Science.gov

Sample records for power train phase

  1. Occupational Safety. Power Tools. Pre-Apprenticeship Phase 1 Training.

    ERIC Educational Resources Information Center

    Lane Community Coll., Eugene, OR.

    This self-paced student training module on safety when using power tools is one of a number of modules developed for Pre-apprenticeship Phase 1 Training. Purpose of the module is to familiarize students with general safety rules and uses of commonly used electrical, pneumatic, hydraulic, and powder-actuated tools. The module may contain some or…

  2. MHD Advanced Power Train Phase I, Final Report, Volume 6

    SciTech Connect

    A. R. Jones

    1985-08-01

    Under contract to the Department of Energy, Westinghouse has prepared the definition of a program plan for the development of an MHD Advanced Power Train (APT). The scope of work of this contract includes conceptual designs of early commercial MHD/steam electric plants (topping/bottoming) ranging from 200 to 1000 Mw(e). These plant designs were prepared during 1982 and made use of a system analysis model that provides performance and design information and economic estimates. In early April 1984, DOE requested westinghouse to perform special studies under the existing APT contract to aid the Department in evaluating MHD program options. Two tasks were defined by DOE: the first task was to evaluate an 80 MW(t) integrated test system (with steam electric bottoming cycle) for installation at the CDIF in Butte, Montana; the second task was to investigate placing a 50 MW(e) MHD topping stage onto an existing steam electric plant (as a retrofit). This volume of the final report documents the results of these special studies. Highlights of the studies were presented orally to DOE on May 15, 1984.

  3. MHD advanced power train. Phase 1, Final report: Volume 1, Executive summary

    SciTech Connect

    Jones, A.R.

    1985-08-01

    The Phase I objective of defining a plan for the development program that will provide qualification of the engineering data base for MHD power trains for MHD/steam plants with 200 MW(e) capacity, has been achieved. A program has been defined for engineering development of components, scale-up of power train components to reach 200 MW(e), integration of components into proof-of-concept power train systems at two logical ratings, and integration of power train system into the total plant at the larger rating. There is no requirement for scientific breakthrough. The plan will produce technical success in the shortest schedule and at lowest cost; it identifies the required management and engineering tools and expertise.

  4. MHD Advanced Power Train Phase I, Final Report, Volume 7

    SciTech Connect

    A. R. Jones

    1985-08-01

    This appendix provides additional data in support of the MHD/Steam Power Plant Analyses reported in report Volume 5. The data is in the form of 3PA/SUMARY computer code printouts. The order of presentation in all four cases is as follows: (1) Overall Performance; (2) Component/Subsystem Information; (3) Plant Cost Accounts Summary; and (4) Plant Costing Details and Cost of Electricity.

  5. Early phase interference between low-intensity running and power training in moderately trained females.

    PubMed

    Terzis, Gerasimos; Spengos, Kostas; Methenitis, Spyros; Aagaard, Per; Karandreas, Nikos; Bogdanis, Gregory

    2016-05-01

    The aim of the study was to investigate the effects of low-intensity running performed immediately after lower-body power-training sessions on power development. Twenty young females participated in 6 weeks, 3/week, of either lower body power training (PT) or lower body power training followed by 30 min of low-intensity running (PET) eliciting 60-70 % of maximal heart rate. The following were measured before and after the training period: counter-movement jump, isometric leg press force and rate of force development (RFD), half squat 1-RM, vastus lateralis fiber type composition and cross sectional area, resting intramuscular fiber conduction velocity (MFCV), and heart rate during the modified Bruce treadmill test. Counter-movement jump height and peak power increased after PT (10.7 ± 6.2 and 12.9 ± 18.7 %, p < 0.05) but not after PET (3.4 ± 7.6 and 5.11 ± 10.94 %, p > 0.05). Maximum isometric force, RFD, and half squat 1-RM increased similarly in both groups. Muscle fiber type composition was not altered in either group. Muscle fiber cross sectional area increased only after PT (17.5 ± 17.4, 14.5 ± 10.4, 20.36 ± 11.3 %, in type I, IIA, and IIX fibers, respectively, p < 0.05). Likewise, mean MFCV increased with PT only (before: 4.53 ± 0.38 m s(-1), after: 5.09 ± 0.39 m s(-1), p = 0.027). Submaximal heart rate during the Bruce treadmill test remained unchanged after PT but decreased after PET. These results suggest that low-intensity running performed after lower-body power training impairs the exercise-induced adaptation in stretch-shortening cycle jumping performance (vertical jump height, peak power), during the first 6 weeks of training, which may be partially linked to inhibited muscle fiber hypertrophy and muscle fiber conduction velocity.

  6. Power Trains.

    ERIC Educational Resources Information Center

    Kukuk, Marvin; Mathis, Joe

    This curriculum guide is part of a series designed to teach students about diesel engines. The materials in this power trains guide apply to both on-road and off-road vehicles and include information about chain and belt drives used in tractors and combines. These instructional materials, containing nine units, are written in terms of student…

  7. MHD advanced power train. Phase 1, Final report: Volume 3, Power train system description and specification for 200MWe Plant

    SciTech Connect

    Jones, A.R.

    1985-08-01

    This System Design Description and Specification provides the basis for the design of the magnetohydrodynamic (MHD) Power Train (PT) for a nominal 200 MWe early commercial tiHD/Steam Power Plant. This document has been developed under Task 2, Conceptual Design, of Contract DE-AC22-83PC60575 and is to be used by the project as the controlling and coordinating documentation during future design efforts. Modification and revision of this specification will occur as the design matures, and tiie-Westinghouse MHD Project Manager will be the focal point for maintaining this document and issuing periodic revisions. This document is intended to delineate the power train and-power train components requirements and assumptions that properly reflect the MHD/Steam Power Plant in the PT design. The parameters discussed in this document have been established through system calculations as well as through constraints set by technology and by limitations on materials, cost, physical processes associated with MHD, and the expected operating data for the plant. The specifications listed in this document have precedence over all referenced documents. Where this specification appears to conflict with the requirements of a reference document, such conflicts should be brought to the attention of the Westinghouse MHD Project Manager for resolution.

  8. Study of multi-phase flow characteristics in an MHD power train

    SciTech Connect

    Chang, S.L.; Lottes, S.A.; Bouillard, J.X.; Petrick, M.

    1993-08-01

    Computer simulation was used to predict two-phase flow processes in the CDIF MHD power train system. The predictions were used to evaluate the effects of operating and design parameters on the performance of the system and a parametric evaluation provides information to enhance the performance of the system. Major components of the system under investigation are the two-stage combustor, the converging/diverging nozzle, the supersonic MHD channel, and the diffuser. Flow in each component was simulated using a computer code. Integrating the computer codes, the two-phase flow processes in the system was calculated. Recently, the computer codes were used to investigate problems of nozzle erosion and the non-uniform iron oxide coverage on the cathode wall in the channel. A limited parametric study was conducted. The results indicated that (1) among the three nozzle geometries under investigation a {number_sign}5 nozzle has the smoothest flow development in the nozzle and has the lowest droplet deposition on wall and (2) smaller particle size and lower injection velocity tend to disperse the iron oxide particles more uniformly in the nozzle.

  9. MHD advanced power train. Phase 1, Final report: Volume 2, Development program plan

    SciTech Connect

    Jones, A.R.

    1985-08-01

    Two scale-up steps are required before the 200 MW(e) power plant could be designed and constructed. The development program plan is designed to meet these 3 needed program elements: (a) design and demonstration test of a 50 MW(t) power train that verifies channel life; (b) design, development, and demonstration of an advanced power train in a 250 MW(t) plant facility; and (c) development of technology for advanced MHD generators that are economic of magnet warm bore, reliable for at least 4000 hours operation, and are amenable to automated production to meet the low cost goal. An implicit program element, Base Technology, provides support to these 3 elements. The overall program will require 11 years and is estimated to cost $278 million in 1984 dollars.

  10. Automotive Power Trains.

    ERIC Educational Resources Information Center

    Marine Corps Inst., Washington, DC.

    This correspondence course, originally developed for the Marine Corps, is designed to provide mechanics with an understanding of the operation, maintenance, and troubleshooting of automotive power trains and certain auxiliary equipment. The course contains six study units covering basic power trains; clutch principles and operations; conventional…

  11. High power phase shifter

    SciTech Connect

    Foster, B.; Gonin, I.; Khabiboulline, T.; Makarov, A.; Solyak, N.; Terechkine, I.; Wildman, D.; /Fermilab

    2005-05-01

    One of the approaches to power distribution system of a superconducting proton linac under discussion at FNAL requires development of a fast-action, megawatt-range phase shifter. Using a couple of this kind of devices with a waveguide hybrid junction can allow independent control of phase and amplitude of RF power at the input of each superconducting cavity, which will result in significant saving in number of klystrons and modulators required for the accelerator. A prototype of a waveguide version of the shifter that uses Yttrium-Iron Garnet (YIG) blocks was developed and tested. This report presents design concept of the device, and main results of simulation and proof-of-principle tests.

  12. Three phase power factor controller

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1984-01-01

    A power control circuit for a three phase induction motor is described. Power factors for the three phases are summed to provide a control signal, and this control signal is particularly filtered and then employed to control the duty cycle of each phase of input power to the motor.

  13. Three phase power factor controller

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1980-01-01

    A power control circuit for a three phase induction motor is described. The power factors for the three phases are summed to provide a control signal. This control signal is particularly filtered and then employed to control the duty cycle of each phase of input power to the motor.

  14. Power Trains. FOS: Fundamentals of Service.

    ERIC Educational Resources Information Center

    John Deere Co., Moline, IL.

    This power trains manual is one of a series of power mechanics for training in the servicing of transmissions, etc., on farm and industrial machines. Materials provide basic information and illustrations for use by vocational students and teachers as well as shop servicemen and laymen. The ten chapters focus on (1) Power Trains: How They Work; (2)…

  15. Multichannel Phase and Power Detector

    NASA Technical Reports Server (NTRS)

    Li, Samuel; Lux, James; McMaster, Robert; Boas, Amy

    2006-01-01

    An electronic signal-processing system determines the phases of input signals arriving in multiple channels, relative to the phase of a reference signal with which the input signals are known to be coherent in both phase and frequency. The system also gives an estimate of the power levels of the input signals. A prototype of the system has four input channels that handle signals at a frequency of 9.5 MHz, but the basic principles of design and operation are extensible to other signal frequencies and greater numbers of channels. The prototype system consists mostly of three parts: An analog-to-digital-converter (ADC) board, which coherently digitizes the input signals in synchronism with the reference signal and performs some simple processing; A digital signal processor (DSP) in the form of a field-programmable gate array (FPGA) board, which performs most of the phase- and power-measurement computations on the digital samples generated by the ADC board; and A carrier board, which allows a personal computer to retrieve the phase and power data. The DSP contains four independent phase-only tracking loops, each of which tracks the phase of one of the preprocessed input signals relative to that of the reference signal (see figure). The phase values computed by these loops are averaged over intervals, the length of which is chosen to obtain output from the DSP at a desired rate. In addition, a simple sum of squares is computed for each channel as an estimate of the power of the signal in that channel. The relative phases and the power level estimates computed by the DSP could be used for diverse purposes in different settings. For example, if the input signals come from different elements of a phased-array antenna, the phases could be used as indications of the direction of arrival of a received signal and/or as feedback for electronic or mechanical beam steering. The power levels could be used as feedback for automatic gain control in preprocessing of incoming signals

  16. Power Line Technician's Training. Instructional Units.

    ERIC Educational Resources Information Center

    Smith, Earle L.

    These instructional units, developed in Oklahoma, are designed for training power line technicians for rural electric cooperatives. Planned to help current employees advance in knowledge and skill, the instructional materials are divided into seven areas of training: Laborer; Groundworker or Equipment Operator; Power Line Technician, Step 1; Power…

  17. Outdoor Power Equipment Technician Program. Apprenticeship Training.

    ERIC Educational Resources Information Center

    Alberta Learning, Edmonton. Apprenticeship and Industry Training.

    This document presents information about the apprenticeship training program of Alberta, Canada, in general and the outdoor power equipment technician program in particular. The first part of the document discusses the following items: Alberta's apprenticeship and industry training system; the apprenticeship and industry training committee…

  18. Training Continued through Plant Phase-Out

    ERIC Educational Resources Information Center

    Judson, James H.

    1976-01-01

    Even when one of its plants was phased out, the Union Carbide Corp. Program continued with regular training programs and also put two additional programs into motion: Training for employees who would be re-entering the job market and training for employees eligible for retirement benefits. (ABM)

  19. Weight Training for Strength and Power.

    ERIC Educational Resources Information Center

    President's Council on Physical Fitness and Sports, Washington, DC.

    This paper begins by defining the terms "weight training,""weight lifting,""strength,""power," and "muscular endurance.""Weight training" is differentiated from "weight lifting" and defined as a systematic series of resistance exercises designed to promote physical development and conditioning or to rehabilitate persons who have suffered injury or…

  20. Single-phase to three-phase power conversion interface

    NASA Astrophysics Data System (ADS)

    Wu, Jinn-Chang; Wang, Yung-Shan; Jou, Hurng-Liahng; Lu, Wei-Tso

    2016-07-01

    This study proposes a single-phase to three-phase power conversion interface which converts the power from a single-phase utility to three-phase power for a three-phase load. The proposed single-phase to three-phase power conversion interface comprises a bridge-type switch set, a set of three-phase inductors, a transformer set and a set of three-phase capacitors. A current-mode control controls the switching of bridge-type switch set, to generate a set of nonzero-sequence (NZS) currents and a set of zero-sequence (ZS) currents. The transformer set is used to decouple the NZS currents and the ZS currents. The NZS currents are used to generate a high-quality three-phase voltage that supplies power to a three-phase load. The ZS currents flow to the single-phase utility so that the utility current is sinusoidal and in phase with the utility voltage. Accordingly, only a bridge-type switch set is used in the single-phase to three-phase power conversion interface to simply the power circuit. A prototype is developed and tested to verify the performance of the proposed single-phase to three-phase power conversion interface.

  1. Power lunch: Teaming to train

    SciTech Connect

    Sartoris, B.E. ); Snow, E.A.; Whitehead, J.K. )

    1991-05-01

    In 1990, the Hanford Site, a US Department of Energy project, changed missions from defense production to environmental restoration. An engineering group at Westinghouse Hanford Company, prime contractor at the Hanford Site, hired a trainer to help publish documents and develop group-specific courses. Boeing Computer Services Richland, subcontractor providing publications services, hired editor trainers. Kaiser Engineers Hanford, another subcontractor, provides site-wide Quality training. Four trainers, friends, met weekly for lunch: These meetings evolved into training exchanges. This presentation illustrates ways that inter- or intra-company teaming can work to improve technical communication. Additional benefits are significant cost and time savings to all companies involved.

  2. Three-Phase Power Factor Controller

    NASA Technical Reports Server (NTRS)

    Nola, F. J.

    1982-01-01

    Three-Phase Power-Factor Controller develops a control signal for each motor winding. As motor loading decreases, rms value of applied voltage is decreased by feedback-control circuit. Power consumption is therefore lower than in unregulated operation. Controller employs phase detector for each of three phases of delta-connected induction motor. Phase-difference sum is basis for control.

  3. Private Security Training. Phase 4: Firearms Training. Instructor Edition.

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This curriculum guide provides instructional materials for the firearms training phase of a private security training course of study. The seven units in the course cover the following topics: safety; revolver nomenclature and maintenance; inspecting revolvers and holsters; fundamentals of revolver shooting; legal issues and deadly force; range…

  4. Plumbing. Pre-Apprenticeship Phase 2 Training. Student Training Modules.

    ERIC Educational Resources Information Center

    Brath, Ed

    These 26 Student Training Modules on plumbing comprise one of nine sets of self-paced learning modules developed for Pre-Apprenticeship Phase 2 Training. (A companion instructor's guide is available separately as CE 031 577.) The modules are designed to impart trade knowledge and skills to the student. Each module contains some or all of the…

  5. Bricklaying. Pre-Apprenticeship Phase 2 Training. Student Training Modules.

    ERIC Educational Resources Information Center

    Cholewinski, Scott

    These 23 Student Training Modules on bricklaying comprise one of nine sets of self-paced learning modules developed for Pre-Apprenticeship Phase 2 Training. (A companion instructor's guide is available separately as CE 031 567.) The modules are designed to impart trade knowledge and skills to the student. Each module contains some or all of the…

  6. Tilesetting. Pre-Apprenticeship Phase 2 Training. Student Training Modules.

    ERIC Educational Resources Information Center

    Ausland, Greg

    These 24 Student Training Modules on tilesetting comprise one of nine sets of self-paced learning modules developed for Pre-Apprenticeship Phase 2 Training. (A companion instructor's guide is available separately as CE 031 563.) The modules are designed to impart trade knowledge and skills to the student. Each module contains some or all of the…

  7. Private Security Training. Phase 4: Firearms Training. Instructor Edition.

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This curriculum guide provides instructional materials for the firearms training phase of a private security training course of study. The seven units in the course cover the following topics: safety; revolver nomenclature and maintenance; inspecting revolvers and holsters; fundamentals of revolver shooting; legal issues and deadly force; range…

  8. Drywall. Pre-Apprenticeship Phase 2 Training. Student Training Modules.

    ERIC Educational Resources Information Center

    Moore, Doug

    These 18 Student Training Modules on drywall comprise one of nine sets of self-paced learning modules developed for Pre-Apprenticeship Phase 2 Training. (A companion instructor's guide is available separately as CE 031 573.) The modules are designed to impart trade knowledge and skills to the student. Each module contains some or all of the…

  9. Plastering. Pre-Apprenticeship Phase 2 Training. Student Training Modules.

    ERIC Educational Resources Information Center

    Hamblen, Ron

    These 20 Student Training Modules on plastering comprise one of nine sets of self-paced learning modules developed for Pre-Apprenticeship Phase 2 Training. (A companion instructor's guide is available separately as CE 031 569.) The modules are designed to impart trade knowledge and skills to the student. Each module contains some or all of the…

  10. Painting. Pre-Apprenticeship Phase 2 Training. Student Training Modules.

    ERIC Educational Resources Information Center

    Kracht, Shannon

    These 21 Student Training Modules on painting comprise one of nine sets of self-paced learning modules developed for Pre-Apprenticeship Phase 2 Training. (A companion instructor's guide is available separately as CE 031 561.) The modules are designed to impart trade knowledge and skills to the student. Each module contains some or all of the…

  11. Power inverter implementing phase skipping control

    DOEpatents

    Somani, Utsav; Amirahmadi, Ahmadreza; Jourdan, Charles; Batarseh, Issa

    2016-10-18

    A power inverter includes a DC/AC inverter having first, second and third phase circuitry coupled to receive power from a power source. A controller is coupled to a driver for each of the first, second and third phase circuitry (control input drivers). The controller includes an associated memory storing a phase skipping control algorithm, wherein the controller is coupled to receive updating information including a power level generated by the power source. The drivers are coupled to control inputs of the first, second and third phase circuitry, where the drivers are configured for receiving phase skipping control signals from the controller and outputting mode selection signals configured to dynamically select an operating mode for the DC/AC inverter from a Normal Control operation and a Phase Skipping Control operation which have different power injection patterns through the first, second and third phase circuitry depending upon the power level.

  12. Phase protection system for ac power lines

    NASA Technical Reports Server (NTRS)

    Wong, W. J. (Inventor)

    1974-01-01

    The system described provides protection for phase sensitive loads from being or remaining connected to ac power lines whenever a phase reversal occurs. It comprises a solid state phase detection circuit, a dc power relay circuit, an ac-to-dc converter for energizing the relay circuit, and a bistable four terminal transducer coupled between the phase detection circuit and the power relay circuit, for controlling both circuits.

  13. Maximum Power Training and Plyometrics for Cross-Country Running.

    ERIC Educational Resources Information Center

    Ebben, William P.

    2001-01-01

    Provides a rationale for maximum power training and plyometrics as conditioning strategies for cross-country runners, examining: an evaluation of training methods (strength training and maximum power training and plyometrics); biomechanic and velocity specificity (role in preventing injury); and practical application of maximum power training and…

  14. Maximum Power Training and Plyometrics for Cross-Country Running.

    ERIC Educational Resources Information Center

    Ebben, William P.

    2001-01-01

    Provides a rationale for maximum power training and plyometrics as conditioning strategies for cross-country runners, examining: an evaluation of training methods (strength training and maximum power training and plyometrics); biomechanic and velocity specificity (role in preventing injury); and practical application of maximum power training and…

  15. Plyometrics: A Legitimate Form of Power Training?

    ERIC Educational Resources Information Center

    Duda, Marty

    1988-01-01

    Plyometric exercises or drills combine speed and strength to produce an explosive-reactive movement or increased power. Some world-class athletes have used plyometric-training in sports such as high-jumping, hurdles, football, baseball, and hockey. The method is still considered experimental. Sample exercises are described. (JL)

  16. Plyometrics: A Legitimate Form of Power Training?

    ERIC Educational Resources Information Center

    Duda, Marty

    1988-01-01

    Plyometric exercises or drills combine speed and strength to produce an explosive-reactive movement or increased power. Some world-class athletes have used plyometric-training in sports such as high-jumping, hurdles, football, baseball, and hockey. The method is still considered experimental. Sample exercises are described. (JL)

  17. Fuel cell power trains for road traffic

    NASA Astrophysics Data System (ADS)

    Höhlein, Bernd; Biedermann, Peter; Grube, Thomas; Menzer, Reinhard

    Legal regulations, especially the low emission vehicle (LEV) laws in California, are the driving forces for more intensive technological developments with respect to a global automobile market. In the future, high efficient vehicles at very low emission levels will include low temperature fuel cell systems (e.g., polymer electrolyte fuel cell (PEFC)) as units of hydrogen-, methanol- or gasoline-based electric power trains. In the case of methanol or gasoline/diesel, hydrogen has to be produced on-board using heated steam or partial oxidation reformers as well as catalytic burners and gas cleaning units. Methanol could also be used for direct electricity generation inside the fuel cell (direct methanol fuel cell (DMFC)). The development potentials and the results achieved so far for these concepts differ extremely. Based on the experience gained so far, the goals for the next few years include cost and weight reductions as well as optimizations in terms of the energy management of power trains with PEFC systems. At the same time, questions of fuel specification, fuel cycle management, materials balances and environmental assessment will have to be discussed more intensively. On the basis of process engineering analyses for net electricity generation in PEFC-powered power trains as well as on assumptions for both electric power trains and vehicle configurations, overall balances have been carried out. They will lead not only to specific energy demand data and specific emission levels (CO 2, CO, VOC, NO x) for the vehicle but will also present data of its full fuel cycle (FFC) in comparison to those of FFCs including internal combustion engines (ICE) after the year 2005. Depending on the development status (today or in 2010) and the FFC benchmark results, the advantages of balances results of FFC with PEFC vehicles are small in terms of specific energy demand and CO 2 emissions, but very high with respect to local emission levels.

  18. RF waveguide phase-directed power combiners

    DOEpatents

    Nantista, Christopher D.; Dolgashev, Valery A.; Tantawi, Sami G.

    2017-05-02

    High power RF phase-directed power combiners include magic H hybrid and/or superhybrid circuits oriented in orthogonal H-planes and connected using E-plane bends and/or twists to produce compact 3D waveguide circuits, including 8.times.8 and 16.times.16 combiners. Using phase control at the input ports, RF power can be directed to a single output port, enabling fast switching between output ports for applications such as multi-angle radiation therapy.

  19. HIGH POWER FERRITE PHASE SHIFTER

    DTIC Science & Technology

    power tests to 100 kw peak are reported for waveguide configurations containing (1) single crystal lithium ferrite; (2) polycrystalline cubic ... structure , nickel ferrite; and (3) polycrystalline hexagonal structure nickel-cobalt ’W’ ferrite with its magnetic anisotropy oriented parallel to the applied

  20. GPS synchronized power system phase angle measurements

    NASA Astrophysics Data System (ADS)

    Wilson, Robert E.; Sterlina, Patrick S.

    1994-09-01

    This paper discusses the use of Global Positioning System (GPS) synchronized equipment for the measurement and analysis of key power system quantities. Two GPS synchronized phasor measurement units (PMU) were installed before testing. It was indicated that PMUs recorded the dynamic response of the power system phase angles when the northern California power grid was excited by the artificial short circuits. Power system planning engineers perform detailed computer generated simulations of the dynamic response of the power system to naturally occurring short circuits. The computer simulations use models of transmission lines, transformers, circuit breakers, and other high voltage components. This work will compare computer simulations of the same event with field measurement.

  1. Environmental Assessment for the Construction of Power and Fiber Optic Lines to Facilities in the Yukon Training Area, Alaska - Phase 4

    DTIC Science & Technology

    2007-11-01

    action will result in the construction of 2.84 miles of electrical transmission and fiber optic communication lines along Beaver Creek Road , with a spur...interior. Historical or Cultural Resources The entire proposed power line corridor along Beaver Creek Road is outside the impact area and was previously...extends from Beaver Creek Road to Camera Site 2 is within the impact area of the Stuart Creek Range and was not surveyed due to the risk of unexploded

  2. Phase detector for three-phase power factor controller

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1984-01-01

    A phase detector for the three phase power factor controller (PFC) is described. The phase detector for each phase includes an operational amplifier which senses the current phase angle for that phase by sensing the voltage across the phase thyristor. Common mode rejection is achieved by providing positive feedback between the input and output of the voltage sensing operational amplifier. this feedback preferably comprises a resistor connected between the output and input of the operational amplifier. The novelty of the invention resides in providing positive feedback such that switching of the operational amplifier is synchronized with switching of the voltage across the thyristor. The invention provides a solution to problems associated with high common mode voltage and enables use of lower cost components than would be required by other approaches.

  3. High power phase locked laser oscillators

    NASA Technical Reports Server (NTRS)

    Hayes, C. L.; Telk, C. L.; Soohoo, J.; Davis, W. C.

    1979-01-01

    The feasibility of mechanizing an adaptive array of independent laser oscillators for generation of a high power coherent output was experimentally investigated. Tests were structured to evaluate component/system requirements for delivery of energy to a low-earth orbit satellite. Initial experiments addressed the control issues of phase locking unstable resonators at low power levels. A successful phase lock demonstration formed the basis for the design and fabrication of the high power, water-cooled, control mirror subsequently installed in the NASA LeRC high power laser. Tests were performed to characterize the operational limits of the laser system and included quantitative assessment of the frequency stability, noise sources, and optical properties of the beam.

  4. Cummins Power Generation SECA Phase 1

    SciTech Connect

    Charles Vesely

    2007-08-17

    The following report documents the progress of the Cummins Power Generation (CPG) SECA Phase 1 SOFC development and final testing under the U.S. Department of Energy Solid State Energy Conversion Alliance (SECA) contract DE-FC26-01NT41244. This report overviews and summarizes CPG and partner research development leading to successful demonstration of the SECA Phase 1 objectives and significant progress towards SOFC commercialization. Significant Phase 1 Milestones: (1) Demonstrated: (a) Operation meeting Phase 1 requirements on commercial natural gas. (b) LPG and Natural Gas CPOX fuel reformers. (c) SOFC systems on dry CPOX reformate. (c) Steam reformed Natural Gas operation. (d) Successful start-up and shut-down of SOFC system without inert gas purge. (e) Utility of stack simulators as a tool for developing balance of plant systems. (2) Developed: (a) Low cost balance of plant concepts and compatible systems designs. (b) Identified low cost, high volume components for balance of plant systems. (c) Demonstrated high efficiency SOFC output power conditioning. (d) Demonstrated SOFC control strategies and tuning methods. The Phase 1 performance test was carried out at the Cummins Power Generation facility in Minneapolis, Minnesota starting on October 2, 2006. Performance testing was successfully completed on January 4, 2007 including the necessary steady-state, transient, efficiency, and peak power operation tests.

  5. Changes in Stress and Appetite Responses in Male Power-Trained Athletes during Intensive Training Camp.

    PubMed

    Oshima, Satomi; Takehata, Chisato; Sasahara, Ikuko; Lee, Eunjae; Akama, Takao; Taguchi, Motoko

    2017-08-21

    An intensive consecutive high-volume training camp may induce appetite loss in athletes. Therefore, this study aimed to investigate the changes in stress and appetite responses in male power-trained athletes during an intensive training camp. The measurements at Day 2 and at the end of a 9-day intensive training camp (Camp1 and Camp2, respectively) were compared with those of the resting period (Rest) and the regular training period (Regular; n = 13). The stress state was assessed based on plasma cortisol level, salivary immunoglobulin A level, and a profile of mood states score. The sensation of appetite was assessed using visual analog scale scores, and fasting plasma acylated ghrelin, insulin, and glucose were measured. The cortisol concentrations were significantly higher at Camp2 (466.7 ± 60.7 nmol∙L(-1)) than at Rest (356.3 ± 100.9 nmol∙L(-1); p = 0.002) or Regular (361.7 ± 111.4 nmol∙L(-1); p = 0.003). Both prospective and actual food consumption significantly decreased at Camp2, and acylated ghrelin concentration was significantly lower at Camp1 (34.2 ± 8.0 pg∙mL(-1)) and Camp2 (32.0 ± 8.7 pg∙mL(-1)) than at Rest (47.2 ± 11.2 pg∙mL(-1)) or Regular (53.4 ± 12.6 pg∙mL(-1)). Furthermore, the change in acylated ghrelin level was negatively correlated with the change in cortisol concentration. This study's findings suggest that an early-phase physiological stress response may decrease the acylated ghrelin level in male power-trained athletes during an intensive training camp.

  6. T-4G Methodology: Undergraduate Pilot Training T-37 Phase.

    ERIC Educational Resources Information Center

    Woodruff, Robert R.; And Others

    The report's brief introduction describes the application of T-4G methodology to the T-37 instrument phase of undergraduate pilot training. The methodology is characterized by instruction in trainers, proficiency advancement, a highly structured syllabus, the training manager concept, early exposure to instrument training, and hands-on training.…

  7. Power system identification toolbox: Phase two progress

    SciTech Connect

    Trudnowski, D.J.

    1994-08-01

    This report describes current progress on a project funded by the Bonneville Power Administration (BPA) to develop a set of state-of-the-art analysis software (termed the Power System Identification [PSI] Toolbox) for fitting dynamic models to measured data. The project is being conducted as a three-phase effort. The first phase, completed in late 1992, involved investigating the characteristics of the analysis techniques by evaluating existing software and developing guidelines for best use. Phase Two includes extending current software, developing new analysis algorithms and software, and demonstrating and developing applications. The final phase will focus on reorganizing the software into a modular collection of documented computer programs and developing user manuals with instruction and application guidelines. Phase Two is approximately 50% complete; progress to date and a vision for the final product of the PSI Toolbox are described. The needs of the power industry for specialized system identification methods are particularly acute. The industry is currently pushing to operate transmission systems much closer to theoretical limits by using real-time, large-scale control systems to dictate power flows and maintain dynamic stability. Reliably maintaining stability requires extensive system-dynamic modeling and analysis capability, including measurement-based methods. To serve this need, the BPA has developed specialized system-identification computer codes through in-house efforts and university contract research over the last several years. To make full integrated use of the codes, as well as other techniques, the BPA has commissioned Pacific Northwest Laboratory (PNL) to further develop the codes and techniques into the PSI Toolbox.

  8. 29 CFR 1915.120 - Powered industrial truck operator training.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Powered industrial truck operator training. 1915.120... Gear and Equipment for Rigging and Materials Handling § 1915.120 Powered industrial truck operator training. Note: The requirements applicable to shipyard employment under this section are identical...

  9. Near-term hybrid vehicle program, phase 1. Appendix B: Design trade-off studies. [various hybrid/electric power train configurations and electrical and mechanical drive-line components

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The relative attractiveness of various hybrid/electric power train configurations and electrical and mechanical drive-line components was studied. The initial screening was concerned primarily with total vehicle weight and economic factors and identified the hybrid power train combinations which warranted detailed evaluation over various driving cycles. This was done using a second-by-second vehicle simulation program which permitted the calculations of fuel economy, electricity usage, and emissions as a function of distance traveled in urban and highway driving. Power train arrangement possibilities were examined in terms of their effect on vehicle handling, safety, serviceability, and passenger comfort. A dc electric drive system utilizing a separately excited motor with field control and battery switching was selected for the near term hybrid vehicle. Hybrid vehicle simulations showed that for the first 30 mi (the electric range of the vehicle) in urban driving, the fuel economy was 80 mpg using a gasoline engine and 100 mpg using a diesel engine. In urban driving the hybrid would save about 75% of the fuel used by the conventional vehicle and in combined urban/highway driving the fuel saving is about 50%.

  10. Trowel Trades. Pre-Apprenticeship Phase 1 Training. Instructor's Guide.

    ERIC Educational Resources Information Center

    Lane Community Coll., Eugene, OR.

    This instructor's guide accompanies the self-paced student training modules on trowel trades, four of which are available separately as CE 032 869-872. Introductory materials include an introduction to pre-apprenticeship and its three phases of training, a recommended procedure for conducting pre-apprenticeship training, and a course outline.…

  11. Carpentry. Pe-Apprenticeship Phase 1 Training. Instructor's Guide.

    ERIC Educational Resources Information Center

    Lane Community Coll., Eugene, OR.

    This instructor's guide accompanies the self-paced student training modules on the carpentry trade, two of which are available separately as CE 032 876-877. Introductory materials include an introduction to pre-apprenticeship and its three phases of training, a recommended procedure for conducting pre-apprenticeship training, and a course outline.…

  12. C-130 Phase I Pilot Training Program (CCTS).

    ERIC Educational Resources Information Center

    Shaw, Jack B.; And Others

    This is a detailed study of the C-130 Phase I (CCTS) pilot training program conducted by the 4442nd Combat Crew Training Wing at Stewart Air Force Base, Tennessee. The purpose of the study was to determine the most effective training program that will continue to produce highly qualified pilots at the least cost. The program was evaluated and…

  13. Undeground Coal Mine Supervisory and Management Training. Phase I Report.

    ERIC Educational Resources Information Center

    Loustaunau, Paul; And Others

    A project was conducted to develop a safety-oriented supervisory and management training program for the underground coal mining industry. The first phase of the project involved research to determine relevant training materials that are available and in use, assessment of supervisory and management training needs, and development of objectives…

  14. Auto Mechanics. Pre-Apprenticeship Phase 1 Training. Instructor's Guide.

    ERIC Educational Resources Information Center

    Lane Community Coll., Eugene, OR.

    This instructor's guide accompanies the self-paced student training modules on auto mechanics, one of which is available separately as CE 032 867. Introductory materials include an introduction to pre-apprenticeship and its three phases of training, a recommended preocedure for conducting pre-apprenticeship training, and a course outline. Teaching…

  15. Thermophotovoltaic space power system, phase 3

    NASA Technical Reports Server (NTRS)

    Horne, W. E.; Lancaster, C.

    1987-01-01

    Work performed on a research and development program to establish the feasibility of a solar thermophotovoltaic space power generation concept was summarized. The program was multiphased. The earlier work is summarized and the work on the current phase is detailed as it pertains to and extends the earlier work. Much of the experimental hardware and materials development was performed on the internal program. Experimental measurements and data evaluation were performed on the contracted effort. The objectives of the most recent phase were: to examine the thermal control design in order to optimize it for lightweight and low cost; to examine the concentrator optics in an attempt to relieve pointing accuracy requirements to + or - 2 degrees about the optical axis; and to use the results of the thermal and optical studies to synthesize a solar thermophotovoltaic (STPV) module design that is optimized for space application.

  16. Design of Training Systems Phase I Summary Report.

    ERIC Educational Resources Information Center

    Lindahl, William H.; And Others

    A summary is provided of the status of Phase I of the three-stage project, "Design of Training Systems" (DOTS). The purpose of the overall project is described as being to introduce the technologies of education, psychology, management and operations research into the management of Navy training. Phase I of the effort is designed to…

  17. Expedition 29/30 crew training during Electrical Power System Major Case training

    NASA Image and Video Library

    2011-06-22

    PHOTO DATE: 22 June 2011 LOCATION: Bldg. 5, Space Station Training Facility. SUBJECT: Expedition 29/30 crew training during Electrical Power System Major Case training event. Astronauts Dan Burbank, Don Pettit and Andre Kuipers working together in mockup. PHOTOGRAPHER: Mark Sowa

  18. Plyometrics: A Legitimate Form of Power Training?

    PubMed

    Duda, M

    1988-03-01

    More and more athletes are training with plyometric exercises, which involve explosive movements such as jumping. Proponents swear by the drills, but researchers have yet to substantiate the risks and benefits.

  19. Effects of high-intensity training by heart rate or power in well-trained cyclists.

    PubMed

    Swart, Jeroen; Lamberts, Robert P; Derman, Wayne; Lambert, Michael I

    2009-03-01

    The aim of this study was to determine whether the performance of cyclists after 4 weeks of high-intensity training improved similarly using either heart rate or power to prescribe training. Twenty-one well-trained men cyclists (age, 32 +/- 6 years; peak power output, 371 +/- 46 W) were randomly assigned to a power-based (GPOWER) or heart rate-based (GHEART) high-intensity training (HIT) group or a control group (GCONTROL). Training consisted of 8 repetitions of 4 minutes at either 80% of peak power output (GPOWER) or at the heart rate coinciding with 80% of peak power output (GHEART), with rest periods of 90 seconds. A 40-km time trial and VO2max test were performed before and after 8 training sessions. There were significant improvements (p < 0.05) in peak power output (GPOWER = 3.5%; GHEART = 5.0%) and 40-km time trial performance (GPOWER = 2.3%; GHEART = 2.1%) for both of the high-intensity groups. Although there were no significant differences between groups for these variables, when the data were analyzed using magnitude-based effects, the GHEART group showed greater probability of a "beneficial" effect for peak power output. The current general perception that prescribing training based only on power is more effective than prescribing training based on heart rate was not supported by the data from this study. Coaches who are unable to monitor progress frequently should prescribe training based on heart rate, when intervals are performed under stable conditions, because this may provide an additional advantage over prescribing training using power.

  20. Phase Change Material Thermal Power Generator

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.

    2013-01-01

    An innovative modification has been made to a previously patented design for the Phase Change Material (PCM) Thermal Generator, which works in water where ocean temperature alternatively melts wax in canisters, or allows the wax to re-solidify, causing high-pressure oil to flow through a hydraulic generator, thus creating electricity to charge a battery that powers the vehicle. In this modification, a similar thermal PCM device has been created that is heated and cooled by the air and solar radiation instead of using ocean temperature differences to change the PCM from solid to liquid. This innovation allows the device to use thermal energy to generate electricity on land, instead of just in the ocean.

  1. Adaptations in athletic performance after ballistic power versus strength training.

    PubMed

    Cormie, Prue; McGuigan, Michael R; Newton, Robert U

    2010-08-01

    To determine whether the magnitude of improvement in athletic performance and the mechanisms driving these adaptations differ in relatively weak individuals exposed to either ballistic power training or heavy strength training. Relatively weak men (n = 24) who could perform the back squat with proficient technique were randomized into three groups: strength training (n = 8; ST), power training (n = 8; PT), or control (n = 8). Training involved three sessions per week for 10 wk in which subjects performed back squats with 75%-90% of one-repetition maximum (1RM; ST) or maximal-effort jump squats with 0%-30% 1RM (PT). Jump and sprint performances were assessed as well as measures of the force-velocity relationship, jumping mechanics, muscle architecture, and neural drive. Both experimental groups showed significant (P < or = 0.05) improvements in jump and sprint performances after training with no significant between-group differences evident in either jump (peak power: ST = 17.7% +/- 9.3%, PT = 17.6% +/- 4.5%) or sprint performance (40-m sprint: ST = 2.2% +/- 1.9%, PT = 3.6% +/- 2.3%). ST also displayed a significant increase in maximal strength that was significantly greater than the PT group (squat 1RM: ST = 31.2% +/- 11.3%, PT = 4.5% +/- 7.1%). The mechanisms driving these improvements included significant (P < or = 0.05) changes in the force-velocity relationship, jump mechanics, muscle architecture, and neural activation that showed a degree of specificity to the different training stimuli. Improvements in athletic performance were similar in relatively weak individuals exposed to either ballistic power training or heavy strength training for 10 wk. These performance improvements were mediated through neuromuscular adaptations specific to the training stimulus. The ability of strength training to render similar short-term improvements in athletic performance as ballistic power training, coupled with the potential long-term benefits of improved maximal strength

  2. Bricklaying. Pre-Apprenticeship Phase 2 Training. Instructor's Guide.

    ERIC Educational Resources Information Center

    Cholewinski, Scott

    This instructor's guide accompanies the self-paced student training modules on bricklaying available separately as CE 031 568. Introductory materials include a description of the components of the pre-apprenticeship project, discussion of teacher's role in students' completion of the modules, and scope and contents of Phase 2 training. Each of the…

  3. Occupational Safety. Hygiene Safety. Pre-Apprenticeship Phase 1 Training.

    ERIC Educational Resources Information Center

    Lane Community Coll., Eugene, OR.

    This self-paced student training module on hygiene safety is one of a number of modules developed for Pre-apprenticeship Phase 1 Training. Purpose of the module is to familiarize students with the different types of airborne contaminants--including noise--which may be health hazards and with the proper hygienic measures for dealing with them. The…

  4. Drywall. Pre-Apprenticeship Phase 2 Training. Instructor's Guide.

    ERIC Educational Resources Information Center

    Moore, Doug

    This instructor's guide accompanies the self-paced student training modules on drywall available separately as CE 031 574. Introductory materials include a description of the components of the pre-apprenticeship project, discussion of teacher's role in students' completion of the modules, and scope and contents of Phase 2 training. Each of the 18…

  5. Coherence control of pulse trains by spectral phase modulation

    NASA Astrophysics Data System (ADS)

    Ding, Chaoliang; Koivurova, Matias; Turunen, Jari; Setälä, Tero; Friberg, Ari T.

    2017-09-01

    We propose a technique to control the spectral and temporal coherence properties of pulsed beams of light via time-dependent manipulation of the spectral phase. Modulation schemes for the generation of partially coherent pulse trains from a train of fully coherent pulses are presented. The feasibility of experimental realization of the method is confirmed by numerical estimates.

  6. Boring and Drilling Tools. Pre-Apprenticeship Phase 1 Training.

    ERIC Educational Resources Information Center

    Lane Community Coll., Eugene, OR.

    This self-paced student training module on boring and drilling tools is one of a number of modules developed for Pre-apprenticeship Phase 1 Training. Purpose of the module is to enable students to identify, select, and understand the proper use of many common awls, bits, and drilling tools. The module may contain some or all of the following: a…

  7. Phase control system concepts and simulations. [solar power satellite system

    NASA Technical Reports Server (NTRS)

    Lindsay, V. C.

    1980-01-01

    A phase control system concept for a solar power satellite is proposed which partitions the system into three major levels. The first level of phase control consists of a reference phase distribution system implemented in the form of phase distribution tree structure. The major purpose of the tree structure is to electronically compensate for the phase shift due to the transition path lengths from the center of the spacetenna to each phase control center located in each subarray. In the reference system, this is accomplished using the master slave returnable timing system technique. The second level of phase control consists of the beam steering and microwave power generating system which houses the power transponders. This transponder consists of a set of phase conjugation multipliers driven by the reference phase distribution system output and the output of a pilot spread spectrum receiver which accepts the received pilot via a diplexer connected to a separate receive horn or the subarray itself. The output of the phase conjugation circuits serve as inputs to the third level of the phase control system. The third level of phase control is associated with maintaining an equal and constant phase shift through the microwave power amplifier devices while minimizing the associated phase noise effects on the generated power beam. This is accomplished by providing a phase locked loop around each high power amplifier.

  8. Mine Hoist Operator Training System. Phase I Report.

    DTIC Science & Technology

    1978-11-01

    validated during Phase II of the contract. Phase I is divided into seven tasks: e Task I - Formulate the project Plan. * Task II - Determine the training...materials that are available. * Task III - Conduct a mine hoist operator’s job task analysis of the duties of the mine hoist operator. e Task IV...Develop training objectives. e Task V - Develop instructional strategies. * Task VI - Conduct trade-off studies for the developed strategies. e Task VII

  9. Design of Training Systems Phase III Report

    DTIC Science & Technology

    1975-09-01

    as the reader is aware of this approach and relies on the T&E Report for a more detailed analysis , this summary should highlight the key T&E concerns... ANALYSIS AND EVALUATION GROUP LIBRARY TECHNICAL REPORT SECTION NAVAL POSTGRADUATE S^ MONTEREY CALliChMA TAEG REPORT NO. 28 DESIGN...EVALUATION SUMMARY I II-l IV PHASE III PRODUCTS CONCLUSIONS AND RECOMMENDATIONS IV-1 PHASE III DOCUMENTATION IV-7 11 TAE6 REPORT NO. 28

  10. Automatic phase control in solar power satellite systems

    NASA Technical Reports Server (NTRS)

    Lindsey, W. C.; Kantak, A. V.

    1978-01-01

    Various approaches to the problem of generating, maintaining and distributing a coherent, reference phase signal over a large area are suggested, mathematically modeled and analyzed with respect to their ability to minimize: phase build-up, beam diffusion and beam steering phase jitter, cable length, and maximize power transfer efficiency. In addition, phase control configurations are suggested which alleviate the need for layout symmetry.

  11. Developing maximal neuromuscular power: part 2 - training considerations for improving maximal power production.

    PubMed

    Cormie, Prue; McGuigan, Michael R; Newton, Robert U

    2011-02-01

    This series of reviews focuses on the most important neuromuscular function in many sport performances: the ability to generate maximal muscular power. Part 1, published in an earlier issue of Sports Medicine, focused on the factors that affect maximal power production while part 2 explores the practical application of these findings by reviewing the scientific literature relevant to the development of training programmes that most effectively enhance maximal power production. The ability to generate maximal power during complex motor skills is of paramount importance to successful athletic performance across many sports. A crucial issue faced by scientists and coaches is the development of effective and efficient training programmes that improve maximal power production in dynamic, multi-joint movements. Such training is referred to as 'power training' for the purposes of this review. Although further research is required in order to gain a deeper understanding of the optimal training techniques for maximizing power in complex, sports-specific movements and the precise mechanisms underlying adaptation, several key conclusions can be drawn from this review. First, a fundamental relationship exists between strength and power, which dictates that an individual cannot possess a high level of power without first being relatively strong. Thus, enhancing and maintaining maximal strength is essential when considering the long-term development of power. Second, consideration of movement pattern, load and velocity specificity is essential when designing power training programmes. Ballistic, plyometric and weightlifting exercises can be used effectively as primary exercises within a power training programme that enhances maximal power. The loads applied to these exercises will depend on the specific requirements of each particular sport and the type of movement being trained. The use of ballistic exercises with loads ranging from 0% to 50% of one-repetition maximum (1RM) and

  12. High-powered vehicle drive train

    SciTech Connect

    Kraus, C.E.

    1987-09-15

    This patent describes a vehicle comprising: an engine having an infinitely variable transmission operatively coupled for transmitting engine power to the transmission's input shaft with the transmission output shaft being operatively connected to the vehicle's drive wheels. The transmission comprising a planetary drive structure includes a drive ring gear carrying a first gear in engagement with a drive gear on the input shaft for rotation of the drive ring gear with the input shaft, a central sun gear and planetary gear members disposed in the annular space between, and in engagement with the drive ring gear and the sun gear and rotatably supported on a planetary carrier. The carrier is supported for rotation with the transmission output shaft and an infinitely variable toroidal traction roller transmission structure including two parallel toridal transmissions having a central input toric disc structure common to both toroidal transmissions and operatively connected to the input shaft. The output toric discs being mounted on a shaft associated with the sun gear of the planetary drive.

  13. Parts Counter. Pre-Apprenticeship Phase 2 Training. Student Training Modules.

    ERIC Educational Resources Information Center

    Snyder, James A.

    These 23 Student Training Modules on parts counter comprise one of nine sets of self-paced learning modules developed for Pre-Apprenticeship Phase 2 Training. (A companion instructor's guide is available separately as CE 031 571.) The modules are designed to impart trade knowledge and skills to the student. Each module contains some or all of the…

  14. Cement Finishing. Pre-Apprenticeship Phase 2 Training. Student Training Modules.

    ERIC Educational Resources Information Center

    Nama, Joe

    These 20 Student Training Modules on cement finishing comprise one of nine sets of self-paced learning modules developed for Pre-Apprenticeship Phase 2 Training. (A companion instructor's guide is available separately as CE 031 575.) The modules are designed to impart trade knowledge and skills to the student. Each module contains some or all of…

  15. Floor Covering. Pre-Apprenticeship Phase 2 Training. Student Training Modules.

    ERIC Educational Resources Information Center

    Hamblen, Ron

    These 21 Student Training Modules on floor covering comprise one of nine sets of self-paced learning modules developed for Pre-Apprenticeship Phase 2 Training. (A companion instructor's guide is available separately as CE 031 565.) The modules are designed to impart trade knowledge and skills to the student. Each module contains some or all of the…

  16. Advanced power plant training simulator for VVER-440/V230 nuclear power plants

    SciTech Connect

    Shier, W.; Kennett, R.; Vaclav, E.; Gieci, A.

    1996-11-01

    An advanced, workstation based, nuclear power plant simulator has been developed for use in training the operational staff of the Bohunice Nuclear Power Plant. This training simulator uses state-of- the-art computer hardware and software and provides the capability to simultaneously include six members of the power plant operating staff in the training sessions. A detailed reactor model has been developed, representing the Bohunice VVER-44O/V230 plants, for use with the RELAP5 simulation software. In addition, a comprehensive validation program has been completed that compares the simulation results of the advanced simulator with the results from a current VVER-44O/V230 simulator. A summary of the training features and capabilities of the simulator is also provided.

  17. Does power mobility training impact a child's mastery motivation and spectrum of EEG activity? An exploratory project.

    PubMed

    Kenyon, Lisa K; Farris, John P; Aldrich, Naomi J; Rhodes, Samhita

    2017-08-30

    The purposes of this exploratory project were: (1) to evaluate the impact of power mobility training with a child who has multiple, severe impairments and (2) to determine if the child's spectrum of electroencephalography (EEG) activity changed during power mobility training. A single-subject A-B-A-B research design was conducted with a four-week duration for each phase. Two target behaviours were explored: (1) mastery motivation assessed via the dimensions of mastery questionnaire (DMQ) and (2) EEG data collected under various conditions. Power mobility skills were also assessed. The participant was a three-year, two-month-old girl with spastic quadriplegic cerebral palsy, gross motor function classification system level V. Each target behaviour was measured weekly. During intervention phases, power mobility training was provided. Improvements were noted in subscale scores of the DMQ. Short-term and long-term EEG changes were also noted. Improvements were noted in power mobility skills. The participant in this exploratory project demonstrated improvements in power mobility skill and function. EEG data collection procedures and variability in an individual's EEG activity make it difficult to determine if the participant's spectrum of EEG activity actually changed in response to power mobility training. Additional studies are needed to investigate the impact of power mobility training on the spectrum of EEG activity in children who have multiple, severe impairments. Implications for Rehabilitation Power mobility training appeared to be beneficial for a child with multiple, severe impairments though the child may never become an independent, community-based power wheelchair user. Electroencephalography may be a valuable addition to the study of power mobility use in children with multiple, severe impairments. Power mobility training appeared to impact mastery motivation (the internal drive to solve complex problems and master new skills) in a child who has multiple

  18. Solar power satellite system definition study, phase 2.

    NASA Technical Reports Server (NTRS)

    1979-01-01

    A program plan for the Solar Power Satellite Program is presented. The plan includes research, development, and evaluation phase, engineering and development and cost verification phase, prototype construction, and commercialization. Cost estimates and task requirements are given for the following technology areas: (1) solar arrays; (2) thermal engines and thermal systems; (3) power transmission (to earth); (4) large space structures; (5) materials technology; (6) system control; (7) space construction; (8) space transportation; (9) power distribution, and space environment effects.

  19. Microwave power transmitting phased array antenna research project

    NASA Technical Reports Server (NTRS)

    Dickinson, R. M.

    1978-01-01

    An initial design study and the development results of an S band RF power transmitting phased array antenna experiment system are presented. The array was to be designed, constructed and instrumented to permit wireless power transmission technology evaluation measurements. The planned measurements were to provide data relative to the achievable performance in the state of the art of flexible surface, retrodirective arrays, as a step in technically evaluating the satellite power system concept for importing to earth, via microwave beams, the nearly continuous solar power available in geosynchronous orbit. Details of the microwave power transmitting phased array design, instrumentation approaches, system block diagrams, and measured component and breadboard characteristics achieved are presented.

  20. Computational Power of Symmetry-Protected Topological Phases

    NASA Astrophysics Data System (ADS)

    Stephen, David T.; Wang, Dong-Sheng; Prakash, Abhishodh; Wei, Tzu-Chieh; Raussendorf, Robert

    2017-07-01

    We consider ground states of quantum spin chains with symmetry-protected topological (SPT) order as resources for measurement-based quantum computation (MBQC). We show that, for a wide range of SPT phases, the computational power of ground states is uniform throughout each phase. This computational power, defined as the Lie group of executable gates in MBQC, is determined by the same algebraic information that labels the SPT phase itself. We prove that these Lie groups always contain a full set of single-qubit gates, thereby affirming the long-standing conjecture that general SPT phases can serve as computationally useful phases of matter.

  1. Resistance Training Using Different Hypoxic Training Strategies: a Basis for Hypertrophy and Muscle Power Development.

    PubMed

    Feriche, Belén; García-Ramos, Amador; Morales-Artacho, Antonio J; Padial, Paulino

    2017-12-01

    The possible muscular strength, hypertrophy, and muscle power benefits of resistance training under environmental conditions of hypoxia are currently being investigated.Nowadays, resistance training in hypoxia constitutes a promising new training strategy for strength and muscle gains. The main mechanisms responsible for these effects seem to be related to increased metabolite accumulation due to hypoxia. However, no data are reported in the literature to describe and compare the efficacy of the different hypertrophic resistance training strategies in hypoxia.Moreover, improvements in sprinting, jumping, or throwing performance have also been described at terrestrial altitude, encouraging research into the speed of explosive movements at altitude. It has been suggested that the reduction in the aerodynamic resistance and/or the increase in the anaerobic metabolism at higher altitudes can influence the metabolic cost, increase the take-off velocities, or improve the motor unit recruitment patterns, which may explain these improvements. Despite these findings, the applicability of altitude conditions in improving muscle power by resistance training remains to be clarified.This review examines current knowledge regarding resistance training in different types of hypoxia, focusing on strategies designed to improve muscle hypertrophy as well as power for explosive movements.

  2. Effectiveness of accommodation and constant resistance training on maximal strength and power in trained athletes.

    PubMed

    Ataee, Jalil; Koozehchian, Majid S; Kreider, Richard B; Zuo, Li

    2014-01-01

    Accommodation resistance is a training technique that may improve strength and power gains beyond those achieved by traditional free weights. In this method, chains are either added on a free-weight bar and combined with traditional plates or added to the bar as the entire load. Purpose. The aim of the current study was to compare the effectiveness of accommodation and constant resistance training methods during a four-week period on maximal strength and power in trained athletes. Methods. This study was comprised of 24 trained athletes, including 16 trained males [8 Wushu athletes (Kung-Fu) and 8 wrestlers, age: 20.5 ± 2.00 yrs. old]. Participants were initially tested on weight, body circumference, fat percent, upper and lower body maximal strength, determined by the 1-repetition maximum (1RM) test, which determines the greatest amount of weight a person can successfully lift, and upper and lower body power. Participants were equally randomized to either accommodation or constant resistance training groups. Both groups underwent resistance training for a four-week period that consisted of three sessions per week. Multivariate repeated-measures analyses of variance of the data were used to verify significant differences in strength and power between groups. The modified Bonferroni post hoc test was used to compare the obtained results in pre-, mid-, and post test. Results. In the accommodation resistance group, there was a significant difference in lower body maximal strength compared to the constant group (163.12 ± 18.82 kg in the accommodation group vs. 142.25 ± 20.04 kg in the constant group, P = 0.04). No significant differences were found in upper body power, lower body power, and upper body maximal strength between the two groups (P > 0.05). Conclusion. Although there was only a significant difference in lower body maximal strength between groups, accommodation resistance training may induce a physiological training response by improving the strength and

  3. Reactive power and harmonic compensation based on the generalized instantaneous reactive power theory for three-phase power systems

    SciTech Connect

    Peng, Fang Zheng; Lai, Jih-Sheng

    1996-10-01

    A generalized theory of instantaneous reactive power for three-phase power systems is proposed in this paper. This theory gives a generalized definition of instantaneous reactive power, which is valid for sinusoidal or nonsinusoidal, balanced or unbalanced, three- phase power systems with or without zero-sequence currents and/or voltages. The properties and physical meanings of the newly defined instantaneous reactive power are discussed in detail. With this new reactive power theory, it is very easy to calculate and decompose all components, such as fundamental active/reactive power and current, harmonic current, etc. Reactive power and/or harmonic compensation systems for a three-phase distorted power system with and without zero-sequence components in the source voltage and/or load current are then used as examples to demonstrate the measurement, decomposition, and compensation of reactive power and harmonics.

  4. An experimental study of a PEM fuel cell power train for urban bus application

    NASA Astrophysics Data System (ADS)

    Corbo, P.; Migliardini, F.; Veneri, O.

    An experimental study was carried out on a fuel cell propulsion system for minibus application with the aim to investigate the main issues of energy management within the system in dynamic conditions. The fuel cell system (FCS), based on a 20 kW PEM stack, was integrated into the power train comprising DC-DC converter, Pb batteries as energy storage systems and asynchronous electric drive of 30 kW. As reference vehicle a minibus for public transportation in historical centres was adopted. A preliminary experimental analysis was conducted on the FCS connected to a resistive load through a DC-DC converter, in order to verify the stack dynamic performance varying its power acceleration from 0.5 kW s -1 to about 4 kW s -1. The experiments on the power train were conducted on a test bench able to simulate the vehicle parameters and road characteristics on specific driving cycles, in particular the European R40 cycle was adopted as reference. The "soft hybrid" configuration, which permitted the utilization of a minimum size energy storage system and implied the use of FCS mainly in dynamic operation, was compared with the "hard hybrid" solution, characterized by FCS operation at limited power in stationary conditions. Different control strategies of power flows between fuel cells, electric energy storage system and electric drive were adopted in order to verify the two above hybrid approaches during the vehicle mission, in terms of efficiencies of individual components and of the overall power train. The FCS was able to support the dynamic requirements typical of R40 cycle, but an increase of air flow rate during the fastest acceleration phases was necessary, with only a slight reduction of FCS efficiency. The FCS efficiency resulted comprised between 45 and 48%, while the overall power train efficiency reached 30% in conditions of constant stack power during the driving cycle.

  5. Preliminary power train design for a state-of-the-art electric vehicle

    NASA Technical Reports Server (NTRS)

    Ross, J. A.; Wooldridge, G. A.

    1978-01-01

    The state-of-the-art (SOTA) of electric vehicles built since 1965 was reviewed to establish a base for the preliminary design of a power train for a SOTA electric vehicle. The performance of existing electric vehicles were evaluated to establish preliminary specifications for a power train design using state-of-the-art technology and commercially available components. Power train components were evaluated and selected using a computer simulation of the SAE J227a Schedule D driving cycle. Predicted range was determined for a number of motor and controller combinations in conjunction with the mechanical elements of power trains and a battery pack of sixteen lead-acid batteries - 471.7 kg at 0.093 MJ/Kg (1040 lbs. at 11.7 Whr/lb). On the basis of maximum range and overall system efficiency using the Schedule D cycle, an induction motor and 3 phase inverter/controller was selected as the optimum combination when used with a two-speed transaxle and steel belted radial tires. The predicted Schedule D range is 90.4 km (56.2 mi). Four near term improvements to the SOTA were identified, evaluated, and predicted to increase range approximately 7%.

  6. Survival Skills. Pre-Apprenticeship Phase 2 Training. Instructors Guide

    ERIC Educational Resources Information Center

    Lane Community Coll., Eugene, OR.

    This instructor's guide contains the 43 Survival Skills modules developed for Pre-Apprenticeship Phase 2 Training. Introductory materials include a description of components of the pre-apprenticeship project, recommendations for module implementation, and synopses of the modules that were developed to prompt social skills development. Each module…

  7. Drywall. Pre-Apprenticeship Phase 1 Training. Instructor's Guide.

    ERIC Educational Resources Information Center

    Lane Community Coll., Eugene, OR.

    This instructor's guide accompanies the self-paced student training modules on drywall, one of which is available separately as CE 032 887. Introductory materials include a description of the components of the pre-apprenticeship project, a discussion of the teacher's role in conducting the course, and scope and content of the four phases of…

  8. Communication: Phase incremented echo train acquisition in NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Baltisberger, Jay H.; Walder, Brennan J.; Keeler, Eric G.; Kaseman, Derrick C.; Sanders, Kevin J.; Grandinetti, Philip J.

    2012-06-01

    We present an improved and general approach for implementing echo train acquisition (ETA) in magnetic resonance spectroscopy, particularly where the conventional approach of Carr-Purcell-Meiboom-Gill (CPMG) acquisition would produce numerous artifacts. Generally, adding ETA to any N-dimensional experiment creates an N + 1 dimensional experiment, with an additional dimension associated with the echo count, n, or an evolution time that is an integer multiple of the spacing between echo maxima. Here we present a modified approach, called phase incremented echo train acquisition (PIETA), where the phase of the mixing pulse and every other refocusing pulse, ϕP, is incremented as a single variable, creating an additional phase dimension in what becomes an N + 2 dimensional experiment. A Fourier transform with respect to the PIETA phase, ϕP, converts the ϕP dimension into a Δp dimension where desired signals can be easily separated from undesired coherence transfer pathway signals, thereby avoiding cumbersome or intractable phase cycling schemes where the receiver phase must follow a master equation. This simple modification eliminates numerous artifacts present in NMR experiments employing CPMG acquisition and allows "single-scan" measurements of transverse relaxation and J-couplings. Additionally, unlike CPMG, we show how PIETA can be appended to experiments with phase modulated signals after the mixing pulse.

  9. TWRS privatization phase 1 electrical power system

    SciTech Connect

    Singh, G.

    1997-05-30

    This document includes Conceptual Design Report (CDR) for a new 11 km (7 miles) 230 kV transmission line and a new 40 MVA substation (A6) which will be located east of Grout Facility in 200E Area tank farm. This substation will provide electrical power up to 20 MW each for two private contractor facilities for immobilization and disposal of low activity waste (LAW).

  10. Trellis phase codes for power-bandwith efficient satellite communications

    NASA Technical Reports Server (NTRS)

    Wilson, S. G.; Highfill, J. H.; Hsu, C. D.; Harkness, R.

    1981-01-01

    Support work on improved power and spectrum utilization on digital satellite channels was performed. Specific attention is given to the class of signalling schemes known as continuous phase modulation (CPM). The specific work described in this report addresses: analytical bounds on error probability for multi-h phase codes, power and bandwidth characterization of 4-ary multi-h codes, and initial results of channel simulation to assess the impact of band limiting filters and nonlinear amplifiers on CPM performance.

  11. Ancient peat and apple extracts supplementation may improve strength and power adaptations in resistance trained men.

    PubMed

    Joy, Jordan M; Vogel, Roxanne M; Moon, Jordan R; Falcone, Paul H; Mosman, Matt M; Pietrzkowski, Zbigniew; Reyes, Tania; Kim, Michael P

    2016-07-18

    Increased cellular ATP levels have the potential to enhance athletic performance. A proprietary blend of ancient peat and apple extracts has been supposed to increase ATP production. Therefore, the purpose of this investigation was to determine the effects of this supplement on athletic performance when used during 12 weeks of supervised, periodized resistance training. Twenty-five healthy, resistance-trained, male subjects completed this study. Subjects supplemented once daily with either 1 serving (150 mg) of a proprietary blend of ancient peat and apple extract (TRT) or an equal-volume, visually-identical placebo (PLA) daily. Supervised resistance training consisted of 8 weeks of daily undulating periodized training followed by a 2 week overreach and a 2 week taper phase. Strength was determined using 1-repetition-maximum (1RM) testing in the barbell back squat, bench press (BP), and deadlift exercises. Peak power and peak velocity were determined during BP at 30 % 1RM and vertical jump tests as well as a 30s Wingate test, which also provided relative power (watt:mass) A group x time interaction was present for squat 1RM, deadlift 1RM, and vertical jump peak power and peak velocity. Squat and deadlift 1RM increased in TRT versus PLA from pre to post. Vertical jump peak velocity increased in TRT versus PLA from pre to week 10 as did vertical jump peak power, which also increased from pre to post. Wingate peak power and watt:mass tended to favor TRT. Supplementing with ancient peat and apple extract while participating in periodized resistance training may enhance performance adaptations. ClinicalTrials.gov registration ID: NCT02819219 , retrospectively registered on 6/29/2016.

  12. Phase locking of wind turbines leads to intermittent power production

    NASA Astrophysics Data System (ADS)

    Anvari, M.; Wächter, M.; Peinke, J.

    2016-12-01

    Wind energy, inserted into the power grid by wind turbines, is strongly influenced by the turbulent fluctuations of wind speed in the atmospheric layer. Here we investigate the power production of a wind farm and show that due to the presence of large-scale and long-time correlation in wind velocity, turbines interact with each other. This interaction can result in phase locking in pairs of turbines. We show that there are time intervals during which some pairs of turbines are temporally phase locked. This intermediate phase locking leads to the statistical effect that the short-time fluctuations of the cumulative power output of the wind farm become non-Gaussian, i.e., intermittent power production occurs. Contrary to phase-locked states, there are some time intervals where all turbines are phase unlocking and consequently the probability density function of the temporal increment of cumulative power production of the wind farm has almost Gaussian distribution. The phase-locked states, which can be distinct from phase-unlocked states by their dynamical features, are evaluated by reconstructed stochastic differential equations.

