Potential for efficient frequency conversion at high average power using solid state nonlinear optical materials

International Nuclear Information System (INIS)

Eimerl, D.

1985-01-01

High-average-power frequency conversion using solid state nonlinear materials is discussed. Recent laboratory experience and new developments in design concepts show that current technology, a few tens of watts, may be extended by several orders of magnitude. For example, using KD*P, efficient doubling (>70%) of Nd:YAG at average powers approaching 100 KW is possible; and for doubling to the blue or ultraviolet regions, the average power may approach 1 MW. Configurations using segmented apertures permit essentially unlimited scaling of average power. High average power is achieved by configuring the nonlinear material as a set of thin plates with a large ratio of surface area to volume and by cooling the exposed surfaces with a flowing gas. The design and material fabrication of such a harmonic generator are well within current technology

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...

Recent developments in high average power driver technology

International Nuclear Information System (INIS)

Prestwich, K.R.; Buttram, M.T.; Rohwein, G.J.

1979-01-01

Inertial confinement fusion (ICF) reactors will require driver systems operating with tens to hundreds of megawatts of average power. The pulse power technology that will be required to build such drivers is in a primitive state of development. Recent developments in repetitive pulse power are discussed. A high-voltage transformer has been developed and operated at 3 MV in a single pulse experiment and is being tested at 1.5 MV, 5 kj and 10 pps. A low-loss, 1 MV, 10 kj, 10 pps Marx generator is being tested. Test results from gas-dynamic spark gaps that operate both in the 100 kV and 700 kV range are reported. A 250 kV, 1.5 kA/cm 2 , 30 ns electron beam diode has operated stably for 1.6 x 10 5 pulses

High Average Power Fiber Laser for Satellite Communications, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Very high average power lasers with high electrical-top-optical (E-O) efficiency, which also support pulse position modulation (PPM) formats in the MHz-data rate...

Improved performance of high average power semiconductor arrays for applications in diode pumped solid state lasers

International Nuclear Information System (INIS)

Beach, R.; Emanuel, M.; Benett, W.; Freitas, B.; Ciarlo, D.; Carlson, N.; Sutton, S.; Skidmore, J.; Solarz, R.

1994-01-01

The average power performance capability of semiconductor diode laser arrays has improved dramatically over the past several years. These performance improvements, combined with cost reductions pursued by LLNL and others in the fabrication and packaging of diode lasers, have continued to reduce the price per average watt of laser diode radiation. Presently, we are at the point where the manufacturers of commercial high average power solid state laser systems used in material processing applications can now seriously consider the replacement of their flashlamp pumps with laser diode pump sources. Additionally, a low cost technique developed and demonstrated at LLNL for optically conditioning the output radiation of diode laser arrays has enabled a new and scalable average power diode-end-pumping architecture that can be simply implemented in diode pumped solid state laser systems (DPSSL's). This development allows the high average power DPSSL designer to look beyond the Nd ion for the first time. Along with high average power DPSSL's which are appropriate for material processing applications, low and intermediate average power DPSSL's are now realizable at low enough costs to be attractive for use in many medical, electronic, and lithographic applications

Design of a high average-power FEL driven by an existing 20 MV electrostatic-accelerator

Energy Technology Data Exchange (ETDEWEB)

Kimel, I.; Elias, L.R. [Univ. of Central Florida, Orlando, FL (United States)

1995-12-31

There are some important applications where high average-power radiation is required. Two examples are industrial machining and space power-beaming. Unfortunately, up to date no FEL has been able to show more than 10 Watts of average power. To remedy this situation we started a program geared towards the development of high average-power FELs. As a first step we are building in our CREOL laboratory, a compact FEL which will generate close to 1 kW in CW operation. As the next step we are also engaged in the design of a much higher average-power system based on a 20 MV electrostatic accelerator. This FEL will be capable of operating CW with a power output of 60 kW. The idea is to perform a high power demonstration using the existing 20 MV electrostatic accelerator at the Tandar facility in Buenos Aires. This machine has been dedicated to accelerate heavy ions for experiments and applications in nuclear and atomic physics. The necessary adaptations required to utilize the machine to accelerate electrons will be described. An important aspect of the design of the 20 MV system, is the electron beam optics through almost 30 meters of accelerating and decelerating tubes as well as the undulator. Of equal importance is a careful design of the long resonator with mirrors able to withstand high power loading with proper heat dissipation features.

High Average Power UV Free Electron Laser Experiments At JLAB

International Nuclear Information System (INIS)

Douglas, David; Benson, Stephen; Evtushenko, Pavel; Gubeli, Joseph; Hernandez-Garcia, Carlos; Legg, Robert; Neil, George; Powers, Thomas; Shinn, Michelle; Tennant, Christopher; Williams, Gwyn

2012-01-01

Having produced 14 kW of average power at ∼2 microns, JLAB has shifted its focus to the ultraviolet portion of the spectrum. This presentation will describe the JLab UV Demo FEL, present specifics of its driver ERL, and discuss the latest experimental results from FEL experiments and machine operations.

Determination of the in-core power and the average core temperature of low power research reactors using gamma dose rate measurements

International Nuclear Information System (INIS)

Osei Poku, L.

2012-01-01

Most reactors incorporate out-of-core neutron detectors to monitor the reactor power. An accurate relationship between the powers indicated by these detectors and actual core thermal power is required. This relationship is established by calibrating the thermal power. The most common method used in calibrating the thermal power of low power reactors is neutron activation technique. To enhance the principle of multiplicity and diversity of measuring the thermal neutron flux and/or power and temperature difference and/or average core temperature of low power research reactors, an alternative and complimentary method has been developed, in addition to the current method. Thermal neutron flux/Power and temperature difference/average core temperature were correlated with measured gamma dose rate. The thermal neutron flux and power predicted using gamma dose rate measurement were in good agreement with the calibrated/indicated thermal neutron fluxes and powers. The predicted data was also good agreement with thermal neutron fluxes and powers obtained using the activation technique. At an indicated power of 30 kW, the gamma dose rate measured predicted thermal neutron flux of (1* 10 12 ± 0.00255 * 10 12 ) n/cm 2 s and (0.987* 10 12 ± 0.00243 * 10 12 ) which corresponded to powers of (30.06 ± 0.075) kW and (29.6 ± 0.073) for both normal level of the pool water and 40 cm below normal levels respectively. At an indicated power of 15 kW, the gamma dose rate measured predicted thermal neutron flux of (5.07* 10 11 ± 0.025* 10 11 ) n/cm 2 s and (5.12 * 10 11 ±0.024* 10 11 ) n/cm 2 s which corresponded to power of (15.21 ± 0.075) kW and (15.36 ± 0.073) kW for both normal levels of the pool water and 40 cm below normal levels respectively. The power predicted by this work also compared well with power obtained from a three-dimensional neutronic analysis for GHARR-1 core. The predicted power also compares well with calculated power using a correlation equation obtained from

Potential of high-average-power solid state lasers

International Nuclear Information System (INIS)

Emmett, J.L.; Krupke, W.F.; Sooy, W.R.

1984-01-01

We discuss the possibility of extending solid state laser technology to high average power and of improving the efficiency of such lasers sufficiently to make them reasonable candidates for a number of demanding applications. A variety of new design concepts, materials, and techniques have emerged over the past decade that, collectively, suggest that the traditional technical limitations on power (a few hundred watts or less) and efficiency (less than 1%) can be removed. The core idea is configuring the laser medium in relatively thin, large-area plates, rather than using the traditional low-aspect-ratio rods or blocks. This presents a large surface area for cooling, and assures that deposited heat is relatively close to a cooled surface. It also minimizes the laser volume distorted by edge effects. The feasibility of such configurations is supported by recent developments in materials, fabrication processes, and optical pumps. Two types of lasers can, in principle, utilize this sheet-like gain configuration in such a way that phase and gain profiles are uniformly sampled and, to first order, yield high-quality (undistorted) beams. The zig-zag laser does this with a single plate, and should be capable of power levels up to several kilowatts. The disk laser is designed around a large number of plates, and should be capable of scaling to arbitrarily high power levels

High-average-power solid state lasers

International Nuclear Information System (INIS)

Summers, M.A.

1989-01-01

In 1987, a broad-based, aggressive R ampersand D program aimed at developing the technologies necessary to make possible the use of solid state lasers that are capable of delivering medium- to high-average power in new and demanding applications. Efforts were focused along the following major lines: development of laser and nonlinear optical materials, and of coatings for parasitic suppression and evanescent wave control; development of computational design tools; verification of computational models on thoroughly instrumented test beds; and applications of selected aspects of this technology to specific missions. In the laser materials areas, efforts were directed towards producing strong, low-loss laser glasses and large, high quality garnet crystals. The crystal program consisted of computational and experimental efforts aimed at understanding the physics, thermodynamics, and chemistry of large garnet crystal growth. The laser experimental efforts were directed at understanding thermally induced wave front aberrations in zig-zag slabs, understanding fluid mechanics, heat transfer, and optical interactions in gas-cooled slabs, and conducting critical test-bed experiments with various electro-optic switch geometries. 113 refs., 99 figs., 18 tabs

Investigations to the potential of the high temperature reactor for steam power processes with highest steam conditions and comparison with according conventional power plants

International Nuclear Information System (INIS)

Mondry, M.

1988-04-01

Already in the fifties conventional power plants with high parameters of the live steam were built to improve the total efficiency. The power plant with the highest steam conditions in the Federal Republic of Germany has 300 bar pressure and 600deg C temperature. Because of high material costs and other problems power plants with such high conditions were not continued to be built. Standard conditions of today's power plants are in the order of 180-250 bar pressure and 535deg C temperature. As the high temperature reactor is partly built up in another way than a conventional power plant, the results regarding the high steam parameters are not transferable. Possibilities for the technical realization of determined HTR-specific components are introduced and discussed. Then different HTR-power plants with steam conditions up to 350 bar pressure and 650deg C temperature are projected. Economical considerations show that an HTR with higher steam parameters brings financial profits. Further efficiency increase, which is possible by the high steam conditions, is shortly presented. The work ends with a technical and economical comparison of corresponding conventional power plants. (orig./UA) [de

Strengthened glass for high average power laser applications

International Nuclear Information System (INIS)

Cerqua, K.A.; Lindquist, A.; Jacobs, S.D.; Lambropoulos, J.

1987-01-01

Recent advancements in high repetition rate and high average power laser systems have put increasing demands on the development of improved solid state laser materials with high thermal loading capabilities. The authors have developed a process for strengthening a commercially available Nd doped phosphate glass utilizing an ion-exchange process. Results of thermal loading fracture tests on moderate size (160 x 15 x 8 mm) glass slabs have shown a 6-fold improvement in power loading capabilities for strengthened samples over unstrengthened slabs. Fractographic analysis of post-fracture samples has given insight into the mechanism of fracture in both unstrengthened and strengthened samples. Additional stress analysis calculations have supported these findings. In addition to processing the glass' surface during strengthening in a manner which preserves its post-treatment optical quality, the authors have developed an in-house optical fabrication technique utilizing acid polishing to minimize subsurface damage in samples prior to exchange treatment. Finally, extension of the strengthening process to alternate geometries of laser glass has produced encouraging results, which may expand the potential or strengthened glass in laser systems, making it an exciting prospect for many applications

Average spectral power changes at the hippocampal electroencephalogram in schizophrenia model induced by ketamine.

Science.gov (United States)

Sampaio, Luis Rafael L; Borges, Lucas T N; Silva, Joyse M F; de Andrade, Francisca Roselin O; Barbosa, Talita M; Oliveira, Tatiana Q; Macedo, Danielle; Lima, Ricardo F; Dantas, Leonardo P; Patrocinio, Manoel Cláudio A; do Vale, Otoni C; Vasconcelos, Silvânia M M

2018-02-01

The use of ketamine (Ket) as a pharmacological model of schizophrenia is an important tool for understanding the main mechanisms of glutamatergic regulated neural oscillations. Thus, the aim of the current study was to evaluate Ket-induced changes in the average spectral power using the hippocampal quantitative electroencephalography (QEEG). To this end, male Wistar rats were submitted to a stereotactic surgery for the implantation of an electrode in the right hippocampus. After three days, the animals were divided into four groups that were treated for 10 consecutive days with Ket (10, 50, or 100 mg/kg). Brainwaves were captured on the 1st or 10th day, respectively, to acute or repeated treatments. The administration of Ket (10, 50, or 100 mg/kg), compared with controls, induced changes in the hippocampal average spectral power of delta, theta, alpha, gamma low or high waves, after acute or repeated treatments. Therefore, based on the alterations in the average spectral power of hippocampal waves induced by Ket, our findings might provide a basis for the use of hippocampal QEEG in animal models of schizophrenia. © 2017 Société Française de Pharmacologie et de Thérapeutique.

Rf system modeling for the high average power FEL at CEBAF

International Nuclear Information System (INIS)

Merminga, L.; Fugitt, J.; Neil, G.; Simrock, S.

1995-01-01

High beam loading and energy recovery compounded by use of superconducting cavities, which requires tight control of microphonic noise, place stringent constraints on the linac rf system design of the proposed high average power FEL at CEBAF. Longitudinal dynamics imposes off-crest operation, which in turn implies a large tuning angle to minimize power requirements. Amplitude and phase stability requirements are consistent with demonstrated performance at CEBAF. A numerical model of the CEBAF rf control system is presented and the response of the system is examined under large parameter variations, microphonic noise, and beam current fluctuations. Studies of the transient behavior lead to a plausible startup and recovery scenario

Recent advances in the development of high average power induction accelerators for industrial and environmental applications

International Nuclear Information System (INIS)

Neau, E.L.

1994-01-01

Short-pulse accelerator technology developed during the early 1960's through the late 1980's is being extended to high average power systems capable of use in industrial and environmental applications. Processes requiring high dose levels and/or high volume throughput will require systems with beam power levels from several hundreds of kilowatts to megawatts. Beam accelerating potentials can range from less than 1 MeV to as much as 10 MeV depending on the type of beam, depth of penetration required, and the density of the product being treated. This paper addresses the present status of a family of high average power systems, with output beam power levels up to 200 kW, now in operation that use saturable core switches to achieve output pulse widths of 50 to 80 nanoseconds. Inductive adders and field emission cathodes are used to generate beams of electrons or x-rays at up to 2.5 MeV over areas of 1000 cm 2 . Similar high average power technology is being used at ≤ 1 MeV to drive repetitive ion beam sources for treatment of material surfaces over 100's of cm 2

A novel Generalized State-Space Averaging (GSSA) model for advanced aircraft electric power systems

International Nuclear Information System (INIS)

Ebrahimi, Hadi; El-Kishky, Hassan

2015-01-01

Highlights: • A study model is developed for aircraft electric power systems. • A novel GSSA model is developed for the interconnected power grid. • The system’s dynamics are characterized under various conditions. • The averaged results are compared and verified with the actual model. • The obtained measured values are validated with available aircraft standards. - Abstract: The growing complexity of Advanced Aircraft Electric Power Systems (AAEPS) has made conventional state-space averaging models inadequate for systems analysis and characterization. This paper presents a novel Generalized State-Space Averaging (GSSA) model for the system analysis, control and characterization of AAEPS. The primary objective of this paper is to introduce a mathematically elegant and computationally simple model to copy the AAEPS behavior at the critical nodes of the electric grid. Also, to reduce some or all of the drawbacks (complexity, cost, simulation time…, etc) associated with sensor-based monitoring and computer aided design software simulations popularly used for AAEPS characterization. It is shown in this paper that the GSSA approach overcomes the limitations of the conventional state-space averaging method, which fails to predict the behavior of AC signals in a circuit analysis. Unlike conventional averaging method, the GSSA model presented in this paper includes both DC and AC components. This would capture the key dynamic and steady-state characteristics of the aircraft electric systems. The developed model is then examined for the aircraft system’s visualization and accuracy of computation under different loading scenarios. Through several case studies, the applicability and effectiveness of the GSSA method is verified by comparing to the actual real-time simulation model obtained from Powersim 9 (PSIM9) software environment. The simulations results represent voltage, current and load power at the major nodes of the AAEPS. It has been demonstrated that

Performance study of highly efficient 520 W average power long pulse ceramic Nd:YAG rod laser

Science.gov (United States)

Choubey, Ambar; Vishwakarma, S. C.; Ali, Sabir; Jain, R. K.; Upadhyaya, B. N.; Oak, S. M.

2013-10-01

We report the performance study of a 2% atomic doped ceramic Nd:YAG rod for long pulse laser operation in the millisecond regime with pulse duration in the range of 0.5-20 ms. A maximum average output power of 520 W with 180 J maximum pulse energy has been achieved with a slope efficiency of 5.4% using a dual rod configuration, which is the highest for typical lamp pumped ceramic Nd:YAG lasers. The laser output characteristics of the ceramic Nd:YAG rod were revealed to be nearly equivalent or superior to those of high-quality single crystal Nd:YAG rod. The laser pump chamber and resonator were designed and optimized to achieve a high efficiency and good beam quality with a beam parameter product of 16 mm mrad (M2˜47). The laser output beam was efficiently coupled through a 400 μm core diameter optical fiber with 90% overall transmission efficiency. This ceramic Nd:YAG laser will be useful for various material processing applications in industry.

Efficient processing of CFRP with a picosecond laser with up to 1.4 kW average power

Science.gov (United States)

Onuseit, V.; Freitag, C.; Wiedenmann, M.; Weber, R.; Negel, J.-P.; Löscher, A.; Abdou Ahmed, M.; Graf, T.

2015-03-01

Laser processing of carbon fiber reinforce plastic (CFRP) is a very promising method to solve a lot of the challenges for large-volume production of lightweight constructions in automotive and airplane industries. However, the laser process is actual limited by two main issues. First the quality might be reduced due to thermal damage and second the high process energy needed for sublimation of the carbon fibers requires laser sources with high average power for productive processing. To achieve thermal damage of the CFRP of less than 10μm intensities above 108 W/cm² are needed. To reach these high intensities in the processing area ultra-short pulse laser systems are favored. Unfortunately the average power of commercially available laser systems is up to now in the range of several tens to a few hundred Watt. To sublimate the carbon fibers a large volume specific enthalpy of 85 J/mm³ is necessary. This means for example that cutting of 2 mm thick material with a kerf width of 0.2 mm with industry-typical 100 mm/sec requires several kilowatts of average power. At the IFSW a thin-disk multipass amplifier yielding a maximum average output power of 1100 W (300 kHz, 8 ps, 3.7 mJ) allowed for the first time to process CFRP at this average power and pulse energy level with picosecond pulse duration. With this unique laser system cutting of CFRP with a thickness of 2 mm an effective average cutting speed of 150 mm/sec with a thermal damage below 10μm was demonstrated.

Application of Bayesian model averaging to measurements of the primordial power spectrum

International Nuclear Information System (INIS)

Parkinson, David; Liddle, Andrew R.

2010-01-01

Cosmological parameter uncertainties are often stated assuming a particular model, neglecting the model uncertainty, even when Bayesian model selection is unable to identify a conclusive best model. Bayesian model averaging is a method for assessing parameter uncertainties in situations where there is also uncertainty in the underlying model. We apply model averaging to the estimation of the parameters associated with the primordial power spectra of curvature and tensor perturbations. We use CosmoNest and MultiNest to compute the model evidences and posteriors, using cosmic microwave data from WMAP, ACBAR, BOOMERanG, and CBI, plus large-scale structure data from the SDSS DR7. We find that the model-averaged 95% credible interval for the spectral index using all of the data is 0.940 s s is specified at a pivot scale 0.015 Mpc -1 . For the tensors model averaging can tighten the credible upper limit, depending on prior assumptions.

An Electrochemical Capacitor with Applicable Energy Density of 7.4 Wh/kg at Average Power Density of 3000 W/kg.

Science.gov (United States)

Zhai, Teng; Lu, Xihong; Wang, Hanyu; Wang, Gongming; Mathis, Tyler; Liu, Tianyu; Li, Cheng; Tong, Yexiang; Li, Yat

2015-05-13

Electrochemical capacitors represent a new class of charge storage devices that can simultaneously achieve high energy density and high power density. Previous reports have been primarily focused on the development of high performance capacitor electrodes. Although these electrodes have achieved excellent specific capacitance based on per unit mass of active materials, the gravimetric energy densities calculated based on the weight of entire capacitor device were fairly small. This is mainly due to the large mass ratio between current collector and active material. We aimed to address this issue by a 2-fold approach of minimizing the mass of current collector and increasing the electrode performance. Here we report an electrochemical capacitor using 3D graphene hollow structure as current collector, vanadium sulfide and manganese oxide as anode and cathode materials, respectively. 3D graphene hollow structure provides a lightweight and highly conductive scaffold for deposition of pseudocapacitive materials. The device achieves an excellent active material ratio of 24%. Significantly, it delivers a remarkable energy density of 7.4 Wh/kg (based on the weight of entire device) at the average power density of 3000 W/kg. This is the highest gravimetric energy density reported for asymmetric electrochemical capacitors at such a high power density.

Development of linear proton accelerators with the high average beam power

CERN Document Server

Bomko, V A; Egorov, A M

2001-01-01

Review of the current situation in the development of powerful linear proton accelerators carried out in many countries is given. The purpose of their creation is solving problems of safe and efficient nuclear energetics on a basis of the accelerator-reactor complex. In this case a proton beam with the energy up to 1 GeV, the average current of 30 mA is required. At the same time there is a needed in more powerful beams,for example, for production of tritium and transmutation of nuclear waste products. The creation of accelerators of such a power will be followed by the construction of linear accelerators of 1 GeV but with a more moderate beam current. They are intended for investigation of many aspects of neutron physics and neutron engineering. Problems in the creation of efficient constructions for the basic and auxiliary equipment, the reliability of the systems, and minimization of the beam losses in the process of acceleration will be solved.

Cloud-based design of high average power traveling wave linacs

Science.gov (United States)

Kutsaev, S. V.; Eidelman, Y.; Bruhwiler, D. L.; Moeller, P.; Nagler, R.; Barbe Welzel, J.

2017-12-01

The design of industrial high average power traveling wave linacs must accurately consider some specific effects. For example, acceleration of high current beam reduces power flow in the accelerating waveguide. Space charge may influence the stability of longitudinal or transverse beam dynamics. Accurate treatment of beam loading is central to the design of high-power TW accelerators, and it is especially difficult to model in the meter-scale region where the electrons are nonrelativistic. Currently, there are two types of available codes: tracking codes (e.g. PARMELA or ASTRA) that cannot solve self-consistent problems, and particle-in-cell codes (e.g. Magic 3D or CST Particle Studio) that can model the physics correctly but are very time-consuming and resource-demanding. Hellweg is a special tool for quick and accurate electron dynamics simulation in traveling wave accelerating structures. The underlying theory of this software is based on the differential equations of motion. The effects considered in this code include beam loading, space charge forces, and external magnetic fields. We present the current capabilities of the code, provide benchmarking results, and discuss future plans. We also describe the browser-based GUI for executing Hellweg in the cloud.

Generation and Applications of High Average Power Mid-IR Supercontinuum in Chalcogenide Fibers

OpenAIRE

Petersen, Christian Rosenberg

2016-01-01

Mid-infrared supercontinuum with up to 54.8 mW average power, and maximum bandwidth of 1.77-8.66 μm is demonstrated as a result of pumping tapered chalcogenide photonic crystal fibers with a MHz parametric source at 4 μm

High average power Q-switched 1314 nm two-crystal Nd:YLF laser

CSIR Research Space (South Africa)

Botha, RC

2015-02-01

Full Text Available . 40, No. 4 / OPTICS LETTERS High average power Q-switched 1314 nm two-crystal Nd:YLF laser R. C. Botha,1,2,* W. Koen,3 M. J. D. Esser,3,4 C. Bollig,3,5 W. L. Combrinck,1,6 H. M. von Bergmann,2 and H. J. Strauss3 1HartRAO, P.O. Box 443...

Angle-averaged effective proton-carbon analyzing powers at intermediate energies

International Nuclear Information System (INIS)

Amir-Ahmadi, H.R.; Berg, A.M. van den; Hunyadi, M.; Kalantar-Nayestanaki, N.; Kis, M.; Mahjour-Shafiei, M.; Messchendorp, J.G.; Woertche, H.J.

2006-01-01

The angle-averaged effective analyzing powers, A-bar c , for proton-carbon inclusive scattering were measured as a function of the kinetic energy of protons in a double scattering experiment. The measurements were performed in the kinetic energy range of 44.8-136.5MeV at the center of 1-5cm thick graphite analyzers using a polarized proton beam on a CH 2 film or liquid hydrogen serving as target for the primary scattering. These data can be used for measuring the polarization of protons emerging from other reactions such as H(d-bar ,p-bar )d

Green-diode-pumped femtosecond Ti:Sapphire laser with up to 450 mW average power.

Science.gov (United States)

Gürel, K; Wittwer, V J; Hoffmann, M; Saraceno, C J; Hakobyan, S; Resan, B; Rohrbacher, A; Weingarten, K; Schilt, S; Südmeyer, T

2015-11-16

We investigate power-scaling of green-diode-pumped Ti:Sapphire lasers in continuous-wave (CW) and mode-locked operation. In a first configuration with a total pump power of up to 2 W incident onto the crystal, we achieved a CW power of up to 440 mW and self-starting mode-locking with up to 200 mW average power in 68-fs pulses using semiconductor saturable absorber mirror (SESAM) as saturable absorber. In a second configuration with up to 3 W of pump power incident onto the crystal, we achieved up to 650 mW in CW operation and up to 450 mW in 58-fs pulses using Kerr-lens mode-locking (KLM). The shortest pulse duration was 39 fs, which was achieved at 350 mW average power using KLM. The mode-locked laser generates a pulse train at repetition rates around 400 MHz. No complex cooling system is required: neither the SESAM nor the Ti:Sapphire crystal is actively cooled, only air cooling is applied to the pump diodes using a small fan. Because of mass production for laser displays, we expect that prices for green laser diodes will become very favorable in the near future, opening the door for low-cost Ti:Sapphire lasers. This will be highly attractive for potential mass applications such as biomedical imaging and sensing.

The Application of Cryogenic Laser Physics to the Development of High Average Power Ultra-Short Pulse Lasers

Directory of Open Access Journals (Sweden)

David C. Brown

2016-01-01

Full Text Available Ultrafast laser physics continues to advance at a rapid pace, driven primarily by the development of more powerful and sophisticated diode-pumping sources, the development of new laser materials, and new laser and amplification approaches such as optical parametric chirped-pulse amplification. The rapid development of high average power cryogenic laser sources seems likely to play a crucial role in realizing the long-sought goal of powerful ultrafast sources that offer concomitant high peak and average powers. In this paper, we review the optical, thermal, thermo-optic and laser parameters important to cryogenic laser technology, recently achieved laser and laser materials progress, the progression of cryogenic laser technology, discuss the importance of cryogenic laser technology in ultrafast laser science, and what advances are likely to be achieved in the near-future.

Specification of optical components for a high average-power laser environment

Energy Technology Data Exchange (ETDEWEB)

Taylor, J.R.; Chow, R.; Rinmdahl, K.A.; Willis, J.B.; Wong, J.N.

1997-06-25

Optical component specifications for the high-average-power lasers and transport system used in the Atomic Vapor Laser Isotope Separation (AVLIS) plant must address demanding system performance requirements. The need for high performance optics has to be balanced against the practical desire to reduce the supply risks of cost and schedule. This is addressed in optical system design, careful planning with the optical industry, demonstration of plant quality parts, qualification of optical suppliers and processes, comprehensive procedures for evaluation and test, and a plan for corrective action.

High-average-power laser medium based on silica glass

Science.gov (United States)

Fujimoto, Yasushi; Nakatsuka, Masahiro

2000-01-01

Silica glass is one of the most attractive materials for a high-average-power laser. We have developed a new laser material base don silica glass with zeolite method which is effective for uniform dispersion of rare earth ions in silica glass. High quality medium, which is bubbleless and quite low refractive index distortion, must be required for realization of laser action. As the main reason of bubbling is due to hydroxy species remained in the gelation same, we carefully choose colloidal silica particles, pH value of hydrochloric acid for hydrolysis of tetraethylorthosilicate on sol-gel process, and temperature and atmosphere control during sintering process, and then we get a bubble less transparent rare earth doped silica glass. The refractive index distortion of the sample also discussed.

Design and component specifications for high average power laser optical systems

Energy Technology Data Exchange (ETDEWEB)

O' Neil, R.W.; Sawicki, R.H.; Johnson, S.A.; Sweatt, W.C.

1987-01-01

Laser imaging and transport systems are considered in the regime where laser-induced damage and/or thermal distortion have significant design implications. System design and component specifications are discussed and quantified in terms of the net system transport efficiency and phase budget. Optical substrate materials, figure, surface roughness, coatings, and sizing are considered in the context of visible and near-ir optical systems that have been developed at Lawrence Livermore National Laboratory for laser isotope separation applications. In specific examples of general applicability, details of the bulk and/or surface absorption, peak and/or average power damage threshold, coating characteristics and function, substrate properties, or environmental factors will be shown to drive the component size, placement, and shape in high-power systems. To avoid overstressing commercial fabrication capabilities or component design specifications, procedures will be discussed for compensating for aberration buildup, using a few carefully placed adjustable mirrors. By coupling an aggressive measurements program on substrates and coatings to the design effort, an effective technique has been established to project high-power system performance realistically and, in the process, drive technology developments to improve performance or lower cost in large-scale laser optical systems. 13 refs.

Design and component specifications for high average power laser optical systems

International Nuclear Information System (INIS)

O'Neil, R.W.; Sawicki, R.H.; Johnson, S.A.; Sweatt, W.C.

1987-01-01

Laser imaging and transport systems are considered in the regime where laser-induced damage and/or thermal distortion have significant design implications. System design and component specifications are discussed and quantified in terms of the net system transport efficiency and phase budget. Optical substrate materials, figure, surface roughness, coatings, and sizing are considered in the context of visible and near-ir optical systems that have been developed at Lawrence Livermore National Laboratory for laser isotope separation applications. In specific examples of general applicability, details of the bulk and/or surface absorption, peak and/or average power damage threshold, coating characteristics and function, substrate properties, or environmental factors will be shown to drive the component size, placement, and shape in high-power systems. To avoid overstressing commercial fabrication capabilities or component design specifications, procedures will be discussed for compensating for aberration buildup, using a few carefully placed adjustable mirrors. By coupling an aggressive measurements program on substrates and coatings to the design effort, an effective technique has been established to project high-power system performance realistically and, in the process, drive technology developments to improve performance or lower cost in large-scale laser optical systems. 13 refs

High-average-power 2 μm few-cycle optical parametric chirped pulse amplifier at 100 kHz repetition rate.

Science.gov (United States)

Shamir, Yariv; Rothhardt, Jan; Hädrich, Steffen; Demmler, Stefan; Tschernajew, Maxim; Limpert, Jens; Tünnermann, Andreas

2015-12-01

Sources of long wavelengths few-cycle high repetition rate pulses are becoming increasingly important for a plethora of applications, e.g., in high-field physics. Here, we report on the realization of a tunable optical parametric chirped pulse amplifier at 100 kHz repetition rate. At a central wavelength of 2 μm, the system delivered 33 fs pulses and a 6 W average power corresponding to 60 μJ pulse energy with gigawatt-level peak powers. Idler absorption and its crystal heating is experimentally investigated for a BBO. Strategies for further power scaling to several tens of watts of average power are discussed.

High-average-power UV generation at 266 and 355 nm in β-BaB/sub 2/O/sub 4/

International Nuclear Information System (INIS)

Liu, K.C.; Rhoades, M.

1987-01-01

UV light has been generated previously by harmonic conversion from Nd:YAG lasers using the nonlinear crystals KD*P and ADP. Most of the previous studies have employed lasers with high peak power due to the low-harmonic-conversion efficiency of these crystals and also low average power due to the phase mismatch caused by temperature detuning resulting from UV absorption. A new nonlinear crystal β-BaB/sub 2/O/sub 4/ has recently been reported which provides for the possibility of overcoming the aforementioned problems. The authors utilized β-BaB/sub 2/O/sub 4/ to frequency triple and frequency quadruple a high-repetition-rate cw-pumped Nd:YAG laser and achieved up to 1-W average power with Gaussian spatial distribution at 266 and 355 nm. β-BaB/sub 2/O/sub 4/ has demonstrated its advantages for high-average-power UV generation. Its major drawback is a low-angular-acceptance bandwidth which requires a high-quality fundamental pump beam

High-throughput machining using high average power ultrashort pulse lasers and ultrafast polygon scanner

Science.gov (United States)

Schille, Joerg; Schneider, Lutz; Streek, André; Kloetzer, Sascha; Loeschner, Udo

2016-03-01

In this paper, high-throughput ultrashort pulse laser machining is investigated on various industrial grade metals (Aluminium, Copper, Stainless steel) and Al2O3 ceramic at unprecedented processing speeds. This is achieved by using a high pulse repetition frequency picosecond laser with maximum average output power of 270 W in conjunction with a unique, in-house developed two-axis polygon scanner. Initially, different concepts of polygon scanners are engineered and tested to find out the optimal architecture for ultrafast and precision laser beam scanning. Remarkable 1,000 m/s scan speed is achieved on the substrate, and thanks to the resulting low pulse overlap, thermal accumulation and plasma absorption effects are avoided at up to 20 MHz pulse repetition frequencies. In order to identify optimum processing conditions for efficient high-average power laser machining, the depths of cavities produced under varied parameter settings are analyzed and, from the results obtained, the characteristic removal values are specified. The maximum removal rate is achieved as high as 27.8 mm3/min for Aluminium, 21.4 mm3/min for Copper, 15.3 mm3/min for Stainless steel and 129.1 mm3/min for Al2O3 when full available laser power is irradiated at optimum pulse repetition frequency.

Laser properties of an improved average-power Nd-doped phosphate glass

International Nuclear Information System (INIS)

Payne, S.A.; Marshall, C.D.; Bayramian, A.J.

1995-01-01

The Nd-doped phosphate laser glass described herein can withstand 2.3 times greater thermal loading without fracture, compared to APG-1 (commercially-available average-power glass from Schott Glass Technologies). The enhanced thermal loading capability is established on the basis of the intrinsic thermomechanical properties (expansion, conduction, fracture toughness, and Young's modulus), and by direct thermally-induced fracture experiments using Ar-ion laser heating of the samples. This Nd-doped phosphate glass (referred to as APG-t) is found to be characterized by a 29% lower gain cross section and a 25% longer low-concentration emission lifetime

Development of high-average-power-laser medium based on silica glass

International Nuclear Information System (INIS)

Fujimoto, Yasushi; Nakatsuka, Masahiro

2000-01-01

We have developed a high-average-power laser material based on silica glass. A new method using Zeolite X is effective for homogeneously dispersing rare earth ions in silica glass to get a high quantum yield. High quality medium, which is bubbleless and quite low refractive index distortion, must be required for realization of laser action, and therefore, we have carefully to treat the gelation and sintering processes, such as, selection of colloidal silica, pH value of for hydrolysis of tetraethylorthosilicate, and sintering history. The quality of the sintered sample and the applications are discussed. (author)

Development of high average power industrial Nd:YAG laser with peak power of 10 kW class

International Nuclear Information System (INIS)

Kim, Cheol Jung; Kim, Jeong Mook; Jung, Chin Mann; Kim, Soo Sung; Kim, Kwang Suk; Kim, Min Suk; Cho, Jae Wan; Kim, Duk Hyun

1992-03-01

We developed and commercialized an industrial pulsed Nd:YAG laser with peak power of 10 kW class for fine cutting and drilling applications. Several commercial models have been investigated in design and performance. We improved its quality to the level of commercial Nd:YAG laser by an endurance test for each parts of laser system. The maximum peak power and average power of our laser were 10 kW and 250 W, respectively. Moreover, the laser pulse width could be controlled from 0.5 msec to 20 msec continuously. Many optical parts were localized and lowered much in cost. Only few parts were imported and almost 90% in cost were localized. Also, to accellerate the commercialization by the joint company, the training and transfer of technology were pursued in the joint participation in design and assembly by company researchers from the early stage. Three Nd:YAG lasers have been assembled and will be tested in industrial manufacturing process to prove the capability of developed Nd:YAG laser with potential users. (Author)

Cooperative AF Relaying in Spectrum-Sharing Systems: Performance Analysis under Average Interference Power Constraints and Nakagami-m Fading

KAUST Repository

Xia, Minghua; Aissa, Sonia

2012-01-01

the optimal end-to-end performance, the transmit powers of the secondary source and the relays are optimized with respect to average interference power constraints at primary users and Nakagami-$m$ fading parameters of interference channels (for mathematical

Spatial models for probabilistic prediction of wind power with application to annual-average and high temporal resolution data

DEFF Research Database (Denmark)

Lenzi, Amanda; Pinson, Pierre; Clemmensen, Line Katrine Harder

2017-01-01

average wind power generation, and for a high temporal resolution (typically wind power averages over 15-min time steps). In both cases, we use a spatial hierarchical statistical model in which spatial correlation is captured by a latent Gaussian field. We explore how such models can be handled...... with stochastic partial differential approximations of Matérn Gaussian fields together with Integrated Nested Laplace Approximations. We demonstrate the proposed methods on wind farm data from Western Denmark, and compare the results to those obtained with standard geostatistical methods. The results show...

Industrial applications of high-average power high-peak power nanosecond pulse duration Nd:YAG lasers

Science.gov (United States)

Harrison, Paul M.; Ellwi, Samir

2009-02-01

Within the vast range of laser materials processing applications, every type of successful commercial laser has been driven by a major industrial process. For high average power, high peak power, nanosecond pulse duration Nd:YAG DPSS lasers, the enabling process is high speed surface engineering. This includes applications such as thin film patterning and selective coating removal in markets such as the flat panel displays (FPD), solar and automotive industries. Applications such as these tend to require working spots that have uniform intensity distribution using specific shapes and dimensions, so a range of innovative beam delivery systems have been developed that convert the gaussian beam shape produced by the laser into a range of rectangular and/or shaped spots, as required by demands of each project. In this paper the authors will discuss the key parameters of this type of laser and examine why they are important for high speed surface engineering projects, and how they affect the underlying laser-material interaction and the removal mechanism. Several case studies will be considered in the FPD and solar markets, exploring the close link between the application, the key laser characteristics and the beam delivery system that link these together.

Relation of average and highest solvent vapor concentrations in workplaces in small to medium enterprises and large enterprises.

Science.gov (United States)

Ukai, Hirohiko; Ohashi, Fumiko; Samoto, Hajime; Fukui, Yoshinari; Okamoto, Satoru; Moriguchi, Jiro; Ezaki, Takafumi; Takada, Shiro; Ikeda, Masayuki

2006-04-01

The present study was initiated to examine the relationship between the workplace concentrations and the estimated highest concentrations in solvent workplaces (SWPs), with special references to enterprise size and types of solvent work. Results of survey conducted in 1010 SWPs in 156 enterprises were taken as a database. Workplace air was sampled at > or = 5 crosses in each SWP following a grid sampling strategy. An additional air was grab-sampled at the site where the worker's exposure was estimated to be highest (estimated highest concentration or EHC). The samples were analyzed for 47 solvents designated by regulation, and solvent concentrations in each sample were summed up by use of additiveness formula. From the workplace concentrations at > or = 5 points, geometric mean and geometric standard deviations were calculated as the representative workplace concentration (RWC) and the indicator of variation in workplace concentration (VWC). Comparison between RWC and EHC in the total of 1010 SWPs showed that EHC was 1.2 (in large enterprises with>300 employees) to 1.7 times [in small to medium (SM) enterprises with enterprises and large enterprises, both RWC and EHC were significantly higher in SM enterprises than in large enterprises. Further comparison by types of solvent work showed that the difference was more marked in printing, surface coating and degreasing/cleaning/wiping SWPs, whereas it was less remarkable in painting SWPs and essentially nil in testing/research laboratories. In conclusion, the present observation as discussed in reference to previous publications suggests that RWC, EHC and the ratio of EHC/WRC varies substantially among different types of solvent work as well as enterprise size, and are typically higher in printing SWPs in SM enterprises.

Operating experience from Swedish nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-06-01

The total production of electricity from Swedish nuclear power plants was 70.5 TWh during 1998, which is the second highest yearly production ever. Production losses due to low demand totaled 5.1 TWh combined for all twelve units and production losses due to coastdown operation totaled an additional 0.5 TWh. The reason for this low power demand was a very good supply of water to the hydropower system. Hydroelectric power production was 73.6 TWh, an increase by roughly 5 TWh since 1997. Hence, the hydroelectric power production substantially exceeded the 64 TWh expected during a normal year, i.e. a year with average rainfall. Remaining production sources, mainly fossil fuel electricity production combined with district heating, contributed with 10 TWh. The total electricity production was 154.2 TWh, the highest yearly production ever. The total electricity consumption including transmission losses was 143.5 TWh. This is also the highest consumption ever and an increase by one percent compared to 1997. The preliminary net result of the electric power trade shows a net export by 10.7 TWh. The figures above are calculated from the preliminary production results. A comprehensive report on electric power supply and consumption in Sweden is given in the 1998 Annual Report from the Swedish Power Association. Besides Oskarshamn 1, all plants have periodically been operated in load-following mode, mostly because of the abundant supply of hydropower. The energy availability for the three boiling water reactors at Forsmark averaged 93.3 % and for the three pressure water reactors at Ringhals 91.0 %, both figures are the highest ever noted. In the section `Special Reports` three events of importance to safety that occurred during 1998 are reported. The events were all rated as level 1 according to the International Nuclear Event Scale (INES) Figs, tabs.; Also available in Swedish

Operating experience from Swedish nuclear power plants

International Nuclear Information System (INIS)

1999-01-01

The total production of electricity from Swedish nuclear power plants was 70.5 TWh during 1998, which is the second highest yearly production ever. Production losses due to low demand totaled 5.1 TWh combined for all twelve units and production losses due to coastdown operation totaled an additional 0.5 TWh. The reason for this low power demand was a very good supply of water to the hydropower system. Hydroelectric power production was 73.6 TWh, an increase by roughly 5 TWh since 1997. Hence, the hydroelectric power production substantially exceeded the 64 TWh expected during a normal year, i.e. a year with average rainfall. Remaining production sources, mainly fossil fuel electricity production combined with district heating, contributed with 10 TWh. The total electricity production was 154.2 TWh, the highest yearly production ever. The total electricity consumption including transmission losses was 143.5 TWh. This is also the highest consumption ever and an increase by one percent compared to 1997. The preliminary net result of the electric power trade shows a net export by 10.7 TWh. The figures above are calculated from the preliminary production results. A comprehensive report on electric power supply and consumption in Sweden is given in the 1998 Annual Report from the Swedish Power Association. Besides Oskarshamn 1, all plants have periodically been operated in load-following mode, mostly because of the abundant supply of hydropower. The energy availability for the three boiling water reactors at Forsmark averaged 93.3 % and for the three pressure water reactors at Ringhals 91.0 %, both figures are the highest ever noted. In the section 'Special Reports' three events of importance to safety that occurred during 1998 are reported. The events were all rated as level 1 according to the International Nuclear Event Scale (INES)

Peak-to-average power ratio reduction in interleaved OFDMA systems

KAUST Repository

Al-Shuhail, Shamael; Ali, Anum; Al-Naffouri, Tareq Y.

2015-01-01

Orthogonal frequency division multiple access (OFDMA) systems suffer from several impairments, and communication system engineers use powerful signal processing tools to combat these impairments and to keep up with the capacity/rate demands. One of these impairments is high peak-to-average power ratio (PAPR) and clipping is the simplest peak reduction scheme. However, in general, when multiple users are subjected to clipping, frequency domain clipping distortions spread over the spectrum of all users. This results in compromised performance and hence clipping distortions need to be mitigated at the receiver. Mitigating these distortions in multiuser case is not simple and requires complex clipping mitigation procedures at the receiver. However, it was observed that interleaved OFDMA presents a special structure that results in only self-inflicted clipping distortions (i.e., the distortions of a particular user do not interfere with other users). In this work, we prove analytically that distortions do not spread over multiple users (while utilizing interleaved carrier assignment in OFDMA) and construct a compressed sensing system that utilizes the sparsity of the clipping distortions and recovers it on each user. We provide numerical results that validate our analysis and show promising performance for the proposed clipping recovery scheme.

Peak-to-average power ratio reduction in interleaved OFDMA systems

KAUST Repository

Al-Shuhail, Shamael

2015-12-07

Orthogonal frequency division multiple access (OFDMA) systems suffer from several impairments, and communication system engineers use powerful signal processing tools to combat these impairments and to keep up with the capacity/rate demands. One of these impairments is high peak-to-average power ratio (PAPR) and clipping is the simplest peak reduction scheme. However, in general, when multiple users are subjected to clipping, frequency domain clipping distortions spread over the spectrum of all users. This results in compromised performance and hence clipping distortions need to be mitigated at the receiver. Mitigating these distortions in multiuser case is not simple and requires complex clipping mitigation procedures at the receiver. However, it was observed that interleaved OFDMA presents a special structure that results in only self-inflicted clipping distortions (i.e., the distortions of a particular user do not interfere with other users). In this work, we prove analytically that distortions do not spread over multiple users (while utilizing interleaved carrier assignment in OFDMA) and construct a compressed sensing system that utilizes the sparsity of the clipping distortions and recovers it on each user. We provide numerical results that validate our analysis and show promising performance for the proposed clipping recovery scheme.

Research on DC-RF superconducting photocathode injector for high average power FELs

International Nuclear Information System (INIS)

Zhao Kui; Hao Jiankui; Hu Yanle; Zhang Baocheng; Quan Shengwen; Chen Jiaer; Zhuang Jiejia

2001-01-01

To obtain high average current electron beams for a high average power Free Electron Laser (FEL), a DC-RF superconducting injector is designed. It consists of a DC extraction gap, a 1+((1)/(2)) superconducting cavity and a coaxial input system. The DC gap, which takes the form of a Pierce configuration, is connected to the 1+((1)/(2)) superconducting cavity. The photocathode is attached to the negative electrode of the DC gap. The anode forms the bottom of the ((1)/(2)) cavity. Simulations are made to model the beam dynamics of the electron beams extracted by the DC gap and accelerated by the superconducting cavity. High quality electron beams with emittance lower than 3 π-mm-mrad can be obtained. The optimization of experiments with the DC gap, as well as the design of experiments with the coaxial coupler have all been completed. An optimized 1+((1)/(2)) superconducting cavity is in the process of being studied and manufactured

The measurement of power losses at high magnetic field densities or at small cross-section of test specimen using the averaging

CERN Document Server

Gorican, V; Hamler, A; Nakata, T

2000-01-01

It is difficult to achieve sufficient accuracy of power loss measurement at high magnetic field densities where the magnetic field strength gets more and more distorted, or in cases where the influence of noise increases (small specimen cross section). The influence of averaging on the accuracy of power loss measurement was studied on the cast amorphous magnetic material Metglas 2605-TCA. The results show that the accuracy of power loss measurements can be improved by using the averaging of data acquisition points.

High-throughput machining using a high-average power ultrashort pulse laser and high-speed polygon scanner

Science.gov (United States)

Schille, Joerg; Schneider, Lutz; Streek, André; Kloetzer, Sascha; Loeschner, Udo

2016-09-01

High-throughput ultrashort pulse laser machining is investigated on various industrial grade metals (aluminum, copper, and stainless steel) and Al2O3 ceramic at unprecedented processing speeds. This is achieved by using a high-average power picosecond laser in conjunction with a unique, in-house developed polygon mirror-based biaxial scanning system. Therefore, different concepts of polygon scanners are engineered and tested to find the best architecture for high-speed and precision laser beam scanning. In order to identify the optimum conditions for efficient processing when using high-average laser powers, the depths of cavities made in the samples by varying the processing parameter settings are analyzed and, from the results obtained, the characteristic removal values are specified. For overlapping pulses of optimum fluence, the removal rate is as high as 27.8 mm3/min for aluminum, 21.4 mm3/min for copper, 15.3 mm3/min for stainless steel, and 129.1 mm3/min for Al2O3, when a laser beam of 187 W average laser powers irradiates. On stainless steel, it is demonstrated that the removal rate increases to 23.3 mm3/min when the laser beam is very fast moving. This is thanks to the low pulse overlap as achieved with 800 m/s beam deflection speed; thus, laser beam shielding can be avoided even when irradiating high-repetitive 20-MHz pulses.

A Hybrid Islanding Detection Technique Using Average Rate of Voltage Change and Real Power Shift

DEFF Research Database (Denmark)

Mahat, Pukar; Chen, Zhe; Bak-Jensen, Birgitte

2009-01-01

The mainly used islanding detection techniques may be classified as active and passive techniques. Passive techniques don't perturb the system but they have larger nondetection znes, whereas active techniques have smaller nondetection zones but they perturb the system. In this paper, a new hybrid...... technique is proposed to solve this problem. An average rate of voltage change (passive technique) has been used to initiate a real power shift (active technique), which changes the eal power of distributed generation (DG), when the passive technique cannot have a clear discrimination between islanding...

Exposure to power frequency electromagnetic fields

International Nuclear Information System (INIS)

Skotte, J.

1993-01-01

The purpose was to asses personal exposure to power frequency electromagnetic fields in Denmark. Exposure to electrical and magnetic 50 Hz fields were measured with personal dosimeters in periods of 24 hours covering both occupational and residential environments. The study included both highly exposed and 'normal' exposed jobs. Measurements were carried out with dosimeters, which sample electrical and magnetic fields every 5 sec. Participants also wore the dosimeter during transportation. The dynamic range of the dosimeters was 0.01-200 μT and 0.6-10000 V/m. The highest average exposure in homes near high power lines was 2.24 μT. In most homes without nearby high power lines the average exposure was below 0.05 μT. Average values of '24-hour-dose' (μT times hours) for the generator facility, transmission line and substation workers were approximately the same as for the people living near high power lines (5 μT x hours). Electric field measurements with personal dosimeters involve several factors of uncertainty, as the body, posture, position of dosimeter etc. influence the results. The highest exposed groups were transmission line workers (GM: 44 V/m) and substation workers (GM: 23 V/m) but there were large variations (GSD: 4.7-4.8). In the work time the exposure level was the same for office workers and workers in the industry groups (GM: 12-13 V/m). In homes near high power lines (GM: 23 V/m) there was a non-significant tendency to higher exposure compared to homes without nearby high power lines. (AB) (11 refs.)

Strips of hourly power options. Approximate hedging using average-based forward contracts

International Nuclear Information System (INIS)

Lindell, Andreas; Raab, Mikael

2009-01-01

We study approximate hedging strategies for a contingent claim consisting of a strip of independent hourly power options. The payoff of the contingent claim is a sum of the contributing hourly payoffs. As there is no forward market for specific hours, the fundamental problem is to find a reasonable hedge using exchange-traded forward contracts, e.g. average-based monthly contracts. The main result is a simple dynamic hedging strategy that reduces a significant part of the variance. The idea is to decompose the contingent claim into mathematically tractable components and to use empirical estimations to derive hedging deltas. Two benefits of the method are that the technique easily extends to more complex power derivatives and that only a few parameters need to be estimated. The hedging strategy based on the decomposition technique is compared with dynamic delta hedging strategies based on local minimum variance hedging, using a correlated traded asset. (author)

Average stopping powers for electron and photon sources for radiobiological modeling and microdosimetric applications

Science.gov (United States)

Vassiliev, Oleg N.; Kry, Stephen F.; Grosshans, David R.; Mohan, Radhe

2018-03-01

This study concerns calculation of the average electronic stopping power for photon and electron sources. It addresses two problems that have not yet been fully resolved. The first is defining the electron spectrum used for averaging in a way that is most suitable for radiobiological modeling. We define it as the spectrum of electrons entering the sensitive to radiation volume (SV) within the cell nucleus, at the moment they enter the SV. For this spectrum we derive a formula that combines linearly the fluence spectrum and the source spectrum. The latter is the distribution of initial energies of electrons produced by a source. Previous studies used either the fluence or source spectra, but not both, thereby neglecting a part of the complete spectrum. Our derived formula reduces to these two prior methods in the case of high and low energy sources, respectively. The second problem is extending electron spectra to low energies. Previous studies used an energy cut-off on the order of 1 keV. However, as we show, even for high energy sources, such as 60Co, electrons with energies below 1 keV contribute about 30% to the dose. In this study all the spectra were calculated with Geant4-DNA code and a cut-off energy of only 11 eV. We present formulas for calculating frequency- and dose-average stopping powers, numerical results for several important electron and photon sources, and tables with all the data needed to use our formulas for arbitrary electron and photon sources producing electrons with initial energies up to  ∼1 MeV.

PEAK-TO-AVERAGE POWER RATIO REDUCTION USING CODING AND HYBRID TECHNIQUES FOR OFDM SYSTEM

OpenAIRE

Bahubali K. Shiragapur; Uday Wali

2016-01-01

In this article, the research work investigated is based on an error correction coding techniques are used to reduce the undesirable Peak-to-Average Power Ratio (PAPR) quantity. The Golay Code (24, 12), Reed-Muller code (16, 11), Hamming code (7, 4) and Hybrid technique (Combination of Signal Scrambling and Signal Distortion) proposed by us are used as proposed coding techniques, the simulation results shows that performance of Hybrid technique, reduces PAPR significantly as compared to Conve...

