as a reference for future research. To that extent, we provide a complete framework to describe wind power uncertainty in terms of single...

  9. NASA Glenn Research Center Program in High Power Density Motors for Aeropropulsion

    Science.gov (United States)

    Brown, Gerald V.; Kascak, Albert F.; Ebihara, Ben; Johnson, Dexter; Choi, Benjamin; Siebert, Mark; Buccieri, Carl

    2005-01-01

    Electric drive of transport-sized aircraft propulsors, with electric power generated by fuel cells or turbo-generators, will require electric motors with much higher power density than conventional room-temperature machines. Cryogenic cooling of the motor windings by the liquid hydrogen fuel offers a possible solution, enabling motors with higher power density than turbine engines. Some context on weights of various systems, which is required to assess the problem, is presented. This context includes a survey of turbine engine weights over a considerable size range, a correlation of gear box weights and some examples of conventional and advanced electric motor weights. The NASA Glenn Research Center program for high power density motors is outlined and some technical results to date are presented. These results include current densities of 5,000 A per square centimeter current density achieved in cryogenic coils, finite element predictions compared to measurements of torque production in a switched reluctance motor, and initial tests of a cryogenic switched reluctance motor.

  10. The Improved Power of the Central Lobe in the Beam Combination and High Power Output

    Institute of Scientific and Technical Information of China (English)

    LIU Hou-Kang; WEI Yun-Rong; DONG Jing-Xing; LOU Qi-Hong; XUE Yu-Hao; LI Zhen; HE Bing; ZHOU Jun; DING Ya-Qian; JIAO Meng-Li; LIU Chi; QI Yun-Feng

    2012-01-01

    In order to increase the power fraction of the central lobe in the coherent beam combination of lasers in an array,the effects of the distance factor of near-field distribution on far-field interference patterns are calculated and demonstrated experimentally.An improved beam array of interwoven distribution is demonstrated to enable the power in the central lobe to reach 41%.An optimized mirror array is carefully designed to obtain a high duty ratio,which is up to 53.3% at a high power level.By using these optimized methods and designs,the passive phase locking of eight Yb-doped fiber amplifiers with ring cavities are obtained,and a pleasing interference pattern with 87% visibility is observed.The maximum coherent output power of the system is up to 1066 W.%In order to increase the power fraction of the central lobe in the coherent beam combination of lasers in an array, the effects of the distance factor of near-field distribution on far-field interference patterns are calculated and demonstrated experimentally. An improved beam array of interwoven distribution is demonstrated to enable the power in the central lobe to reach 41%. An optimized mirror array is carefully designed to obtain a high duty ratio, which is up to 53.3% at a high power level. By using these optimized methods and designs, the passive phase locking of eight Yb-doped fiber amplifiers with ring cavities are obtained, and a pleasing interference pattern with 87% visibility is observed. The maximum coherent output power of the system is up to 1066 W.

  11. High Speed Peltier Calorimeter for the Calibration of High Bandwidth Power Measurement Equipment

    CERN Document Server

    Frost, Damien F

    2015-01-01

    Accurate power measurements of electronic components operating at high frequencies are vital in determining where power losses occur in a system such as a power converter. Such power measurements must be carried out with equipment that can accurately measure real power at high frequency. We present the design of a high speed calorimeter to address this requirement, capable of reaching a steady state in less than 10 minutes. The system uses Peltier thermoelectric coolers to remove heat generated in a load resistance, and was calibrated against known real power measurements using an artificial neural network. A dead zone controller was used to achieve stable power measurements. The calibration was validated and shown to have an absolute accuracy of +/-8 mW (95% confidence interval) for measurements of real power from 0.1 to 5 W.

  12. Iron loss in high-power arc steelmaking furnaces

    Directory of Open Access Journals (Sweden)

    V. P. Karasyov

    2016-07-01

    Full Text Available There is considered the power operating mode of a high-power arc steelmaking furnaces (ASMF in the period of the flat bath. It is revealed that electric energy is mainly spent for heating and overheating the foamed slag. Heat transferring from slag to metal is carried out by the convective agitation of the bath. For agitation there is used intensive purging of the bath with oxygen that causes increased iron losses with the running foamed slag. There are noted the negative points of working with the foamed slag. It is recommended to expand R&D in the field of optimizing the power operating mode of high-power ASMF.

