WorldWideScience

Sample records for body high power

  1. The Effect of High Intensity Intermittent Exercise on Power Output for the Upper Body

    Directory of Open Access Journals (Sweden)

    Leonie Harvey

    2015-06-01

    Full Text Available The aim of the present study was to examine and measure high intensity, intermittent upper body performance, in addition to identifying areas of the body that affect the variance in total work done during the 5 × 6 s sprint test. Fifteen males completed an upper body 5 × 6 s sprint test on a modified electro-magnetically braked cycle ergometer, which consisted of five maximal effort sprints, each 6 s in duration, separated by 24 s of passive recovery. A fly wheel braking force corresponding to 5% of the participants’ body weight was used as the implemented resistance level. Body composition was measured using dual-energy X-ray absorptiometry (DEXA. Percent (% decrement was calculated as 100 − (Total work/ideal work × 100. Significant (P < 0.05 differences were found between sprints for both absolute and relative (W, W·kg−1, W·kg−1 Lean body mass (LBM and W·kg−1 Upper body lean body mass (UBLBM peak (PP and mean (MP power. The % decrement in total work done over the five sprints was 11.4%. Stepwise multiple linear regression analysis revealed that UBLBM accounts for 87% of the variance in total work done during the upper body 5 × 6 s sprint test. These results provide a descriptive analysis of upper body, high intensity intermittent exercise, demonstrating that PP and MP output decreased significantly during the upper body 5 × 6 s sprint test.

  2. Crossfit-based high-intensity power training improves maximal aerobic fitness and body composition.

    Science.gov (United States)

    Smith, Michael M; Sommer, Allan J; Starkoff, Brooke E; Devor, Steven T

    2013-11-01

    The purpose of this study was to examine the effects of a crossfit-based high-intensity power training (HIPT) program on aerobic fitness and body composition. Healthy subjects of both genders (23 men, 20 women) spanning all levels of aerobic fitness and body composition completed 10 weeks of HIPT consisting of lifts such as the squat, deadlift, clean, snatch, and overhead press performed as quickly as possible. Additionally, this crossfit-based HIPT program included skill work for the improvement of traditional Olympic lifts and selected gymnastic exercises. Body fat percentage was estimated using whole-body plethysmography, and maximal aerobic capacity (VO2max) was measured by analyzing expired gasses during a Bruce protocol maximal graded treadmill test. These variables were measured again after 10 weeks of training and compared for significant changes using a paired t-test. Results showed significant (p < 0.05) improvements of VO2max in men (43.10 ± 1.40 to 48.96 ± 1.42 ml · kg · min) and women (35.98 ± 1.60 to 40.22 ± 1.62 ml · kg · min) and decreased body fat percentage in men (22.2 ± 1.3 to 18.0 ± 1.3) and women (26.6 ± 2.0 to 23.2 ± 2.0). These improvements were significant across all levels of initial fitness. Significant correlations between absolute oxygen consumption and oxygen consumption relative to body weight was found in both men (r = 0.83, p < 0.001) and women (r = 0.94, p < 0.001), indicating that HIPT improved VO2max scaled to body weight independent of changes to body composition. Our data show that HIPT significantly improves VO2max and body composition in subjects of both genders across all levels of fitness. PMID:23439334

  3. Powering biomedical devices with body motion.

    Science.gov (United States)

    Romero, Edwar; Warrington, Robert O; Neuman, Michael R

    2010-01-01

    Energy harvesting from body motion is an alternative power source that can be used to energize miniature electronic biomedical devices. This technology can make it possible to recharge batteries to reduce the frequency of or eliminate surgeries to replace depleted cells. Power availability evaluation from walking and running at several body locations and different speeds is presented. Treadmill tests were performed on 11 healthy subjects to measure the accelerations at the ankle, knee, hip, chest, wrist, elbow, upper arm, and side of the head. Power was estimated from the treadmill results since it is proportional to the acceleration magnitudes and the frequency of occurrence. Available power output from walking was found to be more than 0.5 mW/cm(3) for all body locations while being more than 10 mW/cm(3) for the ankle and knee. Running results were at least 10 times higher than those from walking. An axial flux miniature electric dynamo using electromagnetic induction was evaluated for power generation. The device was composed of a rotor with multiple-pole permanent magnets positioned on an annular ring having an eccentric mass, and stacked planar coils as a stator. A 2 cm(3) prototype was found to generate 117 microW of power from the generator placed laterally on the ankle while walking. PMID:21096868

  4. An examination of training on the VertiMax resisted jumping device for improvements in lower body power in highly trained college athletes

    OpenAIRE

    Rhea, Matthew R.; Peterson, M.D.; Oliverson, J. R.; Naclerio Ayllón, Fernando José; Potenziano, B. J.

    2008-01-01

    Training to develop superior muscular power has become a key component to most progressive sport conditioning programs. Conventional resistance training, plyometrics, and speed/agility modalities have all been employed in an effort to realize superlative combinations of training stimuli. New training devices such as the VertiMax resisted jump trainer are marketed as a means of improving lower body reactive power. The purpose of this study was to evaluate the effectiveness of the VertiMax, in ...

  5. High power steam turbine for PWR

    International Nuclear Information System (INIS)

    This turbine having a power greater than 1500 MW at 1500 rpm or 1040 MW at 1800 rpm comprises a single flow HP body, an intermediate moisture separator reheater and a double flow IP body which feeds several LP bodies. The separator reheater can be replaced by high speed driers. 7 figs

  6. High power couplers

    International Nuclear Information System (INIS)

    The break of a high power input window is the most likely and dangerous accident for SC cavity systems. This is a motivation to compare and evaluate different designs and operating experiences and limitations of high power couplers for superconducting as well as normal conducting cavities. Equivalent information of klystron windows will be included for comparison. (author)

  7. Scavenged body heat powered infusion pump

    International Nuclear Information System (INIS)

    An infusion pump powered by body heat is investigated in this paper, with the goal of addressing the needs of dermal wound healing. The infusion pump incorporates a Knudsen gas pump, a type of thermally driven pump, to pneumatic push the pharmaceutical agent from a reservoir. Two designs are considered: an integrated pump and reservoir, and a design with cascaded pump and reservoir. Thermal models are developed for both pumps, and the simulations agree well with the experimental results. The integrated pump and reservoir design uses hydrophobic materials to prevent a flow from occurring unless the infusion pump is placed on a human body. Flow rates in the µL min−1 range for the integrated pump and reservoir, and approximately 70 µL min−1 for the cascaded pump were obtained. The dynamic behavior of the cascaded pump is described based on the thermal models. Multiple copies of the cascaded pump are easily made in series or parallel, to increase either the pressure or the flow rate. The flow rate of multiple pumps in series does not change, and the pressure of multiple pumps in parallel does not change. (paper)

  8. High power microwave sources

    International Nuclear Information System (INIS)

    High power microwaves have known a great expansion with intense relativistic electron beams. CEA-CESTA evolved several HPM sources on electron beam generator CESAR, as the planar VIRCATOR, the REDITRON and the coaxial VIRCATOR. We obtained microwave frequencies located between 2 and 8 GHz with power of some hundreds until 1 gigawatt. Several measurements have been improved to qualify these sources: frequency, power density, energy, wave polarization, modes visualization. A hollow beam generator, relativistic klystron electric source, has also been built to improve a recurrent system and obtain gigawatt microwave power. (author)

  9. High power fiber lasers

    Institute of Scientific and Technical Information of China (English)

    LOU Qi-hong; ZHOU Jun

    2007-01-01

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

  10. Resonant High Power Combiners

    CERN Document Server

    Langlois, Michel; Peillex-Delphe, Guy

    2005-01-01

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

  11. The influence of body mass on calculation of power during lower-body resistance exercises.

    Science.gov (United States)

    Cormie, Prue; McBride, Jeffrey M; McCaulley, Grant O

    2007-11-01

    The objective of this investigation was to examine the influence of body mass in the calculation of power and the subsequent effect on the load-power relationship in the jump squat, squat, and power clean. Twelve Division I male athletes were evaluated on their performance across various intensities in all the 3 lifts. Power output was calculated using 3 separate techniques: (a) including the contribution of body mass in force output (IBM), (b) including the contribution of the mass of body less the mass of the shanks and feet in force output (IBMS), and (c) excluding the contribution of body mass in force output (EBM). Peak power, peak power relative to body mass, and peak force calculated using EBM were significantly (p power curve was affected when derived via the EBM method as a result of the underrepresentation of power output at light loads. This was due to the majority of the load being neglected when the mass of the body was removed from the system mass used in the calculation of force. This study indicates that not only is the actual power output significantly lower when body mass is excluded from the force output of a lower body movement, but the load-power relationship is altered as well. Therefore, it is imperative that the mass of the individual being tested is incorporated into the calculation of force used to determine power output during lower-body movements. PMID:18076268

  12. High power microwaves

    CERN Document Server

    Benford, James; Schamiloglu, Edl

    2016-01-01

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

  13. Effect of Antenna Type on the Capacity of Body-to-Body Capacity When Using Uniform Power Allocation

    KAUST Repository

    Ghanem, Khalida

    2012-09-01

    Body-area networks are led to target multimedia applications where high-data rate is involved. In this paper, the characterization of the measured body-to-body channels and the ergodic capacity with uniform power allocation is discussed when using multiple-input multiple-output (MIMO) PIFA and IFA antenna systems. This capacity is compared to the measured belt-head and belt-chest on-body channels using PIFA antennas in the same environment. It is shown that body channels reach less ergodic capacity than the equivalent Rayleigh channel because of the presence of a LOS component. The capacity is the same for the body-to-body case regardless of the antenna and the on-body channels reach better capacity values compared to these former. © 2012 IEEE.

  14. Influence of 50Hz electric field generated by AC high-voltage overhead power lines on human body%高压交流架空线路工频电场对人体的影响

    Institute of Scientific and Technical Information of China (English)

    王杰; 张小青; 王涛; 陈灏; 盛财旺; 刘峰

    2011-01-01

    This paper is mainly aimed at discussing the calculation method of human-earth induced voltage which is generated by AC high-voltage overhead power lines, as well as touch-current of human body. At the beginning of this paper, the human body is simply equivalent to a cylinder, and the calculation model of human-earth induced voltage generated by single phase high-voltage overhead power line is derived by Equivalent Charge Method. On basis of it, this model and calculation method are further extended to the three-phase high-voltage overhead power lines situation. Secondly, this paper applies the derived model and calculation method to calculate the current through the human body when the human body touches the conductor under overhead power lines. It has the advantages of simple calculation procedure, small calculation burden, and convenient to engineering application.%本文主要讨论了高压交流架空线路下人体对地感应电位和人体接触电流的算法.文中首先把人体简化等效为一个等值圆柱,用等效电荷法导出了单相架空线路下人体对地电位的计算模型.在此基础上,进一步将模型与算法推广到三相高压交流架空线路的情况.然后本文运用所推出的模型与算法计算出人接触架空线路下的导体时通过人体的电流.本文推出的模型与算法具有计算步骤简单,计算量小,便于工程运用等优势.

  15. Switching power converters medium and high power

    CERN Document Server

    Neacsu, Dorin O

    2013-01-01

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

  16. Development of a field test for upper-body power.

    Science.gov (United States)

    Shim, A L; Bailey, M L; Westings, S H

    2001-05-01

    The purpose of this study was to develop a field test capable of measuring upper-body power through the use of a common weight-training apparatus, a Smith machine (SM), set up for bench press (BP) movement. A small, battery-operated digital timing device was designed and constructed to allow a precise calculation of power (in conjunction with measures of distance and force) for this specific movement, which involved an explosive press from the chest to a position just short of full arm extension. In pilot work, 1 repetition maximums (1RM) were determined on the SM BP for 3 male subjects, and by subsequently testing power on the same subjects at varying resistances, an average relative percentage of the 1RM-producing peak power values was found by power curve analysis for test standardization. Reliability was assessed (using 11 men) by SM power measurements taken over 3 days on the SM fitted with the timer. An intraclass R (0.998) indicated a high correlation between the 3 separate field-test trials. Finally, 8 male subjects were used to compare SM scores with a criterion measure, the Linea Isokinetic BP station (Loredan Biomedical, Inc., Sacramento CA). A Pearson product moment coefficient found a high correlation between the field test (SM) and Linea power scores (r = 0.987). A 2-tailed dependent t-test between the field and criterion scores was not significant, suggesting that no consistent error variable was present. It can be concluded that this is a valid field test of power for this movement. PMID:11710404

  17. High power ultrafast lasers

    Energy Technology Data Exchange (ETDEWEB)

    Backus, S.; Durfee, C.G. III; Murnane, M.M.; Kapteyn, H.C. [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109-2099 (United States)

    1998-03-01

    In this article, we review progress in the development of high peak-power ultrafast lasers, and discuss in detail the design issues which determine the performance of these systems. Presently, lasers capable of generating terawatt peak powers with unprecedented short pulse duration can now be built on a single optical table in a small-scale laboratory, while large-scale lasers can generate peak power of over a petawatt. This progress is made possible by the use of the chirped-pulse amplification technique, combined with the use of broad-bandwidth laser materials such as Ti:sapphire, and the development of techniques for generating and propagating very short (10{endash}30 fs) duration light pulses. We also briefly summarize some of the new scientific advances made possible by this technology, such as the generation of coherent femtosecond x-ray pulses, and the generation of MeV-energy electron beams and high-energy ions. {copyright} {ital 1998 American Institute of Physics.}

  18. Quantum power functional theory for many-body dynamics

    International Nuclear Information System (INIS)

    We construct a one-body variational theory for the time evolution of nonrelativistic quantum many-body systems. The position- and time-dependent one-body density, particle current, and time derivative of the current act as three variational fields. The generating (power rate) functional is minimized by the true current time derivative. The corresponding Euler-Lagrange equation, together with the continuity equation for the density, forms a closed set of one-body equations of motion. Space- and time-nonlocal one-body forces are generated by the superadiabatic contribution to the functional. The theory applies to many-electron systems

  19. High-power electronics

    CERN Document Server

    Kapitsa, Petr Leonidovich

    1966-01-01

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

  20. Atomic Beam Merging and Suppression of Alkali Contaminants in Multi Body High Power Targets: Design and Test of Target and Ion Source Prototypes at ISOLDE

    CERN Document Server

    Bouquerel, Elian J A; Lettry, J; Stora, T

    2009-01-01

    The next generation of high power ISOL-facilities will deliver intense and pure radioactive ion beams. Two key issues of developments mandatory for the forthcoming generation of ISOL target-ion source units are assessed and demonstrated in this thesis. The design and production of target and ion-source prototypes is described and dedicated measurements at ISOLDE-CERN of their radioisotope yields are analyzed. The purity of short lived or rare radioisotopes suffer from isobaric contaminants, notably alkalis which are highly volatile and easily ionized elements. Therefore, relying on their chemical nature, temperature controlled transfer lines were equipped with a tube of quartz that aimed at trapping these unwanted elements before they reached the ion source. The successful application yields high alkali-suppression factors for several elements (ie: 80, 82mRb, 126, 142Cs, 8Li, 46K, 25Na, 114In, 77Ga, 95, 96Sr) for quartz temperatures between 300ºC and 1100ºC. The enthalpies of adsorption on quartz were measu...

  1. Power Functions Relating Excretion to Body Burden

    CERN Document Server

    Sanders, S M J

    2003-01-01

    Formulae necessary to relate the quantity of radionuclides excreted to that assimilated in exposures that are acute and those that are multiple or continuous are derived from power function relationships. Particular attention is given to providing equations having variables for which the bioassayer can easily derive numerical values. This paper presents this data.

  2. High tobacco consumption lowers body weight

    DEFF Research Database (Denmark)

    Winsløw, Ulrik C; Rode, Line; Nordestgaard, Børge G

    2015-01-01

    genetic variant in CHRNA3 (rs1051730) as proxy for high tobacco consumption. The cohort consisted of 80,342 participants from the Copenhagen General Population Study, with details on body weight, smoking habits and CHRNA3 genotype, including 15,220 current smokers. RESULTS: In observational analyses, high.......23 kg/m(2) (0.33; 0.13) lower body mass index, 0.32 cm (0.74; 0.003) lower waist circumference and 0.45 cm (0.66; 0.24) lower hip circumference. No association was found between tobacco consumption and waist-hip ratio in genetic analysis, or among CHRNA3 genotype and any of the outcome variables in......BACKGROUND: Conflicting evidence has been found regarding the association between high tobacco consumption and body weight among smokers. We tested the hypothesis that high tobacco consumption is causally associated with low body weight. METHODS: We conducted a Mendelian randomization study with a...

  3. High power communication satellites power systems study

    International Nuclear Information System (INIS)

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

  4. High power communication satellites power systems study

    Science.gov (United States)

    Josloff, Allan T.; Peterson, Jerry R.

    1995-01-01

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

  5. High-Efficiency Power Module

    Science.gov (United States)

    Simons, Rainee N. (Inventor); Wintucky, Edwin G. (Inventor)

    2015-01-01

    One or more embodiments of the present invention pertain to an all solid-state microwave power module. The module includes a plurality of solid-state amplifiers configured to amplify a signal using a low power stage, a medium power stage, and a high power stage. The module also includes a power conditioner configured to activate a voltage sequencer (e.g., bias controller) when power is received from a power source. The voltage sequencer is configured to sequentially apply voltage to a gate of each amplifier and sequentially apply voltage to a drain of each amplifier.

  6. High power ultrasound standard.

    Science.gov (United States)

    Wong, George S K; Wu, Lixue

    2002-04-01

    A sensitive radiation force balance for laboratory measurement of ultrasonic power is presented. The principle of the system is based on measuring the ultrasonic radiation force exerted on a conical float suspended in water. Technical details of the implementation of the economically attractive system are described. The operation of the system is automated with the aid of the IEEE-488 bus and a desktop computer. Design aspects that affect measurement uncertainty are investigated. A theoretical model for the measurement of ultrasonic power with a conical reflector target is discussed. The expanded uncertainty (95% confidence level) of the above radiation force conical float system is estimated to be between 5% to 10%. PMID:12002863

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

    DEFF Research Database (Denmark)

    Nymand, Morten

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

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

    DEFF Research Database (Denmark)

    Nymand, Morten

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

  9. Ultra low power transceiver for wireless body area networks

    CERN Document Server

    Masuch, Jens

    2013-01-01

    This book describes the design of ultra low power transceivers for body area networks.  Since these applications have very limited energy resources, typically powered only by tiny batteries or through energy harvesting techniques, this book describes an architecture for a Bluetooth low energy transceiver to overcome these limitations. Coverage includes not only the main concepts for achieving low power consumption, but also the details of the circuit design and its implementation in a standard CMOS technology.     ·         Guides readers through the design of ultra low power transceivers for body area networks, from architecture to circuit-level implementation; ·         Describes 4 key strategies for ultra-low power transceiver design and specific, innovative techniques for circuit-level design; ·         Enables readers to design transceivers for body area networks that are 27% more energy efficient than those currently available; ·         Includes a review of the st...

  10. High average power supercontinuum sources

    Indian Academy of Sciences (India)

    J C Travers

    2010-11-01

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

  11. High Power Pulsed Gas Lasers

    Science.gov (United States)

    Witteman, W. J.

    1987-09-01

    Gas lasers have shown to be capable of delivering tens of terrawatt aspeak power or tens of kilowatt as average power. The efficiencies of most high power gas lasers are relatively high compared with other types of lasers. For instance molecular lasers, oscillating on low lying vibrational levels, and excimer lasers may have intrinsic efficiencies above 10%.The wavelengths of these gas lasers cover the range from the far infrared to the ultra-violet region, say from 12000 to 193 nm. The most important properties are the scalability, optical homogeneity of the excited medium, and the relatively low price per watt of output power. The disadvantages may be the large size of the systems and the relatively narrow line width with limited tunability compared with solid state systems producing the same peak power. High power gas lasers group into three main categories depending on the waste-heat handling capacity.

  12. High-powered manoeuvres

    CERN Multimedia

    Anaïs Schaeffer

    2013-01-01

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

  13. TRANSISTOR HIGH VOLTAGE POWER SUPPLY

    Science.gov (United States)

    Driver, G.E.

    1958-07-15

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

  14. Pregnancy pragmatics unveiled: on bodies, bellies, and power in Cameroon

    OpenAIRE

    Sijpt, van der, E.

    2014-01-01

    Over the last few decades, anthropologists interested in reproduction have increasingly focused on the relationship between women’s (limited) reproductive agency and (bio)political forces such as patriarchy, medicine, the state, and the global political economy. In their quest for understanding local and global ‘politics of reproduction’, some have turned their gaze towards the female body, considered to be a symbolic arena in which multi-level power relations are played out. These scholars h...

  15. Applications of high power microwaves

    International Nuclear Information System (INIS)

    The authors address a number of applications for HPM technology. There is a strong symbiotic relationship between a developing technology and its emerging applications. New technologies can generate new applications. Conversely, applications can demand development of new technological capability. High-power microwave generating systems come with size and weight penalties and problems associated with the x-radiation and collection of the electron beam. Acceptance of these difficulties requires the identification of a set of applications for which high-power operation is either demanded or results in significant improvements in peRFormance. The authors identify the following applications, and discuss their requirements and operational issues: (1) High-energy RF acceleration; (2) Atmospheric modification (both to produce artificial ionospheric mirrors for radio waves and to save the ozone layer); (3) Radar; (4) Electronic warfare; and (5) Laser pumping. In addition, they discuss several applications requiring high average power than border on HPM, power beaming and plasma heating

  16. High Power Betavoltaic Technology Project

    Data.gov (United States)

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

  17. Towards Power Efficient MAC Protocol for In-Body and On-Body Sensor Networks

    CERN Document Server

    Ullah, Sana; Kwak, Kyung Sup; 10.1007/978-3-642-01665-3_34

    2009-01-01

    This paper presents an empirical discussion on the design and implementation of a power-efficient Medium Access Control (MAC) protocol for in-body and on-body sensor networks. We analyze the performance of a beacon-enabled IEEE 802.15.4, PB-TDMA, and S-MAC protocols for on-body sensor networks. We further present a Traffic Based Wakeup Mechanism that utilizes the traffic patterns of the BAN Nodes (BNs) to accommodate the entire BSN traffic. To enable a logical connection between different BNs working on different frequency bands, a method called Bridging function is proposed. The Bridging function integrates all BNs working on different bands into a complete BSN.

  18. High-average-power lasers

    International Nuclear Information System (INIS)

    The goals of the High-Average-Power Laser Program at LLNL are to develop a broad technology base for solid state lasers and to demonstrate high-average-power laser operation with more efficiency and higher beam quality than has been possible with current technology. Major activities are the zig-zag laser testbed and the gas-cooled-slab laser test bed. This section describes these activities as well as discussion of material development; nonlinear optics; laser materials, and applications

  19. Solid-state gyrotron body power supply, test results

    Energy Technology Data Exchange (ETDEWEB)

    Santinelli, M. [Association Euratom-ENEA, ENEA CR Frascati, 00044 Frascati (Italy)], E-mail: santinelli@frascati.enea.it; Claesen, R.; Coletti, A. [Association Euratom-ENEA, ENEA CR Frascati, 00044 Frascati (Italy); Bonicelli, T.; Mondino, P.L. [EFDA, EFDA CSU Garching, D-85748 Garching (Germany); Pretelli, M.; Rinaldi, L.; Sita, L.; Taddia, G. [OCEM SpA, Via 2 Agosto 1980 no. 11, 40016 San Giorgio di Piano (Italy)

    2007-10-15

    A 170 GHz, 2 MW, steady-state gyrotron is being developed in collaboration between European research associations and industries to be used for the electron cyclotron resonance heating (ECRH) system of ITER, the gyrotron is presently in the prototype state. EFDA entrusted ENEA with the design of a new power supply for the gyrotron's body; in which, the traditional power vacuum tubes are replaced with solid-state components (IGBT); furthermore ENEA had the task of developing the new body power supply (BPS), following the initial conceptual design. The BPS is formed by 50 identical bidirectional (in current) modules, connected in series; the BPS's control system regulates the output voltage by changing the modulation index. OCEM Spa, under ENEA's supervision, has manufactured the BPS. Tests, done at the start of this year, showed the substantial agreement between the initial technical specifications and the values achieved. Particularly the ramp-up/down-emergency time (50-10 {mu}s), the accuracy ({+-}0.5%), the sine wave modulation (45-20 kV at 5 kHz) and the maximum phase shift (<10 deg.) have been tested. In the article, the new stair-way modulation (SWM) scheme will be sketched and the test results will be described in detail.

  20. Diamond for High Power / High Temperature Electronics

    OpenAIRE

    Kohn, E.; Kubovic, M.; Hernandez-Guillen, F.; Denisenko, A.

    2004-01-01

    Diamond is a wide bandgap semiconductor with extremely attractive properties but also many technological difficulties. Doping is restricted to deep impurities and substrate size is very limited. Nevertheless in proof of concept experiments, the potential for high power, high temperature and high frequency applications can already well be estimated. In addition, first passive MEMS elements for advanced circuit applications have also been demonstrated, however still on n...

  1. Integrated high power VCSEL systems

    Science.gov (United States)

    Moench, Holger; Conrads, Ralf; Gronenborn, Stephan; Gu, Xi; Miller, Michael; Pekarski, Pavel; Pollmann-Retsch, Jens; Pruijmboom, Armand; Weichmann, Ulrich

    2016-03-01

    High power VCSEL systems are a novel laser source used for thermal treatment in industrial manufacturing. These systems will be applied in many applications, which have not used a laser source before. This is enabled by the unique combination of efficiency, compactness and robustness. High power VCSEL system technology encompasses elements far beyond the VCSEL chip itself: i.e. heat sinks, bonding technology and integrated optics. This paper discusses the optimization of these components and processes specifically for building high-power laser systems with VCSEL arrays. New approaches help to eliminate components and process steps and make the system more robust and easier to manufacture. New cooler concepts with integrated electrical and mechanical interfaces have been investigated and offer advantages for high power system design. The bonding process of chips on sub-mounts and coolers has been studied extensively and for a variety of solder materials. High quality of the interfaces as well as good reliability under normal operation and thermal cycling have been realized. A viable alternative to soldering is silver sintering. The very positive results which have been achieved with a variety of technologies indicate the robustness of the VCSEL chips and their suitability for high power systems. Beam shaping micro-optics can be integrated on the VCSEL chip in a wafer scale process by replication of lenses in a polymer layer. The performance of VCSEL arrays with integrated collimation lenses has been positively evaluated and the integrated chips are fully compatible with all further assembly steps. The integrated high power systems make the application even easier and more robust. New examples in laser material processing and pumping of solid state lasers are presented.

  2. High-power RF compressor

    International Nuclear Information System (INIS)

    We discuss here the possibility of rapidly compressing resonant RF fields in a coaxial cavity with a moving, magnetically confined plasma ring. The possibility of accelerating a plasma ring and various acceleration configurations was discussed earlier. Since the ring velocity can be high, compression to high energy density and high power can be achieved before significant resistive loss or vaporization of the cavity walls occurs. An example is given of compressing 105 J of lambda = 15 cm stored energy to 2 x 106 J of lambda = 1.0 cm RF energy with the energy released in 3 nsec for a maximum power of 6 x 1014 W. A proof of principle plasma ring accelerator experiment could provide a significant test by compressing 125 joules of 14 cm RF to 1.25 kJ of 1.4 cm radiation, released in 5 nsec for a very respectable peak power of 2.5 x 1011 W

  3. An ECG Compressed Sensing Method of Low Power Body Area Network

    Directory of Open Access Journals (Sweden)

    Jizhong Liu

    2013-07-01

    Full Text Available Aimed at low power problem in body area network, an ECG compressed sensing method of low power body area network based on the compressed sensing theory was proposed. Random binary matrices were used as the sensing matrix to measure ECG signals on the sensor nodes. After measured value is transmitted to remote monitoring center, ECG signal sparse representation under the discrete cosine transform and block sparse Bayesian learning reconstruction algorithm is used to reconstruct the ECG signals. The simulation results show that the 30% of overall signal can get reconstruction signal which’s SNR is more than 60dB, each numbers in each rank of sensing matrix can be controlled below 5, which reduces the power of sensor node sampling, calculation and transmission. The method has the advantages of low power, high accuracy of signal reconstruction and easy to hardware implementation.  

  4. High-Average Power Facilities

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-09-05

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

  5. High Temperature, High Power Piezoelectric Composite Transducers

    Directory of Open Access Journals (Sweden)

    Hyeong Jae Lee

    2014-08-01

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

  6. High temperature, high power piezoelectric composite transducers.

    Science.gov (United States)

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

    2014-01-01

    Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have led to the improvement of overall transducer performance, such as transducer sensitivity and bandwidth, resulting in rapid implementation of piezoelectric composites in medical imaging ultrasounds and other acoustic transducers. Recently, new piezoelectric composite transducers have been developed with optimized composite components that have improved thermal stability and mechanical quality factors, making them promising candidates for high temperature, high power transducer applications, such as therapeutic ultrasound, high power ultrasonic wirebonding, high temperature non-destructive testing, and downhole energy harvesting. This paper will present recent developments of piezoelectric composite technology for high temperature and high power applications. The concerns and limitations of using piezoelectric composites will also be discussed, and the expected future research directions will be outlined. PMID:25111242

  7. High power fast ramping power supplies

    Energy Technology Data Exchange (ETDEWEB)

    Marneris,I.; Bajon, E.; Bonati, R.; Sandberg, J.; Roser, T.; Tsoupas, N.

    2009-05-04

    Hundred megawatt level fast ramping power converters to drive proton and heavy ion machines are under research and development at accelerator facilities in the world. This is a leading edge technology. There are several topologies to achieve this power level. Their advantages and related issues will be discussed.

  8. High power neutron production targets

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-06-01

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

  9. High power, high frequency helix TWT's

    Science.gov (United States)

    Sloley, H. J.; Willard, J.; Paatz, S. R.; Keat, M. J.

    The design and performance characteristics of a 34-GHz pulse tube capable of 75 W peak power output at 30 percent duty cycle and a broadband CW tube are presented. Particular attention is given to the engineering problems encountered during the development of the tubes, including the suppression of backward wave oscillation, the design of electron guns for small-diameter high-current beams, and the thermal capability of small helix structures. The discussion also covers the effects of various design parameters and choice of engineering materials on the ultimate practical limit of power and gain at the operating frequencies. Measurements are presented for advanced experimental tubes.

  10. High Power Thin Disk Laser

    OpenAIRE

    Giesen, Adolf

    2011-01-01

    In this talk, the latest results for thin disk lasers will be presented. Thin disk lasers can be operated in cw-mode as well as in pulsed mode with pulse durations from 100 fs to microseconds. Results from different institutes and companies will be shown demonstrating the power/energy scalability of the thin disk laser design with good beam quality and high efficiency, simultaneously. Several German companies are selling thin disk lasers with up to 16 kW output power (cw) and with up to 1 kW...

  11. High-power fibre lasers

    Science.gov (United States)

    Jauregui, Cesar; Limpert, Jens; Tünnermann, Andreas

    2013-11-01

    Fibre lasers are now associated with high average powers and very high beam qualities. Both these characteristics are required by many industrial, defence and scientific applications, which explains why fibre lasers have become one of the most popular laser technologies. However, this success, which is largely founded on the outstanding characteristics of fibres as an active medium, has only been achieved through researchers around the world striving to overcome many of the limitations imposed by the fibre architecture. This Review focuses on these limitations, both past and current, and the creative solutions that have been proposed for overcoming them. These solutions have enabled fibre lasers to generate the highest diffraction-limited average power achieved to date by solid-state lasers.

  12. High power vircator source development

    International Nuclear Information System (INIS)

    The vircator in its modern form is an essentially new class of microwave tube. It has the attributes of conceptual simplicity, high output power capacity and wide tunability. Frequencies ranging from 800 MHz to over 40 GHz have been witnessed. These features have already been demonstrated experimentally at MRC, on a small scale. Furthermore, experimental work in other laboratories, and the results of particle code simulations, have clearly indicated that the vircator is a source of extraordinarily high power. Hence, it has some unique applications. The virtual cathode oscillator results when the beam current injected into a waveguide or cavity resonator exceeds the space-charge limiting current. The limiting current is defined by the beam energy and waveguide or resonator geometry. The lack of a stable steady state equilibrium for the beam under these conditions results in formation of a virtual cathode, which is a stable oscillatory state of the electron beam

  13. High-power active devices

    CERN Document Server

    Carroll, E

    2006-01-01

    Very high-power (HP) electronics represents a small part of the electronics market. In semiconductor terms, HP represents a world device market of 600 million euros out of a total 200 billion euros for all semiconductors—a mere 0.3 per cent. At the multi-megawatt spectral end, the numbers are even smaller, so that it is quite common for electronics engineers to be unaware of developments in Very High Power (VHP). In this presentation we discuss the categories of VHP active devices, the basic topologies in which they operate, and the trend towards higher voltage and current. New press-pack technologies are introduced and the salient differences between Insulated Gate Bipolar Transistors (IGBTs) and Integrated Gate Commutated Thyristors (IGCTs) are compared. Finally, recent developments in turn-off ratings for both these devices are presented.

  14. TRAINING LOADINGS OF HIGHLY SKILLED BODY BUILDERS

    OpenAIRE

    Kopański, Ryszard; Sławska, Anna

    2007-01-01

    The study concerns women's body-building, taking training process into consideration. Training plans of 14 female body-builders were presented in the study. The firs part comprises detailed training description, including: weekly training plan; training means (the sets of exercises taking a given muscles group into consideration); training loads in series and repetition. The second part of the study based on material analysis. The aim of the research was to determine the frequency of performi...

  15. Evaluation of 137Cs body burden in inhabitants of Bryansk Oblast, Russian Federation, where a high incidence of thyroid cancer was observed after the accident at the Chernobyl nuclear power plant

    International Nuclear Information System (INIS)

    To determine the current risk of internal radiation exposure after the Chernobyl accident, the 137Cs body burden of the inhabitants of Bryansk Oblast (Russian Federation) was evaluated, from 1998 to 2008. The study population is composed of 84 666 people who visited Bryansk No. 2 Hospital. A whole-body counter was used for measurement of 137Cs body burden. 137Cs concentration was significantly higher in the late period during the study and showed seasonal variation, suggesting that inhabitants may have consumed contaminated forest products. However, people with high annual exposure doses were quite rare during all years of the study. In conclusion, although internal radiation exposure from 137Cs continues to this day in Bryansk Oblast, the annual exposure dose is low in almost all inhabitants. Because of the long half-life of 137Cs, the long term follow-up is necessary to monitor the health status and relieve the anxiety of the inhabitants around Chernobyl. (authors)

  16. Turbine Powered Simulator Calibration and Testing for Hybrid Wing Body Powered Airframe Integration

    Science.gov (United States)

    Shea, Patrick R.; Flamm, Jeffrey D.; Long, Kurtis R.; James, Kevin D.; Tompkins, Daniel M.; Beyar, Michael D.

    2016-01-01

    Propulsion airframe integration testing on a 5.75% scale hybrid wing body model us- ing turbine powered simulators was completed at the National Full-Scale Aerodynamics Complex 40- by 80-foot test section. Four rear control surface con gurations including a no control surface de ection con guration were tested with the turbine powered simulator units to investigate how the jet exhaust in uenced the control surface performance as re- lated to the resultant forces and moments on the model. Compared to ow-through nacelle testing on the same hybrid wing body model, the control surface e ectiveness was found to increase with the turbine powered simulator units operating. This was true for pitching moment, lift, and drag although pitching moment was the parameter of greatest interest for this project. With the turbine powered simulator units operating, the model pitching moment was seen to increase when compared to the ow-through nacelle con guration indicating that the center elevon and vertical tail control authority increased with the jet exhaust from the turbine powered simulator units.

  17. High power neutral beam systems

    International Nuclear Information System (INIS)

    Spurred by the requirement to supply megawatts of power to heat magnetically confined plasmas to temperatures of interest for fusion research, a new class of low energy, high power accelerators termed neutral beam injectors has been developed. Industry has played an important role in building upon technology advances at the national laboratories to engineer neutral beam injectors to meet the needs of specific users. A brief retrospective of the field is presented, with emphasis upon one particular application, that of DIII-D, a large tokamak at General Atomics. In this instance, the role of industry has been especially extensive because the user/system integrator is itself an industrial concern. 4 refs., 7 figs., 2 tabs

  18. High power cladding light strippers

    Science.gov (United States)

    Wetter, Alexandre; Faucher, Mathieu; Sévigny, Benoit

    2008-02-01

    The ability to strip cladding light from double clad fiber (DCF) fibers is required for many different reasons, one example is to strip unwanted cladding light in fiber lasers and amplifiers. When removing residual pump light for example, this light is characterized by a large numerical aperture distribution and can reach power levels into the hundreds of watts. By locally changing the numerical aperture (N.A.) of the light to be stripped, it is possible to achieve significant attenuation even for the low N.A. rays such as escaped core modes in the same device. In order to test the power-handling capability of this device, one hundred watts of pump and signal light is launched from a tapered fusedbundle (TFB) 6+1x1 combiner into a high power-cladding stripper. In this case, the fiber used in the cladding stripper and the output fiber of the TFB was a 20/400 0.06/0.46 N.A. double clad fiber. Attenuation of over 20dB in the cladding was measured without signal loss. By spreading out the heat load generated by the unwanted light that is stripped, the package remained safely below the maximum operating temperature internally and externally. This is achieved by uniformly stripping the energy along the length of the fiber within the stripper. Different adhesive and heat sinking techniques are used to achieve this uniform removal of the light. This suggests that these cladding strippers can be used to strip hundreds of watts of light in high power fiber lasers and amplifiers.

  19. Effects of whole-body vibration on muscle strength and power of elderly: A systematic review

    Directory of Open Access Journals (Sweden)

    Monique Opuszcka Campos

    2014-02-01

    Full Text Available The aim of this systematic review was to summarize available scientific evidence on the utilization of whole body vibration as an alternative method to promote effective modifications on muscle strength and power in the aging population.  Scientific studies were retrieved from the following databases: Medline, Scielo, Lillacs, Cochrane Library, PEDro and Science Citation Index. The PEDro scale was used to assess the quality of the included studies, while content went through a critical analysis. From the 91 studies retrieved, 75 were excluded and 16 attended the selection criteria. From the16, the majority (68.8% presented from moderate to high methodological quality. Whole-body vibration associated to both isometric and dynamic exercises seemed to constitute an alternative for therapeutic intervention to improve muscular strength and power of healthy elderly. However, due to the characteristics of the designs of the studies reviewed and the threats to their internal validity (i.e., the absence of the control condition to the vibratory stimulus it was challenging to establish the additional effects of the whole-body vibration on the target population. Divergent findings were found for the whole-body vibration effect on muscular power. It is still necessary to conduct randomized control trials to establish the real effectiveness of this kind of intervention.

  20. High average power solid state laser power conditioning system

    International Nuclear Information System (INIS)

    The power conditioning system for the High Average Power Laser program at Lawrence Livermore National Laboratory (LLNL) is described. The system has been operational for two years. It is high voltage, high power, fault protected, and solid state. The power conditioning system drives flashlamps that pump solid state lasers. Flashlamps are driven by silicon control rectifier (SCR) switched, resonant charged, (LC) discharge pulse forming networks (PFNs). The system uses fiber optics for control and diagnostics. Energy and thermal diagnostics are monitored by computers

  1. The power spectrum and correlation of flow noise for an axisymmetric body in water

    Institute of Scientific and Technical Information of China (English)

    Li Xue-Gang; Yang Kun-De; Wang Yong

    2011-01-01

    Understanding the physical features of the flow noise for an axisymmetric body is important for improving the performance of a sonar mounted on an underwater platform. Analytical calculation and numerical analysis of the physical features of the flow noise for an axisymmetric body are presented and a simulation scheme for the noise correlation on the hydrophones is given. It is shown that the numerical values of the flow noise coincide well with the analytical values. The main physical features of flow noise are obtained. The flow noises of two different models are compared and a model with a rather optimal fore-body shape is given. The flow noise in horizontal symmetry profile of the axisymmetric body is non-uniform, but it is omni-directional and has little difference in the cross section of the body. The loss of noise diffraction has a great effect on the flow noise from boundary layer transition. Meanwhile, based on the simulation, the noise power level increases with velocity to approximately the fifth power at high frequencies,which is consistent with the experiment data reported in the literature. Furthermore, the flow noise received by the acoustic array has lower correlation at a designed central frequency, which is important for sonar system design.

  2. High-power pulsed lasers

    International Nuclear Information System (INIS)

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

  3. Wireless power delivery for wearable sensors and implants in Body Sensor Networks.

    Science.gov (United States)

    Zhang, Fei; Hackwoth, Steve A; Liu, Xiaoyu; Li, Chengliu; Sun, Mingui

    2010-01-01

    A recent study on witricity (wireless electricity) has demonstrated that wireless energy can be delivered over a moderate distance using strongly coupled magnetic resonance. The objective of this work is to apply the witricity technology to the problem of powering a wireless Body Sensor Network (wBSN). The theory of witricity is investigated using coupled mode theory. Compact witricity resonators are designed, and a working prototype of witricity powered wBSN is built and evaluated. An energy transfer efficiency of about 80 % over a distance of 15 cm is achieved. Besides the high efficiency, it has been observed that a certain misalignment between the transmitter and receiver has little effect on the power transfer. Our experimental results indicate that witricity provides a powerful solution to the energy supply problem of wBSN. PMID:21095665

  4. Tradeoff between speed and static power dissipation of ultra-thin body SOI MOSFETs

    Institute of Scientific and Technical Information of China (English)

    Tian Yu; Huang Ru; Zhang Xing; Wang Yang-Yuan

    2007-01-01

    The speed performance and static power dissipation of the ultra-thin-body (UTB) MOSFETs have been comprehensively investigated, with both DC and AC behaviours considered. Source/drain extension width (Lsp) and silicon film thickness (tsi) are two independent parameters that influence the speed and static power dissipation of UTB siliconon-insulator (SOI) MOSFETs respectively, which can result in great design flexibility. Based on the different effects of physical and geometric parameters on device characteristics, a method to alleviate the contradiction between power dissipated and speed of UTB SOI MOSFETs is proposed. The optimal design regions of tsi and Lsp for low operating power and high performance logic applications are given, which may shed light on the design of UTB SOI MOSFETs.

  5. Techno­-Choreographies: Aerial and grounded bodies in the early years of powered flight

    DEFF Research Database (Denmark)

    Simonsen, Dorthe Gert

    . At a time when airplanes were little more than cloth wings attached to motors, their assembly with the body of the aviator was highly visible and essential in the practice and perception of powered flight. Perhaps less visible, but no less essential in this perception, was the embodied experience...... to the embodied history of flight, I discuss the ‘aviation neck’: the new and awkward bodily position of the audience on the ground as they bent their necks backwards to catch sight of the marvelous machines overhead. The aviation neck was depicted in cartoons and declared by commentators to be a new public...... “disease”; it was a humorous shortcut used to describe the challenge that flight, and the air as a new space of mobility, posed to the earthbound body. In contrast to the aviation neck we also find ample experiences and representations of the aerial body co-constituted by the airplanes. The embodiment...