The use of induction linacs with nonlinear magnetic drive as high average power accelerators

International Nuclear Information System (INIS)

Birx, D.L.; Cook, E.G.; Hawkins, S.A.; Newton, M.A.; Poor, S.E.; Reginato, L.L.; Schmidt, J.A.; Smith, M.W.

1985-01-01

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/m, and with power efficiences approaching 50%. A 2 MeV, 5 kA electron accelerator is under construction at Lawrence Livermore National Laboratory (LLNL) to allow us to demonstrate some of these concepts. Progress on this project is reported here. (orig.)

18 CFR 301.7 - Average System Cost methodology functionalization.

Science.gov (United States)

2010-04-01

... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Average System Cost... REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS FOR FEDERAL POWER MARKETING ADMINISTRATIONS AVERAGE SYSTEM COST METHODOLOGY FOR SALES FROM UTILITIES TO BONNEVILLE POWER ADMINISTRATION UNDER NORTHWEST POWER...

A diode-pumped continuous-wave Nd:YAG laser with an average output power of 1 kW

International Nuclear Information System (INIS)

Lee, Sung Man; Cha, Byung Heon; Kim, Cheol Jung

2004-01-01

A diode-pumped Nd:YAG laser with an average output power of 1 kW is developed for industrial applications, such as metal cutting, precision welding, etc. To develop such a diode-pumped high power solid-state laser, a series of laser modules have been used in general with and without thermal birefringence compensation. For example, Akiyama et al. used three laser modules to obtain a output power of 5.4 kW CW.1 In the side-pumped Nd:YAG laser, which is a commonly used pump scheme to obtain high output power, the crystal rod has a short thermal focal length at a high input pump power, and the short thermal focal length in turn leads to beam distortion within a laser resonator. Therefore, to achieve a high output power with good stability, isotropic beam profile, and high optical efficiency, the detailed analysis of the resonator stability condition depending on both mirror distances and a crystal separation is essential

Rationalization of the electric power utilization for the ferro-alloy production at the HEK 'Jugohrom' by means of the follow up and restriction of the highest level loading as well as automatic processing system for the involved electric power (Macedonia)

International Nuclear Information System (INIS)

Koevski, Doncho

2001-01-01

The relations between the electro energetic system and the energetic generally, as well as the chronic energetic crisis, the electric power price, provoked to analyse the application of the economic use forms of the electric power. This paper presents the way of rationalisation of the electric power utilization for the ferro-alloy production in Jugohrom. This is done by appointing the measuring system, control and limitation of the highest level loading as well as automatic processing system for the involved electric power. (Original)

Rationalization of the electric power utilization for the ferro-alloy production at the HEK 'Jugohrom' by means of the follow up and restriction of the highest level loading as well as automatic processing system for the involved electric power (Macedonia)

International Nuclear Information System (INIS)

Koevski, Doncho

2002-01-01

The relations between the electro energetic system and the energetic generally, as well as the chronic energetic crisis, the electric power price, provoked to analyse the application of the economic use forms of the electric power. This paper presents the way of rationalisation of the electric power utilization for the ferro-alloy production in Jugohrom. This is done by appointing the measuring system, control and limitation of the highest level loading as well as automatic processing system for the involved electric power. (Original)

Average stopping powers and the use of non-analyte spiking for the determination of phosphorus and sodium by PIPPS

International Nuclear Information System (INIS)

Olivier, C.; Morland, H.J.

1991-01-01

By using particle induced prompt photon spectrometry, PIPPS, the ratios of the average stopping powers in samples and standards can be used to determine elemental compositions. Since the average stopping powers in the samples are in general unknown, this procedure poses a problem. It has been shown that by spiking the sample with a known amount of a compound with known stopping power and containing a non-analyte element, appropriate stopping powers in the samples can be determined by measuring the prompt gamma-ray yields induced in the spike. Using 5-MeV protons and lithium compounds as non-analyte spikes, sodium and phosphorus were determined in ivory, while sodium was determined in geological samples. For the stopping power determinations in the samples the 429-keV 7 Li n(1,0) and 478-keV 7 Li (1,0) gamma rays were measured, while for phosphorus and sodium determinations the high yield 1,266-keV 31 P (1,0), 440-keV 23 Na (1,0), 1,634-keV, Na 23 α(1,0) and 1,637-keV 23 Na (2,1) gamma rays were used. The method was tested by analyzing the standard reference materials SRM 91, 120c and 694

Cutting-Edge High-Power Ultrafast Thin Disk Oscillators

Directory of Open Access Journals (Sweden)

Thomas Südmeyer

2013-04-01

Full Text Available A growing number of applications in science and industry are currently pushing the development of ultrafast laser technologies that enable high average powers. SESAM modelocked thin disk lasers (TDLs currently achieve higher pulse energies and average powers than any other ultrafast oscillator technology, making them excellent candidates in this goal. Recently, 275 W of average power with a pulse duration of 583 fs were demonstrated, which represents the highest average power so far demonstrated from an ultrafast oscillator. In terms of pulse energy, TDLs reach more than 40 μJ pulses directly from the oscillator. In addition, another major milestone was recently achieved, with the demonstration of a TDL with nearly bandwidth-limited 96-fs long pulses. The progress achieved in terms of pulse duration of such sources enabled the first measurement of the carrier-envelope offset frequency of a modelocked TDL, which is the first key step towards full stabilization of such a source. We will present the key elements that enabled these latest results, as well as an outlook towards the next scaling steps in average power, pulse energy and pulse duration of such sources. These cutting-edge sources will enable exciting new applications, and open the door to further extending the current performance milestones.

Origin of the highest energy cosmic rays

Energy Technology Data Exchange (ETDEWEB)

Biermann, Peter L.; Ahn, Eun-Joo; Medina-Tanco, Gustavo; Stanev, Todor

2000-06-01

Introducing a simple Galactic wind model patterned after the solar wind we show that back-tracing the orbits of the highest energy cosmic events suggests that they may all come from the Virgo cluster, and so probably from the active radio galaxy M87. This confirms a long standing expectation. Those powerful radio galaxies that have their relativistic jets stuck in the interstellar medium of the host galaxy, such as 3C147, will then enable us to derive limits on the production of any new kind of particle, expected in some extensions of the standard model in particle physics. New data from HIRES will be crucial in testing the model proposed here.

Autoregressive moving average fitting for real standard deviation in Monte Carlo power distribution calculation

International Nuclear Information System (INIS)

Ueki, Taro

2010-01-01

The noise propagation of tallies in the Monte Carlo power method can be represented by the autoregressive moving average process of orders p and p-1 (ARMA(p,p-1)], where p is an integer larger than or equal to two. The formula of the autocorrelation of ARMA(p,q), p≥q+1, indicates that ARMA(3,2) fitting is equivalent to lumping the eigenmodes of fluctuation propagation in three modes such as the slow, intermediate and fast attenuation modes. Therefore, ARMA(3,2) fitting was applied to the real standard deviation estimation of fuel assemblies at particular heights. The numerical results show that straightforward ARMA(3,2) fitting is promising but a stability issue must be resolved toward the incorporation in the distributed version of production Monte Carlo codes. The same numerical results reveal that the average performance of ARMA(3,2) fitting is equivalent to that of the batch method in MCNP with a batch size larger than one hundred and smaller than two hundred cycles for a 1100 MWe pressurized water reactor. The bias correction of low lag autocovariances in MVP/GMVP is demonstrated to have the potential of improving the average performance of ARMA(3,2) fitting. (author)

Cooperative AF Relaying in Spectrum-Sharing Systems: Performance Analysis under Average Interference Power Constraints and Nakagami-m Fading

KAUST Repository

Xia, Minghua

2012-06-01

Since the electromagnetic spectrum resource becomes more and more scarce, improving spectral efficiency is extremely important for the sustainable development of wireless communication systems and services. Integrating cooperative relaying techniques into spectrum-sharing cognitive radio systems sheds new light on higher spectral efficiency. In this paper, we analyze the end-to-end performance of cooperative amplify-and-forward (AF) relaying in spectrum-sharing systems. In order to achieve the optimal end-to-end performance, the transmit powers of the secondary source and the relays are optimized with respect to average interference power constraints at primary users and Nakagami-$m$ fading parameters of interference channels (for mathematical tractability, the desired channels from secondary source to relay and from relay to secondary destination are assumed to be subject to Rayleigh fading). Also, both partial and opportunistic relay-selection strategies are exploited to further enhance system performance. Based on the exact distribution functions of the end-to-end signal-to-noise ratio (SNR) obtained herein, the outage probability, average symbol error probability, diversity order, and ergodic capacity of the system under study are analytically investigated. Our results show that system performance is dominated by the resource constraints and it improves slowly with increasing average SNR. Furthermore, larger Nakagami-m fading parameter on interference channels deteriorates system performance slightly. On the other hand, when interference power constraints are stringent, opportunistic relay selection can be exploited to improve system performance significantly. All analytical results are corroborated by simulation results and they are shown to be efficient tools for exact evaluation of system performance.

Design of an L-band normally conducting RF gun cavity for high peak and average RF power

Energy Technology Data Exchange (ETDEWEB)

Paramonov, V., E-mail: paramono@inr.ru [Institute for Nuclear Research of Russian Academy of Sciences, 60-th October Anniversary prospect 7a, 117312 Moscow (Russian Federation); Philipp, S. [Deutsches Elektronen-Synchrotron DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Rybakov, I.; Skassyrskaya, A. [Institute for Nuclear Research of Russian Academy of Sciences, 60-th October Anniversary prospect 7a, 117312 Moscow (Russian Federation); Stephan, F. [Deutsches Elektronen-Synchrotron DESY, Platanenallee 6, D-15738 Zeuthen (Germany)

2017-05-11

To provide high quality electron bunches for linear accelerators used in free electron lasers and particle colliders, RF gun cavities operate with extreme electric fields, resulting in a high pulsed RF power. The main L-band superconducting linacs of such facilities also require a long RF pulse length, resulting in a high average dissipated RF power in the gun cavity. The newly developed cavity based on the proven advantages of the existing DESY RF gun cavities, underwent significant changes. The shape of the cells is optimized to reduce the maximal surface electric field and RF loss power. Furthermore, the cavity is equipped with an RF probe to measure the field amplitude and phase. The elaborated cooling circuit design results in a lower temperature rise on the cavity RF surface and permits higher dissipated RF power. The paper presents the main solutions and results of the cavity design.

Highest manageable level of radioactivity in the waste storage facilities of power plants

International Nuclear Information System (INIS)

Elkert, J.; Lennartsson, R.

1991-01-01

This project presents and discusses an investigation of the highest level of radioactivity possible to handle in the waste storage facilities. The amount of radioactivity, about 0.1% of the fuel inventory, is the same in both of the cases but the amount of water is very different. The hypothetical accident was supposed to be damage of the reactor fuel caused by loss of coolant. (K.A.E.)

Compact Source of Electron Beam with Energy of 200 kEv and Average Power of 2 kW

CERN Document Server

Kazarezov, Ivan; Balakin, Vladimir E; Bryazgin, Alex; Bulatov, Alexandre; Glazkov, Ivan; Kokin, Evgeny; Krainov, Gennady; Kuznetsov, Gennady I; Molokoedov, Andrey; Tuvik, Alfred

2005-01-01

The paper describes a compact electron beam source with average electron energy of 200 keV. The source operates with pulse power up to 2 MW under average power not higher than 2 kW, pulsed beam current up to 10 A, pulse duration up to 2 mks, and repetition rate up to 5 kHz. The electron beam is extracted through aluminium-beryllium alloy foil. The pulse duration and repetition rate can be changed from control desk. High-voltage generator for the source with output voltage up to 220 kV is realized using the voltage-doubling circuit which consists of 30 sections. The insulation type - gas, SF6 under pressure of 8 atm. The cooling of the foil supporting tubes is provided by a water-alcohol mixture from an independent source. The beam output window dimensions are 180?75 mm, the energy spread in the beam +10/-30%, the source weight is 80 kg.

Systematic approach to peak-to-average power ratio in OFDM

Science.gov (United States)

Schurgers, Curt

2001-11-01

OFDM multicarrier systems support high data rate wireless transmission using orthogonal frequency channels, and require no extensive equalization, yet offer excellent immunity against fading and inter-symbol interference. The major drawback of these systems is the large Peak-to-Average power Ratio (PAR) of the transmit signal, which renders a straightforward implementation very costly and inefficient. Existing approaches that attack this PAR issue are abundant, but no systematic framework or comparison between them exist to date. They sometimes even differ in the problem definition itself and consequently in the basic approach to follow. In this work, we provide a systematic approach that resolves this ambiguity and spans the existing PAR solutions. The basis of our framework is the observation that efficient system implementations require a reduced signal dynamic range. This range reduction can be modeled as a hard limiting, also referred to as clipping, where the extra distortion has to be considered as part of the total noise tradeoff. We illustrate that the different PAR solutions manipulate this tradeoff in alternative ways in order to improve the performance. Furthermore, we discuss and compare a broad range of such techniques and organize them into three classes: block coding, clip effect transformation and probabilistic.

Development of laser diode-pumped high average power solid-state laser for the pumping of Ti:sapphire CPA system

Energy Technology Data Exchange (ETDEWEB)

Maruyama, Yoichiro; Tei, Kazuyoku; Kato, Masaaki; Niwa, Yoshito; Harayama, Sayaka; Oba, Masaki; Matoba, Tohru; Arisawa, Takashi; Takuma, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-03-01

Laser diode pumped all solid state, high repetition frequency (PRF) and high energy Nd:YAG laser using zigzag slab crystals has been developed for the pumping source of Ti:sapphire CPA system. The pumping laser installs two main amplifiers which compose ring type amplifier configuration. The maximum amplification gain of the amplifier system is 140 and the condition of saturated amplification is achieved with this high gain. The average power of fundamental laser radiation is 250 W at the PRF of 200 Hz and the pulse duration is around 20 ns. The average power of second harmonic is 105 W at the PRF of 170 Hz and the pulse duration is about 16 ns. The beam profile of the second harmonic is near top hat and will be suitable for the pumping of Ti:sapphire laser crystal. The wall plug efficiency of the laser is 2.0 %. (author)

Half-Watt average power femtosecond source spanning 3-8 µm based on subharmonic generation in GaAs

Science.gov (United States)

Smolski, Viktor; Vasilyev, Sergey; Moskalev, Igor; Mirov, Mike; Ru, Qitian; Muraviev, Andrey; Schunemann, Peter; Mirov, Sergey; Gapontsev, Valentin; Vodopyanov, Konstantin

2018-06-01

Frequency combs with a wide instantaneous spectral span covering the 3-20 µm molecular fingerprint region are highly desirable for broadband and high-resolution frequency comb spectroscopy, trace molecular detection, and remote sensing. We demonstrate a novel approach for generating high-average-power middle-infrared (MIR) output suitable for producing frequency combs with an instantaneous spectral coverage close to 1.5 octaves. Our method is based on utilizing a highly-efficient and compact Kerr-lens mode-locked Cr2+:ZnS laser operating at 2.35-µm central wavelength with 6-W average power, 77-fs pulse duration, and high 0.9-GHz repetition rate; to pump a degenerate (subharmonic) optical parametric oscillator (OPO) based on a quasi-phase-matched GaAs crystal. Such subharmonic OPO is a nearly ideal frequency converter capable of extending the benefits of frequency combs based on well-established mode-locked pump lasers to the MIR region through rigorous, phase- and frequency-locked down conversion. We report a 0.5-W output in the form of an ultra-broadband spectrum spanning 3-8 µm measured at 50-dB level.

Sub-100 fs high average power directly blue-diode-laser-pumped Ti:sapphire oscillator

Science.gov (United States)

Rohrbacher, Andreas; Markovic, Vesna; Pallmann, Wolfgang; Resan, Bojan

2016-03-01

Ti:sapphire oscillators are a proven technology to generate sub-100 fs (even sub-10 fs) pulses in the near infrared and are widely used in many high impact scientific fields. However, the need for a bulky, expensive and complex pump source, typically a frequency-doubled multi-watt neodymium or optically pumped semiconductor laser, represents the main obstacle to more widespread use. The recent development of blue diodes emitting over 1 W has opened up the possibility of directly diode-laser-pumped Ti:sapphire oscillators. Beside the lower cost and footprint, a direct diode pumping provides better reliability, higher efficiency and better pointing stability to name a few. The challenges that it poses are lower absorption of Ti:sapphire at available diode wavelengths and lower brightness compared to typical green pump lasers. For practical applications such as bio-medicine and nano-structuring, output powers in excess of 100 mW and sub-100 fs pulses are required. In this paper, we demonstrate a high average power directly blue-diode-laser-pumped Ti:sapphire oscillator without active cooling. The SESAM modelocking ensures reliable self-starting and robust operation. We will present two configurations emitting 460 mW in 82 fs pulses and 350 mW in 65 fs pulses, both operating at 92 MHz. The maximum obtained pulse energy reaches 5 nJ. A double-sided pumping scheme with two high power blue diode lasers was used for the output power scaling. The cavity design and the experimental results will be discussed in more details.

Lowest cost due to highest productivity and highest quality

Science.gov (United States)

Wenk, Daniel

2003-03-01

Since global purchasing in the automotive industry has been taken up all around the world there is one main key factor that makes a TB-supplier today successful: Producing highest quality at lowest cost. The fact that Tailored Blanks, which today may reach up to 1/3 of a car body weight, are purchased on the free market but from different steel suppliers, especially in Europe and NAFTA, the philosophy on OEM side has been changing gradually towards tough evaluation criteria. "No risk at the stamping side" calls for top quality Tailored- or Tubular Blank products. Outsourcing Tailored Blanks has been starting in Japan but up to now without any quality request from the OEM side like ISO 13919-1B (welding quality standard in Europe and USA). Increased competition will automatically push the quality level and the ongoing approach to combine high strength steel with Tailored- and Tubular Blanks will ask for even more reliable system concepts which enables to weld narrow seams at highest speed. Beside producing quality, which is the key to reduce one of the most important cost driver "material scrap," in-line quality systems with true and reliable evaluation is going to be a "must" on all weld systems. Traceability of all process related data submitted to interfaces according to customer request in combination with ghost-shift-operation of TB systems are tomorrow's state-of-the-art solutions of Tailored Blank-facilities.

Power electronic supply system with the wind turbine dedicated for average power receivers

Science.gov (United States)

Widerski, Tomasz; Skrzypek, Adam

2018-05-01

This article presents the original project of the AC-DC-AC converter dedicated to low power wind turbines. Such a set can be a good solution for powering isolated objects that do not have access to the power grid, for example isolated houses, mountain lodges or forester's lodges, where they can replace expensive diesel engine generators. An additional source of energy in the form of a mini-wind farm is also a good alternative to yachts, marinas and tent sites, which are characterized by relatively low power consumption. This article presents a designed low power wind converter that is dedicated to these applications. The main design idea of the authors was to create a device that converts the very wide range input voltage directly to a stable 230VAC output voltage without the battery buffer. Authors focused on maximum safety of using and service. The converter contains the thermal protection, short-circuit protection and overvoltage protection. The components have been selected in such a way as to ensure that the device functions as efficiently as possible.

7.5 MeV High Average Power Linear Accelerator System for Food Irradiation Applications

International Nuclear Information System (INIS)

Eichenberger, Carl; Palmer, Dennis; Wong, Sik-Lam; Robison, Greg; Miller, Bruce; Shimer, Daniel

2005-09-01

In December 2004 the US Food and Drug Administration (FDA) approved the use of 7.5 MeV X-rays for irradiation of food products. The increased efficiency for treatment at 7.5 MeV (versus the previous maximum allowable X-ray energy of 5 MeV) will have a significant impact on processing rates and, therefore, reduce the per-package cost of irradiation using X-rays. Titan Pulse Sciences Division is developing a new food irradiation system based on this ruling. The irradiation system incorporates a 7.5 MeV electron linear accelerator (linac) that is capable of 100 kW average power. A tantalum converter is positioned close to the exit window of the scan horn. The linac is an RF standing waveguide structure based on a 5 MeV accelerator that is used for X-ray processing of food products. The linac is powered by a 1300 MHz (L-Band) klystron tube. The electrical drive for the klystron is a solid state modulator that uses inductive energy store and solid-state opening switches. The system is designed to operate 7000 hours per year. Keywords: Rf Accelerator, Solid state modulator, X-ray processing

Power Based Phase-Locked Loop Under Adverse Conditions with Moving Average Filter for Single-Phase System

Directory of Open Access Journals (Sweden)

Menxi Xie

2017-06-01

Full Text Available High performance synchronization methord is citical for grid connected power converter. For single-phase system, power based phase-locked loop(pPLL uses a multiplier as phase detector(PD. As single-phase grid voltage is distorted, the phase error information contains ac disturbances oscillating at integer multiples of fundamental frequency which lead to detection error. This paper presents a new scheme based on moving average filter(MAF applied in-loop of pPLL. The signal characteristic of phase error is dissussed in detail. A predictive rule is adopted to compensate the delay induced by MAF, thus achieving fast dynamic response. In the case of frequency deviate from nomimal, estimated frequency is fed back to adjust the filter window length of MAF and buffer size of predictive rule. Simulation and experimental results show that proposed PLL achieves good performance under adverse grid conditions.

A Front End for Multipetawatt Lasers Based on a High-Energy, High-Average-Power Optical Parametric Chirped-Pulse Amplifier

International Nuclear Information System (INIS)

Bagnoud, V.

2004-01-01

We report on a high-energy, high-average-power optical parametric chirped-pulse amplifier developed as the front end for the OMEGA EP laser. The amplifier provides a gain larger than 109 in two stages leading to a total energy of 400 mJ with a pump-to-signal conversion efficiency higher than 25%

PEAK-TO-AVERAGE POWER RATIO REDUCTION USING CODING AND HYBRID TECHNIQUES FOR OFDM SYSTEM

Directory of Open Access Journals (Sweden)

Bahubali K. Shiragapur

2016-03-01

Full Text Available In this article, the research work investigated is based on an error correction coding techniques are used to reduce the undesirable Peak-to-Average Power Ratio (PAPR quantity. The Golay Code (24, 12, Reed-Muller code (16, 11, Hamming code (7, 4 and Hybrid technique (Combination of Signal Scrambling and Signal Distortion proposed by us are used as proposed coding techniques, the simulation results shows that performance of Hybrid technique, reduces PAPR significantly as compared to Conventional and Modified Selective mapping techniques. The simulation results are validated through statistical properties, for proposed technique’s autocorrelation value is maximum shows reduction in PAPR. The symbol preference is the key idea to reduce PAPR based on Hamming distance. The simulation results are discussed in detail, in this article.

Overview of the HiLASE project: high average power pulsed DPSSL systems for research and industry

Czech Academy of Sciences Publication Activity Database

Divoký, Martin; Smrž, Martin; Chyla, Michal; Sikocinski, Pawel; Severová, Patricie; Novák, Ondřej; Huynh, Jaroslav; Nagisetty, Siva S.; Miura, Taisuke; Pilař, Jan; Slezák, Jiří; Sawicka, Magdalena; Jambunathan, Venkatesan; Vanda, Jan; Endo, Akira; Lucianetti, Antonio; Rostohar, Danijela; Mason, P.D.; Phillips, P.J.; Ertel, K.; Banerjee, S.; Hernandez-Gomez, C.; Collier, J.L.; Mocek, Tomáš

2014-01-01

Roč. 2, SI (2014), s. 1-10 ISSN 2095-4719 R&D Projects: GA MŠk ED2.1.00/01.0027; GA MŠk EE2.3.20.0143; GA MŠk EE2.3.30.0057 Grant - others:HILASE(XE) CZ.1.05/2.1.00/01.0027; OP VK 6(XE) CZ.1.07/2.3.00/20.0143; OP VK 4 POSTDOK(XE) CZ.1.07/2.3.00/30.0057 Institutional support: RVO:68378271 Keywords : DPSSL * Yb3C:YAG * thin-disk * multi-slab * pulsed high average power laser Subject RIV: BH - Optics, Masers, Lasers

The final power calibration of the IPEN/MB-01 nuclear reactor for various configurations obtained from the measurements of the absolute average neutron flux

Energy Technology Data Exchange (ETDEWEB)

Silva, Alexandre Fonseca Povoa da, E-mail: alexandre.povoa@mar.mil.br [Centro Tecnologico da Marinha em Sao Paulo (CTMSP), Sao Paulo, SP (Brazil); Bitelli, Ulysses d' Utra; Mura, Luiz Ernesto Credidio; Lima, Ana Cecilia de Souza; Betti, Flavio; Santos, Diogo Feliciano dos, E-mail: ubitelli@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

The use of neutron activation foils is a widely spread technique applied to obtain nuclear parameters then comparing the results with those calculated using specific methodologies and available nuclear data. By irradiation of activation foils and subsequent measurement of its induced activity, it is possible to determine the neutron flux at the position of irradiation. The power level during operation of the reactor is a parameter which is directly proportional to the average neutron flux throughout the core. The objective of this work is to gather data from irradiation of gold foils symmetrically placed along a cylindrically configured core which presents only a small excess reactivity in order to derive the power generated throughout the spatial thermal and epithermal neutron flux distribution over the core of the IPEN/MB-01 Nuclear Reactor, eventually lending to a proper calibration of its nuclear channels. The foils are fixed in a Lucite plate then irradiated with and without cadmium sheaths so as to obtain the absolute thermal and epithermal neutron flux. The correlation between the average power neutron flux resulting from the gold foils irradiation, and the average power digitally indicated by the nuclear channel number 6, allows for the calibration of the nuclear channels of the reactor. The reactor power level obtained by thermal neutron flux mapping was (74.65 ± 2.45) watts to a mean counting per seconds of 37881 cps to nuclear channel number 10 a pulse detector, and 0.719.10{sup -5} ampere to nuclear linear channel number 6 (a non-compensated ionization chamber). (author)

Hydroelectric power in Switzerland: large growth potential by increasing the installed power

International Nuclear Information System (INIS)

Schleiss, A.

2007-01-01

Due to its important hydroelectric power generation facilities (about 525 plants with a total power of 13,314 MW producing about 35.3 TWh annually) Switzerland plays an important role in the interconnected European power system. Large artificial storage lakes in the Swiss Alps can generate peak power during hours of highest demand: 9700 MW are available from accumulated energy and the total power of pumped-storage facilities amounts to 1700 MW. The latter allow refilling the reservoirs at periods of low power demand and generating power at periods of peak demand. In the case of favorable conditions, the yearly average power production could be increased by 6% and the production during the winter period (October to March) by 20% by the year 2020. However, looking forward to the year 2050, the annual production is expected to decrease by 3% despite a possible extension of hydropower. This decrease is due to the enforcement of the minimum residual water flow rates required by a new legislation to protect the rivers. The enforcement is due at latest when the present licenses for water utilization expire. On the other hand, the installed (peak) power might be further increased by 50% by retrofitting the existing installations and constructing the pumped-storage plants currently at the planning stage

Performance of MgO:PPLN, KTA, and KNbO₃ for mid-wave infrared broadband parametric amplification at high average power.

Science.gov (United States)

Baudisch, M; Hemmer, M; Pires, H; Biegert, J

2014-10-15

The performance of potassium niobate (KNbO₃), MgO-doped periodically poled lithium niobate (MgO:PPLN), and potassium titanyl arsenate (KTA) were experimentally compared for broadband mid-wave infrared parametric amplification at a high repetition rate. The seed pulses, with an energy of 6.5 μJ, were amplified using 410 μJ pump energy at 1064 nm to a maximum pulse energy of 28.9 μJ at 3 μm wavelength and at a 160 kHz repetition rate in MgO:PPLN while supporting a transform limited duration of 73 fs. The high average powers of the interacting beams used in this study revealed average power-induced processes that limit the scaling of optical parametric amplification in MgO:PPLN; the pump peak intensity was limited to 3.8  GW/cm² due to nonpermanent beam reshaping, whereas in KNbO₃ an absorption-induced temperature gradient in the crystal led to permanent internal distortions in the crystal structure when operated above a pump peak intensity of 14.4  GW/cm².

The ETA-II linear induction accelerator and IMP wiggler: A high-average-power millimeter-wave free-electron-laser for plasma heating

International Nuclear Information System (INIS)

Allen, S.L.; Scharlemann, E.T.

1992-05-01

We have constructed a 140-GHz free-electron laser to generate high-average-power microwaves for heating the MTX tokamak plasma. A 5.5-m steady-state wiggler (intense Microwave Prototype-IMP) has been installed at the end of the upgraded 60-cell ETA-II accelerator, and is configured as an FEL amplifier for the output of a 140-GHz long-pulse gyrotron. Improvements in the ETA-II accelerator include a multicable-feed power distribution network, better magnetic alignment using a stretched-wire alignment technique (SWAT). and a computerized tuning algorithm that directly minimizes the transverse sweep (corkscrew motion) of the electron beam. The upgrades were first tested on the 20-cell, 3-MeV front end of ETA-II and resulted in greatly improved energy flatness and reduced corkscrew motion. The upgrades were then incorporated into the full 60-cell configuration of ETA-II, along with modifications to allow operation in 50-pulse bursts at pulse repetition frequencies up to 5 kHz. The pulse power modifications were developed and tested on the High Average Power Test Stand (HAPTS), and have significantly reduced the voltage and timing jitter of the MAG 1D magnetic pulse compressors. The 2-3 kA. 6-7 MeV beam from ETA-II is transported to the IMP wiggler, which has been reconfigured as a laced wiggler, with both permanent magnets and electromagnets, for high magnetic field operation. Tapering of the wiggler magnetic field is completely computer controlled and can be optimized based on the output power. The microwaves from the FEL are transmitted to the MTX tokamak by a windowless quasi-optical microwave transmission system. Experiments at MTX are focused on studies of electron-cyclotron-resonance heating (ECRH) of the plasma. We summarize here the accelerator and pulse power modifications, and describe the status of ETA-II, IMP, and MTX operations

The ETA-II linear induction accelerator and IMP wiggler: A high-average-power millimeter-wave free-electron laser for plasma heating

International Nuclear Information System (INIS)

Allen, S.L.; Scharlemann, E.T.

1993-01-01

The authors have constructed a 140-GHz free-electron laser to generate high-average-power microwaves for heating the MTX tokamak plasma. A 5.5-m steady-state wiggler (Intense Microwave, Prototype-IMP) has been installed at the end of the upgraded 60-cell ETA-II accelerator, and is configured as an FEL amplifier for the output of a 140-GHz long-pulse gyrotron. Improvements in the ETA-II accelerator include a multicable-feed power distribution network, better magnetic alignment using a stretched-wire alignment technique (SWAT), and a computerized tuning algorithm that directly minimizes the transverse sweep (corkscrew motion) of the electron beam. The upgrades were first tested on the 20-cell, 3-MeV front end of ETA-II and resulted in greatly improved energy flatness and reduced corkscrew motion. The upgrades were then incorporated into the full 60-cell configuration of ETA-II, along with modifications to allow operation in 50-pulse bursts at pulse repetition frequencies up to 5 kHz. The pulse power modifications were developed and tested on the High Average Power Test Stand (HAPTS), and have significantly reduced the voltage and timing jitter of the MAG 1D magnetic pulse compressors. The 2-3 kA, 6-7 MeV beam from ETA-II is transported to the IMP wiggler, which has been reconfigured as a laced wiggler, with both permanent magnets and electromagnets, for high magnetic field operation. Tapering of the wiggler magnetic field is completely computer controlled and can be optimized based on the output power. The microwaves from the FEL are transmitted to the MTX tokamak by a windowless quasi-optical microwave transmission system. Experiments at MTX are focused on studies of electron-cyclotron-resonance heating (ECRH) of the plasma. The authors summarize here the accelerator and pulse power modifications, and describe the status of ETA-II, IMP, and MTX operations

Short-term load forecasting of power system

Science.gov (United States)

Xu, Xiaobin

2017-05-01

In order to ensure the scientific nature of optimization about power system, it is necessary to improve the load forecasting accuracy. Power system load forecasting is based on accurate statistical data and survey data, starting from the history and current situation of electricity consumption, with a scientific method to predict the future development trend of power load and change the law of science. Short-term load forecasting is the basis of power system operation and analysis, which is of great significance to unit combination, economic dispatch and safety check. Therefore, the load forecasting of the power system is explained in detail in this paper. First, we use the data from 2012 to 2014 to establish the partial least squares model to regression analysis the relationship between daily maximum load, daily minimum load, daily average load and each meteorological factor, and select the highest peak by observing the regression coefficient histogram Day maximum temperature, daily minimum temperature and daily average temperature as the meteorological factors to improve the accuracy of load forecasting indicators. Secondly, in the case of uncertain climate impact, we use the time series model to predict the load data for 2015, respectively, the 2009-2014 load data were sorted out, through the previous six years of the data to forecast the data for this time in 2015. The criterion for the accuracy of the prediction is the average of the standard deviations for the prediction results and average load for the previous six years. Finally, considering the climate effect, we use the BP neural network model to predict the data in 2015, and optimize the forecast results on the basis of the time series model.

Electrical method for the measurements of volume averaged electron density and effective coupled power to the plasma bulk

Science.gov (United States)

Henault, M.; Wattieaux, G.; Lecas, T.; Renouard, J. P.; Boufendi, L.

2016-02-01

Nanoparticles growing or injected in a low pressure cold plasma generated by a radiofrequency capacitively coupled capacitive discharge induce strong modifications in the electrical parameters of both plasma and discharge. In this paper, a non-intrusive method, based on the measurement of the plasma impedance, is used to determine the volume averaged electron density and effective coupled power to the plasma bulk. Good agreements are found when the results are compared to those given by other well-known and established methods.

Internal exposure profile of occupational workers of a BWR type atomic power station

International Nuclear Information System (INIS)

Hegde, A.G.; Bhat, I.S.

1979-01-01

The internal exposure profile of major radionuclides, for Tarapur Atomic Power Station (India) occupational staff for the last 9 years (1970-1978) of station operation, is presented. This power station has two boiling water reactor units. The occupational staff were monitored for internal exposure with the whole body counter. It has been observed that 60 Co, 134 Cs and 137 Cs are major contaminants. The highest yearly average of internal exposure was less than 1% of maximum permissible body burden recommended by ICRP. Depending on the nature of exposures the power station employees were classified under four different groups, (i) maintenance, (ii) operations, (iii) techanical and (iv) non-technical. This study revealed that maintenance group had highest incidence of internal exposure among these. It is also observed that contribution of 60 Co is maximum in the exposure of this group. (B.G.W.)

The mercury laser system - An average power, gas-cooled, Yb:S-FAP based system with frequency conversion and wavefront correction

Energy Technology Data Exchange (ETDEWEB)

Bibeau, C.; Bayramian, A.; Armstrong, P.; Ault, E.; Beach, R.; Benapfl, M.; Campbell, R.; Dawson, J.; Ebbers, C.; Freitas, B.; Kent, R.; Liao, Z.; Ladran, T.; Menapace, J.; Molander, B.; Moses, E.; Oberhelman, S.; Payne, S.; Peterson, N.; Schaffers, K.; Stolz, C.; Sutton, S.; Tassano, J.; Telford, S.; Utterback, E. [Lawrence Livermore National Lab., Livermore, CA (United States); Randles, M. [Northrop Grumman Space Technologies, Charlotte, NC (United States); Chain, B.; Fei, Y. [Crystal Photonics, Sanford, Fl (United States)

2006-06-15

We report on the operation of the Mercury laser with fourteen 4*6 cm{sup 2} Yb:S-FAP amplifier slabs pumped by eight 100 kW peak power diode arrays. The system was continuously run at 55 J and 10 Hz for several hours, (2*10{sup 5} cumulative shots) with over 80% of the energy in a 6 times diffraction limited spot at 1.047 {mu}m. Improved optical quality was achieved in Yb:S-FAP amplifiers with magneto-rheological finishing, a deterministic polishing method. In addition, average power frequency conversion employing YCOB crystal was demonstrated at 50% conversion efficiency or 22.6 J at 10 Hz. (authors)

Bimanual microincision phacoemulsification in treating hard cataracts using different power modes.

Science.gov (United States)

Liu, Yizhi; Jiang, Yuzhen; Wu, Mingxing; Liu, Yuhua; Zhang, Tieying

2008-07-01

To compare the performance of the Multiburst mode, the Shortpulse mode and the Whitestar technology of the Sovereign platform in treating hard cataracts with bimanual microincision phacoemulsification. 101 eyes with hard cataracts (nuclear density Grade 3 and Grade 4 or above) were randomized into three groups. Bimanual microincision phacoemulsification was performed using the Multiburst mode, the Shortpulse mode and the Whitestar technology of the Sovereign phacoemulsification machine respectively. The average power, total duration of ultrasonic power release (US Time), effective phaco time, complications, best-corrected visual acuity and rate of corneal endothelial cell loss were measured and compared among the study groups. For hard cataracts of various nuclear densities, average ultrasonic power was highest in the Whitestar group followed by the Shortpulse group. The Multiburst group had the highest US Time, effective phaco time and rate of corneal endothelial cell loss whereas the Whitestar Group had the lowest.The differences between the groups were found to be statistically significant by variation analysis and the Fisher's least significant difference procedure. However, there were no significant differences between the USTime values of the Shortpulse Group and the Whitestar Group (P = 0.051). In the Multiburst Group, wound burn occurred in one eye, and three eyes had abnormal fluctuations in the anterior chamber depth. The Whitestar technology showed the best performance in this study.The Multiburst mode was proved to be a relatively unsuitable ultrasonic power mode in treating hard cataracts with bimanual microincision phacoemulsification.

Daily Average Wind Power Interval Forecasts Based on an Optimal Adaptive-Network-Based Fuzzy Inference System and Singular Spectrum Analysis

Directory of Open Access Journals (Sweden)

Zhongrong Zhang

2016-01-01

Full Text Available Wind energy has increasingly played a vital role in mitigating conventional resource shortages. Nevertheless, the stochastic nature of wind poses a great challenge when attempting to find an accurate forecasting model for wind power. Therefore, precise wind power forecasts are of primary importance to solve operational, planning and economic problems in the growing wind power scenario. Previous research has focused efforts on the deterministic forecast of wind power values, but less attention has been paid to providing information about wind energy. Based on an optimal Adaptive-Network-Based Fuzzy Inference System (ANFIS and Singular Spectrum Analysis (SSA, this paper develops a hybrid uncertainty forecasting model, IFASF (Interval Forecast-ANFIS-SSA-Firefly Alogorithm, to obtain the upper and lower bounds of daily average wind power, which is beneficial for the practical operation of both the grid company and independent power producers. To strengthen the practical ability of this developed model, this paper presents a comparison between IFASF and other benchmarks, which provides a general reference for this aspect for statistical or artificially intelligent interval forecast methods. The comparison results show that the developed model outperforms eight benchmarks and has a satisfactory forecasting effectiveness in three different wind farms with two time horizons.

Catching the Highest Energy Neutrinos

Energy Technology Data Exchange (ETDEWEB)

Stanev, Todor [Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States)

2011-08-15

We briefly discuss the possible sources of ultrahigh energy neutrinos and the methods for their detection. Then we present the results obtained by different experiments for detection of the highest energy neutrinos.

Optimization and Annual Average Power Predictions of a Backward Bent Duct Buoy Oscillating Water Column Device Using the Wells Turbine.

Energy Technology Data Exchange (ETDEWEB)

Smith, Christopher S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bull, Diana L [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Willits, Steven M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Fontaine, Arnold A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2014-08-01

This Technical Report presents work completed by The Applied Research Laboratory at The Pennsylvania State University, in conjunction with Sandia National Labs, on the optimization of the power conversion chain (PCC) design to maximize the Average Annual Electric Power (AAEP) output of an Oscillating Water Column (OWC) device. The design consists of two independent stages. First, the design of a floating OWC, a Backward Bent Duct Buoy (BBDB), and second the design of the PCC. The pneumatic power output of the BBDB in random waves is optimized through the use of a hydrodynamically coupled, linear, frequency-domain, performance model that links the oscillating structure to internal air-pressure fluctuations. The PCC optimization is centered on the selection and sizing of a Wells Turbine and electric power generation equipment. The optimization of the PCC involves the following variables: the type of Wells Turbine (fixed or variable pitched, with and without guide vanes), the radius of the turbine, the optimal vent pressure, the sizing of the power electronics, and number of turbines. Also included in this Technical Report are further details on how rotor thrust and torque are estimated, along with further details on the type of variable frequency drive selected.

Operating experience from Swedish nuclear power plants 2001

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-07-01

The total production of electricity from Swedish nuclear power plants was 69.2 TWh during 2001, which is an increase of more than 25% compared to 2000. The hydroelectric power production increased to 78.3 TWh, 22% more than during a normal year, i.e. a year with average rainfall. Wind power contributed 0.5 TWh, and remaining production sources, mainly from solid fuel plants combined with district heating, contributed 9.6 TWh. The electricity generation totalled 157.6 TWh, the highest annual production to date. The preliminary figures for export were 18.5 TWh and and for import 11.1 TWh. Operational statistics are presented for each Swedish reactor. Two events, given INES level 1 rating, are reported from Barsebaeck 2 and Ringhals 2.

Operating experience from Swedish nuclear power plants 2001

International Nuclear Information System (INIS)

2002-01-01

The total production of electricity from Swedish nuclear power plants was 69.2 TWh during 2001, which is an increase of more than 25% compared to 2000. The hydroelectric power production increased to 78.3 TWh, 22% more than during a normal year, i.e. a year with average rainfall. Wind power contributed 0.5 TWh, and remaining production sources, mainly from solid fuel plants combined with district heating, contributed 9.6 TWh. The electricity generation totalled 157.6 TWh, the highest annual production to date. The preliminary figures for export were 18.5 TWh and and for import 11.1 TWh. Operational statistics are presented for each Swedish reactor. Two events, given INES level 1 rating, are reported from Barsebaeck 2 and Ringhals 2

Relationship Between Selected Strength and Power Assessments to Peak and Average Velocity of the Drive Block in Offensive Line Play.

Science.gov (United States)

Jacobson, Bert H; Conchola, Eric C; Smith, Doug B; Akehi, Kazuma; Glass, Rob G

2016-08-01

Jacobson, BH, Conchola, EC, Smith, DB, Akehi, K, and Glass, RG. Relationship between selected strength and power assessments to peak and average velocity of the drive block in offensive line play. J Strength Cond Res 30(8): 2202-2205, 2016-Typical strength training for football includes the squat and power clean (PC) and routinely measured variables include 1 repetition maximum (1RM) squat and 1RM PC along with the vertical jump (VJ) for power. However, little research exists regarding the association between the strength exercises and velocity of an actual on-the-field performance. The purpose of this study was to investigate the relationship of peak velocity (PV) and average velocity (AV) of the offensive line drive block to 1RM squat, 1RM PC, the VJ, body mass (BM), and body composition. One repetition maximum assessments for the squat and PC were recorded along with VJ height, BM, and percent body fat. These data were correlated with PV and AV while performing the drive block. Peal velocity and AV were assessed using a Tendo Power and Speed Analyzer as the linemen fired, from a 3-point stance into a stationary blocking dummy. Pearson product analysis yielded significant (p ≤ 0.05) correlations between PV and AV and the VJ, the squat, and the PC. A significant inverse association was found for both PV and AV and body fat. These data help to confirm that the typical exercises recommended for American football linemen is positively associated with both PV and AV needed for the drive block effectiveness. It is recommended that these exercises remain the focus of a weight room protocol and that ancillary exercises be built around these exercises. Additionally, efforts to reduce body fat are recommended.

Quantum-dot saturable absorber and Kerr-lens mode-locked Yb:KGW laser with >450  kW of peak power.

Science.gov (United States)

Akbari, R; Zhao, H; Fedorova, K A; Rafailov, E U; Major, A

2016-08-15

The hybrid action of quantum-dot saturable absorber and Kerr-lens mode locking in a diode-pumped Yb:KGW laser was demonstrated. Using a quantum-dot saturable absorber with a 0.7% (0.5%) modulation depth, the mode-locked laser delivered 90 fs (93 fs) pulses with 3.2 W (2.9 W) of average power at the repetition rate of 77 MHz, corresponding to 462 kW (406 kW) of peak power and 41 nJ (38 nJ) of pulse energy. To the best of our knowledge, this represents the highest average and peak powers generated to date from quantum-dot saturable absorber-based mode-locked lasers.

Average level of satisfaction in 10 European countries: explanation of differences

OpenAIRE

Veenhoven, Ruut

1996-01-01

textabstractABSTRACT Surveys in 10 European nations assessed satisfaction with life-as-a-whole and satisfaction with three life-domains (finances, housing, social contacts). Average satisfaction differs markedly across countries. Both satisfaction with life-as-a-whole and satisfaction with life-domains are highest in North-Western Europe, medium in Southern Europe and lowest in the East-European nations. Cultural measurement bias is unlikely to be involved. The country differences in average ...

The costs of power interruptions in Germany. An assessment in the light of the Energiewende

Energy Technology Data Exchange (ETDEWEB)

Growitsch, Christian; Malischek, Raimund; Nick, Sebastian; Wetzel, Heike

2013-04-15

The German Energiewende's potential effects on the reliability of electricity supply as well as the corresponding economic consequences have recently entered both the political and scientific debate. However, empirical evidence of power outage costs in Germany is rather scarce. Following a macroeconomic approach, we analyse the economic costs imposed by potential power interruptions in Germany. Investigating a rich data set on industry and households we estimate both Values of Lost Load (VoLLs) and associated costs of power interruptions for different German regions and sectors and every hour of the year. This disaggregated approach allows for conclusions for optimal load shedding in case of technical necessity and the economic efficiency of measures to improve security of supply. We find that interruption costs vary significantly over time, between sectors and regions. Peaking on midday of a Monday in December at 750 Mio Euro per hour, the average of total national outage costs amount to approximately 430 Mio Euro per hour. The industrial sectors facing the highest outage costs are the machinery and transport equipment sectors. Their aggregated hourly outage costs average out at approximately 20 Mio Euro. Our results emphasize the prominent regional aspect of the German Energiewende as the regions with the highest estimated cost of interruptions in South and West Germany coincide with the areas which face nuclear power plant shut downs in the near future.

Adaptive Control for Buck Power Converter Using Fixed Point Inducting Control and Zero Average Dynamics Strategies

Science.gov (United States)

Hoyos Velasco, Fredy Edimer; García, Nicolás Toro; Garcés Gómez, Yeison Alberto

In this paper, the output voltage of a buck power converter is controlled by means of a quasi-sliding scheme. The Fixed Point Inducting Control (FPIC) technique is used for the control design, based on the Zero Average Dynamics (ZAD) strategy, including load estimation by means of the Least Mean Squares (LMS) method. The control scheme is tested in a Rapid Control Prototyping (RCP) system based on Digital Signal Processing (DSP) for dSPACE platform. The closed loop system shows adequate performance. The experimental and simulation results match. The main contribution of this paper is to introduce the load estimator by means of LMS, to make ZAD and FPIC control feasible in load variation conditions. In addition, comparison results for controlled buck converter with SMC, PID and ZAD-FPIC control techniques are shown.

Average spectral efficiency analysis of FSO links over turbulence channel with adaptive transmissions and aperture averaging

Science.gov (United States)

Aarthi, G.; Ramachandra Reddy, G.

2018-03-01

In our paper, the impact of adaptive transmission schemes: (i) optimal rate adaptation (ORA) and (ii) channel inversion with fixed rate (CIFR) on the average spectral efficiency (ASE) are explored for free-space optical (FSO) communications with On-Off Keying (OOK), Polarization shift keying (POLSK), and Coherent optical wireless communication (Coherent OWC) systems under different turbulence regimes. Further to enhance the ASE we have incorporated aperture averaging effects along with the above adaptive schemes. The results indicate that ORA adaptation scheme has the advantage of improving the ASE performance compared with CIFR under moderate and strong turbulence regime. The coherent OWC system with ORA excels the other modulation schemes and could achieve ASE performance of 49.8 bits/s/Hz at the average transmitted optical power of 6 dBm under strong turbulence. By adding aperture averaging effect we could achieve an ASE of 50.5 bits/s/Hz under the same conditions. This makes ORA with Coherent OWC modulation as a favorable candidate for improving the ASE of the FSO communication system.

Observer design for DC/DC power converters with bilinear averaged model

NARCIS (Netherlands)

Spinu, V.; Dam, M.C.A.; Lazar, M.

2012-01-01

Increased demand for high bandwidth and high efficiency made full state-feedback control solutions very attractive to power-electronics community. However, full state measurement is economically prohibitive for a large range of applications. Moreover, state measurements in switching power converters

Efficiency of Finish power transmission network companies

International Nuclear Information System (INIS)

Anon.

2001-01-01

The Finnish Energy Market Authority has investigated the efficiency of power transmissions network companies. The results show that the intensification potential of the branch is 402 million FIM, corresponding to about 15% of the total costs of the branch and 7.3 % of the turnout. Energy Market Authority supervises the reasonableness of the power transmission prices, and it will use the results of the research in supervision. The research was carried out by the Quantitative Methods Research Group of Helsinki School of Economics. The main objective of the research was to create an efficiency estimation method for electric power distribution network business used for Finnish conditions. Data of the year 1998 was used as basic material in the research. Twenty-one of the 102 power distribution network operators was estimated to be totally efficient. Highest possible efficiency rate was 100, and the average of the efficiency rates of all the operators was 76.9, the minimum being 42.6

Pareto Principle in Datamining: an Above-Average Fencing Algorithm

Directory of Open Access Journals (Sweden)

K. Macek

2008-01-01

Full Text Available This paper formulates a new datamining problem: which subset of input space has the relatively highest output where the minimal size of this subset is given. This can be useful where usual datamining methods fail because of error distribution asymmetry. The paper provides a novel algorithm for this datamining problem, and compares it with clustering of above-average individuals.

Diode-side-pumped intracavity frequency-doubled Nd:YAG/BaWO4 Raman laser generating average output power of 3.14 W at 590 nm.

Science.gov (United States)

Li, Shutao; Zhang, Xingyu; Wang, Qingpu; Zhang, Xiaolei; Cong, Zhenhua; Zhang, Huaijin; Wang, Jiyang

2007-10-15

We report a linear-cavity high-power all-solid-state Q-switched yellow laser. The laser source comprises a diode-side-pumped Nd:YAG module that produces 1064 nm fundamental radiation, an intracavity BaWO(4) Raman crystal that generates a first-Stokes laser at 1180 nm, and a KTP crystal that frequency doubles the first-Stokes laser to 590 nm. A convex-plane cavity is employed in this configuration to counteract some of the thermal effect caused by high pump power. An average output power of 3.14 W at 590 nm is obtained at a pulse repetition frequency of 10 kHz.

Stochastic Growth Theory of Spatially-Averaged Distributions of Langmuir Fields in Earth's Foreshock

Science.gov (United States)

Boshuizen, Christopher R.; Cairns, Iver H.; Robinson, P. A.

2001-01-01

Langmuir-like waves in the foreshock of Earth are characteristically bursty and irregular, and are the subject of a number of recent studies. Averaged over the foreshock, it is observed that the probability distribution is power-law P(bar)(log E) in the wave field E with the bar denoting this averaging over position, In this paper it is shown that stochastic growth theory (SGT) can explain a power-law spatially-averaged distributions P(bar)(log E), when the observed power-law variations of the mean and standard deviation of log E with position are combined with the log normal statistics predicted by SGT at each location.

High average power, diode pumped petawatt laser systems: a new generation of lasers enabling precision science and commercial applications

Science.gov (United States)

Haefner, C. L.; Bayramian, A.; Betts, S.; Bopp, R.; Buck, S.; Cupal, J.; Drouin, M.; Erlandson, A.; Horáček, J.; Horner, J.; Jarboe, J.; Kasl, K.; Kim, D.; Koh, E.; Koubíková, L.; Maranville, W.; Marshall, C.; Mason, D.; Menapace, J.; Miller, P.; Mazurek, P.; Naylon, A.; Novák, J.; Peceli, D.; Rosso, P.; Schaffers, K.; Sistrunk, E.; Smith, D.; Spinka, T.; Stanley, J.; Steele, R.; Stolz, C.; Suratwala, T.; Telford, S.; Thoma, J.; VanBlarcom, D.; Weiss, J.; Wegner, P.

2017-05-01

Large laser systems that deliver optical pulses with peak powers exceeding one Petawatt (PW) have been constructed at dozens of research facilities worldwide and have fostered research in High-Energy-Density (HED) Science, High-Field and nonlinear physics [1]. Furthermore, the high intensities exceeding 1018W/cm2 allow for efficiently driving secondary sources that inherit some of the properties of the laser pulse, e.g. pulse duration, spatial and/or divergence characteristics. In the intervening decades since that first PW laser, single-shot proof-of-principle experiments have been successful in demonstrating new high-intensity laser-matter interactions and subsequent secondary particle and photon sources. These secondary sources include generation and acceleration of charged-particle (electron, proton, ion) and neutron beams, and x-ray and gamma-ray sources, generation of radioisotopes for positron emission tomography (PET), targeted cancer therapy, medical imaging, and the transmutation of radioactive waste [2, 3]. Each of these promising applications requires lasers with peak power of hundreds of terawatt (TW) to petawatt (PW) and with average power of tens to hundreds of kW to achieve the required secondary source flux.

ship between IS-month mating mass and average lifetime repro

African Journals Online (AJOL)

1976; Elliol, Rae & Wickham, 1979; Napier, et af., 1980). Although being in general agreement with results in the literature, it is evident that the present phenotypic correlations between I8-month mating mass and average lifetime lambing and weaning rate tended to be equal to the highest comparable estimates in the ...