  13. High power RF systems for the BNL ERL project

    Energy Technology Data Exchange (ETDEWEB)

    Zaltsman, A.; Lambiase, R.

    2011-03-28

    The Energy Recovery Linac (ERL) project, now under construction at Brookhaven National Laboratory, requires two high power RF systems. The first RF system is for the 703.75 MHz superconducting electron gun. The RF power from this system is used to drive nearly half an Ampere of beam current to 2 MeV. There is no provision to recover any of this energy so the minimum amplifier power is 1 MW. It consists of 1 MW CW klystron, transmitter and power supplies, 1 MW circulator, 1 MW dummy load and a two-way power splitter. The second RF system is for the 703.75 MHz superconducting cavity. The system accelerates the beam to 54.7 MeV and recovers this energy. It will provide up to 50 kW of CW RF power to the cavity. It consists of 50 kW transmitter, circulator, and dummy load. This paper describes the two high power RF systems and presents the test data for both.

  14. 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

  15. High-power phase locking of a fiber amplifier array

    Science.gov (United States)

    Shay, T. M.; Baker, J. T.; Sanchez, A. D.; Robin, C. A.; Vergien, C. L.; Zeringue, C.; Gallant, D.; Lu, Chunte A.; Pulford, Benjamin; Bronder, T. J.; Lucero, Arthur

    2009-02-01

    We report high power phase locked fiber amplifier array using the Self-Synchronous Locking of Optical Coherence by Single-detector Electronic-frequency Tagging technique. We report the first experimental results for a five element amplifier array with a total locked power of more than 725-W. We will report on experimental measurements of the phase fluctuations versus time when the control loop is closed. The rms phase error was measured to be λ/60. Recent results will be reported. To the best of the authors' knowledge this is the highest fiber laser power to be coherently combined.

  16. High-Power Microwave Switch Employing Electron Beam Triggering

    Energy Technology Data Exchange (ETDEWEB)

    Hirshfield, Jay L

    2012-09-19

    A high-power active microwave pulse compressor is described that modulates the quality factor Q of the energy storage cavity by a new means involving mode conversion controlled by a triggered electron-beam discharge through a switch cavity. The electron beam is emitted from a diamond-coated molybdenum cathode. This report describes the principle of operation, the design of the switch, the configuration used for the test, and the experimental results. The pulse compressor produced output pulses with 140 - 165 MW peak power, power gain of 16 - 20, and pulse duration of 16 - 20 ns at a frequency of 11.43 GHz.

  17. High power solid state rf amplifier for proton accelerator.

    Science.gov (United States)

    Jain, Akhilesh; Sharma, Deepak Kumar; Gupta, Alok Kumar; Hannurkar, P R

    2008-01-01

    A 1.5 kW solid state rf amplifier at 352 MHz has been developed and tested at RRCAT. This rf source for cw operation will be used as a part of rf system of 100 MeV proton linear accelerator. A rf power of 1.5 kW has been achieved by combining output power from eight 220 W rf amplifier modules. Amplifier modules, eight-way power combiner and divider, and directional coupler were designed indigenously for this development. High efficiency, ease of fabrication, and low cost are the main features of this design.

  18. Programmatic status of NASA's CSTI high capacity power Stirling space power converter program

    Science.gov (United States)

    Dudenhoefer, James E.

    1990-01-01

    An overview is presented of the NASA Lewis Research Center Free-Piston Stirling Space Power Converter Technology Development Program. This work is being conducted under NASA's Civil Space Technology Initiative (CSTI). The goal of the CSTI High Capacity Power element is to develop the technology base needed to meet the long duration, high capacity power requirements for future NASA space initiatives. Efforts are focused upon increasing system thermal and electric energy conversion efficiency at least fivefold over current SP-100 technology, and on achieving systems that are compatible with space nuclear reactors. The status of test activities with the Space Power Research Engine (SPRE) is discussed. Design deficiencies are gradually being corrected and the power converter is now outputting 11.5 kWe at a temperature ratio of 2 (design output is 12.5 kWe). Detail designs were completed for the 1050 K Component Test Power Converter (CTPC). The success of these and future designs is dependent upon supporting research and technology efforts including heat pipes, gas bearings, superalloy joining technologies and high efficiency alternators. An update of progress in these technologies is provided.

