WorldWideScience

Sample records for net power output

  1. Semi-fuel cell studies for powering underwater devices: integrated design for maximized net power output

    Science.gov (United States)

    Cardenas-Valencia, Andres M.; Short, R. Timothy; Adornato, Lori; Langebrake, Larry

    2010-04-01

    Use of sensor systems in water bodies has applications that range from environmental and oceanographic research to port and homeland security. Power sources are often the limiting component for further reduction of sensor system size and weight. We present recent investigations of metal-anode water-activated galvanic cells, specifically water-activated Alcells using inorganic alkali peroxides and solid organic oxidizers (heterocyclic halamines), in a semi-fuel cell configuration (i.e., with cathode species generated in situ and flow-through cells). The oxidizers utilized are inexpensive solid materials that are generally (1) safer to handle than liquid solutions or gases, (2) have inherently higher current and energy capacity (as they are not dissolved), and, (3) if appropriately packaged, will not degrade over time. The specific energy (S.E.) of Al-alkali peroxide was found to be 230 Wh/kg (460 Wh/kg, considering only active materials) in a seven-gram cell. Interestingly, when the cell size was increased (making more area of the catalytic cathode electrode available), the results from a single addition of water in an Al-organic oxidizer cell (weighing ~18 grams) showed an S.E. of about 200 Wh/kg. This scalability characteristic suggests that values in excess of 400 Wh/kg could be obtained in a semi-fuel-cell-like system. In this paper, we also present design considerations that take into account the energy requirements of the pumping devices and show that the proposed oxidizers, and the possible control of the chemical equilibrium of these cathodes in solution, may help reduce this power requirement and hence enhance the overall energetic balance.

  2. Exercise efficiency of low power output cycling.

    Science.gov (United States)

    Reger, M; Peterman, J E; Kram, R; Byrnes, W C

    2013-12-01

    Exercise efficiency at low power outputs, energetically comparable to daily living activities, can be influenced by homeostatic perturbations (e.g., weight gain/loss). However, an appropriate efficiency calculation for low power outputs used in these studies has not been determined. Fifteen active subjects (seven females, eight males) performed 14, 5-min cycling trials: two types of seated rest (cranks vertical and horizontal), passive (motor-driven) cycling, no-chain cycling, no-load cycling, cycling at low (10, 20, 30, 40 W), and moderate (50, 60, 80, 100, 120 W) power outputs. Mean delta efficiency was 57% for low power outputs compared to 41.3% for moderate power outputs. Means for gross (3.6%) and net (5.7%) efficiencies were low at the lowest power output. At low power outputs, delta and work efficiency values exceeded theoretical values. In conclusion, at low power outputs, none of the common exercise efficiency calculations gave values comparable to theoretical muscle efficiency. However, gross efficiency and the slope and intercept of the metabolic power vs mechanical power output regression provide insights that are still valuable when studying homeostatic perturbations. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. The Influence of Output Variability from Renewable Electricity Generation on Net Energy Calculations

    Directory of Open Access Journals (Sweden)

    Hannes Kunz

    2014-01-01

    Full Text Available One key approach to analyzing the feasibility of energy extraction and generation technologies is to understand the net energy they contribute to society. These analyses most commonly focus on a simple comparison of a source’s expected energy outputs to the required energy inputs, measured in the form of energy return on investment (EROI. What is not typically factored into net energy analysis is the influence of output variability. This omission ignores a key attribute of biological organisms and societies alike: the preference for stable returns with low dispersion versus equivalent returns that are intermittent or variable. This biologic predilection for stability, observed and refined in academic financial literature, has a direct relationship to many new energy technologies whose outputs are much more variable than traditional energy sources. We investigate the impact of variability on net energy metrics and develop a theoretical framework to evaluate energy systems based on existing financial and biological risk models. We then illustrate the impact of variability on nominal energy return using representative technologies in electricity generation, with a more detailed analysis on wind power, where intermittence and stochastic availability of hard-to-store electricity will be factored into theoretical returns.

  4. System and method for determining the net output torque from a waste heat recovery system

    Science.gov (United States)

    Tricaud, Christophe; Ernst, Timothy C.; Zigan, James A.

    2016-12-13

    The disclosure provides a waste heat recovery system with a system and method for calculation of the net output torque from the waste heat recovery system. The calculation uses inputs from existing pressure and speed sensors to create a virtual pump torque sensor and a virtual expander torque sensor, and uses these sensors to provide an accurate net torque output from the WHR system.

  5. Uncertainties in predicting solar panel power output

    Science.gov (United States)

    Anspaugh, B.

    1974-01-01

    The problem of calculating solar panel power output at launch and during a space mission is considered. The major sources of uncertainty and error in predicting the post launch electrical performance of the panel are considered. A general discussion of error analysis is given. Examples of uncertainty calculations are included. A general method of calculating the effect on the panel of various degrading environments is presented, with references supplied for specific methods. A technique for sizing a solar panel for a required mission power profile is developed.

  6. Advanced Output Coupling for High Power Gyrotrons

    Energy Technology Data Exchange (ETDEWEB)

    Read, Michael [Calabazas Creek Research, Inc., San Mateo, CA (United States); Ives, Robert Lawrence [Calabazas Creek Research, Inc., San Mateo, CA (United States); Marsden, David [Calabazas Creek Research, Inc., San Mateo, CA (United States); Collins, George [Calabazas Creek Research, Inc., San Mateo, CA (United States); Temkin, Richard [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Guss, William [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Lohr, John [General Atomics, La Jolla, CA (United States); Neilson, Jeffrey [Lexam Research, Redwood City, CA (United States); Bui, Thuc [Calabazas Creek Research, Inc., San Mateo, CA (United States)

    2016-11-28

    The Phase II program developed an internal RF coupler that transforms the whispering gallery RF mode produced in gyrotron cavities to an HE11 waveguide mode propagating in corrugated waveguide. This power is extracted from the vacuum using a broadband, chemical vapor deposited (CVD) diamond, Brewster angle window capable of transmitting more than 1.5 MW CW of RF power over a broad range of frequencies. This coupling system eliminates the Mirror Optical Units now required to externally couple Gaussian output power into corrugated waveguide, significantly reducing system cost and increasing efficiency. The program simulated the performance using a broad range of advanced computer codes to optimize the design. Both a direct coupler and Brewster angle window were built and tested at low and high power. Test results confirmed the performance of both devices and demonstrated they are capable of achieving the required performance for scientific, defense, industrial, and medical applications.

  7. Solar Power Station Output Inverter Control Design

    Directory of Open Access Journals (Sweden)

    J. Bauer

    2011-04-01

    Full Text Available The photovoltaic applications spreads in these days fast, therefore they also undergo great development. Because the amount of the energy obtained from the panel depends on the surrounding conditions, as intensity of the sun exposure or the temperature of the solar array, the converter must be connected to the panel output. The Solar system equipped with inverter can supply small loads like notebooks, mobile chargers etc. in the places where the supplying network is not present. Or the system can be used as a generator and it shall deliver energy to the supply network. Each type of the application has different requirements on the converter and its control algorithm. But for all of them the one thing is common – the maximal efficiency. The paper focuses on design and simulation of the low power inverter that acts as output part of the whole converter. In the paper the design of the control algorithm of the inverter for both types of inverter application – for islanding mode and for operation on the supply grid – is discussed. Attention is also paid to the design of the output filter that should reduce negative side effects of the converter on the supply network.

  8. Maximum Output Power Tracking of Wind Turbine Using Intelligent Control

    OpenAIRE

    Mauridhi Hery Purnomo; Mochamad Ashari; Muldi Yuhendri

    2011-01-01

    The output power of wind turbine is determined by wind speed. The Output power can be adjusted by controlling the generator speed and pitch angle of wind turbine. When the wind speed below the wind turbine rated, the output power of generator can be maximized by controlling the generator speed at point of maximum power coefficient. When the wind speed above the wind turbine rated, output power of wind turbine will exceed the power generators rated. In this condition, the output power of wind ...

  9. Experimental Investigation on Power Output in Aged Wind Turbines

    Directory of Open Access Journals (Sweden)

    N. Murugan

    2012-01-01

    Full Text Available An investigation on the power output on effect of tower height with same diameter of rotor was conducted in a wind turbine site. As the wind acceleration is varying with height, 3 levels were selected according to the availability of tower. The responses of power output with respect to variation of wind speed are changing for the tower heights of 30, 40, and 50 m. The study showed that the actual ideal power output and measured real power output follow the same trend within range of operating wind speed. The empirical model used for calculation of actual ideal power output was compared with real power output and the overall concepts in power output also had been analysed.

  10. Net energy analysis: Powerful tool for selecting electric power options

    Science.gov (United States)

    Baron, S.

    A number of net energy analysis studies have been conducted in recent years for electric power production from coal, oil and uranium fuels; synthetic fuels from coal and oil shale; and heat and electric power from solar energy. This technique is an excellent indicator of investment costs, environmental impact and potential economic competitiveness of alternative electric power systems for energy planners from the Eastern European countries considering future options. Energy conservation is also important to energy planners and the net energy analysis technique is an excellent accounting system on the extent of energy resource conservation. The author proposes to discuss the technique and to present the results of his studies and others in the field. The information supplied to the attendees will serve as a powerful tool to the energy planners considering their electric power options in the future.

  11. Net energy analysis - powerful tool for selecting elective power options

    Energy Technology Data Exchange (ETDEWEB)

    Baron, S. [Brookhaven National Laboratory, Upton, NY (United States)

    1995-12-01

    A number of net energy analysis studies have been conducted in recent years for electric power production from coal, oil and uranium fuels; synthetic fuels from coal and oil shale; and heat and electric power from solar energy. This technique is an excellent indicator of investment costs, environmental impact and potential economic competitiveness of alternative electric power systems for energy planners from the Eastern European countries considering future options. Energy conservation is also important to energy planners and the net energy analysis technique is an excellent accounting system on the extent of energy resource conservation. The author proposes to discuss the technique and to present the results of his studies and others in the field. The information supplied to the attendees will serve as a powerful tool to the energy planners considering their electric power options in the future.

  12. Optimizing power output by varying repetition tempo.

    Science.gov (United States)

    Pryor, Riana R; Sforzo, Gary A; King, Deborah L

    2011-11-01

    The effects of varying interrepetition rest and eccentric velocity on power output (PO) and the number of repetitions performed during a bench press set were examined in 24 college-aged resistance trained men. On 6 separate occasions, subjects performed a set of bench press at 80% 1 repetition maximum until volitional fatigue. For each of the 6 repetition tempo trials, the bench press set was paced by metronome to a unique repetition tempo involving a combination of the following: interrepetition rest of 0 or 4 seconds; eccentric velocity of 1 or 4 seconds and bottom rest of 0 or 3 seconds. The velocity of concentric contraction was maximal during all 6 tempo trials. During each trial, video data were captured to determine PO variables and number of successful repetitions completed at each tempo. One-way repeated measures analysis of variance showed tempos with a fast eccentric phase (1 second), and no bottom rest produced significantly greater (p ≤ 0.05) PO and repetitions than tempos involving slower eccentric velocity (4 seconds) or greater bottom rest (4 seconds). This combination of greater repetitions and PO resulted in a greater volume of work. Varying interrepetition rest (1 or 4 seconds) did not significantly affect PO or repetitions. The results of this study support the use of fast eccentric speed and no bottom rest during acute performance testing to maximize PO and number of repetitions during a set of bench press.

  13. The Net Contribution of Nuclear Power to the National Economy in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Manki; Kim, Seung-su; Lee, Jong Hee; Kim, Soo-eun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    The objective of the study is to quantify the net contribution of nuclear power to the national economy in Korea focusing on the operating phase of nuclear power. This study is to see what would have happened to the Korean national economy, if all the nuclear power had been completely replaced with its substitute, coal power, providing a mechanism addressing a possible feedback between price and output on a national economy, triggered by the structural change in power sector. The role of nuclear power is estimated to be significant in terms of total output, GDP, price level, and labor employment in Korean economy. The net contribution of nuclear power estimated in this study can be recognized as positive externalities of nuclear power, which can be used to balance between positive externalities and negative externalities in the estimation of social cost of nuclear power, on which public concerns are substantially growing in the wake of the Fukushima nuclear power accident in Japan.

  14. Effects of Channel Geometry and Coolant Fluid on Thermoelectric Net Power

    DEFF Research Database (Denmark)

    Rezaniakolaei, Alireza; Rosendahl, Lasse; Sørensen, Kim

    2014-01-01

    generation in TEG for different size of hydraulic diameter of plate-fin heat sink and over a wide range of Reynolds number. The particular focus of this study is to find optimal Reynolds number in each considered channel hydraulic diameter and to explore optimal channel hydraulic diameter for maximum TEG net......, and the maximum net power output occurs at smaller Reynolds number when the channel hydraulic diameter reduces.......Channel geometry has a strong influence on the heat transfer coefficient and cooling energy input in a heat sink. The net power output in a thermoelectric generator (TEG) can be defined as power generation minus the required cooling energy in TEG. This study aims to evaluate the net power...

  15. Net energy output from harvesting small-diameter trees using a mechanized system

    Science.gov (United States)

    Fei Pan; Han-Sup Han; Leonard R. Johnson; William J. Elliot

    2008-01-01

    What amount of extra energy can be generated after subtracting the total energy consumed to produce the biomass energy? Knowing the ratio between energy output and input is a valid question when highly mechanized systems that consume fossil fuels are used to harvest and transport forest biomass for energy. We estimated the net energy generated from mechanical fuel...

  16. Temporal Modeling of Neural Net Input/Output Behaviors: The Case of XOR

    Directory of Open Access Journals (Sweden)

    Bernard P. Zeigler

    2017-01-01

    Full Text Available In the context of the modeling and simulation of neural nets, we formulate definitions for the behavioral realization of memoryless functions. The definitions of realization are substantively different for deterministic and stochastic systems constructed of neuron-inspired components. In contrast to earlier generations of neural net models, third generation spiking neural nets exhibit important temporal and dynamic properties, and random neural nets provide alternative probabilistic approaches. Our definitions of realization are based on the Discrete Event System Specification (DEVS formalism that fundamentally include temporal and probabilistic characteristics of neuron system inputs, state, and outputs. The realizations that we construct—in particular for the Exclusive Or (XOR logic gate—provide insight into the temporal and probabilistic characteristics that real neural systems might display. Our results provide a solid system-theoretical foundation and simulation modeling framework for the high-performance computational support of such applications.

  17. Verification of hourly forecasts of wind turbine power output

    Energy Technology Data Exchange (ETDEWEB)

    Wegley, H.L.

    1984-08-01

    A verification of hourly average wind speed forecasts in terms of hourly average power output of a MOD-2 was performed for four sites. Site-specific probabilistic transformation models were developed to transform the forecast and observed hourly average speeds to the percent probability of exceedance of an hourly average power output. (This transformation model also appears to have value in predicting annual energy production for use in wind energy feasibility studies.) The transformed forecasts were verified in a deterministic sense (i.e., as continuous values) and in a probabilistic sense (based upon the probability of power output falling in a specified category). Since the smoothing effects of time averaging are very pronounced, the 90% probability of exceedance was built into the transformation models. Semiobjective and objective (model output statistics) forecasts were made compared for the four sites. The verification results indicate that the correct category can be forecast an average of 75% of the time over a 24-hour period. Accuracy generally decreases with projection time out to approx. 18 hours and then may increase due to the fairly regular diurnal wind patterns that occur at many sites. The ability to forecast the correct power output category increases with increasing power output because occurrences of high hourly average power output (near rated) are relatively rare and are generally not forecast. The semiobjective forecasts proved superior to model output statistics in forecasting high values of power output and in the shorter time frames (1 to 6 hours). However, model output statistics were slightly more accurate at other power output levels and times. Noticeable differences were observed between deterministic and probabilistic (categorical) forecast verification results.

  18. Determining power outputs for cycle ergometers with different sized flywheels.

    Science.gov (United States)

    Gledhill, N; Jamnik, R

    1995-01-01

    A number of cycle ergometers are presently being used in a variety of laboratory applications for which the quantification of power output is required. To calculate the power output of cycle ergometers with varying sized flywheels, the circumference of the resistance track on the flywheel is multiplied by the number of flywheel revolutions produced with one complete revolution of the pedal. This provides the "effective distance travelled," and by selecting an appropriate combination of pedalling rate plus flywheel resistance, any desired power output can be produced.

  19. Complementary power output characteristics of electromagnetic generators and triboelectric generators.

    Science.gov (United States)

    Fan, Feng-Ru; Tang, Wei; Yao, Yan; Luo, Jianjun; Zhang, Chi; Wang, Zhong Lin

    2014-04-04

    Recently, a triboelectric generator (TEG) has been invented to convert mechanical energy into electricity by a conjunction of triboelectrification and electrostatic induction. Compared to the traditional electromagnetic generator (EMG) that produces a high output current but low voltage, the TEG has different output characteristics of low output current but high output voltage. In this paper, we present a comparative study regarding the fundamentals of TEGs and EMGs. The power output performances of the EMG and the TEG have a special complementary relationship, with the EMG being a voltage source and the TEG a current source. Utilizing a power transformed and managed (PTM) system, the current output of a TEG can reach as high as ∼3 mA, which can be coupled with the output signal of an EMG to enhance the output power. We also demonstrate a design to integrate a TEG and an EMG into a single device for simultaneously harvesting mechanical energy. In addition, the integrated NGs can independently output a high voltage and a high current to meet special needs.

  20. Impact of Altitude on Power Output during Cycling Stage Racing.

    Directory of Open Access Journals (Sweden)

    Laura A Garvican-Lewis

    Full Text Available The purpose of this study was to quantify the effects of moderate-high altitude on power output, cadence, speed and heart rate during a multi-day cycling tour.Power output, heart rate, speed and cadence were collected from elite male road cyclists during maximal efforts of 5, 15, 30, 60, 240 and 600 s. The efforts were completed in a laboratory power-profile assessment, and spontaneously during a cycling race simulation near sea-level and an international cycling race at moderate-high altitude. Matched data from the laboratory power-profile and the highest maximal mean power output (MMP and corresponding speed and heart rate recorded during the cycling race simulation and cycling race at moderate-high altitude were compared using paired t-tests. Additionally, all MMP and corresponding speeds and heart rates were binned per 1000 m (3000 m according to the average altitude of each ride. Mixed linear modelling was used to compare cycling performance data from each altitude bin.Power output was similar between the laboratory power-profile and the race simulation, however MMPs for 5-600 s and 15, 60, 240 and 600 s were lower (p ≤ 0.005 during the race at altitude compared with the laboratory power-profile and race simulation, respectively. Furthermore, peak power output and all MMPs were lower (≥ 11.7%, p ≤ 0.001 while racing >3000 m compared with rides completed near sea-level. However, speed associated with MMP 60 and 240 s was greater (p < 0.001 during racing at moderate-high altitude compared with the race simulation near sea-level.A reduction in oxygen availability as altitude increases leads to attenuation of cycling power output during competition. Decrement in cycling power output at altitude does not seem to affect speed which tended to be greater at higher altitudes.

  1. Impact of Altitude on Power Output during Cycling Stage Racing.

    Science.gov (United States)

    Garvican-Lewis, Laura A; Clark, Bradley; Martin, David T; Schumacher, Yorck Olaf; McDonald, Warren; Stephens, Brian; Ma, Fuhai; Thompson, Kevin G; Gore, Christopher J; Menaspà, Paolo

    2015-01-01

    The purpose of this study was to quantify the effects of moderate-high altitude on power output, cadence, speed and heart rate during a multi-day cycling tour. Power output, heart rate, speed and cadence were collected from elite male road cyclists during maximal efforts of 5, 15, 30, 60, 240 and 600 s. The efforts were completed in a laboratory power-profile assessment, and spontaneously during a cycling race simulation near sea-level and an international cycling race at moderate-high altitude. Matched data from the laboratory power-profile and the highest maximal mean power output (MMP) and corresponding speed and heart rate recorded during the cycling race simulation and cycling race at moderate-high altitude were compared using paired t-tests. Additionally, all MMP and corresponding speeds and heart rates were binned per 1000 m (3000 m) according to the average altitude of each ride. Mixed linear modelling was used to compare cycling performance data from each altitude bin. Power output was similar between the laboratory power-profile and the race simulation, however MMPs for 5-600 s and 15, 60, 240 and 600 s were lower (p ≤ 0.005) during the race at altitude compared with the laboratory power-profile and race simulation, respectively. Furthermore, peak power output and all MMPs were lower (≥ 11.7%, p ≤ 0.001) while racing >3000 m compared with rides completed near sea-level. However, speed associated with MMP 60 and 240 s was greater (p cycling power output during competition. Decrement in cycling power output at altitude does not seem to affect speed which tended to be greater at higher altitudes.

  2. Control of proton exchange membrane fuel cell system breathing based on maximum net power control strategy

    Science.gov (United States)

    Li, Qi; Chen, Weirong; Liu, Zhixiang; Guo, Ai; Liu, Shukui

    2013-11-01

    In order to achieve the maximum net power, the analysis for the maximum net power characterization of a proton exchange membrane fuel cell (PEMFC) system is carried out. A maximum net power control (MNPC) strategy based on an implicit generalized predictive control (IGPC) and a reference governor is proposed to keep optimal oxygen excess ratio (OER) trajectory. The IGPC based on an effective informed adaptive particle swarm optimization (EIA-PSO) algorithm is developed to solve the predictive control law and reduce the computational complexity in the rolling optimization process. The simulations of three conditional tests are implemented and the results demonstrate that the proposed strategy can track the optimal OER trajectory, reduce the parasitic power and maximize the output net power. The comprehensive comparisons based on three conditional tests verify that the MNPC-IGPC has better robust performance in the presence of large disturbances, time delay and various noises. The experimental comparison with internal control system of Ballard 1.2 kW Nexa Power Module testifies the validity of the MNPC-IGPC for increasing the net power. Hence, this proposed strategy can provide better behavior to guarantee optimal OER trajectory and the maximum net power even though the disturbances and uncertainties occur.

  3. LOAD THAT MAXIMIZES POWER OUTPUT IN COUNTERMOVEMENT JUMP

    Directory of Open Access Journals (Sweden)

    Pedro Jimenez-Reyes

    2016-02-01

    Full Text Available ABSTRACT Introduction: One of the main problems faced by strength and conditioning coaches is the issue of how to objectively quantify and monitor the actual training load undertaken by athletes in order to maximize performance. It is well known that performance of explosive sports activities is largely determined by mechanical power. Objective: This study analysed the height at which maximal power output is generated and the corresponding load with which is achieved in a group of male-trained track and field athletes in the test of countermovement jump (CMJ with extra loads (CMJEL. Methods: Fifty national level male athletes in sprinting and jumping performed a CMJ test with increasing loads up to a height of 16 cm. The relative load that maximized the mechanical power output (Pmax was determined using a force platform and lineal encoder synchronization and estimating the power by peak power, average power and flight time in CMJ. Results: The load at which the power output no longer existed was at a height of 19.9 ± 2.35, referring to a 99.1 ± 1% of the maximum power output. The load that maximizes power output in all cases has been the load with which an athlete jump a height of approximately 20 cm. Conclusion: These results highlight the importance of considering the height achieved in CMJ with extra load instead of power because maximum power is always attained with the same height. We advise for the preferential use of the height achieved in CMJEL test, since it seems to be a valid indicative of an individual's actual neuromuscular potential providing a valid information for coaches and trainers when assessing the performance status of our athletes and to quantify and monitor training loads, measuring only the height of the jump in the exercise of CMJEL.

  4. Solar power output correlation with utility demand in southern Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Frei, J.A.; Chen, Y.T.; Boehm, R.F. [Univ. of Nevada, Las Vegas, NV (United States). Dept. of Mechanical Engineering

    1996-12-31

    Various solar electric system performance codes are used to predict the power generated by different solar power systems in the Southern Nevada area during 1990 by using the National Solar Radiation Data Base (NSRDB) for the Las Vegas region. The system types evaluated along with the predicted codes (shown in parenthesis) are: a central receiver or a power tower system with various amounts of storage (SOLERGY), a Luz-type SEGS parabolic trough system without fossil fuel backup or storage (LUZERGY), a dish-Stirling system (DISH2, a conversion of direct beam radiation with constant collector/engine efficiency was used for this), and various arrangements of non-concentrating photovoltaic devices (PVFORM). Comparisons of these results are made with the daily variations of load requirements of an electrical utility operating in the same geographical area. It is shown that several of the power generation schemes have peak outputs that occur at times very near to, but not coincident with, the peak utility load requirements. The power with a relatively small amount of thermal storage was the only scheme able to provide full power output at the times of peak demands. Several comparisons are made that illuminate the load serving capability of solar generation. Included in this comparison is the determination of the difference in time between the peak power output and the peak demand, as well as the normalized fraction of the peak power generated at the peak demand times.

  5. Battery Energy Storage System for PV Output Power Leveling

    Directory of Open Access Journals (Sweden)

    Rajkiran Singh

    2014-01-01

    Full Text Available Fluctuating photovoltaic (PV output power reduces the reliability in power system when there is a massive penetration of PV generators. Energy storage systems that are connected to the PV generators using bidirectional isolated dc-dc converter can be utilized for compensating the fluctuating PV power. This paper presents a grid connected energy storage system based on a 2 kW full-bridge bidirectional isolated dc-dc converter and a PWM converter for PV output power leveling. This paper proposes two controllers: a current controller using the d-q synchronous reference and a phase-shift controller. The main function of the current controller is to regulate the voltage at the high-side dc, so that the voltage ratio of the high-voltage side (HVS with low-voltage side (LVS is equal to the transformer turns ratio. The phase-shift controller is employed to manage the charging and discharging modes of the battery based on PV output power and battery voltage. With the proposed system, unity power factor and efficient active power injection are achieved. The feasibility of the proposed control system is investigated using PSCAD simulation.

  6. Solar power output correlation with utility demand in southern Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Frei, J.A.; Chen, Y.T.; Boehm, R.F. [Univ. of Nevada, Las Vegas, NV (United States)

    1997-05-01

    Various solar electric system performance codes are used to predict the power generated by different solar power systems in the Southern Nevada area during 1990 by using the National Solar Radiation Data Base (NSRDB) for Las Vegas. The system types evaluated along with the prediction codes (shown in parenthesis) are as follows: a central receiver or a power tower system with various amounts of storage (SOLERGY), a Luz type SEGS parabolic trough system without fossil fuel backup or storage (LUZERGY), a dish-Stirling system (DISH2, a conversion of direct beam radiation with constant collector/engine efficiency was used for this), and various arrangements of nonconcentrating photovoltaic devices (PVFORM). Comparisons of these results are made with the daily variations of load requirements of an electrical utility operating in the same geographical area. These comparisons are made for summer and winter periods. It is shown that several of the power generation schemes have summer peak outputs that occur at times very near to, but not coincident with, the peak utility load requirements. The power tower with a relatively small amount of thermal storage was the only scheme able to provide full power output at the times of summer peak demands. Winter peaks in this region occur during the night. Two comparisons are made that illuminate the summer load serving capability of solar generation in addition to simply showing time-variations of outputs. Included in these comparisons are the determination of the difference in time between the peak power output and the peak demand, as well as the normalized fraction of the peak power generated at the peak demand times.

  7. Linearised model for PV panel power output variation with changes ...

    Indian Academy of Sciences (India)

    PALLAVI BHARADWAJ

    2017-10-26

    Oct 26, 2017 ... This equivalent resistance represents the load seen at the PV panel terminals. It is dependent on the actual power drawn by the system and the interfacing converter between the PV panels and the load. Thus it is a function of the converter duty ratio and load characteristics. Due to the disturbance, output ...

  8. Quantum dot amplifiers with high output power and low noise

    DEFF Research Database (Denmark)

    Berg, Tommy Winther; Mørk, Jesper

    2003-01-01

    Quantum dot semiconductor optical amplifiers have been theoretically investigated and are predicted to achieve high saturated output power, large gain, and low noise figure. We discuss the device dynamics and, in particular, show that the presence of highly inverted barrier states does not limit...

  9. Intermittent Smoothing Approaches for Wind Power Output: A Review

    Directory of Open Access Journals (Sweden)

    Muhammad Jabir

    2017-10-01

    Full Text Available Wind energy is one of the most common types of renewable energy resource. Due to its sustainability and environmental benefits, it is an emerging source for electric power generation. Rapid and random changes of wind speed makes it an irregular and inconsistent power source when connected to the grid, causing different technical problems in protection, power quality and generation dispatch control. Due to these problems, effective intermittent smoothing approaches for wind power output are crucially needed to minimize such problems. This paper reviews various intermittent smoothing approaches used in smoothing the output power fluctuations caused by wind energy. Problems associated with the inclusion of wind energy resources to grid are also briefly reviewed. From this review, it has been found that battery energy storage system is the most suitable and effective smoothing approach, provided that an effective control strategy is available for optimal utilization of battery energy system. This paper further demonstrates different control strategies built for battery energy storage system to obtain the smooth output wind power.

  10. The influence of tendon compliance on muscle power output and efficiency during cyclic contractions.

    Science.gov (United States)

    Lichtwark, G A; Barclay, C J

    2010-03-01

    Muscle power output and efficiency during cyclical contractions are influenced by the timing and duration of stimulation of the muscle and the interaction of the muscle with its mechanical environment. It has been suggested that tendon compliance may reduce the energy required for power production from the muscle by reducing the required shortening of the muscle fibres. Theoretically this may allow the muscle to maintain both high power output and efficiency during cyclical contraction; however, this has yet to be demonstrated experimentally. To investigate how tendon compliance might act to increase muscle power output and/or efficiency, we attached artificial tendons of varying compliance to muscle fibre bundles in vitro and measured power output and mechanical efficiency during stretch-shorten cycles (2 Hz) with a range of stretch amplitudes and stimulation patterns. The results showed that peak power, average power output and efficiency (none of which can have direct contributions from the compliant tendon) all increased with increasing tendon compliance, presumably due to the tendon acting to minimise muscle energy use by allowing the muscle fibres to shorten at optimal speeds. Matching highly compliant tendons with a sufficiently large amplitude length change and appropriate stimulation pattern significantly increased the net muscle efficiency compared with stiff tendons acting at the same frequency. The maximum efficiency for compliant tendons was also similar to the highest value measured under constant velocity and force conditions, which suggests that tendon compliance can maximise muscle efficiency in the conditions tested here. These results provide experimental evidence that during constrained cyclical contractions, muscle power and efficiency can be enhanced with compliant tendons.