Nuclear power: 2004 world report - evaluation

International Nuclear Information System (INIS)

Anon.

2005-01-01

Last year, 2004, 441 nuclear power plants were available for power supply in 31 countries of the world. Nuclear generating capacity attained its highest level so far at an aggregate gross power of 385,854 MWe and an aggregate net power of 366,682 MWe, respectively. Nine different reactor lines are operated in commercial nuclear power plants. Light water reactors (PWR and BWR) again are in the lead with 362 plants. At year's end, 22 nuclear power plants with an aggregate gross power of 18,553 MWe and an aggregate net power, respectively, of 17,591 MWe were under construction in nine countries. Of these, twelve are light water reactors, nine are CANDU-type reactors, and one is a fast breeder reactor. So far, 104 commercial reactors with powers in excess of 5 MWe have been decommissioned in eighteen countries, most of them low-power prototype plants. 228 nuclear power plants of those in operation, i.e. slightly more than half, were commissioned in the 1980es. Nuclear power plant availabilities in terms of capacity and time again reached record levels. Capacity availability was 84.30%, availability in terms of time, 85.60%. The four nuclear power plants in Finland continue to be world champions in this respect with a cumulated average capacity availability of 90.30%. (orig.)

Capacity factor of nuclear power stations in Japan in fiscal year 1984

International Nuclear Information System (INIS)

Agawa, Takashi

1985-01-01

In Japan presently a total of 28 nuclear power plants are in operation with aggregate capacity 20,561 MW, 22 % of the total power generation. Around 1975 there occurred such as stress corrosion cracking and to repair them much time was consumed, leading to the low capacity factor. With such troubles removed, in fiscal 1984, the capacity factor on average of the nuclear power stations is 73.9 %, the highest so far. Contributing to this are long period of the continuous operation, short period of the periodical inspection and increase in the in-operation capacity factor. Contents are the following : construction state of nuclear power stations, operation state in fiscal 1984, causes leading to the high capacity factor, future directions. (Mori, K.)

Fluorescence-pumped photolytic gas laser system for a commercial laser fusion power plant

International Nuclear Information System (INIS)

Monsler, M.J.

1977-01-01

The first results are given for the conceptual design of a short-wavelength gas laser system suitable for use as a driver (high average power ignition source) for a commercial laser fusion power plant. A comparison of projected overall system efficiencies of photolytically excited oxygen, sulfur, selenium and iodine lasers is described, using a unique windowless laser cavity geometry which will allow scaling of single amplifier modules to 125 kJ per aperture for 1 ns pulses. On the basis of highest projected overall efficiency, a selenium laser is chosen for a conceptual power plant fusion laser system. This laser operates on the 489 nm transauroral transition of selenium, excited by photolytic dissociation of COSe by ultraviolet fluorescence radiation. Power balances and relative costs for optics, electrical power conditioning and flow conditioning of both the laser and fluorescer gas streams are discussed for a system with the following characteristics: 8 operating modules, 2 standby modules, 125 kJ per module, 1.4 pulses per second, 1.4 MW total average power. The technical issues of scaling visible and near-infrared photolytic gas laser systems to this size are discussed

Design and development of a 6 MW peak, 24 kW average power S-band klystron

Energy Technology Data Exchange (ETDEWEB)

Joshi, L.M.; Meena, Rakesh; Nangru, Subhash; Kant, Deepender; Pal, Debashis; Lamba, O.S.; Jindal, Vishnu; Jangid, Sushil Kumar, E-mail: joslm@rediffmail.com [Central Electronics Engineering Research Institute, Council of Scientific and Industrial Research, Pilani (India); Chakravarthy, D.P.; Dixit, Kavita [Bhabha Atomic Research Centre, Mumbai (India)

2011-07-01

A 6 MW peak, 24 kW average power S-band Klystron is under development at CEERI, Pilani under an MoU between BARC and CEERI. The design of the klystron has been completed. The electron gun has been designed using TRAK and MAGIC codes. RF cavities have been designed using HFSS and CST Microwave Studio while the complete beam wave interaction simulation has been done using MAGIC code. The thermal design of collector and RF window has been done using ANSYS code. A Gun Collector Test Module (GCTM) was developed before making actual klystron to validate gun perveance and thermal design of collector. A high voltage solid state pulsed modulator has been installed for performance valuation of the tube. The paper will cover the design aspects of the tube and experimental test results of GCTM and klystron. (author)

Design and development of a 6 MW peak, 24 kW average power S-band klystron

International Nuclear Information System (INIS)

Joshi, L.M.; Meena, Rakesh; Nangru, Subhash; Kant, Deepender; Pal, Debashis; Lamba, O.S.; Jindal, Vishnu; Jangid, Sushil Kumar; Chakravarthy, D.P.; Dixit, Kavita

2011-01-01

A 6 MW peak, 24 kW average power S-band Klystron is under development at CEERI, Pilani under an MoU between BARC and CEERI. The design of the klystron has been completed. The electron gun has been designed using TRAK and MAGIC codes. RF cavities have been designed using HFSS and CST Microwave Studio while the complete beam wave interaction simulation has been done using MAGIC code. The thermal design of collector and RF window has been done using ANSYS code. A Gun Collector Test Module (GCTM) was developed before making actual klystron to validate gun perveance and thermal design of collector. A high voltage solid state pulsed modulator has been installed for performance valuation of the tube. The paper will cover the design aspects of the tube and experimental test results of GCTM and klystron. (author)

High-Average, High-Peak Current Injector Design

CERN Document Server

Biedron, S G; Virgo, M

2005-01-01

There is increasing interest in high-average-power (>100 kW), um-range FELs. These machines require high peak current (~1 kA), modest transverse emittance, and beam energies of ~100 MeV. High average currents (~1 A) place additional constraints on the design of the injector. We present a design for an injector intended to produce the required peak currents at the injector, eliminating the need for magnetic compression within the linac. This reduces the potential for beam quality degradation due to CSR and space charge effects within magnetic chicanes.

Amplified spontaneous emission and thermal management on a high average-power diode-pumped solid-state laser - the Lucia laser system

International Nuclear Information System (INIS)

Albach, D.

2010-01-01

The development of the laser triggered the birth of numerous fields in both scientific and industrial domains. High intensity laser pulses are a unique tool for light/matter interaction studies and applications. However, current flash-pumped glass-based systems are inherently limited in repetition-rate and efficiency. Development within recent years in the field of semiconductor lasers and gain media drew special attention to a new class of lasers, the so-called Diode Pumped Solid State Laser (DPSSL). DPSSLs are highly efficient lasers and are candidates of choice for compact, high average-power systems required for industrial applications but also as high-power pump sources for ultra-high intense lasers. The work described in this thesis takes place in the context of the 1 kilowatt average-power DPSSL program Lucia, currently under construction at the 'Laboratoire d'Utilisation des Laser Intenses' (LULI) at the Ecole Polytechnique, France. Generation of sub-10 nanosecond long pulses with energies of up to 100 joules at repetition rates of 10 hertz are mainly limited by Amplified Spontaneous Emission (ASE) and thermal effects. These limitations are the central themes of this work. Their impact is discussed within the context of a first Lucia milestone, set around 10 joules. The developed laser system is shown in detail from the oscillator level to the end of the amplification line. A comprehensive discussion of the impact of ASE and thermal effects is completed by related experimental benchmarks. The validated models are used to predict the performances of the laser system, finally resulting in a first activation of the laser system at an energy level of 7 joules in a single-shot regime and 6.6 joules at repetition rates up to 2 hertz. Limitations and further scaling approaches are discussed, followed by an outlook for the further development. (author) [fr

Micro-engineered first wall tungsten armor for high average power laser fusion energy systems

Science.gov (United States)

Sharafat, Shahram; Ghoniem, Nasr M.; Anderson, Michael; Williams, Brian; Blanchard, Jake; Snead, Lance; HAPL Team

2005-12-01

The high average power laser program is developing an inertial fusion energy demonstration power reactor with a solid first wall chamber. The first wall (FW) will be subject to high energy density radiation and high doses of high energy helium implantation. Tungsten has been identified as the candidate material for a FW armor. The fundamental concern is long term thermo-mechanical survivability of the armor against the effects of high temperature pulsed operation and exfoliation due to the retention of implanted helium. Even if a solid tungsten armor coating would survive the high temperature cyclic operation with minimal failure, the high helium implantation and retention would result in unacceptable material loss rates. Micro-engineered materials, such as castellated structures, plasma sprayed nano-porous coatings and refractory foams are suggested as a first wall armor material to address these fundamental concerns. A micro-engineered FW armor would have to be designed with specific geometric features that tolerate high cyclic heating loads and recycle most of the implanted helium without any significant failure. Micro-engineered materials are briefly reviewed. In particular, plasma-sprayed nano-porous tungsten and tungsten foams are assessed for their potential to accommodate inertial fusion specific loads. Tests show that nano-porous plasma spray coatings can be manufactured with high permeability to helium gas, while retaining relatively high thermal conductivities. Tungsten foams where shown to be able to overcome thermo-mechanical loads by cell rotation and deformation. Helium implantation tests have shown, that pulsed implantation and heating releases significant levels of implanted helium. Helium implantation and release from tungsten was modeled using an expanded kinetic rate theory, to include the effects of pulsed implantations and thermal cycles. Although, significant challenges remain micro-engineered materials are shown to constitute potential

Micro-engineered first wall tungsten armor for high average power laser fusion energy systems

International Nuclear Information System (INIS)

Sharafat, Shahram; Ghoniem, Nasr M.; Anderson, Michael; Williams, Brian; Blanchard, Jake; Snead, Lance

2005-01-01

The high average power laser program is developing an inertial fusion energy demonstration power reactor with a solid first wall chamber. The first wall (FW) will be subject to high energy density radiation and high doses of high energy helium implantation. Tungsten has been identified as the candidate material for a FW armor. The fundamental concern is long term thermo-mechanical survivability of the armor against the effects of high temperature pulsed operation and exfoliation due to the retention of implanted helium. Even if a solid tungsten armor coating would survive the high temperature cyclic operation with minimal failure, the high helium implantation and retention would result in unacceptable material loss rates. Micro-engineered materials, such as castellated structures, plasma sprayed nano-porous coatings and refractory foams are suggested as a first wall armor material to address these fundamental concerns. A micro-engineered FW armor would have to be designed with specific geometric features that tolerate high cyclic heating loads and recycle most of the implanted helium without any significant failure. Micro-engineered materials are briefly reviewed. In particular, plasma-sprayed nano-porous tungsten and tungsten foams are assessed for their potential to accommodate inertial fusion specific loads. Tests show that nano-porous plasma spray coatings can be manufactured with high permeability to helium gas, while retaining relatively high thermal conductivities. Tungsten foams where shown to be able to overcome thermo-mechanical loads by cell rotation and deformation. Helium implantation tests have shown, that pulsed implantation and heating releases significant levels of implanted helium. Helium implantation and release from tungsten was modeled using an expanded kinetic rate theory, to include the effects of pulsed implantations and thermal cycles. Although, significant challenges remain micro-engineered materials are shown to constitute potential

Investigation of the thermal and optical performance of a spatial light modulator with high average power picosecond laser exposure for materials processing applications

Science.gov (United States)

Zhu, G.; Whitehead, D.; Perrie, W.; Allegre, O. J.; Olle, V.; Li, Q.; Tang, Y.; Dawson, K.; Jin, Y.; Edwardson, S. P.; Li, L.; Dearden, G.

2018-03-01

Spatial light modulators (SLMs) addressed with computer generated holograms (CGHs) can create structured light fields on demand when an incident laser beam is diffracted by a phase CGH. The power handling limitations of these devices based on a liquid crystal layer has always been of some concern. With careful engineering of chip thermal management, we report the detailed optical phase and temperature response of a liquid cooled SLM exposed to picosecond laser powers up to 〈P〉  =  220 W at 1064 nm. This information is critical for determining device performance at high laser powers. SLM chip temperature rose linearly with incident laser exposure, increasing by only 5 °C at 〈P〉  =  220 W incident power, measured with a thermal imaging camera. Thermal response time with continuous exposure was 1-2 s. The optical phase response with incident power approaches 2π radians with average power up to 〈P〉  =  130 W, hence the operational limit, while above this power, liquid crystal thickness variations limit phase response to just over π radians. Modelling of the thermal and phase response with exposure is also presented, supporting experimental observations well. These remarkable performance characteristics show that liquid crystal based SLM technology is highly robust when efficiently cooled. High speed, multi-beam plasmonic surface micro-structuring at a rate R  =  8 cm2 s-1 is achieved on polished metal surfaces at 〈P〉  =  25 W exposure while diffractive, multi-beam surface ablation with average power 〈P〉  =100 W on stainless steel is demonstrated with ablation rate of ~4 mm3 min-1. However, above 130 W, first order diffraction efficiency drops significantly in accord with the observed operational limit. Continuous exposure for a period of 45 min at a laser power of 〈P〉  =  160 W did not result in any detectable drop in diffraction efficiency, confirmed afterwards by the efficient

High-Performance Control in Radio Frequency Power Amplification Systems

DEFF Research Database (Denmark)

Høyerby, Mikkel Christian Kofod

. It is clearly shown that single-phase switch-mode control systems based on oscillation (controlled unstable operation) of the whole power train provide the highest possible control bandwidth. A study of the limitations of cartesian feedback is also included. It is shown that bandwidths in excess of 4MHz can...... frequency power amplifiers (RFPAs) in conjunction with cartesian feedback (CFB) used to linearize the overall transmitter system. On a system level, it is demonstrated how envelope tracking is particularly useful for RF carriers with high peak-to-average power ratios, such as TEDS with 10dB. It is also...... demonstrated how the envelope tracking technique introduces a number of potential pitfalls to the system, namely in the form of power supply ripple intermodulation (PSIM), reduced RFPA linearity and a higherimpedance supply rail for the RFPA. Design and analysis techniques for these three issues are introduced...

Environmental risks of power generation from fossil fuels and nuclear facilities

International Nuclear Information System (INIS)

Probert, D.; Tarrant, C.

1989-01-01

The nuclear power industry, when considered via statistical arguments, is far less dangerous than the average 'man in the street' in the UK perceives it to be. To support this assertion, an elementary analysis of the risk factors associated with commonplace hazards (e.g. road accidents and smoking) is presented. The radiological risks resulting from the Chernobyl nuclear power station accident, even in the most badly affected areas of the UK and at the times of highest intensity, were much less than those due to natural background radiation. Radioactive elements occur naturally in coal and are released as a result of combustion into the UK environment via flue gases and ash in significantly greater amounts than those from nuclear power stations. (author)

High average power CW FELs [Free Electron Laser] for application to plasma heating: Designs and experiments

International Nuclear Information System (INIS)

Booske, J.H.; Granatstein, V.L.; Radack, D.J.; Antonsen, T.M. Jr.; Bidwell, S.; Carmel, Y.; Destler, W.W.; Latham, P.E.; Levush, B.; Mayergoyz, I.D.; Zhang, Z.X.

1989-01-01

A short period wiggler (period ∼ 1 cm), sheet beam FEL has been proposed as a low-cost source of high average power (1 MW) millimeter-wave radiation for plasma heating and space-based radar applications. Recent calculation and experiments have confirmed the feasibility of this concept in such critical areas as rf wall heating, intercepted beam (''body'') current, and high voltage (0.5 - 1 MV) sheet beam generation and propagation. Results of preliminary low-gain sheet beam FEL oscillator experiments using a field emission diode and pulse line accelerator have verified that lasing occurs at the predicted FEL frequency. Measured start oscillation currents also appear consistent with theoretical estimates. Finally, we consider the possibilities of using a short-period, superconducting planar wiggler for improved beam confinement, as well as access to the high gain, strong pump Compton regime with its potential for highly efficient FEL operation

Stable, high power, high efficiency picosecond ultraviolet generation at 355 nm in K3B6O10 Br crystal

Science.gov (United States)

Hou, Z. Y.; Wang, L. R.; Xia, M. J.; Yan, D. X.; Zhang, Q. L.; Zhang, L.; Liu, L. J.; Xu, D. G.; Zhang, D. X.; Wang, X. Y.; Li, R. K.; Chen, C. T.

2018-06-01

We demonstrate a high efficiency and high power picosecond ultraviolet source at 355 nm with stable output by sum frequency generation from a Nd:YAG laser using a type-I critically phase matched K3B6O10 Br crystal as nonlinear optical material. Conversion efficiency as high as 30.8% was achieved using a 25 ps laser at 1064 nm operated at 10 Hz. Similar work is done by using a 35 W 10 ps laser at 1064 nm as the pump source with a repetition rate of 80 MHz, and the highest average output power obtained was up to 5.3 W. In addition, the power stability of the 355 nm output power measurement shows that the standard deviation fluctuations of the average power are ±0.69% and ±0.91% at 3.0 W and 3.5 W, respectively.

LCLS Maximum Credible Beam Power

International Nuclear Information System (INIS)

Clendenin, J.

2005-01-01

The maximum credible beam power is defined as the highest credible average beam power that the accelerator can deliver to the point in question, given the laws of physics, the beam line design, and assuming all protection devices have failed. For a new accelerator project, the official maximum credible beam power is determined by project staff in consultation with the Radiation Physics Department, after examining the arguments and evidence presented by the appropriate accelerator physicist(s) and beam line engineers. The definitive parameter becomes part of the project's safety envelope. This technical note will first review the studies that were done for the Gun Test Facility (GTF) at SSRL, where a photoinjector similar to the one proposed for the LCLS is being tested. In Section 3 the maximum charge out of the gun for a single rf pulse is calculated. In Section 4, PARMELA simulations are used to track the beam from the gun to the end of the photoinjector. Finally in Section 5 the beam through the matching section and injected into Linac-1 is discussed

A high average power beam dump for an electron accelerator

Energy Technology Data Exchange (ETDEWEB)

Liu, Xianghong, E-mail: xl66@cornell.edu [Cornell Laboratory of Accelerator-based Sciences and Education, Cornell University, Ithaca, NY 14853 (United States); Bazarov, Ivan; Dunham, Bruce M.; Kostroun, Vaclav O.; Li, Yulin; Smolenski, Karl W. [Cornell Laboratory of Accelerator-based Sciences and Education, Cornell University, Ithaca, NY 14853 (United States)

2013-05-01

The electron beam dump for Cornell University's Energy Recovery Linac (ERL) prototype injector was designed and manufactured to absorb 600 kW of electron beam power at beam energies between 5 and 15 MeV. It is constructed from an aluminum alloy using a cylindrical/conical geometry, with water cooling channels between an inner vacuum chamber and an outer jacket. The electron beam is defocused and its centroid is rastered around the axis of the dump to dilute the power density. A flexible joint connects the inner body and the outer jacket to minimize thermal stress. A quadrant detector at the entrance to the dump monitors the electron beam position and rastering. Electron scattering calculations, thermal and thermomechanical stress analysis, and radiation calculations are presented.

A high-average power tapered FEL amplifier at submillimeter frequencies using sheet electron beams and short-period wigglers

International Nuclear Information System (INIS)

Bidwell, S.W.; Radack, D.J.; Antonsen, T.M. Jr.; Booske, J.H.; Carmel, Y.; Destler, W.W.; Granatstein, V.L.; Levush, B.; Latham, P.E.; Zhang, Z.X.

1990-01-01

A high-average-power FEL amplifier operating at submillimeter frequencies is under development at the University of Maryland. Program goals are to produce a CW, ∼1 MW, FEL amplifier source at frequencies between 280 GHz and 560 GHz. To this end, a high-gain, high-efficiency, tapered FEL amplifier using a sheet electron beam and a short-period (superconducting) wiggler has been chosen. Development of this amplifier is progressing in three stages: (1) beam propagation through a long length (∼1 m) of short period (λ ω = 1 cm) wiggler, (2) demonstration of a proof-of-principle amplifier experiment at 98 GHz, and (3) designs of a superconducting tapered FEL amplifier meeting the ultimate design goal specifications. 17 refs., 1 fig., 1 tab

18 CFR 301.5 - Changes in Average System Cost methodology.

Science.gov (United States)

2010-04-01

... REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS FOR FEDERAL POWER MARKETING ADMINISTRATIONS AVERAGE... customers, or from three-quarters of Bonneville's direct-service industrial customers may initiate a...

Energy stability in a high average power FEL

International Nuclear Information System (INIS)

Mermings, L.; Bisognano, J.; Delayen, J.

1995-01-01

Recirculating, energy-recovering linacs can be used as driver accelerators for high power FELs. Instabilities which arise from fluctuations of the cavity fields or beam current are investigated. Energy changes can cause beam loss on apertures, or, when coupled to M, phase oscillations. Both effects change the beam induced voltage in the cavities and can lead to unstable variations of the accelerating field. Stability analysis for small perturbations from equilibrium is performed and threshold currents are determined. Furthermore, the analytical model is extended to include feedback. Comparison with simulation results derived from direct integration of the equations of motion is presented. Design strategies to increase the instability threshold are discussed and the UV Demo FEL, proposed for construction at CEBAF, and the INP Recuperatron at Novosibirsk are used as examples

Mixed-mode distribution systems for high average power electron cyclotron heating

International Nuclear Information System (INIS)

White, T.L.; Kimrey, H.D.; Bigelow, T.S.

1984-01-01

The ELMO Bumpy Torus-Scale (EBT-S) experiment consists of 24 simple magnetic mirrors joined end-to-end to form a torus of closed magnetic field lines. In this paper, we first describe an 80% efficient mixed-mode unpolarized heating system which couples 28-GHz microwave power to the midplane of the 24 EBT-S cavities. The system consists of two radiused bends feeding a quasi-optical mixed-mode toroidal distribution manifold. Balancing power to the 24 cavities is determined by detailed computer ray tracing. A second 28-GHz electron cyclotron heating (ECH) system using a polarized grid high field launcher is described. The launcher penetrates the fundamental ECH resonant surface without a vacuum window with no observable breakdown up to 1 kW/cm 2 (source limited) with 24 kW delivered to the plasma. This system uses the same mixed-mode output as the first system but polarizes the launched power by using a grid of WR42 apertures. The efficiency of this system is 32%, but can be improved by feeding multiple launchers from a separate distribution manifold

Investigation on repetition rate and pulse duration influences on ablation efficiency of metals using a high average power Yb-doped ultrafast laser

Directory of Open Access Journals (Sweden)

Lopez J.

2013-11-01

Full Text Available Ultrafast lasers provide an outstanding processing quality but their main drawback is the low removal rate per pulse compared to longer pulses. This limitation could be overcome by increasing both average power and repetition rate. In this paper, we report on the influence of high repetition rate and pulse duration on both ablation efficiency and processing quality on metals. All trials have been performed with a single tunable ultrafast laser (350 fs to 10ps.

Statistics on exponential averaging of periodograms

Energy Technology Data Exchange (ETDEWEB)

Peeters, T.T.J.M. [Netherlands Energy Research Foundation (ECN), Petten (Netherlands); Ciftcioglu, Oe. [Istanbul Technical Univ. (Turkey). Dept. of Electrical Engineering

1994-11-01

The algorithm of exponential averaging applied to subsequent periodograms of a stochastic process is used to estimate the power spectral density (PSD). For an independent process, assuming the periodogram estimates to be distributed according to a {chi}{sup 2} distribution with 2 degrees of freedom, the probability density function (PDF) of the PSD estimate is derived. A closed expression is obtained for the moments of the distribution. Surprisingly, the proof of this expression features some new insights into the partitions and Eulers infinite product. For large values of the time constant of the averaging process, examination of the cumulant generating function shows that the PDF approximates the Gaussian distribution. Although restrictions for the statistics are seemingly tight, simulation of a real process indicates a wider applicability of the theory. (orig.).

Statistics on exponential averaging of periodograms

International Nuclear Information System (INIS)

Peeters, T.T.J.M.; Ciftcioglu, Oe.

1994-11-01

The algorithm of exponential averaging applied to subsequent periodograms of a stochastic process is used to estimate the power spectral density (PSD). For an independent process, assuming the periodogram estimates to be distributed according to a χ 2 distribution with 2 degrees of freedom, the probability density function (PDF) of the PSD estimate is derived. A closed expression is obtained for the moments of the distribution. Surprisingly, the proof of this expression features some new insights into the partitions and Eulers infinite product. For large values of the time constant of the averaging process, examination of the cumulant generating function shows that the PDF approximates the Gaussian distribution. Although restrictions for the statistics are seemingly tight, simulation of a real process indicates a wider applicability of the theory. (orig.)

Lateral dispersion coefficients as functions of averaging time

International Nuclear Information System (INIS)

Sheih, C.M.

1980-01-01

Plume dispersion coefficients are discussed in terms of single-particle and relative diffusion, and are investigated as functions of averaging time. To demonstrate the effects of averaging time on the relative importance of various dispersion processes, and observed lateral wind velocity spectrum is used to compute the lateral dispersion coefficients of total, single-particle and relative diffusion for various averaging times and plume travel times. The results indicate that for a 1 h averaging time the dispersion coefficient of a plume can be approximated by single-particle diffusion alone for travel times <250 s and by relative diffusion for longer travel times. Furthermore, it is shown that the power-law formula suggested by Turner for relating pollutant concentrations for other averaging times to the corresponding 15 min average is applicable to the present example only when the averaging time is less than 200 s and the tral time smaller than about 300 s. Since the turbulence spectrum used in the analysis is an observed one, it is hoped that the results could represent many conditions encountered in the atmosphere. However, as the results depend on the form of turbulence spectrum, the calculations are not for deriving a set of specific criteria but for demonstrating the need in discriminating various processes in studies of plume dispersion

Highest energy cosmic rays

International Nuclear Information System (INIS)

Nikolskij, S.

1984-01-01

Primary particles of cosmic radiation with highest energies cannot in view of their low intensity be recorded directly but for this purpose the phenomenon is used that these particles interact with nuclei in the atmosphere and give rise to what are known as extensive air showers. It was found that 40% of primary particles with an energy of 10 15 to 10 16 eV consist of protons, 12 to 15% of helium nuclei, 15% of iron nuclei, the rest of nuclei of other elements. Radiation intensity with an energy of 10 18 to 10 19 eV depends on the direction of incoming particles. Maximum intensity is in the direction of the centre of the nearest clustre of galaxies, minimal in the direction of the central area of our galaxy. (Ha)

Operating experience from Swedish nuclear power plants 2003

International Nuclear Information System (INIS)

2004-01-01

In safety terms, operations of the Swedish nuclear power plants in 2003 can be summarized as having ben good, with a few exceptions: The thermal mixer problem at Barsebaeck-2; The Highest Permissible Limit Value excursion at OKG-3, which subjected the reactor pressure vessel to a too rapid temperature change; and An INES class 1 incident at Ringhals-1. The Barsebaeck and Ringhals events were not of such seriousness as to represent a threat to reactor safety, but they both had the effect of causing the Nuclear Power Inspectorate to question safety cultures at the plants. The mixer event resulted in a considerable production loss, with the reactor being shut down twice, making a total of five months. OKG-3 was shut down for almost two months during the autumn. Despite the above, production from Swedish NPPs was much the same as during 2002. Total electricity production amounted to 65 TWh (65.2 TWh in 2002). On the average the energy availability of the eleven reactors was 79%. The PWRs at Ringhals had an average energy availability of 89%, while the BWRs reached 76%

Extending a Consensus-based Fuzzy Ordered Weighting Average (FOWA Model in New Water Quality Indices

Directory of Open Access Journals (Sweden)

Mohammad Ali Baghapour

2017-07-01

Full Text Available In developing a specific WQI (Water Quality Index, many water quality parameters are involved with different levels of importance. The impact of experts’ different opinions and viewpoints, current risks affecting their opinions, and plurality of the involved parameters double the significance of the issue. Hence, the current study tries to apply a consensus-based FOWA (Fuzzy Ordered Weighting Average model as one of the most powerful and well-known Multi Criteria Decision Making (MCDM techniques to determine the importance of the used parameters in the development of such WQIs which is shown with an example. This operator has provided the capability of modeling the risks in decision-making through applying the optimistic degree of stakeholders and their power coupled with the use of fuzzy numbers. Totally, 22 water quality parameters for drinking purposes are considered in this study. To determine the weight of each parameter, the viewpoints of 4 decision-making groups of experts are taken into account. After determining the final weights, to validate the use of each parameter in a potential WQI, consensus degrees of both the decision makers and the parameters are calculated. All calculations are carried out by using the expertise software called Group Fuzzy Decision Making (GFDM. The highest and the lowest weight values, 0.999 and 0.073 respectively, are related to Hg and temperature. Regarding the type of consumption that is drinking, the parameters’ weights and ranks are consistent with their health impacts. Moreover, the decision makers’ highest and lowest consensus degrees were 0.9905 and 0.9669, respectively. Among the water quality parameters, temperature (with consensus degree of 0.9972 and Pb (with consensus degree of 0.9665, received the highest and lowest agreement from the decision making group. This study indicates that the weight of parameters in determining water quality largely depends on the experts’ opinions and

Extending a Consensus-based Fuzzy Ordered Weighting Average (FOWA Model in New Water Quality Indices

Directory of Open Access Journals (Sweden)

Mohammad Ali Baghapour

2017-07-01

Full Text Available In developing a specific WQI (Water Quality Index, many quality parameters are involved with different levels of importance. The impact of experts’ different opinions and viewpoints, current risks affecting their opinions, and plurality of the involved parameters double the significance of the issue. Hence, the current study tries to apply a consensus-based FOWA (Fuzzy Ordered Weighting Average model as one of the most powerful and well-known Multi-Criteria Decision- Making (MCDM techniques to determine the importance of the used parameters in the development of such WQIs which is shown with an example. This operator has provided the capability of modeling the risks in decision-making through applying the optimistic degree of stakeholders and their power coupled with the use of fuzzy numbers. Totally, 22 water quality parameters for drinking purposes were considered in this study. To determine the weight of each parameter, the viewpoints of 4 decision-making groups of experts were taken into account. After determining the final weights, to validate the use of each parameter in a potential WQI, consensus degrees of both the decision makers and the parameters are calculated. The highest and the lowest weight values, 0.999 and 0.073 respectively, were related to Hg and temperature. Regarding the type of consumption that was drinking, the parameters’ weights and ranks were consistent with their health impacts. Moreover, the decision makers’ highest and lowest consensus degrees were 0.9905 and 0.9669, respectively. Among the water quality parameters, temperature (with consensus degree of 0.9972 and Pb (with consensus degree of 0.9665, received the highest and lowest agreement with the decision-making group. This study indicated that the weight of parameters in determining water quality largely depends on the experts’ opinions and approaches. Moreover, using the FOWA model provides results accurate and closer- to-reality on the significance of

Evaluation of soft x-ray average recombination coefficient and average charge for metallic impurities in beam-heated plasmas

International Nuclear Information System (INIS)

Sesnic, S.S.; Bitter, M.; Hill, K.W.; Hiroe, S.; Hulse, R.; Shimada, M.; Stratton, B.; von Goeler, S.

1986-05-01

The soft x-ray continuum radiation in TFTR low density neutral beam discharges can be much lower than its theoretical value obtained by assuming a corona equilibrium. This reduced continuum radiation is caused by an ionization equilibrium shift toward lower states, which strongly changes the value of the average recombination coefficient of metallic impurities anti γ, even for only slight changes in the average charge, anti Z. The primary agent for this shift is the charge exchange between the highly ionized impurity ions and the neutral hydrogen, rather than impurity transport, because the central density of the neutral hydrogen is strongly enhanced at lower plasma densities with intense beam injection. In the extreme case of low density, high neutral beam power TFTR operation (energetic ion mode) the reduction in anti γ can be as much as one-half to two-thirds. We calculate the parametric dependence of anti γ and anti Z for Ti, Cr, Fe, and Ni impurities on neutral density (equivalent to beam power), electron temperature, and electron density. These values are obtained by using either a one-dimensional impurity transport code (MIST) or a zero-dimensional code with a finite particle confinement time. As an example, we show the variation of anti γ and anti Z in different TFTR discharges

2002 Nuclear Power World Report - Evaluation

International Nuclear Information System (INIS)

Anon.

2003-01-01

Last year, in 2002, 441 nuclear power plants were available for power supply in 31 countries in the world. With an aggregate gross power of 377,359 MWe, and an aggregate net power of 359,429 MWe, respectively, the nuclear generating capacity reached its highest level so far. Nine different reactor lines are used in commercial facilities. Light water reactors (PWR and BWR) contribute 355 plants, which makes them the most common reactor line. In twelve countries, 32 nuclear power plants with an aggregate gross power of 26,842 MWe and an aggregate net power of 25,546 MWe, respectively, are under construction. Of these, 25 units are light water reactors while eight are CANDU-type plants. In eighteen countries, 94 commercial reactors with more than 5 MWe power have been decommissioned so far. Most of these plants are prototypes with low powers. 228 of the nuclear power plants currently in operation, i.e. slightly more than half of them, were commissioned in the eighties. The oldest commercial nuclear power plant, Calder Hall unit 1, supplied power into the public grid in its 47th year of operation in 2002. The availability in terms of time and capacity of nuclear power plants rose from 74.23% in 1991 to 83.40% in 2001. A continued rise to approx. 85% is expected for 2002. In the same way, the non-availability in terms of time (unscheduled) dropped from 6.90% to 3.48%. The four nuclear power plants in Finland are the world's leaders with a cumulated average capacity availability of 90.00%. (orig.) [de

Evaluation of Dynamic Channel and Power Assignment for Cognitive Networks

Energy Technology Data Exchange (ETDEWEB)

Syed A. Ahmad; Umesh Shukla; Ryan E. Irwin; Luiz A. DaSilva; Allen B. MacKenzie

2011-03-01

In this paper, we develop a unifying optimization formulation to describe the Dynamic Channel and Power Assignment (DCPA) problem and evaluation method for comparing DCPA algorithms. DCPA refers to the allocation of transmit power and frequency channels to links in a cognitive network so as to maximize the total number of feasible links while minimizing the aggregate transmit power. We apply our evaluation method to five algorithms representative of DCPA used in literature. This comparison illustrates the tradeoffs between control modes (centralized versus distributed) and channel/power assignment techniques. We estimate the complexity of each algorithm. Through simulations, we evaluate the effectiveness of the algorithms in achieving feasible link allocations in the network, as well as their power efficiency. Our results indicate that, when few channels are available, the effectiveness of all algorithms is comparable and thus the one with smallest complexity should be selected. The Least Interfering Channel and Iterative Power Assignment (LICIPA) algorithm does not require cross-link gain information, has the overall lowest run time, and highest feasibility ratio of all the distributed algorithms; however, this comes at a cost of higher average power per link.

Development of an Interferometric Phased Array Trigger for Balloon-Borne Detection of the Highest Energy Cosmic Particles

Science.gov (United States)

Vieregg, Abigail

interferometric phased array trigger for these impulsive radio detectors, a new type of trigger that will improve sensitivity substantially and expedite the discovery of the highest energy particles in our universe. We have developed an 8- channel interferometric trigger board for ground-based applications that will be deployed in December 2017 with the ground-based Askaryan Radio Array (ARA) experiment at the South Pole. Preliminary Monte Carlo simulations indicate that the cosmogenic neutrino event rate will go up by a factor of 3 with the new trigger. The true power of the interferometric trigger is in scaling to large numbers of channels, and the discovery space that is only available from a balloon platform at the highest energies is extremely appealing. We will build on and extend the NASA investment in the ANITA Long Duration Balloon (LDB) mission and the many other complementary particle astrophysics LDB missions by developing the electronics required to bring a large-scale radio interferometric trigger to a balloon platform, extending the scientific reach of any future LDB or Super Pressure Balloon (SPB) mission for radio detection of the highest energy cosmic particles. We will develop an interferometric trigger system that is scalable to O(100) channels and suitable for use on a balloon platform. Under this proposal, we will: 1) Design and fabricate interferometric trigger hardware for balloon-borne cosmic particle detectors that is scalable to large numbers of channels O(100) by reducing the power consumption per channel, increasing the number of channels per board, and developing high-speed communication capability between boards. 2) Perform a trade study and inform design decisions for future balloon missions by further developing our Monte Carlo simulation and adapting it to balloon geometries.

Extension of the time-average model to Candu refueling schemes involving reshuffling

International Nuclear Information System (INIS)

Rouben, Benjamin; Nichita, Eleodor

2008-01-01

Candu reactors consist of a horizontal non-pressurized heavy-water-filled vessel penetrated axially by fuel channels, each containing twelve 50-cm-long fuel bundles cooled by pressurized heavy water. Candu reactors are refueled on-line and, as a consequence, the core flux and power distributions change continuously. For design purposes, a 'time-average' model was developed in the 1970's to calculate the average over time of the flux and power distribution and to study the effects of different refueling schemes. The original time-average model only allows treatment of simple push-through refueling schemes whereby fresh fuel is inserted at one end of the channel and irradiated fuel is removed from the other end. With the advent of advanced fuel cycles and new Candu designs, novel refueling schemes may be considered, such as reshuffling discharged fuel from some channels into other channels, to achieve better overall discharge burnup. Such reshuffling schemes cannot be handled by the original time-average model. This paper presents an extension of the time-average model to allow for the treatment of refueling schemes with reshuffling. Equations for the extended model are presented, together with sample results for a simple demonstration case. (authors)

The Average Temporal and Spectral Evolution of Gamma-Ray Bursts

International Nuclear Information System (INIS)

Fenimore, E.E.

1999-01-01

We have averaged bright BATSE bursts to uncover the average overall temporal and spectral evolution of gamma-ray bursts (GRBs). We align the temporal structure of each burst by setting its duration to a standard duration, which we call T left-angleDurright-angle . The observed average open-quotes aligned T left-angleDurright-angle close quotes profile for 32 bright bursts with intermediate durations (16 - 40 s) has a sharp rise (within the first 20% of T left-angleDurright-angle ) and then a linear decay. Exponentials and power laws do not fit this decay. In particular, the power law seen in the X-ray afterglow (∝T -1.4 ) is not observed during the bursts, implying that the X-ray afterglow is not just an extension of the average temporal evolution seen during the gamma-ray phase. The average burst spectrum has a low-energy slope of -1.03, a high-energy slope of -3.31, and a peak in the νF ν distribution at 390 keV. We determine the average spectral evolution. Remarkably, it is also a linear function, with the peak of the νF ν distribution given by ∼680-600(T/T left-angleDurright-angle ) keV. Since both the temporal profile and the peak energy are linear functions, on average, the peak energy is linearly proportional to the intensity. This behavior is inconsistent with the external shock model. The observed temporal and spectral evolution is also inconsistent with that expected from variations in just a Lorentz factor. Previously, trends have been reported for GRB evolution, but our results are quantitative relationships that models should attempt to explain. copyright copyright 1999. The American Astronomical Society

A spectral measurement method for determining white OLED average junction temperatures

Science.gov (United States)

Zhu, Yiting; Narendran, Nadarajah

2016-09-01

The objective of this study was to investigate an indirect method of measuring the average junction temperature of a white organic light-emitting diode (OLED) based on temperature sensitivity differences in the radiant power emitted by individual emitter materials (i.e., "blue," "green," and "red"). The measured spectral power distributions (SPDs) of the white OLED as a function of temperature showed amplitude decrease as a function of temperature in the different spectral bands, red, green, and blue. Analyzed data showed a good linear correlation between the integrated radiance for each spectral band and the OLED panel temperature, measured at a reference point on the back surface of the panel. The integrated radiance ratio of the spectral band green compared to red, (G/R), correlates linearly with panel temperature. Assuming that the panel reference point temperature is proportional to the average junction temperature of the OLED panel, the G/R ratio can be used for estimating the average junction temperature of an OLED panel.

Market Prices in a Power Market with more than 50% Wind Power

DEFF Research Database (Denmark)

Skytte, Klaus; Grohnheit, Poul Erik

2018-01-01

Denmark has the highest proportion of wind power in the world. Wind power provided a world record of 39.1% of the total annual Danish electricity consumption in 2014 with as much as 51.7% in Western Denmark. Many would argue that the present power markets are not designed for such high shares...... of wind power production and that it would be hard to get good and stable prices. However, analyses in this chapter show that the Nordic power market works, extreme events have been few, and the current infrastructure and market organization has been able to handle the amount of wind power installed so...... far. It is found that geographical bidding areas for the wholesale electricity market reflect external transmission constraints caused by wind power. The analyses in this chapter use hourly data from West Denmark—which has the highest share of wind energy in Denmark and which is a separate price area...

Market Prices in a Power Market with more than 50% Wind Power

DEFF Research Database (Denmark)

Skytte, Klaus; Grohnheit, Poul Erik

2017-01-01

Denmark has the highest proportion of wind power in the world. Wind power provided a world record of 39.1% of the total annual Danish electricity consumption in 2014 with as much as 51.7% in Western Denmark. Many would argue that the present power markets are not designed for such high shares...... of wind power production and that it would be hard to get good and stable prices. However, analyses in this chapter show that the Nordic power market works, extreme events have been few, and the current infrastructure and market organization has been able to handle the amount of wind power installed so...... far. It is found that geographical bidding areas for the wholesale electricity market reflect external transmission constraints caused by wind power. The analyses in this chapter use hourly data from West Denmark—which has the highest share of wind energy in Denmark and which is a separate price area...

A ROBUST CLUSTER HEAD SELECTION BASED ON NEIGHBORHOOD CONTRIBUTION AND AVERAGE MINIMUM POWER FOR MANETs

Directory of Open Access Journals (Sweden)

S.Balaji

2015-06-01

Full Text Available Mobile Adhoc network is an instantaneous wireless network that is dynamic in nature. It supports single hop and multihop communication. In this infrastructure less network, clustering is a significant model to maintain the topology of the network. The clustering process includes different phases like cluster formation, cluster head selection, cluster maintenance. Choosing cluster head is important as the stability of the network depends on well-organized and resourceful cluster head. When the node has increased number of neighbors it can act as a link between the neighbor nodes which in further reduces the number of hops in multihop communication. Promisingly the node with more number of neighbors should also be available with enough energy to provide stability in the network. Hence these aspects demand the focus. In weight based cluster head selection, closeness and average minimum power required is considered for purging the ineligible nodes. The optimal set of nodes selected after purging will compete to become cluster head. The node with maximum weight selected as cluster head. Mathematical formulation is developed to show the proposed method provides optimum result. It is also suggested that weight factor in calculating the node weight should give precise importance to energy and node stability.

Computerized system for building 'the rose' of the winds and defining the velocity and the average density of the wind power for a given place

International Nuclear Information System (INIS)

Valkov, I.; Dekova, I.; Arnaudov, A.; Kostadinov, A.

2002-01-01

This paper considers the structure and the working principle of a computerized system for building 'the rose' of the winds. The behaviour of the system has been experimentally investigated and on the basis of the received data 'the rose' of the winds has been built, a diagram of the average wind velocity at a predefined step in the course of time has been made, and the average density of the wind power has been quantitatively defined. The proposed system enables possibilities for creating a data base of wind parameters, their processing and graphical visualizing of the received results. The system allows to improve the work of devices of wild's wind gauge type. (authors)

Protection of Hardware: Powering Systems (Power Converter, Normal Conducting, and Superconducting Magnets)

Energy Technology Data Exchange (ETDEWEB)

Pfeffer, H. [Fermilab; Flora, B. [Fermilab; Wolff, D. [Fermilab

2016-01-01

Along with the protection of magnets and power converters, we have added a section on personnel protection because this is our highest priority in the design and operation of power systems. Thus, our topics are the protection of people, power converters, and magnet loads (protected from the powering equipment), including normal conducting magnets and superconducting magnets.

Preoperational radiation measurements at the Angra-I nuclear power plant. Part 1

International Nuclear Information System (INIS)

Leao, J.L.B.; Barbosa, W.P.; Oberhofer, M.

1991-01-01

During December 10 and 11, 1980, γ-background measurements were performed at the Angra-I nuclear power plant within the reactor containment, within and outside the adjacent building complexes. The dose-rates within the containment averaged around 10,6 μR/h, within the auxiliary building around 14,4 μR/h. The lowest values, 6 μR/h, were measured within the reactor coolant pump and steam generator compartments, the highest value, 25 μR/h, in the charging pump valve operation room, elevation 8,65, close to area monitor No. 4. (author)

Development of a 33 kV, 20 A long pulse converter modulator for high average power klystron

International Nuclear Information System (INIS)

Reghu, T.; Mandloi, V.; Shrivastava, Purushottam

2014-01-01

Research, design, and development of high average power, long pulse modulators for the proposed Indian Spallation Neutron Source are underway at Raja Ramanna Centre for Advanced Technology. With this objective, a prototype of long pulse modulator capable of delivering 33 kV, 20 A at 5 Hz repetition rate has been designed and developed. Three Insulated Gate Bipolar Transistors (IGBT) based switching modules driving high frequency, high voltage transformers have been used to generate high voltage output. The IGBT based switching modules are shifted in phase by 120° with respect to each other. The switching frequency is 25 kHz. Pulses of 1.6 ms pulse width, 80 μs rise time, and 70 μs fall time have been achieved at the modulator output. A droop of ±0.6% is achieved using a simple segmented digital droop correction technique. The total fault energy transferred to the load during fault has been measured by conducting wire burn tests and is found to be within 3.5 J

Development of a 33 kV, 20 A long pulse converter modulator for high average power klystron

Science.gov (United States)

Reghu, T.; Mandloi, V.; Shrivastava, Purushottam

2014-05-01

Research, design, and development of high average power, long pulse modulators for the proposed Indian Spallation Neutron Source are underway at Raja Ramanna Centre for Advanced Technology. With this objective, a prototype of long pulse modulator capable of delivering 33 kV, 20 A at 5 Hz repetition rate has been designed and developed. Three Insulated Gate Bipolar Transistors (IGBT) based switching modules driving high frequency, high voltage transformers have been used to generate high voltage output. The IGBT based switching modules are shifted in phase by 120° with respect to each other. The switching frequency is 25 kHz. Pulses of 1.6 ms pulse width, 80 μs rise time, and 70 μs fall time have been achieved at the modulator output. A droop of ±0.6% is achieved using a simple segmented digital droop correction technique. The total fault energy transferred to the load during fault has been measured by conducting wire burn tests and is found to be within 3.5 J.

Development of a 33 kV, 20 A long pulse converter modulator for high average power klystron

Energy Technology Data Exchange (ETDEWEB)

Reghu, T.; Mandloi, V.; Shrivastava, Purushottam [Pulsed High Power Microwave Section, Raja Ramanna Centre for Advanced Technology, Indore 452013, M.P. (India)

2014-05-15

Research, design, and development of high average power, long pulse modulators for the proposed Indian Spallation Neutron Source are underway at Raja Ramanna Centre for Advanced Technology. With this objective, a prototype of long pulse modulator capable of delivering 33 kV, 20 A at 5 Hz repetition rate has been designed and developed. Three Insulated Gate Bipolar Transistors (IGBT) based switching modules driving high frequency, high voltage transformers have been used to generate high voltage output. The IGBT based switching modules are shifted in phase by 120° with respect to each other. The switching frequency is 25 kHz. Pulses of 1.6 ms pulse width, 80 μs rise time, and 70 μs fall time have been achieved at the modulator output. A droop of ±0.6% is achieved using a simple segmented digital droop correction technique. The total fault energy transferred to the load during fault has been measured by conducting wire burn tests and is found to be within 3.5 J.

High-power noise-like pulse generation using a 1.56-µm all-fiber laser system.

Science.gov (United States)

Lin, Shih-Shian; Hwang, Sheng-Kwang; Liu, Jia-Ming

2015-07-13

We demonstrated an all-fiber, high-power noise-like pulse laser system at the 1.56-µm wavelength. A low-power noise-like pulse train generated by a ring oscillator was amplified using a two-stage amplifier, where the performance of the second-stage amplifier determined the final output power level. The optical intensity in the second-stage amplifier was managed well to avoid not only the excessive spectral broadening induced by nonlinearities but also any damage to the device. On the other hand, the power conversion efficiency of the amplifier was optimized through proper control of its pump wavelength. The pump wavelength determines the pump absorption and therefore the power conversion efficiency of the gain fiber. Through this approach, the average power of the noise-like pulse train was amplified considerably to an output of 13.1 W, resulting in a power conversion efficiency of 36.1% and a pulse energy of 0.85 µJ. To the best of our knowledge, these amplified pulses have the highest average power and pulse energy for noise-like pulses in the 1.56-µm wavelength region. As a result, the net gain in the cascaded amplifier reached 30 dB. With peak and pedestal widths of 168 fs and 61.3 ps, respectively, for the amplified pulses, the pedestal-to-peak intensity ratio of the autocorrelation trace remains at the value of 0.5 required for truly noise-like pulses.

The potential estimation and factor analysis of China′s energy conservation on thermal power industry

International Nuclear Information System (INIS)

Lin, Boqiang; Yang, Lisha

2013-01-01

At present, researches about energy conservation are focused on prediction. But there are few researches focused on the estimation of effective input and energy conservation potential, and there has been even no research on energy conservation of thermal power industry of China. This paper will try to fill in such a blank. Panel data on Chinese thermal power industry over 2005–2010 are established, and we adopt the stochastic frontier analysis approach to estimate the energy saving potential of thermal power industry. The results are as follows: (1) the average efficiency of energy inputs in China′s thermal power industry over 2005–2010 was about 0.85, and cumulative energy saving potential equals to 551.04 (Mtce); (2) by improving the non-efficiency factors, the relatively backward inland cities could achieve higher energy saving in thermal power industry; (3) the energy input efficiency of Eastern China Grid is shown to be the highest; (4) in order to realize the energy-saving goal of thermal power industry, one important policy method the government should adopt is to conduct a market-oriented reform in power industry and break the state-owned monopoly to provide incentives for private and foreign direct investment in thermal power sector. -- Highlights: •We adopt SFA model to estimate the coal input efficiency of power sector in China. •We calculate the cumulative energy saving potential equals to 551.04 Mtce. •East China power grid has the highest energy input efficiency. •Some backward inland cities may be the main force for future energy conservation. •Encourage private and foreign direct investment in power sector might be effective

Isar-2 nuclear power station twenty-five years

International Nuclear Information System (INIS)

Fischer, Erwin; Luginger, Markus

2013-01-01

The Isar-2 nuclear power station (KKI 2) began commercial power operation on April 9, 1988. In these past 25 years the plant generated a total of approx. 285 billion kWh of electricity. The annual electricity production of KKI 2 of approx. 12 billion kWh corresponds to a share of approx. 15 % in the cumulated Bavarian electricity production. This amount of electricity, theoretically, could supply some 3 million three person households, or meet two thirds of the electricity requirement of the Bavarian industry, for one year. In its 25 years of power operation the Isar-2 nuclear power plant has recorded the highest annual gross electricity production of all nuclear power plants in the world nine times so far. A plant performance as impressive as this necessitates a plant availability far above the average. This, in turn, is based on short revision times and faultfree plant operation. However, high plant safety and availability must not be taken for granted, but are the result of responsible, safety-minded plant operation combined with continuous plant optimization and permanent execution of comprehensive checks, inspections, and maintenance measures. Besides plant technology also organization and administration were permanently advanced and adapted to changing requirements so as to safeguard reliable, safe, and non-polluting plant operation.

Ultra-low noise miniaturized neural amplifier with hardware averaging.

Science.gov (United States)

Dweiri, Yazan M; Eggers, Thomas; McCallum, Grant; Durand, Dominique M

2015-08-01

Peripheral nerves carry neural signals that could be used to control hybrid bionic systems. Cuff electrodes provide a robust and stable interface but the recorded signal amplitude is small (concept of hardware averaging to nerve recordings obtained with cuff electrodes. An optimization procedure is developed to minimize noise and power simultaneously. The novel design was based on existing neural amplifiers (Intan Technologies, LLC) and is validated with signals obtained from the FINE in chronic dog experiments. We showed that hardware averaging leads to a reduction in the total recording noise by a factor of 1/√N or less depending on the source resistance. Chronic recording of physiological activity with FINE using the presented design showed significant improvement on the recorded baseline noise with at least two parallel operation transconductance amplifiers leading to a 46.1% reduction at N = 8. The functionality of these recordings was quantified by the SNR improvement and shown to be significant for N = 3 or more. The present design was shown to be capable of generating hardware averaging on noise improvement for neural recording with cuff electrodes, and can accommodate the presence of high source impedances that are associated with the miniaturized contacts and the high channel count in electrode arrays. This technique can be adopted for other applications where miniaturized and implantable multichannel acquisition systems with ultra-low noise and low power are required.

Nuclear fuel management via fuel quality factor averaging

International Nuclear Information System (INIS)

Mingle, J.O.

1978-01-01

The numerical procedure of prime number averaging is applied to the fuel quality factor distribution of once and twice-burned fuel in order to evolve a fuel management scheme. The resulting fuel shuffling arrangement produces a near optimal flat power profile both under beginning-of-life and end-of-life conditions. The procedure is easily applied requiring only the solution of linear algebraic equations. (author)

Outline of Noto Nuclear Power Station, Hokuriku Electric Power Co., Inc

International Nuclear Information System (INIS)

1988-01-01

The location of the power station is in Shiga-cho, Hakui-gun, Ishikawa-ken. One BWR of about 1,600 MWt (540 MWe) capacity is installed. The area of the site is about 1.6 million m 2 , which is on the gentle slope of hilly land at the elevation of about 50 m, and faces Japan Sea. The nuclear reactor proper is installed at the position about 400 m eastward from the coastline. The height of the exhaust stack is about 100 m above the ground. The shortest distance from the center of the reactor core to the boundary of the site is about 450 m in the direction of south and southwest. The objective of use in commercial electric power generation. The start of operation is scheduled in March, 1993. The total cost of construction is about 235 billion yen, which is equivalent to about 435,000 yen-kW. The fuel assemblies are 8 x 8 type, the fuel material is uranium dioxide sintered pellets, and the average degree of enrichment of the initially charged fuel is about 1.6 wt.% in type 1, 2.4 wt.% in type 2 and 3.0 wt.% in type 3 (about 2.3 wt.% on the average). The highest burnup of fuel assemblies is 40,000 MWd-t. The total amount of fuel charged in the core is about 64 t of uranium. The main steam temperature at the reactor exit is 286 deg C, and the feedwater pressure at the reactor entrance is 72 kg-cm 2 g. The steam turbine is a tandem four-flow exhaust condensing turbine of 540 MW output. (Kako, I.)