  19. High Power Operation of the JLab IR FEL Driver Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Kevin Beard; Stephen Benson; George Biallas; James Boyce; Donald Bullard; James Coleman; David Douglas; H. Dylla; Richard Evans; Pavel Evtushenko; Christopher Gould; Albert Grippo; Joseph Gubeli; David Hardy; Carlos Hernandez-Garcia; J. Hovater; Kevin Jordan; John Klopf; Rui Li; Steven Moore; George Neil; Benard Poelker; Thomas Powers; Joseph Preble; Robert Rimmer; Daniel Sexton; Michelle D. Shinn; Christopher Tennant; Richard Walker; Gwyn Williams; Shukui Zhang

    2007-08-01

    Operation of the JLab IR Upgrade FEL at CW powers in excess of 10 kW requires sustained production of high electron beam powers by the driver ERL. This in turn demands attention to numerous issues and effects, including: cathode lifetime; control of beamline and RF system vacuum during high current operation; longitudinal space charge; longitudinal and transverse matching of irregular/large volume phase space distributions; halo management; management of remnant dispersive effects; resistive wall, wake-field, and RF heating of beam vacuum chambers; the beam break up instability; the impact of coherent synchrotron radiation (both on beam quality and the performance of laser optics); magnetic component stability and reproducibility; and RF stability and reproducibility. We discuss our experience with these issues and describe the modus vivendi that has evolved during prolonged high current, high power beam and laser operation.

  20. Shipbuilding power lies in high-end market

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The 2011 edition of Guideline Index for Readjusting Industrial Structure issued by the National Development and Reform Commission underlines the construction of high-end ships and the upgrading of shipbuilding technology.This shows that ifChina's shipbuilding industry is to become powerful,it should go all out to open up the fields of high-end ship construction so that the industry may have a greater share in the world market.Therefore,the power of our shipbuilding industry lies in the high-end market.

  1. Compact high voltage, high peak power, high frequency transformer for converter type modulator applications.

    Science.gov (United States)

    Reghu, T; Mandloi, V; Shrivastava, Purushottam

    2016-04-01

    The design and development of a compact high voltage, high peak power, high frequency transformer for a converter type modulator of klystron amplifiers is presented. The transformer has been designed to operate at a frequency of 20 kHz and at a flux swing of ±0.6 T. Iron (Fe) based nanocrystalline material has been selected as a core for the construction of the transformer. The transformer employs a specially designed solid Teflon bobbin having 120 kV insulation for winding the high voltage secondary windings. The flux swing of the core has been experimentally found by plotting the hysteresis loop at actual operating conditions. Based on the design, a prototype transformer has been built which is per se a unique combination of high voltage, high frequency, and peak power specifications. The transformer was able to provide 58 kV (pk-pk) at the secondary with a peak power handling capability of 700 kVA. The transformation ratio was 1:17. The performance of the transformer is also presented and discussed.

  2. Very-High Efficiency, High Power Laser Diodes Project

    Data.gov (United States)

    National Aeronautics and Space Administration — AdTech Photonics, in collaboration with the Center for Advanced Studies in Photonics Research (CASPR) at UMBC, is pleased to submit this proposal entitled ?Very-High...

  3. Energy Efficient and Compact RF High-Power Amplifiers

    NARCIS (Netherlands)

    Calvillo Cortés, D.A.