  11. Voltage Control in Distribution Systems Considered Reactive Power Output Sharing

    Science.gov (United States)

    Oshiro, Masato; Senjyu, Tomonobu; Yona, Atsushi; Urasaki, Naomitsu; Funabashi, Toshihisa

    In recent years, distributed generation (DG) and renewable energy source (RES) are attracting special attention to distribution systems. Renewable energy such as photovoltaic (PV) system and wind turbine generator are used as a source of clean energy. However, the large amount of distributed generation causes voltage deviation beyond a statutory range in distribution systems. This paper proposes a methodology for voltage control by using inverters interfaced with DG and tap changing transformers. In the proposed method a one-day schedule of voltage references for the control devices are determined by an optimization technique based on predicted values of load demand and PV power generation. Furthermore, decided reactive power output according to the locally measurable voltage based on droop characteristic. Slope and base value on droop characteristic are selected by fuzzy control. The proposed method accomplishes improvement against voltage distribution considered the reactive power output sharing and reduction of distribution loss. The effectiveness of the proposed method is verified by using MATLAB®.

  12. Modeling the power output of piezoelectric energy harvesters

    KAUST Repository

    Al Ahmad, Mahmoud

    2011-04-30

    Design of experiments and multiphysics analyses were used to develop a parametric model for a d 33-based cantilever. The analysis revealed that the most significant parameters influencing the resonant frequency are the supporting layer thickness, piezoelectric layer thickness, and cantilever length. On the other hand, the most important factors affecting the charge output arethe piezoelectric thickness and the interdigitated electrode dimensions. The accuracy of the developed model was confirmed and showed less than 1% estimation error compared with a commercial simulation package. To estimate the power delivered to a load, the electric current output from the piezoelectric generator was calculated. A circuit model was built and used to estimate the power delivered to a load, which compared favorably to experimentally published power data on actual cantilevers of similar dimensions. © 2011 TMS.

  13. Optimal Output of Distributed Generation Based On Complex Power Increment

    Science.gov (United States)

    Wu, D.; Bao, H.

    2017-12-01

    In order to meet the growing demand for electricity and improve the cleanliness of power generation, new energy generation, represented by wind power generation, photovoltaic power generation, etc has been widely used. The new energy power generation access to distribution network in the form of distributed generation, consumed by local load. However, with the increase of the scale of distribution generation access to the network, the optimization of its power output is becoming more and more prominent, which needs further study. Classical optimization methods often use extended sensitivity method to obtain the relationship between different power generators, but ignore the coupling parameter between nodes makes the results are not accurate; heuristic algorithm also has defects such as slow calculation speed, uncertain outcomes. This article proposes a method called complex power increment, the essence of this method is the analysis of the power grid under steady power flow. After analyzing the results we can obtain the complex scaling function equation between the power supplies, the coefficient of the equation is based on the impedance parameter of the network, so the description of the relation of variables to the coefficients is more precise Thus, the method can accurately describe the power increment relationship, and can obtain the power optimization scheme more accurately and quickly than the extended sensitivity method and heuristic method.

  14. Methodological concerns for determining power output in the jump squat.

    Science.gov (United States)

    Cormie, Prue; Deane, Russell; McBride, Jeffrey M

    2007-05-01

    The purpose of this study was to investigate the validity of power measurement techniques during the jump squat (JS) utilizing various combinations of a force plate and linear position transducer (LPT) devices. Nine men with at least 6 months of prior resistance training experience participated in this acute investigation. One repetition maximums (1RM) in the squat were determined, followed by JS testing under 2 loading conditions (30% of 1RM [JS30] and 90% of 1RM [JS90]). Three different techniques were used simultaneously in data collection: (a) 1 linear position transducer (1-LPT); (b) 1 linear position transducer and a force plate (1-LPT + FP); and (c) 2 linear position transducers and a force place (2-LPT + FP). Vertical velocity-, force-, and power-time curves were calculated for each lift using these methodologies and were compared. Peak force and peak power were overestimated by 1-LPT in both JS30 and JS90 compared with 2-LPT + FP and 1-LPT + FP (p power determined by 2-LPT + FP was significantly higher than that determined by 1-LPT + FP under the JS90 loading condition. Peak vertical velocity determined by 2-LPT + FP was significantly lower than that determined by either 1-LPT and 1-LPT + FP in JS90. This investigation indicates that peak power and the timing of power output in the jump squat varies according to the measurement technique utilized. The 1-LPT methodology is not a valid means of determining power output in the jump squat. Furthermore, the 1-LPT + FP method may not accurately represent power output in free weight movements that involve a significant amount of horizontal motion.

  15. Maximum Power Output of Quantum Heat Engine with Energy Bath

    Directory of Open Access Journals (Sweden)

    Shengnan Liu

    2016-05-01

    Full Text Available The difference between quantum isoenergetic process and quantum isothermal process comes from the violation of the law of equipartition of energy in the quantum regime. To reveal an important physical meaning of this fact, here we study a special type of quantum heat engine consisting of three processes: isoenergetic, isothermal and adiabatic processes. Therefore, this engine works between the energy and heat baths. Combining two engines of this kind, it is possible to realize the quantum Carnot engine. Furthermore, considering finite velocity of change of the potential shape, here an infinite square well with moving walls, the power output of the engine is discussed. It is found that the efficiency and power output are both closely dependent on the initial and final states of the quantum isothermal process. The performance of the engine cycle is shown to be optimized by control of the occupation probability of the ground state, which is determined by the temperature and the potential width. The relation between the efficiency and power output is also discussed.

  16. Compact electret energy harvester with high power output

    Energy Technology Data Exchange (ETDEWEB)

    Pondrom, P., E-mail: pondromp@gmail.com [Institute for Telecommunications Technology, Technische Universität Darmstadt, Merckstr. 25, 64283 Darmstadt (Germany); System Reliability and Machine Acoustics SzM, Technische Universität Darmstadt, Magdalenenstr. 4, 64289 Darmstadt (Germany); Sessler, G. M. [Institute for Telecommunications Technology, Technische Universität Darmstadt, Merckstr. 25, 64283 Darmstadt (Germany); Bös, J.; Melz, T. [System Reliability and Machine Acoustics SzM, Technische Universität Darmstadt, Magdalenenstr. 4, 64289 Darmstadt (Germany)

    2016-08-01

    Compact electret energy harvesters, based on a design recently introduced, are presented. Using electret surface potentials in the 400 V regime and a seismic mass of 10 g, it was possible to generate output power up to 0.6 mW at 36 Hz for an input acceleration of 1 g. Following the presentation of an analytical model allowing for the calculation of the power generated in a load resistance at the resonance frequency of the harvesters, experimental results are shown and compared to theoretical predictions. Finally, the performance of the electret harvesters is assessed using a figure of merit.

  17. A model to predict the power output from wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Landberg, L. [Riso National Lab., Roskilde (Denmark)

    1997-12-31

    This paper will describe a model that can predict the power output from wind farms. To give examples of input the model is applied to a wind farm in Texas. The predictions are generated from forecasts from the NGM model of NCEP. These predictions are made valid at individual sites (wind farms) by applying a matrix calculated by the sub-models of WASP (Wind Atlas Application and Analysis Program). The actual wind farm production is calculated using the Riso PARK model. Because of the preliminary nature of the results, they will not be given. However, similar results from Europe will be given.

  18. Listening to music affects diurnal variation in muscle power output.

    Science.gov (United States)

    Chtourou, H; Chaouachi, A; Hammouda, O; Chamari, K; Souissi, N

    2012-01-01

    The purpose of this investigation was to assess the effects of listening to music while warming-up on the diurnal variations of power output during the Wingate test. 12 physical education students underwent four Wingate tests at 07:00 and 17:00 h, after 10 min of warm-up with and without listening to music. The warm-up consisted of 10 min of pedalling at a constant pace of 60 rpm against a light load of 1 kg. During the Wingate test, peak and mean power were measured. The main finding was that peak and mean power improved from morning to afternoon after no music warm-up (pmusic warm-up. Moreover, peak and mean power were significantly higher after music than no music warm-up during the two times of testing. Thus, as it is a legal method and an additional aid, music should be used during warm-up before performing activities requiring powerful lower limbs' muscles contractions, especially in the morning competitive events. © Georg Thieme Verlag KG Stuttgart · New York.

  19. Model output statistics applied to wind power prediction

    Energy Technology Data Exchange (ETDEWEB)

    Joensen, A.; Giebel, G.; Landberg, L. [Risoe National Lab., Roskilde (Denmark); Madsen, H.; Nielsen, H.A. [The Technical Univ. of Denmark, Dept. of Mathematical Modelling, Lyngby (Denmark)

    1999-03-01

    Being able to predict the output of a wind farm online for a day or two in advance has significant advantages for utilities, such as better possibility to schedule fossil fuelled power plants and a better position on electricity spot markets. In this paper prediction methods based on Numerical Weather Prediction (NWP) models are considered. The spatial resolution used in NWP models implies that these predictions are not valid locally at a specific wind farm. Furthermore, due to the non-stationary nature and complexity of the processes in the atmosphere, and occasional changes of NWP models, the deviation between the predicted and the measured wind will be time dependent. If observational data is available, and if the deviation between the predictions and the observations exhibits systematic behavior, this should be corrected for; if statistical methods are used, this approaches is usually referred to as MOS (Model Output Statistics). The influence of atmospheric turbulence intensity, topography, prediction horizon length and auto-correlation of wind speed and power is considered, and to take the time-variations into account, adaptive estimation methods are applied. Three estimation techniques are considered and compared, Extended Kalman Filtering, recursive least squares and a new modified recursive least squares algorithm. (au) EU-JOULE-3. 11 refs.

  20. Changes in muscle coordination and power output during sprint cycling.

    Science.gov (United States)

    O'Bryan, Steven J; Brown, Nicholas A T; Billaut, François; Rouffet, David M

    2014-07-25

    This study investigated the changes in muscle coordination associated to power output decrease during a 30-s isokinetic (120rpm) cycling sprint. Modifications in EMG amplitude and onset/offset were investigated from eight muscles [gluteus maximus (EMGGMAX), vastus lateralis and medialis obliquus (EMGVAS), medial and lateral gastrocnemius (EMGGAS), rectus femoris (EMGRF), biceps femoris and semitendinosus (EMGHAM)]. Changes in co-activation of four muscle pairs (CAIGMAX/GAS, CAIVAS/GAS, CAIVAS/HAM and CAIGMAX/RF) were also calculated. Substantial power reduction (60±6%) was accompanied by a decrease in EMG amplitude for all muscles other than HAM, with the greatest deficit identified for EMGRF (31±16%) and EMGGAS (20±14%). GASonset, HAMonset and GMAXonset shifted later in the pedalling cycle and the EMG offsets of all muscles (except GASoffset) shifted earlier as the sprint progressed (Pfatiguing sprint cycling is accompanied by marked reductions in the EMG activity of bi-articular GAS and RF and co-activation level between GAS and main power producer muscles (GMAX and VAS). The observed changes in RF and GAS EMG activity are likely to result in a redistribution of the joint powers and alterations in the orientation of the pedal forces. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  1. Reactive Power Pricing Model Considering the Randomness of Wind Power Output

    Science.gov (United States)

    Dai, Zhong; Wu, Zhou

    2018-01-01

    With the increase of wind power capacity integrated into grid, the influence of the randomness of wind power output on the reactive power distribution of grid is gradually highlighted. Meanwhile, the power market reform puts forward higher requirements for reasonable pricing of reactive power service. Based on it, the article combined the optimal power flow model considering wind power randomness with integrated cost allocation method to price reactive power. Meanwhile, considering the advantages and disadvantages of the present cost allocation method and marginal cost pricing, an integrated cost allocation method based on optimal power flow tracing is proposed. The model realized the optimal power flow distribution of reactive power with the minimal integrated cost and wind power integration, under the premise of guaranteeing the balance of reactive power pricing. Finally, through the analysis of multi-scenario calculation examples and the stochastic simulation of wind power outputs, the article compared the results of the model pricing and the marginal cost pricing, which proved that the model is accurate and effective.

  2. Power Flows and Efficiency of Output Compound e-CVT

    Directory of Open Access Journals (Sweden)

    Francesco Bottiglione

    2015-01-01

    Full Text Available Hybridization is the most promising vehicular technology to get significant improvements of the vehicle efficiency and performance in the short-term. Mechanical transmissions for hybrid vehicles are very often multiple modes transmission, which permit improving the performance in different working conditions. In this context, optimal design and control of these transmissions are a key point to improve the performance of the vehicles, and mathematical models which supports the design can play an important role in this field. In this work, an approach for evaluating the performance of Output Compound Split e-CVT (electric Continuously Variable Transmission in steady-state is proposed. This approach, in addition to a kinematic analysis of the device, leads to the calculation of the internal power circulation modes and the efficiency of the device in different working conditions.

  3. Output power variations in ND:YAG laser hosts

    Energy Technology Data Exchange (ETDEWEB)

    Maupin, W.B. II

    1976-12-01

    Seemingly identical Nd:YAG laser rods often exhibit significant variations in output power. The purpose of this report is to investigate the possible cause or causes for the performance variations in Nd:YAG laser rods. The fundamental chemical and crystal growth characteristics of Nd:YAG are reviewed. The spectroscopy of Nd:YAG is discussed with emphasis on the laser transition. The more common spectroscopic parameters are defined and the important relationships between them derived. Expressions relating the laser performance of cw and Q-switched systems to the host parameters are developed and the important parameters are discussed. Possible energy transfer mechanisms to account for performance variations are presented and evaluated. It is proposed that concentration variations are primarily responsible for laser performance fluctuations and a method for obtaining experimental verification is outlined.

  4. A Method to Compare the Descriptive Power of Different Types of Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1980-01-01

    The purpose of this paper is to show how the descriptive power of different types of Petri nets can be compared, without the use of Petri net languages. Moreover the paper proposes an extension of condition/event-nets and it is shown that this extension has the same descriptive power as condition/event-nets....

  5. Muscle coordination is key to the power output and mechanical efficiency of limb movements.

    Science.gov (United States)

    Wakeling, J M; Blake, O M; Chan, H K

    2010-02-01

    The purpose of this study was to determine which features of muscle mechanics and muscle coordination affect the power output from a limb during locomotion. Eight subjects were tested while cycling at maximum exertion for 25 min on a stationary dynamometer. Cadence and load were varied to span a range of power outputs and myoelectric activity was measured from 10 muscles in the leg. Cycle-by-cycle variations in muscle coordination, cadence and power output were observed and the EMG intensity across all muscles was used as an estimate of the metabolic cost for each cycle. Data for the cycles at greatest power output were separated into three groups: maximum power, 80% power but lower EMG intensity and 80% power and higher EMG intensity. Torque-angular velocity relations were determined for the ankle and knee joints. During cycling at maximum power output the ankle joint was not extending at the velocity necessary for maximum power output; thus, maximum limb power occurs when some of the individual muscles cannot be generating maximum power output. Increases in EMG intensity occurred with no increase in power output from the limb: these corresponded to decreases in the efficiency and changes in coordination. Increases in power were achieved that were not matched by equivalent increases in EMG intensity, but did occur with changes in coordination. It is proposed that the power output from the limb is limited by the coordination pattern of the muscles rather than the maximum power output from any one muscle itself.

  6. Microtubular Fuel Cell with Ultrahigh Power Output per Footprint.

    Science.gov (United States)

    Miao, Shiding; He, Shulian; Liang, Mengnan; Lin, Gungun; Cai, Bin; Schmidt, Oliver G

    2017-09-01

    A novel realization of microtubular direct methanol fuel cells (µDMFC) with ultrahigh power output is reported by using "rolled-up" nanotechnology. The microtube (Pt-RuO2 -RUMT) is prepared by rolling up Ru2 O layers coated with magnetron-sputtered Pt nanoparticles (cat-NPs). The µDMFC is fabricated by embedding the tube in a fluidic cell. The footprint of per tube is as small as 1.5 × 10-4 cm2 . A power density of ≈257 mW cm-2 is obtained, which is three orders of magnitude higher than the present microsized DFMCs. Atomic layer deposition technique is applied to alleviate the methanol crossover as well as improve stability of the tube, sustaining electrolyte flow for days. A laminar flow driven mechanism is proposed, and the kinetics of the fuel oxidation depends on a linear-diffusion-controlled process. The electrocatalytic performance on anode and cathode is studied by scanning both sides of the tube wall as an ex situ working electrode, respectively. This prototype µDFMC is extremely interesting for integration with micro- and nanoelectronics systems. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Neural-net based real-time economic dispatch for thermal power plants

    Energy Technology Data Exchange (ETDEWEB)

    Djukanovic, M.; Milosevic, B. [Inst. Nikola Tesla, Belgrade (Yugoslavia). Dept. of Power Systems; Calovic, M. [Univ. of Belgrade (Yugoslavia). Dept. of Electrical Engineering; Sobajic, D.J. [Electric Power Research Inst., Palo Alto, CA (United States)

    1996-12-01

    This paper proposes the application of artificial neural networks to real-time optimal generation dispatch of thermal units. The approach can take into account the operational requirements and network losses. The proposed economic dispatch uses an artificial neural network (ANN) for generation of penalty factors, depending on the input generator powers and identified system load change. Then, a few additional iterations are performed within an iterative computation procedure for the solution of coordination equations, by using reference-bus penalty-factors derived from the Newton-Raphson load flow. A coordination technique for environmental and economic dispatch of pure thermal systems, based on the neural-net theory for simplified solution algorithms and improved man-machine interface is introduced. Numerical results on two test examples show that the proposed algorithm can efficiently and accurately develop optimal and feasible generator output trajectories, by applying neural-net forecasts of system load patterns.

  8. Basic study on dynamic reactive-power control method with PV output prediction for solar inverter

    Directory of Open Access Journals (Sweden)

    Ryunosuke Miyoshi

    2016-01-01

    Full Text Available To effectively utilize a photovoltaic (PV system, reactive-power control methods for solar inverters have been considered. Among the various methods, the constant-voltage control outputs less reactive power compared with the other methods. We have developed a constant-voltage control to reduce the reactive-power output. However, the developed constant-voltage control still outputs unnecessary reactive power because the control parameter is constant in every waveform of the PV output. To reduce the reactive-power output, we propose a dynamic reactive-power control method with a PV output prediction. In the proposed method, the control parameter is varied according to the properties of the predicted PV waveform. In this study, we performed numerical simulations using a distribution system model, and we confirmed that the proposed method reduces the reactive-power output within the voltage constraint.

  9. Power-related compatibility and maximum electrical power output of a thermogenerator

    Energy Technology Data Exchange (ETDEWEB)

    Seifert, W. [Institute of Physics, University Halle-Wittenberg, 06099 Halle (Germany); Zabrocki, K.; Mueller, E. [Institute of Materials Research, German Aerospace Center (DLR), 51170 Koeln (Germany); Snyder, G.J. [California Institute of Technology, Pasadena, California 91125 (United States)

    2010-10-15

    The compatibility approach enables the description of thermoelectric effects in terms of intensive state variables. Within the framework of a new optimization strategy based on self-compatible thermoelectric elements,the consequences for the maximum electrical power output from a graded thermoelectric generator with fixed length are discussed. Unlike efficiency and coefficient of performance, no strict local criterion exists for maximum power. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  10. Quaterly Assessment of Irradiance Variation on Power Output and Storable Excess Power of Solar Panels

    National Research Council Canada - National Science Library

    T O Familusi; Y K Sanusi; H O Efunwole; A M Raimi

    2014-01-01

      This paper verified the input solar irradiance and average power output per day of a 10W polycrystalline silicon solar panel and a 10W gallium arsenide solar panel, both of dimension 350x290x25mm^sup 3^, fill-factor...

  11. Power output and carrier dynamics studies of perovskite solar cells under working conditions.

    Science.gov (United States)

    Yu, Man; Wang, Hao-Yi; Hao, Ming-Yang; Qin, Yujun; Fu, Li-Min; Zhang, Jian-Ping; Ai, Xi-Cheng

    2017-08-02

    Perovskite solar cells have emerged as promising photovoltaic systems with superb power conversion efficiency. For the practical application of perovskite devices, the greatest concerns are the power output density and the related dynamics under working conditions. In this study, the working conditions of planar and mesoscopic perovskite solar cells are simulated and the power output density evolutions with the working voltage are highlighted. The planar device exhibits higher capability of outputting power than the mesoscopic one. The transient photoelectric conversion dynamics are investigated under the open circuit, short circuit and working conditions. It is found that the power output and dynamic processes are correlated intrinsically, which suggests that the power output is the competitive result of the charge carrier recombination and transport. The present work offers a unique view to elucidating the relationship between the power output and the charge carrier dynamics for perovskite solar cells in a comprehensive manner, which would be beneficial to their future practical applications.

  12. Abnormally High Power Output of Wind Turbine in Cold Weather: A Preliminary Study

    Directory of Open Access Journals (Sweden)

    Christophe Leclerc

    2003-01-01

    Full Text Available According to popular belief, air temperature effects on wind turbine power output are produced solely by air density variations, and power is proportional to air density. However, some cases have been reported, all involving stall-controlled wind turbines, in which unexpected high power output was observed at very low temperatures.

  13. Comparative analysis of net energy balance for satellite power systems (SPS) and other energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Cirillo, R.R.; Cho, B.S.; Monarch, M.R.; Levine, E.P.

    1980-04-01

    The net energy balance of seven electric energy systems is assessed: two coal-based, one nuclear, two terrestrial solar, and two solar power satellites, with principal emphasis on the latter two systems. Solar energy systems require much less operating energy per unit of electrical output. However, on the basis of the analysis used here, coal and nuclear systems are two to five times more efficient at extracting useful energy from the primary resource base than are the solar energy systems. The payback period for all systems is less than 1.5 years, except for the terrestrial photovoltaic (19.8 yr) and the solar power satellite system (6.4 yr), both of which rely on energy-intensive silicon cells.

  14. Market power and output-based refunding of environmental policy revenues

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Carolyn [Resources for the Future, 1616 P Street NW, Washington, DC 20036 (United States)

    2011-01-15

    Output-based refunding of environmental policy revenues combines a tax on emissions with a production subsidy, typically in a revenue-neutral fashion. With imperfect competition, subsidies can alleviate output underprovision. However, when market shares are significant, endogenous refunding reduces abatement incentives and the marginal net tax or subsidy. If market shares differ, marginal abatement costs will not be equalized, and production is shifted among participants. In an asymmetric Cournot duopoly, endogenous refunding leads to higher output, emissions, and overall costs compared with a fixed rebate program targeting the same emissions intensity. These results hold whether emissions rates are determined simultaneously with output or strategically in a two-stage model. (author)

  15. Numerical Calculation of the Output Power of a MHD Generator

    Directory of Open Access Journals (Sweden)

    Adrian CARABINEANU

    2014-12-01

    Full Text Available Using Lazăr Dragoş’s analytic solution for the electric potential we perform some numerical calculations in order to find the characteristics of a Faraday magnetohydrodymamics (MHD power generator (total power, useful power and Joule dissipation power.

  16. Examining the Variability of Wind Power Output in the Regulation Time Frame: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Hodge, B. M.; Shedd, S.; Florita, A.

    2012-08-01

    This work examines the distribution of changes in wind power for different time scales in the regulation time frame as well as the correlation of changes in power output for individual wind turbines in a wind plant.

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

    Data.gov (United States)

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

  18. Consequences of ankle joint fixation on FES cycling power output: a simulation study

    NARCIS (Netherlands)

    van Soest, A.J.; Gfohler, M.; Casius, L.J.R.

    2005-01-01

    Introduction: During fixed-ankle FES cycling in paraplegics, in which the leg position is completely determined by the crank angle, mechanical power output is low. This low power output limits the cardiovascular load that could be realized during FES ergometer cycling, and limits possibilities for

  19. Method for Prediction of the Power Output from Photovoltaic Power Plant under Actual Operating Conditions

    Science.gov (United States)

    Obukhov, S. G.; Plotnikov, I. A.; Surzhikova, O. A.; Savkin, K. D.

    2017-04-01

    Solar photovoltaic technology is one of the most rapidly growing renewable sources of electricity that has practical application in various fields of human activity due to its high availability, huge potential and environmental compatibility. The original simulation model of the photovoltaic power plant has been developed to simulate and investigate the plant operating modes under actual operating conditions. The proposed model considers the impact of the external climatic factors on the solar panel energy characteristics that improves accuracy in the power output prediction. The data obtained through the photovoltaic power plant operation simulation enable a well-reasoned choice of the required capacity for storage devices and determination of the rational algorithms to control the energy complex.

  20. Study on the Characteristics of Expander Power Output Used for Offsetting Pumping Work Consumption in Organic Rankine Cycles

    Directory of Open Access Journals (Sweden)

    Yu-Ting Wu

    2014-07-01

    Full Text Available The circulation pump in an organic Rankine cycle (ORC increases the pressure of the liquid working fluid from low condensing pressure to high evaporating pressure, and the expander utilizes the pressure difference to generate work. A portion of the expander output power is used to offset the consumed pumping work, and the rest of the expander power is exactly the net work produced by the ORC system. Because of the relatively great theoretical pumping work and very low efficiency of the circulation pump reported in previous papers, the characteristics of the expander power used for offsetting the pumping work need serious consideration. In particular, the present work examines those characteristics. It is found that the characteristics of the expander power used for offsetting the pumping work are satisfactory only under the condition that the working fluid absorbs sufficient heat in the evaporator and its specific volume at the evaporator outlet is larger than or equal to a threshold value.

  1. High Power Tm3+-Doped Fiber Lasers Tuned by a Variable Reflective Output Coupler

    Directory of Open Access Journals (Sweden)

    Yulong Tang

    2008-01-01

    Full Text Available Wide wavelength tuning by a variable reflective output coupler is demonstrated in high-power double-clad Tm3+-doped silica fiber lasers diode-pumped at ∼790  nm. Varying the output coupling from 96% to 5%, the laser wavelength is tuned over a range of 106  nm from 1949 to 2055  nm. The output power exceeds 20  W over 90-nm range and the maximum output power is 32  W at 1949  nm for 51-W launched pump power, corresponding to a slope efficiency of ∼70%. Assisted with different fiber lengths, the tuning range is expanded to 240  nm from 1866 to 2107  nm with the output power larger than 10  W.

  2. Effect of interrepetition rest on power output in the power clean.

    Science.gov (United States)

    Hardee, Justin P; Triplett, N Travis; Utter, Alan C; Zwetsloot, Kevin A; Mcbride, Jeffrey M

    2012-04-01

    The effect of interrepetition rest (IRR) periods on power output during performance of multiple sets of power cleans is unknown. It is possible that IRR periods may attenuate the decrease in power output commonly observed within multiple sets. This may be of benefit for maximizing improvements in power with training. This investigation involved 10 college-aged men with proficiency in weightlifting. The subjects performed 3 sets of 6 repetitions of power cleans at 80% of their 1 repetition maximum with 0 (P0), 20 (P20), or 40 seconds (P40) of IRR. Each protocol (P0, P20, P40) was performed in a randomized order on different days each separated by at least 72 hours. The subjects performed the power cleans while standing on a force plate with 2 linear position transducers attached to the bar. Peak power, force, and velocity were obtained for each repetition and set. Peak power significantly decreased by 15.7% during P0 in comparison with a decrease of 5.5% (R1: 4,303 ± 567 W, R6: 4,055 ± 582 W) during P20 and a decrease of 3.3% (R1: 4,549 ± 659 W, R6: 4,363 ± 476 W) during P40. Peak force significantly decreased by 7.3% (R1: 2,861 ± 247 N, R6: 2,657 ± 225 N) during P0 in comparison with a decrease of 2.7% (R1: 2,811 ± 327 N, R6: 2,730 ± 285 N) during P20 and an increase of 0.4% (R1: 2,861 ± 323 N, R6: 2,862 ± 280 N) during P40. Peak velocity significantly decreased by 10.2% (R1: 1.97 ± 0.15 m·s(-1), R6: 1.79 ± 0.11 m·s(-1)) during P0 in comparison with a decrease of 3.8% (R1: 1.89 ± 0.13 m·s(-1), R6: 1.82 ± 0.12 m·s(-1)) during P20 and a decrease of 1.7% (R1: 1.93 ± 0.17 m·s(-1), R6: 1.89 ± 0.14 m·s(-1)) during P40. The results demonstrate that IRR periods allow for the maintenance of power in the power clean during a multiple set exercise protocol and that this may have implications for improved training adaptations.

  3. Modulating wind power plant output using different frequency modulation components for damping grid oscillations

    DEFF Research Database (Denmark)

    2017-01-01

    A method, controller, wind power plant, and computer program product are disclosed for operating a wind power plant comprising a plurality of wind turbines, the wind power plant producing a plant power output. The method comprises receiving a modulation request signal indicating a requested...

  4. Power output in vertical jumps: does optimum loading depend on activity profiles?

    Science.gov (United States)

    Pazin, Nemanja; Berjan, Bobana; Nedeljkovic, Aleksandar; Markovic, Goran; Jaric, Slobodan

    2013-03-01

    The previously proposed maximum dynamic output hypothesis (MDO: i.e. the optimum load for maximizing the power output during jumping is one's own body) was tested on individuals of various activity profiles. Forty males (10 strength-trained athletes, 10 speed-trained athletes, 10 physically active non-athletes, and 10 sedentary individuals) performed different vertical jumps on a force plate while a pulley system was used to either reduce or increase the subject's body weight by 10-30 %. As expected, an increase in external loading resulted in a significant increase (p power output at approximately the subjects' own body weight although their weight represented prominently different percentage of their maximum dynamic strength. While a significant (p power output, the individual optimum load for maximizing the power output number did not differ among the groups. Although apparently further research on various types of movements is needed, the present results provide, so far, the strongest support of the MDO hypothesis.

  5. Technique for enhancing the power output of an electrostatic generator employing parametric resonance

    Science.gov (United States)

    Post, Richard F.

    2016-02-23

    A circuit-based technique enhances the power output of electrostatic generators employing an array of axially oriented rods or tubes or azimuthal corrugated metal surfaces for their electrodes. During generator operation, the peak voltage across the electrodes occurs at an azimuthal position that is intermediate between the position of minimum gap and maximum gap. If this position is also close to the azimuthal angle where the rate of change of capacity is a maximum, then the highest rf power output possible for a given maximum allowable voltage at the minimum gap can be attained. This rf power output is then coupled to the generator load through a coupling condenser that prevents suppression of the dc charging potential by conduction through the load. Optimized circuit values produce phase shifts in the rf output voltage that allow higher power output to occur at the same voltage limit at the minimum gap position.

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

    Data.gov (United States)

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

  7. Enhanced light output power of quantum cascade lasers from a tilted front facet.

    Science.gov (United States)

    Ahn, Sangil; Schwarzer, Clemens; Zederbauer, Tobias; Detz, Hermann; Andrews, Aaron M; Schrenk, Werner; Strasser, Gottfried

    2013-07-01

    We present a technique for enhancing the light output power of quantum cascade lasers (QCLs) by tilting of the front facet, which leads to a change of the modal reflectivity, resulting in an asymmetric light intensity distribution along the laser cavity. This asymmetry provides most of the light being emitted through one facet of the laser. An experimental study of threshold current, slope efficiency and light output power as a function of the front facet angles were performed and compared to conventional QCLs. The lasers with a front facet angle of 8° shows a 20% improved power output from the front facet.