18 CFR 301.4 - Exchange Period Average System Cost determination.

Science.gov (United States)

2010-04-01

... REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS FOR FEDERAL POWER MARKETING ADMINISTRATIONS AVERAGE... Period and extend through four (4) years after the Exchange Period. The load forecast for Contract System... Utility's ASC until the change in service territory takes place. (g) ASC determination for Consumer-owned...

Performance analysis of joint diversity combining, adaptive modulation, and power control schemes

KAUST Repository

Qaraqe, Khalid A.

2011-01-01

Adaptive modulation and diversity combining represent very important adaptive solutions for future generations of wireless communication systems. Indeed, in order to improve the performance and the efficiency of these systems, these two techniques have been recently used jointly in new schemes named joint adaptive modulation and diversity combining (JAMDC) schemes. Considering the problem of finding low hardware complexity, bandwidth-efficient, and processing-power efficient transmission schemes for a downlink scenario and capitalizing on some of these recently proposed JAMDC schemes, we propose and analyze in this paper three joint adaptive modulation, diversity combining, and power control (JAMDCPC) schemes where a constant-power variable-rate adaptive modulation technique is used with an adaptive diversity combining scheme and a common power control process. More specifically, the modulation constellation size, the number of combined diversity paths, and the needed power level are jointly determined to achieve the highest spectral efficiency with the lowest possible processing power consumption quantified in terms of the average number of combined paths, given the fading channel conditions and the required bit error rate (BER) performance. In this paper, the performance of these three JAMDCPC schemes is analyzed in terms of their spectral efficiency, processing power consumption, and error-rate performance. Selected numerical examples show that these schemes considerably increase the spectral efficiency of the existing JAMDC schemes with a slight increase in the average number of combined paths for the low signal-to-noise ratio range while maintaining compliance with the BER performance and a low radiated power which yields to a substantial decrease in interference to co-existing users and systems. © 2011 IEEE.

Applications of resonance-averaged gamma-ray spectroscopy with tailored beams

International Nuclear Information System (INIS)

Chrien, R.E.

1982-01-01

The use of techniques based on the direct experimental averaging over compound nuclear capturing states has proved valuable for investigations of nuclear structure. The various methods that have been employed are described, with particular emphasis on the transmission filter, or tailored beam technique. The mathematical limitations on averaging imposed by the filter band pass are discussed. It can readily be demonstrated that a combination of filters at different energies can form a powerful method for spin and parity predictions. Several recent examples from the HFBR program are presented

MAIN STAGES SCIENTIFIC AND PRODUCTION MASTERING THE TERRITORY AVERAGE URAL

Directory of Open Access Journals (Sweden)

V.S. Bochko

2006-09-01

Full Text Available Questions of the shaping Average Ural, as industrial territory, on base her scientific study and production mastering are considered in the article. It is shown that studies of Ural resources and particularities of the vital activity of its population were concerned by Russian and foreign scientist in XVIII-XIX centuries. It is noted that in XX century there was a transition to systematic organizing-economic study of production power, society and natures of Average Ural. More attention addressed on new problems of region and on needs of their scientific solving.

Applications of resonance-averaged gamma-ray spectroscopy with tailored beams

International Nuclear Information System (INIS)

Chrien, R.E.

1982-01-01

The use of techniques based on the direct experimental averaging over compound nuclear capturing states has proved valuable for investigations of nuclear structure. The various methods that have been employed are described, with particular emphasis on the transmission filter, or tailored beam technique. The mathematical limitations on averaging imposed by the filtre band pass are discussed. It can readily be demonstrated that a combination of filters at different energies can form a powerful method for spin and parity predictions. Several recent examples from the HFBR program are presented. (author)

Americans' Average Radiation Exposure

International Nuclear Information System (INIS)

2000-01-01

We live with radiation every day. We receive radiation exposures from cosmic rays, from outer space, from radon gas, and from other naturally radioactive elements in the earth. This is called natural background radiation. It includes the radiation we get from plants, animals, and from our own bodies. We also are exposed to man-made sources of radiation, including medical and dental treatments, television sets and emission from coal-fired power plants. Generally, radiation exposures from man-made sources are only a fraction of those received from natural sources. One exception is high exposures used by doctors to treat cancer patients. Each year in the United States, the average dose to people from natural and man-made radiation sources is about 360 millirem. A millirem is an extremely tiny amount of energy absorbed by tissues in the body

Performance model to assist solar thermal power plant siting in northern Chile based on backup fuel consumption

Energy Technology Data Exchange (ETDEWEB)

Larrain, Teresita; Escobar, Rodrigo; Vergara, Julio [Departamento de Ingenieria Mecanica y Metalurgica, Pontificia Universidad Catolica de Chile, Vicuna Mackenna 4860, Macul, Santiago (Chile)

2010-08-15

In response to environmental awareness, Chile introduced sustainability goals in its electricity law. Power producers must deliver 5% from renewable sources by 2010 and 10% by 2024. The Chilean desert has a large available surface with one of the highest radiation levels and clearest skies in the World. These factors imply that solar power is an option for this task. However, a commercial plant requires a fossil fuel system to backup the sunlight intermittency. The authors developed a thermodynamical model to estimate the backup fraction needed in a 100 MW hybrid -solar-fossil- parabolic trough power plant. This paper presents the model aiming to predicting the performance and exploring its usefulness in assisting site selection among four locations. Since solar radiation data are only available in a monthly average, we introduced two approaches to feed the model. One data set provided an average month with identical days throughout and the other one considered an artificial month of different daylight profiles on an hourly basis for the same monthly average. We recommend a best plant location based on minimum fossil fuel backup, contributing to optimal siting from the energy perspective. Utilities will refine their policy goals more closely when a precise solar energy data set becomes available. (author)

Which Kids Are at Highest Risk for Suicide?

Science.gov (United States)

... Share Which Kids are at Highest Risk for Suicide? Page Content Article Body No child is immune, ... who have lost a friend or relative to suicide. Studies show that a considerable number of youth ...

Aperture averaging and BER for Gaussian beam in underwater oceanic turbulence

Science.gov (United States)

Gökçe, Muhsin Caner; Baykal, Yahya

2018-03-01

In an underwater wireless optical communication (UWOC) link, power fluctuations over finite-sized collecting lens are investigated for a horizontally propagating Gaussian beam wave. The power scintillation index, also known as the irradiance flux variance, for the received irradiance is evaluated in weak oceanic turbulence by using the Rytov method. This lets us further quantify the associated performance indicators, namely, the aperture averaging factor and the average bit-error rate (). The effects on the UWOC link performance of the oceanic turbulence parameters, i.e., the rate of dissipation of kinetic energy per unit mass of fluid, the rate of dissipation of mean-squared temperature, Kolmogorov microscale, the ratio of temperature to salinity contributions to the refractive index spectrum as well as system parameters, i.e., the receiver aperture diameter, Gaussian source size, laser wavelength and the link distance are investigated.

Cortex Matures Faster in Youths With Highest IQ

Science.gov (United States)

... NIH Cortex Matures Faster in Youths With Highest IQ Past Issues / Summer 2006 Table of Contents For ... on. Photo: Getty image (StockDisc) Youths with superior IQ are distinguished by how fast the thinking part ...

JAERI femtosecond pulsed and tens-kilowatts average-powered free-electron lasers and their applications of large-scaled non-thermal manufacturing in nuclear energy industry

International Nuclear Information System (INIS)

Minehara, Eisuke J.

2004-01-01

We first reported the novel method that femto-second (fs) lasers of the low average power Ti: Sapphire one, the JAERI high average power free-electron laser, excimer laser, fiber laser and so on could peel off and remove both stress corrosion cracking (SCC) origins of the cold-worked (CW) and very crack-susceptible material, and residual tensile stress in the hardened surface of low-carbon stainless steel cubic samples for nuclear reactor internals as a proof of principle experiment except for the last and third origin of corrosive environment. Because it has been successfully demonstrated that the fs lasers could clearly remove the two SCC origins, we could resultantly prevent the cold-worked SCC in many field near future. The SCC is a well known phenomenon in modern material sciences, technologies, and industries, and defined as an insidious failure mechanism that is caused by the corrosive environment, and the crack-susceptible material and the surface residual tensile stress simultaneously. There are a large number of famous SCC examples for damaging stainless steels, aluminum alloys, brass and other alloy metals in many different cases. In many boiling light-water reactor (BWR) nuclear power plants and a few pressurized light water reactor (PWR) ones in Japan and the world up to now, a large number of the deep and wide cracks have been recently found in the reactor-grade low-carbon stainless steel components of core shroud, control-blade handle, re-circulating pipes, sheath and other internals in the reactor vessel under very low or no applied stresses. These cracks have been thought to be initiated from the crack-susceptible like very small-sized cracks, pinholes, concentrated dislocation defects and so on in the hardened surface, which were originated from cold-work machining processes in reactor manufacturing factories, and to be insidiously penetrated widely into the deep inside under the residual tensile stress and corrosive environment, and under no

2004 world nuclear power report - evaluation

International Nuclear Information System (INIS)

Anon.

2004-01-01

Last year, 2003, 439 nuclear power plants were available for electricity generation in 31 countries of the world. With an aggregate gross capacity of 380,489 MWe and an aggregate net capacity of 361,476MWe, nuclear generating capacity reached its highest level so far. Nine different reactor lines are operated in the commercial nuclear power plants. Light water reactors (PWR and BWR) continue to be in the lead with 355 plants. Twenty-nine nuclear power plants with an aggregate gross capacity of 24,222 MWe and an aggregate net capacity of 23,066 MWe were under construction in eleven countries. Of these, twenty are light water reactors, and seven are CANDU-type reactors. Ninety-nine commercial reactors with a capacity in excess of 5 MWe have so far been decommissioned in eighteen countries, most of them prototype plants of low power. 228 plants, i. e. slightly more than half of the number of plants currently in operation, were commissioned in the 1980s. The oldest commercial nuclear power plant in the world, Calder Hall unit 1, was disconnected from the power grid for good in its 48th year of operation in 2003. For the first time in ten years, the availability in terms of time and capacity of nuclear power plants has decreased from 83,80% in 2002 to 80.50%, and from 84.60% to 81.50%, respectively, in 2003. The main causes are prolonged outages of high-capacity plants in Japan as a consequence of administrative restrictions. The four nuclear power plants in Finland continue to be at the top of the list worldwide with a cumulated average availability of capacity of 90.30%. (orig.)

Public power costs less

International Nuclear Information System (INIS)

Moody, D.

1993-01-01

The reasons why residential customers of public power utilities paid less for power than private sector customers is discussed. Residential customers of investor-owned utilities (IOU's) paid average rates that were 28% above those paid by customers by possibly owned systems during 1990. The reasons for this disparity are that management costs faced by public power systems are below those of private power companies, indicating a greater efficiency of management among public power systems, and customer accounts expenses averaged $33.00 per customer for publicly owned electric utilities compared to $39.00 per customer for private utilities

Record high-average current from a high-brightness photoinjector

Energy Technology Data Exchange (ETDEWEB)

Dunham, Bruce; Barley, John; Bartnik, Adam; Bazarov, Ivan; Cultrera, Luca; Dobbins, John; Hoffstaetter, Georg; Johnson, Brent; Kaplan, Roger; Karkare, Siddharth; Kostroun, Vaclav; Li Yulin; Liepe, Matthias; Liu Xianghong; Loehl, Florian; Maxson, Jared; Quigley, Peter; Reilly, John; Rice, David; Sabol, Daniel [Cornell Laboratory for Accelerator-Based Sciences and Education, Cornell University, Ithaca, New York 14853 (United States); and others

2013-01-21

High-power, high-brightness electron beams are of interest for many applications, especially as drivers for free electron lasers and energy recovery linac light sources. For these particular applications, photoemission injectors are used in most cases, and the initial beam brightness from the injector sets a limit on the quality of the light generated at the end of the accelerator. At Cornell University, we have built such a high-power injector using a DC photoemission gun followed by a superconducting accelerating module. Recent results will be presented demonstrating record setting performance up to 65 mA average current with beam energies of 4-5 MeV.

Experimental Study of a Low-Temperature Power Generation System in an Organic Rankine Cycle

DEFF Research Database (Denmark)

Mu, Yongchao; Zhang, Yufeng; Deng, Na

2015-01-01

This paper presents a new power generation system under the principle of organic Rankine cycle which can generate power with a low-temperature heat source. A prototype was built to investigate the proposed system. In the prototype, an air screw compressor was converted into an expander and used...... as the engine of the power generator. The style of the preheater was a shell and tube heat exchanger, which could provide a long path for the working fluid. A flooded heat exchanger with a high heat transfer coefficient was taken as the evaporator. R134a was used as working fluid for the Rankine cycle......, the average isentropic efficiency of the screw expander was 68%, and the efficiency of power generation varies from 1.2 to 4.56%. The highest value of thermodynamical perfectness was 29.06%. It can be concluded that organic Rankine cycle could be competitive for recovering low-temperature heat source...

Highest priority in Pakistan.

Science.gov (United States)

Adil, E

1968-01-01

Responding to the challenge posed by its population problem, Pakistan's national leadership gave the highest priority to family planning in its socioeconomic development plan. In Pakistan, as elsewhere in the world, the first family planning effort originated in the private sector. The Family Planning Association of Pakistan made a tentative beginning in popularizing family planning in the country. Some clinics were opened and some publicity and education were undertaken to emphasize the need for family limitation. It was recognized soon that the government needed to assume the primarily responsibility if family planning efforts were to be successful. For the 1st plan period, 1955-60, about $10 million was allocated by the central government in the social welfare sector for voluntary family planning. The level of support continued on the same basis during the 2nd plan, 1960-65, but has been raised 4-fold in the 1965-70 scheme of family planning. Pakistan's Family Planning Association continues to play vital collaborative roles in designing and pretesting of prototype publicity material, involvement of voluntary social workers, and functional research in the clinical and public relations fields. The real breakthrough in the program came with the 3rd 5-year plan, 1965-70. High priority assigned to family planning is reflected by the total initial budget of Rs.284 million (about $60,000,000) for the 5-year period. Current policy is postulated on 6 basic assumptions: family planning efforts need to be public relations-oriented; operations should be conducted through autonomous bodies with decentralized authority at all tiers down to the grassroots level, for expeditious decision making; monetary incentives play an important role; interpersonal motivation in terms of life experience of the clientele through various contacts, coupled with mass media for publicity, can produce a sociological breakthrough; supplies and services in all related disciplines should be

State Averages

Data.gov (United States)

U.S. Department of Health & Human Services — A list of a variety of averages for each state or territory as well as the national average, including each quality measure, staffing, fine amount and number of...

A note on moving average models for Gaussian random fields

DEFF Research Database (Denmark)

Hansen, Linda Vadgård; Thorarinsdottir, Thordis L.

The class of moving average models offers a flexible modeling framework for Gaussian random fields with many well known models such as the Matérn covariance family and the Gaussian covariance falling under this framework. Moving average models may also be viewed as a kernel smoothing of a Lévy...... basis, a general modeling framework which includes several types of non-Gaussian models. We propose a new one-parameter spatial correlation model which arises from a power kernel and show that the associated Hausdorff dimension of the sample paths can take any value between 2 and 3. As a result...

How to reliably deliver narrow individual-patient error bars for optimization of pacemaker AV or VV delay using a "pick-the-highest" strategy with haemodynamic measurements.

Science.gov (United States)

Francis, Darrel P

2013-03-10

Intuitive and easily-described, "pick-the-highest" is often recommended for quantitative optimization of AV and especially VV delay settings of biventricular pacemakers (BVP; cardiac resynchronization therapy, CRT). But reliable selection of the optimum setting is challenged by beat-to-beat physiological variation, which "pick-the-highest" combats by averaging multiple heartbeats. Optimization is not optimization unless the optimum is identified confidently. This document shows how to calculate how many heartbeats must be averaged to optimize reliably by pick-the-highest. Any reader, by conducting a few measurements, can calculate for locally-available methods (i) biological scatter between replicate measurements, and (ii) curvature of the biological response. With these, for any clinically-desired precision of optimization, the necessary number of heartbeats can be calculated. To achieve 95% confidence of getting within ±∆x of the true optimum, the number of heartbeats needed is 2(scatter/curvature)(2)/∆x(4) per setting. Applying published scatter/curvature values (which readers should re-evaluate locally) indicates that optimizing AV, even coarsely with a 40ms-wide band of precision, requires many thousand beats. For VV delay, the number approaches a million. Moreover, identifying the optimum twice as precisely requires 30-fold more beats. "Pick the highest" is quick to say but slow to do. We must not expect staff to do the impossible; nor criticise them for not doing so. Nor should we assume recommendations and published protocols are well-designed. Reliable AV or VV optimization, using "pick-the-highest" on commonly-recommended manual measurements, is unrealistic. Improving time-efficiency of the optimization process to become clinically realistic may need a curve-fitting strategy instead, with all acquired data marshalled conjointly. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

On-line calculation of 3-D power distribution

International Nuclear Information System (INIS)

Park, Y. H.; In, W. K.; Park, J. R.; Lee, C. C.; Auh, G. S.

1996-01-01

The 3-D power distribution synthesis scheme was implemented in Totally Integrated Core Operation Monitoring System (TICOMS), which is under development as the next generation core monitoring system. The on-line 3-D core power distribution obtained from the measured fixed incore detector readings is used to construct the hot pin power as well as the core average axial power distribution. The core average axial power distribution and the hot pin power of TICOMS were compared with those of the current digital on-line core monitoring system, COLSS, which construct the core average axial power distribution and the pseudo hot pin power. The comparison shows that TICOMS results in the slightly more accurate core average axial power distribution and the less conservative hot pin power. Therefore, these results increased the core operating margins. In addition, the on-line 3-D power distribution is expected to be very useful for the core operation in the future

Implementation, Comparison and Application of an Average Simulation Model of a Wind Turbine Driven Doubly Fed Induction Generator

Directory of Open Access Journals (Sweden)

Lidula N. Widanagama Arachchige

2017-10-01

Full Text Available Wind turbine driven doubly-fed induction generators (DFIGs are widely used in the wind power industry. With the increasing penetration of wind farms, analysis of their effect on power systems has become a critical requirement. This paper presents the modeling of wind turbine driven DFIGs using the conventional vector controls in a detailed model of a DFIG that represents power electronics (PE converters with device level models and proposes an average model eliminating the PE converters. The PSCAD/EMTDC™ (4.6 electromagnetic transient simulation software is used to develop the detailed and the proposing average model of a DFIG. The comparison of the two models reveals that the designed average DFIG model is adequate for simulating and analyzing most of the transient conditions.

Plasma wakefields driven by an incoherent combination of laser pulses: a path towards high-average power laser-plasma accelerators

Energy Technology Data Exchange (ETDEWEB)

Benedetti, C.; Schroeder, C.B.; Esarey, E.; Leemans, W.P.

2014-05-01

he wakefield generated in a plasma by incoherently combining a large number of low energy laser pulses (i.e.,without constraining the pulse phases) is studied analytically and by means of fully-self-consistent particle-in-cell simulations. The structure of the wakefield has been characterized and its amplitude compared with the amplitude of the wake generated by a single (coherent) laser pulse. We show that, in spite of the incoherent nature of the wakefield within the volume occupied by the laser pulses, behind this region the structure of the wakefield can be regular with an amplitude comparable or equal to that obtained from a single pulse with the same energy. Wake generation requires that the incoherent structure in the laser energy density produced by the combined pulses exists on a time scale short compared to the plasma period. Incoherent combination of multiple laser pulses may enable a technologically simpler path to high-repetition rate, high-average power laser-plasma accelerators and associated applications.

Employment impacts of CDM projects in China's power sector

International Nuclear Information System (INIS)

Wang, Can; Zhang, Weishi; Cai, Wenjia; Xie, Xi

2013-01-01

There are continuous debates around the question of whether CDM really contributes to sustainable development (SD) in host countries. Employment impact is an essential indicator of SD. Based on an input-out approach this research builds a quantitative assessment model to evaluate the employment impacts of CDM. Both direct and indirect jobs creation and job losses of CDM projects in the power sector registered by the end of 2011 are calculated by project types and power grids where the project is located. Results of this study show that, although the above mentioned CDM projects causes about 99,000 net direct job losses, they also create about 3.08 million indirect jobs, resulting in the gross employment of CDM to be about 2.98 million. Thereof, hydro projects induce both direct and indirect job losses, which comes to approximately 0.89 million. Solar projects have the most potential since they own the highest indirect jobs created by one GWh generation, about 104 jobs/GWh. - Highlights: • An input–output model was built for assessment of CDM projects' employment impact; • CDM projects create direct and indirect jobs while cause some losses in short. • Significant indirect job gains of CDM projects were found; • Solar projects cause 104 jobs/GWh in average, ranking as the highest contributor

2 µm high-power dissipative soliton resonance in a compact σ-shaped Tm-doped double-clad fiber laser

Science.gov (United States)

Du, Tuanjie; Li, Weiwei; Ruan, Qiujun; Wang, Kaijie; Chen, Nan; Luo, Zhengqian

2018-05-01

We report direct generation of a high-power, large-energy dissipative soliton resonance (DSR) in a 2 µm Tm-doped double-clad fiber laser. A compact σ-shaped cavity is formed by a fiber Bragg grating and a 10/90 fiber loop mirror (FLM). The 10/90 FLM is not only used as an output mirror, but also acts as a nonlinear optical loop mirror for initiating mode locking. The mode-locked laser can deliver high-power, nanosecond DSR pulses at 2005.9 nm. We further perform a comparison study of the effect of the FLM’s loop length on the mode-locking threshold, peak power, pulse energy, and optical spectrum of the DSR pulses. We achieve a maximum average output power as high as 1.4 W, a maximum pulse energy of 353 nJ, and a maximum peak power of 84 W. This is, to the best of our knowledge, the highest power for 2 µm DSR pulses obtained in a mode-locked fiber laser.

Paris Agreement and opportunities for innovative nuclear power

International Nuclear Information System (INIS)

Tam, Cecilia

2017-01-01

How far can technology take us? Pushing energy technology to achieve carbon neutrality by 2060 could meet the mid-point of the range of ambitions expressed in Paris. Nuclear additions need to double current rate to meet 2DS. 2016 saw the highest nuclear capacity additions since 1990, but new construction starts down sharply. The fuel mix to generate electricity is vastly different to today. The average carbon intensity of power generation falls from around 520 gCO2/kWh today to Below zero in the B2DS. Nuclear innovation could also target need for decarbonised heat. Heating and cooling in industry and buildings accounts for more than 40% of final energy consumption and 30% of global CO2 emissions

Simulation of the energy - environment economic system power generation costs in power-stations

International Nuclear Information System (INIS)

Weible, H.

1978-09-01

The costs of power generation are an important point in the electricity industry. The present report tries to supply a model representation for these problems. The costs of power generation for base load, average and peak load power stations are examined on the basis of fossil energy sources, nuclear power and water power. The methods of calculation where dynamic investment calculation processes are used, are given in the shape of formulae. From the point of view of long term prediction, power generation cost sensitivity studies are added to the technical, economic and energy-political uncertainties. The sensitivity of models for calculations is examined by deterministic and stochastic processes. In the base load and average region, power generation based on nuclear power and water power is economically more favourable than that from fossilfired power stations. Even including subsidies, this cost advantage is not in doubt. In the peak load region, pumped storage power stations are more economic than fossilfired power stations. (orig.) [de

TEDS Base Station Power Amplifier using Low-Noise Envelope Tracking Power Supply

DEFF Research Database (Denmark)

Høyerby, Mikkel Christian Wendelboe; Andersen, Michael A. E.

2009-01-01

This paper demonstrates a highly linear and efficient TETRA enhanced data service (TEDS) base-station RF power amplifier (RFPA). Based on the well-known combination of an envelope tracking (ET) power supply and a linear class-A/B RFPA, adequate adjacent channel power ratio (ACPR) and wideband noise...... experimentally with a 9.6-dB peak-to-average 50-kHz 16 quadrature amplitude modulation TEDS carrier, the setup providing 44-dBm (25 W) average RF output power at 400 MHz with 44% dc-to-RF efficiency state-of-the-art ACPR of less than ${-}$67 dBc, switching noise artifacts around ${-}$ 85 dBc, and an overall rms...

Physical dosimetry and biological indicators of carcinogenic risk in a cohort of persons exposed to unhealthy ecological factors following the Chernobyl Nuclear Power Plant accident.

Science.gov (United States)

Orel, V E; Tereschenki, V M; Czyatkovskaya, N N; Mazepa, M G; Buzunov, V A

1998-01-01

The April 1986 Chernobyl Nuclear Power Plant accident caused ecological changes in the Ovruch State forests in the Zhytomir oblast in the Ukraine. The highest radioactivity existed in moss, followed by the pine-forest substrate and soil. During 1984-1985, the pine needles were primarily surface contaminated, whereas during 1986-1988, they were contaminated secondarily. Radioactivity in air was highest (1.07+/-0.185 Bq/l) during dry and sunny weather and when trees were felled; the lowest levels (0.196+/-0.044 Bq/l) occurred during periods of stable snow coverage. Between 1987 and 1989 (i.e., after the Chernobyl accident), the caesium levels in forestry employees exceeded by 13.9-fold the average levels found in the Ukrainian Polessje population. Ovruch forest guards and woodcutters had the highest effective equivalent doses of radiation, and they therefore exhibited the highest carcinogenic risk.

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

Large-signal analysis of DC motor drive system using state-space averaging technique

International Nuclear Information System (INIS)

Bekir Yildiz, Ali

2008-01-01

The analysis of a separately excited DC motor driven by DC-DC converter is realized by using state-space averaging technique. Firstly, a general and unified large-signal averaged circuit model for DC-DC converters is given. The method converts power electronic systems, which are periodic time-variant because of their switching operation, to unified and time independent systems. Using the averaged circuit model enables us to combine the different topologies of converters. Thus, all analysis and design processes about DC motor can be easily realized by using the unified averaged model which is valid during whole period. Some large-signal variations such as speed and current relating to DC motor, steady-state analysis, large-signal and small-signal transfer functions are easily obtained by using the averaged circuit model

An Experimental Observation of Axial Variation of Average Size of Methane Clusters in a Gas Jet

International Nuclear Information System (INIS)

Ji-Feng, Han; Chao-Wen, Yang; Jing-Wei, Miao; Jian-Feng, Lu; Meng, Liu; Xiao-Bing, Luo; Mian-Gong, Shi

2010-01-01

Axial variation of average size of methane clusters in a gas jet produced by supersonic expansion of methane through a cylindrical nozzle of 0.8 mm in diameter is observed using a Rayleigh scattering method. The scattered light intensity exhibits a power scaling on the backing pressure ranging from 16 to 50 bar, and the power is strongly Z dependent varying from 8.4 (Z = 3 mm) to 5.4 (Z = 11 mm), which is much larger than that of the argon cluster. The scattered light intensity versus axial position shows that the position of 5 mm has the maximum signal intensity. The estimation of the average cluster size on axial position Z indicates that the cluster growth process goes forward until the maximum average cluster size is reached at Z = 9 mm, and the average cluster size will decrease gradually for Z > 9 mm

Electrodynamic wireless power transmission to a torsional receiver

International Nuclear Information System (INIS)

McEachern, K M; Arnold, D P

2013-01-01

This paper presents a wireless power transmission (WPT) concept that uses electrodynamic coupling and torsional motion of a permanent magnet in the receiver. The system is shown to transfer an average power of 3.09 mW (power density equal to 143 μW/cm 3 ) over a distance of 1 cm, an average power of 1.98 mW over a distance of 2 cm, and an average power of 126 μW over a distance of 7 cm. We also demonstrate unaltered power transmission through conductive media, including a human hand and an aluminum plate, highlighting a key advantage of the electrodynamic wireless power transmission approach

The highest energies in the Universe

International Nuclear Information System (INIS)

Rebel, H.

2006-01-01

There are not many issues of fundamental importance which have induced so many problems for astrophysicists like the question of the origin of cosmic rays. This radiation from the outer space has an energy density comparable with that of the visible starlight or of the microwave background radiation. It is an important feature of our environment with many interesting aspects. A most conspicuous feature is that the energy spectrum of cosmic rays seems to have no natural end, though resonant photopion production with the cosmic microwave background predicts a suppression of extragalactic protons above the so-called Greisen-Zatsepin-Kuz’min cutoff at about EGZK = 5 × 10"1"9 eV. In fact the highest particle energies ever observed on the Earth, stem from observations of Ultrahigh Energy Cosmic Rays (E > 3 × 10"1"9 eV). But the present observations by the AGASA and HiRes Collaborations, partly a matter of debate, are origin of a number of puzzling questions, where these particles are coming from, by which gigantic acceleration mechanism they could gain such tremendous energies and how they have been able to propagate to our Earth. These questions imply serious problems of the understanding of our Universe. There are several approaches to clarify the mysteries of the highest energies and to base the observations on larger statistical accuracy. The Pierre Auger Observatory, being in installation in the Pampa Amarilla in the Province Mendoza in Argentina, is a hybrid detector, combining a large array of water Cerenkov detectors (registering charged particles generated in giant extended air showers) with measurements of the fluorescence light produced during the air shower development. This contribution will illustrate the astrophysical motivation and the current status of the experimental efforts, and sketch the ideas about the origin of these particles.

SPATIAL DISTRIBUTION OF THE AVERAGE RUNOFF IN THE IZA AND VIȘEU WATERSHEDS

Directory of Open Access Journals (Sweden)

HORVÁTH CS.

2015-03-01

Full Text Available The average runoff represents the main parameter with which one can best evaluate an area’s water resources and it is also an important characteristic in al river runoff research. In this paper we choose a GIS methodology for assessing the spatial evolution of the average runoff, using validity curves we identifies three validity areas in which the runoff changes differently with altitude. The tree curves were charted using the average runoff values of 16 hydrometric stations from the area, eight in the Vișeu and eight in the Iza river catchment. Identifying the appropriate areas of the obtained correlations curves (between specific average runoff and catchments mean altitude allowed the assessment of potential runoff at catchment level and on altitudinal intervals. By integrating the curves functions in to GIS we created an average runoff map for the area; from which one can easily extract runoff data using GIS spatial analyst functions. The study shows that from the three areas the highest runoff corresponds with the third zone but because it’s small area the water volume is also minor. It is also shown that with the use of the created runoff map we can compute relatively quickly correct runoff values for areas without hydrologic control.

High energy, high average power solid state green or UV laser

Science.gov (United States)

Hackel, Lloyd A.; Norton, Mary; Dane, C. Brent

2004-03-02

A system for producing a green or UV output beam for illuminating a large area with relatively high beam fluence. A Nd:glass laser produces a near-infrared output by means of an oscillator that generates a high quality but low power output and then multi-pass through and amplification in a zig-zag slab amplifier and wavefront correction in a phase conjugator at the midway point of the multi-pass amplification. The green or UV output is generated by means of conversion crystals that follow final propagation through the zig-zag slab amplifier.

Comparison on the Analysis on PM10 Data based on Average and Extreme Series

Directory of Open Access Journals (Sweden)

Mohd Amin Nor Azrita

2018-01-01

Full Text Available The main concern in environmental issue is on extreme phenomena (catastrophic instead of common events. However, most statistical approaches are concerned primarily with the centre of a distribution or on the average value rather than the tail of the distribution which contains the extreme observations. The concept of extreme value theory affords attention to the tails of distribution where standard models are proved unreliable to analyse extreme series. High level of particulate matter (PM10 is a common environmental problem which causes various impacts to human health and material damages. If the main concern is on extreme events, then extreme value analysis provides the best result with significant evidence. The monthly average and monthly maxima PM10 data for Perlis from 2003 to 2014 were analysed. Forecasting for average data is made by Holt-Winters method while return level determine the predicted value of extreme events that occur on average once in a certain period. The forecasting from January 2015 to December 2016 for average data found that the highest forecasted value is 58.18 (standard deviation 18.45 on February 2016 while return level achieved 253.76 units for 24 months (2015-2016 return periods.

Tunable high-power narrow-linewidth green external-cavity GaN diode laser

DEFF Research Database (Denmark)

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

2016-01-01

A tunable high-power green external-cavity diode laser is demonstrated. Up to 290 mW output power and a 9.2 nm tuning is achieve. This constitutes the highest output power from a tunable green diode laser system.......A tunable high-power green external-cavity diode laser is demonstrated. Up to 290 mW output power and a 9.2 nm tuning is achieve. This constitutes the highest output power from a tunable green diode laser system....

High power all-solid-state fourth harmonic generation of 266 nm at the pulse repetition rate of 100 kHz

International Nuclear Information System (INIS)

Liu, Q; Yan, X P; Fu, X; Gong, M; Wang, D S

2009-01-01

14.8 W UV laser at 266 nm was reported with the extra cavity frequency quartered configuration. The fundamental frequency IR source is a high-power high-beam-quality acoustic-optic Q-switched Nd:YVO 4 master-oscillator-power-amplifier laser. The type-I phase-matched LBO and type-I phase-matched BBO crystals were used as the extra-cavity frequency doubled and quartered crystal respectively. 14.8 W UV laser of 266 nm was obtained at the pulse repetition rate of 100 kHz with the conversion efficiency of 18.3% from green to UV, and the pulse duration of the UV laser was 10 ns corresponding to the pulse peak power of 14.8 kW. At 150 kHz, 11.5 W power output was obtained. The highest peak power of 21 kW was also achieved at 80 kHz with the average output power of 14.5 W

Do optimally ripe blackberries contain the highest levels of metabolites?

Science.gov (United States)

Mikulic-Petkovsek, Maja; Koron, Darinka; Zorenc, Zala; Veberic, Robert

2017-01-15

Five blackberry cultivars were selected for the study ('Chester Thornless', 'Cacanska Bestrna', 'Loch Ness', 'Smoothstem' and 'Thornfree') and harvested at three different maturity stages (under-, optimal- and over-ripe). Optimally ripe and over-ripe blackberries contained significantly higher levels of total sugars compared to under-ripe fruit. 'Loch Ness' cultivar was characterized by 2.2-2.6-fold higher levels of total sugars than other cultivars and consequently, the highest sugar/acids ratio. 'Chester Thornless' stands out as the cultivar with the highest level of vitamin C in under-ripe (125.87mgkg(-1)) and optimally mature fruit (127.66mgkg(-1)). Maturity stage significantly affected the accumulation of phenolic compounds. The content of total anthocyanins increased for 43% at optimal maturity stage and cinnamic acid derivatives for 57% compared to under-ripe fruit. Over-ripe blackberries were distinguished by the highest content of total phenolics (1251-2115mg GAE kg(-1) FW) and greatest FRAP values (25.9-43.2mM TE kg(-1) FW). Copyright © 2016 Elsevier Ltd. All rights reserved.

Aerosol particles generated by diesel-powered school buses at urban schools as a source of children's exposure.

Science.gov (United States)

Hochstetler, Heather A; Yermakov, Mikhail; Reponen, Tiina; Ryan, Patrick H; Grinshpun, Sergey A

2011-03-01

Various heath effects in children have been associated with exposure to traffic-related particulate matter (PM), including emissions from school buses. In this study, the indoor and outdoor aerosol at four urban elementary schools serviced by diesel-powered school buses was characterized with respect to the particle number concentrations and size distributions as well as the PM2.5 mass concentrations and elemental compositions. It was determined that the presence of school buses significantly affected the outdoor particle size distribution, specifically in the ultrafine fraction. The time-weighted average of the total number concentration measured outside the schools was significantly associated with the bus and the car counts. The concentration increase was consistently observed during the morning drop-off hours and in most of the days during the afternoon pick-up period (although at a lower degree). Outdoor PM2.5 mass concentrations measured at schools ranged from 3.8 to 27.6 µg m -3 . The school with the highest number of operating buses exhibited the highest average PM2.5 mass concentration. The outdoor mass concentrations of elemental carbon (EC) and organic carbon (OC) were also highest at the school with the greatest number of buses. Most (47/55) correlations between traffic-related elements identified in the outdoor PM2.5 were significant with elements identified in the indoor PM2.5. Significant associations were observed between indoor and outdoor aerosols for EC, EC/OC, and the total particle number concentration. Day-to-day and school-to-school variations in Indoor/Outdoor (I/O) ratios were related to the observed differences in opening windows and doors, which enhanced the particle penetration, as well as indoor activities at schools. Overall, the results on I/O ratio obtained in this study reflect the sizes of particles emitted by diesel-powered school bus engines (primarily, an ultrafine fraction capable of penetrating indoors).

Averaging models: parameters estimation with the R-Average procedure

Directory of Open Access Journals (Sweden)

S. Noventa

2010-01-01

Full Text Available The Functional Measurement approach, proposed within the theoretical framework of Information Integration Theory (Anderson, 1981, 1982, can be a useful multi-attribute analysis tool. Compared to the majority of statistical models, the averaging model can account for interaction effects without adding complexity. The R-Average method (Vidotto & Vicentini, 2007 can be used to estimate the parameters of these models. By the use of multiple information criteria in the model selection procedure, R-Average allows for the identification of the best subset of parameters that account for the data. After a review of the general method, we present an implementation of the procedure in the framework of R-project, followed by some experiments using a Monte Carlo method.

Extreme Markup: The Fifty US Hospitals With The Highest Charge-To-Cost Ratios.

Science.gov (United States)

Bai, Ge; Anderson, Gerard F

2015-06-01

Using Medicare cost reports, we examined the fifty US hospitals with the highest charge-to-cost ratios in 2012. These hospitals have markups (ratios of charges over Medicare-allowable costs) approximately ten times their Medicare-allowable costs compared to a national average of 3.4 and a mode of 2.4. Analysis of the fifty hospitals showed that forty-nine are for profit (98 percent), forty-six are owned by for-profit hospital systems (92 percent), and twenty (40 percent) operate in Florida. One for-profit hospital system owns half of these fifty hospitals. While most public and private health insurers do not use hospital charges to set their payment rates, uninsured patients are commonly asked to pay the full charges, and out-of-network patients and casualty and workers' compensation insurers are often expected to pay a large portion of the full charges. Because it is difficult for patients to compare prices, market forces fail to constrain hospital charges. Federal and state governments may want to consider limitations on the charge-to-cost ratio, some form of all-payer rate setting, or mandated price disclosure to regulate hospital markups. Project HOPE—The People-to-People Health Foundation, Inc.

Simplifying consent for HIV testing is associated with an increase in HIV testing and case detection in highest risk groups, San Francisco January 2003-June 2007.

Directory of Open Access Journals (Sweden)

Nicola M Zetola

2008-07-01

Full Text Available Populations at highest risk for HIV infection face multiple barriers to HIV testing. To facilitate HIV testing procedures, the San Francisco General Hospital Medical Center eliminated required written patient consent for HIV testing in its medical settings in May 2006. To describe the change in HIV testing rates in different hospital settings and populations after the change in HIV testing policy in the SFDH medical center, we performed an observational study using interrupted time series analysis.Data from all patients aged 18 years and older seen from January 2003 through June 2007 at the San Francisco Department of Public Health (SFDPH medical care system were included in the analysis. The monthly HIV testing rate per 1000 had patient-visits was calculated for the overall population and stratified by hospital setting, age, sex, race/ethnicity, homelessness status, insurance status and primary language.By June 2007, the average monthly rate of HIV tests per 1000 patient-visits increased 4.38 (CI, 2.17-6.60, p<0.001 over the number predicted if the policy change had not occurred (representing a 44% increase. The monthly average number of new positive HIV tests increased from 8.9 (CI, 6.3-11.5 to 14.9 (CI, 10.6-19.2, p<0.001, representing a 67% increase. Although increases in HIV testing were seen in all populations, populations at highest risk for HIV infection, particularly men, the homeless, and the uninsured experienced the highest increases in monthly HIV testing rates after the policy change.The elimination of the requirement for written consent in May 2006 was associated with a significant and sustained increase in HIV testing rates and HIV case detection in the SFDPH medical center. Populations facing the higher barriers to HIV testing had the highest increases in HIV testing rates and case detection in response to the policy change.

Case of reforms in the Indian power distribution sector: A move towards eradicating energy poverty

Energy Technology Data Exchange (ETDEWEB)

Madhav, Mrinal; Mehta, Shivika

2010-09-15

India's transmission and distribution losses are among the highest in the world. When non-technical losses such as energy theft are included in the total, losses go as high as 65% in some states and average about 35-40%. The financial loss has been estimated at 1.5% of the national GDP. These act as a major deterrent to the private as well as global investments in the sector. To address the issue of Aggregate Transmission and Commercial (AT&C) losses funding mechanism was introduced for in the form of the Accelerated Power Development Reforms Programme (APDRP).

Case of reforms in the Indian power distribution sector: A move towards eradicating energy poverty

Energy Technology Data Exchange (ETDEWEB)

Madhav, Mrinal; Mehta, Shivika

2010-09-15

India's transmission and distribution losses are among the highest in the world. When non-technical losses such as energy theft are included in the total, losses go as high as 65% in some states and average about 35-40%. The financial loss has been estimated at 1.5% of the national GDP. These act as a major deterrent to the private as well as global investments in the sector. To address the issue of Aggregate Transmission and Commercial (AT&C) losses funding mechanism was introduced for in the form of the Accelerated Power Development Reforms Programme (APDRP).

Laser fiber cleaving techniques: effects on tip morphology and power output.

Science.gov (United States)

Vassantachart, Janna M; Lightfoot, Michelle; Yeo, Alexander; Maldonado, Jonathan; Li, Roger; Alsyouf, Muhannad; Martin, Jacob; Lee, Michael; Olgin, Gaudencio; Baldwin, D Duane

2015-01-01

Proper cleaving of reusable laser fibers is needed to maintain optimal functionality. This study quantifies the effect of different cleaving tools on power output of the holmium laser fiber and demonstrates morphologic changes using microscopy. The uncleaved tips of new 272 μm reusable laser fibers were used to obtain baseline power transmission values at 3 W (0.6 J, 5 Hz). Power output for each of four cleaving techniques-11-blade scalpel, scribe pen cleaving tool, diamond cleaving wheel, and suture scissors-was measured in a single-blinded fashion. Dispersion of light from the fibers was compared with manufacturer specifications and rated as "ideal," "acceptable," or "unacceptable" by blinded reviewers. The fiber tips were also imaged using confocal and scanning electron microscopy. Independent samples Kruskal-Wallis test and chi square were used for statistical analysis (αtrend that was highly significant (Ptrend as the power output results (P<0.001). Microscopy showed that the scribe pen produced small defects along the fiber cladding but maintained a smooth, flat core surface. The other cleaving techniques produced defects on both the core and cladding. Cleaving techniques produce a significant effect on the initial power transmitted by reusable laser fibers. The scribe pen cleaving tool produced the most consistent and highest average power output.

System for forecasting a reactor power distribution

International Nuclear Information System (INIS)

Motoda, Hiroshi; Nishizawa, Yasuo.

1976-01-01

Purpose: To dispense with frequent running of detector in a BWR type reactor and permit calculation of the prevailing value and forecast value of power distribution in a specified region in an on-line basis. Constitution: The prevailing power distribution P sub(OZ) (where Z indicates a position in the axial direction) at a given position is estimated by prevailing power distribution estimating means, and the average prevailing power distribution Q sub(OZ) in the core is estimated while making correction of a primary neutron distribution model by core average characteristic measuring means. Then, the estimated core average power distribution Q sub(Z) after alteration of the core flow rate or alteration of Xe concentration is estimated by core average power distribution estimating means. At this time, a forecast power distribution P sub(Z) in a specified region after alteration of the flow rate or alteration of the Xe concentration is calculated on the basis of a relation P sub(Z) = (Q sub(Z)/Q sub(OZ)) by using P sub(OZ), Q sub(OZ) and Q sub(Z). The above calculations are carried out in a short period of time by using a process computer. (Ikeda, J.)

Up to the highest peak!

CERN Multimedia

CERN Bulletin

2010-01-01

In the early hours of this morning, the beam energy was ramped up to 3.5 TeV, a new world record and the highest energy for this year’s run. Now operators will prepare the machine to make high-energy collisions later this month. CERN Operations Group leader Mike Lamont (foreground) and LHC engineer in charge Alick Macpherson in the CERN Control Centre early this morning. At 5:23 this morning, Friday 19 March, the energy of both beams in the LHC was ramped up to 3.5 TeV, a new world record. During the night, operators had tested the performance of the whole machine with two so-called ‘dry runs’, that is, without beams. Given the good overall response, beams were injected at around 3:00 a.m. and stabilized soon after. The ramp started at around 4:10 and lasted about one hour. Over the last couple of weeks, operation of the LHC at 450 GeV has become routinely reproducible. The operators were able to test and optimize the beam orbit, the beam collimation, the injection and ext...

Challenges for highest energy circular colliders

CERN Document Server

Benedikt, M; Wenninger, J; Zimmermann, F

2014-01-01

A new tunnel of 80–100 km circumference could host a 100 TeV centre-of-mass energy-frontier proton collider (FCC-hh/VHE-LHC), with a circular lepton collider (FCCee/TLEP) as potential intermediate step, and a leptonhadron collider (FCC-he) as additional option. FCC-ee, operating at four different energies for precision physics of the Z, W, and Higgs boson and the top quark, represents a significant push in terms of technology and design parameters. Pertinent R&D efforts include the RF system, topup injection scheme, optics design for arcs and final focus, effects of beamstrahlung, beam polarization, energy calibration, and power consumption. FCC-hh faces other challenges, such as high-field magnet design, machine protection and effective handling of large synchrotron radiation power in a superconducting machine. All these issues are being addressed by a global FCC collaboration. A parallel design study in China prepares for a similar, but smaller collider, called CepC/SppC.

Highest weight representations of the quantum algebra Uh(gl∞)

International Nuclear Information System (INIS)

Palev, T.D.; Stoilova, N.I.

1997-04-01

A class of highest weight irreducible representations of the quantum algebra U h (gl-∞) is constructed. Within each module a basis is introduced and the transformation relations of the basis under the action of the Chevalley generators are explicitly written. (author). 16 refs

Negatively Charged Hyperbranched Polyglycerol Grafted Membranes for Osmotic Power Generation from Municipal Wastewater

KAUST Repository

Li, Xue; Cai, Tao; Chen, Chunyan; Chung, Neal Tai-Shung

2015-01-01

Osmotic power holds great promise as a clean, sustainable and largely unexploited energy resource. Recent membrane development for pressure-retarded osmosis (PRO) is making the osmotic power generation more and more realistic. However, severe performance declines have been observed because the porous layer of PRO membranes is fouled by the feed stream. To overcome it, a negatively charged antifouling PRO hollow fiber membrane has been designed and studied in this work. An antifouling polymer, derived from hyperbranched polyglycerol and functionalized by α-lipoic acid and succinic anhydride, was synthesized and grafted onto the polydopamine (PDA) modified poly(ether sulfone) (PES) hollow fiber membranes. In comparison to unmodified membranes, the charged hyperbranched polyglycerol (CHPG) grafted membrane is much less affected by organic deposition, such as bovine serum albumin (BSA) adsorption, and highly resistant to microbial growths, demonstrated by E. coli adhesion and S. aureus attachment. CHPG-g-TFC was also examined in PRO tests using a concentrated wastewater as the feed. Comparing to the plain PES-TFC and non-charged HPG-g-TFC, the newly developed membrane exhibits not only the smallest decline in water flux but also the highest recovery rate. When using 0.81 M NaCl and wastewater as the feed pair in PRO tests at 15 bar, the average power density remains at 5.6 W/m2 in comparison to an average value of 3.6 W/m2 for unmodified membranes after four PRO runs. In summary, osmotic power generation may be sustained by properly designing and anchoring the functional polymers to PRO membranes.

Negatively Charged Hyperbranched Polyglycerol Grafted Membranes for Osmotic Power Generation from Municipal Wastewater

KAUST Repository

Li, Xue

2015-11-18

Osmotic power holds great promise as a clean, sustainable and largely unexploited energy resource. Recent membrane development for pressure-retarded osmosis (PRO) is making the osmotic power generation more and more realistic. However, severe performance declines have been observed because the porous layer of PRO membranes is fouled by the feed stream. To overcome it, a negatively charged antifouling PRO hollow fiber membrane has been designed and studied in this work. An antifouling polymer, derived from hyperbranched polyglycerol and functionalized by α-lipoic acid and succinic anhydride, was synthesized and grafted onto the polydopamine (PDA) modified poly(ether sulfone) (PES) hollow fiber membranes. In comparison to unmodified membranes, the charged hyperbranched polyglycerol (CHPG) grafted membrane is much less affected by organic deposition, such as bovine serum albumin (BSA) adsorption, and highly resistant to microbial growths, demonstrated by E. coli adhesion and S. aureus attachment. CHPG-g-TFC was also examined in PRO tests using a concentrated wastewater as the feed. Comparing to the plain PES-TFC and non-charged HPG-g-TFC, the newly developed membrane exhibits not only the smallest decline in water flux but also the highest recovery rate. When using 0.81 M NaCl and wastewater as the feed pair in PRO tests at 15 bar, the average power density remains at 5.6 W/m2 in comparison to an average value of 3.6 W/m2 for unmodified membranes after four PRO runs. In summary, osmotic power generation may be sustained by properly designing and anchoring the functional polymers to PRO membranes.

Neutron resonance averaging

International Nuclear Information System (INIS)

Chrien, R.E.

1986-10-01

The principles of resonance averaging as applied to neutron capture reactions are described. Several illustrations of resonance averaging to problems of nuclear structure and the distribution of radiative strength in nuclei are provided. 30 refs., 12 figs

Monitoring device for the power distribution within a nuclear reactor core

International Nuclear Information System (INIS)

Tanzawa, Tomio; Kumanomido, Hironori; Toyoshi, Isamu.

1986-01-01

Purpose: To provide a monitoring device for the power distribution in the reactor core that calculates the power distribution based on the measurement by instruments disposed within the reactor core of BWR type reactors. Constitution: The power distribution monitoring device in a reactor core comprises a signal correcting device, a signal normalizing device and a power distribution calculating device, in which the power distribution calculating device is constituted with an average power calculating device for four fuel assemblies and an average power calculating device for fuel assemblies. Gamma-ray signals corrected by the signal correcting device and signals from neutron detectors are inputted to the signal normalizing device, both of which are calibrated to determine the axial gamma-ray signal distribution in the central water gap region with the four fuel assemblies being as the unit. The average power from the four fuel assemblies are inputted to the fuel assembly average power calculating device to allocate to each of the fuel assembly average power thereby attaining the purpose. Further, thermal restriction values are calculated thereby enabling to secure the fuel integrity. (Kamimura, M.)

Numerical Evaluation of Averaging BDFT(bidirectional flow tube) Flow Meter on Applicability in the Fouling Condition

International Nuclear Information System (INIS)

Park, J. P.; Jeong, J. H.; Yuna, B. J.; Jerng, D. W.

2013-01-01

The results show that the averaging BDFT is a promising flow meter for the accurate measurement of flow rates in the fouling condition of the NPPs. A new instrumentation, an averaging BDFT, was proposed to measure the accurate flow rate under corrosion environment. In this study, to validate the applicability of the averaging BDFT on the fouling conditions, flow analyses using the CFD code were performed. Analyses results show that this averaging BDFT does not lose the measuring performance even under the corrosion environment. Therefore, it is expected that the averaging BDFT can replace the type flow meters for the feedwater pipe of steam generator of NPPs. Most of the NPPs adopt pressure difference type flow meters such as venturi and orifice meters for the measurement of feedwater flow rates to calculate reactor thermal power. However, corrosion products in the feedwater deposits on the flow meter as operating time goes. These effects lead to severe errors in the flow indication and then determination of reactor thermal power. The averaging BDFT has a potentiality to minimize this problem. Therefore, it is expected that the averaging BDFT can replace the type venturi meters for the feedwater pipe of steam generator of NPPs. The present work compares the amplification factor, K, based on CFD calculation against the K obtained from experiments in order to confirm whether a CFD code can be applicable to the evaluation of characteristic for the averaging BDFT. In addition to this, the simulations to take into account of fouling effect are also carried out by rough wall option

Estimation of the hydraulic conductivity of a two-dimensional fracture network using effective medium theory and power-law averaging

Science.gov (United States)

Zimmerman, R. W.; Leung, C. T.