  6. Design of low power SRAM Cell with combined effect of sleep stack and variable body bias technique

    Directory of Open Access Journals (Sweden)

    Anjana R1 , Dr. Ajay kumar somkuwar

    2013-06-01

    Full Text Available Power consumption has become major concern in Very Large Scale Integration circuit and according to International technology roadmap of semiconductors (ITRS leakage power dissipation may dominate more of total power dissipation [1]. Sub threshold leakage power tends to increase as the leakage power increases. Variable sleepy biased keeper is compared with previously available technique like Sleep, Stack, Sleepy Stack, Sleepy Keeper, and Zigzag. In this paper, we design SRAM cell by combining two techniques, namely sleep stack and body biasing technique. The sleepy stack reduces leakage power, but loses its logic state during sleep mode. And body biasing technique reduces the static power consumption and maintains the logic state of the circuit. One main advantage of using variable sleepy biased keeper is, it can also use high Vth transistors

  7. Inductive Power Transfer for On-body Sensors: Defining a design space for safe, wirelessly powered on-body health sensors

    OpenAIRE

    Worgan, Paul; Clare, Lindsay R; Proynov, Plamen; Stark, Bernard H.; Coyle, David

    2016-01-01

    Designers of on-body health sensing devices face a difficult choice. They must either minimise the power consumption of devices, which in reality means reducing the sensing capabilities, or build devices that require regular battery changes or recharging. Both options limit the effectiveness of devices. Here we investigate an alternative. This paper presents a method of designing safe, wireless, inductive power transfer into on-body sensor products. This approach can produce sensing ...

  8. Low-power wireless ECG acquisition and classification system for body sensor networks.

    Science.gov (United States)

    Lee, Shuenn-Yuh; Hong, Jia-Hua; Hsieh, Cheng-Han; Liang, Ming-Chun; Chang Chien, Shih-Yu; Lin, Kuang-Hao

    2015-01-01

    A low-power biosignal acquisition and classification system for body sensor networks is proposed. The proposed system consists of three main parts: 1) a high-pass sigma delta modulator-based biosignal processor (BSP) for signal acquisition and digitization, 2) a low-power, super-regenerative on-off keying transceiver for short-range wireless transmission, and 3) a digital signal processor (DSP) for electrocardiogram (ECG) classification. The BSP and transmitter circuits, which are the body-end circuits, can be operated for over 80 days using two 605 mAH zinc-air batteries as the power supply; the power consumption is 586.5 μW. As for the radio frequency receiver and DSP, which are the receiving-end circuits that can be integrated in smartphones or personal computers, power consumption is less than 1 mW. With a wavelet transform-based digital signal processing circuit and a diagnosis control by cardiologists, the accuracy of beat detection and ECG classification are close to 99.44% and 97.25%, respectively. All chips are fabricated in TSMC 0.18-μm standard CMOS process. PMID:25561446

  9. Optics assembly for high power laser tools

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-07

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

  10. High Power Wideband Class-E Power Amplifier

    OpenAIRE

    Ortega González, Francisco Javier

    2010-01-01

    This letter shows a high-power, high-efficiency, wideband Class-E RF power amplifier designed upon the load admittance synthesis concept and built using an uncomplicated low-loss load network with a low loss wideband admittance transformer as the main component. It uses a power Silicon LDMOS transistor to provide up to 145 W at 28 V peak power, up to 86% drain efficiency over 35% fractional bandwidth (from 85 to 120 MHz) and 15.6 dB gain at peak power without any adjustments. These are clear ...

  11. Wearable thermoelectric generators for body-powered devices

    NARCIS (Netherlands)

    Leonov, V.; Vullers, R.J.M.

    2009-01-01

    This paper presents a discussion on energy scavenging for wearable devices in conjunction with human body properties. Motivation, analysis of the relevant properties of the human body, and results of optimization of a thermopile and a thermoelectric generator for wearable and portable devices are pr

  12. High Energy Two-Body Deuteron Photodisintegration

    Energy Technology Data Exchange (ETDEWEB)

    Terburg, Bart

    1999-07-31

    The differential cross section for two­body deuteron photodisintegration was measured at photon energies between 0.8 and 4.0 GeV and center­of­mass angles theta_cm =37deg, 53deg, 70deg, and 90deg as part of CEBAF experiment E89­012. Constituent counting rules predict a scaling of this cross section at asymptotic energies. In previous experiments this scaling has surprisingly been observed at energies between 1.4 and 2.8 GeV at 90deg. The results from this experiment are in reasonable agreement with previous measurements at lower energies. The data at 70deg and 90deg show a constituent counting rule behavior up to 4.0 GeV photon energy. The 37deg and 53deg data do not agree with the constituent counting rule prediction. The new data are compared with a variety of theoretical models inspired by quantum chromodynamics (QCD) and traditional hadronic nuclear physics.

  13. High power ubitron-klystron

    International Nuclear Information System (INIS)

    A coaxial ubitron is being considered as the rf driver for the Next Linear Collider (NLC). Prior simulation of a traveling-wave ubitron using a self-consistent code found that 200 MW of power and 53 dB of gain could be achieved with 37% efficiency. In a ubiron-klystron, a series of cavities are used to obtain an even tighter electron bunch for higher efficiency. A small-signal theory of the ubitron-klystron shows that gain scales with the square of the cavity separation distance. A linear stability theory has also been developed. Verification of the stability theory has been achieved using the 2-12-D PIC code, MAGIC, and the particle-tracing code. Saturation characteristics of the amplifier will be presented using both MAGIC and a simpler self-consistent slow-timescale code currently under development. The ubitron can also operate as a compact, highly efficient oscillator. Cavities only two wiggler periods in length have yielded up to 40% rf conversion efficiency in simulation. An initial oscillator design for directed energy applications will also be presented

  14. High precision module for Chaos Many-Body Engine

    CERN Document Server

    Grossu, I V; Felea, D; Jipa, Al

    2014-01-01

    In this paper we present a C# high precision relativistic many-body module integrated with Chaos Many-Body Engine. As a direct application, we used it for estimating the butterfly effect involved by the gravitational force in a specific nuclear relativistic collision toy-model.

  15. High power proton accelerator for nuclear power plant

    International Nuclear Information System (INIS)

    The novel nuclear power system--Energy Amplifier, proposed by C. Rubbia, attracts the interest as a prior option for the development of the next generation nuclear power plant in the first half of the 21st century. The accelerator used to drive the system should provide proton beam power tens higher than that of LAMPF. The accelerator physics and technology have been advancing greatly since LAPMF was built more than 20 years ago. These new progresses become the essential basis for the intense beam accelerator to advance up to a much higher beam power. However, some challenges are still being faced, including beam loss, high efficiency, reliability, as well as some technical issues associated with high power CW operation. The accelerator design options to tackle with the difficulties are discussed. The suggestions on R and D of high power accelerator in China are presented

  16. Simplified High-Power Inverter

    Science.gov (United States)

    Edwards, D. B.; Rippel, W. E.

    1984-01-01

    Solid-state inverter simplified by use of single gate-turnoff device (GTO) to commutate multiple silicon controlled rectifiers (SCR's). By eliminating conventional commutation circuitry, GTO reduces cost, size and weight. GTO commutation applicable to inverters of greater than 1-kilowatt capacity. Applications include emergency power, load leveling, drives for traction and stationary polyphase motors, and photovoltaic-power conditioning.

  17. Electronic DC transformer with high power density

    NARCIS (Netherlands)

    Pavlovský, M.

    2006-01-01

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

  18. Self-similar nonequilibrium dynamics of a many-body system with power-law interactions.

    Science.gov (United States)

    Gutiérrez, Ricardo; Garrahan, Juan P; Lesanovsky, Igor

    2015-12-01

    The influence of power-law interactions on the dynamics of many-body systems far from equilibrium is much less explored than their effect on static and thermodynamic properties. To gain insight into this problem we introduce and analyze here an out-of-equilibrium deposition process in which the deposition rate of a given particle depends as a power law on the distance to previously deposited particles. This model draws its relevance from recent experimental progress in the domain of cold atomic gases, which are studied in a setting where atoms that are excited to high-lying Rydberg states interact through power-law potentials that translate into power-law excitation rates. The out-of-equilibrium dynamics of this system turns out to be surprisingly rich. It features a self-similar evolution which leads to a characteristic power-law time dependence of observables such as the particle concentration, and results in a scale invariance of the structure factor. Our findings show that in dissipative Rydberg gases out of equilibrium the characteristic distance among excitations-often referred to as the blockade radius-is not a static but rather a dynamic quantity. PMID:26764669

  19. Modeling lifetime of high power IGBTs in wind power applications

    DEFF Research Database (Denmark)

    Busca, Cristian

    2011-01-01

    The wind power industry is continuously developing bringing to the market larger and larger wind turbines. Nowadays reliability is more of a concern than in the past especially for the offshore wind turbines since the access to offshore wind turbines in case of failures is both costly and difficult...... an overview of the different aspects of lifetime modeling of high power IGBTs in wind power applications. In the beginning, wind turbine reliability survey results are briefly reviewed in order to gain an insight into wind turbine subassembly failure rates and associated downtimes. After that the...... most common high power IGBT failure mechanisms and lifetime prediction models are reviewed in more detail....

  20. High Power Fiber Laser Test Bed

    Data.gov (United States)

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

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

    DEFF Research Database (Denmark)

    Senturk, Osman Selcuk

    -scale 3L-VSC laboratory prototype. Using these validated models, the power density assessments, which include converter power capability and volume determinations, and the reliability assessments, which are based on statistical failure rates of IGBTs and DC capacitors and based on IGBT lifetime determined......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. 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...

  2. High Power Performance of Rod Fiber Amplifiers

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  3. High power quantum cascade lasers

    International Nuclear Information System (INIS)

    We report the most recent state-of-art quantum cascade laser results at wavelengths around 4.8 and 10 μm. At 4.8 μm, a room temperature wall plug efficiency (WPE) of 22 and 15.5% are obtained in pulsed mode and continuous wave (cw) mode, respectively. Room temperature cw output power reaches 3.4 W. The same laser design is able to reach a WPE of 36% at 120 K in pulsed mode. At 10 μm, room temperature average power of 2.2 W and cw power of 0.62 W are obtained. We also explore lasers utilizing the photonic crystal distributed feedback mechanism, and we demonstrate up to 12 W peak power operation at three different wavelengths around 4.7 μm with a waveguide width of 100 μm and diffraction limited beam quality.

  4. Investigation of Power Semiconductor Devices for High Frequency High Density Power Converters

    OpenAIRE

    Wang, Hongfang

    2007-01-01

    The next generation of power converters not only must meet the characteristics demanded by the load, but also has to meet some specific requirements like limited space and high ambient temperature etc. This needs the power converter to achieve high power density and high temperature operation. It is usually required that the active power devices operate at higher switching frequencies to shrink the passive components volume. The power semiconductor devices for high frequency high density ...

  5. High power RF solid state power amplifier system

    Science.gov (United States)

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

    2011-01-01

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

  6. Development of high-power switching power supply

    International Nuclear Information System (INIS)

    We report the development of high power switching power supply to charge a PFN for klystron modulator which is used as RF source of the KEK electron/positron injector linac. This power supply has a maximum output voltage of 43 kV and the charging power of 30 kJ/s. It consists of two high frequency inverters, a high frequency transformer, and a diode bridge circuit, and series resonance circuits to charges the PFN. The output voltage stability is less than 0.2%p-p for 5% deviation of AC 420 V 3-phase input. Also interlock system for abnormal charging such as miss fire of thyratron. The continuous running test at a rated output power is performed at KEK. (author)

  7. Space Solar Power Multi-body Dynamics and Controls, Concepts for the Integrated Symmetrical Concentrator Configuration

    Science.gov (United States)

    Glaese, John R.; McDonald, Emmett J.

    2000-01-01

    Orbiting space solar power systems are currently being investigated for possible flight in the time frame of 2015-2020 and later. Such space solar power (SSP) satellites are required to be extremely large in order to make practical the process of collection, conversion to microwave radiation, and reconversion to electrical power at earth stations or at remote locations in space. These large structures are expected to be very flexible presenting unique problems associated with their dynamics and control. The purpose of this project is to apply the expanded TREETOPS multi-body dynamics analysis computer simulation program (with expanded capabilities developed in the previous activity) to investigate the control problems associated with the integrated symmetrical concentrator (ISC) conceptual SSP system. SSP satellites are, as noted, large orbital systems having many bodies (perhaps hundreds) with flexible arrays operating in an orbiting environment where the non-uniform gravitational forces may be the major load producers on the structure so that a high fidelity gravity model is required. The current activity arises from our NRA8-23 SERT proposal. Funding, as a supplemental selection, has been provided by NASA with reduced scope from that originally proposed.

  8. High-Power Electromagnetic Thruster Being Developed

    Science.gov (United States)

    LaPointe, Michael R.; Mikellides, Pavlos G.

    2001-01-01

    High-power electromagnetic thrusters have been proposed as primary in-space propulsion options for several bold new interplanetary and deep-space missions. As the lead center for electric propulsion, the NASA Glenn Research Center designs, develops, and tests high-power electromagnetic technologies to meet these demanding mission requirements. Two high-power thruster concepts currently under investigation by Glenn are the magnetoplasmadynamic (MPD) thruster and the Pulsed Inductive Thruster (PIT).

  9. High power HBT technologies : present and trends

    OpenAIRE

    Floriot, D.; Delage, S. L.; Piotrowicz, S.; Chartier, E.; Auxemery, P.

    2001-01-01

    The HBT technology is now mature and offers a great variety of RF products for telecom applications, specially power amplifiers for which a high level of linearity is requested. The reliability has been the limiting factor in the supplying of high power amplifiers and nowadays only medium HPA are available in catalogue. Also, regarding the huge quantities of papers published in the mid 90s relating the interest of this technology for high PAE / Power, very few of the competitors have been suc...

  10. THE RELATIONSHIP BETWEEN ANTHROPOMETRIC PARAMETERS, BODY COMPOSITION AND EXPLOSIVE POWER IN CADET WRESTLERS [Sootnosheniia mezhdu antropometricheskimi parametrami, sostavom tela i vzryvnoj siloj iunykh borcov

    Directory of Open Access Journals (Sweden)

    Bahman Mirzaei Mirzaei

    2011-11-01

    Full Text Available Purpose: The purpose of the present study was to investigate the relationship between anthropometric parameters, body composition and explosive power in cadet wrestlers. Methods: Seventeen male cadet wrestlers (age = 15.6 +/- 0.73 yrs from the Kurdistan province wrestling clubs participated in this study. Body composition (percent body fat, anthropometric parameters (height, sitting height, arm-span, upper arm length, leg length, upper leg length, arm circumference, middle thigh and calf circumference, explosive power (standing long jump and Medicine ball throw tests were measured. Results: Explosive power of upper body was significantly correlated with sitting height arm-span, upper arm length, arm circumference, weight and %BF. Explosive power of lower body was significantly correlated with sitting height, arm-span and weight. No significant correlation was found between explosive power of lower body and leg length, upper leg length, middle thigh circumference and maximum calf circumference Explosive power of upper body was also significantly correlated with explosive power of lower body. Conclusion: Explosive power is an important parameter in wrestling. Having a high level of power along with an appropriate arm-span helps to the wrestler for performing techniques successfully in competition. Our study suggested that height isn't the only parameter affecting talent identification and other parameters such as arm span and sitting height should be seriously considered when criteria for the selection of a wrestler are set.

  11. High-speed Power Line Communications

    Directory of Open Access Journals (Sweden)

    Matthew N. O. Sadiku,

    2015-11-01

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

  12. High average power induction accelerators

    International Nuclear Information System (INIS)

    The induction accelerator is discussed with respect to general background and concept, beam transport, scaling, pulse power technology, and the electron beam injector. A discussion of the factors which affect the scaling of the intensity of the beam is given. Limiting factors include collective forces in the beam, virtual cathode formation, surroundings, and beam breakup instability. 24 refs., 11 figs

  13. High power pulse magnetic field power supply system

    International Nuclear Information System (INIS)

    The magnetic field power supply system, control system and experiment results of the power supply of HL-2A device are presented. The total pulse capacity of this power supply is about 250 MVA. The released energy is 1300 MJ in one discharge pulse. The highest DC output voltage of these power supplies is 3510 V and the highest current is 45 kA. All these power supplies are operated in pulsed mode. The pulse duration is 5 s, and the period is 10 min. The main circuit of this power supply consists of flywheel generator set, thyristor convertor and silicon diode rectifier. Many key technologies such as output balance technology of 2 motor generators with diode rectifiers paralleled directly, current balance technology of paralleled rectifiers, constant-angle phase shift control technology which is adequate for dynamic change in large frequency range, all-turn-off detection of 6-phase rectifier with high current, advanced monitoring system and measurement of pulsed high voltage and high current are adopted in HL-2A power supply system. The experiment results show that the performance of power supplies can satisfied the requirement of experiment very well. (authors)

  14. High precision framework for chaos many-body engine

    Science.gov (United States)

    Grossu, I. V.; Besliu, C.; Felea, D.; Jipa, Al.

    2014-04-01

    In this paper we present a C# 4.0 high precision framework for simulation of relativistic many-body systems. In order to benefit from the, previously developed, chaos analysis instruments, all new modules were integrated with Chaos Many-Body Engine (Grossu et al. 2010, 2013). As a direct application, we used 46 digits precision for analyzing the "Butterfly Effect" of the gravitational force in a specific relativistic nuclear collision toy-model.

  15. High Average Power Yb:YAG Laser

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-05-23

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

  16. Fiber MOPAs with high control and high power

    OpenAIRE

    Nilsson, J.; Yoo, S.; Dupriez, P.; Farrell, C.; Abidin, M.S.Z.; Ji, J; Maran, J.-N.; Codemard, C. A.; Jeong, Y.; Sahu, J.K.; Richardson, D J; Payne, D. N.

    2008-01-01

    High power fiber sources have reached several kilowatts of output power, and are now leading contenders for many applications. Important attractions include control, efficiency, manufacturability, and reliability. We will exemplify opportunities and limitations for these revolutionary sources.

  17. High efficiency solar photovoltaic power module concept

    Science.gov (United States)

    Bekey, I.

    1978-01-01

    The investigation of a preliminary concept for high efficiency solar power generation in space is presented. The concept was a synergistic combination of spectral splitting, tailored bandgap cells, high concentration ratios, and cool cell areas.

  18. Packaging of high power semiconductor lasers

    CERN Document Server

    Liu, Xingsheng; Xiong, Lingling; Liu, Hui

    2014-01-01

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

  19. High power laser perforating tools and systems

    Science.gov (United States)

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

    2014-04-22

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

  20. Automated System Tests High-Power MOSFET's

    Science.gov (United States)

    Huston, Steven W.; Wendt, Isabel O.

    1994-01-01

    Computer-controlled system tests metal-oxide/semiconductor field-effect transistors (MOSFET's) at high voltages and currents. Measures seven parameters characterizing performance of MOSFET, with view toward obtaining early indication MOSFET defective. Use of test system prior to installation of power MOSFET in high-power circuit saves time and money.

  1. EFFECTS OF STRENGTH TRAINING ON PHYSICAL FUNCTION: INFLUENCE OF POWER, STRENGTH, AND BODY COMPOSITION

    OpenAIRE

    Hanson, Erik D.; Srivatsan, Sindhu R.; Agrawal, Siddhartha; Menon, Kalapurakkal S.; Delmonico, Matthew J.; Wang, Min Q.; Hurley, Ben F.

    2009-01-01

    The purpose of this study was to determine (a) the effects of strength training (ST) on physical function and (b) the influence of strength, power, muscle volume (MV), and body composition on physical function. Healthy, inactive adults (n = 50) aged 65 years and older underwent strength, power, total body composition (% fat and fat free mass [FFM]), and physical function testing before and after 22 weeks of ST. Physical function testing consisted of tasks designed to mimic common physical act...

  2. High temperature power electronics for space

    Science.gov (United States)

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

    1991-01-01

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

  3. High-power optics lasers and applications

    CERN Document Server

    Apollonov, Victor V

    2015-01-01

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

  4. Using EPSAT to analyze high power systems in the space environment. [Environment Power System Analysis Tool

    Science.gov (United States)

    Kuharski, Robert A.; Jongeward, Gary A.; Wilcox, Katherine G.; Rankin, Tom R.; Roche, James C.

    1991-01-01

    The authors review the Environment Power System Analysis Tool (EPSAT) design and demonstrate its capabilities by using it to address some questions that arose in designing the SPEAR III experiment. It is shown that that the rocket body cannot be driven to large positive voltages under the constraints of this experiment. Hence, attempts to measure the effects of a highly positive rocket body in the plasma environment should not be made in this experiment. It is determined that a hollow cathode will need to draw only about 50 mA to ground the rocket body. It is shown that a relatively small amount of gas needs to be released to induce a bulk breakdown near the rocket body, and this gas release should not discharge the sphere. Therefore, the experiment provides an excellent opportunity to study the neutralization of a differential charge.

  5. High Density Power Converters for Photovoltaic Power Management

    Science.gov (United States)

    Sangwan, Rahul

    In typical photovoltaic systems, PV cells are connected in series to achieve high output voltages, which decreases conduction losses and helps the downstream power electronics operate at higher efficiencies. A series connection means that the current through the string is limited by the worst case cell, substring, or module, which can result in suboptimal operation of the rest of the string. Given how even small shading can have a large effect on performance, there has been growing interest in the use of distributed power management architectures to mitigate losses from variation in PV systems. In particular, partial power processing converters have gained traction as a means to improve the performance of PV arrays with small, distributed converters that configure in parallel with PV cells. These converters can use low voltage components, only process a fraction of the total power allowing them to achieve higher efficiencies and power density and also have higher reliability. This work details the design and operation of a partial power processing converter implemented as a Resonant Switched Capacitor (ReSC) converter. An integrated circuit (IC) is designed in 0.18 mum CMOS process. Operation at high frequencies (20-50 MHz) allows high levels of integration with air core inductors directly attached to the die through a gold bump, solder reflow process. Test results for the IC are presented with power density and efficiency metrics. The IC is then used as a partial power processing converter to implement equalization with a specially constructed PV panel. The converter is shown to mitigate power loss due to mismatch.

  6. Powering the High-Luminosity Triplets

    CERN Document Server

    Ballarino, A

    2015-01-01

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

  7. High-Temperature Passive Power Electronics

    Science.gov (United States)

    1997-01-01

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

  8. Acute negative effect of a hypertrophy-oriented training bout on subsequent upper-body power output.

    Science.gov (United States)

    Baker, Daniel

    2003-08-01

    Athletes regularly combine maximal strength, power, and hypertrophy-oriented training within the same workout. Traditionally, it has been suggested that power-oriented exercises precede strength and hypertrophy-oriented training within a workout to avoid the possible negative effects that the latter types of training may have on power output. However, with regard to upper-body training, little study has been performed to verify this commonly held belief. The purpose of this study was to determine the extent, if any, of a high-repetition, short-rest-period, hypertrophy-oriented training dose on upper-body power output. Twenty-seven college-aged rugby league players were tested for average power output during bench press throws with a resistance of 40 kg (BT P40). The experimental group (Hyp, n = 15) then performed a typical hypertrophy-oriented work bout (3 x 10 at 65% 1 repetition maximum bench press, 1RM BP) before being retested for power output with the same resistance. In comparison with the control group (Con, n = 12), whose power output remained unchanged between the pre- and posttest periods, the Hyp group experienced a large, significant decrease in BT P40 power output. Even after further passive rest of 7 minutes, power output remained suppressed from the pretest values. Furthermore, the strongest 5 subjects experienced significantly larger percentage declines in power output than did the 5 less strong subjects. This study shows that a high-repetition, short-rest-period training can acutely decrease power output. Coaches should plan the order of exercises carefully when combining power and hypertrophy training. PMID:12930181

  9. HIGH AVERAGE POWER OPTICAL FEL AMPLIFIERS

    International Nuclear Information System (INIS)

    Historically, the first demonstration of the optical FEL was in an amplifier configuration at Stanford University [l]. There were other notable instances of amplifying a seed laser, such as the LLNL PALADIN amplifier [2] and the BNL ATF High-Gain Harmonic Generation FEL [3]. However, for the most part FELs are operated as oscillators or self amplified spontaneous emission devices. Yet, in wavelength regimes where a conventional laser seed can be used, the FEL can be used as an amplifier. One promising application is for very high average power generation, for instance FEL's with average power of 100 kW or more. The high electron beam power, high brightness and high efficiency that can be achieved with photoinjectors and superconducting Energy Recovery Linacs (ERL) combine well with the high-gain FEL amplifier to produce unprecedented average power FELs. This combination has a number of advantages. In particular, we show that for a given FEL power, an FEL amplifier can introduce lower energy spread in the beam as compared to a traditional oscillator. This properly gives the ERL based FEL amplifier a great wall-plug to optical power efficiency advantage. The optics for an amplifier is simple and compact. In addition to the general features of the high average power FEL amplifier, we will look at a 100 kW class FEL amplifier is being designed to operate on the 0.5 ampere Energy Recovery Linac which is under construction at Brookhaven National Laboratory's Collider-Accelerator Department

  10. The NASA CSTI High Capacity Power Project

    International Nuclear Information System (INIS)

    This paper describes the elements of NASA's CSTI High Capacity Power Project which include Systems Analysis, Stirling Power Conversion, Thermoelectric Power Conversion, Thermal Management, Power Management, Systems Diagnostics, Environmental Interactions, and Material/Structural Development. Technology advancement in all elements is required to provide the growth capability, high reliability and 7 to 10 year lifetime demanded for future space nuclear power systems. The overall project will develop and demonstrate the technology base required to provide a wide range of modular power systems compatible with the SP-100 reactor which facilitates operation during lunar and planetary day/night cycles as well as allowing spacecraft operation at any attitude or distance from the sun. Significant accomplishments in all of the project elements will be presented, along with revised goals and project timeliness recently developed

  11. High Power Picosecond Laser Pulse Recirculation

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-04-12

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

  12. NASA GRC High Power Electromagnetic Thruster Program

    Science.gov (United States)

    LaPointe, Michael R.; Pensil, Eric J.

    2004-01-01

    High-power electromagnetic thrusters have been proposed as primary in-space propulsion options for several bold new interplanetary and deep-space missions. As the lead center for electric propulsion, the NASA Glenn Research Center designs, develops, and tests high-power electromagnetic technologies to meet these demanding mission requirements. Two high-power thruster concepts currently under investigation by Glenn are the magnetoplasmadynamic (MPD) thruster and the Pulsed Inductive Thruster (PIT). This paper describes the MPD thruster and the test facility.

  13. High-efficiency solid state power amplifier

    Science.gov (United States)

    Wallis, Robert E. (Inventor); Cheng, Sheng (Inventor)

    2005-01-01

    A high-efficiency solid state power amplifier (SSPA) for specific use in a spacecraft is provided. The SSPA has a mass of less than 850 g and includes two different X-band power amplifier sections, i.e., a lumped power amplifier with a single 11-W output and a distributed power amplifier with eight 2.75-W outputs. These two amplifier sections provide output power that is scalable from 11 to 15 watts without major design changes. Five different hybrid microcircuits, including high-efficiency Heterostructure Field Effect Transistor (HFET) amplifiers and Monolithic Microwave Integrated Circuit (MMIC) phase shifters have been developed for use within the SSPA. A highly efficient packaging approach enables the integration of a large number of hybrid circuits into the SSPA.

  14. High average-power induction linacs

    International Nuclear Information System (INIS)

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

  15. Driver Circuit For High-Power MOSFET's

    Science.gov (United States)

    Letzer, Kevin A.

    1991-01-01

    Driver circuit generates rapid-voltage-transition pulses needed to switch high-power metal oxide/semiconductor field-effect transistor (MOSFET) modules rapidly between full "on" and full "off". Rapid switching reduces time of overlap between appreciable current through and appreciable voltage across such modules, thereby increasing power efficiency.

  16. A Pilot Study Involving the Effect of Two Different Complex Training Protocols on Lower Body Power

    OpenAIRE

    Smith Chad E.; Lyons Brian; Hannon James C.

    2014-01-01

    Purpose. Complex training (CT) involves the coupling of two exercises ostensibly to enhance the effect of the second exercise. Typically, the first exercise is a strength exercise and the second exercise is a power exercise involving similar muscles. In most cases, CT is designed to enhance power. The purpose of this study was twofold. First, this study was designed to determine if lower body power could be enhanced using complex training protocols. Second, this study investigated whether the...

  17. Highly integrated low power radars

    CERN Document Server

    Saponara, Sergio; Ragonese, Egidio

    2014-01-01

    In recent years, advances in radio detection and ranging technology, sustained by new achievements in the fields of signal processing and electronic components, have permitted the adoption of radars in many civil and defense applications.This resource discusses how highly integrated radar has been adopted by several new markets such as contactless vital sign monitoring (heart rate, breath rate) or harbour traffic control, as well as several applications for vehicle driver assistance. You are provided with scenarios, applications, and requirements, while focusing on the trade-offs between flexi

  18. Towards an analytical theory of the third-body problem for highly elliptical orbits

    CERN Document Server

    Lion, Guillaume; Deleflie, Florent

    2016-01-01

    When dealing with satellites orbiting a central body on a highly elliptical orbit, it is necessary to consider the effect of gravitational perturbations due to external bodies. Indeed, these perturbations can become very important as soon as the altitude of the satellite becomes high, which is the case around the apocentre of this type of orbit. For several reasons, the traditional tools of celestial mechanics are not well adapted to the particular dynamic of highly elliptical orbits. On the one hand, analytical solutions are quite generally expanded into power series of the eccentricity and therefore limited to quasi-circular orbits [17, 25]. On the other hand, the time-dependency due to the motion of the third-body is often neglected. We propose several tools to overcome these limitations. Firstly, we have expanded the disturbing function into a finite polynomial using Fourier expansions of elliptic motion functions in multiple of the satellite's eccentric anomaly (instead of the mean anomaly) and involving...

  19. High Power Helicon Plasma Propulsion Project

    Data.gov (United States)

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

  20. High Power Helicon Plasma Propulsion Project

    Data.gov (United States)

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

  1. Drivers for High Power Laser Diodes

    Institute of Scientific and Technical Information of China (English)

    Yankov P; Todorov D; Saramov E

    2006-01-01

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

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

    CERN Document Server

    Ahuja, Sumit; Shukla, Sandeep Kumar

    2012-01-01

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

  3. High-Power Testing of the APT Power Coupler

    CERN Document Server

    Schmierer, E N; Gautier, D C; Gioia, J G; Haynes, W B; Krawczyk, F L; Madrid, M A; Schrage, D L; Waynert, J A; Rusnak, B

    2000-01-01

    For the baseline APT (Accelerator Production of Tritium) linac design, power couplers are required to transmit 210-kW of CW RF power to the superconducting cavities. These APT couplers operate at 700 MHz, have a coaxial design and an adjustable coupling to the superconducting cavities. Since May 1999, we have been testing couplers of this design on a room-temperature test stand. We completed tests at transmitted-power and reflected-power conditions up to 1 MW. We also tested the couplers with a portion of the outer conductor cooled by liquid nitrogen. Under this latter condition, we studied the effects of condensed gases on coupler performance. The results of these tests indicate that the APT couplers are capable of delivering more than 500 kW to the cavities. We are in the process of increasing the baseline coupler design requirement to 420 kW of transmitted power to take advantage of this successful development. In this paper, we describe the results of our high-power coupler tests.

  4. High power density carbonate fuel cell

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  5. Methods for High Power EM Pulse Measurement

    OpenAIRE

    Fiala, P.; Drexler, P.

    2006-01-01

    There are some suitable methods for the measurement of ultra-short solitary electromagnetic pulses that can be generated by high power pulsed generators. The measurement methods properties have to correspond to the fact whether we want to measure pulses of voltage, current or free-space electromagnetic wave. The need for specific measurement methods occurred by the development of high power microwave pulse generator. Applicable methods are presented in this paper. The method utilizing Faraday...

  6. Assessment of Body-Powered Upper Limb Prostheses by Able-Bodied Subjects, using the Box and Blocks Test and the Nine Hole Peg Test

    NARCIS (Netherlands)

    Haverkate, L.; Smit, G.; Plettenburg, D.H.

    2014-01-01

    Study Design: Experimental trial. Background: The functional performance of currently available body-powered prostheses is unknown. Objective: The goal of this study was to objectively assess and compare the functional performance of three commonly used body-powered upper limb terminal devices. Meth

  7. Differences in myoelectric and body-powered upper-limb prostheses: Systematic literature review

    Directory of Open Access Journals (Sweden)

    Stephanie L. Carey, PhD

    2015-06-01

    Full Text Available The choice of a myoelectric or body-powered upper-limb prosthesis can be determined using factors including control, function, feedback, cosmesis, and rejection. Although body-powered and myoelectric control strategies offer unique functions, many prosthesis users must choose one. A systematic review was conducted to determine differences between myoelectric and body-powered prostheses to inform evidence-based clinical practice regarding prescription of these devices and training of users. A search of 9 databases identified 462 unique publications. Ultimately, 31 of them were included and 11 empirical evidence statements were developed. Conflicting evidence has been found in terms of the relative functional performance of body-powered and myoelectric prostheses. Body-powered prostheses have been shown to have advantages in durability, training time, frequency of adjustment, maintenance, and feedback; however, they could still benefit from improvements of control. Myoelectric prostheses have been shown to improve cosmesis and phantom-limb pain and are more accepted for light-intensity work. Currently, evidence is insufficient to conclude that either system provides a significant general advantage. Prosthetic selection should be based on a patient's individual needs and include personal preferences, prosthetic experience, and functional needs. This work demonstrates that there is a lack of empirical evidence regarding functional differences in upper-limb prostheses.

  8. Differences in myoelectric and body-powered upper-limb prostheses: Systematic literature review.

    Science.gov (United States)

    Carey, Stephanie L; Lura, Derek J; Highsmith, M Jason

    2015-01-01

    The choice of a myoelectric or body-powered upper-limb prosthesis can be determined using factors including control, function, feedback, cosmesis, and rejection. Although body-powered and myoelectric control strategies offer unique functions, many prosthesis users must choose one. A systematic review was conducted to determine differences between myoelectric and body-powered prostheses to inform evidence-based clinical practice regarding prescription of these devices and training of users. A search of 9 databases identified 462 unique publications. Ultimately, 31 of them were included and 11 empirical evidence statements were developed. Conflicting evidence has been found in terms of the relative functional performance of body-powered and myoelectric prostheses. Body-powered prostheses have been shown to have advantages in durability, training time, frequency of adjustment, maintenance, and feedback; however, they could still benefit from improvements of control. Myoelectric prostheses have been shown to improve cosmesis and phantom-limb pain and are more accepted for light=intensity work. Currently, evidence is insufficient to conclude that either system provides a significant general advantage. Prosthetic selection should be based on a patient's individual needs and include personal preferences, prosthetic experience, and functional needs. This work demonstrates that there is a lack of empirical evidence regarding functional differences in upper-limb prostheses. PMID:26230500

  9. Development of high precision switching power supply

    International Nuclear Information System (INIS)

    A high precision switching power supply was developed for the PFN modulator of RIKEN SACLA. The maximum output voltage is 50 kV, and the maximum repetition rate is 120 pps. The switching power supply consists of main and sub switching circuits. In the sub circuit, the pulse-width-modulation (PWM) method was used in order to obtain high precision charging voltage stability ( < 100 ppm–pp). The switching power supply was tested, and a charging voltage stability of 1 Vpp (20 ppm–pp) and a repetition rate of 120 pps were achieved. (author)

  10. Short pulse high power fiber laser systems

    OpenAIRE

    Malinowski, A.; Piper, A; Price, J.H.V.; He, F.; Ibsen, M; Nilsson, J.; Richardson, D J

    2005-01-01

    We review the rapid recent progress in the development of short pulse high-power fiber laser and amplifier devices. Use of cladding pump technology now provides a route to compact and efficient laser and amplifier systems with high beam quality and high output powers. A new Yb-fiber CPA system incorporating a CFBG stretcher with both 2nd and 3rd order dispersion is presented for high pulse energy applications. In addition, a simplified Yb-fiber parabolic amplifier system is also shown to be s...

  11. High energy radiation effects on the human body

    International Nuclear Information System (INIS)

    High-energy radiation injuries and their risks were recognized, information on low-energy radiation injuries was also arranged, and with these backgrounds, countermeasures against prevention of radiation injuries were considered. Redintegration of DNA and mutation by radiation were described, and relationship between radiation injuries and dose was considered. Interaction of high-energy radiation and substances in the living body and injuries by the interaction were also considered. Expression method of risk was considered, and a concept of protection dose was suggested. Protection dose is dose equivalent which is worthy of value at the point where the ratio to permissible dose distributed among each part of the body is at its maximum in the distribution of dose equivalent formed within the body when standard human body is placed at a certain radiation field for a certain time. Significance and countermeasures of health examination which is under an abligation to make radiation workers receive health check were thought, and problems were proposed on compensation when radiation injuries should appear actually. (Tsunoda, M.)

  12. Development of high power microwave source

    International Nuclear Information System (INIS)

    To achieve thermonuclear fusion it is inevitable to develop high power microwave and millimeter wave sources for plasma heating. In 1990, working group was organized as a collaboration study in National Institute for Fusion Science to review the present status of development on high microwave source. We report the review of development on high power klystron and gyrotron, FEL and microwave power source by REB. Development of high power klystron is almost finished except for cooling of the window, cavity and collector. As for the gyrotron oscillating with the whispering gallery mode one must overcome the same problem for CW operation. In the quasi-optical gyrotron, these is no special progress for increasing the frequency and efficiency. Though the experimental evidence on autoresonance in the development of peniotron is performed, output power and frequency is much smaller than that of the gyrotron. It is difficult to increase in the pluse width of FEL having giant of GW level with several ten ns and the utilization for plasma heating is limited. In addition, we summarize microwave and millimeter wave oscillators with high power which are running in the laboratories and the institutes. (author)

  13. The NASA CSTI High Capacity Power Project

    Energy Technology Data Exchange (ETDEWEB)

    Winter, J.; Dudenhoefer, J.; Juhasz, A.; Schwarze, G.; Patterson, R.; Ferguson, D.; Titran, R. [National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center; Schmitz, P. [Sverdrup Technology, Inc., Brook Park, OH (United States). Lewis Research Center Group; Vandersande, J. [Jet Propulsion Lab., Pasadena, CA (United States)

    1994-09-01

    The SP-100 Space Nuclear Power Program was established in 1983 by DOD, DOE, and NASA as a joint program to develop technology for military and civil applications. Starting in 1986, NASA has funded a technology program to maintain the momentum of promising aerospace technology advancement started during Phase I of SP-100 and to strengthen, in key areas, the changes for successful development and growth capability of space nuclear reactor power systems for a wide range of future space applications. The elements of the CSTI High Capacity Power Project include Systems Analysis, Stirling Power Conversion, Thermoelectric Power Conversion, Thermal Management, Power Management, Systems Diagnostics, Environmental Interactions, and Material/Structural Development. Technology advancement in all elements is required to provide the growth capability, high reliability and 7 to 10 year lifetime demanded for future space nuclear power systems. The overall project with develop and demonstrate the technology base required to provide a wide range of modular power systems compatible with the SP-100 reactor which facilitates operation during lunar and planetary day/night cycles as well as allowing spacecraft operation at any attitude or distance from the sun. Significant accomplishments in all of the project elements will be presented, along with revised goals and project timelines recently developed.

  14. Protection Related to High-power Targets

    CERN Document Server

    Plum, M A

    2016-01-01

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

  15. A very low power MAC (VLPM) protocol for Wireless Body Area Networks.

    Science.gov (United States)

    Ullah, Niamat; Khan, Pervez; Kwak, Kyung Sup

    2011-01-01

    Wireless Body Area Networks (WBANs) consist of a limited number of battery operated nodes that are used to monitor the vital signs of a patient over long periods of time without restricting the patient's movements. They are an easy and fast way to diagnose the patient's status and to consult the doctor. Device as well as network lifetime are among the most important factors in a WBAN. Prolonging the lifetime of the WBAN strongly depends on controlling the energy consumption of sensor nodes. To achieve energy efficiency, low duty cycle MAC protocols are used, but for medical applications, especially in the case of pacemakers where data have time-limited relevance, these protocols increase latency which is highly undesirable and leads to system instability. In this paper, we propose a low power MAC protocol (VLPM) based on existing wakeup radio approaches which reduce energy consumption as well as improving the response time of a node. We categorize the traffic into uplink and downlink traffic. The nodes are equipped with both a low power wake-up transmitter and receiver. The low power wake-up receiver monitors the activity on channel all the time with a very low power and keeps the MCU (Micro Controller Unit) along with main radio in sleep mode. When a node [BN or BNC (BAN Coordinator)] wants to communicate with another node, it uses the low-power radio to send a wakeup packet, which will prompt the receiver to power up its primary radio to listen for the message that follows shortly. The wake-up packet contains the desired node's ID along with some other information to let the targeted node to wake-up and take part in communication and let all other nodes to go to sleep mode quickly. The VLPM protocol is proposed for applications having low traffic conditions. For high traffic rates, optimization is needed. Analytical results show that the proposed protocol outperforms both synchronized and unsynchronized MAC protocols like T-MAC, SCP-MAC, B-MAC and X-MAC in terms

  16. A Very Low Power MAC (VLPM Protocol for Wireless Body Area Networks

    Directory of Open Access Journals (Sweden)

    Kyung Sup Kwak

    2011-03-01

    Full Text Available Wireless Body Area Networks (WBANs consist of a limited number of battery operated nodes that are used to monitor the vital signs of a patient over long periods of time without restricting the patient’s movements. They are an easy and fast way to diagnose the patient’s status and to consult the doctor. Device as well as network lifetime are among the most important factors in a WBAN. Prolonging the lifetime of the WBAN strongly depends on controlling the energy consumption of sensor nodes. To achieve energy efficiency, low duty cycle MAC protocols are used, but for medical applications, especially in the case of pacemakers where data have time-limited relevance, these protocols increase latency which is highly undesirable and leads to system instability. In this paper, we propose a low power MAC protocol (VLPM based on existing wakeup radio approaches which reduce energy consumption as well as improving the response time of a node. We categorize the traffic into uplink and downlink traffic. The nodes are equipped with both a low power wake-up transmitter and receiver. The low power wake-up receiver monitors the activity on channel all the time with a very low power and keeps the MCU (Micro Controller Unit along with main radio in sleep mode. When a node [BN or BNC (BAN Coordinator] wants to communicate with another node, it uses the low-power radio to send a wakeup packet, which will prompt the receiver to power up its primary radio to listen for the message that follows shortly. The wake-up packet contains the desired node’s ID along with some other information to let the targeted node to wake-up and take part in communication and let all other nodes to go to sleep mode quickly. The VLPM protocol is proposed for applications having low traffic conditions. For high traffic rates, optimization is needed. Analytical results show that the proposed protocol outperforms both synchronized and unsynchronized MAC protocols like T-MAC, SCP-MAC, B

  17. Qualifications and training of staff of the regulatory body for nuclear power plants

    International Nuclear Information System (INIS)

    This Safety Guide was prepared as part of the Agency's programme, referred to as the NUSS programme, for establishing Codes of Practice and Safety Guides relating to nuclear power plants. It supplements the Agency's Safety Series No.50-C-G, entitled ''Governmental Organization for the Regulation of Nuclear Power Plants: A Code of Practice'', and is mainly concerned with the qualifications and training requirements of the staff of bodies regulating nuclear power plants. It is not concerned with staff for regulating other phases of the fuel cycle, such as fuel fabrication and management. This Guide provides recommendations and guidance for establishing the qualifications required for the staff of the regulatory body. These requirements include academic training, work experience and other abilities. It also establishes the training programmes and activities necessary for personnel within the regulatory body

  18. Power monitor miter bends for high-power microwave transmission

    Energy Technology Data Exchange (ETDEWEB)

    Doane, John, E-mail: doane@fusion.gat.com; Anderson, James; Grunloh, Howard; Wu, Wen

    2015-04-15

    Two miter bends are described for monitoring the power transmitted in an oversized corrugated wave-guide. One has an array of holes in its mirror that couples a small fraction of the incident power to a rectangular waveguide directly machined into the mirror. Millimeter-wave detectors on the outputs of this miter bend can respond very rapidly to the transmitted power, but the coupling is sensitive to the mode purity in the oversized waveguide. The other miter bend monitors the power by measuring the rise in temperature of the cooling water passing through the mirror. The mirror is well isolated from the miter bend housing to prevent heat from neighboring waveguides from reaching the mirror. The measurement requires about 200 s to reach steady state, but it is relatively insensitive to mode purity. The measurement does require knowledge of the input polarization. Thermo-mechanical analyses of the miter bends indicate that they are capable of reliable operation with 1.5 MW transmitted through them. High-power long-pulse 170 GHz tests of these miter bends at the Japan Atomic Energy Agency (JAEA) are described.