  8. Electrical power converter method and system employing multiple output converters

    Science.gov (United States)

    Beihoff, Bruce C [Wauwatosa, WI; Radosevich, Lawrence D [Muskego, WI; Meyer, Andreas A [Richmond Heights, OH; Gollhardt, Neil [Fox Point, WI; Kannenberg, Daniel G [Waukesha, WI

    2007-05-01

    A support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. The support, in conjunction with other packaging features may form a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

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

    Science.gov (United States)

    Ueno, Toshiyuki

    2015-05-01

    Vibration based power generation technology is utilized effectively in various fields. Author has invented novel vibrational power generation device using magnetostrictive material. The device is based on parallel beam structure consisting of a rod of iron-gallium alloy wound with coil and yoke accompanied with permanent magnet. When bending force is applied on the tip of the device, the magnetization inside the rod varies with induced stress due to the inverse magnetostrictive effect. In vibration, the time variation of the magnetization generates voltage on the wound coil. The magnetostrictive type is advantageous over conventional such using piezoelectric or moving magnet types in high efficiency and high robustness, and low electrical impedance. Here, author has established device configuration, simple, rigid, and high power output endurable for practical applications. In addition, the improved device is lower cost using less volume of Fe-Ga and permanent magnet compared to our conventional, and its assembly by soldering is easy and fast suitable for mass production. Average power of 3 mW/cm3 under resonant vibration of 212 Hz and 1.2 G was obtained in miniature prototype using Fe-Ga rod of 2 × 0.5× 7 mm3. Furthermore, the damping effect was observed, which demonstrates high energy conversion of the generator.

  10. Power Amplifier Module with 734-mW Continuous Wave Output Power

    Science.gov (United States)

    Fung, King Man; Samoska, Lorene A.; Kangaslahti, Pekka P.; Lamgrigtsen, Bjorn H.; Goldsmith, Paul F.; Lin, Robert H.; Soria, Mary M.; Cooperrider, Joelle T.; Micovic, Moroslav; Kurdoghlian, Ara

    2010-01-01

    Research findings were reported from an investigation of new gallium nitride (GaN) monolithic millimeter-wave integrated circuit (MMIC) power amplifiers (PAs) targeting the highest output power and the highest efficiency for class-A operation in W-band (75-110 GHz). W-band PAs are a major component of many frequency multiplied submillimeter-wave LO signal sources. For spectrometer arrays, substantial W-band power is required due to the passive lossy frequency multipliers-to generate higher frequency signals in nonlinear Schottky diode-based LO sources. By advancing PA technology, the LO system performance can be increased with possible cost reductions compared to current GaAs PAs. High-power, high-efficiency GaN PAs are cross-cutting and can enable more efficient local oscillator distribution systems for new astrophysics and planetary receivers and heterodyne array instruments. It can also allow for a new, electronically scannable solid-state array technology for future Earth science radar instruments and communications platforms.

  11. Optimal loading range for the development of peak power output in the hexagonal barbell jump squat.

    Science.gov (United States)

    Turner, Thomas S; Tobin, Daniel P; Delahunt, Eamonn

    2015-06-01

    Recent studies indicate that the utilization of the hexagonal barbell jump squat (HBJS) compared with the traditional barbell jump squat may offer a superior method of developing peak power. The notion that a single optimal load may be prescribed in training programs aiming to develop peak power is subject to debate. The purpose of this study was to identify the optimal load corresponding with peak power output during the HBJS in professional rugby union players. Seventeen professional rugby union players participated in this study. Participants performed 3 unloaded countermovement jumps on a force plate and 3 HBJS at each of the following randomized loads: 10, 20, 30, and 40% of box squat 1 repetition maximum (1RM). Peak power output was the dependent variable of interest. A one-way repeated measures analysis of variance was conducted to compare peak power output across each load. Peak power output was the dependent variable of interest. A significant main effect for load was observed (Wilk's Lambda = 0.11, F(4,13) = 18.07, p power output in the HBJS is optimized at a load range between 10 and 20% of box squat 1RM. The results of this study indicate that the use of the HBJS with a training load between 10 and 20% of box squat 1RM optimizes peak power output in professional rugby union players.

  12. A study on electric power management for power producer-suppliers utilizing output of megawatt-solar power plants

    Directory of Open Access Journals (Sweden)

    Hirotaka Takano

    2016-01-01

    Full Text Available The growth in penetration of photovoltaic generation units (PVs has brought new power management ideas, which achieve more profitable operation, to Power Producer-Suppliers (PPSs. The expected profit for the PPSs will improve if they appropriately operate their controllable generators and sell the generated electricity to contracted customers and Power Exchanges together with the output of Megawatt-Solar Power Plants (MSPPs. Moreover, we can expect that the profitable cooperation between the PPSs and the MSPPs decreases difficulties in the supply-demand balancing operation for the main power grids. However, it is necessary that the PPSs treat the uncertainty in output prediction of PVs carefully. This is because there is a risk for them to pay a heavy imbalance penalty. This paper presents a problem framework and its solution to make the optimal power management plan for the PPSs in consideration with the electricity procurement from the MSPPs. The validity of the authors’ proposal is verified through numerical simulations and discussions of their results.

  13. Output Impedance Shaping for Frequency Compensation of MOS Audio Power Amplifiers

    NARCIS (Netherlands)

    van der Zee, Ronan A.R.; Mostert, Fred

    2009-01-01

    A frequency compensation technique for MOS audio power amplifiers is presented that allows the frequency compensation capacitors around the power transistors to be smaller than the circuit parasitics without power or stability penalty. Stability is analysed by inspecting the output impedance of the

  14. Effect of absorbed pump power on the quality of output beam from ...

    Indian Academy of Sciences (India)

    higher order phase aberrations and can severely degrade the output beam quality. In this paper we have .... verse mode profile of the output beam is defined by the focal length of the thermal lens. [1,2]. Hence the .... operating pump power for designing a monolithic microchip laser with good beam quality. 3. Experiment and ...

  15. Computer controlled pump unit cuts power, increases output

    Energy Technology Data Exchange (ETDEWEB)

    Rosman, A.; Nofal, M. [OroNegro, Inc., Chatsworth, CA (United States)

    1996-11-01

    OroNegro, Inc., a small, high-tech Southern California operating company with a stated mission to find and utilize innovations that lower production costs, adopted that philosophy in applying a new sucker rod pumping system in its shallow, heavy oil fields in Newhall and Bakersfield, California. Six new hydraulic, computer-controlled pumping (CCP) units developed and supplied by DynaPump, Inc., also of Southern California, have been installed, and are producing significant operating and economic benefits. Basic CCP unit features include a very long stroke with a charged gas (nitrogen) counterbalance and automatic computer-controlled speed, to maximize flow. In one case described, an industry-standard 456 (456,000 in. lb torque), 100-hp unit was replaced by a 60-hp CCP unit, nearly doubling pump output. Field installations and pumping systems in Newhall field, and tests in Kern Front field are described, along with the operator`s views on other CCP applications, including its use in deep wells.

  16. Derivation of Output Power of Induction Heater Model

    Directory of Open Access Journals (Sweden)

    Riyadh K. Chillab

    2016-12-01

    Full Text Available The work is concerned with the study of the single phase cylindrical induction heating systems and derive equation power. The presented analysis is analytical and a multi-layer model using cylindrical geometry which is used to obtain the theoretical results. To validate the theoretical results, a practical model is constructed, tested and the results are compared with the theoretical ones. Comparison showed that the adopted analytical method is efficient in describing the performance of such induction heater systems

  17. Improving the Output Power Stability of a High Concentration Photovoltaic System with Supercapacitors: A Preliminary Evaluation

    Directory of Open Access Journals (Sweden)

    Yu-Pei Huang

    2015-01-01

    Full Text Available The output power of a high concentration photovoltaic (HCPV system is very sensitive to fluctuating tracking errors and weather patterns. To help compensate this shortcoming, supercapacitors have been successfully incorporated into photovoltaic systems to improve their output power stability. This study examined the output power stability improvement of an HCPV module with a supercapacitor integrated into its circuit. Furthermore, the equivalent model of the experimental circuit is presented and analyzed. Experimental results suggest that integrating a supercapacitor into an HCPV module could improve its output power stability and further extend its acceptance angle. This paper provides preliminary data of the improvement and its evaluation method, which could be utilized for further improvements to an HCPV system.

  18. 75 FR 3985 - Trade Regulation Rule Relating to Power Output Claims for Amplifiers Utilized in Home...

    Science.gov (United States)

    2010-01-26

    ..., in 2000 the Commission exempted certain advertising from the Rule's Total Harmonic Distortion (THD... notes that pursuant to Sec. 432.2 and Sec. 432.4 of the Rule, marketers must express all power output...

  19. Similar substrate oxidation rates in concentric and eccentric cycling matched for aerobic power output.

    Science.gov (United States)

    Isacco, Laurie; Ritter, Ophélie; Tordi, Nicolas; Laroche, Davy; Degano, Bruno; Bouhaddi, Malika; Rakobowchuk, Mark; Mourot, Laurent

    2016-11-01

    This study investigated substrate oxidation in concentric and eccentric cycling matched for aerobic power output in the postprandial state. Energy expenditure, respiratory exchange ratio, and fat and carbohydrate oxidation rates were measured at rest and after 15, 30, and 45 min of eccentric and concentric cycling in 12 men. Absolute and relative aerobic power output and energy expenditure were similar during concentric and eccentric exercise. No effect of exercise modality was observed for substrate metabolism.

  20. Optimising erbium-doped DFB fibre laser length with respect to maximum output power

    DEFF Research Database (Denmark)

    Lauridsen, Vibeke Claudia; Povlsen, Jørn Hedegaard; Varming, Poul

    1999-01-01

    It is shown that intrinsic loss gives severe limitations on the obtainable output power from a distributed feedback fibre laser and that the optimum coupling coeffcient will decrease when the cavity length is increased.......It is shown that intrinsic loss gives severe limitations on the obtainable output power from a distributed feedback fibre laser and that the optimum coupling coeffcient will decrease when the cavity length is increased....

  1. Maximizing Output Power of a Solar Panel via Combination of Sun Tracking and Maximum Power Point Tracking by Fuzzy Controllers

    Directory of Open Access Journals (Sweden)

    Mohsen Taherbaneh

    2010-01-01

    Full Text Available In applications with low-energy conversion efficiency, maximizing the output power improves the efficiency. The maximum output power of a solar panel depends on the environmental conditions and load profile. In this paper, a method based on simultaneous use of two fuzzy controllers is developed in order to maximize the generated output power of a solar panel in a photovoltaic system: fuzzy-based sun tracking and maximum power point tracking. The sun tracking is performed by changing the solar panel orientation in horizontal and vertical directions by two DC motors properly designed. A DC-DC converter is employed to track the solar panel maximum power point. In addition, the proposed system has the capability of the extraction of solar panel I-V curves. Experimental results present that the proposed fuzzy techniques result in increasing of power delivery from the solar panel, causing a reduction in size, weight, and cost of solar panels in photovoltaic systems.

  2. Artificial Neural Networks to Predict the Power Output of a PV Panel

    Directory of Open Access Journals (Sweden)

    Valerio Lo Brano

    2014-01-01

    Full Text Available The paper illustrates an adaptive approach based on different topologies of artificial neural networks (ANNs for the power energy output forecasting of photovoltaic (PV modules. The analysis of the PV module’s power output needed detailed local climate data, which was collected by a dedicated weather monitoring system. The Department of Energy, Information Engineering, and Mathematical Models of the University of Palermo (Italy has built up a weather monitoring system that worked together with a data acquisition system. The power output forecast is obtained using three different types of ANNs: a one hidden layer Multilayer perceptron (MLP, a recursive neural network (RNN, and a gamma memory (GM trained with the back propagation. In order to investigate the influence of climate variability on the electricity production, the ANNs were trained using weather data (air temperature, solar irradiance, and wind speed along with historical power output data available for the two test modules. The model validation was performed by comparing model predictions with power output data that were not used for the network's training. The results obtained bear out the suitability of the adopted methodology for the short-term power output forecasting problem and identified the best topology.

  3. Gyrotron Output Power Stabilization by PID Feedback Control of Heater Current and Anode Voltage

    Science.gov (United States)

    Khutoryan, E. M.; Idehara, T.; Kuleshov, A. N.; Ueda, K.

    2014-12-01

    To provide stable output power of a gyrotron during long operation time the power stabilization was achieved by two schemes with PID feedback control of heater current and anode voltage. It was based on the dependence of the output power on both the anode voltage and the beam current and also on the dependence of the beam current on the gun heater current. Both schemes provided decrease of the power standard deviation to 0.3-0.5%. The comparison between parameters of both schemes is discussed in the paper.

  4. Mean Power Output Estimation of WECs in Simulated Sea

    Energy Technology Data Exchange (ETDEWEB)

    Saulnier, J.-B.; Clement, A.H. [Laboratoire de Mecanique des Fluides, Ecole Centrale de Nantes, Nantes (France); Ricci, P. [TECNALIA ENERGIA, Sede de ROBOTIKER-TECNALIA, Parque tecnologico, Zamudio, Vizcaya (Spain); Falcao, A.F. de O. [IDMEC, Instituto Superior Tecnico, Lisbon (Portugal)

    2009-07-01

    Based on linear wave theory, two ways of simulating wave records from target spectral densities are implemented in order to assess their impact on the estimation of the mean power extracted from waves by a resonant Wave Energy Converter (WEC). The first one directly comes from the random Gaussian wave representation, while the second - widely used - derives from this latter by abusively neglecting the random nature of the individual wave amplitudes in the frequency-domain. This study investigates the consequences of such an abuse upon the device's response estimation through the consideration of various - linear and non-linear - numerical models, and the possible improvements of the simulation time/precision compromise for further WEC design projects.

  5. Modelling and Prediction of Photovoltaic Power Output Using Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Aminmohammad Saberian

    2014-01-01

    Full Text Available This paper presents a solar power modelling method using artificial neural networks (ANNs. Two neural network structures, namely, general regression neural network (GRNN feedforward back propagation (FFBP, have been used to model a photovoltaic panel output power and approximate the generated power. Both neural networks have four inputs and one output. The inputs are maximum temperature, minimum temperature, mean temperature, and irradiance; the output is the power. The data used in this paper started from January 1, 2006, until December 31, 2010. The five years of data were split into two parts: 2006–2008 and 2009-2010; the first part was used for training and the second part was used for testing the neural networks. A mathematical equation is used to estimate the generated power. At the end, both of these networks have shown good modelling performance; however, FFBP has shown a better performance comparing with GRNN.

  6. Detecting, categorizing and forecasting large romps in wind farm power output using meteorological observations and WPPT

    DEFF Research Database (Denmark)

    Cutler, N.; Kay, M.; Jacka, K.

    2007-01-01

    The Wind Power Prediction Tool (WPPT) has been installed in Australia for the first time, to forecast the power output from the 65MW Roaring 40s Renewable Energy P/L Woolnorth Bluff Point wind form. This article analyses the general performance of WPPT as well as its performance during large romps...... (swings) in power output. In addition to this, detected large ramps are studied in detail and categorized. WPPT combines wind speed and direction forecasts from the Australian Bureau of Meteorology regional numerical weather prediction model, MesoLAPS, with real-time wind power observations to make hourly...... forecasts of the wind farm power output. The general performances of MesoLAPS and WPPTore evaluated over I year using the root mean square error (RMSE). The errors are significantly lower than for basic benchmark forecasts but higher than for many other WPPT installations, where the site conditions...

  7. Calculated power output from a thin iron-seeded plasma

    Energy Technology Data Exchange (ETDEWEB)

    Merts, A.L.; Cowan, R.D.; Magee, N.H. Jr.

    1976-02-01

    Ionization equilibrium calculations are carried out for iron ions at a density of 10/sup 12/ cm/sup -3/ in a (hydrogen) plasma with electron density 10/sup 14/ cm/sup -3/, at temperatures from 0.8 to 10 keV. The computed radiated power loss from this plasma due to the iron ions ranges from about 4 W/cm/sup 3/ at the lowest temperature to about 0.4 W/cm/sup 3/ at the highest temperature; loss rates for other electron and ion densities will scale approximately as N/sub e/N/sub Fe/10/sup 26/. The losses are due principally to collisionally excited line radiation (especially ..delta..n = 0 transitions) at low temperatures, and to collisionally excited ..delta..n not equal to 0 transitions and to continuum radiative recombination at high temperatures. Spectra are also computed for diagnostic x-ray K/sub ..cap alpha../ (1s - 2p) transitions; the change in spectral distribution as a function of temperature agrees well with observations in the ST Tokamak. Bound-bound radiative transitions and dielectronic recombination are discussed at length in appendices; the latter process is of great importance in the establishment of ionization equilibrium, and in the excitation of K/sub ..cap alpha../ radiation at the lower temperatures.

  8. High Power Factor Control Regulating Inverter Output Power in IPM Motor Driven by Inverter System without Electrolytic Capacitor

    Science.gov (United States)

    Inazuma, Kazuya; Ohishi, Kiyoshi; Haga, Hitoshi; Sazawa, Mataki; Kondo, Seiji

    This paper presents a new high power factor control method for a single-to-three-phase power converter without an electrolytic capacitor. The circuit used in the method consists of a single-phase rectifier, a small film capacitor at DC-link, a voltage-source three-phase inverter, and an IPM motor. The inverter regulates both the velocity of the IPM motor and input current waveform. In order to obtain a power factor of unity, we propose a new control method that regulates the inverter output power. The inverter output power controller is placed between the speed controller and the q-axis current controller. The inverter power is regulated by a PI and repetitive controller. When repetitive control is applied to the inverter power controller, the phase delay of the inverter power controller is quite small. The superior performance of the proposed method is demonstrated by experimental results.

  9. Influence of output power of a spin torque oscillator on phase locked loop operation

    Science.gov (United States)

    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.

  10. Predictability of the Power Output of Three Wave Energy Technologies in the Danish North Sea

    DEFF Research Database (Denmark)

    Chozas, Julia Fernandez; Jensen, N. E. Helstrup; Sørensen, H. C.

    2013-01-01

    show that the errors in day-ahead predictions (in terms of scatter index) of the significant wave height, zero crossing period and wave power are 22%, 11% and 74%, respectively; and of the normalised theoretical power outputs of Pelamis, Wave Dragon and Wavestar are 37%, 39% and 54%, respectively...

  11. Determinants of mobile phone output power in a multinational study: implications for exposure assessment

    DEFF Research Database (Denmark)

    Vrijheid, M; Madsen, Stine Mann; di Vecchia, Paolo

    2009-01-01

    OBJECTIVES: The output power of a mobile phone is directly related to its radiofrequency (RF) electromagnetic field strength, and may theoretically vary substantially in different networks and phone use circumstances due to power control technologies. To improve indices of RF exposure...... for epidemiological studies, we assessed determinants of mobile phone output power in a multinational study. METHODS: More than 500 volunteers in 12 countries used Global System for Mobile communications software-modified phones (GSM SMPs) for approximately 1 month each. The SMPs recorded date, time, and duration...... of each call, and the frequency band and output power at fixed sampling intervals throughout each call. Questionnaires provided information on the typical circumstances of an individual's phone use. Linear regression models were used to analyse the influence of possible explanatory variables...

  12. Research on Power Output Characteristics of Magnetic Core in Energy Harvesting Devices

    Directory of Open Access Journals (Sweden)

    Rong-Ping GUO

    2014-07-01

    Full Text Available Magnetic core is the dominant factor in the performance of current transformer energy harvesting devices. The power output model of the magnetic core is established and verified through experiments. According to the actual application requirements, the concept of power density is proposed. The relationships of power density to air gap, material and dimension of the magnetic core are analyzed and verified through experiments.

  13. Smoothing of Grid-connected Wind-Diesel Power Output Using Energy Capacitor System

    Directory of Open Access Journals (Sweden)

    Adel A. Elbaset

    2014-06-01

    Full Text Available This paper presents a small hybrid power system consists of two types of power generation; wind turbine and diesel generation, DG connected to power distribution system. The fluctuations like random nature of wind power, turbulent wind, and sudden changes in load demand create imbalances in power distribution that can affect the frequency and the voltage in the power system. So, addition of Energy capacitor System, ECS is useful for compensation of fluctuating power, since it is capable of controlling both active and reactive power simultaneously and can smooth the output power flow. Hence, this paper proposes herein a dynamic model and simulation of a grid connected wind/DG based-ECS with power flow controllers between load and generation. Moreover, the paper presents a study to analyze the leveling of output fluctuation of wind power with the installation of ECS. To control the power exchanged between the ECS system and the AC grid, a load Following Control, LFC based supervisor is proposed with the aim to minimize variations of the power generated by the diesel generator. The interesting performance of the proposed supervisor is shown with the help of simulations. The computer simulation program is confirmed on a realistic circuit model which implemented in the Simulink environment of Matlab and works as if on line.

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

    Science.gov (United States)

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

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

  15. [Paraplegic cycling using functional electrical stimulation. Experimental and model-based study of power output].

    Science.gov (United States)

    Szecsi, J; Krafczyk, S; Quintern, J; Fiegel, M; Straube, A; Brandt, T

    2004-12-01

    Cycling using functional electrical stimulation offers paraplegics the possibility of muscle and cardiovascular training as well as the chance for independent locomotion. To investigate whether this method might be suitable for a large group of paraplegics, the first German feasibility study of functional electrical stimulation (FES) cycling with seven paraplegic patients was started at the beginning of 2003. Even at the beginning of the study, and without training, these patients were able to drive distances of 0.5-1.6 km. To stimulate cardiovascular adaptation processes in the case of FES ergometer training or to cover useful distances in the case of FES cycling, a minimum amount of generated mechanical output power is required, which as a rule cannot be achieved yet. In this study, we point out two particular aspects of FES cycling, which impair power output: prolonged fatigue mode and viscous joint friction of the paraplegic FES cyclist. We discuss current possibilities for increasing output power and endurance.

  16. Effect of material constants on power output in piezoelectric vibration-based generators.

    Science.gov (United States)

    Takeda, Hiroaki; Mihara, Kensuke; Yoshimura, Tomohiro; Hoshina, Takuya; Tsurumi, Takaaki

    2011-09-01

    A possible power output estimation based on material constants in piezoelectric vibration-based generators is proposed. A modified equivalent circuit model of the generator was built and was validated by the measurement results in the generator fabricated using potassium sodium niobate-based and lead zirconate titanate (PZT) ceramics. Subsequently, generators with the same structure using other PZT-based and bismuth-layered structure ferroelectrics ceramics were fabricated and tested. The power outputs of these generators were expressed as a linear functions of the term composed of electromechanical coupling coefficients k(sys)(2) and mechanical quality factors Q*(m) of the generator. The relationship between device constants (k(sys)(2) and Q*(m)) and material constants (k(31)(2) and Q(m)) was clarified. Estimation of the power output using material constants is demonstrated and the appropriate piezoelectric material for the generator is suggested.

  17. A dual mode charge pump with adaptive output used in a class G audio power amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Feng Yong; Peng Zhenfei; Yang Shanshan; Hong Zhiliang [State Key Laboratory of ASIC and System, Fudan University Shanghai 201203 (China); Liu Yang, E-mail: zlhong@fudan.edu.cn [Shanghai Design Center, Analog Devices, Shanghai 200021 (China)

    2011-04-15

    A dual mode charge pump to produce an adaptive power supply for a class G audio power amplifier is presented. According to the amplitude of the input signals, the charge pump has two level output voltage rails available to save power. It operates both in current mode at high output load and in pulse frequency modulation (PFM) at light load to reduce the power dissipation. Also, dynamic adjustment of the power stage transistor size based on load current at the PFM mode is introduced to reduce the output voltage ripple and prevent the switching frequency from audio range. The prototype is implemented in 0.18 {mu}m 3.3 V CMOS technology. Experimental results show that the maximum power efficiency of the charge pump is 79.5% - 0.5x mode and 83.6% - 1x mode. The output voltage ripple is less than 15 mV while providing 120 mA of the load current at PFM control and less than 18 mV while providing 300 mA of the load current at current mode control. An analytical model for ripple voltage and efficiency calculation of the proposed PFM control demonstrates reasonable agreement with measured results. (semiconductor integrated circuits)

  18. A dual mode charge pump with adaptive output used in a class G audio power amplifier

    Science.gov (United States)

    Yong, Feng; Zhenfei, Peng; Shanshan, Yang; Zhiliang, Hong; Yang, Liu

    2011-04-01

    A dual mode charge pump to produce an adaptive power supply for a class G audio power amplifier is presented. According to the amplitude of the input signals, the charge pump has two level output voltage rails available to save power. It operates both in current mode at high output load and in pulse frequency modulation (PFM) at light load to reduce the power dissipation. Also, dynamic adjustment of the power stage transistor size based on load current at the PFM mode is introduced to reduce the output voltage ripple and prevent the switching frequency from audio range. The prototype is implemented in 0.18 μm 3.3 V CMOS technology. Experimental results show that the maximum power efficiency of the charge pump is 79.5% @ 0.5x mode and 83.6% @ 1x mode. The output voltage ripple is less than 15 mV while providing 120 mA of the load current at PFM control and less than 18 mV while providing 300 mA of the load current at current mode control. An analytical model for ripple voltage and efficiency calculation of the proposed PFM control demonstrates reasonable agreement with measured results.

  19. Peak Power Output Test on a Rowing Ergometer: A Methodological Study.

    Science.gov (United States)

    Metikos, Boris; Mikulic, Pavle; Sarabon, Nejc; Markovic, Goran

    2015-10-01

    We aimed to examine the reliability and validity of the peak power output test on a rowing ergometer (Concept II Model D Inc.) and to establish the "optimal resistance" at which this peak power output was observed in 87 participants with varying levels of physical activity and rowing expertise: 15 male and 12 female physically inactive students (age: 21 ± 2 years), 16 male and 20 female physically active students (age: 23 ± 2 years), and 15 male and 9 female trained rowers (age: 19 ± 2 years). The participants performed countermovement jump (CMJ) test on a force plate, followed by 3 maximal-effort rowing trials using the lowest, medium, and the highest adjustable resistance settings (i.e., "1", "5," and "10" on the resistance control dial on the ergometer) in randomized order. The test proved to be reliable (coefficients of variation: 2.6-6.5%; intraclass correlation coefficients: 0.87-0.98). The correlation coefficients between CMJ peak power and rowing peak power (both in watts per kilogram) were fairly consistent across all 3 groups of participants and resistance levels, ranging between r = 0.70 and r = 0.78. Finally, the highest power output was observed at the highest resistance setting in 2 nonathletic groups (p rowing ergometer may serve as a reliable and valid tool for assessing whole-body peak power output in untrained individuals and rowing athletes.

  20. Optimal design parameters of the bicycle-rider system for maximal muscle power output.

    Science.gov (United States)

    Yoshihuku, Y; Herzog, W

    1990-01-01

    The purpose of this study was to find the optimal values of design parameters for a bicycle-rider system (crank length, pelvic inclination, seat height, and rate of crank rotation) which maximize the power output from muscles of the human lower limb during bicycling. The human lower limb was modelled as a planar system of five rigid bodies connected by four smooth pin joints and driven by seven functional muscle groups. The muscles were assumed to behave according to an adapted form of Hill's equation. The dependence of the average power on the design parameters was examined. The instantaneous power of each muscle group was studied and simultaneous activity of two seemingly antagonistic muscle groups was analyzed. Average peak power for one full pedal revolution was found to be around 1100 W. The upper body position corresponding to this peak power output was slightly reclined, and the pedalling rate was 155 rpm for a nominal crank length of 170 mm.

  1. Universal efficiency bounds of weak-dissipative thermodynamic cycles at the maximum power output.

    Science.gov (United States)

    Guo, Juncheng; Wang, Junyi; Wang, Yuan; Chen, Jincan

    2013-01-01

    Based on the assumption of weak dissipation introduced by Esposito et al. [Phys. Rev. Lett. 105, 150603 (2010)], analytic expressions for the efficiency bounds of several classes of typical thermodynamic cycles at the maximum power output are derived. The results obtained are of universal significance. They can be used to conveniently reveal the general characteristics of not only Carnot heat engines, but also isothermal chemical engines, non-Carnot heat engines, flux flow engines, gravitational engines, quantum Carnot heat engines, and two-level quantum Carnot engines at the maximum power output and to directly draw many important conclusions in the literature.

  2. Somatotype-variables related to muscle torque and power output in female volleyball players.

    Science.gov (United States)

    Buśko, Krzysztof; Lewandowska, Joanna; Lipińska, Monika; Michalski, Radosław; Pastuszak, Anna

    2013-01-01

    The purpose of this study was to investigate the relationship between somatotype, muscle torque, maximal power output and height of rise of the body mass centre measured in akimbo counter movement jump (ACMJ), counter movement jump (CMJ) and spike jump (SPJ), and power output measured in maximal cycle ergometer exercise bouts in female volleyball players. Fourteen players participated in the study. Somatotype was determined using the Heath-Carter method. Maximal muscle torque was measured under static conditions. Power output was measured in 5 maximal cycle ergometer exercise bouts, 10 s each, at increasing external loads equal to 2.5, 5.0, 7.5, 10.0 and 12.5% of body weight (BW). All jump trials (ACMJ, SPJ and CMJ) were performed on a force plate. The mean somatotype of volleyball players was: 4.9-3.5-2.5. The value of the sum of muscle torque of the left upper extremities was significantly correlated only with mesomorphic component. Mesomorphic and ectomorphic components correlated significantly with values of maximal power measured during ACMJ and CMJ. Power output measured in maximal cycle ergometer exercise bouts at increasing external loads equal to 2.5, 5.0 and 7.5% of BW was significantly correlated with endomorphy, mesomorphy and ectomorphy.

  3. Improved thermoelectric power output from multilayered polyethylenimine doped carbon nanotube based organic composites

    Energy Technology Data Exchange (ETDEWEB)

    Hewitt, Corey A.; Montgomery, David S.; Barbalace, Ryan L.; Carlson, Rowland D.; Carroll, David L., E-mail: carroldl@wfu.edu [Center for Nanotechnology and Molecular Materials, Wake Forest University, 501 Deacon Blvd., Winston Salem, North Carolina 27105 (United States)

    2014-05-14

    By appropriately selecting the carbon nanotube type and n-type dopant for the conduction layers in a multilayered carbon nanotube composite, the total device thermoelectric power output can be increased significantly. The particular materials chosen in this study were raw single walled carbon nanotubes for the p-type layers and polyethylenimine doped single walled carbon nanotubes for the n-type layers. The combination of these two conduction layers leads to a single thermocouple Seebeck coefficient of 96 ± 4 μVK{sup −1}, which is 6.3 times higher than that previously reported. This improved Seebeck coefficient leads to a total power output of 14.7 nW per thermocouple at the maximum temperature difference of 50 K, which is 44 times the power output per thermocouple for the previously reported results. Ultimately, these thermoelectric power output improvements help to increase the potential use of these lightweight, flexible, and durable organic multilayered carbon nanotube based thermoelectric modules in low powered electronics applications, where waste heat is available.