2009-12-01

Most oil and gas reservoirs, as well as most potential sites for nuclear waste disposal, are naturally fractured. In these sites, the network of fractures will provide the main path for fluid to flow through the rock mass. In many cases, the fracture density is so high as to make it impractical to model it with a discrete fracture network (DFN) approach. For such rock masses, it would be useful to have recourse to analytical, or semi-analytical, methods to estimate the macroscopic hydraulic conductivity of the fracture network. We have investigated single-phase fluid flow through generated stochastically two-dimensional fracture networks. The centers and orientations of the fractures are uniformly distributed, whereas their lengths follow a lognormal distribution. The aperture of each fracture is correlated with its length, either through direct proportionality, or through a nonlinear relationship. The discrete fracture network flow and transport simulator NAPSAC, developed by Serco (Didcot, UK), is used to establish the “true” macroscopic hydraulic conductivity of the network. We then attempt to match this value by starting with the individual fracture conductances, and using various upscaling methods. Kirkpatrick’s effective medium approximation, which works well for pore networks on a core scale, generally underestimates the conductivity of the fracture networks. We attribute this to the fact that the conductances of individual fracture segments (between adjacent intersections with other fractures) are correlated with each other, whereas Kirkpatrick’s approximation assumes no correlation. The power-law averaging approach proposed by Desbarats for porous media is able to match the numerical value, using power-law exponents that generally lie between 0 (geometric mean) and 1 (harmonic mean). The appropriate exponent can be correlated with statistical parameters that characterize the fracture density.

White syndrome on massive corals: A case study in Paiton power plant, East Java

Science.gov (United States)

Muzaki, Farid Kamal; Saptarini, Dian; Riznawati, Aida Efrini

2017-06-01

As a stenothermal organism, coral easily affected by high-temperature cooling water discharged by a power plant into surrounding waters; which may lead to a rapid spread and transmission of coral disease, including White Syndrome. This study aimed to measure the prevalence of WS on massive corals in Paiton Power Plant waters. Research was conductedduring May 2015 at three observation stations; west and east side of water discharge canal (DB and DT) and water intake canal (WI). Observed parameters including ambient environmental variables (sea surface and bottom temperature, salinity, dissolved oxygen/DO, pH, and visibility); the cover of life corals (percent and genera composition) and prevalence of coral disease at 5 m depth. One-way ANOVA (analysis of variance, p=0.05) was performed to test the difference of coral disease prevalence from different observation stations. As the results, Coral coverage percentage in WI (85.75%), DB (60.75%), and DT (40.8%). Prevalence of WS in DB was highest (40.49±2.12% in DB, 13.53±11.5% in DT and 6.44±3.6 %, respectively). It can be assumed that prevalence of White Syndrome in those locations may be correlated to temperature which highest average temperature occurred in DB stations.

Corrosion measurements on apt prototypic materials in the Lansce high-power proton beam and applicability to other systems

International Nuclear Information System (INIS)

Lillard, R.S.; Gac, F.D.; James, M.R.; Maloy, S.A.; Paciotti, M.A.; Waters, L.S.; Willcutt, G.J.; Chandler, G.T.; Ferguson, P.D.

2003-01-01

The corrosion rates of several corrosion resistant materials behave in a similar manner even under the intense radiation of the LANSCE high-power beam. A second observation was made, showing that the corrosion rates saturated under high instantaneous radiation intensity in corrosion experiments conducted for the accelerator production of tritium (APT) programme. The LANSCE H + beam is not prototypic of the proposed APT production plant in several respects. The instantaneous proton flux in the APT production plant beam is about 10 times that of the LANSCE beam. The small transverse APT beam spot is rastered to spread the power density over the area of the target, and as the beam rasters, it creates a pulsed character to the beam at a specific location. In order to develop correlations that would enable extrapolation of the corrosion data to the proposed APT production plant, the experimental programme included measurements over a range of average beam currents, measurements at high and low instantaneous beam current, and measurements at various combinations of pulse width and repetition rate. The correlations that were developed are based on an approximately linear dependence of corrosion rate on average beam current (average radiation intensity) and the saturation effect observed at high instantaneous radiation intensity. For a given transverse beam profile and for the same average beam current, the correlations predict the highest corrosion rate in a do beam and the lowest corrosion rate in the lowest duty cycle beams. In the case of the APT extrapolation, the predicted corrosion rates were a factor of 5 lower than for a do beam depositing the same average power density. The measured corrosion rates and the formulated extrapolations are applicable to water-cooled targets and components in proton beams. (authors)

High-resolution Tangential AXUV Arrays for Radiated Power Density Measurements on NSTX-U

Energy Technology Data Exchange (ETDEWEB)

Delgado-Aparicio, L [PPPL; Bell, R E [PPPL; Faust, I [MIT; Tritz, K [The Johns Hopkins University, Baltimore, MD, 21209, USA; Diallo, A [PPPL; Gerhardt, S P [PPPL; Kozub, T A [PPPL; LeBlanc, B P [PPPL; Stratton, B C [PPPL

2014-07-01

Precise measurements of the local radiated power density and total radiated power are a matter of the uttermost importance for understanding the onset of impurity-induced instabilities and the study of particle and heat transport. Accounting of power balance is also needed for the understanding the physics of various divertor con gurations for present and future high-power fusion devices. Poloidal asymmetries in the impurity density can result from high Mach numbers and can impact the assessment of their flux-surface-average and hence vary the estimates of P[sub]rad (r, t) and (Z[sub]eff); the latter is used in the calculation of the neoclassical conductivity and the interpretation of non-inductive and inductive current fractions. To this end, the bolometric diagnostic in NSTX-U will be upgraded, enhancing the midplane coverage and radial resolution with two tangential views, and adding a new set of poloidally-viewing arrays to measure the 2D radiation distribution. These systems are designed to contribute to the near- and long-term highest priority research goals for NSTX-U which will integrate non-inductive operation at reduced collisionality, with high-pressure, long energy-confinement-times and a divertor solution with metal walls.

Local Impacts of Mercury Emissions from the Three Pennsylvania Coal Fired Power Plants.

Energy Technology Data Exchange (ETDEWEB)

Sullivan,T.; Adams,J.; Bender, M.; Bu, C.; Piccolo, N.; Campbell, C.

2008-02-01

found the following: (1) There was some correlation between the prevailing wind direction and measured soil and oak leaf concentrations. This correlation was not statistically significant, but higher soil concentrations were generally found in the east and southeast from the plants and lower soil concentrations were found west/southwest from the plants. The prevailing winds are to the east. The Conemaugh plant which was the most southeast of the three plants did have the highest average oak leaf and soil mercury concentrations. Based on emissions, the Keystone plant would be expected to see the highest concentrations as it emitted about 25% more mercury than the other two plants. (2) The results of this study did not turn up strong evidence for large areas (several square miles) of elevated mercury concentrations around the three coal-fired power plants that were tested. This does not mean that there is no effect, there was some evidence of increasing mercury content to the east and south of these plants, however, the trends were not statistically significant suggesting that if the effects exist, they are small.

Impact of integrating wind power in the Norwegian power system

International Nuclear Information System (INIS)

Tande, John Olav

2006-04-01

Wind power may in the future constitute a significant part of the Norwegian electricity supply. 20 TWh annual wind generation is a realistic goal for 2020 assuming wind farms on-land and offshore. The development of grid codes for wind farms is sound. It is recognising that large wind farms are basically power plants and may participate in securing efficient and stable power system operation. Modern wind farms may control the reactive power or voltage as any other power plant, and may also control active power or frequency as long as wind conditions permits. Grid code requirements must however be carefully assessed and possibly adjusted over time aiming for overall least cost solutions. Development of wind farms are today to some degree hindered by conservative assumptions being made on operation of wind farms in areas with limited power transfer capacity. By accepting temporary grid congestions, however, a large increase installed wind power is viable. For grid congestion that appears a few hours per year only, the cost of lost generation will be modest and may be economic over the alternatives of limiting wind farm capacities or increasing the grid transfer capacity. Wind generation impact on power system operation and adequacy will be overall positive. Combining wind and hydro provides for a more stable annual energy supply than hydro alone, and wind generation will generally be higher in the winter period than in the summer. Wind will replace the generation with the highest operating cost, and reduce the average Nord Pool spot market price. 20 TWh wind will reduce price with about 3 oere/kWh and CO 2 emissions by 12-14 million tons for the case of replacing coal, and about 6 million tons for replacing natural gas. Wind impact on need for balancing power is small, i.e. the extra balancing cost is about 0,8 oere per kWh wind, and about half if investment in new reserve capacity is not needed. In summary this report demonstrates options for large scale integration

Lung Cancer Screening May Benefit Those at Highest Risk

Science.gov (United States)

People at the highest risk for lung cancer, based on a risk model, may be more likely to benefit from screening with low-dose CT, a new analysis suggests. The study authors believe the findings may better define who should undergo lung cancer screening, as this Cancer Currents blog post explains.

Towards highest peak intensities for ultra-short MeV-range ion bunches

Science.gov (United States)

Busold, Simon; Schumacher, Dennis; Brabetz, Christian; Jahn, Diana; Kroll, Florian; Deppert, Oliver; Schramm, Ulrich; Cowan, Thomas E.; Blažević, Abel; Bagnoud, Vincent; Roth, Markus

2015-01-01

A laser-driven, multi-MeV-range ion beamline has been installed at the GSI Helmholtz center for heavy ion research. The high-power laser PHELIX drives the very short (picosecond) ion acceleration on μm scale, with energies ranging up to 28.4 MeV for protons in a continuous spectrum. The necessary beam shaping behind the source is accomplished by applying magnetic ion lenses like solenoids and quadrupoles and a radiofrequency cavity. Based on the unique beam properties from the laser-driven source, high-current single bunches could be produced and characterized in a recent experiment: At a central energy of 7.8 MeV, up to 5 × 108 protons could be re-focused in time to a FWHM bunch length of τ = (462 ± 40) ps via phase focusing. The bunches show a moderate energy spread between 10% and 15% (ΔE/E0 at FWHM) and are available at 6 m distance to the source und thus separated from the harsh laser-matter interaction environment. These successful experiments represent the basis for developing novel laser-driven ion beamlines and accessing highest peak intensities for ultra-short MeV-range ion bunches. PMID:26212024

Towards highest peak intensities for ultra-short MeV-range ion bunches

Science.gov (United States)

Busold, Simon; Schumacher, Dennis; Brabetz, Christian; Jahn, Diana; Kroll, Florian; Deppert, Oliver; Schramm, Ulrich; Cowan, Thomas E.; Blažević, Abel; Bagnoud, Vincent; Roth, Markus

2015-07-01

A laser-driven, multi-MeV-range ion beamline has been installed at the GSI Helmholtz center for heavy ion research. The high-power laser PHELIX drives the very short (picosecond) ion acceleration on μm scale, with energies ranging up to 28.4 MeV for protons in a continuous spectrum. The necessary beam shaping behind the source is accomplished by applying magnetic ion lenses like solenoids and quadrupoles and a radiofrequency cavity. Based on the unique beam properties from the laser-driven source, high-current single bunches could be produced and characterized in a recent experiment: At a central energy of 7.8 MeV, up to 5 × 108 protons could be re-focused in time to a FWHM bunch length of τ = (462 ± 40) ps via phase focusing. The bunches show a moderate energy spread between 10% and 15% (ΔE/E0 at FWHM) and are available at 6 m distance to the source und thus separated from the harsh laser-matter interaction environment. These successful experiments represent the basis for developing novel laser-driven ion beamlines and accessing highest peak intensities for ultra-short MeV-range ion bunches.

Application of the Periodic Average System Model in Dam Deformation Analysis

Directory of Open Access Journals (Sweden)

Yueqian Shen

2015-01-01

Full Text Available Dams are among the most important hydraulic engineering facilities used for water supply, flood control, and hydroelectric power. Monitoring of dams is crucial since deformation might have occurred. How to obtain the deformation information and then judge the safe conditions is the key and difficult problem in dam deformation monitoring field. This paper proposes the periodic average system model and creates the concept of “settlement activity” based on the dam deformation issue. Long-term deformation monitoring data is carried out in a pumped-storage power station, this model combined with settlement activity is used to make the single point deformation analysis, and then the whole settlement activity profile is drawn by clustering analysis. Considering the cumulative settlement value of every point, the dam deformation trend is analyzed in an intuitive effect way. The analysis mode of combined single point with multipoints is realized. The results show that the key deformation information of the dam can be easily grasped by the application of the periodic average system model combined with the distribution diagram of settlement activity. And, above all, the ideas of this research provide an effective method for dam deformation analysis.

Evaluation of a microwave high-power reception-conversion array for wireless power transmission

Science.gov (United States)

Dickinson, R. M.

1975-01-01

Initial performance tests of a 24-sq m area array of rectenna elements are presented. The array is used as the receiving portion of a wireless microwave power transmission engineering verification test system. The transmitting antenna was located at a range of 1.54 km. Output dc voltage and power, input RF power, efficiency, and operating temperatures were obtained for a variety of dc load and RF incident power levels at 2388 MHz. Incident peak RF intensities of up to 170 mW/sq cm yielded up to 30.4 kW of dc output power. The highest derived collection-conversion efficiency of the array was greater than 80 percent.

High average power scaling of optical parametric amplification through cascaded difference-frequency generators

Science.gov (United States)

Jovanovic, Igor; Comaskey, Brian J.

2004-09-14

A first pump pulse and a signal pulse are injected into a first optical parametric amplifier. This produces a first amplified signal pulse. At least one additional pump pulse and the first amplified signal pulse are injected into at least one additional optical parametric amplifier producing an increased power coherent optical pulse.

The highest energy cosmic rays, photons and neutrinos

International Nuclear Information System (INIS)

Zas, Enrique

1998-01-01

In these lectures I introduce and discuss aspects of currently active fields of interest related to the production, transport and detection of high energy particles from extraterrestrial sources. I have payed most attention to the highest energies and I have divided the material according to the types of particles which will be searched for with different experimental facilities in planning: hadrons, gamma rays and neutrinos. Particular attention is given to shower development, stochastic acceleration and detection techniques

Danish Wind Power

DEFF Research Database (Denmark)

Lund, Henrik; Hvelplund, Frede; Østergaard, Poul Alberg

In a normal wind year, Danish wind turbines generate the equivalent of approx. 20 percent of the Danish electricity demand. This paper argues that only approx. 1 percent of the wind power production is exported. The rest is used to meet domestic Danish electricity demands. The cost of wind power...... misleading. The cost of CO2 reduction by use of wind power in the period 2004-2008 was only 20 EUR/ton. Furthermore, the Danish wind turbines are not paid for by energy taxes. Danish wind turbines are given a subsidy via the electricity price which is paid by the electricity consumers. In the recent years...... is paid solely by the electricity consumers and the net influence on consumer prices was as low as 1-3 percent on average in the period 2004-2008. In 2008, the net influence even decreased the average consumer price, although only slightly. In Denmark, 20 percent wind power is integrated by using both...

Attractiveness of the female body: Preference for the average or the supernormal?

Directory of Open Access Journals (Sweden)

Marković Slobodan

2017-01-01

Full Text Available The main purpose of the present study was to contrast the two hypotheses of female body attractiveness. The first is the “preference-for-the average” hypothesis: the most attractive female body is the one that represents the average body proportions for a given population. The second is the “preference-for-the supernormal” hypothesis: according to the so-called “peak shift effect”, the most attractive female body is more feminine than the average. We investigated the preference for three female body characteristics: waist to hip ratio (WHR, buttocks and breasts. There were 456 participants of both genders. Using a program for computer animation (DAZ 3D three sets of stimuli were generated (WHR, buttocks and breasts. Each set included six stimuli ranked from the lowest to the highest femininity level. Participants were asked to choose the stimulus within each set which they found most attractive (task 1 and average (task 2. One group of participants judged the body parts that were presented in the global context (whole body, while the other group judged the stimuli in the local context (isolated body parts only. Analyses have shown that the most attractive WHR, buttocks and breasts are more feminine (meaning smaller for WHR and larger for breasts and buttocks than average ones, for both genders and in both presentation contexts. The effect of gender was obtained only for the most attractive breasts: males prefer larger breasts than females. Finally, most attractive and average WHR and breasts were less feminine in the local than in the global context. These results support the preference-for the supernormal hypothesis: all analyses have shown that both male and female participants preferred female body parts which are more feminine than those judged average. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 179033

Study on reactor power change and ambiguous control of third Qinshan Nuclear Power Plant

International Nuclear Information System (INIS)

Wang Gongzhan

2006-01-01

The phenomenon of the average power reduction during long term full power operating in Third Qinshan nuclear power plant is analyzed . According to the basic conclusions of reactor power fluctuating derived by probability statistic and calculation the corresponding ambiguous control project is proposed. The operating performance could be achieved by the present controlling project is predicted additionally. (authors)

Improved lifetime of chitosan film in converting water vapor to electrical power by adding carboxymethyl cellulose

Science.gov (United States)

Nasution, T. I.; Balyan, M.; Nainggolan, I.

2018-02-01

A Water vapor cell based on chitosan film has been successfully fabricated in film form to convert water vapor to electrical power. In order to improve the lifetime of water vapor cell, Carboxymethyl Cellulose (CMC) was added into 1% chitosan solution within concentration variations of 0.01, 0.05, 0.1 and 0.5%. The result showed that the lifetime of water vapor cell increased higher by adding the higher concentration of Carboxymethyl cellulose. The highest lifetime was evidenced by adding 0.5%CMC which maintained for 48 weeks. However, the average electrical power became lower to 4.621 µW. This electrical power lower than the addition of 0.1%CMC which maintained for 5.167 µW. While, the lifetime of chitosan-0.1%CMC film of 44 weeks is shorter compared to chitosan-0.5%CMC film. Based on FTIR characterization, it was founded that the chitosan structure did not change until the addition of 0.1%CMC. This caused the electrical power of water vapor cell degenerated. Therefore, chitosan-0.5%CMC film has excellent lifetime in converting water vapor to electrical power.

A new derivation of the highest-weight polynomial of a unitary lie algebra

International Nuclear Information System (INIS)

P Chau, Huu-Tai; P Van, Isacker

2000-01-01

A new method is presented to derive the expression of the highest-weight polynomial used to build the basis of an irreducible representation (IR) of the unitary algebra U(2J+1). After a brief reminder of Moshinsky's method to arrive at the set of equations defining the highest-weight polynomial of U(2J+1), an alternative derivation of the polynomial from these equations is presented. The method is less general than the one proposed by Moshinsky but has the advantage that the determinantal expression of the highest-weight polynomial is arrived at in a direct way using matrix inversions. (authors)

High Power Density Power Electronic Converters for Large Wind Turbines

DEFF Research Database (Denmark)

Senturk, Osman Selcuk

. For these VSCs, high power density is required due to limited turbine nacelle space. Also, high reliability is required since maintenance cost of these remotely located wind turbines is quite high and these turbines operate under harsh operating conditions. In order to select a high power density and reliability......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...... VSC solution for wind turbines, first, the VSC topology and the switch technology to be employed should be specified such that the highest possible power density and reliability are to be attained. Then, this qualitative approach should be complemented with the power density and reliability...

1999 Annual report: compression + power + service

International Nuclear Information System (INIS)

2000-01-01

Enerflex manufactures, services and leases compression systems for the production and processing of natural gas and gas-fueled power generation systems. Design, engineering, project management, financing, installation commissioning and after-sales service are also part of Enerflex's arsenal of tools to ensure innovation, and high standards of quality and service. In 1999, Enerflex suffered an 18 per cent decline in revenues from $315 million in 1998 to $257 million in 1999, entirely due to lower sales of big ticket compression equipment in Canada. At the same time, revenues from international sales and service increased to $ 61.8 million in 1999, from $ 53 million in 1998. The company successfully completed the move to a new 328,000 sq. ft state-of-the-art manufacturing facility, and made its first significant sale to the United States in 1999 in the form of delivering a coal bed methane project in the Powder River area of Wyoming, and power generation equipment to Massachusetts. Although in the short term unusually warm average temperatures, industry cash flows, and access to capital may determine demand for the company's products and services, the long-term fundamentals are positive and demand for compression equipment and power generation systems is likely to grow. Indeed, in the fourth quarter of 1999, market conditions improved significantly and the company recorded its highest quarterly revenues and earnings during the last quarter. The annual review provides further details about the operations of the company's various divisions, (Compression and Power Systems, Parts and Compression Services, Leasing and Financing), management's review of the company's overall operations and finances, audited financial statements, and shareholders' information

47 CFR 27.50 - Power limits and duty cycle.

Science.gov (United States)

2010-10-01

... MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Technical Standards § 27.50 Power limits and duty cycle. (a) The.... In measuring transmissions in this band using an average power technique, the peak-to-average ratio (PAR) of the transmission may not exceed 13 dB. (6) Peak transmit power must be measured over any...

Environmental and industrial applications of pulsed power systems

International Nuclear Information System (INIS)

Neau, E.L.

1993-01-01

The technology base formed by the development of high peak power simulators, laser drivers, free electron lasers (FEL's), and Inertial Confinement Fusion (ICF) drivers from the early 60's through the late 80's is being extended to high average power short-pulse machines with the capabilities of performing new roles in environmental cleanup applications and in supporting new types of industrial manufacturing processes. Some of these processes will require very high average beam power levels of hundreds of kilowatts to perhaps megawatts. In this paper we briefly discuss new technology capabilities and then concentrate on specific application areas that may benefit from the high specific energies and high average powers attainable with short-pulse machines

Familiarity and Voice Representation: From Acoustic-Based Representation to Voice Averages

Directory of Open Access Journals (Sweden)

Maureen Fontaine

2017-07-01

Full Text Available The ability to recognize an individual from their voice is a widespread ability with a long evolutionary history. Yet, the perceptual representation of familiar voices is ill-defined. In two experiments, we explored the neuropsychological processes involved in the perception of voice identity. We specifically explored the hypothesis that familiar voices (trained-to-familiar (Experiment 1, and famous voices (Experiment 2 are represented as a whole complex pattern, well approximated by the average of multiple utterances produced by a single speaker. In experiment 1, participants learned three voices over several sessions, and performed a three-alternative forced-choice identification task on original voice samples and several “speaker averages,” created by morphing across varying numbers of different vowels (e.g., [a] and [i] produced by the same speaker. In experiment 2, the same participants performed the same task on voice samples produced by familiar speakers. The two experiments showed that for famous voices, but not for trained-to-familiar voices, identification performance increased and response times decreased as a function of the number of utterances in the averages. This study sheds light on the perceptual representation of familiar voices, and demonstrates the power of average in recognizing familiar voices. The speaker average captures the unique characteristics of a speaker, and thus retains the information essential for recognition; it acts as a prototype of the speaker.

The highest velocity and the shortest duration permitting attainment of VO2max during running

Directory of Open Access Journals (Sweden)

Tiago Turnes

2015-02-01

Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2015v17n2p226   The severe-intensity domain has important applications for the prescription of running training and the elaboration of experimental designs. The objectives of this study were: 1 to investigate the validity of a previously proposed model to estimate the shortest exercise duration (TLOW and the highest velocity (VHIGH at which VO2max is reached during running, and 2 to evaluate the effects of aerobic training status on these variables. Eight runners and eight physically active subjects performed several treadmill running exercise tests to fatigue in order to mathematically estimate and to experimentally determine TLOW and VHIGH. The relationship between the time to achieve VO2max and time to exhaustion (Tlim was used to estimate TLOW. VHIGH was estimated using the critical velocity model. VHIGH was assumed to be the highest velocity at which VO2 was equal to or higher than the average VO2max minus one standard deviation. TLOW was defined as Tlim associated with VHIGH. Runners presented better aerobic fitness and higher VHIGH (22.2 ± 1.9 km.h-1 than active subjects (20.0 ± 2.1 km.h-1. However, TLOW did not differ between groups (runners: 101 ± 39 s; active subjects: 100 ± 35 s. TLOW and VHIGH were not well estimated by the model proposed, with high coefficients of variation (> 6% and a low correlation coefficient (r<0.70, a fact reducing the validity of the model. It was concluded that aerobic training status positively affected only VHIGH. Furthermore, the model proposed presented low validity to estimate the upper boundary of the severe-intensity domain (i.e., VHIGH, irrespective of the subjects’ training status.

Negatively charged hyperbranched polyglycerol grafted membranes for osmotic power generation from municipal wastewater.

Science.gov (United States)

Li, Xue; Cai, Tao; Chen, Chunyan; Chung, Tai-Shung

2016-02-01

Osmotic power holds great promise as a clean, sustainable and largely unexploited energy resource. Recent membrane development for pressure-retarded osmosis (PRO) is making the osmotic power generation more and more realistic. However, severe performance declines have been observed because the porous layer of PRO membranes is fouled by the feed stream. To overcome it, a negatively charged antifouling PRO hollow fiber membrane has been designed and studied in this work. An antifouling polymer, derived from hyperbranched polyglycerol and functionalized by α-lipoic acid and succinic anhydride, was synthesized and grafted onto the polydopamine (PDA) modified poly(ether sulfone) (PES) hollow fiber membranes. In comparison to unmodified membranes, the charged hyperbranched polyglycerol (CHPG) grafted membrane is much less affected by organic deposition, such as bovine serum albumin (BSA) adsorption, and highly resistant to microbial growths, demonstrated by Escherichia coli adhesion and Staphylococcus aureus attachment. CHPG-g-TFC was also examined in PRO tests using a concentrated wastewater as the feed. Comparing to the plain PES-TFC and non-charged HPG-g-TFC, the newly developed membrane exhibits not only the smallest decline in water flux but also the highest recovery rate. When using 0.81 M NaCl and wastewater as the feed pair in PRO tests at 15 bar, the average power density remains at 5.6 W/m(2) in comparison to an average value of 3.6 W/m(2) for unmodified membranes after four PRO runs. In summary, osmotic power generation may be sustained by properly designing and anchoring the functional polymers to PRO membranes. Copyright © 2015 Elsevier Ltd. All rights reserved.

On Averaging Rotations

DEFF Research Database (Denmark)

Gramkow, Claus

1999-01-01

In this article two common approaches to averaging rotations are compared to a more advanced approach based on a Riemannian metric. Very offten the barycenter of the quaternions or matrices that represent the rotations are used as an estimate of the mean. These methods neglect that rotations belo...... approximations to the Riemannian metric, and that the subsequent corrections are inherient in the least squares estimation. Keywords: averaging rotations, Riemannian metric, matrix, quaternion......In this article two common approaches to averaging rotations are compared to a more advanced approach based on a Riemannian metric. Very offten the barycenter of the quaternions or matrices that represent the rotations are used as an estimate of the mean. These methods neglect that rotations belong...

Ultra-short pulse delivery at high average power with low-loss hollow core fibers coupled to TRUMPF's TruMicro laser platforms for industrial applications

Science.gov (United States)

Baumbach, S.; Pricking, S.; Overbuschmann, J.; Nutsch, S.; Kleinbauer, J.; Gebs, R.; Tan, C.; Scelle, R.; Kahmann, M.; Budnicki, A.; Sutter, D. H.; Killi, A.

2017-02-01

Multi-megawatt ultrafast laser systems at micrometer wavelength are commonly used for material processing applications, including ablation, cutting and drilling of various materials or cleaving of display glass with excellent quality. There is a need for flexible and efficient beam guidance, avoiding free space propagation of light between the laser head and the processing unit. Solid core step index fibers are only feasible for delivering laser pulses with peak powers in the kW-regime due to the optical damage threshold in bulk silica. In contrast, hollow core fibers are capable of guiding ultra-short laser pulses with orders of magnitude higher peak powers. This is possible since a micro-structured cladding confines the light within the hollow core and therefore minimizes the spatial overlap between silica and the electro-magnetic field. We report on recent results of single-mode ultra-short pulse delivery over several meters in a lowloss hollow core fiber packaged with industrial connectors. TRUMPF's ultrafast TruMicro laser platforms equipped with advanced temperature control and precisely engineered opto-mechanical components provide excellent position and pointing stability. They are thus perfectly suited for passive coupling of ultra-short laser pulses into hollow core fibers. Neither active beam launching components nor beam trackers are necessary for a reliable beam delivery in a space and cost saving packaging. Long term tests with weeks of stable operation, excellent beam quality and an overall transmission efficiency of above 85 percent even at high average power confirm the reliability for industrial applications.

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.

Repetitively pulsed power for meat pasteurization

International Nuclear Information System (INIS)

Patterson, E.L.; Kaye, R.J.; Neau, E.L.

1994-01-01

Electronic pasteurization of meat offers the potential for drastically reducing the incidence of food poisoning caused by biological pathogens accidentally introduced into meat products. Previous work has shown that γ-rays are an effective method of destroying E. coli 0157:H7, Salmonella, C. jejuni, L. monocytogenes, Listeria, and S. aureus bacteria types. The concern with the use of γ-rays is that radioactive material must be used in the pasteurization process that can lead to some market resistance and activist pressure on the meat industry. The use of accelerator generated high average power electron beams, at energies less than 10 MeV, or X-rays, with energies below 5 MeV, have been approved by the FDA for use in pasteurizing foods. Accelerator produced electronic pasteurization has the advantage that no radioactive material inventory is required. Electronic pasteurization has the additional benefit that it removes bacterial pathogens on the meat surface as well as within the volume of the meat product. High average power, repetitively-pulsed, broad-area electron beam sources being developed in the RHEPP program are suitable for large scale meat treatment in packing plant environments. RHEPP-II, which operates at 2.5 MeV and 25 kA at pulse repetition frequencies up to 120 Hz has adequate electron energy to penetrate hamburger patties which comprise about half of the beef consumption in the United States. Ground beef also has the highest potential for contamination since considerable processing is required in its production. A meat pasteurization facility using this size of accelerator source should be capable of treating 10 6 pounds of hamburger patties per hour to a dose of up to 3 kGy (300 kilorads). The RHEPP modular accelerator technology can easily be modified for other production rates and types of products

Average-energy games

Directory of Open Access Journals (Sweden)

Patricia Bouyer

2015-09-01

Full Text Available Two-player quantitative zero-sum games provide a natural framework to synthesize controllers with performance guarantees for reactive systems within an uncontrollable environment. Classical settings include mean-payoff games, where the objective is to optimize the long-run average gain per action, and energy games, where the system has to avoid running out of energy. We study average-energy games, where the goal is to optimize the long-run average of the accumulated energy. We show that this objective arises naturally in several applications, and that it yields interesting connections with previous concepts in the literature. We prove that deciding the winner in such games is in NP inter coNP and at least as hard as solving mean-payoff games, and we establish that memoryless strategies suffice to win. We also consider the case where the system has to minimize the average-energy while maintaining the accumulated energy within predefined bounds at all times: this corresponds to operating with a finite-capacity storage for energy. We give results for one-player and two-player games, and establish complexity bounds and memory requirements.

Justification of the averaging method for parabolic equations containing rapidly oscillating terms with large amplitudes

International Nuclear Information System (INIS)

Levenshtam, V B

2006-01-01

We justify the averaging method for abstract parabolic equations with stationary principal part that contain non-linearities (subordinate to the principal part) some of whose terms are rapidly oscillating in time with zero mean and are proportional to the square root of the frequency of oscillation. Our interest in the exponent 1/2 is motivated by the fact that terms proportional to lower powers of the frequency have no influence on the average. For linear equations of the same type, we justify an algorithm for the study of the stability of solutions in the case when the stationary averaged problem has eigenvalues on the imaginary axis (the critical case)

The fifty highest cited papers in anterior cruciate ligament injury.

Science.gov (United States)

Vielgut, Ines; Dauwe, Jan; Leithner, Andreas; Holzer, Lukas A

2017-07-01

The anterior cruciate ligament (ACL) is one of the most common injured knee ligaments and at the same time, one of the most frequent injuries seen in the sport orthopaedic practice. Due to the clinical relevance of ACL injuries, numerous papers focussing on this topic including biomechanical-, basic science-, clinical- or animal studies, were published. The purpose of this study was to determine the most frequently cited scientific articles which address this subject, establish a ranking of the 50 highest cited papers and analyse them according to their characteristics. The 50 highest cited articles related to Anterior Cruciate Ligament Injury were searched in Thomson ISI Web of Science® by the use of defined search terms. All types of scientific papers with reference to our topic were ranked according to the absolute number of citations and analyzed for the following characteristics: journal title, year of publication, number of citations, citation density, geographic origin, article type and level of evidence. The 50 highest cited articles had up to 1624 citations. The top ten papers on this topic were cited 600 times at least. Most papers were published in the American Journal of Sports Medicine. The publication years spanned from 1941 to 2007, with the 1990s and 2000s accounting for half of the articles (n = 25). Seven countries contributed to the top 50 list, with the USA having by far the most contribution (n = 40). The majority of articles could be attributed to the category "Clinical Science & Outcome". Most of them represent a high level of evidence. Scientific articles in the field of ACL injury are highly cited. The majority of these articles are clinical studies that have a high level of evidence. Although most of the articles were published between 1990 and 2007, the highest cited articles in absolute and relative numbers were published in the early 1980s. These articles contain well established scoring- or classification systems. The

Input of biomass in power plants or the power generation. Calculation of the financial gap

International Nuclear Information System (INIS)

De Vries, H.J.; Van Tilburg, X.; Pfeiffer, A.E.; Cleijne, H.

2005-09-01

The project on the title subject concerns two questions: (1) Are projects in which wood-pellets are co-fired in a coalfired power plant representative for bio-oil fueled co-firing projects in a gas-fired plant?; and (2) are new projects representative for existing projects? To answer those questions the financial gaps have been calculated for five different situations: Co-firing bio-oil in a gas-fired power plant; Co-firing bio-oil in a coal-fired power plant; Co-firing wood pellets in a coal-fired power plant; Co-firing agro-residues in a coal-fired power plant; and Co-firing waste-wood (A- and B-grade) in a coal-fired power plant. The ranges and reference cases in this report show that co-firing bio-oil on average has a smaller financial gap than the solid biomass reference case. On average it can also be concluded that by using waste wood or agro-residues, the financial gaps can decrease [nl

METHODS OF CONTROLLING THE AVERAGE DIAMETER OF THE THREAD WITH ASYMMETRICAL PROFILE

Directory of Open Access Journals (Sweden)

L. M. Aliomarov

2015-01-01

Full Text Available To handle the threaded holes in hard materials made of marine machinery, operating at high temperatures, heavy loads and in aggressive environments, the authors have developed the combined tool core drill -tap with a special cutting scheme, which has an asymmetric thread profile on the tap part. In order to control the average diameter of the thread of tap part of the combined tool was used the method three wires, which allows to make continuous measurement of the average diameter of the thread along the entire profile. Deviation from the average diameter from the sample is registered by inductive sensor and is recorded by the recorder. In the work are developed and presented control schemes of the average diameter of the threads with a symmetrical and asymmetrical profile. On the basis of these schemes are derived formulas for calculating the theoretical option to set the wires in the thread profile in the process of measuring the average diameter. Conducted complex research and the introduction of the combined instrument core drill-tap in the production of products of marine engineering, shipbuilding, ship repair power plants made of hard materials showed a high efficiency of the proposed technology for the processing of high-quality small-diameter threaded holes that meet modern requirements.

Average BER analysis of SCM-based free-space optical systems by considering the effect of IM3 with OSSB signals under turbulence channels.

Science.gov (United States)

Lim, Wansu; Cho, Tae-Sik; Yun, Changho; Kim, Kiseon

2009-11-09

In this paper, we derive the average bit error rate (BER) of subcarrier multiplexing (SCM)-based free space optics (FSO) systems using a dual-drive Mach-Zehnder modulator (DD-MZM) for optical single-sideband (OSSB) signals under atmospheric turbulence channels. In particular, we consider the third-order intermodulation (IM3), a significant performance degradation factor, in the case of high input signal power systems. The derived average BER, as a function of the input signal power and the scintillation index, is employed to determine the optimum number of SCM users upon the designing FSO systems. For instance, when the user number doubles, the input signal power decreases by almost 2 dBm under the log-normal and exponential turbulence channels at a given average BER.

An averaging battery model for a lead-acid battery operating in an electric car

Science.gov (United States)

Bozek, J. M.

1979-01-01

A battery model is developed based on time averaging the current or power, and is shown to be an effective means of predicting the performance of a lead acid battery. The effectiveness of this battery model was tested on battery discharge profiles expected during the operation of an electric vehicle following the various SAE J227a driving schedules. The averaging model predicts the performance of a battery that is periodically charged (regenerated) if the regeneration energy is assumed to be converted to retrievable electrochemical energy on a one-to-one basis.

Summary of operating experience in Swiss nuclear power plants 1993

International Nuclear Information System (INIS)

1994-07-01

In 1993 the Swiss nuclear power plants produced their third highest combined annual output. The contribution to the total electricity generation in the country was close to 37%. Replacement of the steam generators in Beznau Unit 1 resulted in a longer than usual annual outage. For the other four units the availability figures were close to, or exceeded, those of previous years. The energy utilization was, however, lowered due to load reduction in autumn resulting from unusually high production by the hydro-electric power plants. The steam generator replacement at Beznau enabled an increase in electrical power of about 2% without increase in reactor power. With the approval of the Swiss government in December 1992, the output of the Muehleberg power plant was increased in two stages by a total of 10%. The application for an unlimited operating license for Beznau Unit 2, and for a power uprate at the Leibstadt power plant, are still pending. The average number of scrams at the Swiss plants remained stable, at less than one scram per reactor year. As a result of experience in the Swedish nuclear power plant at Barsebaeck, the suction strainers of the emergency core cooling systems of the boiling water reactors at Muehleberg and Leibstadt were replaced by strainers with larger surface areas. The re-inspection of crack indications previously detected in the core shroud of the Muehleberg reactor and the penetration tubes in the reactor pressure vessel closure head of Beznau revealed no growth during the intervening operating periods. Following the completion of installation activities during the annual outages at Beznau Unit 1, Goesgen and Leibstadt, all Swiss nuclear power plants are now equipped with filtered containment venting systems. (author) figs., tabs

Averaging of nonlinearity-managed pulses

International Nuclear Information System (INIS)

Zharnitsky, Vadim; Pelinovsky, Dmitry

2005-01-01

We consider the nonlinear Schroedinger equation with the nonlinearity management which describes Bose-Einstein condensates under Feshbach resonance. By using an averaging theory, we derive the Hamiltonian averaged equation and compare it with other averaging methods developed for this problem. The averaged equation is used for analytical approximations of nonlinearity-managed solitons

Improving wind power quality with energy storage

DEFF Research Database (Denmark)

Rasmussen, Claus Nygaard

2009-01-01

The results of simulation of the influence of energy storage on wind power quality are presented. Simulations are done using a mathematical model of energy storage. Results show the relation between storage power and energy, and the obtained increase in minimum available power from the combination...... of wind and storage. The introduction of storage enables smoothening of wind power on a timescale proportional to the storage energy. Storage does not provide availability of wind power at all times, but allows for a certain fraction of average power in a given timeframe to be available with high...... probability. The amount of storage capacity necessary for significant wind power quality improvement in a given period is found to be 20 to 40% of the energy produced in that period. The necessary power is found to be 80 to 100% of the average power of the period....

Power trip : stumbling toward a policy for NB power

International Nuclear Information System (INIS)

Tucker, T.L.; Norris, B.A.

2003-10-01

New Brunswick Power has one of the highest debt burdens of any crown utility along with one of the highest operating costs of any publicly owned electric utility in Canada. NB Power has borrowed heavily to invest in capital projects such as the expansion of its aging Point Lepreau nuclear plant. The current assets will not generate sufficient revenues to recover the investment. Kyoto requirements to reduce emissions have placed additional financial strain on the utility. It must also ensure funds for the eventual decommissioning of its nuclear facility. The utility's high operating costs are due to the high cost of coal used in its thermal generating plants. Since the utility relies on nuclear energy for 40 per cent of its output, it must maintain a high and costly reserve capacity in case the nuclear facility shuts down. In 2002, the government of New Brunswick announced plans to reorganize NB Power by creating a parent holding company with separate business units responsible for power generation, nuclear generation, power transmission, power distribution and customer service. A system operator will supervise access to the transmission system. The author argued that the restructuring will not address the problem of excessive costs and high debt. The NB Electric Finance Corporation will be created to service and retire the province's portion of the utility's debt. Instead of taxes and dividends on its equity position, NB Power will make payments to achieve the debt repayment. The restructured utility will still have to generate sufficient revenues to meet expenses. The following recommendations were presented: the government should privatize NB Power to cap taxpayers' debt liability; the government should assume an appropriate protion of the stranded debt liabilities to attract private investors to purchase the utility; electricity rates should be allowed to rise over time to reflect the real cost of operating the system; and, the government should open both the

Excess Capacity in China’s Power Systems: A Regional Analysis

Energy Technology Data Exchange (ETDEWEB)

Lin, Jiang [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area. Energy Analysis and Environmental Impacts Dept.. China Energy Group; Liu, Xu [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area. Energy Analysis and Environmental Impacts Dept.. China Energy Group; Karl, Fredrich [Energy and Environmental Economics, Inc. (E3), San Francisco, CA (United States)

2016-11-01

This paper examines China’s regional electricity grids using a reliability perspective, which is commonly measured in terms of a reserve margin. Our analysis shows that at the end of 2014, the average reserve margin for China as a whole was roughly 28%, almost twice as high as a typical planning reserve margin in the U.S. However, this national average masks huge variations in reserve margins across major regional power grid areas: the northeastern region has the highest reserve margin of over 60%, followed by the northwestern region at 49%, and the southern grid area at 35%. In this analysis, we also examined future reserve margins for regional electricity grids in China under two scenarios: 1) a low scenario of national annual electricity consumption growth rates of 1.5% between 2015 and 2020 and 1.0% between 2020 and 2025, and 2) a high scenario of annual average growth rates of 3.0% and 2.0%, respectively. Both scenarios suggest that the northeastern, northwestern, and southern regions have significant excess generation capacity, and that this excess capacity situation will continue over the next decade without regulatory intervention. The northern and central regions could have sufficient generation capacity to 2020, but may require additional resources in a higher growth scenario. The eastern region requires new resources by 2020 in both scenarios.

Aerosol particles generated by diesel-powered school buses at urban schools as a source of children’s exposure

Science.gov (United States)

Hochstetler, Heather A.; Yermakov, Mikhail; Reponen, Tiina; Ryan, Patrick H.; Grinshpun, Sergey A.

2015-01-01

Various heath effects in children have been associated with exposure to traffic-related particulate matter (PM), including emissions from school buses. In this study, the indoor and outdoor aerosol at four urban elementary schools serviced by diesel-powered school buses was characterized with respect to the particle number concentrations and size distributions as well as the PM2.5 mass concentrations and elemental compositions. It was determined that the presence of school buses significantly affected the outdoor particle size distribution, specifically in the ultrafine fraction. The time-weighted average of the total number concentration measured outside the schools was significantly associated with the bus and the car counts. The concentration increase was consistently observed during the morning drop-off hours and in most of the days during the afternoon pick-up period (although at a lower degree). Outdoor PM2.5 mass concentrations measured at schools ranged from 3.8 to 27.6 µg m−3. The school with the highest number of operating buses exhibited the highest average PM2.5 mass concentration. The outdoor mass concentrations of elemental carbon (EC) and organic carbon (OC) were also highest at the school with the greatest number of buses. Most (47/55) correlations between traffic-related elements identified in the outdoor PM2.5 were significant with elements identified in the indoor PM2.5. Significant associations were observed between indoor and outdoor aerosols for EC, EC/OC, and the total particle number concentration. Day-to-day and school-to-school variations in Indoor/Outdoor (I/O) ratios were related to the observed differences in opening windows and doors, which enhanced the particle penetration, as well as indoor activities at schools. Overall, the results on I/O ratio obtained in this study reflect the sizes of particles emitted by diesel-powered school bus engines (primarily, an ultrafine fraction capable of penetrating indoors). PMID:25904818

Newton-Krylov Methods in Power Flow and Contingency Analysis

NARCIS (Netherlands)

Idema, R.

2012-01-01

A power system is a system that provides for the generation, transmission, and distribution of electrical energy. Power systems are considered to be the largest and most complex man-made systems. As electrical energy is vital to our society, power systems have to satisfy the highest security and

High average power 1314 nm Nd:YLF laser, passively Q-switched with V:YAG

CSIR Research Space (South Africa)

Botha, RC

2013-03-01

Full Text Available A 1314 nm Nd:YLF laser was designed and operated both CW and passively Q-switched. Maximum CW output of 10.4 W resulted from 45.2 Wof incident pump power. Passive Q-switching was obtained by inserting a V:YAG saturable absorber in the cavity...

Capillary Electrophoresis Sensitivity Enhancement Based on Adaptive Moving Average Method.

Science.gov (United States)

Drevinskas, Tomas; Telksnys, Laimutis; Maruška, Audrius; Gorbatsova, Jelena; Kaljurand, Mihkel

2018-06-05

In the present work, we demonstrate a novel approach to improve the sensitivity of the "out of lab" portable capillary electrophoretic measurements. Nowadays, many signal enhancement methods are (i) underused (nonoptimal), (ii) overused (distorts the data), or (iii) inapplicable in field-portable instrumentation because of a lack of computational power. The described innovative migration velocity-adaptive moving average method uses an optimal averaging window size and can be easily implemented with a microcontroller. The contactless conductivity detection was used as a model for the development of a signal processing method and the demonstration of its impact on the sensitivity. The frequency characteristics of the recorded electropherograms and peaks were clarified. Higher electrophoretic mobility analytes exhibit higher-frequency peaks, whereas lower electrophoretic mobility analytes exhibit lower-frequency peaks. On the basis of the obtained data, a migration velocity-adaptive moving average algorithm was created, adapted, and programmed into capillary electrophoresis data-processing software. Employing the developed algorithm, each data point is processed depending on a certain migration time of the analyte. Because of the implemented migration velocity-adaptive moving average method, the signal-to-noise ratio improved up to 11 times for sampling frequency of 4.6 Hz and up to 22 times for sampling frequency of 25 Hz. This paper could potentially be used as a methodological guideline for the development of new smoothing algorithms that require adaptive conditions in capillary electrophoresis and other separation methods.

The difference between alternative averages

Directory of Open Access Journals (Sweden)

James Vaupel

2012-09-01

Full Text Available BACKGROUND Demographers have long been interested in how compositional change, e.g., change in age structure, affects population averages. OBJECTIVE We want to deepen understanding of how compositional change affects population averages. RESULTS The difference between two averages of a variable, calculated using alternative weighting functions, equals the covariance between the variable and the ratio of the weighting functions, divided by the average of the ratio. We compare weighted and unweighted averages and also provide examples of use of the relationship in analyses of fertility and mortality. COMMENTS Other uses of covariances in formal demography are worth exploring.

Highest Resolution Gaspra Mosaic

Science.gov (United States)

1992-01-01

This picture of asteroid 951 Gaspra is a mosaic of two images taken by the Galileo spacecraft from a range of 5,300 kilometers (3,300 miles), some 10 minutes before closest approach on October 29, 1991. The Sun is shining from the right; phase angle is 50 degrees. The resolution, about 54 meters/pixel, is the highest for the Gaspra encounter and is about three times better than that in the view released in November 1991. Additional images of Gaspra remain stored on Galileo's tape recorder, awaiting playback in November. Gaspra is an irregular body with dimensions about 19 x 12 x 11 kilometers (12 x 7.5 x 7 miles). The portion illuminated in this view is about 18 kilometers (11 miles) from lower left to upper right. The north pole is located at upper left; Gaspra rotates counterclockwise every 7 hours. The large concavity on the lower right limb is about 6 kilometers (3.7 miles) across, the prominent crater on the terminator, center left, about 1.5 kilometers (1 mile). A striking feature of Gaspra's surface is the abundance of small craters. More than 600 craters, 100-500 meters (330-1650 feet) in diameter are visible here. The number of such small craters compared to larger ones is much greater for Gaspra than for previously studied bodies of comparable size such as the satellites of Mars. Gaspra's very irregular shape suggests that the asteroid was derived from a larger body by nearly catastrophic collisions. Consistent with such a history is the prominence of groove-like linear features, believed to be related to fractures. These linear depressions, 100-300 meters wide and tens of meters deep, are in two crossing groups with slightly different morphology, one group wider and more pitted than the other. Grooves had previously been seen only on Mars's moon Phobos, but were predicted for asteroids as well. Gaspra also shows a variety of enigmatic curved depressions and ridges in the terminator region at left. The Galileo project, whose primary mission is the

Gaspra - Highest Resolution Mosaic

Science.gov (United States)

1992-01-01

This picture of asteroid 951 Gaspra is a mosaic of two images taken by the Galileo spacecraft from a range of 5,300 kilometers (3,300 miles), some 10 minutes before closest approach on October 29, 1991. The Sun is shining from the right; phase angle is 50 degrees. The resolution, about 54 meters/pixel, is the highest for the Gaspra encounter and is about three times better than that in the view released in November 1991. Additional images of Gaspra remain stored on Galileo's tape recorder, awaiting playback in November. Gaspra is an irregular body with dimensions about 19 x 12 x 11 kilometers (12 x 7.5 x 7 miles). The portion illuminated in this view is about 18 kilometers (11 miles) from lower left to upper right. The north pole is located at upper left; Gaspra rotates counterclockwise every 7 hours. The large concavity on the lower right limb is about 6 kilometers (3.7 miles) across, the prominent crater on the terminator, center left, about 1.5 kilometers (1 mile). A striking feature of Gaspra's surface is the abundance of small craters. More than 600 craters, 100-500 meters (330-1650 feet) in diameter are visible here. The number of such small craters compared to larger ones is much greater for Gaspra than for previously studied bodies of comparable size such as the satellites of Mars. Gaspra's very irregular shape suggests that the asteroid was derived from a larger body by nearly catastrophic collisions. Consistent with such a history is the prominence of groove-like linear features, believed to be related to fractures. These linear depressions, 100-300 meters wide and tens of meters deep, are in two crossing groups with slightly different morphology, one group wider and more pitted than the other. Grooves had previously been seen only on Mars's moon Phobos, but were predicted for asteroids as well. Gaspra also shows a variety of enigmatic curved depressions and ridges in the terminator region at left. The Galileo project, whose primary mission is the

Alpha-1-antitrypsin deficiency in Madeira (Portugal): the highest prevalence in the world.

Science.gov (United States)

Spínola, Carla; Bruges-Armas, Jácome; Pereira, Conceição; Brehm, António; Spínola, Hélder

2009-10-01

Alpha-1-antitrypsin (AAT) deficiency is a common genetic disease which affects both lung and liver. Early diagnosis can help asymptomatic patients to adjust their lifestyle choices in order to reduce the risk of Chronic Obstructive Pulmonary Disease (COPD). The determination of this genetic deficiency prevalence in Madeira Island (Portugal) population is important to clarify susceptibility and define the relevance of performing genetic tests for AAT on individuals at risk for COPD. Two hundred samples of unrelated individuals from Madeira Island were genotyped for the two most common AAT deficiency alleles, PI*S and PI*Z, using Polymerase Chain Reaction-Mediated Site-Directed Mutagenesis. Our results show one of the highest frequencies for both mutations when compared to any already studied population in the world. In fact, PI*S mutation has the highest prevalence (18%), and PI*Z mutation (2.5%) was the third highest worldwide. The frequency of AAT deficiency genotypes in Madeira (PI*ZZ, PI*SS, and PI*SZ) is estimated to be the highest in the world: 41 per 1000. This high prevalence of AAT deficiency on Madeira Island reveals an increased genetic susceptibility to COPD and suggests a routine genetic testing for individuals at risk.

Program THEK energy production units of average power and using thermal conversion of solar radiation

Science.gov (United States)

1978-01-01

General studies undertaken by the C.N.R.S. in the field of solar power plants have generated the problem of building energy production units in the medium range of electrical power, in the order of 100 kW. Among the possible solutions, the principle of the use of distributed heliothermal converters has been selected as being, with the current status of things, the most advantageous solution. This principle consists of obtaining the conversion of concentrated radiation into heat by using a series of heliothermal conversion modules scattered over the ground; the produced heat is collected by a heat-carrying fluid circulating inside a thermal loop leading to a device for both regulation and storage.

High power passive μDMFC with low catalyst loading for small power generation

International Nuclear Information System (INIS)

Ahmad, M.M.; Kamarudin, S.K.; Daud, W.R.W.; Yaakub, Z.

2010-01-01

The main constraint for commercialization of micro direct methanol fuel cell (μDMFC) for small power generation is the performance of the fuel cell. In this study, a high power μDMFC with a power output of 56 mW and an active area of 4 cm 2 was successfully developed. The cell required low catalyst loading of 5 mg cm -2 and 0.5 mg cm -2 at the anode and cathode, respectively. Optimal design parameters for methanol concentration and catalyst loading were examined. Finally, long-term performance testing was performed and OCV curves are reported. The results obtained for this gives the highest power density at low catalyst loading as compare to other researchers in this area.

Directional clustering in highest energy cosmic rays

International Nuclear Information System (INIS)

Goldberg, Haim; Weiler, Thomas J.