  13. Transference of kettlebell training to strength, power, and endurance.

    PubMed

    Manocchia, Pasquale; Spierer, David K; Lufkin, Adrienne K S; Minichiello, Jacqueline; Castro, Jessica

    2013-02-01

    Kettlebells are a popular implement in many strength and conditioning programs, and their benefits are touted in popular literature, books, and videos. However, clinical data on their efficacy are limited. The purpose of this study was to examine whether kettlebell training transfers strength and power to weightlifting and powerlifting exercises and improves muscular endurance. Thirty-seven subjects were assigned to an experimental (EXP, n = 23; mean age = 40.9 ± 12.9 years) or a control group (CON; n = 14; mean age = 39.6 ± 15.8 years), range 18-72 years. The participants were required to perform assessments including a barbell clean and jerk, barbell bench press, maximal vertical jump, and 45° back extensions to volitional fatigue before and after a 10-week kettlebell training program. Training was structured in a group setting for 2 d·wk(-1) for 10 weeks. A repeated measures analysis of variance was conducted to determine group × time interactions and main effects. Post hoc pairwise comparisons were conducted when appropriate. Bench press revealed a time × group interaction and a main effect (p < 0.05). Clean and jerk and back extension demonstrated a trend toward a time × group interaction, but it did not reach significance (p = 0.053). However, clean and jerk did reveal a main effect for time (p < 0.05). No significant findings were reported for maximal vertical jump. The results demonstrate a transfer of power and strength in response to 10 weeks of training with kettlebells. Traditional training methods may not be convenient or accessible for strength and conditioning specialists, athletes, coaches, and recreational exercisers. The current data suggest that kettlebells may be an effective alternative tool to improve performance in weightlifting and powerlifting.

  14. Pulsed High Power Microwave (HPM) Oscillator with Phasing Capability

    DTIC Science & Technology

    2013-06-01

    REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Pulsed High Power Microwave (HPM) Oscillator with Phasing Capability 5a. CONTRACT...public release, distribution unlimited 13. SUPPLEMENTARY NOTES See also ADM002371. 2013 IEEE Pulsed Power Conference, Digest of Technical Papers 1976

  15. 49 CFR 238.447 - Train operator's controls and power car cab layout.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Train operator's controls and power car cab layout... Specific Requirements for Tier II Passenger Equipment § 238.447 Train operator's controls and power car cab layout. (a) Train operator controls in the power car cab shall be arranged so as to minimize the chance...

  16. 49 CFR 238.447 - Train operator's controls and power car cab layout.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Train operator's controls and power car cab layout... Specific Requirements for Tier II Passenger Equipment § 238.447 Train operator's controls and power car cab layout. (a) Train operator controls in the power car cab shall be arranged so as to minimize the...

  17. Spectrophotovoltaic orbital power generation, phase 2

    NASA Technical Reports Server (NTRS)

    Lo, S. K.; Stoltzman, D.; Knowles, G.; Lin, R.

    1981-01-01

    A subscale model of the spectral splitting concentrator system with 10" aperture is defined and designed. The model is basically a scaled down version of Phase 1 design with an effective concentration ratio up to 1000:1. The system performance is predicted to be 21.5% for the 2 cell GaAs/Si system, and 20% for Si/GaAs at AM2 using realistic component efficiencies. Component cost of the model is projected in the $50K range. Component and system test plans are also detailed.

  18. Space power demonstrator engine, phase 1

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The design, analysis, and preliminary test results for a 25 kWe Free-Piston Stirling engine with integral linear alternators are described. The project is conducted by Mechanical Technology under the direction of LeRC as part of the SP-100 Nuclear Space Power Systems Program. The engine/alternator system is designed to demonstrate the following performance: (1) 25 kWe output at a specific weight less than 8 kg/kW; (2) 25 percent efficiency at a temperature ratio of 2.0; (3) low vibration (amplitude less than .003 in); (4) internal gas bearings (no wear, no external pump); and (5) heater temperature/cooler temperature from 630 to 315 K. The design approach to minimize vibration is a two-module engine (12.5 kWe per module) in a linearly-opposed configuration with a common expansion space. The low specific weight is obtained at high helium pressure (150 bar) and high frequency (105 Hz) and by using high magnetic strength (samarium cobalt) alternator magnets. Engine tests began in June 1985; 16 months following initiation of engine and test cell design. Hydrotest and consequent engine testing to date has been intentionally limited to half pressure, and electrical power output is within 15 to 20 percent of design predictions.

  19. Fuel cell power systems for remote applications. Phase 1 final report and business plan

    SciTech Connect

    1998-02-01

    The goal of the Fuel Cell Power Systems for Remote Applications project is to commercialize a 0.1--5 kW integrated fuel cell power system (FCPS). The project targets high value niche markets, including natural gas and oil pipelines, off-grid homes, yachts, telecommunication stations and recreational vehicles. Phase 1 includes the market research, technical and financial analysis of the fuel cell power system, technical and financial requirements to establish manufacturing capability, the business plan, and teaming arrangements. Phase 1 also includes project planning, scope of work, and budgets for Phases 2--4. The project is a cooperative effort of Teledyne Brown Engineering--Energy Systems, Schatz Energy Research Center, Hydrogen Burner Technology, and the City of Palm Desert. Phases 2 through 4 are designed to utilize the results of Phase 1, to further the commercial potential of the fuel cell power system. Phase 2 focuses on research and development of the reformer and fuel cell and is divided into three related, but potentially separate tasks. Budgets and timelines for Phase 2 can be found in section 4 of this report. Phase 2 includes: Task A--Develop a reformate tolerant fuel cell stack and 5 kW reformer; Task B--Assemble and deliver a fuel cell that operates on pure hydrogen to the University of Alaska or another site in Alaska; Task C--Provide support and training to the University of Alaska in the setting up and operating a fuel cell test lab. The Phase 1 research examined the market for power systems for off-grid homes, yachts, telecommunication stations and recreational vehicles. Also included in this report are summaries of the previously conducted market reports that examined power needs for remote locations along natural gas and oil pipelines. A list of highlights from the research can be found in the executive summary of the business plan.

  20. Cognitive skill training for nuclear power plant operational decision making

    SciTech Connect

    Mumaw, R.J.; Swatzler, D.; Roth, E.M.; Thomas, W.A.

    1994-06-01

    Training for operator and other technical positions in the commercial nuclear power industry traditionally has focused on mastery of the formal procedures used to control plant systems and processes. However, decisionmaking tasks required of nuclear power plant operators involve cognitive skills (e.g., situation assessment, planning). Cognitive skills are needed in situations where formal procedures may not exist or may not be as prescriptive, as is the case in severe accident management (SAM). The Westinghouse research team investigated the potential cognitive demands of SAM on the control room operators and Technical Support Center staff who would be most involved in the selection and execution of severe accident control actions. A model of decision making, organized around six general cognitive processes, was developed to identify the types of cognitive skills that may be needed for effective performance. Also, twelve SAM scenarios were developed to reveal specific decision-making difficulties. Following the identification of relevant cognitive skills, 19 approaches for training individual and team cognitive skills were identified. A review of these approaches resulted in the identification of general characteristics that are important in effective training of cognitive skills.

  1. Power transmission line operating modes calculation with controllable phase shifters

    NASA Astrophysics Data System (ADS)

    Astashev, M. G.; Novikov, M. A.; Panfilov, D. I.; Rashitov, P. A.; Remizevich, T. V.; Fedorova, M. I.

    2016-12-01

    The article contains the analysis of the influence of the phase shifter (PS) on the energy processes in the power transmission line in terms of the two-unit model of the electric network. The approach to synthesis of the models regulated by the phase shifter providing for both calculation of the steady operation modes of the electric networks with the phase shifters and research of the electromagnetic processes and designing of the device itself is offered.

  2. Nonequilibrium Phase Behavior from Minimization of Free Power Dissipation

    NASA Astrophysics Data System (ADS)

    Krinninger, Philip; Schmidt, Matthias; Brader, Joseph M.

    2016-11-01

    We develop a general theory for describing phase coexistence between nonequilibrium steady states in Brownian systems, based on power functional theory [M. Schmidt and J. M. Brader, J. Chem. Phys. 138, 214101 (2013)]. We apply the framework to the special case of fluid-fluid phase separation of active soft sphere swimmers. The central object of the theory, the dissipated free power, is calculated via computer simulations and compared to a simple analytical approximation. The theory describes well the simulation data and predicts motility-induced phase separation due to avoidance of dissipative clusters.

  3. Beam shaping with multiple-powered phase masks

    NASA Astrophysics Data System (ADS)

    Kuang, Dengfeng; Lépine, Thierry; Tian, Jianliang; Dufouleur, Paul

    2014-11-01

    We present multiple-powered phase masks to convert a plane wave beam into different shaped beams. With the squared phase mask, a hollow beam is obtained before the Fourier plane of the converging lens and a highly focused beam is obtained after the Fourier plane. With the fourth-power phase mask, a crosshair beam with highly focused point in the center is formed on the Fourier plane, then a beam lattice with strong light spots on the four corners is generated after the Fourier plane and the beam lattice has different size on different observing distances. With the fifth-power phase mask, a self-bending beam is generated over long propagation distances.

  4. Caustic beams from unusual powers of the spectral phase.

    PubMed

    Vaveliuk, Pablo; Lencina, Alberto; Martínez-Matos, Óscar

    2017-10-01

    Caustic optical beams arising from a spectral phase whose power lies in an unusual range of values less than two are presented. Unlike what happens for conventional phase powers greater than two, it is feasible to generate caustic structures having properties that do not follow the established sorting. For instance, an asymptotic cusp caustic beam having a cusp point at infinity is demonstrated. For the sake of completeness, the caustic beam properties are analyzed within the whole real range of the phase power. Accurate behavior rules between the symmetries of the beam spectral phase and its intensity distribution are found. These findings strengthen the fundamentals and engineering on caustic beams in diverse optical and physical branches.

  5. Nevada Renewable Energy Training Project: Geothermal Power Plant Operators

    SciTech Connect

    Jim, Nichols

    2014-04-29

    The purpose of this project was to develop and institute a training program for certified geothermal power plant operators (GPO). An advisory board consisting of subject matter experts from the geothermal energy industry and academia identified the critical skill sets required for this profession. A 34-credit Certificate of Achievement (COA), Geothermal Power Plant Operator, was developed using eight existing courses and developing five new courses. Approval from the Nevada System of Higher Education Board of Regents was obtained. A 2,400 sq. ft. geothermal/fluid mechanics laboratory and a 3,000 sq. ft. outdoor demonstration laboratory were constructed for hands-on training. Students also participated in field trips to geothermal power plants in the region. The majority of students were able to complete the program in 2-3 semesters, depending on their level of math proficiency. Additionally the COA allowed students to continue to an Associate of Applied Science (AAS), Energy Technologies with an emphasis in Geothermal Energy (26 additional credits), if they desired. The COA and AAS are stackable degrees, which provide students with an ongoing career pathway. Articulation agreements with other NSHE institutions provide students with additional opportunities to pursue a Bachelor of Applied Science in Management or Instrumentation. Job placement for COA graduates has been excellent.

  6. Electric vehicle power train instrumentation: Some constraints and considerations

    NASA Technical Reports Server (NTRS)

    Triner, J. E.; Hansen, I. G.

    1977-01-01

    The application of pulse modulation control (choppers) to dc motors creates unique instrumentation problems. In particular, the high harmonic components contained in the current waveforms require frequency response accommodations not normally considered in dc instrumentation. In addition to current sensing, accurate power measurement requires not only adequate frequency response but must also address phase errors caused by the finite bandwidths and component characteristics involved. The implications of these problems are assessed.

  7. A novel high power X-band ferrite phase shifter

    NASA Astrophysics Data System (ADS)

    Deng, G. J.; Huang, W. H.; Li, J. W.; Ba, T.; Guo, L. T.; Jiang, Y.

    2017-01-01

    A novel high power X-band ferrite phase shifter (PS) employing the structure of several waveguides connected in parallel is proposed. Each of the waveguides is a phase shift unit utilizing a dual-toroid structure. First, the phase shift unit is designed, manufactured, and tested. The results indicate that the power capacity reaches 115 kW. At this power, the maximum magnetic field strength of ferrite is 7.9 kA/m, beyond which the nonlinear effect of ferrite will occur. On this basis, the PS that consists of four units connected in parallel is designed. According to the threshold of ferrite, the power capacity of the PS can theoretically reach 430 kW. Limited by the maximum output power of the microwave source, the preliminary high-power test results demonstrate that the PS can operate properly at 270 kW. The PS exhibits an insertion loss of 0.82 dB and a maximum differential phase shift of approximately 300° at 9.3 GHz. The return loss of the PS is more than 16 dB from 9.0 to 9.5 GHz.

  8. A novel high power X-band ferrite phase shifter.

    PubMed

    Deng, G J; Huang, W H; Li, J W; Ba, T; Guo, L T; Jiang, Y

    2017-01-01

    A novel high power X-band ferrite phase shifter (PS) employing the structure of several waveguides connected in parallel is proposed. Each of the waveguides is a phase shift unit utilizing a dual-toroid structure. First, the phase shift unit is designed, manufactured, and tested. The results indicate that the power capacity reaches 115 kW. At this power, the maximum magnetic field strength of ferrite is 7.9 kA/m, beyond which the nonlinear effect of ferrite will occur. On this basis, the PS that consists of four units connected in parallel is designed. According to the threshold of ferrite, the power capacity of the PS can theoretically reach 430 kW. Limited by the maximum output power of the microwave source, the preliminary high-power test results demonstrate that the PS can operate properly at 270 kW. The PS exhibits an insertion loss of 0.82 dB and a maximum differential phase shift of approximately 300° at 9.3 GHz. The return loss of the PS is more than 16 dB from 9.0 to 9.5 GHz.

  9. Power Day: Addressing the Use and Abuse of Power in Medical Training.

    PubMed

    Angoff, Nancy R; Duncan, Laura; Roxas, Nichole; Hansen, Helena

    2016-06-01

    Medical student mistreatment, as well as patient and staff mistreatment by all levels of medical trainees and faculty, is still prevalent in U.S. clinical training. Largely missing in interventions to reduce mistreatment is acknowledgement of the abuse of power produced by the hierarchical structure in which medicine is practiced. Beginning in 2001, Yale School of Medicine has held annual "Power Day" workshops for third year medical students and advanced practice nursing students, to define and analyse power dynamics within the medical hierarchy and hidden curriculum using literature, guest speakers, and small groups. During rotations, medical students write narratives about the use of power witnessed in the wards. In response to student and small group leader feedback, workshop organizers have developed additional activities related to examining and changing the use of power in clinical teams. Emerging narrative themes included the potential impact of small acts and students feeling "mute" and "complicit" in morally distressing situations. Small groups provided safe spaces for advice, support, and professional identity formation. By 2005, students recognized residents that used power positively with Power Day awards and alumni served as keynote speakers on the use of power in medicine. By 2010, departments including OB/GYN, surgery, psychiatry, and paediatrics, had added weekly team Power Hour discussions. The authors highlight barriers, benefits, and lessons learned. Barriers include the notion of clinical irrelevance and resistance to the word "power" due to perceived accusation of abuse. Benefits include promoting open dialogue about power, fostering inter-professional collaboration, rewarding positive role modelling by residents and faculty, and creating a network of trainee empowerment and leadership. Furthermore, faculty have started to ask that issues of power be addressed in a more transparent way at their level of the hierarchy as well.

  10. Simulators for Mariner Training and Licensing. Phase 3, Task C. Performance Standards for Master Level Simulator Training.

    DTIC Science & Technology

    1982-03-01

    AD-A16 536 NATIONAL MARITIME RESEARCH CENTER KINGS POINT NY COM-ETC F/S 5/9 SIMULATORS FOR MARINER TRAINING AND LICENSING. PHASE 3 , TASK C.-ETC(U...EEIIEIIIIIEIIE EEIIEEEEIIEIIE EIIIIIEEEEEIIE CG-D- 15-82 CAORF 50-8007-02 SIMULATORS FOR MARINER TRAINING AND LICENSING PHASE 3 , TASK C: & PERFORMANCE...Accession No 4 Title and Subtitle .. .....- 5 Report Oat Simulators for Mar inel Training and Licensing, Phase 3 , Task C: Performance Standards fo

  11. Input Power Factor Control of Three-Phase to Three-Phase Matrix Converters

    NASA Astrophysics Data System (ADS)

    Ishikawa, Shuta; Takeshita, Takaharu

    This paper presents input power factor control of three-phase to three-phase matrix converters. The authors propose the three kinds of switching patterns for the matrix converters that can realize arbitrary input-power-factor angle between 0 to 2π and reduce the number of commutations in all of the three phases to four times during the control period. Also, the control range of the output voltage reference in the proposed control scheme is derived. The improvement of the input power factor by using of the proposed control algorithm has been verified by experiments.

  12. Power Day: Addressing the Use and Abuse of Power in Medical Training

    PubMed Central

    Duncan, Laura; Roxas, Nichole; Hansen, Helena

    2016-01-01

    Problem Medical student mistreatment, as well as patient and staff mistreatment by all levels of medical trainees and faculty, is still prevalent in U.S. clinical training. Largely missing in interventions to reduce mistreatment is acknowledgement of the abuse of power produced by the hierarchical structure in which medicine is practiced. Approach Beginning in 2001, Yale School of Medicine has held annual “Power Day” workshops for third year medical students and advanced practice nursing students, to define and analyse power dynamics within the medical hierarchy and hidden curriculum using literature, guest speakers, and small groups. During rotations, medical students write narratives about the use of power witnessed in the wards. In response to student and small group leader feedback, workshop organizers have developed additional activities related to examining and changing the use of power in clinical teams. Outcome Emerging narrative themes included the potential impact of small acts and students feeling “mute” and “complicit” in morally distressing situations. Small groups provided safe spaces for advice, support, and professional identity formation. By 2005, students recognized residents that used power positively with Power Day awards and alumni served as keynote speakers on the use of power in medicine. By 2010, departments including OB/GYN, surgery, psychiatry, and paediatrics, had added weekly team Power Hour discussions. Next Steps The authors highlight barriers, benefits, and lessons learned. Barriers include the notion of clinical irrelevance and resistance to the word “power” due to perceived accusation of abuse. Benefits include promoting open dialogue about power, fostering inter-professional collaboration, rewarding positive role modelling by residents and faculty, and creating a network of trainee empowerment and leadership. Furthermore, faculty have started to ask that issues of power be addressed in a more transparent way at

  13. 4-kW multi-phase battery powered power supply

    NASA Astrophysics Data System (ADS)

    Ponomarev, A. V.; Korzhenevskiy, S. R.; Komarskiy, A. A.; Chepusov, A. S.; Mamontov, Y. I.; Ponomarev, S. V.

    2017-05-01

    A method was developed for building the powerful battery power supplies. Using the method, the battery power supply with a 4 kW max power and up to 93% efficiency was developed to supply the “Yasen” X-ray apparatus. Two 60 A·h series-connected starter lead-acid batteries were used as a primary power supply. A DC output voltage of the source is stable over the entire power range and equals to 310 V. The power supply is based on a 5-phase HF-inverter. There is no difficulty in designing such power supplies with different power outputs. It can be done by the increasing or the decreasing number of phases (of inverter channels). This approach is not limited by the increased number of the inverter channels. The maximum output power will be determined by the battery characteristics only. The power supply is mounted on a mobile trolley, to increase the mobility of the entire set of equipment. The unit dimensions are 410×320×440, the weight is about 40 kg. The unit is forced air-cooled. A power operating mode is short and periodic.

  14. Effect of traditional resistance and power training using rated perceived exertion for enhancement of muscle strength, power, and functional performance.

    PubMed

    Tiggemann, Carlos Leandro; Dias, Caroline Pieta; Radaelli, Regis; Massa, Jéssica Cassales; Bortoluzzi, Rafael; Schoenell, Maira Cristina Wolf; Noll, Matias; Alberton, Cristine Lima; Kruel, Luiz Fernando Martins

    2016-04-01

    The present study compared the effects of 12 weeks of traditional resistance training and power training using rated perceived exertion (RPE) to determine training intensity on improvements in strength, muscle power, and ability to perform functional task in older women. Thirty healthy elderly women (60-75 years) were randomly assigned to traditional resistance training group (TRT; n = 15) or power training group (PT; n = 15). Participants trained twice a week for 12 weeks using six exercises. The training protocol was designed to ascertain that participants exercised at an RPE of 13-18 (on a 6-20 scale). Maximal dynamic strength, muscle power, and functional performance of lower limb muscles were assessed. Maximal dynamic strength muscle strength leg press (≈58 %) and knee extension (≈20 %) increased significantly (p < 0.001) and similarly in both groups after training. Muscle power also increased with training (≈27 %; p < 0.05), with no difference between groups. Both groups also improved their functional performance after training period (≈13 %; p < 0.001), with no difference between groups. The present study showed that TRT and PT using RPE scale to control intensity were significantly and similarly effective in improving maximal strength, muscle power, and functional performance of lower limbs in elderly women.

  15. Lightweight Phase-Change Material For Solar Power

    NASA Technical Reports Server (NTRS)

    Stark, Philip

    1993-01-01

    Lightweight panels containing phase-change materials developed for use as heat-storage elements of compact, lightweight, advanced solar dynamic power system. During high insolation, heat stored in panels via latent heat of fusion of phase-change material; during low insolation, heat withdrawn from panels. Storage elements consist mainly of porous carbon-fiber structures imbued with germanium. Developed for use aboard space station in orbit around Earth, also adapted to lightweight, compact, portable solar-power systems for use on Earth.

  16. Lightweight Phase-Change Material For Solar Power

    NASA Technical Reports Server (NTRS)

    Stark, Philip

    1993-01-01

    Lightweight panels containing phase-change materials developed for use as heat-storage elements of compact, lightweight, advanced solar dynamic power system. During high insolation, heat stored in panels via latent heat of fusion of phase-change material; during low insolation, heat withdrawn from panels. Storage elements consist mainly of porous carbon-fiber structures imbued with germanium. Developed for use aboard space station in orbit around Earth, also adapted to lightweight, compact, portable solar-power systems for use on Earth.

  17. Solid-state retrodirective phased array concepts for microwave power transmission from Solar Power Satellite

    NASA Technical Reports Server (NTRS)

    Schroeder, K. G.; Petroff, I. K.

    1980-01-01

    Two prototype solid-state phased array systems concepts for potential use in the Solar Power Satellite are described. In both concepts, the beam is centered on the rectenna by means of phase conjugation of a pilot signal emanating from the ground. Also discussed is on-going solid-state amplifier development.

  18. Measurement of power in selectorized strength-training equipment.

    PubMed

    Biscarini, Andrea

    2012-07-01

    The author derived the exact analytical expression of the instantaneous joint power in exercises with single-joint, variable-resistance, selectorized strength-training equipment, taking into account all the relevant geometric, kinematic, and dynamic variables of both the movable equipment elements (resistance input lever, cam-pulley system, weight stack) and of the user's exercising limb. A numerical algorithm was also designed to express, in the presence of a cam, the rectilinear kinematic variables of the weight stack as a function of the rotational kinematic variables of the resistance input lever, and vice versa. Given that information, one can measure the value of the instantaneous and mean joint power exclusively by means of a linear encoder placed on the weight stack or, alternatively, only by the use of an angular encoder placed on the rotational axis of the resistance lever. The results highlight that, for knee extension exercises with leg extension equipment, the real values of both instantaneous and mean joint power may differ by more than 50% in comparison with the values obtained by taking into account only the mass and velocity of the weight stack. These differences are notable not only in explosive exercises, but also whenever considerable joint velocities/accelerations occur within the range of motion.

  19. Phase change energy storage for solar dynamic power systems

    NASA Technical Reports Server (NTRS)

    Chiaramonte, F. P.; Taylor, J. D.

    1992-01-01

    This paper presents the results of a transient computer simulation that was developed to study phase change energy storage techniques for Space Station Freedom (SSF) solar dynamic (SD) power systems. Such SD systems may be used in future growth SSF configurations. Two solar dynamic options are considered in this paper: Brayton and Rankine. Model elements consist of a single node receiver and concentrator, and takes into account overall heat engine efficiency and power distribution characteristics. The simulation not only computes the energy stored in the receiver phase change material (PCM), but also the amount of the PCM required for various combinations of load demands and power system mission constraints. For a solar dynamic power system in low earth orbit, the amount of stored PCM energy is calculated by balancing the solar energy input and the energy consumed by the loads corrected by an overall system efficiency. The model assumes an average 75 kW SD power system load profile which is connected to user loads via dedicated power distribution channels. The model then calculates the stored energy in the receiver and subsequently estimates the quantity of PCM necessary to meet peaking and contingency requirements. The model can also be used to conduct trade studies on the performance of SD power systems using different storage materials.

  20. Phase change energy storage for solar dynamic power systems

    NASA Technical Reports Server (NTRS)

    Chiaramonte, F. P.; Taylor, J. D.

    1992-01-01

    This paper presents the results of a transient computer simulation that was developed to study phase change energy storage techniques for Space Station Freedom (SSF) solar dynamic (SD) power systems. Such SD systems may be used in future growth SSF configurations. Two solar dynamic options are considered in this paper: Brayton and Rankine. Model elements consist of a single node receiver and concentrator, and takes into account overall heat engine efficiency and power distribution characteristics. The simulation not only computes the energy stored in the receiver phase change material (PCM), but also the amount of the PCM required for various combinations of load demands and power system mission constraints. For a solar dynamic power system in low earth orbit, the amount of stored PCM energy is calculated by balancing the solar energy input and the energy consumed by the loads corrected by an overall system efficiency. The model assumes an average 75 kW SD power system load profile which is connected to user loads via dedicated power distribution channels. The model then calculates the stored energy in the receiver and subsequently estimates the quantity of PCM necessary to meet peaking and contingency requirements. The model can also be used to conduct trade studies on the performance of SD power systems using different storage materials.

  1. Single phase inverter for a three phase power generation and distribution system

    NASA Technical Reports Server (NTRS)

    Lindena, S. J.

    1976-01-01

    A breadboard design of a single-phase inverter with sinusoidal output voltage for a three-phase power generation and distribution system was developed. The three-phase system consists of three single-phase inverters, whose output voltages are connected in a delta configuration. Upon failure of one inverter the two remaining inverters will continue to deliver three-phase power. Parallel redundancy as offered by two three-phase inverters is substituted by one three-phase inverter assembly with high savings in volume, weight, components count and complexity, and a considerable increase in reliability. The following requirements must be met: (1) Each single-phase, current-fed inverter must be capable of being synchronized to a three-phase reference system such that its output voltage remains phaselocked to its respective reference voltage. (2) Each single-phase, current-fed inverter must be capable of accepting leading and lagging power factors over a range from -0.7 through 1 to +0.7.

  2. Multimegawatt space nuclear power supply: Phase 1, Final report

    SciTech Connect

    Not Available

    1989-02-17

    The preliminary safety assessment report analyzes the potential radiological risk of the integrated MSNPS with the launch vehicle including interface with the weapon system. Most emphasis will be placed the prime power concept design. Safety problems can occur any time during the entire life cycle of the system including contingency phases. The preliminary safety assessment report is to be delivered at the end of phase 2. This assessment will be the basis of the safety requirements which will be applied to the design of the MSNPS as it develops in subsequent phases. The assessment also focuses design activities on specific high-risk scenarios and missions that may impact safety.

  3. Is power training or conventional resistance training better for function in elderly persons? A meta-analysis.

    PubMed

    Tschopp, Marielle; Sattelmayer, Martin Karl; Hilfiker, Roger

    2011-09-01

    to determine the effects of power training with high movement velocity compared with conventional resistance training with low movement velocity for older community-dwelling people. systematic review of randomised controlled trials. the Cochrane Central Register of Controlled TRIALS, PubMed (Medline), EMBASE, CINAHL, PEDro and Scholar-Google. all randomised or quasi-randomised trials investigating power training with high movement velocity versus conventional resistance training with low movement velocity in elderly persons over the age of 60 years. The primary outcomes were measures of functional outcomes; secondary outcomes were balance, gait, strength, power, muscle volume and adverse effects. eleven trials were identified involving 377 subjects. The pooled effect size for the follow-up values of the functional outcomes was 0.32 in favour of the power training (95% CI 0.06 to 0.57) and 0.38 (95% CI -0.51 to 1.28) for the change value. The pooled effect from three studies for self-reported function was 0.16 in favour of power training (95% CI -0.17 to 0.49). power training is feasible for elderly persons and has a small advantage over strength training for functional outcomes. No firm conclusion can be made for safety.

  4. AUTOMOTIVE DIESEL MAINTENANCE 2. UNIT XXI, MICHIGAN/CLARK TRANSMISSION--COMPLETE POWER TRAIN.

    ERIC Educational Resources Information Center

    Minnesota State Dept. of Education, St. Paul. Div. of Vocational and Technical Education.

    THIS MOSULE OF A 25-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF A SPECIFIC POWER TRAIN SYSTEM USED ON DIESEL POWERED EQUIPMENT. TOPICS ARE EXAMINING THE POWER FLOW, UNIT OIL FLOW, AND OIL PRESSURE IN THE CONVERTER AND TRANSMISSION SYSTEM. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL PROGRAM TRAINING FILM "UNDERSTANDING THE…

  5. 10 CFR 50.120 - Training and qualification of nuclear power plant personnel.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Training and qualification of nuclear power plant... Training and qualification of nuclear power plant personnel. (a) Applicability. The requirements of this... each holder of a combined license issued under part 52 of this chapter for a nuclear power plant of the...

  6. 10 CFR 50.120 - Training and qualification of nuclear power plant personnel.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Training and qualification of nuclear power plant... Training and qualification of nuclear power plant personnel. (a) Applicability. The requirements of this... each holder of a combined license issued under part 52 of this chapter for a nuclear power plant of the...

  7. 10 CFR 50.120 - Training and qualification of nuclear power plant personnel.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Training and qualification of nuclear power plant... Training and qualification of nuclear power plant personnel. (a) Applicability. The requirements of this... each holder of a combined license issued under part 52 of this chapter for a nuclear power plant of the...

  8. 10 CFR 50.120 - Training and qualification of nuclear power plant personnel.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Training and qualification of nuclear power plant... Training and qualification of nuclear power plant personnel. (a) Applicability. The requirements of this... each holder of a combined license issued under part 52 of this chapter for a nuclear power plant of the...

  9. 10 CFR 50.120 - Training and qualification of nuclear power plant personnel.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Training and qualification of nuclear power plant... Training and qualification of nuclear power plant personnel. (a) Applicability. The requirements of this... each holder of a combined license issued under part 52 of this chapter for a nuclear power plant of the...

  10. 49 CFR 238.447 - Train operator's controls and power car cab layout.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Train operator's controls and power car cab layout... layout. (a) Train operator controls in the power car cab shall be arranged so as to minimize the chance.... (d) Power car cab information displays shall be designed with the following characteristics:...

  11. Power production with two-phase expansion through vapor dome

    SciTech Connect

    Amend, W.E.; Toner, S.J.

    1984-08-07

    In a system wherein a fluid exhibits a regressive vapor dome in a T-S diagram, the following are provided: a two-phase nozzle receiving the fluid in pressurized and heated liquid state and expanding the received liquid into saturated or superheated vapor state, and apparatus receiving the saturated or superheated vapor to convert the kinetic energy thereof into power.

  12. Electric vehicle power train instrumentation - Some constraints and considerations

    NASA Technical Reports Server (NTRS)

    Triner, J. E.; Hansen, I. G.

    1977-01-01

    The application of pulse modulation control (choppers) to dc motors creates unique instrumentation problems. In particular, the high-harmonic components contained in the current waveforms require frequency-response accommodations not normally considered in dc instrumentation. In addition to current sensing, accurate power measurement not only requires adequate frequency response but also must address phase errors caused by the finite bandwidths and component characteristics involved. This paper discusses the implications of these problems and reports on the degree to which they have been solved at Lewis Research Center.

  13. Variable Resistance Training Promotes Greater Strength and Power Adaptations Than Traditional Resistance Training in Elite Youth Rugby League Players.

    PubMed

    Rivière, Maxence; Louit, Loic; Strokosch, Alasdair; Seitz, Laurent B

    2017-04-01

    Rivière, M, Louit, L, Strokosch, A, and Seitz, LB. Variable resistance training promotes greater strength and power adaptations than traditional resistance training in elite youth rugby league players. J Strength Cond Res 31(4): 947-955, 2017-The purpose of this study was to examine the strength, velocity, and power adaptations in youth rugby league players in response to a variable resistance training (VRT) or traditional free-weight resistance training (TRAD) intervention. Sixteen elite youth players were assigned to a VRT or TRAD group and completed 2 weekly upper- and lower-body strength and power sessions for 6 weeks. Training programs were identical except that the VRT group trained the bench press exercise with 20% of the prescribed load coming from elastic bands. Bench press 1 repetition maximum (1RM) and bench press mean velocity and power at 35, 45, 65, 75, and 85% of 1RM were measured before and after the training intervention, and the magnitude of the changes was determined using effect sizes (ESs). The VRT group experienced larger increases in both absolute (ES = 0.46 vs. 0.20) and relative (ES = 0.41 vs. 0.19) bench press 1RM. Similar results were observed for mean velocity as well as both absolute and relative mean power at 35, 45, 65, 75, and 85% of 1RM. Furthermore, both groups experienced large gains in both velocity and power in the heavier loads but small improvements in the lighter loads. The improvements in both velocity and power against the heavier loads were larger for the VRT group, whereas smaller differences existed between the 2 groups in the lighter loads. Variable resistance training using elastic bands may offer a greater training stimulus than traditional free-weight resistance training to improve upper-body strength, velocity, and power in elite youth rugby league players.

  14. Dynamic model of a three-phase power transformer

    SciTech Connect

    Dolinar, D.; Pihler, J.; Grcar, B. . Faculty of Technical Sciences)

    1993-10-01

    An adequate mathematical model of a three-phase power transformer is one of the important elements in the programs for the computer analysis of power system transients. Featured in this paper is the simulation model of a three-phase, three-limb core-type power transformer. Non-linear effects of saturation, hysteresis and eddy currents are considered. Two ways of creating major and minor hysteresis loops are presented. The transformer model, described by a system of time dependent differential equations, is solved by an efficient numerical algorithm. The behavior of the transformer model during switching-in and fault transients, as well as other types of transients, has been tested. The computed transient waveforms are compared with the measured ones of there exists very close agreement between them.

  15. Trimode optimizes hybrid power plants. Final report: Phase 2

    SciTech Connect

    O`Sullivan, G.A.; O`Sullivan, J.A.

    1998-07-01

    In the Phase 2 project, Abacus Controls Inc. did research and development of hybrid systems that combine the energy sources from photovoltaics, batteries, and diesel-generators and demonstrated that they are economically feasible for small power plants in many parts of the world. The Trimode Power Processor reduces the fuel consumption of the diesel-generator to its minimum by presenting itself as the perfect electrical load to the generator. A 30-kW three-phase unit was tested at Sandia National Laboratories to prove its worthiness in actual field conditions. The use of photovoltaics at remote locations where reliability of supply requires a diesel-generator will lower costs to operate by reducing the run time of the diesel generator. The numerous benefits include longer times between maintenance for the diesel engine and better power quality from the generator. 32 figs.

  16. Three-phase power factor controller with induced EMF sensing

    NASA Astrophysics Data System (ADS)

    Nola, F. J.

    1984-09-01

    A power factor controller for an ac induction motor is provided which is of the type comprising thyristor switches connected in series with the motor, phase detectors for sensing the motor current and voltage and providing an output proportional to the phase difference between the motor voltage and current, and a control circuit, responsive to the output of the phase detector and to a power factor command signal, for controlling switching of the thyristor. The invention involves sensing the induced emf produced by the motor during the time interval when the thyristor is off and for producing a corresponding feedback signal for controlling switching of the thyristor. The sensed emf is also used to enhance soft starting of the motor.

  17. Three-phase power factor controller with induced EMF sensing

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1984-01-01

    A power factor controller for an ac induction motor is provided which is of the type comprising thyristor switches connected in series with the motor, phase detectors for sensing the motor current and voltage and providing an output proportional to the phase difference between the motor voltage and current, and a control circuit, responsive to the output of the phase detector and to a power factor command signal, for controlling switching of the thyristor. The invention involves sensing the induced emf produced by the motor during the time interval when the thyristor is off and for producing a corresponding feedback signal for controlling switching of the thyristor. The sensed emf is also used to enhance soft starting of the motor.

  18. Preliminary power train design for a state-of-the-art electric vehicle (executive summary)

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The preliminary design of a state-of-the-art electric power train is part of a national effort to reap the potential benefit of useful urban electric passenger vehicles. Outlined in a detailed presentation are: (1) assessment of the state-of-the-art in electric vehicle technology; (2) state-of-the-art power train design; (3) improved power train; and (4) summary and recommendations.

  19. Dexamphetamine reduces auditory P3 delta power and phase-locking while increasing gamma power.

    PubMed

    Albrecht, Matthew A; Price, Greg; Lee, Joseph; Iyyalol, Rajan; Martin-Iverson, Mathew T

    2012-10-01

    Auditory P3 amplitude reduction is one of the most robust and replicated findings in schizophrenia. Recent evidence suggests that these reductions are due to reductions in both power and phase-locking at delta and theta frequencies. We have previously shown that the auditory, but not visual, P3 is reduced in healthy participants given the catecholamine releasing agent dexamphetamine. Our aim was to determine whether the auditory P3 amplitude reduction induced by dexamphetamine has similar power and phase locking characteristics to that seen in schizophrenia. Forty-four healthy participants were given 0.45 mg/kg dexamphetamine and placebo, in a double-blinded, placebo-controlled, cross-over design. The task was a three-stimulus auditory odd-ball task, target stimuli were the major stimuli of interest. Individual target trials underwent wavelet analysis to give power and phase-locking of delta (3 Hz), theta (4-7 Hz), alpha (8-12 Hz), beta (13-30 Hz) and gamma (30-50 Hz) frequencies for a 50 ms time window centred around the peak of the target P3. Delta power around the P3 peak was significantly reduced when participants were given dexamphetamine. Delta phase-locking was also reduced but only when analysis was targeted at the location of the peak P3 amplitude. In contrast, theta power and phase-locking were not affected by dexamphetamine. These findings suggest that increased catecholamine activity may be responsible for the power and phase-locking reductions of the auditory P3 delta component in patients with schizophrenia. Interestingly, dexamphetamine significantly increased gamma power around the P3 peak. We attempt to link this finding with the gamma alterations that have been found in patients with schizophrenia.

  20. Effects of Strength vs. Ballistic-Power Training on Throwing Performance

    PubMed Central

    Zaras, Nikolaos; Spengos, Konstantinos; Methenitis, Spyridon; Papadopoulos, Constantinos; Karampatsos, Giorgos; Georgiadis, Giorgos; Stasinaki, Aggeliki; Manta, Panagiota; Terzis, Gerasimos

    2013-01-01

    The purpose of the present study was to investigate the effects of 6 weeks strength vs. ballistic-power (Power) training on shot put throwing performance in novice throwers. Seventeen novice male shot-put throwers were divided into Strength (N = 9) and Power (n = 8) groups. The following measurements were performed before and after the training period: shot put throws, jumping performance (CMJ), Wingate anaerobic performance, 1RM strength, ballistic throws and evaluation of architectural and morphological characteristics of vastus lateralis. Throwing performance increased significantly but similarly after Strength and Power training (7.0-13.5% vs. 6.0-11.5%, respectively). Muscular strength in leg press increased more after Strength than after Power training (43% vs. 21%, respectively), while Power training induced an 8.5% increase in CMJ performance and 9.0 - 25.8% in ballistic throws. Peak power during the Wingate test increased similarly after Strength and Power training. Muscle thickness increased only after Strength training (10%, p < 0.05). Muscle fibre Cross Sectional Area (fCSA) increased in all fibre types after Strength training by 19-26% (p < 0.05), while only type IIx fibres hypertrophied significantly after Power training. Type IIx fibres (%) decreased after Strength but not after Power training. These results suggest that shot put throwing performance can be increased similarly after six weeks of either strength or ballistic power training in novice throwers, but with dissimilar muscular adaptations. Key points Ballistic-power training with 30% of 1RM is equally effective in increasing shot put performance as strength training, in novice throwers, during a short training cycle of six weeks. In novice shot putters with relatively low initial muscle strength/mass, short-term strength training might be more important since it can increase both muscle strength and shot put performance. The ballistic type of power training resulted in a significant

  1. Effects of Strength vs. Ballistic-Power Training on Throwing Performance.

    PubMed

    Zaras, Nikolaos; Spengos, Konstantinos; Methenitis, Spyridon; Papadopoulos, Constantinos; Karampatsos, Giorgos; Georgiadis, Giorgos; Stasinaki, Aggeliki; Manta, Panagiota; Terzis, Gerasimos

    2013-01-01

    The purpose of the present study was to investigate the effects of 6 weeks strength vs. ballistic-power (Power) training on shot put throwing performance in novice throwers. Seventeen novice male shot-put throwers were divided into Strength (N = 9) and Power (n = 8) groups. The following measurements were performed before and after the training period: shot put throws, jumping performance (CMJ), Wingate anaerobic performance, 1RM strength, ballistic throws and evaluation of architectural and morphological characteristics of vastus lateralis. Throwing performance increased significantly but similarly after Strength and Power training (7.0-13.5% vs. 6.0-11.5%, respectively). Muscular strength in leg press increased more after Strength than after Power training (43% vs. 21%, respectively), while Power training induced an 8.5% increase in CMJ performance and 9.0 - 25.8% in ballistic throws. Peak power during the Wingate test increased similarly after Strength and Power training. Muscle thickness increased only after Strength training (10%, p < 0.05). Muscle fibre Cross Sectional Area (fCSA) increased in all fibre types after Strength training by 19-26% (p < 0.05), while only type IIx fibres hypertrophied significantly after Power training. Type IIx fibres (%) decreased after Strength but not after Power training. These results suggest that shot put throwing performance can be increased similarly after six weeks of either strength or ballistic power training in novice throwers, but with dissimilar muscular adaptations. Key pointsBallistic-power training with 30% of 1RM is equally effective in increasing shot put performance as strength training, in novice throwers, during a short training cycle of six weeks.In novice shot putters with relatively low initial muscle strength/mass, short-term strength training might be more important since it can increase both muscle strength and shot put performance.The ballistic type of power training resulted in a significant increase

  2. Effects of high-speed power training on muscle strength and power in patients with multiple sclerosis.

    PubMed

    Medina-Perez, Carlos; de Souza-Teixeira, Fernanda; Fernandez-Gonzalo, Rodrigo; Hernandez-Murua, Jose-Aldo; Antonio de Paz-Fernandez, Jose

    2016-01-01

    This study examined the effects of a high-speed power training program in peak muscle power and maximal voluntary isometric contraction (MVIC) of knee extensors in patients with relapsing-remitting multiple sclerosis (MS). Forty patients, 20 women (age 42.8 +/- 10.3 yr) and 20 men (age 44.0 +/- 8.7 yr) diagnosed with relapsing-remitting MS were randomly assigned, with respect to sex, to either an exercise group or a control group. Participants from the exercise group performed 12 wk of supervised muscle power training of knee extensors. All subjects were tested for MVIC and peak muscle power at baseline and after the training intervention. A strain gauge was used to measure the MVIC, and peak muscle power was assessed with a linear encoder at five relative loads. The training-related effects were assessed using a t-test. The results showed no significant changes in the control group from baseline to postintervention evaluation. In contrast, the exercise group significantly increased MVIC (10.8%; p < 0.05) and muscle power at 40, 50, 60, 70, and 80% of the MVIC by 21.8, 14.5, 17.3, 19.4, and 22.3%, respectively (p < 0.01), after the training. These findings suggest that 12 wk of high-speed power training improve both MVIC and muscle power at five different loads in patients with relapsing-remitting MS.

  3. High power compatible internally sensed optical phased array.

    PubMed

    Roberts, Lyle E; Ward, Robert L; Francis, Samuel P; Sibley, Paul G; Fleddermann, Roland; Sutton, Andrew J; Smith, Craig; McClelland, David E; Shaddock, Daniel A

    2016-06-13

    The technical embodiment of the Huygens-Fresnel principle, an optical phased array (OPA) is an arrangement of optical emitters with relative phases controlled to create a desired beam profile after propagation. One important application of an OPA is coherent beam combining (CBC), which can be used to create beams of higher power than is possible with a single laser source, especially for narrow linewidth sources. Here we present an all-fiber architecture that stabilizes the relative output phase by inferring the relative path length differences between lasers using the small fraction of light that is back-reflected into the fiber at the OPA's glass-air interface, without the need for any external sampling optics. This architecture is compatible with high power continuous wave laser sources (e.g., fiber amplifiers) up to 100 W per channel. The high-power compatible internally sensed OPA was implemented experimentally using commercial 15 W fiber amplifiers, demonstrating an output RMS phase stability of λ/194, and the ability to steer the beam at up to 10 kHz.

  4. The influence of isometric preload on power expressed during bench press in strength-trained men.

    PubMed

    Bartolomei, Sandro; Fukuda, David H; Hoffman, Jay R; Stout, Jeffrey R; Merni, Franco

    2017-03-01

    The purpose of this study was to compare the power expressed during the bench press exercise in resistance-trained men following different pre-activation conditions. Twenty-two trained men (age 24.1 ± 1.7 years, height 178.6 ± 6.1 cm, body mass 81.1 ± 10.6 kg) completed a maximal effort bench press (1-RM) test (100.0 kg ± 8.1 kg). In a subsequent assessment, each participant performed concentric bench press movements with loads of 20%, 30%, 40% and 50% of their 1-RM preceded by either a concentric contraction (CC), a low isometric preload (LIP; 70% 1-RM) or a high isometric preload (HIP; 100% 1-RM) conditions. All movements were performed in a Smith machine with a settable quick-release device. Participants performed all three conditions in randomized fashion. Results indicated that power outputs during the bench press exercise following HIP were significantly (p < 0.05) greater than CC at 20% 1-RM (+9%), 30% 1-RM (+16%) and 40% 1-RM (+14%), and LIP at 20% 1-RM (+4%), 30% 1-RM (+20%) and 40% 1-RM (+15%). No differences were found between conditions at 50% 1-RM. Area under the force-power curve with HIP was greater (p < 0.05) than with CC and LIP. In conclusion, results of this study indicate that the use of a HIP (100% 1-RM) in trained participants results in significantly greater power output during the concentric phase of a multi-joint exercise when compared to standard concentric movement.

  5. Technology verification phase. Dynamic isotope power system. Final report

    SciTech Connect

    Halsey, D.G.

    1982-03-10

    The Phase I requirements of the Kilowatt Isotope Power System (KIPS) program were to make a detailed Flight System Conceptual Design (FSCD) for an isotope fueled organic Rankine cycle power system and to build and test a Ground Demonstration System (GDS) which simulated as closely as possible the operational characteristics of the FSCD. The activities and results of Phase II, the Technology Verification Phase, of the program are reported. The objectives of this phase were to increase system efficiency to 18.1% by component development, to demonstrate system reliability by a 5000 h endurance test and to update the flight system design. During Phase II, system performance was improved from 15.1% to 16.6%, an endurance test of 2000 h was performed while the flight design analysis was limited to a study of the General Purpose Heat Source, a study of the regenerator manufacturing technique and analysis of the hardness of the system to a laser threat. It was concluded from these tests that the GDS is basically prototypic of a flight design; all components necessary for satisfactory operation were demonstrated successfully at the system level; over 11,000 total h of operation without any component failure attested to the inherent reliability of this type of system; and some further development is required, specifically in the area of performance. (LCL)

  6. Phased array of high-power, coherent, monolithic flared amplifier master oscillator power amplifiers

    NASA Astrophysics Data System (ADS)

    Osinski, J. S.; Mehuys, D.; Welch, D. F.; Waarts, R. G.; Major, J. S., Jr.; Dzurko, K. M.; Lang, R. J.

    1995-01-01

    A monolithically integrated array of InGaAs/AlGaAs flared amplifiers driven by a single DBR laser through a power splitter network and individually addressed phase modulators is described. Phase adjustment of ≳2π per element by free-carrier effects is verified by monitoring the interference pattern of all four emitters, and typically requires <15 mA of current to obtain a 2π phase shift. Phase matching is achieved among all four diffraction-limited emitters at a pulsed output power of ≳5 W, and, combined with the proper external lensing, could therefore result in an ultranarrow, single-lobed far-field pattern whose width is determined by the extended aperture of the array.

  7. Single-phase power distribution system power flow and fault analysis

    NASA Technical Reports Server (NTRS)

    Halpin, S. M.; Grigsby, L. L.

    1992-01-01

    Alternative methods for power flow and fault analysis of single-phase distribution systems are presented. The algorithms for both power flow and fault analysis utilize a generalized approach to network modeling. The generalized admittance matrix, formed using elements of linear graph theory, is an accurate network model for all possible single-phase network configurations. Unlike the standard nodal admittance matrix formulation algorithms, the generalized approach uses generalized component models for the transmission line and transformer. The standard assumption of a common node voltage reference point is not required to construct the generalized admittance matrix. Therefore, truly accurate simulation results can be obtained for networks that cannot be modeled using traditional techniques.

  8. Emerging Two-Phase Cooling Technologies for Power Electronic Inverters

    SciTech Connect

    Hsu, J.S.

    2005-08-17

    In order to meet the Department of Energy's (DOE's) FreedomCAR and Vehicle Technologies (FVCT) goals for volume, weight, efficiency, reliability, and cost, the cooling of the power electronic devices, traction motors, and generators is critical. Currently the power electronic devices, traction motors, and generators in a hybrid electric vehicle (HEV) are primarily cooled by water-ethylene glycol (WEG) mixture. The cooling fluid operates as a single-phase coolant as the liquid phase of the WEG does not change to its vapor phase during the cooling process. In these single-phase systems, two cooling loops of WEG produce a low temperature (around 70 C) cooling loop for the power electronics and motor/generator, and higher temperature loop (around 105 C) for the internal combustion engine. There is another coolant option currently available in automobiles. It is possible to use the transmission oil as a coolant. The oil temperature exists at approximately 85 C which can be utilized to cool the power electronic and electrical devices. Because heat flux is proportional to the temperature difference between the device's hot surface and the coolant, a device that can tolerate higher temperatures enables the device to be smaller while dissipating the same amount of heat. Presently, new silicon carbide (SiC) devices and high temperature direct current (dc)-link capacitors, such as Teflon capacitors, are available but at significantly higher costs. Higher junction temperature (175 C) silicon (Si) dies are gradually emerging in the market, which will eventually help to lower hardware costs for cooling. The development of high-temperature devices is not the only way to reduce device size. Two-phase cooling that utilizes the vaporization of the liquid to dissipate heat is expected to be a very effective cooling method. Among two-phase cooling methods, different technologies such as spray, jet impingement, pool boiling and submersion, etc. are being developed. The Oak Ridge

  9. Phase synchronized quasiperiodicity in power electronic inverter systems

    NASA Astrophysics Data System (ADS)

    Zhusubaliyev, Zhanybai T.; Mosekilde, Erik; Andriyanov, Alexey I.; Shein, Vladimir V.

    2014-02-01

    The development of switch-mode operated power electronic converter systems has provided a broad range of new effective approaches to the conversion of electric power. In this paper we describe the transitions from regular periodic operation to quasiperiodicity and high-periodic resonance behavior that can be observed in a pulse-width modulated DC/AC converter operating with high feedback gain. We demonstrate the occurrence of two different types of torus birth bifurcations and present a series of phase portraits illustrating the appearance of phase-synchronized quasiperiodicity. Our numerical findings are verified through comparison with an experimental inverter system. The results shed light on the transitions to quasiperiodicity and to various forms of three-frequency dynamics in non-smooth systems.

  10. Effects of endurance training on the isocapnic buffering and hypocapnic hyperventilation phases in professional cyclists

    PubMed Central

    Chicharro, J.; Hoyos, J.; Lucia, A.

    2000-01-01

    Objectives—To evaluate the changes produced in both the isocapnic buffering and hypocapnic hyperventilation (HHV) phases of professional cyclists (n = 11) in response to endurance training, and to compare the results with those of amateur cyclists (n = 11). Methods—Each professional cyclist performed three laboratory exercise tests to exhaustion during the active rest (autumn: November), precompetition (winter: January), and competition (spring: May) periods of the sports season. Amateur cyclists only performed one exercise test during the competition period. The isocapnic buffering and HHV ranges were calculated during each test and defined as VO2 and power output (W). Results—No significant differences were found in the isocapnic buffering range in each of the periods of the sports season in professional cyclists. In contrast, there was a significant reduction in the HHV range (expressed in W) during both the competition (p<0.01) and precompetition(p<0.05) periods compared with the rest period. On the other hand, a longer HHV range (p<0.01) was observed in amateur cyclists than in professional cyclists (whether this was expressed in terms of VO2 or W). Conclusions—No change is observed in the isocapnic buffering range of professional cyclists throughout a sports season despite a considerable increase in training loads and a significant reduction in HHV range expressed in terms of power output. Key Words: training; cycling; isocapnic buffering; hypocapnic hyperventilation PMID:11131234

  11. Mobility Outcomes Following Five Training Sessions with a Powered Exoskeleton.

    PubMed

    Hartigan, Clare; Kandilakis, Casey; Dalley, Skyler; Clausen, Mike; Wilson, Edgar; Morrison, Scott; Etheridge, Steven; Farris, Ryan

    2015-01-01

    Loss of legged mobility due to spinal cord injury (SCI) is associated with multiple physiological and psychological impacts. Powered exoskeletons offer the possibility of regained mobility and reversal or prevention of the secondary effects associated with immobility. This study was conducted to evaluate mobility outcomes for individuals with SCI after 5 gait-training sessions with a powered exoskeleton, with a primary goal of characterizing the ease of learning and usability of the system. Sixteen subjects with SCI were enrolled in a pilot clinical trial at Shepherd Center, Atlanta, Georgia, with injury levels ranging from C5 complete to L1 incomplete. An investigational Indego exoskeleton research kit was evaluated for ease of use and efficacy in providing legged mobility. Outcome measures of the study included the 10-meter walk test (10 MWT) and the 6-minute walk test (6 MWT) as well as measures of independence including donning and doffing times and the ability to walk on various surfaces. At the end of 5 sessions (1.5 hours per session), average walking speed was 0.22 m/s for persons with C5-6 motor complete tetraplegia, 0.26 m/s for T1-8 motor complete paraplegia, and 0.45 m/s for T9-L1 paraplegia. Distances covered in 6 minutes averaged 64 meters for those with C5-6, 74 meters for T1-8, and 121 meters for T9-L1. Additionally, all participants were able to walk on both indoor and outdoor surfaces. Results after only 5 sessions suggest that persons with tetraplegia and paraplegia learn to use the Indego exoskeleton quickly and can manage a variety of surfaces. Walking speeds and distances achieved also indicate that some individuals with paraplegia can quickly become limited community ambulators using this system.

  12. Mobility Outcomes Following Five Training Sessions with a Powered Exoskeleton

    PubMed Central

    Hartigan, Clare; Kandilakis, Casey; Dalley, Skyler; Clausen, Mike; Wilson, Edgar; Morrison, Scott; Etheridge, Steven

    2015-01-01

    Background: Loss of legged mobility due to spinal cord injury (SCI) is associated with multiple physiological and psychological impacts. Powered exoskeletons offer the possibility of regained mobility and reversal or prevention of the secondary effects associated with immobility. Objective: This study was conducted to evaluate mobility outcomes for individuals with SCI after 5 gait-training sessions with a powered exoskeleton, with a primary goal of characterizing the ease of learning and usability of the system. Methods: Sixteen subjects with SCI were enrolled in a pilot clinical trial at Shepherd Center, Atlanta, Georgia, with injury levels ranging from C5 complete to L1 incomplete. An investigational Indego exoskeleton research kit was evaluated for ease of use and efficacy in providing legged mobility. Outcome measures of the study included the 10-meter walk test (10MWT) and the 6-minute walk test (6MWT) as well as measures of independence including donning and doffing times and the ability to walk on various surfaces. Results: At the end of 5 sessions (1.5 hours per session), average walking speed was 0.22 m/s for persons with C5-6 motor complete tetraplegia, 0.26 m/s for T1-8 motor complete paraplegia, and 0.45 m/s for T9-L1 paraplegia. Distances covered in 6 minutes averaged 64 meters for those with C5-6, 74 meters for T1-8, and 121 meters for T9-L1. Additionally, all participants were able to walk on both indoor and outdoor surfaces. Conclusions: Results after only 5 sessions suggest that persons with tetraplegia and paraplegia learn to use the Indego exoskeleton quickly and can manage a variety of surfaces. Walking speeds and distances achieved also indicate that some individuals with paraplegia can quickly become limited community ambulators using this system. PMID:26364278

  13. Effect of a Periodized Power Training Program on the Functional Performances and Contractile Properties of the Quadriceps in Sprinters

    ERIC Educational Resources Information Center

    Kamandulis, Sigitas; Skurvydas, Albertas; Brazaitis, Marius; Stanislovaitis, Aleksas; Duchateau, Jacques; Stanislovaitiene, Jurate

    2012-01-01

    Our purpose was to compare the effect of a periodized preparation consisting of power endurance training and high-intensity power training on the contractile properties of the quadriceps muscle and functional performances in well trained male sprinters (n = 7). After 4 weeks of high-intensity power training, 60-m sprint running time improved by an…

  14. Effect of a Periodized Power Training Program on the Functional Performances and Contractile Properties of the Quadriceps in Sprinters

    ERIC Educational Resources Information Center

    Kamandulis, Sigitas; Skurvydas, Albertas; Brazaitis, Marius; Stanislovaitis, Aleksas; Duchateau, Jacques; Stanislovaitiene, Jurate

    2012-01-01

    Our purpose was to compare the effect of a periodized preparation consisting of power endurance training and high-intensity power training on the contractile properties of the quadriceps muscle and functional performances in well trained male sprinters (n = 7). After 4 weeks of high-intensity power training, 60-m sprint running time improved by an…

  15. A Low Power Low Phase Noise Oscillator for MICS Transceivers

    PubMed Central

    Li, Dawei; Liu, Dongsheng; Kang, Chaojian; Zou, Xuecheng

    2017-01-01

    A low-power, low-phase-noise quadrature oscillator for Medical Implantable Communications Service (MICS) transceivers is presented. The proposed quadrature oscillator generates 349~689 MHz I/Q (In-phase and Quadrature) signals covering the MICS band. The oscillator is based on a differential pair with positive feedback. Each delay cell consists of a few transistors enabling lower voltage operation. Since the oscillator is very sensitive to disturbances in the supply voltage and ground, a self-bias circuit for isolating the voltage disturbance is proposed to achieve bias voltages which can track the disturbances from the supply and ground. The oscillation frequency, which is controlled by the bias voltages, is less sensitive to the supply and ground noise, and a low phase noise is achieved. The chip is fabricated in the UMC (United Microelectronics Corporation) 0.18 μm CMOS (Complementary Metal Oxide Semiconductor) process; the core just occupies a 28.5 × 22 μm2 area. The measured phase noise is −108.45 dBc/Hz at a 1 MHz offset with a center frequency of 540 MHz. The gain of the oscillator is 0.309 MHz/mV with a control voltage from 0 V to 1.1 V. The circuit can work with a supply voltage as low as 1.2 V and the power consumption is only 0.46 mW at a 1.8 V supply voltage. PMID:28085107

  16. A Low Power Low Phase Noise Oscillator for MICS Transceivers.

    PubMed

    Li, Dawei; Liu, Dongsheng; Kang, Chaojian; Zou, Xuecheng

    2017-01-12

    A low-power, low-phase-noise quadrature oscillator for Medical Implantable Communications Service (MICS) transceivers is presented. The proposed quadrature oscillator generates 349~689 MHz I/Q (In-phase and Quadrature) signals covering the MICS band. The oscillator is based on a differential pair with positive feedback. Each delay cell consists of a few transistors enabling lower voltage operation. Since the oscillator is very sensitive to disturbances in the supply voltage and ground, a self-bias circuit for isolating the voltage disturbance is proposed to achieve bias voltages which can track the disturbances from the supply and ground. The oscillation frequency, which is controlled by the bias voltages, is less sensitive to the supply and ground noise, and a low phase noise is achieved. The chip is fabricated in the UMC (United Microelectronics Corporation) 0.18 μm CMOS (Complementary Metal Oxide Semiconductor) process; the core just occupies a 28.5 × 22 μm² area. The measured phase noise is -108.45 dBc/Hz at a 1 MHz offset with a center frequency of 540 MHz. The gain of the oscillator is 0.309 MHz/mV with a control voltage from 0 V to 1.1 V. The circuit can work with a supply voltage as low as 1.2 V and the power consumption is only 0.46 mW at a 1.8 V supply voltage.

  17. Phased Array Technology with Phase and Amplitude Controlled Magnetron for Microwave Power Transmission

    NASA Astrophysics Data System (ADS)

    Shinohara, N.; Matsumoto, H.

    2004-12-01

    We need a microwave power transmitter with light weight and high DC-RF conversion efficiency for an economical SSPS (Space Solar Power System). We need a several g/W for a microwave power transmission (MPT) system with a phased array with 0.0001 degree of beam control accuracy (=tan-1 (100m/36,000km)) and over 80 % of DC-RF conversion efficiency when the weight of the 1GW-class SPS is below a several thousand ton - a several tens of thousand ton. We focus a microwave tube, especially magnetron by economical reason and by the amount of mass-production because it is commonly used for microwave oven in the world. At first, we have developed a phase controlled magnetron (PCM) with different technologies from what Dr. Brown developed. Next we have developed a phase and amplitude controlled magnetron (PACM). For the PACM, we add a feedback to magnetic field of the PCM with an external coil to control and stabilize amplitude of the microwave. We succeed to develop the PACM with below 10-6 of frequency stability and within 1 degree of an error in phase and within 1% of amplitude. We can control a phase and amplitude of the PACM and we have developed a phased array the PCMs. With the PCM technology, we have developed a small light weight MPT transmitter COMET (Compact Microwave Energy Transmitter) with consideration of heat radiation for space use and with consideration of mobility to space.

  18. Power System Electrician: Apprenticeship Course Outline. Apprenticeship and Industry Training. 4609

    ERIC Educational Resources Information Center

    Alberta Advanced Education and Technology, 2009

    2009-01-01

    The graduate of the Power System Electrician apprenticeship training is a journeyman who will be able to: (1) responsibly do all work tasks expected of a journeyman; (2) supervise, train and coach apprentices; (3) use and maintain hand and power tools to the standards of competency and safety required in the trade; (4) read and interpret drawing,…

  19. Lower Extremity Power Training in Elderly Subjects with Mobility Limitations: A Randomized Controlled Trial

    USDA-ARS?s Scientific Manuscript database

    Background and Aims This study investigated whether high-velocity high-power training (POW) improved lower extremity muscle power and quality in functionally-limited elders greater than traditional slow-velocity progressive resistance training (STR). Methods Fifty-seven community-dwelling older adul...

  20. Lower extremity power training in elderly subjects with moderate mobility limitations: A randomized controlled trial

    USDA-ARS?s Scientific Manuscript database

    Fifty-seven community-dwelling older adults were randomized to either high-velocity high-power training (POW), slow-velocity progressive resistance training (STR) or a control group of lower extremity stretching (CON). Training was performed three times per week for 12 weeks and subjects completed t...

  1. 30 CFR 75.1915 - Training and qualification of persons working on diesel-powered equipment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., repairs, examinations and tests. (b) A training and qualification program under this section must: (1) Be... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Training and qualification of persons working... Diesel-Powered Equipment § 75.1915 Training and qualification of persons working on...

  2. 30 CFR 75.1915 - Training and qualification of persons working on diesel-powered equipment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., repairs, examinations and tests. (b) A training and qualification program under this section must: (1) Be... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Training and qualification of persons working... Diesel-Powered Equipment § 75.1915 Training and qualification of persons working on...

  3. 30 CFR 75.1915 - Training and qualification of persons working on diesel-powered equipment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., repairs, examinations and tests. (b) A training and qualification program under this section must: (1) Be... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Training and qualification of persons working... Diesel-Powered Equipment § 75.1915 Training and qualification of persons working on...

  4. 30 CFR 75.1915 - Training and qualification of persons working on diesel-powered equipment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., repairs, examinations and tests. (b) A training and qualification program under this section must: (1) Be... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Training and qualification of persons working... Diesel-Powered Equipment § 75.1915 Training and qualification of persons working on...

  5. Multimegawatt space nuclear power supply, Phase 1 Final report

    SciTech Connect

    Not Available

    1989-02-17

    This Specification establishes the performance, design, development, and test requirements for the Boeing Multimegawatt Space Nuclear Power System (MSNPS). The Boeing Multimegawatt Space Power System is part of the DOE/SDIO Multimegawatt Space Nuclear Power Program. The purpose of this program is to provide a space-based nuclear power system to meet the needs of SDIO missions. The Boeing MSNPS is a category 1 concept which is capable of delivering 10's of MW(e) for 100's of seconds with effluent permitted. A design goal is for the system to have growth or downscale capability for other power system concepts. The growth objective is to meet the category 3 capability of 100's of MW(e) for 100's of seconds, also with effluent permitted. The purpose of this preliminary document is to guide the conceptual design effort throughout the Phase 1 study effort. This document will be updated through out the study. It will thus result in a record of the development of the design effort.