  4. Improved thermoelectric power output from multilayered polyethylenimine doped carbon nanotube based organic composites

    Science.gov (United States)

    Hewitt, Corey A.; Montgomery, David S.; Barbalace, Ryan L.; Carlson, Rowland D.; Carroll, David L.

    2014-05-01

    By appropriately selecting the carbon nanotube type and n-type dopant for the conduction layers in a multilayered carbon nanotube composite, the total device thermoelectric power output can be increased significantly. The particular materials chosen in this study were raw single walled carbon nanotubes for the p-type layers and polyethylenimine doped single walled carbon nanotubes for the n-type layers. The combination of these two conduction layers leads to a single thermocouple Seebeck coefficient of 96 ± 4 μVK-1, which is 6.3 times higher than that previously reported. This improved Seebeck coefficient leads to a total power output of 14.7 nW per thermocouple at the maximum temperature difference of 50 K, which is 44 times the power output per thermocouple for the previously reported results. Ultimately, these thermoelectric power output improvements help to increase the potential use of these lightweight, flexible, and durable organic multilayered carbon nanotube based thermoelectric modules in low powered electronics applications, where waste heat is available.

  5. Coordinated Power Dispatch of a PMSG based Wind Farm for Output Power Maximizing Considering the Wake Effect and Losses

    DEFF Research Database (Denmark)

    Zhang, Baohua; Hu, Weihao; Hou, Peng

    2016-01-01

    converters and transformers of WTs and the losses along the transmission cables. The active power reference and reactive power reference of each WT are chosen as the optimization variables and a partial swarm optimizing (PSO) algorithm is used for solving the problem. The proposed strategy is compared......The energy loss in a wind farm (WF) caused by wake interaction between wind turbines (WTs) is quite high, which can be reduced by proper active power dispatch. The electrical loss inside a WF by improper active power and reactive power dispatch is also considerable. In this paper, a coordinated...... active power and reactive power dispatch strategy is proposed for a Permanent magnet synchronous generator (PMSG) based WF, in order to maximize the total output power by reducing the wake effect and losses inside the devices of the WF, including the copper loss and iron loss of PMSGs, losses inside...

  6. Variable gas spring for matching power output from FPSE to load of refrigerant compressor

    Science.gov (United States)

    Chen, G.; Beale, W.T.

    1990-04-03

    The power output of a free piston Stirling engine is matched to a gas compressor which it drives and its stroke amplitude is made relatively constant as a function of power by connecting a gas spring to the drive linkage from the engine to the compressor. The gas spring is connected to the compressor through a passageway in which a valve is interposed. The valve is linked to the drive linkage so it is opened when the stroke amplitude exceeds a selected limit. This allows compressed gas to enter the spring, increase its spring constant, thus opposing stroke increase and reducing the phase lead of the displacer ahead of the piston to reduce power output and match it to a reduced load power demand. 6 figs.

  7. New Driver For The Powerful Output Rf Amplifier Of Mmf Dtl Rf System

    CERN Document Server

    Kvasha, A I; Vassilyev, A G

    2004-01-01

    More than 30 years ago a few powerful vacuum tubes were specially designed and produced in the former design office Swetlana for the Moscow meson factory DTL RF system. Among them was tetrode GI-51A with output pulse RF power up to 300 kW at frequency 198.2 MHz, which was used as driver for RF power amplifier with output RF pulse power (2-3) MW. In connection with well-known events in our country manufacture of these tubes, including GI-51A was finished about 10 years ago. In "SED-SPb" (successor of the design office Swetlana) triode GI-57A was offered instead of GI-51A. In this paper results of calculations and design of RF amplifier with new triode are presented. Preliminary results of RF amplifier tests, also presented in the paper, showed that triode GI-57A will be able successfully used in the DTL RF system channels.

  8. Quantifying the Impact of Wind Turbine Wakes on Power Output at Offshore Wind Farms

    DEFF Research Database (Denmark)

    Barthelmie, Rebecca Jane; Pryor, Sara; Frandsen, Sten Tronæs

    2010-01-01

    There is an urgent need to develop and optimize tools for designing large wind farm arrays for deployment offshore. This research is focused on improving the understanding of, and modeling of, wind turbine wakes in order to make more accurate power output predictions for large offshore wind farms....... Detailed data ensembles of power losses due to wakes at the large wind farms at Nysted and Horns Rev are presented and analyzed. Differences in turbine spacing (10.5 versus 7 rotor diameters) are not differentiable in wake-related power losses from the two wind farms. This is partly due to the high...... of power output moving through the wind farm. Root-mean-square errors indicate a generally better model performance for higher wind speeds (10 rather than 6 m s−1) and for direct down the row flow than for oblique angles. Despite this progress, wake modeling of large wind farms is still subject...

  9. Optimal cycling time trial position models: aerodynamics versus power output and metabolic energy.

    Science.gov (United States)

    Fintelman, D M; Sterling, M; Hemida, H; Li, F-X

    2014-06-03

    The aerodynamic drag of a cyclist in time trial (TT) position is strongly influenced by the torso angle. While decreasing the torso angle reduces the drag, it limits the physiological functioning of the cyclist. Therefore the aims of this study were to predict the optimal TT cycling position as function of the cycling speed and to determine at which speed the aerodynamic power losses start to dominate. Two models were developed to determine the optimal torso angle: a 'Metabolic Energy Model' and a 'Power Output Model'. The Metabolic Energy Model minimised the required cycling energy expenditure, while the Power Output Model maximised the cyclists׳ power output. The input parameters were experimentally collected from 19 TT cyclists at different torso angle positions (0-24°). The results showed that for both models, the optimal torso angle depends strongly on the cycling speed, with decreasing torso angles at increasing speeds. The aerodynamic losses outweigh the power losses at cycling speeds above 46km/h. However, a fully horizontal torso is not optimal. For speeds below 30km/h, it is beneficial to ride in a more upright TT position. The two model outputs were not completely similar, due to the different model approaches. The Metabolic Energy Model could be applied for endurance events, while the Power Output Model is more suitable in sprinting or in variable conditions (wind, undulating course, etc.). It is suggested that despite some limitations, the models give valuable information about improving the cycling performance by optimising the TT cycling position. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2011-01-01

    Future remote sensing instruments will require focal plane spectrometer arrays with higher resolution at high frequencies. One of the major components of spectrometers are the local oscillator (LO) signal sources that are used to drive mixers to down-convert received radio-frequency (RF) signals to intermediate frequencies (IFs) for analysis. By advancing LO technology through increasing output power and efficiency, and reducing component size, these advances will improve performance and simplify architecture of spectrometer array systems. W-band power amplifiers (PAs) are an essential element of current frequency-multiplied submillimeter-wave LO signal sources. This work utilizes GaN monolithic millimeter-wave integrated circuit (MMIC) PAs developed from a new HRL Laboratories LLC 0.15- m gate length GaN semiconductor transistor. By additionally waveguide power combining PA MMIC modules, the researchers here target the highest output power performance and efficiency in the smallest volume achievable for W-band.

  11. Human power output during repeated sprint cycle exercise: the influence of thermal stress

    NARCIS (Netherlands)

    Ball, D.; Burrows, C.; Sargeant, A.J.

    1999-01-01

    Thermal stress is known to impair endurance capacity during moderate prolonged exercise. However, there is relatively little available information concerning the effects of thermal stress on the performance of high-intensity short-duration exercise. The present experiment examined human power output

  12. Current drive and mode stabilization experiments with real-time control of the gyrotron output power

    NARCIS (Netherlands)

    Oomens, A. A. M.; Lok, J.; Salzedas, F.; Schüller, F. C.; Dam, R.; de Groot, B.; R. T. P. Team,

    2001-01-01

    Real-time control of the gyrotron output power has been obtained by controlling the gyrotron cathode voltage. This control system has been used to explore feedback control of global and local plasma parameters. A description is given of technical set-up and of the results, which include control of

  13. Effect of turbine alignment on the average power output of wind-farms

    NARCIS (Netherlands)

    Stevens, Richard Johannes Antonius Maria; Gayme, Dennice F.; Meneveau, Charles

    2013-01-01

    Using Large Eddy Simulation (LES), we investigate the influence of the alignment of successive turbine rows on the average power output of a finite length wind-farm with a stream-wise spacing between the turbines of Sx = 7:85D and a span-wise spacing of Sy = 5:23D, where D is the turbine diameter.

  14. The effect of pole's height on the output performance of solar power ...

    African Journals Online (AJOL)

    Solar energy is a renewable (non-conventional) source of energy supply that has been used as a reliable energy source in view of its economic importance and its wide range of applications. In this study the effect of pole's height on the output performance of solar power system has been investigated. A solar panel of 45 ...

  15. A 5 cm single-discharge CO2 laser having high power output

    NARCIS (Netherlands)

    Ernst, G.J.; Boer, A.G.

    1980-01-01

    A single-discharge self-sustained CO2 laser has been constructed with a gap distance of 5 cm. The system has a very simple construction; it produces a very uniform discharge with an output power of 50 Joules per liter for a CO2 : N2 : He = 1 : 1 : 3 mixture. The efficiency can be as high as 19%.

  16. Integrating wind output with bulk power operations and wholesale electricity markets

    Energy Technology Data Exchange (ETDEWEB)

    Hirst, E. [Consulting in Electric-Industry Restructuring, Oak Ridge, TN (United States)

    2002-07-01

    Wind farms have three characteristics that complicate their widespread application as an electricity resource: limited control, unpredictability and variability. Therefore the integration of wind output into bulk power electric systems is qualitatively different from that of other types of generators. The electric system operator must move other generators up or down to offset the time-varying wind fluctuations. Such movements raise the costs of fuel and maintenance for these other generators. Not only is wind power different, it is new. The operators of bulk power systems have limited experience in integrating wind output into the larger system. As a consequence, market rules that treat wind fairly - neither subsidizing nor penalizing its operation - have not yet been developed. The lack of data and analytical methods encourages wind advocates and sceptics to rely primarily on their biases and beliefs in suggesting how wind should be integrated into bulk power systems. This project helps fill this data and analysis gap. Specifically, it develops and applies a quantitative method for the integration of a wind resource into a large electric system. The method permits wind to bid its output into a short-term forward market (specifically, an hour-ahead energy market) or to appear in real time and accept only intrahour and hourly imbalance payments for the unscheduled energy it delivers to the system. Finally, the method analyses the short-term (minute-to-minute) variation in wind output to determine the regulation requirement the wind resource imposes on the electrical system. (author)

  17. Increase of power output by change of ion transport direction in a plant microbial fuel cell

    NARCIS (Netherlands)

    Timmers, R.A.; Strik, D.P.B.T.B.; Hamelers, H.V.M.; Buisman, C.J.N.

    2013-01-01

    The plant microbial fuel cell (PMFC) is a technology for the production of renewable and clean bioenergy based on photosynthesis. To increase the power output of the PMFC, the internal resistance (IR) must be reduced. The objective of the present study was to reduce the membrane resistance by

  18. Relative importance of pacing strategy and mean power output in 1500-m self-paced cycling

    NARCIS (Netherlands)

    Hettinga, F. J.; de Koning, J. J.; Hulleman, M.; Foster, C.

    Introduction Both mean power output (MPO) and the distribution of the available energy over the race, that is, pacing strategy, are critical factors in performance. The purpose of this study was to determine the relative importance of both pacing strategy and MPO to performance. Methods Six

  19. Electrospun ion gel nanofibers for flexible triboelectric nanogenerator: electrochemical effect on output power.

    Science.gov (United States)

    Ye, Byeong Uk; Kim, Byoung-Joon; Ryu, Jungho; Lee, Joo Yul; Baik, Jeong Min; Hong, Kihyon

    2015-10-21

    A simple fabrication route for ion gel nanofibers in a triboelectric nanogenerator was demonstrated. Using an electrospinning technique, we could fabricate a large-area ion gel nanofiber mat. The triboelectric nanogenerator was demonstrated by employing an ion gel nanofiber and the device exhibited an output power of 0.37 mW and good stability under continuous operation.

  20. CMOS upconversion mixer with filterless carrier feedthrough cancelation and output power tuning

    NARCIS (Netherlands)

    Sanchez Gaspariano, Luis Abraham; Annema, Anne J.; Muniz Montero, Carlos; Diaz Sanchez, Alejandro

    2014-01-01

    The synthesis, design and implementation of a CMOS upconversion mixer that both can adjust, by means of a DC voltage control, its output power and that cancels the carrier feedthrough is presented. Aiming at very low cost medical implant applications, a prototype of the architecture was implemented

  1. Applications of Petri net in power systems; Aplicacao de redes de Petri a sistemas de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Yoshihiro, Claudio K.; Senger, Eduardo C.

    1995-12-31

    With the increasing automation of the electric power systems, the logic control complexity of such systems is also increasing. Even the most simple equipment or operation nowadays require complexes sequences or logics of protection and operation. This work presents some possibilities concerning the application of Petri nets in power systems. A study case is presented. 7 refs., 13 figs.

  2. Effect of twine diameter on fishing power of experimental gill nets used in Greenland waters

    DEFF Research Database (Denmark)

    Hovgård, Holger

    1996-01-01

    The relative fishing powers of experimental gill nets were estimated for shorthorn sculpin (Myoxocephalus scorpius), Greenland cod (Gadus ogac), and Atlantic cod (Gadus morhua). The results suggested that fishing power was negatively correlated to the ratio between twine diameter and mesh size...

  3. Contrast Loading Increases Upper Body Power Output in Junior Volleyball Athletes.

    Science.gov (United States)

    Smilios, Ilias; Sotiropoulos, Konstantinos; Barzouka, Karolina; Christou, Marios; Tokmakidis, Savvas P

    2017-02-01

    This study examined the acute effects of contrast loading on mechanical power output during bench-press throws in junior volleyball players. Eleven males (age: 16.5 ± 0.5 years) performed a contrast loading and a control protocol. The contrast protocol included the execution of 3 bench-throws with a 30% load of 1RM, after 3 min a conditioning set of 5 bench-throws with a 60% load of 1RM and after 3 and 5 min two more sets of 3 bench-throws with a 30% load of 1RM. The control protocol included the execution of 3 sets of 3 bench-throws with a 30% load of 1RM at the same time points as in the contrast protocol without the execution of the conditioning set. Mechanical power with a 30% load was higher (p < .05) 3 and 5 min following the conditioning set at the contrast protocol compared with the control protocol (8.7 ± 7.5 and 10.4 ± 3.4%, respectively). High correlations (p < .05) were obtained between participant's relative maximal strength (r = .87) and power (r = .82) and the increases in power output. Contrast loading increases upper body power output produced with a light load by junior athletes. The potential for increased upper body performance is more evident in stronger or more powerful individuals.

  4. Low Power Very High Frequency Switch-Mode Power Supply with 50 V Input and 5 V Output

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    This paper presents the design of a resonant converter with a switching frequency in the very high frequencyrange (30-300 MHz), a large step down ratio (10 times) and low output power (1 W). Several different invertersand rectifiers are analyzed and compared. The class E inverter and rectifier...

  5. Power-Law Distributions in a Two-sided Market and Net Neutrality

    OpenAIRE

    Deng, Xiaotie; Feng, Zhe; Papadimitriou, Christos H.

    2016-01-01

    "Net neutrality" often refers to the policy dictating that an Internet service provider (ISP) cannot charge content providers (CPs) for delivering their content to consumers. Many past quantitative models designed to determine whether net neutrality is a good idea have been rather equivocal in their conclusions. Here we propose a very simple two-sided market model, in which the types of the consumers and the CPs are {\\em power-law distributed} --- a kind of distribution known to often arise p...

  6. The effects of training with loads that maximise power output and individualised repetitions vs. traditional power training.

    Directory of Open Access Journals (Sweden)

    J M Sarabia

    Full Text Available It has been suggested that strength training effects (i.e. neural or structural vary, depending on the total repetitions performed and velocity loss in each training set.The aim of this study is to compare the effects of two training programmes (i.e. one with loads that maximise power output and individualised repetitions, and the other following traditional power training.Twenty-five males were divided into three groups (optimum power [OP = 10], traditional training [TT = 9] and control group [CG = 6]. The training load used for OP was individualised using loads that maximised power output (41.7% ± 5.8 of one repetition maximum [1RM] and repetitions at maximum power (4 to 9 repetitions, or 'reps'. Volume (sets x repetitions was the same for both experimental groups, while intensity for TT was that needed to perform only 50% of the maximum number of possible repetitions (i.e. 61.1%-66.6% of 1RM. The training programme ran over 11 weeks (2 sessions per week; 4-5 sets per session; 3-minute rests between sets, with pre-, intermediate and post-tests which included: anthropometry, 1RM, peak power output (PPO with 30%, 40% and 50% of 1RM in the bench press throw, and salivary testosterone (ST and cortisol (SC concentrations. Rate of perceived exertion (RPE and power output were recorded in all sessions.Following the intermediate test, PPO was increased in the OP group for each load (10.9%-13.2%. Following the post-test, both experimental groups had increased 1RM (11.8%-13.8% and PPO for each load (14.1%-19.6%. Significant decreases in PPO were found for the TT group during all sets (4.9%-15.4%, along with significantly higher RPE (37%.OP appears to be a more efficient method of training, with less neuromuscular fatigue and lower RPE.

  7. An optically coupled power stimulus isolation unit with high voltage and fast rise time output

    Directory of Open Access Journals (Sweden)

    R.O. Brasil

    1999-06-01

    Full Text Available Recent technological developments have created new devices that could improve and simplify the construction of stimulus isolators. HEXFET transistors can switch large currents and hundreds of volts in nanoseconds. The newer opto-isolators can give a pulse rise time of a few nanoseconds, with output compatible with MOSFET devices, in which delays are reduced to nanoseconds. Integrated DC/DC converters are now available. Using these new resources we developed a new electrical stimulus isolator circuit with selectable constant-current and constant-voltage modes, which are precise and easy to construct. The circuit works like a regulated power supply in both modes with output switched to zero or to free mode through an opto-isolator device. The isolator analyses showed good practical performance. The output to ground resistance was 1011 ohms and capacitance 35 picofarads. The rise time and fall time were identical (5 µs and constant. The selectable voltage or current output mode made it very convenient to use. The current mode, with higher output resistance values in low current ranges, permits intracellular stimulation even with tip resistances close to 100 megaohms. The high compliance of 200 V guarantees the value of the current stimulus. The very low output resistance in the voltage mode made the device highly suitable for extracellular stimulation with low impedance electrodes. Most importantly, these characteristics were achieved with a circuit that was easy to build and modify and assembled with components available in Brazil.

  8. An optically coupled power stimulus isolation unit with high voltage and fast rise time output.

    Science.gov (United States)

    Brasil, R O; Leal-Cardoso, J H

    1999-06-01

    Recent technological developments have created new devices that could improve and simplify the construction of stimulus isolators. HEXFET transistors can switch large currents and hundreds of volts in nanoseconds. The newer opto-isolators can give a pulse rise time of a few nanoseconds, with output compatible with MOSFET devices, in which delays are reduced to nanoseconds. Integrated DC/DC converters are now available. Using these new resources we developed a new electrical stimulus isolator circuit with selectable constant-current and constant-voltage modes, which are precise and easy to construct. The circuit works like a regulated power supply in both modes with output switched to zero or to free mode through an opto-isolator device. The isolator analyses showed good practical performance. The output to ground resistance was 10(11) ohms and capacitance 35 picofarads. The rise time and fall time were identical (5 microseconds) and constant. The selectable voltage or current output mode made it very convenient to use. The current mode, with higher output resistance values in low current ranges, permits intracellular stimulation even with tip resistances close to 100 megaohms. The high compliance of 200 V guarantees the value of the current stimulus. The very low output resistance in the voltage mode made the device highly suitable for extracellular stimulation with low impedance electrodes. Most importantly, these characteristics were achieved with a circuit that was easy to build and modify and assembled with components available in Brazil.

  9. Wind tunnel study of the power output spectrum in a micro wind farm

    Science.gov (United States)

    Bossuyt, Juliaan; Howland, Michael F.; Meneveau, Charles; Meyers, Johan

    2016-09-01

    Instrumented small-scale porous disk models are used to study the spectrum of a surrogate for the power output in a micro wind farm with 100 models of wind turbines. The power spectra of individual porous disk models in the first row of the wind farm show the expected -5/3 power law at higher frequencies. Downstream models measure an increased variance due to wake effects. Conversely, the power spectrum of the sum of the power over the entire wind farm shows a peak at the turbine-to-turbine travel frequency between the model turbines, and a near -5/3 power law region at a much wider range of lower frequencies, confirming previous LES results. Comparison with the spectrum that would result when assuming that the signals are uncorrelated, highlights the strong effects of correlations and anti-correlations in the fluctuations at various frequencies.

  10. An Improved Mathematical Model for Computing Power Output of Solar Photovoltaic Modules

    Directory of Open Access Journals (Sweden)

    Abdul Qayoom Jakhrani

    2014-01-01

    Full Text Available It is difficult to determine the input parameters values for equivalent circuit models of photovoltaic modules through analytical methods. Thus, the previous researchers preferred to use numerical methods. Since, the numerical methods are time consuming and need long term time series data which is not available in most developing countries, an improved mathematical model was formulated by combination of analytical and numerical methods to overcome the limitations of existing methods. The values of required model input parameters were computed analytically. The expression for output current of photovoltaic module was determined explicitly by Lambert W function and voltage was determined numerically by Newton-Raphson method. Moreover, the algebraic equations were derived for the shape factor which involves the ideality factor and the series resistance of a single diode photovoltaic module power output model. The formulated model results were validated with rated power output of a photovoltaic module provided by manufacturers using local meteorological data, which gave ±2% error. It was found that the proposed model is more practical in terms of precise estimations of photovoltaic module power output for any required location and number of variables used.

  11. Dynamic Floating Output Stage for Low Power Buffer Amplifier for LCD Application

    OpenAIRE

    Hari Shanker Srivastava; R.K Baghel

    2015-01-01

    This topic proposes low-power buffer means low quiescent current buffer amplifier. A dynamic floating current node is used at the output of two-stage amplifier to increase the charging and discharging of output capacitor as well as settling time of buffer. It is designed for 10 bit digital analog converter to support for LCD column driver it is implemented in 180 nm CMOS technology with the quiescent current of 5 µA for 30 pF capacitance, the settling time calculated as 4.5µs, the...

  12. Output Regulation of Large-Scale Hydraulic Networks with Minimal Steady State Power Consumption

    DEFF Research Database (Denmark)

    Jensen, Tom Nørgaard; Wisniewski, Rafal; De Persis, Claudio

    2014-01-01

    An industrial case study involving a large-scale hydraulic network is examined. The hydraulic network underlies a district heating system, with an arbitrary number of end-users. The problem of output regulation is addressed along with a optimization criterion for the control. The fact...... that the system is overactuated is exploited for minimizing the steady state electrical power consumption of the pumps in the system, while output regulation is maintained. The proposed control actions are decentralized in order to make changes in the structure of the hydraulic network easy to implement....

  13. Pulse-width modulated external resistance increases the microbial fuel cell power output.

    Science.gov (United States)

    Coronado, J; Perrier, M; Tartakovsky, B

    2013-11-01

    This study describes MFC operation with a pulse-width modulated connection of the external resistor (R-PWM mode) at low and high frequencies. Analysis of the output voltage profiles acquired during R-PWM tests showed the presence of slow and fast dynamic components, which can be described by a simple equivalent circuit model suitable for process control applications. At operating frequencies above 100 Hz a noticeable improvement in MFC performance was observed with the power output increase of 22-43% as compared to MFC operation with a constant external resistance. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  14. Linear Robust Output Regulation in a Class of Switched Power Converters

    Directory of Open Access Journals (Sweden)

    Josep M. Olm

    2010-01-01

    Full Text Available This article addresses the robust output regulation problem for a class of nonlinear switched power converters after its linearization by means of a change of the control vector variable. The methodology employs a dynamic state feedback control law and considers parametric uncertainty due to unknown values of resistive loads. Restrictions arising from the fact that the control gains exhibit fixed values are taken into account. The proposed technique is exemplified with the output voltage regulation of a Noninverting Buck-Boost converter and tested through realistic numerical simulations.

  15. 915 MHz microwave ablation with high output power in in vivo porcine spleens

    Energy Technology Data Exchange (ETDEWEB)

    Gao Yongyan, E-mail: gaoyongyan301@hotmail.co [Department of Ultrasound, Chinese PLA General Hospital, 28 Fuxing Rd., Beijing 100853 (China); Department of Special Diagnosis, The General Hospital of Chinese People' s Armed Police Forces, 69 Yongding Rd., Beijing 100039 (China); Wang Yang, E-mail: wangyang301301@yahoo.com.c [Department of Ultrasound, Chinese PLA General Hospital, 28 Fuxing Rd., Beijing 100853 (China); Duan Yaqi, E-mail: yaqiduan@hotmail.co [Department of Ultrasound, Chinese PLA General Hospital, 28 Fuxing Rd., Beijing 100853 (China); Li Chunling, E-mail: lichunling301@hotmail.co [Department of Special Diagnosis, The General Hospital of Chinese People' s Armed Police Forces, 69 Yongding Rd., Beijing 100039 (China); Sun Yuanyuan, E-mail: syymail@hotmail.co [Department of Ultrasound, Chinese PLA General Hospital, 28 Fuxing Rd., Beijing 100853 (China); Zhang Dakun, E-mail: zdk002@163.co [Department of Ultrasound, Chinese PLA General Hospital, 28 Fuxing Rd., Beijing 100853 (China); Lu Tong, E-mail: lutong_java@yahoo.com.c [Department of Ultrasound, Chinese PLA General Hospital, 28 Fuxing Rd., Beijing 100853 (China); Liang Ping, E-mail: liangping301@hotmail.co [Department of Ultrasound, Chinese PLA General Hospital, 28 Fuxing Rd., Beijing 100853 (China)

    2010-07-15

    Objective: The purpose of this study was to evaluate the efficacy of 915 MHz microwave (MW) ablation with high output power in in vivo porcine spleens. Materials and methods: MW ablations were performed in 9 porcine spleens with an internally cooled 915 MHz antenna. Thermocouples were placed at 5, 10, 15, 20 mm away from the antenna to measure temperatures in real-time during MW emission. The energy was applied for 10 min at high output power of 60 W, 70 W or 80 W. Gross specimens were sectioned and measured to determine ablation size. Representative areas were examined by light microscopy and electron microscopy. Coagulation sizes and temperatures were compared among the three power groups. Results: Hematoxylin-eosin staining showed irreversible necrosis in the splenic coagulation area after MW ablation. As the power was increased, long-axis diameter enlarged significantly (p < .05). Short-axis diameter also tended to increase, but there were no statistical difference (p > .05). The coagulation size of long-axis and short-axis diameter with 80 W in vivo spleen ablation was 6.43 {+-} 0.52 and 4.95 {+-} 0.30 cm, respectively. With the increase of output power, maximum temperatures at 5, 10, 15, 20 mm from the antenna were increased accordingly (p < .05). The maximum temperature with 80 W at 5 and 20 mm from the antenna reached 146.17 {+-} 6.65 and 72.38 {+-} 4.23 {sup o}C respectively. Conclusion: With internally cooled antenna and high output power, 915 MHz MW ablation in the spleen could produce irreversible tissue necrosis of clinical significance. MW ablation may be used as a promising minimally invasive method for the treatment of splenic diseases.

  16. Output regularization of SVM seizure predictors: Kalman Filter versus the "Firing Power" method.

    Science.gov (United States)

    Teixeira, Cesar; Direito, Bruno; Bandarabadi, Mojtaba; Dourado, António

    2012-01-01

    Two methods for output regularization of support vector machines (SVMs) classifiers were applied for seizure prediction in 10 patients with long-term annotated data. The output of the classifiers were regularized by two methods: one based on the Kalman Filter (KF) and other based on a measure called the "Firing Power" (FP). The FP is a quantification of the rate of the classification in the preictal class in a past time window. In order to enable the application of the KF, the classification problem was subdivided in a two two-class problem, and the real-valued output of SVMs was considered. The results point that the FP method raise less false alarms than the KF approach. However, the KF approach presents an higher sensitivity, but the high number of false alarms turns their applicability negligible in some situations.

  17. Exploring the Power Output of Small Wind Turbines in Urban San Antonio, Texas

    Science.gov (United States)

    Casillas, Jose; Sperduti, Stephanie; Cardenas, Rosa

    2015-03-01

    The means of transporting power from a centralized power plant by transmission lines has several disadvantages. Electricity transmission and distribution networks are costly, require long planning processes and are unsightly to residents. These networks are also susceptible to natural disasters creating massive disruptions to consumers. For these reasons distributed power sources such as solar panels and small wind turbines are becoming a more desirable and viable means of energy production. We report on the status of a study to determine the maximum output power of small wind turbines in urban San Antonio, Texas. Wind speed data along with power measurements from small wind turbines in urban San Antonio will be reported. U.S. Department of Education Title V HSI-STEM and Articulation Award No. P031C110145.

  18. Enhanced optical output power of blue light-emitting diodes with quasi-aligned gold nanoparticles

    Science.gov (United States)

    Jin, Yuanhao; Li, Qunqing; Li, Guanhong; Chen, Mo; Liu, Junku; Zou, Yuan; Jiang, Kaili; Fan, Shoushan

    2014-01-01

    The output power of the light from GaN-based light-emitting diodes (LEDs) was enhanced by fabricating gold (Au) nanoparticles on the surface of p-GaN. Quasi-aligned Au nanoparticle arrays were prepared by depositing Au thin film on an aligned suspended carbon nanotube thin film surface and then putting the Au-CNT system on the surface of p-GaN and thermally annealing the sample. The size and position of the Au nanoparticles were confined by the carbon nanotube framework, and no other additional residual Au was distributed on the surface of the p-GaN substrate. The output power of the light from the LEDs with Au nanoparticles was enhanced by 55.3% for an injected current of 100 mA with the electrical property unchanged compared with the conventional planar LEDs. The enhancement may originate from the surface plasmon effect and scattering effect of the Au nanoparticles.