    2014-01-01

    The main objectives of this thesis are to improve the energy efficiency and physical form-factor of high-power amplifiers in base station applications. As such, the focus of this dissertation is placed on the outphasing amplifier concept, which can offer high-efficiency, good linearity and excellent

  4. Simulation and Design of High Power Phase Shifter

    Institute of Scientific and Technical Information of China (English)

    YANG; Yu

    2015-01-01

    Particle accelerators have a wide application in scientific research,medical treatment and other fields.To satisfy the need of scientific research and industrial production,high power and high intensity accelerators are under development.The related technology of each part is required to be improved,

  5. Quantum dot amplifiers with high output power and low noise

    DEFF Research Database (Denmark)

    Berg, Tommy Winther; Mørk, Jesper

    2003-01-01

    Quantum dot semiconductor optical amplifiers have been theoretically investigated and are predicted to achieve high saturated output power, large gain, and low noise figure. We discuss the device dynamics and, in particular, show that the presence of highly inverted barrier states does not limit ...

  6. Cryostat for a high-temperature superconducting power cable

    NARCIS (Netherlands)

    Chevtchenko, O.A.; Smit, J.J.; Geschiere, A.

    2010-01-01

    Cryostat for a high-temperature superconducting power cable, comprising concentric tubes, an annular region between said tubes, wherein a multilayer thermal insulation and getter material for supporting high vacuum conditions are provided in said annular region, and wherein the multilayer insulation

  7. Prospective study of long-term impact of adjuvant high-dose and conventional-dose chemotherapy on health-related quality of life

    NARCIS (Netherlands)

    Buijs, C.; Rodenhuis, S.; Seynaeve, C.M.; van Hoesel, Q.G.; van der Wall, E.; Smit, W.J.; Nooij, M.A.; Voest, E.; Hupperets, P.; TenVergert, E.M.; van Tinteren, H.; Willemse, P.H.; Mourits, M.J.; Aaronson, N.K.; Post, W.J.; de Vries, E.G.

    2007-01-01

    Purpose To evaluate and compare health-related quality of life (HRQOL) after conventional- and high-dose adjuvant chemotherapy in patients with high-risk breast cancer. Patients and Methods Patients were randomly assigned to either a conventional or high-dose chemotherapy regimen; both regimens were

  8. High-Temperature, Wirebondless, Ultracompact Wide Bandgap Power Semiconductor Modules

    Science.gov (United States)

    Elmes, John

    2015-01-01

    Silicon carbide (SiC) and other wide bandgap semiconductors offer great promise of high power rating, high operating temperature, simple thermal management, and ultrahigh power density for both space and commercial power electronic systems. However, this great potential is seriously limited by the lack of reliable high-temperature device packaging technology. This Phase II project developed an ultracompact hybrid power module packaging technology based on the use of double lead frames and direct lead frame-to-chip transient liquid phase (TLP) bonding that allows device operation up to 450 degC. The new power module will have a very small form factor with 3-5X reduction in size and weight from the prior art, and it will be capable of operating from 450 degC to -125 degC. This technology will have a profound impact on power electronics and energy conversion technologies and help to conserve energy and the environment as well as reduce the nation's dependence on fossil fuels.

  9. High-average-power high-beam-quality vis-UV sources based on kinetically enhanced copper vapor lasers

    Science.gov (United States)

    Brown, Daniel J. W.; Withford, Michael J.; Carman, Robert J.; Mildren, Richard P.; Piper, James A.

    2000-04-01

    Investigations of the factors that limit average power scaling of elemental copper vapor lasers (CVLs) have demonstrated that decay of the electron density in the interpulse period is critical in restricting pulse repetition rate and laser aperture scaling. We have recently developed the 'kinetic enhancement' (or KE) technique to overcome these limitations, whereby optimal plasma conditions are engineered using low concentrations of HCl/H2 additive gases in the Ne buffer. Dissociative electron attachment of HCl and subsequent mutual neutralization of Cl- and Cu+ promote rapid plasma relaxation and fast recovery of Cu densities, permitting operation at elevated Cu densities and pulse rates for given apertures. Using this approach, we have demonstrated increases in output power and efficiency of a factor of 2 or higher over conventional CVLs of the same size. For a 38 mm- bore KE-CVL, output powers up to 150 W have been achieved at 22 kHz, corresponding to record specific powers (80 mW/cm3) for such a 'small/medium-scale' device. In addition, kinetic enhancement significantly extends the gain duration and restores gain on-axis, even for high pulse rates, thereby promoting substantial increases (5 - 10x) in high- beam-quality power levels when operating with unstable resonators. This has enabled us to achieve much higher powers in second-harmonic generation from the visible copper laser output to the ultraviolet (e.g. 5 W at 255 nm from a small- scale KE-CVL). Our approach to developing KE-CVLs including computer modeling and experimental studies will be reviewed, and most recent results in pulse rate scaling and scaling of high-beam-quality power using oscillator-amplifier configurations, will be presented.