  6. Enhanced INL Power Grid Test Bed Infrastructure – Phase I

    SciTech Connect

    Reid, Carol Ann; West, Grayson Shawn; McBride, Scott Alan

    2014-06-01

    Idaho National Laboratory (INL), a Department of Energy (DOE) laboratory, owns, operates, and maintains transmission and distribution power grid infrastructure to support the INL multi program mission. Sections of this power infrastructure, known as the INL Power Grid Test Bed, have been and are being used by government and industry to develop, demonstrate, and validate technologies for the modern grid, including smart grid, on a full scale utility test bed. INL’s power grid includes 61 miles of 140 MW, 138 kV rated electrical power transmission supplying seven main substations, each feeding a separate facility complex (or ‘city’) within the INL’s 890 square mile Site. This power grid is fed by three commercial utilities into the INL’s main control substation, but is operated independently from the commercial utility through its primary substation and command and control center. Within the INL complex, one of the seven complexes, the Critical Infrastructure Test Range Complex (CITRC), has been designated as the INL complex for supporting critical infrastructure research and testing. This complex includes its own substation and 13.8kV distribution network, all configurable and controlled by the INL research and development programs. Through investment partnership with the DOE Office of Electricity Delivery and Energy Reliability (DOE OE), INL is enhancing its existing distribution infrastructure to expand the types of testing that can be conducted and increase flexibility for testing configurations. The enhancement of the INL Power Grid Test Bed will enable development and full scale testing of smart-grid-related technologies and smart devices including testing interoperability, operational performance, reliability, and resiliency contribution at multiple distribution voltage classes, specifically 15kV, 25kV, and 35kV. The expected time frame for completion of the Phase I portion of the enhancement would be 4th quarter fiscal year (FY) 2015.

  7. Zero-static-power phase-change optical modulator.

    PubMed

    Jafari, Mohsen; Rais-Zadeh, Mina

    2016-03-15

    This Letter presents an innovative design of an electro-optical modulator using germanium telluride (GeTe) phase change material with an integrated nano-heater. The refractive index and the electrical conductivity of GeTe significantly change as the GeTe goes though the crystallographic phase change. Amorphization and crystallization of GeTe is achieved using the Joule heating method by passing current through an array of metal gratings, where GeTe fills the slits between the metal lines. These metal slits also increase the contrast between the amorphous (on) and crystalline (off) phases of the modulator by having extraordinary transmission and reflection response based on interactions of surface plasmon polaritons (SPPs) with the incoming light. The modulator is designed for 1550 nm wavelength, where GeTe is transparent in the amorphous phase and provides high optical on/off contrast. The metal-insulator-metal (MIM) is designed in such a way to only support SPP excitation when GeTe is crystalline and slit resonance when it is amorphous to increase the modulation index. The modulator is stable in both phases with higher than 12 dB change in transmission with zero static power consumption at room temperature.

  8. Effectiveness of Traditional Strength vs. Power Training on Muscle Strength, Power and Speed with Youth: A Systematic Review and Meta-Analysis.

    PubMed

    Behm, David G; Young, James D; Whitten, Joseph H D; Reid, Jonathan C; Quigley, Patrick J; Low, Jonathan; Li, Yimeng; Lima, Camila D; Hodgson, Daniel D; Chaouachi, Anis; Prieske, Olaf; Granacher, Urs

    2017-01-01

    Numerous national associations and multiple reviews have documented the safety and efficacy of strength training for children and adolescents. The literature highlights the significant training-induced increases in strength associated with youth strength training. However, the effectiveness of youth strength training programs to improve power measures is not as clear. This discrepancy may be related to training and testing specificity. Most prior youth strength training programs emphasized lower intensity resistance with relatively slow movements. Since power activities typically involve higher intensity, explosive-like contractions with higher angular velocities (e.g., plyometrics), there is a conflict between the training medium and testing measures. This meta-analysis compared strength (e.g., training with resistance or body mass) and power training programs (e.g., plyometric training) on proxies of muscle strength, power, and speed. A systematic literature search using a Boolean Search Strategy was conducted in the electronic databases PubMed, SPORT Discus, Web of Science, and Google Scholar and revealed 652 hits. After perusal of title, abstract, and full text, 107 studies were eligible for inclusion in this systematic review and meta-analysis. The meta-analysis showed small to moderate magnitude changes for training specificity with jump measures. In other words, power training was more effective than strength training for improving youth jump height. For sprint measures, strength training was more effective than power training with youth. Furthermore, strength training exhibited consistently large magnitude changes to lower body strength measures, which contrasted with the generally trivial, small and moderate magnitude training improvements of power training upon lower body strength, sprint and jump measures, respectively. Maturity related inadequacies in eccentric strength and balance might influence the lack of training specificity with the unilateral

  9. Effectiveness of Traditional Strength vs. Power Training on Muscle Strength, Power and Speed with Youth: A Systematic Review and Meta-Analysis

    PubMed Central

    Behm, David G.; Young, James D.; Whitten, Joseph H. D.; Reid, Jonathan C.; Quigley, Patrick J.; Low, Jonathan; Li, Yimeng; Lima, Camila D.; Hodgson, Daniel D.; Chaouachi, Anis; Prieske, Olaf; Granacher, Urs

    2017-01-01

    Numerous national associations and multiple reviews have documented the safety and efficacy of strength training for children and adolescents. The literature highlights the significant training-induced increases in strength associated with youth strength training. However, the effectiveness of youth strength training programs to improve power measures is not as clear. This discrepancy may be related to training and testing specificity. Most prior youth strength training programs emphasized lower intensity resistance with relatively slow movements. Since power activities typically involve higher intensity, explosive-like contractions with higher angular velocities (e.g., plyometrics), there is a conflict between the training medium and testing measures. This meta-analysis compared strength (e.g., training with resistance or body mass) and power training programs (e.g., plyometric training) on proxies of muscle strength, power, and speed. A systematic literature search using a Boolean Search Strategy was conducted in the electronic databases PubMed, SPORT Discus, Web of Science, and Google Scholar and revealed 652 hits. After perusal of title, abstract, and full text, 107 studies were eligible for inclusion in this systematic review and meta-analysis. The meta-analysis showed small to moderate magnitude changes for training specificity with jump measures. In other words, power training was more effective than strength training for improving youth jump height. For sprint measures, strength training was more effective than power training with youth. Furthermore, strength training exhibited consistently large magnitude changes to lower body strength measures, which contrasted with the generally trivial, small and moderate magnitude training improvements of power training upon lower body strength, sprint and jump measures, respectively. Maturity related inadequacies in eccentric strength and balance might influence the lack of training specificity with the unilateral

  10. Enhancement of peak and mean power in concentric phase of resistance exercises.

    PubMed

    Zemková, Erika; Jeleň, Michal N; Kováčiková, Zuzana C; Ollé, Gábor; Vilman, Tomáš S; Hamar, Dušan S

    2014-10-01

    The study compares the differences in peak and mean power of concentric-only and countermovement resistance exercises (ΔP) with different weights. A group of 27 fit men randomly performed 3 repetitions of either barbell bench presses or barbell squats on different days. The initial weight of 20 kg was increased by 10 or 5 kg (at higher loads) up to at least 85% of a previously established 1 repetition maximum (1RM). A computer-based system FiTRO Dyne Premium was used to monitor force and velocity and to calculate power. The peak values and mean values of power during the entire concentric phase of lifting and during the acceleration phase were analyzed. Results showed that maximal ΔP calculated from the peak and mean values in the acceleration phase of bench presses was achieved at lower weights (118.4 ± 19.0 W at 47% of 1RM and 116.2 ± 15.3 W at 48% of 1RM, respectively) than the one calculated from mean values in the entire concentric phase of lifting (114.8 ± 14.8 W at 57% 1RM). Likewise, maximal ΔP calculated from the peak and mean values in the acceleration phase of squats was achieved at lower weights (127.7 ± 20.4 W at 67% of 1RM and 124.3 ± 22.1 W at 69% of 1RM, respectively) than the one calculated from the mean values in the entire concentric phase of lifting (125.0 ± 19.2 W at 77% of 1RM). This fact has to be taken into account when training efficiency is evaluated, namely, in sports requiring the production of maximal force in a short time.

  11. Impact of Inertial Training on Strength and Power Performance in Young Active Men.

    PubMed

    Naczk, Mariusz; Naczk, Alicja; Brzenczek-Owczarzak, Wioletta; Arlet, Jarosław; Adach, Zdzisław

    2016-08-01

    Naczk, M, Naczk, A, Brzenczek-Owczarzak, W, Arlet, J, and Adach, Z. Impact of inertial training on strength and power performance in young active men. J Strength Cond Res 30(8): 2107-2113, 2016-This study evaluated how 5 weeks of inertial training using 2 different loads influenced strength and power performance. Fifty-eight male physical education students were randomly divided into training and control groups. The 2 training groups (T0 and T10) performed inertial training 3 times per week for 5 weeks using the new Inertial Training and Measurement System (ITMS). Each training session included 3 exercise sets involving the knee extensors muscles. The T0 group used only the mass of the ITMS flywheel (19.4 kg), whereas the T10 group had an additional 10 kg on the flywheel. Before and after training, we evaluated maximum force and power of knee extensors muscles, countermovement jump (CMJ), squat jump (SJ), maximal power output achieved during ergometer test PVT, electromyography of quadriceps, and muscle mass. In T0 and T10, respectively, ITMS training induced significant increases in muscle force (25.2 and 23.3%), muscle power (33.2 and 27%), CMJ (3.8 and 6.7%), SJ (2.2 and 6.1%), PVT (8 and 7.4%), and muscle mass (9.8 and 15%). The changes did not significantly differ between T0 and T10. A 16% significant increase of electromyography amplitude (quadriceps muscle) was noted only in T0. The novel ITMS training method is effective for improving muscular strength and power. Improvements in PVT, CMJ, and SJ indicate that the increased strength and power elicited by ITMS training can translate to improvements in sport performance. The ITMS training can also be useful for building muscle mass.

  12. Nuclear power plant simulators: their use in operator training and requalification

    SciTech Connect

    Jones, D.W.; Baer, D.K.; Francis, C.C.

    1980-07-01

    This report presents the results of a study performed for the Nuclear Regulatory Commission to evaluate the capabilities and use of nuclear power plant simulators either built or being built by the US nuclear power industry; to determine the adequacy of existing standards for simulator design and for the training of power plant operators on simulators; and to assess the issues about simulator training programs raised by the March 28, 1979, accident at Three Mile Island Unit 2.

  13. Solar Power Satellite antenna phase control system hardware simulation, phase 4. Volume 2: Analytical simulation of SPS system performance

    NASA Technical Reports Server (NTRS)

    Lindsey, W. C.; Kantak, A. V.; Chie, C. M.

    1981-01-01

    The pilot signal parameter optimization and power transponder analyses are presented. The SPS antenna phase control system is modeled and the hardware simulation study described. Ionospheric and system phase error effects and the effects of high power amplifier phase and amplitude jitters are considered. Parameter optimization of the spread spectrum receiver, consisting of the carrier tracking loop and the code tracking loop, is described.

  14. Neuromuscular And Cardiovascular Adaptations In Response To High Intensity Interval Power Training.

    PubMed

    Romero-Arenas, Salvador; Ruiz, Rubén; Vera, Antonio; Colomer-Poveda, David; Grau, Amelia Guadalupe; Márquez, Gonzalo

    2017-01-11

    The aim of the present study was to determine the efficacy of a high-intensity power training (HIPT) program, and to compare the effects of HIPT to traditional power training (TPT) on the aerobic and power performance. For this purpose, 29 healthy men (23.1±2.7 years) were recruited and randomly distributed into three different groups. One group performed traditional power training (TPT n=10), the second group performed power training organized as a circuit (HIPT; n=10) and the third group served as control (CG; n=9). Training consisted of weight lifting thrice per week for six weeks. TPT subjects performed three to five sets of each exercises with inter-set rest of 90 s, and HIPT subjects executed the training in a short circuit (15 s of rest between exercises). In order to known the effects in aerobic performance, maximal aerobic speed (MAS) was measured. In order to identify the effects on power performance subjects performed a Wingate test, a countermovement jump (CMJ) test and a power-load curve in bench press. The main results showed that after both power training protocols subjects increased significantly (p<0.05) the power production during the Wingate Test, the height and power reached during the CMJ test and the peak power produced during the power-load curve. However, only the HIPT group improved significantly MAS (p<0.05). There were no changes in any variables in CG. Hence, our results suggest that HIPT may be as effective as TPT for improving power performance in young adults. Additionally, only HIPT elicited improvements in MAS.

  15. Heuristic scenario builder for power system operator training

    SciTech Connect

    Irisarri, G.; Rafian, M. ); Miller, B.N. ); Dobrowolski, E.J. )

    1992-05-01

    The Heuristic Scenario Builder (HSB), a knowledge-based training scenario builder for the EPRI Operator Training Simulator (OTS), is described in this paper. Expert systems and heuristic searches are used in the HSB to find training scenarios that closely fit trainee profiles and that address particular training requirements. Expert knowledge obtained from instructors and other operations personnel is used throughout the HSB to determine the scenarios. The HSB is an integral part of the OTS and is currently in operation at Philadelphia Electric's OTS installation.

  16. Three-phase Unbalanced Interval Power Flow Calculation of Low-voltage Distribution Network with Distributed PV Power Generation

    NASA Astrophysics Data System (ADS)

    Yuan, Yan; Shunjiang, Lin; Yuan, Lu

    2017-05-01

    Low-voltage distribution network is a three-phase unbalanced system due to the integration of single-phase loads and single-phase distributed PV arrays. In this paper, three-phase unbalanced interval power flow calculation model of three-phase four-wire low voltage distribution network with distributed PV power generation is established. In the model, intensity of illumination and battery temperature which influence the power output of distributed PV power generation is described as intervals. Then, through the affine interval algorithm, the interval power flow problem is transformed into a deterministic power flow problem and two linear optimization problems. By solving the above problems, the interval power flow solution can be obtained. Finally, the proposed algorithm is applied to an actual 22-bus low-voltage distribution network, and the solution of the affine interval algorithm is compared to the solution of the Monte Carlo sampling method, which verifies the correctness and effectiveness of the proposed algorithm.

  17. Effect of strength training with blood flow restriction on muscle power and submaximal strength in eumenorrheic women.

    PubMed

    Gil, Ana L S; Neto, Gabriel R; Sousa, Maria S C; Dias, Ingrid; Vianna, Jeferson; Nunes, Rodolfo A M; Novaes, Jefferson S

    2017-03-01

    Blood flow restriction (BFR) training stimulates muscle size and strength by increasing muscle activation, accumulation of metabolites and muscle swelling. This method has been used in different populations, but no studies have evaluated the effects of training on muscle power and submaximal strength (SS) in accounted for the menstrual cycle. The aim of this study was to analyse the effect of strength training (ST) with BFR on the muscle power and SS of upper and lower limbs in eumenorrheic women. Forty untrained women (18-40 years) were divided randomly and proportionally into four groups: (i) high-intensity ST at 80% of 1RM (HI), (ii) low-intensity ST at 20% of 1RM combined with partial blood flow restriction (LI + BFR), (iii) low-intensity ST at 20% of 1RM (LI) and d) control group (CG). Each training group performed eight training sessions. Tests with a medicine ball (MB), horizontal jump (HJ), vertical jump (VJ), biceps curls (BC) and knee extension (KE) were performed during the 1st day follicular phase (FP), 14th day (ovulatory phase) and 26-28th days (luteal phase) of the menstrual cycle. There was no significant difference among groups in terms of the MB, HJ, VJ or BC results at any time point (P>0·05). SS in the KE exercise was significantly greater in the LI + BFR group compared to the CG group (P = 0·014) during the LP. Therefore, ST with BFR does not appear to improve the power of upper and lower limbs and may be an alternative to improve the SS of lower limbs of eumenorrheic women.

  18. StayFit: a wearable application for Gym based power training.

    PubMed

    Maheedhar, Maram; Gaurav, Aman; Jilla, Vivek; Tiwari, Vijay N; Narayanan, Rangavittal

    2016-08-01

    Comprehensive fitness training involves both cardiorespiratory and power components. Often power/muscle strength training is confused with cardiorespiratory endurance training. However, each of them target different physiological aspects of fitness. Although, wearable based fitness trackers designed towards cardiorespiratory endurance training are available in the market, a dedicated wearable based fitness application designed for power training/tracking is still not readily available to fitness enthusiasts. With growing usage of wearable technology to manage and track personal health, it is imperative to develop health/fitness applications for wearables. A wearable based application for power training will allow the user to track build-up of muscle strength unobtrusively over a period of time. This work provides a framework and design for automatic detection, counting repetitions of strength training Gym exercises (covering all the major muscle groups), estimate personalized calories spent in each session and track power on a standalone Gear watch (both analysis and display including User Experience(UX) design). Our proposed method detects activity with ~96% sensitivity and ~96% specificity on an average and count repetitions with an overall accuracy of >95% using motion sensor data (accelerometer, gyroscope) for eight major Gym exercises. Additionally, using heart rate sensor data we have provided a mechanism to individually track the power/muscle strength of a person. This work will give further impetus towards developing wearable based systems for personalized fitness tracking and training. This will also give an option for wearable users to address both the crucial aspects of fitness (cardiorespiratory and muscle strength).

  19. Unity Power Factor Operation Control Method For Single-phase to Three-phase Matrix Converter

    NASA Astrophysics Data System (ADS)

    Haga, Hitoshi; Takahashi, Isao; Ohishi, Kiyoshi

    This paper proposes a new control method of matrix converter to obtain the unity power factor operation. Source side of the matrix converter is single-phase voltage, and the load side is three-phase ac motor. The number of switching device is six, and the converter does not require a reactor or an electrolytic capacitor. Generally, it is difficult for matrix converter to control both its input current waveform and the output voltage waveform, because the switching devices are connected to both source side and load side. In this paper, applying an algebraic transfer matrix, the control method of single-phase to three-phase matrix converter applies the indirect modulation model. The indirect modulation model treats a matrix converter as a two-stage transformation converter. The rectifier of proposed model consists only diode and small L-C filter. Hence, the switching frequency is lower than the conventional model one. The inverter of the proposed model regulates both the input current waveform and the motor speed. The inverter control scheme for IPM motor is based on direct torque control (DTC). The additional current controller improves its input current waveform. Hence, an optimum switching pattern of the matrix converter realizes quick torque response and unity power factor operation. This paper describes that the proposed method achieves the power factor 97.6% by experimental tests. The experimental results confirm the feasibility of the proposed method for matrix converter.

  20. Optimizing Soft Magnetic Composites for Power Frequency Applications and Power-Trains

    NASA Astrophysics Data System (ADS)

    Lemieux, Patrick; Guthrie, Roderick; Isac, Mihaiela

    2012-03-01

    A new approach, together with a new family of soft magnetic composites (SMCs), has been developed and optimized for power alternating-current applications. The different technological and economic restrictions needed to maximize a composite's performance-to-cost ratio are presented. The experimental procedures to produce sintered lamellar SMCs are reported, together with magnetic results and the effects of different processing parameters on their performance. The present results are compared with corresponding data available for soft magnetic materials available on the market (laminations and composites). Data on the mechanical strength of these new SMC structures are also given. The new process results in magnetic and mechanical properties of different alloy systems that are better than those of any of the SMCs available. The present materials' energetic losses can be under 2 W/kg at 60 Hz, at 1 T, whilst their permeability exceeds 2000, while maintaining maximum induction above 1.7 T. These properties are very close to the best results for standard laminations on the market. The present process has the potential to be very inexpensive, owing to its simplicity. Even though not fully isotropic, recent three-dimensional machine designs and process advantages conferred by powder metallurgy techniques can be applied to this new family of lamellar particle composites. Through theoretical calculations and modeling exercises, it is briefly shown that this new kind of material can result in an improvement to the transportation sector where weight and efficiency of newly emerging electrical and hybrid power-trains are of prime importance.

  1. Outdoor Power Equipment Technician: Apprenticeship Course Outline. Apprenticeship and Industry Training. 5111.1

    ERIC Educational Resources Information Center

    Alberta Advanced Education and Technology, 2011

    2011-01-01

    The graduate of the Outdoor Power Equipment Technician apprenticeship program is a certified journeyperson who will be able to: (1) supervise, train and coach apprentices; (2) service, maintain, repair and rebuild outdoor power equipment and outdoor power equipment accessories; (3) communicate clearly with customers, staff, suppliers, as required;…

  2. Small, Mid-Sized Businesses Power Up with Workforce Training.

    ERIC Educational Resources Information Center

    WorkAmerica, 2000

    2000-01-01

    Increasingly, small and mid-sized businesses are becoming just as focused on work force training as large corporations are. The training being provided by smaller companies is extending beyond nuts-and-bolts instruction into the area of core business skills, such as leading, managing, thinking creatively, and solving problems. States are…

  3. Four-to-one power combiner for 20 GHz phased array antenna using RADC MMIC phase shifters

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The design and microwave simulation of two-to-one microstrip power combiners is described. The power combiners were designed for use in a four element phase array receive antenna subarray at 20 GHz. Four test circuits are described which were designed to enable testing of the power combiner and the four element phased array antenna. Test Circuit 1 enables measurement of the two-to-one power combiner. Test Circuit 2 enables measurement of the four-to-one power combiner. Test Circuit 3 enables measurement of a four element antenna array without phase shifting MMIC's in order to characterize the power combiner with the antenna patch-to-microstrip coaxial feedthroughs. Test circuit 4 is the four element phased array antenna including the RADC MMIC phase shifters and appropriate interconnects to provide bias voltages and control phase bits.

  4. Kinematic Mechanisms of How Power Training Improves Healthy Old Adults' Gait Velocity.

    PubMed

    Beijersbergen, Chantal M I; Granacher, Urs; Gäbler, Martijn; Devita, Paul; Hortobágyi, Tibor

    2017-01-01

    Slow gait predicts many adverse clinical outcomes in old adults, but the mechanisms of how power training can minimize the age-related loss of gait velocity is unclear. We examined the effects of 10 wk of lower extremity power training and detraining on healthy old adults' lower extremity muscle power and gait kinematics. As part of the Potsdam Gait Study, participants started with 10 wk of power training followed by 10 wk of detraining (n = 16), and participants started with a 10-wk control period followed by 10 wk of power training (n = 16). We measured gait kinematics (stride characteristic and joint kinematics) and isokinetic power of the ankle plantarflexor (20°·s, 40°·s, and 60°·s) and knee extensor and flexor (60°·s, 120°·s, and 180°·s) muscles at weeks 0, 10, and 20. Power training improved isokinetic muscle power by ~30% (P ≤ 0.001) and fast (5.9%, P < 0.05) but not habitual gait velocity. Ankle plantarflexor velocity measured during gait at fast pace decreased by 7.9% (P < 0.05). The changes isokinetic muscle power and joint kinematics did not correlate with increases in fast gait velocity. The mechanisms that increased fast gait velocity involved higher cadence (r = 0.86, P ≤ 0.001) rather than longer strides (r = 0.49, P = 0.066). Detraining did not reverse the training-induced increases in muscle power and fast gait velocity. Because increases in muscle power and modifications in joint kinematics did not correlate with increases in fast gait velocity, kinematic mechanisms seem to play a minor role in improving healthy old adults' fast gait velocity after power training.

  5. Legionnaires' disease bacteria in power plant cooling systems: Phase 2

    SciTech Connect

    Tyndall, R.L.; Christensen, S.W.; Solomon, J.A.

    1985-04-01

    Legionnaires' Disease Bacteria (Legionella) are a normal component of the aquatic community. The study investigated various environmental factors that affect Legionella profiles in power plant cooling waters. The results indicate that each of the four factors investigated (incubation temperature, water quality, the presence and type of associated biota, and the nature of the indigenous Legionella population) is important in determining the Legionella profile of these waters. Simple predictive relationships were not found. At incubation temperatures of 32/sup 0/ and 37/sup 0/C, waters from a power plant where infectious Legionella were not observed stimulated the growth of stock Legionella cultures more than did waters from plants where infectious Legionella were prevalent. This observation is consistent with Phase I results, which showed that densities of Legionella were frequently reduced in closed-cycle cooling systems despite the often higher infectivity of Legionella in closed-cycle waters. In contrast, water from power plants where infectious Legionella were prevalent supported the growth of indigenous Legionella pneumophila at 42/sup 0/C, while water from a power plant where infectious Legionella were absent did not support growth of indigenous Legionella. Some Legionella are able to withstand a water temperature of 85/sup 0/C for several hours, thus proving more tolerant than was previously realized. Finally, the observation that water from two power plants where infectious Legionella were prevalent usually supported the growth of Group A Legionella at 45/sup 0/C indicates the presence, of soluble Legionella growth promoters in these waters. This test system could allow for future identification and control of these growth promoters and, hence, of Legionella. 25 refs., 23 figs., 10 tabs.

  6. Development of a full-scale training simulator for an 800-MW power unit

    NASA Astrophysics Data System (ADS)

    Zhuravlev, S. K.; Andreev, A. M.

    2013-07-01

    Stages of work involving preparation of requirements specification, development, and subsequent implementation of a project for constructing a full-scale training simulator of an 800-MW power unit are considered. The training simulator is constructed using the Kosmotronika-Venets computerized automation system developed by PIK Progress (Moscow). The entire personnel training system, the arrangement of drills, and the concept of structuring the entire personnel education system at the Surgut GRES-2 district power station, a branch of E.ON Rossiya, had to be touched in drawing up the requirements specification for elaborating the training simulator. The article describes how these problems were solved.

  7. The effects of passive leg press training on jumping performance, speed, and muscle power.

    PubMed

    Liu, Chiang; Chen, Chuan-Shou; Ho, Wei-Hua; Füle, Róbert János; Chung, Pao-Hung; Shiang, Tzyy-Yuang

    2013-06-01

    Passive leg press (PLP) training was developed based on the concepts of the stretch-shortening cycle (SSC) and the benefits of high muscle contraction velocity. Passive leg press training enables lower limb muscle groups to apply a maximum downward force against a platform moved up and down at high frequency by an electric motor. Thus, these muscle groups accomplished both concentric and eccentric isokinetic contractions in a passive, rapid, and repetitive manner. This study investigates the effects of 10 weeks of PLP training at high and low movement frequencies have on jumping performance, speed, and muscle power. The authors selected 30 college students who had not performed systematic resistance training in the previous 6 months, including traditional resistance training at a squat frequency of 0.5 Hz, PLP training at a low frequency of 0.5 Hz, and PLP training at a high frequency of 2.5 Hz, and randomly divided them into 3 groups (n = 10). The participants' vertical jump, drop jump, 30-m sprint performance, explosive force, and SSC efficiency were tested under the same experimental procedures at pre- and post-training. Results reveal that high-frequency PLP training significantly increased participants' vertical jump, drop jump, 30-m sprint performance, instantaneous force, peak power, and SSC efficiency (p < 0.05). Additionally, their change rate abilities were substantially superior to those of the traditional resistance training (p < 0.05). The low-frequency PLP training significantly increased participants' vertical jump, 30-m sprint performance, instantaneous force, and peak power (p < 0.05). However, traditional resistance training only increased participants' 30-m sprint performance and peak power (p < 0.05). The findings suggest that jump performance, speed, and muscle power significantly improved after 10 weeks of PLP training at high movement frequency. A PLP training machine powered by an electrical motor enables muscles of the lower extremities to

  8. Analysis of acute explosive training modalities to improve lower-body power in baseball players.

    PubMed

    Dodd, Daniel J; Alvar, Brent A

    2007-11-01

    Complex training is the simultaneous combination of heavy resistance training and plyometrics. The objective of this study was to test the effects of complex training vs. heavy resistance or plyometric interventions alone on various power-specific performance measures. Forty-five male division II junior college baseball players participated in 3 separate 4-week resistance training interventions. Subjects were randomly assigned to one of three groups. In a counterbalanced rotation design, each group participated in complex, heavy resistance, and plyometric training interventions. Each individual was tested in 20-yd (SP20), 40-yd (SP40), 60-yd (SP60), vertical jump, standing broad jump, and T-agility measures pre- and post-4-week training interventions. There was no statistical significant difference (p = 0.11) between groups across all performance measures. Review of each distinct training intervention revealed greater percent improvements in SP20 (0.55; -0.49; -0.12), SP40 (0.26; -0.72; -1.33), SP60 (0.27; 0.15; -0.27), standing broad jump (1.80; 0.67; 1.1), and T-agility (2.33; 1.23; -0.04) with complex training interventions than with the heavy resistance or plyometric training interventions, respectively. Plyometric-only training showed greater percent changes in vertical jump (1.90) than with complex (0.97) or heavy resistance training (0.36). The present results indicate that complex training can provide strength and conditioning professionals equal, if not slightly greater, improvements in muscular power than traditional heavy resistance- and plyometric-only interventions in moderately trained athletes. Complex training can be another valuable method for short-term power and speed improvements in athletes in isolation or in conjunction with other power development methods.

  9. Early-phase strength gains during traditional resistance training compared with an upper-body air-resistance training device.

    PubMed

    McGinley, Cian; Jensen, Randall L; Byrne, Ciarán A; Shafat, Amir

    2007-05-01

    The purpose of this study was to examine the early-phase adaptations of traditional dynamic constant external resistance (DCER) training vs. a portable upper-body training device (Fortex). The Fortex is a concentric training device based on air resistance. Contractions using this device are slow (1.5-3 s) and have a limited range of motion. The exercises potentially allow maximal muscle action during each contraction. Healthy, sedentary men (n = 30) were assigned to begin either 8 weeks of weight training (W, n = 12) or 8 weeks of Fortex training (F, n = 9), and were compared with a control group (C, n = 9). Exercises were chosen for the W group that would train similar muscle groups and contain a similar volume of repetitions as the F group. However, movement patterns and force curves were not identical. Increases in the upper-arm cross-sectional area were not detected in any of the groups. Both training groups showed strength gains in the various strength tests that were distinct from each other. Our results indicate that both Fortex and DCER training proved effective in eliciting strength gains in sedentary men over an 8-week training period. There are, however, limitations with the Fortex in terms of progression needs and training asymmetry that indicate it should be used as a complement to other training.

  10. Numerical analysis of phase change materials for thermal control of power battery of high power dissipations

    NASA Astrophysics Data System (ADS)

    Xia, X.; Zhang, H. Y.; Deng, Y. C.

    2016-08-01

    Solid-fluid phase change materials have been of increasing interest in various applications due to their high latent heat with minimum volume change. In this work, numerical analysis of phase change materials is carried out for the purpose of thermal control of the cylindrical power battery cells for applications in electric vehicles. Uniform heat density is applied at the battery cell, which is surrounded by phase change material (PCM) of paraffin wax type and contained in a metal housing. A two-dimensional geometry model is considered due to the model symmetry. The effects of power densities, heat transfer coefficients and onset melting temperatures are examined for the battery temperature evolution. Temperature plateaus can be observed from the present numerical analysis for the pure PCM cases, with the temperature level depending on the power densities, heat transfer coefficients, and melting temperatures. In addition, the copper foam of high thermal conductivity is inserted into the copper foam to enhance the heat transfer. In the modeling, the local thermal non-equilibrium between the metal foam and the PCM is taken into account and the temperatures for the metal foam and PCM are obtained respectively.

  11. Digital regulation of a phase controlled power converter

    SciTech Connect

    Schultheiss, C.; Haque, T.

    1995-12-01

    The Relativistic Heavy Ion Collider, now in construction at Brookhaven National Laboratory, will use phase controlled power converters for the main dipole and quadrupole magnet strings. The rectifiers in these power supplies will be controlled by a digital regulator based on the TI 320C30 Digital Signal Processor (DSP). The DSP implements the current loop, the voltage loop, and a system to actively reduce the sub-harmonic ripple components. Digital firing circuits consisting of a phase locked lop and counters are used to fire the SCRs. Corrections for the sub-harmonic reduction are calculated by the DSP and stored in registers in the firing circuit. These corrections are added in hardware, to the over-all firing count provided by the DSP. the resultant count is compared to a reference counter to fire the SCRs. This combination of a digital control system and the digital firing circuits allows the correction of the sub-harmonics in a real-time sense. A prototype of the regulator has been constructed, and the preliminary testing indicates a sub-harmonic reduction of 60 dB.

  12. High-power phase-locked arrays of antiguides

    NASA Astrophysics Data System (ADS)

    Botez, D.

    1991-12-01

    Phase-locked arrays of antiguides are a unique class of (monolithic) coherent diode lasers in that they provide both strong overall interelement coupling as well as strong optical-mode confinement. The leaky-wave characteristics of antiguides allow for a resonant condition; that is, when the interelement regions are odd integer numbers of the leaky-wave (lateral) half wavelength all elements equally couple to each other creating so called parallel coupling. By contrast, for the vast majority of coherent arrays published to date interelement coupling is of the nearest-neighbor type, so called series coupling, which gives weak coherence and poor intermodal discrimination. Parallel-coupled arrays of antiguides are called resonant-optical-waveguide (ROW) arrays. ROW devices posses such desirable properties as: full coherence, uniform intensity profile, and large intermodal discrimination. Thus, high coherent powers can be achieved without active phase control. The theory of operation for ROW arrays will be outlined. Experimental results include diffraction-limited-operation from both 20- and 40-element devices to high drive levels (10×threshold) and powers (0.5-1.5 W). CW diffraction-limited operation has been achieved to 0.5 W, while in pulsed operation up to 2 W is obtained in a nearly diffraction-limited beam. Devices can be driven to 5 W with beamwidths 3×diffraction limit.

  13. Effects of endurance training on the isocapnic buffering and hypocapnic hyperventilation phases in professional cyclists.

    PubMed

    Chicharro, J L; Hoyos, J; Lucía, A

    2000-12-01

    To evaluate the changes produced in both the isocapnic buffering and hypocapnic hyperventilation (HHV) phases of professional cyclists (n = 11) in response to endurance training, and to compare the results with those of amateur cyclists (n = 11). Each professional cyclist performed three laboratory exercise tests to exhaustion during the active rest (autumn: November), precompetition (winter: January), and competition (spring: May) periods of the sports season. Amateur cyclists only performed one exercise test during the competition period. The isocapnic buffering and HHV ranges were calculated during each test and defined as Vo2 and power output (W). No significant differences were found in the isocapnic buffering range in each of the periods of the sports season in professional cyclists. In contrast, there was a significant reduction in the HHV range (expressed in W) during both the competition (p<0.01) and precompetition(p<0.05) periods compared with the rest period. On the other hand, a longer HHV range (p<0.01) was observed in amateur cyclists than in professional cyclists (whether this was expressed in terms of Vo2 or W). No change is observed in the isocapnic buffering range of professional cyclists throughout a sports season despite a considerable increase in training loads and a significant reduction in HHV range expressed in terms of power output.

  14. The Training Information Management System. Volume 2. Phase 2 evaluation Report

    DTIC Science & Technology

    1986-07-01

    01 m.4wl Hi l I I ARI Research Note 86-78 THE TRAINING INFORMATION MANAGEMENT SYSTEM : Phase II Evaluation Report oq N N Perceptroni cst Ifor ARI...8217 IP ) / 4. TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED THE TRAINING INFORMATION MANAGEMENT SYSTEM : Final Report, Vol. 2 Phase II...ABTRACT ’awt m reverse astd N rmev awd Ide lifi by block nIhawb•e) .The Training Information Management System (TIMS) is a computer-based system

  15. Velocity during Strength and Power Training of the Ankle Plantar and Dorsiflexor Muscles in Older Patients Attending Day Hospital Rehabilitation.

    PubMed

    Rajan, Pavithra; Porter, Michelle M

    2015-01-01

    Power training has been proposed as a more effective type of resistance training for older adults for functional performance. It is not yet known whether older adults respond appropriately to instructions for power versus strength training. The purpose of this study was to determine the velocity during strength and power training, with elastic resistance bands, in older adults attending a geriatric rehabilitation day program. It was hypothesized that power training would be faster than strength training, but that there would be large interindividual differences. Nine older patients (70 to 86 years) performed power and strength training of the ankle dorsiflexor and plantar flexor muscles using elastic resistance bands. Training sessions were filmed to assess the velocity of training. Power training occurred at faster velocities as compared to strength training (P < 0.01) for both muscle groups. However, a wide variation was observed between participants in the training velocities. Older adults attending geriatric rehabilitation do have the potential to develop faster contractions during power training as compared to strength training. Nevertheless, the actual velocities achieved differed between individuals. This could explain some of the mixed findings of studies on power training. Hence, researchers should monitor velocity when comparing different types of resistance training.

  16. Passive Two-Phase Cooling of Automotive Power Electronics: Preprint

    SciTech Connect

    Moreno, G.; Jeffers, J. R.; Narumanchi, S.; Bennion, K.

    2014-08-01

    Experiments were conducted to evaluate the use of a passive two-phase cooling strategy as a means of cooling automotive power electronics. The proposed cooling approach utilizes an indirect cooling configuration to alleviate some reliability concerns and to allow the use of conventional power modules. An inverter-scale proof-of-concept cooling system was fabricated, and tests were conducted using the refrigerants hydrofluoroolefin HFO-1234yf and hydrofluorocarbon HFC-245fa. Results demonstrated that the system can dissipate at least 3.5 kW of heat with 250 cm3 of HFC-245fa. An advanced evaporator design that incorporates features to improve performance and reduce size was conceived. Simulation results indicate its thermal resistance can be 37% to 48% lower than automotive dual side cooled power modules. Tests were also conducted to measure the thermal performance of two air-cooled condensers--plain and rifled finned tube designs. The results combined with some analysis were then used to estimate the required condenser size per operating conditions and maximum allowable system (i.e., vapor and liquid) temperatures.

  17. Passive Two-Phase Cooling for Automotive Power Electronics

    SciTech Connect

    Moreno, G.; Jeffers, J. R.; Narumanchi, S.; Bennion, K.

    2014-01-01

    Experiments were conducted to evaluate the use of a passive two-phase cooling strategy as a means of cooling automotive power electronics. The proposed cooling approach utilizes an indirect cooling configuration to alleviate some reliability concerns and to allow the use of conventional power modules. An inverter-scale proof-of-concept cooling system was fabricated and tested using the refrigerants hydrofluoroolefin HFO-1234yf and hydrofluorocarbon HFC-245 fa. Results demonstrated that the system can dissipate at least 3.5 kW of heat with 250 cm3 of HFC-245fa. An advanced evaporator concept that incorporates features to improve performance and reduce its size was designed. Simulation results indicate the concept's thermal resistance can be 58% to 65% lower than automotive dual-side-cooled power modules. Tests were also conducted to measure the thermal performance of two air-cooled condensers-plain and rifled finned tube designs. The results combined with some analysis were then used to estimate the required condenser size per operating conditions and maximum allowable system (i.e., vapor and liquid) temperatures.

  18. Impact of inertial training on strength and power performance in young active men.

    PubMed

    Naczk, Mariusz; Naczk, Alicja; Brzenczek-Owczarzak, Wioletta; Arlet, Jarosław; Adach, Zdzisław

    2013-11-20

    This study evaluated how five weeks of inertial training using two different loads influenced strength and power performance. Fifty-eight male physical education students were randomly divided into training and control groups. The two training groups (T0 and T10) performed inertial training three times per week for five weeks using the new Inertial Training Measurement System (ITMS). Each training session included three exercise sets involving the knee extensors muscles. The T0 group used only the mass of the ITMS flywheel (19.4 kg), while the T10 group had an additional 10 kg on the flywheel. Before and after training, we evaluated maximum force and power of knee extensors muscles, countermovement jump (CMJ), squat jump (SJ), maximal power output achieved during ergometer test PVT, electromyography of quadriceps, and muscle mass. In T0 and T10, respectively, ITMS training induced significant increases in muscle force (25.2% and 23.3%), muscle power (33.2% and 27%), CMJ (3.8% and 6.7%), SJ (2.2% and 6.1%), PVT (8% and 7.4%), and muscle mass (9.8% and 15%). The changes did not significantly differ between T0 and T10. A 16% significant increase of electromyography amplitude (quadriceps muscle) was noted only in T0. The novel ITMS training method is effective for improving muscular strength and power. Improvements in PVT, CMJ, and SJ indicate that the increased strength and power elicited by ITMS training can translate to improvements in sport performance. ITMS training can also be useful for building muscle mass.

  19. A ground based phase control system for the solar power satellite. Executive summary, volume 1, phase 3

    NASA Technical Reports Server (NTRS)

    Chie, C. M.

    1980-01-01

    The Solar Power Satellite (SPS) concept and the reference phase control system investigated in earlier efforts are reviewed. A summary overview of the analysis and selection of the pilot signal and power transponder design is presented along with the SOLARSIM program development and the simulated SPS phase control performance. Evaluations of the ground based phase control system as an alternate phase control concept are summarized.

  20. Signal with Flat Phase Noise Using a Carrier and the Power Spectral Density of White Noise for Phase Noise Standards

    NASA Astrophysics Data System (ADS)

    Watabe, Ken-ichi; Yanagimachi, Shinya; Ikegami, Takeshi; Iida, Hitoshi; Shimada, Yozo

    2012-01-01

    We have realized a phase noise standard of a signal with a -100 dBc/Hz flat phase noise at 10 MHz for Fourier frequencies of 1 Hz to 100 kHz, which ensures traceability to the International System of Units (SI). The flat phase noise signal is produced using a carrier combined with white noise. To ensure traceability, both the flat phase noise signal power and the power spectral density of white noise are determined with a calibrated power meter and the noise standard, respectively. The flatness of the phase noise standard is within ±0.7 dB.

  1. Effect of resistance training on women's strength/power and occupational performances.

    PubMed

    Kraemer, W J; Mazzetti, S A; Nindl, B C; Gotshalk, L A; Volek, J S; Bush, J A; Marx, J O; Dohi, K; Gómez, A L; Miles, M; Fleck, S J; Newton, R U; Häkkinen, K

    2001-06-01

    The effects of resistance training programs on strength, power, and military occupational task performances in women were examined. Untrained women aged (mean +/- SD) 23 +/- 4 yr were matched and randomly placed in total- (TP, N = 17 and TH, N = 18) or upper-body resistance training (UP, N = 18 and UH, N = 15), field (FLD, N = 14), or aerobic training groups (AER, N = 11). Two periodized resistance training programs (with supplemental aerobic training) emphasized explosive exercise movements using 3- to 8-RM training loads (TP, UP), whereas the other two emphasized slower exercise movements using 8- to 12-RM loads (TH, UH). The FLD group performed plyometric and partner exercises. Subjects were tested for body composition, strength, power, endurance, maximal and repetitive box lift, 2-mile loaded run, and U.S. Army Physical Fitness Tests before (T0) and after 3 (T3) and 6 months of training (T6). For comparison, untrained men (N = 100) (MEN) were tested once. Specific training programs resulted in significant increases in body mass (TP), 1-RM squat (TP, TH, FLD), bench press (all except AER), high pull (TP), squat jump (TP, TH, FLD), bench throw (all except AER), squat endurance (all except AER), 1-RM box lift (all except aerobic), repetitive box lift (all), push-ups (all except AER), sit-ups (all except AER), and 2-mile run (all). Strength training improved physical performances of women over 6 months and adaptations in strength, power, and endurance were specific to the subtle differences (e.g., exercise choice and speeds of exercise movement) in the resistance training programs (strength/power vs strength/hypertrophy). Upper- and total-body resistance training resulted in similar improvements in occupational task performances, especially in tasks that involved upper-body musculature. Finally, gender differences in physical performance measures were reduced after resistance training in women, which underscores the importance of such training for physically

  2. Phase diagram of power law and Lennard-Jones systems: Crystal phases

    SciTech Connect

    Travesset, Alex

    2014-10-28

    An extensive characterization of the low temperature phase diagram of particles interacting with power law or Lennard-Jones potentials is provided from Lattice Dynamical Theory. For power law systems, only two lattice structures are stable for certain values of the exponent (or softness) (A15, body centered cube (bcc)) and two more (face centered cubic (fcc), hexagonal close packed (hcp)) are always stable. Among them, only the fcc and bcc are equilibrium states. For Lennard-Jones systems, the equilibrium states are either hcp or fcc, with a coexistence curve in pressure and temperature that shows reentrant behavior. The hcp solid never coexists with the liquid. In all cases analyzed, for both power law and Lennard-Jones potentials, the fcc crystal has higher entropy than the hcp. The role of anharmonic terms is thoroughly analyzed and a general thermodynamic integration to account for them is proposed.

  3. Phase diagram of power law and Lennard-Jones systems: Crystal phases

    SciTech Connect

    Travesset, Alex

    2014-10-28

    An extensive characterization of the low temperature phase diagram of particles interacting with power law or Lennard-Jones potentials is provided from Lattice Dynamical Theory. For power law systems, only two lattice structures are stable for certain values of the exponent (or softness) (A15, body centered cube (bcc)) and two more (face centered cubic (fcc), hexagonal close packed (hcp)) are always stable. Among them, only the fcc and bcc are equilibrium states. For Lennard-Jones systems, the equilibrium states are either hcp or fcc, with a coexistence curve in pressure and temperature that shows reentrant behavior. The hcp solid never coexists with the liquid. In all cases analyzed, for both power law and Lennard-Jones potentials, the fcc crystal has higher entropy than the hcp. The role of anharmonic terms is thoroughly analyzed and a general thermodynamic integration to account for them is proposed.

  4. Phase diagram of power law and Lennard-Jones systems: Crystal phases

    NASA Astrophysics Data System (ADS)

    Travesset, Alex

    2014-10-01

    An extensive characterization of the low temperature phase diagram of particles interacting with power law or Lennard-Jones potentials is provided from Lattice Dynamical Theory. For power law systems, only two lattice structures are stable for certain values of the exponent (or softness) (A15, body centered cube (bcc)) and two more (face centered cubic (fcc), hexagonal close packed (hcp)) are always stable. Among them, only the fcc and bcc are equilibrium states. For Lennard-Jones systems, the equilibrium states are either hcp or fcc, with a coexistence curve in pressure and temperature that shows reentrant behavior. The hcp solid never coexists with the liquid. In all cases analyzed, for both power law and Lennard-Jones potentials, the fcc crystal has higher entropy than the hcp. The role of anharmonic terms is thoroughly analyzed and a general thermodynamic integration to account for them is proposed.

  5. Phase diagram of power law and Lennard-Jones systems: crystal phases.

    PubMed

    Travesset, Alex

    2014-10-28

    An extensive characterization of the low temperature phase diagram of particles interacting with power law or Lennard-Jones potentials is provided from Lattice Dynamical Theory. For power law systems, only two lattice structures are stable for certain values of the exponent (or softness) (A15, body centered cube (bcc)) and two more (face centered cubic (fcc), hexagonal close packed (hcp)) are always stable. Among them, only the fcc and bcc are equilibrium states. For Lennard-Jones systems, the equilibrium states are either hcp or fcc, with a coexistence curve in pressure and temperature that shows reentrant behavior. The hcp solid never coexists with the liquid. In all cases analyzed, for both power law and Lennard-Jones potentials, the fcc crystal has higher entropy than the hcp. The role of anharmonic terms is thoroughly analyzed and a general thermodynamic integration to account for them is proposed.

  6. Training Technology Handbook Development. Phase I. Annotated Literature Review.

    DTIC Science & Technology

    1981-08-01

    DTIC TAB ] " Unannounced " Just if icatiorl. D stribultion/ ’ OSTI\\Iv1ai~t ce Dist Spoc l iiiV...prepared by the Chief, Naval Education and Training (CNET) with assistance of a Training Resources Panel (TRP). Manpower planning as related to the...system requirements, define education /training requirements, develop objectives and tests, plan/develop/validate in- S struction, conduct and evaluate

  7. Vibration training: could it enhance the strength, power, or speed of athletes?

    PubMed

    Wilcock, Ian M; Whatman, Chris; Harris, Nigel; Keogh, Justin W L

    2009-03-01

    The aim of this literature review was to determine whether vibration training could produce chronic improvements in the physical performance of trained athletes. Although the main objective was to analyze any performance benefits, a brief review of possible mechanisms linked to performance enhancement is also included. Vibration causes an increase in the g-forces acting on the muscles, increasing the loading parameters of any exercise. Increased loading should aid muscle hypertrophy, and some authors have suggested that vibration may enhance neuromuscular potentiation. Considering the 6 studies on trained athletes, there does seem to be some evidence to suggest that vibration may provide a small benefit to maximal strength (1-repetition maximum) and power (countermovement jumps) of trained athletes. Speed does not seem to be enhanced by vibration training. There is a lack of evidence to support the theory that long-term vibration training increases neuromuscular potentiation in trained athletes. What mechanism(s) could be responsible for possible strength and power enhancement is unclear. Because whole-body vibration does not seem to be detrimental to performance when used in a controlled manner, it could provide an additional training stimulus for athletes. However, further research is required to determine optimum vibration training protocols and to clarify whether vibration training produces performance benefits greater than those of traditional training methods.

  8. Solar Collector Thermal Power System. Volume 3. Basic Study and Experimental Evaluation of Thermal Train Components

    DTIC Science & Technology

    1974-11-01

    AD/A-000 942 SOLAR -COLLECTOR THERMAL POWER SYSTEM. VOLUME III. BASIC STUDY AND EXPERIMENTAL EVALUATION OF THERMAL TRAIN COMPONENTS Robert Richter...Experimental 16 Aug 1971 to 28 Jun 1974 Evaluation of Thermal Train 6. PERFORMING ORG. REPORT NUMBER Components 4074-Final 7. AUTHOR(s) 1. CONTRACT OR GRANT...complete thermal train . The effort comprised the design, fabrication, and testing of the heat pipe as an individual component and the integration and

  9. Phase 1 results from the Stirling-powered vehicle project

    NASA Technical Reports Server (NTRS)

    Shaltens, Richard K.

    1988-01-01

    The NASA Technology Utilization (TU) Office is sponsoring a multiyear, multiphase demonstration program to assess the technology developed under the DOE/NASA automotive Stirling engine (ASE) program with engines installed in various Air Force vehicles while being evaluated by independent third parties under realistic conditions. This paper reviews the operational history of Phase 1 with a Mod 1 Stirling engine installed in an Air Force multistop van in a variety of missions. Ten months of operation were with Air Force personnel at Langley Air Force Base, Virginia, where over 1100 hr and 4000 mi were logged on the Langley flight line. The Stirling-powered van operated on unleaded gasoline, JP-4 aircraft fuel, and diesel fuel at Langley Air Force Base. Two months of operation were completed with Deere and Company personnel in the Moline, Illinois area where over 175 hr and 2650 mi were logged on a Deere mail delivery route.

  10. Results from the Stirling-powered vehicle project: Phase 1

    SciTech Connect

    Shaltens, R.K.

    1988-01-01

    The NASA Technology Utilization (TU) Office is sponsoring a multiyear, multiphase demonstration program to assess the technology developed under the DOE/NASA automotive Stirling engine (ASE) program with engines installed in various Air Force vehicles while being evaluated by independent third parties under realistic conditions. This paper reviews the operational history of Phase I and a Mod I Stirling engine installed in an Air Force multistop van in a variety of missions. Ten months of operation were with Air Force personnel at Langley Air Force Base, Virginia, where over 1100 hr and 4000 mi were logged on the Langley flight line. The Stirling-powered van was operated on unleaded gasoline, JP-4 aircraft fuel, and diesel fuel at Langley Air Force Base. Two months of operation were completed with Deere Company personnel in the Moline, Illinois, area where over 175 h and 2650 miles were logged on a Deere mail delivery route. 8 refs., 12 figs., 6 tabs.

  11. Phased laser array for generating a powerful laser beam

    DOEpatents

    Holzrichter, John F.; Ruggiero, Anthony J.

    2004-02-17

    A first injection laser signal and a first part of a reference laser beam are injected into a first laser element. At least one additional injection laser signal and at least one additional part of a reference laser beam are injected into at least one additional laser element. The first part of a reference laser beam and the at least one additional part of a reference laser beam are amplified and phase conjugated producing a first amplified output laser beam emanating from the first laser element and an additional amplified output laser beam emanating from the at least one additional laser element. The first amplified output laser beam and the additional amplified output laser beam are combined into a powerful laser beam.

  12. Neuromuscular and Blood Lactate Responses to Squat Power Training with Different Rest Intervals Between Sets

    PubMed Central

    Martorelli, André; Bottaro, Martim; Vieira, Amilton; Rocha-Júnior, Valdinar; Cadore, Eduardo; Prestes, Jonato; Wagner, Dale; Martorelli, Saulo

    2015-01-01

    Studies investigating the effect of rest interval length (RI) between sets on neuromuscular performance and metabolic response during power training are scarce. Therefore, the purpose of this study was to compare maximal power output, muscular activity and blood lactate concentration following 1, 2 or 3 minutes RI between sets during a squat power training protocol. Twelve resistance-trained men (22.7 ± 3.2 years; 1.79 ± 0.08 cm; 81.8 ± 11.3 kg) performed 6 sets of 6 repetitions of squat exercise at 60% of their 1 repetition maximum. Peak and average power were obtained for each repetition and set using a linear position transducer. Muscular activity and blood lactate were measured pre and post-exercise session. There was no significant difference between RI on peak power and average power. However, peak power decreased 5.6%, 1.9%, and 5.9% after 6 sets using 1, 2 and 3 minutes of RI, respectively. Average power also decreased 10.5% (1 min), 2.6% (2 min), and 4.3% (3 min) after 6 sets. Blood lactate increased similarly during the three training sessions (1-min: 5.5 mMol, 2-min: 4.3 mMol, and 3-min: 4.0 mMol) and no significant changes were observed in the muscle activity after multiple sets, independent of RI length (pooled ES for 1-min: 0.47, 2-min: 0.65, and 3-min: 1.39). From a practical point of view, the results suggest that 1 to 2 minute of RI between sets during squat exercise may be sufficient to recover power output in a designed power training protocol. However, if training duration is malleable, we recommend 2 min of RI for optimal recovery and power output maintenance during the subsequent exercise sets. Key points This study demonstrates that 1 minute of RI between sets is sufficient to maintain maximal power output during multiple sets of a power-based exercise when it is composed of few repetitions and the sets are not performed until failure. Therefore, a short RI should be considered when designing training programs for the development of

  13. Neuromuscular and blood lactate responses to squat power training with different rest intervals between sets.

    PubMed

    Martorelli, André; Bottaro, Martim; Vieira, Amilton; Rocha-Júnior, Valdinar; Cadore, Eduardo; Prestes, Jonato; Wagner, Dale; Martorelli, Saulo

    2015-06-01

    Studies investigating the effect of rest interval length (RI) between sets on neuromuscular performance and metabolic response during power training are scarce. Therefore, the purpose of this study was to compare maximal power output, muscular activity and blood lactate concentration following 1, 2 or 3 minutes RI between sets during a squat power training protocol. Twelve resistance-trained men (22.7 ± 3.2 years; 1.79 ± 0.08 cm; 81.8 ± 11.3 kg) performed 6 sets of 6 repetitions of squat exercise at 60% of their 1 repetition maximum. Peak and average power were obtained for each repetition and set using a linear position transducer. Muscular activity and blood lactate were measured pre and post-exercise session. There was no significant difference between RI on peak power and average power. However, peak power decreased 5.6%, 1.9%, and 5.9% after 6 sets using 1, 2 and 3 minutes of RI, respectively. Average power also decreased 10.5% (1 min), 2.6% (2 min), and 4.3% (3 min) after 6 sets. Blood lactate increased similarly during the three training sessions (1-min: 5.5 mMol, 2-min: 4.3 mMol, and 3-min: 4.0 mMol) and no significant changes were observed in the muscle activity after multiple sets, independent of RI length (pooled ES for 1-min: 0.47, 2-min: 0.65, and 3-min: 1.39). From a practical point of view, the results suggest that 1 to 2 minute of RI between sets during squat exercise may be sufficient to recover power output in a designed power training protocol. However, if training duration is malleable, we recommend 2 min of RI for optimal recovery and power output maintenance during the subsequent exercise sets. Key pointsThis study demonstrates that 1 minute of RI between sets is sufficient to maintain maximal power output during multiple sets of a power-based exercise when it is composed of few repetitions and the sets are not performed until failure. Therefore, a short RI should be considered when designing training programs for the development of

  14. Critical assessment of power trains with fuel-cell systems and different fuels

    NASA Astrophysics Data System (ADS)

    Höhlein, B.; von Andrian, S.; Grube, Th; Menzer, R.

    Legal regulations (USA, EU) are a major driving force for intensifying technological developments with respect to the global automobile market. In the future, highly efficient vehicles with very low emission levels will include low-temperature fuel-cell systems (PEFC) as units of electric power trains. With alcohols, ether or hydrocarbons used as fuels for these new electric power trains, hydrogen as PEFC fuel has to be produced on board. These concepts including the direct use of methanol in fuel-cell systems, differ considerably in terms of both their development prospects and the results achieved so far. Based on process engineering analyses for net electricity generation in PEFC-powered power trains, as well as on assumptions for electric power trains and vehicle configurations, different fuel-cell performances and fuel processing units for octane, diesel, methanol, ethanol, propane and dimethylether have been evaluated as fuels. The possible benefits and key challenges for different solutions of power trains with fuel-cell systems/on-board hydrogen production and with direct methanol fuel-cell (DMFC) systems have been assessed. Locally, fuel-cell power trains are almost emission-free and, unlike battery-powered vehicles, their range is comparable to conventional vehicles. Therefore, they have application advantages cases of particularly stringent emission standards requiring zero emission. In comparison to internal combustion engines, using fuel-cell power trains can lead to clear reductions in primary energy demand and global, climate-relevant emissions providing the advantage of the efficiency of the hydrogen/air reaction in the fuel cell is not too drastically reduced by additional conversion steps of on-board hydrogen production, or by losses due to fuel supply provision.

  15. Electrical. Pre-Apprenticeship Phase 1 Training. Instructor's Guide.

    ERIC Educational Resources Information Center

    Lane Community Coll., Eugene, OR.

    This instructor's guide accompanies the self-paced student training modules on the electrical trade, one of which is available separately as CE 032 874. Introductory materials include an introduction to pre-apprenticeship training, and a course outline. Teaching outlines are then provided for the 11 modules that comprise this course. For each…

  16. Parts Counter. Pre-Apprenticeship Phase 1 Training. Instructor's Guide.

    ERIC Educational Resources Information Center

    Lane Community Coll., Eugene, OR.

    This instructor's guide is designed to accompany self-paced student training modules on the Parts Counter Trade. Introductory materials include an introduction to pre-apprenticeship training, and a course outline. Teaching outlines are then provided for the 11 modules that comprise this course. For each module some or all of this material may be…

  17. Giving and Receiving Feedback. Pre-Apprenticeship Phase 1 Training.

    ERIC Educational Resources Information Center

    Lane Community Coll., Eugene, OR.

    One of a series of pre-apprenticeship training modules, this self-paced student training module deals with giving and receiving feedback. Included in the module are the following: cover sheet listing module title, goals, and performance indicators; introduction; study guide/check list with directions for module completion; information sheet…

  18. Power training using pneumatic machines vs. plate-loaded machines to improve muscle power in older adults.

    PubMed

    Balachandran, Anoop T; Gandia, Kristine; Jacobs, Kevin A; Streiner, David L; Eltoukhy, Moataz; Signorile, Joseph F

    2017-11-01

    Power training has been shown to be more effective than conventional resistance training for improving physical function in older adults; however, most trials have used pneumatic machines during training. Considering that the general public typically has access to plate-loaded machines, the effectiveness and safety of power training using plate-loaded machines compared to pneumatic machines is an important consideration. The purpose of this investigation was to compare the effects of high-velocity training using pneumatic machines (Pn) versus standard plate-loaded machines (PL). Independently-living older adults, 60years or older were randomized into two groups: pneumatic machine (Pn, n=19) and plate-loaded machine (PL, n=17). After 12weeks of high-velocity training twice per week, groups were analyzed using an intention-to-treat approach. Primary outcomes were lower body power measured using a linear transducer and upper body power using medicine ball throw. Secondary outcomes included lower and upper body muscle muscle strength, the Physical Performance Battery (PPB), gallon jug test, the timed up-and-go test, and self-reported function using the Patient Reported Outcomes Measurement Information System (PROMIS) and an online video questionnaire. Outcome assessors were blinded to group membership. Lower body power significantly improved in both groups (Pn: 19%, PL: 31%), with no significant difference between the groups (Cohen's d=0.4, 95% CI (-1.1, 0.3)). Upper body power significantly improved only in the PL group, but showed no significant difference between the groups (Pn: 3%, PL: 6%). For balance, there was a significant difference between the groups favoring the Pn group (d=0.7, 95% CI (0.1, 1.4)); however, there were no statistically significant differences between groups for PPB, gallon jug transfer, muscle muscle strength, timed up-and-go or self-reported function. No serious adverse events were reported in either of the groups. Pneumatic and plate

  19. Redistributing load using wearable resistance during power clean training improves athletic performance.

    PubMed

    Marriner, Caleb R; Cronin, John B; Macadam, Paul; Storey, Adam

    2017-10-01

    A popular method to improve athletic performance and lower body power is to train with wearable resistance (WR), for example, weighted vests. However, it is currently unknown what training effect this loading method has on full-body explosive movements such as the power clean. The purpose of this study was to determine what effects WR equivalent to 12% body mass (BM) had on the power clean and countermovement jump (CMJ) performance. Sixteen male subjects (age: 23.2 ± 2.7 years; BM: 90.5 ± 10.3 kg) were randomly assigned to five weeks of traditional (TR) power clean training or training with 12% BM redistributed from the bar to the body using WR. Variables of interest included pre and post CMJ height, power clean one repetition maximum (1RM), peak ground reaction force, power output (PO), and several bar path kinematic variables across loads at 50%, 70%, and 90% of 1RM. The main findings were that WR training: (1) increased CMJ height (8.7%; ES = 0.53) and 1RM power clean (4.2%; ES = 0.2) as compared to the TR group (CMJ height = -1.4%; 1RM power clean = 1.8%); (2) increased PO across all 1RM loads (ES = 0.33-0.62); (3) increased barbell velocity at 90% 1RM (3.5%; ES = 0.74) as compared to the TR group (-4.3%); and (4) several bar path kinematic variables improved at 70% and 90% 1RM loads. WR power clean training with 12% BM can positively influence power clean ability and CMJ performance, as well as improve technique factors.

  20. Time course of strength and power recovery after resistance training with different movement velocities.

    PubMed

    Ide, Bernardo N; Leme, Thomaz C F; Lopes, Charles R; Moreira, Alexandre; Dechechi, Clodoaldo J; Sarraipa, Mário F; Da Mota, Gustavo R; Brenzikofer, René; Macedo, Denise V

    2011-07-01

    The purpose of this study was to evaluate the time course of strength and power recovery after a single bout of strength training designed with fast and slow contraction velocities. Nineteen male subjects were randomly divided into 2 groups: the slow-velocity contraction (SV) group and the fast velocity contraction (FV) group. Resistance training protocols consisted of 5 sets of 12 repetition maximum (5 × 12RM) with 50 seconds of rest between sets and 2 minutes between exercises. Contraction velocity was controlled by the execution time for each repetition (SV-6 seconds to complete concentric and eccentric phases and for FV-1.5 seconds). Leg Press 45° 1RM (LP 1RM), horizontal countermovement jump (HCMJ), and right thigh circumference (TC) were accessed in 6 distinct moments: base (1 week before exercise), 0 (immediately after exercises), 24, 48, 72, and 96 hours after exercise protocol. The SV and FV presented significant LP 1RM decrements at 0, and these were still evident 24-48 hours postexercise. The magnitude of decline was significantly (p < 0.05) higher for FV. The SV and FV presented significant HCMJ decrements at 0, but only for FV were these still evident 24-72 hours postexercise. The SV and FV presented significant TC increments at 0, and these were still evident 24-48 hours postexercise for SV but for FV it continued up to 96 hours. The magnitude of increase was significantly (p < 0.05) higher for FV. In conclusion, the fast contraction velocity protocol resulted in greater decreases in LP 1RM and HCMJ performance, when compared with slow velocity. The results lead us to interpret that this variable may exert direct influence on acute muscle strength and power generation capacity.

  1. Neuromuscular Characteristics of Endurance--And Power-Trained Athletes

    ERIC Educational Resources Information Center

    Koceja, David M.; Davison, Edwin; Robertson, Christopher T.

    2004-01-01

    In response to chronic physical training, the human neuromuscular system undergoes significant and specific adaptations. More importantly, these influences are the result of the type and quantity of physical activity. One of the simplest neuromuscular mechanisms is the spinal stretch reflex. The reflex system was previously viewed as inflexible,…

  2. Neuromuscular Characteristics of Endurance--And Power-Trained Athletes

    ERIC Educational Resources Information Center

    Koceja, David M.; Davison, Edwin; Robertson, Christopher T.

    2004-01-01

    In response to chronic physical training, the human neuromuscular system undergoes significant and specific adaptations. More importantly, these influences are the result of the type and quantity of physical activity. One of the simplest neuromuscular mechanisms is the spinal stretch reflex. The reflex system was previously viewed as inflexible,…

  3. Effects of Menstrual Phase-Dependent Resistance Training Frequency on Muscular Hypertrophy and Strength.

    PubMed

    Sakamaki-Sunaga, Mikako; Min, Seokki; Kamemoto, Kayoko; Okamoto, Takanobu

    2016-06-01

    The present study investigated how different training frequencies during menstrual phases affect muscle hypertrophy and strength. Fourteen eumenorrheic women performed 3 sets of arm curls (8-15 repetitions) until failure for 12 weeks. Depending on the menstrual cycle phase, each subject trained each arm separately after either a 3- or a 1-d·wk training protocol during the follicular phase (FP-T) and a 3- or 1-d·wk training protocol during the luteal phase (LP-T). Cross-sectional area (CSA), 1 repetition maximum, and maximum voluntary contraction significantly increased 6.2 ± 4.4, 36.4 ± 11.9, and 16.7 ± 5.6%, respectively (p ≤ 0.05 vs. before training), in the FP-T group and 7.8 ± 4.2, 31.8 ± 14.1, and 14.9 ± 12.7%, respectively (p ≤ 0.05 vs. before training), in the LP-T group. Changes in CSA between the FP-T and the LP-T groups significantly and positively correlated (r = 0.54, p ≤ 0.05). There were no major differences among the different training protocols with regard to muscle hypertrophy and strength. Therefore, we suggest that variations in female hormones induced by the menstrual cycle phases do not significantly contribute to muscle hypertrophy and strength gains during 12 weeks of resistance training.