  19. Efficiency at maximum power output of linear irreversible Carnot-like heat engines.

    Science.gov (United States)

    Wang, Yang; Tu, Z C

    2012-01-01

    The efficiency at maximum power output of linear irreversible Carnot-like heat engines is investigated based on the assumption that the rate of irreversible entropy production of the working substance in each "isothermal" process is a quadratic form of the heat exchange rate between the working substance and the reservoir. It is found that the maximum power output corresponds to minimizing the irreversible entropy production in two isothermal processes of the Carnot-like cycle, and that the efficiency at maximum power output has the form η(mP)=η(C)/(2-γη(C)), where η(C) is the Carnot efficiency, while γ depends on the heat transfer coefficients between the working substance and two reservoirs. The value of η(mP) is bounded between η(-)≡η(C)/2 and η(+)≡η(C)/(2-η(C)). These results are consistent with those obtained by Chen and Yan [J. Chem. Phys. 90, 3740 (1989)] based on the endoreversible assumption, those obtained by Esposito et al. [Phys. Rev. Lett. 105, 150603 (2010)] based on the low-dissipation assumption, and those obtained by Schmiedl and Seifert [Europhys. Lett. 81, 20003 (2008)] for stochastic heat engines which in fact also satisfy the low-dissipation assumption. Additionally, we find that the endoreversible assumption happens to hold for Carnot-like heat engines operating at the maximum power output based on our fundamental assumption, and that the Carnot-like heat engines that we focused on do not strictly satisfy the low-dissipation assumption, which implies that the low-dissipation assumption or our fundamental assumption is a sufficient but non-necessary condition for the validity of η(mP)=η(C)/(2-γη(C)) as well as the existence of two bounds, η(-)≡η(C)/2 and η(+)≡η(C)/(2-η(C)). © 2012 American Physical Society

  20. High Voltage Power Supply With High Output Current and Low Power Consumption for Photomultiplier Tubes

    Science.gov (United States)

    Cunha, José Paulo V. S.; Begalli, Marcia; Bellar, Maria Dias

    2012-04-01

    In some applications, photomultiplier tubes (PMTs) are powered by battery based circuits, where the available energy is severely limited. The most simple approach to design high voltage power supplies (HVPS) for PMTs has considered resistive voltage dividers in order to bias the dynodes. However, this approach usually results in high power losses and, consequently, this undermines the PMT performance. In this work, the proposed solution is the use of a power circuit based on the forward converter connected to a transformer built with several secondary windings. Each secondary voltage is rectified and filtered to eliminate voltage ripple. Each dynode voltage is supplied by a rectified secondary voltage. The proposed topology provides low power consumption as well as low sensitivity of the PMT gain with respect to the dynode currents. Taking into account the Waste Electrical and Electronic Equipment Directive (WEEE), this HVPS has been designed to allow the recycling of old PMTs.

  1. Balancing Europe's wind power output through spatial deployment informed by weather regimes.

    Science.gov (United States)

    Grams, Christian M; Beerli, Remo; Pfenninger, Stefan; Staffell, Iain; Wernli, Heini

    2017-08-01

    As wind and solar power provide a growing share of Europe's electricity1, understanding and accommodating their variability on multiple timescales remains a critical problem. On weekly timescales, variability is related to long-lasting weather conditions, called weather regimes2-5, which can cause lulls with a loss of wind power across neighbouring countries6. Here we show that weather regimes provide a meteorological explanation for multi-day fluctuations in Europe's wind power and can help guide new deployment pathways which minimise this variability. Mean generation during different regimes currently ranges from 22 GW to 44 GW and is expected to triple by 2030 with current planning strategies. However, balancing future wind capacity across regions with contrasting inter-regime behaviour - specifically deploying in the Balkans instead of the North Sea - would almost eliminate these output variations, maintain mean generation, and increase fleet-wide minimum output. Solar photovoltaics could balance low-wind regimes locally, but only by expanding current capacity tenfold. New deployment strategies based on an understanding of continent-scale wind patterns and pan-European collaboration could enable a high share of wind energy whilst minimising the negative impacts of output variability.

  2. Somatotype variables related to strength and power output in male basketball players.

    Science.gov (United States)

    Buśko, Krzysztof; Pastuszak, Anna; Lipińska, Monika; Lipińska, Marta; Gryko, Karol

    2017-01-01

    The purpose of this study was to investigate the relationship between somatotype, muscular strength, power output measured in maximal cycle ergometer exercise bouts, and maximal power output and height of rise of the body mass centre (jump height) measured in akimbo counter movement jump (ACMJ), counter movement jump (CMJ) and spike jump (SPJ), in male basketball players. Thirteen male basketball players (second division, age 19.4 ± 0.8 years, body height 192.9 ± 5.6 cm, body mass 88.8 ± 8.6 kg, training experience 9.3 ± 0.8 years) participated in the study. Somatotype was determined using the Heath-Carter method. Maximal joint torques were measured under static conditions. Power output was measured in 2 maximal cycle ergometer exercise bouts, 10 seconds each, with increasing external loads equal to 7.5 and 10.0% of the body weight (BW). All jump trials (ACMJ, CMJ and SPJ) were performed on a force plate. The mean somatotype of basketball players amounted to: 2.8-4.2-3.2. The sum of the joint torques for left and right lower extremities (0.613), trunk (0.631) and all six measured muscle groups (0.647) were significantly correlated (p basketball players' anthropometric characteristics can influence their level of performance but it is not a decisive factor.

  3. A Free-Piston Linear Generator Control Strategy for Improving Output Power

    Directory of Open Access Journals (Sweden)

    Chi Zhang

    2018-01-01

    Full Text Available This paper presents a control strategy to improve the output power for a single-cylinder two-stroke free-piston linear generator (FPLG. The comprehensive simulation model of this FPLG is established and the operation principle is introduced. The factors that affect the output power are analyzed theoretically. The characteristics of the piston motion are studied. Considering the different features of the piston motion respectively in acceleration and deceleration phases, a ladder-like electromagnetic force control strategy is proposed. According to the status of the linear electric machine, the reference profile of the electromagnetic force is divided into four ladder-like stages during one motion cycle. The piston motions, especially the dead center errors, are controlled by regulating the profile of the electromagnetic force. The feasibility and advantage of the proposed control strategy are verified through comparison analyses with two conventional control strategies via MatLab/Simulink. The results state that the proposed control strategy can improve the output power by around 7–10% with the same fuel cycle mass.

  4. Some observations on stray magnetic fields and power outputs from short-wave diathermy equipment

    Energy Technology Data Exchange (ETDEWEB)

    Lau, R.W.M.; Dunscombe, P.B.

    1984-04-01

    Recent years have seen increasing interest in the possible hazards arising from the use of nonionizing electromagnetic radiation. Relatively large and potentially hazardous fields are to be found in the vicinity of short-wave and microwave equipment used in physiotherapy departments to produce therapeutic temperature rises. This note reports the results of measurements of the stray magnetic field and power output of a conventional short-wave diathermy unit when applied to tissue-equivalent phantoms. The dependence of these quantities on the variables, i.e. power setting of the unit, capacitor plate size, phantom size and phantom-capacitor plate separation, are discussed.

  5. Integrated Tm:fiber MOPA with polarized output and narrow linewidth with 100 W average power.

    Science.gov (United States)

    Shah, Lawrence; Sims, R Andrew; Kadwani, Pankaj; Willis, Christina C C; Bradford, Joshua B; Pung, Aaron; Poutous, Menelaos K; Johnson, Eric G; Richardson, Martin

    2012-08-27

    We report on a Tm:fiber master oscillator power amplifier (MOPA) system producing 109 W CW output power, with >15 dB polarization extinction ratio, sub-nm spectral linewidth, and M2 fiber and PM-fiber components including tapered fiber bundle pump combiners, a single-mode to large mode area mode field adapter, and a fiber-coupled isolator. The laser components ultimately determine the system architecture and the limits of laser performance, particularly considering the immature and rapidly developing state of fiber components in the 2 μm wavelength regime.

  6. Smoothing of wind farm output power using prediction based flywheel energy storage system

    Science.gov (United States)

    Islam, Farzana

    Being socially beneficial, economically competitive and environment friendly, wind energy is now considered to be the world's fastest growing renewable energy source. However, the stochastic nature of wind imposes a considerable challenge in the optimal management and operation of wind power system. Wind speed prediction is critical for wind energy conversion system since it greatly influences the issues related to effective energy management, dynamic control of wind turbine, and improvement of the overall efficiency of the power generation system. This thesis focuses on integration of energy storage system with wind farm, considering wind speed prediction in the control scheme to overcome the problems associated with wind power fluctuations. In this thesis, flywheel energy storage system (FESS) with adjustable speed rotary machine has been considered for smoothing of output power in a wind farm composed of a fixed speed wind turbine generator (FSWTG). Since FESS has both active and reactive power compensation ability, it enhances the stability of the system effectively. An efficient energy management system combined with supervisory control unit (SCU) for FESS and wind speed prediction has been developed to improve the smoothing of the wind farm output effectively. Wind speed prediction model is developed by artificial neural network (ANN) which has advantages over the conventional prediction scheme including data error tolerance and ease in adaptability. The model for prediction with ANN is developed in MATLAB/Simulink and interfaced with PSCAD/EMTDC. Effectiveness of the proposed control system is illustrated using real wind speed data in various operating conditions.

  7. Dynamic Modeling and Very Short-term Prediction of Wind Power Output Using Box-Cox Transformation

    Science.gov (United States)

    Urata, Kengo; Inoue, Masaki; Murayama, Dai; Adachi, Shuichi

    2016-09-01

    We propose a statistical modeling method of wind power output for very short-term prediction. The modeling method with a nonlinear model has cascade structure composed of two parts. One is a linear dynamic part that is driven by a Gaussian white noise and described by an autoregressive model. The other is a nonlinear static part that is driven by the output of the linear part. This nonlinear part is designed for output distribution matching: we shape the distribution of the model output to match with that of the wind power output. The constructed model is utilized for one-step ahead prediction of the wind power output. Furthermore, we study the relation between the prediction accuracy and the prediction horizon.

  8. Predicting Power Output of Upper Body using the OMNI-RES Scale

    Directory of Open Access Journals (Sweden)

    Bautista Iker J.

    2014-12-01

    Full Text Available The main aim of this study was to determine the optimal training zone for maximum power output. This was to be achieved through estimating mean bar velocity of the concentric phase of a bench press using a prediction equation. The values for the prediction equation would be obtained using OMNI-RES scale values of different loads of the bench press exercise. Sixty males ( voluntarily participated in the study and were tested using an incremental protocol on a Smith machine to determine one repetition maximum (1RM in the bench press exercise. A linear regression analysis produced a strong correlation (r = -0.94 between rating of perceived exertion (RPE and mean bar velocity (Velmean. The Pearson correlation analysis between real power output (PotReal and estimated power (PotEst showed a strong correlation coefficient of r = 0.77, significant at a level of p = 0.01. Therefore, the OMNI-RES scale can be used to predict Velmean in the bench press exercise to control the intensity of the exercise. The positive relationship between PotReal and PotEst allowed for the identification of a maximum power-training zone.

  9. Impact of CDMA wireless phone power output and puncture rate on hearing aid interference levels.

    Science.gov (United States)

    Fry, T L; Schlegel, R E; Grant, H

    2000-01-01

    Interference between digital wireless phones and hearing aids occurs when the radiofrequency bursts from the phone transmission are demodulated by the hearing aid amplifier. The amplified interference signal is heard as a "buzz" or "static" by the hearing aid wearer. Most research and standards development activity has focused on worst-case scenarios with the phone operating at its maximum power. Since this power level is often not typical in urban and suburban settings, it is of value to determine the impact of lower power levels on the overall level of audible interference. Using a frequency analyzer, and several hearings aids and code division multiple access (CDMA) phones, the audio frequency spectrum of interference was recorded for each phone-aid combination and for a range of power levels producing from no interference to maximum interference. As phone power is increased, the interference signal becomes distinguishable from the ambient noise level and a linear response region is observed in which a specified increase in power output results in a proportional increase in the overall input referenced interference level (OIRIL). As power is increased beyond the linear region, the hearing aid enters a saturation region where an additional power increase results in a reduction or no increase in the OIRIL. The numeric differences in interference documented in this study were used in conjunction with the results of a previous study by the authors to determine the impact of reduced power on speech intelligibility and annoyance. The amount of improvement for a given power reduction depends on the radiofrequency immunity of the hearing aid and is substantial for hearing aids with poor immunity. For high-immunity aids, the level of audible interference remains low even at high phone power levels.

  10. Lack of maintenance of shortwave diathermy equipment has a negative impact on power output.

    Science.gov (United States)

    Guirro, Rinaldo Roberto de Jesus; Guirro, Elaine Caldeira de Oliveira; Alves de Sousa, Natanael Teixeira

    2014-04-01

    Although shortwave diathermy has been widely used by physiotherapists, there are a few studies assessing the performance of the equipment in use. The aim of the present study was to evaluate the procedures adopted by physiotherapists as users of shortwave diathermy continuous (CSWD), as well as to measure the power output and frequency of CSWD equipment. [Subjects and Methods] Twenty-three physical therapists were interviewed and 23 CSWD equipment were evaluated. Admeasurement was carried out by using a standard phantom to simulate the electrode-skin distance, which ranged from 0.5 to 3.0 cm. Data analysis was performed by using descriptive statistics, ANOVA, and a post-hoc Tukey's test or Pearson's correlation coefficient. [Results] The questionnaires showed that 48% of the interviewees use the correct electrode-skin distance, 70% use a single electrical outlet, and 35% use a grounded electrical outlet, and that 48% of the physiotherapy tables and 61% of the plinths were made of wood. However, only 13% of the interviewees perform yearly preventive maintenance. The highest power (95.56 W) was achieved at electrode-skin distances ranging from 1.0 to 1.5 cm, with distances of 2.5 cm and 3.0 cm being null in four and eight equipment, respectively. There was a negative correlation between power output and electrode-skin distance as well as between power output and purchase date. [Conclusion] The physiotherapists involved in this study had inadequate knowledge about the correct use of CSWD equipment, which may adversely affect its performance and patient safety.

  11. Output Power Leveling of Wind Turbine Generator by EDLC Energy Storage System

    Science.gov (United States)

    Kinjyo, Tatsuto; Senjyu, Tomonobu; Uezato, Katsumi; Fujita, Hideki

    The increased renewable energy utilization, especially photovoltaic panels using solar energy or wind turbine generators (WTGs) using wind energy, has been expected in recent years from view point of CO2 gas emission reduction and environmental conservation. However, the generated power is always fluctuating because the WTGs are driven by fluctuating wind. Therefore, an energy storage system should be installed to compensate these fluctuating elements. The energy capacitor system (ECS) which combined the electric double-layer capacitor (EDLC) and the electronic circuits are now under development. In this paper, control system configuration for active and reactive output power simultaneous control and the bi-directional inverter using current source EDLC are proposed. Moreover, we discusse control methods required in generating-power leveling for WTGs, and show the effectiveness of the proposed system through simulations.

  12. Effects of superpositions of quantum states on quantum isoenergetic cycles: Efficiency and maximum power output

    Science.gov (United States)

    Niu, X. Y.; Huang, X. L.; Shang, Y. F.; Wang, X. Y.

    2015-04-01

    Superposition principle plays a crucial role in quantum mechanics, thus its effects on thermodynamics is an interesting topic. Here, the effects of superpositions of quantum states on isoenergetic cycle are studied. We find superposition can improve the heat engine efficiency and release the positive work condition in general case. In the finite time process, we find the efficiency at maximum power output in superposition case is lower than the nonsuperposition case. This efficiency depends on one index of the energy spectrum of the working substance. This result does not mean the superposition discourages the heat engine performance. For fixed efficiency or fixed power, the superposition improves the power or efficiency respectively. These results show how quantum mechanical properties affect the thermodynamical cycle.

  13. Robust H∞ output feedback control of bidirectional inductive power transfer systems

    Directory of Open Access Journals (Sweden)

    Swain Akshya

    2017-03-01

    Full Text Available Bidirectional Inductive power transfer (IPT systems behave as high order resonant networks and hence are highly sensitive to changes in system parameters. Traditional PID controllers often fail to maintain satisfactory power regulation in the presence of parametric uncertainties. To overcome these problems, this paper proposes a robust controller which is designed using linear matrix inequality (LMI techniques. The output sensitivity to parametric uncertainty is explored and a linear fractional transformation of the nominal model and its uncertainty is discussed to generate a standard configuration for μ-synthesis and LMI analysis. An H∞ controller is designed based on the structured singular value and LMI feasibility analysis with regard to uncertainties in the primary tuning capacitance, the primary and pickup inductors and the mutual inductance. Robust stability and robust performance of the system is studied through μ-synthesis and LMI feasibility analysis. Simulations and experiments are conducted to verify the power regulation performance of the proposed controller.

  14. In situ measurements of wind and current speed and relationship between output power and turbulence

    Science.gov (United States)

    Duran Medina, Olmo; Schmitt, François G.; Sentchev, Alexei; Calif, Rudy

    2015-04-01

    In a context of energy transition, wind and tidal energy are sources of clean energy with the potential of partially satisfying the growing demand. The main problem of this type of energy, and other types of renewable energy remains the discontinuity of the electric power produced in different scales, inducing large fluctuations also called intermittency. This intermittency of wind and tidal energy is inherent to the turbulent nature of wind and marine currents. We consider this intermittent power production in strong relation with the turbulent intermittency of the resource. The turbulence theory is multifractal energy cascades models, a classic in physics of turbulence. From earlier studies in atmospheric sciences, we learn that wind speed and the aggregate power output are intermittent and multifractal over a wide range of scales [Calif and Schmitt 2014]. We want to extend this study to a marine current turbine and compare the scaling properties for those renewable energy sources. We consider here coupling between simultaneous velocity time series and output power from a wind turbine and a marine current turbine. Wind turbine data were obtained from Denmark and marine current data from Western Scheldt, Belgium where a prototype of a vertical and horizontal marine current turbines are tested. After an estimation of their Fourier density power spectra, we study their scaling properties in Kolmogorov's theory and the framework of fully developed turbulence. Hence, we employ a Hilbert-based methodology, namely arbitrary-order Hilbert spectral analysis [Calif et al. 2013a, 2013b] to characterize the intermittent property of the wind and marine current velocity in order to characterize the intermittent nature of the fluid. This method is used in order to obtain the spectrum and the corresponding power law for non-linear and non-stationary time series. The goal is to study the non-linear transfer characteristics in a multi-scale and multi-intensity framework.

  15. Comparison of power output during ergometer and track cycling in adolescent cyclists.

    Science.gov (United States)

    Nimmerichter, Alfred; Williams, Craig A

    2015-04-01

    The aim of this study is to establish the level of agreement between test performance of young elite cyclists in a laboratory and a track field-based trial. Fourteen adolescent cyclists (age: 14.8 ± 1.1 years; (Equation is included in full-text article.): 63.5 ± 5.6 ml·min(-1)·kg(-1)) performed 3 tests of 10 seconds, 1 minute, and 3 minutes on an air-braked ergometer (Wattbike) and on a 250-m track using their own bikes mounted with mobile power meters (SRM). The agreement between the maximum and mean power output (Pmax and Pmean) measured on the Wattbike and SRM was assessed with the 95% limits of agreement (LoA). Power output was strongly correlated between Wattbike and SRM for all tests (r = 0.94-0.96; p track cycling during all tests. The bias and 95% LoA were 76 ± 78 W (8.8 ± 9.5%; p = 0.003, d = 0.38) for Pmax10s and 82 ± 55 W (10.9 ± 7.9%; p track field-based test using a mobile ergometer. These results might be attributed to the technical ability of the riders and their experience to optimize gearing and cadence to maximize performance. Prediction of field-based testing on the track from laboratory tests should be used with caution.

  16. Comparing short-term complex and compound training programs on vertical jump height and power output.

    Science.gov (United States)

    Mihalik, Jason P; Libby, Jeremiah J; Battaglini, Claudio L; McMurray, Robert G

    2008-01-01

    The purpose of this study was to determine whether there were differences in vertical jump height and lower body power production gains between complex and compound training programs. A secondary purpose was to determine whether differences in gains were observed at a faster rate between complex and compound training programs. Thirty-one college-aged club volleyball players (11 men and 20 women) were assigned into either a complex training group or a compound training group based on gender and pre-training performance measures. Both groups trained twice per week for 4 weeks. Work was equated between the 2 groups. Complex training alternated between resistance and plyometric exercises on each training day; whereas, compound training consisted of resistance training on one day and plyometric training on the other. Our analyses showed significant improvements in vertical jump height in both training groups after only 3 weeks of training (P vertical jump height increased by approximately 5% and 9% in the complex and compound training groups, respectively. However, neither group improved significantly better than the other, nor did either group experience faster gains in vertical leap or power output. The results of this study suggest that performing a minimum of 3 weeks of either complex or compound training is effective for improving vertical jump height and power output; thus, coaches should choose the program which best suits their training schedules.

  17. Techniques for increasing output power from mode-locked semiconductor lasers

    Energy Technology Data Exchange (ETDEWEB)

    Mar, A.; Vawter, G.A.

    1996-02-01

    Mode-locked semiconductor lasers have drawn considerable attention as compact, reliable, and relatively inexpensive sources of short optical pulses. Advances in the design of such lasers have resulted in vast improvements in pulsewidth and noise performance, at a very wide range of repetition rates. An attractive application for these lasers would be to serve as alternatives for large benchtop laser systems such as dye lasers and solid-state lasers. However, mode-locked semiconductor lasers have not yet approached the performance of such systems in terms of output power. Different techniques for overcoming the problem of low output power from mode-locked semiconductor lasers will be discussed. Flared and arrayed lasers have been used successfully to increase the pulse saturation energy limit by increasing the gain cross section. Further improvements have been achieved by use of the MOPA configuration, which utilizes a flared semiconductor amplifier s amplify pulses to energies of 120 pJ and peak powers of nearly 30W.

  18. The new automotive 42V PowerNet. Preparing for mass production

    Energy Technology Data Exchange (ETDEWEB)

    Graf, A. (ed.)

    2001-07-01

    A number of international auto makers have set themselves the target of getting an automobile with a dual 12V/42V PowerNet into mass production by the year 2005. Reports on practical experience of current projects at leading international auto makers and suppliers allow the reader to get a picture of the status of introduction of the 42V PowerNet and of the problems associated with translating development work into mass production, providing them with an idea of the opportunities for structuring their own company or organizing company activities. The book gives an overview of the problems of introducing the 42V PowerNet into automotive engineering. The basic question here is not 'Why 42V?' but rather 'How can a 42V system be introduced into mass production alongside an existing 12V system?''. It provides information from the standpoint of the engineer and the businessman on: The problems of introduction as seen by the auto maker - Proposed solutions to detailed problems such as short circuits and sparking-System reviews, such as Intelligent Power Management - Suggestions for individual components, such as individual semiconductors - Suggested solutions involving new materials - Solution variants and verification by simulation. (orig.)

  19. Zinc oxide integrated area efficient high output low power wavy channel thin film transistor

    KAUST Repository

    Hanna, Amir

    2013-11-26

    We report an atomic layer deposition based zinc oxide channel material integrated thin film transistor using wavy channel architecture allowing expansion of the transistor width in the vertical direction using the fin type features. The experimental devices show area efficiency, higher normalized output current, and relatively lower power consumption compared to the planar architecture. This performance gain is attributed to the increased device width and an enhanced applied electric field due to the architecture when compared to a back gated planar device with the same process conditions.

  20. The Influence of Serial Carbohydrate Mouth Rinsing on Power Output during a Cycle Sprint.

    Science.gov (United States)

    Phillips, Shaun M; Findlay, Scott; Kavaliauskas, Mykolas; Grant, Marie Clare

    2014-05-01

    The objective of the study was to investigate the influence of serial administration of a carbohydrate (CHO) mouth rinse on performance, metabolic and perceptual responses during a cycle sprint. Twelve physically active males (mean (± SD) age: 23.1 (3.0) years, height: 1.83 (0.07) m, body mass (BM): 86.3 (13.5) kg) completed the following mouth rinse trials in a randomized, counterbalanced, double-blind fashion; 1. 8 x 5 second rinses with a 25 ml CHO (6% w/v maltodextrin) solution, 2. 8 x 5 second rinses with a 25 ml placebo (PLA) solution. Following mouth rinse administration, participants completed a 30 second sprint on a cycle ergometer against a 0.075 g·kg(-1) BM resistance. Eight participants achieved a greater peak power output (PPO) in the CHO trial, resulting in a significantly greater PPO compared with PLA (13.51 ± 2.19 vs. 13.20 ± 2.14 W·kg(-1), p 0.05). No significant between-trials difference was reported for fatigue index, perceived exertion, arousal and nausea levels, or blood lactate and glucose concentrations. Serial administration of a CHO mouth rinse may significantly improve PPO during a cycle sprint. This improvement appears confined to the first 5 seconds of the sprint, and may come at a greater relative cost for the remainder of the sprint. Key pointsThe paper demonstrates that repeated administration of a carbohydrate mouth rinse can significantly improve peak power output during a single 30 second cycle sprint.The ergogenic effect of the carbohydrate mouth rinse may relate to the duration of exposure of the oral cavity to the mouth rinse, and associated greater stimulation of oral carbohydrate receptors.The significant increase in peak power output with the carbohydrate mouth rinse may come at a relative cost for the remainder of the sprint, evidenced by non-significantly lower mean power output and a greater fatigue index in the carbohydrate vs. placebo trial.Serial administration of a carbohydrate mouth rinse may be beneficial for

  1. Measuring cutaneous thermal nociception in group-housed pigs using laser technique-Effects of laser power output

    DEFF Research Database (Denmark)

    Herskin, Mette S; Ladevig, Jan; Arendt-Nielsen, Lars

    2009-01-01

    nociceptive stimulation from a computer-controlled CO2-laser beam applied to either the caudal part of the metatarsus on the hind legs or the shoulder region of gilts. In Exp. 1, effects of laser power output (0, 0.5, 1, 1.5 and 2 W) on nociceptive responses toward stimulation on the caudal aspects...... of the metatarsus were examined using 15 gilts kept in one group and tested in individual feeding stalls after feeding. Increasing the power output led to gradually decreasing latency to respond (P ... gilts kept under the same conditions. Again, increasing the power output led to gradually decreasing latency to respond (P 

  2. Methods of increasing net work output of organic Rankine cycles for low-grade waste heat recovery with a detailed analysis using a zeotropic working fluid mixture and scroll expander

    Science.gov (United States)

    Woodland, Brandon Jay

    An organic Rankine cycle (ORC) is a thermodynamic cycle that is well-suited for waste heat recovery. It is generally employed for waste heat with temperatures in the range of 80 °C -- 300 °C. When the application is strictly to convert waste heat into work, thermal efficiency is not recommended as a key performance metric. In such an application, maximization of the net power output should be the objective rather than maximization of the thermal efficiency. Two alternative cycle configurations that can increase the net power produced from a heat source with a given temperature and flow rate are proposed and analyzed. These cycle configurations are 1) an ORC with two-phase flash expansion and 2) an ORC with a zeotropic working fluid mixture (ZRC). A design-stage ORC model is presented for consistent comparison of multiple ORC configurations. The finite capacity of the heat source and heat sink fluids is a key consideration in this model. Of all working fluids studied for the baseline ORC, R134a and R245fa yield the highest net power output from a given heat source. Results of the design-stage model indicate that the ORC with two-phase flash expansion offers the most improvement over the baseline ORC. However, the level of improvement that could be achieved in practice is highly uncertain due to the requirement of highly efficient two-phase expansion. The ZRC shows improvement over the baseline as long as the condenser fan power requirement is not negligible. At the highest estimated condenser fan power, the ZRC shows the most improvement, while the ORC with flash expansion is no longer beneficial. The ZRC was selected for detailed study because it does not require two-phase expansion. An experimental test rig was used to evaluate baseline ORC performance with R134a and with R245fa. The ZRC was tested on the same rig with a mixture of 62.5% R134a and 37.5% R245fa. The tested expander is a minimally-modified, of-the-shelf automotive scroll compressor. The high

  3. Test-retest reliability of the net joint power transferred by the lower limbs during walking in healthy men

    Directory of Open Access Journals (Sweden)

    Daniel Jandačka

    2013-09-01

    Full Text Available OBJECTIVE: To determine the reliability of the measurement of net joint power during repeated gait measurements within one day and between two different measurement days. METHODS: Thirty able-bodied men who underwent repeated gait measurements within a day and between days participated in this research. An acceptable trial was one in which the participant complied with the range of walking speed 1.45 m/s ± 5%. Three-dimensional angles, angular velocities, net moments of force and net power for the ankle, knee and hip joints were determined using external passive reflective markers, an 8-camera motion analysis system and two force plates. RESULTS: This study presents the patterns of the net power in the fundamental joints of the lower limbs in young healthy men at standard gait velocity. Intraclass correlation coefficients for net joint power measure reached values in the range of .70 to .89 on the first day, from .69 to .86 on the second day, and from .67 to .83 in total. CONCLUSION: The reliability of the measurement of the peak net joint power within one day and between the two measurement days was evaluated as satisfactory. The study provides the value of minimal detectable change for the peak net power of the lower limb in the sagittal plane during gait. The net joint power appears to be a reliable measure and could be used in practice.

  4. Power converter using near-load output capacitance, direct inductor contact, and/or remote current sense

    Science.gov (United States)

    Coteus, Paul W.; Ferencz, Andrew; Hall, Shawn A.; Takken, Todd E.; Tian, Shurong; Zhang, Xin

    2017-11-28

    An apparatus includes a first circuit board including first components including a load, and a second circuit board including second components including switching power devices and an output inductor. Ground and output voltage contacts between the circuit boards are made through soldered or connectorized interfaces. Certain components on the first circuit board and certain components, including the output inductor, on the second circuit board act as a DC-DC voltage converter for the load. An output capacitance for the conversion is on the first circuit board with no board-to-board interface between the output capacitance and the load. The inductance of the board-to-board interface functions as part of the output inductor's inductance and not as a parasitic inductance. Sense components for sensing current through the output inductor are located on the first circuit board. Parasitic inductance of the board-to-board interface has less effect on a sense signal provided to a controller.

  5. Determining the Frequency for Load-Independent Output Current in Three-Coil Wireless Power Transfer System

    Directory of Open Access Journals (Sweden)

    Longzhao Sun

    2015-09-01

    Full Text Available Conditions for load-independent output voltage or current in two-coil wireless power transfer (WPT systems have been studied. However, analysis of load-independent output current in three-coil WPT system is still lacking in previous studies. This paper investigates the output current characteristics of a three-coil WPT system against load variations, and determines the operating frequency to achieve a constant output current. First, a three-coil WPT system is modeled by circuit theory, and the analytical expression of the root-mean-square of the output current is derived. By substituting the coupling coefficients, the quality factor, and the resonant frequency of each coil, we propose a method of calculating the frequency for load-independent output current in a three-coil WPT system, which indicates that there are two frequencies that can achieve load-independent output current. Experiments are conducted to validate these analytical results.