  19. Power production locality of bluff body flutter mills using fully coupled 2D direct numerical simulation

    Science.gov (United States)

    Kuhl, J. M.; Desjardin, P. E.

    2012-01-01

    Two-dimensional, fully coupled direct numerical simulations (DNS) are conducted to examine the local energy dynamics of a flexible cantilevered plate in the wake of a two-dimensional circular cylinder. The motion of the cantilevered plate is described using a finite element formulation and a fully compressible, finite volume Navier Stokes solver is used to compute the flow field. A sharp interface level set method is employed in conjunction with a ghost fluid method to describe the immersed boundaries of the bluff body and flexible plate. DNS is first conducted to validate the numerical methodology and compared with previous studies of flexible cantilevered plates and flow over bluff bodies; excellent agreement with previous results is observed. A newly defined power production/loss geometry metric is introduced based on surface curvature and plate velocity. The metric is found to be useful for determining which sections of the plate will produce energy based on curvature and deflection rate. Scatter plots and probability measures are presented showing a high correlation between the direction of energy transfer (i.e., to or from the plate) and the sign of the newly defined curvature-deflection-rate metric. The findings from this study suggest that a simple local geometry/kinematic based metric can be devised to aid in the development and design of flexible wind energy harvesting flutter mills.

  20. Chiral power counting of one- and two-body currents in direct detection of dark matter

    International Nuclear Information System (INIS)

    We present a common chiral power-counting scheme for vector, axial-vector, scalar, and pseudoscalar WIMP–nucleon interactions, and derive all one- and two-body currents up to third order in the chiral expansion. Matching our amplitudes to non-relativistic effective field theory, we find that chiral symmetry predicts a hierarchy amongst the non-relativistic operators. Moreover, we identify interaction channels where two-body currents that previously have not been accounted for become relevant

  1. What lies beyond consciousness? Nietzschean reworking of the mind-body relationship in terms of power

    Directory of Open Access Journals (Sweden)

    Óscar Quejido Alonso

    2014-11-01

    Full Text Available Nietzsche's critique of the notion of soul is inevitably linked to his more general claim for the role of the body in its relation to conscious thought. This alternative can be considered as a new interpretative and conceptual framework from which to address the issue of the relationship between body and mind, on the basis of the redefinition of psychology in terms of power relations

  2. Tapered fiber based high power random laser.

    Science.gov (United States)

    Zhang, Hanwei; Du, Xueyuan; Zhou, Pu; Wang, Xiaolin; Xu, Xiaojun

    2016-04-18

    We propose a novel high power random fiber laser (RFL) based on tapered fiber. It can overcome the power scaling limitation of RFL while maintaining good beam quality to a certain extent. An output power of 26.5 W has been achieved in a half-open cavity with one kilometer long tapered fiber whose core diameter gradually changes from 8 μm to 20 μm. The steady-state light propagation equations have been modified by taking into account the effective core area to demonstrate the tapered RFL through numerical calculations. The numerical model effectively describes the power characteristics of the tapered fiber based RFL, and both the calculating and experimental results show higher power exporting potential compared with the conventional single mode RFL. PMID:27137338

  3. Power and physiological changes in the body of aerobics competitors with different skills at the moment of exercise performing

    OpenAIRE

    Baranauskaitė, Asta

    2005-01-01

    The aim of the present work is to determine power and physiological changes in the body of aerobics competitors with different skills at the moment of exercise performing. 24 aerobic competitors were selected as a research object. All the members of the research group were divided into three groups with reference to their personal data (obtained after the assessment of the relations between their indices and their skills). The groups were as follows: group 1 – highly skilled aerobic comp...

  4. Field emission cathode for high power beams

    International Nuclear Information System (INIS)

    Field emission is identified as the mechanism responsible for high current emission (50 A/cm2 at 3000K) from a dispenser-type cathode. This cathode has advantages for high power operation, and should be suitable for practical applications. (author)

  5. ATF2 High Availability Power Supplies

    Energy Technology Data Exchange (ETDEWEB)

    Bellomo, A; Lira, C.de; Lam, B.; MacNair, D.; White, G.; /SLAC

    2008-06-27

    ATF2 is an accelerator test facility modeled after the final focus beamline envisioned for the ILC. By the end of 2008, KEK plans to commission the ATF2 [1]. SLAC and OCEM collaborated on the design of 38 power systems for beamline magnets. The systems range in output power from 1.5 kW to 6 kW. Since high availability is essential for the success of the ILC, Collaborators employed an N+1 modular approach, allowing for redundancy and the use of a single power module rating. This approach increases the availability of the power systems. Common power modules reduces inventory and eases maintenance. Current stability requirements are as tight as 10 ppm. A novel, SLAC designed 20-bit Ethernet Power Supply Controller provides the required precision current regulation. In this paper, Collaborators present the power system design, the expected reliability, fault immunity features, and the methods for satisfying the control and monitoring challenges. Presented are test results and the status of the power systems.

  6. High voltage beam power source for high frequency heating

    International Nuclear Information System (INIS)

    Recently, the importance of the plasma heating by high frequency electric power has increased in the research and development of nuclear fusion. There are three methods in the plasma heating by high frequency electric power, that is, electron cyclotron heating, lower hybrid resonance frequency heating and ion cyclotron range of frequency heating. In all cases, the vacuum tubes requiring high voltage beam power sources are used as the high frequency electric power generator, and the typical vacuum tubes are a gyrotron in ECH, a Klystron in LHRF and a quadrupole tube in ICRF. The gyrotron is a special millimeter wave vibrating tube, while the other two are amplifying tubes, accordingly, severe specification is imposed on the stability of beam voltage and the protection function against load short circuit of the gyrotron. The typical specifications of beam power sources are shown. The vibrating characteristics of a gyrotron are dependent largely on beam voltage and anode voltage. The beam power source for a gyrotron is the type using commercial power or the output of a flywheel generator on-line, or the type making the constant voltage control of the energy accumulated in a condenser bank and supplying it to a gyrotron. The control of beam voltage and anode voltage in the beam power source for a gyrotron and the protection of a gyrotron are discussed. (Kako, I.)

  7. The Effect of High-Intensity Intermittent Exercise on Body Composition of Overweight Young Males

    Directory of Open Access Journals (Sweden)

    M. Heydari

    2012-01-01

    Full Text Available To determine the effect of a 12-week high intensity intermittent exercise (HIIE intervention on total body, abdominal, trunk, visceral fat mass, and fat free mass of young overweight males. Participants were randomly assigned to either exercise or control group. The intervention group received HIIE three times per week, 20 min per session, for 12 weeks. Aerobic power improved significantly (P0.05 occurred in levels of insulin, HOMA-IR, and blood lipids. Twelve weeks of HIIE resulted in significant reductions in total, abdominal, trunk, and visceral fat and significant increases in fat free mass and aerobic power.

  8. The Effect of High-Intensity Intermittent Exercise on Body Composition of Overweight Young Males

    Science.gov (United States)

    Heydari, M.; Freund, J.; Boutcher, S. H.

    2012-01-01

    To determine the effect of a 12-week high intensity intermittent exercise (HIIE) intervention on total body, abdominal, trunk, visceral fat mass, and fat free mass of young overweight males. Participants were randomly assigned to either exercise or control group. The intervention group received HIIE three times per week, 20 min per session, for 12 weeks. Aerobic power improved significantly (P 0.05) occurred in levels of insulin, HOMA-IR, and blood lipids. Twelve weeks of HIIE resulted in significant reductions in total, abdominal, trunk, and visceral fat and significant increases in fat free mass and aerobic power. PMID:22720138

  9. Advanced High Voltage Power Device Concepts

    CERN Document Server

    Baliga, B Jayant

    2012-01-01

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

  10. Adaptations in upper-body maximal strength and power output resulting from long-term resistance training in experienced strength-power athletes.

    Science.gov (United States)

    Baker, Daniel G; Newton, Robert U

    2006-08-01

    The purpose of this investigation was to observe changes in maximal upper-body strength and power and shifts in the load-power curve across a multiyear period in experienced resistance trainers. Twelve professional rugby league players who regularly performed combined maximal strength and power training were observed across a 4-year period with test data reported every 2 years (years 1998, 2000, and 2002). Upper-body strength was assessed by the 1 repetition maximum bench press and maximum power during bench press throws (BT Pmax) with various barbell resistances of 40-80 kg. During the initial testing, players also were identified as elite (n = 6) or subelite (n = 6), depending upon whether they participated in the elite first-division national league or second-division league. This subgrouping allowed for a comparison of the scope of changes dependent upon initial strength and training experience. The subelite group was significantly younger, less strong, and less powerful than the elite group, but no other difference existed in height or body mass in 1998. Across the 4-year period, significant increases in strength occurred for the group as a whole and larger increases were observed for the subelite than the elite group, verifying the limited scope that exists for strength gain in more experienced, elite resistance-trained athletes. A similar trend occurred for changes in BT Pmax. This long-term observation confirms that the rate of progress in strength and power development diminishes with increased strength levels and resistance training experience. Furthermore, it also indicates that strength and power can still be increased despite a high volume of concurrent resistance and endurance training. PMID:16937966

  11. Relationships Among Lower Body Strength, Power and Performance of Functional Tasks

    Science.gov (United States)

    Ploutz-Snyder, Lori

    2010-01-01

    There is a large degree of variability among crewmembers with respect to decrements in muscle strength and power following long duration spaceflight, ranging from 0 to approx.30% reductions. The purpose of this study was to investigate the influence of varying decrements in lower body muscle strength and power (relative to body weight) on the performance of 2 occupationally relevant tasks (ladder climb and supine egress & walk). Seventeen participants with leg strength similar to US crewmembers performed a leg press power test, an isokinetic knee extension strength test and they were asked to complete the 2 functional tasks as quickly as possible. On additional test days the participants were asked to repeat the functional tasks under 3 conditions where a different external load was applied each time using a weighted suit in order to experimentally manipulate participants strength/body weight and power/body weight ratios. The weight in the suit ranged from 20-120% of body weight and was distributed in proportion to limb segment weights to minimize changes in center of gravity. The ladder task consisted of climbing 40 rungs on a ladder treadmill as fast as possible. The supine egress & walk task consisted of rising from a supine position and walking through an obstacle course. Results show a relatively linear relationship between strength/body weight and task time and power/body weight with task time such that the fastest performance times are associated with higher strength and power with about half the variance in task time is accounted for by a single variable (either strength or power). For the average person, a 20% reduction in power/body weight (from 18 to 14.4 W/kg) induces an increase (slowing) of about 10 seconds in the ladder climb task from 14 to 24 seconds (approx.70%) and a slowing of the supine egress & walk task from 14 to 21 seconds (approx.50%). Similar relationships were observed with strength/body weight and task performance. For the average

  12. 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.

  13. 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

  14. High Power Microwave Sources : design and experiments

    OpenAIRE

    Möller, Cecilia

    2011-01-01

    High-Power Microwaves (HPM) can be used to intentionally disturb or destroy electronic equipment at a distance by inducing high voltages and currents. This thesis presents results from experiments with a narrow band HPM source, the vircator. The high voltages needed to generate HPM puts the vircator under great stress, especially the electrode materials. Several electrode materials have been tested for endurance and their influence on the characteristics of the microwave pulse. With the prope...

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

    OpenAIRE

    Tanveer Ahmed; Haralambos Mouratidis; David Preston

    2009-01-01

    This paper aims to address the question of offering a culturally adapted website for a local audience. So far, in the website design arena the vast majority of studies examined mainly Western and the American (low power distance and low context) culture disregarding possible cultural discrepancies. This study fills this gap and explores the key cultural parameters that are likely to have an impact on local website design for Asian-Eastern culture high power distance and high context correlati...

  16. Technology development for high power induction accelerators

    International Nuclear Information System (INIS)

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

  17. Hypersonic aerodynamic characteristics of a family of power-law, wing body configurations

    Science.gov (United States)

    Townsend, J. C.

    1973-01-01

    The configurations analyzed are half-axisymmetric, power-law bodies surmounted by thin, flat wings. The wing planform matches the body shock-wave shape. Analytic solutions of the hypersonic small disturbance equations form a basis for calculating the longitudinal aerodynamic characteristics. Boundary-layer displacement effects on the body and the wing upper surface are approximated. Skin friction is estimated by using compressible, laminar boundary-layer solutions. Good agreement was obtained with available experimental data for which the basic theoretical assumptions were satisfied. The method is used to estimate the effects of power-law, fineness ratio, and Mach number variations at full-scale conditions. The computer program is included.

  18. High power collimated diode laser stack

    Institute of Scientific and Technical Information of China (English)

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

    2006-01-01

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

  19. High power switches for ion induction linacs

    International Nuclear Information System (INIS)

    The success of linear induction ion accelerators for accelerator inertial fusion (AIF) applications depends largely on innovations in pulsed power technology. There are tight constraints on the accuracy of accelerating voltage waveforms to maintain a low momentum spread. Furthermore, the non-relativistic ion beams may be subject to a klystron-like interaction with the accelerating cavities leading to enhanced momentum spread. In this paper, the author describe a novel high power switch with a demonstrated ability to interrupt 300 A at 20 kV in less than 60 ns. The switch may allow the replacement of pulse modulators in linear induction accelerators with hard tube pulsers. A power system based on a hard tube pulser could solve the longitudinal instability problem while maintaining high energy transfer efficiency. The problem of longitudinal beam control in ion induction linacs is reviewed in Section 2. Section 3 describes the principles of the plasma flow switch. Experimental results are summarized in Section 4

  20. Gender differences in body size dissatisfaction among individuals with low, medium, or high levels of body focus.

    Science.gov (United States)

    Lokken, Kristine; Ferraro, F Richard; Kirchner, Tara; Bowling, Margo

    2003-07-01

    The authors designed the present study to test whether women reported higher levels of body dissatisfaction than did men even when the 2 genders were matched on a measure of degree of body focus. Sixty undergraduates (30 men, 30 women) were screened on attention-to-body-shape scores and divided into high, medium, and low body-shape-focus groups. The participants also completed questionnaires that provided information on age, education, vocabulary ability, levels of depression, and body-image assessment. The groups did not differ (ps > .05) on age, education, vocabulary ability, or levels of depression. However, women in all 3 body-shape-focus categories indicated a larger discrepancy between their real vs. ideal body images (p < .01) than did the men. In the high-body-focus group, there was an 11:1ratio between women's and men's reported real-ideal body-shape discrepancies. Women showed greater body dissatisfaction than did men, even when the genders were matched on a measure of body focus. PMID:12926515

  1. High Power 35GHz Gyroklystron Amplifiers

    Science.gov (United States)

    Choi, Jin; McCurdy, A.; Wood, F.; Kyser, R.; Danly, B.; Levush, B.; Parker, R.

    1997-05-01

    High power coherent radiation sources at 35GHz are attractive for next generation high gradient particle accelerators. A multi-cavity gyroklystron amplifier is considered a promising candidate for high power millimeter wave generation. Experiments on two-cavity and three cavity gyroklystron amplifiers are underway to demonstrate a 140kW, 35GHz coherent radiation amplification. Though this power is low compared with that needed for colliders, many of the issues associated with the bandwidth of such devices can be addressed in the present experiments. High bandwidth is important to permit the rapid phase shifts required for RF pulse compression schemes presently under investigation. Large signal calculations (P.E. Latham, W. Lawson, V. Irwin, IEEE Trans. Plasma Sci., Vol. 22, No. 5, pp. 804-817, 1994.) predict that the two-cavity gyroklystron produces a peak power of 140kW, corresponding to 33% efficiency. Calculations also show that a stagger tuned three cavity circuit increases a bandwidth to more than 0.7%. Experimental results of the amplifier will be presented and compared with the theory.

  2. Secondary radiation dose during high-energy total body irradiation

    International Nuclear Information System (INIS)

    The goal of this work was to assess the additional dose from secondary neutrons and γ-rays generated during total body irradiation (TBI) using a medical linac X-ray beam. Nuclear reactions that occur in the accelerator construction during emission of high-energy beams in teleradiotherapy are the source of secondary radiation. Induced activity is dependent on the half-lives of the generated radionuclides, whereas neutron flux accompanies the treatment process only. The TBI procedure using a 18 MV beam (Clinac 2100) was considered. Lateral and anterior-posterior/posterior-anterior fractions were investigated during delivery of 2 Gy of therapeutic dose. Neutron and photon flux densities were measured using neutron activation analysis (NAA) and semiconductor spectrometry. The secondary dose was estimated applying the fluence-to-dose conversion coefficients. The main contribution to the secondary dose is associated with fast neutrons. The main sources of γ-radiation are the following: 56Mn in the stainless steel and 187W of the collimation system as well as positron emitters, activated via (n,γ) and (γ,n) processes, respectively. In addition to 12 Gy of therapeutic dose, the patient could receive 57.43 mSv in the studied conditions, including 4.63 μSv from activated radionuclides. Neutron dose is mainly influenced by the time of beam emission. However, it is moderated by long source-surface distances (SSD) and application of plexiglass plates covering the patient body during treatment. Secondary radiation gives the whole body a dose, which should be taken into consideration especially when one fraction of irradiation does not cover the whole body at once. (orig.)

  3. High power electronic devices cooling at minimum ventilation power

    Energy Technology Data Exchange (ETDEWEB)

    Fabbri, Giampietro [University of Bologna, Department of Energetic, Nuclear, and Environmental Control Engineering, Bologna (Italy)

    2008-01-15

    In the present work, the cooling of a high power electronic device is studied. The device is in contact with a heat dissipator crossed by air. The air motion through the dissipator is forced by a fan whose supplied power is to be minimized. A finite element dynamic model of the dissipator is firstly created, taking geometrical and physical properties into account as well as steady state experimental data. A simplified model is then obtained, which reproduces the time pattern of the maximum dissipator temperature as a response of the thermal flux removed from the electronic device and the mass flow rate of the air. Afterwards, the simplified model is utilized to build a control system which allows the electronic device to be correctly cooled at minimum air ventilation power during transition to steady states. Genetic algorithms are used to find the parameters of the finite element model and of the control system. Some functioning conditions of the electronic device are lastly considered and discussed. (orig.)

  4. Effect of Load on Peak Power of the Bar, Body and System during the Deadlift

    Directory of Open Access Journals (Sweden)

    Justin A. Blatnik, Courtney L. Goodman, Christopher R. Capps, Olumide O. Awelewa, Travis N. Triplett, Travis M. Erickson, Jeffery M. McBride

    2014-09-01

    Full Text Available The purpose of this investigation was to examine how load would affect peak power (PP of the bar, body and system (bar + body during the deadlift. Eight healthy males (age = 22.00 ± 2.38 years; height = 1.80 ± 0.05 m; body mass = 88.97 ± 14.88 kg; deadlift one repetition maximum [1RM] = 203.44 ± 21.59 kg, 1RM/BM = 2.32 ± 0.31 with a minimum of 2 years’ resistance training experience and a deadlift 1RM over 1.5 times their bodyweight participated in the investigation. During the first session, anthropometric data were recorded and a 1RM deadlift was obtained from the participants. During the second session, participants performed two repetitions at intensities of 30, 40, 50, 60, 70, 80 and 90% of their 1RM in a randomized order. Three-dimensional videography with a force plate was used for data collection and analysis. Peak force (PF, peak velocity (PV, an d PP were calculated for the bar, body, and system (bar + body during the deadlift. PP occurred at 50%, 30%, and 70% of 1RM for the bar, body, and system, respectively. The optimal loading for the deadlift exercise may vary depending on the desired stimulus and whether the bar, body, or system variables are of most interest.

  5. Improved Spatial Filter for high power Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Estabrook, Kent G.; Celliers, Peter M.; Murray, James E.; DaSilva, Luiz; MacGowan, Brian J.; Rubenchik, Alexander M.; Manes, Kenneth R.; Drake, Robert P.; Afeyan, Bedros

    1998-06-01

    A new pinhole architecture incorporates features intended to reduce the rate of plasma generation in a spatial filter for high-energy laser pulse beams. An elongated pinhole aperture is provided in an apertured body for rejecting off-axis rays of the laser pulse beam. The internal surface of the elongated aperture has a diameter which progressively tapers from a larger entrance cross-sectional area at an inlet to a smaller output cross-sectional area at an outlet. The tapered internal surface causes off-axis rays to be refracted in a low density plasma layer that forms on the internal surface or specularly reflected at grazing incidence from the internal surface. Off-axis rays of the high-energy pulse beam are rejected by this design. The external surface of the apertured body adjacent to the larger entrance cross-sectional area at the inlet to the elongated aperture is angled obliquely with respect to the to direction of the path of the high-energy laser pulse beam to backscatter off-axis rays away from the high-energy pulse beam. The aperture is formed as a truncated cone or alternatively with a tapered square cross-section. The internal surface of the aperture is coated with an ablative material, preferably high-density material which can be deposited with an exploding wire.

  6. Demonstration of novel high-power acoustic through-the-wall sensor

    OpenAIRE

    Felber, Franklin

    2015-01-01

    A high-power acoustic sensor, capable of detecting and tracking persons through steel walls of cargo containers, trailer truck bodies, and train cars, has been developed and demonstrated. The sensor is based on a new concept for narrowband mechanical-impact acoustic transmitters and matched resonant receivers. The lightweight, compact, and low-cost transmitters produce high-power acoustic pulses at one or more discrete frequencies with little input power. The energy for each pulse is accumula...

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

    Directory of Open Access Journals (Sweden)

    Tanveer Ahmed

    2009-06-01

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

  8. MI high power operation and future plans

    Energy Technology Data Exchange (ETDEWEB)

    Kourbanis, Ioanis; /Fermilab

    2008-09-01

    Fermilab's Main Injector on acceleration cycles to 120 GeV has been running a mixed mode operation delivering beam to both the antiproton source for pbar production and to the NuMI[1] target for neutrino production since 2005. On January 2008 the slip stacking process used to increase the beam to the pbar target was expanded to include the beam to the NuMI target increasing both the beam intensity and power. The current high power MI operation will be described along with the near future plans.

  9. Voluntary Running Aids to Maintain High Body Temperature in Rats Bred for High Aerobic Capacity

    Science.gov (United States)

    Karvinen, Sira M.; Silvennoinen, Mika; Ma, Hongqiang; Törmäkangas, Timo; Rantalainen, Timo; Rinnankoski-Tuikka, Rita; Lensu, Sanna; Koch, Lauren G.; Britton, Steven L.; Kainulainen, Heikki

    2016-01-01

    The production of heat, i.e., thermogenesis, is a significant component of the metabolic rate, which in turn affects weight gain and health. Thermogenesis is linked to physical activity (PA) level. However, it is not known whether intrinsic exercise capacity, aging, and long-term voluntary running affect core body temperature. Here we use rat models selectively bred to differ in maximal treadmill endurance running capacity (Low capacity runners, LCR and High capacity Runners, HCR), that as adults are divergent for aerobic exercise capacity, aging, and metabolic disease risk to study the connection between PA and body temperature. Ten high capacity runner (HCR) and ten low capacity runner (LCR) female rats were studied between 9 and 21 months of age. Rectal body temperature of HCR and LCR rats was measured before and after 1-year voluntary running/control intervention to explore the effects of aging and PA. Also, we determined whether injected glucose and spontaneous activity affect the body temperature differently between LCR and HCR rats at 9 vs. 21 months of age. HCRs had on average 1.3°C higher body temperature than LCRs (p < 0.001). Aging decreased the body temperature level of HCRs to similar levels with LCRs. The opportunity to run voluntarily had a significant impact on the body temperature of HCRs (p < 0.001) allowing them to maintain body temperature at a similar level as when at younger age. Compared to LCRs, HCRs were spontaneously more active, had higher relative gastrocnemius muscle mass and higher UCP2, PGC-1α, cyt c, and OXPHOS levels in the skeletal muscle (p < 0.050). These results suggest that higher PA level together with greater relative muscle mass and higher mitochondrial content/function contribute to the accumulation of heat in the HCRs. Interestingly, neither aging nor voluntary training had a significant impact on core body temperature of LCRs. However, glucose injection resulted in a lowering of the body temperature of LCRs (p < 0

  10. MULTIPULSE - high resolution and high power in one TDEM system

    Science.gov (United States)

    Chen, Tianyou; Hodges, Greg; Miles, Philip

    2015-09-01

    An airborne time domain electromagnetic (TEM) system with high resolution and great depth of exploration is desired for geological mapping as well as for mineral exploration. The MULTIPULSE technology enables an airborne TEM system to transmit a high power pulse (a half-sine, for instance) and one or multiple low power pulse(s) (trapezoid or square) within a half-cycle. The high power pulse ensures good depth of exploration and the low power pulse allows a fast transmitter current turn off and earlier off-time measurement thus providing higher frequency signals, which allows higher near-surface resolution and better sensitivity to weak conductors. The power spectrum of the MULTIPULSE waveform comprising a half-sine and a trapezoid pulse clearly shows increased power in the higher frequency range (> ~2.3 kHz) compared to that of a single half-sine waveform. The addition of the low power trapezoid pulse extends the range of the sensitivity 10-fold towards the weak conductors, expanding the geological conductivity range of a system and increasing the scope of its applications. The MULTIPULSE technology can be applied to standard single-pulse airborne TEM systems on both helicopter and fixed-wing. We field tested the HELITEM MULTIPULSE system over a wire-loop in Iroquois Falls, demonstrating the different sensitivity of the high and low power pulses to the overburden and the wire-loop. We also tested both HELITEM and GEOTEM MULTIPULSE systems over a layered oil sand geologic setting in Fort McMurray, Alberta, Canada. The results show comparable shallow geologic resolution of the MULTIPULSE to that of the RESOLVE system while maintaining superior depth of exploration, confirming the increased geological conductivity range of a system employing MULTIPULSE compared to the standard single-pulse systems.

  11. A High Power Linear Solid State Pulser

    International Nuclear Information System (INIS)

    Particle Accelerators require high voltage and often high power. Typically the high voltage/power generation utilizes a topology with an extra energy store and a switching means to extract that stored energy. The switches may be active or passive devices. Active switches are hard or soft vacuum tubes, or semiconductors. When required voltages exceed tens of kilovolts, numerous semiconductors are stacked to withstand that potential. Such topologies can use large numbers of critical parts that, when in series, compromise the system reliability and performance. This paper describes a modular, linear, solid state amplifier which uses a parallel array of semiconductors, coupled with transmission line transformers. Such a design can provide output signals with voltages exceeding 10kV (into 50-ohms), and with rise and fall times (10-90 % amplitude) that are less than 1--ns. This compact solid state amplifier is modular, and has both hot-swap and soft fail capabilities

  12. Vacuum requirements in high power microwave tubes

    Energy Technology Data Exchange (ETDEWEB)

    Dammertz, Guenter [Kernforschungszentrum Karlsruhe GmbH (Germany). Inst. fuer Technische Physik

    1995-08-01

    During recent years microwave tubes for low and medium power have been replaced by solid state devices. However, the generation of microwaves at high power is still only possible by the use of high-vacuum electron tubes. For reliable operation and sufficiently long life times severe requirements on vacuum conditions have to be fulfilled. To avoid poisoning of the electron emitter material, high voltage and rf breakdowns, multipactoring and beam instabilities caused by ion oscillations, the pressure in the tubes should not exceed 10{sup -5} Pa. In many cases the tubes are used without any additional pumps or with very small pumps. To preserve the good vacuum conditions over long periods, only very low degassing rates and very low leaking rates (10{sup -12} Pa M{sup 3} s{sup -1}) are required. (author).

  13. A Pilot Study Involving the Effect of Two Different Complex Training Protocols on Lower Body Power

    Directory of Open Access Journals (Sweden)

    Smith Chad E.

    2014-09-01

    Full Text Available Purpose. Complex training (CT involves the coupling of two exercises ostensibly to enhance the effect of the second exercise. Typically, the first exercise is a strength exercise and the second exercise is a power exercise involving similar muscles. In most cases, CT is designed to enhance power. The purpose of this study was twofold. First, this study was designed to determine if lower body power could be enhanced using complex training protocols. Second, this study investigated whether the inclusion of a power exercise instead of a strength exercise as the first exercise in CT would produce differences in lower body power. Methods. Thirty-six recreationally-trained men and women aged 20 to 29 years attending a college physical education course were randomly assigned to one of three groups: squat and countermovement squat jumps (SSJ, kettlebell swings and countermovement squat jumps (KSJ, and a control (CON. Training involving CT lasted 6 weeks. All participants were pre- and posttested for vertical jump performance in order to assess lower body power. Results. Vertical jump scores improved for all groups (p < 0.01. The results also indicated that there were no statistically significant differences between group scores across time (p = 0.215. The statistical power for this analysis was low (0.312, most likely due to the small sample size. However, the results did reveal a trend suggesting that the training improvements were greater for both the SSJ and KSJ groups compared with the CON (by 171% and 107%, respectively although significance was not reached. Conclusions. Due to the observed trend, a replication of this study with a greater number of participants over a longer period of time is warranted.

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

    CERN Document Server

    Aspin, Adam

    2014-01-01

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

  15. Income of Local Budgets as a Tool of Ensuring Powers of Self-Governance Bodies

    OpenAIRE

    Lamskyy Maksym D.

    2013-01-01

    The goal of the article lies in the study, analysis and assessment of the state of income of local budgets. The article identifies main sources of income of local budgets in Ukraine and their importance in formation of main money funds of the local self-governance bodies. It studies problems of scantiness of the income part of budgets in the process of performance of powers by the local bodies of authority. It identifies and analyses changes and reforms after introduction of the Tax Code, whi...

  16. Link-state-estimation-based transmission power control in wireless body area networks.

    Science.gov (United States)

    Kim, Seungku; Eom, Doo-Seop

    2014-07-01

    This paper presents a novel transmission power control protocol to extend the lifetime of sensor nodes and to increase the link reliability in wireless body area networks (WBANs). We first experimentally investigate the properties of the link states using the received signal strength indicator (RSSI). We then propose a practical transmission power control protocol based on both short- and long-term link-state estimations. Both the short- and long-term link-state estimations enable the transceiver to adapt the transmission power level and target the RSSI threshold range, respectively, to simultaneously satisfy the requirements of energy efficiency and link reliability. Finally, the performance of the proposed protocol is experimentally evaluated in two experimental scenarios-body posture change and dynamic body motion-and compared with the typical WBAN transmission power control protocols, a real-time reactive scheme, and a dynamic postural position inference mechanism. From the experimental results, it is found that the proposed protocol increases the lifetime of the sensor nodes by a maximum of 9.86% and enhances the link reliability by reducing the packet loss by a maximum of 3.02%. PMID:24107988

  17. HML's whole body counter: measuring highly radioactive persons.

    Science.gov (United States)

    Kramer, Gary H; Capello, Kevin; Chiang, Albert; Hauck, Barry M

    2009-12-01

    The National Internal Radiation Assessment Section's Human Monitoring Laboratory (HML) has the responsibility to measure persons who may become internally contaminated following an accidental or intentional release of radioactivity. In preparation for measuring individuals who may be highly internally contaminated, the HML has reconfigured and recalibrated its whole body counter for this event. The calibration was performed using Monte Carlo simulations and validated by experimental measurements. An equation was developed that related the counting efficiency as a function of photon energy and phantom-to-detector distance. The equation could predict efficiencies to within 10% or better. Dead time problems, as a result of high internal activities, have been minimized by having a variety of counting positions. Six example nuclides have been used (Co, Co, Y, Ba, Cs, and Am) to show what is achievable and what is not. PMID:19901599

  18. Low reflectance high power RF load

    Energy Technology Data Exchange (ETDEWEB)

    Ives, R. Lawrence; Mizuhara, Yosuke M.

    2016-02-02

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

  19. Theoretical assessment of the maximum obtainable power in wireless power transfer constrained by human body exposure limits in a typical room scenario.

    Science.gov (United States)

    Chen, Xi Lin; De Santis, Valerio; Umenei, Aghuinyue Esai

    2014-07-01

    In this study, the maximum received power obtainable through wireless power transfer (WPT) by a small receiver (Rx) coil from a relatively large transmitter (Tx) coil is numerically estimated in the frequency range from 100 kHz to 10 MHz based on human body exposure limits. Analytical calculations were first conducted to determine the worst-case coupling between a homogeneous cylindrical phantom with a radius of 0.65 m and a Tx coil positioned 0.1 m away with the radius ranging from 0.25 to 2.5 m. Subsequently, three high-resolution anatomical models were employed to compute the peak induced field intensities with respect to various Tx coil locations and dimensions. Based on the computational results, scaling factors which correlate the cylindrical phantom and anatomical model results were derived. Next, the optimal operating frequency, at which the highest transmitter source power can be utilized without exceeding the exposure limits, is found to be around 2 MHz. Finally, a formulation is proposed to estimate the maximum obtainable power of WPT in a typical room scenario while adhering to the human body exposure compliance mandates. PMID:24889372

  20. Theoretical assessment of the maximum obtainable power in wireless power transfer constrained by human body exposure limits in a typical room scenario

    International Nuclear Information System (INIS)

    In this study, the maximum received power obtainable through wireless power transfer (WPT) by a small receiver (Rx) coil from a relatively large transmitter (Tx) coil is numerically estimated in the frequency range from 100 kHz to 10 MHz based on human body exposure limits. Analytical calculations were first conducted to determine the worst-case coupling between a homogeneous cylindrical phantom with a radius of 0.65 m and a Tx coil positioned 0.1 m away with the radius ranging from 0.25 to 2.5 m. Subsequently, three high-resolution anatomical models were employed to compute the peak induced field intensities with respect to various Tx coil locations and dimensions. Based on the computational results, scaling factors which correlate the cylindrical phantom and anatomical model results were derived. Next, the optimal operating frequency, at which the highest transmitter source power can be utilized without exceeding the exposure limits, is found to be around 2 MHz. Finally, a formulation is proposed to estimate the maximum obtainable power of WPT in a typical room scenario while adhering to the human body exposure compliance mandates. (paper)

  1. High Power UV LED Industrial Curing Systems

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-05-14

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

  2. High power, high efficiency diode pumped Raman fiber laser

    Science.gov (United States)

    Glick, Yaakov; Fromzel, Viktor; Zhang, Jun; Dahan, Asaf; Ter-Gabrielyan, Nikolay; Pattnaik, Radha K.; Dubinskii, Mark

    2016-06-01

    We demonstrate a high power high efficiency Raman fiber laser pumped directly by a laser diode module at 976 nm. 80 Watts of CW power were obtained at a wavelength of 1020 nm with an optical-to-optical efficiency of 53%. When working quasi-CW, at a duty cycle of 30%, 85 W of peak power was produced with an efficiency of 60%. A commercial graded-index (GRIN) core fiber acts as the Raman fiber in a power oscillator configuration, which includes spectral selection to prevent generation of the 2nd Stokes. In addition, significant brightness enhancement of the pump beam is attained due to the Raman gain distribution profile in the GRIN fiber. To the best of our knowledge, this is the highest power Raman fiber laser directly pumped by laser diodes, which also exhibits a record efficiency for such a laser. In addition, it is the highest power Raman fiber laser (regardless of pumping source) demonstrated based on a GRIN fiber.

  3. Methods for High Power EM Pulse Measurement

    Directory of Open Access Journals (Sweden)

    P. Fiala

    2006-12-01

    Full Text Available There are some suitable methods for the measurement of ultra-short solitary electromagnetic pulses that can be generated by high power pulsed generators. The measurement methods properties have to correspond to the fact whether we want to measure pulses of voltage, current or free-space electromagnetic wave. The need for specific measurement methods occurred by the development of high power microwave pulse generator. Applicable methods are presented in this paper. The method utilizing Faraday's induction law allows the measurement of generated current. For the same purpose the magneto-optic method can be utilized, with its advantages. For measurement of output microwave pulse of the generator the calorimetric method was designed and realized.

  4. Power Supplies for High Energy Particle Accelerators

    Science.gov (United States)

    Dey, Pranab Kumar

    2016-06-01

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

  5. Power balance in highly loaded fluorescent lamps

    Energy Technology Data Exchange (ETDEWEB)

    Lister, G G [Osram Sylvania, 71 Cherry Hill Drive, Beverly, MA 01915 (United States); Curry, J J [National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899-8422 (United States); Lawler, J E [Department of Physics, University of Wisconsin, 1150 University Avenue, Madison, WI 53706 (United States)

    2004-11-21

    Discrepancies reported in the literature between numerical predictions and experimental measurements in low-pressure Hg discharges at high current densities are considered. Elements of a one-dimensional fluid model and recent spectroscopic and Langmuir probe measurements are combined in a semi-empirical way to individually examine components of the positive column power balance and the discharge conductivity. At a Hg vapour pressure of 0.81 Pa (6.1 mTorr) and a current density of 300 mA cm{sup -2}, previous discrepancies in the power balance and discharge conductivity are simultaneously resolved by assuming a higher electron density than that obtained from the Langmuir probe measurements. This conclusion is supported by independent measurements of ion density reported in a companion paper. The importance of radial cataphoresis under these conditions, particularly with regard to radiation transport, is highlighted. This work is of particular interest for the design of fluorescent lamps operating at high current densities.

  6. Power Supplies for High Energy Particle Accelerators

    Science.gov (United States)

    Dey, Pranab Kumar

    2015-05-01

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

  7. High-power and superpower Cerenkov masers

    International Nuclear Information System (INIS)

    The linear and nonlinear theory of the efficient operation of high-power (gigawatt) and superpower (50 GW) Cerenkov masers is developed and discussed. Important technology issues such as breakdown, plasma production, and coupling to the output device are discussed. The relative merits of dielectric Cerenkov masers (DCM's) and plasma Cerenkov masers (PCM's) are considered. The principal design tool is a new particle simulation model that has been developed to investigate Cerenkov masers. The novel aspects of this model are briefly described along with a comparison of calculated and experimental results. The agreement between calculations and measurements is generally good. Finally, designs for a high-power and superpower PCM are described. These generators are compact and efficient (10- to 20- percent conversion from beam energy to microwave energy)

  8. Industrial Applications of High Power Ultrasonics

    Science.gov (United States)

    Patist, Alex; Bates, Darren

    Since the change of the millennium, high-power ultrasound has become an alternative food processing technology applicable to large-scale commercial applications such as emulsification, homogenization, extraction, crystallization, dewatering, low-temperature pasteurization, degassing, defoaming, activation and inactivation of enzymes, particle size reduction, extrusion, and viscosity alteration. This new focus can be attributed to significant improvements in equipment design and efficiency during the late 1990 s. Like most innovative food processing technologies, high-power ultrasonics is not an off-the-shelf technology, and thus requires careful development and scale-up for each and every application. The objective of this chapter is to present examples of ultrasonic applications that have been successful at the commercialization stage, advantages, and limitations, as well as key learnings from scaling up an innovative food technology in general.

  9. Silent Bodies in Religion and Work: Migrant Filipinas and the Construction of Relational Power

    Directory of Open Access Journals (Sweden)

    Pinelopi Topali

    2013-12-01

    Full Text Available The present article explores the relationship of silences, as vocal and non-vocal bodily practices, to forms of power in religion and work. More specifically, it focuses on Filipina domestic workers in Greece who are members of Iglesia ni Cristo, an independent Filipino church. In the hierarchical contexts of the church and paid domestic work, where the church expands its influence, silence is a dominant embodied religious ethos, an ideal behavior for female workers and an expression of obedience. This silence enhances women’s subordination resulting in strict power relationships. Silencing the body, however, is also an agential practice of Filipina immigrants themselves, a tool to transform power relationships into more reciprocal ones. By reflective and unreflective practices of bodily silence, migrant Filipinas reverse subjection, transform the power relationships in which they are involved and attribute to them a more relational character.

  10. Deformable mirror for high power laser applications

    Czech Academy of Sciences Publication Activity Database

    Mrňa, Libor; Šarbort, Martin; Holá, Miroslava

    Bellingham : SPIE, 2014, 94420W: 1-5. ISBN 9781628415575. ISSN 0277-786X. [ Optics and Measurement Conference 2014 (OaM 2014). Liberec (CZ), 07.10.2014-10.10.2014] R&D Projects: GA MŠk ED0017/01/01; GA MŠk(CZ) LO1212; GA TA ČR TA04020456 Institutional support: RVO:68081731 Keywords : deformable mirror * high power laser * adaptive optics Subject RIV: BH - Optics , Masers, Laser s

  11. High power microwave generation in vircators

    International Nuclear Information System (INIS)

    Vircator as high-power microwave source has recently become an intensive area of research. It is the device in which own beams fields dominate. Triod with reflex cathode investigated by H. Barkhausen and K. Kurz has been considered as low current analog of vircator. It is shown that such analogy is not correct, but parametric amplifier which is based on triod with reflex cathode is real analog of vircator. The theory of vircator is developed for broad range of electron velocities

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

    OpenAIRE

    Prechanon Kumkratug

    2010-01-01

    Problem statement: High voltage direct current transmission line system has been widely applied for control power flow in power system. The power flow analysis was the one of powerful tools by which the power system equipped was analyzed both for planning and operation strategies. Approach: This study presented the method to analyze power flow of power system consisted of HVDC system. HVDC was modeled as the complex power injections. The presented complex power injected was incorporated into ...

  13. Extended Cooling System for High Power Reactors

    International Nuclear Information System (INIS)

    In-vessel retention (IVR) of core melt is a key severe accident management strategy adopted by some operating nuclear power plants (NPPs) and proposed for advanced light water reactors (LWRs). However, it is not clear that currently proposed external reactor vessel cooling (ERVC) could provide sufficient heat removal for higher power reactors. This paper proposes a dual retention strategy to realize fail-proof defense-in-depth in the APR1400 (Advanced Power Reactor 1400 MWe) and the OPR 1000 (Optimized Power Reactor 1000 MWe). The dual retention has the advantage of IVR-ERVC as well as ex-vessel cooling (EVC) strategies. The multilateral, multidisciplinary project calls for national and international cutting-edge technologies to research and produce (R and P) the D2R2 (Duel Retention Demonstration Reactor) equipped with OASIS (Optimized Advanced Safety Injection System) and ROSIS (Reactor Outer Safety Injection System) to cope with design-basis accidents and beyond in a coherent, continual, comprehensive manner. The enterprise aims to develop the design-basis and severe accident engineering solutions. The enterprise aims to develop the design-basis and severe accident engineering solutions. The former embraces ISAIAH (Injection System Annular Interactive Aero Hydrodynamics) and MESIAH (Methodical Evaluation System Interactive Aero Hydrodynamics). The latter comprises GODIVA (Geo metrics of Direct Injection Versatile Arrangement), SONATA (Simulation of Narrow Annular Thermomechanical Arrest or), TOCATA (Termination of Corium Ablation Thermal Attack) and STRADA (Solution to Reactor Advanced Design Alternatives). D2R2 will contribute to enhancement of both safety and economics for an advanced high power particular and nuclear power in general

  14. High-Efficiency and High-Power CMOS Power Amplifiers for Millimeter-Wave Applications /

    OpenAIRE

    Agah, Amir

    2013-01-01

    This research focuses on the analysis and design of stacked-FET power amplifiers for millimeter-wave applications. We analyze the loss mechanisms in the stacked-FET PA circuit to develop the fundamental bounds on PAE and output power. Two-stack power amplifiers are designed and implemented at 45 and 90GHz achieving 19 and 15.8dbm output power with 34% and 11% PAE, respectively. The gate resistance of the stacked-FET PA is demonstrated to be a dominant source of loss at high frequency. To over...