  10. Comparative effectiveness of low- and high-fidelity bronchoscopy simulation for training in conventional transbronchial needle aspiration and user preferences.

    Science.gov (United States)

    Davoudi, Mohsen; Wahidi, Momen M; Zamanian Rohani, Nazanin; Colt, Henri G

    2010-01-01

    Conventional transbronchial needle aspiration (TBNA) can be learned using high-fidelity virtual-reality platforms and low-fidelity models comprised of molded silicone or excised animal airways. The purpose of this study was to determine perceptions and preferences of learners and instructors regarding the comparative effectiveness of low-fidelity and high-fidelity bronchoscopy simulation for training in TBNA. During the 2008 annual CHEST conference, a prospective randomized crossover design was used to train study participants in three methods of conventional TBNA using low- and high-fidelity models. Likert style questions were administered to learners and instructors in order to elicit preferences and opinions regarding educational effectiveness of the models. Results were tabulated and depicted in graphic format, with medians calculated. Learners felt that the models were equally enjoyable (13-13) and enthusiasm generating (low 17-high 15). There was preference for low-fidelity in terms of realism (23-17), ease of learning (20-6), and learning all three TBNA methods (31-7 for hub-against-wall, 31-6 for jabbing, 29-6 for piggyback). Low-fidelity was preferred as an ideal model overall (19-11). Instructors thought that low-fidelity was more useful in teaching TBNA (9-0 for all three methods). Instructors perceived the low-fidelity model overall as an ideal tool for learning TBNA (8-0) and a more effective teaching instrument (8-0). Based on learner and instructor perceptions, a low-fidelity model is superior to a high-fidelity platform for training in three methods of conventional TBNA. Copyright © 2010 S. Karger AG, Basel.

  11. Modular High-Energy Systems for Solar Power Satellites

    Science.gov (United States)

    Howell, Joe T.; Carrington, Connie K.; Marzwell, Neville I.; Mankins, John C.

    2006-01-01

    Modular High-Energy Systems are Stepping Stones to provide capabilities for energy-rich infrastructure located in space to support a variety of exploration scenarios as well as provide a supplemental source of energy during peak demands to ground grid systems. Abundant renewable energy at lunar or other locations could support propellant production and storage in refueling scenarios that enable affordable exploration. Renewable energy platforms in geosynchronous Earth orbits can collect and transmit power to satellites, or to Earth-surface locations. Energy-rich space technologies also enable the use of electric-powered propulsion systems that could efficiently deliver cargo and exploration facilities to remote locations. A first step to an energy-rich space infrastructure is a 100-kWe class solar-powered platform in Earth orbit. The platform would utilize advanced technologies in solar power collection and generation, power management and distribution, thermal management, electric propulsion, wireless avionics, autonomous in space rendezvous and docking, servicing, and robotic assembly. It would also provide an energy-rich free-flying platform to demonstrate in space a portfolio of technology flight experiments. This paper summary a preliminary design concept for a 100-kWe solar-powered satellite system to demonstrate in-flight a variety of advanced technologies, each as a separate payload. These technologies include, but are not limited to state-of-the-art solar concentrators, highly efficient multi-junction solar cells, integrated thermal management on the arrays, and innovative deployable structure design and packaging to enable the 100-kW satellite feasible to launch on one existing launch vehicle. Higher voltage arrays and power distribution systems (PDS) reduce or eliminate the need for massive power converters, and could enable direct-drive of high-voltage solar electric thrusters.