  4. Mixed-Methods Resistance Training Increases Power and Strength of Young and Older Men.

    ERIC Educational Resources Information Center

    Newton, Robert U.; Hakkinen, Keijo; Hakkinen, Arja; McCormick, Matt; Volek, Jeff; Kraemer, William J.

    2002-01-01

    Examined the effects of a 10-week, mixed-methods resistance training program on young and older men. Although results confirmed some age-related reductions in muscle strength and power, the older men demonstrated similar capacity to the younger men for increases in muscle strength and power via an appropriate, periodized resistance training…

  5. Mixed-Methods Resistance Training Increases Power and Strength of Young and Older Men.

    ERIC Educational Resources Information Center

    Newton, Robert U.; Hakkinen, Keijo; Hakkinen, Arja; McCormick, Matt; Volek, Jeff; Kraemer, William J.

    2002-01-01

    Examined the effects of a 10-week, mixed-methods resistance training program on young and older men. Although results confirmed some age-related reductions in muscle strength and power, the older men demonstrated similar capacity to the younger men for increases in muscle strength and power via an appropriate, periodized resistance training…

  6. Does Powerful Language Training Affect Student Participation, Impression Formation, and Gender Communication in Online Discussions?

    ERIC Educational Resources Information Center

    Thomas, Crystal Ann

    2012-01-01

    The purpose of this dissertation was to investigate whether powerful language training affected student participation, impression formation, and gender communication style in online discussions. Powerful language was defined as a lack of the use of powerless language. Participants in this study were 507 freshmen taking a first-year college…

  7. Effects on strength, power, and flexibility in adolescents of nonperiodized vs. daily nonlinear periodized weight training.

    PubMed

    Moraes, Eveline; Fleck, Steven J; Ricardo Dias, Marcelo; Simão, Roberto

    2013-12-01

    The aim of this study was to compare 2 models of resistance training (RT) programs, nonperiodized (NP) training and daily nonlinear periodized (DNLP) training, on strength, power, and flexibility in untrained adolescents. Thirty-eight untrained male adolescents were randomly assigned to 1 of 3 groups: a control group, NP RT program, and DNLP program. The subjects were tested pretraining and after 4, 8, and 12 weeks for 1 repetition maximum (1RM) resistances in the bench press and 45° leg press, sit and reach test, countermovement vertical jump (CMVJ), and standing long jump (SLJ). Both training groups performed the same sequence of exercises 3 times a week for a total of 36 sessions. The NP RT consisted of 3 sets of 10-12RM throughout the training period. The DNLP training consisted of 3 sets using different training intensities for each of the 3 training sessions per week. The total volume of the training programs was not significantly different. Both the NP and DNLP groups exhibited a significant increase in the 1RM for the bench press and 45° leg press posttraining compared with that pretraining, but there were no significant differences between groups (p ≤ 0.05). The DNLP group's 1RM changes showed greater percentage improvements and effect sizes. Training intensity for the bench press and 45° leg press did not significantly change during the training. In the CMVJ and SLJ tests, NP and DNLP training showed no significant change. The DNLP group showed a significant increase in the sit and reach test after 8 and 12 weeks of training compared with pretraining; this did not occur with NP training. In summary, in untrained adolescents during a 12-week training period, a DNLP program can be used to elicit similar and possible superior maximal strength and flexibility gains compared with an NP multiset training model.

  8. Analysis of Commercial Contract Training for the Marine Corps (Phase II) [And] Commercial Contract Training Marine Corps Area VOTEC Support Center (AVSC) Guidelines. Final Report.

    ERIC Educational Resources Information Center

    Copeland, D. Robert; And Others

    The two-part report describing the Phase 2 findings of a two-phase study demonstrates the utility of the commercial contract training concept for satisfying certain Marine Corps skill training requirements. Part 1 concerns source evaluation, skill analysis and selection, contractual considerations, and comparative training capability evaluation.…

  9. Analysis of Commercial Contract Training for the Navy (Phase II) [And] Commercial Contract Training Navy Area VOTEC Support Center (AVSC) Guidelines. Final Report.

    ERIC Educational Resources Information Center

    Copeland, D. Robert; And Others

    The two-part report describing the Phase 2 findings of a two-phase study demonstrates the utility of the commercial contract training concept for satisfying certain Navy skill training requirements. Part 1 concerns source evaluation, skill analysis and selection, contractual considerations, and comparative training capability evaluation. It…

  10. Complex motion of a vehicle through a series of signals controlled by power-law phase

    NASA Astrophysics Data System (ADS)

    Nagatani, Takashi

    2017-07-01

    We study the dynamic motion of a vehicle moving through the series of traffic signals controlled by the position-dependent phase of power law. All signals are controlled by both cycle time and position-dependent phase. The dynamic model of the vehicular motion is described in terms of the nonlinear map. The vehicular motion varies in a complex manner by varying cycle time for various values of the power of the position-dependent phase. The vehicle displays the periodic motion with a long cycle for the integer power of the phase, while the vehicular motion exhibits the very complex behavior for the non-integer power of the phase.

  11. Muscle performance and functional capacity retention in older women after high-speed power training cessation.

    PubMed

    Pereira, Ana; Izquierdo, Mikel; Silva, António J; Costa, Aldo M; González-Badillo, Juan José; Marques, Mário C

    2012-08-01

    Power declines more steeply than strength with advancing age and training cessation among older women and is associated with the loss of functional ability. We tested the hypothesis that the impact of 6 weeks of detraining (DT) subsequent to 12 weeks of high-speed power training on maximal strength (1RM) of the arm and leg muscles, power performance (counter movement jump and ball throwing) and functional task (sit-to-stand test) would decrease physical performance, and specifically power performance. Thirty-seven older women were divided into an experimental group and a control group [EG, n=20, 65.8 (2.5) years; CG: n=17, 64.8 (2.8) years]. Muscular strength, power and functional testings were conducted before the initiation of training (T1), after 12 weeks (T2) and after 6 weeks of DT (T3). During the 12 weeks of training, EG significantly increased their dynamic strength performance (range from 41.9 to 64.1%), muscle power output (range from 18.2 to 33.6%) (p<0.05) and function (15.8%) (p<0.05). No significant differences were observed in the magnitude of the increases in CG. Short-term DT led to larger effects on maximal strength (18.1-23.8%) (p<0.05) of both upper and lower extremity muscles than in muscle power (2-4.5%) and function (2.8%) (p<0.05). However, all measurements remained higher (12.6-36.4%; p<0.05) than in pre-training levels. These data indicated that DT may induce larger declines in muscle strength than in power output and preserved physical independence, mediated in part, by the effectiveness of high-speed power training particularly developed for older women. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Electrical heating of soils using high efficiency electrode patterns and power phases

    DOEpatents

    Buettner, Harley M.

    1999-01-01

    Powerline-frequency electrical (joule) heating of soils using a high efficiency electrode configuration and power phase arrangement. The electrode configuration consists of several heating or current injection electrodes around the periphery of a volume of soil to be heated, all electrodes being connected to one phase of a multi-phase or a single-phase power system, and a return or extraction electrode or electrodes located inside the volume to be heated being connected to the remaining phases of the multi-phase power system or to the neutral side of the single-phase power source. This electrode configuration and power phase arrangement can be utilized anywhere where powerline frequency soil heating is applicable and thus has many potential uses including removal of volatile organic compounds such as gasoline and tricholorethylene (TCE) from contaminated areas.

  13. Free-Piston Stirling Power Conversion Unit for Fission Power System, Phase II Final Report

    NASA Technical Reports Server (NTRS)

    Wood, J. Gary; Stanley, John

    2016-01-01

    In Phase II, the manufacture and testing of two 6-kW(sub e)Stirling engines was completed. The engines were delivered in an opposed 12-kW(sub e) arrangement with a common expansion space heater head. As described in the Phase I report, the engines were designed to be sealed both hermetically and with a bolted O-ring seal. The completed Phase II convertor is in the bolted configuration to allow future disassembly. By the end of Phase II, the convertor had passed all of the final testing requirements in preparation for delivery to the NASA Glenn Research Center. The electronic controller also was fabricated and tested during Phase II. The controller sets both piston amplitudes and maintains the phasing between them. It also sets the operating frequency of the machine. Details of the controller are described in the Phase I final report. Fabrication of the direct-current to direct-current (DC-DC) output stage, which would have stepped down the main controller output voltage from 700 to 120 V(sub DC), was omitted from this phase of the project for budgetary reasons. However, the main controller was successfully built, tested with the engines, and delivered. We experienced very few development issues with this high-power controller. The project extended significantly longer than originally planned because of yearly funding delays. The team also experienced several hardware difficulties along the development path. Most of these were related to the different thermal expansions of adjacent parts constructed of different materials. This issue was made worse by the large size of the machine. Thermal expansion problems also caused difficulties in the brazing of the opposed stainless steel sodium-potassium (NaK) heater head. Despite repeated attempts Sunpower was not able to successfully braze the opposed head under this project. Near the end of the project, Glenn fabricated an opposed Inconel NaK head, which was installed prior to delivery for testing at Glenn. Engine

  14. Metasurface with Reconfigurable Reflection Phase for High-Power Microwave Applications (Briefing Charts)

    DTIC Science & Technology

    2014-06-25

    Metasurfaces with Reconfigurable Reflection Phase for High-Power Microwave Applications Kenneth L. Morgan, Clinton P. Scarborough, Micah D...TITLE AND SUBTITLE Metasurface with Reconfigurable Reflection Phase for High- Power Microwave Applications 5a. CONTRACT NUMBER 5b...Examples that demonstrate theoretical methods for extending the operating power levels of metasurface reflectarrays have been given •The proposed

  15. Maximum power training load determination and its effects on load-power relationship, maximum strength, and vertical jump performance.

    PubMed

    Smilios, Ilias; Sotiropoulos, Konstantinos; Christou, Marios; Douda, Helen; Spaias, Aggelos; Tokmakidis, Savvas P

    2013-05-01

    This study examines the changes in maximum strength, vertical jump performance, and the load-velocity and load-power relationship after a resistance training period using a heavy load and an individual load that maximizes mechanical power output with and without including body mass in power calculations. Forty-three moderately trained men (age: 22.7 ± 2.5 years) were separated into 4 groups, 2 groups of maximum power, 1 where body mass was not included in the calculations of the load that maximizes mechanical power (Pmax - bw, n = 11) and another where body mass was included in the calculations (Pmax + bw, n = 9), a high load group (HL-90%, n = 12), and a control group (C, n = 11). The subjects performed 4-6 sets of jump squat and the repeated-jump exercises for 6 weeks. For the jump squat, the HL-90% group performed 3 repetitions at each set with a load of 90% of 1 repetition maximum (1RM), the Pmax - bw group 5 repetitions with loads 48-58% of 1RM and the Pmax + bw 8 repetitions with loads 20-37% of 1RM. For the repeated jump, all the groups performed 6 repetitions at each set. All training groups improved (p < 0.05) maximum strength in the semisquat exercise (HL-90%: 15.2 ± 7.1, Pmax - bw: 6.6 ± 4.7, Pmax + bw: 6.9 ± 7.1, and C: 0 ± 4.3%) and the HL-90% group presented higher values (p < 0.05) than the other groups did. All training groups improved similarly (p < 0.05) squat (HL-90%: 11.7 ± 7.9, Pmax - bw: 14.5 ± 11.8, Pmax + bw: 11.3 ± 7.9, and C: -2.2 ± 5.5%) and countermovement jump height (HL-90%: 8.6 ± 7.9, Pmax - bw: 10.9 ± 9.4, Pmax + bw: 8.8 ± 4.3, and C: 0.4 ± 6%). The HL-90% and the Pmax - bw group increased (p < 0.05) power output at loads of 20, 35, 50, 65, and 80% of 1RM and the Pmax + bw group at loads of 20 and 35% of 1RM. The inclusion or not of body mass to determine the load that maximizes mechanical power output affects the long-term adaptations differently in the load-power relationship. Thus, training load selection will depend

  16. Training Strategies to Improve Muscle Power: Is Olympic-style Weightlifting Relevant?

    PubMed

    Helland, Christian; Hole, Eirik; Iversen, Erik; Olsson, Monica Charlotte; Seynnes, Olivier; Solberg, Paul Andre; Paulsen, Gøran

    2017-04-01

    This efficacy study investigated the effects of 1) Olympic-style weightlifting (OWL), 2) motorized strength and power training (MSPT), and 3) free weight strength and power training (FSPT) on muscle power. Thirty-nine young athletes (20 ± 3 yr; ice hockey, volleyball, and badminton) were randomized into the three training groups. All groups participated in two to three sessions per week for 8 wk. The MSPT and FSPT groups trained using squats (two legs and single leg) with high force and high power, whereas the OWL group trained using clean and snatch exercises. MSPT was conducted as slow-speed isokinetic strength training and isotonic power training with augmented eccentric load, controlled by a computerized robotic engine system. FSPT used free weights. The training volume (sum of repetitions × kg) was similar between all three groups. Vertical jumping capabilities were assessed by countermovement jump (CMJ), squat jump (SJ), drop jump (DJ), and loaded CMJ (10-80 kg). Sprinting capacity was assessed in a 30-m sprint. Secondary variables were squat one-repetition maximum (1RM), body composition, quadriceps thickness, and architecture. OWL resulted in trivial improvements and inferior gains compared with FSPT and MSPT for CMJ, SJ, DJ, and 1RM. MSPT demonstrated small but robust effects on SJ, DJ, loaded CMJ, and 1RM (3%-13%). MSPT was superior to FSPT in improving 30-m sprint performance. FSPT and MSPT, but not OWL, demonstrated increased thickness in the vastus lateralis and rectus femoris (4%-7%). MSPT was time-efficient and equally or more effective than FSPT training in improving vertical jumping and sprinting performance. OWL was generally ineffective and inferior to the two other interventions.

  17. DC-to-dc converter power-train optimization for maximum efficiency

    NASA Astrophysics Data System (ADS)

    Wilson, T. G., Jr.; Whelan, E. W., Jr.; Rodriguez, R.; Dishman, J. M.

    This paper presents a new way of describing the independent and dependent design variables of the power train of a dc-to-dc converter in terms of a multi-dimensional design-parameter space. These concepts provide a framework for examining the problem of design optimization of the power train, with particular emphasis on the maximization of converter efficiency. Numerous examples of important parameter-space surfaces illustrate some of the major relationships between core volume, switching frequency and output power, and between efficiency, ripple, and temperature rise of the energy-storage reactor. Also, we explore the difference in performance between the continuous and discontinuous mmf modes of operation.

  18. The Power of Randomization Tests for Single-Case Phased Designs.

    ERIC Educational Resources Information Center

    Ferron, John; Onghena, Patrick

    1996-01-01

    Monte Carlo methods were used to estimate the power of randomization tests used with single-case designs involving random assignment of treatments to phases. Simulations of two treatments and six phases showed an adequate level of power when effect sizes were large, phase lengths exceeded five, and autocorrelation was not negative. (SLD)

  19. Effectiveness of a Wheelchair Skills Training Program for Powered Wheelchair Users: A Randomized Controlled Trial

    PubMed Central

    Kirby, R. Lee; Miller, William C.; Routhier, Francois; Demers, Louise; Mihailidis, Alex; Polgar, Jan Miller; Rushton, Paula W.; Titus, Laura; Smith, Cher; McAllister, Mike; Theriault, Chris; Thompson, Kara; Sawatzky, Bonita

    2015-01-01

    Objectives To test the hypothesis that powered wheelchair users who receive the Wheelchair Skills Training Program (WSTP) improve their wheelchair skills in comparison with a Control group that receives standard care. Our secondary objectives were to assess goal achievement, satisfaction with training, retention, injury rate, confidence with wheelchair use and participation. Design Randomized controlled trial (RCT). Setting Rehabilitation centers and communities. Participants 116 powered wheelchair users. Intervention Five 30-minute WSTP training sessions. Main Outcome Measures Assessments were done at baseline (T1), post-training (T2) and 3 months post-training (T3) using the Wheelchair Skills Test Questionnaire (WST-Q 4.1), Goal Attainment Score (GAS), Satisfaction Questionnaire, Injury Rate, Wheelchair Use Confidence Scale for Power Wheelchair Users (WheelCon) and Life Space Assessment (LSA). Results There was no significant T2-T1 difference between the groups for WST-Q capacity scores (p = 0.600) but the difference for WST-Q performance scores was significant (p = 0.016) with a relative (T2/T1 x 100%) improvement of the median score for the Intervention group of 10.8%. The mean (SD) GAS for the Intervention group after training was 92.8% (11.4) and satisfaction with training was high. The WST-Q gain was not retained at T3. There was no clinically significant difference between the groups in injury rate and no statistically significant differences in WheelCon or LSA scores at T3. Conclusions Powered wheelchair users who receive formal wheelchair skills training demonstrate modest transient post-training improvements in their WST-Q performance scores, they have substantial improvements on individualized goals and they are positive about training. PMID:26232684

  20. Air-Sea Battle through Joint Training: Power Projection Sustainability

    DTIC Science & Technology

    2014-05-15

    misconception is that the ASB Concept relies on the development of new 25 U.S. Office of the Chairman, Joint...advanced tactics, techniques, and procedures (TTP), vice the integration of existing capabilities. 30 The risk of this misconception is that U.S...insufficient joint training and planning involving the denial of the electro- magnetic spectrum. 67 With the changes in the global A2/AD environment, the CVW

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

    PubMed

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

    2017-05-01

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

  2. The effects of cycling cadence on the phases of joint power, crank power, force and force effectiveness.

    PubMed

    Ettema, Gertjan; Lorås, Håvard; Leirdal, Stig

    2009-04-01

    We examined the influence of cadence in cycling technique by quantifying phase relationships for a number of important variables at the crank and lower extremity joints. Any difference in the effect of cadence on force, effectiveness, and power phases would indicate an essential change in coordination pattern. Cycle kinetics was recorded for 10 male competitive cyclists at five cadences (60-100 rpm) at submaximal load (260 W). Joint powers were calculated using inverse dynamics methods. All data were expressed as a function of crank position. The phase of the crank mechanical profiles (total force, crank and joint power, and effectiveness) was calculated using four methods: crank angle of maximum (MA) and minimum (MI), fitting a sine wave (SI) and by cross-correlation (XC). These methods, apart from the MA method, showed the same relative phase. The variables, however, showed different phases being expressed as time lag: force effectiveness: 0.131 (+/-0.034)s; total force: 0.149 (+/-0.021)s; power: 0.098 (+/-0.027)s. The phases in joint powers hip 0.071 (+/-0.008), knee 0.082 (+/-0.009), and hip 0.077 (+/-0.012) were only well described by XC, and were somewhat lower than the crank power phase. These differences indicate the potential effect of inertia of the lower limb in phase shifts from joints to crank. Furthermore, the differences between the various crank variables indicate a change of technique with cadence.

  3. Model predictive direct power control for active power decoupled single-phase quasi-Z -source inverter

    DOE PAGES

    Liu, Yushan; Ge, Baoming; Abu-Rub, Haitham; ...

    2016-06-14

    In this study, the active power filter (APF) that consists of a half-bridge leg and an ac capacitor is integrated in the single-phase quasi-Z-source inverter (qZSI) in this paper to avoid the second harmonic power flowing into the dc side. The capacitor of APF buffers the second harmonic power of the load, and the ac capacitor allows highly pulsating ac voltage, so that the capacitances of both dc and ac sides can be small. A model predictive direct power control (DPC) is further proposed to achieve the purpose of this newtopology through predicting the capacitor voltage of APF at eachmore » sampling period and ensuring the APF power to track the second harmonic power of single-phase qZSI. Simulation and experimental results verify the model predictive DPC for the APF-integrated single-phase qZSI.« less

  4. Model predictive direct power control for active power decoupled single-phase quasi-Z -source inverter

    SciTech Connect

    Liu, Yushan; Ge, Baoming; Abu-Rub, Haitham; Sun, Hexu; Peng, Fang Zheng; Xue, Yaosuo

    2016-06-14

    In this study, the active power filter (APF) that consists of a half-bridge leg and an ac capacitor is integrated in the single-phase quasi-Z-source inverter (qZSI) in this paper to avoid the second harmonic power flowing into the dc side. The capacitor of APF buffers the second harmonic power of the load, and the ac capacitor allows highly pulsating ac voltage, so that the capacitances of both dc and ac sides can be small. A model predictive direct power control (DPC) is further proposed to achieve the purpose of this newtopology through predicting the capacitor voltage of APF at each sampling period and ensuring the APF power to track the second harmonic power of single-phase qZSI. Simulation and experimental results verify the model predictive DPC for the APF-integrated single-phase qZSI.

  5. Ageing, Muscle Power and Physical Function: A Systematic Review and Implications for Pragmatic Training Interventions.

    PubMed

    Byrne, Christopher; Faure, Charles; Keene, David J; Lamb, Sarah E

    2016-09-01

    The physiological impairments most strongly associated with functional performance in older people are logically the most efficient therapeutic targets for exercise training interventions aimed at improving function and maintaining independence in later life. The objectives of this review were to (1) systematically review the relationship between muscle power and functional performance in older people; (2) systematically review the effect of power training (PT) interventions on functional performance in older people; and (3) identify components of successful PT interventions relevant to pragmatic trials by scoping the literature. Our approach involved three stages. First, we systematically reviewed evidence on the relationship between muscle power, muscle strength and functional performance and, second, we systematically reviewed PT intervention studies that included both muscle power and at least one index of functional performance as outcome measures. Finally, taking a strong pragmatic perspective, we conducted a scoping review of the PT evidence to identify the successful components of training interventions needed to provide a minimally effective training dose to improve physical function. Evidence from 44 studies revealed a positive association between muscle power and indices of physical function, and that muscle power is a marginally superior predictor of functional performance than muscle strength. Nine studies revealed maximal angular velocity of movement, an important component of muscle power, to be positively associated with functional performance and a better predictor of functional performance than muscle strength. We identified 31 PT studies, characterised by small sample sizes and incomplete reporting of interventions, resulting in less than one-in-five studies judged as having a low risk of bias. Thirteen studies compared traditional resistance training with PT, with ten studies reporting the superiority of PT for either muscle power or functional

  6. Seismic fragility of nuclear power plant components. Phase I

    SciTech Connect

    Bandyopadhyay, K.K.; Hofmayer, C.H.

    1986-06-01

    As part of the Component Fragility Research Program, sponsored by the US Nuclear Regulatory Commission, BNL is involved in establishing seismic fragility levels for various nuclear power plant equipment by identifying, collecting and analyzing existing test data from various sources. In Phase I of this program, BNL has reviewed approximately seventy test reports to collect fragility or high level test data for switchgears, motor control centers and similar electrical cabinets, valve actuators and numerous electrical devices of various manufacturers and models. This report provides an assessment and evaluation of the data collected in Phase I. The fragility data for medium voltage and low voltage switchgears and motor control centers are analyzed using the test response spectra (TRS) as a measure of the fragility level. The analysis reveals that fragility levels can best be described by a group of TRS curves corresponding to various failure modes. The lower-bound curve indicates the initiation of malfunctioning or structural damage; whereas, the upper-bound curve corresponds to overall failure of the equipment based on known failure modes. High level test data for some components are included in the report. These data indicate that some components are inherently strong and do not exhibit any failure mode even when tested at the vibration limit of a shake table. The common failure modes are identified in the report. The fragility levels determined in this report have been compared with those used in the PRA and Seismic Margin Studies. It appears that the BNL data better correlate with the HCLPF (High Confidence of a Low Probability of Failure) level used in Seismic Margin Studies and can improve this level as high as 60% for certain applications. Specific recommendations are provided for proper application of BNL fragility data to other studies.

  7. Baseline tests of the power-train electric delivery van

    NASA Technical Reports Server (NTRS)

    Lumannick, S.; Dustin, M. O.; Bozek, J. M.

    1977-01-01

    Vehicle maximum speed, range at constant speed, range over stop-and-go driving schedules, maximum acceleration, gradeability, gradeability limit, road energy consumption, road power, indicated energy consumption, braking capability, battery charger efficiency, and battery characteristics were determined for a modified utility van powered by sixteen 6-volt batteries connected in series. A chopper controller actuated by a foot accelerator pedal changes the voltage applied to the 22-kilowatt (30-hp) series-wound drive motor. In addition to the conventional hydraulic braking system, the vehicle has hydraulic regenerative braking. Cycle tests and acceleration tests were conducted with and without hydraulic regeneration.

  8. Design of Training Systems, Phase I Final Report Appendices, Volume II of II.

    ERIC Educational Resources Information Center

    Bellamy, Harold J.; And Others

    A series of five appendixes presents details related to Phase I of the three-stage project "Design of Training Systems" (DOTS). The first appendix discusses strategic assumptions and processes, while the second reviews mathematical models and data bases operational within the navel education and training command. The third appendix…

  9. Cutting Tools, Files and Abrasives. Pre-Apprenticeship Phase 1 Training.

    ERIC Educational Resources Information Center

    Lane Community Coll., Eugene, OR.

    This self-paced student training module on cutting tools, files, and abrasives is one of a number of modules developed for Pre-apprenticeship Phase 1 Training. Purpose of the module is to enable students to identify and explain the proper use and care of various knives, saws, snips, chisels, and abrasives. The module may contain some or all of the…

  10. 76 FR 22729 - Chrysler Group, LLC, Power Train Division, Mack Avenue Engine Plant #1, Including On-Site Leased...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-22

    ... Employment and Training Administration Chrysler Group, LLC, Power Train Division, Mack Avenue Engine Plant 1... to Apply for Worker Adjustment Assistance on April 6, 2011, applicable to workers of Chrysler Group, LLC, Power Train Division, Mack Avenue Engine Plant 1, including on-site leased workers of...

  11. Simulators for Mariner Training and Licensing. Phase 2: Investigation of Simulator Characteristics for Training Senior Mariners,

    DTIC Science & Technology

    1981-10-01

    effective simulator-based training program . The importance design in which multiple variables are simultaneously of a well qualified instructor and other...intangible training manipulated, resulting in the presence of numerous inter- program aspects has been well known for many years (Caro, action effects... well as the training program itself. The capabilities of the simulator would be used by the instructor to develop and evaluate exercises prior to using

  12. [Voluntary alpha-power increasing training impact on the heart rate variability].

    PubMed

    Bazanova, O M; Balioz, N V; Muravleva, K B; Skoraia, M V

    2013-01-01

    In order to study the effect of the alpha EEG power increasing training at heart rate variability (HRV) as the index of the autonomic regulation of cognitive functions there were follow tasks: (1) to figure out the impact of biofeedback in the voluntary increasing the power in the individual high-frequency alpha-band effect on heart rate variability and related characteristics of cognitive and emotional spheres, (2) to determine the nature of the relationship between alpha activity indices and heart rate variability, depending on the alpha-frequency EEG pattern at rest (3) to examine how the individual alpha frequency EEG pattern is reflected in changes HRV as a result of biofeedback training. Psychometric indicators of cognitive performance, the characteristics of the alpha-EEG activity and heart rate variability (HRV) as LF/HF and pNN50 were recorded in 27 healthy men aged 18-34 years, before, during, and after 10 sessions of training of voluntary increase in alpha power in the individual high-frequency alpha band with eyes closed. To determine the biofeedback effect on the alpha power increasing training, data subjects are compared in 2 groups: experimental (14) with the real and the control group (13 people)--with mock biofeedback. The follow up effect of trainings was studied through month over the 10 training sessions. Results showed that alpha biofeedback training enhanced the fluency and accuracy in cognitive performance, decreased anxiety and frontal EMG, increased resting frequency, width and power in individual upper alpha range only in participants with low baseline alpha frequency. While mock biofeedback increased resting alpha power only in participants with high baseline resting alpha frequency and did change neither cognitive performance, nor HRV indices. Biofeedback training eliminated the alpha power decrease in response to arithmetic task in both with high and low alpha frequency participants and this effect was followed up over the month. Mock

  13. Methods of Upper Body Training to Increase Overhand Throwing Power

    ERIC Educational Resources Information Center

    McDaniel, Larry W.; Jackson, Allen; Gaudet, Laura; Tonkin, Shea

    2009-01-01

    Those who have taught motor skills would most likely agree that the overhand throw may be the most difficult skill for students to master and for instructors or coaches to teach. The timing involved when generating power to performing the overhand throw begins in the toes/feet and moves up the leg, hip, thorax (core muscles), arm, and ends in the…

  14. Artificial Intelligence Based Control Power Optimization on Tailless Aircraft. [ARMD Seedling Fund Phase I

    NASA Technical Reports Server (NTRS)

    Gern, Frank; Vicroy, Dan D.; Mulani, Sameer B.; Chhabra, Rupanshi; Kapania, Rakesh K.; Schetz, Joseph A.; Brown, Derrell; Princen, Norman H.

    2014-01-01

    Traditional methods of control allocation optimization have shown difficulties in exploiting the full potential of controlling large arrays of control devices on innovative air vehicles. Artificial neutral networks are inspired by biological nervous systems and neurocomputing has successfully been applied to a variety of complex optimization problems. This project investigates the potential of applying neurocomputing to the control allocation optimization problem of Hybrid Wing Body (HWB) aircraft concepts to minimize control power, hinge moments, and actuator forces, while keeping system weights within acceptable limits. The main objective of this project is to develop a proof-of-concept process suitable to demonstrate the potential of using neurocomputing for optimizing actuation power for aircraft featuring multiple independently actuated control surfaces. A Nastran aeroservoelastic finite element model is used to generate a learning database of hinge moment and actuation power characteristics for an array of flight conditions and control surface deflections. An artificial neural network incorporating a genetic algorithm then uses this training data to perform control allocation optimization for the investigated aircraft configuration. The phase I project showed that optimization results for the sum of required hinge moments are improved by more than 12% over the best Nastran solution by using the neural network optimization process.

  15. Solar power satellite system definition study, volume 4, phase 2

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Results of an overall evaluation of the solar power satellite concept are reported. Specific topics covered include: solid state sandwich configuration; parametric development of reliability design; power distribution system for solid state solar power satellites; multibeam transmission; GEO base system configuration; suppression of the heavy lift launch vehicle trajectory; conceptual design of an offshore space center facility; solar power satellite development and operations scenario; and microwave power transmission technology, advancement, development, and facility requirements.

  16. Transference of Traditional Versus Complex Strength and Power Training to Sprint Performance

    PubMed Central

    Loturco, Irineu; Tricoli, Valmor; Roschel, Hamilton; Nakamura, Fabio Yuzo; Cal Abad, Cesar Cavinato; Kobal, Ronaldo; Gil, Saulo; González-Badillo, Juan José

    2014-01-01

    The purpose of this study was to determine the effects of two different strength-power training models on sprint performance. Forty-eight soldiers of the Brazilian brigade of special operations with at least one year of army training experience were divided into a control group (CG: n = 15, age: 20.2 ± 0.7 years, body height: 1.74 ± 0.06 m, and body mass: 66.7 ± 9.8 kg), a traditional training group (TT: n = 18, age: 20.1 ± 0.7 years, body height: 1.71 ± 0.05 m, and body mass: 64.2 ± 4.7 kg), and a complex training group (CT: n = 15, age: 20.3 ± 0.8 years, body height: 1.71 ± 0.07 m; and body mass: 64.0 ± 8.8 kg). Maximum strength (25% and 26%), CMJ height (36% and 39%), mean power (30% and 35%) and mean propulsive power (22% and 28%) in the loaded jump squat exercise, and 20-m sprint speed (16% and 14%) increased significantly (p≤0.05) following the TT and CT, respectively. However, the transfer effect coefficients (TEC) of strength and power performances to 20-m sprint performance following the TT were greater than the CT throughout the 9-week training period. Our data suggest that TT is more effective than CT to improve sprint performance in moderately trained subjects. PMID:25114753

  17. Loads and Movement Speeds Dictate Differences in Power Output During Circuit Training.

    PubMed

    Roberson, Kirk B; Chowdhari, Sean S; White, Morgan J; Signorile, Joseph F

    2017-10-01

    Roberson, KB, Chowdhari, SS, White, MJ, and Signorile, JF. Loads and movement speeds dictate differences in power output during circuit training. J Strength Cond Res 31(10): 2765-2776, 2017-Power training has become a common exercise intervention for improving muscle strength, power, and physical function while reducing injury risk. Few studies, however, have evaluated acute load changes on power output during traditional resistance training protocols. Therefore, the aim of this study was to quantify the effects of different loading patterns on power output during a single session of circuit resistance training (CRT). Nine male (age = 19.4 ± 0.9 years) and 11 female participants (age = 20.6 ± 1.6 years) completed 3 CRT protocols during separate testing sessions using 7 pneumatic exercises. Protocols included heavy load explosive contraction (HLEC: 80% one repetition maximum [1RM], maximum speed concentric-2 seconds eccentric), heavy load controlled contraction (HLCC: 80% 1RM, 2 seconds concentric-2 seconds eccentric), and moderate load explosive contraction (MLEC: 50% 1RM, maximum speed concentric-2 seconds eccentric). Protocols were assigned randomly using a counterbalanced design. Power for each repetition and set were determined using computerized software interfaced with each machine. Blood lactate was measured at rest and immediately postexercise. For male and female participants, average power was significantly greater during all exercises for HLEC and MLEC than HLCC. Average power was greatest during the HLEC for leg press (LP), hip adduction (ADD), and hip abduction (ABD) (p ≤ 0.05), whereas male participants alone produced their greatest power during HLEC for leg curl (LC) (p < 0.001). For male and female participants, significantly greater power was detected by set for LP, lat pull-down (LAT), ADD, LC, and ABD for the MLEC protocol (p < 0.02) and for LP, LAT, CP, and LC for the HLEC protocol (p < 0.03). A condition × sex interaction was seen for

  18. Anaerobic power in road cyclists is improved after 10 weeks of whole-body vibration training.

    PubMed

    Oosthuyse, Tanja; Viedge, Alison; McVeigh, Joanne; Avidon, Ingrid

    2013-02-01

    Whole-body vibration (WBV) training has previously improved muscle power in various athletic groups requiring explosive muscle contractions. To evaluate the benefit of including WBV as a training adjunct for improving aerobic and anaerobic cycling performance, road cyclists (n = 9) performed 3 weekly, 10-minute sessions of intermittent WBV on synchronous vertical plates (30 Hz) while standing in a static posture. A control group of cyclists (n = 8) received no WBV training. Before and after the 10-week intervention period, lean body mass (LBM), cycling aerobic peak power (Wmax), 4 mM lactate concentration (OBLA), VO2peak, and Wingate anaerobic peak and mean power output were determined. The WBV group successfully completed all WBV sessions but reported a significant 30% decrease in the weekly cycling training time (pre: 9.4 ± 3.3 h·wk(-1); post: 6.7 ± 3.7 h·wk(-1); p = 0.01) that resulted in a 6% decrease in VO2peak and a 4% decrease in OBLA. The control group reported a nonsignificant 6% decrease in cycling training volume (pre: 9.5 ± 3.6 h·wk(-1); 8.6 ± 2.9 h·wk(-1); p = 0.13), and all measured variables were maintained. Despite the evidence of detraining in the WBV group, Wmax was maintained (pre: 258 ± 53 W; post: 254 ± 57 W; p = 0.43). Furthermore, Wingate peak power increased by 6% (668 ± 189 to 708 ± 220 W; p = 0.055), and Wingate mean power increased by 2% (553 ± 157 to 565 ± 157 W; p = 0.006) in the WBV group from preintervention to postintervention, respectively, without any change to LBM. The WBV training is an attractive training supplement for improving anaerobic power without increasing muscle mass in road cyclists.

  19. Effects of high intensity training by heart rate or power in recreational cyclists.

    PubMed

    Robinson, Michael E; Plasschaert, Jeff; Kisaalita, Nkaku R

    2011-01-01

    Technological advances in interval training for cyclists have led to the development of both heart rate (HR) monitors and powermeters (PM). Despite the growing popularity of PM use, the superiority of PM-based training has not been established. The aim of the present study was to investigate the relative effectiveness of HR-based versus PM-based interval training on 20 km time trial (20km TT), lactate threshold (LT) power, and peak aerobic capacity (VO2max) in recreational cyclists. Participants (n =20; M age=33.9, SD =13) completed a baseline 20km TT to establish their VO2max and LT and were then randomly assigned to either HR-determined or PM-determined training sessions. Over a period of up to 5 weeks participants completed 7.2 (± 1.1) interval training sessions at their specific LT for their respective interval training method. Repeated measures analyses of variances (ANOVAs) showed that both HR-based and PM-based training groups significantly improved their LT power (F(1,16) = 28., p < 0.01, eta(2) = 0.63) and 20km TT time (F(1,16) = 4.92, p = 0.04, eta(2) = 0.24) at posttest, showing a 17 watt increase (9.8%) and a near 3-and-a-half minute improvement (7.8%) in 20km TT completion time. There were no significant group (HR vs. PM) x time (baseline vs. posttest) interactions for 20km TT completion time, LT power, or VO2max ratings. Our results coincide with the literature supporting the effectiveness of interval training for endurance athletes. Furthermore, our findings indicate that there is no empirical evidence for the superiority of any single type of device in the implementation of interval training. This study indicates that there are no noticeable advantages to using PM to increase performance in the average recreational cyclist, suggesting that low cost HR monitor are equally capable as training devices. Key pointsInterval training improves performance for recreational cyclists as measure by changes in lactate threshold watts and 20km time trial time

  20. Innovative Phase Change Thermal Energy Storage Solution for Baseload Power Phase 1 Final Report

    SciTech Connect

    Qiu, Songgang

    2013-05-15

    The primary purpose of this project is to develop and validate an innovative, scalable phase change salt thermal energy storage (TES) system that can interface with Infinia’s family of free-piston Stirling engines (FPSE). This TES technology is also appropriate for Rankine and Brayton power converters. Solar TES systems based on latent heat of fusion rather than molten salt temperature differences, have many advantages that include up to an order of magnitude higher energy storage density, much higher temperature operation, and elimination of pumped loops for most of Infinia’s design options. DOE has funded four different concepts for solar phase change TES, including one other Infinia awarded project using heat pipes to transfer heat to and from the salt. The unique innovation in this project is an integrated TES/pool boiler heat transfer system that is the simplest approach identified to date and arguably has the best potential for minimizing the levelized cost of energy (LCOE). The Phase 1 objectives are to design, build and test a 1-hour TES proof-of-concept lab demonstrator integrated with an Infinia 3 kW Stirling engine, and to conduct a preliminary design of a 12-hour TES on-sun prototype.

  1. The effects of power and strength training on bone mineral density in premenopausal women.

    PubMed

    Gray, M; Di Brezzo, R; Fort, I L

    2013-08-01

    The purpose of this 48-week exercise intervention was designed to examine the effects of power and resistance training on bone mineral density (BMD). Premenopausal women were recruited and randomly assigned to either a power (N.=8) or resistance (N.=11) training group. The power exercises included jumping rope, skipping, hopping, and other power-type exercises. The resistance training group performed 8-10 whole-body strengthening exercises at 70% one-repetition maximum (1RM). Before and after the exercise intervention, BMD was measured via dual energy x-ray absorptiometry (DXA) for the total-body, lumbar spine, left femoral neck, and left greater trochanter. Muscular strength was measured by hand grip dynamometer and 1RM of chest press and leg press. Muscular power was assessed by the Margaria-Kalamen stair climb test. Data were analyzed using repeated measures ANOVA. There were no statistical differences between the two training groups for any of the BMD measurements. Chest press strength was different between the two groups, increasing 6.41 and 1.1kg for the resistance and power groups, respectively over the course of the training period (F[1.15]=9.44, P<0.01). There was a significant time effect for leg press 1RM (F[1.15]=6.04, P=0.03). The participants increased by 12.37kg after the 48-week intervention. Hand grip strength also increased after the study intervention (F[1.16]=46.32, P<0.01). The results of this study suggest that power and resistance training are comparable techniques for maintaining bone density.

  2. Welding. Pre-Apprenticeship Phase 1 Training. Instructor's Guide.

    ERIC Educational Resources Information Center

    Lane Community Coll., Eugene, OR.

    This instructor's guide accompanies the self-paced student training modules on welding, three of which are available separately as CE 032 889-891. Introductory materials include a description of the components of the pre-apprenticeship project, a discussion of the teacher's role in conducting the course, and scope and contents of the four phases…

  3. Phases of Development of a Multinational Training Group.

    ERIC Educational Resources Information Center

    Franck, Barbara Mann; Hare, Paul

    A study was made of 36 people from the United States and five developing nations (Pakistan, India, Ceylon, Indonesia, the Philippines) assembled for a special six month rice production training course. The course was designed to produce agricultural technicians who would introduce the International Rice Research Institute's new high yielding rice…

  4. Benefit-Cost Analysis of TAT Phase I Worker Training. Training and Technology Project. Special Report.

    ERIC Educational Resources Information Center

    Kirby, Frederick C.; Castagna, Paul A.

    The purpose of this study is to estimate costs and benefits and to compute alternative benefit-cost ratios for both the individuals and the Federal Government as a result of investing time and resources in the Training and Technology (TAT) Project. TAT is a continuing experimental program in training skilled workers for private industry. The five…

  5. Payload specialists Garneau and Scully-Power discuss training

    NASA Image and Video Library

    1984-09-04

    41D-3185 (S14-3185) (4 Sept 1984) --- The two payload specialists for NASA's 41-G mission aboard the Challenger chat prior to a simulation session in the Shuttle mockup and integration laboratory at the Johnson Space Center. They are Marc Garneau, left, representing the Canadian National Research Council, and Paul D. Scully-Power, an oceanographer with the U.S. Navy. They are standing near the manipulator development facility (MDF), pictured in background.

  6. Quasi-phase-matched high-order harmonic generation using tunable pulse trains.

    PubMed

    O'Keeffe, Kevin; Lloyd, David T; Hooker, Simon M

    2014-04-07

    A simple technique for generating trains of ultrafast pulses is demonstrated in which the linear separation between pulses can be varied continuously over a wide range. These pulse trains are used to achieve tunable quasi-phase-matching of high harmonic generation over a range of harmonic orders up to the harmonic cut-off, resulting in enhancements of the harmonic intensity in excess of an order of magnitude. The peak enhancement of the harmonics is clearly shown to depend on the separation between pulses, as well as the number of pulses in the train, representing an easily tunable source of quasi-phase-matched high harmonic generation.

  7. Power training-induced increases in muscle activation during gait in old adults.

    PubMed

    Beijersbergen, Chantal M I; Granacher, Urs; Gäbler, Martijn; DeVita, Paul; Hortobágyi, Tibor

    2017-06-07

    Aging modifies neuromuscular activation of agonist and antagonist muscles during walking. Power training can evoke adaptations in neuromuscular activation that underlie gains in muscle strength and power but it is unknown if these adaptations transfer to dynamic tasks such as walking. We examined the effects of lower extremity power training on neuromuscular activation during level gait in old adults. Twelve community dwelling old adults (age ≥ 65 years) completed a 10-week lower extremity power-training program and thirteen old adults completed a 10-week control period. Before and after the interventions, we measured maximal isometric muscle strength and electromyographic (EMG) activation of the right knee flexor, knee extensor, and plantarflexor muscles on a dynamometer and we measured EMG amplitudes, activation onsets and offsets, and activation duration of the knee flexors, knee extensors, and plantarflexors during gait at habitual, fast, and standardized (1.25±0.6m/s) speeds. Power training-induced increases in EMG amplitude (~41%; 0.47≤d≤1.47; p≤0.05) explained 33% (p=0.049) of increases in isometric muscle strength (~43%; 0.34≤d≤0.80; p≤0.05). Power training-induced gains in plantarflexor activation during push-off (+11%; d=0.38; p=0.045) explained 57% (p=0.004) of the gains in fast gait velocity (+4%; d=0.31; p=0.059). Furthermore, power training increased knee extensor activation (~18%; 0.26≤d≤0.29; p≤0.05) and knee extensor coactivation during the main knee flexor burst (~24%, 0.26≤d≤0.44; p≤0.05) at habitual and fast speed but these adaptations did not correlate with changes in gait velocity Conclusion: Power training increased neuromuscular activation during isometric contractions and level gait in old adults. The power training-induced neuromuscular adaptations were associated with increases in isometric muscle strength and partly with increases in fast gait velocity.

  8. Interaction of an ultrarelativistic electron bunch train with a W-band accelerating structure: High power and high gradient

    DOE PAGES

    Wang, D.; Antipov, S.; Jing, C.; ...

    2016-02-05

    Electron beam interaction with high frequency structures (beyond microwave regime) has a great impact on future high energy frontier machines. We report on the generation of multimegawatt pulsed rf power at 91 GHz in a planar metallic accelerating structure driven by an ultrarelativistic electron bunch train. This slow-wave wakefield device can also be used for high gradient acceleration of electrons with a stable rf phase and amplitude which are controlled by manipulation of the bunch train. To achieve precise control of the rf pulse properties, a two-beam wakefield interferometry method was developed in which the rf pulse, due to themore » interference of the wakefields from the two bunches, was measured as a function of bunch separation. As a result, measurements of the energy change of a trailing electron bunch as a function of the bunch separation confirmed the interferometry method.« less

  9. Interaction of an ultrarelativistic electron bunch train with a W-band accelerating structure: High power and high gradient

    SciTech Connect

    Wang, D.; Antipov, S.; Jing, C.; Power, J. G.; Conde, M.; Wisniewski, E.; Liu, W.; Qiu, J.; Ha, G.; Dolgashev, V.; Tang, C.; Gai, W.

    2016-02-05

    Electron beam interaction with high frequency structures (beyond microwave regime) has a great impact on future high energy frontier machines. We report on the generation of multimegawatt pulsed rf power at 91 GHz in a planar metallic accelerating structure driven by an ultrarelativistic electron bunch train. This slow-wave wakefield device can also be used for high gradient acceleration of electrons with a stable rf phase and amplitude which are controlled by manipulation of the bunch train. To achieve precise control of the rf pulse properties, a two-beam wakefield interferometry method was developed in which the rf pulse, due to the interference of the wakefields from the two bunches, was measured as a function of bunch separation. As a result, measurements of the energy change of a trailing electron bunch as a function of the bunch separation confirmed the interferometry method.

  10. Interaction of an Ultrarelativistic Electron Bunch Train with a W -Band Accelerating Structure: High Power and High Gradient

    NASA Astrophysics Data System (ADS)

    Wang, D.; Antipov, S.; Jing, C.; Power, J. G.; Conde, M.; Wisniewski, E.; Liu, W.; Qiu, J.; Ha, G.; Dolgashev, V.; Tang, C.; Gai, W.

    2016-02-01

    Electron beam interaction with high frequency structures (beyond microwave regime) has a great impact on future high energy frontier machines. We report on the generation of multimegawatt pulsed rf power at 91 GHz in a planar metallic accelerating structure driven by an ultrarelativistic electron bunch train. This slow-wave wakefield device can also be used for high gradient acceleration of electrons with a stable rf phase and amplitude which are controlled by manipulation of the bunch train. To achieve precise control of the rf pulse properties, a two-beam wakefield interferometry method was developed in which the rf pulse, due to the interference of the wakefields from the two bunches, was measured as a function of bunch separation. Measurements of the energy change of a trailing electron bunch as a function of the bunch separation confirmed the interferometry method.

  11. Preliminary power train design for a state-of-the-art electric vehicle

    NASA Technical Reports Server (NTRS)

    Mighdoll, P.; Hahn, W. F.

    1978-01-01

    Power train designs which can be implemented within the current state-of-the-art were identified by means of a review of existing electric vehicles and suitable off-the-shelf components. The affect of various motor/transmission combinations on vehicle range over the SAE J227a schedule D cycle was evaluated. The selected, state-of-the-art power train employs a dc series wound motor, SCR controller, variable speed transmission, regenerative braking, drum brakes and radial ply tires. Vehicle range over the SAE cycle can be extended by approximately 20% by the further development of separately excited, shunt wound DC motors and electrical controllers. Approaches which could improve overall power train efficiency, such as AC motor systems, are identified. However, future emphasis should remain on batteries, tires and lightweight structures if substantial range improvements are to be achieved.

  12. Optimal sliding guidance algorithm for Mars powered descent phase

    NASA Astrophysics Data System (ADS)

    Wibben, Daniel R.; Furfaro, Roberto

    2016-02-01

    Landing on large planetary bodies (e.g. Mars) with pinpoint accuracy presents a set of new challenges that must be addressed. One such challenge is the development of new guidance algorithms that exhibit a higher degree of robustness and flexibility. In this paper, the Zero-Effort-Miss/Zero-Effort-Velocity (ZEM/ZEV) optimal sliding guidance (OSG) scheme is applied to the Mars powered descent phase. This guidance algorithm has been specifically designed to combine techniques from both optimal and sliding control theories to generate an acceleration command based purely on the current estimated spacecraft state and desired final target state. Consequently, OSG yields closed-loop trajectories that do not need a reference trajectory. The guidance algorithm has its roots in the generalized ZEM/ZEV feedback guidance and its mathematical equations are naturally derived by defining a non-linear sliding surface as a function of the terms Zero-Effort-Miss and Zero-Effort-Velocity. With the addition of the sliding mode and using Lyapunov theory for non-autonomous systems, one can formally prove that the developed OSG law is globally finite-time stable to unknown but bounded perturbations. Here, the focus is on comparing the generalized ZEM/ZEV feedback guidance with the OSG law to explicitly demonstrate the benefits of the sliding mode augmentation. Results show that the sliding guidance provides a more robust solution in off-nominal scenarios while providing similar fuel consumption when compared to the non-sliding guidance command. Further, a Monte Carlo analysis is performed to examine the performance of the OSG law under perturbed conditions.

  13. SPS pilot signal design and power transponder analysis, volume 2, phase 3

    NASA Technical Reports Server (NTRS)

    Lindsey, W. C.; Scholtz, R. A.; Chie, C. M.

    1980-01-01

    The problem of pilot signal parameter optimization and the related problem of power transponder performance analysis for the Solar Power Satellite reference phase control system are addressed. Signal and interference models were established to enable specifications of the front end filters including both the notch filter and the antenna frequency response. A simulation program package was developed to be included in SOLARSIM to perform tradeoffs of system parameters based on minimizing the phase error for the pilot phase extraction. An analytical model that characterizes the overall power transponder operation was developed. From this model, the effects of different phase noise disturbance sources that contribute to phase variations at the output of the power transponders were studied and quantified. Results indicate that it is feasible to hold the antenna array phase error to less than one degree per power module for the type of disturbances modeled.

  14. Framing the Cultural Training Landscape: Phase I Findings

    DTIC Science & Technology

    2008-12-01

    of Hall had what he called an “ intercultural ” focus. His emphasis in terms of training was not only to “understand the mentality of complex...awareness of what it is. It has become a symbol for the very worst outcome of the marriage of social science and the Department of Defense. The...effectively in cross-cultural environments. Cross-cultural competence is defined here as an individual capability that contributes to intercultural

  15. Powered wheelchair skills training for persons with stroke: a randomized controlled trial.

    PubMed

    Mountain, Anita D; Kirby, R Lee; Smith, Cher; Eskes, Gail; Thompson, Kara

    2014-12-01

    The aims of this study were to test the hypothesis that people with stroke who receive formal powered wheelchair skills training improve their wheelchair skills to a significantly greater extent than participants in a control group who do not and to explore the influence of spatial neglect. Seventeen participants with stroke (including nine with spatial neglect) were randomly allocated to intervention (n = 9) or control (n = 8) groups. Those in the intervention group received up to five 30-min training sessions based on the Wheelchair Skills Training Program 4.1. The powered Wheelchair Skills Test version 4.1 was administered at baseline (T1) and after training (T2). A rank order analysis of covariance on the T2 Wheelchair Skills Test score, having adjusted for the T1 score, showed a significant effect caused by group (P = 0.0001). A secondary analysis showed no significant effect caused by spatial neglect (P = 0.923). People with stroke who receive formal powered wheelchair skills training improve their powered wheelchair skills to a significantly greater extent (30%) than participants who do not (0%). The extent of change was not affected by the presence of spatial neglect. These findings have significance for the wheelchair provision process and the rehabilitation of people with stroke.

  16. Feasibility of eyes open alpha power training for mental enhancement in elite gymnasts.

    PubMed

    Dekker, Marian K J; van den Berg, Berber R; Denissen, Ad J M; Sitskoorn, Margriet M; van Boxtel, Geert J M

    2014-01-01

    This study focuses on a novel, easy to use and instruction-less method for mental training in athletes. Previous findings suggest that particular mental capacities are needed for achieving peak performance; including attentional control, focus, relaxation and positive affect. Electroencephalography (EEG) alpha brain activity has been associated with neural inhibition during processes of selective attention, for improving efficiency in information processing. Here we hypothesised that eyes open alpha power training by music teaches athletes to (1) learn to self-regulate their brain activity, and (2) learn to increase their baseline alpha power, herewith improving mental capacities such as focusing the allocation of attention. The study was double-blind and placebo-controlled. Twelve elite gymnasts were either given eyes open alpha power training or random beta power training (controls). Results indicate small improvements in sleep quality, mental and physical shape. In our first attempt at getting a grip on mental capacities in athletes, we think this novel training method can be promising. Because gymnastics is one of the most mentally demanding sports, we value even small benefits for the athlete and consider them indicative for future research.

  17. Power outputs in the concentric phase of resistance exercises performed in the interval mode on stable and unstable surfaces.

    PubMed

    Zemková, Erika; Jeleň, Michal; Kováčiková, Zuzana; Ollé, Gábor; Vilman, Tomáš; Hamar, Dušan

    2012-12-01

    The study compares power outputs in the concentric phase of chest presses and squats performed in the interval mode on stable and unstable surface, respectively. A group of 16 physical education students performed randomly on different days 6 sets of 8 repetitions of (a) chest presses on the bench and Swiss ball, respectively, and (b) squats on stable support base and Bosu ball, respectively, with 2 minutes of rest period between sets. The exercises were performed with previously established 70% of 1 repetition maximum under stable conditions. A PC-based system FiTRO Dyne Premium was used to monitor force and velocity and to calculate power. The results showed significantly lower power outputs when resistance exercises were performed on an unstable than a stable support base. In the initial set, mean power in concentric phase of lifting decreased more profoundly under unstable than under stable conditions during both chest presses (13.2 and 7.7%, respectively) and squats (10.3 and 7.2%, respectively). In the final set, the reduction rates of mean power in the concentric phase of chest presses were significantly (p < 0.05) greater on the Swiss ball than on the bench (19.9 and 11.8%, respectively). On the other hand, there were no significant differences in decline of mean power in the concentric phase of squats on the Bosu ball and on stable support base (11.4 and 9.6%, respectively). It may be concluded that power outputs during resistance exercises is more profoundly compromised under unstable than under stable conditions, and this effect is more evident for barbell chest presses on the Swiss ball than for barbell squats on the Bosu ball. These findings have to be taken into account when instability resistance exercises are implemented into the training program, namely, for sports that require production of maximal force in short time.

  18. Power train analysis for the DOE/NASA 100-kW wind turbine generator

    NASA Technical Reports Server (NTRS)

    Seidel, R. C.; Gold, H.; Wenzel, L. M.

    1978-01-01

    Progress in explaining variations of power experienced in the on-line operation of a 100 kW experimental wind turbine-generator is reported. Data are presented that show the oscillations tend to be characteristic of a wind-driven synchronous generator because of low torsional damping in the power train, resonances of its large structure, and excitation by unsteady and nonuniform wind flow. The report includes dynamic analysis of the drive-train torsion, the generator, passive driveline damping, and active pitch control as well as correlation with experimental recordings. The analysis assumes one machine on an infinite bus with constant generator-field excitation.

  19. Influence of resistance training on cardiorespiratory endurance and muscle power and strength in young athletes.

    PubMed

    Ignjatovic, Aleksandar; Radovanovic, D; Stankovic, R; Marković, Z; Kocic, J

    2011-09-01

    The purpose of this study was to investigate the influence of additional resistance training on cardiorespiratory endurance in young (15.8 ± 0.8 yrs) male basketball players. Experimental group subjects (n=23) trained twice per week for 12 weeks using a variety of general free-weight and machine exercises designed for strength acquisition, beside ongoing regular basketball training program. Control group subject (n=23) participated only in basketball training program. Oxygen uptake (VO(2max)) and related gas exchange measures were determined continuously during maximal exercise test using an automated cardiopulmonary exercise system. Muscle power of the extensors and flexors was measured by a specific computerized tensiometer. Results from the experimental group (VO(2max) 51.6 ± 5.7 ml.min(-1).kg(-1) pre vs. 50.9 ± 5.4 ml.min(-1).kg(-1) post resistance training) showed no change (p>0.05) in cardiorespiratory endurance, while muscle strength and power of main muscle groups increased significantly. These data demonstrate no negative cardiorespiratory performance effects on adding resistance training to ongoing regular training program in young athletes.

  20. Advanced Gas Turbine (AGT) power-train system development

    NASA Technical Reports Server (NTRS)

    Helms, H. E.; Johnson, R. A.; Gibson, R. K.

    1982-01-01

    Technical work on the design and component testing of a 74.5 kW (100 hp) advanced automotive gas turbine is described. Selected component ceramic component design, and procurement were tested. Compressor tests of a modified rotor showed high speed performance improvement over previous rotor designs; efficiency improved by 2.5%, corrected flow by 4.6%, and pressure ratio by 11.6% at 100% speed. The aerodynamic design is completed for both the gasifier and power turbines. Ceramic (silicon carbide) gasifier rotors were spin tested to failure. Improving strengths is indicated by burst speeds and the group of five rotors failed at speeds between 104% and 116% of engine rated speed. The emission results from combustor testing showed NOx levels to be nearly one order of magnitude lower than with previous designs. A one piece ceramic exhaust duct/regenerator seal platform is designed with acceptable low stress levels.

  1. Alternative Training Agents Phase 4. Large-Scale Tests

    DTIC Science & Technology

    1992-02-01

    20 BLEND BY MOLES OF 2,2-DICHLORO-1,1,1-TRIFLUOROETHANE AND 1-CHLORO-1,1- DIFLUOROETHANE , BOTH TECHNICAL GRADES)** 1.0 SCOPE 1.1 This specification...pure 1-chloro- 1,1- difluoroethane , suitable as a fire extinguishing fluid for firefighter training and shall conform to the requirements of Table B-1...percent by moles 1-Chloro-1,l- difluoroethane 20.0 ± 1 4.4.1 percent by moles Boiling Point, degrees Celsius -10 to +28 4.4.2 at 760 mm Hg (14 to 82 ’F

  2. Effectiveness of a Wheelchair Skills Training Program for Powered Wheelchair Users: A Randomized Controlled Trial.

    PubMed

    Kirby, R Lee; Miller, William C; Routhier, Francois; Demers, Louise; Mihailidis, Alex; Polgar, Jan Miller; Rushton, Paula W; Titus, Laura; Smith, Cher; McAllister, Mike; Theriault, Chris; Thompson, Kara; Sawatzky, Bonita

    2015-11-01

    To test the hypothesis that powered wheelchair users who receive the Wheelchair Skills Training Program (WSTP) improve their wheelchair skills in comparison with a control group that receives standard care, and secondarily to assess goal achievement, satisfaction with training, retention, injury rate, confidence with wheelchair use, and participation. Randomized controlled trial. Rehabilitation centers and communities. Powered wheelchair users (N=116). Five 30-minute WSTP training sessions. Assessments were done at baseline (t1), posttraining (t2), and 3 months posttraining (t3) using the Wheelchair Skills Test Questionnaire (WST-Q version 4.1), Goal Attainment Score (GAS), Satisfaction Questionnaire, injury rate, Wheelchair Use Confidence Scale for Power Wheelchair Users (WheelCon), and Life Space Assessment (LSA). There was no significant t2-t1 difference between the groups for WST-Q capacity scores (P=.600), but the difference for WST-Q performance scores was significant (P=.016) with a relative (t2/t1 × 100%) improvement of the median score for the intervention group of 10.8%. The mean GAS ± SD for the intervention group after training was 92.8%±11.4%, and satisfaction with training was high. The WST-Q gain was not retained at t3. There was no clinically significant difference between the groups in injury rate and no statistically significant differences in WheelCon or LSA scores at t3. Powered wheelchair users who receive formal wheelchair skills training demonstrate modest, transient posttraining improvements in their WST-Q performance scores, have substantial improvements on individualized goals, and are positive about training. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  3. Power Mobility Training for Young Children with Multiple, Severe Impairments: A Case Series.

    PubMed

    Kenyon, Lisa K; Farris, John P; Gallagher, Cailee; Hammond, Lyndsay; Webster, Lauren M; Aldrich, Naomi J

    2017-02-01

    Young children with neurodevelopmental conditions are often limited in their ability to explore and learn from their environment. The purposes of this case series were to (1) describe the outcomes of using an alternative power mobility device with young children who had multiple, severe impairments; (2) develop power mobility training methods for use with these children; and (3) determine the feasibility of using various outcome measures. Three children with cerebral palsy (Gross Motor Function Classification System Levels IV, V, and V) ages 17 months to 3.5 years participated in the case series. Examination included the Pediatric Evaluation of Disability Inventory-Computer Adaptive Test (PEDI-CAT) and the Dimensions of Mastery Questionnaire (DMQ). An individualized, engaging power mobility training environment was created for each participant. Intervention was provided for 60 minutes per week over 12 weeks. All participants exhibited improvements in power mobility skills. Post-intervention PEDI-CAT scores increased in various domains for all participants. Post-intervention DMQ scores improved in Participants 1 and 2. The participants appeared to make improvements in their beginning power mobility skills. Additional research is planned to further explore the impact of power mobility training in this unique population.

  4. Dynamic behaviour of Li batteries in hydrogen fuel cell power trains

    NASA Astrophysics Data System (ADS)

    Veneri, O.; Migliardini, F.; Capasso, C.; Corbo, P.

    A Li ion polymer battery pack for road vehicles (48 V, 20 Ah) was tested by charging/discharging tests at different current values, in order to evaluate its performance in comparison with a conventional Pb acid battery pack. The comparative analysis was also performed integrating the two storage systems in a hydrogen fuel cell power train for moped applications. The propulsion system comprised a fuel cell generator based on a 2.5 kW polymeric electrolyte membrane (PEM) stack, fuelled with compressed hydrogen, an electric drive of 1.8 kW as nominal power, of the same typology of that installed on commercial electric scooters (brushless electric machine and controlled bidirectional inverter). The power train was characterized making use of a test bench able to simulate the vehicle behaviour and road characteristics on driving cycles with different acceleration/deceleration rates and lengths. The power flows between fuel cell system, electric energy storage system and electric drive during the different cycles were analyzed, evidencing the effect of high battery currents on the vehicle driving range. The use of Li batteries in the fuel cell power train, adopting a range extender configuration, determined a hydrogen consumption lower than the correspondent Pb battery/fuel cell hybrid vehicle, with a major flexibility in the power management.

  5. Effects of high-speed power training on muscle performance and braking speed in older adults.

    PubMed

    Sayers, Stephen P; Gibson, Kyle

    2012-01-01

    We examined whether high-speed power training (HSPT) improved muscle performance and braking speed using a driving simulator. 72 older adults (22 m, 50 f; age = 70.6 ± 7.3 yrs) were randomized to HSPT at 40% one-repetition maximum (1RM) (HSPT: n = 25; 3 sets of 12-14 repetitions), slow-speed strength training at 80%1RM (SSST: n = 25; 3 sets of 8-10 repetitions), or control (CON: n = 22; stretching) 3 times/week for 12 weeks. Leg press and knee extension peak power, peak power velocity, peak power force/torque, and braking speed were obtained at baseline and 12 weeks. HSPT increased peak power and peak power velocity across a range of external resistances (40-90% 1RM; P < 0.05) and improved braking speed (P < 0.05). Work was similar between groups, but perceived exertion was lower in HSPT (P < 0.05). Thus, the less strenuous HSPT exerted a broader training effect and improved braking speed compared to SSST.