  15. Effect of Protein Intake on Strength, Body Composition and Endocrine Changes in Strength/Power Athletes

    Directory of Open Access Journals (Sweden)

    Kang Jie

    2006-12-01

    Full Text Available Abstract Comparison of protein intakes on strength, body composition and hormonal changes were examined in 23 experienced collegiate strength/power athletes participating in a 12-week resistance training program. Subjects were stratified into three groups depending upon their daily consumption of protein; below recommended levels (BL; 1.0 – 1.4 g·kg-1·day-1; n = 8, recommended levels (RL; 1.6 – 1.8 g·kg-1·day-1; n = 7 and above recommended levels (AL; > 2.0 g·kg-1·day-1; n = 8. Subjects were assessed for strength [one-repetition maximum (1-RM bench press and squat] and body composition. Resting blood samples were analyzed for total testosterone, cortisol, growth hormone, and insulin-like growth factor. No differences were seen in energy intake (3,171 ± 577 kcal between the groups, and the energy intake for all groups were also below the recommended levels for strength/power athletes. No significant changes were seen in body mass, lean body mass or fat mass in any group. Significant improvements in 1-RM bench press and 1-RM squat were seen in all three groups, however no differences between the groups were observed. Subjects in AL experienced a 22% and 42% greater change in Δ 1-RM squat and Δ 1-RM bench press than subjects in RL, however these differences were not significant. No significant changes were seen in any of the resting hormonal concentrations. The results of this study do not provide support for protein intakes greater than recommended levels in collegiate strength/power athletes for body composition improvements, or alterations in resting hormonal concentrations.

  16. Control Power Optimization using Artificial Intelligence for Hybrid Wing Body Aircraft

    OpenAIRE

    Chhabra, Rupanshi

    2015-01-01

    Traditional methods of control allocation optimization have shown difficulties in exploiting the full potential of controlling a large array of control surfaces. This research investigates the potential of employing artificial intelligence methods like neurocomputing to the control allocation optimization problem of Hybrid Wing Body (HWB) aircraft concepts for minimizing control power, hinge moments, and actuator forces, while keeping the system weights within acceptable limits. The main obje...

  17. Piezoelectric transformer and modular connections for high power and high voltage power supplies

    Science.gov (United States)

    Vazquez Carazo, Alfredo (Inventor)

    2006-01-01

    A modular design for combining piezoelectric transformers is provided for high voltage and high power conversion applications. The input portions of individual piezoelectric transformers are driven for a single power supply. This created the vibration and the conversion of electrical to electrical energy from the input to the output of the transformers. The output portions of the single piezoelectric transformers are combining in series and/or parallel to provide multiple outputs having different rating of voltage and current.

  18. Production of high power femtosecond terahertz radiation

    Science.gov (United States)

    Neil, George R.; Carr, G. L.; Gubeli, Joseph F.; Jordan, K.; Martin, Michael C.; McKinney, Wayne R.; Shinn, Michelle; Tani, Masahiko; Williams, G. P.; Zhang, X.-C.

    2003-07-01

    The terahertz (THz) region of the electromagnetic spectrum is attracting interest for a broad range of applications ranging from diagnosing electron beams to biological imaging. Most sources of short pulse THz radiation utilize excitation of biased semiconductors or electro-optic crystals by high peak power lasers. For example, this was done by using an un-doped InAs wafer irradiated by a femtosecond free-electron laser (FEL) at the Thomas Jefferson National Accelerator Facility. Microwatt levels of THz radiation were detected when excited with FEL pulses at 1.06 μm wavelength and 10 W average power. Recently substantially higher powers of femtosecond THz pulses produced by synchrotron emission were extracted from the electron beamline. Calculations and measurements confirm the production of coherent broadband THz radiation from relativistic electrons with an average power of nearly 20 W, a world record in this wavelength range by a factor of 10,000. We describe the source, presenting theoretical calculations and their experimental verification. Potential applications of this exciting new source include driving new non-linear phenomena, performing pump-probe studies of dynamical properties of novel materials, and studying molecular vibrations and rotations, low frequency protein motions, phonons, superconductor bandgaps, electronic scattering, collective electronic excitations (e.g., charge density waves), and spintronics.

  19. Natural orbital expansions of highly accurate three-body wavefunctions

    International Nuclear Information System (INIS)

    Natural orbital expansions are considered for highly accurate three-body wavefunctions written in the relative coordinates r32, r31 and r21. Our present method is applied to the ground S(L = 0) -state wavefunctions of the Ps- and inftyH- ions. Our best variational energies computed herein for these systems are E(Ps-) = -0.262 005 070 232 980 107 7666 au and E(inftyH- =-0.5277510165443771965865 au, respectively. The variational wavefunctions determined for these systems contain between 2000 and 4200 exponential basis functions. In general, the natural orbital expansions of these functions are compact and rapidly convergent functions, which are represented as linear combinations of some relatively simple functions. The natural orbitals can be very useful in various applications, including photodetachment and scattering problems

  20. Comparison of body-powered voluntary opening and voluntary closing prehensor for activities of daily life

    Directory of Open Access Journals (Sweden)

    Kelsey Berning

    2014-05-01

    Full Text Available Persons with an upper-limb amputation who use a body-powered prosthesis typically control the prehensor through contralateral shoulder movement, which is transmitted through a Bowden cable. Increased cable tension either opens or closes the prehensor; when tension is released, some passive element, such as a spring, returns the prehensor to the default state (closed or open. In this study, we used the Southampton Hand Assessment Procedure to examine functional differences between these two types of prehensors in 29 nondisabled subjects (who used a body-powered bypass prosthesis and 2 persons with unilateral transradial amputations (who used a conventional body-powered device. We also administered a survey to determine whether subjects preferred one prehensor or the other for specific tasks, with a long-term goal of assessing whether a prehensor that could switch between both modes would be advantageous. We found that using the voluntary closing prehensor was 1.3 s faster (p = 0.02 than using the voluntary opening prehensor, across tasks, and that there was consensus among subjects on which types of tasks they preferred to do with each prehensor type. Twenty-five subjects wanted a device that could switch between the two modes in order to perform particular tasks.

  1. High-power LEDs for plant cultivation

    Science.gov (United States)

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

    2004-10-01

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

  2. Reduced filamentation in high power semiconductor lasers

    DEFF Research Database (Denmark)

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

    1999-01-01

    High brightness semiconductor lasers have applications in fields ranging from material processing to medicine. The main difficulty associated with high brightness is that high optical power densities cause damage to the laser facet and thus require large apertures. This, in turn, results in spatio......-temporal instabilities such as filamentation which degrades spatial coherence and brightness. We first evaluate performance of existing designs with a “top-hat” shaped transverse current density profile. The unstable nature of highly excited semiconductor material results in a run-away process where small modulations in...... the optical field causes spatial hole-burning and thus filamentation. To reduce filamentation we propose a new, relatively simple design based on inhomogeneous pumping in which the injected current has a gradual transverse profile. We confirm the improved laser performance theoretically and...

  3. 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...

  4. Advances in Very High Frequency Power Conversion

    DEFF Research Database (Denmark)

    Kovacevic, Milovan

    drive solution, which is applicable in cases when there are at least two power stages, and with minimal additional hardware requirements. It is experimentally confirmed that the method is suitable for both parallel and serial input configurations. Compared to state-of-the-art solutions, the proposed...... the use of conventional ICs, while still providing high control bandwidth and performance comparable to state-of-the-art solutions. Since in many applications of interest galvanic isolation is not a requirement, the thesis proposes a method for providing a DC power path from input to output...... response of VHF converters, on/off control schemes are often used for their output control. The options presented so far demonstrated excellent performance, but with very strict timing constraints on all functional blocks in the feedback loop. Therefore, an on/off control method is proposed which allows...

  5. Efficient, monochromatic, high-power microwave generator

    International Nuclear Information System (INIS)

    Microwave generation by electron beams in virtual cathode configurations can achieve significant power levels. However, most designs inherently have two competing mechanisms generating microwaves; namely the oscillating virtual cathode and the reflexing electrons. These two mechanisms tend to interfere destructively with each other. Specifically, the reflexing electrons subject the electron beam to two-stream instability, causing considerable heating of the electron beam. In addition, the space-charge of the reflexing electrons can cause the diode independence to fluctuate, resulting in oscillations of the electron beam energy. We have investigated a novel idea to remove these undesirable effects and we found that high-power, narrow-band, and monochromatic microwaves could be generated with efficiency of 10 to 20%. 16 refs., 7 figs

  6. Environmental applications of high power accelerators

    International Nuclear Information System (INIS)

    High power DC accelerators in the power range 50-600 kW have been employed in recent years in some countries on experimental basis for Flue Gas and Wastewater treatment. A 3 MeV, 30 kW DC accelerator, built indigenously by Accelerator and Pulse Power Division, BARC at Electron Beam Centre, Kharghar, will undergo commissioning trials shortly. Experiments on Flue Gas treatment by EB will be conducted in active collaboration with BHEL, Ranipet at beam parameters of 1 MeV, 5 kW. Flue gas will be simulated by first producing carbon dioxide from the combustion of LPG and then diluting it with air. External cylinders of SO2, NO, NH3 will be used to introduce these gases into the main flow in a controlled manner by using mass flow controllers realizing concentrations of SO2, NH3 in the range 500-2500 ppm and NO 100-500 ppm. Humidity and temperature will be controlled to optimize removal process. The flue gas will pass through a water-cooled reaction vessel of dimension 100 cm (length) x 35 cm (width) x 100 cm (depth) fitted with a 50 μm thick Titanium foil window at the top to allow beam electrons to pass through and interact with the Flue Gas. The production of high density of oxidizing OH free radicals, which react with the pollutants to produce sulphuric acid and nitric acids, results in high throughput. The acids are neutralized by ammonia in the moist environment to produce the useful fertilizers ammonium sulphate and ammonium nitrate. Prior to experiments, simulation work has been carried out with the software package CKS for our experimental parameters and it indicates highly efficient simultaneous removal of SO2 and NO2 at a dose of 15kGy

  7. The JLab high power ERL light source

    Science.gov (United States)

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

    2006-02-01

    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 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 ˜ 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 [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 100 fs pulses with >200 W of average power. The FELs also provide record-breaking laser power [Neil, et al., Phys. Rev. Lett. 84 (2000) 662]: up to 10 kW of average power in the IR from 1 to 14 μm 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 ms 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

  8. 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

  9. Application of high power microwave vacuum electron devices

    International Nuclear Information System (INIS)

    High power microwave vacuum electron devices can work at high frequency, high peak and average power. They have been widely used in military and civil microwave electron systems, such as radar, communication,countermeasure, TV broadcast, particle accelerators, plasma heating devices of fusion, microwave sensing and microwave heating. In scientific research, high power microwave vacuum electron devices are used mainly on high energy particle accelerator and fusion research. The devices include high peak power klystron, CW and long pulse high power klystron, multi-beam klystron,and high power gyrotron. In national economy, high power microwave vacuum electron devices are used mainly on weather and navigation radar, medical and radiation accelerator, TV broadcast and communication system. The devices include high power pulse and CW klystron, extended interaction klystron, traveling wave tube (TWT), magnetron and induced output tube (IOT). The state of art, common technology problems and trends of high power microwave vacuum electron devices are introduced in this paper. (authors)

  10. Implementing molecular dynamics on hybrid high performance computers—Three-body potentials

    Science.gov (United States)

    Brown, W. Michael; Yamada, Masako

    2013-12-01

    The use of coprocessors or accelerators such as graphics processing units (GPUs) has become popular in scientific computing applications due to their low cost, impressive floating-point capabilities, high memory bandwidth, and low electrical power requirements. Hybrid high-performance computers, defined as machines with nodes containing more than one type of floating-point processor (e.g. CPU and GPU), are now becoming more prevalent due to these advantages. Although there has been extensive research into methods to use accelerators efficiently to improve the performance of molecular dynamics (MD) codes employing pairwise potential energy models, little is reported in the literature for models that include many-body effects. 3-body terms are required for many popular potentials such as MEAM, Tersoff, REBO, AIREBO, Stillinger-Weber, Bond-Order Potentials, and others. Because the per-atom simulation times are much higher for models incorporating 3-body terms, there is a clear need for efficient algorithms usable on hybrid high performance computers. Here, we report a shared-memory force-decomposition for 3-body potentials that avoids memory conflicts to allow for a deterministic code with substantial performance improvements on hybrid machines. We describe modifications necessary for use in distributed memory MD codes and show results for the simulation of water with Stillinger-Weber on the hybrid Titan supercomputer. We compare performance of the 3-body model to the SPC/E water model when using accelerators. Finally, we demonstrate that our approach can attain a speedup of 5.1 with acceleration on Titan for production simulations to study water droplet freezing on a surface.

  11. Power allocation strategies to minimize energy consumption in wireless body area networks.

    Science.gov (United States)

    Kailas, Aravind

    2011-01-01

    The wide scale deployment of wireless body area networks (WBANs) hinges on designing energy efficient communication protocols to support the reliable communication as well as to prolong the network lifetime. Cooperative communications, a relatively new idea in wireless communications, offers the benefits of multi-antenna systems, thereby improving the link reliability and boosting energy efficiency. In this short paper, the advantages of resorting to cooperative communications for WBANs in terms of minimized energy consumption are investigated. Adopting an energy model that encompasses energy consumptions in the transmitter and receiver circuits, and transmitting energy per bit, it is seen that cooperative transmission can improve energy efficiency of the wireless network. In particular, the problem of optimal power allocation is studied with the constraint of targeted outage probability. Two strategies of power allocation are considered: power allocation with and without posture state information. Using analysis and simulation-based results, two key points are demonstrated: (i) allocating power to the on-body sensors making use of the posture information can reduce the total energy consumption of the WBAN; and (ii) when the channel condition is good, it is better to recruit less relays for cooperation to enhance energy efficiency. PMID:22254777

  12. High Efficiency Reversible Fuel Cell Power Converter

    DEFF Research Database (Denmark)

    Pittini, Riccardo

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

  13. High power, lossless, rigid line 2-way RF power combiners

    International Nuclear Information System (INIS)

    Development of 30 kW Solid State RF Power amplifier is under progress at RRCAT for particle accelerator applications. Efficient power combining is basic requirement for amplifier, as output of solid state RF devices is power limited. As a part of this system, 10 kW 2-Way RF power combiners were designed and fabricated at 352, 505.812 and 650 MHz. These power combiners have output and two inputs at 3 1/8 inches and 1 5/8 inches rigid coaxial line respectively. Being lossless in nature, these combiners exhibit negligible insertion loss which leads to no efficiency degradation and lesser heat dissipation. Measured performance of these power combiners is in excellent agreement with theoretical results. (author)

  14. Inspection and enforcement by the regulatory body for nuclear power plants

    International Nuclear Information System (INIS)

    This Safety Guide was prepared as part of the Agency's programme, referred to as the NUSS programme, for establishing Codes of Practice and Safety Guides relating to nuclear power plants. It supplements the Code of Practice on Governmental Organization for the Regulation of Nuclear Power Plants, IAEA Safety Series No.50-C-G and should be used in conjunction with that document. The purpose of this Guide is to provide information, guidance and recommendations to assist Member States in (1) establishing and conducting a regulatory inspection programme for nuclear power plants, (2) establishing requirements for the applicant/licensee in regard to regulatory inspection, (3) establishing a system for enforcing compliance with the requirements and decisions of the regulatory body

  15. The Power and the Promise of Cell Reprogramming: Personalized Autologous Body Organ and Cell Transplantation

    Directory of Open Access Journals (Sweden)

    Ana Belen Alvarez Palomo

    2014-04-01

    Full Text Available Reprogramming somatic cells to induced pluripotent stem cells (iPSCs or direct reprogramming to desired cell types are powerful and new in vitro methods for the study of human disease, cell replacement therapy, and drug development. Both methods to reprogram cells are unconstrained by the ethical and social questions raised by embryonic stem cells. iPSC technology promises to enable personalized autologous cell therapy and has the potential to revolutionize cell replacement therapy and regenerative medicine. Potential applications of iPSC technology are rapidly increasing in ambition from discrete cell replacement applications to the iPSC assisted bioengineering of body organs for personalized autologous body organ transplant. Recent work has demonstrated that the generation of organs from iPSCs is a future possibility. The development of embryonic-like organ structures bioengineered from iPSCs has been achieved, such as an early brain structure (cerebral organoids, bone, optic vesicle-like structures (eye, cardiac muscle tissue (heart, primitive pancreas islet cells, a tooth-like structure (teeth, and functional liver buds (liver. Thus, iPSC technology offers, in the future, the powerful and unique possibility to make body organs for transplantation removing the need for organ donation and immune suppressing drugs. Whilst it is clear that iPSCs are rapidly becoming the lead cell type for research into cell replacement therapy and body organ transplantation strategies in humans, it is not known whether (1 such transplants will stimulate host immune responses; and (2 whether this technology will be capable of the bioengineering of a complete and fully functional human organ. This review will not focus on reprogramming to iPSCs, of which a plethora of reviews can be found, but instead focus on the latest developments in direct reprogramming of cells, the bioengineering of body organs from iPSCs, and an analysis of the immune response induced by i

  16. High-Power Testing of the APT Power Coupler

    OpenAIRE

    Schmierer, E. N.; Chan, K. C. D.; Gautier, D. C.; Gioia, J. G.; Haynes, W. B.; Krawczyk, F. L.; Madrid, M. A.; Schrage, D. L.; Waynert, J. A.; Rusnak, B.

    2000-01-01

    For the baseline APT (Accelerator Production of Tritium) linac design, power couplers are required to transmit 210-kW of CW RF power to the superconducting cavities. These APT couplers operate at 700 MHz, have a coaxial design and an adjustable coupling to the superconducting cavities. Since May 1999, we have been testing couplers of this design on a room-temperature test stand. We completed tests at transmitted-power and reflected-power conditions up to 1 MW. We also tested the couplers with...

  17. High average power laser for EUV lithography

    Energy Technology Data Exchange (ETDEWEB)

    Kania, D.R.; Gaines, D.P.; Hermann, M.; Honig, J.; Hostetler, R.; Levesque, R.; Sommargren, G.E.; Spitzer, R.C.; Vernon, S.P.

    1995-01-19

    We have demonstrated the operation of a high average power, all solid state laser and target system for EUV lithography. The laser operates at 1.06 {mu}m with a pulse repetition rate of 200 Hz. Each pulse contains up to 400 mJ of energy and is less than 10 ns in duration. The ELTV conversion efficiency measured with the laser is independent of the laser repetition rate. Operating at 200 Hz, the laser has been used for lithography using a 3 bounce Kohler illuminator.

  18. High power distributed x-ray source

    Science.gov (United States)

    Frutschy, Kris; Neculaes, Bogdan; Inzinna, Lou; Caiafa, Antonio; Reynolds, Joe; Zou, Yun; Zhang, Xi; Gunturi, Satish; Cao, Yang; Waters, Bill; Wagner, Dave; De Man, Bruno; McDevitt, Dan; Roffers, Rick; Lounsberry, Brian; Pelc, Norbert J.

    2010-04-01

    This paper summarizes the development of a distributed x-ray source with up to 60kW demonstrated instantaneous power. Component integration and test results are shown for the dispenser cathode electron gun, fast switching controls, high voltage stand-off insulator, brazed anode, and vacuum system. The current multisource prototype has been operated for over 100 hours without failure, and additional testing is needed to discover the limiting component. Example focal spot measurements and x-ray radiographs are included. Lastly, future development opportunities are highlighted.

  19. Specialty fibers for high power fiber lasers

    OpenAIRE

    Jayanta K. Sahu; Jain, Deepak; Jung, Yongmin

    2015-01-01

    This paper reviews our recent work on novel large-mode area fibers for high power lasers and amplifiers. An ultra-low-NA fiber and single-trench fiber have been proposed for mode area scaling of the fundamental mode. In case of single trench fiber design, resonant coupling of the higher order modes has been exploited to achieve effective single mode operation in fiber with large effective mode area. Our proposed fiber designs are easy to fabricate using conventional low-loss fiber fabrication...

  20. Gain measurement of high power FEL

    International Nuclear Information System (INIS)

    We have developed a novel method to measure a gain of a free electron laser (FEL) with a modulation spectroscopy. An an intensity of a FEL grows over eight order from spontaneous radiation to saturation, we use a silicon (Si) bolometer which shows a linear response to this large intensity region. The Si bolometer measures the integrated intensity, energy of the FEL macropulse generated with changing the number of amplifications repeatedly in two steps, then a simple Fourier analysis of this measured energy finds values synchronized to the modulation and including the energy, the power and the gain of the FEL macropulse. This measurement and analysis are continued with the number of amplification increased, so we derive the FEL gain variation with time and the developments of the FEL energy and power. Today, the THz-FEL of ISIR, Osaka Univ. has generated a high power FEL with electron bunches have four times charges of the conventional FEL mode. We measure the gain of this mode with the new method as the one of the evaluation of the specification. The measured gain variation shows its maximum value, ∼200% and a falling process because of the FEL saturation. (author)

  1. Recent progress in high power ultrafast MIXSELs

    Science.gov (United States)

    Alfieri, C. G. E.; Waldburger, D.; Link, S. M.; Gini, E.; Golling, M.; Tilma, B. W.; Mangold, M.; Keller, U.

    2016-03-01

    The modelocked integrated external-cavity surface emitting laser (MIXSEL) is the most compact technology of ultrafast semiconductor disk laser, combining in the same epitaxial structure an active region and a saturable absorber for stable and self-starting passive modelocking in a linear straight cavity. Here we present the first MIXSEL structure able to produce sub-300-fs pulses at an average output power of 235 mW and 3.35 GHz pulse repetition rate, resulting in a record-high peak power of 240 W. At 10 GHz repetition rate the same MIXSEL generated 279-fs pulses with 310 mW of average output power. An optimized antireflection coating for dispersion minimization together with a reduced field enhancement inside the structure enabled the sensible improvement and the record performances of this novel MIXSEL. Furthermore, thanks to the development of suitable saturable absorbers with fast recovery dynamics and low saturation fluence, we demonstrate the first entirely MOVPE-grown MIXSEL.

  2. High Magnetic Field Rotation-powered Pulsars

    CERN Document Server

    Ng, C -Y

    2010-01-01

    Anomalous X-ray pulsars and soft gamma repeaters have recently emerged as a unified class of neutron stars, identified by dramatic X-ray and gamma-ray outbursts and via luminous X-ray pulsations, both thought to be powered by the decay of an enormous internal magnetic field. This "magnetar" hypothesis has raised the question of these objects' physical relationship with conventional rotation-powered pulsars (RPPs). The highest magnetic-field RPPs might therefore be expected to be transition objects between the two populations. The recently reported magnetar-like outburst of PSR J1846-0258, previously thought to be purely rotation-powered, clearly supports this suggestion. Here we review the observational properties of the highest magnetic-field RPPs known, and show some common characteristics that are notable among RPPs, which are plausibly related to their high fields. Using these objects, we consider the evidence for proposed "magneto-thermal evolution" in neutron stars, and argue that while some exists, it ...

  3. Photovoltaics for high capacity space power systems

    Science.gov (United States)

    Flood, Dennis J.

    1988-01-01

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

  4. EFFECTS OF STRENGTH TRAINING ON PHYSICAL FUNCTION: INFLUENCE OF POWER, STRENGTH, AND BODY COMPOSITION

    Science.gov (United States)

    Hanson, Erik D.; Srivatsan, Sindhu R.; Agrawal, Siddhartha; Menon, Kalapurakkal S.; Delmonico, Matthew J.; Wang, Min Q.; Hurley, Ben F.

    2010-01-01

    The purpose of this study was to determine (a) the effects of strength training (ST) on physical function and (b) the influence of strength, power, muscle volume (MV), and body composition on physical function. Healthy, inactive adults (n = 50) aged 65 years and older underwent strength, power, total body composition (% fat and fat free mass [FFM]), and physical function testing before and after 22 weeks of ST. Physical function testing consisted of tasks designed to mimic common physical activities of daily living (ADL). To improve internal validity of the assessment of mid-thigh intermuscular fat, subcutaneous fat, and knee extensors MV, a 10-week unilateral ST program using the untrained leg as an internal control preceded 12 weeks of whole-body ST. Strength, power, and FFM increased significantly with ST (all p < 0.05), whereas rapid walk, 5 chair stands, and get up and go time decreased significantly with ST in the overall group (all p < 0.05). Women improved significantly in both walking test times (both p < 0.05) but not in the stair climb test, whereas men improved in the stair climb test (p < 0.05) but not in walking test times. Multiple regression analysis revealed the highest R2 (0.28) for the change in chair stands time, followed by stair climb and usual walk at 0.27 and 0.21, respectively. ST improves performance in functional tasks important for ADLs. Changes in strength, power, and FFM are predictors of ST-induced improvements in these tasks. PMID:19910811

  5. High voltage insulation of bushing for HTS power equipment

    Science.gov (United States)

    Kim, Woo-Jin; Choi, Jae-Hyeong; Kim, Sang-Hyun

    2012-12-01

    For the operation of high temperature superconducting (HTS) power equipments, it is necessary to develop insulating materials and high voltage (HV) insulation technology at cryogenic temperature of bushing. Liquid nitrogen (LN2) is an attractive dielectric liquid. Also, the polymer insulating materials are expected to be used as solid materials such as glass fiber reinforced plastic (GFRP), polytetra-fluoroethylene (PTFE, Teflon), Silicon (Si) rubber, aromatic polyamide (Nomex), EPDM/Silicon alloy compound (EPDM/Si). In this paper, the surface flashover characteristics of various insulating materials in LN2 are studied. These results are studied at both AC and impulse voltage under a non-uniform field. The use of GFRP and Teflon as insulation body for HTS bushing should be much desirable. Especially, GFRP is excellent material not only surface flashover characteristics but also mechanical characteristics at cryogenic temperature. The surface flashover is most serious problem for the shed design in LN2 and operation of superconducting equipments.

  6. Influence of road incline and body position on power-cadence relationship in endurance cycling.

    Science.gov (United States)

    Emanuele, Umberto; Denoth, Jachen

    2012-07-01

    In race cycling, the external power-cadence relationship at the performance level, that is sustainable for the given race distance, plays a key role. The two variables of interest from this relationship are the maximal external power output (P (max)) and the corresponding optimal cadence (C (opt)). Experimental studies and field observations of cyclists have revealed that when cycling uphill is compared to cycling on level ground, the freely chosen cadence is lower and a more upright body position seems to be advantageous. To date, no study has addressed whether P (max) or C (opt) is influenced by road incline or body position. Thus, the main aim of this study was to examine the effect of road incline (0 vs. 7%) and racing position (upright posture vs. dropped posture) on P (max) and C (opt). Eighteen experienced cyclists participated in this study. Experiment I tested the hypothesis that road incline influenced P (max) and C (opt) at the second ventilatory threshold ([Formula: see text] and [Formula: see text]). Experiment II tested the hypothesis that the racing position influenced [Formula: see text], but not [Formula: see text]. The results of experiment I showed that [Formula: see text] and [Formula: see text] were significantly lower when cycling uphill compared to cycling on level ground (P cadence and (2) a more upright body position. PMID:22045414

  7. Characteristics of high power LEDs at high and low temperature*

    Institute of Scientific and Technical Information of China (English)

    Guo Weling; Jia Xuejiao; Yin Fei; Cui Bifeng; Gao Wei; Liu Ying; Yan Weiwei

    2011-01-01

    The high power light emitting diodes (LEDs) based on InGaN and AlGaInP individually are tested on line at temperatures from -30 to 100 ℃. The data are fitted to measure the relationship between temperature and the properties of forward voltage, relative light intensity, wavelength, and spectral bandwidth of two different kinds of LEDs. Why these properties changed and how these changes reflected on applicatons are also analyzed and compared with each other. The results show that temperature has a great influence on the performance and application of power LEDs. For applications at low temperature, the forward voltage rising and the peak wavelength blue-shifting must be considered; and at high temperature, the relative light intensity decreasing and the peak wavelength red-shifting must be considered

  8. Improved cooling design for high power waveguide system

    Science.gov (United States)

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

    1981-01-01

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

  9. Gender, Body Size and Social Relations in American High Schools

    Science.gov (United States)

    Crosnoe, Robert; Frank, Kenneth; Mueller, Anna Strassmann

    2008-01-01

    To investigate the role of body size in social networks, this study estimated cross-nested multilevel network models (p2) with longitudinal data from the 16 saturated schools in the National Longitudinal Study of Adolescent Health. As body mass index increased, the likelihood of being nominated by schoolmates as friends--but not the likelihood of…

  10. High School Students' Understanding of the Human Body System

    Science.gov (United States)

    Assaraf, Orit Ben-Zvi; Dodick, Jeff; Tripto, Jaklin

    2013-01-01

    In this study, 120 tenth-grade students from 8 schools were examined to determine the extent of their ability to perceive the human body as a system after completing the first stage in their biology curriculum--"The human body, emphasizing homeostasis". The students' systems thinking was analyzed according to the STH thinking model, which roughly…

  11. Power excursion analysis for high burnup cores

    International Nuclear Information System (INIS)

    A study was undertaken of power excursions in high burnup cores. There were three objectives in this study. One was to identify boiling water reactor (BWR) and pressurized water reactor (PWR) transients in which there is significant energy deposition in the fuel. Another was to analyze the response of BWRs to the rod drop accident (RDA) and other transients in which there is a power excursion. The last objective was to investigate the sources of uncertainty in the RDA analysis. In a boiling water reactor, the events identified as having significant energy deposition in the fuel were a rod drop accident, a recirculation flow control failure, and the overpressure events; in a pressurized water reactor, they were a rod ejection accident and boron dilution events. The RDA analysis was done with RAMONA-4B, a computer code that models the space- dependent neutron kinetics throughout the core along with the thermal hydraulics in the core, vessel, and steamline. The results showed that the calculated maximum fuel enthalpy in high burnup fuel will be affected by core design, initial conditions, and modeling assumptions. The important uncertainties in each of these categories are discussed in the report

  12. Body composition changes in monkeys during long-term exposure to high acceleration fields

    Science.gov (United States)

    Pace, N.; Rahlmann, D. F.; Kodama, A. M.; Smith, A. H.

    1977-01-01

    Adult male pig-tailed monkeys, weighing 10-14 kg, were subjected to continuous centrifuging stress for 7 months in acceleration fields up to 2.5 g. In vivo analytical techniques were used to evaluate parameters of body composition, body-fluid distribution, and hematology. Statistically significant losses in total body mass, lean body mass, total body water, extracellular water content and interstitial water content proportional to the level of high g were demonstrated.

  13. Income of Local Budgets as a Tool of Ensuring Powers of Self-Governance Bodies

    Directory of Open Access Journals (Sweden)

    Lamskyy Maksym D.

    2013-11-01

    Full Text Available The goal of the article lies in the study, analysis and assessment of the state of income of local budgets. The article identifies main sources of income of local budgets in Ukraine and their importance in formation of main money funds of the local self-governance bodies. It studies problems of scantiness of the income part of budgets in the process of performance of powers by the local bodies of authority. It identifies and analyses changes and reforms after introduction of the Tax Code, which did not provide solution of the issue of sufficiency of the income part of the financial resource of local self-governance. In the result of the study the article gives recommendations with respect to a possibility of expansion of the income base of local budgets for financing both the social and economic directions by local authorities. It develops specific proposals on strengthening the financial base of regions.

  14. Innovations in high power fiber laser applications

    Science.gov (United States)

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

    2012-02-01

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

  15. Bidirectional pumped high power Raman fiber laser.

    Science.gov (United States)

    Xiao, Q; Yan, P; Li, D; Sun, J; Wang, X; Huang, Y; Gong, M

    2016-03-21

    This paper presents a 3.89 kW 1123 nm Raman all-fiber laser with an overall optical-to-optical efficiency of 70.9%. The system consists of a single-wavelength (1070nm) seed and one-stage bidirectional 976 nm non-wavelength-stabilized laser diodes (LDs) pumped Yb-doped fiber amplifier. The unique part of this system is the application of non-wavelength-stabilized LDs in high power bidirectional pumping configuration fiber amplifier via refractive index valley fiber combiners. This approach not only increases the pump power, but also shortens the length of fiber by avoiding the usage of multi-stage amplifier. Through both theoretical research and experiment, the bidirectional pumping configuration presented in this paper proves to be able to convert 976 nm pump laser to 1070 nm laser via Yb3+ transfer, which is then converted into 1123 nm Raman laser via the first-order Raman effect without the appearance of any higher-order Raman laser. PMID:27136862

  16. Design of an integrated thermoelectric generator power converter for ultra-low power and low voltage body energy harvesters aimed at ExG active electrodes

    Science.gov (United States)

    Ataei, Milad; Robert, Christian; Boegli, Alexis; Farine, Pierre-André

    2015-10-01

    This paper describes a detailed design procedure for an efficient thermal body energy harvesting integrated power converter. The procedure is based on the examination of power loss and power transfer in a converter for a self-powered medical device. The efficiency limit for the system is derived and the converter is optimized for the worst case scenario. All optimum system parameters are calculated respecting the transducer constraints and the application form factor. Circuit blocks including pulse generators are implemented based on the system specifications and optimized converter working frequency. At this working condition, it has been demonstrated that the wide area capacitor of the voltage doubler, which provides high voltage switch gating, can be eliminated at the expense of wider switches. With this method, measurements show that 54% efficiency is achieved for just a 20 mV transducer output voltage and 30% of the chip area is saved. The entire electronic board can fit in one EEG or ECG electrode, and the electronic system can convert the electrode to an active electrode.

  17. Design of an integrated thermoelectric generator power converter for ultra-low power and low voltage body energy harvesters aimed at ExG active electrodes

    International Nuclear Information System (INIS)

    This paper describes a detailed design procedure for an efficient thermal body energy harvesting integrated power converter. The procedure is based on the examination of power loss and power transfer in a converter for a self-powered medical device. The efficiency limit for the system is derived and the converter is optimized for the worst case scenario. All optimum system parameters are calculated respecting the transducer constraints and the application form factor. Circuit blocks including pulse generators are implemented based on the system specifications and optimized converter working frequency. At this working condition, it has been demonstrated that the wide area capacitor of the voltage doubler, which provides high voltage switch gating, can be eliminated at the expense of wider switches. With this method, measurements show that 54% efficiency is achieved for just a 20 mV transducer output voltage and 30% of the chip area is saved. The entire electronic board can fit in one EEG or ECG electrode, and the electronic system can convert the electrode to an active electrode. (paper)

  18. TRIM5α Cytoplasmic Bodies Are Highly Dynamic Structures

    OpenAIRE

    Campbell, Edward M.; Dodding, Mark P.; Yap, Melvyn W.; Wu, Xiaolu; Gallois-Montbrun, Sarah; Malim, Michael H.; Stoye, Jonathan P.; Hope, Thomas J.

    2007-01-01

    Tripartite motif (TRIM)5α has recently been identified as a host restriction factor that has the ability to block infection by certain retroviruses in a species-dependent manner. One interesting feature of this protein is that it is localized in distinct cytoplasmic clusters designated as cytoplasmic bodies. The potential role of these cytoplasmic bodies in TRIM5α function remains to be defined. By using fluorescent fusion proteins and live cell microscopy, we studied the localization and dyn...

  19. Survey on modern pulsed high power lasers

    International Nuclear Information System (INIS)

    The requirements to be met by lasers for particle acceleration are partially similar to those already known for fusion lasers. The power level wanted in both caes is up to 100 TW or even more. The pulse durations favourable for laser accelerators are in the range from 1 ps to 1000 ps whereas fusion lasers require several ns. The energy range for laser accelerators is thus correspondingly smaller than that for fusion lasers: 1-100 kJ versus several 100 kJ. The design criteria of lasers meeting the requirements are discussed in the following. The CO2, iodine, Nd:glass and excimer lasers are treated in detail. The high repetition rate aspect will not be particularly addressed since for the present generation of lasers the wanted rates of far above 1 Hz are completely out of scope. Moreover, for the demonstration of principle these rates are not needed. (orig./HSI)

  20. Multiphoton imaging with high peak power VECSELs

    Science.gov (United States)

    Mirkhanov, Shamil; Quarterman, Adrian H.; Swift, Samuel; Praveen, Bavishna B.; Smyth, Conor J. C.; Wilcox, Keith G.

    2016-03-01

    Multiphoton imaging (MMPI) has become one of thee key non-invasive light microscopy techniques. This technique allows deep tissue imaging with high resolution and less photo-damage than conventional confocal microscopy. MPI is type of laser-scanning microscopy that employs localized nonlinear excitation, so that fluorescence is excited only with is scanned focal volume. For many years, Ti: sapphire femtosecond lasers have been the leading light sources for MPI applications. However, recent developments in laser sources and new types of fluorophores indicate that longer wavelength excitation could be a good alternative for these applications. Mode-locked VECSEELs have the potential to be low cost, compact light sources for MPI systems, with the additional advantage of broad wavelength coverage through use of different semiconductor material systems. Here, we use a femtosecond fibber laser to investigate the effect average power and repetition rate has on MPI image quality, to allow us to optimize our mode-locked VVECSELs for MPI.

  1. Splitting of high power, cw proton beams

    CERN Document Server

    Facco, Alberto; Berkovits, Dan; Yamane, Isao

    2007-01-01

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

  2. Supervision system for high power transformers

    International Nuclear Information System (INIS)

    This paper is concerned with a monitoring and diagnostics system currently in operation for a high power autotransformer and is associated bays. The diagnostics system analyses and crosschecks in a statistical way all the recorded data and diagnostic indicators (voltages, currents, pressures, temperatures, dissolved gases, alarms, controls and positions), increasing the quality and the amount of the technical information available to maintenance personnel. The system prototype is divided into two separate units, communicating via a fiber optic link, which are permanently installed, the latter near the autotransformer. The data processing unit is based upon a VME Bus and is made up of a data acquisition system, an on-line processor and an off-line CPU. During the system design, care was taken not only to avoid environmental as well as EMC troubles, but also to prevent disturbing the operation of the transformer bay itself and the connected equipment

  3. Switching transients in high-frequency high-power converters using power MOSFET's

    Science.gov (United States)

    Sloane, T. H.; Owen, H. A., Jr.; Wilson, T. G.

    1979-01-01

    The use of MOSFETs in a high-frequency high-power dc-to-dc converter is investigated. Consideration is given to the phenomena associated with the paralleling of MOSFETs and to the effect of stray circuit inductances on the converter circuit performance. Analytical relationships between various time constants during the turning-on and turning-off intervals are derived which provide estimates of plateau and peak levels during these intervals.

  4. Evolution of Very High Frequency Power Supplies

    DEFF Research Database (Denmark)

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

    2013-01-01

    The ongoing demand for smaller and lighter power supplies is driving the motivation to increase the switching frequencies of power converters. Drastic increases however come along with new challenges, namely the increase of switching losses in all components. The application of power circuits used...

  5. High grade power from fissioning gases

    International Nuclear Information System (INIS)

    Fissioning plasmas are the gaseous fuel in high-temperature cavity reactors that originally were conceived for nuclear rocket propulsion in space. For achieving a specific impulse up to 5000 sec, the nuclear fuel must burn at a temperature in excess of 10,000 K. For criticality, the uranium particle density must be not less than the molecular density of gases at standard conditions. In previous investigations it was, therefore, assumed that the fissioning plasma is optically thick. However, in gaseous matter the energy release of fissions can lead to ionization and excitation that deviate from Maxwell-Boltzmann distributions. This condition can be exploited for the direct conversion of fission fragment energy into coherent light. Recent research has culminated in the first experimental nuclear-pumped lasers. At about the same time, a program of gaseous fuel reactor experiments with enriched uranium hexafluoride was started. Criticality tests were conducted with uranium foils simulating the gaseous fuel. Gaseous uranium hexafluoride will be used in a series of forthcoming experiments. A variety of applications of gaseous fuel reactors and nuclear-pumped lasers is envisioned for benefits in space and on Earth. The use of nuclear energy at temperatures exceeding those of solid core reactors and laser radiation is called ''high grade power.'' (auth.)

  6. High power accelerators and wastewater treatment

    International Nuclear Information System (INIS)

    The problems of environmental damage and degradation of natural resources are receiving increasing attention throughout the world. The increased population, higher living standards, increased urbanization and enhanced industrial activities of humankind are all leading to degradation of the environment. Increasing urbanization has been accompanied by significant water pollution. Given the seriousness of the situation and future risk of crises, there is an urgent need to develop the water-efficient technologies including economical treatment methods of wastewater and polluted water. Therefore, cost-effective treatment of the municipal and industrial wastewater containing refractory pollutant with electron beam is actively studied in EB TECH Co.. Electron beam treatment of wastewater is caused by the decomposition of pollutants as a result of their reactions with highly reactive species formed from water radiolysis (hydrated electron, OH free radical and H atom). However, to have advantages over existing processes, the electron beam process should have cost-effective and reliable in operation. Therefore high power accelerators (400kW∼1MW) are developed for environmental application and they show the decrease in the cost of construction and operation of electron beam plant. In other way to reduce the cost for wastewater treatment, radical reactions accompanied by the other processes are introduced, and the synergistic effect upon the use of combined methods such as electron beam treatment with ozonation, biological treatment and physico-chemical adsorption and others also show the improvement of the effect of electron beam treatment for the wastewater purification. (author)

  7. On reactive high power impulse magnetron sputtering

    Science.gov (United States)

    Gudmundsson, J. T.

    2016-01-01

    High power impulse magnetron sputtering (HiPIMS) is an ionized physical vapor deposition (IPVD) technique that is particularly promising for reactive sputtering applications. However, there are few issues that have to be resolved before the full potential of this technique can be realized. Here we give an overview of the key experimental findings for the reactive HiPIMS discharge. An increase in the discharge current is commonly observed with increased partial pressure of the reactive gas or decreased repetition pulse frequency. There are somewhat conflicting claims regarding the hysteresis effect in the reactive HiPIMS discharge as some report reduction or elimination of the hysteresis effect while others claim a feedback control is essential. The ion energy distribution of the metal ion and the atomic ion of the reactive gas are similar and extend to very high energies while the ion energy distribution of the working gas and the molecular ion of the reactive gas are similar and are much less energetic.

  8. High power accelerator for environmental application

    International Nuclear Information System (INIS)

    The problems of environmental damage and degradation of natural resources are receiving increasing attention throughout the world. The increased population, higher living standards, increased urbanization and enhanced industrial activities of humankind are all leading to degradation of the environment. Increasing urbanization has been accompanied by significant environmental pollution, given the seriousness of the situation and future risk of crises, there is an urgent need to develop the efficient technologies including economical treatment methods. Therefore, cost-effective treatment of the stack gases, wastewater and sludge containing refractory pollutant with electron beam is actively studied in EB TECH Co. Electron beam treatment of such hazardous wastes is caused by the decomposition of pollutants as a result of their reactions with highly reactive species formed from radiolysis. However, to have advantages over existing processes, the electron beam process should have cost-effective and reliable in operation. Therefore high power accelerators (400kW~1MW) are developed for environmental application and they show the decrease in the cost of construction and operation of electron beam plant. In other way to reduce the cost for treatment, radical reactions accompanied by the other processes are introduced, and the synergistic effect upon the use of combined methods such as electron beam treatment with catalytic system, biological treatment and physico-chemical adsorption and others also show the improvement of the effect of electron beam treatment. (author)

  9. High-average-power solid state lasers

    International Nuclear Information System (INIS)

    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

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

    OpenAIRE

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

    2015-01-01

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

  11. High frequency body mass measurement, feedback, and health behaviors

    NARCIS (Netherlands)

    Kooreman, P.; Scherpenzeel, A.