2001-01-01

An unexpected degree of small-scale clustering is observed in highest-energy cosmic ray events. Some directional clustering can be expected due to purely statistical fluctuations for sources distributed randomly in the sky. This creates a background for events originating in clustered sources. We derive analytic formulas to estimate the probability of random cluster configurations, and use these formulas to study the strong potential of the HiRes, Auger, Telescope Array and EUSO-OWL-AirWatch facilities for deciding whether any observed clustering is most likely due to nonrandom sources. For a detailed comparison to data, our analytical approach cannot compete with Monte Carlo simulations, including experimental systematics. However, our derived formulas do offer two advantages: (i) easy assessment of the significance of any observed clustering, and most importantly, (ii) an explicit dependence of cluster probabilities on the chosen angular bin size

Solving The Longstanding Problem Of Low-Energy Nuclear Reactions At the Highest Microscopic Level - Final Report

Energy Technology Data Exchange (ETDEWEB)

Quaglioni, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2016-09-22

A 2011 DOE-NP Early Career Award (ECA) under Field Work Proposal (FWP) SCW1158 supported the project “Solving the Long-Standing Problem of Low-Energy Nuclear Reactions at the Highest Microscopic Level” in the five-year period from June 15, 2011 to June 14, 2016. This project, led by PI S. Quaglioni, aimed at developing a comprehensive and computationally efficient framework to arrive at a unified description of structural properties and reactions of light nuclei in terms of constituent protons and neutrons interacting through nucleon-nucleon (NN) and three-nucleon (3N) forces. Specifically, the project had three main goals: 1) arriving at the accurate predictions for fusion reactions that power stars and Earth-based fusion facilities; 2) realizing a comprehensive description of clustering and continuum effects in exotic nuclei, including light Borromean systems; and 3) achieving fundamental understanding of the role of the 3N force in nuclear reactions and nuclei at the drip line.

Exploring the cultural dimensions of the right to the highest ...

African Journals Online (AJOL)

The right to enjoying the highest attainable standard of health is incorporated in many international and regional human rights instruments. This right contains both freedoms and entitlements, including the freedom to control one's own health and body and the right to an accessible system of health care, goods and services.

Deregulated power prices: comparison of diurnal patterns

International Nuclear Information System (INIS)

Ying Li; Flynn, P.C.

2004-01-01

We examine electrical power price, and in particular its daily and average weekday vs. weekend pattern of change, for 14 deregulated markets. Power price in deregulated markets shows fundamentally different patterns. North American markets show a monotonic diurnal weekday price pattern, while all other markets studied show more than one price peak. Deregulated power markets differ in maximum vs. minimum daily average price and in average weekday to weekend price, in turn creating a different incentive for a consumer to time shift power consuming activities. Markets differ in the extent to which a small fraction of the days shapes the average diurnal pattern and value of price. Deregulated markets show a wide variation in the correlation between load and price. Some deregulated markets, most notably Britain and Spain, show patterns that are predictable and consistent, and hence that can encourage a customer to shape consumption behaviors. Other markets, for example South Australia, have patterns that are inconsistent and irregular, and hence are hard for a customer to interpret; a customer in such a market will have a higher incentive to escape risk through hedging mechanisms. (Author)

Deregulated power prices: comparison of diurnal patterns

International Nuclear Information System (INIS)

Li Ying; Flynn, Peter C.

2004-01-01

We examine electrical power price, and in particular its daily and average weekday vs. weekend pattern of change, for 14 deregulated markets. Power price in deregulated markets shows fundamentally different patterns. North American markets show a monotonic diurnal weekday price pattern, while all other markets studied show more than one price peak. Deregulated power markets differ in maximum vs. minimum daily average price and in average weekday to weekend price, in turn creating a different incentive for a consumer to time shift power consuming activities. Markets differ in the extent to which a small fraction of the days shapes the average diurnal pattern and value of price. Deregulated markets show a wide variation in the correlation between load and price. Some deregulated markets, most notably Britain and Spain, show patterns that are predictable and consistent, and hence that can encourage a customer to shape consumption behaviors. Other markets, for example South Australia, have patterns that are inconsistent and irregular, and hence are hard for a customer to interpret; a customer in such a market will have a higher incentive to escape risk through hedging mechanisms

Analysis of mobile phone design features affecting radiofrequency power absorbed in a human head phantom.

Science.gov (United States)

Kuehn, Sven; Kelsh, Michael A; Kuster, Niels; Sheppard, Asher R; Shum, Mona

2013-09-01

The US FCC mandates the testing of all mobile phones to demonstrate compliance with the rule requiring that the peak spatial SAR does not exceed the limit of 1.6 W/kg averaged over any 1 g of tissue. These test data, measured in phantoms with mobile phones operating at maximum antenna input power, permitted us to evaluate the variation in SARs across mobile phone design factors such as shape and antenna design, communication technology, and test date (over a 7-year period). Descriptive statistical summaries calculated for 850 MHz and 1900 MHz phones and ANOVA were used to evaluate the influence of the foregoing factors on SARs. Service technology accounted for the greatest variability in compliance test SARs that ranged from AMPS (highest) to CDMA, iDEN, TDMA, and GSM (lowest). However, the dominant factor for SARs during use is the time-averaged antenna input power, which may be much less than the maximum power used in testing. This factor is largely defined by the communication system; e.g., the GSM phone average output can be higher than CDMA by a factor of 100. Phone shape, antenna type, and orientation of a phone were found to be significant but only on the order of up to a factor of 2 (3 dB). The SAR in the tilt position was significantly smaller than for touch. The side of the head did not affect SAR levels significantly. Among the remaining factors, external antennae produced greater SARs than internal ones, and brick and clamshell phones produced greater SARs than slide phones. Assuming phone design and usage patterns do not change significantly over time, we have developed a normalization procedure and formula that permits reliable prediction of the relative SAR between various communication systems. This approach can be applied to improve exposure assessment in epidemiological research. Copyright © 2013 Wiley Periodicals, Inc.

Characterizing individual painDETECT symptoms by average pain severity

Directory of Open Access Journals (Sweden)

Sadosky A

2016-07-01

Full Text Available Alesia Sadosky,1 Vijaya Koduru,2 E Jay Bienen,3 Joseph C Cappelleri4 1Pfizer Inc, New York, NY, 2Eliassen Group, New London, CT, 3Outcomes Research Consultant, New York, NY, 4Pfizer Inc, Groton, CT, USA Background: painDETECT is a screening measure for neuropathic pain. The nine-item version consists of seven sensory items (burning, tingling/prickling, light touching, sudden pain attacks/electric shock-type pain, cold/heat, numbness, and slight pressure, a pain course pattern item, and a pain radiation item. The seven-item version consists only of the sensory items. Total scores of both versions discriminate average pain-severity levels (mild, moderate, and severe, but their ability to discriminate individual item severity has not been evaluated.Methods: Data were from a cross-sectional, observational study of six neuropathic pain conditions (N=624. Average pain severity was evaluated using the Brief Pain Inventory-Short Form, with severity levels defined using established cut points for distinguishing mild, moderate, and severe pain. The Wilcoxon rank sum test was followed by ridit analysis to represent the probability that a randomly selected subject from one average pain-severity level had a more favorable outcome on the specific painDETECT item relative to a randomly selected subject from a comparator severity level.Results: A probability >50% for a better outcome (less severe pain was significantly observed for each pain symptom item. The lowest probability was 56.3% (on numbness for mild vs moderate pain and highest probability was 76.4% (on cold/heat for mild vs severe pain. The pain radiation item was significant (P<0.05 and consistent with pain symptoms, as well as with total scores for both painDETECT versions; only the pain course item did not differ.Conclusion: painDETECT differentiates severity such that the ability to discriminate average pain also distinguishes individual pain item severity in an interpretable manner. Pain

Power generation statistics

International Nuclear Information System (INIS)

Kangas, H.

2001-01-01

The frost in February increased the power demand in Finland significantly. The total power consumption in Finland during January-February 2001 was about 4% higher than a year before. In January 2001 the average temperature in Finland was only about - 4 deg C, which is nearly 2 degrees higher than in 2000 and about 6 degrees higher than long term average. Power demand in January was slightly less than 7.9 TWh, being about 0.5% less than in 2000. The power consumption in Finland during the past 12 months exceeded 79.3 TWh, which is less than 2% higher than during the previous 12 months. In February 2001 the average temperature was - 10 deg C, which was about 5 degrees lower than in February 2000. Because of this the power consumption in February 2001 increased by 5%. Power consumption in February was 7.5 TWh. The maximum hourly output of power plants in Finland was 13310 MW. Power consumption of Finnish households in February 2001 was about 10% higher than in February 2000, and in industry the increase was nearly zero. The utilization rate in forest industry in February 2001 decreased from the value of February 2000 by 5%, being only about 89%. The power consumption of the past 12 months (Feb. 2000 - Feb. 2001) was 79.6 TWh. Generation of hydroelectric power in Finland during January - February 2001 was 10% higher than a year before. The generation of hydroelectric power in Jan. - Feb. 2001 was nearly 2.7 TWh, corresponding to 17% of the power demand in Finland. The output of hydroelectric power in Finland during the past 12 months was 14.7 TWh. The increase from the previous 12 months was 17% corresponding to over 18% of the power demand in Finland. Wind power generation in Jan. - Feb. 2001 was exceeded slightly 10 GWh, while in 2000 the corresponding output was 20 GWh. The degree of utilization of Finnish nuclear power plants in Jan. - Feb. 2001 was high. The output of these plants was 3.8 TWh, being about 1% less than in Jan. - Feb. 2000. The main cause for the

On critical cases in limit theory for stationary increments Lévy driven moving averages

DEFF Research Database (Denmark)

Basse-O'Connor, Andreas; Podolskij, Mark

averages. The limit theory heavily depends on the interplay between the given order of the increments, the considered power, the Blumenthal-Getoor index of the driving pure jump Lévy process L and the behavior of the kernel function g at 0. In this work we will study the critical cases, which were...

Pulsed high-power beams

International Nuclear Information System (INIS)

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

1988-01-01

The marriage of induction linac technology with nonlinear magnetic modulators has produced some unique capabilities. It is now possible to produce short-pulse electron beams with average currents measured in amperes, at gradients approaching 1-MeV/m, and with power efficiencies exceeding 50%. This paper reports on a 70-MeV, 3-kA induction accelerator (ETA II) constructed at the Lawrence Livermore National Laboratory that incorporates the pulse technology concepts that have evolved over the past several years. The ETA II is a linear induction accelerator and provides a test facility for demonstration of the high-average-power components and high-brightness sources used in such accelerators. The pulse drive of the accelerator is based on state-of-the-art magnetic pulse compressors with very high peak-power capability, repetition rates exceeding 1 kHz, and excellent reliability

Peak-to-average power ratio reduction in orthogonal frequency division multiplexing-based visible light communication systems using a modified partial transmit sequence technique

Science.gov (United States)

Liu, Yan; Deng, Honggui; Ren, Shuang; Tang, Chengying; Qian, Xuewen

2018-01-01

We propose an efficient partial transmit sequence technique based on genetic algorithm and peak-value optimization algorithm (GAPOA) to reduce high peak-to-average power ratio (PAPR) in visible light communication systems based on orthogonal frequency division multiplexing (VLC-OFDM). By analysis of hill-climbing algorithm's pros and cons, we propose the POA with excellent local search ability to further process the signals whose PAPR is still over the threshold after processed by genetic algorithm (GA). To verify the effectiveness of the proposed technique and algorithm, we evaluate the PAPR performance and the bit error rate (BER) performance and compare them with partial transmit sequence (PTS) technique based on GA (GA-PTS), PTS technique based on genetic and hill-climbing algorithm (GH-PTS), and PTS based on shuffled frog leaping algorithm and hill-climbing algorithm (SFLAHC-PTS). The results show that our technique and algorithm have not only better PAPR performance but also lower computational complexity and BER than GA-PTS, GH-PTS, and SFLAHC-PTS technique.

A novel power spectrum calculation method using phase-compensation and weighted averaging for the estimation of ultrasound attenuation.

Science.gov (United States)

Heo, Seo Weon; Kim, Hyungsuk

2010-05-01

An estimation of ultrasound attenuation in soft tissues is critical in the quantitative ultrasound analysis since it is not only related to the estimations of other ultrasound parameters, such as speed of sound, integrated scatterers, or scatterer size, but also provides pathological information of the scanned tissue. However, estimation performances of ultrasound attenuation are intimately tied to the accurate extraction of spectral information from the backscattered radiofrequency (RF) signals. In this paper, we propose two novel techniques for calculating a block power spectrum from the backscattered ultrasound signals. These are based on the phase-compensation of each RF segment using the normalized cross-correlation to minimize estimation errors due to phase variations, and the weighted averaging technique to maximize the signal-to-noise ratio (SNR). The simulation results with uniform numerical phantoms demonstrate that the proposed method estimates local attenuation coefficients within 1.57% of the actual values while the conventional methods estimate those within 2.96%. The proposed method is especially effective when we deal with the signal reflected from the deeper depth where the SNR level is lower or when the gated window contains a small number of signal samples. Experimental results, performed at 5MHz, were obtained with a one-dimensional 128 elements array, using the tissue-mimicking phantoms also show that the proposed method provides better estimation results (within 3.04% of the actual value) with smaller estimation variances compared to the conventional methods (within 5.93%) for all cases considered. Copyright 2009 Elsevier B.V. All rights reserved.

Combined peak-to-average power ratio reduction and physical layer security enhancement in optical orthogonal frequency division multiplexing visible-light communication systems

Science.gov (United States)

Wang, Zhongpeng; Chen, Shoufa

2016-07-01

A physical encryption scheme for discrete Hartley transform (DHT) precoded orthogonal frequency division multiplexing (OFDM) visible-light communication (VLC) systems using frequency domain chaos scrambling is proposed. In the scheme, the chaos scrambling, which is generated by a modified logistic mapping, is utilized to enhance the physical layer of security, and the DHT precoding is employed to reduce of OFDM signal for OFDM-based VLC. The influence of chaos scrambling on peak-to-average power ratio (PAPR) and bit error rate (BER) of systems is studied. The experimental simulation results prove the efficiency of the proposed encryption method for DHT-precoded, OFDM-based VLC systems. Furthermore, the influence of the proposed encryption to the PAPR and BER of systems is evaluated. The experimental results show that the proposed security scheme can protect the DHT-precoded, OFDM-based VLC from eavesdroppers, while keeping the good BER performance of DHT-precoded systems. The BER performance of the encrypted and DHT-precoded system is almost the same as that of the conventional DHT-precoded system without encryption.

Nuclear Power Prospects

International Nuclear Information System (INIS)

Cintra do Prado, L.

1966-01-01

The present trend is to construct larger plants: the average power of the plants under construction at present, including prototypes, is 300 MW(e), i.e. three times higher than in the case of plants already in operation. Examples of new large-scale plants ares (a) Wylfa, Anglesey, United Kingdom - scheduled power of 1180 MW(e) (800 MW to be installed by 1967), to be completed in 1968; (b) ''Dungeness B'', United Kingdom - scheduled power of 1200 MW(e); (c) second unit for United States Dresden power plant - scheduled power of 715 MW(e) minimum to almost 800 MW(e). Nuclear plants on the whole serve the same purpose as conventional thermal plants

Bayesian model averaging and weighted average least squares : Equivariance, stability, and numerical issues

NARCIS (Netherlands)

De Luca, G.; Magnus, J.R.

2011-01-01

In this article, we describe the estimation of linear regression models with uncertainty about the choice of the explanatory variables. We introduce the Stata commands bma and wals, which implement, respectively, the exact Bayesian model-averaging estimator and the weighted-average least-squares

A Highest Order Hypothesis Compatibility Test for Monocular SLAM

OpenAIRE

Edmundo Guerra; Rodrigo Munguia; Yolanda Bolea; Antoni Grau

2013-01-01

Simultaneous Location and Mapping (SLAM) is a key problem to solve in order to build truly autonomous mobile robots. SLAM with a unique camera, or monocular SLAM, is probably one of the most complex SLAM variants, based entirely on a bearing-only sensor working over six DOF. The monocular SLAM method developed in this work is based on the Delayed Inverse-Depth (DI-D) Feature Initialization, with the contribution of a new data association batch validation technique, the Highest Order Hyp...

An approach of raising the low power reactor trip block (P-7) in Maanshan Power Plant

International Nuclear Information System (INIS)

Wang, L.C.

1984-01-01

The technical specification for the Maanshan Nuclear Power Station (FSAR Table 16.2.2-3) requires that with an increasing reactor power level above the setpoint of low power reactor trip block (P-7), a turbine trip shall initiate a reactor trip. This anticipatory reactor trip on turbine trip prevents the pressurizer PORV from openning during turbine trip event. In order to reduce unnecessary reactor trip due to turbine trip on low reactor power level during Maanshan start-up stage, Taiwan Power Company performed a transient analysis for turbine trip event by using RETRAN code. The highest reactor power level at which a turbine trip will not open the pressurizer PORV is searched. The results demonstrated that this power level can be increased from the original value-10% of the rated thermal power-to about 48% of the rated thermal power

Propulsion element requirements using electrical power system unscheduled power

Science.gov (United States)

Zimmermann, Frank; Hodge, Kathy

1989-01-01

The suitability of using the electrical energy from the Space Station's Electrical Power System (EPS) during the periods of peak solar insolation which is currently not specifically allocated (unscheduled power) to produce propulsion propellants, gaseous hydrogen, and oxygen by electrolyzing water is investigated. Reboost propellant requirements are emphasized, but the results are more generally relevant because the balance of recurring propellant requirements are an order of magnitude smaller and the nonrecurring requirements are not significant on an average basis.

Initial Beam Dynamics Simulations of a High-Average-Current Field-Emission Electron Source in a Superconducting RadioFrequency Gun

Energy Technology Data Exchange (ETDEWEB)

Mohsen, O. [Northern Illinois U.; Gonin, I. [Fermilab; Kephart, R. [Fermilab; Khabiboulline, T. [Fermilab; Piot, P. [Northern Illinois U.; Solyak, N. [Fermilab; Thangaraj, J. C. [Fermilab; Yakovlev, V. [Fermilab

2018-01-05

High-power electron beams are sought-after tools in support to a wide array of societal applications. This paper investigates the production of high-power electron beams by combining a high-current field-emission electron source to a superconducting radio-frequency (SRF) cavity. We especially carry out beam-dynamics simulations that demonstrate the viability of the scheme to form $\\sim$ 300 kW average-power electron beam using a 1+1/2-cell SRF gun.

Wind power and market power in competitive markets

International Nuclear Information System (INIS)

Twomey, Paul; Neuhoff, Karsten

2010-01-01

Average market prices for intermittent generation technologies are lower than for conventional generation. This has a technical reason but can be exaggerated in the presence of market power. When there is much wind smaller amounts of conventional generation technologies are required, and prices are lower, while at times of little wind prices are higher. This effect reflects the value of different generation technologies to the system. But under conditions of market power, conventional generators with market power can further depress the prices if they have to buy back energy at times of large wind output and can increase prices if they have to sell additional power at times of little wind output. This greatly exaggerates the effect. Forward contracting does not reduce the effect. An important consequence is that allowing market power profit margins as a support mechanism for generation capacity investment is not a technologically neutral policy.

Soft power as part of China's strategy for national image cultivation

DEFF Research Database (Denmark)

Overgaard, Signe

In recent years soft power has become a key issue at the highest political level in China, focusing especially on cultural soft power. This is reflected in important political documents, such as five year plans, plenum meeting summaries, as well as speeches by Hu Jintao and other politicians...... at the highest level. This interest in soft power is generally seen as part of an important foreign policy shift, and the huge amounts of money spent by the government on cultural diplomacy testify to the importance attached to it. Understanding what might be the goal of China’s soft power strategy is however...... difficult. The question can be analysed from various perspectives focusing on the use of power, the peaceful development discourse, or national image cultivation, and finding a straight forward answer is therefore difficult. If we go deeper and see the soft power discourse in the context of the worries...

Nuclear Power in South-Central Brazil

International Nuclear Information System (INIS)

Cintra do Prado, L.

1966-01-01

The region of South-Central Brazil includes the states of Sao Paulo, Rio de Janeiro, Guanabara and Minas Gerais. The most recent power study was made by Canambra Engineering Consultants Limited. This group reported that the public-grid electricity output for the area in 1962 was 2.16 GW (average generation), with an installed capacity of 3.41 GW and annual mean load factor of 63.4; an increase in power requirements for 1970 was forecast, corresponding to an average output of 5.37 GW and an installed capacity of 8.3 GW. This forecast was based on an annual growth rate of 11.9% in generation. ''The energy requirements have grown at an average annual rate of 10.9% since 1955; however, the present forecast is based on the assumption of power being available as required, and hence includes the suppressed demand resulting from existing restrictions in generating and distribution capacity''

A Statistical Model for Uplink Intercell Interference with Power Adaptation and Greedy Scheduling

KAUST Repository

Tabassum, Hina

2012-10-03

This paper deals with the statistical modeling of uplink inter-cell interference (ICI) considering greedy scheduling with power adaptation based on channel conditions. The derived model is implicitly generalized for any kind of shadowing and fading environments. More precisely, we develop a generic model for the distribution of ICI based on the locations of the allocated users and their transmit powers. The derived model is utilized to evaluate important network performance metrics such as ergodic capacity, average fairness and average power preservation numerically. Monte-Carlo simulation details are included to support the analysis and show the accuracy of the derived expressions. In parallel to the literature, we show that greedy scheduling with power adaptation reduces the ICI, average power consumption of users, and enhances the average fairness among users, compared to the case without power adaptation. © 2012 IEEE.

A Statistical Model for Uplink Intercell Interference with Power Adaptation and Greedy Scheduling

KAUST Repository

Tabassum, Hina; Yilmaz, Ferkan; Dawy, Zaher; Alouini, Mohamed-Slim

2012-01-01

This paper deals with the statistical modeling of uplink inter-cell interference (ICI) considering greedy scheduling with power adaptation based on channel conditions. The derived model is implicitly generalized for any kind of shadowing and fading environments. More precisely, we develop a generic model for the distribution of ICI based on the locations of the allocated users and their transmit powers. The derived model is utilized to evaluate important network performance metrics such as ergodic capacity, average fairness and average power preservation numerically. Monte-Carlo simulation details are included to support the analysis and show the accuracy of the derived expressions. In parallel to the literature, we show that greedy scheduling with power adaptation reduces the ICI, average power consumption of users, and enhances the average fairness among users, compared to the case without power adaptation. © 2012 IEEE.

Effect of random edge failure on the average path length

Energy Technology Data Exchange (ETDEWEB)

Guo Dongchao; Liang Mangui; Li Dandan; Jiang Zhongyuan, E-mail: mgliang58@gmail.com, E-mail: 08112070@bjtu.edu.cn [Institute of Information Science, Beijing Jiaotong University, 100044, Beijing (China)

2011-10-14

We study the effect of random removal of edges on the average path length (APL) in a large class of uncorrelated random networks in which vertices are characterized by hidden variables controlling the attachment of edges between pairs of vertices. A formula for approximating the APL of networks suffering random edge removal is derived first. Then, the formula is confirmed by simulations for classical ER (Erdoes and Renyi) random graphs, BA (Barabasi and Albert) networks, networks with exponential degree distributions as well as random networks with asymptotic power-law degree distributions with exponent {alpha} > 2. (paper)

Are powerful females powerful enough? Acceleration in gravid green iguanas (Iguana iguana).

Science.gov (United States)

Scales, Jeffrey; Butler, Marguerite

2007-08-01

One demand placed exclusively on the musculoskeletal system of females is maintaining locomotor performance with an increasing load over the reproductive cycle. Here, we examine whether gravid (i.e., "pregnant") iguanas can increase their force and power production to support, stabilize, and accelerate the additional mass of a clutch of eggs. At any acceleration, gravid iguanas produced very high mechanical power (average total power = 673 w/kg; total peak power = 1175 w/kg). While the increase in total power was partly a result of greater propulsive power (average propulsive power = 25% higher, peak propulsive power = 38% higher), increased vertical power (roughly 200% increase) was the main contributor. Gravid iguanas were also able to increase peak forces (propulsive = 23%, mediolateral = 44%, vertical = 42%), and step duration (44%) resulting in greater impulses (i.e., the sum of force produced during a step) to accelerate, balance, and support their increased mass. The increase in step duration and smaller increase in peak propulsive force suggests that gravid iguanas may be force-limited in the direction of motion. We discuss how biomechanical constraints due to females' reproductive role may influence the evolution of the female musculoskeletal systems and contribute to the evolution and maintenance of ecological dimorphism in lizards.

High power diode pumped solid state lasers

International Nuclear Information System (INIS)

Solarz, R.; Albrecht, G.; Beach, R.; Comaskey, B.

1992-01-01

Although operational for over twenty years, diode pumped solid state lasers have, for most of their existence, been limited to individual diodes pumping a tiny volume of active medium in an end pumped configuration. More recent years have witnessed the appearance of diode bars, packing around 100 diodes in a 1 cm bar which have enabled end and side pumped small solid state lasers at the few Watt level of output. This paper describes the subsequent development of how proper cooling and stacking of bars enables the fabrication of multi kill average power diode pump arrays with irradiances of 1 kw/cm peak and 250 W/cm 2 average pump power. Since typical conversion efficiencies from the diode light to the pumped laser output light are of order 30% or more, kW average power diode pumped solid state lasers now are possible

Dynamic average modeling of a bidirectional solid state transformer for feasibility studies and real-time implementation

OpenAIRE

Martínez Velasco, Juan Antonio; Alepuz Menéndez, Salvador; Gonzalez Molina, Francisco; Martín Arnedo, Jacinto

2014-01-01

Detailed switching models of power electronics devices often lead to long computing times, limiting the size of the system to be simulated. This drawback is especially important when the goal is to implement the model in a real-time simulation platform. An alternative is to use dynamic average models (DAM) for analyzing the dynamic behavior of power electronic devices. This paper presents the development of a DAM for a bidirectional solid-state transformer and its implementation in a real-tim...

Averaging in spherically symmetric cosmology

International Nuclear Information System (INIS)

Coley, A. A.; Pelavas, N.

2007-01-01

The averaging problem in cosmology is of fundamental importance. When applied to study cosmological evolution, the theory of macroscopic gravity (MG) can be regarded as a long-distance modification of general relativity. In the MG approach to the averaging problem in cosmology, the Einstein field equations on cosmological scales are modified by appropriate gravitational correlation terms. We study the averaging problem within the class of spherically symmetric cosmological models. That is, we shall take the microscopic equations and effect the averaging procedure to determine the precise form of the correlation tensor in this case. In particular, by working in volume-preserving coordinates, we calculate the form of the correlation tensor under some reasonable assumptions on the form for the inhomogeneous gravitational field and matter distribution. We find that the correlation tensor in a Friedmann-Lemaitre-Robertson-Walker (FLRW) background must be of the form of a spatial curvature. Inhomogeneities and spatial averaging, through this spatial curvature correction term, can have a very significant dynamical effect on the dynamics of the Universe and cosmological observations; in particular, we discuss whether spatial averaging might lead to a more conservative explanation of the observed acceleration of the Universe (without the introduction of exotic dark matter fields). We also find that the correlation tensor for a non-FLRW background can be interpreted as the sum of a spatial curvature and an anisotropic fluid. This may lead to interesting effects of averaging on astrophysical scales. We also discuss the results of averaging an inhomogeneous Lemaitre-Tolman-Bondi solution as well as calculations of linear perturbations (that is, the backreaction) in an FLRW background, which support the main conclusions of the analysis

Emissions from cycling of thermal power plants in electricity systems with high penetration of wind power: Life cycle assessment for Ireland

DEFF Research Database (Denmark)

Turconi, Roberto; O'Dwyer, C.; Flynn, D.

2014-01-01

demand. The environmental impacts related to potential future energy systems in Ireland for 2025 with high shares of wind power were evaluated using life cycle assessment (LCA), focusing on cycling emissions (due to part-load operation and start-ups) from dispatchable generators. Part-load operations...... significantly affect the average power plant efficiency, with all units seeing an average yearly efficiency noticeably less than optimal. In particular, load following units, on average, saw an 11% reduction. Given that production technologies are typically modeled assuming steady-state operation at full load...

How long the singular value decomposed entropy predicts the stock market? - Evidence from the Dow Jones Industrial Average Index

Science.gov (United States)

Gu, Rongbao; Shao, Yanmin

2016-07-01

In this paper, a new concept of multi-scales singular value decomposition entropy based on DCCA cross correlation analysis is proposed and its predictive power for the Dow Jones Industrial Average Index is studied. Using Granger causality analysis with different time scales, it is found that, the singular value decomposition entropy has predictive power for the Dow Jones Industrial Average Index for period less than one month, but not for more than one month. This shows how long the singular value decomposition entropy predicts the stock market that extends Caraiani's result obtained in Caraiani (2014). On the other hand, the result also shows an essential characteristic of stock market as a chaotic dynamic system.

Reactor power control device

International Nuclear Information System (INIS)

Kobayashi, Akira.

1980-01-01

Purpose: To prevent misoperation in a control system for the adjustment of core coolant flow rate, and the increase in the neutron flux density caused from the misoperation in BWR type reactors. Constitution: In a reactor power control system adapted to control the reactor power by the adjustment of core flow rate, average neutron flux signals of a reactor core, entire core flow rate signals and operation state signals for coolant recycling system are inputted to a microcomputer. The outputs from the computer are sent to a recycling MG set speed controller to control the reactor core flow rate. The computer calculates the change ratio with time in the average neutron flux signals, correlation between the average neutron flux signals and the entire core flow rate signals, change ratio with time in the operation state signals for the coolant recycling system and the like and judges the abnormality in the coolant recycling system based on the calculated results. (Ikeda, J.)

Analysis of mercury in rock varnish samples in areas impacted by coal-fired power plants

International Nuclear Information System (INIS)

Nowinski, Piotr; Hodge, Vernon F.; Gerstenberger, Shawn; Cizdziel, James V.

2013-01-01

Rock varnish is a manganese–iron rich coating that forms on rocks, most often in arid climates. To assess its utility as an environmental monitor of mercury contamination, cold vapor atomic absorption spectrometry (CVAAS) was used for analysis. Samples were collected in the fallout patterns of two coal-fired power plants in southern Nevada: the defunct Mohave Power Plant (MPP) and the operating Reid Gardner Power Plant (RGPP). The resultant Hg concentrations in rock varnishes were plotted as a function of the distance from each power plant. The highest concentrations of Hg occurred at locations that suggest the power plants are the main source of pollutants. In addition, past tracer plume studies carried out at MPP show that the highest tracer concentrations coincide with the highest rock varnish Hg concentrations. However, additional samples are required to further demonstrate that power plants are indeed the sources of mercury in varnishes. -- Highlights: •We analyze desert varnish samples collected in the fallout patterns of two coal-fired and analyzed for Hg by CVAA. •The resultant Hg concentrations in the desert varnish samples were plotted as a function of the distance from each power plant. •The highest concentrations of Hg occurred at locations that suggest the power plants are the main source of pollutants. •Data indicate the utility of desert varnish as a passive environmental monitor for Hg atmospheric pollution. -- Cold vapor atomic absorption spectrometry (CVAAS) was used for analysis of mercury in varnished rocks collected in the fallout zones of two coal-fired power plants

Wind power, distrubted generation and transmission

DEFF Research Database (Denmark)

Østergaard, Poul Alberg

the possibilities for integration of even more wind power using new power balancing strategies that exploit the possibilities given by the existence of CHP plants as well as the impact of heat pumps for district heating. The analyses demonstrate that it is possible to accommodate 50% or more wind power without......Denmark has the World?s highest penetration of wind power in electricity generation with a share of 15.0% of total domestic demand in 2002 (DEA, 2004). This is unevenly distributed in the two electricity systems of Denmark giving a share as high as 20.7% in Western Denmark in 2003 up from 18...... power balancing strategies are not applied, costly grid expansions will follow expansions in installed wind power capacity....

How to average logarithmic retrievals?

Directory of Open Access Journals (Sweden)

B. Funke

2012-04-01

Full Text Available Calculation of mean trace gas contributions from profiles obtained by retrievals of the logarithm of the abundance rather than retrievals of the abundance itself are prone to biases. By means of a system simulator, biases of linear versus logarithmic averaging were evaluated for both maximum likelihood and maximum a priori retrievals, for various signal to noise ratios and atmospheric variabilities. These biases can easily reach ten percent or more. As a rule of thumb we found for maximum likelihood retrievals that linear averaging better represents the true mean value in cases of large local natural variability and high signal to noise ratios, while for small local natural variability logarithmic averaging often is superior. In the case of maximum a posteriori retrievals, the mean is dominated by the a priori information used in the retrievals and the method of averaging is of minor concern. For larger natural variabilities, the appropriateness of the one or the other method of averaging depends on the particular case because the various biasing mechanisms partly compensate in an unpredictable manner. This complication arises mainly because of the fact that in logarithmic retrievals the weight of the prior information depends on abundance of the gas itself. No simple rule was found on which kind of averaging is superior, and instead of suggesting simple recipes we cannot do much more than to create awareness of the traps related with averaging of mixing ratios obtained from logarithmic retrievals.

Assessment of an Average Controller for a DC/DC Converter via Either a PWM or a Sigma-Delta-Modulator

Directory of Open Access Journals (Sweden)

R. Silva-Ortigoza

2014-01-01

Full Text Available Sliding mode control is a discontinuous control technique that is, by its nature, appropriate for controlling variable structure systems, such as the switch regulated systems employed in power electronics. However, when designing control laws based on the average models of these systems a modulator is necessary for their experimental implementation. Among the most widely used modulators in power electronics are the pulse width modulation (PWM and, more recently, the sigma-delta-modulator (Σ-Δ-modulator. Based on the importance of achieving an appropriate implementation of average control laws and the relevance of the trajectory tracking task in DC/DC power converters, for the first time, this research presents the assessment of the experimental results obtained when one of these controllers is implemented through either a PWM or a Σ-Δ-modulator to perform such a task. A comparative assessment based on the integral square error (ISE index shows that, at frequencies with similar efficiency, the Σ-Δ-modulator provides a better tracking performance for the DC/DC Buck converter. In this paper, an average control based on differential flatness was used to perform the experiments. It is worth mentioning that a different trajectory tracking controller could have been selected for this research.

Business case uncertainty of power plants in future energy systems with wind power

International Nuclear Information System (INIS)

Brouwer, Anne Sjoerd; Broek, Machteld van den; Özdemir, Özge; Koutstaal, Paul; Faaij, André

2016-01-01

The European power sector is transforming due to climate policies and an increased deployment of intermittent RES. The sector will require thermal power plants for the decades to come, but their business cases are (negatively) affected by this transformation. This study presents a novel tool to quantify the effect of policy, price and project-related uncertainties on power plant business cases. This tool can support policymakers in stimulating necessary investments in new thermal generation capacity. We find that these investments are currently unsound (power plants recoup on average –12% to 59% of their initial investment). Future climate policy, i.e. the CO_2 price, has a very strong impact on business cases (affects the profitability by 5–40%-points). The impact of the deployment of wind power is average (2–8%-point difference between 10% and 21% wind penetration). Variations in annual wind power production barely affect the profitability (variation of ±1%-point). To stimulate new investments, policymakers should first decrease the uncertainty in business cases caused by policy. Durable climate policy is especially important. Also, policies to increase the profits of thermal power plants should be carefully considered and implemented. This combined approach will reduce the revenue gap that needs to be bridged by supportive policies. - Highlights: • The operation of thermal power plants is affected by CO_2 prices and wind power. • A new tool quantifies the effect of their uncertainty on power plant profitability. • New power plants are unprofitable and show a large spread in expected profits. • Uncertain future climate policy is a key factor in all business cases (±56% change). • Increasing wind power penetration (10–21%) decreases profitability by 14%.

Impact of connected vehicle guidance information on network-wide average travel time

Directory of Open Access Journals (Sweden)

Jiangfeng Wang

2016-12-01

Full Text Available With the emergence of connected vehicle technologies, the potential positive impact of connected vehicle guidance on mobility has become a research hotspot by data exchange among vehicles, infrastructure, and mobile devices. This study is focused on micro-modeling and quantitatively evaluating the impact of connected vehicle guidance on network-wide travel time by introducing various affecting factors. To evaluate the benefits of connected vehicle guidance, a simulation architecture based on one engine is proposed representing the connected vehicle–enabled virtual world, and connected vehicle route guidance scenario is established through the development of communication agent and intelligent transportation systems agents using connected vehicle application programming interface considering the communication properties, such as path loss and transmission power. The impact of connected vehicle guidance on network-wide travel time is analyzed by comparing with non-connected vehicle guidance in response to different market penetration rate, following rate, and congestion level. The simulation results explore that average network-wide travel time in connected vehicle guidance shows a significant reduction versus that in non–connected vehicle guidance. Average network-wide travel time in connected vehicle guidance have an increase of 42.23% comparing to that in non-connected vehicle guidance, and average travel time variability (represented by the coefficient of variance increases as the travel time increases. Other vital findings include that higher penetration rate and following rate generate bigger savings of average network-wide travel time. The savings of average network-wide travel time increase from 17% to 38% according to different congestion levels, and savings of average travel time in more serious congestion have a more obvious improvement for the same penetration rate or following rate.

Experimental assessment of blade tip immersion depth from free surface on average power and thrust coefficients of marine current turbine

Science.gov (United States)

Lust, Ethan; Flack, Karen; Luznik, Luksa

2014-11-01

Results from an experimental study on the effects of marine current turbine immersion depth from the free surface are presented. Measurements are performed with a 1/25 scale (diameter D = 0.8m) two bladed horizontal axis turbine towed in the large towing tank at the U.S. Naval Academy. Thrust and torque are measured using a dynamometer, mounted in line with the turbine shaft. Shaft rotation speed and blade position are measured using a shaft position indexing system. The tip speed ratio (TSR) is adjusted using a hysteresis brake which is attached to the output shaft. Two optical wave height sensors are used to measure the free surface elevation. The turbine is towed at 1.68 m/s, resulting in a 70% chord based Rec = 4 × 105. An Acoustic Doppler Velocimeter (ADV) is installed one turbine diameter upstream of the turbine rotation plane to characterize the inflow turbulence. Measurements are obtained at four relative blade tip immersion depths of z/D = 0.5, 0.4, 0.3, and 0.2 at a TSR value of 7 to identify the depth where free surface effects impact overall turbine performance. The overall average power and thrust coefficient are presented and compared to previously conducted baseline tests. The influence of wake expansion blockage on the turbine performance due to presence of the free surface at these immersion depths will also be discussed.

Wind Power Potential at Abandoned Mines in Korea

Science.gov (United States)

jang, M.; Choi, Y.; Park, H.; Go, W.

2013-12-01

This study performed an assessment of wind power potential at abandoned mines in the Kangwon province by analyzing gross energy production, greenhouse gas emission reduction and economic effects estimated from a 600 kW wind turbine. Wind resources maps collected from the renewable energy data center in Korea Institute of Energy Research(KIER) were used to determine the average wind speed, temperature and atmospheric pressure at hub height(50 m) for each abandoned mine. RETScreen software developed by Natural Resources Canada(NRC) was utilized for the energy, emission and financial analyses of wind power systems. Based on the results from 5 representative mining sites, we could know that the average wind speed at hub height is the most critical factor for assessing the wind power potential. Finally, 47 abandoned mines that have the average wind speed faster than 6.5 m/s were analyzed, and top 10 mines were suggested as relatively favorable sites with high wind power potential in the Kangwon province.

Competition and Cooperation of Distributed Generation and Power System

Science.gov (United States)

Miyake, Masatoshi; Nanahara, Toshiya

Advances in distributed generation technologies together with the deregulation of an electric power industry can lead to a massive introduction of distributed generation. Since most of distributed generation will be interconnected to a power system, coordination and competition between distributed generators and large-scale power sources would be a vital issue in realizing a more desirable energy system in the future. This paper analyzes competitions between electric utilities and cogenerators from the viewpoints of economic and energy efficiency based on the simulation results on an energy system including a cogeneration system. First, we examine best response correspondence of an electric utility and a cogenerator with a noncooperative game approach: we obtain a Nash equilibrium point. Secondly, we examine the optimum strategy that attains the highest social surplus and the highest energy efficiency through global optimization.

The JLab high power ERL light source

International Nuclear Information System (INIS)

Neil, G.R.; Behre, C.; Benson, S.V.

2006-01-01

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 160MeV electron beam and an average current of 10mA in 75MHz 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 ∼ half cycle pulse whose average brightness is >5 orders of magnitude higher than synchrotron IR sources. Previous measurements showed 20W of average power extracted [Carr, et al., Nature 420 (2002) 153]. The new facility offers simultaneous synchrotron light from the visible through the FIR along with broadband THz production of 100fs pulses with >200W of average power. The FELs also provide record-breaking laser power [Neil, et al., Phys. Rev. Lett. 84 (2000) 662]: up to 10kW of average power in the IR from 1 to 14μm in 400fs pulses at up to 74.85MHz repetition rates and soon will produce similar pulses of 300-1000nm light at up to 3kW 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 10ms 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

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

Wind speed power spectrum analysis for Bushland, Texas

Energy Technology Data Exchange (ETDEWEB)

Eggleston, E.D. [USDA-Agricultural Research Service, Bushland, TX (United States)

1996-12-31

Numerous papers and publications on wind turbulence have referenced the wind speed spectrum presented by Isaac Van der Hoven in his article entitled Power Spectrum of Horizontal Wind Speed Spectrum in the Frequency Range from 0.0007 to 900 Cycles per Hour. Van der Hoven used data measured at different heights between 91 and 125 meters above the ground, and represented the high frequency end of the spectrum with data from the peak hour of hurricane Connie. These facts suggest we should question the use of his power spectrum in the wind industry. During the USDA - Agricultural Research Service`s investigation of wind/diesel system power storage, using the appropriate wind speed power spectrum became a significant issue. We developed a power spectrum from 13 years of hourly average data, 1 year of 5 minute average data, and 2 particularly gusty day`s 1 second average data all collected at a height of 10 meters. While the general shape is similar to the Van der Hoven spectrum, few of his peaks were found in the Bushland spectrum. While higher average wind speeds tend to suggest higher amplitudes in the high frequency end of the spectrum, this is not always true. Also, the high frequency end of the spectrum is not accurately described by simple wind statistics such as standard deviation and turbulence intensity. 2 refs., 5 figs., 1 tab.

Experimental study on a resorption system for power and refrigeration cogeneration

International Nuclear Information System (INIS)

Jiang, L.; Wang, L.W.; Liu, C.Z.; Wang, R.Z.

2016-01-01

Energy conversion technologies, especially for power generation and refrigeration technologies driven by the low temperature heat, are gathering the momentum recently. This paper presents a novel resorption system for electricity and refrigeration cogeneraion. Compared with adsorption refrigeration system, resorption refrigeration is characterized as safety and simple structure since there is no ammonia liquid in the system. The cogeneration system is mainly composed of three HTS (high temperature salt) unit beds; three LTS (low temperature salts) unit beds, one expander, three ammonia valves, two oil valves, four water valves and connection pipes. Chemical working pair of MnCl 2 –CaCl 2 –NH 3 is selected. Since scroll expander is suitable for small type power generation system, it is chosen for expansion process. 4.8 kg MnCl 2 and 3.9 kg CaCl 2 impregnated in expanded natural graphite treated with sulfuric acid (ENG-TSA) are filled in the cogeneration system. Experimental results show that maximum cooling power 2.98 kW is able to be obtained while maximum shaft power is about 253 W with 82.3 W average value. The cogeneration system can be utilized for the heat source temperature lower than 170 °C. Total energy efficiency increases from 0.293 to 0.417 then decreases to 0.407 while exergy efficiency increases from 0.12 to 0.16. - Highlights: • A resorption system for power and refrigeration cogeneration is established and investigated. • ENG-TSA as the additive improves the heat and mass performance of composite adsorbent. • The highest shaft power and refrigeration power are 253 W and 2.98 kW, respectively. • Total energy efficiency of the system increases from 0.293 to 0.417 then decreases to 0.407.

The Mass Elevation Effect of the Central Andes and Its Implications for the Southern Hemisphere's Highest Treeline

Directory of Open Access Journals (Sweden)

Wenhui He

2016-05-01

Full Text Available One of the highest treelines in the world is at 4810 m above sea level on the Sajama Volcano in the central Andes. The climatological cause of that exceptionally high treeline position is still unclear. Although it has been suggested that the mass elevation effect (MEE explains the upward shift of treelines in the Altiplano region, the magnitude of MEE has not yet been quantified for that region. This paper defines MEE as the air temperature difference in summer at the same elevation between the inner mountains/plateaus (Altiplano and the free atmosphere above the adjacent lowlands of the Andean Cordillera. The Altiplano air temperature was obtained from the Global Historical Climatology Network-Monthly temperature database, and the air temperature above the adjacent lowlands was interpolated based on the National Center for Environmental Prediction/National Center for Atmospheric Research Reanalysis 1 data set. We analyzed the mean air temperature differences for January, July, and the warm months from October to April. The air temperature was mostly higher on the Altiplano than over the neighboring lowlands at the same altitude. The air temperature difference increased from the outer Andean east-facing slope to the interior of the Altiplano in summer, and it increased from high latitudes to low latitudes in winter. The mean air temperature in the Altiplano in summer is approximately 5 K higher than it is above the adjacent lowlands at the same mean elevation, averaging about 3700 m above sea level. This upward shift of isotherms in the inner part of the Cordillera enables the treeline to climb to 4810 m, with shrub-size trees reaching even higher. Therefore, the MEE explains the occurrence of one of the world’s highest treelines in the central Andes.

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.

Low power predictable memory and processing architectures

OpenAIRE

Chen, Jiaoyan

2013-01-01

Great demand in power optimized devices shows promising economic potential and draws lots of attention in industry and research area. Due to the continuously shrinking CMOS process, not only dynamic power but also static power has emerged as a big concern in power reduction. Other than power optimization, average-case power estimation is quite significant for power budget allocation but also challenging in terms of time and effort. In this thesis, we will introduce a methodology to support mo...

On Averaging Rotations

DEFF Research Database (Denmark)

Gramkow, Claus

2001-01-01

In this paper two common approaches to averaging rotations are compared to a more advanced approach based on a Riemannian metric. Very often the barycenter of the quaternions or matrices that represent the rotations are used as an estimate of the mean. These methods neglect that rotations belong ...... approximations to the Riemannian metric, and that the subsequent corrections are inherent in the least squares estimation.......In this paper two common approaches to averaging rotations are compared to a more advanced approach based on a Riemannian metric. Very often the barycenter of the quaternions or matrices that represent the rotations are used as an estimate of the mean. These methods neglect that rotations belong...

Low flows and water temperature risks to Asian coal power plants in a warming world

Science.gov (United States)

Wang, Y.; Byers, E.; Parkinson, S.; Wanders, N.; Wada, Y.; Bielicki, J. M.

2017-12-01

Thermoelectric power generation requires cooling, normally provided by wet cooling systems. The withdrawal and discharge of cooling water are subject to regulation. Therefore, operation of power plants may be vulnerable to changes in streamflow and rises in water temperatures. In Asia, about 489 GW of coal-fired power plants are currently under construction, permitted, or announced. Using a comprehensive dataset of these planned coal power plants (PCPPs) and cooling water use models, we investigated whether electricity generation at these power plants will be limited by streamflow and water temperature. Daily streamflow and water temperature time series are from the high-resolution (0.08ox0.08o) runs of the PCRGLOBWB hydrological model, driven by downscaled meteorological forcing from five global climate models. We compared three climate change scenarios (1.5oC, 2oC, and 3oC warming in global mean temperature) and three cooling system choice scenarios (freshwater once-through, freshwater cooling tower, and "business-as-usual" - where a PCPP uses the same cooling system as the nearest existing coal power plant). The potential available capacity of the PCPPs increase slightly from the 1.5oC to the 2oC and 3oC warming scenario due to increase in streamflow. The once-through cooling scenario results in virtually zero available capacity at the PCPPs. The other two cooling scenarios result in about 20% of the planned capacity being unavailable under all warming scenarios. Hotspots of the most water-limited PCPPs are in Pakistan, northwestern India, northwestern and north-central China, and northern Vietnam, where most of the PCPPs will face 30% to 90% unavailable nameplate capacity on annual average. Since coal power plants cannot operate effectively when the capacity factor falls below a minimum load level (about 20% to 50%), the actual limitation on generation capacity would be larger. In general, the PCPPs that will have the highest limitation on annual average

A new approach to the design of the large turbofan power plant

Energy Technology Data Exchange (ETDEWEB)

Wilde, G L [Economobile Projects Ltd., Belper (United Kingdom)

1995-06-01

The lower direct operating costs of the Big Twin subsonic transports encourage the building of ever larger turbofan engines installed on the wings. The steadily improving reliability of the turbofan and the good safety statistics of twin-engined aircraft over many years encourages this trend. Fuel economy is still the dominant factor in determining the design layout of turbofan engines. It requires the combination of the highest possible thermal efficiency of the gas generator core of the engine with optimum propulsion efficiency of the power plant as a whole in cruise flight, allowing for engine nacelle drag and nacelle to wing interference drag. The paper presents two possible turbofan design layouts intended to overcome the limitation of current turbofan power plant designs. The aim is to design a power plant with the highest thrust per unit frontal area combined with the highest air miles per gallon in cruise flight. (author)

Probabilistic Linguistic Power Aggregation Operators for Multi-Criteria Group Decision Making

Directory of Open Access Journals (Sweden)

Agbodah Kobina

2017-12-01

Full Text Available As an effective aggregation tool, power average (PA allows the input arguments being aggregated to support and reinforce each other, which provides more versatility in the information aggregation process. Under the probabilistic linguistic term environment, we deeply investigate the new power aggregation (PA operators for fusing the probabilistic linguistic term sets (PLTSs. In this paper, we firstly develop the probabilistic linguistic power average (PLPA, the weighted probabilistic linguistic power average (WPLPA operators, the probabilistic linguistic power geometric (PLPG and the weighted probabilistic linguistic power geometric (WPLPG operators. At the same time, we carefully analyze the properties of these new aggregation operators. With the aid of the WPLPA and WPLPG operators, we further design the approaches for the application of multi-criteria group decision-making (MCGDM with PLTSs. Finally, we use an illustrated example to expound our proposed methods and verify their performances.

Assessment of Extremely Low Frequency (ELF Electric and Magnetic Fields in Hamedan High Electrical Power Stations and their Effects on Workers

Directory of Open Access Journals (Sweden)

Farshid Ghorbani Shahna

2011-09-01

Full Text Available Introduction: Public and occupational exposure to extremely low frequency (ELF electric and magnetic fields induced by electrical equipment is a significant issue in the environment and at the workplace due to their potential health effects on public health. The purpose of this study was assessment of the electric and magnetic fields intensities and determination of mental and psychological effects of occupational exposure in the high voltage electric power stations in the city of Hamadan, Iran. Material and Methods: The intensities of the magnetic and electric fields were measured at eight high voltage electric power stations at three different intervals of sources using an HI-3604 instrument. A two-part questionnaire was used to assess mental and psychological effects of the exposure to these fields. Two groups of control and case workers including 30 samples were selected to determine the exposure effects. Results: The results of field measurements showed the highest average electric field intensity was related to the CVT unit with 3110 V/m at a 2 m distance from the source and the lowest average was related to the control room with 1.35 V/m next to the source. Also, the highest and lowest magnetic field intensities were close to the transformator 2 and the battery room (50.42 and 1.31 mG, respectively. Discussion and Conclusion: The intensities of electric and magnetic fields in the selected stations are lower than the ACGIH and ICNIRP standard levels for occupational exposures. The results obtained indicate that the distribution of these fields was nonlinear around the sources and the effects observed on exposed workers were non-thermal.

Multi-objective optimization of MOSFETs channel widths and supply voltage in the proposed dual edge-triggered static D flip-flop with minimum average power and delay by using fuzzy non-dominated sorting genetic algorithm-II.

Science.gov (United States)

Keivanian, Farshid; Mehrshad, Nasser; Bijari, Abolfazl

2016-01-01

D Flip-Flop as a digital circuit can be used as a timing element in many sophisticated circuits. Therefore the optimum performance with the lowest power consumption and acceptable delay time will be critical issue in electronics circuits. The newly proposed Dual-Edge Triggered Static D Flip-Flop circuit layout is defined as a multi-objective optimization problem. For this, an optimum fuzzy inference system with fuzzy rules is proposed to enhance the performance and convergence of non-dominated sorting Genetic Algorithm-II by adaptive control of the exploration and exploitation parameters. By using proposed Fuzzy NSGA-II algorithm, the more optimum values for MOSFET channel widths and power supply are discovered in search space than ordinary NSGA types. What is more, the design parameters involving NMOS and PMOS channel widths and power supply voltage and the performance parameters including average power consumption and propagation delay time are linked. To do this, the required mathematical backgrounds are presented in this study. The optimum values for the design parameters of MOSFETs channel widths and power supply are discovered. Based on them the power delay product quantity (PDP) is 6.32 PJ at 125 MHz Clock Frequency, L = 0.18 µm, and T = 27 °C.

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

OpenAIRE

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 vehicles (EDV) as flexible loads can improve the system operation. Bidirectional power exchange through batteries (vehicle to grid) can be seen as a storage system in the grid. An analysis of possible e...

Power station instrumentation

International Nuclear Information System (INIS)

Jervis, M.W.

1993-01-01

Power stations are characterized by a wide variety of mechanical and electrical plant operating with structures, liquids and gases working at high pressures and temperatures and with large mass flows. The voltages and currents are also the highest that occur in most industries. In order to achieve maximum economy, the plant is operated with relatively small margins from conditions that can cause rapid plant damage, safety implications, and very high financial penalties. In common with other process industries, power stations depend heavily on control and instrumentation. These systems have become particularly significant, in the cost-conscious privatized environment, for providing the means to implement the automation implicit in maintaining safety standards, improving generation efficiency and reducing operating manpower costs. This book is for professional instrumentation engineers who need to known about their use in power stations and power station engineers requiring information about the principles and choice of instrumentation available. There are 8 chapters; chapter 4 on instrumentation for nuclear steam supply systems is indexed separately. (Author)

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.