  6. Influence of strength on magnitude and mechanisms of adaptation to power training.

    PubMed

    Cormie, Prue; McGuigan, Michael R; Newton, Robert U

    2010-08-01

    To determine whether the magnitude of performance improvements and the mechanisms driving adaptation to ballistic power training differ between strong and weak individuals. Twenty-four men were divided into three groups on the basis of their strength level: stronger (n = 8, one-repetition maximum-to-body mass ratio (1RM/BM) = 1.97 +/- 0.08), weaker (n = 8, 1RM/BM = 1.32 +/- 0.14), or control (n = 8, 1RM/BM = 1.37 +/- 0.13). The stronger and weaker groups trained three times per week for 10 wk. During these sessions, subjects performed maximal-effort jump squats with 0%-30% 1RM. The impact of training on athletic performance was assessed using a 2-d testing battery that involved evaluation of jump and sprint performance as well as measures of the force-velocity relationship, jumping mechanics, muscle architecture, and neural drive. Both experimental groups showed significant (P < or = 0.05) improvements in jump (stronger: peak power = 10.0 +/- 5.2 W.kg, jump height = 0.07 +/- 0.04 m; weaker: peak power = 9.1 +/- 2.3 W.kg, jump height = 0.06 +/- 0.04 m) and sprint performance after training (stronger: 40-m time = -2.2% +/- 2.0%; weaker: 40-m time = -3.6% +/- 2.3%). Effect size analyses revealed a tendency toward practically relevant differences existing between stronger and weaker individuals in the magnitude of improvements in jump performance (effect size: stronger: peak power = 1.55, jump height = 1.46; weaker: peak power = 1.03, jump height = 0.95) and especially after 5 wk of training (effect size: stronger: peak power = 1.60, jump height = 1.59; weaker: peak power = 0.95, jump height = 0.61). The mechanisms driving these improvements included significant (P < or = 0.05) changes in the force-velocity relationship, jump mechanics, and neural activation, with no changes to muscle architecture observed. The magnitude of improvements after ballistic power training was not significantly influenced by strength level. However, the training had a tendency toward

  7. Power combiner with high power capacity and high combination efficiency for two phase-locked relativistic backward wave oscillators

    NASA Astrophysics Data System (ADS)

    Xiao, Renzhen; Deng, Yuqun; Wang, Yue; Song, Zhimin; Li, Jiawei; Sun, Jun; Chen, Changhua

    2015-09-01

    To realize power combination of two phase-locked relativistic backward wave oscillators (RBWOs), a compact power combiner is designed and investigated by 3-D particle-in-cell (PIC) simulation and experiment. The power combiner consists of two TM01-TE11 serpentine mode converters with a common output. When the two incident ports are fed with TM01 modes with a relative phase of 180° and power of 2.5 GW at each port, the conversion efficiency from the incident TM01 modes to the combined TE11 mode is 95.2% at 9.3 GHz, and the maximum electric field in the combiner is 714 kV/cm. The PIC simulation shows that the output power from the common port is 4.2 GW when the power combiner is connected to the two RBWOs with input signals, both producing 2.2 GW microwave, corresponding to a combination efficiency of 95.4%. In the high power microwave test, a method is proposed to obtain the combination efficiency without breaking the vacuum, which is 94.1% when the two phase-locked RBWOs output 1.8 GW and 2.2 GW. The power capacity of multi-gigawatts has been demonstrated.

  8. Development of Buck-Type Single-Phase to Three-Phase Power Converter with Active Buffer

    NASA Astrophysics Data System (ADS)

    Ohnuma, Yoshiya; Itoh, Jun-Ichi

    This paper proposes a novel single-phase to three-phase power converter that can reduce the capacitance value of the smoothing capacitor in the DC link part. In the case of the single-phase converter, a large smoothing capacitor is required to absorb a power ripple with a frequency twice that of the power supply. The proposed method involves the use of an indirect matrix converter with an active snubber to absorb the power ripple. Therefore, the proposed system does not require a reactor and large energy buffer, such as a smoothing capacitor. Moreover, a diode bridge can be used on the rectifier stage in the proposed circuit. In this paper, the basic operation and validity of the proposed method are confirmed by simulation and experiment result. Thus, it is confirmed that good waveforms for input and output currents can be obtained by the proposed method.

  9. A Meta-Analysis of Periodized Versus Nonperiodized Strength and Power Training Programs

    ERIC Educational Resources Information Center

    Rhea, Matthew R.; Alderman, Brandon L.

    2004-01-01

    The purpose of this study was to quantitatively combine and examine the results of studies examining the effectiveness of periodized (PER) compared to nonperiodized (Non-PER) training programs for strength and/or power development. Two analyses were conducted to (a) examine the magnitude of treatment effect elicited by PER strength training…

  10. Effect of Vibration Training on Anaerobic Power and Quardroceps Surface EMG in Long Jumpers

    ERIC Educational Resources Information Center

    Liu, Bin; Luo, Jiong

    2015-01-01

    Objective: To explore the anaerobic power and surface EMG (sEMG) of quardrocep muscle in lower extremities after single vibration training intervention. Methods: 8 excellent male long jumpers voluntarily participated in this study. Four intervention modes were devised, including high frequency high amplitude (HFHA,30Hz,6mm), low frequency low…

  11. Menstrual Cycle Effects on Anaerobic Power, Muscular Strength, and Muscular Endurance in Trained and Untrained Females.

    ERIC Educational Resources Information Center

    Rosenburg, Beth S.; And Others

    A study determined if anaerobic power, isometric strength, and isometric endurance are affected by the menstrual cycle and if endurance trained females and untrained females are affected in the same manner on these performance parameters. Subjects were healthy, normally menstruating females, ages 18-34 years who were classified as either trained…

  12. A Meta-Analysis of Periodized Versus Nonperiodized Strength and Power Training Programs

    ERIC Educational Resources Information Center

    Rhea, Matthew R.; Alderman, Brandon L.

    2004-01-01

    The purpose of this study was to quantitatively combine and examine the results of studies examining the effectiveness of periodized (PER) compared to nonperiodized (Non-PER) training programs for strength and/or power development. Two analyses were conducted to (a) examine the magnitude of treatment effect elicited by PER strength training…

  13. Menstrual Cycle Effects on Anaerobic Power, Muscular Strength, and Muscular Endurance in Trained and Untrained Females.

    ERIC Educational Resources Information Center

    Rosenburg, Beth S.; And Others

    A study determined if anaerobic power, isometric strength, and isometric endurance are affected by the menstrual cycle and if endurance trained females and untrained females are affected in the same manner on these performance parameters. Subjects were healthy, normally menstruating females, ages 18-34 years who were classified as either trained…

  14. The Development of a Computer-Directed Training Subsystem and Computer Operator Training Material for the Air Force Phase II Base Level System. Final Report.

    ERIC Educational Resources Information Center

    System Development Corp., Santa Monica, CA.

    The design, development, and evaluation of an integrated Computer-Directed Training Subsystem (CDTS) for the Air Force Phase II Base Level System is described in this report. The development and evaluation of a course to train computer operators of the Air Force Phase II Base Level System under CDTS control is also described. Detailed test results…

  15. Effects of Instability Versus Traditional Resistance Training on Strength, Power and Velocity in Untrained Men

    PubMed Central

    Maté-Muñoz, José Luis; Monroy, Antonio J. Antón; Jodra Jiménez, Pablo; Garnacho-Castaño, Manuel V.

    2014-01-01

    The purpose of this study was compare the effects of a traditional and an instability resistance circuit training program on upper and lower limb strength, power, movement velocity and jumping ability. Thirty-six healthy untrained men were assigned to two experimental groups and a control group. Subjects in the experimental groups performed a resistance circuit training program consisting of traditional exercises (TRT, n = 10) or exercises executed in conditions of instability (using BOSU® and TRX®) (IRT, n = 12). Both programs involved three days per week of training for a total of seven weeks. The following variables were determined before and after training: maximal strength (1RM), average (AV) and peak velocity (PV), average (AP) and peak power (PP), all during bench press (BP) and back squat (BS) exercises, along with squat jump (SJ) height and counter movement jump (CMJ) height. All variables were found to significantly improve (p <0.05) in response to both training programs. Major improvements were observed in SJ height (IRT = 22.1%, TRT = 20.1%), CMJ height (IRT = 17.7%, TRT = 15.2%), 1RM in BS (IRT = 13.03%, TRT = 12.6%), 1RM in BP (IRT = 4.7%, TRT = 4.4%), AP in BS (IRT = 10.5%, TRT = 9.3%), AP in BP (IRT = 2.4%, TRT = 8.1%), PP in BS (IRT=19.42%, TRT = 22.3%), PP in BP (IRT = 7.6%, TRT = 11.5%), AV in BS (IRT = 10.5%, TRT = 9.4%), and PV in BS (IRT = 8.6%, TRT = 4.5%). Despite such improvements no significant differences were detected in the posttraining variables recorded for the two experimental groups. These data indicate that a circuit training program using two instability training devices is as effective in untrained men as a program executed under stable conditions for improving strength (1RM), power, movement velocity and jumping ability. Key Points Similar adaptations in terms of gains in strength, power, movement velocity and jumping ability were produced in response to both training programs. Both the stability and instability approaches

  16. Effects of instability versus traditional resistance training on strength, power and velocity in untrained men.

    PubMed

    Maté-Muñoz, José Luis; Monroy, Antonio J Antón; Jodra Jiménez, Pablo; Garnacho-Castaño, Manuel V

    2014-09-01

    The purpose of this study was compare the effects of a traditional and an instability resistance circuit training program on upper and lower limb strength, power, movement velocity and jumping ability. Thirty-six healthy untrained men were assigned to two experimental groups and a control group. Subjects in the experimental groups performed a resistance circuit training program consisting of traditional exercises (TRT, n = 10) or exercises executed in conditions of instability (using BOSU® and TRX®) (IRT, n = 12). Both programs involved three days per week of training for a total of seven weeks. The following variables were determined before and after training: maximal strength (1RM), average (AV) and peak velocity (PV), average (AP) and peak power (PP), all during bench press (BP) and back squat (BS) exercises, along with squat jump (SJ) height and counter movement jump (CMJ) height. All variables were found to significantly improve (p <0.05) in response to both training programs. Major improvements were observed in SJ height (IRT = 22.1%, TRT = 20.1%), CMJ height (IRT = 17.7%, TRT = 15.2%), 1RM in BS (IRT = 13.03%, TRT = 12.6%), 1RM in BP (IRT = 4.7%, TRT = 4.4%), AP in BS (IRT = 10.5%, TRT = 9.3%), AP in BP (IRT = 2.4%, TRT = 8.1%), PP in BS (IRT=19.42%, TRT = 22.3%), PP in BP (IRT = 7.6%, TRT = 11.5%), AV in BS (IRT = 10.5%, TRT = 9.4%), and PV in BS (IRT = 8.6%, TRT = 4.5%). Despite such improvements no significant differences were detected in the posttraining variables recorded for the two experimental groups. These data indicate that a circuit training program using two instability training devices is as effective in untrained men as a program executed under stable conditions for improving strength (1RM), power, movement velocity and jumping ability. Key PointsSimilar adaptations in terms of gains in strength, power, movement velocity and jumping ability were produced in response to both training programs.Both the stability and instability approaches seem

  17. A three-phase soft-switched high-power-density dc/dc converter for high power applications

    SciTech Connect

    DeDoncker, R.W.A.A. ); Divan, D.M.; Kheraluwala, M.H. )

    1991-01-01

    In this paper three dc/dc converter topologies suitable for high-power-density high-power applications are presented. All three circuits operate in a soft-switched manner, making possible a reduction in device switching losses and an increase in switching frequency. The three-phase dual-bridge converter proposed is seen to have the most favorable characteristics. This converter consists of two three-phase inverter stages operating in a high-frequency six-step mode. In contrast to existing single-phase ac-link dc/dc converters, lower turn-off peak currents in the power devices and lower rms current ratings for both the input and output filter capacitors are obtained. This is in addition to smaller filter element values due to the higher-frequency content of the input and output waveforms. Furthermore, the use of a three phase symmetrical transformer instead of single-phase transformers and a better utilization of the available apparent power of the transformer (as a consequence of the controlled output inverter) significantly increase the power density attainable.

  18. Effect of concurrent training, flexible nonlinear periodization, and maximal-effort cycling on strength and power.

    PubMed

    McNamara, John M; Stearne, David J

    2013-06-01

    Although there is considerable research on concurrent training, none has integrated flexible nonlinear periodization and maximal-effort cycling in the same design. The purpose of this investigation was to test outcome measures of strength and power using a pretest-posttest randomized groups design. A strength and endurance (SE) group was compared with a strength, endurance, and maximal-effort cycling (SEC) group. Both groups used a flexible nonlinear periodization design. Thirteen male and 7 female students (mean ± SD: age, 22.5 ± 4.1 years; height, 173.5 ± 12.4 cm; weight, 79.4 ± 20.2 kg; strength training experience, 2.4 ± 2.2 years) participated in this study. Groups were not matched for age, height, weight, strength training experience, or sex, but were randomly assigned to an SE (n = 10) or SEC (n = 10) group. All training was completed within 45 minutes, twice per week (Monday and Wednesday), over 12 consecutive weeks. Both groups were assigned 6.75 total hours of aerobic conditioning, and 13.5 hours of free weight and machine exercises totaling 3,188 repetitions ranging from 5 to 20 repetition maximums. The SEC group performed 2 cycling intervals per workout ranging from 10 to 45 seconds. Pretest and posttest measures included chest press and standing broad jump. Analysis of variance showed that there were no significant differences between the SE and SEC groups on measures of chest press or standing broad jump performance (p, not significant). Paired sample t-tests (p = 0.05) showed significant improvement in strength and power in all groups (pretest to posttest), except for SE jump performance (p, not significant). In conclusion, adding maximal-effort cycling does not provide additional strength or power benefits to a concurrent flexible nonlinear training program. However, an exercise professional can take confidence that a concurrent flexible nonlinear training program can increase strength and power in healthy individuals.

  19. Inhomogeneous Quadriceps Femoris Hypertrophy in Response to Strength and Power Training.

    PubMed

    Earp, Jacob E; Newton, Robert U; Cormie, Prue; Blazevich, Anthony J

    2015-11-01

    Previous studies have reported inhomogeneous changes in quadriceps femoris (QF) cross-sectional area (CSA) in response to strength training. It is assumed that these differential changes in muscle shape influence the muscle's functional capacity during high-force and high-power movements. The purpose of the current study was to compare intermuscular and intramuscular QF adaptations to high-load strength training and fast-speed power training. Thirty-six non-strength-trained men were randomly assigned to four groups and completed 8 wk of parallel-depth heavy squat-lift training (HS-P), parallel-depth jump squat training (JS-P), volitional-depth jump squat training (JS-V), or no training (C). Quadriceps femoris, vastus lateralis (VL), intermedius (VI), medialis (VM), and rectus femoris (RF) CSA were measured in distal-, mid-, and proximal-thigh regions using extended field-of-view ultrasonography and compared using a 3 × 2 mixed-model MANOVA with Bonferroni post hoc tests (P < 0.05). Parallel-depth heavy squat-lift training and JS-P elicited similar changes in mid-CSA(QF) as well as summed CSA of the QF, VL, VI, and VM. Cross-sectional area of the VL (CSA(VL)) and CSA(VI) increased in both HS-P and JS-P at mid-thigh, but only JS-P significantly increased CSA proximally, and only HS-P significantly increased CSA distally. Cross-sectional area of the VM (CSA(VM)) increased in HS-P and JS-P distally, but only HS-P increased at mid-thigh. No hypertrophy was observed in RF at any location and no significant differences were observed between JS-P and JS-V. Parallel-depth heavy squat-lift training elicited greater proximal hypertrophy in each of the vasti muscles, whereas only JS-P elicited distal VL and VI hypertrophy. These observed inhomogeneous changes in CSA may alter the thigh's moment of inertia and moment arms of muscle "compartments," and the influence of elastic component force transmission on the muscular force expression. Such selective hypertrophy is

  20. Infusion of lidocaine into the dorsal hippocampus before or after the shock training phase impaired conditioned freezing in a two-phase training task of contextual fear conditioning.

    PubMed

    Chang, Shih-Dar; Chen, Der-Yow; Liang, K C

    2008-02-01

    Learning in a contextual fear conditioning task involves forming a context representation and associating it with a shock. The dorsal hippocampus (DH) is implicated in representing the context, but whether it also has a role in associating the context and shock is unclear. To address this issue, male Wistar rats were trained on the task by a two-phase training paradigm, in which rats learned the context representation on day 1 and then reactivated it to associate with the shock on day 2; conditioned freezing was tested on day 3. Lidocaine was infused into the DH at various times in each of the two training sessions. Results showed that intra-DH infusion of lidocaine shortly before or after the context training session on day 1 impaired conditioned freezing, attesting to the DH involvement in context representation. Intra-DH infusion of lidocaine shortly before or after the shock training session on day 2 also impaired conditioned freezing. This deficit was reproduced by infusing lidocaine or APV (alpha-amino-5-phosphonovaleric acid) into the DH after activation of the context memory but before shock administration. The deficit was not due to drug-induced state-dependency, decreased shock sensitivity or reconsolidation failure of the contextual memory. These results suggest that in contextual fear conditioning integrity of the DH is required for memory processing of not only context representation but also context-shock association.

  1. Multiple intravenous infusions phase 1b: practice and training scan.

    PubMed

    Cassano-Piché, A; Fan, M; Sabovitch, S; Masino, C; Easty, A C

    2012-01-01

    Minimal research has been conducted into the potential patient safety issues related to administering multiple intravenous (IV) infusions to a single patient. Previous research has highlighted that there are a number of related safety risks. In Phase 1a of this study, an analysis of 2 national incident-reporting databases (Institute for Safe Medical Practices Canada and United States Food and Drug Administration MAUDE) found that a high percentage of incidents associated with the administration of multiple IV infusions resulted in patient harm. The primary objectives of Phase 1b of this study were to identify safety issues with the potential to cause patient harm stemming from the administration of multiple IV infusions; and to identify how nurses are being educated on key principles required to safely administer multiple IV infusions. A field study was conducted at 12 hospital clinical units (sites) across Ontario, and telephone interviews were conducted with program coordinators or instructors from both the Ontario baccalaureate nursing degree programs and the Ontario postgraduate Critical Care Nursing Certificate programs. Data were analyzed using Rasmussen's 1997 Risk Management Framework and a Health Care Failure Modes and Effects Analysis. Twenty-two primary patient safety issues were identified with the potential to directly cause patient harm. Seventeen of these (critical issues) were categorized into 6 themes. A cause-consequence tree was established to outline all possible contributing factors for each critical issue. Clinical recommendations were identified for immediate distribution to, and implementation by, Ontario hospitals. Future investigation efforts were planned for Phase 2 of the study. This exploratory field study identifies the potential for errors, but does not describe the direct observation of such errors, except in a few cases where errors were observed. Not all issues are known in advance, and the frequency of errors is too low to be

  2. Effects of follicular versus luteal phase-based strength training in young women.

    PubMed

    Sung, Eunsook; Han, Ahreum; Hinrichs, Timo; Vorgerd, Matthias; Manchado, Carmen; Platen, Petra

    2014-01-01

    Hormonal variations during the menstrual cycle (MC) may influence trainability of strength. We investigated the effects of a follicular phase-based strength training (FT) on muscle strength, muscle volume and microscopic parameters, comparing it to a luteal phase-based training (LT). Eumenorrheic women without oral contraception (OC) (N = 20, age: 25.9 ± 4.5 yr, height: 164.2 ± 5.5 cm, weight: 60.6 ± 7.8 kg) completed strength training on a leg press for three MC, and 9 of them participated in muscle biopsies. One leg had eight training sessions in the follicular phases (FP) and only two sessions in the luteal phases (LP) for follicular phase-based training (FT), while the other leg had eight training sessions in LP and only two sessions in FP for luteal phase-based training (LT). Estradiol (E2), progesterone (P4), total testosterone (T), free testosterone (free T) and DHEA-s were analysed once during FP (around day 11) and once during LP (around day 25). Maximum isometric force (Fmax), muscle diameter (Mdm), muscle fibre composition (No), fibre diameter (Fdm) and cell nuclei-to-fibre ratio (N/F) were analysed before and after the training intervention. T and free T were higher in FP compared to LP prior to the training intervention (P < 0.05). The increase in Fmax after FT was higher compared to LT (P <0.05). FT also showed a higher increase in Mdm than LT (P < 0.05). Moreover, we found significant increases in Fdm of fibre type ΙΙ and in N/F only after FT; however, there was no significant difference from LT. With regard to change in fibre composition, no differences were observed between FT and LT. FT showed a higher gain in muscle strength and muscle diameter than LT. As a result, we recommend that eumenorrheic females without OC should base the periodization of their strength training on their individual MC.

  3. A Cost-Effective Virtual Environment for Simulating and Training Powered Wheelchairs Manoeuvres.

    PubMed

    Headleand, Christopher J; Day, Thomas; Pop, Serban R; Ritsos, Panagiotis D; John, Nigel W

    2016-01-01

    Control of a powered wheelchair is often not intuitive, making training of new users a challenging and sometimes hazardous task. Collisions, due to a lack of experience can result in injury for the user and other individuals. By conducting training activities in virtual reality (VR), we can potentially improve driving skills whilst avoiding the risks inherent to the real world. However, until recently VR technology has been expensive and limited the commercial feasibility of a general training solution. We describe Wheelchair-Rift, a cost effective prototype simulator that makes use of the Oculus Rift head mounted display and the Leap Motion hand tracking device. It has been assessed for face validity by a panel of experts from a local Posture and Mobility Service. Initial results augur well for our cost-effective training solution.

  4. Space shuttle auxiliary power unit study, phase 2

    NASA Technical Reports Server (NTRS)

    Binsley, R. L.; Krause, A. A.; Maddox, R. D.; Marcy, R. D.; Siegler, R. S.

    1972-01-01

    A study was performed to establish the preliminary design of the space shuttle auxiliary power unit. Details of the analysis, optimizations, and design of the components, subsystems and systems are presented.

  5. Expression of genes related to muscle plasticity after strength and power training regimens.

    PubMed

    Lamas, L; Aoki, M S; Ugrinowitsch, C; Campos, G E R; Regazzini, M; Moriscot, A S; Tricoli, V

    2010-04-01

    The purpose of our study was to compare the effects of 8-week progressive strength and power training regimens on strength gains and muscle plasticity [muscle fiber hypertrophy and phenotype shift, mammalian target of rapamycin (mTOR), regulatory-associated protein of mTOR (RAPTOR), rapamycin-insensitive companion of m-TOR (RICTOR), calcineurin and calcipressin gene expression]. Twenty-nine physically active subjects were divided into three groups: strength training (ST), power training (PT) and control (C). Squat 1 RM and muscle biopsies were obtained before and after the training period. Strength increased similarly for both ST and PT groups (P<0.001). Fiber types I, IIa and IIb presented hypertrophy main time effect (P<0.05). Only type IIb percentage decreased from pre- to post-test (main time effect, P<0.05). mTOR and RICTOR mRNA expression increased similarly from pre- to post-test (P<0.01). RAPTOR increased after training for both groups (P<0.0001), but to a greater extent in the ST (P<0.001) than in the PT group. 4EBP-1 decreased after training when the ST and PT groups were pooled (P<0.05). Calcineurin levels did not change after training, while calcipressin increased similarly from pre- to post-test (P<0.01). In conclusion, our data indicate that these training regimens produce similar performance improvements; however, there was a trend toward greater hypertrophy-related gene expression and muscle fiber hypertrophy in the ST group.

  6. Maximal strength, power, and aerobic endurance adaptations to concurrent strength and sprint interval training.

    PubMed

    Cantrell, Gregory S; Schilling, Brian K; Paquette, Max R; Murlasits, Zsolt

    2014-04-01

    This study was designed to examine whether concurrent sprint interval and strength training (CT) would result in compromised strength development when compared to strength training (ST) alone. In addition, maximal oxygen consumption (VO2max) and time to exhaustion (TTE) were measured to determine if sprint interval training (SIT) would augment aerobic performance. Fourteen recreationally active men completed the study. ST (n = 7) was performed 2 days/week and CT (n = 7) was performed 4 days/week for 12 weeks. CT was separated by 24 h to reduce the influence of acute fatigue. Body composition was analyzed pre- and post-intervention. Anaerobic power, one-repetition maximum (1RM) lower- and upper-body strength, VO2max and TTE were analyzed pre-, mid-, and post-training. Training intensity for ST was set at 85 % 1RM and SIT trained using a modified Wingate protocol, adjusted to 20 s. Upper- and lower-body strength improved significantly after training (p < 0.001) with no difference between the groups (p > 0.05). VO2max increased 40.9 ± 8.4 to 42.3 ± 7.1 ml/kg/min (p < 0.05) for CT, whereas ST remained unchanged. A significant difference in VO2max (p < 0.05) was observed between groups post-intervention (CT: 42.3 ± 7.1 vs. ST: 36.0 ± 3.0 ml/kg/min). A main effect for time and group was observed in TTE (p < 0.05). A significant main effect for time was observed in average power (p < 0.05). Preliminary findings suggest that performing concurrent sprint interval and strength training does not attenuate the strength response when compared to ST alone, while also improves aerobic performance measures, such as VO2max at the same time.

  7. The effect of plyometric training on power and kicking distance in female adolescent soccer players.

    PubMed

    Rubley, Mack D; Haase, Amaris C; Holcomb, William R; Girouard, Tedd J; Tandy, Richard D

    2011-01-01

    The purpose of this study was to measure the effects of low-frequency, low-impact plyometric training on vertical jump (VJ) and kicking distance in female adolescent soccer players. Sixteen adolescent soccer players were studied (age 13.4 ± 0.5 years) across 14 weeks. The control group (general soccer training only) had 6 subjects, and the plyometric training (general soccer training plus plyometric exercise) group had 10 subjects. All subjects were tested for VJ and kicking distance on 3 occasions: pre-test, 7 weeks, and 14 weeks. Data were analyzed using a 2 (Training) × 3 (Test) analysis of variance (ANOVA) with repeated measures on the factor test. No significant difference in kicking distance was found between groups at pre-test (p = 0.688) or 7 weeks (p = 0.117). The plyometric group had significantly greater kicking distance after 14 weeks (p < 0.001). No significant difference in VJ height was found between groups at pre-test (p = 0.837) or 7 weeks (p = 0.108). The plyometric group had a significantly higher VJ after 14 weeks (p = 0.014). These results provide strength coaches with a safe and effective alternative to high-intensity plyometric training. Based on these findings, to increase lower-body power resulting in increased VJ and kicking distance, strength coaches should implement once-weekly, low-impact plyometric training programs with their adolescent athletes.

  8. Plyometric training improves power and agility in Jamaica's national netball team.

    PubMed

    Roopchand-Martin, S; Lue-Chin, P

    2010-03-01

    Plyometric training is widely used in conditioning, power training and in prevention and rehabilitation of injuries in some sports. This study sought to investigate the effect of a three-week plyometric training programme on jump performance and agility in Jamaican national netball players. Eighteen national netballers participated in a Plyometric training programme. Subjects were evaluated using the Vertical Jump Test, the Broad Jump Test and the Illinois Agility Test prior to the start of the programme and at week 3. The data were analysed using SPSS version 12 for Windows. A One-Sample Kolmogorov-Smirnov Test showed normal distribution of data and a paired samples t-test was used to determine whether the mean change in jump performance and agility was significant. All eighteen subjects completed the three weeks of training. Three subjects were shown to be outliers at week 3 and this resulted in data from 15 subjects being analysed. At the end of the three weeks, there were significant improvements in Vertical Jump Scores (p = 0.023), Broad Jump Scores (p = 0.002) and Agility scores (p = 0.045). Three weeks of Plyometric training can lead to significant improvements in jump performance and agility and should be integrated into the national training programme at intervals yet to be determined.

  9. Effect of one- vs. two-stair climb training on sprint power.

    PubMed

    Harris, Kenten B; Brown, Lee E; Statler, Traci A; Noffal, Guillermo J; Bartolini, J Albert

    2014-11-01

    Although running stairs is often used in sport conditioning programs, at present, little research has examined the effect of stair climb training on sprint power. The purpose of this study was to investigate the effects of running stairs either 1 stair (1S) or 2 stairs (2S) at a time on power. Fourteen male college track and field athletes were randomized into 3 groups; 1S, 2S, or control (C). All groups were pre- and posttested for 1S, 2S, and 40-m sprint split times. The 1S and 2S groups trained twice per week, for 4 weeks, performing 10 sets of climbing 68 total stairs with 2.5-minute rest between trials. The greatest power values (W) from pre- and poststairs and sprint splits were used for statistical analyses. There was a significant (p < 0.05) interaction of group × time for stair climb. The 1S group increased power for the 1S test (pre-1,492.89 ± 123.76; post-1,647.41 ± 73.65) with no change in the 2S test (pre-2,428.80 ± 414.81; post-2,430.32 ± 154.90), whereas the 2S group increased power for the 2S test (pre-2,343.73 ± 317.50; post-2,646.17 ± 305.43) with no change in the 1S test (pre-1,516.69 ± 210.64; post-1,529.38 ± 236.69). The C group showed no change in either stair test (1S: pre-1,403.35 ± 238.67, post-1,384.38 ± 153.32; 2S: pre-2,285.93 ± 345.03, post-2,261.85 ± 356.88). There were no significant interactions or main effects for any sprint split power (40 m: pre-5,337.13 ± 611.86, post-5,318.68 ± 586.24).Therefore, stair climb training either 1 or 2 at a time did not affect 40-m sprint split power but increased power for the specific stair training type. Coaches should choose the number of stairs that are similar in time and power output to sprint training.

  10. Multimegawatt space nuclear power supply: Phase 1, Final report

    SciTech Connect

    Not Available

    1989-02-17

    The Phase 2 program objectives are to (1) demonstrate concept feasibility, (2) develop a preliminary design, and (3) complete Phase 3 engineering development and ground test plans. The approach to accomplish these objectives is to prove technical feasibility of our baseline design early in the program while maintaining flexibility to easily respond to changing requirements and advances in technology. This approach recognizes that technology is advancing rapidly while the operational phase MSNPS is 15 to 20 years in the future. This plan further recognizes that the weapons platform and Advanced Launch System (ALS) are in very early program definition stages; consequently, their requirements, interfaces, and technological basis will evolve. This document outlines the Phase 2 plan along with task scheduling of the various program aspects.

  11. High Power Low Impedance Therapeutic Intracavitary Phased Array

    NASA Astrophysics Data System (ADS)

    Kukic, Aleksandra; Hynynen, Kullervo

    2010-03-01

    Ultrasound phased arrays can be used for noninvasive surgical applications, and are ideal for intracavitary applications, where their properties of dynamic focusing and beam steering compensate for the spatial constraints. Phase shifting without grating lobes requires small elements, which results in low width-thickness ratios and thus high electrical impedance. This study demonstrates, for the first time, a method of lateral coupling for the purposes of reduction of electrical impedance of linear phased arrays. Fabrication procedure for a lateral coupled array for therapeutic purposes is demonstrated. Impedance analysis of a thickness mode driven phased array is compared to a lateral coupling mode array. For a 1.5 MHz resonant frequency, impedance drop of 33 times is seen at antiresonance, and 6 times at resonance. Thickness mode phase peak is never higher than -41.3°, whereas it reaches to 42.3° in the lateral coupling mode. This allows for a phase crossing of 0° for lateral mode transducer, where the impedance is 111Ω, eliminating the need for matching circuits. Scanning laser vibrometer measurements of surface displacements show that a lateral mode element can achieve intensity levels greater than 20 W/cm2, when an unmatched element is tested.

  12. How Competency-Based Training Locks the Working Class out of Powerful Knowledge: A Modified Bernsteinian Analysis

    ERIC Educational Resources Information Center

    Wheelahan, Leesa

    2007-01-01

    This paper argues that competency-based training in vocational education and training in Australia is one mechanism through which the working class is denied access to powerful knowledge represented by the academic disciplines. The paper presents a modified Bernsteinian analysis to argue that vocational education and training students need access…

  13. Conducting Effective Simulator Training.

    ERIC Educational Resources Information Center

    Gerling, Kenneth D.

    This paper describes the simulator phase of Commonwealth Edison's program for training and licensing operators of nuclear power stations. Topics covered include (1) preparing the students before starting the simulator phase; (2) the simulator schedule and the number of students that can be trained effectively in a class; (3) format and structure…

  14. Power Electronic Transformer based Three-Phase PWM AC Drives

    NASA Astrophysics Data System (ADS)

    Basu, Kaushik

    A Transformer is used to provide galvanic isolation and to connect systems at different voltage levels. It is one of the largest and most expensive component in most of the high voltage and high power systems. Its size is inversely proportional to the operating frequency. The central idea behind a power electronic transformer (PET) also known as solid state transformer is to reduce the size of the transformer by increasing the frequency. Power electronic converters are used to change the frequency of operation. Steady reduction in the cost of the semiconductor switches and the advent of advanced magnetic materials with very low loss density and high saturation flux density implies economic viability and feasibility of a design with high power density. Application of PET is in generation of power from renewable energy sources, especially wind and solar. Other important application include grid tied inverters, UPS e.t.c. In this thesis non-resonant, single stage, bi-directional PET is considered. The main objective of this converter is to generate adjustable speed and magnitude pulse width modulated (PWM) ac waveforms from an ac or dc grid with a high frequency ac link. The windings of a high frequency transformer contains leakage inductance. Any switching transition of the power electronic converter connecting the inductive load and the transformer requires commutation of leakage energy. Commutation by passive means results in power loss, decrease in the frequency of operation, distortion in the output voltage waveform, reduction in reliability and power density. In this work a source based partially loss-less commutation of leakage energy has been proposed. This technique also results in partial soft-switching. A series of converters with novel PWM strategies have been proposed to minimize the frequency of leakage inductance commutation. These PETs achieve most of the important features of modern PWM ac drives including 1) Input power factor correction, 2) Common

  15. Enhanced power quality based single phase photovoltaic distributed generation system

    NASA Astrophysics Data System (ADS)

    Panda, Aurobinda; Pathak, M. K.; Srivastava, S. P.

    2016-08-01

    This article presents a novel control strategy for a 1-ϕ 2-level grid-tie photovoltaic (PV) inverter to enhance the power quality (PQ) of a PV distributed generation (PVDG) system. The objective is to obtain the maximum benefits from the grid-tie PV inverter by introducing current harmonics as well as reactive power compensation schemes in its control strategy, thereby controlling the PV inverter to achieve multiple functions in the PVDG system such as: (1) active power flow control between the PV inverter and the grid, (2) reactive power compensation, and (3) grid current harmonics compensation. A PQ enhancement controller (PQEC) has been designed to achieve the aforementioned objectives. The issue of underutilisation of the PV inverter in nighttime has also been addressed in this article and for the optimal use of the system; the PV inverter is used as a shunt active power filter in nighttime. A prototype model of the proposed system is developed in the laboratory, to validate the effectiveness of the control scheme, and is tested with the help of the dSPACE DS1104 platform.

  16. Power generation by exchange of latent heats of phase transition

    SciTech Connect

    Ehrlich, S.; Levenson, W.L.

    1981-08-11

    A power system is provided that uses the latent heat of fusion of water to raise the potential energy of a working fluid to a level that upon release generates power, preferably electrical power. The system is self-sustaining except for the energy that is supplied in water entering the system. The inlet water can be at any temperature within its liquid range under atmospheric or super atmospheric pressure, can advantageously contain the sensible waste heat typical of effluent from fossil fuel or nuclear power plants, can be relatively pure or be contaminated as with sewage or be the medium of a colloidal suspension, or consist of marine or other saline waters. In every case, purification of the water by freezing, for example, desalination, is accomplished without additional power consumption. A selected working fluid that boils at a temperature substantially below the freezing point of water is brought in the liquid state into contact with the water or other aqueous medium, causing the water to freeze and the working fluid to vaporize under pressure; the produced ice is removed; a portion of the so-produced ice is admixed with a eutectic forming salt to create a cooling medium at a temperature below the condensation temperature of the cooling fluid; the working-fluid vapors are preferably superheated by inlet aqueous medium and are released from autogenic elevated pressure to drive a turbine. Working fluid vapors are condensed by said cooling medium and returned by pumping into contact with inlet aqueous medium.

  17. A topological investigation of phase transitions of cascading failures in power grids

    NASA Astrophysics Data System (ADS)

    Koç, Yakup; Warnier, Martijn; Van Mieghem, Piet; Kooij, Robert E.; Brazier, Frances M. T.

    2014-12-01

    Cascading failures are one of the main reasons for blackouts in electric power transmission grids. The economic cost of such failures is in the order of tens of billion dollars annually. The loading level of power system is a key aspect to determine the amount of the damage caused by cascading failures. Existing studies show that the blackout size exhibits phase transitions as the loading level increases. This paper investigates the impact of the topology of a power grid on phase transitions in its robustness. Three spectral graph metrics are considered: spectral radius, effective graph resistance and algebraic connectivity. Experimental results from a model of cascading failures in power grids on the IEEE power systems demonstrate the applicability of these metrics to design/optimise a power grid topology for an enhanced phase transition behaviour of the system.

  18. Exposure to ultrafine particles and black carbon in diesel-powered commuter trains

    NASA Astrophysics Data System (ADS)

    Jeong, Cheol-Heon; Traub, Alison; Evans, Greg J.

    2017-04-01

    Ultrafine particle (UFP), black carbon (BC) and lung deposited surface area (LDSA) concentrations measured during 43 trips on diesel-powered commuter trains revealed elevated exposures under some conditions. When the passenger coaches were pulled by a locomotive, the geometric mean concentrations of UFP, LDSA, and BC were 18, 10, and 6 times higher than the exposure levels when the locomotive pushed the coaches, respectively. In addition, UFP, LDSA, and BC concentrations in pull-trains were 5, 3, and 4 times higher than concentrations measured while walking on city sidewalks, respectively. Exposure to these pollutants was most elevated in the coach located closest to the locomotive: geometric means were 126,000 # cm-3 for UFP, 249 μm2 cm-3 for LDSA, and 17,800 ng m-3 of BC; these concentrations are much higher than those previously reported for other modes of public transportation. Markedly high levels of diesel exhaust are present in passenger trains powered by diesel locomotives operated in pull-mode. Thus, it is recommended that immediate steps be taken to evaluate, and where needed, mitigate exposure in diesel-powered passenger trains, both commuter and inter-city.

  19. A training method for locomotion mode prediction using powered lower limb prostheses.

    PubMed

    Young, Aaron J; Simon, Ann M; Hargrove, Levi J

    2014-05-01

    Recently developed lower-limb prostheses are capable of actuating the knee and ankle joints, allowing amputees to perform advanced locomotion modes such as step-over-step stair ascent and walking on sloped surfaces. However, transitions between these locomotion modes and walking are neither automatic nor seamless. This study describes methods for construction and training of a high-level intent recognition system for a lower-limb prosthesis that provides natural transitions between walking, stair ascent, stair descent, ramp ascent, and ramp descent. Using mechanical sensors onboard a powered prosthesis, we collected steady-state and transition data from six transfemoral amputees while the five locomotion modes were performed. An intent recognition system built using only mechanical sensor data was 84.5% accurate using only steady-state training data. Including training data collected while amputees performed seamless transitions between locomotion modes improved the overall accuracy rate to 93.9%. Training using a single analysis window at heel contact and toe off provided higher recognition accuracy than training with multiple analysis windows. This study demonstrates the capability of an intent recognition system to provide automatic, natural, and seamless transitions between five locomotion modes for transfemoral amputees using powered lower limb prostheses.

  20. Effects of heavy resistance training on strength and power in upper extremities in wheelchair athletes.

    PubMed

    Turbanski, Stephan; Schmidtbleicher, Dietmar

    2010-01-01

    Little is known about strength training in subjects with spinal cord injury (SCI), especially in athletes performing competitive sports. Sixteen male subjects participated in this study-8 with SCI and 8 healthy physical education students (control subjects). The 8-week program consisted of heavy-resistance exercise performed twice per week with 10 to 12 repetitions in 5 sets. Subjects' performances were tested in static and in dynamic conditions concerning several strength and power parameters. Furthermore, we tested 10-m sprinting performance in wheelchair athletes. Overall, wheelchair athletes and control subjects achieved similar results; in almost all parameters both groups improved considerably in post-testing. Regarding percentages in most strength and power parameters, wheelchair athletes showed a tendency to benefit more from the strength training performed in the present study. Using analyses of group differences, however, only the comparison of effects on rate of force development (p = 0.010) resulted in a significant higher improvement for wheelchair athletes. In contrast to previous assumptions about minor adaptation capacities to training exercises in patients with SCI, our study proved clear effects of strength training. In conclusion, we suggest that heavy resistance training should be of increasing importance in wheelchair sports.

  1. Free-space microwave power transmission study, phase 3

    NASA Technical Reports Server (NTRS)

    Brown, W. C.

    1975-01-01

    The results of an investigation of the technology of free-space power transmission by microwave beam are presented. A description of the steps that were taken to increase the overall dc to dc efficiency of microwave power transmission from 15 percent to over 50 percent is given. Included in this overall efficiency were the efficiencies of the dc to microwave conversion, the microwave transmission itself, and the microwave to dc conversion. Improvements in launching the microwave beam with high efficiency by means of a dual mode horn resulted in 95 percent of the output of the microwave generator reaching the receiving area. Emphasis was placed upon successive improvements in reception and rectification of the microwave power, resulting in the design of a rectenna device for this purpose whose efficiency was 75 percent. The procedures and the hardware developed were the basis for tests certified by the Jet Propulsion Laboratory in which an overall dc to dc efficiency of 54 percent was achieved.

  2. Effectiveness of the Power Dry-Land Training Programmes in Youth Swimmers

    PubMed Central

    Sadowski, Jerzy; Mastalerz, Andrzej; Gromisz, Wilhelm; NiŸnikowski, Tomasz

    2012-01-01

    The aim of the study was to evaluate the effects of the dry-land power training on swimming force, swimming performance and strength in youth swimmers. Twenty six male swimmers, free from injuries and training regularly at least 6 times a week, were enrolled in the study and randomly assigned to one of two groups: experimental (n=14, mean age 14.0 ± 0.5 yrs, mean height 1.67±0.08 m and mean body mass 55.71 ±9.55 kg) and control (n=12, mean age 14.1 ± 0.5 yrs, mean height 1.61±0.11 m and mean body mass 49.07 ±8.25 kg). The experimental group took part in a combined swimming and dry-land power training. The control group took part in swimming training only. The training programmes in water included a dominant aerobic work in front crawl. In this research the experimental group tended to present slightly greater improvements in sprint performance. However, the stroke frequency insignificantly decreased (−4.30%, p>0.05) in the experimental group and increased (6.28%, p>0.05) in the control group. The distance per stroke insignificantly increased in the experimental group (5.98%, p>0.05) and insignificantly decreased in the control group (−5.36%, p>0.05). A significant improvement of tethered swimming force for the experimental group (9.64%, p<0.02) was found, whereas the increase was not statistically significant in the control group (2.86%, p>0.05). The main data cannot clearly state that power training allowed an enhancement in swimming performance, although a tendency to improve swimming performance in tethered swimming was noticed. PMID:23486353

  3. Subpicosecond electron bunch train production using a phase-space exchange technique

    SciTech Connect

    Sun, Y.-E.; Piot, P.; Johnson, A.S.; Lumpkin, A.H.; Maxwell, T.J.; Ruan, J.; Thurman-Keup, R.M.; /Fermilab

    2011-03-01

    Our recent experimental demonstration of a photoinjector electron bunch train with sub-picosecond structures is reported in this paper. The experiment is accomplished by converting an initially horizontal beam intensity modulation into a longitudinal phase space modulation, via a beamline capable of exchanging phase-space coordinates between the horizontal and longitudinal degrees of freedom. The initial transverse modulation is produced by intercepting the beam with a multislit mask prior to the exchange. We also compare our experimental results with numerical simulations.

  4. Effects of speed, agility, quickness training method on power performance in elite soccer players.

    PubMed

    Jovanovic, Mario; Sporis, Goran; Omrcen, Darija; Fiorentini, Fredi

    2011-05-01

    The purpose of this study was to evaluate the effects of the speed, agility, quickness (SAQ) training method on power performance in soccer players. Soccer players were assigned randomly to 2 groups: experimental group (EG; n = 50) and control group (n = 50). Power performance was assessed by a test of quickness--the 5-m sprint, a test of acceleration--the 10-m sprint, tests of maximal speed--the 20- and the 30-m sprint along with Bosco jump tests--squat jump, countermovement jump (CMJ), maximal CMJ, and continuous jumps performed with legs extended. The initial testing procedure took place at the beginning of the in-season period. The 8-week specific SAQ training program was implemented after which final testing took place. The results of the 2-way analysis of variance indicated that the EG improved significantly (p < 0.05) in 5-m (1.43 vs. 1.39 seconds) and in 10-m (2.15 vs. 2.07 seconds) sprints, and they also improved their jumping performance in countermovement (44.04 vs. 4.48 cm) and continuous jumps (41.08 vs. 41.39 cm) performed with legs extended (p < 0.05). The SAQ training program appears to be an effective way of improving some segments of power performance in young soccer players during the in-season period. Soccer coaches could use this information in the process of planning in-season training. Without proper planning of the SAQ training, soccer players will most likely be confronted with decrease in power performance during in-season period.

  5. Low-load Slow Movement Squat Training Increases Muscle Size and Strength but Not Power.

    PubMed

    Usui, S; Maeo, S; Tayashiki, K; Nakatani, M; Kanehisa, H

    2016-04-01

    We tested a hypothesis that low-load squat training with slow movement and tonic force generation (LST) would increase muscle size and strength but not necessarily power. Healthy young men were assigned to LST [50% one-repetition maximum (1-RM) load, 3 s for lowering/lifting without pause: n=9] or low-load normal speed (LN: 50% 1-RM load, 1 s for lowering/lifting with 1-s pause; n=7) groups. Both groups underwent an 8-week squat training program (10 repetitions/set, 3 sets/day, and 3 days/week) using the assigned methods. Before and after the intervention, quadriceps femoris muscle thickness, maximal torque during isometric hip extension and knee extension, 1-RM squat, lifting power from squatting position and rate of electromyography rise (RER) in knee extensors during the task, leg extension power and vertical jump height were measured. After the intervention, the LN group showed no changes in all the variables. The LST group significantly (P<0.05) increased muscle thickness (6-10%), isometric hip extension torque (18%) and 1-RM squat (10%), but not isometric knee extension torque, lifting power and RER, leg extension power and vertical jump height. These results suggest that LST can increase muscle size and task-related strength, but has little effect on power production during dynamic explosive movements. © Georg Thieme Verlag KG Stuttgart · New York.

  6. Interaction of Beta-Hydroxy-Beta-Methylbutyrate Free Acid and Adenosine Triphosphate on Muscle Mass, Strength, and Power in Resistance Trained Individuals.

    PubMed

    Lowery, Ryan P; Joy, Jordan M; Rathmacher, John A; Baier, Shawn M; Fuller, John C; Shelley, Mack C; Jäger, Ralf; Purpura, Martin; Wilson, Stephanie M C; Wilson, Jacob M

    2016-07-01

    Lowery, RP, Joy, JM, Rathmacher, JA, Baier, SM, Fuller, JC Jr, Shelley, MC II, Jäger, R, Purpura, M, Wilson, SMC, and Wilson, JM. Interaction of beta-hydroxy-beta-methylbutyrate free acid and adenosine triphosphate on muscle mass, strength, and power in resistance trained individuals. J Strength Cond Res 30(7): 1843-1854, 2016-Adenosine-5'-triphosphate (ATP) supplementation helps maintain performance under high fatiguing contractions and with greater fatigue recovery demands also increase. Current evidence suggests that the free acid form of β-hydroxy-β-methylbutyrate (HMB-FA) acts by speeding regenerative capacity of skeletal muscle after high-intensity or prolonged exercise. Therefore, we investigated the effects of 12 weeks of HMB-FA (3 g) and ATP (400 mg) administration on lean body mass (LBM), strength, and power in trained individuals. A 3-phase double-blind, placebo-, and diet-controlled study was conducted. Phases consisted of an 8-week periodized resistance training program (phase 1), followed by a 2-week overreaching cycle (phase 2), and a 2-week taper (phase 3). Lean body mass was increased by a combination of HMB-FA/ATP by 12.7% (p < 0.001). In a similar fashion, strength gains after training were increased in HMB-FA/ATP-supplemented subjects by 23.5% (p < 0.001). Vertical jump and Wingate power were increased in the HMB-FA/ATP-supplemented group compared with the placebo-supplemented group, and the 12-week increases were 21.5 and 23.7%, respectively. During the overreaching cycle, strength and power declined in the placebo group (4.3-5.7%), whereas supplementation with HMB-FA/ATP resulted in continued strength gains (1.3%). In conclusion, HMB-FA and ATP in combination with resistance exercise training enhanced LBM, power, and strength. In addition, HMB-FA plus ATP blunted the typical response to overreaching, resulting in a further increase in strength during that period. It seems that the combination of HMB-FA/ATP could benefit those who

  7. The Effects of High-Intensity versus Low-Intensity Resistance Training on Leg Extensor Power and Recovery of Knee Function after ACL-Reconstruction

    PubMed Central

    Aue Sobol, Nanna; Andersen, Lars L.; Kiel, Peter; Løfholm, Peter; Magnusson, S. Peter; Krogsgaard, Michael R.

    2014-01-01

    Objective. Persistent weakness is a common problem after anterior cruciate ligament- (ACL-) reconstruction. This study investigated the effects of high-intensity (HRT) versus low-intensity (LRT) resistance training on leg extensor power and recovery of knee function after ACL-reconstruction. Methods. 31 males and 19 females were randomized to HRT (n = 24) or LRT (n = 26) from week 8–20 after ACL-reconstruction. Leg extensor power, joint laxity, and self-reported knee function were measured before and 7, 14, and 20 weeks after surgery. Hop tests were assessed before and after 20 weeks. Results. Power in the injured leg was 90% (95% CI 86–94%) of the noninjured leg, decreasing to 64% (95% CI 60–69%) 7 weeks after surgery. During the resistance training phase there was a significant group by time interaction for power (P = 0.020). Power was regained more with HRT compared to LRT at week 14 (84% versus 73% of noninjured leg, resp.; P = 0.027) and at week 20 (98% versus 83% of noninjured leg, resp.; P = 0.006) without adverse effects on joint laxity. No other between-group differences were found. Conclusion. High-intensity resistance training during rehabilitation after ACL-reconstruction can improve muscle power without adverse effects on joint laxity. PMID:24877078

  8. Auditory-evoked cortical activity: contribution of brain noise, phase locking, and spectral power.

    PubMed

    Harris, Kelly C; Vaden, Kenneth I; Dubno, Judy R

    2014-09-01

    The N1-P2 is an obligatory cortical response that can reflect the representation of spectral and temporal characteristics of an auditory stimulus. Traditionally,mean amplitudes and latencies of the prominent peaks in the averaged response are compared across experimental conditions. Analyses of the peaks in the averaged response only reflect a subset of the data contained within the electroencephalogram(EEG) signal. We used single-trial analyses techniques to identify the contribution of brain noise,neural synchrony, and spectral power to the generation of P2 amplitude and how these variables may change across age group. This information is important for appropriate interpretation of event-related potentials (ERPs) results and in understanding of age-related neural pathologies. EEG was measured from 25 younger and 25 older normal hearing adults. Age-related and individual differences in P2 response amplitudes, and variability in brain noise, phase locking value (PLV), and spectral power (4-8 Hz) were assessed from electrode FCz. Model testing and linear regression were used to determine the extent to which brain noise, PLV, and spectral power uniquely predicted P2 amplitudes and varied by age group. Younger adults had significantly larger P2 amplitudes, PLV, and power compared to older adults. Brain noise did not differ between age groups. The results of regression testing revealed that brain noise and PLV, but not spectral power were unique predictors of P2 amplitudes. Model fit was significantly better in younger than in older adults. ERP analyses are intended to provide a better understanding of the underlying neural mechanisms that contribute to individual and group differences in behavior. The current results support that age-related declines in neural synchrony contribute to smaller P2 amplitudes in older normal hearing adults. Based on our results, we discuss potential models in which differences in neural synchrony and brain noise can account for

  9. Resistance training status and effectiveness of low frequency resistance training on upper-body strength and power in highly trained soccer players.

    PubMed

    Hertzog, Maxime; Rumpf, Michael Clemens; Hader, Karim

    2017-08-26

    Soccer is classified as a contact/collision sport with many player-to-player duels. Winning these duels, shielding the ball or fending off an opponent requires upper-body strength and power. Therefore this study aimed, a) to examine the time-related effect of an upper-body RT on maximal strength and power changes in highly trained soccer players, b) to investigate if the resistance-training (RT) status influences these changes throughout a competitive season. Twenty-eight soccer players participated in this study and were divided into an untrained (UG) and a trained (TG) group, according to their RT status. Both groups performed the same upper-body RT once a week, over 30 weeks. Maximal strength (1RM) and maximal power (MP) were assessed before, during and after the competitive season. Both groups significantly improved 1RM and MP over the entire competitive season, with a moderate (TG, 13%) to very large (UG, 21%) magnitude in 1RM and with a small (TG, 8%) to moderate (UG, 13%) magnitude in MP. After the initial 10 weeks of RT, UG presented significant and slightly (1RM) to moderately (MP) greater improvements than TG. For all other time intervals, the between-groups changes in 1RM were rated as similar. For the last 20 weeks of the RT, the change in MP was significantly lower for UG compared to TG. One upper-body RT-session per week will provide sufficient stimulus to enable an almost certain improvement in strength and power throughout a competitive season for all players disregarding their initial RT status.

  10. Control Method for Achieving High Power Factor in Single-Phase to Three-Phase Converters without Electrolytic Capacitors

    NASA Astrophysics Data System (ADS)

    Yokoyama, Takahiro; Ohishi, Kiyoshi; Haga, Hitoshi; Shibata, Junji

    In this paper, we propose a method for the digital control of IPM motors in order to achieve a high power factor in single-phase to three-phase power converters without reactors or electrolytic capacitors. For achieving the unity power factor under any load condition and any speed condition, we propose a new digital control method that involves the use of a new feedback technique and a new feedforward technique on the source-current regulator side. The proposed digital control system is constructed by using DSP devices. In this paper, we also propose a new method for the compensation of one sampling delay time. The superior performance of the proposed method is demonstrated by experimental results. The experimental results were obtained using 1.5[kW] inverter system, which consists of a vector control system with a 14[μF] dc-link capacitor. The maximum power factor obtained in the experiments was 96.8[%].

  11. Power Efficient Hydraulic Systems. Volume 1. Study Phase

    DTIC Science & Technology

    1988-07-01

    AIRCRAFT SUBSYSTEMS TABLE 14. Baseline aircraft systems o HYDRAULIC SYSTEM o ELECTRICAL SYSTEM o 8000 PSI, 3 INDEPENDENT SYSTEMS o HVDC POWER o APU...valve (pump) HM hinge moment hp horsepower hr hour HVDC high voltage direct current Hz Hertz (cycles per second) IAP integrated actuator package I.D

  12. Effects of unilateral and bilateral plyometric training on power and jumping ability in women.

    PubMed

    Makaruk, Hubert; Winchester, Jason B; Sadowski, Jerzy; Czaplicki, Adam; Sacewicz, Tomasz

    2011-12-01

    Makaruk, H, Winchester, JB, Sadowski, J, Czaplicki, A, and Sacewicz, T. Effects of unilateral and bilateral plyometric training on power and jumping ability in women. J Strength Cond Res 25(12): 3311-3318, 2011-The purpose of this study was to examine the effects of unilateral and bilateral plyometric exercise on peak power and jumping performance during different stages of a 12-week training and detraining in women. Forty-nine untrained but physically active female college students were randomly assigned to 1 of 3 groups: unilateral plyometric group (n = 16), bilateral plyometric group (BLE; n = 18), and a control group (n = 15). Peak power and jumping ability were assessed by means of the alternate leg tests (10-second Wingate test and 5 alternate leg bounds), bilateral leg test (countermovement jump [CMJ]) and unilateral leg test (unilateral CMJ). Performance indicators were measured pretraining, midtraining, posttraining, and detraining. Differences between dependent variables were assessed with a 3 × 4 (group × time) repeated analysis of variance with Tukey's post hoc test applied where appropriate. Effect size was calculated to determine the magnitude of significant differences between the researched parameters. Only the unilateral plyometric training produced significant (p < 0.05) improvement in all tests from pretraining to midtraining, but there was no significant (p < 0.05) increase in performance indicators from midtraining to posttraining. The BLE group significantly (p < 0.05) improved in all tests from pretraining to posttraining and did not significantly (p > 0.05) decrease power and jumping ability in all tests during detraining. These results suggest that unilateral plyometric exercises produce power and jumping performance during a shorter period when compared to bilateral plyometric exercises but achieved performance gains last longer after bilateral plyometric training. Practitioners should consider the inclusion of both unilateral and

  13. Effect of abdominal bracing training on strength and power of trunk and lower limb muscles.

    PubMed

    Tayashiki, Kota; Maeo, Sumiaki; Usui, Seiji; Miyamoto, Naokazu; Kanehisa, Hiroaki

    2016-09-01

    It is unknown whether maximal voluntary co-contraction of abdominal muscles, called abdominal bracing, can be a training maneuver for improving strength and power of trunk and lower limb muscles. The present study aimed to elucidate this. Twenty young adult men (23.3 ± 1.8 years) were allocated to training (TG, n = 11) or control (CG, n = 9) group. TG conducted an 8-week training program (3 days/week) consisting of 2-s maximal abdominal bracing followed by 2-s muscle relaxation (5 × 10 repetitions/day). Maximal voluntary isometric strength during trunk flexion and extension, hip extension, and knee extension, maximal lifting power from sitting position, and the thicknesses of abdominal muscles were measured before and after the intervention. In addition, surface electromyograms from trunk and lower limb muscles and intra-abdominal pressure (IAP) during the maximal abdominal bracing and maximal lifting tasks were also determined. After the intervention, TG showed significant increases in isometric trunk extension (+14.4 %) and hip extension (+34.7 %) strength and maximal lifting power (+15.6 %), while CG did not show any changes in strength and power variables. Furthermore, TG had significant gains in the muscle thickness of the oblique internal (+22.4 %), maximal IAP during abdominal bracing (+36.8 %), and the rate of IAP rise during lifting task (+58.8 %), without corresponding changes in CG. The current study indicates that a training style with maximal voluntary co-contraction of abdominal muscles can be an effective maneuver for increasing strength and power during movements involving trunk and hip extensions, without using external load.

  14. Multicomponent exercises including muscle power training enhance muscle mass, power output, and functional outcomes in institutionalized frail nonagenarians.

    PubMed

    Cadore, Eduardo L; Casas-Herrero, Alvaro; Zambom-Ferraresi, Fabricio; Idoate, Fernando; Millor, Nora; Gómez, Marisol; Rodriguez-Mañas, Leocadio; Izquierdo, Mikel

    2014-04-01

    This randomized controlled trial examined the effects of multicomponent training on muscle power output, muscle mass, and muscle tissue attenuation; the risk of falls; and functional outcomes in frail nonagenarians. Twenty-four elderly (91.9 ± 4.1 years old) were randomized into intervention or control group. The intervention group performed a twice-weekly, 12-week multicomponent exercise program composed of muscle power training (8-10 repetitions, 40-60 % of the one-repetition maximum) combined with balance and gait retraining. Strength and power tests were performed on the upper and lower limbs. Gait velocity was assessed using the 5-m habitual gait and the time-up-and-go (TUG) tests with and without dual-task performance. Balance was assessed using the FICSIT-4 tests. The ability to rise from a chair test was assessed, and data on the incidence and risk of falls were assessed using questionnaires. Functional status was assessed before measurements with the Barthel Index. Midthigh lower extremity muscle mass and muscle fat infiltration were assessed using computed tomography. The intervention group showed significantly improved TUG with single and dual tasks, rise from a chair and balance performance (P < 0.01), and a reduced incidence of falls. In addition, the intervention group showed enhanced muscle power and strength (P < 0.01). Moreover, there were significant increases in the total and high-density muscle cross-sectional area in the intervention group. The control group significantly reduced strength and functional outcomes. Routine multicomponent exercise intervention should be prescribed to nonagenarians because overall physical outcomes are improved in this population.

  15. Evaluation of training programs and entry-level qualifications for nuclear-power-plant control-room personnel based on the systems approach to training

    SciTech Connect

    Haas, P M; Selby, D L; Hanley, M J; Mercer, R T

    1983-09-01

    This report summarizes results of research sponsored by the US Nuclear Regulatory Commission (NRC) Office of Nuclear Regulatory Research to initiate the use of the Systems Approach to Training in the evaluation of training programs and entry level qualifications for nuclear power plant (NPP) personnel. Variables (performance shaping factors) of potential importance to personnel selection and training are identified, and research to more rigorously define an operationally useful taxonomy of those variables is recommended. A high-level model of the Systems Approach to Training for use in the nuclear industry, which could serve as a model for NRC evaluation of industry programs, is presented. The model is consistent with current publically stated NRC policy, with the approach being followed by the Institute for Nuclear Power Operations, and with current training technology. Checklists to be used by NRC evaluators to assess training programs for NPP control-room personnel are proposed which are based on this model.

  16. Power System Control Study. Phase I. Integrated Control Techniques. Phase II. Detail Design and System Modeling.

    DTIC Science & Technology

    1981-03-01

    reliable and fault tolerant system. The advanced control technologies integrated include:electric engine start, automatic load manage- ment...Generation System Study .............................. 104 5.2 Reliability Assessment of Power System .................... 119 5.3 EMUX Processor...132 30 Best Main Power System Configuration Based on Reliability Assessment ..................................... 133 31 Main and Emergency Power

  17. Influence of the cubic spectral phase of high-power laser pulses on their self-phase modulation

    SciTech Connect

    Ginzburg, V N; Kochetkov, A A; Yakovlev, I V; Mironov, S Yu; Shaykin, A A; Khazanov, E A

    2016-02-28

    Spectral broadening of high-power transform-limited laser pulses under self-phase modulation in a medium with cubic nonlinearity is widely used to reduce pulse duration and to increase its power. It is shown that the cubic spectral phase of the initial pulse leads to a qualitatively different broadening of its spectrum: the spectrum has narrow peaks and broadening decreases. However, the use of chirped mirrors allows such pulses to be as effectively compressed as transform-limited pulses. (nonlinear optical phenomena)

  18. Closed Brayton Cycle Power Conversion Unit for Fission Surface Power Phase I Final Report

    NASA Technical Reports Server (NTRS)

    Fuller, Robert L.

    2010-01-01

    A Closed Brayton cycle power conversion system has been developed to support the NASA fission surface power program. The goal is to provide electricity from a small nuclear reactor heat source for surface power production for lunar and Mars environments. The selected media for a heat source is NaK 78 with water as a cooling source. The closed Brayton cycle power was selected to be 12 kWe output from the generator terminals. A heat source NaK temperature of 850 K plus or minus 25 K was selected. The cold source water was selected at 375 K plus or minus 25 K. A vacuum radiation environment of 200 K is specified for environmental operation. The major components of the system are the power converter, the power controller, and the top level data acquisition and control unit. The power converter with associated sensors resides in the vacuum radiation environment. The power controller and data acquisition system reside in an ambient laboratory environment. Signals and power are supplied across the pressure boundary electrically with hermetic connectors installed on the vacuum vessel. System level analyses were performed on working fluids, cycle design parameters, heater and cooling temperatures, and heat exchanger options that best meet the needs of the power converter specification. The goal is to provide a cost effective system that has high thermal-to-electric efficiency in a compact, lightweight package.

  19. Differential-phase-shift quantum key distribution with segmented pulse trains

    SciTech Connect

    Kawahara, Hiroki; Inoue, Kyo

    2011-06-15

    We present a modified scheme of differential-phase-shift (DPS) quantum key distribution (QKD) for improving its performance. A transmitter sends a weak coherent pulse train segmented with vacant pulses. Then, a receiver can find eavesdropping by monitoring the photon detection rate at particular time slots. Simulations show that the proposed scheme is robust against a sequential attack and a general individual attack.

  20. Effects of PECS Phase III Application Training on Independent Mands in Young Children with Autism

    ERIC Educational Resources Information Center

    Love, Jessica June

    2013-01-01

    The purpose of this study was to examine the effects of PECS phase III application training on independent mands in young children with autism. Participants were five children with autism ranging from ages 2 to 4 years old. A multiple baseline across participants was used to evaluate acquisition of independent correct mands across baseline and…

  1. The Orthopaedic Training Study, Phase II 1968-1972. Final Report, Volume I.

    ERIC Educational Resources Information Center

    Olson, Carl J.; And Others

    Phase two of the Orthopaedic Training Study was designed to examine time, sequence, and content requirements of existing orthopaedic programs. Specifically, the proposal was designed to achieve the following objectives: (1) to provide a model of individualized graduate education in medicine in which the demonstration of individual competence marks…

  2. Ubiquinol supplementation enhances peak power production in trained athletes: a double-blind, placebo controlled study

    PubMed Central

    2013-01-01

    Background To investigate the effect of Ubiquinol supplementation on physical performance measured as maximum power output in young and healthy elite trained athletes. Methods In this double-blind, placebo-controlled study, 100 young German well trained athletes (53 male, 47 female, age 19.9 ± 2.3 years) received either 300 mg Ubiquinol or placebo for 6 weeks. Athletes had to perform a maximum power output test and the performance in W/kg of bodyweight was measured at the 4 mmol lactate threshold on a cycling ergometer before the supplementation treatment (T1), after 3 weeks (T2) and after 6 weeks (T3) of treatment. In these 6 weeks all athletes trained individually in preparation for the Olympic Games in London 2012. The maximum power output was measured in Watt/kilogram body weight (W/kg bw). Results Both groups, placebo and Ubiquinol, significantly increased their physical performance measured as maximum power output over the treatment period from T1 to T3. The placebo group increased from 3.64 ± 0.49 W/kg bw to 3.94 ± 0.47 W/kg bw which is an increase of +0.30 ± 0.18 W/kg bw or +8.5% (±5.7). The Ubiquinol group increased performance levels from 3.70 W/kg bw (±0.56) to 4.08 W/kg bw (±0.48) from time point T1 to T3 which is an increase of +0.38 ± 0.22 W/kg bw or +11.0% (±8.2). The absolute difference in the enhancement of the physical performance between the placebo and the Ubiquinol group of +0.08 W/kg bodyweight was significant (p < 0.03). Conclusions This study demonstrates that daily supplementation of 300 mg Ubiquinol for 6 weeks significantly enhanced physical performance measured as maximum power output by +0.08 W/kg bw (+2.5%) versus placebo in young healthy trained German Olympic athletes. While adherence to a training regimen itself resulted in an improvement in peak power output, as observed by improvement in placebo, the effect of Ubiquinol supplementation significantly enhanced peak power production

  3. GPS-Like Phasing Control of the Space Solar Power System Transmission Array

    NASA Technical Reports Server (NTRS)

    Psiaki, Mark L.