    2014-01-01

    We analyze weight and fat percentage measurements of respondents in an online general population panel in the Netherlands, collected using wireless scales, with an average frequency of 1.6 measurements per week. First, we document the existence of a weekly cycle; body mass is lowest on Fridays and h

  12. Test of a High Power Target Design

    CERN Multimedia

    2002-01-01

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

  13. High power electrical wire explosion in water

    International Nuclear Information System (INIS)

    Full Text:Experimental and magneto-hydro-dynamic simulation results of nanosecond time scale underwater electrical Al, Cu and W wires explosions are presented. A water forming line generator with current amplitude up to 100 kA was used. Maximal current rise rate and maximal Joule heating power achieved during wire explosions were 500 Ga/s and 6 GW, respectively. Extremely high energy deposition of up to 60 times the atomization enthalpy was registered comparing to the best reported result of energy deposition obtained in vacuum wire explosion of 20 times the atomization enthalpy. A discharge channel evolution and surface temperature were analyzed by streak shadow imaging and using fast photo-diode with a set of interference filters, respectively. A 1D magneto-hydro-dynamic simulation demonstrated good agreement with such experimental parameters as discharge channel current, voltage, radius, and temperature. Material conductivity has been calculated to produce best correlation of the simulated and experimentally obtained voltage. It has been shown that conductivity may significantly vary as a function of energy deposition rate in nanosecond time scale underwater electrical wire explosions

  14. Developments of high voltage pulse power systems

    International Nuclear Information System (INIS)

    The facilities built at the Plasma Physics Section of the Bhabha Atomic Research Centre, Bombay (India), include charging power supplies upto 300 KV DC, capacitor energy banks upto 6 KJ and pulse forming Marx generator upto 600 KV. The work on the construction of 25 KJ capacitor energy bank and 600 KV transformer is in progress. The activities built around these facilities include an exploding wire system, a flash X-ray generator and a magnetic field flux concentrator. The exploding wire system is used presently for generation of shockwaves. The high dose rate (108 R/Sec.) flash X-ray generator has been successfully employed for dynamic radiographs. Magnetic fields of 200-300 kG generated by the flux concentrator are being used for magnetoforming and cold weld studies. An experimental scheme for the generation of relativistic electron beam of 600 KeV is under fabrication and experiments have been planned for the study of transport of beam and beam interactions with solids, gases and plasma. (K.B.)

  15. High-resolution gamma spectroscopy with whole-body and partial-body counters. Experience, recommendations. Report

    International Nuclear Information System (INIS)

    The application of high-resolution gamma spectroscopy with whole-body and partial-body counters shows a steadily rising upward trend over the last few years. This induced the ''Arbeitskreis Inkorporationsueberwachung'' of the association ''Fachverband fuer Strahlenschutz e.V.'' to organise a meeting for joint elaboration of a guide on recommended applications of this measuring technique, based on a review of existing experience and results. A key item on the agenda of the meeting was the comparative evaluation of the Ge semiconductor detector and the NaI solid scintillation detector. (orig./CB)

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

    OpenAIRE

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

    2014-01-01

    Secure power system operation of a highly wind power integrated power system is always at risk during critical weather conditions, e.g. in extreme high winds. The risk is even higher when 50% of the total electricity consumption has to be supplied by wind power, as the case for the future Danish power system in 2020. This paper analyses and compares the performance of the future Danish power system during extreme wind speeds, where wind power plants are either controlled through a traditional...

  17. Radiation of long and high power arcs

    Science.gov (United States)

    Cressault, Y.; Bauchire, J. M.; Hong, D.; Rabat, H.; Riquel, G.; Sanchez, F.; Gleizes, A.

    2015-10-01

    The operators working on electrical installations of low, medium and high voltages can be accidentally exposed to short-circuit arcs ranging from a few kA to several tens of kA. To protect them from radiation, according to the exposure limits, we need to characterize the radiation emitted by the powerful arc. Therefore, we have developed a general experimental and numerical study in order to estimate the spectral irradiance received at a given distance from the arc. The experimental part was based on a very long arc (up to 2 m) with high ac current (between 4 and 40 kA rms, duration 100 ms) using 3 kinds of metallic contacts (copper, steel and aluminium). We measured the irradiance received 10m from the axis of the arc, and integrated on 4 spectral intervals corresponding to the UV, visible, IRA  +  B and IRC. The theoretical part consisted of calculating the radiance of isothermal plasmas in mixtures of air and metal vapour, integrated over the same spectral intervals as defined in the experiments. The comparison between the theoretical and experimental results has allowed the defining of three isothermal radiation sources whose combination leads to a spectral irradiation equivalent to the experimental one. Then the calculation allowed the deduction of the spectral description of the irradiance over all the wavelength range, between 200 nm and 20 μm. The final results indicate that the influence of metal is important in the visible and UVA ranges whereas the IR radiation is due to the air plasma and surrounding hot gas and fumes.

  18. Self-biased circulators for high power applications

    Science.gov (United States)

    Sokolov, Alexander S.

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

  19. Effect of a combination of whole body vibration exercise and squat training on body balance, muscle power, and walking ability in the elderly

    Directory of Open Access Journals (Sweden)

    Osugi T

    2014-02-01

    Full Text Available Tomohiro Osugi,1 Jun Iwamoto,2 Michio Yamazaki,1 Masayuki Takakuwa3 1Department of Rehabilitation, Takakuwa Orthopaedic Nagayama Clinic, Asahikawa, Hokkaido, 2Institute for Integrated Sports Medicine, Keio University School of Medicine, Shinjuku-ku, Tokyo, 3Department of Orthopaedic Surgery, Takakuwa Orthopaedic Nagayama Clinic, Asahikawa, Hokkaido, Japan Abstract: A randomized controlled trial was conducted to clarify the beneficial effect of whole body vibration (WBV exercise plus squat training on body balance, muscle power, and walking ability in the elderly with knee osteoarthritis and/or spondylosis. Of 35 ambulatory patients (14 men and 21 women who were recruited at our outpatient clinic, 28 (80.0%, 12 men and 16 women participated in the trial. The subjects (mean age 72.4 years were randomly divided into two groups (n=14 in each group, ie, a WBV exercise alone group and a WBV exercise plus squat training group. A 4-minute WBV exercise (frequency 20 Hz was performed 2 days per week in both groups; squat training (20 times per minute was added during the 4-minute WBV training session in the WBV exercise plus squat training group. The duration of the trial was 6 months. The exercise and training program was safe and well tolerated. WBV exercise alone improved indices of body balance and walking velocity from baseline values. However, WBV exercise plus squat training was more effective for improving tandem gait step number and chair-rising time compared with WBV exercise alone. These results suggest the benefit and safety of WBV exercise plus squat training for improving physical function in terms of body balance and muscle power in the elderly. Keywords: whole body vibration exercise, squat training, body balance, walking velocity, muscle power

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

    CERN Document Server

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

    2015-01-01

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

  1. High-power converters for space applications

    Science.gov (United States)

    Park, J. N.; Cooper, Randy

    1991-01-01

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

  2. High Precision Current Measurement for Power Converters

    OpenAIRE

    Bastos, M. Cerqueira

    2016-01-01

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

  3. Bipolar high voltage pulse power generator

    Czech Academy of Sciences Publication Activity Database

    Lukeš, Petr; Člupek, Martin; Babický, Václav; Šunka, Pavel

    Monterey, 2005, s. 44. [IEEE International Pulsed Power Conference/15th./. Portola Plaza Hotel, Monterey, CA, USA (US), 13.06.2005-17.06.2005] R&D Projects: GA AV ČR KSK2043105 Keywords : bipolar * pulse power generator * corona discharge Subject RIV: BL - Plasma and Gas Discharge Physics

  4. Power Law Decay in High Intensity Turbulence

    Science.gov (United States)

    Koster, Timothy; Puga, Alejandro; Nguyen, Baolong; Larue, John

    2015-11-01

    In the study reported herein, the region where the power decay law is applicable for active grid generated turbulence is found by an iterative approach which determines the largest range where the ratio of the dissipation from the power law and the dissipation from the temporal velocity derivative are unity. The square of the Taylor microscale, as noted by Batchelor (1953), is linearly related to downstream distance relative to the virtual origin and can be used in a straightforward manner to find the virtual origin. The fact that the decay of downstream velocity variance is described by a power law is shown to imply power law behavior for various other parameters such as the dissipation, the integral length scale, the Taylor microscale, the Kolmogorov microscale and the Taylor Reynolds number and that there is an algebraic relationship between the various power law exponents. Results are presented for various mean velocities to show the decay exponent as a function of the Taylor Reynolds number.

  5. High School Students' Understanding of the Human Body System

    Science.gov (United States)

    Assaraf, Orit Ben-Zvi; Dodick, Jeff; Tripto, Jaklin

    2013-02-01

    In this study, 120 tenth-grade students from 8 schools were examined to determine the extent of their ability to perceive the human body as a system after completing the first stage in their biology curriculum - "The human body, emphasizing homeostasis". The students' systems thinking was analyzed according to the STH thinking model, which roughly divides it into three main levels that are arranged "pyramid" style, in an ascending order of difficulty: 1. Analysis of system components—the ability to identify the components and processes existing in the human body system; 2. Synthesis of system components—ability to identify dynamic relations within the system; 3. Implementation—ability to generalize and identify patterns in the system, and to identify its hidden dimensions. The students in this study proved largely incapable of achieving systems thinking beyond the primary STH level of identifying components. An overwhelming majority if their responses corresponded to this level of the STH model, further indicating a pronounced favoring of structure over process, and of larger, macro elements over microscopic ones.

  6. Solid state high power RF system for superconducting cavities

    International Nuclear Information System (INIS)

    Solid State High Power RF System is proposed for XFEL and ILC. It includes individual RF power supply for each SC cavity and common control system. Each RF power supply includes Solid State Generator, circulator and Q-tuner. Triggering, synchronization, output power and phase of each Solid State Generator are controlled from the common control system through fiber-optic lines. Main parameters of Solid State Generator are: frequency 1.3 GHz, peak power 128 kW, pulse length 1.4 msec, repetition rate 10 Hz, average power 1.8 kW, CW power 2.5 kW. Advantages of Solid State High Power RF System are: simple triggering, synchronization, output power and phase adjustment for all cavities separately, operation both in pulse and in CW modes, unlimited lifetime, no high voltage, no oil-tank, compactness.

  7. High-dispersive mirrors for high power applications.

    Science.gov (United States)

    Pervak, V; Pronin, O; Razskazovskaya, O; Brons, J; Angelov, I B; Trubetskov, M K; Tikhonravov, A V; Krausz, F

    2012-02-13

    We report on the development and manufacturing of two different types of high-dispersive mirrors (HDM). One of them provides a record value for the group delay dispersion (GDD) of -4000 fs2 and covers the wavelength range of 1027-1033 nm, whereas the other one provides -3000 fs2 over the wavelength range of 1020-1040 nm. Both of the fabricated mirrors exhibit a reflectance of >99.9% and are well suited for intracavity applications. Mirrors of the second type have been successfully employed in a Kerr-lens mode-locked Yb:YAG thin-disk oscillator for the generation of 200-fs pulses with multi-10-W average power. PMID:22418209

  8. High power densities from high-temperature material interactions

    Energy Technology Data Exchange (ETDEWEB)

    Morris, J.F.

    1981-01-01

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

  9. High quality, high efficiency welding technology for nuclear power plants

    International Nuclear Information System (INIS)

    For nuclear power plants, it is required to ensure the safety under the high reliability and to attain the high rate of operation. In the manufacture and installation of the machinery and equipment, the welding techniques which become the basis exert large influence to them. For the purpose of improving joint performance and excluding human errors, welding heat input and the number of passes have been reduced, the automation of welding has been advanced, and at present, narrow gap arc welding and high energy density welding such as electron beam welding and laser welding have been put to practical use. Also in the welding of pipings, automatic gas metal arc welding is employed. As for the welding of main machinery and equipment, there are the welding of the joints that constitute pressure boundaries, the build-up welding on the internal surfaces of pressure vessels for separating primary water from them, and the sealing welding of heating tubes and tube plates in steam generators. These weldings are explained. The welding of pipings and the state of development and application of new welding methods are reported. (K.I.)

  10. Advanced Capacitors for High-Power Applications Project

    Data.gov (United States)

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

  11. High-power microwaves for defense and accelerator applications

    Energy Technology Data Exchange (ETDEWEB)

    Manheimer, W. (Plasma Physics Division, Naval Research Laboratory, Washington, DC 20337 (United States))

    1992-03-11

    This paper discusses high-power microwaves for application to the Defense Department and to the powering of large accelerators. The microwave sources discussed are the SLAC klystron, the relativistic klystron, the magnetron and the vircator.

  12. Measurement of the whole-body 137Cs in residents around the Chernobyl Nuclear Power Plant

    International Nuclear Information System (INIS)

    To understand the current situation of internal radiation exposure in the population around the Chernobyl Nuclear Power Plant (CNPP), we examined the 137Cs body burden in six residents of Belarus, Ukraine and Russia in 2002 and 2004 using the whole-body counter (WBC) at Nagasaki Univ. (Japan). The data were compared with those of our previous study performed in 1993-1994 using the same method. In 2002 and 2004, peaks of 137Cs were detected in two residents from Gomel, which was heavily contaminated by the CNPP accident, one from Minsk (Belarus) and one from Kiev (Ukraine), but another resident from Minsk showed no 137Cs peaks. The results of the present study suggests that residents around the CNPP are still exposed to chronic 137Cs internal irradiation, probably due to the daily consumption of contaminated domestic foods, but the risk of any disease by the irradiation is quite low. Long-term follow-up of WBC around the CNPP is useful and may contribute to radiation safety regulation together with a reduction of unnecessary radio-phobia for the residents. (authors)

  13. An overview of the reliability prediction related aspects of high power IGBTs in wind power applications

    DEFF Research Database (Denmark)

    Busca, Christian; Teodorescu, Remus; Blaabjerg, Frede;

    2011-01-01

    high power Insulated Gate Bipolar Transistors (IGBTs) in the context of wind power applications. At first the latest developments and future predictions about wind energy are briefly discussed. Next the dominant failure mechanisms of high power IGBTs are described and the most commonly used lifetime...... prediction models are reviewed. Also the concept of Accelerated Life Testing (ALT) is briefly reviewed....

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

    DEFF Research Database (Denmark)

    Hu, Weihao; Su, Chi; Chen, Zhe;

    2013-01-01

    The Danish power system has a large penetration of wind power. The wind fluctuation causes a high variation in the power generation, which must be balanced by other sources. The battery storage based Plug-In Electric Vehicles (PEV) may be a possible solution to balance the wind power variations in...... the power systems with high wind power penetrations. In this paper, the integration of plug-in electric vehicles in the power systems with high wind power penetrations is proposed and discussed. Optimal operation strategies of PEV in the spot market are proposed in order to decrease the energy cost...... electrical energy demand is chosen as the studied case. The results show that an optimal operation of PEV in both spot market and regulation market can not only decrease the energy costs for PEV owners, but also significantly decrease the power deviations between West Denmark and Union for the Coordination...

  15. Controlled Compact High Voltage Power Lines

    Directory of Open Access Journals (Sweden)

    Postolati V.

    2016-04-01

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

  16. A New Power Combining and Outphasing Modulation System for High-Efficiency Power Amplification

    OpenAIRE

    Perreault, David J.

    2010-01-01

    This paper describes a new power combining and outphasing system that provides both high efficiency and linear output control. Whereas conventional outphasing systems utilize two power amplifiers, the system introduced here combines power from four or more amplifiers. The proposed technique overcomes the loss and reactive loading problems of previous outphasing systems. It provides ideally lossless power combining, along with resistive loading of the individual power amplifiers over a very wi...

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

    OpenAIRE

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

    2015-01-01

    A high power microwave system based on power combining and pulse compression of conventional klystrons is introduced in this paper. This system mainly consists of pulse modulator, power combiner, driving source of klystrons and pulse compressor. A solid state induction modulator and pulse transformer were used to drive two 50 MW S-band klystrons with pulse widths 4 {\\mu}s in parallel, after power combining and pulse compression, the tested peak power had reached about 210 MW with pulse widths...

  18. Bipolar high voltage pulse power generator

    Czech Academy of Sciences Publication Activity Database

    Lukeš, Petr; Člupek, Martin; Babický, Václav; Šunka, Pavel

    Monterey : IEEE, 2007 - (Maenchen, J.; Schamiloglu, E.), s. 1061-1064 ISBN 0-7803-9190-X. [IEEE International Pulsed Power Conference/15th./. Portola Plaza Hotel, Monterey (US), 13.06.2005-17.06.2005] R&D Projects: GA AV ČR KSK2043105 Institutional research plan: CEZ:AV0Z20430508 Keywords : bipolar * pulse power generator * corona discharge Subject RIV: BL - Plasma and Gas Discharge Physics

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

    Data.gov (United States)

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

  20. A device for power level measurement in high pressure environments

    International Nuclear Information System (INIS)

    In a gamma thermometer the heat generating body and the interior covering of the high pressure barrier is made of zircaloy metal. The interior covering having a smaller cross section than the heat generating body, constitutes a hydrogen gas barrier that prevents a weakening of the low thermal conductivity in the resistance region in the gamma thermometer

  1. Effects of high-intensity strength interval training program on body composition

    OpenAIRE

    Juránková, Michaela; Bílý, Jiří; Hrazdíra, Eduard

    2015-01-01

    The aim of this work was to examine effects of 10-week high-intensity strength interval training (HIIT) program on body composition. Seven women (31.0 ± 6.0 years old, 65.7 ± 9.8 kg body weight, 23.6 ± 2.8 kg*m−2 BMI, 18.6 ± 5.8 kg body fat, 26.0 ± 3.4 kg muscle mass) completed intervention program. We performed an analyze of body composition before and after training program. We focused especially on body fat and muscle mass. Each session consisted of short term bouts (until 30 s duration) w...

  2. Design of high power rectification power supply based on digital control

    International Nuclear Information System (INIS)

    For typical high power rectification power supply, a design based on digital control is introduced. The feasibility and superiority of the digital control scheme were verified through the design and experimental results of the filament power supply for high current ion source of NBI. The application of digital control scheme, making the filament power supply design is more intelligent and simple, as related applications provide a reference. (authors)

  3. Marine applications of power supply and conditioning interfaces for high power pulse devices

    OpenAIRE

    Rutan, Ronald J.

    2002-01-01

    Numerous high power pulse devices are being considered for marine applications, particularly military vessels to include Electro Magnetic Aircraft Launching System, Electro Thermal Gun (ETG), Particle Beam Weapons, High Powered Lasers, and Rail Guns which are directly considered in this thesis. Currently marine vessels do not have the power generation capability to deliver the massive power over the short duration required. The weight, volume, and environment constraints inherent in marine ve...

  4. High power quantum cascade lasers operating at room temperature

    International Nuclear Information System (INIS)

    In this paper, some key design and technology issues for development of high power quantum cascade lasers are discussed. The scaling of power output with the number of emitting stages is shown. As part of this work, high power, 75-stage, λ = 9 μm lasers have been demonstrated with a peak power of 7 W at room temperature. This power is a direct result of high quality material growth and a low loss waveguide design. Similar results are demonstrated at a shorter wavelength (λ = 6.1μm) utilizing a strain-balanced active region/injector design. For a 30-stage structure, 2 W peak power and 250 mW average power have been demonstrated at room temperature. Lastly, a timeline comparison of QCL laser performance is presented in terms of room temperature threshold current density and peak output power for various groups

  5. Do highly body dissatisfied women exhibit attentional biases towards thin and overweight figures?

    Directory of Open Access Journals (Sweden)

    2015-09-01

    Full Text Available Aims: Body dissatisfaction has been linked as a direct precursor for life threatening eating disorders such as Anorexia Nervosa and Bulimia Nervosa. Current research indicates that attentional bias may play a key role in the development and maintenance of body dissatisfaction in women due to the constant exposure to media depicted images. Therefore, we conducted an eye-tracking study to investigate whether individuals with high body dissatisfaction show a heightened attentional bias towards images of thin and overweight bodies compared to low body dissatisfied individuals. We also examined whether there was a general tendency for participants to show an attentional bias towards overweight bodies opposed to medium bodies and thin bodies opposed to medium bodies. Method: Thirty six participants completed a body dissatisfaction scale, and subsequently took part in an eye-tracking study. An eye-tracker was used to measure and record both gaze direction and gaze duration frequencies whilst exposing participants to images of females presented for 2000ms. Each trial compared either thin with medium images, or overweight with medium images. Results: Results indicated that overall participants viewed the thin images for a significantly longer time (M=.451, M= .534 respectively than the overweight images F(1, 34= 9.806, p = .04, ηp2= .224. However, there were no significant effects of gaze direction towards the thin or overweight bodies. Similarly, no significant effects were obtained for direction or duration bias towards the thin or overweight bodies across the high and low body dissatisfied groups. Conclusions: These data show that overall, participants orient their attention more towards thin body images. However, body dissatisfaction level appears to have no effect on such attentional biases.

  6. Novel DC/DC Converters For High-Power Distributed Power Systems

    OpenAIRE

    Francisco Venustiano, Canales Abarca

    2003-01-01

    One of the requirements for the next generation of power supplies for distributed power systems (DPSs) is to achieve high power density with high efficiency. In the traditional front-end converter based on the two-stage approach for high-power three-phase DPSs, the DC-link voltage coming from the power factor correction (PFC) stage penalizes the second-stage DC/DC converter. This DC/DC converter not only has to meet the characteristics demanded by the load, but also must process energy w...

  7. An Ecological Momentary Assessment of the Effects of Weight and Shape Social Comparisons on Women With Eating Pathology, High Body Dissatisfaction, and Low Body Dissatisfaction

    OpenAIRE

    Leahey, Tricia M.; Crowther, Janis H.; Ciesla, Jeffrey A.

    2011-01-01

    This research examined the effects of naturally occurring appearance comparisons on women’s affect, body satisfaction, and compensatory cognitions and behaviors. Using ecological momentary assessment, women with high body dissatisfaction and eating pathology (EPHB), high body dissatisfaction (HB), or low body dissatisfaction (LB) recorded their reactions to appearance-focused social comparisons. EPHB and HB women made more upward appearance comparisons than LB women. All women experienced neg...

  8. High power single-frequency Innoslab amplifier.

    Science.gov (United States)

    Han, Ke-Zhen; Ning, Jian; Zhang, Bai-Tao; Wang, Yi-Ran; Zhang, Hai-Kun; Nie, Hong-Kun; Sun, Xiao-Li; He, Jing-Liang

    2016-07-10

    A laser diode array (LDA) end-pumped continuous-wave single-frequency Innoslab amplifier has been demonstrated. The Gaussian ray bundle method was used to model the light propagation in the Innoslab amplifier for the first time to the best of our knowledge. With discrete reflectors, the maximum output of 60 W with a linewidth of 44 MHz was achieved under the pump power of 245 W, corresponding to the optical-optical efficiency of 24.5%. The beam quality factor M2 at the output power of 51 W in the horizontal and vertical direction was measured to be 1.4 and 1.3, respectively. The long-term power instability in 2 h was less than 0.25%. PMID:27409308

  9. High-Gain Textile Antenna Array System for Off-Body Communication

    Directory of Open Access Journals (Sweden)

    Maria Lucia Scarpello

    2012-01-01

    Full Text Available A novel high-gain textile antenna array system, fully integrated into a rescue-worker’s vest and operating in the Industrial, Scientific, and Medical wireless band (2.4–2.4835 GHz, is presented. The system comprises an array consisting of four tip-truncated equilateral triangular microstrip patch antennas (ETMPAs, a power divider, line stretchers, and coaxial cables. The array is vertically positioned on the human torso to produce a narrow beam in elevation, as such reducing fading and allowing to steer the maximum gain in a small angular sector centered around the broadside direction. To allow simple low-cost beam steering, we specifically minimize mutual coupling by using a relative large distance between the patches and by selecting the ETMPA element as the most suited topology from three potential patch geometries. Moreover, we investigate the stability of return loss and mutual coupling characteristics under different relative humidity conditions, when bending the array, when placing the system on-body, and when covering it by different textile layers. Reflection coefficient and gain patterns are simulated and measured for the antenna system in free space and placed on the human body.

  10. Advanced pulsed and CW high-power fiber lasers

    OpenAIRE

    Nilsson, J.; Grudinin, A.B.; Turner, P.W.

    2000-01-01

    We examine design issues for high-energy pulsed as well as for high-power cw fiber lasers. Power handling and pump scalability are primary issues for kilowatt fiber lasers. Special core designs are needed for high-energy pulse generation.

  11. High Efficiency Hall Thruster Discharge Power Converter Project

    Data.gov (United States)

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

  12. High-Power Electroabsorption Modulator Using Intrastep Quantum Well

    Institute of Scientific and Technical Information of China (English)

    CHENG Yuan-Bing; PAN Jiao-Qing; ZHOU Fan; ZHU Hong-Liang; ZHAO Ling-Juan; WANG Wei

    2007-01-01

    An electroabsorption modulator using the intrastep quantum well (IQW) active region is fabricated for optical network systems. The strain-compensated InGaAsP/InGaAsP IQW shows good material quality and improved modulation properties, high extinction ratio efficiency 10 dB/V and low capacitance (< 0.42 pF), with which an ultra high frequency (> 15 GHz) can be obtained. High-speed measurement under high-power excitation shows no power saturation up to excitation power of 21 dBm. To our knowledge, the input optical power is the highest reported for multi-quantum well EAMs without heat sinks.

  13. High specific power flexible integrated IMM photovoltaic blanket Project

    Data.gov (United States)

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

  14. High Power PCU For Alphabus: PSR100V

    Science.gov (United States)

    Soubrier, L.; Trehet, E.

    2011-10-01

    Astrium, supported by ESA, has developed and qualified a new Power Conditioning Unit (PCU) in the frame of the Alphabus development for high power communications satellites. Thanks to its modular architecture, the PSR100V is able to supply 100 V power bus from 8kW to 20kW with optimized recurring costs.

  15. High-voltage power supply based on piezoelectric transformer

    OpenAIRE

    Kryvoshei, Dmytro; Paerand, Yuriy

    2012-01-01

    High-voltage power supply based on piezoelectric transformer instead of traditional electromagnetic transformer is offered in the paper. The structure of the power supply is represented. The power supply operation principle is described, the diagrams that illustrate its operation are given.

  16. Designing high efficient solar powered lighting systems

    DEFF Research Database (Denmark)

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

    -Port-Converters respectively for 1-10Wp and 10-50 Wp with a peak efficiency of 97% at 1.8 W of PV power for the 10 Wp version. Furthermore, a modelling tool for L2L products has been developed and a laboratory for feeding in component data not available in the datasheets to the model is described....

  17. Designing high efficient solar powered lighting systems

    DEFF Research Database (Denmark)

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

    2016-01-01

    -Port-Converters respectively for 1-10Wp and 10-50 Wp with a peak efficiency of 97% at 1.8 W of PV power for the 10 Wp version. Furthermore, a modelling tool for L2L products has been developed and a laboratory for feeding in component data not available in the datasheets to the model is described....

  18. A highly linear power amplifier for WLAN

    Science.gov (United States)

    Jie, Jin; Jia, Shi; Baoli, Ai; Xuguang, Zhang

    2016-02-01

    A three-stage power amplifier (PA) for WLAN application in 2.4-2.5 GHz is presented. The proposed PA employs an adaptive bias circuit to adjust the operating point of the PA to improve the linearity of the PA. Two methods to short the 2nd harmonic circuit are compared in the area of efficiency and gain of the PA. The PA is taped out in the process of 2 μm InGaP/GaAs HBT and is tested by the evaluation board. The measured results show that 31.5 dB power gain and 29.3 dBm P1dB with an associated 40.4% power added efficiency (PAE) under the single tone stimulus. Up to 26.5 dBm output power can be achieved with an error vector magnitude (EVM) of lower than 3% under the 64QAM/OFDM WLAN stimulus. Project supported by the National Natural Science Foundation of China (No. 61201244) and the Natural Science Fund of SUES (No. E1-0501-14-0168).

  19. High-Speed Low Power Design in CMOS

    DEFF Research Database (Denmark)

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

    2004-01-01

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

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

    Science.gov (United States)

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

    2014-02-01

    This study compared conventional, complex, and contrast protocols on peak power (PP) output. Static vs. dynamic contractions were also manipulated to determine the effect of these confounding variables. Eighteen recreationally trained men [age, 21.1 ± 3.3 years; body mass, 81.7 ± 15.9 kg; height, 182.8 ± 6.2 cm; 5 repetition maximum (5RM) half back squat, 119.2 ± 25.4 kg; 5RM/BW, 1.5 ± 0.2 kg] involved in sports including Australian Rules football, basketball, soccer, and rugby participated in this investigation. Five protocols were executed in a randomized order, a conventional protocol in which 3 sets of 4 countermovement jumps (CMJs) were performed 2 minutes apart. Contrast protocols using a heavy resistance conditioning action of either 4 repetitions with a 5RM load or a 5-second static back squat were alternated with sets of 4 CMJs. Complex conditions with 3 sets of 4 repetitions of a 5RM back squat or a 5-second static back squat were performed before the 3 sets of CMJs. In all conditions, 4 minutes of rest followed sets of heavy resistance exercises and 2 minutes of rest followed each set of CMJs. Individual set means and a total session mean were calculated from each CMJ performed during the session. Results showed that the conventional protocol produced significantly greater PP than all conditions except for the dynamic complex and the static contrast. Results suggest that the use of the complex and contrast protocols used in this investigation should not be used for acute increases in lower-body PP in recreationally trained individuals. PMID:23689340

  1. Ultra low power CMOS-based sensor for on-body radiation dose measurements

    KAUST Repository

    Arsalan, Muhammad

    2012-03-01

    For the first time, a dosimeter employing two floating gate radiation field effect transistors (FGRADFET) and operating at mere 0.1 V is presented. The novel dosimeter requires no power during irradiation and consumes only 1 μ Wduring readout. Besides the low power operation, structural changes at the device level have enhanced the sensitivity of the dosimeter considerably as compared to previous designs. The dosimeter is integrated with a wireless transmitter chip, thus eliminating all unwanted communication and power cables. It has been realized monolithically in DALSA\\'s 0.8 μ m complementary metal-oxide-semiconductor process and characterized with X-ray and γ-ray sources. A maximum sensitivity of 5 mV/rad for X-rays and 1.1 mV/rad for gamma;-rays have been achieved in measurements. Due to its small size, low-power, and wireless operation, the design is highly suitable for miniaturized, wearable, and battery operated dosimeters intended for radiotherapy and space applications. © 2012 IEEE.

  2. Studies on the influence of high power microwave radiation on energy metabolism of brain in rats

    International Nuclear Information System (INIS)

    Objective: To investigate the effect of high power microwave (HPM) radiation on energy metabolism of brains in Wistar rats. Methods: 120 Wistar rats were exposed to HPM of which the average power densities were respectively 3, 10, 30 and 100 mW/cm2. Toluidine blue staining, method of Wachstein-Meisel's magnesium activating enzyme, method of Nachlas's nitroblue tetrazolium and electron telescope were used to study the change of Nissel body, adenosine triphosphatase (ATPase), succinate dehydrogenase (SDH), and ultrastructure of cerebral cortex, hippocampus and thalamencephalon. Results: 3-100 mW/cm2 HPM radiation caused the decrease, even the disappearance of Nissel body of cerebral cortex, hippocampus and thalamencephalon in 6h-3d after radiation (P2 HPM radiation can induce the disorder of energy metabolism of brains, represented the decrease of Nissel body and SDH, injuries of ATPase, injuries of mitochondrion and rough endoplasmic reticulum. (authors)

  3. High Performance Power Module for Hall Effect Thrusters

    Science.gov (United States)

    Pinero, Luis R.; Peterson, Peter Y.; Bowers, Glen E.

    2002-01-01

    Previous efforts to develop power electronics for Hall thruster systems have targeted the 1 to 5 kW power range and an output voltage of approximately 300 V. New Hall thrusters are being developed for higher power, higher specific impulse, and multi-mode operation. These thrusters require up to 50 kW of power and a discharge voltage in excess of 600 V. Modular power supplies can process more power with higher efficiency at the expense of complexity. A 1 kW discharge power module was designed, built and integrated with a Hall thruster. The breadboard module has a power conversion efficiency in excess of 96 percent and weighs only 0.765 kg. This module will be used to develop a kW, multi-kW, and high voltage power processors.

  4. Offshore Power Transmission : Submarine high voltage transmission alternatives

    OpenAIRE

    Ulsund, Ragnar

    2009-01-01

    Offshore power transmission is becoming an increasingly important issue. To moderate climate change, world leaders have set environmental goals that will be very difficult to reach without renewable power production and the removal of production units with high emissions. Wind power and electrification have been the focus in this report. Plans for the expensive wind power are already moving offshore. This report has made an attempt at suggesting a guideline for well-suited transmission syst...

  5. Cutting-Edge High-Power Ultrafast Thin Disk Oscillators

    OpenAIRE

    Thomas Südmeyer; Matthias Golling; Christian Kränkel; Kolja Beil; Martin Hoffmann; Baer, Cyrill R. E.; Oliver H. Heckl; Cinia Schriber; Florian Emaury; Clara J. Saraceno; Ursula Keller

    2014-01-01

    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 demonstr...

  6. GENDER VIOLENCE AND CONTROL BODIES: A CASE ANALYSIS OF MIDDLE AND HIGH SCHOOL STUDENTS IN THE SOUTHERN STATE OF GUANAJUATO

    Directory of Open Access Journals (Sweden)

    Rocío Rosas-Vargas

    2014-07-01

    Full Text Available This paper derives from a research project on gender violence to students in middle and high Guanajuato. Surveys, interviews and workshops were applied were performed. During the course of the latter, the high level of youth reported being raped because you do not meet the image that are supposed to have the body that the media tells them to show. Anxiety over what is apparently not conducive indicates serious trouble and sometimes they have attempted suicide. In this sense, we approach the work from the idea that female bodies which are normalized, and where social norms of womanhood (Harcourt, 2011 will also resist. It is in bodies, socio-culturally constructed, where power games enroll. Butler (2010: 93 states that "we are exposed to others, and while this may be a condition of our desire, it also raises the possibility of subjugation and cruelty This results from the fact that the bodies are closely related to each other. through the material, the feel, language and a number of relationships without which we can not survive. "That is, the need for others, for recognition tell us that to meet our needs, we must be as we are told and if we are not then we will not get the recognition and yes cruelty, but as we can not survive and may reactions are self-destruction and violence. What then are the bodies that represent a problem?

  7. Gender Associated High Body Mass Index in Allergic Diseases

    Directory of Open Access Journals (Sweden)

    Violeta Lokaj-Berisha

    2015-03-01

    RESULTS:The study population was grouped into asthma, asthmarhinitis, rhinitis, Urticaria oreczema and controls by BMI and sex. Females with the highest BMI were in asthma and urticaria/eczema group. Males with the highest BMI were in asthmarhinitis and urticariaeczema group. High BMI was associated with atopy in both genders of healthy controls. High levels of total IgE were in male allergic patients. CONCLUSION:High BMI was associated with asthma in females, urticaria/eczema in both genders and atopy in both genders of healthy controls. Higher levels of total IgE were concluded in male patients.

  8. An Evaluation of Polarisability Tensors of Arbitrarily Shaped Highly Conducting Bodies

    CERN Document Server

    Jelinek, L; Capek, M

    2016-01-01

    A full-wave numerical scheme of polarisability tensors evaluation is presented. The method accepts highly conducting bodies of arbitrary shape and explicitly accounts for the radiation as well as ohmic losses. The method is verified on canonical bodies with known polarisability tensors, such as a sphere and a cube, as well as on realistic scatterers. The theoretical developments are followed by a freely available code whose sole user input is the triangular mesh covering the surface of the body under consideration.

  9. Fusion blankets for high efficiency power cycles

    International Nuclear Information System (INIS)

    Definitions are given of 10 generic blanket types and the specific blanket chosen to be analyzed in detail from each of the 10 types. Dimensions, compositions, energy depositions and breeding ratios (where applicable) are presented for each of the 10 designs. Ultimately, based largely on neutronics and thermal hyraulics results, breeding an nonbreeding blanket options are selected for further design analysis and integration with a suitable power conversion subsystem

  10. High Speed Peltier Calorimeter for the Calibration of High Bandwidth Power Measurement Equipment

    OpenAIRE

    Frost, Damien F.; Howey, David A.

    2015-01-01

    Accurate power measurements of electronic components operating at high frequencies are vital in determining where power losses occur in a system such as a power converter. Such power measurements must be carried out with equipment that can accurately measure real power at high frequency. We present the design of a high speed calorimeter to address this requirement, capable of reaching a steady state in less than 10 minutes. The system uses Peltier thermoelectric coolers to remove heat generat...

  11. Power affects performance when the pressure is on: evidence for low-power threat and high-power lift.

    Science.gov (United States)

    Kang, Sonia K; Galinsky, Adam D; Kray, Laura J; Shirako, Aiwa

    2015-05-01

    The current research examines how power affects performance in pressure-filled contexts. We present low-power-threat and high-power-lift effects, whereby performance in high-stakes situations suffers or is enhanced depending on one's power; that is, the power inherent to a situational role can produce effects similar to stereotype threat and lift. Three negotiations experiments demonstrate that role-based power affects outcomes but only when the negotiation is diagnostic of ability and, therefore, pressure-filled. We link these outcomes conceptually to threat and lift effects by showing that (a) role power affects performance more strongly when the negotiation is diagnostic of ability and (b) underperformance disappears when the low-power negotiator has an opportunity to self-affirm. These results suggest that stereotype threat and lift effects may represent a more general phenomenon: When the stakes are raised high, relative power can act as either a toxic brew (stereotype/low-power threat) or a beneficial elixir (stereotype/high-power lift) for performance. PMID:25888684

  12. Circadian variation of EEG power spectra in NREM and REM sleep in humans: dissociation from body temperature

    Science.gov (United States)

    Dijk, D. J.

    1999-01-01

    In humans, EEG power spectra in REM and NREM sleep, as well as characteristics of sleep spindles such as their duration, amplitude, frequency and incidence, vary with circadian phase. Recently it has been hypothesized that circadian variations in EEG spectra in humans are caused by variations in brain or body temperature and may not represent phenomena relevant to sleep regulatory processes. To test this directly, a further analysis of EEG power spectra - collected in a forced desynchrony protocol in which sleep episodes were scheduled to a 28-h period while the rhythms of body temperature and plasma melatonin were oscillating at their near 24-h period - was carried out. EEG power spectra were computed for NREM and REM sleep occurring between 90-120 and 270-300 degrees of the circadian melatonin rhythm, i.e. just after the clearance of melatonin from plasma in the 'morning' and just after the 'evening' increase in melatonin secretion. Average body temperatures during scheduled sleep at these two circadian phases were identical (36.72 degrees C). Despite identical body temperatures, the power spectra in NREM sleep were very different at these two circadian phases. EEG activity in the low frequency spindle range was significantly and markedly enhanced after the evening increase in plasma melatonin as compared to the morning phase. For REM sleep, significant differences in power spectra during these two circadian phases, in particular in the alpha range, were also observed. The results confirm that EEG power spectra in NREM and REM sleep vary with circadian phase, suggesting that the direct contribution of temperature to the circadian variation in EEG power spectra is absent or only minor, and are at variance with the hypothesis that circadian variations in EEG power spectra are caused by variations in temperature.

  13. A Dynamic Programming based method for optimizing power system restoration with high wind power penetration

    DEFF Research Database (Denmark)

    Hu, Rui; Hu, Weihao; Li, Pengfei;

    2016-01-01

    to its stable limits. Once the blackout happens, a well-designed restoration strategy is significant. This paper focuses on how to ameliorate the power system restoration procedures to adapt the high wind power penetration and how to take full advantages of the wind power plants during the...... and relatively low cost. Thus, many countries are increasing the wind power penetration in their power system step by step, such as Denmark, Spain and Germany. The incremental wind power penetration brings a lot of new issues in operation and programming. The power system sometimes will operate close...... restoration. In this paper, the possibility to exploit the stochastic wind power during restoration was discussed, and a Dynamic Programming (DP) method was proposed to make wind power contribute in the restoration rationally as far as possible. In this paper, the method is tested and verified by a modified...

  14. A portable high power microwave source with permanent magnets

    Science.gov (United States)

    Li, Wei; Zhang, Jun; Li, Zhi-qiang; Yang, Jian-Hua

    2016-06-01

    A high power microwave source with permanent magnets is proposed in this paper. The source has the length 330 mm, maximum diameter 350 mm, and total weight 50 kg, including 25 kg of permanent magnets. 1 GW of microwave power with Gaussian radiation pattern and 24% of microwave power generation efficiency in a pulse duration of 75 ns are obtained in the experiment. Operating frequency of the source is 2.32 GHz. Such a small size, light weight, and highly stable in operation source will be used in portable repetitive high power microwave generation systems.

  15. Self-commutating converters for high power applications

    CERN Document Server

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

    2010-01-01

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

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

    OpenAIRE

    Bahman, Amir Sajjad

    2015-01-01

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

  17. Development of high coherence high power 193nm laser

    Science.gov (United States)

    Tanaka, Satoshi; Arakawa, Masaki; Fuchimukai, Atsushi; Sasaki, Yoichi; Onose, Takashi; Kamba, Yasuhiro; Igarashi, Hironori; Qu, Chen; Tamiya, Mitsuru; Oizumi, Hiroaki; Ito, Shinji; Kakizaki, Koji; Xuan, Hongwen; Zhao, Zhigang; Kobayashi, Yohei; Mizoguchi, Hakaru

    2016-03-01

    We have been developing a hybrid 193 nm ArF laser system that consists of a solid state seeding laser and an ArF excimer laser amplifier for power-boosting. The solid state laser consists of an Yb-fiber-solid hybrid laser system and an Er-fiber laser system as fundamentals, and one LBO and three CLBO crystals for frequency conversion. In an ArF power amplifier, the seed laser passes through the ArF gain media three times, and an average power of 110 W is obtained. As a demonstration of the potential applications of the laser, an interference exposure test is performed.

  18. Application of high temperature superconductivity in power systems

    International Nuclear Information System (INIS)

    The system study 'High Temperature Superconductivity (HTS) in power systems' lists the technical and economical advantages for power generation, transmission and distribution systems using components made of HTS material as seen in the light of current knowledge in the superconductivity area. This report lists the advantages of using high-temperature superconductivity in the power industry area and summarises the results obtained in various case studies on the subject

  19. Some aspects of radioecological monitoring of high aquatic plants from water bodies within the Chernobyl accident exclusion zone - 16368

    International Nuclear Information System (INIS)

    The impact analysis of low doses of ionizing radiation on the breathers in natural populations is an important part of radiobiological studies of non-human biota. The main aim of our studies was to investigate some cytogenetic, morphological and reproductive rates of the common reed (Phragmites australis (Cav.) Trin. ex. Steud.) from different water bodies within the Chernobyl accident exclusion zone. The absorbed dose rate for littoral emergent plants in sampling water bodies was varied from 1.3 E-02 to 1.6 E-01 Gy/h. The rate and main types of chromosome aberrations in roots meristems, morphological damages in seed germs, as well as rates of germinating ability and power were analyzed. There were registered rather low rate of germinating ability (14-48 %) and germinating power (<1) of seeds from all sampling water bodies with high levels of radioactive contamination in comparison to control ones. Against the general suppressed background the effect of relative stimulation of more affected seeds was observed. With increase of absorbed dose in range of 1.3 E-02-1.6 E-01 Gy/h the number of germinated seeds was increased. At the same time the number of morphological damages of seeds was increased as well. There was determined the positive correlation between absorbed dose rate and chromosome aberration rate in roots of the common reed from sampling water bodies. The highest rate of chromosome aberrations (up to 17 %) were registered in plants with high level of morphological deviations in seeds germs. The data obtained from the complex analysis of natural populations of the common reed from the radioactive contaminated water bodies testify about rather high level of genetic efficiency of low doses of long-term exposure. (authors)

  20. 1.55 Micron High Peak Power Fiber Amplifier Project

    Data.gov (United States)

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

  1. Applications of high-temperature superconductors in electric power supply

    International Nuclear Information System (INIS)

    The author reports on a study in which the characteristics, applications and effects of equipment with high-temperature superconductors in power transmission and distribution networks were investigated. At the present state of the art, it is impossible to say when and in what form high-temperature superconductor materials will be available for low-cost, large-area power supply. (orig.)