Optimal power flow for technically feasible Energy Management systems in Islanded Microgrids

DEFF Research Database (Denmark)

Sanseverino, Eleonora Riva; T. T. Quynh, T.; Di Silvestre, Maria Luisa

2016-01-01

This paper presents a combined optimal energy and power flow management for islanded microgrids. The highest control level in this case will provide a feasible and optimized operating point around the economic optimum. In order to account for both unbalanced and balanced loads, the optimal power...... flow is carried out using a Glow-worm Swarm Optimizer. The control level is organized into two different sub-levels, the highest of which accounts for minimum cost operation and the lowest one solving the optimal power flow and devising the set points of inverter interfaced generation units...... and rotating machines with a minimum power loss. A test has been carried out for 6 bus islanded microgrids to show the efficiency and feasibility of the proposed technique....

Convergence and approximate calculation of average degree under different network sizes for decreasing random birth-and-death networks

Science.gov (United States)

Long, Yin; Zhang, Xiao-Jun; Wang, Kui

2018-05-01

In this paper, convergence and approximate calculation of average degree under different network sizes for decreasing random birth-and-death networks (RBDNs) are studied. First, we find and demonstrate that the average degree is convergent in the form of power law. Meanwhile, we discover that the ratios of the back items to front items of convergent reminder are independent of network link number for large network size, and we theoretically prove that the limit of the ratio is a constant. Moreover, since it is difficult to calculate the analytical solution of the average degree for large network sizes, we adopt numerical method to obtain approximate expression of the average degree to approximate its analytical solution. Finally, simulations are presented to verify our theoretical results.

Peak power ratio generator

Science.gov (United States)

Moyer, R.D.

A peak power ratio generator is described for measuring, in combination with a conventional power meter, the peak power level of extremely narrow pulses in the gigahertz radio frequency bands. The present invention in a preferred embodiment utilizes a tunnel diode and a back diode combination in a detector circuit as the only high speed elements. The high speed tunnel diode provides a bistable signal and serves as a memory device of the input pulses for the remaining, slower components. A hybrid digital and analog loop maintains the peak power level of a reference channel at a known amount. Thus, by measuring the average power levels of the reference signal and the source signal, the peak power level of the source signal can be determined.

Competitiveness of nuclear power generation

International Nuclear Information System (INIS)

Sumi, Yoshihiko

1998-01-01

In view of the various merits of nuclear power generation, Japanese electric utilities will continue to promote nuclear power generation. At the same time, however, it is essential to further enhance cost performance. Japanese electric utilities plan to reduce the cost of nuclear power generation, such as increasing the capacity factor, reducing operation and maintenance costs, and reducing construction costs. In Asia, nuclear power will also play an important role as a stable source of energy in the future. For those countries planning to newly introduce nuclear power, safety is the highest priority, and cost competitiveness is important. Moreover, financing will be an essential issue to be resolved. Japan is willing to support the establishment of nuclear power generation in Asia, through its experience and achievements. In doing this, support should not only be bilateral, but should include all nuclear nations around the Pacific rim in a multilateral support network. (author)

Low-peak-to-average power ratio and low-complexity asymmetrically clipped optical orthogonal frequency-division multiplexing uplink transmission scheme for long-reach passive optical network.

Science.gov (United States)

Zhou, Ji; Qiao, Yaojun

2015-09-01

In this Letter, we propose a discrete Hartley transform (DHT)-spread asymmetrically clipped optical orthogonal frequency-division multiplexing (DHT-S-ACO-OFDM) uplink transmission scheme in which the multiplexing/demultiplexing process also uses the DHT algorithm. By designing a simple encoding structure, the computational complexity of the transmitter can be reduced from O(Nlog(2)(N)) to O(N). At the probability of 10(-3), the peak-to-average power ratio (PAPR) of 2-ary pulse amplitude modulation (2-PAM)-modulated DHT-S-ACO-OFDM is approximately 9.7 dB lower than that of 2-PAM-modulated conventional ACO-OFDM. To verify the feasibility of the proposed scheme, a 4-Gbit/s DHT-S-ACO-OFDM uplink transmission scheme with a 1∶64 way split has been experimentally implemented using 100-km standard single-mode fiber (SSMF) for a long-reach passive optical network (LR-PON).

Fuel Cell and Battery Powered Forklifts

DEFF Research Database (Denmark)

Zhang, Zhe; Mortensen, Henrik H.; Jensen, Jes Vestervang

2013-01-01

A hydrogen-powered materials handling vehicle with a fuel cell combines the advantages of diesel/LPG and battery powered vehicles. Hydrogen provides the same consistent power and fast refueling capability as diesel and LPG, whilst fuel cells provide energy efficient and zero emission Electric...... propulsion similar to batteries. In this paper, the performance of a forklift powered by PEM fuel cells and lead acid batteries as auxiliary energy source is introduced and investigated. In this electromechanical propulsion system with hybrid energy/power sources, fuel cells will deliver average power...

Lagrangian averaging with geodesic mean.

Science.gov (United States)

Oliver, Marcel

2017-11-01

This paper revisits the derivation of the Lagrangian averaged Euler (LAE), or Euler- α equations in the light of an intrinsic definition of the averaged flow map as the geodesic mean on the volume-preserving diffeomorphism group. Under the additional assumption that first-order fluctuations are statistically isotropic and transported by the mean flow as a vector field, averaging of the kinetic energy Lagrangian of an ideal fluid yields the LAE Lagrangian. The derivation presented here assumes a Euclidean spatial domain without boundaries.

Averaging Principle for the Higher Order Nonlinear Schrödinger Equation with a Random Fast Oscillation

Science.gov (United States)

Gao, Peng

2018-04-01

This work concerns the problem associated with averaging principle for a higher order nonlinear Schrödinger equation perturbed by a oscillating term arising as the solution of a stochastic reaction-diffusion equation evolving with respect to the fast time. This model can be translated into a multiscale stochastic partial differential equations. Stochastic averaging principle is a powerful tool for studying qualitative analysis of stochastic dynamical systems with different time-scales. To be more precise, under suitable conditions, we prove that there is a limit process in which the fast varying process is averaged out and the limit process which takes the form of the higher order nonlinear Schrödinger equation is an average with respect to the stationary measure of the fast varying process. Finally, by using the Khasminskii technique we can obtain the rate of strong convergence for the slow component towards the solution of the averaged equation, and as a consequence, the system can be reduced to a single higher order nonlinear Schrödinger equation with a modified coefficient.

Averaging Principle for the Higher Order Nonlinear Schrödinger Equation with a Random Fast Oscillation

Science.gov (United States)

Gao, Peng

2018-06-01

This work concerns the problem associated with averaging principle for a higher order nonlinear Schrödinger equation perturbed by a oscillating term arising as the solution of a stochastic reaction-diffusion equation evolving with respect to the fast time. This model can be translated into a multiscale stochastic partial differential equations. Stochastic averaging principle is a powerful tool for studying qualitative analysis of stochastic dynamical systems with different time-scales. To be more precise, under suitable conditions, we prove that there is a limit process in which the fast varying process is averaged out and the limit process which takes the form of the higher order nonlinear Schrödinger equation is an average with respect to the stationary measure of the fast varying process. Finally, by using the Khasminskii technique we can obtain the rate of strong convergence for the slow component towards the solution of the averaged equation, and as a consequence, the system can be reduced to a single higher order nonlinear Schrödinger equation with a modified coefficient.

Contingency management of power system with Interline Power Flow Controller using Real Power Performance Index and Line Stability Index

Directory of Open Access Journals (Sweden)

Akanksha Mishra

2016-03-01

Full Text Available As a result of privatization of the electrical industry the power transmission lines have to transfer power at their maximum transmission limits because of the competitive scenario of the electrical market. Hence, secured operation of power system has become one of the most important issues of modern era. In this paper, a probability of severity based placement strategy for Interline Power Flow Controller (IPFC has been proposed based on Composite Severity Index (CSI. The composite severity index provides an exact measure of stress in the line in terms of mega watt overloading and voltage instability. IPFC is placed on the line which has the highest probability of severity during the occurrence of different outages. The IPFC has been tuned for a multi-objective function using Differential Evolution (DE and the results have been compared with genetic Algorithm (GA. To verify the proposed method, it has been tested and implemented on IEEE 14 and 57 bus systems.

On energy efficient power allocation for power-constrained systems

KAUST Repository

Sboui, Lokman

2014-09-01

Recently, the energy efficiency (EE) has become an important factor when designing new wireless communication systems. Due to economic and environmental challenges, new trends and efforts are oriented toward “green” communication especially for energy-constrained applications such as wireless sensors network and cognitive radio. To this end, we analyze the power allocation scheme that maximizes the EE defined as rate over the total power including circuit power. We derive an explicit expression of the optimal power with instantaneous channel gain based on EE criterion. We show that the relation between the EE and the spectral efficiency (SE) when the optimal power is adopted is strictly increasing in contrast with the SE-EE trade-off discussed in the literature. We also solve a non-convex problem and compute explicitly the optimal power for ergodic EE under either a peak or an average power constraint. When the instantaneous channel is not available, we provide the optimal power equation and compute simple sub-optimal power. In the numerical results, we show that the sup-optimal solution is very close to the optimal solution. In addition, we show that the absence of the channel state information (CSI) only affects the EE and the SE performances at high power regime compared to the full CSI case.

The countermovement jump to monitor neuromuscular status: A meta-analysis.

Science.gov (United States)

Claudino, João Gustavo; Cronin, John; Mezêncio, Bruno; McMaster, Daniel Travis; McGuigan, Michael; Tricoli, Valmor; Amadio, Alberto Carlos; Serrão, Julio Cerca

2017-04-01

The primary objective of this meta-analysis was to compare countermovement jump (CMJ) performance in studies that reported the highest value as opposed to average value for the purposes of monitoring neuromuscular status (i.e., fatigue and supercompensation). The secondary aim was to determine the sensitivity of the dependent variables. Systematic review with meta-analysis. The meta-analysis was conducted on the highest or average of a number of CMJ variables. Multiple literature searches were undertaken in Pubmed, Scopus, and Web of Science to identify articles utilizing CMJ to monitor training status. Effect sizes (ES) with 95% confidence interval (95% CI) were calculated using the mean and standard deviation of the pre- and post-testing data. The coefficient of variation (CV) with 95% CI was also calculated to assess the level of instability of each variable. Heterogeneity was assessed using a random-effects model. 151 articles were included providing a total of 531 ESs for the meta-analyses; 85.4% of articles used highest CMJ height, 13.2% used average and 1.3% used both when reporting changes in CMJ performance. Based on the meta-analysis, average CMJ height was more sensitive than highest CMJ height in detecting CMJ fatigue and supercompensation. Furthermore, other CMJ variables such as peak power, mean power, peak velocity, peak force, mean impulse, and power were sensitive in tracking the supercompensation effects of training. The average CMJ height was more sensitive than highest CMJ height in monitoring neuromuscular status; however, further investigation is needed to determine the sensitivity of other CMJ performance variables. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Microbial fuel cells as power supply of a low-power temperature sensor

Science.gov (United States)

Khaled, Firas; Ondel, Olivier; Allard, Bruno

2016-02-01

Microbial fuel cells (MFCs) show great promise as a concomitant process for water treatment and as renewable energy sources for environmental sensors. The small energy produced by MFCs and the low output voltage limit the applications of MFCs. Specific converter topologies are required to step-up the output voltage of a MFC. A Power Management Unit (PMU) is proposed for operation at low input voltage and at very low power in a completely autonomous way to capture energy from MFCs with the highest possible efficiency. The application of sensors for monitoring systems in remote locations is an important approach. MFCs could be an alternative energy source in this case. Powering a sensor with MFCs may prove the fact that wastewater may be partly turned into renewable energy for realistic applications. The Power Management Unit is demonstrated for 3.6 V output voltage at 1 mW continuous power, based on a low-cost 0.7-L MFC. A temperature sensor may operate continuously on 2-MFCs in continuous flow mode. A flyback converter under discontinuous conduction mode is also tested to power the sensor. One continuously fed MFC was able to efficiently and continuously power the sensor.

Output power analyses for the thermodynamic cycles of thermal power plants

International Nuclear Information System (INIS)

Sun Chen; Cheng Xue-Tao; Liang Xin-Gang

2014-01-01

Thermal power plant is one of the important thermodynamic devices, which is very common in all kinds of power generation systems. In this paper, we use a new concept, entransy loss, as well as exergy destruction, to analyze the single reheating Rankine cycle unit and the single stage steam extraction regenerative Rankine cycle unit in power plants. This is the first time that the concept of entransy loss is applied to the analysis of the power plant Rankine cycles with reheating and steam extraction regeneration. In order to obtain the maximum output power, the operating conditions under variant vapor mass flow rates are optimized numerically, as well as the combustion temperatures and the off-design flow rates of the flue gas. The relationship between the output power and the exergy destruction rate and that between the output power and the entransy loss rate are discussed. It is found that both the minimum exergy destruction rate and the maximum entransy loss rate lead to the maximum output power when the combustion temperature and heat capacity flow rate of the flue gas are prescribed. Unlike the minimum exergy destruction rate, the maximum entransy loss rate is related to the maximum output power when the highest temperature and heat capacity flow rate of the flue gas are not prescribed. (general)

Development of 360-W LD pumped Nd:YAG amplifier with a phase conjugation mirror

International Nuclear Information System (INIS)

Kiriyama, Hiromitsu; Nagai, Toru; Yamakawa, Koichi; Kageyama, Nobuto; Miyajima, Hirofumi; Kan, Hirofumi; Yoshida, Hidetsugu; Nakatsuka, Masahiro

2004-01-01

We report on a high-average-power laser-diode (LD) pumped Nd:YAG master-oscillator-power-amplifier (MOPA) system with a minimum number of element for the single multi-pass zigzag-slab amplifier-stage for pumping of a high-peak and high-average power Ti:sapphire laser system. This phase conjugated system produces an average-power of 362 W at 1 kHz in a 30 ns pulse with an optical-to-optical conversion efficiency of 14%. With an external KTP doubler, this system generates 132 W of green average-output-power at 1 kHz with a conversion efficiency of 60% when pumped at a power level of 222 W. To the best of our knowledge, these results represent the highest average-output-power at both infrared and green wavelengths achieved in a single-amplifier-stage. (author)

Estimation of the Power Peaking Factor in a Nuclear Reactor Using Support Vector Machines and Uncertainty Analysis

International Nuclear Information System (INIS)

Bae, In Ho; Na, Man Gyun; Lee, Yoon Joon; Park, Goon Cherl

2009-01-01

Knowing more about the Local Power Density (LPD) at the hottest part of a nuclear reactor core can provide more important information than knowledge of the LPD at any other position. The LPD at the hottest part needs to be estimated accurately in order to prevent the fuel rod from melting in a nuclear reactor. Support Vector Machines (SVMs) have successfully been applied in classification and regression problems. Therefore, in this paper, the power peaking factor, which is defined as the highest LPD to the average power density in a reactor core, was estimated by SVMs which use numerous measured signals of the reactor coolant system. The SVM models were developed by using a training data set and validated by an independent test data set. The SVM models' uncertainty was analyzed by using 100 sampled training data sets and verification data sets. The prediction intervals were very small, which means that the predicted values were very accurate. The predicted values were then applied to the first fuel cycle of the Yonggwang Nuclear Power Plant Unit 3. The root mean squared error was approximately 0.15%, which is accurate enough for use in LPD monitoring and for core protection that uses LPD estimation

energy and exergy evaluation of a 220mw thermal power plant

African Journals Online (AJOL)

HOD

The outcomes of this work provide the exergy consumption and distribution profiles of the thermal power plant ... power plant with post-combustion CO2 capture. The once-through boiler exhibited the highest exergy destruction of all the plants ...

Power Systems Development Facility Gasification Test Run TC08

Energy Technology Data Exchange (ETDEWEB)

Southern Company Services

2002-06-30

This report discusses Test Campaign TC08 of the Kellogg Brown & Root, Inc. (KBR) Transport Gasifier train with a Siemens Westinghouse Power Corporation (Siemens Westinghouse) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The Transport Gasifier is an advanced circulating fluidized-bed gasifier designed to operate as either a combustor or a gasifier in air- or oxygen-blown mode using a particulate control device (PCD). The Transport Gasifier was operated as a pressurized gasifier in air- and oxygen-blown modes during TC08. Test Run TC08 was started on June 9, 2002 and completed on June 29. Both gasifier and PCD operations were stable during the test run with a stable baseline pressure drop. The oxygen feed supply system worked well and the transition from air to oxygen blown was smooth. The gasifier temperature was varied between 1,710 and 1,770 F at pressures from 125 to 240 psig. The gasifier operates at lower pressure during oxygen-blown mode due to the supply pressure of the oxygen system. In TC08, 476 hours of solid circulation and 364 hours of coal feed were attained with 153 hours of pure oxygen feed. The gasifier and PCD operations were stable in both enriched air and 100 percent oxygen blown modes. The oxygen concentration was slowly increased during the first transition to full oxygen-blown operations. Subsequent transitions from air to oxygen blown could be completed in less than 15 minutes. Oxygen-blown operations produced the highest synthesis gas heating value to date, with a projected synthesis gas heating value averaging 175 Btu/scf. Carbon conversions averaged 93 percent, slightly lower than carbon conversions achieved during air-blown gasification.

Danish Wind Power Export and Cost

DEFF Research Database (Denmark)

Lund, Henrik; Hvelplund, Frede; Alberg Østergaard, Poul

In a normal wind year, Danish wind turbines generate the equivalent of approx. 20 percent of the Danish electricity demand. This paper argues that only approx. 1 percent of the wind power production is exported. The rest is used to meet domestic Danish electricity demands. The cost of wind power...... misleading. The cost of CO2 reduction by use of wind power in the period 2004-2008 was only 20 EUR/ton. Furthermore, the Danish wind turbines are not paid for by energy taxes. Danish wind turbines are given a subsidy via the electricity price which is paid by the electricity consumers. In the recent years...... is paid solely by the electricity consumers and the net influence on consumer prices was as low as 1-3 percent on average in the period 2004-2008. In 2008, the net influence even decreased the average consumer price, although only slightly. In Denmark, 20 percent wind power is integrated by using both...

Spacetime averaging of exotic singularity universes

International Nuclear Information System (INIS)

Dabrowski, Mariusz P.

2011-01-01

Taking a spacetime average as a measure of the strength of singularities we show that big-rips (type I) are stronger than big-bangs. The former have infinite spacetime averages while the latter have them equal to zero. The sudden future singularities (type II) and w-singularities (type V) have finite spacetime averages. The finite scale factor (type III) singularities for some values of the parameters may have an infinite average and in that sense they may be considered stronger than big-bangs.

Reliability of the emergency AC power system at nuclear power plants

International Nuclear Information System (INIS)

Battle, R.E.; Campbell, D.J.; Baranowsky, P.W.

1983-01-01

The reliability of the emergency ac power systems typical of most nuclear power plants was estimated, and the cost and increase in reliability for several improvements were estimated. Fault trees were constructed based on a detailed design review of the emergency ac power systems of 18 nuclear plants. The failure probabilities used in the fault trees were calculated from extensive historical data collected from Licensee Event Reports (LERs) and from operating experience information obtained from nuclear plant licensees. No one or two improvements can be made at all plants to significantly increase the industry-average emergency ac power system reliability; rather the most beneficial improvements are varied and plant specific. Improvements in reliability and the associated costs are estimated using plant specific designs and failure probabilities

An implementation of the maximum-caliber principle by replica-averaged time-resolved restrained simulations.

Science.gov (United States)

Capelli, Riccardo; Tiana, Guido; Camilloni, Carlo

2018-05-14

Inferential methods can be used to integrate experimental informations and molecular simulations. The maximum entropy principle provides a framework for using equilibrium experimental data, and it has been shown that replica-averaged simulations, restrained using a static potential, are a practical and powerful implementation of such a principle. Here we show that replica-averaged simulations restrained using a time-dependent potential are equivalent to the principle of maximum caliber, the dynamic version of the principle of maximum entropy, and thus may allow us to integrate time-resolved data in molecular dynamics simulations. We provide an analytical proof of the equivalence as well as a computational validation making use of simple models and synthetic data. Some limitations and possible solutions are also discussed.

Accurate expressions for the power efficiency of a class-D power amplifier in a limit-cycle transmitter configuration

NARCIS (Netherlands)

Sarkeshi, M.; Mahmoudi, R.; Roermund, van A.H.M.

2009-01-01

Limit-cycle based, self-oscillating amplifiers are promising candidates for linear amplification of complex signals with high peak-to-average ratio, while maintaining high power efficiency. Limit-cycle transmitters employ switch class-D power amplifiers in order to achieve high Efficiency. In this

The metabolic power and energetic demands of elite Gaelic football match play.

Science.gov (United States)

Malone, Shane; Solan, Barry; Collins, Kieran; Doran, Dominic

2017-05-01

Metabolic power has not yet been investigated within elite Gaelic football. The aim of the current investigation was to compare the metabolic power demands between positional groups and examine the temporal profile of elite Gaelic football match play. Global positional satellite system (GPS) data were collected from 50 elite Gaelic football players from 4 inter-county teams during 35 elite competitive matches over a three season period. A total of 351 complete match samples were obtained for final analysis. Players were categorized based on positional groups; full-back, half-back, midfield, half-forward and full-forward. Instantaneous raw velocity data was obtained from the GPS and exported to a customized spreadsheet which provided estimations of both speed based, derived metabolic power and energy expenditure variables (total distance, high speed distance, average metabolic power, high power distance and total energy expenditure). Match mean distance was 9222±1588 m, reflective of an average metabolic power of 9.5-12.5 W·kg-1, with an average energy expenditure of 58-70 Kj·kg-1 depending on position. There were significant differences between positional groups for both speed-based and metabolic power indices. Midfielders covered more total and high-speed distance, as well as greater average and overall energy expenditure compared to other positions (Ppower distance, as well as average metabolic power throughout the match (Ppower and traditional running based variables. The middle three positions (midfield, half-back and half-forward) possess greater activity profiles when compared to other positional groups. The reduction in metabolic power and traditional running based variables are comparable across match play. The current study demonstrates that metabolic power may contribute to our understanding of Gaelic football match-play.

Optimized Envelope Tracking Power Supply for Tetra2 Base Station RF Power Amplifier

DEFF Research Database (Denmark)

Høyerby, Mikkel Christian Wendelboe; Andersen, Michael Andreas E.

2008-01-01

An ultra-fast tracking power supply (UFTPS) for envelope tracking in a 50kHz 64-QAM Tetra2 base station power amplification system is demonstrated. A simple method for optimizing the step response of the PID+PD sliding-mode control system is presented and demonstrated, along with a PLL-based scheme...... application. Also demonstrated is the effect of non-zero UFTPS output impedance on envelope tracking performance. At 13W average (156W peak) RF output, a reduction of DC input power consumption from 93W (14% efficiency) to 54W (24% efficiency) is obtained by moving from a fixed RF power amplifier supply...

TEP Power Partners Project [Tucson Electric Power

Energy Technology Data Exchange (ETDEWEB)

None, None

2014-02-06

The Arizona Governor’s Office of Energy Policy, in partnership with Tucson Electric Power (TEP), Tendril, and Next Phase Energy (NPE), formed the TEP Power Partners pilot project to demonstrate how residential customers could access their energy usage data and third party applications using data obtained from an Automatic Meter Reading (AMR) network. The project applied for and was awarded a Smart Grid Data Access grant through the U.S. Department of Energy. The project participants’ goal for Phase I is to actively engage 1,700 residential customers to demonstrate sustained participation, reduction in energy usage (kWh) and cost ($), and measure related aspects of customer satisfaction. This Demonstration report presents a summary of the findings, effectiveness, and customer satisfaction with the 15-month TEP Power Partners pilot project. The objective of the program is to provide residential customers with energy consumption data from AMR metering and empower these participants to better manage their electricity use. The pilot recruitment goals included migrating 700 existing customers from the completed Power Partners Demand Response Load Control Project (DRLC), and enrolling 1,000 new participants. Upon conclusion of the project on November 19, 2013; 1,390 Home Area Networks (HANs) were registered; 797 new participants installed a HAN; Survey respondents’ are satisfied with the program and found value with a variety of specific program components; Survey respondents report feeling greater control over their energy usage and report taking energy savings actions in their homes after participating in the program; On average, 43 % of the participants returned to the web portal monthly and 15% returned weekly; and An impact evaluation was completed by Opinion Dynamics and found average participant savings for the treatment period1 to be 2.3% of their household use during this period.2 In total, the program saved 163 MWh in the treatment period of 2013.

Brayton cycle space power systems

International Nuclear Information System (INIS)

Pietsch, A.; Trimble, S.W.; Harper, A.D.

1985-01-01

The latest accomplishments in the design and development of the Brayton Isotope Power System (BIPS) for space applications are described, together with a reexamination of the design/cost tradeoffs with respect to current economic parameters and technology status. The results of tests performed on a ground test version of the flight configuration, the workhorse loop, were used to confirm the performance projections made for the flight system. The results of cost-model analysis indicate that the use of the highest attainable power conversion system efficiency will yield the most cost-effective systems. 13 references

Statistical modelling of space-time processes with application to wind power

DEFF Research Database (Denmark)

Lenzi, Amanda

. This thesis aims at contributing to the wind power literature by building and evaluating new statistical techniques for producing forecasts at multiple locations and lead times using spatio-temporal information. By exploring the features of a rich portfolio of wind farms in western Denmark, we investigate...... propose spatial models for predicting wind power generation at two different time scales: for annual average wind power generation and for a high temporal resolution (typically wind power averages over 15-min time steps). In both cases, we use a spatial hierarchical statistical model in which spatial...

A Decentralized Eigenvalue Computation Method for Spectrum Sensing Based on Average Consensus

Science.gov (United States)

Mohammadi, Jafar; Limmer, Steffen; Stańczak, Sławomir

2016-07-01

This paper considers eigenvalue estimation for the decentralized inference problem for spectrum sensing. We propose a decentralized eigenvalue computation algorithm based on the power method, which is referred to as generalized power method GPM; it is capable of estimating the eigenvalues of a given covariance matrix under certain conditions. Furthermore, we have developed a decentralized implementation of GPM by splitting the iterative operations into local and global computation tasks. The global tasks require data exchange to be performed among the nodes. For this task, we apply an average consensus algorithm to efficiently perform the global computations. As a special case, we consider a structured graph that is a tree with clusters of nodes at its leaves. For an accelerated distributed implementation, we propose to use computation over multiple access channel (CoMAC) as a building block of the algorithm. Numerical simulations are provided to illustrate the performance of the two algorithms.

Chromospheric oscillations observed with OSO 8. III. Average phase spectra for Si II

International Nuclear Information System (INIS)

White, O.R.; Athay, R.G.

1979-01-01

Time series of intensity and Doppler-shift fluctuations in the Si II emission lines lambda816.93 and lambda817.45 are Fourier analyzed to determine the frequency variation of phase differences between intensity and velocity and between these two lines formed 300 km apart in the middle chromosphere. Average phase spectra show that oscillations between 2 and 9 mHz in the two lines have time delays from 35 to 40 s, which is consistent with the upward propagation of sound wave at 8.6-7.5 km s -1 . In this same frequency band near 3 mHz, maximum brightness leads maximum blueshift by 60 0 . At frequencies above 11 mHz where the power spectrum is flat, the phase differences are uncertain, but approximately 65% of the cases indicate upward propagation. At these higher frequencies, the phase lead between intensity and blue Doppler shift ranges from 0 0 to 180 0 with an average value of 90 0 . However, the phase estimates in this upper band are corrupted by both aliasing and randomness inherent to the measured signals. Phase differences in the two narrow spectral features seen at 10.5 and 27 mHz in the power spectra are shown to be consistent with properties expected for aliases of the wheel rotation rate of the spacecraft wheel section

Some implications of batch average burnup calculations on predicted spent fuel compositions

International Nuclear Information System (INIS)

Alexander, C.W.; Croff, A.G.

1984-01-01

The accuracy of using batch-averaged burnups to determine spent fuel characteristics (such as isotopic composition, activity, etc.) was examined for a typical pressurized-water reactor (PWR) fuel discharge batch by comparing characteristics computed by (a) performing a single depletion calculation using the average burnup of the spent fuel and (b) performing separate depletion calculations based on the relative amounts of spent fuel in each of twelve burnup ranges and summing the results. The computations were done using ORIGEN 2. Procedure (b) showed a significant shift toward a greater quantity of the heavier transuranics, which derive from multiple neutron captures, and a corresponding decrease in the amounts of lower transuranics. Those characteristics which derive primarily from fission products, such as total radioactivity and total thermal power, are essentially identical for the two procedures. Those characteristics that derive primarily from the heavier transuranics, such as spontaneous fission neutrons, are underestimated by procedure (a)

Robert Aymar receives one of the highest Finnish distinctions

CERN Multimedia

2008-01-01

On 9 December 2008 Robert Aymar, CERN Director-General, was awarded the decoration of Commander, first class, of the Order of the Lion of Finland by the President of the Republic of Finland. This decoration, one of the highest of Finland, was presented in a ceremony by the Ambassador Hannu Himanen, Permanent Representative of Finland to the UN and other international organisations in Geneva. Robert Aymar was honoured for his service to CERN, the LHC, his role in the cooperation between Finland and CERN, as well as his contribution to science in general. In his speech the ambassador underlined CERN’s efforts in the field of education, mentioning the High school teachers programme.

Practical computer analysis of switch mode power supplies

CERN Document Server

Bennett, Johnny C

2006-01-01

When designing switch-mode power supplies (SMPSs), engineers need much more than simple "recipes" for analysis. Such plug-and-go instructions are not at all helpful for simulating larger and more complex circuits and systems. Offering more than merely a "cookbook," Practical Computer Analysis of Switch Mode Power Supplies provides a thorough understanding of the essential requirements for analyzing SMPS performance characteristics. It demonstrates the power of the circuit averaging technique when used with powerful computer circuit simulation programs. The book begins with SMPS fundamentals and the basics of circuit averaging models, reviewing most basic topologies and explaining all of their various modes of operation and control. The author then discusses the general analysis requirements of power supplies and how to develop the general types of SMPS models, demonstrating the use of SPICE for analysis. He examines the basic first-order analyses generally associated with SMPS performance along with more pra...

Sensitivity analysis for matched pair analysis of binary data: From worst case to average case analysis.

Science.gov (United States)

Hasegawa, Raiden; Small, Dylan

2017-12-01

In matched observational studies where treatment assignment is not randomized, sensitivity analysis helps investigators determine how sensitive their estimated treatment effect is to some unmeasured confounder. The standard approach calibrates the sensitivity analysis according to the worst case bias in a pair. This approach will result in a conservative sensitivity analysis if the worst case bias does not hold in every pair. In this paper, we show that for binary data, the standard approach can be calibrated in terms of the average bias in a pair rather than worst case bias. When the worst case bias and average bias differ, the average bias interpretation results in a less conservative sensitivity analysis and more power. In many studies, the average case calibration may also carry a more natural interpretation than the worst case calibration and may also allow researchers to incorporate additional data to establish an empirical basis with which to calibrate a sensitivity analysis. We illustrate this with a study of the effects of cellphone use on the incidence of automobile accidents. Finally, we extend the average case calibration to the sensitivity analysis of confidence intervals for attributable effects. © 2017, The International Biometric Society.

Laser power meters as an X-ray power diagnostic for LCLS-II.

Science.gov (United States)

Heimann, Philip; Moeller, Stefan; Carbajo, Sergio; Song, Sanghoon; Dakovski, Georgi; Nordlund, Dennis; Fritz, David

2018-01-01

For the LCLS-II X-ray instruments, laser power meters are being developed as compact X-ray power diagnostics to operate at soft and tender X-ray photon energies. These diagnostics can be installed at various locations along an X-ray free-electron laser (FEL) beamline in order to monitor the transmission of X-ray optics along the beam path. In addition, the power meters will be used to determine the absolute X-ray power at the endstations. Here, thermopile power meters, which measure average power, and have been chosen primarily for their compatibility with the high repetition rates at LCLS-II, are evaluated. A number of characteristics in the soft X-ray range are presented including linearity, calibrations conducted with a photodiode and a gas monitor detector as well as ultra-high-vacuum compatibility tests using residual gas analysis. The application of these power meters for LCLS-II and other X-ray FEL sources is discussed.

Evaluation of a solar-powered organic Rankine cycle using dry organic working fluids

Directory of Open Access Journals (Sweden)

Emily Spayde

2015-12-01

Full Text Available This paper presents a model to evaluate the performance of a solar-powered organic Rankine cycle (ORC. The system was evaluated in Jackson, MS, using five dry organic working fluids, R218, R227ea, R236ea, R236fa, and RC318. The purpose of this study is to investigate how hourly temperature change affects the electricity production and exergy destruction rates of the solar ORC, and to determine the effect of the working fluid on the proposed system. The system was also evaluated in Tucson, AZ, to investigate the effect of average hourly outdoor temperatures on its performance. The potential of the system to reduce primary energy consumption and carbon dioxide emissions is also investigated. A parametric analysis to determine how temperature and pressure of the organic working fluid, the solar collector area, and the turbine efficiency affect the electricity production is performed. Results show that the ORC produces the most electricity during the middle of the day, when the temperatures are the highest and when the solar collectors have the highest efficiency. Also, R-236ea is the working fluid that shows the best performance of the evaluated fluids. An economic analysis was performed to determine the capital cost available for the proposed system.

Dipole model analysis of highest precision HERA data, including very low Q"2's

International Nuclear Information System (INIS)

Luszczak, A.; Kowalski, H.

2016-12-01

We analyse, within a dipole model, the final, inclusive HERA DIS cross section data in the low χ region, using fully correlated errors. We show, that these highest precision data are very well described within the dipole model framework starting from Q"2 values of 3.5 GeV"2 to the highest values of Q"2=250 GeV"2. To analyze the saturation effects we evaluated the data including also the very low 0.35< Q"2 GeV"2 region. The fits including this region show a preference of the saturation ansatz.

Hydro-engineering structure and Liptovska Mara Pumped Storage Power Plant

International Nuclear Information System (INIS)

Regula, E.

2005-01-01

In this paper thirty years history of the Hydro-engineering structure and Liptovska Mara Pumped Storage Power Plant (PSPP) is presented. In 1975 year the Liptovska Mara PSPP was commissioned. There are 2 Kaplan turbines and 2 Derezias reversible turbines with a total installed power 198 MW. The average annual output is 134.5 GWh. As a part of this hydro-engineering structure is Besenova Small-scale power plants with 2 turbines and with installed power 4.64 MW. The average annual output consists 18.3 GWh. There up to end of 2004 year 3,620.172 MWh of electricity was produced. Environmental effects are discussed

A high-power compact regenerative amplifier FEL

International Nuclear Information System (INIS)

Nguyen, D.C.; Sheffield, R.L.; Fortgang, C.M.; Kinross-Wright, J.M.; Ebrahim, N.A.; Goldstein, J.C.

1997-01-01

The Regenerative Amplifier FEL (RAFEL) is a new FEL approach aimed at achieving the highest optical power from a compact rf-linac FEL. The key idea is to feed back a small fraction ( 5 in single pass) wiggler to enable the FEL to reach saturation in a few passes. This paper summarizes the design of a high-power compact regenerative amplifier FEL and describes the first experimental demonstration of the RAFEL concept

Reliability of the emergency ac-power system at nuclear power plants

International Nuclear Information System (INIS)

Battle, R.E.; Campbell, D.J.; Baranowsky, P.W.

1982-01-01

The reliability of the emergency ac-power systems typical of several nuclear power plants was estimated, the costs of several possible improvements was estimated. Fault trees were constructed based on a detailed design review of the emergency ac-power systems of 18 nuclear plants. The failure probabilities used in the fault trees were calculated from extensive historical data collected from Licensee Event Reports (LERs) and from operating experience information obtained from nuclear plant licensees. It was found that there are not one or two improvements that can be made at all plants to significantly increase the industry-average emergency ac-power-system reliability, but the improvements are varied and plant-specific. Estimates of the improvements in reliability and the associated cost are estimated using plant-specific designs and failure probabilities

Power transformers - Part 11: Dry-type transformers

CERN Document Server

International Electrotechnical Commission. Geneva

2004-01-01

Applies to dry-type power transformers (including auto-transformers) having values of highest voltage for equipment up to and including 36 kV and at least one winding operating at greater than 1,1 kV. Applies to all construction technologies.

Global (volume-averaged) model of inductively coupled chlorine plasma : influence of Cl wall recombination and external heating on continuous and pulse-modulated plasmas

NARCIS (Netherlands)

Kemaneci, E.H.; Carbone, E.A.D.; Booth, J.P.; Graef, W.A.A.D.; Dijk, van J.; Kroesen, G.M.W.

An inductively coupled radio-frequency plasma in chlorine is investigated via a global (volume-averaged) model, both in continuous and square wave modulated power input modes. After the power is switched off (in a pulsed mode) an ion–ion plasma appears. In order to model this phenomenon, a novel

Parents' Reactions to Finding Out That Their Children Have Average or above Average IQ Scores.

Science.gov (United States)

Dirks, Jean; And Others

1983-01-01

Parents of 41 children who had been given an individually-administered intelligence test were contacted 19 months after testing. Parents of average IQ children were less accurate in their memory of test results. Children with above average IQ experienced extremely low frequencies of sibling rivalry, conceit or pressure. (Author/HLM)

Evaluations of average level spacings

International Nuclear Information System (INIS)

Liou, H.I.

1980-01-01

The average level spacing for highly excited nuclei is a key parameter in cross section formulas based on statistical nuclear models, and also plays an important role in determining many physics quantities. Various methods to evaluate average level spacings are reviewed. Because of the finite experimental resolution, to detect a complete sequence of levels without mixing other parities is extremely difficult, if not totally impossible. Most methods derive the average level spacings by applying a fit, with different degrees of generality, to the truncated Porter-Thomas distribution for reduced neutron widths. A method that tests both distributions of level widths and positions is discussed extensivey with an example of 168 Er data. 19 figures, 2 tables

Solar PV-based rooftop power plant

International Nuclear Information System (INIS)

Ashok Kumar, B.; Kumar, Chaitanya; Patel, C.B.; Pattanaik, B.R.; Panda, P.K.; Kaul, S.K.; Mishra, H.

2017-01-01

Technical Services Division (TSD) is responsible for providing reliable power supply to various operating reactors, laboratories and facilities of BARC. The power supply to BARC is derived from TATA Power at 110 KV and 22 KV at an average HT tariff of Rs.8.49 per unit at present. Peak power demand of BARC in summer season goes up to 23 MW. TSD has implemented several energy conservation measures to reduce the energy consumption and as well taken initiatives to install solar PV based rooftop power plants to reduce the cost of energy consumption in BARC

LTE UE Power Consumption Model

DEFF Research Database (Denmark)

Jensen, Anders Riis; Lauridsen, Mads; Mogensen, Preben

2012-01-01

is based on a review of the major power consuming parts in an LTE UE radio modem. The model includes functions of UL and DL power and data rate. Measurements on a commercial LTE USB dongle were used to assign realistic power consumption values to each model parameter. Verification measurements......In this work a novel LTE user equipment (UE) power consumption model is presented. It was developed for LTE system level optimization, because it is important to understand how network settings like scheduling of resources and transmit power control affect the UE’s battery life. The proposed model...... on the dongle show that the model results in an average error of 2.6%. The measurements show that UL transmit power and DL data rate determines the overall power consumption, while UL data rate and DL receive power have smaller impact....

Discrete rate and variable power adaptation for underlay cognitive networks

KAUST Repository

Abdallah, Mohamed M.

2010-01-01

We consider the problem of maximizing the average spectral efficiency of a secondary link in underlay cognitive networks. In particular, we consider the network setting whereby the secondary transmitter employs discrete rate and variable power adaptation under the constraints of maximum average transmit power and maximum average interference power allowed at the primary receiver due to the existence of an interference link between the secondary transmitter and the primary receiver. We first find the optimal discrete rates assuming a predetermined partitioning of the signal-to-noise ratio (SNR) of both the secondary and interference links. We then present an iterative algorithm for finding a suboptimal partitioning of the SNR of the interference link assuming a fixed partitioning of the SNR of secondary link selected for the case where no interference link exists. Our numerical results show that the average spectral efficiency attained by using the iterative algorithm is close to that achieved by the computationally extensive exhaustive search method for the case of Rayleigh fading channels. In addition, our simulations show that selecting the optimal partitioning of the SNR of the secondary link assuming no interference link exists still achieves the maximum average spectral efficiency for the case where the average interference constraint is considered. © 2010 IEEE.

Averaged RMHD equations

International Nuclear Information System (INIS)

Ichiguchi, Katsuji

1998-01-01

A new reduced set of resistive MHD equations is derived by averaging the full MHD equations on specified flux coordinates, which is consistent with 3D equilibria. It is confirmed that the total energy is conserved and the linearized equations for ideal modes are self-adjoint. (author)

Availability of thermal power plants 1977-1986

International Nuclear Information System (INIS)

Nitsch, D.; Schmitz, H.

1987-01-01

To get a picture of power plant availability and its influencing factors, availability data have been acquired and evaluated by VGB according to different design and operation parameters since 1970. The present volume is the 16th annual statistics since 1970. It covers the decade of 1977 to 1986 and contains availability data of 384 power plants in Germany and abroad, with a total of 94.896 MW and 3.768 plant years. Data are presented on fossil-fuelled units, units with a combined gas/steam cycle, nuclear power plants and gas turbine systems, with further sub-categories according to unit size, fuel, type, years of operation, and operating regime. German plants are reviewed separately. All power data are gross data measured at the generator terminals. For a comparative evaluation, the data of 1986 are supplemented by yearly averages since 1977 and averages for the decade from 1977 to 1986. Since 1978, nonavailability data are categorized as 'unscheduled' and 'scheduled' nonavailabilities. For availability data of 1970 to 1976, see the VGB publication 'Availability of thermal power plants, 1970 to 1981'. (orig./UA) [de

Criticality evaluation of BWR MOX fuel transport packages using average Pu content

International Nuclear Information System (INIS)

Mattera, C.; Martinotti, B.

2004-01-01

Currently in France, criticality studies in transport configurations for Boiling Water Reactor Mixed Oxide fuel assemblies are based on conservative hypothesis assuming that all rods (Mixed Oxide (Uranium and Plutonium), Uranium Oxide, Uranium and Gadolinium Oxide rods) are Mixed Oxide rods with the same Plutonium-content, corresponding to the maximum value. In that way, the real heterogeneous mapping of the assembly is masked and covered by a homogeneous Plutonium-content assembly, enriched at the maximum value. As this calculation hypothesis is extremely conservative, COGEMA LOGISTICS has studied a new calculation method based on the average Plutonium-content in the criticality studies. The use of the average Plutonium-content instead of the real Plutonium-content profiles provides a highest reactivity value that makes it globally conservative. This method can be applied for all Boiling Water Reactor Mixed Oxide complete fuel assemblies of type 8 x 8, 9 x 9 and 10 x 10 which Plutonium-content in mass weight does not exceed 15%; it provides advantages which are discussed in our approach. With this new method, for the same package reactivity, the Pu-content allowed in the package design approval can be higher. The COGEMA LOGISTICS' new method allows, at the design stage, to optimise the basket, materials or geometry for higher payload, keeping the same reactivity

Highest cited papers published in Neurology India: An analysis for the years 1993-2014.

Science.gov (United States)

Pandey, Paritosh; Subeikshanan, V; Madhugiri, Venkatesh S

2016-01-01

The highest cited papers published in a journal provide a snapshot of the clinical practice and research in that specialty and/or region. The aim of this study was to determine the highest cited papers published in Neurology India and analyze their attributes. This study was a citation analysis of all papers published in Neurology India since online archiving commenced in 1993. All papers published in Neurology India between the years 1993-2014 were listed. The number of times each paper had been cited up till the time of performing this study was determined by performing a Google Scholar search. Published papers were then ranked on the basis of total times cited since publication and the annual citation rate. Statistical Techniques: Simple counts and percentages were used to report most results. The mean citations received by papers in various categories were compared using the Student's t-test or a one-way analysis of variance, as appropriate. All analyses were carried out on SAS University Edition (SAS/STAT®, SAS Institute Inc, NC, USA) and graphs were generated on MS Excel 2016. The top papers on the total citations and annual citation rate rank lists pertained to basic neuroscience research. The highest cited paper overall had received 139 citations. About a quarter of the papers published had never been cited at all. The major themes represented were vascular diseases and infections. The highest cited papers reflect the diseases that are of major concern in India. Certain domains such as trauma, allied neurosciences, and basic neuroscience research were underrepresented.

Power-Combined GaN Amplifier with 2.28-W Output Power at 87 GHz

Science.gov (United States)

Fung, King Man; Ward, John; Chattopadhyay, Goutam; Lin, Robert H.; Samoska, Lorene A.; Kangaslahti, Pekka P.; Mehdi, Imran; Lambrigtsen, Bjorn H.; Goldsmith, Paul F.; Soria, Mary M.;

Reproducing multi-model ensemble average with Ensemble-averaged Reconstructed Forcings (ERF) in regional climate modeling

Science.gov (United States)

Erfanian, A.; Fomenko, L.; Wang, G.

2016-12-01

Multi-model ensemble (MME) average is considered the most reliable for simulating both present-day and future climates. It has been a primary reference for making conclusions in major coordinated studies i.e. IPCC Assessment Reports and CORDEX. The biases of individual models cancel out each other in MME average, enabling the ensemble mean to outperform individual members in simulating the mean climate. This enhancement however comes with tremendous computational cost, which is especially inhibiting for regional climate modeling as model uncertainties can originate from both RCMs and the driving GCMs. Here we propose the Ensemble-based Reconstructed Forcings (ERF) approach to regional climate modeling that achieves a similar level of bias reduction at a fraction of cost compared with the conventional MME approach. The new method constructs a single set of initial and boundary conditions (IBCs) by averaging the IBCs of multiple GCMs, and drives the RCM with this ensemble average of IBCs to conduct a single run. Using a regional climate model (RegCM4.3.4-CLM4.5), we tested the method over West Africa for multiple combination of (up to six) GCMs. Our results indicate that the performance of the ERF method is comparable to that of the MME average in simulating the mean climate. The bias reduction seen in ERF simulations is achieved by using more realistic IBCs in solving the system of equations underlying the RCM physics and dynamics. This endows the new method with a theoretical advantage in addition to reducing computational cost. The ERF output is an unaltered solution of the RCM as opposed to a climate state that might not be physically plausible due to the averaging of multiple solutions with the conventional MME approach. The ERF approach should be considered for use in major international efforts such as CORDEX. Key words: Multi-model ensemble, ensemble analysis, ERF, regional climate modeling

Averaging for solitons with nonlinearity management

International Nuclear Information System (INIS)

Pelinovsky, D.E.; Kevrekidis, P.G.; Frantzeskakis, D.J.

2003-01-01

We develop an averaging method for solitons of the nonlinear Schroedinger equation with a periodically varying nonlinearity coefficient, which is used to effectively describe solitons in Bose-Einstein condensates, in the context of the recently proposed technique of Feshbach resonance management. Using the derived local averaged equation, we study matter-wave bright and dark solitons and demonstrate a very good agreement between solutions of the averaged and full equations

Stochastic Optimization of Wind Turbine Power Factor Using Stochastic Model of Wind Power

DEFF Research Database (Denmark)

Chen, Peiyuan; Siano, Pierluigi; Bak-Jensen, Birgitte

2010-01-01

This paper proposes a stochastic optimization algorithm that aims to minimize the expectation of the system power losses by controlling wind turbine (WT) power factors. This objective of the optimization is subject to the probability constraints of bus voltage and line current requirements....... The optimization algorithm utilizes the stochastic models of wind power generation (WPG) and load demand to take into account their stochastic variation. The stochastic model of WPG is developed on the basis of a limited autoregressive integrated moving average (LARIMA) model by introducing a crosscorrelation...... structure to the LARIMA model. The proposed stochastic optimization is carried out on a 69-bus distribution system. Simulation results confirm that, under various combinations of WPG and load demand, the system power losses are considerably reduced with the optimal setting of WT power factor as compared...

The Highest Good and the Practical Regulative Knowledge in Kant’s Critique of Practical Reason

OpenAIRE

Joel Thiago Klein

2016-01-01

In this paper I defend three different points: first, that the concept of highest good is derived from an a priori but subjective argument, namely a maxim of pure practical reason; secondly, that the theory regarding the highest good has the validity of a practical regulative knowledge; and thirdly, that the practical regulative knowledge can be understood as the same “holding something to be true” as Kant attributes to hope and believe.

Development of copper bromide laser master oscillator power

Indian Academy of Sciences (India)

2014-02-09

Feb 9, 2014 ... Development of master oscillator power amplifier (MOPA) system of copper bromide laser (CBL) operating at 110 W average power is reported. The spectral distribution of power at green (510.6 nm) and yellow (578.2 nm) components in the output of a copper bromide laser is studied as a function of ...

Survival of fishes after impingement on traveling screens at Hudson River power plants

International Nuclear Information System (INIS)

Muessig, P.H.; Hutchison, J.B.; King, L.R.; Ligotino, R.J.; Daley, M.

1988-01-01

The survival of Hudson River fishes, juveniles and adults, after they had been impinged on continuously rotated traveling screens at the Bowline Point and Danskammer Point power plants was examined. Survival of principal species was similar at the two plants, and estimates of survival improved as monitoring stress was reduced. Adjusted for survival of control fish, survival over 84-108 h after fish were recovered from the screens was highest for Atlantic tomcod, striped bass, and white perch (50-90%) and lowest for bay anchovy, alewife, and blueback herring; other species showed intermediate survival. Survival of striped bass and white perch was positively correlated with water temperature in winter and with conductivity in spring and fall. Continual rotation of the screens, which shortens the average time that fish are impinged, increased survival over that associated with intermittent rotation. 24 refs., 9 figs., 4 tabs

Input of biomass in power plants for power generation. Calculation of the financial gap. Final report

International Nuclear Information System (INIS)

Van Tilburg, X.; De Vries, H.J.; Pfeiffer, A.E.; Cleijne, J.W.

2005-09-01

The Ministry of Economic Affairs has requested ECN and KEMA to answer two questions. (1) Are the costs and benefits of projects in which wood-pellets are co-fired in a coal fired power plant representative for those of bio-oil fueled co-firing projects in a gas fired plant?; and (2) Are new projects representative for existing projects? To answer these questions, ECN and KEMA have calculated the financial gaps in six different situations: co-firing bio-oil in a gas fired power plant; co-firing bio-oil in a coal fired power plant; gasification of solid biomass; co-firing wood pellets in a coal fired power plant; co-firing agricultural residues in a coal fired power plant; and co-firing waste wood (A- and B-grade) in a coal fired power plant. The ranges and reference cases show that co-firing bio-oil on average has a smaller financial gap than the solid biomass reference case. On average it can also be concluded that when using waste wood or agro-residues, the financial gaps are smaller. Based on these findings it is concluded that: (1) The reference case of co-firing wood pellets in a coal fired power plant are not representative for bio-fuel options. A new category for bio-oil options seems appropriate; and (2) The financial gap of new projects as calculated in November 2004, is often higher then the ranges for existing projects indicate [nl

Three-dimensional Core Design of a Super Fast Reactor with a High Power Density

International Nuclear Information System (INIS)

Cao, Liangzhi; Oka, Yoshiaki; Ishiwatari, Yuki; Ikejiri, Satoshi; Ju, Haitao

2010-01-01

The SuperCritical Water-cooled Reactor (SCWR) pursues high power density to reduce its capital cost. The fast spectrum SCWR, called a super fast reactor, can be designed with a higher power density than thermal spectrum SCWR. The mechanism of increasing the average power density of the super fast reactor is studied theoretically and numerically. Some key parameters affecting the average power density, including fuel pin outer diameter, fuel pitch, power peaking factor, and the fraction of seed assemblies, are analyzed and optimized to achieve a more compact core. Based on those sensitivity analyses, a compact super fast reactor is successfully designed with an average power density of 294.8 W/cm 3 . The core characteristics are analyzed by using three-dimensional neutronics/thermal-hydraulics coupling method. Numerical results show that all of the design criteria and goals are satisfied

Frame average optimization of cine-mode EPID images used for routine clinical in vivo patient dose verification of VMAT deliveries

Energy Technology Data Exchange (ETDEWEB)

McCowan, P. M., E-mail: pmccowan@cancercare.mb.ca [Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada and Medical Physics Department, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada); McCurdy, B. M. C. [Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Medical Physics Department, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada); Department of Radiology, University of Manitoba, 820 Sherbrook Street, Winnipeg, Manitoba R3A 1R9 (Canada)

2016-01-15

Purpose: The in vivo 3D dose delivered to a patient during volumetric modulated arc therapy (VMAT) delivery can be calculated using electronic portal imaging device (EPID) images. These images must be acquired in cine-mode (i.e., “movie” mode) in order to capture the time-dependent delivery information. The angle subtended by each cine-mode EPID image during an arc can be changed via the frame averaging number selected within the image acquisition software. A large frame average number will decrease the EPID’s angular resolution and will result in a decrease in the accuracy of the dose information contained within each image. Alternatively, less EPID images acquired per delivery will decrease the overall 3D patient dose calculation time, which is appealing for large-scale clinical implementation. Therefore, the purpose of this study was to determine the optimal frame average value per EPID image, defined as the highest frame averaging that can be used without an appreciable loss in 3D dose reconstruction accuracy for VMAT treatments. Methods: Six different VMAT plans and six different SBRT-VMAT plans were delivered to an anthropomorphic phantom. Delivery was carried out on a Varian 2300ix model linear accelerator (Linac) equipped with an aS1000 EPID running at a frame acquisition rate of 7.5 Hz. An additional PC was set up at the Linac console area, equipped with specialized frame-grabber hardware and software packages allowing continuous acquisition of all EPID frames during delivery. Frames were averaged into “frame-averaged” EPID images using MATLAB. Each frame-averaged data set was used to calculate the in vivo dose to the patient and then compared to the single EPID frame in vivo dose calculation (the single frame calculation represents the highest possible angular resolution per EPID image). A mean percentage dose difference of low dose (<20% prescription dose) and high dose regions (>80% prescription dose) was calculated for each frame averaged

Frame average optimization of cine-mode EPID images used for routine clinical in vivo patient dose verification of VMAT deliveries

International Nuclear Information System (INIS)

McCowan, P. M.; McCurdy, B. M. C.