    2003-01-01

    The problem of phasing of the Space Solar Power System's transmission array has been addressed by developing a GPS-like radio navigation system. The goal of this system is to provide power transmission phasing control for each node of the array that causes the power signals to add constructively at the ground reception station. The phasing control system operates in a distributed manner, which makes it practical to implement. A leader node and two radio navigation beacons are used to control the power transmission phasing of multiple follower nodes. The necessary one-way communications to the follower nodes are implemented using the RF beacon signals. The phasing control system uses differential carrier phase relative navigation/timing techniques. A special feature of the system is an integer ambiguity resolution procedure that periodically resolves carrier phase cycle count ambiguities via encoding of pseudo-random number codes on the power transmission signals. The system is capable of achieving phasing accuracies on the order of 3 mm down to 0.4 mm depending on whether the radio navigation beacons operate in the L or C bands.

  4. Dynamic Power Flow Controller: Compact Dynamic Phase Angle Regulators for Transmission Power Routing

    SciTech Connect

    2012-01-03

    GENI Project: Varentec is developing compact, low-cost transmission power controllers with fractional power rating for controlling power flow on transmission networks. The technology will enhance grid operations through improved use of current assets and by dramatically reducing the number of transmission lines that have to be built to meet increasing contributions of renewable energy sources like wind and solar. The proposed transmission controllers would allow for the dynamic control of voltage and power flow, improving the grid’s ability to dispatch power in real time to the places where it is most needed. The controllers would work as fail-safe devices whereby the grid would be restored to its present operating state in the event of a controller malfunction instead of failing outright. The ability to affordably and dynamically control power flow with adequate fail-safe switchgear could open up new competitive energy markets which are not possible under the current regulatory structure and technology base.

  5. Single-Phase Active Boost Rectifier with Power Factor Correction for Wireless Power Transfer Applications

    SciTech Connect

    Chinthavali, Madhu Sudhan; Onar, Omer C; Miller, John M; Tang, Lixin

    2013-01-01

    Wireless Power Transfer (WPT) technology is a novel research area in the charging technology that bridges utility and the automotive industries. There are various solutions that are currently being evaluated by several research teams to find the most efficient way to manage the power flow from the grid to the vehicle energy storage system. There are different control parameters that can be utilized to compensate for the change in the impedance. To understand the power flow through the system this paper presents a novel approach to the system model and the impact of different control parameters on the load power. The implementation of an active front-end rectifier on the grid side for power factor control and voltage boost capability for load power regulation is also discussed.

  6. A 12 GHz solid state power amplifier, phase 1B

    NASA Astrophysics Data System (ADS)

    Bestwick, P. R.

    1986-05-01

    Attempts to develop a balanced amplifier developing 4 W power output at 12.6 GHz, with a gain of 3.5 dB are summarized. Calculation of the device large-signal conjugate match points, measurement of the points, design and tuning of single-ended amplifier, modules, and a bias insertion network are described. A Lange coupler and a termination for it are presented. The performance of the balanced amplifier, and that of a competing Fujitsu amplifier, are analyzed. The differences in device structure between the PRCL 4820 device and the Fujitsu device are assessed. The amplifier developed gives (at 1 dB gain compression) a gain of 2.4 dB and a power output of 3.2 dB. Difficulties stem from the use of the double-cell 4820 device, and of the Lange type quadrature couplers.

  7. A Master-Oscillator-Power-Amplifier 2-micron Laser Using Fiber Phase-conjugate Mirror

    NASA Technical Reports Server (NTRS)

    Yu, Jirong; Bai, Yingxin; Shkunov, V.; Rockwell, D.; Betin, A.; Wang, J.; Petros, M.; Petzar, Paul; Trieu, Bo

    2007-01-01

    For the first time, a 2-micron master-oscillator-power-amplifier laser using a fiber based phase conjugation mirror has been demonstrated. The beam quality improvement and 56% of the PCM reflectivity have been achieved.

  8. Optical phase dynamics in mutually coupled diode laser systems exhibiting power synchronization

    NASA Astrophysics Data System (ADS)

    Pal, Vishwa; Prasad, Awadhesh; Ghosh, R.

    2011-12-01

    We probe the physical mechanism behind the known phenomenon of power synchronization of two diode lasers that are mutually coupled via their delayed optical fields. In a diode laser, the amplitude and the phase of the optical field are coupled by the so-called linewidth enhancement factor, α. In this work, we explore the role of optical phases of the electric fields in amplitude (and hence power) synchronization through α in such mutually delay-coupled diode laser systems. Our numerical results show that the synchronization of optical phases drives the powers of lasers to synchronized death regimes. We also find that as α varies for different diode lasers, the system goes through a sequence of in-phase amplitude-death states. Within the windows between successive amplitude-death regions, the cross-correlation between the field amplitudes exhibits a universal power-law behaviour with respect to α.

  9. The effect of loss of visual input on muscle power in resistance trained and untrained young men and women.

    PubMed

    Killebrew, Shanna S; Petrella, John K; Jung, Alan P; Hensarling, Robert W

    2013-02-01

    Visual impairment has been shown to reduce muscle power when compared with that in sighted individuals. The purpose of this study was to assess whether the loss of visual input affects lower limb muscle power production in sighted men and women who are resistance trained and untrained. Twenty-seven college-aged participants (19-23 years) performed a seated double-leg press with and without visual input (resulting from being blindfold) in 2 separate counterbalanced trials. Lower limb concentric power was calculated by measuring the distance and time a leg press footplate was displaced while lifting 60% of 1-repetition maximum as quickly as possible. Loss of visual input reduced power output by 22.8 W (-6.4%) in all participants (p < 0.01). When resistance training status was taken into account, resistance trained participants (n = 12, trained >2× per week) did not lose power output (4.4 W, -1.1%, p = 0.90), whereas untrained men and women (n = 15) had significantly less power when visual input was removed via blindfold (37.6 W, -11.7%, p < 0.01). Untrained women experienced the greatest decrease in power when blindfolded (39 W, -15.9%, p < 0.01). Muscle power decreases in the absence of vision, but a regular strength training program attenuates this occurrence in young men and women. In practical application, strength training interventions may be successful in protecting individuals from losses in muscle power when visual input is removed.

  10. Formation of visual memories controlled by gamma power phase-locked to alpha oscillations

    PubMed Central

    Park, Hyojin; Lee, Dong Soo; Kang, Eunjoo; Kang, Hyejin; Hahm, Jarang; Kim, June Sic; Chung, Chun Kee; Jiang, Haiteng; Gross, Joachim; Jensen, Ole

    2016-01-01

    Neuronal oscillations provide a window for understanding the brain dynamics that organize the flow of information from sensory to memory areas. While it has been suggested that gamma power reflects feedforward processing and alpha oscillations feedback control, it remains unknown how these oscillations dynamically interact. Magnetoencephalography (MEG) data was acquired from healthy subjects who were cued to either remember or not remember presented pictures. Our analysis revealed that in anticipation of a picture to be remembered, alpha power decreased while the cross-frequency coupling between gamma power and alpha phase increased. A measure of directionality between alpha phase and gamma power predicted individual ability to encode memory: stronger control of alpha phase over gamma power was associated with better memory. These findings demonstrate that encoding of visual information is reflected by a state determined by the interaction between alpha and gamma activity. PMID:27306959

  11. Formation of visual memories controlled by gamma power phase-locked to alpha oscillations.

    PubMed

    Park, Hyojin; Lee, Dong Soo; Kang, Eunjoo; Kang, Hyejin; Hahm, Jarang; Kim, June Sic; Chung, Chun Kee; Jiang, Haiteng; Gross, Joachim; Jensen, Ole

    2016-06-16

    Neuronal oscillations provide a window for understanding the brain dynamics that organize the flow of information from sensory to memory areas. While it has been suggested that gamma power reflects feedforward processing and alpha oscillations feedback control, it remains unknown how these oscillations dynamically interact. Magnetoencephalography (MEG) data was acquired from healthy subjects who were cued to either remember or not remember presented pictures. Our analysis revealed that in anticipation of a picture to be remembered, alpha power decreased while the cross-frequency coupling between gamma power and alpha phase increased. A measure of directionality between alpha phase and gamma power predicted individual ability to encode memory: stronger control of alpha phase over gamma power was associated with better memory. These findings demonstrate that encoding of visual information is reflected by a state determined by the interaction between alpha and gamma activity.

  12. Formation of visual memories controlled by gamma power phase-locked to alpha oscillations

    NASA Astrophysics Data System (ADS)

    Park, Hyojin; Lee, Dong Soo; Kang, Eunjoo; Kang, Hyejin; Hahm, Jarang; Kim, June Sic; Chung, Chun Kee; Jiang, Haiteng; Gross, Joachim; Jensen, Ole

    2016-06-01

    Neuronal oscillations provide a window for understanding the brain dynamics that organize the flow of information from sensory to memory areas. While it has been suggested that gamma power reflects feedforward processing and alpha oscillations feedback control, it remains unknown how these oscillations dynamically interact. Magnetoencephalography (MEG) data was acquired from healthy subjects who were cued to either remember or not remember presented pictures. Our analysis revealed that in anticipation of a picture to be remembered, alpha power decreased while the cross-frequency coupling between gamma power and alpha phase increased. A measure of directionality between alpha phase and gamma power predicted individual ability to encode memory: stronger control of alpha phase over gamma power was associated with better memory. These findings demonstrate that encoding of visual information is reflected by a state determined by the interaction between alpha and gamma activity.

  13. Biomass power for rural development: Phase 2. Technical progress report, April 1--June 30, 1998

    SciTech Connect

    Neuhauser, E.

    1998-11-01

    The project undertaken by the Salix Consortium is a multi-phased, multi-partner endeavor. Phase-1 focused on initial development and testing of the technology and agreements necessary to demonstrate commercial willow production in Phase-2. The Phase-1 objectives have been successfully completed: preparing final design plans for two utility pulverized coal boilers, developing fuel supply plans for the project, obtaining power production commitments from the power companies for Phase-2, obtaining construction and environmental permits, and developing an experimental strategy for crop production and power generation improvements needed to assure commercial success. The R and D effort also addresses environmental issues pertaining to introduction of the willow energy system. Beyond those Phase-1 requirements the Consortium has already successfully demonstrated cofiring at Greenidge Station and developed the required nursery capacity for acreage scale-up. This past summer 105 acres were prepared in advance for the spring planting in 1998. Having completed the above tasks, the Consortium is well positioned to begin Phase-2. In phase-2 every aspect of willow production and power generation from willow will be demonstrated. The ultimate objective of Phase-2 is to transition the work performed under the Rural Energy for the Future project into a thriving, self-supported energy crop enterprise.

  14. Reproducibility of limb power outputs and cardiopulmonary responses to exercise using a novel swimming training machine.

    PubMed

    Swaine, I L; Hunter, A M; Carlton, K J; Wiles, J D; Coleman, D

    2010-12-01

    The purpose of this study was to determine the reproducibility of limb power outputs and cardiopulmonary responses, to incremental whole-body exercise using a novel swimming training machine. 8 swimmers with a mean age of 23.7 ± 4.6 (yrs), stature 1.77 ± 0.13 (m) and body mass of 74.7 ± 2.8 (kg) gave informed consent and participated in repeat exercise testing on the machine. All subjects performed 2 incremental exercise tests to exhaustion using front crawl movements. From these tests peak oxygen consumption (VO(₂peak)), peak heart rate (HR(peak)), peak power output (W (peak)) and individual limb power outputs were determined. Results showed there were no significant differences between test 1 and 2 for any variable at exhaustion, and the CV% ranged from 2.8 to 3.4%. The pooled mean values were; VO(₂peak) 3.7 ± 0.65 L.min⁻¹, HR (peak) 178.7 ± 6.6 b.min⁻¹ and W (peak) 349.7 ± 16.5 W. The mean contributions to the total power output from the legs and arms were (37.3 ± 4.1% and 62.7 ± 5.1% respectively). These results show that it is possible to measure individual limb power outputs and cardiopulmonary parameters reproducibly during whole-body exercise using this training machine, at a range of exercise intensities.

  15. Power Source Status Estimation and Drive Control Method for Autonomous Decentralized Hybrid Train

    NASA Astrophysics Data System (ADS)

    Furuya, Takemasa; Ogawa, Kenichi; Yamamoto, Takamitsu; Hasegawa, Hitoshi

    A hybrid control system has two main functions: power sharing and equipment protection. In this paper, we discuss the design, construction and testing of a drive control method for an autonomous decentralized hybrid train with 100-kW-class fuel cells (FC) and 36-kWh lithium-ion batteries (Li-Batt). The main objectives of this study are to identify the operation status of the power sources on the basis of the input voltage of the traction inverter and to estimate the maximum traction power control basis of the power-source status. The proposed control method is useful in preventing overload operation of the onboard power sources in an autonomous decentralized hybrid system that has a flexible main circuit configuration and a few control signal lines. Further, with this method, the initial cost of a hybrid system can be reduced and the retrofit design of the hybrid system can be simplified. The effectiveness of the proposed method is experimentally confirmed by using a real-scale hybrid train system.

  16. Rule Extracting based on MCG with its Application in Helicopter Power Train Fault Diagnosis

    NASA Astrophysics Data System (ADS)

    Wang, M.; Hu, N. Q.; Qin, G. J.

    2011-07-01

    In order to extract decision rules for fault diagnosis from incomplete historical test records for knowledge-based damage assessment of helicopter power train structure. A method that can directly extract the optimal generalized decision rules from incomplete information based on GrC was proposed. Based on semantic analysis of unknown attribute value, the granule was extended to handle incomplete information. Maximum characteristic granule (MCG) was defined based on characteristic relation, and MCG was used to construct the resolution function matrix. The optimal general decision rule was introduced, with the basic equivalent forms of propositional logic, the rules were extracted and reduction from incomplete information table. Combined with a fault diagnosis example of power train, the application approach of the method was present, and the validity of this method in knowledge acquisition was proved.

  17. The Effects of Cold Water Immersion after Rugby Training on Muscle Power and Biochemical Markers

    PubMed Central

    Takeda, Masaki; Sato, Takashi; Hasegawa, Tatsushi; Shintaku, Hiroto; Kato, Hisashi; Yamaguchi, Yoshihiko; Radak, Zsolt

    2014-01-01

    During rugby game, or intensive rugby training there are many high intensity explosive exercises and eccentric muscle contractions, therefore adequate recovery is very important to rugby players. In the present study we have tested the effects of cold water immersion (CWI) after game-simulated (80 min.) rugby training on muscle power recovery and blood markers of muscle damage. Twenty well-trained collegiate male rugby players (age: 20.3 ± 0.6 years old, body height: 1.74 ± 0.05 m, body weight: 85.4 ± 2.0 kg, body fat: 18.2 ± 1.4 %) volunteered for this study. This study was conducted as a cross-over design; i.e., the subjects were randomly assigned either to CWI (n = 10) or passive rest condition (n = 10) for the 1st trial and 1 week later the subjects were switched conditions for the 2nd trial. After the simulated rugby training, including tackles and body contacts, muscle functional ability and blood markers of muscle damage were tested immediately, after CWI or passive rest, and again 24 hours later. Statistical analysis of all muscle functional tests (10 m dash, counter movement jump, reaction time, side steps) except for 10 seconds maximal pedaling power and blood makers of muscle damage (aspartate aminotransferase, lactate dehydrogenase, creatine kinase, and creatinine) revealed significant main effects for time (p < 0.05). However, no statistically significant interactions were found in any of the muscle functional tests and blood markers between groups and time courses. Our results suggest that a rugby game induces muscle damage and reduces muscle function. However, CWI has no significant restorative effect after an 80-minute rugby game in terms of muscle damage. Key Points Cold water immersion study for the recovery of rugby players Muscle strength and muscle power were mainly evaluated as well as muscle enzymes of muscle break down Subjects were highly trained rugby players with control group PMID:25177190

  18. Effect of Plyometric Training on Handspring Vault Performance and Functional Power in Youth Female Gymnasts

    PubMed Central

    Hall, Emma; Bishop, Daniel C.; Gee, Thomas I.

    2016-01-01

    This study aimed to determine the effect of plyometric training (PT) when added to habitual gymnastic training (HT) on handspring vault (HV) performance variables. Twenty youth female competitive gymnasts (Age: 12.5 ± 1.67 y) volunteered to participate and were randomly assigned to two independent groups. The experimental plyometric training group (PTG) undertook a six-week plyometric program, involving two additional 45 min PT sessions a week, alongside their HT, while the control group (CG) performed regular HT only. Videography was used (120 Hz) in the sagittal plane to record both groups performing three HVs for both the baseline and post-intervention trials. Furthermore, participants completed a countermovement jump test (CMJ) to assess the effect of PT on functional power. Through the use of Quintic biomechanics software, significant improvements (P < 0.05) were found for the PTG for run-up velocity, take-off velocity, hurdle to board distance, board contact time, table contact time and post-flight time and CMJ height. However, there were no significant improvements on pre-flight time, shoulder angle or hip angle on the vault for the PTG. The CG demonstrated no improvement for all HV measures. A sport-specific PT intervention improved handspring vault performance measures and functional power when added to the habitual training of youth female gymnasts. The additional two hours plyometric training seemingly improved the power generating capacity of movement-specific musculature, which consequently improved aspects of vaulting performance. Future research is required to examine the whether the improvements are as a consequence of the additional volume of sprinting and jumping activities, as a result of the specific PT method or a combination of these factors. PMID:26859381

  19. Reducing Electromagnetic Interference in a Grid Tied Single Phase Power Inverter

    DTIC Science & Technology

    2016-09-01

    ELECTROMAGNETIC INTERFERENCE IN A GRID TIED SINGLE PHASE POWER INVERTER by Jason Hassan Valiani September 2016 Thesis Advisor: Giovanna Oriti...3. REPORT TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE REDUCING ELECTROMAGNETIC INTERFERENCE IN A GRID TIED SINGLE PHASE POWER...explored. The primary goal is to understand the effects each modulation strategy has on the conducted electromagnetic interference (EMI) and then

  20. Phase diagram of softly repulsive systems: the Gaussian and inverse-power-law potentials.

    PubMed

    Prestipino, Santi; Saija, Franz; Giaquinta, Paolo V

    2005-10-08

    We redraw, using state-of-the-art methods for free-energy calculations, the phase diagrams of two reference models for the liquid state: the Gaussian and inverse-power-law repulsive potentials. Notwithstanding the different behaviors of the two potentials for vanishing interparticle distances, their thermodynamic properties are similar in a range of densities and temperatures, being ruled by the competition between the body-centered-cubic (bcc) and face-centered-cubic (fcc) crystalline structures and the fluid phase. We confirm the existence of a reentrant bcc phase in the phase diagram of the Gaussian-core model, just above the triple point. We also trace the bcc-fcc coexistence line of the inverse-power-law model as a function of the power exponent n and relate the common features in the phase diagrams of such systems to the softness degree of the interaction.

  1. Interval Running Training Improves Cognitive Flexibility and Aerobic Power of Young Healthy Adults.

    PubMed

    Venckunas, Tomas; Snieckus, Audrius; Trinkunas, Eugenijus; Baranauskiene, Neringa; Solianik, Rima; Juodsnukis, Antanas; Streckis, Vytautas; Kamandulis, Sigitas

    2016-08-01

    Venckunas, T, Snieckus, A, Trinkunas, E, Baranauskiene, N, Solianik, R, Juodsnukis, A, Streckis, V, and Kamandulis, S. Interval running training improves cognitive flexibility and aerobic power of young healthy adults. J Strength Cond Res 30(8): 2114-2121, 2016-The benefits of regular physical exercise may well extend beyond the reduction of chronic diseases risk and augmentation of working capacity, to many other aspects of human well-being, including improved cognitive functioning. Although the effects of moderate intensity continuous training on cognitive performance are relatively well studied, the benefits of interval training have not been investigated in this respect so far. The aim of the current study was to assess whether 7 weeks of interval running training is effective at improving both aerobic fitness and cognitive performance. For this purpose, 8 young dinghy sailors (6 boys and 2 girls) completed the interval running program with 200 m and 2,000 m running performance, cycling maximal oxygen uptake, and cognitive function was measured before and after the intervention. The control group consisted of healthy age-matched subjects (8 boys and 2 girls) who continued their active lifestyle and were tested in the same way as the experimental group, but did not complete any regular training. In the experimental group, 200 m and 2,000 m running performance and cycling maximal oxygen uptake increased together with improved results on cognitive flexibility tasks. No changes in the results of short-term and working memory tasks were observed in the experimental group, and no changes in any of the measured indices were evident in the controls. In conclusion, 7 weeks of interval running training improved running performance and cycling aerobic power, and were sufficient to improve the ability to adjust behavior to changing demands in young active individuals.

  2. The Effects of Eccentric, Velocity-Based Training on Strength and Power in Collegiate Athletes.

    PubMed

    Dolezal, Samantha M; Frese, Derek L; Llewellyn, Tamra L

    2016-01-01

    The purpose of this study was to determine if combining velocity-based training with eccentric focus (VEB) and velocity-based training (VBT) results in power and strength gains. Nineteen men and women collegiate track and field athletes participated in this study. The subjects completed a 12-week intervention with either a VEB program or a VBT program. To determine the effectiveness of each program, the subjects completed four exercise tests before and after the training period: vertical jump, medicine ball put test, 1RM projected bench press and 1RM projected squat. There were no significant differences between the VBT results and the VEB results. However, there were significant improvements between the pre-test and post-test measures for each group. There were increases in 1RM projected squat for VEB men, VBT men, and VBT women. There were also significant improvements in the VEB male vertical jump and medicine ball put test pre- to post-intervention. For track and field athletes, both programs may result in strength and power gains, however, the results cannot be used to conclude that one resistance training program is superior.

  3. The Effects of Eccentric, Velocity-Based Training on Strength and Power in Collegiate Athletes

    PubMed Central

    DOLEZAL, SAMANTHA M.; FRESE, DEREK L.; LLEWELLYN, TAMRA L.

    2016-01-01

    The purpose of this study was to determine if combining velocity-based training with eccentric focus (VEB) and velocity-based training (VBT) results in power and strength gains. Nineteen men and women collegiate track and field athletes participated in this study. The subjects completed a 12-week intervention with either a VEB program or a VBT program. To determine the effectiveness of each program, the subjects completed four exercise tests before and after the training period: vertical jump, medicine ball put test, 1RM projected bench press and 1RM projected squat. There were no significant differences between the VBT results and the VEB results. However, there were significant improvements between the pre-test and post-test measures for each group. There were increases in 1RM projected squat for VEB men, VBT men, and VBT women. There were also significant improvements in the VEB male vertical jump and medicine ball put test pre- to post-intervention. For track and field athletes, both programs may result in strength and power gains, however, the results cannot be used to conclude that one resistance training program is superior. PMID:27990226

  4. Experimental study of a fuel cell power train for road transport application

    NASA Astrophysics Data System (ADS)

    Corbo, P.; Corcione, F. E.; Migliardini, F.; Veneri, O.

    The development of fuel cell electric vehicles requires the on-board integration of fuel cell systems and electric energy storage devices, with an appropriate energy management system. The optimization of performance and efficiency needs an experimental analysis of the power train, which has to be effected in both stationary and transient conditions (including standard driving cycles). In this paper experimental results concerning the performance of a fuel cell power train are reported and discussed. In particular characterization results for a small sized fuel cell system (FCS), based on a 2.5 kW PEM stack, alone and coupled to an electric propulsion chain of 3.7 kW are presented and discussed. The control unit of the FCS allowed the main stack operative parameters (stoichiometric ratio, hydrogen and air pressure, temperature) to be varied and regulated in order to obtain optimized polarization and efficiency curves. Experimental runs effected on the power train during standard driving cycles have allowed the performance and efficiency of the individual components (fuel cell stack and auxiliaries, dc-dc converter, traction batteries, electric engine) to be evaluated, evidencing the role of output current and voltage of the dc-dc converter in directing the energy flows within the propulsion system.

  5. Changes in bar path kinematics and kinetics through use of summary feedback in power snatch training.

    PubMed

    Winchester, Jason B; Porter, Jared M; McBride, Jeffrey M

    2009-03-01

    This study investigated kinematic and kinetic variable changes in the power snatch (PS) after 4 weeks of training and the use of summary feedback. Twenty-four collegiate football players participated as subjects in this study. The subjects were pretested for their 1-repetition maximum (1RM) and were separated into feedback (FG; n = 12) and control (CG; n = 12) groups. The FG was provided with augmented feedback (AF) during power snatch training sessions, which took place 3 times per week for 4 weeks. The AF is defined as information that is received in addition to what is naturally available. Variables measured include peak force (PF), peak power (PP), and several kinematic variables at 50, 70, and 90% of the subjects' pre-1RM. The PF was improved at 50% 1RM from 567 +/- 202 to 769 +/- 230 N, at 70% from 725 +/- 186 to 890 +/- 199 N, and at 90% from 822 +/- 197 to 1008 +/- 201 N in the FG (p training and AF. Practitioners wishing to improve weightlifting performance should attempt to use evidence-based AF.

  6. Biomass power for rural development. Technical progress report, Phase 2, July 1--September 30, 1998

    SciTech Connect

    Neuhauser, E.

    1999-01-01

    The project undertaken by the Salix Consortium is a multi-phased, multi-partner endeavor. Phase 1 focused on initial development and testing of the technology and forging the necessary agreements to demonstrate commercial willow production. The Phase 1 objectives have been successfully completed: preparing final design plans for two utility pulverized coal boiler for 20 MW of biopower capacity; developing fuel supply plans for the project with a goal of establishing 365 ha (900 ac) of willow; obtaining power production commitments from the power companies for Phase 2; obtaining construction and environmental permits; and developing an experimental strategy for crop production and power generation improvements needed to assure commercial success. The R and D effort also addresses environmental issues pertaining to introduction of the willow energy system. Beyond those Phase 1 requirements, the Consortium has already successfully demonstrated cofiring at Greenidge Station and has initiated development of the required nursery capacity for acreage scale-up. In Phase 2 every aspect of willow production and power generation from willow biomass will be demonstrated. The ultimate objective of Phase 2 is to transition the work performed under the Biomass Power for Rural Development project into a thriving, self-supported energy crop enterprise.

  7. SPSP Phase III Recruiting, Selecting, and Developing Secure Power Systems Professionals. Job Profiles

    SciTech Connect

    O'Neil, Lori Ross; Conway, T. J.; Tobey, D. H.; Greitzer, Frank L.; Dalton, Angela C.; Pusey, Portia K.

    2015-03-01

    The Secure Power Systems Professional Phase III final report was released last year which an appendix of Job Profiles. This new report is that appendix broken out as a standalone document to assist utilities in recruiting and developing Secure Power Systems Professionals at their site.

  8. SPSP Phase III Recruiting, Selecting, and Developing Secure Power Systems Professionals. Individual and Team Performance Guidelines

    SciTech Connect

    O'Neil, Lori Ross; Conway, T. J.; Tobey, D. H.; Greitzer, Frank L.; Dalton, Angela C.; Pusey, Portia K.

    2015-03-01

    The Secure Power Systems Professional Phase III final report was released last year which an appendix of Individual and Team Performance Guidelines. This new report is that appendix broken out as a standalone document to assist utilities in recruiting and developing Secure Power Systems Professionals at their site.

  9. Rate of Muscle Activation in Power- and Endurance-Trained Boys

    PubMed Central

    Mitchell, Cameron; Cohen, Rotem; Dotan, Raffy; Gabriel, David; Klentrou, Panagiota; Falk, Bareket

    2013-01-01

    Previous studies in adults have demonstrated power athletes as having greater muscle force and muscle activation than nonathletes. Findings on endurance athletes are scarce and inconsistent. No comparable data on child athletes exist. Purpose This study compared peak torque (Tq), peak rate of torque development (RTD), and rate of muscle activation (EMG rise, Q30), in isometric knee extension (KE) and flexion (KF), in pre- and early-pubertal power- and endurance-trained boys vs minimally active nonathletes. Methods Nine gymnasts, 12 swimmers, and 18 nonathletes (7–12 y), performed fast, maximal isometric KE and KF. Values for Tq, RTD, electromechanical delay (EMD), and Q30 were calculated from averaged torque and surface EMG traces. Results No group differences were observed in Tq, normalized for muscle cross-sectional area. The Tq-normalized KE RTD was highest in power athletes (6.2 ± 1.9, 4.7 ± 1.2, 5.0 ± 1.5 N·m·s−1, for power, endurance, and nonathletes, respectively), whereas no group differences were observed for KF. The KE Q30 was significantly greater in power athletes, both in absolute terms and relative to peak EMG amplitude (9.8 ± 7.0, 5.9 ± 4.2, 4.4 ± 2.2 mV·ms and 1.7 ± 0.8, 1.1 ± 0.6, 0.9 ± 0.5 (mV·ms)/(mV) for power, endurance, and nonathletes, respectively), with no group differences in KF. The KE EMD tended to be shorter (P = .07) in power athletes during KE (71.0 ± 24.1, 87.8 ± 18.0, 88.4 ± 27.8 ms, for power, endurance, and nonathletes), with no group differences in KF. Conclusions Pre- and early-pubertal power athletes have enhanced rate of muscle activation in specifically trained muscles compared with controls or endurance athletes, suggesting that specific training can result in muscle activation-pattern changes before the onset of puberty. PMID:21487153

  10. Quantum dot SOA input power dynamic range improvement for differential-phase encoded signals.

    PubMed

    Vallaitis, T; Bonk, R; Guetlein, J; Hillerkuss, D; Li, J; Brenot, R; Lelarge, F; Duan, G H; Freude, W; Leuthold, J

    2010-03-15

    Experimentally we find a 10 dB input power dynamic range advantage for amplification of phase encoded signals with quantum dot SOA as compared to low-confinement bulk SOA. An analysis of amplitude and phase effects shows that this improvement can be attributed to the lower alpha-factor found in QD SOA.

  11. Theta phase synchrony and conscious target perception: impact of intensive mental training.

    PubMed

    Slagter, Heleen A; Lutz, Antoine; Greischar, Lawrence L; Nieuwenhuis, Sander; Davidson, Richard J

    2009-08-01

    The information processing capacity of the human mind is limited, as is evidenced by the attentional blink-a deficit in identifying the second of two targets (T1 and T2) presented in close succession. This deficit is thought to result from an overinvestment of limited resources in T1 processing. We previously reported that intensive mental training in a style of meditation aimed at reducing elaborate object processing, reduced brain resource allocation to T1, and improved T2 accuracy [Slagter, H. A., Lutz, A., Greischar, L. L., Francis, A. D., Nieuwenhuis, S., Davis, J., et al. Mental training affects distribution of limited brain resources. PloS Biology, 5, e138, 2007]. Here we report EEG spectral analyses to examine the possibility that this reduction in elaborate T1 processing rendered the system more available to process new target information, as indexed by T2-locked phase variability. Intensive mental training was associated with decreased cross-trial variability in the phase of oscillatory theta activity after successfully detected T2s, in particular, for those individuals who showed the greatest reduction in brain resource allocation to T1. These data implicate theta phase locking in conscious target perception, and suggest that after mental training the cognitive system is more rapidly available to process new target information. Mental training was not associated with changes in the amplitude of T2-induced responses or oscillatory activity before task onset. In combination, these findings illustrate the usefulness of systematic mental training in the study of the human mind by revealing the neural mechanisms that enable the brain to successfully represent target information.

  12. Microscale phase change of fuels for MEMS power applications

    NASA Astrophysics Data System (ADS)

    Haendler, Brenda

    As portable electronics technology advances, systems are becoming smaller and more energy intensive. While batteries are currently the only commercial power source for these applications, work is being done to create liquid fuel based portable power packs. These systems would leverage the higher energy density (W-hr/l) and specific energy (W-hr/kg) of liquid hydrocarbon fuels over available battery chemistries. For micro engines and small fuels cells there are advantages to preheating and vaporizing the fuel in a microchannel. The work presented in this dissertation focuses on understanding and characterizing the temperature and pressure signatures that result from microscale boiling of fuels in etched silicon channels approximately 100 mm in diameter. Building on previous microscale boiling work which used water as the working fluid for electronics cooling applications, the studies presented in this dissertation use both water and fuels including methanol, ethanol, and octane. Results are presented in the form of pressure and temperature measurements for a range of working fluids, volumetric flow rates, superheat temperatures and channel geometries. From a Fourier transform analysis of the pressure signatures, it was found that the frequency of the pressure fluctuations increases with superheat for ethanol as the working fluid while for methanol the frequency increases with volumetric flow rate. Tests were also conducted with sudden expansion geometries, which reduce the amplitude of the pressure fluctuations and create a localized cooling in the working fluid. Results are compared using fluid properties, including surface tension and heat of vaporization, and non-dimensional numbers including the Weber and the Jakob number. This study presents a significant contribution to the body of knowledge on microscale boiling. One application of microscale boiling for portable power technologies is also presented. Fuel cracking, breaking apart of long hydrocarbon chain

  13. SiC MOSFET Based Single Phase Active Boost Rectifier with Power Factor Correction for Wireless Power Transfer Applications

    SciTech Connect

    Onar, Omer C; Tang, Lixin; Chinthavali, Madhu Sudhan; Campbell, Steven L; Miller , John M.

    2014-01-01

    Wireless Power Transfer (WPT) technology is a novel research area in the charging technology that bridges the utility and the automotive industries. There are various solutions that are currently being evaluated by several research teams to find the most efficient way to manage the power flow from the grid to the vehicle energy storage system. There are different control parameters that can be utilized to compensate for the change in the impedance due to variable parameters such as battery state-of-charge, coupling factor, and coil misalignment. This paper presents the implementation of an active front-end rectifier on the grid side for power factor control and voltage boost capability for load power regulation. The proposed SiC MOSFET based single phase active front end rectifier with PFC resulted in >97% efficiency at 137mm air-gap and >95% efficiency at 160mm air-gap.

  14. Salton Sea Project, Phase 1. [solar pond power plant

    NASA Technical Reports Server (NTRS)

    Peelgren, M. L.

    1982-01-01

    A feasibility study was made for a salt gradient solar pond power plant in or near the Salton Sea of California. The conclusions support continuance 5-MWe proof-of-concept experiment, and ultimate construction by an electric utility company of a 600-MWe plant. The Solar Pond concept would be an environmental benefit to the Salton Sea by reversing the increasing salinity trend. The greatest cost drivers are the lake dike construction and pond sealing. Problems to be resolved include method of brine production from Salton Sea water for the first unit (which requires evaporation pond area and time), the high turbidity and color content of the Salton Sea water (which requires pretreatment), and other questions related to pond permeability, bio-activity and soil/brine chemical reactions. All technical and environmental problems appear solvable and/or manageable if care is taken in mitigating impacts.

  15. Metasurface with Reconfigurable Reflection Phase for High-Power Microwave Applications

    DTIC Science & Technology

    2014-01-07

    Paper 3. DATES COVERED (From - To) 15-08-2012 to 07-01-2014 4. TITLE AND SUBTITLE Metasurface with Reconfigurable Reflection Phase for High- Power...unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT We propose a metasurface with reconfigurable reflection phase that can be utilized in high...the metasurface has a reflection phase tuning range of approximately 300 degrees with an associated change in capacitance of 2.7 pF. 15. SUBJECT

  16. Investigations of SBS and Laser Gain Competition in High-Power Phase Modulated Fiber Amplifiers (Postprint)

    DTIC Science & Technology

    2014-02-26

    through radio frequency (RF) phase modulation. Generally, linewidth broadening is achieved through a filtered microwave white noise source (WNS). WNS...signals. By seeding with appropriate wavelengths and seed powers, the effective length of the amplifier is shortened as the narrow linewidth signal...line (phase modulated) 1064 nm seed in conjunction with a broadband 1036 nm seed source. 2. PHASE MODULATED LASER GAIN COMPETITION Recently, we have

  17. Interferometric phase shift compensation technique for high-power, tiled-aperture coherent beam combination.

    PubMed

    Chosrowjan, Haik; Furuse, Hiroaki; Fujita, Masayuki; Izawa, Yasukazu; Kawanaka, Junji; Miyanaga, Noriaki; Hamamoto, Koichi; Yamada, Takahiro

    2013-04-15

    We propose a simple coherent beam combining technique for applications in high-power multichannel laser amplifier systems with tiled aperture design. Using a photodiode pair coupled with piezo-actuator mirrors, we demonstrated robust beam combining bandwidth (~1 KHz) and root mean-square deviation (~λ/25) for two beam channels. We estimate that the performance of this technique can be further enhanced in terms of operational bandwidth and phase locking accuracy. It is not limited by single beam power or channel number restrictions, does not require optical phase retrieval algorithms, or calibrations, and can be integrated into various master oscillator power amplifier architectures.

  18. Quasi-phase-matching high harmonic generation using trains of pulses produced using an array of birefringent plates.

    PubMed

    O'Keeffe, Kevin; Robinson, Tom; Hooker, Simon M

    2012-03-12

    Quasi-phase-matched high harmonic generation using trains of up to 8 counter-propagating pulses is explored. For trains of up to 4 pulses the measured enhancement of the harmonic signal scales with the number of pulses N as (N + 1)², as expected. However, for trains with N > 4, no further enhancement of the harmonic signal is observed. This effect is ascribed to changes of the coherence length Lc within the generating medium. Techniques for overcoming the variation of Lc are discussed. The pressure dependence of quasi-phase-matching is investigated and the switch from true-phase-matching to quasi-phase-matching is observed.

  19. High-power coherent phased array of monolithic flared amplifier-master oscillator power amplifiers (MFA-MOPAs)

    NASA Astrophysics Data System (ADS)

    Osinski, Jules S.; Mehuys, David G.; Welch, David F.; Dzurko, Kenneth M.; Lang, Robert J.

    1995-04-01

    A monolithically integrated array of InGaAs/AlGaAs flared amplifiers driven by a single DBR laser through a power splitter network and individually addressed phase modulators is described. Phase adjustment of > 2(pi) per element by free-carrier effects is verified by monitoring the interference pattern of 4 emitters, and typically requires < 15 mA of current to obtain a 2(pi) phase shift. Phase matching is achieved among all four diffraction-limited emitters at a pulsed output power of > 5 W, and, combined with the proper external lensing, could therefore result in an ultra-narrow, single-lobed far-field pattern whose width is determined by the extended aperture of the array. This architecture is capable of providing single-mode, diffraction-limited performance from each emitter and is scalable to unprecedented power levels. Over 20 W of pulsed, spectrally coherent emission is generated at 955 nm from a 4-element array, and 39 W is obtained from an 8-element array.

  20. A Linear Model of Phase-Dependent Power Correlations in Neuronal Oscillations

    PubMed Central

    Eriksson, David; Vicente, Raul; Schmidt, Kerstin

    2011-01-01

    Recently, it has been suggested that effective interactions between two neuronal populations are supported by the phase difference between the oscillations in these two populations, a hypothesis referred to as “communication through coherence” (CTC). Experimental work quantified effective interactions by means of the power correlations between the two populations, where power was calculated on the local field potential and/or multi-unit activity. Here, we present a linear model of interacting oscillators that accounts for the phase dependency of the power correlation between the two populations and that can be used as a reference for detecting non-linearities such as gain control. In the experimental analysis, trials were sorted according to the coupled phase difference of the oscillators while the putative interaction between oscillations was taking place. Taking advantage of the modeling, we further studied the dependency of the power correlation on the uncoupled phase difference, connection strength, and topology. Since the uncoupled phase difference, i.e., the phase relation before the effective interaction, is the causal variable in the CTC hypothesis we also describe how power correlations depend on that variable. For uni-directional connectivity we observe that the width of the uncoupled phase dependency is broader than for the coupled phase. Furthermore, the analytical results show that the characteristics of the phase dependency change when a bidirectional connection is assumed. The width of the phase dependency indicates which oscillation frequencies are optimal for a given connection delay distribution. We propose that a certain width enables a stimulus-contrast dependent extent of effective long-range lateral connections. PMID:21808618

  1. Effects of a resistance training program and subsequent detraining on muscle strength and muscle power in multiple sclerosis patients.

    PubMed

    Medina-Perez, Carlos; de Souza-Teixeira, Fernanda; Fernandez-Gonzalo, Rodrigo; de Paz-Fernandez, Jose Antonio

    2014-01-01

    Although resistance training adaptations in multiple sclerosis (MS) patients have been described, the detraining response in this population is largely unknown. [corrected] This study was designed to evaluate the effects of a 12-week detraining period on muscle strength (isometric and endurance) and muscle power of multiple sclerosis (MS) patients that had previously carried out a 12-week resistance training program (RTP). Forty-two MS patients were randomly assigned into two groups: an exercise group (EG) that performed a 12-week RTP for the knee extensors muscles; and a control group (CG), that did not perform any specific training. Knee extension maximal voluntary isometric contraction (MVIC), muscle power and muscle endurance were evaluated before and after the RTP, as well as 12 weeks after training completion. A strain gauge was used to measure the maximal voluntary isometric contraction and muscle power was assessed with a linear encoder. Muscle endurance was interpreted as the number of repetitions that a patient could perform in a single set of knee extension exercise. The EG increased MVIC and muscle power after the training period, although the training did not affect muscle endurance. After 12 weeks of detraining, MVIC returned to pre-training values but muscle power was still greater than pre-training values in the EG. The CG did not present any change in the variables measured during the intervention. A 12-week RTP improved MVIC and muscle power in MS patients. Additionally, 12 weeks of detraining blunted strength training adaptations in MS patients, although muscle power training adaptations were still evident after the detraining period.

  2. A preliminary study of solar powdered aircraft and associated power trains

    NASA Technical Reports Server (NTRS)

    Hall, D. W.; Fortenbach, C. D.; Dimiceli, E. V.; Parks, R. W.

    1983-01-01

    The feasibility of regeneratively powered solar high altitude powered platform (HAPP) remotely piloted vehicles was assessed. Those technologies which must be pursued to make long duration solar HAPPs feasible are recommended. A methodology which involved characterization and parametric analysis of roughly two dozen variables to determine vehicles capable of fulfilling the primary mission are defined. One of these vehicles was then conceptually designed. Variations of each major design parameter were investigated along with state-of-the-art changes in power train component capabilities. The midlatitude mission studied would be attainable by a solar HAPP if fuel cell, electrolyzer and photovoltaic technologies are pursued. Vehicles will be very large and have very lightweight structures in order to attain the combinations of altitude and duration required by the primary mission.

  3. High speed, high power one-dimensional beam steering from a 6-element optical phased array.

    PubMed

    Huang, W Ronny; Montoya, Juan; Kansky, Jan E; Redmond, Shawn M; Turner, George W; Sanchez-Rubio, Antonio

    2012-07-30

    Beam steering at high speed and high power is demonstrated from a 6-element optical phased array using coherent beam combining (CBC) techniques. The steering speed, defined as the inverse of the time to required to sweep the beam across the steering range, is 40 MHz and the total power is 396 mW. The measured central lobe FWHM width is 565 μrad. High on-axis intensity is maintained periodically by phase-locking the array via a stochastic-parallel-gradient-descent (SPGD) algorithm. A master-oscillator-power-amplifier (MOPA) configuration is used where the amplifier array elements are semiconductor slab-coupled-optical-waveguide-amplifiers (SCOWAs). The beam steering is achieved by LiNbO(3) phase modulators; the phase-locking occurs by current adjustment of the SCOWAs. The system can be readily scaled to GHz steering speed and multiwatt-class output.

  4. Effects of a Supervised versus an Unsupervised Combined Balance and Strength Training Program on Balance and Muscle Power in Healthy Older Adults: A Randomized Controlled Trial.

    PubMed

    Lacroix, André; Kressig, Reto W; Muehlbauer, Thomas; Gschwind, Yves J; Pfenninger, Barbara; Bruegger, Othmar; Granacher, Urs

    2016-01-01

    Losses in lower extremity muscle strength/power, muscle mass and deficits in static and particularly dynamic balance due to aging are associated with impaired functional performance and an increased fall risk. It has been shown that the combination of balance and strength training (BST) mitigates these age-related deficits. However, it is unresolved whether supervised versus unsupervised BST is equally effective in improving muscle power and balance in older adults. This study examined the impact of a 12-week BST program followed by 12 weeks of detraining on measures of balance and muscle power in healthy older adults enrolled in supervised (SUP) or unsupervised (UNSUP) training. Sixty-six older adults (men: 25, women: 41; age 73 ± 4 years) were randomly assigned to a SUP group (2/week supervised training, 1/week unsupervised training; n = 22), an UNSUP group (3/week unsupervised training; n = 22) or a passive control group (CON; n = 22). Static (i.e., Romberg Test) and dynamic (i.e., 10-meter walk test) steady-state, proactive (i.e., Timed Up and Go Test, Functional Reach Test), and reactive balance (e.g., Push and Release Test), as well as lower extremity muscle power (i.e., Chair Stand Test; Stair Ascent and Descent Test) were tested before and after the active training phase as well as after detraining. Adherence rates to training were 92% for SUP and 97% for UNSUP. BST resulted in significant group × time interactions. Post hoc analyses showed, among others, significant training-related improvements for the Romberg Test, stride velocity, Timed Up and Go Test, and Chair Stand Test in favor of the SUP group. Following detraining, significantly enhanced performances (compared to baseline) were still present in 13 variables for the SUP group and in 10 variables for the UNSUP group. Twelve weeks of BST proved to be safe (no training-related injuries) and feasible (high attendance rates of >90%). Deficits of balance and lower extremity muscle power can be

  5. RF peak power reduction in CAIPIRINHA excitation by interslice phase optimization.

    PubMed

    Sbrizzi, Alessandro; Poser, Benedikt A; Tse, Desmond H Y; Hoogduin, Hans; Luijten, Peter R; van den Berg, Cornelis A T

    2015-11-01

    The purpose of this work was to show that the overall peak power of RF pulses for CAIPIRINHA excitation can be substantially reduced by applying interslice phase relaxation. The optimal phases are scan dependent and can be quickly calculated by the proposed method. The multi-band RF pulse design is implemented as the minimization of a linear objective function with quadratic constraints. The interslice phase is considered to be a variable for optimization. In the case of a phase cycling scheme (CAIPIRINHA), the peak power is considered over all pulses. The computation time (about 1 s) is compatible with online RF pulse design. It is shown that the optimal interslice phases depend on the CAIPIRINHA scheme used and that RF peak power is reduced when the CAIPIRINHA phase cycling is taken into account in the optimization. The proposed method is extremely fast and results in RF pulses with low peak power for CAIPIRINHA excitation. The MATLAB implementation is given in the appendix; it allows for online determination of scan-dependent phase parameters. Furthermore, the method can be easily extended to pTx shimming systems in the context of multi-slice excitations, and this possibility is included in the software.

  6. High-Power Amplifier Compatible Internally Sensed Optical Phased Array for Space Debris Tracking and Maneuvering

    NASA Astrophysics Data System (ADS)

    Roberts, L.; Francis, S.; Sibley, P.; Ward, R.; Smith, C.; McClelland, D.; Shaddock, D.

    2016-09-01

    Optical phased arrays (OPAs) provide a way to scale optical power beyond the capabilities of conventional CW lasers via coherent beam combination. By stabilising the relative output phase of multiple spatially separate lasers, OPAs form a coherent optical wavefront in the far field. Since the phase of each laser can be controlled independently, OPAs also have the ability to manipulate the distribution of optical power in the far field, and therefore may provide the capability to compensate for atmospheric turbulence. Combined with their inherent scalability and high power handling capabilities, OPAs are a promising technology for CW space debris ranging and manoeuvring. The OPA presented here is unique in its ability to sense the phase of each laser internally, without requiring any external sampling optics between it and the telescope. This allows the internally sensed OPA to be constructed entirely within fibre, utilising high-power fiber amplifiers to scale optical power beyond the limits of any conventional single lasers. The total power that can be delivered by each emitter in the OPA is limited only by the onset of stimulated Brillouin scattering, a non-linear effect that clamps the amount of power that can be delivered through a fiber waveguide. A three element internally sensed OPA developed at the Australian National University has been demonstrated to coherently combine three commercial 15 Watt fiber amplifiers with an output phase stability of one 200th of a wavelength. We have also demonstrated the ability to dynamically manipulate the distribution of optical power in the far-field at a bandwidth of up to 10 kHz. Since the OPA's control system is implemented using field-programmable gate-array technology, the system may be scaled beyond 100 emitters, potentially reaching the kilowatt level optical powers required to perturb the orbit of space debris.

  7. Effects of Traditional Versus Horizontal Inertial Flywheel Power Training on Common Sport-Related Tasks

    PubMed Central

    de Hoyo, Moisés; Sañudo, Borja; Carrasco, Luis; Domínguez-Cobo, Sergio; Mateo-Cortes, Jesús; Cadenas-Sánchez, María Monserrat; Nimphius, Sophia

    2015-01-01

    This study aimed to analyze the effects of power training using traditional vertical resistance exercises versus direction specific horizontal inertial flywheel training on performance in common sport-related tasks. Twenty-three healthy and physically active males (age: 22.29 ± 2.45 years) volunteered to participate in this study. Participants were allocated into either the traditional training (TT) group where the half squat exercise on a smith machine was applied or the horizontal flywheel training (HFT) group performing the front step exercise with an inertial flywheel. Training volume and intensity were matched between groups by repetitions (5–8 sets with 8 repetitions) and relative intensity (the load that maximized power (Pmax)) over the period of six weeks. Speed (10 m and 20 m), countermovement jump height (CMJH), 20 m change of direction ability (COD) and strength during a maximal voluntary isometric contraction (MVIC) were assessed before and after the training program. The differences between groups and by time were assessed using a two-way analysis of variance with repeated measures, followed by paired t-tests. A significant group by time interaction (p=0.004) was found in the TT group demonstrating a significantly higher CMJH. Within-group analysis revealed statistically significant improvements in a 10 m sprint (TT: −0.17 0.27 s vs. HFT: −0.11 0.10 s), CMJH (TT: 4.92 2.58 cm vs. HFT: 1.55 2.44 cm) and MVIC (TT: 62.87 79.71 N vs. HFT: 106.56 121.63 N) in both groups (p < 0.05). However, significant differences only occurred in the 20 m sprint time in the TT group (−0.04 0.12 s; p = 0.04). In conclusion, the results suggest that TT at the maximal peak power load is more effective than HFT for counter movement jump height while both TT and HFT elicited significant improvements in 10 m sprint performance while only TT significantly improved 20 m sprint performance. PMID:26557200

  8. Effects of Traditional Versus Horizontal Inertial Flywheel Power Training on Common Sport-Related Tasks.

    PubMed

    de Hoyo, Moisés; Sañudo, Borja; Carrasco, Luis; Domínguez-Cobo, Sergio; Mateo-Cortes, Jesús; Cadenas-Sánchez, María Monserrat; Nimphius, Sophia

    2015-09-29

    This study aimed to analyze the effects of power training using traditional vertical resistance exercises versus direction specific horizontal inertial flywheel training on performance in common sport-related tasks. Twenty-three healthy and physically active males (age: 22.29 ± 2.45 years) volunteered to participate in this study. Participants were allocated into either the traditional training (TT) group where the half squat exercise on a smith machine was applied or the horizontal flywheel training (HFT) group performing the front step exercise with an inertial flywheel. Training volume and intensity were matched between groups by repetitions (5-8 sets with 8 repetitions) and relative intensity (the load that maximized power (Pmax)) over the period of six weeks. Speed (10 m and 20 m), countermovement jump height (CMJH), 20 m change of direction ability (COD) and strength during a maximal voluntary isometric contraction (MVIC) were assessed before and after the training program. The differences between groups and by time were assessed using a two-way analysis of variance with repeated measures, followed by paired t-tests. A significant group by time interaction (p=0.004) was found in the TT group demonstrating a significantly higher CMJH. Within-group analysis revealed statistically significant improvements in a 10 m sprint (TT: -0.17 0.27 s vs. HFT: -0.11 0.10 s), CMJH (TT: 4.92 2.58 cm vs. HFT: 1.55 2.44 cm) and MVIC (TT: 62.87 79.71 N vs. HFT: 106.56 121.63 N) in both groups (p < 0.05). However, significant differences only occurred in the 20 m sprint time in the TT group (-0.04 0.12 s; p = 0.04). In conclusion, the results suggest that TT at the maximal peak power load is more effective than HFT for counter movement jump height while both TT and HFT elicited significant improvements in 10 m sprint performance while only TT significantly improved 20 m sprint performance.

  9. Concurrent neuromechanical and functional gains following upper-extremity power training post-stroke

    PubMed Central

    2013-01-01

    Background Repetitive task practice is argued to drive neural plasticity following stroke. However, current evidence reveals that hemiparetic weakness impairs the capacity to perform, and practice, movements appropriately. Here we investigated how power training (i.e., high-intensity, dynamic resistance training) affects recovery of upper-extremity motor function post-stroke. We hypothesized that power training, as a component of upper-extremity rehabilitation, would promote greater functional gains than functional task practice without deleterious consequences. Method Nineteen chronic hemiparetic individuals were studied using a crossover design. All participants received both functional task practice (FTP) and HYBRID (combined FTP and power training) in random order. Blinded evaluations performed at baseline, following each intervention block and 6-months post-intervention included: Wolf Motor Function Test (WMFT-FAS, Primary Outcome), upper-extremity Fugl-Meyer Motor Assessment, Ashworth Scale, and Functional Independence Measure. Neuromechanical function was evaluated using isometric and dynamic joint torques and concurrent agonist EMG. Biceps stretch reflex responses were evaluated using passive elbow stretches ranging from 60 to 180º/s and determining: EMG onset position threshold, burst duration, burst intensity and passive torque at each speed. Results Primary outcome: Improvements in WMFT-FAS were significantly greater following HYBRID vs. FTP (p = .049), regardless of treatment order. These functional improvements were retained 6-months post-intervention (p = .03). Secondary outcomes: A greater proportion of participants achieved minimally important differences (MID) following HYBRID vs. FTP (p = .03). MIDs were retained 6-months post-intervention. Ashworth scores were unchanged (p > .05). Increased maximal isometric joint torque, agonist EMG and peak power were significantly greater following HYBRID vs. FTP (p < .05) and effects were

  10. Phase coded, micro-power impulse radar motion sensor

    DOEpatents

    McEwan, Thomas E.

    1996-01-01

    A motion sensing, micro-power impulse radar MIR impresses on the transmitted signal, or the received pulse timing signal, one or more frequencies lower than the pulse repetition frequency, that become intermediate frequencies in a "IF homodyne" receiver. Thus, many advantages of classical RF receivers can be thereby be realized with ultra-wide band radar. The sensor includes a transmitter which transmits a sequence of electromagnetic pulses in response to a transmit timing signal at a nominal pulse repetition frequency. A receiver samples echoes of the sequence of electromagnetic pulses from objects within the field with controlled timing, in response to a receive timing signal, and generates a sample signal in response to the samples. A timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The relative timing of the transmit timing signal and the receive timing signal is modulated between a first relative delay and a second relative delay at an intermediate frequency, causing the receiver to sample the echoes such that the time between transmissions of pulses in the sequence and samples by the receiver is modulated at the intermediate frequency. Modulation may be executed by modulating the pulse repetition frequency which drives the transmitter, by modulating the delay circuitry which controls the relative timing of the sample strobe, or by modulating amplitude of the transmitted pulses. The electromagnetic pulses will have a nominal center frequency related to pulse width, and the first relative delay and the second relative delay between which the timing signals are modulated, differ by less than the nominal pulse width, and preferably by about one-quarter wavelength at the nominal center frequency of the transmitted pulses.

  11. Phase coded, micro-power impulse radar motion sensor

    DOEpatents

    McEwan, T.E.

    1996-05-21

    A motion sensing, micro-power impulse radar MIR impresses on the transmitted signal, or the received pulse timing signal, one or more frequencies lower than the pulse repetition frequency, that become intermediate frequencies in a ``IF homodyne`` receiver. Thus, many advantages of classical RF receivers can be thereby be realized with ultra-wide band radar. The sensor includes a transmitter which transmits a sequence of electromagnetic pulses in response to a transmit timing signal at a nominal pulse repetition frequency. A receiver samples echoes of the sequence of electromagnetic pulses from objects within the field with controlled timing, in response to a receive timing signal, and generates a sample signal in response to the samples. A timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The relative timing of the transmit timing signal and the receive timing signal is modulated between a first relative delay and a second relative delay at an intermediate frequency, causing the receiver to sample the echoes such that the time between transmissions of pulses in the sequence and samples by the receiver is modulated at the intermediate frequency. Modulation may be executed by modulating the pulse repetition frequency which drives the transmitter, by modulating the delay circuitry which controls the relative timing of the sample strobe, or by modulating amplitude of the transmitted pulses. The electromagnetic pulses will have a nominal center frequency related to pulse width, and the first relative delay and the second relative delay between which the timing signals are modulated, differ by less than the nominal pulse width, and preferably by about one-quarter wavelength at the nominal center frequency of the transmitted pulses. 5 figs.

  12. Effects of Different Concurrent Resistance and Aerobic Training Frequencies on Muscle Power and Muscle Quality in Trained Elderly Men: A Randomized Clinical Trial.

    PubMed

    Ferrari, Rodrigo; Fuchs, Sandra C; Kruel, Luiz Fernando Martins; Cadore, Eduardo Lusa; Alberton, Cristine Lima; Pinto, Ronei Silveira; Radaelli, Régis; Schoenell, Maira; Izquierdo, Mikel; Tanaka, Hirofumi; Umpierre, Daniel

    2016-12-01

    Muscle power is a strong predictor of functional status in the elderly population and is required to perform different daily activities. To compare the effects of different weekly training frequencies on muscle power and muscle quality induced by concurrent training (resistance + aerobic) in previously trained elderly men. Twenty-four trained elderly men (65 ± 4 years), previously engaged in a regular concurrent training program, three times per week, for the previous five months, were randomly allocated to concurrent training programs in which training was performed either twice a week (2·week(-1), n = 12) or three times per week (3·week(-1), n = 12). The groups trained with an identical exercise intensity and volume per session for 10 weeks. Before and after the exercise training, we examined muscle power, as estimated by countermovement jump height; knee extensor isokinetic peak torque at 60 and 180(o.)s(-1); and muscle quality, a quotient between the one-repetition maximum of the knee extensors and the sum of quadriceps femoris muscle thickness determined by ultrasonography. Additionally, as secondary outcomes, blood pressure and reactive hyperemia were evaluated. Two-way ANOVA with repeated measures were used and statistical significance was set at α = 0.05. Muscular power (2·week(-1): 7%, and 3·week(-1): 10%) and muscle quality (2·week(-1): 15%, and 3·week(-1): 8%) improved with the concurrent exercise training (p < 0.001) but with no differences between groups. The isokinetic peak torque at 60 (2·week(-1): 4%, and 3·week(-1): 2%) and 180(o.)s(-1) (2·week(-1): 7%, and 3·week(-1): 1%) increased in both groups (p = 0.036 and p=0.014, respectively). There were no changes in blood pressure or reactive hyperemia with the concurrent training. Concurrent training performed twice a week promotes similar adaptations in muscular power and muscle quality when compared with the same program performed three times per week in previously trained elderly men.

  13. Effects of Different Concurrent Resistance and Aerobic Training Frequencies on Muscle Power and Muscle Quality in Trained Elderly Men: A Randomized Clinical Trial

    PubMed Central

    Ferrari, Rodrigo; Fuchs, Sandra C.; Kruel, Luiz Fernando Martins; Cadore, Eduardo Lusa; Alberton, Cristine Lima; Pinto, Ronei Silveira; Radaelli, Régis; Schoenell, Maira; Izquierdo, Mikel; Tanaka, Hirofumi; Umpierre, Daniel

    2016-01-01

    Muscle power is a strong predictor of functional status in the elderly population and is required to perform different daily activities. To compare the effects of different weekly training frequencies on muscle power and muscle quality induced by concurrent training (resistance + aerobic) in previously trained elderly men. Twenty-four trained elderly men (65 ± 4 years), previously engaged in a regular concurrent training program, three times per week, for the previous five months, were randomly allocated to concurrent training programs in which training was performed either twice a week (2·week-1, n = 12) or three times per week (3·week-1, n = 12). The groups trained with an identical exercise intensity and volume per session for 10 weeks. Before and after the exercise training, we examined muscle power, as estimated by countermovement jump height; knee extensor isokinetic peak torque at 60 and 180o.s-1; and muscle quality, a quotient between the one-repetition maximum of the knee extensors and the sum of quadriceps femoris muscle thickness determined by ultrasonography. Additionally, as secondary outcomes, blood pressure and reactive hyperemia were evaluated. Two-way ANOVA with repeated measures were used and statistical significance was set at α = 0.05. Muscular power (2·week-1: 7%, and 3·week-1: 10%) and muscle quality (2·week-1: 15%, and 3·week-1: 8%) improved with the concurrent exercise training (p < 0.001) but with no differences between groups. The isokinetic peak torque at 60 (2·week-1: 4%, and 3·week-1: 2%) and 180o.s-1 (2·week-1: 7%, and 3·week-1: 1%) increased in both groups (p = 0.036 and p=0.014, respectively). There were no changes in blood pressure or reactive hyperemia with the concurrent training. Concurrent training performed twice a week promotes similar adaptations in muscular power and muscle quality when compared with the same program performed three times per week in previously trained elderly men. PMID:28053820

  14. The effect of two plyometric training techniques on muscular power and agility in youth soccer players.

    PubMed

    Thomas, Kevin; French, Duncan; Hayes, Philip R

    2009-01-01

    The aim of this study was to compare the effects of two plyometric training techniques on power and agility in youth soccer players. Twelve males from a semiprofessional football club's academy (age = 17.3 +/- 0.4 years, stature = 177.9 +/- 5.1 cm, mass = 68.7 +/- 5.6 kg) were randomly assigned to 6 weeks of depth jump (DJ) or countermovement jump (CMJ) training twice weekly. Participants in the DJ group performed drop jumps with instructions to minimize ground-contact time while maximizing height. Participants in the CMJ group performed jumps from a standing start position with instructions to gain maximum jump height. Posttraining, both groups experienced improvements in vertical jump height (p < 0.05) and agility time (p < 0.05) and no change in sprint performance (p > 0.05). There were no differences between the treatment groups (p > 0.05). The study concludes that both DJ and CMJ plyometrics are worthwhile training activities for improving power and agility in youth soccer players.

  15. NASA satellite communications application research. Phase 2: Efficient high power, solid state amplifier for EFH communications

    NASA Technical Reports Server (NTRS)

    Benet, James

    1993-01-01

    The final report describes the work performed from 9 Jun. 1992 to 31 Jul. 1993 on the NASA Satellite Communications Application Research (SCAR) Phase 2 program, Efficient High Power, Solid State Amplifier for EHF Communications. The purpose of the program was to demonstrate the feasibility of high-efficiency, high-power, EHF solid state amplifiers that are smaller, lighter, more efficient, and less costly than existing traveling wave tube (TWT) amplifiers by combining the output power from up to several hundred solid state amplifiers using a unique orthomode spatial power combiner (OSPC).

  16. The Formation of Phase Structure in the Creation of Soliton Trains

    NASA Astrophysics Data System (ADS)

    Nguyen, Jason; Luo, De; Hulet, Randall

    2016-05-01

    Matter-wave soliton trains were initially observed following an interaction quench in a condensate of 7Li atoms. The relative phase between neighboring solitons was inferred to differ by π, giving the appearance of a repulsive interaction between them. The process by which this phase structure is formed is unknown. Starting with a condensate of 7Li atoms in the | 1 , 1 > state, we study the initial formation of soliton trains by quenching the magnetic field to rapidly vary the interaction from repulsive to attractive in a quasi-1-D system. We study the dynamics of the system shortly after the quench, using multiple in situ images. We previously used this technique to study soliton-soliton collisions. Work supported by the NSF, an ARO MURI Grant, and the Welch Foundation.

  17. Moderate intensity, but not high intensity, treadmill exercise training alters power output properties in myocardium from aged rats.

    PubMed

    Chung, Eunhee; Diffee, Gary M

    2012-11-01

    Aging is characterized by a progressive decline in cardiac function, but endurance exercise training has been shown to retard a number of deleterious effects of aging. However, underlying mechanisms by which exercise training improves age-related decrements in myocardial contractile function are not well understood. The purpose of this study was to determine the effects of exercise training on power output properties in permeablized (skinned) myocytes of old rats. Thirty-month-old rats were divided into sedentary control (C) and groups undergoing 11 weeks of treadmill exercise training at moderate intensity (MI) and at high intensity (HI). Peak power output normalized to maximal force was significantly increased in MI but not in HI compared to C with significant increases in atrial myosin light chain 1 in ventricle. These results suggest that MI exercise training is beneficial as a significant increase was seen in the ability of the myocardium to do work, but this effect was not seen with HI training.

  18. Phase-Controlled Bistability of a Dark Soliton Train in a Polariton Fluid

    NASA Astrophysics Data System (ADS)

    Goblot, V.; Nguyen, H. S.; Carusotto, I.; Galopin, E.; Lemaître, A.; Sagnes, I.; Amo, A.; Bloch, J.

    2016-11-01

    We use a one-dimensional polariton fluid in a semiconductor microcavity to explore the nonlinear dynamics of counterpropagating interacting Bose fluids. The intrinsically driven-dissipative nature of the polariton fluid allows us to use resonant pumping to impose a phase twist across the fluid. When the polariton-polariton interaction energy becomes comparable to the kinetic energy, linear interference fringes transform into a train of solitons. A novel type of bistable behavior controlled by the phase twist across the fluid is experimentally evidenced.