  2. Computing High Accuracy Power Spectra with Pico

    OpenAIRE

    Fendt, William A.; Wandelt, Benjamin D.

    2007-01-01

    This paper presents the second release of Pico (Parameters for the Impatient COsmologist). Pico is a general purpose machine learning code which we have applied to computing the CMB power spectra and the WMAP likelihood. For this release, we have made improvements to the algorithm as well as the data sets used to train Pico, leading to a significant improvement in accuracy. For the 9 parameter nonflat case presented here Pico can on average compute the TT, TE and EE spectra to better than 1% ...

  3. Laser Cooled High-Power Fiber Amplifier

    OpenAIRE

    Nemova, Galina

    2009-01-01

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

  4. 29 W High Power CW Supercontinuum Source

    CERN Document Server

    Cumberland, B A; Popov, S V; Taylor, J R

    2008-01-01

    A 29 W CW supercontinuum spanning from 1.06 to 1.67 um is generated in a short length of PCF with two zero dispersion wavelengths. The continuum has the highest spectral power density, greater than 50 mW/nm up to 1.4 um, reported to date. The use of a short length of PCF enables the continuum to expand beyond the water loss at 1.4 um. The dynamics of the continuum evolution are studied experimentally and numerically with close attention given to the effects of the water loss and the second zero dispersion wavelength.

  5. High-power microwave diplexers for advanced ECRH systems

    International Nuclear Information System (INIS)

    In electron cyclotron resonance heating systems, high-power multiplexers can be employed as power combiners, adjustable power dividers, fast switches to toggle the power between two launchers, as well as frequency sensitive directional couplers to combine heating and diagnostic applications on one launcher. In the paper, various diplexer designs for quasi-optical and corrugated waveguide transmission systems are discussed. Numerical calculations, low-power tests and especially high-power experiments performed at the ECRH system of W7-X are shown, which demonstrate the capability of these devices. Near term plans for applications on ASDEX Upgrade and FTU are presented. Based on the present results, options for implementation of power combiners and fast switches in the ECRH system of ITER is discussed.

  6. High density operation for reactor-relevant power exhaust

    Science.gov (United States)

    Wischmeier, M.

    2015-08-01

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

  7. High density operation for reactor-relevant power exhaust

    Energy Technology Data Exchange (ETDEWEB)

    Wischmeier, M., E-mail: marco.wischmeier@ipp.mpg.de [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany)

    2015-08-15

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

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

    Data.gov (United States)

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

  9. A bibliography of high energy two-body and inclusive scattering data

    International Nuclear Information System (INIS)

    A bibliography is presented of the data on high energy two-body and quasi-two-body final state scattering processes. This updated edition also covers one and two-particle inclusive production. It contains references to those published papers whose main purpose is to provide data on high energy two-body and inclusive hadronic scattering cross-sections rather than just properties of the produced particles. It covers the leading high energy physics journals and the period up to June 1977. The entries are grouped by process in the order indicated in the Table of Contents, and an author index is also provided. (author)

  10. Evaluation of the body bearing of high performance female volleyball players

    Directory of Open Access Journals (Sweden)

    Stech M.

    2010-09-01

    Full Text Available In the present paper the results of the study of body bearing in 12 high performance female volleyball players of polish team (TPS Rumia are presented. To estimate body bearing the New-York's test of the body bearing classification was used. The results of the study have shown that asymmetrical positions of volleyball players in the time of services and attacks are contributed to formed some asymmetrical disturbances of body bearing. At the majority of sportsmen it is exhibited in omitting the left brachium and the left blade, in a right-hand scoliosis, in the tendency to a platypodia. It requires use of special preventive and adjusting exercises.

  11. 3-D Printed High Power Microwave Magnetrons

    Science.gov (United States)

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

    2015-11-01

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

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

    OpenAIRE

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Wu Xiao-po

    2014-06-01

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

  14. Medical surveillance of nuclear power plant workers during reactor shutdown using whole-body counting and excretion analysis

    International Nuclear Information System (INIS)

    After a review of radioactivity basis and radiation protection principles, the various aspects of medical surveillance of nuclear power plant workers during reactor shutdown, are presented. Internal contamination incidents that happened during 1986-1987 shutdown of Paluel reactor are exposed. Internal contamination levels are evaluated using whole-body counting and radionuclide determination in feces and urine and compared with dose limits

  15. Two-body form factors at high Q2

    International Nuclear Information System (INIS)

    The charge form factor of a scalar deuteron at high momentum transfer is examined in a model employing scalar nucleons and mesons. With an eye toward establishing consistency criteria for more realistic calculations, several aspects of the model are examined in detail: the role of nucleon and meson singularities in the one-loop impulse diagram, the role of positive-and negative-energy nucleons, and the relationship to time-ordered perturbation theory. It is found that at large Q2 (1) the form factor is dominated by a term in which the spectator nucleon is on the mass shell, and (2) the meson singularity structure of the d-n-p vertex function is unimportant in determining the overall high-Q2 behaviour of the form factor

  16. Overview on the high power excimer laser technology

    Science.gov (United States)

    Liu, Jingru

    2013-05-01

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

  17. Cascade: a high-efficiency ICF power reactor

    International Nuclear Information System (INIS)

    Cascade attains a net power-plant efficiency of 49% and its cost is competitive with high-temperature gas-cooled reactor, pressurized-water reactor, and coal-fired power plants. The Cascade reactor and blanket are made of ceramic materials and activation is 6 times less than that of the MARS Tandem Mirror Reactor operating at comparable power. Hands-on maintenance of the heat exchangers is possible one day after shutdown. Essentially all tritium is recovered in the vacuum system, with the remainder recovered from the helium power conversion loop. Tritium leakage external to the vacuum system and power conversion loop is only 0.03 Ci/d

  18. High efficiency fuel cell/advanced turbine power cycles

    Energy Technology Data Exchange (ETDEWEB)

    Morehead, H. [Westinghouse Electric Corp., Orlando, FL (United States)

    1995-10-19

    An outline of the Westinghouse high-efficiency fuel cell/advanced turbine power cycle is presented. The following topics are discussed: The Westinghouse SOFC pilot manufacturing facility, cell scale-up plan, pressure effects on SOFC power and efficiency, sureCell versus conventional gas turbine plants, sureCell product line for distributed power applications, 20 MW pressurized-SOFC/gas turbine power plant, 10 MW SOFC/CT power plant, sureCell plant concept design requirements, and Westinghouse SOFC market entry.

  19. Safeguarding radiation protection by the V-1 nuclear power plant operator and checking the job by hygiene service bodies

    International Nuclear Information System (INIS)

    Radiation protection in the V-1 nuclear power plant is controlled by a dosimetry service unit on the basis of information on the radiation situation obtained using stationary and portable dosimetric systems. Hygiene services bodies check the work by separate tests and measurements. It was found that the radiation burden of the nuclear power staff has so far been minimal. No environmental impact has been recorded of the V-1 nuclear power plant, even when available sensitive radiometric methods were used. The radiation protection aspects of the first refuelling are also mentioned. (author)

  20. Ultra high performance connectors for power transmission applications

    Science.gov (United States)

    Wang, Jy-An; Ren, Fei; Lee, Dominic F; Jiang, Hao

    2014-03-04

    Disclosed are several examples of an apparatus for connecting the free ends of two electrical power transmission lines having conductor strands disposed around a central, reinforcing core. The examples include an inner sleeve having a body defining an inner bore passing through an axially-extending, central axis, an outer rim surface disposed radially outward from the central bore, and one or more axially-extending grooves penetrating the body at the outer rim surface. Also included is an outer splice having a tubular shaped body with a bore passing coaxially through the central axis, the bore defining an inner rim surface for accepting the inner sleeve. The inner bore of the inner sleeve accepts the reinforcement cores of the two conductors, and the grooves accept the conductor strands in an overlapping configuration so that a majority of the electrical current flows between the overlapped conductor strands when the conductors are transmitting electrical current.

  1. Design and development of power supplies for high power IOT based RF amplifier

    International Nuclear Information System (INIS)

    Design, development, circuit topology, function of system components and key system specifications of different power supplies for biasing electrodes of Thales Inductive Output Tube (IOT) based high power RF amplifier are presented in this paper. A high voltage power supply (-30 kV, 3.2A dc) with fast (∼microsecond) crowbar protection circuit is designed, developed and commissioned at VECC for testing the complete setup. Other power supplies for biasing grid electrode (300V, 0.5A dc) and Ion Pump (3 kV, 0.1mA dc) of IOT are also designed, developed and tested with actual load. A HV Deck (60kV Isolation) is specially designed in house to place these power supplies which are floating at 30 kV. All these power supplies are powered by an Isolation Transformer (5 kVA, 60 kV isolation) designed and developed in VECC. (author)

  2. Wireless power transfer and fault diagnosis of high-voltage power line via robotic bird

    Science.gov (United States)

    Liu, Chunhua; Chau, K. T.; Zhang, Zhen; Qiu, Chun; Li, Wenlong; Ching, T. W.

    2015-05-01

    This paper presents a new idea of wireless power transfer (WPT) and fault diagnosis (FD) of high-voltage power line via robotic bird. The key is to present the conceptual robotic bird with WPT coupling coil for detecting and capturing the energy from the high-voltage power line. If the power line works in normal condition, the robotic bird is able to stand on the power line and extract energy from it. If fault occurs on the power line, the corresponding magnetic field distribution will become different from that in the normal situation. By analyzing the magnetic field distribution of the power line, the WPT to the robotic bird and the FD by the robotic bird are performed and verified.

  3. High voltage, magnetically switched pulsed power systems

    International Nuclear Information System (INIS)

    The principles of magnetic switching are briefly described. Then the results of experiments on the following substantive topics for magnetic switching are presented: material properties and how they relate to switch performance, risetime limitations, and core insulation. Magnetic switching is then evaluated from a system perspective. An idealized pulse power system with 200 kJ or stored energy and a 40 ns output pulse is examined. The multi-megavolt electrical insulation requirements impose limitations on the switches. The cost of the magnetically switched system exceeds the cost of the conventional superpower generator system by up to 75%. The potential for reliability, reproducibility, and repetitive pulse capability must be evaluated for each application to offset the increased cost

  4. THE AGS HIGH POWER UPGRADE PLAN.

    Energy Technology Data Exchange (ETDEWEB)

    WENG,W.T.; ROSER,T.

    2002-04-08

    BNL could provide a Megawatt class neutrino beam from the AGS for very long baseline neutrino experiments. We have studied two possible approaches to upgrade the AGS to 1.0 MW beam power. The first is the linac option, comprising a new superconducting linac injector of 1.2 GeV, accelerating 9 x 10{sup 3} proton per pulse in the AGS to 28 GeV at 2.5 Hz. The second option is to extend the existing 200 MeV linac to 400 MeV. ramp the Booster to 2.5 GeV at 6 Hz. add a new 2.5 GeV accumulator ring in the AGS tunnel. and finally ramp the AGS to 28 GeV at 2.5 Hz. Due to the simplicity of the linac approach and minimum interference with the on going research program. the linac option is the preferred one.

  5. High power UV and VUV pulsed excilamps

    Science.gov (United States)

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

    2008-07-01

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

  6. Is high body fat estimated by body mass index and waist circumference a predictor of hypertension in adults? A population-based study

    Directory of Open Access Journals (Sweden)

    Silva Diego Augusto Santos

    2012-12-01

    Full Text Available Abstract Background The aim of this study was to assess the predictive capacity of body fat percentage (%BF estimated by equations using body mass index (BMI and waist circumference (WC to identify hypertension and estimate measures of association between high %BF and hypertension in adults. Methods This is a cross-sectional population-based study conducted with 1,720 adults (20–59 years from Florianopolis, southern Brazil. The area under the ROC curve, sensitivity, specificity, predictive values, and likelihood ratios of cutoffs for %BF were calculated. The association between %BF and hypertension was analyzed using Poisson regression, estimating the unadjusted and adjusted prevalence ratios and 95% CI. Results The %BF equations showed good discriminatory power for hypertension (area under the ROC curve > 0.50. Considering the entire sample, the cutoffs for %BF with better properties for screening hypertension were identified in the equation with BMI for men (%BF = 20.4 and with WC for women (%BF = 34.1. Adults with high %BF had a higher prevalence of hypertension. Conclusions The use of simple anthropometric measurements allowed identifying the %BF, diagnosing obesity, and screening people at risk of hypertension in order to refer them for more careful diagnostic evaluation.

  7. High power photoconductive semiconductor switches treated with amorphic diamond coatings

    International Nuclear Information System (INIS)

    Our recent efforts have resulted in implementation and demonstration of several intense photoconductively switched stacked Blumlein pulsers producing high power output pulses with risetimes as fast as 200 ps. A single GaAs photoconductive switch triggered with a low power laser diode array commutates these devices. During the avalanche-mode photoconductive switching of these pulsers at high powers, current filamentation associated with the high gain GaAs switches produces such high current density that switches are damaged near the metal-semiconductor interface and the lifetime is limited. This report presents progress toward improving the switch operation and lifetime by advanced treatments with the amorphic diamond coatings

  8. Experiments on high power EB evaporation of niobium

    International Nuclear Information System (INIS)

    Full text: The versatility of electron beam evaporation makes the deposition of many new and unusual materials possible. This technique offers freedom from contamination and precise control. High power electron guns are especially used for obtaining high evaporation rates for large area coatings. This paper deals with the coating experiments carried out on an indigenously developed high power strip electron gun with niobium as evaporant at 40 kW on S.S. substrate. The practical problems of conditioning the gun and venting the vacuum system after the high power operation are also discussed. The coating rate was calculated by weight difference method

  9. Pulsed power drivers for ICF and high energy density physics

    International Nuclear Information System (INIS)

    This document presents the advantages of the use of nanosecond pulsed power for the generating of high energy and high power at a low cost and high efficiency. The Sandia National Laboratories Particle-beam Fusion program applies these pulse techniques to the Inertial Fusion Energy national goal. Pulsed power has also been used to generate intense, high-energy X-ray sources for application to X-ray laser and radiation effects science research. Results of experiments performed on the Saturn accelerator as well as a design concept for the proposed Jupiter facility are also presented. (TEC). 16 refs., 8 figs

  10. Inspection and enforcement by the regulatory body for nuclear power plants. A safety guide. A publication within the NUSS programme

    International Nuclear Information System (INIS)

    The purpose of this Safety Guide is to provide guidance on fulfilling the requirements for inspection and enforcement by the regulatory body, as set out in the Code on the Safety of Nuclear Power Plants; Governmental Organization. This Safety Guide deals with the responsibilities of the regulatory body, the organization of inspection programmes, the inspection resources of the regulatory body, methods of inspection, requirements on the applicant/licensee in regard to regulatory inspection, inspection reports, and regulatory action and enforcement. It is recognized that many of the provisions of this Safety Guide may be applicable to the regulations of other nuclear facilities and related activities including research reactors, fuel processing and manufacturing plants, irradiated fuel processing plants and radioactive waste management facilities. This Safety Guide does not deal specifically with the functions of a regulatory body responsible for such matters; however, the guidance presented here may be applied as appropriate to these activities. 11 refs, 1 fig

  11. Power Control and Data Acquisition System for High Power Microwave Test Bench

    International Nuclear Information System (INIS)

    The 6 MW/4.6 GHz lower hybrid current drive (LHCD) system will be set up on the experimental advanced superconducting tokamak (EAST) for achieving a steady-state operation. The high power and continuous wave (CW) mode microwave test bench operating at 250 kW/4.6 GHz has already been finished, which can be used to simulate different kinds of high power microwave environments to test microwave components and units for the new LHCD system. The power control and data acquisition system on the test bench composed of power control, high reflected power protection and data acquisition function is described here in detail. Long-term operation of the test bench showed that the power control and data acquisition system is very stable and reliable. (fusion engineering)

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

    DEFF Research Database (Denmark)

    Nielsen, Sune Fallgaard; Madsen, Jan

    2003-01-01

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

  13. Application of parallel connected power-MOSFET elements to high current d.c. power supply

    International Nuclear Information System (INIS)

    The low aspect ratio spherical torus (ST), which has single turn toroidal field coil, requires the extremely high d.c. current like as 20 MA to energize the coil. Considering the ratings of such extremely high current and low voltage, power-MOSFET element is employed as the switching device for the a.c./d.c. converter of power supply. One of the advantages of power-MOSFET element is low on-state resistance, which is to meet the high current and low voltage operation. Recently, the capacity of power-MOSFET element has been increased and its on-state resistance has been decreased, so that the possibility of construction of high current and low voltage a.c./d.c. converter with parallel connected power-MOSFET elements has been growing. With the aim of developing the high current d.c. power supply using power-MOSFET, the basic characteristics of parallel operation with power-MOSFET elements are experimentally investigated. And, the synchronous rectifier type and the bi-directional self commutated type a.c./d.c. converters using parallel connected power-MOSFET elements are proposed

  14. A Low Power Low Voltage High Performance CMOS Current Mirror

    OpenAIRE

    Sirish Rao,; Sampath Kumar V

    2015-01-01

    The current mirrors are one of the most important circuits in designing the analog and mixed-mode circuit. A low power and low voltage high-performance CMOS current mirror with optimized input and output resistance are presented in this paper. SPICE simulations confirm the high-performance CMOS current mirror with power supply close to the threshold voltage of the transistor. In this paper, for achieving the low input resistance and a very high output resistance, the combination o...

  15. Modular high voltage power supply for chemical analysis

    Science.gov (United States)

    Stamps, James F.; Yee, Daniel D.

    2008-07-15

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

  16. Development on a pulse power supply for high power Klystron using semiconductor switch

    International Nuclear Information System (INIS)

    Technical development in displacing thyratron switch used conventionally for pulse power supply for high power Klystron to semiconductor switch has been attempted. Now, by using SI-thyristor for a semiconductor device, some evaluation tests on high speed turn-on features of the device with low inductance circuit were carried out. And, by trial production of 45 kV semiconductor switch connected fifteen elements of this device in series, high power evaluation tests were conducted. As a result, it was found that the SI-thyristor had extremely superior turn-on features by a device evaluation test using low inductance circuit, and it was also verified that 45 kV semiconductor switch connected fifteen elements in series had switching capacity sufficient to match with high power thyratron by testing under actual Klystron pulse power supply. (G.K.)

  17. GaN High Power Devices

    Energy Technology Data Exchange (ETDEWEB)

    PEARTON,S.J.; REN,F.; ZHANG,A.P.; DANG,G.; CAO,X.A.; LEE,K.P.; CHO,H.; GILA,B.P.; JOHNSON,J.W.; MONIER,C.; ABERNATHY,C.R.; HAN,JUNG; BACA,ALBERT G.; CHYI,J.-I.; LEE,C.-M.; NEE,T.-E.; CHUO,C.-C.; CHI,G.C.; CHU,S.N.G.

    2000-07-17

    A brief review is given of recent progress in fabrication of high voltage GaN and AlGaN rectifiers, GaN/AlGaN heterojunction bipolar transistors, GaN heterostructure and metal-oxide semiconductor field effect transistors. Improvements in epitaxial layer quality and in fabrication techniques have led to significant advances in device performance.

  18. Cryogenic cooling for high power laser amplifiers

    International Nuclear Information System (INIS)

    The Extreme Light Infrastructure (ELI) will be a new scientific European infrastructure devoted to scientific research in lasers field, dedicated to the investigation and applications of laser-matter interaction at the highest intensity level (more than 6 orders of magnitude higher than today’s laser intensity). The ELI project, a collaboration of 13 European countries, will comprise three branches: Ultra High Field Science that will explore laser-matter interaction, attosecond Laser Science designed to conduct temporal investigation of electron dynamics in atoms, molecules, plasmas and solids at attosecond scale, High Energy Beam Science devoted to the development and usage o f dedicated beam lines with ultra short pulses of high energy radiation. Using DPSSL (Diode Pumped Solid State Lasers) as pumping technology, PW-cIass lasers with enhanced repetition rates are developed. Each of the Yb YaG amplifiers will be diode-pumped at a wavelength of 940 nm. This is a prerequisite for achieving high repetition rates (light amplification duration 1 millisecond and repetition rate 10 Hz), The efficiency of DPSSL is inversely proportional to the temperature, for this reason the slab amplifier have to be cooled at a temperature in the range of 100K-170K with a heat flux of 1 MW*m-2. This paper describes the thermo-mechanical analysis for the design of the amplification laser head, presents a preliminary proposal for the required cryogenic cooling system and finally outlines the gain of cryogenic operation for the efficiency of high pulsed laser. (author)

  19. Cryogenic cooling for high power laser amplifiers

    International Nuclear Information System (INIS)

    The Extreme Light Infrastructure (ELI) will be a new scientific European infrastructure devoted to scientific research in lasers field, dedicated to the investigation and applications of laser-matter interaction at the highest intensity level (more than 6 orders of magnitude higher than today's laser intensity). The ELI project, a collaboration of 13 European countries, will comprise three branches: Ultra High Field Science that will explore laser-matter interaction, atto-second Laser Science designed to conduct temporal investigation of electron dynamics in atoms, molecules, plasmas and solids at atto-second scale, High Energy Beam Science devoted to the development and usage of dedicated beam lines with ultra short pulses of high energy radiation. Using DPSSL (Diode Pumped Solid State Lasers) as pumping technology, PW-class lasers with enhanced repetition rates are developed. Each of the Yb YaG amplifiers will be diode-pumped at a wavelength of 940 nm. This is a prerequisite for achieving high repetition rates (light amplification duration 1 millisecond and repetition rate 10 Hz). The efficiency of DPSSL is inversely proportional to the temperature, for this reason the slab amplifier have to be cooled at a temperature in the range of 100 K-170 K with a heat flux of 1 MW.m-2. This paper describes the thermo-mechanical analysis for the design of the amplification laser head, presents a preliminary proposal for the required cryogenic cooling system and finally outlines the gain of cryogenic operation for the efficiency of high pulsed laser. (authors)

  20. Benefits of Nanostructuring Electrodes for High-Energy and High-Power Lithium Batteries

    Institute of Scientific and Technical Information of China (English)

    Joachim; Maier

    2007-01-01

    1 Results One of the greatest challenges for our society is providing powerful electrochemical energy storage devices with both high energy and high power densities. Rechargeable lithium-based batteries are amongst the most promising candidates in terms of energy density,the achievement of high power density is hindered by kinetic problems of the electrode materials.This contribution that emphasizes the power of nanostructuring for electrodes in lithium-based batteries,deals with several nanostructured ...

  1. High-order large-eddy simulation of flow over the ``Ahmed body'' car model

    Science.gov (United States)

    Minguez, M.; Pasquetti, R.; Serre, E.

    2008-09-01

    The structure of the turbulent flow over a simplified automotive model, the Ahmed body (S. R. Ahmed and G. Ramm, SAE Paper No. 8403001, 1984) with a 25° slanted back face, is investigated using high-order large-eddy simulations (LESs) at Reynolds number Re =768000. The numerical approach is carried out with a multidomain spectral Chebyshev-Fourier solver and the bluff body is modeled with a pseudopenalization method. The LES capability is implemented thanks to a spectral vanishing viscosity (SVV) technique, with particular attention to the near wall region. Such a SVV-LES approach is extended for the first time to an industrial three-dimensional turbulent flow over a complex geometry. In order to better understand the interactions between flow separations and the dynamic behavior of the released vortex wake, a detailed analysis of the flow structures is provided. The topology of the flow is well captured showing a partial separation of the boundary layer over the slanted face and the occurrence of two strong contrarotating trailing vortices expanding farther in the wake. The interactions of these large vortices with smaller structures reminiscent of horseshoe vortices, within the shear layer over the slanted face, form large helical structures providing strong unsteady phenomena in the wake. Mean velocity fields and turbulence statistics show a global agreement with the reference experiments of Lienhart et al. (DGLR Fach Symposium der AG SRAB, Stuttgart University, 15-17 November 2000). In order to provide a deeper insight into the nature of turbulence, the flow is analyzed using power spectra and the invariant theory of turbulence of Lumley [Adv. Appl. Mech. 18, 123 (1978)].

  2. ACIGA's high optical power test facility

    Energy Technology Data Exchange (ETDEWEB)

    Ju, L [School of Physics, University of Western Australia, Perth (Australia); Aoun, M [Computer and Information Science, Edith Cowan University, Perth (Australia); Barriga, P [School of Physics, University of Western Australia, Perth (Australia)] [and others

    2004-03-07

    Advanced laser interferometer detectors utilizing more than 100 W of laser power and with {approx}10{sup 6} W circulating laser power present many technological problems. The Australian Consortium for Interferometric Gravitational Astronomy (ACIGA) is developing a high power research facility in Gingin, north of Perth, Western Australia, which will test techniques for the next generation interferometers. In particular it will test thermal lensing compensation and control strategies for optical cavities in which optical spring effects and parametric instabilities may present major difficulties.

  3. Effects of a whole body vibration training program on strength, power, and functional tests in the physically active elderly

    Directory of Open Access Journals (Sweden)

    Renata Gonçalves da Silva

    2009-04-01

    Full Text Available The aim of this study was to investigate the effect of a whole body vibration training program on knee extensor isokinetic peak torque, average power, and functional tests in the physically active elderly. Forty-seven subjects, who participated in a training program for the elderly, were recruited. The subjects were divided into two groups: whole body vibration group (WBV (n=24, 70.7±5.8 years, 62.7±12.3 kg and 155.9±8.0 cm and control group (n=23. 70.0±5.7 years, 65.3±10.7 kg and 157.9±6.6 cm. The WBS group underwent whole body vibration exercise and their regular training program for 13 weeks, 2 times per week, whereas the control group performed the regular training program only. Whole body vibration training was not effective in increasing isokinetic peak torque, average power, or performance in the functional tests. On the other hand, the regular training program was effective in increasing elbow flexor strength endurance, distance covered in the 6-min walk test, and speed in the timed up and go test. The results suggest that vibration training is not effective in modifying functionality or muscle strength and power in the physically active elderly.

  4. High performance protection circuit for power electronics applications

    International Nuclear Information System (INIS)

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

  5. High performance protection circuit for power electronics applications

    Science.gov (United States)

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

    2015-12-01

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

  6. A New Transformer for High Voltage Charging Power Supply

    Directory of Open Access Journals (Sweden)

    Jianming Liu

    2013-09-01

    Full Text Available In this paper, the authers present a new high-frequency transformer for high-voltage capacitor charging power supply. They also establish a new topology structure and the charging control strategy for the charging power supply. The effects of leakage inductance and distributed capacitance by using the soft switching in the transformer were then analyzed. Finally, the different leakage inductances in the two transformers were tested. The results of the above study provide a theoratical basis for the application of the new high frequency transformer in pulsed power supply.  

  7. High performance protection circuit for power electronics applications

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-12-23

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

  8. Cryogenic cooling for high power laser amplifiers

    International Nuclear Information System (INIS)

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

  9. Cryogenic cooling for high power laser amplifiers

    Science.gov (United States)

    Perin, J. P.; Millet, F.; Divoky, M.; Rus, B.

    2013-11-01

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

  10. Cryogenic cooling for high power laser amplifiers

    Directory of Open Access Journals (Sweden)

    Perin J.P.

    2013-11-01

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

  11. Repetitive high energy pulsed power technology development for industrial applications

    International Nuclear Information System (INIS)

    The technology base for Repetitive High Energy Pulsed Power (RHEPP) was originally developed to support defense program applications. As RHEPP technology matures, its potential for use in commercial applications can be explored based on inherent strengths of high average power, high dose rate, cost efficient scaling with power, and potential for long life performance. The 300 kW, 2 MeV RHEPP II accelerator is now in operation as a designated DOE User Facility, exploring applications where high dose-rate (> 108 Gy/s) may be advantageous, or very high average power is needed to meet throughput requirements. Material surface and bulk property modification, food safety, and large-scale timber disinfestation are applications presently under development. Work is also in progress to generate the reliability database required for the design of 2nd generation systems

  12. High-power generator of singlet oxygen

    Czech Academy of Sciences Publication Activity Database

    Jirásek, Vít; Čenský, Miroslav; Špalek, Otomar; Kodymová, Jarmila

    2013-01-01

    Roč. 36, č. 10 (2013), s. 1755-1763. ISSN 0930-7516 Grant ostatní: Laser Science and Technology Centre(IN) LASTEC/FE/RKT/54/10-11 Institutional research plan: CEZ:AV0Z10100523 Keywords : high-pressure singlet oxygen generator * spray generator * centrifugal separation Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.175, year: 2013

  13. Dry Dilution Refrigerator with High Cooling Power

    Science.gov (United States)

    Uhlig, K.

    2008-03-01

    We present the construction concept and cooling capacity measurements of a 3,4He dilution refrigerator (DR), which was pre-cooled by a commercial pulse tube refrigerator (PTR). No cryogens are needed for the operation of this type of cryostat. The condensation of the helium mash was done in an integrated Joule-Thomson circuit, which was part of the dilution unit. The composition of the dilution unit was standard, but its components (still, heat exchangers, mixing chamber) were designed for high 3He flow. For thermometry, calibrated RuO chip resistance thermometers were available. In order to condense the mixture before an experiment, the fridge was operated like a Joule-Thomson liquefier with a relatively high inlet pressure (4 bar), where the liquid fraction of the circulating 3,4He mixture was accumulated in the dilution unit. The condensation took about 2 hours, and after 2 more hours of running, the temperature of the mixing chamber approached its minimum temperature of 10 mK. The maximum flow rate of the fridge was 1 mmol/s, and the refrigeration capacity of the mixing chamber was 700 μW at 100 mK. High cooling capacity, ease of operation and reliability distinguish this type of milli-Kelvin cooler.

  14. MGX: a high-power, pulsed microwave generator development project

    Energy Technology Data Exchange (ETDEWEB)

    Scarpetti, R.; Vogtlin, G.; Lundberg, R.; Burkhart, S.; Hofer, W.

    1983-06-03

    A high-power, short-pulse microwave source, MGX, is being developed at Lawrence Livermore National Laboratory. It will be used for high-power microwave vulnerability and lethality studies, investigation of air breakdown, and high-power microwave diagnostic development. The microwave source, a virtual cathode oscillator (VIRCATOR), is initially designed to operate at 8 GHz, with an output power greater than 1 GW, and 70 ns pulse width. The pulsed power source is a modified one-unit FXR Blumlein system charged to approximately 650 kV. A new insulator and electron-beam diode have been designed. In addition, a water-breakdown gap has been included to suppress diode prepulse and to sharpen the pulse rise time. The VIRCATOR has been extensively modeled with the MASK code at LLNL. Preliminary results are presented.

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

    International Nuclear Information System (INIS)

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

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

    CERN Document Server

    Wake, M; Suda, K

    2002-01-01

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

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

    DEFF Research Database (Denmark)

    Tarnowski, Germán Claudio

    particular views. These models were developed and verified during this work, basedaround a particular manufacturer’s wind turbine and on said isolated power system withwind power. The capability of variable speed wind turbines for providing Inertial Response is analysed. To perform this assessment, a control...... stability and high wind power penetration or in islanding situations are addressed. The review of relevant theoretical concepts is supported by measurements carried out on an isolated power system characterized by high wind power penetration. Different mathematical and simulation models are used in several...... between the developed control systems and the conventional plants responses is studied. A methodology for determiningthe necessary wind power reserve and control parameters such as frequency response characteristic (droop) and deadband is presented. The performance and the capability for supporting the...

  18. Proceedings of the meeting on few-body problems in high and medium energy physics

    International Nuclear Information System (INIS)

    The study meeting on few-body problems in high and medium energy physics was held from October 3 to 5, 1985, at National Laboratory for High Energy Physics. Two meetings were held already concerning few body physics, but most of the participants were theorists. In this meeting, high priority was put on the attendance of experimental physicists. As a bridge between particle and nuclear physics, the few body physics in an intermediate energy region has become important recently. The topics in this meeting were meson spectroscopy, baryonium, kaon physics, muonic fusion, dibaryon, φNN system, quarks and skyrmions, NN correlation, and symmetry test in few-body system. The gists of the papers presented are collected in this book. (Kako, I.)

  19. Body water metabolism in high altitude natives during and after a stay at sea level

    Science.gov (United States)

    Jain, S. C.; Bardhan, Jaya; Swamy, Y. V.; Grover, A.; Nayar, H. S.

    1981-03-01

    Body fluid compartments were studied in a group of high altitude natives after a stay of two months at sea level and during 12 days at an altitude of 3,500 m. Measurements of total body water and extracellular water were made on day 3 and 12 of reinduction to altitude, while plasma volume was measured on day 12 only. The intracellular water, blood volume and red cell mass were computed from the above parameters. Total body water and intracellular water decreased by 3.3% (Paltitude and did not change thereafter. Extracellular water increased progressively at altitude, but the increase was not significant. Blood volume and red cell mass increased significantly while plasma volume decreased at altitude. These data were compared with that of low landers. This study suggested body hypohydration on high altitude induction in low landers as well as in high altitude natives on reinduction.

  20. High power cooled mini-DIL pump lasers

    Science.gov (United States)

    Liang, Bo; Zayer, Nadhum; Chen, Bob; He, Dylan; Pliska, Tomas

    2009-11-01

    The miniature dual-inline (mini-DIL) pump laser becomes more attactive for compact optical amplifiers designs due to the advantage of smaller footprint, lower power consumption and lower cost. In this paper we report the development of a new generation of small form factor, high power "cooled" mini-DIL 980-nm pump lasers module for compact EDFA application.

  1. High Power RF Transmitters for ICRF Applications on EAST

    Science.gov (United States)

    Mao, Yuzhou; Yuan, Shuai; Zhao, Yanping; Zhang, Xinjun; Chen, Gen; Kumazawa, R.; Cheng, Yan; Wang, Lei; Ju, Songqing; Deng, Xu; Qin, Chengming; Yang, Lei

    2013-03-01

    An Ion Cyclotron Range of Frequency (ICRF) system with a radio frequency (RF) power of 4 × 1.5 MW was developed for the Experimental Advanced Superconducting Tokamak (EAST). High RF power transmitters were designed as a part of the research and development (R&D) for an ICRF system with long pulse operation at megawatt levels in a frequency range of 25 MHz to 70 MHz. Studies presented in this paper cover the following parts of the high power transmitter: the three staged high power amplifier, which is composed of a 5 kW wideband solid state amplifier, a 100 kW tetrode drive stage amplifier and a 1.5 MW tetrode final stage amplifier, and the DC high voltage power supply (HVPS). Based on engineering design and static examinations, the RF transmitters were tested using a matched dummy load where an RF output power of 1.5 MW was achieved. The transmitters provide 6 MW RF power in primary phase and will reach a level up to 12 MW after a later upgrade. The transmitters performed successfully in stable operations in EAST and HT-7 devices. Up to 1.8 MW of RF power was injected into plasmas in EAST ICRF heating experiments during the 2010 autumn campaign and plasma performance was greatly improved.

  2. High Power RF Transmitters for ICRF Applications on EAST

    International Nuclear Information System (INIS)

    An Ion Cyclotron Range of Frequency (ICRF) system with a radio frequency (RF) power of 4 × 1.5 MW was developed for the Experimental Advanced Superconducting Tokamak (EAST). High RF power transmitters were designed as a part of the research and development (R and D) for an ICRF system with long pulse operation at megawatt levels in a frequency range of 25 MHz to 70 MHz. Studies presented in this paper cover the following parts of the high power transmitter: the three staged high power amplifier, which is composed of a 5 kW wideband solid state amplifier, a 100 kW tetrode drive stage amplifier and a 1.5 MW tetrode final stage amplifier, and the DC high voltage power supply (HVPS). Based on engineering design and static examinations, the RF transmitters were tested using a matched dummy load where an RF output power of 1.5 MW was achieved. The transmitters provide 6 MW RF power in primary phase and will reach a level up to 12 MW after a later upgrade. The transmitters performed successfully in stable operations in EAST and HT-7 devices. Up to 1.8 MW of RF power was injected into plasmas in EAST ICRF heating experiments during the 2010 autumn campaign and plasma performance was greatly improved.

  3. Amplified spontaneous emission pulses for high-power supercontinuum generation

    Directory of Open Access Journals (Sweden)

    Huan Huan Liu

    2016-03-01

    Full Text Available The authors demonstrate an incoherent light source based on a reflective semiconductor optical amplifier as pump for high-power supercontinuum generation for the first time. The obtained power level is about 160 mW and 20 dB spectral bandwidth is around 170 nm.

  4. Electron accleration using high power laser

    Science.gov (United States)

    Najmudin, Zulfikar

    1998-04-01

    The 30 TW Nd:Glass Vulcan laser has been used to extensively study the Forward Raman Scatter instability in plasmas. This instability is of interest since it produces large amplitude relativistic plasma waves, which can trap and accelerate plasma electrons to high energies. Recently we have accelerated particles up to 100 MeV with this process. This is beyond the expected classical dephasing energy, for the plasma waves in our experiment which have a Lorentz factor γ ≈ 7. The greater acceleration has been attributed to the dynamics of the beam loading process of the plasma waves due to wavebreaking. By imaging the small angle Thomson scattered light from an orthogonally injected probe beam, we observe the dimensions of the accelerating plasma wave. It is seen that electron energies are almost independent of the length of the plasma wave. This is because the dephasing length is of the order of the Rayleigh length (≈ 100 μm). However the plasma wave is seen to extend to lengths as great as 3.5 mm. This is indicative of a high intensity being present throughout the length of the gas jet used, and indicates the presence of channelling of the laser beam. However the unstable nature of FRS, means that it is unsuitable for next generation high energy particle acclerators. For this we require much more controllable acceleration over greater distances. This can be achieved with the laser wakefield accelerator. For this purpose we have also been performing experiments at the LULI short pulse facility at Ecole Polytechnique. In these experiments we have been able to accelerate large numbers of injected electrons at 3 MeV to 4 MeV and above, after carefully taking into consideration sources of noise.

  5. Cryogenic cooling for high power laser amplifiers

    OpenAIRE

    Perin J.P.; Millet F.; Divoky M.; Rus B.

    2013-01-01

    Using DPSSL (Diode Pumped Solid State Lasers) as pumping technology, PW-class lasers with enhanced repetition rates are developed. Each of the Yb YAG amplifiers will be diode-pumped at a wavelength of 940 nm. This is a prerequisite for achieving high repetition rates (light amplification duration 1 millisecond and repetition rate 10 Hz). The efficiency of DPSSL is inversely proportional to the temperature, for this reason the slab amplifier have to be cooled at a temperature in the range of 1...

  6. Development of high voltage power supply for nuclear radiation detectors

    International Nuclear Information System (INIS)

    The purpose of this thesis is to develop a versatile NIM compatible high voltage power supply for proper operation of nuclear radiation detectors especially for those high resolution detectors such as semiconductor detectors, and proportional counters which require high voltage power supply with very low output ripple and high output stability. A driven type dc-ac inverter and a voltage multiplier are applied to convert a low de voltage to high dc voltage. The filter circuit is used to reduce the output ripple when the power supply is loaded and a close-loop voltage control circuit is used to minimize the drift in the output voltage. Adjustment of the output level for desired value is done through a three turn high precision potentiometer. Besides, micro-circuits are used in order to reduce undesirable temperature effect and at the same time to minimize size and weight of the high voltage module

  7. High-power arrays of quantum cascade laser master-oscillator power-amplifiers.

    Science.gov (United States)

    Rauter, Patrick; Menzel, Stefan; Goyal, Anish K; Wang, Christine A; Sanchez, Antonio; Turner, George; Capasso, Federico

    2013-02-25

    We report on multi-wavelength arrays of master-oscillator power-amplifier quantum cascade lasers operating at wavelengths between 9.2 and 9.8 μm. All elements of the high-performance array feature longitudinal (spectral) as well as transverse single-mode emission at peak powers between 2.7 and 10 W at room temperature. The performance of two arrays that are based on different seed-section designs is thoroughly studied and compared. High output power and excellent beam quality render the arrays highly suitable for stand-off spectroscopy applications. PMID:23481985

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

    Science.gov (United States)

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

    2015-01-01

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

  9. Multi-mode multi-band power amplifier module with high low-power efficiency

    Science.gov (United States)

    Xuguang, Zhang; Jie, Jin

    2015-10-01

    Increasingly, mobile communications standards require high power efficiency and low currents in the low power mode. This paper proposes a fully-integrated multi-mode and multi-band power amplifier module (PAM) to meet these requirements. A dual-path PAM is designed for high-power mode (HPM), medium-power mode (MPM), and low-power mode (LPM) operations without any series switches for different mode selection. Good performance and significant current saving can be achieved by using an optimized load impedance design for each power mode. The PAM is tapeout with the InGaP/GaAs heterojunction bipolar transistor (HBT) process and the 0.18-μm complementary metal-oxide semiconductor (CMOS) process. The test results show that the PAM achieves a very low quiescent current of 3 mA in LPM. Meanwhile, across the 1.7-2.0 GHz frequency, the PAM performs well. In HPM, the output power is 28 dBm with at least 39.4% PAE and -40 dBc adjacent channel leakage ratio 1 (ACLR1). In MPM, the output power is 17 dBm, with at least 21.3% PAE and -43 dBc ACLR1. In LPM, the output power is 8 dBm, with at least 18.2% PAE and -40 dBc ACLR1. Project supported by the National Natural Science Foundation of China (No. 61201244).

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

    Science.gov (United States)

    Schwarze, Gene E.

    1994-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  12. Calorimetric Measuring Systems for Characterizing High Frequency Power Losses in Power Electronic Components and Systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Pedersen, John Kim; Ritchie, Andrew Ewen

    2002-01-01

    High frequency power losses in power electronic components and systems are very difficult to measure. The same applies to the efficiency of high-efficiency systems and components. An important method to measure losses with high accuracy is the calorimetric measuring systems. This paper describes...... two different calorimetric measuring systems, one for power losses up to 50 W and one for power losses up to 1500 W. These differ in size and also the systems which can be analysed. The basic concept of calorimetry is discussed and the overall performance of the two systems is specified. Methods to...... calibrate such systems are proposed and different applications of the system are given. Two practical examples end the description of the research. It is concluded that such systems have a relative long time-constant but they are accurate and useful for precise power loss measurement....