  6. Power converter using near-load output capacitance, direct inductor contact, and/or remote current sense

    Energy Technology Data Exchange (ETDEWEB)

    Coteus, Paul W.; Ferencz, Andrew; Hall, Shawn A.; Takken, Todd E.; Tian, Shurong; Zhang, Xin

    2017-11-28

    An apparatus includes a first circuit board including first components including a load, and a second circuit board including second components including switching power devices and an output inductor. Ground and output voltage contacts between the circuit boards are made through soldered or connectorized interfaces. Certain components on the first circuit board and certain components, including the output inductor, on the second circuit board act as a DC-DC voltage converter for the load. An output capacitance for the conversion is on the first circuit board with no board-to-board interface between the output capacitance and the load. The inductance of the board-to-board interface functions as part of the output inductor's inductance and not as a parasitic inductance. Sense components for sensing current through the output inductor are located on the first circuit board. Parasitic inductance of the board-to-board interface has less effect on a sense signal provided to a controller.

  7. Dynamic Output Feedback Power-Level Control for the MHTGR Based On Iterative Damping Assignment

    Directory of Open Access Journals (Sweden)

    Zhe Dong

    2012-06-01

    Full Text Available Because of its strong inherent safety features and high outlet temperature, the modular high temperature gas-cooled nuclear reactor (MHTGR is already seen as the central part of the next generation of nuclear plants. Such power plants are being considered for industrial applications with a wide range of power levels, and thus power-level control is an important technique for their efficient and stable operation. Stimulated by the high regulation performance provided by nonlinear controllers, a novel dynamic output-feedback nonlinear power-level regulator is developed in this paper based on the technique of iterative damping assignment (IDA. This control strategy can provide the L2 disturbance attenuation performance under modeling uncertainty or exterior disturbance, and can also guarantee the globally asymptotic closed-loop stability without uncertainty and disturbance. This newly built control strategy is then applied to the power-level regulation of the HTR-PM plant, and numerical simulation results show both the feasibility and high performance of this newly-built control strategy. Furthermore, the relationship between the values of the parameters and the performance of this controller is not only illustrated numerically but also analyzed theoretically.

  8. Updated Eastern Interconnect Wind Power Output and Forecasts for ERGIS: July 2012

    Energy Technology Data Exchange (ETDEWEB)

    Pennock, K.

    2012-10-01

    AWS Truepower, LLC (AWST) was retained by the National Renewable Energy Laboratory (NREL) to update wind resource, plant output, and wind power forecasts originally produced by the Eastern Wind Integration and Transmission Study (EWITS). The new data set was to incorporate AWST's updated 200-m wind speed map, additional tall towers that were not included in the original study, and new turbine power curves. Additionally, a primary objective of this new study was to employ new data synthesis techniques developed for the PJM Renewable Integration Study (PRIS) to eliminate diurnal discontinuities resulting from the assimilation of observations into mesoscale model runs. The updated data set covers the same geographic area, 10-minute time resolution, and 2004?2006 study period for the same onshore and offshore (Great Lakes and Atlantic coast) sites as the original EWITS data set.

  9. Generalized design of high performance shunt active power filter with output LCL filter

    DEFF Research Database (Denmark)

    Tang, Yi; Loh, Poh Chiang; Wang, Peng

    2012-01-01

    filter, which in turn minimizes the possibility of overmodulation, particularly for cases where high modulation index is desired. These advantages, together with overall system stability, are guaranteed only through proper consideration of critical design and control issues, like the selection of LCL...... parameters, interactions between resonance damping and harmonic compensation, bandwidth design of the closed-loop system, and active damping implementation with fewer current sensors. These described design concerns, together with their generalized design procedure, are applied to an analytical example......This paper concentrates on the design, control, and implementation of an LCL-filter-based shunt active power filter (SAPF), which can effectively compensate for harmonic currents produced by nonlinear loads in a three-phase three-wire power system. With an LCL filter added at its output...

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

    NARCIS (Netherlands)

    Ma, H.; van der Zee, Ronan A.R.; Nauta, Bram

    2015-01-01

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

  11. Advisory system for the diagnosis of lost electric output in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Gyunyoung Heo; Soon Heung Chang [Korea Advanced Institute of Science and Technology, Daejeon (Korea). Dept. of Nuclear and Quantum Engineering; Seong Soo Choi [Atomic Creative Technology, Daejeon (Korea); Gwang Hee Choi; Moon Hak Jee [Korea Power Electric Research Institute, Daejeon (Korea)

    2005-11-15

    The enhancement of efficiency is world-wide trend to survive under intense competition. In recent years, the efficiency in the power industry is also one of the important topics. In case of nuclear power plants(NPPs), the period and quality of maintenance is an especially important factor to increase efficiency as well as availability. Therefore, the accurate identification of the root causes for lost electric output is indispensable to decrease the period and to increase quality of maintenance. The diagnosis in NPPs is more difficult because the turbine cycle of NPPs uses saturated steam as working fluid. In this study, authors tried to develop an advisory system with the quantitative diagnosis model consisting of statistical regression analysis and Bayesian network for the support of nuclear turbine cycle diagnosis. The proposed advisory system includes the knowledge-base representing the normal or abnormal behavior of nuclear turbine cycle. Authors selected 34 boundary parameters that independently influence to electric output. Using the data collected from a turbine cycle simulation tool, the statistical correlation between a boundary parameter and electric output was analyzed. To give the belief, that is the degree of accuracy, of root causes under various uncertainty sources, belief module for the boundary parameters is developed on the basis of Bayesian network. In conclusion, this diagnosis module can give the impacts of the root causes and their uncertainty simultaneously, so we call it 'Lost MW calculator'. After the validation using simulated data and actual performance data, this module was installed in Younggwang NPP units 3 and 4 in Korea. (author)

  12. Power output of microbial fuel cell emphasizing interaction of anodic binder with bacteria

    Science.gov (United States)

    Li, Hongying; Liao, Bo; Xiong, Juan; Zhou, Xingwang; Zhi, Huozhen; Liu, Xiang; Li, Xiaoping; Li, Weishan

    2018-03-01

    Electrochemically active biofilm is necessary for the electron transfer between bacteria and anodic electrode in microbial fuel cells and selecting the type of anodic electrode material that favours formation of electrochemically active biofilm is crucial for the microbial fuel cell operation. We report a new finding that the interaction of anodic binder with bacteria plays more important role than its hydrophilicity for forming an electrochemically active biofilm, which is emphasized by applying poly(bisphenol A-co-epichorohydrin) as an anodic binder of the microbial fuel cell based on carbon nanotubes as anodic electrode and Escherichia coli as bacterium. The physical characterizations and electrochemical measurements demonstrate that poly(bisphenol A-co-epichorohydrin) exhibits a strong interaction with bacteria and thus provides the microbial fuel cell with excellent power density output. The MFC using poly(bisphenol A-co-epichorohydrin) reaches a maximum power density output of 3.8 W m-2. This value is larger than that of the MFCs using polytetrafluoroethylene that has poorer hydrophilicity, or polyvinyl alcohol that has better hydrophilicity but exhibits weaker interaction with bacteria than poly(bisphenol A-co-epichorohydrin).

  13. The role of sense of effort on self-selected cycling power output

    Directory of Open Access Journals (Sweden)

    Ryan James Christian

    2014-03-01

    Full Text Available Purpose: We explored the effects of the sense of effort and accompanying perceptions of peripheral discomfort on self-selected cycle power output under two different inspired O2 fractions.Methods: On separate days, eight trained males cycled for 5 minutes at a constant subjective effort (sense of effort of ‘3’ on a modified Borg CR10 scale, immediately followed by five 4-s progressive submaximal (sense of effort of 4, 5, 6, 7 and 8; 40 s between bouts and two 4-s maximal (sense of effort of 10; 3 min between bouts bouts under normoxia (NM: fraction of inspired O2 [FiO2] 0.21 and hypoxia (HY: [FiO2] 0.13. Physiological (Heart Rate, arterial oxygen saturation (SpO2 and quadriceps Root Mean Square (RMS electromyographical activity and perceptual responses (overall peripheral discomfort, difficulty breathing and limb discomfort were recorded.Results: Power output and normalized quadriceps RMS activity were not different between conditions during any exercise bout (p > 0.05 and remained unchanged across time during the constant-effort cycling. SpO2 was lower, while heart rate and ratings of perceived difficulty breathing were higher under HY, compared to NM, at all time points (p

  14. Physiology, power output, and racing strategy of a Race Across America finisher.

    Science.gov (United States)

    Schumacher, Yorck Olaf; Ahlgrim, Christoph; Prettin, Stephan; Pottgiesser, Torben

    2011-05-01

    The Race Across America, a 4800-km nonstop cycle race, is one of the most demanding endurance sports events. We display the racing strategy, power output, HR, hormonal levels, and inflammatory markers of an athlete before and during the race, which he completed in 10 d 23 h.The athlete showed physiological characteristics of a well-trained (nonelite) cyclist (V˙O2peak=63 mL·min·kg, heart volume=11.3 mL·kg). The race was mainly performed at low intensities (mean ± SD: power output=141 ± 76 W, HR=117 ± 14 bpm). During the race, testosterone levels dropped initially by 30-40% and returned to baseline toward the end. Cortisol remained elevated throughout (+75%-90% compared with baseline). Markers of inflammation (C-reactive protein), dehydration, and protein catabolism (albumin) were not affected. The athlete used a race strategy with regular sleeping breaks (total rest=91 h, 45 h of sleep).Contrasting conventional racing strategies for the Race Across America, which aim at minimizing sleep and maximizing ride time, our case demonstrates that by emphasizing regular recovery and sleep, such alternative strategy might lead an equally successful race result. © 2011 by the American College of Sports Medicine

  15. Design of a pulsewidth-modulated resonant converter for a high-output-voltage power supply

    Science.gov (United States)

    Turnbull, Fred G.; Tompkins, Russell E.

    1987-12-01

    The design and fabrication of a parallel resonant converter circuit and a high-frequency step-up transformer used to supply an adjustable dc voltage to a load is described. The 500-W system is operated from 115/230 V single-phase 60Hz power, which is rectified and filtered to form a 310-V dc link. A two-transistor half-bridge circuit operating at a fixed frequency above the ciruits resonant frequency converts the dc voltage to an ac voltage at approximately 20 kHx. This high-frequency voltage is transformed with a low-capacitance oil-impregnated ferrite transformer. The output voltage is rectified to form a dc voltage with a maximum value of 90-kV peak. The output voltage is adjustable using pulsewidth modulation of the conduction time of the two transistors in the power circuit. The energy stored in the resonant circuit provides a sinusoidal transformer voltage at fixed frequency over a wide range of control. The system is provided with a closed-loop peak-voltage regulator and an on-off capability from the control electronics. The transformer is designed for a specific value of inductance and capacitance to operate at the desired resonant frequency and characteristic impedance.

  16. Progress in increasing the maximum achievable output power of broad area diode lasers

    Science.gov (United States)

    Crump, P.; Wenzel, H.; Erbert, G.; Tränkle, G.

    2012-03-01

    High power broad area diode lasers provide the optical energy for all high performance laser systems, either directly or as pump sources for solid-state lasers. Continuous improvement is required in the peak achievable output power of these diode laser devices in order to enable performance improvements in full laser systems. In recent years, device technology has advanced to the point where the main limit to optical power is no longer device failure, but is instead power saturation due to various physical effects within the semiconductor device itself. For example, the combination of large optical cavity designs with advanced facet passivation means that facet failure is no longer the dominant limiting factor. Increases in the optical power therefore require firstly a clear identification of the limiting mechanisms, followed by design changes and material improvements to address these. Recent theoretical and experimental diagnostic studies at the Ferdinand-Braun-Institut have helped trace the saturation effects to three main effects: gain saturation, longitudinal-holeburning and current driven carrier leakage. Design changes based on these studies have enabled increases in the achievable emitted power density from broad area lasers. Recent experimental examples include ~100W from 100μm stripes under short-pulsed conditions, > 30W from 100μm stripes under quasi-continuous wave conditions and > 10W from 30μm stripes under continuous wave conditions. An overview of the results of the diagnostic studies performed at the FBH will be presented, and the design changes necessary to address the observed power saturation will be discussed.

  17. A Simple MPPT Algorithm for Novel PV Power Generation System by High Output Voltage DC-DC Boost Converter

    DEFF Research Database (Denmark)

    Sanjeevikumar, Padmanaban; Grandi, Gabriele; Wheeler, Patrick

    2015-01-01

    substantially improves the high output-voltage by a simple MPPT closed loop proportional-integral (P-I) controller, and requires only two sensor for feedback needs. The complete numerical model of the converter circuit along with PV MPPT algorithm is developed in numerical simulation (Matlab/Simulink) software......This paper presents the novel topology of Photo Voltaic (PV) power generation system with simple Maximum Power Point Tracking (MPPT) algorithm in voltage operating mode. Power circuit consists of high output voltage DC-DC boost converter which maximizes the output of PV panel. Usually traditional...... DC-DC boost converters are used for such application, but they are not the most suitable solution due to output limitation, lower efficiency and require more sensors with complex control algorithm. Further on, the effects of parasitic elements are suppressed, as well as the power transfer efficiency...

  18. Probabilistic Physics-Based Risk Tools Used to Analyze the International Space Station Electrical Power System Output

    Science.gov (United States)

    Patel, Bhogila M.; Hoge, Peter A.; Nagpal, Vinod K.; Hojnicki, Jeffrey S.; Rusick, Jeffrey J.

    2004-01-01

    This paper describes the methods employed to apply probabilistic modeling techniques to the International Space Station (ISS) power system. These techniques were used to quantify the probabilistic variation in the power output, also called the response variable, due to variations (uncertainties) associated with knowledge of the influencing factors called the random variables. These uncertainties can be due to unknown environmental conditions, variation in the performance of electrical power system components or sensor tolerances. Uncertainties in these variables, cause corresponding variations in the power output, but the magnitude of that effect varies with the ISS operating conditions, e.g. whether or not the solar panels are actively tracking the sun. Therefore, it is important to quantify the influence of these uncertainties on the power output for optimizing the power available for experiments.

  19. The dynamics of distance, velocity and acceleration of power output in the 30-s Wingate Anaerobic Test.

    Science.gov (United States)

    Bell, W; Cobner, D

    2011-02-01

    The purpose of the present study was to analyse the dynamics of distance, velocity and acceleration of the 30-s Wingate Anaerobic Test. Participants were 53 young adult Rugby Union football players of mean age 21.6±2.5 yr, 180.5±7.2 cm height and 89.3±12.7 kg body mass. Measurements of power were obtained using a friction-belt cycle ergometer (Monark 864, Varberg, Sweden). Individual data were aligned according to peak power output, which resulted in a mean value of 1 216±256 W, compared with one of 1 180±256 W when calculated cross-sectionally (pMathcad. Distance, velocity and acceleration curves were plotted simultaneously at 1 s intervals before and after peak power output (-4 s to +28 s). The initial rise of the distance curve was the result of a general trend in decreasing positive velocities as far as peak power output, followed thereafter by a gradual deterioration of power, the result of negative velocities from peak power output to +28 s peak power output. The initial values of the acceleration curve showed a fluctuating decelerating trend of negative values to peak power output; subsequently all values remained positive running along the zero acceleration time axis. Coefficients of correlation between peak power output and power values at -1 s to -3 s were 0.80, 0.65 and 0.63 respectively (p<0.001). The relationship between velocity and acceleration was - 0.968 (p<0.01). © Georg Thieme Verlag KG Stuttgart · New York.

  20. Changes of maximal muscle torque and maximal power output of lower extremities in male judoists during training

    OpenAIRE

    Buśko, Krzysztof; Nowak, Anna

    2008-01-01

    Purpose. The aim of the study was to follow changes of the maximal muscle torque and maximal power output of lower extremities in male judoists during pre-competition training (PCT). The original hypothesis assumed that different training loads would cause changes of the maximal muscle torque and maximal power output of legs in male judoists during pre-competition training, but not changes of the topography of the maximal muscle torque in all muscle groups. Basic procedures. The study sample ...

  1. Optimal Allocation of Heat Exchanger Inventory Associated with Fixed Power Output or Fixed Heat Transfer Rate Input

    OpenAIRE

    COSTEA M.; Petrescu, S; K. Le Saos; Michel Feidt

    2010-01-01

    The purpose of this study is to determine the optimal distribution of the heat transfer surface area or conductance among the Stirling engine heat exchangers when the minimum of the total heat transfer surface area of the heat exchangers is sought. The optimization procedure must fulfill one of the following constraints: (1) fixed power output of the engine, (2) fixed heat transfer rate available at the source, or (3) fixed power output and heat transfer rate at the source. Internal and exter...

  2. The acute effect of lower-body training on average power output measured by loaded half-squat jump exercise

    OpenAIRE

    Matúš Krčmár; Jaromír Šimonek; Ivan Vasiľovský

    2015-01-01

    Background: High muscular power output is required in many athletic endeavors in order for success to be achieved. In the scientific community postactivation potentiation and its effect on performance are often discussed. There are many studies where the effect of resistance exercise on motor performance (such as vertical jump performance and running speed) has been investigated but only a few of them studied power output. Objective: The purpose of this study was to determine the acute ...

  3. The Effects of Load on Peak Power Output Fatigue During the Bench Throw.

    Science.gov (United States)

    Boffey, David; Sokmen, Bulent; Sollanek, Kurt; Boda, Wanda; Winter, Steven

    2017-11-14

    The ability to create power is an important variable for athletic success. No study to date has compared peak power output (PPO) fatigue across multiple sets and with different loads with the bench throw. This study aimed to begin the process of establishing empirical upper body power training guidelines for moderately strong athletes by determining how load (30%, 45%, 60% 1RM) affects PPO (Watts) dropoff during 3 sets of 10 repetitions of the bench throw. 10 resistance-trained male volunteers ((mean ± SD): age 20.58 ± 1.36 years, height 176.05 ± 9.09 cm., weight 78.65 ± 9.93 kg, bench press 1RM 99.79 ±18.52 kg) performed 3 sets of 10 repetitions of the bench throw with one of the three loads during 3 weekly sessions. A Humac 360 device collected concentric phase PPO data during each repetition. The data were analyzed using one-way (Treatment) and two-way (Treatment × Time) repeated measures ANOVA. A significant decrease in PPO was observed during repetitions 5-7 at 30%, 3-4 at 45%, and 2-3 at 60% 1RM. Based on the results of this study, coaches who want to maximize power should potentially keep sets of upper body plyometrics within these repetition ranges. The authors recommend that moderately strong athletes perform the bench throw on a Smith machine at 45% or 60% 1RM to produce high PPO over multiple sets.

  4. Functional Strength Training Effects on Knee Flexors and Extensors Power Output in Football Players

    Directory of Open Access Journals (Sweden)

    Izet Radjo

    2016-06-01

    Full Text Available Study aim was to compare and reevaluate effects of additional strength training program in football players after eight week application. Program was design to increase power and strength of knee extensors and flexors using neuromuscular adaptation. In overall, 18 senior level football players completed intervention in preparation period executing program as part of warm up 2-3 times per week. Using t-test for dependent samples statistical significance of the possible change was evaluated in peak torque, total and average work changes measured using Biodex isokinetic dynamometer. All measuring procedures were done for both limbs. Results are suggesting that statistically significant change observed in both limbs for the peak power output and average work load in flexion and extension, respectively. Other research papers are suggesting that increase of power and strength of knee muscles can help in preventing of injurie occurrence. LCA injurie can be prevention when femoral biceps strength is increase. This training modality based on neuromuscular adaptation is noninvasive with good effects in performance increase. Using training loads with body weight intensity is a good way to establish prevention to possible knee injurie with simultaneous power increase, with minimum of chance to reach unwanted overtraining.

  5. WindNet: Improving the impact assessment of wind power projects

    Directory of Open Access Journals (Sweden)

    Christopher R. Jones

    2014-12-01

    Full Text Available Growing international demand for renewable energy has led to rapid growth in the wind power sector and wind farms are becoming an increasingly common feature of landscapes and seascapes in many countries. However, as the most appropriate locations within established markets are taken up, and as wind power penetrates new markets, there is an increasing likelihood that proposed projects will encroach on sensitive landscapes and residential areas. This will present challenges for the industry, particularly due to the impact that public opinion can have upon the outcomes of planning decisions about specific projects. This article introduces the four key dimensions of the WindNet programme, which are helping to elucidate some of the socio-technical debates that will likely shape the future of the wind power sector. The article outlines studies investigating (1 public responses to cumulative landscape and visual impacts, (2 the auditory impact of wind power projects on human health, (3 the science of wind farm design and its implications for planning, and (4 the relevance of the democratic deficit explanation of the so-called "social gap" in wind farm siting. The outcomes of the research being conducted by WindNet stand to help reduce uncertainty within the planning process and assist in providing a more comprehensive and fairer assessment of the possible impacts associated with wind power project development.

  6. Distribution of power output during the cycling stage of a Triathlon World Cup.

    Science.gov (United States)

    Bernard, Thierry; Hausswirth, Christophe; Le Meur, Yann; Bignet, Frank; Dorel, Sylvain; Brisswalter, Jeanick

    2009-06-01

    The aim of this study was to evaluate the power output (PO) during the cycle phase of the Beijing World Cup test event of the Olympic triathlon in China 2008. Ten elite triathletes (5 females, 5 males) performed two laboratory tests: an incremental cycling test during which PO, HR at ventilatory thresholds (VT1 and VT2), and maximal aerobic power (MAP) were assessed, and a brief all-out test to determine maximal anaerobic power output (MAnP). During the cycle part of competition, PO and HR were measured directly with portable device. The amount of time spent below PO at VT1 (zone 1), between PO at VT1 and VT2 (zone 2), between PO at VT2 and MAP (zone 3) and above MAP (zone 4) was analyzed. A significant decrease in PO, speed, and HR values was observed during the race. The distribution of time was 51 +/- 9% for zone 1, 17 +/- 6% for zone 2, 15 +/- 3% for zone 3, and 17 +/- 6% was performed at workloads higher than MAP (zone 4). From HR values, the triathletes spent 27 +/- 12% in zone 1, 26 +/- 8% in zone 2, and 48 +/- 14% above VT2. This study indicates a progressive reduction in speed, PO, and HR, coupled with an increase in variability during the event. The Olympic distance triathlon requires a higher aerobic and anaerobic involvement than constant-workload cycling exercises classically analyzed in laboratory settings (i.e., time trial) or Ironman triathlons. Furthermore, monitoring direct PO could be more suitable to quantify the intensity of a race with pacing strategies than classic HR measurements.

  7. Power Output Stability Research for Harvesting Automobile Exhaust Energy with Heat Capacity Material as Intermediate Medium

    Science.gov (United States)

    Xiao, Longjie; He, Tianming; Mei, Binyu; Wang, Yiping; Wang, Zongsong; Tan, Gangfeng

    2018-01-01

    Automobile exhaust energy thermoelectric utilization can promote energy-saving and emission-reduction. Unexpected urban traffic conditions lead to the hot-end temperature instability of the exhaust pipe-mounted thermoelectric generator (TEG), and influence the TEG power generation efficiency. The heat conduction oil circulation located at the hot-end could smooth the temperature fluctuation, at the expense of larger system size and additional energy supply. This research improves the TEG hot-end temperature stability by installing solid heat capacity material (SHCM) to the area between the outer wall of the exhaust pipe and the TEG, which has the merits of simple structure, light weight and no additional energy consumption. The exhaust temperature and flow rate characteristics with various driving conditions are firstly studied for the target engine. Then the convective heat transfer models of SHCM's hot-end and thermoelectric material's cold-end are established. Meanwhile, SHCM thermal properties' effects on the amplitude and response speed of the TEG hot-end temperature are studied. The candidate SHCM with the characteristics of low thermal resistance and high heat capacity is determined. And the heat transfer model going through from TEG's hot-end to the cold-end is established. The results show that the SHCM significantly improves the TEG hot-end temperature stability but slightly reduces the average power output. When the engine working conditions change a lot, the SHCM's improvement on the TEG hot-end temperature stability is more significant, but the reduction of the average power output becomes more remarkable.

  8. Flexible, transparent and exceptionally high power output nanogenerators based on ultrathin ZnO nanoflakes

    Science.gov (United States)

    van Ngoc, Huynh; Kang, Dae Joon

    2016-02-01

    Novel nanogenerator structures composed of ZnO nanoflakes of less than 10 nm thickness were fabricated using a novel method involving a facile synthetic route and a rational design. The fabricated nanogenerators exhibited a short-circuit current density of 67 μA cm-2, a peak-to-peak open-circuit voltage of 110 V, and an overall output power density exceeding 1.2 mW cm-2, and to the best of our knowledge, these are the best values that have been reported so far in the literature on ZnO-based nanogenerators. We demonstrated that our nanogenerator design could instantaneously power 20 commercial green light-emitting diodes without any additional energy storage processes. Both the facile synthetic route for the ZnO nanoflakes and the straightforward device fabrication process present great scaling potential in order to power mobile and personal electronics that can be used in smart wearable systems, transparent and flexible devices, implantable telemetric energy receivers, electronic emergency equipment, and other self-powered nano/micro devices.Novel nanogenerator structures composed of ZnO nanoflakes of less than 10 nm thickness were fabricated using a novel method involving a facile synthetic route and a rational design. The fabricated nanogenerators exhibited a short-circuit current density of 67 μA cm-2, a peak-to-peak open-circuit voltage of 110 V, and an overall output power density exceeding 1.2 mW cm-2, and to the best of our knowledge, these are the best values that have been reported so far in the literature on ZnO-based nanogenerators. We demonstrated that our nanogenerator design could instantaneously power 20 commercial green light-emitting diodes without any additional energy storage processes. Both the facile synthetic route for the ZnO nanoflakes and the straightforward device fabrication process present great scaling potential in order to power mobile and personal electronics that can be used in smart wearable systems, transparent and flexible

  9. Suction power output and the inertial cost of rotating the neurocranium to generate suction in fish.

    Science.gov (United States)

    Van Wassenbergh, Sam; Day, Steven W; Hernández, L Patricia; Higham, Timothy E; Skorczewski, Tyler

    2015-05-07

    To expand the buccal cavity, many suction-feeding fishes rely on a considerable contribution from dorsal rotation of the dorsal part of the head including the brains, eyes, and several bones forming the braincase and skull roof (jointly referred to as the neurocranium). As the neurocranium takes up a large part of the total mass of the head, this rotation may incur a considerable inertial cost. If so, this would suggest a significant selective pressure on the kinematics and mass distribution of the neurocranium of suction feeders. Here, an inverse dynamic model is formulated to calculate the instantaneous power required to rotate the neurocranium, approximated by a quarter ellipsoid volume of homogeneous density, as well as to calculate the instantaneous suction power based on intra-oral pressure and head volume quantifications. We applied this model to largemouth bass (Micropterus salmoides) and found that the power required to rotate the neurocranium accounts for only about 4% of the power required to suck water into the mouth. Furthermore, recovery of kinetic energy from the rotating neurocranium converted into suction work may be possible during the phase of neurocranial deceleration. Thus, we suggest that only a negligible proportion of the power output of the feeding muscles is lost as inertial costs in the largemouth bass. Consequently, the feeding performance of piscivorous suction feeders with generalised morphology, comparable to our model species, is not limited by neurocranial motion during head expansion. This suggests that it is thus not likely to be a factor of importance in the evolution of cranial shape and size. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. The Measurement of Maximal (Anaerobic Power Output on a Cycle Ergometer: A Critical Review

    Directory of Open Access Journals (Sweden)

    Tarak Driss

    2013-01-01

    Full Text Available The interests and limits of the different methods and protocols of maximal (anaerobic power ( assessment are reviewed: single all-out tests versus force-velocity tests, isokinetic ergometers versus friction-loaded ergometers, measure of during the acceleration phase or at peak velocity. The effects of training, athletic practice, diet and pharmacological substances upon the production of maximal mechanical power are not discussed in this review mainly focused on the technical (ergometer, crank length, toe clips, methodological (protocols and biological factors (muscle volume, muscle fiber type, age, gender, growth, temperature, chronobiology and fatigue limiting in cycling. Although the validity of the Wingate test is questionable, a large part of the review is dedicated to this test which is currently the all-out cycling test the most often used. The biomechanical characteristics specific of maximal and high speed cycling, the bioenergetics of the all-out cycling exercises and the influence of biochemical factors (acidosis and alkalosis, phosphate ions… are recalled at the beginning of the paper. The basic knowledge concerning the consequences of the force-velocity relationship upon power output, the biomechanics of sub-maximal cycling exercises and the study on the force-velocity relationship in cycling by Dickinson in 1928 are presented in Appendices.

  11. Nanogenerator power output: influence of particle size and crystallinity of BaTiO3

    Science.gov (United States)

    Nutal Schädli, Gian; Büchel, Robert; Pratsinis, Sotiris E.

    2017-07-01

    Lead-free piezoelectric nanogenerators made with BaTiO3 offer an attractive energy harvesting solution towards portable, battery-free medical devices such as self-powered pacemakers. Here, we assembled nanogenerators made of thin, flexible poly(vinylidene fluoride-co-hexafluoropropylene) films containing either polycrystalline BaTiO3 nanoparticles of various sizes or commercial monocrystalline particles of 64 or 278 nm in average diameter. The nanoparticles were prepared by hydrogen-driven flame aerosol technology and had an average diameter of 24-50 nm with an average crystal size of about 10 nm. The rapid cooling during nanoparticle formation facilitated the synthesis of polycrystalline, multi-domain, piezoelectrically active tetragonal BaTiO3 with a high c/a lattice ratio. Using these particles, 2 μm thin polymer nanocomposites were formed, assembled into nanogenerators that exhibited a 1.4 V time-averaged output, almost twice that of the best commercial BaTiO3 particles. That output was maintained stable for over 45 000 cycles with each cycle corresponding to a heartbeat of 60 bpm. The exceptional piezoelectric performance of these nanogenerators is traced to their constituent polycrystalline nanoparticles, having high degree of domain orientation upon poling and exhibiting the flexoelectric effect, polarization induced by a strain gradient.

  12. Efficiency at maximum power output of an irreversible Carnot-like cycle with internally dissipative friction.

    Science.gov (United States)

    Wang, Jianhui; He, Jizhou

    2012-11-01

    We investigate the efficiency at the maximum power output (EMP) of an irreversible Carnot engine performing finite-time cycles between two reservoirs at constant temperatures T(h) and T(c) (friction in two "adiabatic" processes. The EMP is retrieved to be situated between η(C)/2 and η(C)/(2-η(C)), with η(C) = 1-T(c)/T(h) being the Carnot efficiency, whether the internally dissipative friction is considered or not. When dissipations of two "isothermal" and two "adiabatic" processes are symmetric, respectively, and the time allocation between the adiabats and the contact time with the reservoir satisfy a certain relation, the Curzon-Ahlborn (CA) efficiency η(CA) = 1-sqrt[T(c)/T(h)] is derived.