  19. Influence of Strength Level on the Rest Interval Required During an Upper-Body Power Training Session.

    PubMed

    Hernández Davó, Jose Luis; Botella Ruiz, Javier; Sabido, Rafael

    2017-02-01

    Hernández Davó, JL, Botella Ruiz, J, and Sabido, R. Influence of strength level on the rest interval required during an upper-body power training session. J Strength Cond Res 31(2): 339-347, 2017-The present study aimed to investigate the influence of subjects' strength level on both the ability to maintain power output performance and the physiological and perceived exertion responses during a power training session when different rest intervals (RI) are used. Thirty-eight (18 men and 20 women) subjects were divided into a stronger or weaker group based on their ability to produce peak power output. Testing was performed using the same protocol (5 sets of 8 repetitions with 40% of 1 repetition maximum) in the bench press throw exercise, but differing the RI between sets (1, 2, and 3 minutes). During the sessions, mechanical (peak power), physiological ([La]) and perceptual (RPE) variables were measured. In addition, delayed onset muscular soreness (DOMS) 24 and 48 hours after the training session was reported. Both stronger and weaker (men and women) groups showed significant impairments in mechanical, physiological, and perceptual data when resting 1 minute. Nevertheless, although stronger groups were able to sustain power output over the sets when using the 2-minute RI, weaker groups needed at least 3 minutes to maintain power output performance. Therefore, strength level heavily influences the rest interval required during a power training session and should be taken into account when prescribing such training sessions.

  20. Aircrew Training Devices: Utility and Utilization of Advanced Instructional Features. Phase III. Electronic Warfare Trainers.

    DTIC Science & Technology

    1986-04-01

    Devices: Utility and Utilization of Advanced Instructional Features (Phase III- Electronic Warfare Trainers) 12 PERSONAL AUTHOR(S) Polzella . Donald J...Features, addressed a portion of this subthrust. Dr. Wayne Waag (AFHRL/OTU) was the Contract Monitor and Dr. Donald J. Polzella and Dr. David C. Hubbard...training is practicable (see Polzella , 1983, p.8). However, instructional features are expensive to implement, especially those features that require the

  1. A 6-week Sprint Interval Training Program Changes Anaerobic Power, Quadriceps Moment, and Subcutaneous Tissue Thickness.

    PubMed

    Han, Seunguk; Lee, Hyungkyu; Kim, Hyungkee; Kim, Dasol; Choi, Changkyu; Park, Jihong

    2017-02-01

    We examined the effects of a 6-week 40-m one-way sprint interval training program (based on sprint time). 13 untrained healthy male collegiate students performed six 40-m sprints with a 60-s resting interval between sprints during the first week, and one sprint was added each week until the sixth week. If the 40-m sprint time exceeded 110% of the fastest baseline 40-m sprint time, the run was repeated. Repeated-sprint cycling test (every 3 weeks), quadriceps moment (every 2 weeks), and abdominal and thigh subcutaneous tissue thickness (every 2 weeks) were measured. Compared to baseline, mean power output improved at week 3 (16.27 vs. 17.73 Watt/kg, p=0.004). Regardless of side, quadriceps moment began to increase at week 4 (2.88 vs. 3.15 N·m/kg, p=0.03). Subcutaneous tissue thickness was reduced at week 2 (abdominal: 11.19 vs. 9.65 mm, p=0.01; thigh: 9.17 vs. 8.12 mm, p=0.009). Our results suggest that (1) sprint training with an intensity of 110% of the fastest baseline 40-m sprint time with the addition of one sprint per week produces similar effects to other training programs, and (2) untrained individuals need 4 weeks of training for strength development in the quadriceps and 2 weeks for reduction in fat tissue thickness.

  2. Advanced virtual energy simulation training and research: IGCC with CO2 capture power plant

    SciTech Connect

    Zitney, S.; Liese, E.; Mahapatra, P.; Bhattacharyya, D.; Provost, G.

    2011-01-01

    In this presentation, we highlight the deployment of a real-time dynamic simulator of an integrated gasification combined cycle (IGCC) power plant with CO{sub 2} capture at the Department of Energy's (DOE) National Energy Technology Laboratory's (NETL) Advanced Virtual Energy Simulation Training and Research (AVESTARTM) Center. The Center was established as part of the DOE's accelerating initiative to advance new clean coal technology for power generation. IGCC systems are an attractive technology option, generating low-cost electricity by converting coal and/or other fuels into a clean synthesis gas mixture in a process that is efficient and environmentally superior to conventional power plants. The IGCC dynamic simulator builds on, and reaches beyond, conventional power plant simulators to merge, for the first time, a 'gasification with CO{sub 2} capture' process simulator with a 'combined-cycle' power simulator. Fueled with coal, petroleum coke, and/or biomass, the gasification island of the simulated IGCC plant consists of two oxygen-blown, downward-fired, entrained-flow, slagging gasifiers with radiant syngas coolers and two-stage sour shift reactors, followed by a dual-stage acid gas removal process for CO{sub 2} capture. The combined cycle island consists of two F-class gas turbines, steam turbine, and a heat recovery steam generator with three-pressure levels. The dynamic simulator can be used for normal base-load operation, as well as plant start-up and shut down. The real-time dynamic simulator also responds satisfactorily to process disturbances, feedstock blending and switchovers, fluctuations in ambient conditions, and power demand load shedding. In addition, the full-scope simulator handles a wide range of abnormal situations, including equipment malfunctions and failures, together with changes initiated through actions from plant field operators. By providing a comprehensive IGCC operator training system, the AVESTAR Center is poised to develop a

  3. Magnetic field simulation of magnetic phase detection sensor for steam generator tube in nuclear power plants

    NASA Astrophysics Data System (ADS)

    Ryu, Kwon-sang; Son, Derac; Park, Duck-gun; Kim, Yong-il

    2010-05-01

    Magnetic phases and defects are partly produced in steam generator tubes by stress and heat, because steam generator tubes in nuclear power plants are used under high temperature, high pressure, and radioactivity. The magnetic phases induce an error in the detection of the defects in steam generator tubes by the conventional eddy current method. So a new method is needed for detecting the magnetic phases in the steam generator tubes. We designed a new U-type yoke which has two kinds of coils and simulated the signal by the magnetic phases and defects in the Inconnel 600 tube.

  4. Open-phase operating modes of power flow control topologies in a Smart Grid Distribution Network

    NASA Astrophysics Data System (ADS)

    Astashev, M. G.; Novikov, M. A.; Panfilov, D. I.; Rashitov, P. A.; Remizevich, T. V.; Fedorova, M. I.

    2015-12-01

    The power flow regulating circuit node in an alternating current system is reviewed. The circuit node is accomplished based on a thyristor controlled phase angle regulator (TCPAR) with controlled thyristor switch. Research results of the individual phase control of the output voltage for the TCPAR are presented. Analytical expressions for the overvoltage factor calculation in the thyristor switch circuit for open-phase operating modes are received. Based on evaluation of overvoltage in operational and emergency modes, the implementability conditions of the individual phase control of the output voltage are determined. Under these conditions, maximal performance and complete controllability are provided.

  5. The fault monitoring and diagnosis knowledge-based system for space power systems: AMPERES, phase 1

    NASA Technical Reports Server (NTRS)

    Lee, S. C.

    1989-01-01

    The objective is to develop a real time fault monitoring and diagnosis knowledge-based system (KBS) for space power systems which can save costly operational manpower and can achieve more reliable space power system operation. The proposed KBS was developed using the Autonomously Managed Power System (AMPS) test facility currently installed at NASA Marshall Space Flight Center (MSFC), but the basic approach taken for this project could be applicable for other space power systems. The proposed KBS is entitled Autonomously Managed Power-System Extendible Real-time Expert System (AMPERES). In Phase 1 the emphasis was put on the design of the overall KBS, the identification of the basic research required, the initial performance of the research, and the development of a prototype KBS. In Phase 2, emphasis is put on the completion of the research initiated in Phase 1, and the enhancement of the prototype KBS developed in Phase 1. This enhancement is intended to achieve a working real time KBS incorporated with the NASA space power system test facilities. Three major research areas were identified and progress was made in each area. These areas are real time data acquisition and its supporting data structure; sensor value validations; development of inference scheme for effective fault monitoring and diagnosis, and its supporting knowledge representation scheme.

  6. Electrical and mechanical H(max)-to-M(max) ratio in power- and endurance-trained athletes.

    PubMed

    Maffiuletti, N A; Martin, A; Babault, N; Pensini, M; Lucas, B; Schieppati, M

    2001-01-01

    The aim of this study was to compare the mechanical and electromyographic (EMG) characteristics of soleus motor units activated during maximal H reflex and direct M response among subjects with different histories of physical activity. Power-trained athletes produced stronger twitches, with a higher rate of twitch tension buildup and relaxation, than their endurance counterparts for both maximal H-reflex and maximal M-wave responses. The maximal H-reflex-to-maximal M-wave ratios for both force output (twitch) and EMG wave amplitude were significantly lower in power-trained than endurance-trained athletes. However, power-trained athletes exhibited a significantly greater twitch-to-EMG ratio for the reflexly activated motor units with respect to the entire motor pool, whereas endurance-trained athletes had comparable twitch-to-EMG ratios for both reflexly and directly activated units. Power training increases the force output of the whole ensemble of the motor units, thereby compensating for the lower efficacy of the reflex transmission between Ia spindle afferent input and soleus alpha-motoneuron. On the other hand, the lower level of force evoked by the reflexly activated units in endurance-trained athletes is associated with a greater motor pool reflex excitability. Therefore, endurance-trained athletes produce the necessary force by recruitment of more slow-twitch units than do other subjects for comparable levels of force and type of task.

  7. Effect of muscular ultrasound stimulation on power spectrum electromyography during a strengthening training.

    PubMed

    Montes Molina, R; Martin Garcia, M S; Gonzalez Mayoral, M L

    2000-01-01

    The purpose of this study is to describe the electromyographic (EMG) power spectral evolution during a muscle strengthening training based on ultrasound stimulation applied to the right rectus femoris muscle simultaneously with its maximum voluntary isometric contraction (MVIC) in ten healthy subjects. From the surface EMG of rectus femoris the Zero Crossing (ZC) and integrated EMG (IEMG) were calculated. The Mean Power Frequency (MPF) and Median Frequency (MF) from the EMG power spectrum were obtained using a maximum entropy method. An Analysis of Variance (ANOVA) for repeated measures showed significant changes for IEMG and ZC throughout sessions and for MPF, MF and ZC between the pretest and posttest. Immediate increases in MPF, MF and ZC were observed (paired t-test, p < 0.05) after training and an increment of IEMG during sessions (one-way ANOVA, p = 0.01). The ultrasound pulsed stimulation applied simultaneously with a MVIC produced the development of the muscle force. The mechanism of action of this application could be the mechanical effect, compression and rarefaction, produced by the ultrasound stimulation during the muscle contraction process.

  8. Viewpoint: power and communication: why simulation training ought to be complemented by experiential and humanist learning.

    PubMed

    Hanna, Michael; Fins, Joseph J

    2006-03-01

    The authors present an analysis of communication training for medical students using simulation patients, and its possible influence on later doctor-patient relationships. Many empirical studies have shown the various benefits of using simulation patients to teach communication skills, but theoretical sociology and humanistic reflection shed light on some fundamental differences between the student-doctor/actor-patient interactions practiced in simulation encounters and real doctor-patient relationships. In contrast to the usual power dynamics of a doctor-patient relation, those of simulation encounters are inverted and overwritten by an entirely different set of power relations, namely, those of the evaluator-student relationship. Since the power dynamics of real doctor-patient relations are generally overlooked, the altered dynamics of the simulation encounter are not readily perceived, and simulation encounters are thus often mistaken as accurate representations of clinical reality. Exclusive reliance on this pedagogic approach of simulation training may be encouraging students to become "simulation doctors" who act out a good relationship to their patients but have no authentic connection with them. The authors propose that liberal-arts learning and encounters with real patients should be used to cultivate students' abilities to create good doctor-patient relationships, as a compliment to the pedagogic benefits of simulation encounters.

  9. Single Phase Passive Rectification Versus Active Rectification Applied to High Power Stirling Engines

    NASA Technical Reports Server (NTRS)

    Santiago, Walter; Birchenough, Arthur G.

    2006-01-01

    Stirling engine converters are being considered as potential candidates for high power energy conversion systems required by future NASA explorations missions. These types of engines typically contain two major moving parts, the displacer and the piston, in which a linear alternator is attached to the piston to produce a single phase sinusoidal waveform at a specific electric frequency. Since all Stirling engines perform at low electrical frequencies (less or equal to 100 Hz), space explorations missions that will employ these engines will be required to use DC power management and distribution (PMAD) system instead of an AC PMAD system to save on space and weight. Therefore, to supply such DC power an AC to DC converter is connected to the Stirling engine. There are two types of AC to DC converters that can be employed, a passive full bridge diode rectifier and an active switching full bridge rectifier. Due to the inherent line inductance of the Stirling Engine-Linear Alternator (SE-LA), their sinusoidal voltage and current will be phase shifted producing a power factor below 1. In order to keep power the factor close to unity, both AC to DC converters topologies will implement power factor correction. This paper discusses these power factor correction methods as well as their impact on overall mass for exploration applications. Simulation results on both AC to DC converters topologies with power factor correction as a function of output power and SE-LA line inductance impedance are presented and compared.

  10. FC vehicle hybridisation: an affordable solution for an energy-efficient FC powered drive train

    NASA Astrophysics Data System (ADS)

    Pede, G.; Iacobazzi, A.; Passerini, S.; Bobbio, A.; Botto, G.

    Fuel cells (FCs) have potential as clean and efficient energy sources for automotive applications without sacrifice in performance or driving range. However, the complete FC system must operate as efficiently as possible over the range of driving conditions that may be encountered while maintaining a low cost. To achieve this target, a storage unit can be introduced in the FC system to reduce the size of the fuel cell that is the most expensive component. This "hybrid" concept would not only reduce the drive train total cost but it also allow the recover of the braking energy and the operation at the voltage-current point of maximum efficiency for the FC system. Pro-and-cons of the "full-power" versus the "hybrid" configuration are shown in this work. The "Hybridisation rate" or "Hybridisation degree", a parameter expressed by the relationship between two installed powers, the generation power and the traction power, is also introduced and it is demonstrated that for each category of hybrid vehicles there is an optimal value of hybridisation degree. The storage systems considered are based on high power batteries or ultra capacitors (UCs) or a combination of them. A preliminary design of a sport utility vehicle (SUV) using a combined storage system and a FC energy source (called Triple Hybrid), is proposed. Finally, the experience of the Italian industry in this field is also reviewed.

  11. Switching speed effect of phase shift keying in SLED for generating high power microwaves

    NASA Astrophysics Data System (ADS)

    Xiong, Zheng-Feng; Cheng, Cheng; Yu, Jian; Chen, Huai-Bi; Ning, Hui

    2016-01-01

    SLAC energy doubler (SLED) type radio-frequency pulse compressors are widely used in large-scale particle accelerators for converting long-duration moderate-power input pulses into short-duration high-power output pulses. Phase shift keying (PSK) is one of the key components in SLED pulse compression systems. Performance of the PSK will influence the output characteristics of the SLED, such as the rise-time of the output pulse, maximal peak power gain, and energy efficiency. In this paper, a high power microwave source based on power combining and pulse compression of conventional klystrons is introduced. The effects of nonideal PSK with slow switching speed and PSK without power output during the switching process are investigated, and the experimental results with nonideal PSK agree well with the analytical results.

  12. Performance improvement from use of low ripple three phase power supply for electrostatic precipitators

    SciTech Connect

    Boyle, P.D.; Paradiso, G.; Thelen, P.L.

    1999-11-01

    Theory predicts potential improvement in electrostatic precipitator collection efficiency from the use of low ripple (near pure DC) high voltage. In recognition of this fact, Zero Emissions Technology Inc. designed and built a /transformer-rectifier (TR) set with substantially less ripple than occurs with conventional single-phase full wave rectified units. The Zero Emissions Technology TR set utilizes three-phase primary windings and wye-delta secondary windings configured to minimize the ripple in the output voltage. The authors previously reported on the results of initial testing of this power supply at the Moores Park Facility of the Lansing Board of Water and Light. Testing had shown that the three phase power supply was able to provide steadier and higher average voltages than the single phase conventional power supply and that collection efficiency appeared to improve also, based on reduced opacity. However, slow response of the analog-based three-phase TR set controller hampered performance of the unit and prevented definitive conclusions. A modern microprocessor based controller has now been adapted to operate the three-phase TR set. This paper is a follow-on to the previous report. It describes the results of the testing accomplished since issuance of that paper. Readers are encouraged to review the earlier paper for more details on the theory, test setup, and electrical performance of the three phase TR set.

  13. Alterations in speed of squat movement and the use of accommodated resistance among college athletes training for power.

    PubMed

    Rhea, Matthew R; Kenn, Joseph G; Dermody, Bryan M

    2009-12-01

    The purpose of this study was to assess the effect of heavy/slow movements and variable resistance training on peak power and strength development. Forty-eight National Collegiate Athletic Association (NCAA) Division I athletes (age: 21.4 +/- 2.1 years, all men) were recruited for this 12-week training intervention study. Maximum strength and jumping power were assessed before and after the training program. Athletes were randomly assigned to 1 of 3 training groups: heavy resistance/slow movement (Slow), lighter resistance and fast movement (Fast), or fast movements with accommodated resistance (FACC). All training groups performed similar training programs comprising free weight resistance training with lower-body compound exercises. The only difference among the training interventions was the speed at which subjects performed the squat exercise and the use of bands (Slow group: 0.2-0.4 meters/second; Fast group: 0.6-0.8 meters/second; FACC group trained 0.6-0.8 meters/second with the addition of accommodated resistance in the form of large elastic bands). Post-test data revealed a significant difference between power improvements between the Slow and FACC groups (p = 0.02). Percent increases and effect sizes (ES) demonstrated a much greater treatment effect in the FACC group (17.8%, ES = 1.06) with the Fast group (11.0%, ES = 0.80) adapting more than the Slow group (4.8%, ES = 0.28). The FACC and Slow groups improved strength comparatively (FACC: 9.44%, ES = 1.10; Slow: 9.59%, ES = 1.08). The Fast group improved strength considerably less, 3.20% with an effect size of only 0.38. Variable resistance training with elastic bands appears to provide greater performance benefits with regard to peak force and peak power than heavy, slow resistance exercise. Sports conditioning professionals can utilize bands, and high-speed contractions, to increase power development.

  14. Transient stability enhancement of electric power generating systems by 120-degree phase rotation

    DOEpatents

    Cresap, Richard L.; Taylor, Carson W.; Kreipe, Michael J.

    1982-01-01

    A method and system for enhancing the transient stability of an intertied three-phase electric power generating system. A set of power exporting generators (10) is connected to a set of power importing generators (20). When a transient cannot be controlled by conventional stability controls, and imminent loss of synchronism is detected (such as when the equivalent rotor angle difference between the two generator sets exceeds a predetermined value, such as 150 degrees), the intertie is disconnected by circuit breakers. Then a switch (30) having a 120-degree phase rotation, or a circuit breaker having a 120-degree phase rotation is placed in the intertie. The intertie is then reconnected. This results in a 120-degree reduction in the equivalent rotor angle difference between the two generator sets, making the system more stable and allowing more time for the conventional controls to stabilize the transient.

  15. Phase scintillations due to equatorial F region irregularities with two-component power law spectrum

    NASA Astrophysics Data System (ADS)

    Bhattacharyya, A.; Rastogi, R. G.

    1986-10-01

    Power spectra of weak phase scintillations on a 140-MHz signal, transmitted from the geostationary satellite ATS 6 and observed during premidnight and postmidnight periods at an equatorial station Ootacamund (magnetic dip 6 N), show that the nighttime equatorial F region irregularities in the wavelength range of about hundred meters to a few kilometers exhibit a two-component power law spectrum. The long- and short-wavelength spectral indices and the break scale at which the transition from a shallow to a steep slope occurs are determined self-consistently using both the phase and amplitude scintillation data. As the power spectra of phase scintillations do not exhibit the effect of Fresnel filtering, they provide fairly accurate estimates of the spectral indices and the break scale. These estimated parameters are utilized in a model calculation of the dependence of the S4 index on signal frequency based on weak scattering theory.

  16. Influence of length-restricted strength training on athlete's power-load curves of knee extensors and flexors.

    PubMed

    Ullrich, Boris; Kleinöder, Heinz; Brüggemann, Gert-Peter

    2010-03-01

    This study investigated whether different length-restricted strength training regimens affect voluntary explosive concentric power-load curves of the quadriceps femoris (QF) and hamstring (HAM) muscles. Thirty-two athletes were divided into 3 different training groups (G1-G3): G1 performed isometric training at knee joint angles corresponding to long muscle-tendon unit (MTU) length for QF and HAM; G2 conducted concentric-eccentric contraction cycles that were restricted to a knee joint range of motion corresponding to predominantly long MTU length for QF and HAM; and G3 combined the protocols of G1 and G2. Knee joint angle-dependent power-load curves during maximal voluntary explosive concentric knee extensions and flexions were measured for loads corresponding to 40, 60, and 80% of individual 1 repetition maximum at 5 different occasions: 2 times before, after 5 and 8 weeks of training, and 4 weeks post training. Power values of each subject were normalized to the largest value produced at any knee joint position (percent maximum). Obtained by curve fitting, the optimal knee joint angle for power production of QF and HAM remained unaltered throughout the course of the study for all testing loads and training groups. Therefore, different strength training regimens with a common restriction to long MTU lengths failed to induce length-dependent alterations in athlete's voluntary concentric power-load curves of knee extensors and flexors. The approach to develop strength training programs that induce systematic shifts in length-dependent power production of QF and HAM is of direct practical relevance for athletic activities such as cycling, ice skating, and skiing. However, restricting the muscle excursion range during loading seems to be an inappropriate trigger to cause length-dependent alterations in athlete's voluntary concentric power-load curves.

  17. Computation of inflationary cosmological perturbations in the power-law inflationary model using the phase-integral method

    SciTech Connect

    Rojas, Clara; Villalba, Victor M.

    2007-03-15

    The phase-integral approximation devised by Froeman and Froeman, is used for computing cosmological perturbations in the power-law inflationary model. The phase-integral formulas for the scalar and tensor power spectra are explicitly obtained up to ninth-order of the phase-integral approximation. We show that, the phase-integral approximation exactly reproduces the shape of the power spectra for scalar and tensor perturbations as well as the spectral indices. We compare the accuracy of the phase-integral approximation with the results for the power spectrum obtained with the slow-roll and uniform-approximation methods.

  18. Development of a DC-DC conversion powering scheme for the CMS Phase-1 pixel upgrade

    NASA Astrophysics Data System (ADS)

    Feld, L.; Fimmers, C.; Karpinski, W.; Klein, K.; Lipinski, M.; Preuten, M.; Rauch, M.; Rittich, D.; Sammet, J.; Wlochal, M.

    2014-01-01

    A novel powering scheme based on the DC-DC conversion technique will be exploited to power the CMS Phase-1 pixel detector. DC-DC buck converters for the CMS pixel project have been developed, based on the AMIS5 ASIC designed by CERN. The powering system of the Phase-1 pixel detector is described and the performance of the converter prototypes is detailed, including power efficiency, stability of the output voltage, shielding, and thermal management. Results from a test of the magnetic field tolerance of the DC-DC converters are reported. System tests with pixel modules using many components of the future pixel barrel system are summarized. Finally first impressions from a pre-series of 200 DC-DC converters are presented.

  19. The periodization of resistance training in soccer players: changes in maximal strength, lower extremity power, body composition, and muscle volume.

    PubMed

    Barjaste, Amir; Mirzaei, Bahman

    2017-02-22

    The purpose of this study was to investigate the effect of 12-weeks traditional periodized resistance training on some physical capacities of soccer players. Eighteen amateur soccer players with very little experience in resistance training voluntarily participated in this study. Subjects were assigned into two groups; Experimental (EX) group (n: 10) that conducted a traditional linear periodized resistance training program and a control (C) group (n: 8) that did not participate in any resistance training. Periodized resistance training in two mesocycles was used in this study: general or anatomical adaptation phase (6 wk, 65%-75% of 1RM, eleven exercises in each session) and maximal strength phase (6 wk, 85%-95% of 1RM, three to four exercises in each session). One Repetition Maximum (1RM) strength in lower and upper body, Vertical Jump (VJ) height, Body Composition, and Muscle Volume were measured at three different time points; baseline, after general phase, and after maximal strength phase. The average of the increase in 1RM all exercises in general phase was greater than the maximal strength phase, on average 29.38% and 9.67% respectively (P≤0.05). Also, the Percentage of change in VJ height in general phase was greater than the maximal strength phase (11.93% vs 3.97% respectively) (P≤0.05).0 CONCLUSIONS: The results of this study indicated that muscle strength and explosive performance in players with the little experience in resistance training can be significantly improved with the completion of general phase of resistance training periodization using moderate loads.

  20. Power-scalable system of phase-locked single-mode diode lasers.

    PubMed

    Bartelt-Berger, L; Brauch, U; Giesen, A; Huegel, H; Opower, H

    1999-09-20

    The direct use of diode lasers for high-power applications in material processing is limited to applications with relatively low beam quality and power density requirements. To achieve high beam quality one must use single-mode diode lasers, however with the drawback of relatively low optical output powers from these components. To realize a high-power system while conserving the high beam quality of the individual emitters requires coherent coupling of the emitters. Such a power-scalable system consisting of 19 slave lasers that are injection locked by one master laser has been built and investigated, with low-power diode lasers used for system demonstration. The optical power of the 19 injection-locked lasers is coupled into polarization-maintaining single-mode fibers and geometrically superimposed by a lens array and a focusing lens. The phase of each emitter is controlled by a simple electronic phase-control loop. The coherence of each slave laser is stabilized by computer control of the laser current and guarantees a stable degree of coherence of the whole system of 0.7. An enhancement factor of 13.2 in peak power density compared with that which was achievable with the incoherent superposition of the diode lasers was observed.

  1. Early-phase adaptations to intrahospital training in strength and functional mobility of children with leukemia.

    PubMed

    San Juan, Alejandro F; Fleck, Steven J; Chamorro-Viña, Carolina; Maté-Muñoz, José L; Moral, Susana; García-Castro, Javier; Ramírez, Manuel; Madero, Luis; Lucia, Alejandro

    2007-02-01

    Improvements in chemotherapy and radiotherapy have contributed to the high survival rate (approximately 70%) of childhood acute lymphoblastic leukemia (ALL). However, during treatment, lack of physical activity and treatment cause various short- to long-term side effects, such as muscle atrophy and physical deconditioning. The purpose of this study was to determine the effects of an intrahospital, short-duration (8 weeks) exercise training program on muscle strength and endurance and functional mobility of children with ALL. Seven children (4 boys and 3 girls; 4-7 years of age) who were in the maintenance phase of treatment for ALL were selected as subjects. Three training sessions of 90- to 120-minute duration were performed each week. Each session included 11 different strength exercises engaging the major muscle groups and aerobic training. Gains in strength and endurance were assessed with a 6 repetition maximum test for upper (seated bench press and seated lateral row) and lower extremities (leg press). Gains in functional mobility were assessed with the time up and go test (TUG) and the timed up and down stairs test (TUDS). Performance was significantly improved after the training program in all strength tests (p < 0.01 for seated bench press and p < 0.05 for both seated lateral row and seated leg press) and in the TUG test (p < 0.05). In summary, a period of time as short as 8 weeks is enough to produce clinically relevant early-phase adaptations in children receiving treatment against ALL (i.e., improved functional mobility and muscle strength). Although more research is needed in the area of exercise training and pediatric cancer, exercise sciences can play a beneficial role in assisting both oncologists in treating cancer and improving children's quality of life during and after treatment.

  2. Simple model to explain instabilities in passively-phased high-power fiber laser arrays

    SciTech Connect

    Bochove, Erik J.; Shakir, Sami A.; Aceves, Alejandro B.; Braiman, Yehuda; Deiterding, Ralf; Miller, Casey A; Colet, Pere R.; Jacobo, Adrian; Rhodes, Charles

    2011-01-01

    We propose a simple physical mechanism to explain observed instabilities in the dynamics of passively phased fiber amplifier arrays that arises from two properties: First that a weak phase disturbance of the output field of the array is converted into a strong intensity disturbance through the mode-selective feedback mechanism. Second, that this intensity fluctuation regenerates a phase fluctuation due to the nonlinear properties of the amplifying media. At sufficiently high operating power levels this cyclic disturbance continues to grow upon each cavity round trip, creating instability. This simple picture is supported by the results of a linear stability analysis of the set of propagation and population rate equations, which are in good agreement with observed critical power levels. A third level of quantitative confirmation was obtained by comparison to the results of numerical integration of the original set of nonlinear equations. This predicted instability is entirely a property of passively phased arrays of more than one element.

  3. Dynamic Comparison of Three- and Four-Equation Reactor Core Models in a Full-Scope Power Plant Training Simulator

    SciTech Connect

    Espinosa-Paredes, Gilberto; Alvarez-Ramirez, Jose; Nunez-Carrera, Alejandro; Garcia-Gutierrez, Alfonso; Martinez-Mendez, Elizabeth Jeannette

    2004-02-15

    A comparative analysis of the dynamic behavior of a boiling water reactor in a full-scope power plant simulator for operator training is presented. Three- and four-equation reactor core models were used to examine three transients following tests described in acceptance test procedures: scram, loss of feedwater flow, and closure of main isolation valves. The three-equation model consists of water and steam mixture momentum, including mass and energy balances. The four-equation model is based on liquid and gas phase mass balances, together with a drift-flux approach for the analysis of phase separation. Analysis of the models showed that the scram transient was slightly different for three- and four-equation models. The drift-flux effects can explain such differences. Regarding the loss-of-feedwater transient, the predicted steam flow after scram is larger for the three-equation model. Finally, for the transient related to the closure of main steam isolation valves, the three-equation model provides slightly different results for the pressure change, which affects reactor level behavior.

  4. Demonstration of a Variable Phase Turbine Power System for Low Temperature Geothermal Resources

    SciTech Connect

    Hays, Lance G

    2014-07-07

    A variable phase turbine assembly will be designed and manufactured having a turbine, operable with transcritical, two-phase or vapor flow, and a generator – on the same shaft supported by process lubricated bearings. The assembly will be hermetically sealed and the generator cooled by the refrigerant. A compact plate-fin heat exchanger or tube and shell heat exchanger will be used to transfer heat from the geothermal fluid to the refrigerant. The demonstration turbine will be operated separately with two-phase flow and with vapor flow to demonstrate performance and applicability to the entire range of low temperature geothermal resources. The vapor leaving the turbine is condensed in a plate-fin refrigerant condenser. The heat exchanger, variable phase turbine assembly and condenser are all mounted on single skids to enable factory assembly and checkout and minimize installation costs. The system will be demonstrated using low temperature (237F) well flow from an existing large geothermal field. The net power generated, 1 megawatt, will be fed into the existing power system at the demonstration site. The system will demonstrate reliable generation of inexpensive power from low temperature resources. The system will be designed for mass manufacturing and factory assembly and should cost less than $1,200/kWe installed, when manufactured in large quantities. The estimated cost of power for 300F resources is predicted to be less than 5 cents/kWh. This should enable a substantial increase in power generated from low temperature geothermal resources.

  5. Phase incremented echo train acquisition applied to magnetic resonance pore imaging

    NASA Astrophysics Data System (ADS)

    Hertel, S. A.; Galvosas, P.

    2017-02-01

    Efficient phase cycling schemes remain a challenge for NMR techniques if the pulse sequences involve a large number of rf-pulses. Especially complex is the Carr Purcell Meiboom Gill (CPMG) pulse sequence where the number of rf-pulses can range from hundreds to several thousands. Our recent implementation of Magnetic Resonance Pore Imaging (MRPI) is based on a CPMG rf-pulse sequence in order to refocus the effect of internal gradients inherent in porous media. While the spin dynamics for spin- 1 / 2 systems in CPMG like experiments are well understood it is still not straight forward to separate the desired pathway from the spectrum of unwanted coherence pathways. In this contribution we apply Phase Incremented Echo Train Acquisition (PIETA) to MRPI. We show how PIETA offers a convenient way to implement a working phase cycling scheme and how it allows one to gain deeper insights into the amplitudes of undesired pathways.

  6. Weight lifted and countermovement potentiation of power in concentric phase of unstable and traditional resistance exercise.

    PubMed

    Zemková, Erika; Jelen, Michal; Kováciková, Zuzana; Ollé, Gábor; Vilman, Tomás; Hamar, Dusan

    2014-04-01

    The study evaluates the effect of weight lifted on power in the concentric phase of resistance exercises on stable and unstable surfaces. A group of 19 fit men performed randomly on different days 3 reps of (a) barbell chest presses on the bench and Swiss ball, and (b) barbell squats on stable base and BOSU ball. Exercises were performed without and with countermovement (CM) using maximal effort in concentric phase. Initial weight of 20 kg was increased by 10 kg or 5 kg (at higher loads) up to at least 85% of previously established 1RM under stable conditions. Results showed no significant differences in mean power in the concentric phase of stable and unstable CM chest presses at lower weights lifted (from 20 to 50 kg). However, its values were significantly higher during chest presses on the bench than on Swiss ball while lifting higher weights (from 60 to 90 kg). Similarly, mean power in the concentric phase of squats was significantly higher on stable base than on BOSU ball at higher weights lifted (from 60 to 90 kg). Though a set of data showed significant differences, the effect sizes≤0.7 suggest no practically meaningful differences. It may be concluded that unstable base compromises the power in the concentric phase of resistance exercises, however, only at higher weights lifted.

  7. Optical retrodirective tracking system approach using an array of phase conjugators for communication and power transmission.

    PubMed

    Schäfer, Christian A; Matoba, Osamu; Kaya, Nobuyuki

    2007-07-20

    A new concept for a retrodirective tracking system applicable for communication and power transmission is proposed. In the proposed concept, the power transmitter utilizes a receiver's pilot signal to obtain information about its direction by conjugating the signal's phase inside a nonlinear medium. Power is therefore transmitted back to the receiver by the phase-conjugated signal beam. The power can be concentrated by an array of phase conjugators, which provides a large aperture so that the intensity can be increased on the receiver's photovoltaic panels compared to a single element. Controlling the phase and the direction of the readout beams in the four-wave-mixing process provides control over the interference pattern, its position, and its size. A numerical analysis is given for the phase and spot size control, and measurements with two Co-doped Sr(x)Ba(1-x)Nb(2)O(6) (Co:SBN) crystals confirm the occurrence of interference that is achieved for the case of two beams.

  8. Three-Phase Time-Multiplexed Planar Power Transmission to Distributed Implants.

    PubMed

    Lee, Byunghun; Ahn, Dukju; Ghovanloo, Maysam

    2016-03-01

    A platform has been presented for wireless powering of receivers (Rx's) that are arbitrarily distributed over a large area. A potential application could be powering of small Rx implants, distributed over large areas of the brain. The transmitter (Tx) consists of three overlapping layers of hexagonal planar spiral coils (hex-PSC) that are horizontally shifted to provide the strongest and most homogeneous electromagnetic flux coverage. The three-layer hex-PSC array is driven by a three-phase time-division-multiplexed power Tx that takes the advantage of the carrier phase shift, coil geometries, and Rx time constant to homogeneously power the arbitrarily distributed Rx's regardless of their misalignments. The functionality of the proposed three-phase power transmission concept has been verified in a detailed scaled-up high-frequency structure simulator Advanced Design System simulation model and measurement setup, and compared with a conventional Tx. The new Tx delivers 5.4 mW to each Rx and achieves, on average, 5.8% power transfer efficiency to the Rx at the worst case 90° angular misalignment, compared with 1.4% by the conventional Tx.

  9. Design requirements document for the phase 1 privatization electrical power system

    SciTech Connect

    Singh, G.

    1997-10-31

    The electrical system for the Phase 1 privatization facilities will support the TWRS mission by providing the electrical power to the Phase 1 privatized facilities. This system will receive power from the Department of Energy-Richland Operations (RL) A4-8 230 kV transmission system powered from Bonneville Power Administration (BPA) Ashe and Midway 230 kV Substations. The existing RL 230 kV transmission line will be modified and looped 1021 into the new 230 kV substation bus. The new substation will be located in the vicinity of the privatized facilities, approximately 3.2 km (2 mi) south of the existing RL A4-8 230 kV transmission line. The substation will be capable of providing up to 40 MW of electrical power to support the Phase 1 privatization facilities and has space for accommodating future expansions. The substation will require at least two 230-13.8 kV transformers, 13.8 kV split bus switchgear, switchgear building, grounding transformers, instrument transformers, control and monitoring equipment, associated protection and isolation devices, lightning protection, yard lighting, cable and raceways, and infrastructure needed to provide desired availability and reliability. The power from the 13.8 kV switchgear located in the switchgear building will be delivered at the privatization facilities site boundaries. The 13.8 kV distribution system inside the privatization facilities site boundaries is the responsibility of the privatization contract.

  10. Three-Phase Time-Multiplexed Planar Power Transmission to Distributed Implants

    PubMed Central

    Lee, Byunghun; Ahn, Dukju; Ghovanloo, Maysam

    2015-01-01

    A platform has been presented for wireless powering of receivers (Rx's) that are arbitrarily distributed over a large area. A potential application could be powering of small Rx implants, distributed over large areas of the brain. The transmitter (Tx) consists of three overlapping layers of hexagonal planar spiral coils (hex-PSC) that are horizontally shifted to provide the strongest and most homogeneous electromagnetic flux coverage. The three-layer hex-PSC array is driven by a three-phase time-division-multiplexed power Tx that takes the advantage of the carrier phase shift, coil geometries, and Rx time constant to homogeneously power the arbitrarily distributed Rx's regardless of their misalignments. The functionality of the proposed three-phase power transmission concept has been verified in a detailed scaled-up high-frequency structure simulator Advanced Design System simulation model and measurement setup, and compared with a conventional Tx. The new Tx delivers 5.4 mW to each Rx and achieves, on average, 5.8% power transfer efficiency to the Rx at the worst case 90° angular misalignment, compared with 1.4% by the conventional Tx. PMID:27034913

  11. The effect of ephedra and caffeine on maximal strength and power in resistance-trained athletes.

    PubMed

    Williams, Andrew D; Cribb, Paul J; Cooke, Matthew B; Hayes, Alan

    2008-03-01

    Caffeine and ephedrine-related alkaloids recently have been removed from International Olympic Committee banned substances lists, whereas ephedrine itself is now permissible at urinary concentrations less than 10 mug.mL. The changes to the list may contribute to an increased use of caffeine and ephedra as ergogenic aids by athletes. Consequently, we sought to investigate the effects of ingesting caffeine (C) or a combination of ephedra and caffeine (C + E) on muscular strength and anaerobic power using a double-blind, crossover design. Forty-five minutes after ingesting a glucose placebo (P: 300 mg), C (300 mg) or C + E (300 mg + 60 mg), 9 resistance-trained male participants were tested for maximal strength by bench press [BP; 1 repetition maximum (1RM)] and latissimus dorsi pull down (LP; 1RM). Subjects also performed repeated repetitions at 80% of 1RM on both BP and LP until exhaustion. After this test, subjects underwent a 30-second Wingate test to determine peak anaerobic cycling power, mean power, and fatigue index. Although subjects reported increased alertness and enhanced mood after supplementation with caffeine and ephedra, there were no significant differences between any of the treatments in muscle strength, muscle endurance, or peak anaerobic power. Our results do not support the contention that supplementation with ephedra or caffeine will enhance either muscle strength or anaerobic exercise performance.

  12. Volume and Mass Estimation of Three-Phase High Power Transformers for Space Applications

    NASA Technical Reports Server (NTRS)

    Kimnach, Greg L.

    2004-01-01

    Spacecraft historically have had sub-1kW(sub e), electrical requirements for GN&C, science, and communications: Galileo at 600W(sub e), and Cassini at 900W(sub e), for example. Because most missions have had the same order of magnitude power requirements, the Power Distribution Systems (PDS) use existing, space-qualified technology and are DC. As science payload and mission duration requirements increase, however, the required electrical power increases. Subsequently, this requires a change from a passive energy conversion (solar arrays and batteries) to dynamic (alternator, solar dynamic, etc.), because dynamic conversion has higher thermal and conversion efficiencies, has higher power densities, and scales more readily to higher power levels. Furthermore, increased power requirements and physical distribution lengths are best served with high-voltage, multi-phase AC to maintain distribution efficiency and minimize voltage drops. The generated AC-voltage must be stepped-up (or down) to interface with various subsystems or electrical hardware. Part of the trade-space design for AC distribution systems is volume and mass estimation of high-power transformers. The volume and mass are functions of the power rating, operating frequency, the ambient and allowable temperature rise, the types and amount of heat transfer available, the core material and shape, the required flux density in a core, the maximum current density, etc. McLyman has tabulated the performance of a number of transformers cores and derived a "cookbook" methodology to determine the volume of transformers, whereas Schawrze had derived an empirical method to estimate the mass of single-phase transformers. Based on the work of McLyman and Schwarze, it is the intent herein to derive an empirical solution to the volume and mass estimation of three-phase, laminated EI-core power transformers, having radiated and conducted heat transfer mechanisms available. Estimation of the mounting hardware, connectors

  13. Strength training increases endurance time to exhaustion during high-intensity exercise despite no change in critical power.

    PubMed

    Sawyer, Brandon J; Stokes, David G; Womack, Christopher J; Morton, R Hugh; Weltman, Arthur; Gaesser, Glenn A

    2014-03-01

    The purpose of this study was to determine whether improvements in endurance exercise performance elicited by strength training were accurately reflected by changes in parameters of the power-duration hyperbola for high-intensity exercise. Before and after 8 weeks of strength training (N = 14) or no exercise, control (N = 5), 19 males (age: 20.6 ± 2.0 years; weight: 78.2 ± 15.9 kg) performed a maximal incremental exercise test on a cycle ergometer and also cycled to exhaustion during 4 constant-power exercise bouts. Critical power (CP) and anaerobic work capacity (W') were estimated using nonlinear and linear models. Subjects in the strength training group improved significantly more than controls (p < 0.05) for strength (~30%), power at V[Combining Dot Above]O2peak (7.9%), and time to exhaustion (TTE) for all 4 constant-power tests (~39%). Contrary to our hypothesis, CP did not change significantly after strength training (p > 0.05 for all models). Strength training improved W' (mean range of improvement = +5.8 to +10.0 kJ; p < 0.05) for both linear models. Increases in W' were consistently positively correlated with improvements in TTE, whereas changes in CP were not. Our findings indicate that strength training alters the power-duration hyperbola such that W' is enhanced without any improvement in CP. Consequently, CP may not be robust enough to track changes in endurance capacity elicited by strength training, and we do not recommend it to be used for this purpose. Conversely, W' may be the better indicator of improvement in endurance performance elicited by strength training.

  14. Performance test results for the Eaton dc development power train in an electric test bed vehicle

    NASA Astrophysics Data System (ADS)

    Crumley, R. L.; Donaldson, M. R.

    1987-09-01

    This report presents the results of the tests performed on a direct current (dc) power train in a test bed vehicle developed by the Eaton Corporation for the U.S. Department of Energy (DOE). The tests were performed by EG and G Idaho, Inc. at the Idaho National Engineering Laboratory (INEL). The purpose of the INEL testing was to provide test results from which an evaluation of the performance capabilities of the Eaton dc power train could be made and compared with other vehicle propulsion systems. The planned tests were primarily oriented toward road testing, chassis dynamometer testing, and associated dynamometer coastdown tests for road loss determination. Range tests of the Eaton dc test bed vehicle using an ALCO 2200 lead acid battery pack, produced ranges of 97 km at 56 km/h (60 miles at 35 mph), 79 km at 72 km/h (49 miles at 45 mph), and 47 km at 88 km/h (29 miles at 55 mph). The corresponding net dc energy consumptions are 135 Wh/km (217 Wh/mile), 145 Wh/km (233 Wh/mile), and 178 Wh/km (287 Wh/mile). The energy consumption for the D-cycle test was 241 Wh/km (387 Wh/mile).

  15. Body-building without power training: endogenously regulated pectoral muscle hypertrophy in confined shorebirds

    PubMed

    Dietz; Piersma; Dekinga

    1999-10-01

    Shorebirds such as red knots Calidris canutus routinely make migratory flights of 3000 km or more. Previous studies on this species, based on compositional analyses, suggest extensive pectoral muscle hypertrophy in addition to fat storage before take-off. Such hypertrophy could be due to power training and/or be effected by an endogenous circannual rhythm. Red knots of two subspecies with contrasting migration patterns were placed in a climate-controlled aviary (12 h:12 h L:D photoperiod) where exercise was limited. Using ultrasonography, we measured pectoral muscle size as the birds stored fat in preparation for migration. At capture, there were no differences in body mass and pectoral muscle mass between the two subspecies. As they prepared for southward and northward migration, respectively, the tropically wintering subspecies (C. c. canutus) gained 31 g and the temperate wintering subspecies (C. c. islandica) gained 41 g. During this time, pectoral mass increased by 43-44 % of initial mass, representing 39 % (C. c. canutus) and 29 % (C. c. islandica) of the increase in body mass. The gizzard showed atrophy in conjunction with a diet change from molluscs to food pellets. Although we cannot exclude the possibility that the birds' limited movement may still be a prerequisite for pectoral muscle hypertrophy, extensive power training is certainly not a requirement. Muscle hypertrophy in the absence of photoperiod cues suggests the involvement of an endogenous circannual process.

  16. Effects of strength and power training on neuromuscular variables in older adults.

    PubMed

    Wallerstein, Lilian França; Tricoli, Valmor; Barroso, Renato; Rodacki A, L F; Russo, Luciano; Aihara, André Yui; da Rocha Correa Fernandes, Artur; de Mello, Marco Tulio; Ugrinowitsch, Carlos

    2012-04-01

    The purpose of this study was to compare the neuromuscular adaptations produced by strength-training (ST) and power-training (PT) regimens in older individuals. Participants were balanced by quadriceps cross-sectional area (CSA) and leg-press 1-repetition maximum and randomly assigned to an ST group (n = 14; 63.6 ± 4.0 yr, 79.7 ± 17.2 kg, and 163.9 ± 9.8 cm), a PT group (n = 16; 64.9 ± 3.9 yr, 63.9 ± 11.9 kg, and 157.4 ± 7.7 cm), or a control group (n = 13; 63.0 ± 4.0 yr, 67.2 ± 10.8 kg, and 159.8 ± 6.8 cm). ST and PT were equally effective in increasing (a) maximum dynamic and isometric strength (p < .05), (b) increasing quadriceps muscle CSA (p < .05), and (c) decreasing electrical mechanical delay of the vastus lateralis muscle (p < .05). There were no significant changes in neuromuscular activation after training. The novel finding of the current study is that PT seems to be an attractive alternative to regular ST to maintain and improve muscle mass.

  17. A Low Power Linear Phase Digital FIR Filter for Wearable ECG Devices.

    PubMed

    Lian, Yong; Yu, Jianghong

    2005-01-01

    In this paper we present a low power linear phase digital FIR filter which is a part of an ECG-on-Chip. The ECG-on-Chip can be embedded into clothing to acquire the electrocardiogram (ECG) signal and send a warning message to a mobile phone or PDA if an abnormal ECG is detected. The proposed new filter structure significantly reduces the arithmetic operations for each sample which in turn lowers the power consumption. The filter is developed based on the interpolated finite impulse filter technique and is very attractive for a low cost and low power VLSI implementation.

  18. Feasibility Study of a 400 Hz, 4160 Volt 3-Phase Electrical Power Distribution System

    DTIC Science & Technology

    1977-02-25

    application of 400 Hz power at 4160 volts that has not been achieved until now except for an experimental installation at Patuxent River NATC, Maryland (Refer...d. TRAINING FACILITIES e. SPECIAL REQUIREMENTS - Tacamo (Pax River NATC), Radar Test Cells (Oceana NAS) (Reference Number 3). 1,4.2 Maximum Demand...a maximum length of 16,000 feet has been used as this Is the largest run encountered. This maximum length occurs at SPotuxent River NATC, Maryland

  19. Improved Walking Capacity and Muscle Strength After Functional Power-Training in Young Children With Cerebral Palsy.

    PubMed

    van Vulpen, Liesbeth F; de Groot, Sonja; Rameckers, Eugene; Becher, Jules G; Dallmeijer, Annet J

    2017-09-01

    Strength training programs for children with cerebral palsy (CP) showed inconclusive evidence for improving walking, despite improvements in strength. Recent studies have suggested that strength training with high movement velocity is more effective for improving walking than traditional resistance training. The purpose of this study was to evaluate the effect of functional high-velocity resistance training (power-training) to improve muscle strength and walking capacity of children with CP. Twenty-two children with spastic CP participated (13 bilateral, Gross Motor Function Classification System [GMFCS] level I [n = 10] and II [n = 12], 7.5 years [SD 1.8, range 4-10 years]). Within-subjects changes in a 14-weeks usual care period were compared with changes in a 14-week functional power-training period (in groups, 3×/wk). Outcome measures were the muscle power sprint test (MPST), 1-minute walk test (1MWT), 10-m shuttle run test (SRT), gross motor function (GMFM-66), isometric strength of lower-limb muscles and dynamic ankle plantar flexor strength. Changes during the training period were significantly larger than changes in the usual care period for all outcome measures ( P < .05). Large improvements were found during the training period for walking capacity (ΔMPST [mean]: 27.6 W [95%CI 15.84-39.46, 83% increase], Δ1MWT: 9.4 m [95% CI 4.17-14.68, 13%], ΔSRT: 4.2 [95%CI 2.57-5.83, 56%], ΔGMFM-66: 5.5 [95% CI 3.33-7.74, 7%]) and muscle strength (18%-128%), while outcomes remained stable in the usual care period. The results indicate that functional power-training is an effective training for improving walking capacity in young children with cerebral palsy.

  20. Effect of Different Training Methods on Stride Parameters in Speed Maintenance Phase of 100m Sprint Runningmel.

    PubMed

    Cetin, Emel; Hindistan, Ibrahim Ethem; Ozkaya, Yasar Gul

    2017-04-27

    This study examined the effects of two different training methods relevant to sloping surface on stride parameters in speed maintenance phase of 100 m sprint running. Twenty recreationally active students were assigned into one of three groups: combined training (Com), horizontal training (H), and control (C) group. Com group performed uphill and downhill training on a sloping surface with an angle of 4°, while H group trained on a horizontal surface, 3 days a week for 8 weeks. Speed maintenance and deceleration phases were divided into distances with 10m intervals, and running time (t), running velocity (RV), step frequency (SF) and step length (SL) were measured at pre-, and post-exercise period. After 8-weeks of training program, t was shortened by 3.97% in Com group, and 2.37% in H group. RV also increased for totally 100m of running distance by 4,13% and 2,35% in Com, and H groups, respectively. At the speed maintenance phase, although t and maximal RV (RVmax) found to be statistically unaltered during overall phase, t was found to be decreased, and RVmax was preceded by 10m in distance in both training groups. SL was increased at 60-70m, and SF was decreased at 70-80m in H group. SL was increased with concomitant decrease in SF at 80-90m in Com group. Both training groups were maintained the RVmax with a great percentage at the speed maintenance phase. In conclusion, although both training methods resulted an increase in running time and RV, Com training method was more prominently effective method in improving RV, and this improvement was originated from the positive changes in SL during the speed maintaining phase.

  1. Resting-state EEG power and coherence vary between migraine phases.

    PubMed

    Cao, Zehong; Lin, Chin-Teng; Chuang, Chun-Hsiang; Lai, Kuan-Lin; Yang, Albert C; Fuh, Jong-Ling; Wang, Shuu-Jiun

    2016-12-01

    Migraine is characterized by a series of phases (inter-ictal, pre-ictal, ictal, and post-ictal). It is of great interest whether resting-state electroencephalography (EEG) is differentiable between these phases. We compared resting-state EEG energy intensity and effective connectivity in different migraine phases using EEG power and coherence analyses in patients with migraine without aura as compared with healthy controls (HCs). EEG power and isolated effective coherence of delta (1-3.5 Hz), theta (4-7.5 Hz), alpha (8-12.5 Hz), and beta (13-30 Hz) bands were calculated in the frontal, central, temporal, parietal, and occipital regions. Fifty patients with episodic migraine (1-5 headache days/month) and 20 HCs completed the study. Patients were classified into inter-ictal, pre-ictal, ictal, and post-ictal phases (n = 22, 12, 8, 8, respectively), using 36-h criteria. Compared to HCs, inter-ictal and ictal patients, but not pre- or post-ictal patients, had lower EEG power and coherence, except for a higher effective connectivity in fronto-occipital network in inter-ictal patients (p < .05). Compared to data obtained from the inter-ictal group, EEG power and coherence were increased in the pre-ictal group, with the exception of a lower effective connectivity in fronto-occipital network (p < .05). Inter-ictal and ictal patients had decreased EEG power and coherence relative to HCs, which were "normalized" in the pre-ictal or post-ictal groups. Resting-state EEG power density and effective connectivity differ between migraine phases and provide an insight into the complex neurophysiology of migraine.

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

    PubMed

    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.

  3. Simulation of a Three-Phase Multilevel Unified Power Flow Controller UPFC

    NASA Astrophysics Data System (ADS)

    Mailah, N. F.; Bashi, S. M.; Mariun, N.; Aris, I.

    This work deals with the study and simulation of Unified Power Flow Control (UPFC) at its normal and abnormal conditions. The systems are modeled and simulated using MATLAB software. Shunt inverter or Static Compensator (STATCOM) is modeled as a 3-phase multipulse converter and the series inverter or SSSC has been constructed as a 3-phase, 3-level multilevel converter. Faults are set to the system to observe the operation of STATCOM and phase shift, φ of the SSSC is varied to observe the operation of SSSC. Simulations are carried out and the results obtained agreed with the theory of operation of the UPFC.

  4. Long Term Effects of Different Training Modalities on Power, Speed, Skill and Anaerobic Capacity in Young Male Basketball Players

    PubMed Central

    Balčiūnas, Mindaugas; Stonkus, Stanislovas; Abrantes, Catarina; Sampaio, Jaime

    2006-01-01

    The purpose of this study was to identify the effect of 4 months of different training modalities on power, speed, skill and anaerobic capacity in 15-16 year old male basketball players. Thirty five Lithuanian basketball players were randomly assigned into three groups: power endurance group (intermittent exercise, PE, n = 12), general endurance group (continuous exercise, GE, n = 11) and control group (regular basketball training, CG, n = 12). The power endurance model was based in basketball game external structure whereas the general endurance model was based in continuous actions that frequently occur during the basketball game. The training models were used for 16 weeks in sessions conducted 3 times a week during 90 minutes each in the competition period. The following tests were performed: 20 m speed run, Squat jump, Countermovement jump, Running-based Anaerobic Sprint Test (RAST), 2 min. shooting test and the Shuttle ball-dribbling test. A 3×2 repeated measures ANOVA revealed no statistically significant differences in the 20 m speed run, Squat jump and Countermovement jump (p > 0.05). On the other hand, RAST showed significant increases in PE, with greater increases during the 5th and 6th runs. The PE training model also produced a significant improvement in the shuttle ball-dribbling test (48.7 ± 1.5 in the pretest, 45.5 ± 1.3 in the posttest, p < 0.05). Globally, our results suggest that both training modalities were able to maintain initial values of speed and power, however, the anaerobic capacity and skill increased only in the players from the power endurance group. Therefore, the power endurance training (intermittent high intensity exercise) may be more beneficial to prepare junior players according to the game cardiovascular and metabolic specific determinants. Key Points Power endurance training produced significant increases in anaerobic capacity during the competition period. Power endurance training did not have a detrimental effect on power

  5. Design of Training Systems, Phase II Report, Volume II; Detailed Model Descriptions. TAEG Report No. 12-2.

    ERIC Educational Resources Information Center

    Naval Training Equipment Center, Orlando, FL. Training Analysis and Evaluation Group.

    The Design of Training Systems (DOTS) project was initiated by the Department of Defense (DOD) to develop tools for the effective management of military training organizations. Phase 2 involved the design and development of three computer-based mathematical models, described in detail in this report. The models described are the System…

  6. Phase-locking and coherent power combining of broadband linearly chirped optical waves.

    PubMed

    Satyan, Naresh; Vasilyev, Arseny; Rakuljic, George; White, Jeffrey O; Yariv, Amnon

    2012-11-05

    We propose, analyze and demonstrate the optoelectronic phase-locking of optical waves whose frequencies are chirped continuously and rapidly with time. The optical waves are derived from a common optoelectronic swept-frequency laser based on a semiconductor laser in a negative feedback loop, with a precisely linear frequency chirp of 400 GHz in 2 ms. In contrast to monochromatic waves, a differential delay between two linearly chirped optical waves results in a mutual frequency difference, and an acoustooptic frequency shifter is therefore used to phase-lock the two waves. We demonstrate and characterize homodyne and heterodyne optical phase-locked loops with rapidly chirped waves, and show the ability to precisely control the phase of the chirped optical waveform using a digital electronic oscillator. A loop bandwidth of ~ 60 kHz, and a residual phase error variance of < 0.01 rad(2) between the chirped waves is obtained. Further, we demonstrate the simultaneous phase-locking of two optical paths to a common master waveform, and the ability to electronically control the resultant two-element optical phased array. The results of this work enable coherent power combining of high-power fiber amplifiers-where a rapidly chirping seed laser reduces stimulated Brillouin scattering-and electronic beam steering of chirped optical waves.

  7. Sake Protein Supplementation Affects Exercise Performance and Biochemical Profiles in Power-Exercise-Trained Mice

    PubMed Central

    Chen, Yi-Ming; Lin, Che-Li; Wei, Li; Hsu, Yi-Ju; Chen, Kuan-Neng; Huang, Chi-Chang; Kao, Chin-Hsung

    2016-01-01

    Exercise and fitness training programs have attracted the public’s attention in recent years. Sports nutrition supplementation is an important issue in the global sports market. Purpose: In this study, we designed a power exercise training (PET) program with a mouse model based on a strength and conditional training protocol for humans. We tested the effect of supplementation with functional branched-chain amino acid (BCAA)-rich sake protein (SP) to determine whether the supplement had a synergistic effect during PET and enhanced athletic performance and resistance to fatigue. Methods: Male ICR mice were divided into three groups (n = 8 per group) for four-week treatment: sedentary controls with vehicle (SC), and PET and PET groups with SP supplementation (3.8 g/kg, PET + SP). Exercise performance was evaluated by forelimb grip strength and exhaustive swimming time as well as changes in body composition and anti-fatigue activity levels of serum lactate, ammonia, glucose, and creatine kinase (CK) after a 15-min swimming exercise. The biochemical parameters were measured at the end of the experiment. Results: four-week PET significantly increased grip strength and exhaustive swimming time and decreased epididymal fat pad (EFP) weight and area. Levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, and uric acid (UA) were significantly increased. PET + SP supplementation significantly decreased serum lactate, ammonia and CK levels after the 15-min swimming exercise. The resting serum levels of AST, ALT, CREA and UA were all significantly decreased with PET + SP. Conclusion: The PET program could increase the exercise performance and modulate the body composition of mice. PET with SP conferred better anti-fatigue activity, improved biochemical profiles, and may be an effective ergogenic aid in strength training. PMID:26907336

  8. Training Persons with Spinal Cord Injury to Ambulate Using a Powered Exoskeleton

    PubMed Central

    Asselin, Pierre K.; Avedissian, Manuel; Knezevic, Steven; Kornfeld, Stephen; Spungen, Ann M.

    2016-01-01

    Powered exoskeletons have become available for overground ambulation in persons with paralyses due to spinal cord injury (SCI) who have intact upper extremity function and are able to maintain upright balance using forearm crutches. To ambulate in an exoskeleton, the user must acquire the ability to maintain balance while standing, sitting and appropriate weight shifting with each step. This can be a challenging task for those with deficits in sensation and proprioception in their lower extremities. This manuscript describes screening criteria and a training program developed at the James J. Peters VA Medical Center, Bronx, NY to teach users the skills needed to utilize these devices in institutional, home or community environments. Before training can begin, potential users are screened for appropriate range of motion of the hip, knee and ankle joints. Persons with SCI are at an increased risk of sustaining lower extremity fractures, even with minimal strain or trauma, therefore a bone mineral density assessment is performed to reduce the risk of fracture. Also, as part of screening, a physical examination is performed in order to identify additional health-related contraindications. Once the person has successfully passed all screening requirements, they are cleared to begin the training program. The device is properly adjusted to fit the user. A series of static and dynamic balance tasks are taught and performed by the user before learning to walk. The person is taught to ambulate in various environments ranging from indoor level surfaces to outdoors over uneven or changing surfaces. Once skilled enough to be a candidate for home use with the exoskeleton, the user is then required to designate a companion-walker who will train alongside them. Together, the pair must demonstrate the ability to perform various advanced tasks in order to be permitted to use the exoskeleton in their home/community environment. PMID:27340808

  9. Training Persons with Spinal Cord Injury to Ambulate Using a Powered Exoskeleton.

    PubMed

    Asselin, Pierre K; Avedissian, Manuel; Knezevic, Steven; Kornfeld, Stephen; Spungen, Ann M

    2016-06-16

    Powered exoskeletons have become available for overground ambulation in persons with paralyses due to spinal cord injury (SCI) who have intact upper extremity function and are able to maintain upright balance using forearm crutches. To ambulate in an exoskeleton, the user must acquire the ability to maintain balance while standing, sitting and appropriate weight shifting with each step. This can be a challenging task for those with deficits in sensation and proprioception in their lower extremities. This manuscript describes screening criteria and a training program developed at the James J. Peters VA Medical Center, Bronx, NY to teach users the skills needed to utilize these devices in institutional, home or community environments. Before training can begin, potential users are screened for appropriate range of motion of the hip, knee and ankle joints. Persons with SCI are at an increased risk of sustaining lower extremity fractures, even with minimal strain or trauma, therefore a bone mineral density assessment is performed to reduce the risk of fracture. Also, as part of screening, a physical examination is performed in order to identify additional health-related contraindications. Once the person has successfully passed all screening requirements, they are cleared to begin the training program. The device is properly adjusted to fit the user. A series of static and dynamic balance tasks are taught and performed by the user before learning to walk. The person is taught to ambulate in various environments ranging from indoor level surfaces to outdoors over uneven or changing surfaces. Once skilled enough to be a candidate for home use with the exoskeleton, the user is then required to designate a companion-walker who will train alongside them. Together, the pair must demonstrate the ability to perform various advanced tasks in order to be permitted to use the exoskeleton in their home/community environment.

  10. Flow simulation of the Component Development Integration Facility magnetohydrodynamic power train system

    SciTech Connect

    Chang, S.L.; Lottes, S.A.; Bouillard, J.X.; Petrick, M.

    1997-11-01

    This report covers application of Argonne National Laboratory`s (ANL`s) computer codes to simulation and analysis of components of the magnetohydrodynamic (MHD) power train system at the Component Development and Integration Facility (CDIF). Major components of the system include a 50-MWt coal-fired, two-stage combustor and an MHD channel. The combustor, designed and built by TRW, includes a deswirl section between the first and the second-stage combustor and a converging nozzle following the second-stage combustor, which connects to the MHD channel. ANL used computer codes to simulate and analyze flow characteristics in various components of the MHD system. The first-stage swirl combustor was deemed a mature technology and, therefore, was not included in the computer simulation. Several versions of the ICOMFLO computer code were used for the deswirl section and second-stage combustor. The MGMHD code, upgraded with a slag current leakage submodel, was used for the MHD channel. Whenever possible data from the test facilities were used to aid in calibrating parameters in the computer code, to validate the computer code, or to set base-case operating conditions for computations with the computer code. Extensive sensitivity and parametric studies were done on cold-flow mixing in the second-stage combustor, reacting flow in the second-stage combustor and converging nozzle, and particle-laden flow in the deswirl zone of the first-stage combustor, the second-stage combustor, and the converging nozzle. These simulations with subsequent analysis were able to show clearly in flow patterns and various computable measures of performance a number of sensitive and problematical areas in the design of the power train. The simulations of upstream components also provided inlet parameter profiles for simulation of the MHD power generating channel. 86 figs., 18 tabs.

  11. Ultra-low-power silicon photonics wavelength converter for phase-encoded telecommunication signals

    NASA Astrophysics Data System (ADS)

    Lacava, C.; Ettabib, M. A.; Cristiani, I.; Fedeli, J.-M.; Richardson, D. J.; Petropoulos, P.

    2016-03-01

    The development of compact, low power, silicon photonics CMOS compatible components for all-optical signal processing represents a key step towards the development of fully functional platforms for next generation all-optical communication networks. The wavelength conversion functionality at key nodes is highly desirable to achieve transparent interoperability and wavelength routing allowing efficient management of network resources operated with high speed, phase encoded signals. All optical wavelength conversion has already been demonstrated in Si-based devices, mainly utilizing the strong Kerr effect that silicon exhibits at telecommunication wavelengths. Unfortunately, Two Photon Absorption (TPA) and Free Carrier (FC) effects strongly limit their performance, even at moderate power levels, making them unsuitable for practical nonlinear applications. Amorphous silicon has recently emerged as a viable alternative to crystalline silicon (c-Si), showing both an enhanced Kerr as well as a reduced TPA coefficient at telecom wavelengths, with respect to its c-Si counterpart. Here we present an ultra-low power wavelength converter based on a passive, CMOS compatible, 1-mm long amorphous silicon waveguide operated at a maximum pump power level of only 70 mW. We demonstrate TPA-free Four Wave Mixing (FWM)-based wavelength conversion of Binary Phase Shift Keyed (BPSK) and Quadrature Phase Shift Keyed (QPSK) signals at 20 Gbit/s with <1 dB power penalty at BER = 10-5.