2016-01-01

Purpose: The in vivo 3D dose delivered to a patient during volumetric modulated arc therapy (VMAT) delivery can be calculated using electronic portal imaging device (EPID) images. These images must be acquired in cine-mode (i.e., “movie” mode) in order to capture the time-dependent delivery information. The angle subtended by each cine-mode EPID image during an arc can be changed via the frame averaging number selected within the image acquisition software. A large frame average number will decrease the EPID’s angular resolution and will result in a decrease in the accuracy of the dose information contained within each image. Alternatively, less EPID images acquired per delivery will decrease the overall 3D patient dose calculation time, which is appealing for large-scale clinical implementation. Therefore, the purpose of this study was to determine the optimal frame average value per EPID image, defined as the highest frame averaging that can be used without an appreciable loss in 3D dose reconstruction accuracy for VMAT treatments. Methods: Six different VMAT plans and six different SBRT-VMAT plans were delivered to an anthropomorphic phantom. Delivery was carried out on a Varian 2300ix model linear accelerator (Linac) equipped with an aS1000 EPID running at a frame acquisition rate of 7.5 Hz. An additional PC was set up at the Linac console area, equipped with specialized frame-grabber hardware and software packages allowing continuous acquisition of all EPID frames during delivery. Frames were averaged into “frame-averaged” EPID images using MATLAB. Each frame-averaged data set was used to calculate the in vivo dose to the patient and then compared to the single EPID frame in vivo dose calculation (the single frame calculation represents the highest possible angular resolution per EPID image). A mean percentage dose difference of low dose ( 80% prescription dose) was calculated for each frame averaged scenario for each plan. The authors defined their

ORC power plant for electricity production from forest and agriculture biomass

International Nuclear Information System (INIS)

Borsukiewicz-Gozdur, A.; Wiśniewski, S.; Mocarski, S.; Bańkowski, M.

2014-01-01

Highlights: • Results for three variants of CHP plant fuelled by sawmill biomass are presented. • Octamethyltrisiloxane, MDM, methanol and H 2 O working fluids was conducted in CHP. • CHP with internal regeneration and “dry” working fluid has the highest electric power. • Power output, drying heat and drying temperature depend on CHP variant and ORC fluid. - Abstract: The paper presents the calculation results for three variants of CHP plant fuelled by sawmill biomass. The plant shall produce electricity and heat for a drying chamber. An analysis of the system efficiency for four different working fluids was conducted: octamethyltrisiloxane, methylcyclohexane, methanol and water. The highest electric power was obtained for the system with internal regeneration and methylcyclohexane applied as the “dry” working fluid, the highest temperature to supply the drying chamber was obtained for the system with external regeneration and octamethyltrisiloxane applied as the working fluid. The results of the analysis indicate that, by proper choice of the working fluid and of the regeneration variant (internal or external), it is possible to “adjust” the work of the system to the needs and expectations of the plant investor (user)

Novel screening techniques for wind turbine power converters

DEFF Research Database (Denmark)

Jørgensen, Asger Bjørn; Sønderskov, Simon Dyhr; Christensen, Nicklas

2016-01-01

Power converters represent one of the highest failure rates in the wind turbine. Therefore converter manufacturers perform burn-in tests to prevent shipping of faulty converters. Recent developments in junction temperature estimation, based on accurate online IGBT collector-emitter voltage...... measurements, allow for thermal stress estimation of the IGBT modules. This is utilized to detect infant mortalities in power converters, by comparing thermal responses of IGBTs for faulty and non-faulty converters. The method proves to be a time and cost efficient candidate to replace burn-in tests of power...... converters for wind turbines applications....

Performance evaluation of UO2-Zr fuel in power ramp tests

International Nuclear Information System (INIS)

Knudsen, P.; Bagger, C.

1977-01-01

In power reactors using UO 2 -Zr fuel, rapid power increases may lead to failures in fuel pins that have been irradiated at steady or decreasing heat loads. This paper presents results which extend the experience with power ramp performance of high burn-up fuel pins. A test fuel element containing both pellet and vipac UO 2 -Zr fuel pins was irradiated in the HBWR at Halden for effectively 2 1/2 years to an average burn-up of 21,000 MWD/te UO 2 at gradually decreasing power levels. The subsequent non-destructive characterization revealed formation of transverse cracks in the vipac fuel columns. After the HBWR irradiation, five of the fuel pins were power ramp tested individually in the DR 3 Reactor at Riso. The ramp rates in this test series were in the range 3-60 W/cm min. The maximum local heat loads seen in the ramp tests were 20-120% above the highest levels experienced at the same axial positions during the HBWR irradiation. Three pellets and one vipac fuel pin failed, whereas another vipac pin gave no indication of clad penetration. Profilometry after the ramp testing indicated the formation of small ridges for both types of fuel pins. For vipac fuel, the ridges were less regularly distributed along the pin length than for pellet fuel. Neutron radiography revealed the formation of additional transverse and longitudinal fuel cracks during the power ramps for both types of fuel pins. The observed failures seemed to be marginal since little or no indication as to the locations of the clad penetrations could be derived from the non-destructive post-irradiation examinations. The cases have been analyzed by means of the Danish fuel performance codes. The calculations, which are in general agreement with the observations, are discussed. The results of the investigations indicate qualitative similarities in over power performance of the two fuel types

Nuclear power statistics 1985

International Nuclear Information System (INIS)

Oelgaard, P.L.

1986-06-01

In this report an attempt is made to collect literature data on nuclear power production and to present it on graphical form. Data is given not only for 1985, but for a number of years so that the trends in the development of nuclear power can be seen. The global capacity of nuclear power plants in operation and those in operation, under construction, or on order is considered. Further the average capacity factor for nuclear plants of a specific type and for various geographical areas is given. The contribution of nuclear power to the total electricity production is considered for a number of countries and areas. Finally, the accumulated years of commercial operation for the various reactor types up to the end of 1985 is presented. (author)

Summary of operating experience in Swiss nuclear power plants 1994

International Nuclear Information System (INIS)

1995-05-01

In 1994 the Swiss nuclear power plants produced their highest-ever combined annual output. Their contribution to total electricity generation in the country was 36%. At Muehleberg the power uprate, undertaken in 1993, was effective for the first time for an entire year. The larger capacity of the new steam generators installed in 1993 in unit 1 of the Beznau NPP allows for an electric output of 103% of nominal power. The plant efficiency of the Goesgen and Leibstadt units was increased by replacing the low pressure turbines by the new ones with a modern design. The application for a power uprate of the Leibstadt reactor is still pending. For the first time in Switzerland, one of the reactor units, Beznau 2, operated on an extended cycle of one and a half years, with no refuelling outage in 1994. In spite of the replacements of two of its three low pressure turbines, Goesgen had the shortest refuelling shutdown since the start of commercial operation. The average number of reactor scrams at the Swiss plants remained stable, at less than one scram per reactor year. Re-inspection of crack indications detected in 1990 in the core shroud of the Muehleberg reactor revealed no significant changes. A crack indication was found in one of the other welds inspected. The Swiss government issued a limited operating licence for Beznau 2 for the next ten years, i.e. until the end of 2004. The only other unit with a limited operating licence (until 2003) is Muehleberg. The remaining three reactor units, have no time limits on their operating licences, in accordance with the Atomic Law. Goesgen is the first Swiss nuclear power plant having now produced more than 100 billion kWh. As from January 1, 1995, the nominal net power of the largest Swiss reactor unit, Leibstadt, has been fixed at 1030 MW; that of the Goesgen NPP has been increased by 25 MW to 965 MW. (author) figs., tabs

Summary of operating experience in Swiss nuclear power plants 1994

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-05-01

In 1994 the Swiss nuclear power plants produced their highest-ever combined annual output. Their contribution to total electricity generation in the country was 36%. At Muehleberg the power uprate, undertaken in 1993, was effective for the first time for an entire year. The larger capacity of the new steam generators installed in 1993 in unit 1 of the Beznau NPP allows for an electric output of 103% of nominal power. The plant efficiency of the Goesgen and Leibstadt units was increased by replacing the low pressure turbines by the new ones with a modern design. The application for a power uprate of the Leibstadt reactor is still pending. For the first time in Switzerland, one of the reactor units, Beznau 2, operated on an extended cycle of one and a half years, with no refuelling outage in 1994. In spite of the replacements of two of its three low pressure turbines, Goesgen had the shortest refuelling shutdown since the start of commercial operation. The average number of reactor scrams at the Swiss plants remained stable, at less than one scram per reactor year. Re-inspection of crack indications detected in 1990 in the core shroud of the Muehleberg reactor revealed no significant changes. A crack indication was found in one of the other welds inspected. The Swiss government issued a limited operating licence for Beznau 2 for the next ten years, i.e. until the end of 2004. The only other unit with a limited operating licence (until 2003) is Muehleberg. The remaining three reactor units, have no time limits on their operating licences, in accordance with the Atomic Law. Goesgen is the first Swiss nuclear power plant having now produced more than 100 billion kWh. As from January 1, 1995, the nominal net power of the largest Swiss reactor unit, Leibstadt, has been fixed at 1030 MW; that of the Goesgen NPP has been increased by 25 MW to 965 MW. (author) figs., tabs.

Synchronously pumped optical parametric oscillation in periodically poled lithium niobate with 1-W average output power

NARCIS (Netherlands)

Graf, T.; McConnell, G.; Ferguson, A.I.; Bente, E.A.J.M.; Burns, D.; Dawson, M.D.

1999-01-01

We report on a rugged all-solid-state laser source of near-IR radiation in the range of 1461–1601 nm based on a high-power Nd:YVO4 laser that is mode locked by a semiconductor saturable Bragg reflector as the pump source of a synchronously pumped optical parametric oscillator with a periodically

Performance of a geostationary mission, geoCARB, to measure CO2, CH4 and CO column-averaged concentrations

Directory of Open Access Journals (Sweden)

I. N. Polonsky

2014-04-01

Full Text Available GeoCARB is a proposed instrument to measure column averaged concentrations of CO2, CH4 and CO from geostationary orbit using reflected sunlight in near-infrared absorption bands of the gases. The scanning options, spectral channels and noise characteristics of geoCARB and two descope options are described. The accuracy of concentrations from geoCARB data is investigated using end-to-end retrievals; spectra at the top of the atmosphere in the geoCARB bands are simulated with realistic trace gas profiles, meteorology, aerosol, cloud and surface properties, and then the concentrations of CO2, CH4 and CO are estimated from the spectra after addition of noise characteristic of geoCARB. The sensitivity of the algorithm to aerosol, the prior distributions assumed for the gases and the meteorology are investigated. The contiguous spatial sampling and fine temporal resolution of geoCARB open the possibility of monitoring localised sources such as power plants. Simulations of emissions from a power plant with a Gaussian plume are conducted to assess the accuracy with which the emission strength may be recovered from geoCARB spectra. Scenarios for "clean" and "dirty" power plants are examined. It is found that a reliable estimate of the emission rate is possible, especially for power plants that have particulate filters, by averaging emission rates estimated from multiple snapshots of the CO2 field surrounding the plant. The result holds even in the presence of partial cloud cover.

Unity power factor switching regulator

Science.gov (United States)

Rippel, Wally E. (Inventor)

1983-01-01

A single or multiphase boost chopper regulator operating with unity power factor, for use such as to charge a battery is comprised of a power section for converting single or multiphase line energy into recharge energy including a rectifier (10), one inductor (L.sub.1) and one chopper (Q.sub.1) for each chopper phase for presenting a load (battery) with a current output, and duty cycle control means (16) for each chopper to control the average inductor current over each period of the chopper, and a sensing and control section including means (20) for sensing at least one load parameter, means (22) for producing a current command signal as a function of said parameter, means (26) for producing a feedback signal as a function of said current command signal and the average rectifier voltage output over each period of the chopper, means (28) for sensing current through said inductor, means (18) for comparing said feedback signal with said sensed current to produce, in response to a difference, a control signal applied to the duty cycle control means, whereby the average inductor current is proportionate to the average rectifier voltage output over each period of the chopper, and instantaneous line current is thereby maintained proportionate to the instantaneous line voltage, thus achieving a unity power factor. The boost chopper is comprised of a plurality of converters connected in parallel and operated in staggered phase. For optimal harmonic suppression, the duty cycles of the switching converters are evenly spaced, and by negative coupling between pairs 180.degree. out-of-phase, peak currents through the switches can be reduced while reducing the inductor size and mass.

Improving Power Converter Reliability

DEFF Research Database (Denmark)

Ghimire, Pramod; de Vega, Angel Ruiz; Beczkowski, Szymon

2014-01-01

of a high-power IGBT module during converter operation, which may play a vital role in improving the reliability of the power converters. The measured voltage is used to estimate the module average junction temperature of the high and low-voltage side of a half-bridge IGBT separately in every fundamental......The real-time junction temperature monitoring of a high-power insulated-gate bipolar transistor (IGBT) module is important to increase the overall reliability of power converters for industrial applications. This article proposes a new method to measure the on-state collector?emitter voltage...... is measured in a wind power converter at a low fundamental frequency. To illustrate more, the test method as well as the performance of the measurement circuit are also presented. This measurement is also useful to indicate failure mechanisms such as bond wire lift-off and solder layer degradation...

40 CFR 600.510-12 - Calculation of average fuel economy and average carbon-related exhaust emissions.

Science.gov (United States)

2010-07-01

... and average carbon-related exhaust emissions. 600.510-12 Section 600.510-12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) ENERGY POLICY FUEL ECONOMY AND CARBON-RELATED EXHAUST EMISSIONS OF... Transportation. (iv) [Reserved] (2) Average carbon-related exhaust emissions will be calculated to the nearest...

Improved averaging for non-null interferometry

Science.gov (United States)

Fleig, Jon F.; Murphy, Paul E.

2013-09-01

Arithmetic averaging of interferometric phase measurements is a well-established method for reducing the effects of time varying disturbances, such as air turbulence and vibration. Calculating a map of the standard deviation for each pixel in the average map can provide a useful estimate of its variability. However, phase maps of complex and/or high density fringe fields frequently contain defects that severely impair the effectiveness of simple phase averaging and bias the variability estimate. These defects include large or small-area phase unwrapping artifacts, large alignment components, and voids that change in number, location, or size. Inclusion of a single phase map with a large area defect into the average is usually sufficient to spoil the entire result. Small-area phase unwrapping and void defects may not render the average map metrologically useless, but they pessimistically bias the variance estimate for the overwhelming majority of the data. We present an algorithm that obtains phase average and variance estimates that are robust against both large and small-area phase defects. It identifies and rejects phase maps containing large area voids or unwrapping artifacts. It also identifies and prunes the unreliable areas of otherwise useful phase maps, and removes the effect of alignment drift from the variance estimate. The algorithm has several run-time adjustable parameters to adjust the rejection criteria for bad data. However, a single nominal setting has been effective over a wide range of conditions. This enhanced averaging algorithm can be efficiently integrated with the phase map acquisition process to minimize the number of phase samples required to approach the practical noise floor of the metrology environment.

The electrical power sector in Turkey

International Nuclear Information System (INIS)

Gengyilmaz, Nese; Savruk, Nurettin

1998-01-01

In Turkey, highest priority is given to domestic resources, whenever economical. Imports are considered in case it is feasible. Diversification of resources is also taken into account. Efficient utilization of the resources and energy conservation are ensured ant supported. Measures for environmental and public health protection are taken into consideration during power generation and planing. In energy investments, foreign capital and domestic private sector are promoted along with the public sector. A rational structure in energy pricing is applied without any subsidies. Feasible interconnections and higher electric power exchanges with neighbouring countries are supported

Average and dispersion of the luminosity-redshift relation in the concordance model

Energy Technology Data Exchange (ETDEWEB)

Ben-Dayan, I. [DESY Hamburg (Germany). Theory Group; Gasperini, M. [Bari Univ. (Italy). Dipt. di Fisica; Istituto Nazionale di Fisica Nucleare, Bari (Italy); Marozzi, G. [College de France, 75 - Paris (France); Geneve Univ. (Switzerland). Dept. de Physique Theorique and CAP; Nugier, F. [Ecole Normale Superieure CNRS, Paris (France). Laboratoire de Physique Theorique; Veneziano, G. [College de France, 75 - Paris (France); CERN, Geneva (Switzerland). Physics Dept.; New York Univ., NY (United States). Dept. of Physics

2013-03-15

Starting from the luminosity-redshift relation recently given up to second order in the Poisson gauge, we calculate the effects of the realistic stochastic background of perturbations of the so-called concordance model on the combined light-cone and ensemble average of various functions of the luminosity distance, and on their variance, as functions of redshift. We apply a gauge-invariant light-cone averaging prescription which is free from infrared and ultraviolet divergences, making our results robust with respect to changes of the corresponding cutoffs. Our main conclusions, in part already anticipated in a recent letter for the case of a perturbation spectrum computed in the linear regime, are that such inhomogeneities not only cannot avoid the need for dark energy, but also cannot prevent, in principle, the determination of its parameters down to an accuracy of order 10{sup -3} - 10{sup -5}, depending on the averaged observable and on the regime considered for the power spectrum. However, taking into account the appropriate corrections arising in the non-linear regime, we predict an irreducible scatter of the data approaching the 10% level which, for limited statistics, will necessarily limit the attainable precision. The predicted dispersion appears to be in good agreement with current observational estimates of the distance-modulus variance due to Doppler and lensing effects (at low and high redshifts, respectively), and represents a challenge for future precision measurements.

[The gender gap in highest quality medical research - A scientometric analysis of the representation of female authors in highest impact medical journals].

Science.gov (United States)

Bendels, Michael H K; Wanke, Eileen M; Benik, Steffen; Schehadat, Marc S; Schöffel, Norman; Bauer, Jan; Gerber, Alexander; Brüggmann, Dörthe; Oremek, Gerhard M; Groneberg, David A

2018-05-01

 The study aims to elucidate the state of gender equality in high-impact medical research, analyzing the representation of female authorships from January, 2008 to September, 2017.  133 893 male and female authorships from seven high-impact medical journals were analyzed. The key methodology was the combined analysis of the relative frequency, odds ratio and citations of female authorships. The Prestige Index measures the distribution of prestigious authorships between the two genders.  35.0 % of all authorships and 34.3 % of the first, 36.1 % of the co- and 24.2 % of the last authorships were held by women. Female authors have an odds ratio of 0.97 (KI: 0.93 - 1.01) for first, 1.36 (KI: 1.32 - 1.40) for co- und 0.57 (KI: 0.54 - 0.60) for last authorships compared to male authors. The proportion of female authorships exhibits an annual growth of 1.3 % overall, with 0.5 % for first, 1.2 % for co-, and 0.8 % for last authorships. Women are underrepresented at prestigious authorship compared to men (Prestige Index = -0.38). The underrepresentation accentuates in highly competitive articles attracting the highest citation rates, namely, articles with many authors and articles that were published in highest-impact journals. Multi-author articles with male key authors are more frequently cited than articles with female key authors. The gender-specific differences in citation rates increase the more authors contribute to an article. Women publish fewer articles compared to men (39.6 % female authors are responsible for 35.0 % of the authorships) and are underrepresented at productivity levels of more than 1 article per author. Distinct differences at the country level were revealed.  High impact medical research is characterized by few female group leaders as last authors and many female researchers being first or co-authors early in their career. It is very likely that this gender-specific career dichotomy will persistent in

SiC for microwave power transistors

Energy Technology Data Exchange (ETDEWEB)

Sriram, S.; Siergiej, R.R.; Clarke, R.C.; Agarwal, A.K.; Brandt, C.D. [Northrop Grumman Sci. and Technol. Center, Pittsburgh, PA (United States)

1997-07-16

The advantages of SiC for high power, microwave devices are discussed. The design considerations, fabrication, and experimental results are described for SiC MESFETs and SITs. The highest reported f{sub max} for a 0.5 {mu}m MESFET using semi-insulating 4H-SiC is 42 GHz. These devices also showed a small signal gain of 5.1 dB at 20 GHz. Other 4H-SiC MESFETs have shown a power density of 3.3 W/mm at 850 MHz. The largest SiC power transistor reported is a 450 W SIT measured at 600 MHz. The power output density of this SIT is 2.5 times higher than that of comparable silicon devices. SITs have been designed to operate as high as 3.0 GHz, with a 3 cm periphery part delivering 38 W of output power. (orig.) 28 refs.

Automatic orbital GTAW welding: Highest quality welds for tomorrow's high-performance systems

Science.gov (United States)

Henon, B. K.

1985-01-01

Automatic orbital gas tungsten arc welding (GTAW) or TIG welding is certain to play an increasingly prominent role in tomorrow's technology. The welds are of the highest quality and the repeatability of automatic weldings is vastly superior to that of manual welding. Since less heat is applied to the weld during automatic welding than manual welding, there is less change in the metallurgical properties of the parent material. The possibility of accurate control and the cleanliness of the automatic GTAW welding process make it highly suitable to the welding of the more exotic and expensive materials which are now widely used in the aerospace and hydrospace industries. Titanium, stainless steel, Inconel, and Incoloy, as well as, aluminum can all be welded to the highest quality specifications automatically. Automatic orbital GTAW equipment is available for the fusion butt welding of tube-to-tube, as well as, tube to autobuttweld fittings. The same equipment can also be used for the fusion butt welding of up to 6 inch pipe with a wall thickness of up to 0.154 inches.

Carrier Distortion in Hysteretic Self-Oscillating Class-D Audio Power

DEFF Research Database (Denmark)

Høyerby, Mikkel Christian Kofod; Andersen, Michael A. E.

2009-01-01

An important distortion mechanism in hysteretic self-oscillating (SO) class-D (switch mode) power amplifiers-–carrier distortion-–is analyzed and an optimization method is proposed. This mechanism is an issue in any power amplifier application where a high degree of proportionality between input...... and output is required, such as in audio power amplifiers or xDSL drivers. From an average-mode point of view, carrier distortion is shown to be caused by nonlinear variation of the hysteretic comparator input average voltage with the output average voltage. This easily causes total harmonic distortion...... figures in excess of 0.1–0.2%, inadequate for high-quality audio applications. Carrier distortion is shown to be minimized when the feedback system is designed to provide a triangular carrier (sliding) signal at the input of a hysteretic comparator. The proposed optimization method is experimentally...

High power industrial picosecond laser from IR to UV

Science.gov (United States)

Saby, Julien; Sangla, Damien; Pierrot, Simonette; Deslandes, Pierre; Salin, François

2013-02-01

Many industrial applications such as glass cutting, ceramic micro-machining or photovoltaic processes require high average and high peak power Picosecond pulses. The main limitation for the expansion of the picosecond market is the cost of high power picosecond laser sources, which is due to the complexity of the architecture used for picosecond pulse amplification, and the difficulty to keep an excellent beam quality at high average power. Amplification with fibers is a good technology to achieve high power in picosecond regime but, because of its tight confinement over long distances, light undergoes dramatic non linearities while propagating in fibers. One way to avoid strong non linearities is to increase fiber's mode area. Nineteen missing holes fibers offering core diameter larger than 80μm have been used over the past few years [1-3] but it has been shown that mode instabilities occur at approximately 100W average output power in these fibers [4]. Recently a new fiber design has been introduced, in which HOMs are delocalized from the core to the clad, preventing from HOMs amplification [5]. In these so-called Large Pitch Fibers, threshold for mode instabilities is increased to 294W offering robust single-mode operation below this power level [6]. We have demonstrated a high power-high efficiency industrial picosecond source using single-mode Large Pitch rod-type fibers doped with Ytterbium. Large Pitch Rod type fibers can offer a unique combination of single-mode output with a very large mode area from 40 μm up to 100μm and very high gain. This enables to directly amplify a low power-low energy Mode Locked Fiber laser with a simple amplification architecture, achieving very high power together with singlemode output independent of power level or repetition rate.

A time-averaged cosmic ray propagation theory

International Nuclear Information System (INIS)

Klimas, A.J.

1975-01-01

An argument is presented, which casts doubt on our ability to choose an appropriate magnetic field ensemble for computing the average behavior of cosmic ray particles. An alternate procedure, using time-averages rather than ensemble-averages, is presented. (orig.) [de

The part of the solar spectrum with the highest influence on the formation of SOA in the continental boundary layer

Directory of Open Access Journals (Sweden)

M. Boy

2002-01-01

Full Text Available The relationship between nucleation events and spectral solar irradiance was analysed using two years of data collected at the Station for Measuring Forest Ecosystem-Atmosphere Relations (SMEAR II in Hyytiälä, Finland. We analysed the data in two different ways. In the first step we calculated ten nanometer average values from the irradiance measurements between 280 and 580 nm and explored if any special wavelengths groups showed higher values on event days compared to a spectral reference curve for all the days for 2 years or to reference curves for every month. The results indicated that short wavelength irradiance between 300 and 340 nm is higher on event days in winter (February and March compared to the monthly reference graph but quantitative much smaller than in spring or summer. By building the ratio between the average values of different event classes and the yearly reference graph we obtained peaks between 1.17 and 1.6 in the short wavelength range (300--340 nm. In the next step we included number concentrations of particles between 3 and 10 nm and calculated correlation coefficients between the different wavelengths groups and the particles. The results were quite similar to those obtained previously; the highest correlation coefficients were reached for the spectral irradiance groups 3--5 (300--330 nm with average values for the single event classes around 0.6 and a nearly linear decrease towards higher wavelengths groups by 30%. Both analyses indicate quite clearly that short wavelength irradiance between 300 and 330 or 340 nm is the most important solar spectral radiation for the formation of newly formed aerosols. In the end we introduce a photochemical mechanism as one possible pathway how short wavelength irradiance can influence the formation of SOA by calculating the production rate of excited oxygen. This mechanism shows in which way short wavelength irradiance can influence the formation of new particles even though the

ANALISIS CURAH HUJAN DAN DEBIT MODEL SWAT DENGAN METODE MOVING AVERAGE DI DAS CILIWUNG HULU

Directory of Open Access Journals (Sweden)

Defri Satiya Zuma

2017-09-01

Full Text Available Watershed can be regarded as a hydrological system that has a function in transforming rainwater as an input into outputs such as flow and sediment. The transformation of inputs into outputs has specific forms and properties. The transformation involves many processes, including processes occurred on the surface of the land, river basins, in soil and aquifer. This study aimed to apply the SWAT model  in  Ciliwung Hulu Watershed, asses the effect of average rainfall  on 3 days, 5 days, 7 days and 10 days of the hydrological characteristics in Ciliwung Hulu Watershed. The correlation coefficient (r between rainfall and discharge was positive, it indicated that there was an unidirectional relationship between rainfall and discharge in the upstream, midstream and downstream of the watershed. The upper limit ratio of discharge had a downward trend from upstream to downstream, while the lower limit ratio of  discharge had an upward trend from upstream to downstream. It showed that the discharge peak in Ciliwung  Hulu Watershed from upstream to downstream had a downward trend while the baseflow from upstream to downstream had an upward trend. It showed that the upstream of Ciliwung Hulu Watershed had the highest ratio of discharge peak  and baseflow so it needs the soil and water conservations and technical civil measures. The discussion concluded that the SWAT model could be well applied in Ciliwung Hulu Watershed, the most affecting average rainfall on the hydrological characteristics was the average rainfall of 10 days. On average  rainfall of 10 days, all components had contributed maximally for river discharge.

Wind power and the conditions at a liberalized power market

International Nuclear Information System (INIS)

Morthorst, P.E.

2003-01-01

Wind power is undergoing a rapid development nationally as well as globally and in a number of countries covers an increasing part of the power supply. At the same time an ongoing liberalization of power markets is taking place and to an increasing extent the owners of wind power plants will themselves have to be responsible for trading the power at the spot market and financially handling the balancing. In the western part of Denmark (Jutland/Funen area), wind-generated power from time to time covers almost 100% of total power consumption. Therefore some examples are chosen from this area to analyse in more detail how well large amounts of wind power in the short-term are handled at the power spot market. It turns out that there is a tendency that more wind power in the system in the short run leads to relatively lower spot prices, while less wind power implies relatively higher spot prices, although, with the exception of December 2002, in general no strong relationship is found. A stronger relationship is found at the regulating market, where there is a fairly clear tendency that the more wind power produced, the higher is the need for down-regulation, and, correspondingly, the less wind power produced, the higher is the need for up-regulation. In general for the Jutland/Funen area the average cost of down-regulation is calculated as 1 2 c euros/kWh regulated for 2002, while the cost of up-regulation amounts to 0 7 c euros/kWh regulated. (author)

The influence of geographic location on population exposure to emissions from power plants throughout China

International Nuclear Information System (INIS)

Ying Zhou; Levy, J.I.; Evans, J.S.; Hammitt, J.K.

2006-01-01

This analysis seeks to evaluate the influence of emission source location on population exposure in China to fine particles and sulfur dioxide. We use the concept of intake fraction, defined as the fraction of material or its precursor released from a source that is eventually inhaled or ingested by a population. We select 29 power-plant sites throughout China and estimate annual average intake fractions at each site, using identical source characteristics to isolate the influence of geographic location. In addition, we develop regression models to interpret the intake fraction values and allow for extrapolation to other sites. To model the concentration increase due to emissions from selected power plants, we used a detailed long-range atmospheric dispersion model, CALPUFF. Primary fine particles have the highest average intake fraction (1 x 10 -5 ), followed by sulfur dioxide (5 x 10 -6 ), sulfate from sulfur dioxide (4 x 10 -6 ), and nitrate from nitrogen oxides (4 x 10 -6 ). For all pollutants, the intake fractions span approximately an order of magnitude across sites. In the regression analysis, the independent variables are meteorological proxies (such as climate region and precipitation) and population at various distances from the source. We find that population terms can explain a substantial percentage of variability in the intake fraction for all pollutants (R 2 between 0.86 and 0.95 across pollutants), with a significant modifying influence of meteorological regime. Near-source population is more important for primary coarse particles while population at medium to long distance is more important for primary fine particles and secondary particles. A significant portion of intake fraction (especially for secondary particles and primary fine particles) occurs beyond 500 km of the source, emphasizing the need for detailed long-range dispersion modeling. These findings demonstrate that intake fractions for power plants in China can be estimated with

The influence of geographic location on population exposure to emissions from power plants throughout China

Energy Technology Data Exchange (ETDEWEB)

Ying Zhou; Levy, J.I. [Harvard School of Public Health, Boston, MA (United States); Evans, J.S.; Hammitt, J.K. [Harvard Center for Risk Analysis, Boston, MA (United States)

2006-04-15

This analysis seeks to evaluate the influence of emission source location on population exposure in China to fine particles and sulfur dioxide. We use the concept of intake fraction, defined as the fraction of material or its precursor released from a source that is eventually inhaled or ingested by a population. We select 29 power-plant sites throughout China and estimate annual average intake fractions at each site, using identical source characteristics to isolate the influence of geographic location. In addition, we develop regression models to interpret the intake fraction values and allow for extrapolation to other sites. To model the concentration increase due to emissions from selected power plants, we used a detailed long-range atmospheric dispersion model, CALPUFF. Primary fine particles have the highest average intake fraction (1 x 10{sup -5}), followed by sulfur dioxide (5 x 10{sup -6}), sulfate from sulfur dioxide (4 x 10{sup -6}), and nitrate from nitrogen oxides (4 x 10{sup -6}). For all pollutants, the intake fractions span approximately an order of magnitude across sites. In the regression analysis, the independent variables are meteorological proxies (such as climate region and precipitation) and population at various distances from the source. We find that population terms can explain a substantial percentage of variability in the intake fraction for all pollutants (R{sup 2} between 0.86 and 0.95 across pollutants), with a significant modifying influence of meteorological regime. Near-source population is more important for primary coarse particles while population at medium to long distance is more important for primary fine particles and secondary particles. A significant portion of intake fraction (especially for secondary particles and primary fine particles) occurs beyond 500 km of the source, emphasizing the need for detailed long-range dispersion modeling. These findings demonstrate that intake fractions for power plants in China can be

Dynamic Average-Value Modeling of Doubly-Fed Induction Generator Wind Energy Conversion Systems

Science.gov (United States)

Shahab, Azin

In a Doubly-fed Induction Generator (DFIG) wind energy conversion system, the rotor of a wound rotor induction generator is connected to the grid via a partial scale ac/ac power electronic converter which controls the rotor frequency and speed. In this research, detailed models of the DFIG wind energy conversion system with Sinusoidal Pulse-Width Modulation (SPWM) scheme and Optimal Pulse-Width Modulation (OPWM) scheme for the power electronic converter are developed in detail in PSCAD/EMTDC. As the computer simulation using the detailed models tends to be computationally extensive, time consuming and even sometimes not practical in terms of speed, two modified approaches (switching-function modeling and average-value modeling) are proposed to reduce the simulation execution time. The results demonstrate that the two proposed approaches reduce the simulation execution time while the simulation results remain close to those obtained using the detailed model simulation.

Characterization and design of a low-power wireless power delivery system

Science.gov (United States)

Falkenstein, Erez Avigdor

There is an increased demand for wireless sensors for data gathering and transmission where running wires to power a device or changing/charging batteries is difficult. Often the data is gathered at locations that are difficult to access, that need to be covert, and/or where the sensors cannot be easily maintained. Some examples are implanted sensors for medical diagnostics and therapy, structural monitoring sensors, sensors inside hazardous manufacturing or other hazardous environments, etc. For any low power sensor that operates at a low duty cycle, and in an environment with low levels of light or vibration, RF wireless powering offers the potential for maintenance-free operation. The thesis focuses on a design methodology for low-power non-directional far-field wireless powering. The power receiver consists of one or more antennae which receive plane waves transmitted by the powering source, and deliver the RF power to a rectifying element. The resulting DC power is optimally transferred to the electronic application via a power management circuit. The powering is independent of the electronic application which can include wireless transmission of sensor data. The design and implementation of an integrated rectifier-antenna at low incident power densities (from 25--200 muW/cm2) is presented. Nonlinear source-pull measurements and harmonic balance simulations are used for finding the optimal rectifying device RF and DC impedances for efficient rectification. Experimental results show that an antenna design with a specific complex impedance reaches the highest rectification efficiency. Several examples of the design methodology will be shown. In specific, characterization of a rectifying patch antenna at frequency of 2.45GHz will be detailed, with an optimal RF impedance of 137+j149O and an optimal DC load of 365O resulting in RF to DC conversion efficiency of 63% for the rectifier alone and 56% for the total rectifying antenna.

Average Heating Rate of Hot Atmospheres in Distant Galaxy Clusters by Radio AGN: Evidence for Continuous AGN Heating

Science.gov (United States)

Ma, Cheng-Jiun; McNamara, B.; Nulsen, P.; Schaffer, R.

2011-09-01

X-ray observations of nearby clusters and galaxies have shown that energetic feedback from AGN is heating hot atmospheres and is probably the principal agent that is offsetting cooling flows. Here we examine AGN heating in distant X-ray clusters by cross correlating clusters selected from the 400 Square Degree X-ray Cluster survey with radio sources in the NRAO VLA Sky Survey. The jet power for each radio source was determined using scaling relations between radio power and cavity power determined for nearby clusters, groups, and galaxies with atmospheres containing X-ray cavities. Roughly 30% of the clusters show radio emission above a flux threshold of 3 mJy within the central 250 kpc that is presumably associated with the brightest cluster galaxy. We find no significant correlation between radio power, hence jet power, and the X-ray luminosities of clusters in redshift range 0.1 -- 0.6. The detection frequency of radio AGN is inconsistent with the presence of strong cooling flows in 400SD, but cannot rule out the presence of weak cooling flows. The average jet power of central radio AGN is approximately 2 10^{44} erg/s. The jet power corresponds to an average heating of approximately 0.2 keV/particle for gas within R_500. Assuming the current AGN heating rate remained constant out to redshifts of about 2, these figures would rise by a factor of two. Our results show that the integrated energy injected from radio AGN outbursts in clusters is statistically significant compared to the excess entropy in hot atmospheres that is required for the breaking of self-similarity in cluster scaling relations. It is not clear that central AGN in 400SD clusters are maintained by a self-regulated feedback loop at the base of a cooling flow. However, they may play a significant role in preventing the development of strong cooling flows at early epochs.

Improving consensus structure by eliminating averaging artifacts

Directory of Open Access Journals (Sweden)

KC Dukka B

2009-03-01

Full Text Available Abstract Background Common structural biology methods (i.e., NMR and molecular dynamics often produce ensembles of molecular structures. Consequently, averaging of 3D coordinates of molecular structures (proteins and RNA is a frequent approach to obtain a consensus structure that is representative of the ensemble. However, when the structures are averaged, artifacts can result in unrealistic local geometries, including unphysical bond lengths and angles. Results Herein, we describe a method to derive representative structures while limiting the number of artifacts. Our approach is based on a Monte Carlo simulation technique that drives a starting structure (an extended or a 'close-by' structure towards the 'averaged structure' using a harmonic pseudo energy function. To assess the performance of the algorithm, we applied our approach to Cα models of 1364 proteins generated by the TASSER structure prediction algorithm. The average RMSD of the refined model from the native structure for the set becomes worse by a mere 0.08 Å compared to the average RMSD of the averaged structures from the native structure (3.28 Å for refined structures and 3.36 A for the averaged structures. However, the percentage of atoms involved in clashes is greatly reduced (from 63% to 1%; in fact, the majority of the refined proteins had zero clashes. Moreover, a small number (38 of refined structures resulted in lower RMSD to the native protein versus the averaged structure. Finally, compared to PULCHRA 1, our approach produces representative structure of similar RMSD quality, but with much fewer clashes. Conclusion The benchmarking results demonstrate that our approach for removing averaging artifacts can be very beneficial for the structural biology community. Furthermore, the same approach can be applied to almost any problem where averaging of 3D coordinates is performed. Namely, structure averaging is also commonly performed in RNA secondary prediction 2, which

Electric power annual, 1991

International Nuclear Information System (INIS)

1993-01-01

The Electric Power Annual is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration (EIA); US Department of Energy. The 1991 edition has been enhanced to include statistics on electric utility demand-side management and nonutility supply. ''The US Electric Power Industry at a Glance'' section presents a profile of the electric power industry ownership and performance, and a review of key statistics for the year. Subsequent sections present data on generating capability, including proposed capability additions; net generation; fossil-fuel statistics; electricity sales, revenue, and average revenue per kilowatthour sold; financial statistics; environmental statistics; electric power transactions; demand-side management; and nonutility power producers. In addition, the appendices provide supplemental data on major disturbances and unusual occurrences in US electricity power systems. Each section contains related text and tables and refers the reader to the appropriate publication that contains more detailed data on the subject matter. Monetary values in this publication are expressed in nominal terms

Wave power potential at a few shallow-water locations around Indian coast

Digital Repository Service at National Institute of Oceanography (India)

SanilKumar, V.; Dubhashi, K.K.; Nair, T.M.B.; Singh, J.

less with maximum value of 31.8 kW m sup(-1). The average wave power during the summer monsoon is high (15.5-19.3 kW m sup(-1)) along the west coast of India. The study shows that the annual average wave power (1.8-7.6 kW m sup(-1)) along the locations...

Operation of Finnish nuclear power plants

International Nuclear Information System (INIS)

Tossavainen, K.

1994-03-01

In the third quarter of 1993, all of Finland's four nuclear power plant units were in power operation, with the exception of the annual maintenance outages of the Loviisa units. The load factor average of the plant units was 83.6 %. None of the events which occurred during this annual quarter had any bearing on nuclear or radiation safety. (4 figs., 5 tabs.)

A data mining approach: Analyzing wind speed and insolation period data in Turkey for installations of wind and solar power plants

International Nuclear Information System (INIS)

Colak, Ilhami; Sagiroglu, Seref; Demirtas, Mehmet; Yesilbudak, Mehmet

2013-01-01

Highlights: ► Wind speed and insolation period data were analyzed using a data mining approach. ► Most of the studies in the literature were based on Weibull and Rayleigh models. ► Nearest and farest neighbor algorithms were used with different distance metrics. ► Many inferences were achieved in efficient limits for wind and solar farm analyses. - Abstract: Wind and solar power plant installations have been recently increased rapidly with respect to the depletion of fossil-based fuels all over the world. Due to stochastic nature of meteorological conditions, wind and solar energies have a non-schedulable nature and they require several installation analyses to determine the location and the capacities of wind and solar power to be produced. This paper focuses on the similarity, feasibility and numerical analyses of 75 cities in Turkey based on the monthly average wind speed and insolation period data. The nearest and the farest neighbor algorithms are used as agglomerative hierarchical clustering methods with Euclidean, Manhattan and Minkowski distance metrics in the stage of making the similarity and feasibility analyses. The maximum cophenetic correlation coefficient is achieved by the nearest neighbor algorithm with the Minkowski distance metric in the similarity and feasibility analyses. On the other hand, graphical representations of the monthly average wind speed and insolation period data are utilized for making the numerical analysis. The highest annual average wind speed and insolation period are obtained as 3.88 m/s and 8.45 h/day, respectively. Overall, many inferences were achieved in acceptable and efficient limits for wind and solar energy.

LNG plant combined with power plant

Energy Technology Data Exchange (ETDEWEB)

Aoki, I; Kikkawa, Y [Chiyoda Chemical Engineering and Construction Co. Ltd., Tokyo (Japan)

1997-06-01

The LNG plant consumers a lot of power of natural gas cooling and liquefaction. In some LNG plant location, a rapid growth of electric power demand is expected due to the modernization of area and/or the country. The electric power demand will have a peak in day time and low consumption in night time, while the power demand of the LNG plant is almost constant due to its nature. Combining the LNG plant with power plant will contribute an improvement the thermal efficiency of the power plant by keeping higher average load of the power plant, which will lead to a reduction of electrical power generation cost. The sweet fuel gas to the power plant can be extracted from the LNG plant, which will be favorable from view point of clean air of the area. (Author). 5 figs.

LNG plant combined with power plant

International Nuclear Information System (INIS)

Aoki, I.; Kikkawa, Y.

1997-01-01

The LNG plant consumers a lot of power of natural gas cooling and liquefaction. In some LNG plant location, a rapid growth of electric power demand is expected due to the modernization of area and/or the country. The electric power demand will have a peak in day time and low consumption in night time, while the power demand of the LNG plant is almost constant due to its nature. Combining the LNG plant with power plant will contribute an improvement the thermal efficiency of the power plant by keeping higher average load of the power plant, which will lead to a reduction of electrical power generation cost. The sweet fuel gas to the power plant can be extracted from the LNG plant, which will be favorable from view point of clean air of the area. (Author). 5 figs

40 CFR 1045.140 - What is my engine's maximum engine power?

Science.gov (United States)

2010-07-01

...) Maximum engine power for an engine family is generally the weighted average value of maximum engine power... engine family's maximum engine power apply in the following circumstances: (1) For outboard or personal... value for maximum engine power from all the different configurations within the engine family to...

Reconstruction of the time-averaged sheath potential profile in an argon RF plasma using the ion energy distribution

International Nuclear Information System (INIS)

Fivaz, M.; Brunner, S.; Schwarzenbach, W.; Howling, A.A.; Hollenstein, C.

1994-10-01

Charge-exchange collisions and radio-frequency excitation combine to give peaks in the ion energy distribution measured at the ground electrode of an argon plasma in a capacitive reactor. These peaks are used as a diagnostic to reconstruct the profile of the time-averaged potential in the sheath. Particle-In-Cell simulations show that the method is accurate. The method is applied to investigate the sheath thickness as a function of excitation frequency at constant plasma power. The time-averaged potential is found to be parabolic in both experimental measurements and numerical simulation. (author) 6 figs., 1 tab., 15 refs

Performance analysis of an integrated gas-, steam- and organic fluid-cycle thermal power plant

International Nuclear Information System (INIS)

Oko, C.O.C.; Njoku, I.H.

2017-01-01

This paper presents the performance analysis of an existing combined cycle power plant augmented with a waste heat fired organic Rankine cycle power plant for extra power generation. This was achieved by performing energy and exergy analysis of the integrated gas-, steam- and organic fluid-cycle thermal power plant (IPP). Heat source for the subcritical organic Rankine cycle (ORC) was the exhaust flue gases from the heat recovery steam generators of a 650 MW natural gas fired combined cycle power plant. The results showed that extra 12.4 MW of electricity was generated from the attached ORC unit using HFE7100 as working fluid. To select ORC working fluid, ten isentropic fluids were screened and HFE7100 produced the highest net power output and cycle efficiency. Exergy and energy efficiencies of the IPP improved by 1.95% and 1.93%, respectively. The rate of exergy destruction in the existing combined cycle plant was highest in the combustion chamber, 59%, whereas in the ORC, the highest rate of exergy destruction occurred in the evaporator, 62%. Simulations showed exergy efficiency of the IPP decreased with increasing ambient temperature. Exit stack flue gas temperature reduced from 126 °C in the combined cycle power plant to 100 °C in the integrated power plant. - Highlights: • Combined cycle plant retrofitted with ORC produced extra 12.4 MW electric power. • ORC is powered with low temperature flue gas from an existing combined cycle plant. • Exergy destruction rate in integrated plant(IPP) is less than in combined plant. • Exit stack temperature of the IPP has less environmental thermal pollution. • Exergy and energy efficiencies of the IPP improved by 1.95% and 1.93%, respectively.

Contribution to evaluating nuclear power plant accidents

International Nuclear Information System (INIS)

Razga, J.; Horacek, P.

1990-01-01

Large-scale accidents pose the highest risk in the use of nuclear power. They are the major factor that has to be taken into account when assessing the effect of nuclear power plants on human health and on the environment. In Czechoslovak conditions, the effectiveness of provisions made to reduce the hazard of large-scale nuclear power plant accidents must be considered from the following aspects: effect on human health, consequences of long-term disabling of the infrastructure, potential of human and material reserves in coping with the accident, consequences of power failure for the electricity system, effect on agricultural production and catering, risk of ground and surface water contamination in the Labe or Danube river basin, and international political aspects. (Z.M.). 3 tabs., 18 refs

Large Scale Integration of Renewable Power Sources into the Vietnamese Power System

Science.gov (United States)

Kies, Alexander; Schyska, Bruno; Thanh Viet, Dinh; von Bremen, Lueder; Heinemann, Detlev; Schramm, Stefan

2017-04-01

The Vietnamese Power system is expected to expand considerably in upcoming decades. Power capacities installed are projected to grow from 39 GW in 2015 to 129.5 GW by 2030. Installed wind power capacities are expected to grow to 6 GW (0.8 GW 2015) and solar power capacities to 12 GW (0.85 GW 2015). This goes hand in hand with an increase of the renewable penetration in the power mix from 1.3% from wind and photovoltaics (PV) in 2015 to 5.4% by 2030. The overall potential for wind power in Vietnam is estimated to be around 24 GW. Moreover, the up-scaling of renewable energy sources was formulated as one of the priorized targets of the Vietnamese government in the National Power Development Plan VII. In this work, we investigate the transition of the Vietnamese power system towards high shares of renewables. For this purpose, we jointly optimise the expansion of renewable generation facilities for wind and PV, and the transmission grid within renewable build-up pathways until 2030 and beyond. To simulate the Vietnamese power system and its generation from renewable sources, we use highly spatially and temporally resolved historical weather and load data and the open source modelling toolbox Python for Power System Analysis (PyPSA). We show that the highest potential of renewable generation for wind and PV is observed in southern Vietnam and discuss the resulting need for transmission grid extensions in dependency of the optimal pathway. Furthermore, we show that the smoothing effect of wind power has several considerable beneficial effects and that the Vietnamese hydro power potential can be efficiently used to provide balancing opportunities. This work is part of the R&D Project "Analysis of the Large Scale Integration of Renewable Power into the Future Vietnamese Power System" (GIZ, 2016-2018).

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

Power scaling of supercontinuum seeded megahertz-repetition rate optical parametric chirped pulse amplifiers.

Science.gov (United States)

Riedel, R; Stephanides, A; Prandolini, M J; Gronloh, B; Jungbluth, B; Mans, T; Tavella, F

2014-03-15

Optical parametric chirped-pulse amplifiers with high average power are possible with novel high-power Yb:YAG amplifiers with kW-level output powers. We demonstrate a compact wavelength-tunable sub-30-fs amplifier with 11.4 W average power with 20.7% pump-to-signal conversion efficiency. For parametric amplification, a beta-barium borate crystal is pumped by a 140 W, 1 ps Yb:YAG InnoSlab amplifier at 3.25 MHz repetition rate. The broadband seed is generated via supercontinuum generation in a YAG crystal.

Sound power radiated by sources in diffuse fields

DEFF Research Database (Denmark)

Polack, Jean-Dominique

2000-01-01

Sound power radiated by sources at low frequency notoriously depends on source position. We sampled the sound field of a rectangular room at 18 microphone and 4 source positions. Average power spectra were extrapolated from the reverberant field, taking into account the frequency dependent...

Power facility plan and power supply plan of Japan in 1988

Energy Technology Data Exchange (ETDEWEB)

Yoshino, Shoji; Makino, Masao

1988-06-01

The power facility plan and the power supply plan for 1988 are described. The demand by non-industrial use will grow at an average of 3.8% for the 1986-97 period due to changes in the life style, construction and extension of buildings and increasing use of OA equipment although the power conservation is promoted. The industrial consumption will increase at only 1.2% a year due to the slowed growth and energy saving. As a result, the total demand will be 778,200 million kWh in 1997 with annual growth of 2.4%. The maximum demand will be 151,210 kW in 1997 with annual growth of 2.9%. The annual load rate will decrease to 56.9%, showing a continuously worsening utilization efficiency of power facilities. The development of 29 power units with total capacity of 2,760 MW is planned in 1988 for a stable power supply with a sufficient margin regarding maximum demand. The plan requires the investment of 3,700 billion yen, including the power transmission systems and substations. The power supply plan in 1988 is aimed at the effective operation of facilities and cost reduction by regional management under proper recognition of local characteristics of each power source, while maintaining a stable power supply with specified margins. (1 fig, 11 tabs)

[Study of personal best value of peak expiratory flow in patients with asthma--comparison of the highest value of daily PEF under good control and the highest value of daily PEF obtained after using repeated inhaled beta2-agonist during high-dose inhaled steroid treatment].

Science.gov (United States)

Watanabe, Naoto; Makino, Sohei; Kihara, Norio; Fukuda, Takeshi

2008-12-01

In the guideline for asthma management, it is important to find the personal best value of peak expiratory flow (best PEF). Recently, we have substituted the highest value of PEF in daily life under good control (daily highest PEF) for the best PEF. In the present study, we considered whether the daily highest PEF could be used as the best PEF or not. Subjects were 30 asthmatics who were well controlled but whose baseline PEF values were less than 80 percent of predicted values. We compared the daily highest PEF and the highest of PEF obtained after repeated inhaled beta2-agonist (salbutamol MDI every 20 minutes three times). All subjects then received 1600 microg/day of beclomethasone dipropionate (BDP) for 4 to 8 weeks. We studied the effect of high-dose inhaled steroid treatment on each PEF value and compared the daily highest PEF and the highest PEF obtained after using repeated salbutamol MDI during high dose inhaled steroid therapy on the examination day again. The baseline PEF, daily highest PEF and the highest PEF obtained after salbutamol MDI were significantly less than the each values obtained after high-dose BDP. The best PEF value of them was the value obtained after repeated salbutamol MDI during high dose BDP. We suggest that the daily highest PEF under good control is not a substitute for best PEF because it changes according to the degree of improvement of airway inflammation. We recommend that a course of high dose inhaled steroid is effective in finding the best value of PEF for each individual with moderate asthma.

40 CFR 76.11 - Emissions averaging.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Emissions averaging. 76.11 Section 76.11 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.11 Emissions averaging. (a) General...

A practical guide to averaging functions

CERN Document Server

Beliakov, Gleb; Calvo Sánchez, Tomasa

2016-01-01

This book offers an easy-to-use and practice-oriented reference guide to mathematical averages. It presents different ways of aggregating input values given on a numerical scale, and of choosing and/or constructing aggregating functions for specific applications. Building on a previous monograph by Beliakov et al. published by Springer in 2007, it outlines new aggregation methods developed in the interim, with a special focus on the topic of averaging aggregation functions. It examines recent advances in the field, such as aggregation on lattices, penalty-based aggregation and weakly monotone averaging, and extends many of the already existing methods, such as: ordered weighted averaging (OWA), fuzzy integrals and mixture functions. A substantial mathematical background is not called for, as all the relevant mathematical notions are explained here and reported on together with a wealth of graphical illustrations of distinct families of aggregation functions. The authors mainly focus on practical applications ...

7 CFR 51.2561 - Average moisture content.

Science.gov (United States)