  13. Design of high power feedthrough for High Power Industrial Accelerator (HPIA)

    International Nuclear Information System (INIS)

    This paper reports the design, assembly and dismantling and maintenance of a feedthrough for High Power Industrial Accelerator (HPIA). It has been designed to serve three purposes. It provides electrical insulation between primary windings (at ∼ 2.5 kV) and cover flange (at ground potential) with the help of Nylon bushes. It also ensures leak tightness for SF6 gas filled inside the vessel at 10 bar. It also provides sealing for water connectors between the primary winding and secondary winding. The key function of this feedthrough is to supply ∼ 800 A of current to the primary circuit. Technical requirement/constraint is leak tightness and electrical isolation of feedthrough. This feedthrough will be connected to the primary windings inside the vessel. Current will flow through a copper tube conductor which is at a potential of ∼ 800 V. Inside the tube water is flowing. Inlet water temperature is ∼ 30℃. Flow rate of water is 35 litres/minute at 6 kg/cm2 pressure to remove the heat losses. (author)

  14. High Power Local Oscillator Sources for 1-2 THz

    Science.gov (United States)

    Mehdi, Imran; Thomas, Bertrand; Lin, Robert; Maestrini, Alain; Ward, John; Schlecht, Erich; Gill, John; Lee, Choonsup; Chattopadhyay, Goutam; Maiwald, Frank

    2010-01-01

    Recent results from the Heterodyne Instrument for Far-Infrared (HIFI) on the Herschel Space Telescope have confirmed the usefulness of high resolution spectroscopic data for a better understanding of our Universe. This paper will explore the current status of tunable local oscillator sources beyond HIFI and provide demonstration of how power combining of GaAs Schottky diodes can be used to increase both power and upper operating frequency for heterodyne receivers. Availability of power levels greater than 1 watt in the W-band now makes it possible to design a 1900 GHz source with more than 100 microwatts of expected output power.

  15. Primary reserve studies for high wind power penetrated systems

    DEFF Research Database (Denmark)

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

    2015-01-01

    With high penetration of non-synchronous wind generations replacing conventional generators, the inertia of power system will reduce. A large disturbance in such a power system can cause faster frequency change in this power system and might invoke emergency defence strategies like underfrequency...... load shedding. The impact of low inertia caused due to displacement of conventional generators by wind penetration on the power system frequency is investigated in this paper. The possibilities of improving frequency with increase in primary reserve supplied from conventional generators are analyzed...

  16. The Quest for Ultimate Broadband High Power Microwaves

    CERN Document Server

    Podgorski, Andrew S

    2014-01-01

    Paper describes High Power Microwave research of combining GW peak power to achieve MV/m and GV/m radiated fields in 1 to 500 GHz band. To achieve such fields multiple independently triggered broadband GW sources, supplying power to multiple spatially distributed broadband radiators/antennas are used. Single TW array is used as an ultimate microwave weapon in 1 to 5 GHz range while multiple TW arrays provide GV/m radiating field at plasma frequencies in 300 GHz range leading to fusion power.

  17. High power microwave sources; Generateur microondes de grande puissance

    Energy Technology Data Exchange (ETDEWEB)

    Angles, M. [CEA Cesta, 33 - Bordeaux (France)

    1998-03-01

    High power microwaves have known a great expansion with intense relativistic electron beams. CEA-CESTA evolved several HPM sources on electron beam generator CESAR, as the planar VIRCATOR, the REDITRON and the coaxial VIRCATOR. We obtained microwave frequencies located between 2 and 8 GHz with power of some hundreds until 1 gigawatt. Several measurements have been improved to qualify these sources: frequency, power density, energy, wave polarization, modes visualization. A hollow beam generator, relativistic klystron electric source, has also been built to improve a recurrent system and obtain gigawatt microwave power. (author) 7 refs.

  18. High and low voltage power supply

    International Nuclear Information System (INIS)

    A converter is designed to convert 2 bateries input voltage of 1.5 volt each, to obtain the desired dc output voltage to perform a low voltage of 10 volt, 3mA and a high voltage of 600 volt, 20 A. The L.V. of 10 volt is operated to provide some transistor bias voltages, to a preamplifier and a discriminator, and the H.V. of 600 volt supply a GM tube (type 18555) bias voltage. The converter comprise of a blocking oscillator, a transformer, a double ended clipper, a rectifier and a filter. The waveform of the ac voltage to be generated in the blocking oscillator is square wave approximately. The 2N 2907-type transistor as a blocking oscillator operates in the linear region. The saturation region of the 58T3-type ferrite transformer never been reached. Even the efficiency is rather low; the bat-tery life can reach 25 hours approximately. (author)

  19. High-power lasers for directed-energy applications.

    Science.gov (United States)

    Sprangle, Phillip; Hafizi, Bahman; Ting, Antonio; Fischer, Richard

    2015-11-01

    In this article, we review and discuss the research programs at the Naval Research Laboratory (NRL) on high-power lasers for directed-energy (DE) applications in the atmosphere. Physical processes affecting propagation include absorption/scattering, turbulence, and thermal blooming. The power levels needed for DE applications require combining a number of lasers. In atmospheric turbulence, there is a maximum intensity that can be placed on a target that is independent of the initial beam spot size and laser beam quality. By combining a number of kW-class fiber lasers, scientists at the NRL have successfully demonstrated high-power laser propagation in a turbulent atmosphere and wireless recharging. In the NRL experiments, four incoherently combined fiber lasers having a total power of 5 kW were propagated to a target 3.2 km away. These successful high-power experiments in a realistic atmosphere formed the basis of the Navy's Laser Weapon System. We compare the propagation characteristics of coherently and incoherently combined beams without adaptive optics. There is little difference in the energy on target between coherently and incoherently combined laser beams for multi-km propagation ranges and moderate to high levels of turbulence. Unlike incoherent combining, coherent combining places severe constraints on the individual lasers. These include the requirement of narrow power spectral linewidths in order to have long coherence times as well as polarization alignment of all the lasers. These requirements are extremely difficult for high-power lasers. PMID:26560609

  20. Atmospheric propagation and combining of high-power lasers.

    Science.gov (United States)

    Nelson, W; Sprangle, P; Davis, C C

    2016-03-01

    In this paper, we analyze beam combining and atmospheric propagation of high-power lasers for directed-energy (DE) applications. The large linewidths inherent in high-power fiber and slab lasers cause random phase and intensity fluctuations that occur on subnanosecond time scales. Coherently combining these high-power lasers would involve instruments capable of precise phase control and operation at rates greater than ∼10  GHz. To the best of our knowledge, this technology does not currently exist. This presents a challenging problem when attempting to phase lock high-power lasers that is not encountered when phase locking low-power lasers, for example, at milliwatt power levels. Regardless, we demonstrate that even if instruments are developed that can precisely control the phase of high-power lasers, coherent combining is problematic for DE applications. The dephasing effects of atmospheric turbulence typically encountered in DE applications will degrade the coherent properties of the beam before it reaches the target. Through simulations, we find that coherent beam combining in moderate turbulence and over multikilometer propagation distances has little advantage over incoherent combining. Additionally, in cases of strong turbulence and multikilometer propagation ranges, we find nearly indistinguishable intensity profiles and virtually no difference in the energy on the target between coherently and incoherently combined laser beams. Consequently, we find that coherent beam combining at the transmitter plane is ineffective under typical atmospheric conditions. PMID:26974640

  1. High Power Room Temperature Terahertz Local Oscillator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to build a high-power, room temperature compact continuous wave terahertz local oscillator for driving heterodyne receivers in the 1-5 THz frequency...

  2. High Power Room Temperature Terahertz Local Oscillator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The motivation of the proposed SBIR is to develop, demonstrate and commercialize a compact, low-mass, high output power (1-10 milliwatt), tunable source of CW THz...

  3. High Power Uplink Amplifier for Deep Space Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Critical to the success of delivering on the promise of deep space optical communications is the creation of a stable and reliable high power multichannel optical...

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

    International Nuclear Information System (INIS)

    Reactors based on direct cooled HTGR type particle fuel are described. The small diameter particle fuel is packed between concentric porous cylinders to make annular fuel elements, with the inlet coolant gas flowing inwards. Hot exit gas flows out long the central channel of each element. Because of the very large heat transfer area in the packed beds, power densities in particle bed reactors (PBR's) are extremely high resulting in compact, lightweight systems. Coolant exit temperatures are high, because of the ceramic fuel temperature capabilities, and the reactors can be ramped to full power and temperature very rapidly. PBR systems can generate very high burst power levels using open cycle hydrogen coolant, or high continuous powers using closed cycle helium coolant. PBR technology is described and development requirements assessed. 12 figs

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

    CERN Document Server

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

    2014-01-01

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

  6. Does whole-body cryotherapy improve vertical jump recovery following a high-intensity exercise bout?

    Science.gov (United States)

    Vieira, Amilton; Bottaro, Martim; Ferreira-Junior, Joao B; Vieira, Carlos; Cleto, Vitor A; Cadore, Eduardo L; Simões, Herbert G; Carmo, Jake Do; Brown, Lee E

    2015-01-01

    Whole-body cryotherapy (WBC) has been used as a recovery strategy following different sports activities. Thus, the aim of the study reported here was to examine the effect of WBC on vertical jump recovery following a high-intensity exercise (HIE) bout. Twelve trained men (mean ± standard deviation age = 23.9±5.9 years) were randomly exposed to two different conditions separated by 7 days: 1) WBC (3 minutes of WBC at -110°C immediately after the HIE) and 2) control (CON; no WBC after the HIE). The HIE consisted of six sets of ten repetitions of knee extensions at 60° · s(-1) concentric and 180° · s(-1) eccentric on an isokinetic dynamometer. The vertical jump test was used to evaluate the influence of HIE on lower extremity muscular performance. The vertical jump was performed on a force platform before HIE (T1) and 30 minutes after (T2) the WBC and CON conditions. As a result of HIE, jump height, muscle power, and maximal velocity (Vmax) had significant decreases between T1 and T2, however no significance was found between the WBC and CON conditions. The results indicate that one session of WBC had no effect on vertical jump following an HIE compared with a CON condition. WBC may not improve muscle-function (dependent on stretch-shortening cycle) recovery in very short periods (ie, 30 minutes) following HIE. PMID:25750548

  7. Enhancing Plasma Surface Modification using high Intensity and high Power Ultrasonic Acoustic Waves

    DEFF Research Database (Denmark)

    2010-01-01

    high intensity and high power acoustic waves (102) by at least one ultrasonic high intensity and high power acoustic wave generator (101 ), wherein the ultrasonic acoustic waves are directed to propagate towards said surface (314) of the object (100) so that a laminar boundary layer (313) of a gas or a...

  8. A double-band high-power microwave source

    Science.gov (United States)

    Fan, Yu-Wei; Zhong, Hui-Huang; Li, Zhi-Qiang; Shu, Ting; Zhang, Jian-De; Zhang, Jun; Zhang, Xiao-Ping; Yang, Jian-Hua; Luo, Ling

    2007-11-01

    In order to increase the power conversion efficiency of a magnetically insulated line oscillator (MILO), an axially extracted virtual cathode oscillator (VCO) is introduced to utilize the load current in the MILO, so it is called the MILO-VCO. In this device, the MILO and VCO are operated synchronously and generate high-power microwaves. The MILO-VCO is investigated in detail with particle-in-cell (PIC) methods (KARAT code). In simulation, the diode voltage is 640 kV and the current is 50 kA. The total peak power of the MILO-VCO is 5.22 GW and the corresponding power conversion efficiency is 16.3%. In the MILO-VCO, the peak power of the MILO is 3.91 GW and its frequency is 1.76 GHz; the peak power of the VCO is 1.33 GW and its frequency is 3.79 GHz.

  9. Efficient development of highly linear MMIC power amplifiers

    OpenAIRE

    Bignamini, M.; Favre, G.; Meazza, A.; Pagani, M.; Palomba, F.; Sivverini, G.

    2001-01-01

    Highly linear power amplifiers are key components of high capacity radio transmitters. This paper describes the complete procedure we established to develop a family of new MMIC power amplifiers aimed at achieving state-of-the-art performance as needed for a new M-QAM microwave radio. A cost effective approach dedicated to volume production has been addressed. The most important experimental characteristics for each of the developed MMIC PAs are also reported in order to demostrate the effect...

  10. Advanced waveguides for high power optical fibre sources

    OpenAIRE

    Soh, Daniel Beom Soo

    2005-01-01

    This thesis reports on theoretical and experimental studies of wavelength-selective waveguide structures for high-power Nd3+- and Yb3+-doped fibre lasers. Cladding-pumped high-power fibre lasers based on these novel waveguide designs and operating at desired unconventional wavelengths were investigated through numerical simulations and fibre laser experiments. Rare earth doped fibres have typically multiple emission bands of different effective strengths. Stimulate emission from strong ba...

  11. Fast-Recovery, High-Voltage Power Diode

    Science.gov (United States)

    Sundberg, G.; Berman, A.; Balodis, V.; Gaugh, C.; Duffin, J.; Karatnicki, H.; Larson, E.

    1985-01-01

    New family of fast-recovery high-voltage power diodes compatible with D60T and D7ST transistors developed. Have wide range of applications in spacecraft and aircraft electrical distribution equipment, dc/dc inverters, and ac motor controllers for high-horsepower electric motors operating from 480-volt ac lines. Fast-Recovery 1,200-V Power Diodes use chip of hexagonal geometry to maximize effective silicon area.

  12. A New Transformer for High Voltage Charging Power Supply

    OpenAIRE

    Jianming Liu; Meng Wang; Fucai Liu

    2013-01-01

    In this paper, the authers present a new high-frequency transformer for high-voltage capacitor charging power supply. They also establish a new topology structure and the charging control strategy for the charging power supply. The effects of leakage inductance and distributed capacitance by using the soft switching in the transformer were then analyzed. Finally, the different leakage inductances in the two transformers were tested. The results of the above study provide a theoratical basis f...

  13. Development of a high power NPC inverter

    International Nuclear Information System (INIS)

    It has been widely reported that the Common-Mode-Current disturbs a stable operation in various accelerator complex. The reason why we have such an undesired noise current is that, in an inverter circuit, the potential of neutral point will be fluctuated between high-voltage to ground-potential during each switching modes. In the Neutral-Point-Clamped (NPC) inverters, on the other hands, the neutral point of output terminals can be always clamped to the ground-potential if we chose a proper switching algorism. So that no voltage will be applied across the neutral-point and the ground potential. This is the reason why we have initiated a development of the NPC inverter to apply it into the accelerator complex. In an inverter circuit, undesirable surge voltage will be applied during its switching period. This surge voltage exceeds the maximum rating of an IGBT in worst case. Moreover, the surge voltage will increase the switching loss in devices. It is important to reduce this surge voltage to secure a stable operation of the inverter circuit. Details of our approach to minimize the surge voltage and the operational results of a developed NPC inverter are reviewed in this article. (author)

  14. High Performance Plasma Channel Insulators for High Power Hall Thrusters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA missions for planetary exploration require high power, long-life Hall thrusters. However, thruster power and lifetime are limited by the erosion of plasma...

  15. High Efficiency, High Temperature Foam Core Heat Exchanger for Fission Surface Power Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Fission-based power systems are anticipated for various planetary surface human base applications with power levels of 30?100+ kWe. The development of high...

  16. Investigation of a High-Power, High-Pressure Spark Gap Switch with High Repetition Rate

    OpenAIRE

    Rahaman, Hasibur

    2007-01-01

    Micro plasmas in a pressurized spark gap switch were under investigation in the present dissertation. In contrast to the requirements of commonly used high power switches, this work was focused on investigations of a high repetition rate and simultaneously maintaining a fast switching time at a low energy transfer per pulse. The spark gap was operating in a free running mode, without any triggering. The breakdown was only initiated by overvoltage. For this particular switch, a theoretical cha...

  17. High Power High Thrust Ion Thruster (HPHTion): 50 CM Ion Thruster for Near-Earth Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advances in high power, photovoltaic technology has enabled the possibility of reasonably sized, high specific power, high power, solar arrays. At high specific...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-05-23

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

  19. Establishment of high ground power supply center at Onagawa Nuclear Power Station

    International Nuclear Information System (INIS)

    A large earthquake occurred on March 11, 2011 and tsunami was generated following it. The East Japan suffered serious damage by the earthquake and tsunami. This is called the Great East Japan Earthquake. Onagawa Nuclear Power Station (NPS) is located closest to the epicenter of Great East Japan Earthquake. We experienced intense shake by the earthquake and some flooding from the tsunami, however, we have succeeded safely cold shutdown of the reactors. In this paper, we introduce the reinforcement of power supply to increase reliability and power supply center with high voltage electric power supply trucks which is original treatment at Onagawa NPS. (author)

  20. Compact high voltage, high peak power, high frequency transformer for converter type modulator applications.

    Science.gov (United States)

    Reghu, T; Mandloi, V; Shrivastava, Purushottam

    2016-04-01

    The design and development of a compact high voltage, high peak power, high frequency transformer for a converter type modulator of klystron amplifiers is presented. The transformer has been designed to operate at a frequency of 20 kHz and at a flux swing of ±0.6 T. Iron (Fe) based nanocrystalline material has been selected as a core for the construction of the transformer. The transformer employs a specially designed solid Teflon bobbin having 120 kV insulation for winding the high voltage secondary windings. The flux swing of the core has been experimentally found by plotting the hysteresis loop at actual operating conditions. Based on the design, a prototype transformer has been built which is per se a unique combination of high voltage, high frequency, and peak power specifications. The transformer was able to provide 58 kV (pk-pk) at the secondary with a peak power handling capability of 700 kVA. The transformation ratio was 1:17. The performance of the transformer is also presented and discussed. PMID:27131709

  1. Compact high voltage, high peak power, high frequency transformer for converter type modulator applications

    Science.gov (United States)

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

    2016-04-01

    The design and development of a compact high voltage, high peak power, high frequency transformer for a converter type modulator of klystron amplifiers is presented. The transformer has been designed to operate at a frequency of 20 kHz and at a flux swing of ±0.6 T. Iron (Fe) based nanocrystalline material has been selected as a core for the construction of the transformer. The transformer employs a specially designed solid Teflon bobbin having 120 kV insulation for winding the high voltage secondary windings. The flux swing of the core has been experimentally found by plotting the hysteresis loop at actual operating conditions. Based on the design, a prototype transformer has been built which is per se a unique combination of high voltage, high frequency, and peak power specifications. The transformer was able to provide 58 kV (pk-pk) at the secondary with a peak power handling capability of 700 kVA. The transformation ratio was 1:17. The performance of the transformer is also presented and discussed.

  2. Automatic high power RF processing system using PLC

    International Nuclear Information System (INIS)

    We have developed the automatic control system using Programmable Logic Controller (PLC) for the high power RF processing, which is used for the C-band (5712-MHz) accelerating structure and the klystron in SPring-8 Compact SASE Source (SCSS) project. The PLC has been used in industry to have many advantages, such as reliable, compact, low-cost. In addition the PLC is recently able to communicate with the upper-layer controller through a network. We use this system for the klystron RF power test. In this paper, we will describe the configuration of the system and the detail of the high power RF processing. (author)

  3. QED effects in high-Z atoms; three-body potentials

    International Nuclear Information System (INIS)

    Electromagnetic three-body potentials were first studied by Primakoff and Holstein. Later, Chamugan and Schweber rederived these potentials and pointed out that they might be important in highly relativistic systems, however, their formulation was basically nonrelativistic. Mittleman, in a series of papers, constructed configuration space equations that included three-body potentials. His derivation started from first principles i.e. QED, and the resulting three-body potentials are more general than the Primakoff-Holstein potentials. In this thesis the contribution to the binding energy of a simple high-Z ion from the three-body potentials is calculated. In addition, the nature and structure of these potentials in greater detail are studied. Some ambiguities that arise when the transition from Fock to configuration space is made are studied in detail

  4. Practical investigation of the gate bias effect on the reverse recovery behavior of the body diode in power MOSFETs

    DEFF Research Database (Denmark)

    Lindberg-Poulsen, Kristian; Petersen, Lars Press; Ouyang, Ziwei; Andersen, Michael A. E.

    reverse recovery at high di=dt. Different bias voltages and dead times are combined, giving a loss map which makes it possible to evaluate the practical efficacy of gate bias on reducing the MOSFET body diode reverse recovery, while comparing it to the well known methods of dead time optimization. A......This work considers an alternative method of reducing the body diode reverse recovery by taking advantage of the MOSFET body effect, and applying a bias voltage to the gate before reverse recovery. A test method is presented, allowing the accurate measurement of voltage and current waveforms during...

  5. Practical investigation of the gate bias effect on the reverse recovery behavior of the body diode in power MOSFETs

    DEFF Research Database (Denmark)

    Lindberg-Poulsen, Kristian; Petersen, Lars Press; Ouyang, Ziwei;

    2014-01-01

    This work considers an alternative method of reducing the body diode reverse recovery by taking advantage of the MOSFET body effect, and applying a bias voltage to the gate before reverse recovery. A test method is presented, allowing the accurate measurement of voltage and current waveforms during...... reverse recovery at high di=dt. Different bias voltages and dead times are combined, giving a loss map which makes it possible to evaluate the practical efficacy of gate bias on reducing the MOSFET body diode reverse recovery, while comparing it to the well known methods of dead time optimization. A...

  6. Design of 1 MHz solid state high frequency power supply

    International Nuclear Information System (INIS)

    A High Voltage High Frequency (HVHF) Power supply is used for various applications, like AM Transmitters, metallurgical applications, Wireless Power Transfer, RF Ion Sources, etc. The Ion Source for a Neutral beam Injector at ITER-India uses inductively coupled power source at High Frequency (∼ 1 MHz). Switching converter based topology used to generate 1 MHz sinusoidal output is expected to have advantages on efficiency and reliability as compared to traditional RF Tetrode tubes based oscillators. In terms of Power Electronics, thermal and power coupling issues are major challenges at such a high frequency. A conceptual design for a 200 kW, 1 MHz power supply and a prototype design for a 600W source been done. The prototype design is attempted with Class-E amplifier topology where a MOSFET is switched resonantly. The prototype uses two low power modules and a ferrite combiner to add the voltage and power at the output. Subsequently solution with class-D H-Bridge configuration have been evaluated through simulation where module design is stable as switching device do not participate in resonance, further switching device voltage rating is substantially reduced. The rating of the modules is essentially driven by the maximum power handling capacity of the MOSFETs and ferrites in the combiner circuit. The output passive network including resonance tuned network and impedance matching network caters for soft switching and matches the load impedance to 50 ohm respectively. This paper describes the conceptual design of a 200 kW power supply and experimental results of the prototype 600 W, 1 MHz source. (author)

  7. Using a Balun Transformer Combiner for High Power RF Experiments

    Science.gov (United States)

    Kaufman, M. C.; Pesavento, P. V.

    2011-10-01

    A novel coaxial power combiner design has been duplicated that has distinct advantages over other combiner geometries that can handle high power. This design is being applied to combine four 3 kW power supplies to obtain a 12 kW, 5 MHz system for an ICRF antenna on HSX. In the past, Wilkinson type combiners have had limited application to high power systems because of the lack of non-inductive, high power, 100 Ω balance loads. With this new design, standard 50 Ω dummy loads can be used instead for the balance load. The cost is considerably lower than lumped element combiner designs which are dominated by capacitor costs. At such a relatively low frequency, a 3-dB quarter-wave coupled-line coupler becomes impractically long, and a conventional branch-line hybrid requires 35 Ω-line, which is commercially unavailable. The balun combiner uses less transmission line than a ring hybrid and has good bandwidth characteristics even away from its best line impedance. Theoretical calculations and modeling were performed for line impedances from 65 Ω to 75 Ω. Measurements from a low-power test device show excellent agreement with theory, and construction of the high power system is underway. Work supported by US DOE under Contract No DE-AC05-00OR22725.

  8. Analysis of replies to an IAEA questionnaire on inspection and enforcement by the regulatory body for nuclear power plants

    International Nuclear Information System (INIS)

    At a Special Session of the IAEA General Conference in September 1986, it was suggested that the IAEA could play a role in assisting Member States in the enhancement of their regulatory practices with the objective of increasing the confidence of the international community in the safety of nuclear power programmes. As the first stage of this assistance, the Agency initiated an IAEA Questionnaire on Regulatory Practices in Member States with Nuclear Power Programmes and summarized the results of an analysis of replies to the questionnaire, issued as IAEA-TECDOC--485 (October 1988). The IAEA Questionnaire on Inspection and Enforcement by the Regulatory Body for Nuclear Power Plants, drafted by a group of consultants and IAEA staff members in August 1989, was initiated as a follow-up to the general questionnaire on regulatory practices. This questionnaire on inspection and enforcement was sent on 3 October 1989 to 31 Member States in which nuclear power plants are under construction and/or in operation. Replies to the questionnaire received from 26 Member States were analysed by IAEA staff members with the assistance of consultants in order to identify the main differences in approach and important aspects of inspection and enforcement by the regulatory body for nuclear power plants. This report is the summary report on the results of the analysis of the replies to the questionnaire from 26 Member States. 12 tabs

  9. Solid-state high voltage, DC power distribution and control

    CERN Document Server

    Gaudreau, M P J; Hawkey, T J; Kempkes, M A; Mulvaney, J M; Ver Planck, P

    1999-01-01

    Future high voltage, high power systems in the early stages of planning include U.S. large accelerator programs such as the Next Linear Collider (NLC), Spallation Neutron Source (SNS), and international systems at DESY, CERN and KEK. There are also many nuclear fusion and multi-megawatt systems proposed for construction or upgrade. Each of these programs faces the challenge of distributing and controlling the high power required by tens to hundreds of RF amplifier tubes (e.g., klystrons) cost effectively. In this paper, we present a new approach for distributing and modulating power based upon recent technological developments in high voltage, high power, solid state switching. DTI's development of fast, high voltage, opening and closing solid state switches enable, for the first time at high voltage, a nearly lossless "DC transformer". With this DC transformer (i.e., down converter or buck regulator), it is now possible to distribute unregulated high voltage DC power in a large facility, and regulate and con...

  10. Experimental approach to high power long duration neutral beams

    International Nuclear Information System (INIS)

    Experimental studies of ion sources and beam dumps for the development of a high power long duration neutral beam injector for JT-60 are presented. Long pulse operation of high power beams requires a high degree of reliability. To develop a reliable ion source with large extraction area, a new duoPIGatron ion source with a coaxially shaped intermediate electrode is proposed and tested. Magnetic configuration is examined numerically to obtain high current arc discharge and source plasma with small density variation. Experimental results show that primary electrons were fed widely from the cathode plasma region to the source plasma region and that dense uniform source plasma could be obtained easily. Source plasma characteristics are studied and comparison of these with other sources are also described. To develop extraction electrode of high power ion source, experimental studies were made on the cooling of the electrode. Long Pulse beams were extracted safely under the condition of high heat loading on the electrode. Finally, burnout study for the development of high power beam dumps is presented. Burnout data were obtained from subcooled forced-convective boiling of water in a copper finned tube irradiated by high power ion beams. The results yield simple burnout correlations which can be used for the prediction of burnout heat flux of the beam dump. (author)

  11. Numerical Modeling of Thermal Pollution of Large Water Bodies from Thermal and Nuclear Power Plants

    Science.gov (United States)

    Lyubimova, Tatyana; Lepikhin, Anatoly; Lyakhin, Yury; Parshakova, Yanina; Tiunov, Alexey

    2016-04-01

    Currently, the major manufacturers of electrical energy are the thermal and nuclear power plants including the cooling ponds in the processing chains. For a wide range of both environmental and technological problems, the evaluation of the temperature fields in the cooling ponds at certain critical values of hydrological and meteorological parameters is important. The present paper deals with the evaluation of the thermal effect of one of the largest thermal power plant in Europe - Perm GRES - to its cooling pond which is the Kama Reservoir. Since the area of the possible impact is rather large and the reservoir itself is characterized by a very complex morphometry, numerical modeling of thermal spot propagation in the Kama River due to the discharge of warm water by Perm GRES for the entire area in the 3D-formulation with the desired detail setting morphometric characteristics of the water body meets very serious difficulties. Because of that, to solve the problem, a combined scheme of calculations based on the combination of hydrodynamic models in 2D and 3D formulations was used. At the first stage of the combined scheme implementation, 2D hydrodynamical model was developed for all possible area, using software SMS v.11.1. The boundary and initial conditions for this model were formulated on the basis of calculations made using 1D hydrodynamical model developed and applied for the entire Kama Reservoir. Application of 2D hydrodynamical model for solving the problem under consideration was needed to obtain the necessary information for setting the boundary conditions for the 3D model. Software package ANSYS Fluent v.6.3 was used for the realization of 3D model. 3D modeling was performed for different wind speeds and directions and quantitative characteristics of the discharge of warm water. To verify the models, the data of the detailed field measurements in the zones of thermal pollution of the Kama reservoir due to impact of the Perm GRES were used. A

  12. Development of power measuring device of transmission type with dielectric for high power millimeter wave

    International Nuclear Information System (INIS)

    A power measuring device using a dielectric disk for a high power millimeter waves is investigated. In the device, a high power wave is transmitted in a waveguide and then heats the dielectric disk installed in the waveguide. The transmitted power is estimated from the temperature rise of the dielectric disk. It is a new type of power measurement device, which is not sensitive to higher modes and change of their polarization in time. It also can measure the wide power range of kW to MW levels flexibly by choosing dielectric material proper to the power level as a detector. In the report, materials that have small dielectric loss for millimeter waves are chosen, and their properties of temperature rise and millimeter wave power capacity are estimated. On the basis of these results, design of the power measurement device and fabrication of its prototype are described for practical use in the electron cyclotron heating systems for the JT-60U and JT-60SA. (author)

  13. On-Chip Power-Combining for High-Power Schottky Diode-Based Frequency Multipliers

    Science.gov (United States)

    Chattopadhyay, Goutam; Mehdi, Imran; Schlecht, Erich T.; Lee, Choonsup; Siles, Jose V.; Maestrini, Alain E.; Thomas, Bertrand; Jung, Cecile D.

    2013-01-01

    A 1.6-THz power-combined Schottky frequency tripler was designed to handle approximately 30 mW input power. The design of Schottky-based triplers at this frequency range is mainly constrained by the shrinkage of the waveguide dimensions with frequency and the minimum diode mesa sizes, which limits the maximum number of diodes that can be placed on the chip to no more than two. Hence, multiple-chip power-combined schemes become necessary to increase the power-handling capabilities of high-frequency multipliers. The design presented here overcomes difficulties by performing the power-combining directly on-chip. Four E-probes are located at a single input waveguide in order to equally pump four multiplying structures (featuring two diodes each). The produced output power is then recombined at the output using the same concept.

  14. Design of Instantaneous High Power Supply System with power distribution management for portable military devices

    Science.gov (United States)

    Kwak, Kiho; Kwak, Dongmin; Yoon, Joohong

    2015-08-01

    A design of an Instantaneous High Power Supply System (IHPSS) with a power distribution management (PDM) for portable military devices is newly addressed. The system includes a power board and a hybrid battery that can not only supply instantaneous high power but also maintain stable operation at critical low temperature (-30 °C). The power leakage and battery overcharge are effectively prevented by the optimal PDM. The performance of the proposed system under the required pulse loads and the operating conditions of a Korean Advanced Combat Rifle employed in the battlefield is modeled with simulations and verified experimentally. The system with the IHPSS charged the fuse setter with 1.7 times higher voltage (8.6 V) than the one without (5.4 V) under the pulse discharging rate (1 A at 0.5 duty, 1 ms) for 500 ms.

  15. Conceptual analytical production of high power fuel and high fiber protein through sensible source

    International Nuclear Information System (INIS)

    Agricultural material (corn, wheat, barley, oat, rye and molasses) was subjected to fermentation to produce high fiber protein (HFP). Ethanol produced was further processed into high power alcohol and compared its characteristic properties with that of the natural fuel. The high power alcohol was transformed into high power fueld by the interaction of potassium salts of the derivative of carbohydrates with high power alcohol. The potassium salts of carbohydrate was prepared at two stages. The derivative so produced was treated with chlorosulphonic acid in presence of potassium carbonate to produce potassium salts of the derivative of carbohydrates. (Orig./A.B.)

  16. Uppsala High Power Test Stand for ESS Spoke Cavities

    CERN Document Server

    Yogi, RA; Dancila, D; Gajewski, K; Hermansson, L; Noor, M; Wedberg, R; Santiago-Kern, R; Ekelöf, T; Lofnes, T; Ziemann, V; Goryashko, V; Ruber, R

    2013-01-01

    The European Spallation Source (ESS) is one of the world’s most powerful neutron source. The ESS linac will accelerate 50mA pulse current of protons to 2.5GeV in 2.86 ms long pulses at a repetition rate of 14 Hz. It produces a beam with 5MW average power and 125MW peak power. ESS Spoke Linac consist of 28 superconducting spoke cavities, which will be developed by IPN Orsay, France. These Spoke Cavities will be tested at low power at IPN Orsay and high power testing will be performed in a high power test stand at Uppsala University. The test stand consists of tetrode based RF amplifier chain (352MHz, 350 kW) power and related RF distribution. Outputs of two tetrodes shall be combined with the hybrid coupler to produce 350 kW power. Preamplifier for a tetrode shall be solid state amplifier. As the spoke cavities are superconducting, the test stand also includes horizontal cryostat, Helium liquefier, test bunker etc. The paper describes features of the test stand in details.

  17. High-power, electron beam-induced switching in diamond

    International Nuclear Information System (INIS)

    The authors are developing a high-voltage, high-average-power, electron beam-controlled diamond switch that could significantly impact high power solid-state electronics in industrial and defense applications. An electron beam-controlled, thin film diamond could switch, with high efficiency, well over 100 kW average power at MHz frequencies greater than 5kV. This performance is due to the excellent thermal and electronic properties of diamond, the high efficiency achieved with electron beam control, and the demonstrated effectiveness of microchannel cooling. The authors' electron beam penetration-depth measurements agree with their Monte Carlo calculations. They have not observed electron beam damage in diamond for beam energies up to 150 keV. This report describes their experimental and calculational results and research objectives

  18. The psychological mechanism of making administrative decisions in the bodies of state power.

    OpenAIRE

    Aleksandr VORONOV

    2016-01-01

    The concept of psychological mechanism as the basic category of professional activity is articulated in the article. The specifics of making administrative and government decisions in government bodies of Ukraine are characterised. The concept of psychological mechanisms of making managerial decisions is presented. The model of psychological mechanisms of making managerial decisions in government bodies is formed and described. It is shown that the model involves psychological ...

  19. High Speed Peltier Calorimeter for the Calibration of High Bandwidth Power Measurement Equipment

    CERN Document Server

    Frost, Damien F

    2015-01-01

    Accurate power measurements of electronic components operating at high frequencies are vital in determining where power losses occur in a system such as a power converter. Such power measurements must be carried out with equipment that can accurately measure real power at high frequency. We present the design of a high speed calorimeter to address this requirement, capable of reaching a steady state in less than 10 minutes. The system uses Peltier thermoelectric coolers to remove heat generated in a load resistance, and was calibrated against known real power measurements using an artificial neural network. A dead zone controller was used to achieve stable power measurements. The calibration was validated and shown to have an absolute accuracy of +/-8 mW (95% confidence interval) for measurements of real power from 0.1 to 5 W.

  20. High Efficiency, High Linearity, Switch Mode Power Amplifiers for Varying envelop Signal Applications

    DEFF Research Database (Denmark)

    Tong, Tian; Sira, Daniel; Nielsen, Michael; Mikkelsen, Jan H.; Larsen, Torben

    Transmission of big h-order modulated signals at sufficient linearity while maintaining high power efficiency is always a challenge in modern communication application. Using conventional transmitter topologies, high linearity and high efficiency are two conflicting parameters somehow. However...

  1. Advanced, High Power, Next Scale, Wave Energy Conversion Device

    Energy Technology Data Exchange (ETDEWEB)

    Mekhiche, Mike [Principal Investigator; Dufera, Hiz [Project Manager; Montagna, Deb [Business Point of Contact

    2012-10-29

    The project conducted under DOE contract DE‐EE0002649 is defined as the Advanced, High Power, Next Scale, Wave Energy Converter. The overall project is split into a seven‐stage, gated development program. The work conducted under the DOE contract is OPT Stage Gate III work and a portion of Stage Gate IV work of the seven stage product development process. The project effort includes Full Concept Design & Prototype Assembly Testing building on our existing PowerBuoy technology to deliver a device with much increased power delivery. Scaling‐up from 150kW to 500kW power generating capacity required changes in the PowerBuoy design that addressed cost reduction and mass manufacturing by implementing a Design for Manufacturing (DFM) approach. The design changes also focused on reducing PowerBuoy Installation, Operation and Maintenance (IO&M) costs which are essential to reducing the overall cost of energy. In this design, changes to the core PowerBuoy technology were implemented to increase capability and reduce both CAPEX and OPEX costs. OPT conceptually envisaged moving from a floating structure to a seabed structure. The design change from a floating structure to seabed structure would provide the implementation of stroke‐ unlimited Power Take‐Off (PTO) which has a potential to provide significant power delivery improvement and transform the wave energy industry if proven feasible.

  2. Power performance improvements for high pressure ripple energy harvesting

    International Nuclear Information System (INIS)

    A hydraulic pressure energy harvester (HPEH) device, which utilizes a housing in order to isolate a piezoelectric stack from the hydraulic fluid via a mechanical interface, generates power by converting the dynamic pressure within the system into electricity. Energy harvester prototypes were designed for generating low-power electricity from pressure ripples. These devices generate low-power electricity from off-resonance dynamic pressure excitation. The power produced per volume of piezoelectric material is analyzed to increase the power density; this is accomplished through evaluating piezoelectric stack characteristics, adding an inductor to the system circuit, and solving for optimal loading in order to achieve maximum power output. The prototype device utilizes a piezoelectric stack with high overall capacitance, which allows for inductance matching without using an active circuit. This work presents an electromechanical model and the experimental results of the HPEH devices using a parallel connection of inductive and resistive loads as the energy harvesting circuit. A non-ideal inductive load case is also considered and successfully modeled by accounting for the parasitic resistance of the inductive load. Various HPEH prototypes are fabricated, modeled, and compared in terms of their normalized power density levels, and milli-Watt level average power generation is demonstrated. The highest power density is reported for the single-crystal HPEH prototype. (paper)

  3. E-beam high voltage switching power supply

    International Nuclear Information System (INIS)

    A high power, solid state power supply is described for producing a controllable, constant high voltage output under varying and arcing loads suitable for powering an electron beam gun or other ion source. The present power supply is most useful for outputs in a range of about 100-400 kW or more. The power supply is comprised of a plurality of discrete switching type dc-dc converter modules, each comprising a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, and an output rectifier for producing a dc voltage at the output of each module. The inputs to the converter modules are fed from a common dc rectifier/filter and are linked together in parallel through decoupling networks to suppress high frequency input interactions. The outputs of the converter modules are linked together in series and connected to the input of the transmission line to the load through a decoupling and line matching network. The dc-dc converter modules are phase activated such that for n modules, each module is activated equally 360 degree/n out of phase with respect to a successive module. The phased activation of the converter modules, combined with the square current waveforms out of the step up transformers, allows the power supply to operate with greatly reduced output capacitance values which minimizes the stored energy available for discharge into an electron beam gun or the like during arcing. The present power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle using simulated voltage feedback signals and voltage feedback loops. Circuitry is also provided for sensing incipient arc currents reflected at the output of the power supply and for simultaneously decoupling the power supply circuitry from the arcing load. 7 figs

  4. A high efficiency, high power 100 GHz gyrotron

    International Nuclear Information System (INIS)

    Gyrotrons, operating at 28 GHz, 35 GHz and 60 GHz are currently producing 100-200 KW, pulsed and CW, for electron cyclotron heating experiments in magnetically-confined gaseous fusion machines. Recently, considerable interest has been expressed towards the development of a 100 GHz, 1.0 MW CW gyrotron for increasing the electron temperature above that achieved with the lower frequency, lower power devices listed above. Toward this goal, Hughes Aircraft Company has developed a 100 GHz, 0.5 MW gyrotron operating at low duty at 30 msec pulse widths. This device employs a single anode magnetron injection gun operating at a cathode voltage of 90 kV at 14A cathode current. Control of the electron beam is by cathode pulsing or CW. RF control is accomplished by low-level cathode magnetic field modulation. Computations show that velocity spread, both perpendicular and parallel, is considerable lower, rotational energy is higher and voltage gradients are significantly lower than for a comparable double anode magnetron injection gun, typically employed on lower frequency gyrotrons

  5. Development of Discrete Power Supply with Charge Pump Method for High Powered Sonar System

    Directory of Open Access Journals (Sweden)

    Kristian Ismail

    2012-07-01

    Full Text Available Power supply is one of the electronic devices that can provide electric energy for electronic systems or other systems. There are several types of power supplies that can be applied depend on the requirement and functions. One example is the use of power supply for sonar systems. Sonar system is a device which can be used to detect a target under water. The sonar system is an electronic circuit that requires a power supply with specific characteristics when the sonar functions as a transmitter and a receiver in the specific span time (when on and the specific lag time (when off. This paper discusses the design of power supply for high-powered sonar systems with discrete methods in which high power supply is only applied when the acoustic waves radiated under water. Charge pump was used to get the appropriate output voltage from lower input voltage. Charge pump utilized a combination of series and parallel connections of capacitors. The working mode of this power supply used the lag time as the calculation of time to charge charge pump capacitors in parallel while the span time was used for the calculation of discharging the charge pump capacitors in series.

  6. Analysis of Capacitor Placement in Power Distribution Networks Using Body Immune Algorithm

    OpenAIRE

    Majid Davoodi; Mohsen Davoudi; Iraj Ganjkhany; Morteza Arfand; Ali Aref

    2012-01-01

    In this study we present a new technique for analysis of capacitor placement in the power distribution systems considering the most of the parameters affected in this problem. Detection of capacitance and optimal placement of capacitors in power distribution system can lead to decrement in losses, enhancement in voltage profile, increment of power factor and freeing up generation capacityand energy distribution. The majority of literatures pay more attention to solve this problem considering ...

  7. Development and advances in conventional high power RF systems

    International Nuclear Information System (INIS)

    The development of rf systems capable of producing high peak power (hundreds of megawatts) at relatively short pulse lengths (0.1--5 microseconds) is currently being driven mainly by the requirements of future high energy linear colliders, although there may be applications to industrial, medical and research linacs as well. The production of high peak power rf typically involves four basic elements: a power supply to convert ac from the ''wall plug'' to dc; a modulator, or some sort of switching element, to produce pulsed dc power; an rf source to convert the pulsed dc to pulsed rf power; and possibly an rf pulse compression system to further enhance the peak rf power. Each element in this rf chain from wall plug to accelerating structure must perform with high efficiency in a linear collider application, such that the overall system efficiency is 30% or more. Basic design concepts are discussed for klystrons, modulators and rf pulse compression systems, and their present design status is summarized for applications to proposed linear colliders

  8. GaN Electronics For High Power, High Temperature Applications

    Energy Technology Data Exchange (ETDEWEB)

    PEARTON,S.J.; REN,F.; ZHANG,A.P.; DANG,G.; CAO,X.A.; LEE,K.P.; CHO,H.; GILA,B.P.; JOHNSON,J.W.; MONIER,C.; ABERNATHY,C.R.; HAN,JUNG; BACA,ALBERT G.; CHYI,J.-I.; LEE,C.-M.; NEE,T.-E.; CHUO,C.-C.; CHU,S.N.G.

    2000-06-12

    A brief review is given of recent progress in fabrication of high voltage GaN and AlGaN rectifiers. GaN/AlGaN heterojunction bipolar transistors and GaN metal-oxide semiconductor field effect transistors. Improvements in epitaxial layer quality and in fabrication techniques have led to significant advances in device performance.

  9. Human muscle power output during upper- and lower-body exercises.

    Science.gov (United States)

    Siegel, Judith A; Gilders, Roger M; Staron, Robert S; Hagerman, Frederick C

    2002-05-01

    The purpose of this study was to evaluate the use of traditional resistance training equipment in the measurement of muscular power. This was accomplished by measuring the velocity of movement through a measured distance during maximal effort lifts using a Smith rack. The reliability of the method was established using 10 male volunteers who performed both bench press and squat exercises in a Smith rack. Maximal power output was determined at 30, 40, 50, 60, 70, 80, and 90% of the subject's 1 repetition maximum (1RM). Test-retest power values were not statistically different. Another 15 male volunteers who had previous muscle biopsy data from the vastus lateralis muscle performed the same maximal power output evaluation. There were no significant relationships between peak power outputs and fiber-type expressions when linear regressions were performed. The power curve produced by graphing power output vs. the percentage of 1RM indicates that peak power output occurs between 50 and 70% of 1RM for the squat and between 40 and 60% of 1RM for the bench press. These data indicate that this method of evaluation of muscle power is reliable, although it is not predictive of muscle fiber-type percentages. PMID:11991767

  10. Experimental demonstration of high power millimeter wave gyro-amplifiers

    Science.gov (United States)

    Blank, M.; Garven, M.; Calame, J. P.; Choi, J. J.; Danly, B. G.; Levush, B.; Nguyen, K.; Pershing, D. E.