  12. Construction of a high resolution microscope with conventional and holographic optical trapping capabilities.

    Science.gov (United States)

    Butterfield, Jacqualine; Hong, Weili; Mershon, Leslie; Vershinin, Michael

    2013-04-22

    High resolution microscope systems with optical traps allow for precise manipulation of various refractive objects, such as dielectric beads (1) or cellular organelles (2,3), as well as for high spatial and temporal resolution readout of their position relative to the center of the trap. The system described herein has one such "traditional" trap operating at 980 nm. It additionally provides a second optical trapping system that uses a commercially available holographic package to simultaneously create and manipulate complex trapping patterns in the field of view of the microscope (4,5) at a wavelength of 1,064 nm. The combination of the two systems allows for the manipulation of multiple refractive objects at the same time while simultaneously conducting high speed and high resolution measurements of motion and force production at nanometer and piconewton scale.

  13. Temperature measurements of a high-power microwave feedhorn window

    Science.gov (United States)

    Hoppe, Daniel J.; Perez, Raul M.; Glazer, Stuart D.

    1990-06-01

    Temperature measurements of a high-power microwave feedhorn window, obtained using an imaging IR radiometer during transmitter operation at 365 kW CW and 8.5 GHz, are discussed. The window under investigation was constructed of HTP-6, a high-thermal-performance material developed to shield the Space Shuttle Orbiter from the heat of reentry. The measurement technique is described, and experimental results are presented. The window performed adequately at 365 kW CW with a center temperature of 475 C. The tests verify that HTP-6 can be used as a window material or a support structure in high-power waveguides at power densities of 1.47 kW/sq cm for extended periods of time, with no change in its mechanical characteristics.

  14. High power pulses extracted from the Peregrine rogue wave

    CERN Document Server

    Yang, Guangye; Jia, SuoTang; Mihalache, Dumitru

    2013-01-01

    We address the various initial excitations of the Peregrine rogue wave and establish a robust transmission scheme of high power pulses extracted from the Peregrine rogue wave in a standard telecommunications fiber. The results show that the Peregrine rogue wave can be excited by using a weak pulse atop a continuous wave background and that the high power pulses extracted from the Peregrine rogue wave exhibit the typical characteristics of breathing solitons. The influence of higher-order effects, such as the third-order dispersion, the self-steepening and the Raman effect, on the propagation of the pulse extracted from the peak position and the interaction between neighboring high power pulses induced by initial perturbations are also investigated.

  15. Compact piezoelectric stacked actuators for high power applications.

    Science.gov (United States)

    Yao, K; Uchino, K; Xu, Y; Dong, S; Lim, L C

    2000-01-01

    Small, hollow, multilayer actuators with a diameter of 3 mm were fabricated by the stacking method from piezoelectric hard lead zirconate titanate (PZT) ceramics. Langevin vibrators were also constructed with the hollow multilayer actuators. The performance capabilities of the actuator and Langevin vibrator samples were examined under high-power conditions. The high-power vibration level at a given sinusoidal drive voltage was significantly enhanced by using a multilayer structure under either a nonresonance or resonance condition. A maximum vibration velocity of 0.17 m/sec was obtained for the 9-layer actuator sample under nonresonance conditions. The vibration velocity was further improved with the Langevin vibrator driven at the resonance frequency. The temperature rise due to heat generation under high-power conditions was the immediate limitation on the maximum accessible vibration velocity for the stacked actuators.

  16. High Power Fiber Lasers and Applications to Manufacturing

    Science.gov (United States)

    Richardson, Martin; McComb, Timothy; Sudesh, Vikas

    2008-09-01

    We summarize recent developments in high power fiber laser technologies and discuss future trends, particularly in their current and future use in manufacturing technologies. We will also describe our current research programs in fiber laser development, ultra-fast and new lasers, and will mention the expectations in these areas for the new Townes Laser Institute. It will focus on new core laser technologies and their applications in medical technologies, advanced manufacturing technologies and defense applications. We will describe a program on large mode area fiber development that includes results with the new gain-guiding approach, as well as high power infra-red fiber lasers. We will review the opportunities for high power fiber lasers in various manufacturing technologies and illustrate this with applications we are pursuing in the areas of femtosecond laser applications, advanced lithographies, and mid-IR technologies.

  17. High Efficiency Ka-Band Solid State Power Amplifier Waveguide Power Combiner

    Science.gov (United States)

    Wintucky, Edwin G.; Simons, Rainee N.; Chevalier, Christine T.; Freeman, Jon C.