  12. Hypertrophy-type Resistance Training Improves Phase Angle in Young Adult Men and Women.

    PubMed

    Ribeiro, A S; Avelar, A; Dos Santos, L; Silva, A M; Gobbo, L A; Schoenfeld, B J; Sardinha, L B; Cyrino, E S

    2017-01-01

    The main purpose of the present study was to investigate the effect of a hypertrophy-type resistance training protocol on phase angle, an indicator of cellular integrity, in young adult men and women. 28 men (22.2±4.3 years, 67.8±9.0 kg and 174.2±6.8 cm) and 31 women (23.2±4.1 years, 58.7±12.1 kg and 162.7±6.4 cm) underwent a progressive RT for 16 weeks (2 phases, 8 weeks each), 3 times per week, consisting of 10 to 12 whole body exercises with 3 sets of 8-12 repetitions maximum. Phase angle, resistance, reactance and total body water (intra and extracellular water compartments) were assessed by bioimpedance spectroscopy (Xitron 4200 Bioimpedance Spectrum Analyzer). Total body water, intracellular water and phase angle increased significantly (P<0.05) in men (7.8, 8.3, and 4.3%, respectively) and women (7.6, 11.7, and 5.8% respectively), with no significant difference between sexes (P>0.05). Bioimpedance resistance decreased (P<0.05) similarly in both sex (men=-4.8%, women=-3.8%). The results suggest that regardless of sex, progressive RT induces an increase in phase angle and a rise in cellular hydration. © Georg Thieme Verlag KG Stuttgart · New York.

  13. The effect of a complex training and detraining programme on selected strength and power variables in early pubertal boys.

    PubMed

    Ingle, Lee; Sleap, Mike; Tolfrey, Keith

    2006-09-01

    Complex training, a combination of resistance training and plyometrics is growing in popularity, despite limited support for its efficacy. In pre- and early pubertal children, the study of complex training has been limited, and to our knowledge an examination of its effect on anaerobic performance characteristics of the upper and lower body has not been undertaken. Furthermore, the effect of detraining after complex training requires clarification. The physical characteristics (mean+/-s) of the 54 male participants in the present study were as follows: age 12.3 +/- 0.3 years, height 1.57 +/- 0.07 m, body mass 50.3 +/- 11.0 kg. Participants were randomly assigned to an experimental (n = 33) or control group (n = 21). The training, which was performed three times a week for 12 weeks, included a combination of dynamic constant external resistance and plyometrics. After training, participants completed 12 weeks of detraining. At baseline, after training and after detraining, peak and mean anaerobic power, dynamic strength and athletic performance were assessed. Twenty-six participants completed the training and none reported any training-related injury. Complex training was associated with small increases (< or =5.5%) in peak and mean power during training, followed by decreases of a similar magnitude (< or = -5.9%) during detraining (P < 0.05). No changes or minor, progressive increases (< or =1.5%) were evident in the control group (P > 0.05). In the experimental group, dynamic strength was increased by 24.3 - 71.4% (dependent on muscle group; P < 0.01), whereas growth-related changes in the control group varied from 0 to 4.4% (P > 0.05). For 40-m sprint running, basketball chest pass and vertical jump test performance, the experimental group saw a small improvement (< or =4.0%) after training followed by a decline (< or = -4.4%) towards baseline during detraining (P < 0.05), whereas the control group experienced no change (P > 0.05). In conclusion, in pre- and early

  14. One order of magnitude faster phase change at reduced power in Ti-Sb-Te.

    PubMed

    Zhu, Min; Xia, Mengjiao; Rao, Feng; Li, Xianbin; Wu, Liangcai; Ji, Xinglong; Lv, Shilong; Song, Zhitang; Feng, Songlin; Sun, Hongbo; Zhang, Shengbai

    2014-07-08

    To date, slow Set operation speed and high Reset operation power remain to be important limitations for substituting dynamic random access memory by phase change memory. Here, we demonstrate phase change memory cell based on Ti0.4Sb2Te3 alloy, showing one order of magnitude faster Set operation speed and as low as one-fifth Reset operation power, compared with Ge2Sb2Te5-based phase change memory cell at the same size. The enhancements may be rooted in the common presence of titanium-centred octahedral motifs in both amorphous and crystalline Ti0.4Sb2Te3 phases. The essentially unchanged local structures around the titanium atoms may be responsible for the significantly improved performance, as these structures could act as nucleation centres to facilitate a swift, low-energy order-disorder transition for the rest of the Sb-centred octahedrons. Our study may provide an alternative to the development of high-speed, low-power dynamic random access memory-like phase change memory technology.

  15. One order of magnitude faster phase change at reduced power in Ti-Sb-Te

    PubMed Central

    Zhu, Min; Xia, Mengjiao; Rao, Feng; Li, Xianbin; Wu, Liangcai; Ji, Xinglong; Lv, Shilong; Song, Zhitang; Feng, Songlin; Sun, Hongbo; Zhang, Shengbai

    2014-01-01

    To date, slow Set operation speed and high Reset operation power remain to be important limitations for substituting dynamic random access memory by phase change memory. Here, we demonstrate phase change memory cell based on Ti0.4Sb2Te3 alloy, showing one order of magnitude faster Set operation speed and as low as one-fifth Reset operation power, compared with Ge2Sb2Te5-based phase change memory cell at the same size. The enhancements may be rooted in the common presence of titanium-centred octahedral motifs in both amorphous and crystalline Ti0.4Sb2Te3 phases. The essentially unchanged local structures around the titanium atoms may be responsible for the significantly improved performance, as these structures could act as nucleation centres to facilitate a swift, low-energy order-disorder transition for the rest of the Sb-centred octahedrons. Our study may provide an alternative to the development of high-speed, low-power dynamic random access memory-like phase change memory technology. PMID:25001009

  16. Effects of Combined Strength and Sprint Training on Lean Mass, Strength, Power and Sprint Performance in Masters Road Cyclists.

    PubMed

    Del Vecchio, Luke; Stanton, Robert; Reaburn, Peter; Macgregor, Campbell; Meerkin, Jarrod; Villegas, Jerome; Korhonen, Marko T

    2017-05-25

    Strength and sprint training exercises are integral part of training in many younger endurance cyclists to improve cycling efficiency and sprinting ability. This study was undertaken to examine whether muscle and performance characteristics could be improved in endurance-trained masters cyclist by adding strength and sprint training stimuli into their training regimen. Twenty five masters road cyclists were assigned to a combined strength and sprint training group (CT; n=9, 53.5 ± 9.3 years), a sprint training group (ST, n=7, 49.4 ± 4.8 years) or a control group (CG, n=9, 56.9 ± 8.6 years). Before and after the 12 week intervention, whole body lean mass (WBLM), total lower limb lean mass (LLLM), countermovement jump height (CMJ), peak isometric torque of quadriceps (QPT) and hamstring (HPT) muscles were examined. For evaluation of sport-specific performance, 10 second sprint cycling peak power (PP10), total 30 second work (TW), peak power output (PPO) and flying 200 meter time trial performance (TT) were assessed. No pre-training differences were observed between CT, ST and CG groups for any of the dependant variables. After training, a significant (p<0.05) between group difference was observed in TW between CT and CG groups. A significant effect of time (p<0.05) was observed for LLLM in CT and ST groups, and for TT in the CT group. These results suggest including strength and sprint exercises in training can increase lower limb lean mass and sprint performance in endurance trained masters road cyclists. Further research is warranted to find out an ideal pattern of training to maintain aerobic capabilities along with sprint performance in aging road cyclists.

  17. Power-law distribution of phase-locking intervals does not imply critical interaction

    NASA Astrophysics Data System (ADS)

    Botcharova, M.; Farmer, S. F.; Berthouze, L.

    2012-11-01

    Neural synchronization plays a critical role in information processing, storage, and transmission. Characterizing the pattern of synchronization is therefore of great interest. It has recently been suggested that the brain displays broadband criticality based on two measures of synchronization, phase-locking intervals and global lability of synchronization, showing power-law statistics at the critical threshold in a classical model of synchronization. In this paper, we provide evidence that, within the limits of the model selection approach used to ascertain the presence of power-law statistics, the pooling of pairwise phase-locking intervals from a noncritically interacting system can produce a distribution that is similarly assessed as being power law. In contrast, the global lability of synchronization measure is shown to better discriminate critical from noncritical interaction.

  18. Power-law distribution of phase-locking intervals does not imply critical interaction.

    PubMed

    Botcharova, M; Farmer, S F; Berthouze, L

    2012-11-01

    Neural synchronization plays a critical role in information processing, storage, and transmission. Characterizing the pattern of synchronization is therefore of great interest. It has recently been suggested that the brain displays broadband criticality based on two measures of synchronization, phase-locking intervals and global lability of synchronization, showing power-law statistics at the critical threshold in a classical model of synchronization. In this paper, we provide evidence that, within the limits of the model selection approach used to ascertain the presence of power-law statistics, the pooling of pairwise phase-locking intervals from a noncritically interacting system can produce a distribution that is similarly assessed as being power law. In contrast, the global lability of synchronization measure is shown to better discriminate critical from noncritical interaction.

  19. Data evaluation plan for the 10 MWe solar thermal central receiver pilot plant power production phase

    SciTech Connect

    Radosevich, L.G.

    1984-10-01

    This report describes the planned data evaluation for the three-year Power Production Phase of the 10 MWe Solar Thermal Central Receiver Pilot Plant near Barstow, California. The Power Production Phase, which began in August 1984, will demonstrate the operational capability of the plant to reliably supply electrical power to the utility grid. Data evaluation will be performed for design point and annual plant energy output; heliostat optical performance and mirror module corrosion; receiver tube life and absorber coating life; storage fluid degradation and storage tank thermal stresses; plant availability, operating procedures, and operating costs; and component reliability and maintenance costs. The objective, test needs, data needs, approach, expected output, and planned data dissemination are presented for each evaluation.

  20. Temporal Aspects of the V[o.sub.2] Response at the Power Output Associated with V[o.sub.2]peak in Well Trained Cyclists-Implications for Interval Training Prescription

    ERIC Educational Resources Information Center

    Laursen, Paul B.; Shing, Cecilia M.; Jenkins, David G.

    2004-01-01

    The power output achieved at peak oxygen consumption (V[O.sub.2]peak) and the time this power can be maintained (i.e., Tmax) have been used in prescribing high-intensity interval training. In this context, the present study examined temporal aspects of the V[O.sub.2] response to exercise at the cycling power that output well trained cyclists…

  1. Temporal Aspects of the V[o.sub.2] Response at the Power Output Associated with V[o.sub.2]peak in Well Trained Cyclists-Implications for Interval Training Prescription

    ERIC Educational Resources Information Center

    Laursen, Paul B.; Shing, Cecilia M.; Jenkins, David G.

    2004-01-01

    The power output achieved at peak oxygen consumption (V[O.sub.2]peak) and the time this power can be maintained (i.e., Tmax) have been used in prescribing high-intensity interval training. In this context, the present study examined temporal aspects of the V[O.sub.2] response to exercise at the cycling power that output well trained cyclists…

  2. Muscle Strength, Power, and Morphologic Adaptations After 6 Weeks of Compound vs. Complex Training in Healthy Men.

    PubMed

    Stasinaki, Angeliki-Nikoletta; Gloumis, Giorgos; Spengos, Konstantinos; Blazevich, Anthony J; Zaras, Nikolaos; Georgiadis, Giorgos; Karampatsos, Giorgos; Terzis, Gerasimos

    2015-09-01

    The aim of the study was to compare the effects of compound vs. complex resistance training on strength, high-speed movement performance, and muscle composition. Eighteen young men completed compound (strength and power sessions on alternate days) or complex training (strength and power sets within a single session) 3 times per week for 6 weeks using bench press, leg press, Smith machine box squat, and jumping exercises. Pre- and posttraining, jumping and throwing performance and maximum bench press, leg press, and Smith machine box squat strength were evaluated. The architecture of vastus lateralis and gastrocnemius muscle was assessed using ultrasound imaging. Vastus lateralis morphology was assessed from muscle biopsies. Jumping (4 ± 3%) and throwing (9 ± 8%) performance increased only with compound training (p < 0.02). Bench press (5 vs. 18%), leg press (17 vs. 28%), and Smith machine box squat (27 vs. 35%) strength increased after both compound and complex training. Vastus lateralis thickness and fascicle angle and gastrocnemius fascicle angle were increased with both compound and complex training. Gastrocnemius fascicle length decreased only after complex training (-11.8 ± 9.4%, p = 0.006). Muscle fiber cross-sectional areas increased only after complex training (p ≤ 0.05). Fiber type composition was not affected by either intervention. These results suggest that short-term strength and power training on alternate days is more effective for enhancing lower-limb and whole-body power, whereas training on the same day may induce greater increases in strength and fiber hypertrophy.

  3. Power and Phase of Alpha Oscillations Reveal an Interaction between Spatial and Temporal Visual Attention.

    PubMed

    Kizuk, Sayeed A D; Mathewson, Kyle E

    2017-03-01

    Oscillatory brain rhythms can bias attention via phase and amplitude changes, which modulate sensory activity, biasing information to be processed or ignored. Alpha band (7-14 Hz) oscillations lateralize with spatial attention and rhythmically inhibit visual activity and awareness through pulses of inhibition. Here we show that human observers' awareness of spatially unattended targets is dependent on both alpha power and alpha phase at target onset. Following a predictive directional cue, alpha oscillations were entrained bilaterally using repetitive visual stimuli. Subsequently, we presented either spatially cued or uncued targets at SOAs either validly or invalidly predicted in time by the entrainers. Temporal validity maximally modulated perceptual performance outside the spatial focus of attention and was associated with both increased alpha power and increased neural entrainment of phase in the hemisphere processing spatially unattended information. The results demonstrate that alpha oscillations represent a pulsating inhibition, which impedes visual processing for unattended space.

  4. Changes in Maximal Strength, Velocity, and Power After 8 Weeks of Training With Pneumatic or Free Weight Resistance.

    PubMed

    Frost, David M; Bronson, Stefanie; Cronin, John B; Newton, Robert U

    2016-04-01

    Because free weight (FW) and pneumatic (PN) resistance are characterized by different inertial properties, training with either resistance could afford unique strength, velocity, and power adaptations. Eighteen resistance-trained men completed baseline tests to determine their FW and PN bench press 1 repetition maximum (1RM). During the FW session, 4 explosive repetitions were performed at loads of 15, 30, 45, 60, 75, and 90% 1RM to assess force, velocity, and power. Participants were then assigned to a FW or PN training group, which involved three 90-minute sessions per week for 8 weeks. Both intervention groups completed identical periodized programs with the exception of the resistance used to perform all bench press movements. Free weight participants significantly increased their FW and PN 1RM (10.4 and 9.4%), and maximum (any load) force (9.8%), velocity (11.6%), and power (22.5%). Pneumatic-trained participants also exhibited increases in FW and PN 1RM (11.6 and 17.5%), and maximum force (8.4%), velocity (13.6%), and power (33.4%). Both interventions improved peak barbell velocity at loads of 15 and 30% 1RM; however, only the PN-trained individuals displayed improvements in peak force and power at these same loads. Training with PN resistance may offer advantages if attempting to improve power at lighter relative loads by affording an opportunity to consistently achieve higher accelerations and velocities (F = ma), in comparison with FW. Exploiting the inertial properties of the resistance, whether mass, elastic or PN, could afford an opportunity to develop mixed-method training strategies and/or elicit unique neuromuscular adaptations to suit the specific needs of athletes from sports characterized by varying demands.

  5. High Power Passive Phase Locking of Four Yb-Doped Fiber Amplifiers by an All-Optical Feedback Loop

    NASA Astrophysics Data System (ADS)

    Xue, Yu-Hao; He, Bing; Zhou, Jun; Li, Zhen; Fan, Yuan-Yuan; Qi, Yun-Feng; Liu, Chi; Yuan, Zhi-Jun; Zhang, Hai-Bo; Lou, Qi-Hong

    2011-05-01

    We report the passive phase locking of four high power Yb-doped fiber amplifiers with ring cavity. The interference patterns at different output power are observed and the Strehl ratios are measured. The maximum coherent output power of the fiber array is up to 1062 W by multi-stage amplification. The stable beam profiles of various phase relationships are observed by controlling the position of the feedback fiber, in good agreement with the calculated results. By using master oscillator power-amplifier (MOPA) architecture and broadband operation of passively phased systems, higher power scaling with high beam quality appears to be feasible.

  6. Naturalistic Decision Making in Power Grid Operations: Implications for Dispatcher Training and Usability Testing

    SciTech Connect

    Greitzer, Frank L.; Podmore, Robin

    2008-11-17

    The focus of the present study is on improved training approaches to accelerate learning and improved methods for analyzing effectiveness of tools within a high-fidelity power grid simulated environment. A theory-based model has been developed to document and understand the mental processes that an expert power system operator uses when making critical decisions. The theoretical foundation for the method is based on the concepts of situation awareness, the methods of cognitive task analysis, and the naturalistic decision making (NDM) approach of Recognition Primed Decision Making. The method has been systematically explored and refined as part of a capability demonstration of a high-fidelity real-time power system simulator under normal and emergency conditions. To examine NDM processes, we analyzed transcripts of operator-to-operator conversations during the simulated scenario to reveal and assess NDM-based performance criteria. The results of the analysis indicate that the proposed framework can be used constructively to map or assess the Situation Awareness Level of the operators at each point in the scenario. We can also identify the mental models and mental simulations that the operators employ at different points in the scenario. This report documents the method, describes elements of the model, and provides appendices that document the simulation scenario and the associated mental models used by operators in the scenario.

  7. The Effects of a Maximal Power Training Cycle on the Strength, Maximum Power, Vertical Jump Height and Acceleration of High-Level 400-Meter Hurdlers

    PubMed Central

    Balsalobre-Fernández, Carlos; Tejero-González, Carlos Mª; del Campo-Vecino, Juan; Alonso-Curiel, Dionisio

    2013-01-01

    The aim of this study was to determine the effects of a power training cycle on maximum strength, maximum power, vertical jump height and acceleration in seven high-level 400-meter hurdlers subjected to a specific training program twice a week for 10 weeks. Each training session consisted of five sets of eight jump-squats with the load at which each athlete produced his maximum power. The repetition maximum in the half squat position (RM), maximum power in the jump-squat (W), a squat jump (SJ), countermovement jump (CSJ), and a 30-meter sprint from a standing position were measured before and after the training program using an accelerometer, an infra-red platform and photo-cells. The results indicated the following statistically significant improvements: a 7.9% increase in RM (Z=−2.03, p=0.021, δc=0.39), a 2.3% improvement in SJ (Z=−1.69, p=0.045, δc=0.29), a 1.43% decrease in the 30-meter sprint (Z=−1.70, p=0.044, δc=0.12), and, where maximum power was produced, a change in the RM percentage from 56 to 62% (Z=−1.75, p=0.039, δc=0.54). As such, it can be concluded that strength training with a maximum power load is an effective means of increasing strength and acceleration in high-level hurdlers. PMID:23717361

  8. Effects of different resistance training volumes on strength and power in team sport athletes.

    PubMed

    Naclerio, Fernando; Faigenbaum, Avery D; Larumbe-Zabala, Eneko; Perez-Bibao, Txomin; Kang, Jie; Ratamess, Nicholas A; Triplett, N T

    2013-07-01

    The aim of this study was to compare the effects of 3 different volume of resistance training (RT) on maximum strength and average power in college team sport athletes with no previous RT experience. Thirty-two subjects (20 men and 12 women, age = 23.1 ± 1.57 years) were randomly divided into 4 groups: low volume (LV; n = 8), 1 set per exercise and 3 sets per muscle group; moderate volume (MV; n = 8), 2 sets per exercise and 6 sets per muscle group; high volume (HV; n = 8), 3 sets per exercise and 9 sets per muscle group; and a non-RT control group (n = 8). The 3 intervention groups were trained for 6 weeks thrice weekly after a nonperiodized RT program differentiated only by the volume. Before (T1) and after training (T2), 1 repetition maximum (1RM) and maximal average power (AP) produced on the bench press (BP), upright row (UR), and squat (SQ) were assessed by progressive resistance tests. One repetition maximum-BP and 1RM-UR increased significantly in the 3 interventions groups (p < 0.05), whereas only the HV group significantly improved 1RM-SQ (p < 0.01). The MV and HV groups increased AP-BP (p < 0.05), whereas only the LV group improved AP-SQ (p < 0.01). Moderate effect sizes (ES; >0.20 < 0.60) were observed for the 1RM-BP and 1RM-UR in the 3 training groups. High-volume group showed the larger ES for 1RM-BP (0.45), 1RM-UR (0.60), and 1RM-SQ (0.47), whereas the LV produced the higher ES for SQ-AP (0.53). During the initial adaptation period, a HV RT program seems to be a better strategy for improving strength, whereas during the season, an LV RT could be a reasonable option for maintaining strength and enhancing lower-body AP in team sport athletes.

  9. Effects of saddle height on economy and anaerobic power in well-trained cyclists.

    PubMed

    Peveler, Willard W; Green, James M

    2011-03-01

    In cycling, saddle height adjustment is critical for optimal performance and injury prevention. A 25-35° knee angle is recommended for injury prevention, whereas 109% of inseam, measured from floor to ischium, is recommended for optimal performance. Previous research has demonstrated that these 2 methods produce significantly different saddle heights and may influence cycling performance. This study compared performance between these 2 methods for determining saddle height. Subjects consisted of 11 well-trained (VO2max = 61.55 ± 4.72 ml·kg·min) male cyclists. Subjects completed a total of 8 performance trials consisting of a graded maximal protocol, three 15-minute economy trials, and 4 anaerobic power trials. Dependent measures for economy (VO2, heart rate, and rating of perceived exertion) and anaerobic power (peak power and mean power) were compared using repeated measures analysis of variance (α = 0.05). VO2 was significantly lower (reflecting greater economy) at a 25° knee angle (44.77 ± 6.40 ml·kg·min) in comparison to a 35° knee angle (45.22 ± 6.79 ml·kg·min) and 109% of inseam (45.98 ± 5.33 ml·kg·min). Peak power at a 25° knee angle (1,041.55 ± 168.72 W) was significantly higher in relation to 109% of inseam (1,002.05 ± 147.65 W). Mean power at a 25° knee angle (672.37 ± 90.21 W) was significantly higher in relation to a 35° knee angle (654.71 ± 80.67 W). Mean power was significantly higher at 109% of inseam (662.86 ± 79.72 W) in relation to a 35° knee angle (654.71 ± 80.67 W). Use of 109% of inseam fell outside the recommended 25-35° range 73% of the time. Use of 25° knee angle appears to provide optimal performance while keeping knee angle within the recommended range for injury prevention.

  10. Phasing of a two-channel continuous-wave master oscillator-power amplifier by use of a fiber phase-conjugate mirror.

    PubMed

    Grime, Brent W; Roh, Won B; Alley, Thomas G

    2005-09-15

    Phasing of two-channel cw master-oscillator-power-amplifier beams by using a phase-conjugate mirror has been demonstrated for the first time to the best of our knowledge. Phasing was achieved with two fiber amplifiers in conjunction with a single-frequency Nd:YAG master oscillator by using a fiber phase-conjugate mirror in a double-pass geometry. The successful demonstration of phasing of two cw amplifier beams with a fiber phase-conjugate mirror greatly enhances the prospects for phasing of multiple laser amplifiers without complex servo-loop control systems.

  11. One session of high-intensity interval training (HIIT) every 5 days, improves muscle power but not static balance in lifelong sedentary ageing men

    PubMed Central

    Sculthorpe, Nicholas F.; Herbert, Peter; Grace, Fergal

    2017-01-01

    Abstract Background: Declining muscle power during advancing age predicts falls and loss of independence. High-intensity interval training (HIIT) may improve muscle power, but remains largely unstudied in ageing participants. Methods: This randomized controlled trial (RCT) investigated the efficacy of a low-frequency HIIT (LfHIIT) intervention on peak muscle power (peak power output [PPO]), body composition, and balance in lifelong sedentary but otherwise healthy males. Methods: Thirty-three lifelong sedentary ageing men were randomly assigned to either intervention (INT; n = 22, age 62.3 ± 4.1 years) or control (n = 11, age 61.6 ± 5.0 years) who were both assessed at 3 distinct measurement points (phase A), after 6 weeks of conditioning exercise (phase B), and after 6 weeks of HIIT once every 5 days in INT (phase C), where control remained inactive throughout the study. Results: Static balance remained unaffected, and both absolute and relative PPO were not different between groups at phases A or B, but increased significantly in INT after LfHIIT (P < 0.01). Lean body mass displayed a significant interaction (P < 0.01) due to an increase in INT between phases B and C (P < 0.05). Conclusions: 6 weeks of LfHIIT exercise feasible and effective method to induce clinically relevant improvements in absolute and relative PPO, but does not improve static balance in sedentary ageing men. PMID:28178145

  12. The AGT Gene M235T Polymorphism and Response of Power-Related Variables to Aerobic Training.

    PubMed

    Aleksandra, Zarębska; Zbigniew, Jastrzębski; Waldemar, Moska; Agata, Leońska-Duniec; Mariusz, Kaczmarczyk; Marek, Sawczuk; Agnieszka, Maciejewska-Skrendo; Piotr, Żmijewski; Krzysztof, Ficek; Grzegorz, Trybek; Ewelina, Lulińska-Kuklik; Semenova, Ekaterina A; Ahmetov, Ildus I; Paweł, Cięszczyk

    2016-12-01

    The C allele of the M235T (rs699) polymorphism of the AGT gene correlates with higher levels of angiotensin II and has been associated with power and strength sport performance. The aim of the study was to investigate whether or not selected power-related variables and their response to a 12-week program of aerobic dance training are modulated by the AGT M235T genotype in healthy participants. Two hundred and one Polish Caucasian women aged 21 ± 1 years met the inclusion criteria and were included in the study. All women completed a 12-week program of low and high impact aerobics. Wingate peak power and total work capacity, 5 m, 10 m, and 30 m running times and jump height and jump power were determined before and after the training programme. All power-related variables improved significantly in response to aerobic dance training. We found a significant association between the M235T polymorphism and jump-based variables (squat jump (SJ) height, p = 0.005; SJ power, p = 0.015; countermovement jump height, p = 0.025; average of 10 countermovement jumps with arm swing (ACMJ) height, p = 0.001; ACMJ power, p = 0.035). Specifically, greater improvements were observed in the C allele carriers in comparison with TT homozygotes. In conclusion, aerobic dance, one of the most commonly practiced adult fitness activities in the world, provides sufficient training stimuli for augmenting the explosive strength necessary to increase vertical jump performance. The AGT gene M235T polymorphism seems to be not only a candidate gene variant for power/strength related phenotypes, but also a genetic marker for predicting response to training.

  13. Design and real time implementation of fuzzy switched controller for single phase active power filter.

    PubMed

    Afghoul, Hamza; Krim, Fateh; Chikouche, Djamel; Beddar, Antar

    2015-09-01

    This paper proposes a novel fuzzy switched controller (FSC) integrated in direct current control (DCC) algorithm for single phase active power filter (SPAPF). The controller under study consists of conventional PI controller, fractional order PI controller (FO-PI) and fuzzy decision maker (FDM) that switches between them using reduced fuzzy logic control. The proposed controller offers short response time with low damping and deals efficiently with the external disturbances while preserving the robustness properties. To fulfill the requirements of power quality, unity power factor and harmonics limitations in active power filtering an experimental test bench has been built using dSPACE 1104 to demonstrate the feasibility and effectiveness of the proposed controller. The obtained results present high performance in steady and transient states. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  14. Phase boundaries of power-law Anderson and Kondo models: A poor man's scaling study

    NASA Astrophysics Data System (ADS)

    Cheng, Mengxing; Chowdhury, Tathagata; Mohammed, Aaron; Ingersent, Kevin

    2017-07-01

    We use the poor man's scaling approach to study the phase boundaries of a pair of quantum impurity models featuring a power-law density of states ρ (ɛ ) ∝|ɛ| r , either vanishing (for r >0 ) or diverging (for r <0 ) at the Fermi energy ɛ =0 , that gives rise to quantum phase transitions between local-moment and Kondo-screened phases. For the Anderson model with a pseudogap (i.e., r >0 ), we find the phase boundary for (a) 0 1 , where the phases are separated by first-order quantum phase transitions that are accessible only for broken p-h symmetry. For the p-h-symmetric Kondo model with easy-axis or easy-plane anisotropy of the impurity-band spin exchange, the phase boundary and scaling trajectories are obtained for both r >0 and r <0 . Throughout the regime of weak-to-moderate impurity-band coupling in which poor man's scaling is expected to be valid, the approach predicts phase boundaries in excellent qualitative and good quantitative agreement with the nonperturbative numerical renormalization group, while also establishing the functional relations between model parameters along these boundaries.

  15. The effects of incline and level-grade high-intensity interval treadmill training on running economy and muscle power in well-trained distance runners.

    PubMed

    Ferley, Derek D; Osborn, Roy W; Vukovich, Matthew D

    2014-05-01

    Despite a paucity of evidence, uphill running has been touted as a sport-specific resistance-to-movement training tactic capable of enhancing metabolic, muscular, and neuromuscular processes in distance runners in ways similar to previously established resistance-to-movement training methods, such as heavy and/or explosive strength training and plyometric training. Therefore, the purpose of this investigation included documenting the effects of incline and level-grade interval treadmill training on indices of running economy (RE) (i.e., oxygen consumption [VO2] and blood lactate [BLa] responses of submaximal running) and muscle power. Thirty-two well-trained distance runners (age, 27.4 ± 3.8 years; body mass, 64.8 ± 8.9 kg; height, 173.6 ± 6.4 cm; and VO2max, 60.9 ± 8.5 ml·min(-1)·kg(-1)) received assignment to an uphill (GHill = 12), level-grade (GFlat = 12), or control (GCon = 8) group. GHill and GFlat completed 12 interval and 12 continuous run sessions over 6 weeks, whereas GCon maintained their normal training. Dependent variables measured before and after training were VO2 and BLa at 2 separate velocities associated with lactate threshold (VLT) (VO2-60% and VO2-80%; and BLa-60% and BLa-80%, respectively); percentage of VO2max at lactate threshold (%VO2max at VLT); muscle power as assessed through a horizontal 5-jump test (5Jmax); and isokinetic knee extension and flexion at 3 angular velocities (90, 180, and 300°·s(-1)). Statistical significance was set to p ≤ 0.05. All groups significantly improved 5Jmax, VO2-60%, VO2-80%, BLa-60%, and BLa-80%. Additionally, GHill and GFlat significantly improved %VO2max at VLT. Other indices of RE and muscle power did not improve. We conclude incline treadmill training effective for improving the components of RE, but insufficient as a resistance-to-movement exercise for enhancing muscle power output.

  16. A high-power microwave circular polarizer and its application on phase shifter.

    PubMed

    Shao, Hao; Hu, Yongmei; Chang, Chao; Guo, Letian

    2016-04-01

    A high-power waveguide dual circular polarizer was theoretically designed and proof-of-principle was experimentally tested. It consists of two incident rectangular waveguides with a perpendicular H-plane junction, one circular waveguide with a pair of trapezoidal grooves coupled in E-plane at the top, a spherical crown located at the bottom, and an iris at the perpendicular junction of two rectangular waveguides. When wave incidents at one of the two separated rectangular waveguides, it, respectively, generates a left-hand circular polarized wave or a right-hand circular polarized wave in the circular waveguide. By adding a dumbbell-like metal plug driven with a high speed servomotor, a movable short circuit is formed along the circular waveguide to adjust the output RF phase of the rectangular port, realizing a high-speed high-power phase shifter. The C-band high power microwave (HPM) experiments were carried out, and the power capacity of the HPM polarizer and phase shifter was demonstrated to reach gigawatt level.

  17. Functional Outcomes After the Prosthetic Training Phase of Rehabilitation After Dysvascular Lower Extremity Amputation.

    PubMed

    Christiansen, Cory L; Fields, Thomas; Lev, Guy; Stephenson, Ryan O; Stevens-Lapsley, Jennifer E

    2015-11-01

    To describe physical function outcomes and modes of physical therapy intervention for a cohort of patients with dysvascular lower extremity amputation (LEA) during the prosthetic training phase of rehabilitation. A retrospective cohort study. Physical rehabilitation clinics at a Veterans Affairs medical center and a university hospital. Forty-two patients (38 men, 4 women, age 60.2 ± 8.4 years) who completed outpatient physical therapy rehabilitation with prosthetic training after dysvascular LEA. All patients underwent a prosthetic training phase of rehabilitation, with standardized outcome measures performed at initiation and discharge. Performance-based physical function measures included Two-Minute Walk (2 MW), Timed-Up and Go (TUG), and 5-meter gait speed. Self-report physical function measures included the Prosthesis Evaluation Questionnaire-Mobility Section (PEQ-MS) and the Patient-Specific Functional Scale. Rehabilitation dose was tracked as total number of clinic visits, rehabilitation duration, and specific intervention modes. There were significant improvements between initial and discharge values (mean ± SD) for the Two-Minute Walk (67.5 ± 29.9 m and 103.3 ± 45.8 m, respectively, P < .001), gait speed (0.58 ± 0.27 m/s and 0.88 ± 0.39 m/s, respectively, P < .001), TUG (34.8 ± 21.3 seconds and 18.6 ± 13.9 seconds, respectively, P < .001), PEQ-MS (2.2 ± 0.9 and 2.8 ± 0.8, respectively, P < .001), and Patient-Specific Functional Scale (3.2 ± 2.0 and 5.9 ± 2.3, respectively, P < .001). Performance-based (TUG) and self-report (PEQ-MS) changes in functional mobility from initial exam to discharge had low or no correlations with rehabilitation dose measures. The number of clinic visits was 12.7 ± 13.1 and rehabilitation duration was 13.7 ± 16.8 weeks. Significant improvements in performance-based and self-report measures of physical function occurred during the prosthetic training phase of physical rehabilitation after dysvascular major LEA

  18. Functional outcomes following the prosthetic training phase of rehabilitation after dysvascular lower extremity amputation

    PubMed Central

    Christiansen, Cory; Fields, Thomas; Lev, Guy; Stephenson, Ryan O.; Stevens-Lapsley, Jennifer E.

    2015-01-01

    Objective To describe physical function outcomes and modes of physical therapy intervention for a cohort of patients with dysvascular lower extremity amputation (LEA) during the prosthetic training phase of rehabilitation. Design A retrospective cohort study. Setting Physical rehabilitation clinics at a Veterans Affairs Medical Center and a University Hospital. Patients Forty-two patients (38 men, 4 women, age 60.2±8.4 years) who completed outpatient physical therapy rehabilitation with prosthetic training after dysvascular LEA. Methods All patients underwent a prosthetic training phase of rehabilitation, with standardized outcome measures performed at initiation and discharge. Main Outcome Measures Performance-based physical function measures included: Two-Minute Walk (2MW), Timed-Up and Go (TUG), and 5-meter gait speed. Self-report physical function measures included: the Prosthesis Evaluation Questionnaire – Mobility Section (PEQ-MS) and the Patient-Specific Functional Scale (PSFS). Rehabilitation dose was tracked as total number of clinic visits, rehabilitation duration, and specific intervention modes. Results There were significant improvements in 2MW (mean±SD) [67.5±29.9 m (initial) and 103.3±45.8 m (discharge) (p<0.001)], gait speed [0.58±0.27 m/s (initial) and 0.88±0.39 m/s (discharge) (p<0.001)], TUG [34.8±21.3 s (initial) and 18.6±13.9 s (discharge) (p<0.001)], PEQ-MS [2.2±0.9 (initial) and 2.8±0.8 (discharge) (p<0.001)], and PSFS [3.2±2.0 (initial) and 5.9±2.3 (discharge) (p<0.001)]. Performance-based (TUG) and self-report (PEQ-MS) changes in functional mobility from initial exam to discharge had low or no correlations with rehabilitation dose measures. Number of clinic visits was 12.7±13.1 and rehabilitation duration was 13.7±16.8 weeks. Conclusions Significant improvements in performance-based and self-report measures of physical function occurred during the prosthetic training phase of physical rehabilitation following dysvascular

  19. The AGT Gene M235T Polymorphism and Response of Power-Related Variables to Aerobic Training

    PubMed Central

    Aleksandra, Zarębska; Zbigniew, Jastrzębski; Waldemar, Moska; Agata, Leońska-Duniec; Mariusz, Kaczmarczyk; Marek, Sawczuk; Agnieszka, Maciejewska-Skrendo; Piotr, Żmijewski; Krzysztof, Ficek; Grzegorz, Trybek; Ewelina, Lulińska-Kuklik; Semenova, Ekaterina A.; Ahmetov, Ildus I.; Paweł, Cięszczyk

    2016-01-01

    The C allele of the M235T (rs699) polymorphism of the AGT gene correlates with higher levels of angiotensin II and has been associated with power and strength sport performance. The aim of the study was to investigate whether or not selected power-related variables and their response to a 12-week program of aerobic dance training are modulated by the AGT M235T genotype in healthy participants. Two hundred and one Polish Caucasian women aged 21 ± 1 years met the inclusion criteria and were included in the study. All women completed a 12-week program of low and high impact aerobics. Wingate peak power and total work capacity, 5 m, 10 m, and 30 m running times and jump height and jump power were determined before and after the training programme. All power-related variables improved significantly in response to aerobic dance training. We found a significant association between the M235T polymorphism and jump-based variables (squat jump (SJ) height, p = 0.005; SJ power, p = 0.015; countermovement jump height, p = 0.025; average of 10 countermovement jumps with arm swing (ACMJ) height, p = 0.001; ACMJ power, p = 0.035). Specifically, greater improvements were observed in the C allele carriers in comparison with TT homozygotes. In conclusion, aerobic dance, one of the most commonly practiced adult fitness activities in the world, provides sufficient training stimuli for augmenting the explosive strength necessary to increase vertical jump performance. The AGT gene M235T polymorphism seems to be not only a candidate gene variant for power/strength related phenotypes, but also a genetic marker for predicting response to training. Key points Aerobic dance provides sufficient training stimuli for the improvement of explosive power. The AGT gene M235T polymorphism is associated with individual variation in the change of power-related phenotypes in response to aerobic dance training. The C allele carriers of the AGT gene M235T polymorphism show greater improvements of jump

  20. Neural Spike-Train Analyses of the Speech-Based Envelope Power Spectrum Model

    PubMed Central

    Rallapalli, Varsha H.

    2016-01-01

    Diagnosing and treating hearing impairment is challenging because people with similar degrees of sensorineural hearing loss (SNHL) often have different speech-recognition abilities. The speech-based envelope power spectrum model (sEPSM) has demonstrated that the signal-to-noise ratio (SNRENV) from a modulation filter bank provides a robust speech-intelligibility measure across a wider range of degraded conditions than many long-standing models. In the sEPSM, noise (N) is assumed to: (a) reduce S + N envelope power by filling in dips within clean speech (S) and (b) introduce an envelope noise floor from intrinsic fluctuations in the noise itself. While the promise of SNRENV has been demonstrated for normal-hearing listeners, it has not been thoroughly extended to hearing-impaired listeners because of limited physiological knowledge of how SNHL affects speech-in-noise envelope coding relative to noise alone. Here, envelope coding to speech-in-noise stimuli was quantified from auditory-nerve model spike trains using shuffled correlograms, which were analyzed in the modulation-frequency domain to compute modulation-band estimates of neural SNRENV. Preliminary spike-train analyses show strong similarities to the sEPSM, demonstrating feasibility of neural SNRENV computations. Results suggest that individual differences can occur based on differential degrees of outer- and inner-hair-cell dysfunction in listeners currently diagnosed into the single audiological SNHL category. The predicted acoustic-SNR dependence in individual differences suggests that the SNR-dependent rate of susceptibility could be an important metric in diagnosing individual differences. Future measurements of the neural SNRENV in animal studies with various forms of SNHL will provide valuable insight for understanding individual differences in speech-in-noise intelligibility.

  1. Effect of different bicycle body positions on power output in aerobically trained females.

    PubMed

    Hubenig, Lindsay R; Game, Alex B; Kennedy, Michael D

    2011-10-01

    Aerodynamic bicycle positioning reduces drag but also reduces power output (PO) in males. The effect of aerodynamic bicycle positioning in trained endurance females is unknown. Eighteen females participants (VO2max 49.7 ± 6.3 ml · kg(-1) · min(-1)) all with competitive experience performed cycling trials at ventilatory threshold 1 and 2 (VT-1, VT-2) in both an aerodynamic and an upright position. There was a significant difference in PO between the aerodynamic and upright positions at VT-1 (152.7 ± 28.0 Watts and 159.7 ± 33.1 Watts, respectively) but not at VT-2 (191.2 ± 39.1 Watts and 192.4 ± 40.0 Watts, respectively). There were no significant differences in heart rate, oxygen consumption, or cadence between positions at either intensity. At both intensities the individual response was varied and no trends due to years of experience or background (triathlete or cyclist) explained this variability. Therefore, despite the significant mean difference in PO at VT-1, these results indicate that in trained females the effect of aerodynamic positioning is individual.

  2. Hysteresis, phase transitions, and dangerous transients in electrical power distribution systems

    NASA Astrophysics Data System (ADS)

    Duclut, Charlie; Backhaus, Scott; Chertkov, Michael

    2013-06-01

    The majority of dynamical studies in power systems focus on the high-voltage transmission grids where models consider large generators interacting with crude aggregations of individual small loads. However, new phenomena have been observed indicating that the spatial distribution of collective, nonlinear contribution of these small loads in the low-voltage distribution grid is crucial to the outcome of these dynamical transients. To elucidate the phenomenon, we study the dynamics of voltage and power flows in a spatially extended distribution feeder (circuit) connecting many asynchronous induction motors and discover that this relatively simple 1+1 (space+time) dimensional system exhibits a plethora of nontrivial spatiotemporal effects, some of which may be dangerous for power system stability. Long-range motor-motor interactions mediated by circuit voltage and electrical power flows result in coexistence and segregation of spatially extended phases defined by individual motor states, a “normal” state where the motors’ mechanical (rotation) frequency is slightly smaller than the nominal frequency of the basic ac flows and a “stalled” state where the mechanical frequency is small. Transitions between the two states can be initiated by a perturbation of the voltage or base frequency at the head of the distribution feeder. Such behavior is typical of first-order phase transitions in physics, and this 1+1 dimensional model shows many other properties of a first-order phase transition with the spatial distribution of the motors’ mechanical frequency playing the role of the order parameter. In particular, we observe (a) propagation of the phase-transition front with the constant speed (in very long feeders) and (b) hysteresis in transitions between the normal and stalled (or partially stalled) phases.

  3. Hysteresis, phase transitions, and dangerous transients in electrical power distribution systems.

    PubMed

    Duclut, Charlie; Backhaus, Scott; Chertkov, Michael

    2013-06-01

    The majority of dynamical studies in power systems focus on the high-voltage transmission grids where models consider large generators interacting with crude aggregations of individual small loads. However, new phenomena have been observed indicating that the spatial distribution of collective, nonlinear contribution of these small loads in the low-voltage distribution grid is crucial to the outcome of these dynamical transients. To elucidate the phenomenon, we study the dynamics of voltage and power flows in a spatially extended distribution feeder (circuit) connecting many asynchronous induction motors and discover that this relatively simple 1+1 (space+time) dimensional system exhibits a plethora of nontrivial spatiotemporal effects, some of which may be dangerous for power system stability. Long-range motor-motor interactions mediated by circuit voltage and electrical power flows result in coexistence and segregation of spatially extended phases defined by individual motor states, a "normal" state where the motors' mechanical (rotation) frequency is slightly smaller than the nominal frequency of the basic ac flows and a "stalled" state where the mechanical frequency is small. Transitions between the two states can be initiated by a perturbation of the voltage or base frequency at the head of the distribution feeder. Such behavior is typical of first-order phase transitions in physics, and this 1+1 dimensional model shows many other properties of a first-order phase transition with the spatial distribution of the motors' mechanical frequency playing the role of the order parameter. In particular, we observe (a) propagation of the phase-transition front with the constant speed (in very long feeders) and (b) hysteresis in transitions between the normal and stalled (or partially stalled) phases.

  4. On the apparent power law in CDM halo pseudo-phase space density profiles

    NASA Astrophysics Data System (ADS)

    Nadler, Ethan O.; Oh, S. Peng; Ji, Suoqing

    2017-09-01

    We investigate the apparent power-law scaling of the pseudo-phase space density (PPSD) in cold dark matter (CDM) haloes. We study fluid collapse, using the close analogy between the gas entropy and the PPSD in the fluid approximation. Our hydrodynamic calculations allow for a precise evaluation of logarithmic derivatives. For scale-free initial conditions, entropy is a power law in Lagrangian (mass) coordinates, but not in Eulerian (radial) coordinates. The deviation from a radial power law arises from incomplete hydrostatic equilibrium (HSE), linked to bulk inflow and mass accretion, and the convergence to the asymptotic central power-law slope is very slow. For more realistic collapse, entropy is not a power law with either radius or mass due to deviations from HSE and scale-dependent initial conditions. Instead, it is a slowly rolling power law that appears approximately linear on a log-log plot. Our fluid calculations recover PPSD power-law slopes and residual amplitudes similar to N-body simulations, indicating that deviations from a power law are not numerical artefacts. In addition, we find that realistic collapse is not self-similar; scalelengths such as the shock radius and the turnaround radius are not power-law functions of time. We therefore argue that the apparent power-law PPSD cannot be used to make detailed dynamical inferences or extrapolate halo profiles inwards, and that it does not indicate any hidden integrals of motion. We also suggest that the apparent agreement between the PPSD and the asymptotic Bertschinger slope is purely coincidental.

  5. The Effects of Tai Chi Chuan Combined with Vibration Training on Balance Control and Lower Extremity Muscle Power

    PubMed Central

    Chung, Pao-Hung; Lin, Guan-Lun; Liu, Chiang; Chuang, Long-Ren; Shiang, Tzyy-Yuang

    2013-01-01

    The aim of this study was to determine whether performing Tai Chi Chuan on a customized vibration platform could enhance balance control and lower extremity muscle power more efficiently than Tai Chi Chuan alone in an untrained young population. Forty-eight healthy young adults were randomly assigned to the following three groups: a Tai Chi Chuan combined with vibration training group (TCV), a Tai Chi Chuan group (TCC) or a control group. The TCV group underwent 30 minutes of a reformed Tai Chi Chuan program on a customized vibration platform (32 Hz, 1 mm) three times a week for eight weeks, whereas the TCC group was trained without vibration stimuli. A force platform was used to measure the moving area of a static single leg stance and the heights of two consecutive countermovement jumps. The activation of the knee extensor and flexor was also measured synchronously by surface electromyography in all tests. The results showed that the moving area in the TCV group was significantly decreased by 15.3%. The second jump height in the TCV group was significantly increased by 8.14%, and the activation of the knee extensor/flexor was significantly decreased in the first jump. In conclusion, Tai Chi Chuan combined with vibration training can more efficiently improve balance control, and the positive training effect on the lower extremity muscle power induced by vibration stimuli still remains significant because there is no cross-interaction between the two different types of training methods. Key points Eight weeks of Tai Chi Chuan combined with vibration training can more efficiently improve balance control for an untrained young population. The positive training effect on the lower extremity muscle power induced by vibration stimuli during Tai Chi Chuan movements still remains significant because of SSC mechanism. Combining Tai Chi Chuan with vibration training is more efficient and does not decrease the overall training effects due to a cross-interaction of each other

  6. The effects of tai chi chuan combined with vibration training on balance control and lower extremity muscle power.

    PubMed

    Chung, Pao-Hung; Lin, Guan-Lun; Liu, Chiang; Chuang, Long-Ren; Shiang, Tzyy-Yuang

    2013-01-01

    The aim of this study was to determine whether performing Tai Chi Chuan on a customized vibration platform could enhance balance control and lower extremity muscle power more efficiently than Tai Chi Chuan alone in an untrained young population. Forty-eight healthy young adults were randomly assigned to the following three groups: a Tai Chi Chuan combined with vibration training group (TCV), a Tai Chi Chuan group (TCC) or a control group. The TCV group underwent 30 minutes of a reformed Tai Chi Chuan program on a customized vibration platform (32 Hz, 1 mm) three times a week for eight weeks, whereas the TCC group was trained without vibration stimuli. A force platform was used to measure the moving area of a static single leg stance and the heights of two consecutive countermovement jumps. The activation of the knee extensor and flexor was also measured synchronously by surface electromyography in all tests. The results showed that the moving area in the TCV group was significantly decreased by 15.3%. The second jump height in the TCV group was significantly increased by 8.14%, and the activation of the knee extensor/flexor was significantly decreased in the first jump. In conclusion, Tai Chi Chuan combined with vibration training can more efficiently improve balance control, and the positive training effect on the lower extremity muscle power induced by vibration stimuli still remains significant because there is no cross-interaction between the two different types of training methods. Key pointsEight weeks of Tai Chi Chuan combined with vibration training can more efficiently improve balance control for an untrained young population.The positive training effect on the lower extremity muscle power induced by vibration stimuli during Tai Chi Chuan movements still remains significant because of SSC mechanism.Combining Tai Chi Chuan with vibration training is more efficient and does not decrease the overall training effects due to a cross-interaction of each other.

  7. The effects of plyometric vs. dynamic stabilization and balance training on power, balance, and landing force in female athletes.

    PubMed

    Myer, Gregory D; Ford, Kevin R; Brent, Jensen L; Hewett, Timothy E

    2006-05-01

    Neuromuscular training protocols that include both plyometrics and dynamic balance exercises can significantly improve biomechanics and neuromuscular performance and reduce anterior cruciate ligament injury risk in female athletes. The purpose of this study was to compare the effects of plyometrics (PLYO) versus dynamic stabilization and balance training (BAL) on power, balance, strength, and landing force in female athletes. Either PLYO or BAL were included as a component of a dynamic neuromuscular training regimen that reduced measures related to ACL injury and increased measures of performance. Nineteen high school female athletes participated in training 3 times a week for 7 weeks. The PLYO (n = 8) group did not receive any dynamic balance exercises and the BAL (n = 11) group did not receive any maximum effort jumps during training. Pretraining vs. posttraining measures of impact force and standard deviation of center of pressure (COP) were recorded during a single leg hop and hold. Subjects were also tested for training effects in strength (isokinetic and isoinertial) and power (vertical jump). The percent change from pretest to posttest in vertical ground reaction force was significantly different between the BAL and PLYO groups on the dominant side (p < 0.05). Both groups decreased their standard deviation of center of pressure (COP) during hop landings in the medial/lateral direction on their dominant side, which equalized pretested side to side differences. Both groups increased hamstrings strength and vertical jump. The results of this study suggest that both PLYO and BAL training are effective at increasing measures of neuromuscular power and control. A combination of PLYO and BAL training may further maximize the effectiveness of preseason training for female athletes.

  8. Muscle power patterns in the mid-acceleration phase of sprinting.

    PubMed

    Johnson, M D; Buckley, J G

    2001-04-01

    To assess the role of the lower limb joints in generating velocity in the mid-acceleration phase of sprinting, muscle power patterns of the hip, knee and ankle were determined. Six male sprinters with a mean 100 m time of 10.75 s performed repeated maximal sprints along a 35 m indoor track. A complete stride across a force platform, positioned at approximately 14 m into the sprint, was video-recorded for analysis. Smoothed coordinate data were obtained from manual digitization of (50 Hz) video images and were then interpolated to match the sampling rate of the recorded ground reaction force (1000 Hz). The moment at each joint was then calculated using inverse dynamics and multiplied by the angular velocity to determine the muscle power. The results showed a proximal-to-distal timing in the generation of peak extensor power during stance at the hip, the knee and then the ankle, with the plantar flexors producing the greatest peak power. Apart from a moderate power generation peak towards toe-off, knee power was negligible despite a large extensor moment throughout stance. The role of the knee thus appears to be one of maintaining the centre of mass height and enabling the power generated at the hip to be transferred to the ankle.

  9. [Effects of Reactive Jump Training in Handball Players Regarding Jump Height and Power Development in the Triceps Surae Muscle].

    PubMed

    Rensing, N; Westermann, A; Möller, D; von Piekartz, H

    2015-12-01

    Studies have shown changes in the technical and physical demands in modern handball. The game has increased considerably in speed, power and dynamics. Jump training has, therefore, become ever more important in the training of the athletes. These developments contribute to the fact that handball is now one of the most injury-prone types of sport, with the lower extremities being most frequently affected. Reactive jump training is not only used in training by now, but also increasingly in injury prevention. The aim of this study was to investigate the effectiveness of reactive jump training with handball players. 21 regional league handball players were randomly divided into an intervention group (n = 12) and a control group (n = 9). The intervention group completed a six-week reactive jump training programme while the control group went through a non-specific training programme. Jump height (squat and counter movement jump), isokinetic and isometric maximum power as well as muscle activity served as measuring parameters. A comparison of the intervention and control groups revealed that the reactive jump training led to significant improvements in jump height. The isometric and isokinetic maximum power measurements and the electromyographic activities of the triceps surae muscle demonstrated an improvement in the values within the intervention group. However, this improvement was not significant compared with the control group. Likewise both jumps correlated with the muscle activity of the soleus muscle as shown by electromyography. A moderate correlation was noticed between the isokinetic maximum power measurement and the electromyographic activity of the soleus and gastrocnemius medialis muscles. Furthermore, the correlations of the isometric and isokinetic maximum power meas-urements resulted in a strong correlation coefficient. This study revealed a significant increase in jump height after reactive jump training. There was no significant difference in

  10. Effect of phase morphology on bulk strength for power-law materials

    NASA Astrophysics Data System (ADS)

    Gerbi, Christopher; Johnson, Scott E.; Cook, Alden; Vel, Senthil S.

    2015-01-01

    The strength of a polyphase aggregate comprising power-law materials is a function of the constitutive laws of the phases present, the arrangement of those phases and environmental conditions such as temperature. Primarily for geological applications, we consider the degree to which the arrangement of the phases has a significant influence on bulk strength. Calculations based on current single-mineral experimental data indicate that the absolute and relative strength differences between the upper and lower theoretical bounds vary widely with mineral pair, environmental conditions and strain rate. For example, at 850 °C, some pairs, such as plagioclase-clinopyroxene, are highly sensitive to phase morphology, whereas others, such as quartz-plagioclase, are not. Using a finite-element implementation of asymptotic expansion homogenization, we have calculated the bulk strength of natural and synthetic microstructures across macroscale strain gradients. We find that phase morphology does not change sufficiently in most cases to be the dominant factor in bulk strength variation. Thus on its own, phase morphology in an aggregate of power-law materials does not appear to be a major control on bulk strength under typical viscous geological conditions. However, phase morphology does affect microscale stress and strain rate patterns, which in turn can induce microscale variations in constitutive laws and diffusional pathways. These factors, including reactions and changing deformation mechanisms, are strongly influenced by phase morphology and do cause strength variation in rocks. As a result, any parametrization of rock strength needs to account for evolving modal mineralogy and deformation mechanisms in addition to morphological changes alone.

  11. Effects of two and five days of creatine loading on muscular strength and anaerobic power in trained athletes.

    PubMed

    Law, Yu Li Lydia; Ong, Wee Sian; GillianYap, Tsien Lin; Lim, Su Ching Joselin; Von Chia, Ee

    2009-05-01

    The purpose of this study was to establish the effects of 2 and 5 days of creatine loading, coupled with resistance training, on muscular strength and anaerobic performance in trained athletes. Seventeen trained men were randomly assigned to a creatine or a placebo group. The creatine supplementation group consumed 20 g of creatine per day (4 doses of 5 g per day), whereas the placebo group was given a placebo similar in appearance and taste over the 5-day supplementation duration. Anaerobic power and strength performance measures, in addition to blood and urine analysis, were conducted in the morning before the supplementation began and on the third and sixth day to establish the effect of 2 and 5 days of creatine loading, respectively. The study found that a 5-day creatine loading regime coupled with resistance training resulted in significant improvements in both average anaerobic power, as measured by the 30-second Wingate test and back squat strength compared with just training alone. However, 2 days of supplementation was not sufficient to produce similar performance gains as that observed at the end of 5 days of loading in trained men, despite increases in creatine uptake in the body. The standard 5-day loading regime should hence be prescribed to individuals supplementing with creatine for enhanced strength and power.

  12. Intracranial electroencephalography power and phase synchronization changes during monaural and binaural beat stimulation.

    PubMed

    Becher, Ann-Katrin; Höhne, Marlene; Axmacher, Nikolai; Chaieb, Leila; Elger, Christian E; Fell, Juergen

    2015-01-01

    Auditory stimulation with monaural or binaural auditory beats (i.e. sine waves with nearby frequencies presented either to both ears or to each ear separately) represents a non-invasive approach to influence electrical brain activity. It is still unclear exactly which brain sites are affected by beat stimulation. In particular, an impact of beat stimulation on mediotemporal brain areas could possibly provide new options for memory enhancement or seizure control. Therefore, we examined how electroencephalography (EEG) power and phase synchronization are modulated by auditory stimulation with beat frequencies corresponding to dominant EEG rhythms based on intracranial recordings in presurgical epilepsy patients. Monaural and binaural beat stimuli with beat frequencies of 5, 10, 40 and 80 Hz and non-superposed control signals were administered with low amplitudes (60 dB SPL) and for short durations (5 s). EEG power was intracranially recorded from mediotemporal, temporo-basal and temporo-lateral and surface sites. Evoked and total EEG power and phase synchronization during beat vs. control stimulation were compared by the use of Bonferroni-corrected non-parametric label-permutation tests. We found that power and phase synchronization were significantly modulated by beat stimulation not only at temporo-basal, temporo-lateral and surface sites, but also at mediotemporal sites. Generally, more significant decreases than increases were observed. The most prominent power increases were seen after stimulation with monaural 40-Hz beats. The most pronounced power and synchronization decreases resulted from stimulation with monaural 5-Hz and binaural 80-Hz beats. Our results suggest that beat stimulation offers a non-invasive approach for the modulation of intracranial EEG characteristics. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  13. Influence of output power of a spin torque oscillator on phase locked loop operation

    NASA Astrophysics Data System (ADS)

    Tamaru, Shingo; Kubota, Hitoshi; Yakushiji, Kay; Fukushima, Akio; Yuasa, Shinji

    2016-09-01

    This work investigates the influence of the output power of a spin torque oscillator (STO) on the operation of a phase locked loop (PLL) circuit. Timing jitter and minimum output power for stable PLL operation determined by Johnson noise and shot noise are first theoretically calculated, and compared with experimental results. The theory and experiment show a reasonably good agreement, indicating that smaller than -50 dBm (10 nW), or -60 dBm (1 nW) when a low pass filter is used, of output power is sufficient for stable PLL operation if a large timing jitter is acceptable. However, it is also shown that a large output power is needed to suppress timing jitter down to the level comparable to state-of-the-art commercial PLL circuits. The estimate of minimum output power for stable PLL operation is verified by intentionally attenuating the STO output signal down to -55 dBm (3.2 nW) and demonstrating a stable phase locked oscillation.

  14. SEMICONDUCTOR INTEGRATED CIRCUITS: A 0.8 V low power low phase-noise PLL

    NASA Astrophysics Data System (ADS)

    Yan, Han; Xiao, Liang; Haifeng, Zhou; Yinfang, Xie; Waisum, Wong

    2010-08-01

    A low power and low phase noise phase-locked loop (PLL) design for low voltage (0.8 V) applications is presented. The voltage controlled oscillator (VCO) operates from a 0.5 V voltage supply, while the other blocks operate from a 0.8 V supply. A differential NMOS-only topology is adopted for the oscillator, a modified precharge topology is applied in the phase-frequency detector (PFD), and a new feedback structure is utilized in the charge pump (CP) for ultra-low voltage applications. The divider adopts the extended true single phase clock DFF in order to operate in the high frequency region and save circuit area and power. In addition, several novel design techniques, such as removing the tail current source, are demonstrated to cut down the phase noise. Implemented in the SMIC 0.13 μm RF CMOS process and operated at 0.8 V supply voltage, the PLL measures a phase noise of-112.4 dBc/Hz at an offset frequency of 1 MHz from the carrier and a frequency range of 3.166-3.383 GHz. The improved PFD and the novel CP dissipate 0.39 mW power from a 0.8 V supply. The occupied chip area of the PFD and CP is 100 × 100 μm2. The chip occupies 0.63 mm2, and draws less than 6.54 mW from a 0.8 V supply.

  15. Solar power satellite system definition study. Volume 1: Executive summary, phase 3

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Results of a three phase study of the Solar Power Satellite System are summarized. Various options and alternate systems were considered and the following conclusions were reached: antenna mounted solid state transmitters are potentially as cost effective as the klystron approach, althrough limited to 2500 megawatts net output; the free electron laser and optical diode laser appear most promising for laser power transmission; ground antenna siting need not be restricted to below 35 degrees of latitude; and nonrecurring cost reductions attainable by using a smaller Heavy Lift Launch Vehicle are highly attractive.

  16. Modeling Single-Phase and Boiling Liquid Jet Impingement Cooling in Power Electronics

    SciTech Connect

    Narumanchi, S. V. J.; Hassani, V.; Bharathan, D.

    2005-12-01

    Jet impingement has been an attractive cooling option in a number of industries over the past few decades. Over the past 15 years, jet impingement has been explored as a cooling option in microelectronics. Recently, interest has been expressed by the automotive industry in exploring jet impingement for cooling power electronics components. This technical report explores, from a modeling perspective, both single-phase and boiling jet impingement cooling in power electronics, primarily from a heat transfer viewpoint. The discussion is from the viewpoint of the cooling of IGBTs (insulated-gate bipolar transistors), which are found in hybrid automobile inverters.

  17. Short-term high intensity plyometric training program improves strength, power and agility in male soccer players.

    PubMed

    Váczi, Márk; Tollár, József; Meszler, Balázs; Juhász, Ivett; Karsai, István

    2013-03-01

    The aim of the present study was to investigate the effects of a short-term in-season plyometric training program on power, agility and knee extensor strength. Male soccer players from a third league team were assigned into an experimental and a control group. The experimental group, beside its regular soccer training sessions, performed a periodized plyometric training program for six weeks. The program included two training sessions per week, and maximal intensity unilateral and bilateral plyometric exercises (total of 40 - 100 foot contacts/session) were executed. Controls participated only in the same soccer training routine, and did not perform plyometrics. Depth vertical jump height, agility (Illinois Agility Test, T Agility Test) and maximal voluntary isometric torque in knee extensors using Multicont II dynamometer were evaluated before and after the experiment. In the experimental group small but significant improvements were found in both agility tests, while depth jump height and isometric torque increments were greater. The control group did not improve in any of the measures. Results of the study indicate that plyometric training consisting of high impact unilateral and bilateral exercises induced remarkable improvements in lower extremity power and maximal knee extensor strength, and smaller improvements in soccer-specific agility. Therefore, it is concluded that short-term plyometric training should be incorporated in the in-season preparation of lower level players to improve specific performance in soccer.

  18. Short-Term High Intensity Plyometric Training Program Improves Strength, Power and Agility in Male Soccer Players

    PubMed Central

    Váczi, Márk; Tollár, József; Meszler, Balázs; Juhász, Ivett; Karsai, István

    2013-01-01

    The aim of the present study was to investigate the effects of a short-term in-season plyometric training program on power, agility and knee extensor strength. Male soccer players from a third league team were assigned into an experimental and a control group. The experimental group, beside its regular soccer training sessions, performed a periodized plyometric training program for six weeks. The program included two training sessions per week, and maximal intensity unilateral and bilateral plyometric exercises (total of 40 – 100 foot contacts/session) were executed. Controls participated only in the same soccer training routine, and did not perform plyometrics. Depth vertical jump height, agility (Illinois Agility Test, T Agility Test) and maximal voluntary isometric torque in knee extensors using Multicont II dynamometer were evaluated before and after the experiment. In the experimental group small but significant improvements were found in both agility tests, while depth jump height and isometric torque increments were greater. The control group did not improve in any of the measures. Results of the study indicate that plyometric training consisting of high impact unilateral and bilateral exercises induced remarkable improvements in lower extremity power and maximal knee extensor strength, and smaller improvements in soccer-specific agility. Therefore, it is concluded that short-term plyometric training should be incorporated in the in-season preparation of lower level players to improve specific performance in soccer. PMID:23717351

  19. Development of a single-phase harmonic power flow program to study the 20 kHz AC power system for large spacecraft

    NASA Technical Reports Server (NTRS)

    Kraft, L. Alan; Kankam, M. David

    1991-01-01

    The development of software is described to aid in design and analysis of AC power systems for large spacecraft. The algorithm is an important version of harmonic power flow program, HARMFLO, used for the study of AC power quality. The new program is applicable to three-phase systems typified by terrestrial power systems, and single-phase systems characteristic of space power systems. The modified HARMFLO accommodates system operating frequencies ranging from terrestrial 60 Hz to and beyond aerospace 20 kHz, and can handle both source and load-end harmonic distortions. Comparison of simulation and test results of a representative spacecraft power system shows a satisfactory correlation. Recommendations are made for the direction of future improvements to the software, to enhance its usefulness to power system designer and analysts.

  20. Simulators for Mariner Training and Licensing. Phase I. The Role of Simulators in the Mariner Training and Licensing Process. Volume I

    DTIC Science & Technology

    1980-07-01

    0d LEY CAORF 00-7810-01 Report No. CG-D-12-80 ,-- UA-RD-O30-80033 -SIMULATORS FOR MARINER TRAINING AND LICENSING PHASE 1: THE ROLE OF SIMULATORS IN...1976 College of Nautical Studies, Warsash (Near Southampton) 1976 Navigation Simulator System, Tokyo University of Mercantile Marine 1976 Steering