    1999-05-01

    The Naval Research Laboratory is currently investigating gyro-amplifiers as high power, broadband sources for millimeter wave radars. A three-cavity Ka-band gyroklystron achieved 225 kW peak output power with 0.82% bandwidth. At W-band, several multi-cavity gyro-amplifiers have been experimentally demonstrated. A four-cavity gyroklystron amplifier has achieved 84 kW peak output power at 34% efficiency with 370 MHz bandwidth. A five-cavity gyroklystron demonstrated 72 kW peak output power with 410 MHz bandwidth and 50 dB saturated gain. For applications requiring greater bandwidth, gyrotwystron amplifiers are also under study. A four section W-band gyrotwystron demonstrated 50 kW peak output power at 925 MHz bandwidth. The results of recent Ka-band and W-band gyro-amplifier experiments and comparisons of measured data with predictions of theory are presented.

  11. HIGH EFFICIENCY FOSSIL POWER PLANT (HEFPP) CONCEPTUALIZATION PROGRAM

    Energy Technology Data Exchange (ETDEWEB)

    J.L. Justice

    1999-03-25

    This study confirms the feasibility of a natural gas fueled, 20 MW M-C Power integrated pressurized molten carbonate fuel cell combined in a topping cycle with a gas turbine generator plant. The high efficiency fossil power plant (HEFPP) concept has a 70% efficiency on a LHV basis. The study confirms the HEFPP has a cost advantage on a cost of electricity basis over the gas turbine based combined cycle plants in the 20 MW size range. The study also identifies the areas of further development required for the fuel cell, gas turbine generator, cathode blower, inverter, and power module vessel. The HEFPP concept offers an environmentally friendly power plant with minuscule emission levels when compared with the combined cycle power plant.

  12. Shipbuilding power lies in high-end market

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The 2011 edition of Guideline Index for Readjusting Industrial Structure issued by the National Development and Reform Commission underlines the construction of high-end ships and the upgrading of shipbuilding technology.This shows that ifChina's shipbuilding industry is to become powerful,it should go all out to open up the fields of high-end ship construction so that the industry may have a greater share in the world market.Therefore,the power of our shipbuilding industry lies in the high-end market.

  13. Quantum dot amplifiers with high output power and low noise

    DEFF Research Database (Denmark)

    Berg, Tommy Winther; Mørk, Jesper

    2003-01-01

    Quantum dot semiconductor optical amplifiers have been theoretically investigated and are predicted to achieve high saturated output power, large gain, and low noise figure. We discuss the device dynamics and, in particular, show that the presence of highly inverted barrier states does not limit...

  14. Design of measurement equipment for high power laser beam shapes

    DEFF Research Database (Denmark)

    Hansen, K. S.; Olsen, F. O.; Kristiansen, Morten;

    2013-01-01

    To analyse advanced high power beam patterns, a method, which is capable of analysing the intensity distribution in 3D is needed. Further a measuring of scattered light in the same system is preferred. This requires a high signal to noise ratio. Such a system can be realised by a CCD-chip impleme...

  15. A Lemon Cell Battery for High-Power Applications

    Science.gov (United States)

    Muske, Kenneth R.; Nigh, Christopher W.; Weinstein, Randy D.

    2007-04-01

    This article discusses the development of a lemon cell battery for high-power applications. The target application is the power source of a dc electric motor for a model car constructed by first-year engineering students as part of their introductory course design project and competition. The battery is composed of a series of lemon juice cells made from UV vis cuvets that use a magnesium anode and copper cathode. Dilution of the lemon juice to reduce the rate of corrosion of the magnesium anode and the addition of table salt to reduce the internal resistance of the cell are examined. Although our specific interest is the use of this lemon cell battery to run an electric dc motor, high-power applications such as radios, portable cassette or CD players, and other battery-powered toys are equally appropriate for demonstration and laboratory purposes using this battery.

  16. Embedded control system for high power RF amplifiers

    International Nuclear Information System (INIS)

    RF power devices are usually very sensitive to overheat and reflected RF power; hence a protective interlock system is required to be embedded with high power solid state RF amplifiers. The solid state RF amplifiers have salient features of graceful degradation and very low mean time to repair (MTTR). In order to exploit these features in favour of lowest system downtime, a real-time control system is embedded with high power RF amplifiers. The control system is developed with the features of monitoring, measurement and network publishing of various parameters, historical data logging, alarm generation, displaying data to the operator and tripping the system in case of any interlock failure. This paper discusses the design philosophy, features, functions and implementation details of the embedded control system. (author)

  17. A High Power Amplifier for a Single Mode 1064 Laser

    Science.gov (United States)

    Stites, R. W.; O'Hara, K. M.

    2011-05-01

    We report on the construction of a high power amplifier system for a single mode 1064 nm laser. At the heart of this device is a 0.27% neodymium doped yttrium orthovanadate crystal that is double end pumped by two 30 Watt broadband diode arrays at 808 nm. For a 50 Watt TEM00 single freqency seed laser, we have observed an amplified power output in excess of 60 Watts for single pass configuration. A further increase in output power can be attained by retroreflecting the beam back through the crystal a second time. Such a device has direct application in the construction of optical lattices where high power single frequency lasers are required.

  18. High Power Laser Hybrid Welding - Challenges and Perspectives

    Science.gov (United States)

    Nielsen, Steen Erik

    High power industrial lasers at power levels up to 100 kW is now available on the market. Therefore, welding of thicker materials has become of interest for the heavy metal industry e.g. shipyards and wind mill producers. Further, the power plant industry, producers of steel pipes, heavy machinery and steel producers are following this new technology with great interest. At Lindø Welding Technology (LWT), which is a subsidiary to FORCE Technology, a 32-kwatt disc laser is installed. At this laser facility, welding procedures related to thick section steel applications are developed. Material thicknesses between 40 and 100 mm are currently of interest. This paper describes some of the challenges that are related to the development of the high power hybrid laser welding process as well as to the perspectives for the technology as a production tool for the heavy metal industry.

  19. Iron loss in high-power arc steelmaking furnaces

    Directory of Open Access Journals (Sweden)

    V. P. Karasyov

    2016-07-01

    Full Text Available There is considered the power operating mode of a high-power arc steelmaking furnaces (ASMF in the period of the flat bath. It is revealed that electric energy is mainly spent for heating and overheating the foamed slag. Heat transferring from slag to metal is carried out by the convective agitation of the bath. For agitation there is used intensive purging of the bath with oxygen that causes increased iron losses with the running foamed slag. There are noted the negative points of working with the foamed slag. It is recommended to expand R&D in the field of optimizing the power operating mode of high-power ASMF.

  20. Body dissatisfaction and mirror exposure: evidence for a dissociation between self-report and physiological responses in highly body-dissatisfied women.

    Directory of Open Access Journals (Sweden)

    Fátima Servián-Franco

    Full Text Available Weight and shape concerns are widespread in the general population. Mirror exposure has been used to reduce body dissatisfaction but little is known about the mechanisms which underlie this therapeutic technique. The present study examined emotional, cognitive, and psychophysiological responses, in women with high and low levels of body dissatisfaction, exposed to their own bodies in a mirror.Forty-two university-attending women (21 high body-dissatisfied (HBD and 21 low body-dissatisfied (LBD, were confronted with their own body during four 5-min trials in which participants were instructed to focus their attention on different parts of their body under standardized conditions. Emotional and cognitive measures were taken after each exposure trial. Heart rate (HR and skin conductance (SC were recorded continuously.HBD women experienced more negative emotions and cognitions following body exposure compared to LBD women but, conversely, showed a reduced physiological reaction in terms of HR and SC. In both groups greater physiological responses were observed looking at the thighs, buttocks, and abdomen. Extent of negative emotions and cognitions were positively associated with HR and/or SC in LBD women but no associations were observed in HBD women.The dissociation between self-report and psychophysiological measures in HBD women supports the existence of a passive-behavioral inhibited coping style in HBD women and suggests deficiencies in the generation of physiological correlates of emotion related to body dissatisfaction.

  1. Implications of high temperature superconductors for power generation

    International Nuclear Information System (INIS)

    Superconducting generators for high power applications have been of interest for a number of years. Superconducting generators using low temperature superconductors (LTS) have been manufactured to produce up to 20 MW of electrical power and have been configured in either synchronous alternators which have an AC output that may be subsequently rectified to produce DC and homopolar generators which produce low voltage DC. Typically these generators require scrupulous attention to vacuum integrity for cryogenic insulation at 4.2K and tend to be somewhat fragile because of extensive thermal and magnetic shields that are not required in conventional power generators. Recently, high purity aluminum composites have been developed for a high power AC generator that is cooled by cryogenic hydrogen at 21K. This aluminum generator is very compact and lightweight and is much more robust than a generator made with LTS because extensive thermal and magnetic shields are not required internally. The advent of high temperature superconductors (HTS) has resulted in new potential for the superconducting generator because HTS can operate at and above 21K in a generator that does not require elaborate thermal and electromagnetic shields similar to the aluminum generator. since the great advantage of cryogenic generators is gained at high power, the paper is limited to generators of roughly one megawatt and greater. The implications of HTS for high power generator applications are discussed with emphasis on conceptualizing an early feasibility demonstrator that benefits from rudimentary HTS that exist now or in the near future. While the technology of HTS is in its infancy, the successful early demonstration of the feasibility of a powerful generator employing HTS should lead to future applications

  2. Constrained body shape among highly genetically divergent allopatric lineages of the supralittoral isopod Ligia occidentalis (Oniscidea).

    Science.gov (United States)

    Santamaria, Carlos A; Mateos, Mariana; DeWitt, Thomas J; Hurtado, Luis A

    2016-03-01

    Multiple highly divergent lineages have been identified within Ligia occidentalis sensu lato, a rocky supralittoral isopod distributed along a ~3000 km latitudinal gradient that encompasses several proposed marine biogeographic provinces and ecoregions in the eastern Pacific. Highly divergent lineages have nonoverlapping geographic distributions, with distributional limits that generally correspond with sharp environmental changes. Crossbreeding experiments suggest postmating reproductive barriers exist among some of them, and surveys of mitochondrial and nuclear gene markers do not show evidence of hybridization. Populations are highly isolated, some of which appear to be very small; thus, the effects of drift are expected to reduce the efficiency of selection. Large genetic divergences among lineages, marked environmental differences in their ranges, reproductive isolation, and/or high isolation of populations may have resulted in morphological differences in L. occidentalis, not detected yet by traditional taxonomy. We used landmark-based geometric morphometric analyses to test for differences in body shape among highly divergent lineages of L. occidentalis, and among populations within these lineages. We analyzed a total of 492 individuals from 53 coastal localities from the southern California Bight to Central Mexico, including the Gulf of California. We conducted discriminant function analyses (DFAs) on body shape morphometrics to assess morphological variation among genetically differentiated lineages and their populations. We also tested for associations between phylogeny and morphological variation, and whether genetic divergence is correlated to multivariate morphological divergence. We detected significant differences in body shape among highly divergent lineages, and among populations within these lineages. Nonetheless, neither lineages nor populations can be discriminated on the basis of body shape, because correct classification rates of cross

  3. Eating behavior and body image perception of pregnant women attending a high-risk outpatient center

    Directory of Open Access Journals (Sweden)

    Raquel Guimarães Nobre

    2014-06-01

    Full Text Available Objective: To investigate the eating behavior and body image perception in pregnant women attending a high-risk outpatient center. Methods: A quantitative, cross-sectional, observational study conducted with 28 overweight pregnant women attending the first consultation in the nutrition outpatient center of a maternity hospital in Fortaleza-CE, from December 2010 to February 2011. It has been used a pre-established form containing data on the characterization of the sample (socioeconomic, obstetric, and nutritional, the BES (Binge Eating Scale to assess binge eating and BSQ (Body Shape Questionnaire to assess the severity or absence of body image disorder. The variables were presented as mean ± standard deviation and simple frequency and percentage. The Pearson’s correlation was used to verify the relation between body image and binge eating, considering p <0.05. Results: The pregnant women studied had a mean age of 29.4 ± 6.3 years and mean gestational age of 24.6 ± 8.2 weeks. It was found a prevalence of 71.5% (n=20 of body image disorder and 17.8% (n=5 of binge eating. It was also observed a direct and significant correlation between the body image perception and the degree of binge eating (r=0.4358, p=0.020. Conclusion: The high rate of body image disorder positively related to a significant binge eating indicates an unfavorable adjustment of this group of pregnant women to alterations in weight and body shape and size, which are inherent to pregnancy, standing out as group that needs special attention by the professional team. doi:10.5020/18061230.2014.p256

  4. High Power High Thrust Ion Thruster (HPHTion): 50 CM Ion Thruster for Near-Earth Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advances in high power, photovoltaic technology has enabled the possibility of reasonably sized, high specific power, high power, solar arrays. New thin film solar...

  5. Design of high power solid-state pulsed laser resonators

    International Nuclear Information System (INIS)

    Methods and configurations for the design of high power solid-state pulsed laser resonators, operating in free running, are presented. For fundamental mode high power resonators, a method is proposed for the design of a resonator with joined stability zones. In the case of multimode resonators, two configurations are introduced for maximizing the laser overall efficiency due to the compensation of the astigmatism induced by the excitation. The first configuration consists in a triangular ring resonator. The results for this configuration are discussed theoretically, showing that it is possible to compensate the astigmatism of the thermal lens virtually in a 100%; however this is only possible for a specific pumping power. The second configuration proposes a dual-active medium resonator, rotated 90 degree one from the other around the optical axis, where each active medium acts as an astigmatic lens of the same dioptric power. The reliability of this configuration is corroborated experimentally using a Nd:YAG dual-active medium resonator. It is found that in the pumping power range where the astigmatism compensation is possible, the overall efficiency is constant, even when increasing the excitation power with the consequent increase of the thermal lens dioptric power. (Author)

  6. R&D ERL: High power RF systems

    Energy Technology Data Exchange (ETDEWEB)

    Zaltsman, A.

    2010-01-15

    The Energy Recovery Linac (ERL) project, now under construction at Brookhaven National Laboratory, requires two high power RF systems. The first RF system is for the 703.75 MHz superconducting electron gun. The RF power from this system is used to drive nearly half an Ampere of beam current to 2.5 MeV. There is no provision to recover any of this energy so the minimum amplifier power is 1 MW. It consists of 1 MW CW klystron, transmitter and power supplies, 1 MW circulator, 1 MW dummy load and a two-way power splitter. The second RF system is for the 703.75 MHz superconducting cavity. The system accelerates the beam to 54.7 MeV and recovers this energy. It will provide up to 50 kW of CW RF power to the cavity. It consists of 50 kW transmitter, circulator, and dummy load. This paper describes the two high power RF systems and presents the test data for both.

  7. High power RF systems for the BNL ERL project

    Energy Technology Data Exchange (ETDEWEB)

    Zaltsman, A.; Lambiase, R.

    2011-03-28

    The Energy Recovery Linac (ERL) project, now under construction at Brookhaven National Laboratory, requires two high power RF systems. The first RF system is for the 703.75 MHz superconducting electron gun. The RF power from this system is used to drive nearly half an Ampere of beam current to 2 MeV. There is no provision to recover any of this energy so the minimum amplifier power is 1 MW. It consists of 1 MW CW klystron, transmitter and power supplies, 1 MW circulator, 1 MW dummy load and a two-way power splitter. The second RF system is for the 703.75 MHz superconducting cavity. The system accelerates the beam to 54.7 MeV and recovers this energy. It will provide up to 50 kW of CW RF power to the cavity. It consists of 50 kW transmitter, circulator, and dummy load. This paper describes the two high power RF systems and presents the test data for both.

  8. Air Cooling for High Temperature Power Electronics (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Waye, S.; Musselman, M.; King, C.

    2014-09-01

    Current emphasis on developing high-temperature power electronics, including wide-bandgap materials such as silicon carbide and gallium nitride, increases the opportunity for a completely air-cooled inverter at higher powers. This removes the liquid cooling system for the inverter, saving weight and volume on the liquid-to-air heat exchanger, coolant lines, pumps, and coolant, replacing them with just a fan and air supply ducting. We investigate the potential for an air-cooled heat exchanger from a component and systems-level approach to meet specific power and power density targets. A proposed baseline air-cooled heat exchanger design that does not meet those targets was optimized using a parametric computational fluid dynamics analysis, examining the effects of heat exchanger geometry and device location, fixing the device heat dissipation and maximum junction temperature. The CFD results were extrapolated to a full inverter, including casing, capacitor, bus bar, gate driver, and control board component weights and volumes. Surrogate ducting was tested to understand the pressure drop and subsequent system parasitic load. Geometries that met targets with acceptable loads on the system were down-selected for experimentation. Nine baseline configuration modules dissipated the target heat dissipation, but fell below specific power and power density targets. Six optimized configuration modules dissipated the target heat load, exceeding the specific power and power density targets. By maintaining the same 175 degrees C maximum junction temperature, an optimized heat exchanger design and higher device heat fluxes allowed a reduction in the number of modules required, increasing specific power and power density while still maintaining the inverter power.

  9. High-Power Microwave Switch Employing Electron Beam Triggering

    Energy Technology Data Exchange (ETDEWEB)

    Jay L. Hirshfield

    2012-09-19

    A high-power active microwave pulse compressor is described that modulates the quality factor Q of the energy storage cavity by a new means involving mode conversion controlled by a triggered electron-beam discharge through a switch cavity. The electron beam is emitted from a diamond-coated molybdenum cathode. This report describes the principle of operation, the design of the switch, the configuration used for the test, and the experimental results. The pulse compressor produced output pulses with 140 - “165 MW peak power, power gain of 16 - 20, and pulse duration of 16 - 20 ns at a frequency of 11.43 GHz.

  10. High power, diode pumped Er:YAG for dentistry

    Science.gov (United States)

    Hagen, C.; Heinrich, A.; Nussbaumer, B.

    2011-03-01

    Pantec Medical Laser presents a diode pumped Er:YAG laser for dental and hard tissue applications. The diode pumped laser is practically maintenance free and ensures reliable operation over several thousand hours. The high repetition rate with up to 15 W average output power, allows treatments otherwise not feasible with low repetition rate, lamp pumped Er:YAG systems. The variable pulse duration of 10 to 200 μs combined with the good beam quality ensures precise and fast treatment. First results on enamel ablation as well as the power scalability of the technology to 200 mJ and 30 W average power are also shown.

  11. High-power phase locking of a fiber amplifier array

    Science.gov (United States)

    Shay, T. M.; Baker, J. T.; Sanchez, A. D.; Robin, C. A.; Vergien, C. L.; Zeringue, C.; Gallant, D.; Lu, Chunte A.; Pulford, Benjamin; Bronder, T. J.; Lucero, Arthur

    2009-02-01

    We report high power phase locked fiber amplifier array using the Self-Synchronous Locking of Optical Coherence by Single-detector Electronic-frequency Tagging technique. We report the first experimental results for a five element amplifier array with a total locked power of more than 725-W. We will report on experimental measurements of the phase fluctuations versus time when the control loop is closed. The rms phase error was measured to be λ/60. Recent results will be reported. To the best of the authors' knowledge this is the highest fiber laser power to be coherently combined.

  12. Treatment of multicomponent microbarographic signals excited by high power explosions

    International Nuclear Information System (INIS)

    A method for analysis of microbarographic signals recorded on a sensor network is developed, the aim is the localization of the source with maximum accuracy. It is shown that the method using the interspectral matrix finds a direct application in the discrimination of waves from high power explosion in a noisy environment. Its powerfulness is demonstrated on actual signals (explosion of the volcano Mt St Helens) allowing interesting results on propagation mechanisms (Brunt period, Lamb modes and acoustic modes)

  13. Status Of The Novosibirsk High Power Free Electron Laser

    CERN Document Server

    Bolotin, V P; Knyazev, B A; Kolobanov, E I; Kotenkov, V V; Kubarev, V V; Kulipanov, G N; Matveenko, A N; Medvedev, L E; Miginsky, S V; Mironenko, L A; Oreshkov, A D; Ovchar, V K; Popik, V M; Salikova, T V; Scheglov, M A; Serednyakov, S I; Shevchenko, O A; Skrinsky, A N; Vinokurov, N A; Zaigraeva, N S

    2004-01-01

    The first stage of Novosibirsk high power free electron laser (FEL) was commissioned in 2003. It is based on normal conducting CW energy recovery linac. Now the FEL provides electromagnetic radiation in the wavelength range 120-180 micron. The average power is 200 W. The measured linewidth is 0.3%, which is close to the Fourier-transform limit. The assembly of user beamline is in progress. Plans of future developments are discussed.

  14. Computational component analysis techniques for high temperature power plant applications

    OpenAIRE

    Rouse, James Paul

    2014-01-01

    There is a trend in the power industry for high temperature components (such as steam pipe work) to be operated in an increasingly arduous fashion. This would involve the use of elevated steam temperatures/pressures and a greater frequency of start up/shut down cycles. Such generation strategies are being adopted due to the need for thermally efficient power supply that can match fluctuating market demands. If these generation strategies are to be implemented safely it is critical that carefu...

  15. A condenser for very high power steam turbines

    International Nuclear Information System (INIS)

    The invention relates to a condenser for very high power steam turbines under the masonry-block supporting the low-pressure stages of the turbine, that condenser comprises two horizontal aligned water-tube bundles passing through the steam-exhaust sleeves of the low-pressure stages, on both sides of a common inlet water box. The invention can be applied in particular to the 1000-2000 MW turbines of light water nuclear power stations

  16. A high-power compact regenerative amplifier FEL

    International Nuclear Information System (INIS)

    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

  17. Power Input of High-Speed Rotary Impellers

    OpenAIRE

    K. R. Beshay; J. Kratěna; I. Fořt; O. Brůha

    2001-01-01

    This paper presents the results of an experimental investigation of the power input of pitched blade impellers and standard Rushton turbine impellers in a cylindrical vessel provided with four radial baffles at its wall under a turbulent regime of flow of an agitated liquid. The influence of the geometry of the pitched blade impellers (pitch angle, number of blades) and the off-bottom impeller clearance of both high-speed impellers tested on the impeller power input is determined in two sizes...

  18. High quantum efficiency annular backside silicon photodiodes for reflectance pulse oximetry in wearable wireless body sensors

    DEFF Research Database (Denmark)

    Duun, Sune Bro; Haahr, Rasmus Grønbek; Hansen, Ole;

    2010-01-01

    The development of annular photodiodes for use in a reflectance pulse oximetry sensor is presented. Wearable and wireless body sensor systems for long-term monitoring require sensors that minimize power consumption. We have fabricated large area 2D ring-shaped silicon photodiodes optimized for...... minimizing the optical power needed in reflectance pulse oximetry. To simplify packaging, backside photodiodes are made which are compatible with assembly using surface mounting technology without pre-packaging. Quantum efficiencies up to 95% and area-specific noise equivalent powers down to 30 fW Hz(-1....../2) cm(-1) are achieved. The photodiodes are incorporated into a wireless pulse oximetry sensor system embedded in an adhesive patch presented elsewhere as 'The Electronic Patch'. The annular photodiodes are fabricated using two masked diffusions of first boron and subsequently phosphor. The surface is...

  19. RF Input Power Couplers for High Current SRF Applications

    Energy Technology Data Exchange (ETDEWEB)

    Khan, V. F. [Helmholtz Zentrum Berlin, Germany; Anders, W. [Helmholtz Zentrum Berlin, Germany; Burrill, Andrew [Helmholtz Zentrum Berlin, Germany; Knobloch, Jens [Helmholtz Zentrum Berlin, Germany; Kugeler, Oliver [Helmholtz Zentrum Berlin, Germany; Neumann, Axel [Helmholtz Zentrum Berlin, Germany; Wang, Haipeng [JLAB

    2014-12-01

    High current SRF technology is being explored in present day accelerator science. The bERLinPro project is presently being built at HZB to address the challenges involved in high current SRF machines with the goal of generating and accelerating a 100 mA electron beam to 50 MeV in continuous wave (cw) mode at 1.3 GHz. One of the main challenges in this project is that of handling the high input RF power required for the photo-injector as well as booster cavities where there is no energy recovery process. A high power co-axial input power coupler is being developed to be used for the photo-injector and booster cavities at the nominal beam current. The coupler is based on the KEK–cERL design and has been modified to minimise the penetration of the coupler tip in the beam pipe without compromising on beam-power coupling (Qext ~105). Herein we report on the RF design of the high power (115 kW per coupler, dual couplers per cavity) bERLinPro (BP) coupler along with initial results on thermal calculations. We summarise the RF conditioning of the TTF-III couplers (modified for cw operation) performed in the past at BESSY/HZB. A similar conditioning is envisaged in the near future for the low current SRF photo-injector and the bERLinPro main linac cryomodule.

  20. High voltage generator circuit with low power and high efficiency applied in EEPROM

    International Nuclear Information System (INIS)

    This paper presents a low power and high efficiency high voltage generator circuit embedded in electrically erasable programmable read-only memory (EEPROM). The low power is minimized by a capacitance divider circuit and a regulator circuit using the controlling clock switch technique. The high efficiency is dependent on the zero threshold voltage (Vth) MOSFET and the charge transfer switch (CTS) charge pump. The proposed high voltage generator circuit has been implemented in a 0.35 μm EEPROM CMOS process. Measured results show that the proposed high voltage generator circuit has a low power consumption of about 150.48 μW and a higher pumping efficiency (83.3%) than previously reported circuits. This high voltage generator circuit can also be widely used in low-power flash devices due to its high efficiency and low power dissipation. (semiconductor integrated circuits)

  1. High voltage generator circuit with low power and high efficiency applied in EEPROM

    Institute of Scientific and Technical Information of China (English)

    Liu Yan; Zhang Shilin; Zhao Yiqiang

    2012-01-01

    This paper presents a low power and high efficiency high voltage generator circuit embedded in electrically erasable programmable read-only memory (EEPROM).The low power is minimized by a capacitance divider circuit and a regulator circuit using the controlling clock switch technique.The high efficiency is dependent on the zero threshold voltage (Vth) MOSFET and the charge transfer switch (CTS) charge pump.The proposed high voltage generator circuit has been implemented in a 0.35μm EEPROM CMOS process.Measured results show that the proposed high voltage generator circuit has a low power consumption of about 150.48 μW and a higher pumping efficiency (83.3%) than previously reported circuits.This high voltage generator circuit can also be widely used in low-power flash devices due to its high efficiency and low power dissipation.

  2. Radioecology on a nuclear power station site using recapturable wild birds and whole-body gamma spectroscopic analysis

    International Nuclear Information System (INIS)

    Free-ranging populations of wild birds captured at a nuclear power station site and two control sites within a radius of 10 km were marked by banding and then counted in a whole-body counter to determine spatial and temporal distributions of gamma-emitting radionuclides. After counting, birds were returned to their capture site and released, allowing repeated recapture that permitted long-term determination of environmental radionuclide levels and the impact, if any, of a nuclear power station. Species-dependent recapture rates ranged from 28% to 80%. A specially designed whole-body counter was able to measure body burdens at 0.05 to 0.08 pCi/g levels for 100-minute counts of 100-gram birds. In the six-year study, over 8500 birds were captured, banded and counted, with the bulk of the study sample consisting of 15 common species. The use of accepted bird census techniques demonstrated that the trapping procedures produced an accurate representative sample of the avifauna present at the study sites. Comparison of radionuclide levels, mainly 137Cs, between birds captured at the reactor site and the control sites showed that there were, within a given species, both geographic differences and temporal variations in radionuclide body burdens. Within the relatively homogeneous geographic area encompassing the reactor site and the control sites it was found that mean 137Cs body burdens at the control sites ranged from three times less to three times more than those at the reactor site. These differences were reproducible and did not correlate with meteorological conditions or with 137Cs concentrations in soil and vegetation samples taken at each site

  3. RF power requirements for a high intensity proton collider

    International Nuclear Information System (INIS)

    In the new generation of circular accelerators or colliders where the average beam currents are pushed up to their ultimate limits, the power exchanged between the RF power source and the beam becomes much larger than the losses in the RF system itself (cavity, amplifier, circulator load). This situation of high beam loading has been analyzed previously with respect to the stability of the radiofrequency system. Without any electronic loops, one obtains the well known high current Robinson stability limit, which is somewhat modified by the presence of the phase, amplitude and tuning loops. To go beyond these limits the usual recipe is to employ RF feedback around the power amplifier-cavity combination. The beam current thresholds are simply increased by the RF feedback loop gain, without changing the static RF power balance. However when transient effects are considered, the peak RF power demanded by RF feedback may dominate the static power requirements, in particular for hadron storage rings where φB (synchronous phase angle) equals zero. During acceleration or storage periodic transient beam loading is due to the non-uniform structure of the beam. With high RF feedback gains and therefore large equivalent cavity bandwidths this effect becomes more and more important, especially for large machines with a low revolution frequency. In addition, non-periodic transient beam loading effects occur during the filling phase of the machine, when newly injected particles are added to the already circulating beam

  4. High-power master-oscillator power amplifiers based on rare-earth-doped fibres

    OpenAIRE

    Jeong, Y.; Nilsson, J; Dupriez, P.; Codemard, C.; Farrell, C.; Sahu, J. K.; Kim, J; Yoo, S.; Richardson, D.J.; Payne, D. N.

    2006-01-01

    In recent years there have been dramatic advances in fibre lasers. Currently, conventional single-strand cladding-pumped fibre lasers can generate output powers beyond 1 kW with high beam quality. Indeed, this fibre circuitry combined with pump-diode technology provides a unique high-gain environment for robust designs, which is also all-solid state, compact, stable, reliable, and reproducible. Here we review the recent progress in high-power MOPAs based on rare-earth-doped fibres and discuss...

  5. The paradox of low body mass index and high body fat percentage among Chinese, Malays and Indians in Singapore

    NARCIS (Netherlands)

    Deurenberg-Yap, M.; Schmidt, G.; Staveren, van W.A.; Deurenberg, P.

    2000-01-01

    To study the relationship between body fat percentage and body mass index (BMI) in three different ethnic groups in Singapore (Chinese, Malays and Indians) in order to evaluate the validity of the BMI cut-off points for obesity. DESIGN: Cross-sectional study. SUBJECTS: Two-hundred and ninety-one sub

  6. The Improved Power of the Central Lobe in the Beam Combination and High Power Output

    International Nuclear Information System (INIS)

    In order to increase the power fraction of the central lobe in the coherent beam combination of lasers in an array, the effects of the distance factor of near-field distribution on far-field interference patterns are calculated and demonstrated experimentally. An improved beam array of interwoven distribution is demonstrated to enable the power in the central lobe to reach 41%. An optimized mirror array is carefully designed to obtain a high duty ratio, which is up to 53.3% at a high power level. By using these optimized methods and designs, the passive phase locking of eight Yb-doped fiber amplifiers with ring cavities are obtained, and a pleasing interference pattern with 87% visibility is observed. The maximum coherent output power of the system is up to 1066 W. (fundamental areas of phenomenology(including applications))

  7. Toward High-Power Klystrons With RF Power Conversion Efficiency on the Order of 90%

    CERN Document Server

    Baikov, Andrey Yu; Syratchev, Igor

    2015-01-01

    The increase in efficiency of RF power generation for future large accelerators is considered a high priority issue. The vast majority of the existing commercial high-power RF klystrons operates in the electronic efficiency range between 40% and 55%. Only a few klystrons available on the market are capable of operating with 65% efficiency or above. In this paper, a new method to achieve 90% RF power conversion efficiency in a klystron amplifier is presented. The essential part of this method is a new bunching technique - bunching with bunch core oscillations. Computer simulations confirm that the RF production efficiency above 90% can be reached with this new bunching method. The results of a preliminary study of an L-band, 20-MW peak RF power multibeam klystron for Compact Linear Collider with the efficiency above 85% are presented.

  8. Mathematical study of very high voltage power networks I: The optimal DC power flow problem

    OpenAIRE

    Bonnans, J. Frederic

    1994-01-01

    The optimal power flow problem consists in setting the voltage and power delivered at the nodes of an electrical network, in order to minimize the loss of power over the lines. This paper is the first of a series dedicated to the mathematical study of this problem, based on an asymptotic analysis, in which the small parameter is the inverse of the reference voltage of the network. We call this scheme the very high voltage approximation. Here we deal with the case of direct current. We obtain ...

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    In a power system with a high share of wind energy the wind fluctuation causes a variation in the power generation, which must be compensated from other sources. The situation in Denmark with a penetration of more than 20% wind in yearly average is presented. The introduction of electric drive...... 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 economical incentives for the vehicle owners will be shown. By control of EDV charging through a price...

  10. A 15 MHz bandwidth, 60 Vpp, low distortion power amplifier for driving high power piezoelectric transducers

    International Nuclear Information System (INIS)

    This paper presents the design and the realization of a linear power amplifier with large bandwidth (15 MHz) capable of driving low impedance ultrasonic transducers. The output current driving capability (up to 5 A) and low distortion makes it suitable for new research applications using high power ultrasound in the medical and industrial fields. The electronic design approach is modular so that the characteristics can be scaled according to specific applications and implementation details for the circuit layout are reported. Finally the characterization of the power amplifier module is presented

  11. Power Requirements Determined for High-Power-Density Electric Motors for Electric Aircraft Propulsion

    Science.gov (United States)

    Johnson, Dexter; Brown, Gerald V.

    2005-01-01

    Future advanced aircraft fueled by hydrogen are being developed to use electric drive systems instead of gas turbine engines for propulsion. Current conventional electric motor power densities cannot match those of today s gas turbine aircraft engines. However, if significant technological advances could be made in high-power-density motor development, the benefits of an electric propulsion system, such as the reduction of harmful emissions, could be realized.

  12. Development of high voltage power supply for the KSTAR 170 GHz ECH and CD system

    International Nuclear Information System (INIS)

    Highlights: • A 3.6 MW (−66 kV/55 A) gyrotron power supply system was developed for the 170 GHz ECH system in KSTAR. • The main power supply includes a total of 32 PSM based HV power supply modules. • The voltage regulation of individual HV power module and LV power module is 3 kV and 0.5 kV, respectively. • The gyrotron is protected by means of a fast solid-state switch (MOS-FET). • The HV switching system can turn off the 60 kV to the cathode within 3 μs in the event of gyrotron faults. -- Abstract: A 3.6 MW (66 kV/55 A) DC power supply system was developed for the 170 GHz EC H and CD system in KSTAR. The power supply system consists of a cathode power supply (CPS), an anode power supply (APS) and a body power supply (BPS). The cathode power supply is capable of supplying a maximum voltage of −66 kV and a current of 55 A to the cathode with respect to the collector using pulse step modulation (PSM). The high voltage switching system for the cathode is made by a fast MOS-FET solid-state switch which can turn off the high voltage to the cathode within 3 μs in the occurrence of gyrotron faults. The APS is a voltage divider system consisting of a fixed resistor and zener diode units with the capability of 60 kV stand-off voltage. The anode voltage with respect to the cathode is controlled in a range of 0–60 kV by turning the MOS-FET switches connected in parallel to each zener diode on and off. For high frequency current modulation of the gyrotron, the parallel discharge switch is introduced between the cathode and anode in order to clamp the charged voltage in the stray capacitance. The BPS is a DC power supply with the capability of 50 kV/160 mA. The nominal operation parameter of BPS was 23 kV and 10 mA, respectively, and the voltage output is regulated with a stability of 0.025% of the rated voltage. The series MOS-FET solid-state switch is used for on/off modulation in the body voltage sychronizing with anode voltage. The parallel discharge

  13. High Power Fiber Lasers and Applications to Manufacturing

    Science.gov (United States)

    Richardson, Martin; McComb, Timothy; Sudesh, Vikas

    2008-09-01

    We summarize recent developments in high power fiber laser technologies and discuss future trends, particularly in their current and future use in manufacturing technologies. We will also describe our current research programs in fiber laser development, ultra-fast and new lasers, and will mention the expectations in these areas for the new Townes Laser Institute. It will focus on new core laser technologies and their applications in medical technologies, advanced manufacturing technologies and defense applications. We will describe a program on large mode area fiber development that includes results with the new gain-guiding approach, as well as high power infra-red fiber lasers. We will review the opportunities for high power fiber lasers in various manufacturing technologies and illustrate this with applications we are pursuing in the areas of femtosecond laser applications, advanced lithographies, and mid-IR technologies.

  14. Modular High-Energy Systems for Solar Power Satellites

    Science.gov (United States)

    Howell, Joe T.; Carrington, Connie K.; Marzwell, Neville I.; Mankins, John C.

    2006-01-01

    Modular High-Energy Systems are Stepping Stones to provide capabilities for energy-rich infrastructure located in space to support a variety of exploration scenarios as well as provide a supplemental source of energy during peak demands to ground grid systems. Abundant renewable energy at lunar or other locations could support propellant production and storage in refueling scenarios that enable affordable exploration. Renewable energy platforms in geosynchronous Earth orbits can collect and transmit power to satellites, or to Earth-surface locations. Energy-rich space technologies also enable the use of electric-powered propulsion systems that could efficiently deliver cargo and exploration facilities to remote locations. A first step to an energy-rich space infrastructure is a 100-kWe class solar-powered platform in Earth orbit. The platform would utilize advanced technologies in solar power collection and generation, power management and distribution, thermal management, electric propulsion, wireless avionics, autonomous in space rendezvous and docking, servicing, and robotic assembly. It would also provide an energy-rich free-flying platform to demonstrate in space a portfolio of technology flight experiments. This paper summary a preliminary design concept for a 100-kWe solar-powered satellite system to demonstrate in-flight a variety of advanced technologies, each as a separate payload. These technologies include, but are not limited to state-of-the-art solar concentrators, highly efficient multi-junction solar cells, integrated thermal management on the arrays, and innovative deployable structure design and packaging to enable the 100-kW satellite feasible to launch on one existing launch vehicle. Higher voltage arrays and power distribution systems (PDS) reduce or eliminate the need for massive power converters, and could enable direct-drive of high-voltage solar electric thrusters.

  15. Colonizing Bodies: Corporate Power and Biotechnology in Young Adult Science Fiction

    Science.gov (United States)

    Guerra, Stephanie

    2009-01-01

    The American cultural and political landscape has seen changes on the level of seismic shifts in the past four decades, thanks in part to the two very diverse fields of big business and biotechnology. Linking the two arenas together in the literary landscape is a growing body of young adult science fiction that envisions a future shaped profoundly…

  16. Experimental assessment of the mooring influence on the power output of floating Wave Activated Body WECs

    DEFF Research Database (Denmark)

    Angelelli, Elisa; Zanuttigh, Barbara; Ferri, Francesco;

    2013-01-01

    The paper presents the preliminary results of new physical tests carried out in the directional wave basin of Aalborg University (DK). The devices under exams are two floating 7 Degrees of Freedom Wave Activated Bodies moored with a spread system composed by 4 steel chains. The devices were subject...

  17. High-performance radial AMTEC cell design for ultra-high-power solar AMTEC systems

    Energy Technology Data Exchange (ETDEWEB)

    Hendricks, T.J.; Huang, C.

    1999-07-01

    Alkali Metal Thermal to Electric Conversion (AMTEC) technology is rapidly maturing for potential application in ultra-high-power solar AMTEC systems required by potential future US Air Force (USAF) spacecraft missions in medium-earth and geosynchronous orbits (MEO and GEO). Solar thermal AMTEC power systems potentially have several important advantages over current solar photovoltaic power systems in ultra-high-power spacecraft applications for USAF MEO and GEO missions. This work presents key aspects of radial AMTEC cell design to achieve high cell performance in solar AMTEC systems delivering larger than 50 kW(e) to support high power USAF missions. These missions typically require AMTEC cell conversion efficiency larger than 25%. A sophisticated design parameter methodology is described and demonstrated which establishes optimum design parameters in any radial cell design to satisfy high-power mission requirements. Specific relationships, which are distinct functions of cell temperatures and pressures, define critical dependencies between key cell design parameters, particularly the impact of parasitic thermal losses on Beta Alumina Solid Electrolyte (BASE) area requirements, voltage, number of BASE tubes, and system power production for both maximum power-per-BASE-area and optimum efficiency conditions. Finally, some high-level system tradeoffs are demonstrated using the design parameter methodology to establish high-power radial cell design requirements and philosophy. The discussion highlights how to incorporate this methodology with sophisticated SINDA/FLUINT AMTEC cell modeling capabilities to determine optimum radial AMTEC cell designs.

  18. High-level power analysis and optimization techniques

    Science.gov (United States)

    Raghunathan, Anand

    1997-12-01

    This thesis combines two ubiquitous trends in the VLSI design world--the move towards designing at higher levels of design abstraction, and the increasing importance of power consumption as a design metric. Power estimation and optimization tools are becoming an increasingly important part of design flows, driven by a variety of requirements such as prolonging battery life in portable computing and communication devices, thermal considerations and system cooling and packaging costs, reliability issues (e.g. electromigration, ground bounce, and I-R drops in the power network), and environmental concerns. This thesis presents a suite of techniques to automatically perform power analysis and optimization for designs at the architecture or register-transfer, and behavior or algorithm levels of the design hierarchy. High-level synthesis refers to the process of synthesizing, from an abstract behavioral description, a register-transfer implementation that satisfies the desired constraints. High-level synthesis tools typically perform one or more of the following tasks: transformations, module selection, clock selection, scheduling, and resource allocation and assignment (also called resource sharing or hardware sharing). High-level synthesis techniques for minimizing the area, maximizing the performance, and enhancing the testability of the synthesized designs have been investigated. This thesis presents high-level synthesis techniques that minimize power consumption in the synthesized data paths. This thesis investigates the effects of resource sharing on the power consumption in the data path, provides techniques to efficiently estimate power consumption during resource sharing, and resource sharing algorithms to minimize power consumption. The RTL circuit that is obtained from the high-level synthesis process can be further optimized for power by applying power-reducing RTL transformations. This thesis presents macro-modeling and estimation techniques for switching

  19. Soft Magnetic Materials in High-Frequency, High-Power Conversion Applications

    Energy Technology Data Exchange (ETDEWEB)

    Leary, AM; Ohodnicki, PR; McHenry, ME

    2012-07-04

    Advanced soft magnetic materials are needed to match high-power density and switching frequencies made possible by advances in wide band-gap semiconductors. Magnetics capable of operating at higher operating frequencies have the potential to greatly reduce the size of megawatt level power electronics. In this article, we examine the role of soft magnetic materials in high-frequency power applications and we discuss current material's limitations and highlight emerging trends in soft magnetic material design for high-frequency and power applications using the materials paradigm of synthesis -> structure -> property -> performance relationships.

  20. Soft Magnetic Materials in High-Frequency, High-Power Conversion Applications

    Science.gov (United States)

    Leary, Alex M.; Ohodnicki, Paul R.; McHenry, Michael E.

    2012-07-01

    Advanced soft magnetic materials are needed to match high-power density and switching frequencies made possible by advances in wide band-gap semiconductors. Magnetics capable of operating at higher operating frequencies have the potential to greatly reduce the size of megawatt level power electronics. In this article, we examine the role of soft magnetic materials in high-frequency power applications and we discuss current material's limitations and highlight emerging trends in soft magnetic material design for high-frequency and power applications using the materials paradigm of synthesis → structure → property → performance relationships.