    2010-01-01

    A novel Ka-band high efficiency asymmetric waveguide four-port combiner for coherent combining of two Monolithic Microwave Integrated Circuit (MMIC) Solid State Power Amplifiers (SSPAs) having unequal outputs has been successfully designed, fabricated and characterized over the NASA deep space frequency band from 31.8 to 32.3 GHz. The measured combiner efficiency is greater than 90 percent, the return loss greater than 18 dB and input port isolation greater than 22 dB. The manufactured combiner was designed for an input power ratio of 2:1 but can be custom designed for any arbitrary power ratio. Applications considered are NASA s space communications systems needing 6 to 10 W of radio frequency (RF) power. This Technical Memorandum (TM) is an expanded version of the article recently published in Institute of Engineering and Technology (IET) Electronics Letters.

  18. High Average Power Diode Pumped Solid State Lasers: Power Scaling With High Spectral and Spatial Coherence

    Science.gov (United States)

    2009-03-30

    sensing and coherent LIDAR systems, will require kW class lasers in the near future. The zigzag slab architecture [2], with its nearly one-dimensional... photodetectors ; PM1, PM2, PM3: thermal power meters; HBS1: 1064 nm holographic beam sampler; HBS2: 532-nm holographic beam sampler; LD: laser diode; CCD: charge...recombining pairs is measured by a photodetector . This measurement shows higher PL intensity as the material is improved by reducing defect density. We tried

  19. Coal-fired power plants and the causes of high temperature corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Oakey, J.E.; Simms, N.J. [British Coal Corporation, Coal Technology Development Div., Cheltenham, Glos (United Kingdom); Tomkings, A.B. [ERA Technology Ltd., Leatherhead, Surrey (United Kingdom)

    1996-12-01

    The heat exchangers in all types of coal-fired power plant operate in aggressive, high temperature environments where high temperature corrosion can severely limit their service lives. The extent of this corrosion is governed by the combined effects of the operating conditions of the heat exchanger and the presence of corrosive species released from the coal during operation. This paper reviews the coal-related factors, such as ash deposition, which influence the operating environments of heat exchangers in three types of coal-fired power plant - conventional pulverized coal boilers, fluidized bed boilers and coal gasification systems. The effects on the performance of the materials used for these heat exchangers are then compared. (au) 35 refs.

  20. Modified retro-tubercle opening-wedge versus conventional high tibial osteotomy.

    Science.gov (United States)

    Keyhani, Sohrab; Abbasian, Mohammad Reza; Kazemi, Seyed Morteza; Esmailiejah, Ali Akbar; Seyed Hosseinzadeh, Hamid Reza; Shahi, Alisina; Shahi, Ali Sina; Firouzi, Farzad

    2011-01-01

    Despite the fact that common surgical techniques for the treatment of genu varum usually correct the malalignment in the affected knee, these methods have significant complications and cause problems in the long term. Retro-tubercle opening-wedge high tibial osteotomy is among the newer techniques for the treatment of genu varum. The goal of this study was to compare the results of retro-tubercle opening-wedge high tibial osteotomy with those of medial opening-wedge osteotomy. In a randomized, controlled trial, 72 patients with varus knees who were scheduled for surgery were assigned into either the retro-tubercle opening-wedge high tibial osteotomy (n=34) or medial opening-wedge osteotomy groups (n=38). Groups were matched for age and sex. The position of the patella was compared with respect to the tuberosity and the upper tibial slope pre- and postoperatively. Patients were followed for an average of 13 months (range, 10-21 months). In the retro-tubercle opening-wedge high tibial osteotomy group, the length of the patellar tendon did not significantly differ pre- and postoperatively (P≥.5); however, in the medial opening-wedge osteotomy group, a statistically significant shortening was noted in patellar tendon postoperatively (P≤.05). Similarly, the tibial plateau inclination showed a statistically significant difference postoperatively in the medial opening-wedge osteotomy group, while the difference in the retro-tubercle opening-wedge high tibial osteotomy group did not reach statistical significance.