  13. Design of spherical electron gun for ultra high frequency, CW power inductive output tube

    Energy Technology Data Exchange (ETDEWEB)

    Kaushik, Meenu, E-mail: mkceeri@gmail.com; Joshi, L. M., E-mail: lmj1953@gmail.com [Microwave Tubes Division, CSIR-Central Electronics Engineering Research Institute (CEERI), Pilani, Rajasthan (India); Academy of Scientific and Innovative Research (AcSIR), New Delhi (India)

    2016-03-09

    Inductive Output Tube (IOT) is an amplifier that usually operates in UHF range. It is an electron tube whose basic structure is similar to conventional vacuum devices. This device is widely used in broadcast applications but is now being explored for scientific applications also specifically, particle accelerators and fusion plasma heating purposes. The paper describes the design approach of a spherical gridded electron gun of a 500 MHz, 100 kW CW power IOT. The electron gun structure has been simulated and optimized for operating voltage and current of 40kV and 3.5 A respectively. The electromagnetic analysis of this spherical electron gun has been carried out in CST and TRAK codes.

  14. The mechanical power output of the pectoralis muscle of cockatiel (Nymphicus hollandicus): the in vivo muscle length trajectory and activity patterns and their implications for power modulation.

    Science.gov (United States)

    Morris, Charlotte R; Askew, Graham N

    2010-08-15

    In order to meet the varying demands of flight, pectoralis muscle power output must be modulated. In birds with pectoralis muscles with a homogeneous fibre type composition, power output can be modulated at the level of the motor unit (via changes in muscle length trajectory and the pattern of activation), at the level of the muscle (via changes in the number of motor units recruited), and at the level of the whole animal (through the use of intermittent flight). Pectoralis muscle length trajectory and activity patterns were measured in vivo in the cockatiel (Nymphicus hollandicus) at a range of flight speeds (0-16 m s(-1)) using sonomicrometry and electromyography. The work loop technique was used to measure the mechanical power output of a bundle of fascicles isolated from the pectoralis muscle during simulated in vivo length change and activity patterns. The mechanical power-speed relationship was U-shaped, with a 2.97-fold variation in power output (40-120 W kg(-1)). In this species, modulation of neuromuscular activation is the primary strategy utilised to modulate pectoralis muscle power output. Maximum in vivo power output was 22% of the maximum isotonic power output (533 W kg(-1)) and was generated at a lower relative shortening velocity (0.28 V(max)) than the maximum power output during isotonic contractions (0.34 V(max)). It seems probable that the large pectoralis muscle strains result in a shift in the optimal relative shortening velocity in comparison with the optimum during isotonic contractions as a result of length-force effects.

  15. A Comparison of Isokinetic Knee Strength and Power Output Ratios Between Female Basketball and Volleyball Players

    Directory of Open Access Journals (Sweden)

    Kabaciński Jarosław

    2017-09-01

    Full Text Available Purpose. Tests such as the counter movement jump (CMJ and squat jump (SJ allow for determining the ratio of maximal power output generated during SJ to CMJ (S/C. The isokinetic peak torque ratio of the hamstrings contracting eccentrically to the quadriceps contracting concentrically (H/Q is defined as functional H/Q. The purpose of this study was to compare the S/C and functional H/Q between female basketball and volleyball players. Methods. The total of 14 female basketball players (age, 19.8 ± 1.4 years and 12 female volleyball players (age, 22.3 ± 4.2 years participated in the study. A piezoelectric force platform was used for the CMJ and SJ. Moreover, isokinetic tests of the hamstrings and quadriceps muscle torque during eccentric and concentric contraction were performed. Results. The results of the S/C and functional H/Q at 90 deg · s-1/60 deg · s-1 velocities were higher in basketball players (87.3 ± 9.1% and 91.4 ± 9.3%, respectively than in volleyball players (83.1 ± 9.8% and 83.6 ± 16.5%, respectively. No significant differences in S/C or functional H/Q values between the two groups were found (p > 0.05. Conclusions. Decreasing the S/C may result from an improvement in the power output during CMJ and a better utilization of the stretch-shortening cycle effect. Balancing the functional H/Q through increasing the eccentric hamstrings strength can provide dynamic knee joint stabilization.

  16. Synchronous Generator with HTS-2G field coils for Windmills with output power 1 MW

    Science.gov (United States)

    Kovalev, K.; Kovalev, L.; Poltavets, V.; Samsonovich, S.; Ilyasov, R.; Levin, A.; Surin, M.

    2014-05-01

    Nowadays synchronous generators for wind-mills are developed worldwide. The cost of the generator is determined by its size and weight. In this deal the implementation of HTS-2G generators is very perspective. The application of HTS 2G field coils in the rotor allows to reduce the size of the generator is 1.75 times. In this work the design 1 MW HTS-2G generator is considered. The designed 1 MW HTS-2G generator has the following parameters: rotor diameter 800 mm, active length 400 mm, phase voltage 690V, rotor speed 600 min-1 rotor field coils with HTS-2G tapes. HTS-2G field coils located in the rotating cryostat and cooled by liquid nitrogen. The simulation and optimization of HTS-2G field coils geometry allowed to increase feed DC current up to 50A. Copper stator windings are water cooled. Magnetic and electrical losses in 1 MW HTS-2G generator do not exceed 1.6% of the nominal output power. In the construction of HTS-2G generator the wave multiplier with ratio 1:40 is used. The latter allows to reduce the total mass of HTS-2G generator down to 1.5 tons. The small-scale model of HTS-2G generator with output power 50 kW was designed, manufactured and tested. The test results showed good agreement with calculation results. The manufacturing of 1 MW HTS-2G generator is planned in 2014. This work is done under support of Rosatom within the frames of Russian Project "Superconducting Industry".

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

    Science.gov (United States)

    Wakeling, James M.

    2015-01-01

    This study investigated the influence of cycle frequency and workload on muscle coordination and the ensuing relationship with mechanical efficiency and power output of human limb movement. Eleven trained cyclists completed an array of cycle frequency (cadence)-power output conditions while excitation from 10 leg muscles and power output were recorded. Mechanical efficiency was maximized at increasing cadences for increasing power outputs and corresponded to muscle coordination and muscle fiber type recruitment that minimized both the total muscle excitation across all muscles and the ineffective pedal forces. Also, maximum efficiency was characterized by muscle coordination at the top and bottom of the pedal cycle and progressive excitation through the uniarticulate knee, hip, and ankle muscles. Inefficiencies were characterized by excessive excitation of biarticulate muscles and larger duty cycles. Power output and efficiency were limited by the duration of muscle excitation beyond a critical cadence (120–140 rpm), with larger duty cycles and disproportionate increases in muscle excitation suggesting deteriorating muscle coordination and limitations of the activation-deactivation capabilities. Most muscles displayed systematic phase shifts of the muscle excitation relative to the pedal cycle that were dependent on cadence and, to a lesser extent, power output. Phase shifts were different for each muscle, thereby altering their mechanical contribution to the pedaling action. This study shows that muscle coordination is a key determinant of mechanical efficiency and power output of limb movement across a wide range of mechanical demands and that the excitation and coordination of the muscles is limited at very high cycle frequencies. PMID:26445873

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

    Science.gov (United States)

    Blake, Ollie M; Wakeling, James M

    2015-12-01

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

  19. Energy efficiency based joint cell selection and power allocation scheme for HetNets

    Directory of Open Access Journals (Sweden)

    Kwabena Kobia Mensah

    2016-11-01

    Full Text Available Heterogeneous networks (HetNets composed of overlapped cells with different sizes are expected to improve the transmission performance of data service significantly. User equipments (UEs in the overlapped area of multiple cells might be able to access various base stations (BSs of the cells, resulting in various transmission performances due to cell heterogeneity. Hence, designing optimal cell selection scheme is of particular importance for it may affect user quality of service (QoS and network performance significantly. In this paper, we jointly consider cell selection and transmit power allocation problem in a HetNet consisting of multiple cells. For a single UE case, we formulate the energy efficiency of the UE, and propose an energy efficient optimization scheme which selects the optimal cell corresponding to the maximum energy efficiency of the UE. The problem is then extended to multiple UEs case. To achieve joint performance optimization of all the UEs, we formulate an optimization problem with the objective of maximizing the sum energy efficiency of UEs subject to QoS and power constraints. The formulated nonlinear fractional optimization problem is equivalently transformed into two subproblems, i.e., power allocation subproblem of each UE-cell pair, and cell selection subproblem of UEs. The two subproblems are solved respectively through applying Lagrange dual method and Kuhn–Munkres (K-M algorithm. Numerical results demonstrate the efficiency of the proposed algorithm.

  20. Prediction of Francis Turbine Prototype Part Load Pressure and Output Power Fluctuations with Hydroelectric Model

    Science.gov (United States)

    Alligné, S.; Nicolet, C.; Béguin, A.; Landry, C.; Gomes, J.; Avellan, F.

    2017-04-01

    The prediction of pressure and output power fluctuations amplitudes on Francis turbine prototype is a challenge for hydro-equipment industry since it is subjected to guarantees to ensure smooth and reliable operation of the hydro units. The European FP7 research project Hyperbole aims to setup a methodology to transpose the pressure fluctuations induced by the cavitation vortex rope from the reduced scale model to the prototype generating units. A Francis turbine unit of 444MW with a specific speed value of ν = 0.29, is considered as case study. A SIMSEN model of the power station including electrical system, controllers, rotating train and hydraulic system with transposed draft tube excitation sources is setup. Based on this model, a frequency analysis of the hydroelectric system is performed for all technologies to analyse potential interactions between hydraulic excitation sources and electrical components. Three technologies have been compared: the classical fixed speed configuration with Synchronous Machine (SM) and the two variable speed technologies which are Doubly Fed Induction Machine (DFIM) and Full Size Frequency Converter (FSFC).

  1. Evaluation of Resting Cardiac Power Output as a Prognostic Factor in Patients with Advanced Heart Failure.

    Science.gov (United States)

    Yildiz, Omer; Aslan, Gamze; Demirozu, Zumrut T; Yenigun, Cemal Deniz; Yazicioglu, Nuran

    2017-09-15

    If the heart is represented by a hydraulic pump, cardiac power represents the hydraulic function of the heart. Cardiac pump function is frequently determined through left ventricular ejection fraction using imaging. This study aims to validate resting cardiac power output (CPO) as a predictive biomarker in patients with advanced heart failure (HF). One hundred and seventy-two patients with HF severe enough to warrant cardiac transplantation were retrospectively reviewed at a single tertiary care institution between September 2010 and July 2013. Patients were initially evaluated with simultaneous right-sided and left-sided cardiac catheter-based hemodynamic measurements, followed by longitudinal follow-up (median of 52 months) for adverse events (cardiac mortality, cardiac transplantation, or ventricular assist device placement). Median resting CPO was 0.54 W (long rank chi-square = 33.6; p CPO (CPO remained significant after adjustment for age, gender, left ventricular ejection fraction, mean arterial pressure, pulmonary vascular resistance, right atrial pressure, and estimated glomerular filtration rate (HR, 3.53; 95% confidence interval, 1.66 to 6.77; p = 0.0007). In conclusion, lower resting CPO supplies independent prediction of adverse outcomes. Thus, it could be effectively used for risk stratification in patients with advanced HF. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Bifacial dye-sensitized solar cells with enhanced rear efficiency and power output.

    Science.gov (United States)

    Cai, Hongyuan; Tang, Qunwei; He, Benlin; Li, Ru; Yu, Liangmin

    2014-12-21

    Pursuing a high power conversion efficiency with no sacrifice of cost-effectiveness has been a persistent objective for dye-sensitized solar cells (DSSCs). One promising solution to this impasse is increased light harvesting. Previous efforts in light harvesting have been made on setting blocking layers or reflecting layers, or adding a light harvester, resulting in tedious procedures without reducing the expenses. We present a mild solution strategy for synthesizing transparent Ru-Se alloy counter electrodes (CEs) for bifacial DSSC applications, displaying optimal front and rear efficiencies of 8.76% and 5.90%, respectively. In comparison with pristine Pt-based solar cells, the maximum power output has also been markedly enhanced. Moreover, fast start-up, high multiple start capability, and good stability are observed in the bifacial DSSCs with transparent Ru-Se binary alloy electrodes. The impressive efficiencies along with simple preparation of the cost-effective Ru-Se alloy CEs demonstrates their potential application in robust DSSCs.

  3. RECOVERY OF POWER OUTPUT AND HEART RATE KINETICS DURING REPEATED BOUTS OF ROWING EXERCISE WITH DIFFERENT REST INTERVALS

    Directory of Open Access Journals (Sweden)

    Evangelia Mavrommataki

    2006-03-01

    Full Text Available This study examined the effect of recovery time on the maintenance of power output and the heart rate response during repeated maximal rowing exercise. Nine male, junior rowers (age: 16 ± 1 years; body mass: 74.0 ± 9.1 kg; height: 1.78 ± 0.03 m performed two consecutive all-out 1000 m bouts on a rowing ergometer on three separate occasions. The rest interval between the two bouts was 1.5 (INT1.5, 3 (INT3 and 6 min (INT6, allocated in random order. Power output was averaged for each 1000 m bout and for the first and last 500 m of each bout. Heart rate kinetics were determined using a two-component exponential model. Performance time and mean power output for the first bout was 209 ± 3 s and 313 ± 10 W respectively. Recovery of mean power output was incomplete even after 6 min (78 ± 2, 81 ± 2 and 84 ± 2 % for INT1.5, INT3 and INT6 respectively. Mean power output after INT6 was higher (p < 0.01 only compared with INT1.5. Power output during the first 500 m of bout 2 after INT6 was 10% higher compared with the second 500 m. During INT1.5 and INT3 power output during the first and the second 500 m of bout 2 was similar. Peak heart rate (~197 b·min-1 and the HR time constant (~13 s were unaffected by prior exercise and recovery time. However, when the recovery was short (INT1.5, HR during the first 50 s of bout 2 was significantly higher compared with corresponding values during bout 1. The present study has shown that in order to maintain similar power outputs during repeated maximal rowing exercise, the recovery interval must be greater than 6 min. The influence of a longer recovery time (INT6 on maintenance of power output was only evident during the first half of the second 1000 m bout.

  4. Joint moment and muscle power output characteristics of below knee amputees during running: the influence of energy storing prosthetic feet.

    Science.gov (United States)

    Czerniecki, J M; Gitter, A; Munro, C

    1991-01-01

    Stance phase joint moments, muscle power outputs and mechanical energy characteristics were determined in five normal and five below knee amputee subjects running at 2.8 m s-1. The amputees were studied sequentially on three different prosthetic feet: the SACH foot (solid ankle cushion heel), and two energy storing feet, Seattle and Flex. While wearing the SACH foot, the amputees exhibited major alterations in the distribution and magnitude of muscle power output and muscle work: (1) the total work done by the lower extremity was reduced; (2) the hip extensors became the main source of energy absorption and generation, while in normal subjects the ankle plantarflexors were the major energy generators and the knee extensors the major energy absorbers; (3) the eccentric and concentric knee extensor power outputs were reduced and an abnormal concentric knee flexor power output was noted immediately after heel contact. In four of the amputees, energy storing feet resulted in improvements in the power output and mechanical work characteristics of the lower extremity: (1) the energy storing prosthetic feet generated 2-3 times greater energy than the SACH foot; (2) with the Flex foot the amputees exhibited a more normal pattern and magnitude of hip and knee extensor muscle work. One of the subjects, however, exhibited increased abnormalities with the energy storing prosthetic feet. The amount of energy restored relative to the amount of energy absorbed by each of the prosthetic feet was greater with the energy storing feet than the SACH foot (Flex 84%, Seattle 52%, SACH 31%).

  5. Lowest of AC-DC power output for electrostrictive polymers energy harvesting systems

    Science.gov (United States)

    Meddad, Mounir; Eddiai, Adil; Hajjaji, Abdelowahed; Guyomar, Daniel; Belkhiat, Saad; Boughaleb, Yahia; Chérif, Aida

    2013-11-01

    Advances in technology led to the development of electronic circuits and sensors with extremely low electricity consumption. At the same time, structural health monitoring, technology and intelligent integrated systems created a need for wireless sensors in hard to reach places in aerospace vehicles and large civil engineering structures. Powering sensors with energy harvesters eliminates the need to replace batteries on a regular basis. Scientists have been forced to search for new power source that are able to harvested energy from their surrounding environment (sunlight, temperature gradients etc.). Electrostrictive polymer belonging to the family of electro-active polymers, offer unique properties for the electromechanical transducer technology has been of particular interest over the last few years in order to replace conventional techniques such as those based on piezoelectric or electromagnetic, these materials are highly attractive for their low-density, with large strain capability that can be as high as two orders of magnitude greater than the striction-limited, rigid and fragile electroactive ceramics. Electrostrictive polymers sensors respond to vibration with an ac output signal, one of the most important objectives of the electronic interface is to realize the required AC-DC conversion. The goal of this paper is to design an active, high efficiency power doubler converter for electrostrictive polymers exclusively uses a fraction of the harvested energy to supply its active devices. The simulation results show that it is possible to obtain a maximum efficiency of the AC-DC converter equal to 80%. Premiliminary experimental measurements were performed and the results obtained are in good agreement with simulations.

  6. Systematic Observation of Time-Dependent Phenomena in the RF Output Spectrum of High Power Gyrotrons

    Directory of Open Access Journals (Sweden)

    Kern Stefan

    2012-09-01

    Full Text Available At IHM/KIT, high power gyrotrons with conventional cavity (e.g. 1 MW CW at 140 GHz for the stellarator Wendelstein 7-X and coaxial cavity (2 MW shortpulse at 170 GHz for ITER for fusion applications are being developed and verified experimentally. Especially with respect to the problem of parasitic RF oscillations in the beam tunnel of some W7-X tubes, investigations of the gyrotron RF output spectrum have proved to be a valuable source of diagnostic information. Signs of transient effects in millisecond pulses, like frequency switching or intermittent low-frequency modulation, have indicated that truly time-dependent measurements with high frequency resolution and dynamic range could give deeper insight into these phenomena. In this paper, an improved measurement system is presented, which employs a fast oscilloscope as receiver. Shorttime Fourier transform (STFT is applied to the time-domain signal, yielding time-variant spectra with frequency resolutions only limited by acquisition length and STFT segmentation choice. Typical reasonable resolutions are in the range of 100 kHz to 10 MHz with a currently memory-limited maximum acquisition length of 4 ms. A key feature of the system consists in the unambiguity of frequency measurement: The system receives through two parallel channels, each using a harmonic mixer (h = 9 – 12 to convert the signal from RF millimeter wave frequencies (full D-Band, 110 – 170 GHz to IF (0 – 3 GHz. For each IF output signal of each individual mixer, injection side and receiving harmonic are initially not known. Using accordingly determined LO frequencies, this information is retrieved from the redundancy of the channels, yielding unambiguously reconstructed RF spectra with a total span of twice the usable receiver IF bandwidth, up to ≈ 6 GHz in our case. Using the system, which is still being improved continuously, various transient effects like cavity mode switching, parasitic oscillation frequency variation

  7. Increasing the output power of single 808-nm laser diodes using diamond submounts produced by microwave plasma chemical vapour deposition

    Energy Technology Data Exchange (ETDEWEB)

    Ashkinazi, E E; Bezotosnyi, V V; Bondarev, Vadim Yu; Kovalenko, V I; Konov, Vitalii I; Krokhin, Oleg N; Oleshchenko, V A; Pevtsov, Valerii F; Popov, Yurii M; Popovich, A F; Ral' chenko, Viktor G; Cheshev, E A

    2012-11-30

    We have designed and fabricated submounts from synthetic diamond grown by microwave plasma chemical vapour deposition and developed an economical process for metallising such submounts. Laser diode chips having an 808-nm emission wavelength, 3-mm-long cavity and 130-mm-wide stripe contact were mounted on copper heat sinks with the use of diamond submounts differing in quality. The devices were tested for more than 150 h in continuous mode at an output power of 8 W on diamond with a thermal conductivity of 700 W m{sup -1} K{sup -1}, and no changes in their output power were detected. On diamond with a thermal conductivity of 1600 W m{sup -1} K{sup -1}, stable cw operation for 24 h at an output power of 12 W was demonstrated. (letters)

  8. 16 W output power by high-efficient spectral beam combining of DBR-tapered diode lasers

    DEFF Research Database (Denmark)

    Müller, André; Vijayakumar, Deepak; Jensen, Ole Bjarlin

    2011-01-01

    Up to 16 W output power has been obtained using spectral beam combining of two 1063 nm DBR-tapered diode lasers. Using a reflecting volume Bragg grating, a combining efficiency as high as 93.7% is achieved, resulting in a single beam with high spatial coherence. The result represents the highest...... output power achieved by spectral beam combining of two single element tapered diode lasers. Since spectral beam combining does not affect beam propagation parameters, M2-values of 1.8 (fast axis) and 3.3 (slow axis) match the M2- values of the laser with lowest spatial coherence. The principle...... of spectral beam combining used in our experiments can be expanded to combine more than two tapered diode lasers and hence it is expected that the output power may be increased even further in the future....

  9. Acute Effects of Static and Proprioceptive Neuromuscular Facilitation Stretching on Muscle Strength and Power Output.

    Science.gov (United States)

    Marek, Sarah M; Cramer, Joel T; Fincher, A Louise; Massey, Laurie L; Dangelmaier, Suzanne M; Purkayastha, Sushmita; Fitz, Kristi A; Culbertson, Julie Y

    2005-06-01

    Context: Stretching is commonly used as a technique for injury prevention in the clinical setting. Our findings may improve the understanding of the neuromuscular responses to stretching and help clinicians make decisions for rehabilitation progression and return to play.Objective: To examine the short-term effects of static and proprioceptive neuromuscular facilitation stretching on peak torque (PT), mean power output (MP), active range of motion (AROM), passive range of motion (PROM), electromyographic (EMG) amplitude, and mechanomyographic (MMG) amplitude of the vastus lateralis and rectus femoris muscles during voluntary maximal concentric isokinetic leg extensions at 60 and 300 degrees .s.Design: A randomized, counterbalanced, cross-sectional, repeated-measures design.Setting: A university human research laboratory.Patients or Other Participants: Ten female (age, 23 +/- 3 years) and 9 male (age, 21 +/- 3 years) apparently healthy and recreationally active volunteers.Intervention(s): Four static or proprioceptive neuromuscular facilitation stretching exercises to stretch the leg extensor muscles of the dominant limb during 2 separate, randomly ordered laboratory visits.Main Outcome Measure(s): The PT and MP were measured at 60 and 300 degrees .s, EMG and MMG signals were recorded, and AROM and PROM were measured at the knee joint before and after the stretching exercises.Results: Static and proprioceptive neuromuscular facilitation stretching reduced PT (P = .051), MP (P = .041), and EMG amplitude (P = .013) from prestretching to poststretching at 60 and 300 degrees .s (P static and proprioceptive neuromuscular facilitation stretching. The MMG amplitude increased in the rectus femoris muscle in response to the static stretching at 60 degrees .s (P = .031), but no other changes in MMG amplitude were observed (P > .05).Conclusions: Both static and proprioceptive neuromuscular facilitation stretching caused similar deficits in strength, power output, and muscle

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  11. Single- and dual-band filtering-response power dividers embedded SIW filter with improved output isolation.

    Science.gov (United States)

    Song, Kaijun; Zhu, Yu; Zhang, Fan

    2017-06-13

    Two filtering-response power dividers embedded substrate integrated waveguide (SIW) filter are presented in this paper. By employing different SIW resonators, single- and dual-band filtering response are achieved, respectively. The even- and odd-mode method and the coupled resonator theory are applied to analyze the presented power dividers. In addition, a novel isolation technique using multiple isolation resistors is proposed to improve the output isolation performance of the filtering-response power divider with multiple resonators. To verify the proposed circuits, the single- and dual-band filtering-response power dividers are designed, fabricated and measured. Reasonable agreement between the simulated and measured results is achieved. Moreover, the measured output isolation of the fabricated dual-band filtering-response power divider with multiple resonators is about 20 dB, which demonstrates the theoretical predication.

  12. 270 nm Pseudomorphic Ultraviolet Light-Emitting Diodes with Over 60 mW Continuous Wave Output Power

    Science.gov (United States)

    Grandusky, James R.; Chen, Jianfeng; Gibb, Shawn R.; Mendrick, Mark C.; Moe, Craig G.; Rodak, Lee; Garrett, Gregory A.; Wraback, Michael; Schowalter, Leo J.

    2013-03-01

    In this letter, the achievement of over 60 mW output power from pseudomorphic ultraviolet light-emitting diodes in continuous wave operation is reported. Die thinning and encapsulation improved the photon extraction efficiency to over 15%. Improved thermal management and a high characteristic temperature resulted in a low thermal rolloff up to 300 mA injection current with an output power of 67 mW, an external quantum efficiency (EQE) of 4.9%, and a wall plug efficiency (WPE) of 2.5% for a single-chip device emitting at 271 nm in continuous wave operation.

  13. PI and Fuzzy Control Strategies for High Voltage Output DC-DC Boost Power Converter - Hardware Implementation and Analysis

    DEFF Research Database (Denmark)

    Padmanaban, Sanjeevi Kumar; Blaabjerg, Frede; Siano, Pierluigi

    2016-01-01

    This paper presents the control strategies by Proportional-Integral (P-I) and Fuzzy Logic (FL) for a DC-DC boost power converter for high output voltage configuration. Standard DC-DC converters are traditionally used for high voltage direct current (HVDC) power transmission systems. But, lack its...... converter with inbuilt voltage-lift technique and overcome the aforementioned deficiencies. Further, the control strategy is adapted based on proportional-integral (P-I) and fuzzy logic, closed-loop controller to regulate the outputs and ensure the performances. Complete hardware prototype of EHV converter...

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    This paper presents the design of a 300-Watt isolated power supply for MOS gate driver circuit in medium and high voltage applications. The key feature of the developed power supply is having a very low circuit input-to-output parasitic capacitance, thus maximizing its noise immunity. This makes...... it suitable for modular stacking applications. The converter is a voltage-controlled current source, utilizing a transformer that has an extremely low inter-winding parasitic capacitance. The experiments show that an overall circuit input-to-output parasitic capacitance of 10 pF can be achieved. Design...

  15. Effect of Carbohydrate Intake on Maximal Power Output and Cognitive Performances

    Directory of Open Access Journals (Sweden)

    Laura Pomportes

    2016-10-01

    Full Text Available The present study aimed to assess the beneficial effect of acute carbohydrate (7% CHO intake on muscular and cognitive performances. Seventeen high levels athletes in explosive sports (fencing and squash participated in a randomized, double-blind study consisting in series of 6 sprints (5s with a passive recovery (25s followed by 15 min submaximal cycling after either maltodextrine and fructose (CHO or placebo (Pl intake. Cognitive performances were assessed before and after sprint exercise using a simple reaction time (SRT task at rest, a visual scanning task (VS and a Go/Nogo task (GNG during a submaximal cycling exercise. Results showed a beneficial effect of exercise on VS task on both conditions (Pl: −283 ms; CHO: −423 ms and on SRT only during CHO condition (−26 ms. In the CHO condition, SRT was faster after exercise whereas no effect of exercise was observed in the Pl condition. According to a qualitative statistical method, a most likely and likely positive effect of CHO was respectively observed on peak power (+4% and tiredness (−23% when compared to Pl. Furthermore, a very likely positive effect of CHO was observed on SRT (−8% and a likely positive effect on visual scanning (−6% and Go/Nogo tasks (−4% without any change in accuracy. In conclusion acute ingestion of 250 mL of CHO, 60 min and 30 min before exercise, improve peak power output, decrease muscular tiredness and speed up information processing and visual detection without changing accuracy.

  16. Biological maturity-associated variance in peak power output and momentum in academy rugby union players.

    Science.gov (United States)

    Howard, Sean M A; Cumming, Sean P; Atkinson, Mark; Malina, Robert M

    2016-11-01

    The study aimed to evaluate the mediating effect of biological maturation on anthropometrical measurements, performance indicators and subsequent selection in a group of academy rugby union players. Fifty-one male players 14-17 years of age were assessed for height, weight and BMI, and percentage of predicted mature status attained at the time of observation was used as an indicator of maturity status. Following this, initial sprint velocity (ISV), Wattbike peak power output (PPO) and initial sprint momentum (ISM) were assessed. A bias towards on-time (n = 44) and early (n = 7) maturers was evident in the total sample and magnified with age cohort. Relative to UK reference values, weight and height were above the 90th and 75th centiles, respectively. Significant (p ≤ .01) correlations were observed between maturity status and BMI (r = .48), weight (r = .63) and height (r = .48). Regression analysis (controlling for age) revealed that maturity status and height explained 68% of ISM variance; however, including BMI in the model attenuated the influence of maturity status below statistical significance (p = .72). Height and BMI explained 51% of PPO variance, while no initial significant predictors were identified for ISV. The sample consisted of players who were on-time and early in maturation with no late maturers represented. This was attributable, in part, to the mediating effect of maturation on body size, which, in turn, predicted performance variables.

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

    Directory of Open Access Journals (Sweden)

    Leonie Harvey

    2015-06-01

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

  18. The Influence of Serial Carbohydrate Mouth Rinsing on Power Output during a Cycle Sprint

    Directory of Open Access Journals (Sweden)

    Shaun M. Phillips, Scott Findlay, Mykolas Kavaliauskas, Marie Clare Grant

    2014-06-01

    Full Text Available The objective of the study was to investigate the influence of serial administration of a carbohydrate (CHO mouth rinse on performance, metabolic and perceptual responses during a cycle sprint. Twelve physically active males (mean (± SD age: 23.1 (3.0 years, height: 1.83 (0.07 m, body mass (BM: 86.3 (13.5 kg completed the following mouth rinse trials in a randomized, counterbalanced, double-blind fashion; 1. 8 x 5 second rinses with a 25 ml CHO (6% w/v maltodextrin solution, 2. 8 x 5 second rinses with a 25 ml placebo (PLA solution. Following mouth rinse administration, participants completed a 30 second sprint on a cycle ergometer against a 0.075 g·kg-1 BM resistance. Eight participants achieved a greater peak power output (PPO in the CHO trial, resulting in a significantly greater PPO compared with PLA (13.51 ± 2.19 vs. 13.20 ± 2.14 W·kg-1, p 0.05. No significant between-trials difference was reported for fatigue index, perceived exertion, arousal and nausea levels, or blood lactate and glucose concentrations. Serial administration of a CHO mouth rinse may significantly improve PPO during a cycle sprint. This improvement appears confined to the first 5 seconds of the sprint, and may come at a greater relative cost for the remainder of the sprint.

  19. Balancing Power Output and Structural Fatigue of Wave Energy Converters by Means of Control Strategies

    Directory of Open Access Journals (Sweden)

    Francesco Ferri

    2014-04-01

    Full Text Available In order to reduce the cost of electricity produced by wave energy converters (WECs, the benefit of selling electricity as well as the investment costs of the structure has to be considered. This paper presents a methodology for assessing the control strategy for a WEC with respect to both energy output and structural fatigue loads. Different active and passive control strategies are implemented (proportional (P controller, proportional-integral (PI controller, proportional-integral-derivative with memory compensation (PID controller, model predictive control (MPC and maximum energy controller (MEC, and load time-series resulting from numerical simulations are used to design structural parts based on fatigue analysis using rain-flow counting, Stress-Number (SN curves and Miner’s rule. The objective of the methodology is to obtain a cost-effective WEC with a more comprehensive analysis of a WEC based on a combination of well known control strategies and standardised fatigue methods. The presented method is then applied to a particular case study, the Wavestar WEC, for a specific location in the North Sea. Results, which are based on numerical simulations, show the importance of balancing the gained power against structural fatigue. Based on a simple cost model, the PI controller is shown as a viable solution.

  20. Measuring recovery: An adapted Brief Assessment of Mood (BAM+) compared to biochemical and power output alterations.

    Science.gov (United States)

    Shearer, David A; Sparkes, William; Northeast, Jonny; Cunningham, Daniel J; Cook, Christian J; Kilduff, Liam P

    2017-05-01

    Biochemical (e.g. creatine kinase (CK)) and neuromuscular (e.g. peak power output (PPO)) markers of recovery are expensive and require specialist equipment. Perceptual measures are an effective alternative, yet most validated scales are too long for daily use. This study utilises a longitudinal multi-level design to test an adapted Brief Assessment of Mood (BAM+), with four extra items and a 100mm visual analogue scale to measure recovery. Elite under-21 academy soccer players (N=11) were monitored across five games with data (BAM+, CK and PPO) collected for each game at 24h pre, 24h and 48h post-match. Match activity data for each participant was also collected using GPS monitors on players. BAM+, CK and PPO had significant (pBAM+ scores (pBAM+ scores from baseline at 24 and 48h post-match for total distance covered per minute, high intensity distance covered per minute, and total number of sprints per minute. Visual and inferential results indicate that the BAM+ appears effective for monitoring longitudinal recovery cycles in elite level athletes. Future research is needed to confirm both the scales reliability and validity. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  1. Influence of ballistic bench press on upper body power output in professional rugby players.

    Science.gov (United States)

    West, Daniel J; Cunningham, Daniel J; Crewther, Blair T; Cook, Christian J; Kilduff, Liam P

    2013-08-01

    The use of heavy resistance exercise provides an effective preload stimulus for inducing postactivation potentiation (PAP) and increasing peak power output (PPO). However, this approach has limited application in many sporting situations (e.g., incorporation in a precompetition warm-up); and therefore, more practical strategies for inducing PAP need to be investigated. The aim of the present study was to compare the PPO changes after performing a preload stimulus of either a ballistic exercise or a traditional heavy resistance exercise. Twenty professional rugby union players completed 3 testing sessions, each separated by 48 hours. On the first occasion, subjects underwent a 3 repetition maximum (3RM)-bench press testing session. On the next 2 occasions, subjects performed a ballistic bench throw at baseline (30% of 1RM), followed by a preload stimulus of either heavy resistance training (HRT) (heavy bench press: 3 sets of 3 repetitions at 87% 1RM) or BBP (3 sets of 3 repetitions at 30% on 1RM) followed by ballistic bench throw after 8 minutes recovery. The trials were randomized and counterbalanced. Both preload stimuli protocols increased PPO compared with baseline (BBP baseline 892 ± 108 vs. 8 minutes 924 ± 119 W, p body PPO; moreover, this elicited similar increases in PPO as a traditional heavy resistance exercise preloading stimulus.

  2. Implementation of a Model Output Statistics based on meteorological variable screening for short‐term wind power forecast

    DEFF Research Database (Denmark)

    Ranaboldo, Matteo; Giebel, Gregor; Codina, Bernat

    2013-01-01

    A combination of physical and statistical treatments to post‐process numerical weather predictions (NWP) outputs is needed for successful short‐term wind power forecasts. One of the most promising and effective approaches for statistical treatment is the Model Output Statistics (MOS) technique....... In this study, a MOS based on multiple linear regression is proposed: the model screens the most relevant NWP forecast variables and selects the best predictors to fit a regression equation that minimizes the forecast errors, utilizing wind farm power output measurements as input. The performance of the method...... is evaluated in two wind farms, located in different topographical areas and with different NWP grid spacing. Because of the high seasonal variability of NWP forecasts, it was considered appropriate to implement monthly stratified MOS. In both wind farms, the first predictors were always wind speeds (at...

  3. Input and output filter design of current source PWM converter for high-precision magnet power supply

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyo Sung [Cheonan National Junior Technical College, Cheonan (Korea, Republic of); Choi, Jae Ho [Chungbuk National University, Chongju (Korea, Republic of)

    1996-01-01

    Current Source PWM converter is appropriate for the magnet power supply system which requests high power and high precision current control. Input and output filters should be installed to eliminate the current or voltage harmonics caused by the PWM switching for the current source PWM converter. But the input/output filters limit the output DC current range and may destroy the system with filter resonance, and make the system equation more complicated. In this paper, systematic and simple filter design method which considers not only the harmonic attenuation but also the total system good transfer function characteristics in the dc filter. The simulated and experimental results verify the proposed theory. (author). 14 refs., 12 figs., 8 tabs.

  4. Low Power Continuous-Time Delta-Sigma ADC with Current Output DAC

    DEFF Research Database (Denmark)

    Marker-Villumsen, Niels; Jørgensen, Ivan Harald Holger; Bruun, Erik

    2015-01-01

    The paper presents a continuous-time (CT) DeltaSigma (∆Σ) analog-to-digital converter (ADC) using a current output digital-to-analog converter (DAC) for the feedback. From circuit analysis it is shown that using a current output DAC makes it possible to relax the noise requirements of the 1st...

  5. Power Outputs and Volumetric Eruption Rates for Ionian Volcanoes from Galileo-NIMS Data

    Science.gov (United States)

    Davies, A. G.

    2001-01-01

    Volumetric eruption rates for a number of Io volcanoes are calculated as a function of volcanic thermal output. Thermal output is determined using 2-temperature fits to NIMS data. Typical eruption rates are larger than terrestrial eruptions of similar style. Additional information is contained in the original extended abstract.

  6. Coupling/Tradeoff Analysis and Novel Containment Control for Reactive Power, Output Voltage in Islanded Micro-Grid

    DEFF Research Database (Denmark)

    Han, Renke; Meng, Lexuan; Guerrero, Josep M.

    2016-01-01

    Based on the hierarchical control structure in islanded Micro-Grid (MG) systems, the coupling/tradeoff effects in different control levels are analyzed in details. In the primary level, analyses of the coupling effects among droop control gains, line impedance differences, output reactive power a...

  7. Optimal Velocity to Achieve Maximum Power Output – Bench Press for Trained Footballers

    Directory of Open Access Journals (Sweden)

    Richard Billich

    2015-03-01

    Full Text Available Optimal Velocity to Achieve Maximum Power Output – Bench Press for Trained Footballers In today’s world of strength training there are many myths surrounding effective exercising with the least possible negative effect on one’s health. In this experiment we focus on the finding of a relationship between maximum output, used load and the velocity with which the exercise is performed. The main objective is to find the optimal speed of the exercise motion which would allow us to reach the maximum mechanic muscle output during a bench press exercise. This information could be beneficial to sporting coaches and recreational sportsmen alike in helping them improve the effectiveness of fast strength training. Fifteen football players of the FK Třinec football club participated in the experiment. The measurements were made with the use of 3D cinematic and dynamic analysis, both experimental methods. The research subjects participated in a strength test, in which the mechanic muscle output of 0, 10, 30, 50, 70, 90% and one repetition maximum (1RM was measured. The acquired result values and other required data were modified using Qualisys Track Manager and Visual 3D software (C-motion, Rockville, MD, USA. During the bench press exercise the maximum mechanic muscle output of the set of research subjects was reached at 75% of maximum exercise motion velocity. Optimální rychlost pohybu pro dosažení maxima výstupního výkonu – bench press u trénovaných fotbalistů Dnešní svět silového tréninku přináší řadu mýtů o tom, jak cvičit efektivně a zároveň s co nejmenším negativním vlivem na zdraví člověka. V tomto experimentu se zabýváme nalezením vztahu mezi maximálním výkonem, použitou zátěží a rychlostí. Hlavním úkolem je nalezení optimální rychlosti pohybu pro dosažení maximálního mechanického svalového výkonu při cvičení bench press, což pomůže nejenom trenérům, ale i rekreačním sportovc

  8. Investigation of neural-net based control strategies for improved power system dynamic performance

    Energy Technology Data Exchange (ETDEWEB)

    Sobajic, D.J. [Electric Power Research Institute, Palo Alto, CA (United States)

    1995-12-31

    The ability to accurately predict the behavior of a dynamic system is of essential importance in monitoring and control of complex processes. In this regard recent advances in neural-net base system identification represent a significant step toward development and design of a new generation of control tools for increased system performance and reliability. The enabling functionality is the one of accurate representation of a model of a nonlinear and nonstationary dynamic system. This functionality provides valuable new opportunities including: (1) The ability to predict future system behavior on the basis of actual system observations, (2) On-line evaluation and display of system performance and design of early warning systems, and (3) Controller optimization for improved system performance. In this presentation, we discuss the issues involved in definition and design of learning control systems and their impact on power system control. Several numerical examples are provided for illustrative purpose.

  9. The Net Climate Impact of Coal-Fired Power Plant Emissions

    Science.gov (United States)

    Shindell, D.; Faluvegi, G.

    2010-01-01

    Coal-fired power plants influence climate via both the emission of long-lived carbon dioxide (CO2) and short-lived ozone and aerosol precursors. Using a climate model, we perform the first study of the spatial and temporal pattern of radiative forcing specifically for coal plant emissions. Without substantial pollution controls, we find that near-term net global mean climate forcing is negative due to the well-known aerosol masking of the effects of CO2. Imposition of pollution controls on sulfur dioxide and nitrogen oxides leads to a rapid realization of the full positive forcing from CO2, however. Long-term global mean forcing from stable (constant) emissions is positive regardless of pollution controls. Emissions from coal-fired power plants until 1970, including roughly 1/3 of total anthropogenic CO2 emissions, likely contributed little net global mean climate forcing during that period though they may have induce weak Northern Hemisphere mid-latitude (NHml) cooling. After that time many areas imposed pollution controls or switched to low sulfur coal. Hence forcing due to emissions from 1970 to 2000 and CO2 emitted previously was strongly positive and contributed to rapid global and especially NHml warming. Most recently, new construction in China and India has increased rapidly with minimal application of pollution controls. Continuation of this trend would add negative near-term global mean climate forcing but severely degrade air quality. Conversely, following the Western and Japanese pattern of imposing air quality pollution controls at a later time could accelerate future warming rates, especially at NHmls. More broadly, our results indicate that due to spatial and temporal inhomogeneities in forcing, climate impacts of multi-pollutant emissions can vary strongly from region to region and can include substantial effects on maximum rate-of-change, neither of which are captured by commonly used global metrics. The method we introduce here to estimate

  10. Influence of different output powers on the efficacy of photodynamic therapy with 809-nm diode laser and indocyanine green

    Science.gov (United States)

    Topaloglu, Nermin; Yuksel, Sahru; Gulsoy, Murat

    2013-02-01

    Photodynamic therapy (PDT) is an alternative antimicrobial treatment method. Different wavelengths of light sources mostly in the visible spectrum have been investigated for antimicrobial Photodynamic Therapy. Even though the wavelengths in near infrared spectrum have the advantage of higher penetration capability in biological tissue, they have not been preferred for PDT because of their possible photothermal effect in biological tissues. In our previous studies, the desired PDT effect was achieved with 809-nm diode laser and indocyanine green (ICG) on drug resistant pathogens. In this study, it was aimed to investigate the influence of different output powers during PDT applications with 809-nm diode laser to clarify whether there is a photothermal effect to kill the pathogens or only the photochemical effect of photodynamic therapy. 4 different output powers (500 mW, 745 mW, 1000 mW, 1500 mW) were examined in Laseronly and PDT groups of P. aeruginosa ATCC 27853 in vitro. In the PDT groups, a non-phototoxic ICG concentration (50 μl/ml) has been chosen to eliminate the toxic effect of ICG and evaluate only the thermal effect of laser. Applied energy dose (252 J/cm2) was kept constant by increasing the exposure duration (300, 240, 180 and 120 seconds respectively). These output powers in Laser-only or PDT groups did not seem to cause photothermal effect. There was not any significant decrease or increase on bacterial load after the applications with different output powers. Higher output powers in PDT groups with the same ICG concentration did not cause any higher killing effect.

  11. Leg joint power output during progressive resistance FES-LCE cycling in SCI subjects: developing an index of fatigue

    Directory of Open Access Journals (Sweden)

    Faghri Pouran D

    2008-04-01

    Full Text Available Abstract Background The purpose of this study was to investigate the biomechanics of the hip, knee and ankle during a progressive resistance cycling protocol in an effort to detect and measure the presence of muscle fatigue. It was hypothesized that knee power output can be used as an indicator of fatigue in order to assess the cycling performance of SCI subjects. Methods Six spinal cord injured subjects (2 incomplete, 4 complete between the ages of twenty and fifty years old and possessing either a complete or incomplete spinal cord injury at or below the fourth cervical vertebra participated in this study. Kinematic data and pedal forces were recorded during cycling at increasing levels of resistance. Ankle, knee and hip power outputs and resultant pedal force were calculated. Ergometer cadence and muscle stimulation intensity were also recorded. Results The main findings of this study were: (a ankle and knee power outputs decreased, whereas hip power output increased with increasing resistance, (b cadence, stimulation intensity and resultant pedal force in that combined order were significant predictors of knee power output and (c knowing the value of these combined predictors at 10 rpm, an index of fatigue can be developed, quantitatively expressing the power capacity of the knee joint with respect to a baseline power level defined as fatigue. Conclusion An index of fatigue was successfully developed, proportionalizing knee power capacity during cycling to a predetermined value of fatigue. The fatigue index value at 0/8th kp, measured 90 seconds into active, unassisted pedaling was 1.6. This indicates initial power capacity at the knee to be 1.6 times greater than fatigue. The fatigue index decreased to 1.1 at 2/8th kp, representing approximately a 30% decrease in the knee's power capacity within a 4 minute timespan. These findings suggest that the present cycling protocol is not sufficient for a rider to gain the benefits of FES and thus

  12. A neural network based computational model to predict the output power of different types of photovoltaic cells.

    Directory of Open Access Journals (Sweden)

    WenBo Xiao

    Full Text Available In this article, we introduced an artificial neural network (ANN based computational model to predict the output power of three types of photovoltaic cells, mono-crystalline (mono-, multi-crystalline (multi-, and amorphous (amor- crystalline. The prediction results are very close to the experimental data, and were also influenced by numbers of hidden neurons. The order of the solar generation power output influenced by the external conditions from smallest to biggest is: multi-, mono-, and amor- crystalline silicon cells. In addition, the dependences of power prediction on the number of hidden neurons were studied. For multi- and amorphous crystalline cell, three or four hidden layer units resulted in the high correlation coefficient and low MSEs. For mono-crystalline cell, the best results were achieved at the hidden layer unit of 8.

  13. Enhancing efficiency and power output of gas turbines using either renewable energy or heat recovery cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Nasser, A.E.M. [Higher Technological Inst., Tenth of Ramadan (Egypt). Dept. of Mechanical Engineering

    2006-07-01

    An absorption system to cool intake air to the compressor of an air conditioning system was presented. The system used both solar energy and the waste heat of the exhaust gases to obtain higher temperatures during the summer months. The lithium bromide-water absorption system increased power output by more than 20 per cent during the summer months without consuming more fuel. The system was designed to conserve energy and output power in gas turbine power stations. The system operated by using hot effluent gases leaving the turbine and entered the flue stacks, where heat exchangers recovered the heat energy. Excess electricity produced by the turbine was then used to cool the ambient air before it entered the compressor. Studies have confirmed that the system is financially viable and suited for use in Arabian Gulf countries where temperatures regularly exceed 40 degrees C. 6 refs., 6 figs.

  14. A neural network based computational model to predict the output power of different types of photovoltaic cells.

    Science.gov (United States)

    Xiao, WenBo; Nazario, Gina; Wu, HuaMing; Zhang, HuaMing; Cheng, Feng

    2017-01-01

    In this article, we introduced an artificial neural network (ANN) based computational model to predict the output power of three types of photovoltaic cells, mono-crystalline (mono-), multi-crystalline (multi-), and amorphous (amor-) crystalline. The prediction results are very close to the experimental data, and were also influenced by numbers of hidden neurons. The order of the solar generation power output influenced by the external conditions from smallest to biggest is: multi-, mono-, and amor- crystalline silicon cells. In addition, the dependences of power prediction on the number of hidden neurons were studied. For multi- and amorphous crystalline cell, three or four hidden layer units resulted in the high correlation coefficient and low MSEs. For mono-crystalline cell, the best results were achieved at the hidden layer unit of 8.

  15. Analysis of Possible Application of High-Temperature Nuclear Reactors to Contemporary Large-Output Steam Power Plants on Ships

    Directory of Open Access Journals (Sweden)

    Kowalczyk T.

    2016-04-01

    Full Text Available This paper is aimed at analysis of possible application of helium to cooling high-temperature nuclear reactor to be used for generating steam in contemporary ship steam-turbine power plants of a large output with taking into account in particular variable operational parameters. In the first part of the paper types of contemporary ship power plants are presented. Features of today applied PWR reactors and proposed HTR reactors are discussed. Next, issues of load variability of the ship nuclear power plants, features of the proposed thermal cycles and results of their thermodynamic calculations in variable operational conditions, are presented.

  16. Waveguide Multimode Directional Coupler for Harvesting Harmonic Power from the Output of Traveling-Wave Tube Amplifiers

    Science.gov (United States)

    Simons, Rainee N.; Wintucky, Edwin G.

    2017-01-01

    The paper presents the design, fabrication, and test results for a novel waveguide multimode directional coupler (MDC). The coupler fabricated from dissimilar frequency band waveguides, is capable of isolating power at the 2nd harmonic frequency from the fundamental power at the output port of a high power traveling-wave tube amplifier. The major advantage of the MDC is significantly lower insertion loss compared to a diplexer. The presentation slides for the paper that was approved is attached. The tracking number for the paper that was approved is TN 37015.

  17. Work output and efficiency at maximum power of linear irreversible heat engines operating with a finite-sized heat source.

    Science.gov (United States)

    Izumida, Yuki; Okuda, Koji

    2014-05-09

    We formulate the work output and efficiency for linear irreversible heat engines working between a finite-sized hot heat source and an infinite-sized cold heat reservoir until the total system reaches the final thermal equilibrium state with a uniform temperature. We prove that when the heat engines operate at the maximum power under the tight-coupling condition without heat leakage the work output is just half of the exergy, which is known as the maximum available work extracted from a heat source. As a consequence, the corresponding efficiency is also half of its quasistatic counterpart.

  18. Cluster Formation and Joint Power-Bandwidth Allocation for Imperfect NOMA in DL-HetNets

    KAUST Repository

    Celik, Abdulkadir

    2017-04-15

    Non-orthogonal multiple access (NOMA) has recently drawn attentions on its ability to fairly serve multiple users on the same radio resource with a desirable performance. However, achievable NOMA gain is primarily limited by channel gain disparity and successive interference cancellation (SIC) receiver characteristics. Accordingly, we introduce an imperfect SIC receiver model considering the power disparity and sensitivity constraints, delay tolerance, and residual interference due to detection and estimation errors. Then, a generic cluster formation (CF) and Power-Bandwidth Allocation (PBA) is formulated as a mixed-integer non-linear programming (MINLP) problem for downlink (DL) heterogeneous networks (HetNets). After dividing the MINLP problem into mixed-integer and non-linear subprobems, we first transform CF into a multi-partite matching, which is solved sequentially using bi-partite matching techniques. For sumrate maximization, max-min fairness, and energy & spectrum efficiency objectives, we secondly put highly non-convex joint PBA into a convex form using geometric programming (GP). Extensive simulations unleash the potential of NOMA to handle large number of users, traffic offloading, and user fairness.

  19. Understanding Net Zero Energy Buildings

    DEFF Research Database (Denmark)

    Salom, Jaume; Widén, Joakim; Candanedo, José

    2011-01-01

    Although several alternative definitions exist, a Net-Zero Energy Building (Net ZEB) can be succinctly described as a grid-connected building that generates as much energy as it uses over a year. The “net-zero” balance is attained by applying energy conservation and efficiency measures...... and by incorporating renewable energy systems. While based on annual balances, a complete description of a Net ZEB requires examining the system at smaller time-scales. This assessment should address: (a) the relationship between power generation and building loads and (b) the resulting interaction with the power grid....... This paper presents and categorizes quantitative indicators suitable to describe both aspects of the building’s performance. These indicators, named LMGI - Load Matching and Grid Interaction indicators, are easily quantifiable and could complement the output variables of existing building simulation tools...

  20. Interleaved Flyback DC-DC Converter Design with 350 W Power Output Using LT 3757 in LT Spice

    Science.gov (United States)

    Rahayu, S.; Firmansyah, E.; Isnaeni, M.

    2017-04-01

    DC-DC converter becomes one important part in micro-inverter used in solar panel application. Its function is to convert output voltage level of solar panel 42-48 Vdc to a voltage level of 350 Vdc before being converted into an AC voltage at the inverter. The proposed converter topology is a flyback because the number of components used is not too much which can suppress the production cost. In this paper, simulation of flyback converter on the interleaved operating mode with a maximum output power of 350 W using software Ltspicewas conducted. From the simulation results, obtained that by applying a switching frequency of 100 kHz, the obtained value of the components of the primary inductor (LP) 3.3 μH, the secondary inductor (LS) 27 μH, the output capacitor (Cout) 47μF and ripple voltage (Vr) 212.65 mV.

  1. Control and Design of Input Series-Output Parallel Connected Converter for High Speed Train Power System

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Won; Cho, Bo H. [Seoul National University (Korea); You, Jung Sik [Hyosung Heavy Industry (Korea)

    2000-04-01

    In this paper, the charge control with the input voltage feedback is proposed for the input series-output parallel connected converter configuration for the high speed train power system application. This control scheme accomplishes the output current sharing for the output-parallel connected modules as well as the input voltage sharing for the input series connected modules for all operating conditions including the transients. It also offers the robustness for the input series sharing control according to the component value mismatches among the modules. And this configuration enables the usage of MOSFET for a high voltage system allowing a higher switching frequency for lighter system weight and smaller size. The performance of the proposed scheme is verified through the experimental results. (author). 11 refs., 19 figs., 1 tab.

  2. Universal and inductorless DC/DC converter for multi-output power supplies in sensor and actuator networks

    Science.gov (United States)

    Saponara, Sergio; Ciarpi, Gabriele

    2017-05-01

    This work proposes a universal and inductorless DC/DC converter that can be used for a wide input range, from few V to 60 V, to regulate output voltages from 5 V down to 1 V in Sensor and Actuator Network nodes. The proposed converter has been developed within the Athenis3D European project. It is composed by a cascade of multiple switching capacitor stages, with a proper skip-mode control to implement both step-down and step-up converting ratios, thus regulating all input sources to a voltage of about 6 V. These switching stages are further cascaded with linear regulators, which can provide stable output voltages down to 1 V. The multi-output regulator has been realized as a single-chip in a low-cost 0.35 μm CMOS technology. It is available as a naked die or in a ceramic package. The only needed external components are surface mount capacitors, which can be integrated on top of the naked chip die, creating a 3D structure, using trench capacitors embedded in a passive interposing layer. This way the size of the power management unit is further minimized. An advantage of the proposed converter is that it isn't optimized for a particular input voltage, therefore it can be used with no constant input power, like power harvesting systems (e.g. solar cells, wind and water turbines) and very disturbed power supplies.

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

    Science.gov (United States)

    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 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.

  4. The left ventricle as a mechanical engine: from Leonardo da Vinci to the echocardiographic assessment of peak power output-to-left ventricular mass.

    Science.gov (United States)

    Dini, Frank L; Guarini, Giacinta; Ballo, Piercarlo; Carluccio, Erberto; Maiello, Maria; Capozza, Paola; Innelli, Pasquale; Rosa, Gian M; Palmiero, Pasquale; Galderisi, Maurizio; Razzolini, Renato; Nodari, Savina

    2013-03-01

    The interpretation of the heart as a mechanical engine dates back to the teachings of Leonardo da Vinci, who was the first to apply the laws of mechanics to the function of the heart. Similar to any mechanical engine, whose performance is proportional to the power generated with respect to weight, the left ventricle can be viewed as a power generator whose performance can be related to left ventricular mass. Stress echocardiography may provide valuable information on the relationship between cardiac performance and recruited left ventricular mass that may be used in distinguishing between adaptive and maladaptive left ventricular remodeling. Peak power output-to-mass, obtained during exercise or pharmacological stress echocardiography, is a measure that reflects the number of watts that are developed by 100 g of left ventricular mass under maximal stimulation. Power output-to-mass may be calculated as left ventricular power output per 100 g of left ventricular mass: 100× left ventricular power output divided by left ventricular mass (W/100 g). A simplified formula to calculate power output-to-mass is as follows: 0.222 × cardiac output (l/min) × mean blood pressure (mmHg)/left ventricular mass (g). When the integrity of myocardial structure is compromised, a mismatch becomes apparent between maximal cardiac power output and left ventricular mass; when this occurs, a reduction of the peak power output-to-mass index is observed.

  5. The net climate impact of coal-fired power plant emissions

    Directory of Open Access Journals (Sweden)

    D. Shindell

    2010-04-01

    Full Text Available Coal-fired power plants influence climate via both the emission of long-lived carbon dioxide (CO2 and short-lived ozone and aerosol precursors. Using a climate model, we perform the first study of the spatial and temporal pattern of radiative forcing specifically for coal plant emissions. Without substantial pollution controls, we find that near-term net global mean climate forcing is negative due to the well-known aerosol masking of the effects of CO2. Imposition of pollution controls on sulfur dioxide and nitrogen oxides leads to a rapid realization of the full positive forcing from CO2, however. Long-term global mean forcing from stable (constant emissions is positive regardless of pollution controls. Emissions from coal-fired power plants until ~1970, including roughly 1/3 of total anthropogenic CO2 emissions, likely contributed little net global mean climate forcing during that period though they may have induce weak Northern Hemisphere mid-latitude (NHml cooling. After that time many areas imposed pollution controls or switched to low-sulfur coal. Hence forcing due to emissions from 1970 to 2000 and CO2 emitted previously was strongly positive and contributed to rapid global and especially NHml warming. Most recently, new construction in China and India has increased rapidly with minimal application of pollution controls. Continuation of this trend would add negative near-term global mean climate forcing but severely degrade air quality. Conversely, following the Western and Japanese pattern of imposing air quality pollution controls at a later time could accelerate future warming rates, especially at NHmls. More broadly, our results indicate that due to spatial and temporal inhomogenaities in forcing, climate impacts of multi-pollutant emissions can vary strongly from region to region and can include substantial effects on maximum rate-of-change, neither of which are captured by

  6. Actively mode-locked Tm(3+)-doped silica fiber laser with wavelength-tunable, high average output power.

    Science.gov (United States)

    Kneis, Christian; Donelan, Brenda; Berrou, Antoine; Manek-Hönninger, Inka; Robin, Thierry; Cadier, Benoît; Eichhorn, Marc; Kieleck, Christelle

    2015-04-01

    A diode-pumped, actively mode-locked high-power thulium (Tm3+)-doped double-clad silica fiber laser is demonstrated, providing an average output power in mode-locked (continuous wave) operation of 53 W (72 W) with a slope efficiency of 34% (38%). Mode-locking in the 6th-harmonic order was obtained by an acousto-optic modulator driven at 66 MHz without dispersion compensation. The shortest measured output pulse width was 200 ps. Owing to a diffraction grating as cavity end mirror, the central wavelength could be tuned from 1.95 to 2.13 μm. The measured beam quality in mode-locked and continuous wave operation has been close to the diffraction limit.

  7. 10kV SiC MOSFET split output power module

    DEFF Research Database (Denmark)

    Beczkowski, Szymon; Li, Helong; Uhrenfeldt, Christian

    2015-01-01

    The poor body diode performance of the first generation of 10kV SiC MOSFETs and the parasitic turn-on phenomenon limit the performance of SiC based converters. Both these problems can potentially be mitigated using a split output topology. In this paper we present a comparison between a classical...

  8. Output regulation of large-scale hydraulic networks with minimal steady state power consumption

    NARCIS (Netherlands)

    Jensen, Tom Nørgaard; Wisniewski, Rafał; De Persis, Claudio; Kallesøe, Carsten Skovmose

    2014-01-01

    An industrial case study involving a large-scale hydraulic network is examined. The hydraulic network underlies a district heating system, with an arbitrary number of end-users. The problem of output regulation is addressed along with a optimization criterion for the control. The fact that the

  9. Effect of pedal cadence on mechanical power output and physiological variables

    Directory of Open Access Journals (Sweden)

    Jefferson da Silva Novaes

    2007-09-01

    Full Text Available The objective of this study was to compare the responses of the variables maximal power output (POmax, heart rate (HR, rating of perceived exertion (RPE, systolic blood pressure (SBP, diastolic blood pressure (DBP and double product (DP in the maximum reached load and during 60 and 90 rev.min-1 tests. The study sample consisted of 14 men (26.5 ± 3.5 years, 78.5 ± 7.8 kg and 178.1 ± 7.0 cm engaged in indoor cycling classes, who undertook two tests of maximum effort using Balke’s incremental protocol. The fi rst test (test60 consisted of a pedal cadence of 60 rev.min-1 throughout the test, until voluntary exhaustion or the appearance of signs or symptom limits. The second test (test90 was at a pedal cadence of 90 rev.min-1. There were no signifi cant difference between the cadences tested in terms of HRmax (test60: 189.7±12.0 beats.min-1; test90: 190.9±10.7 beats.min-1, RPEmax (test60: 20.0±0.3; test90: 20.0±1.0 or DBPmean (test60: 76.7±4.9 mmHg; test90: 79.1 ± 5.3 mmHg. On the other hand, the values of POmax (test60: 344.6±70.1 W; test90: 285.7±61.8 W, SBPmax (test60: 186.1±14.7 mmHg; test90: 202.1±21.5 mmHg and DPmax (test60: 35402.9±4431.7; test90: 38655.0±5270.5 were different. In relation to the behavior of the variables during the tests, there were signifi cant difference in HR between the tests up to a level of 225 W. It was observed that neither RPE or DBP indicated signifi cant difference in absolute power. There were only differences in SBP and DP between the cadences at 300 W absolute power. With this, it is clear that to carry out maximum tests, even in protocols that do not prescribe the pedal cadence, it appears thet a 60 rev.min-1 pedalling speed is indicated. ABSTRACT O objetivo deste estudo foi comparar as respostas das variáveis potência máxima (Pmax, freqüência cardíaca (FC, percepção de esforço (PE, pressão arterial sistólica (PAS, pressão arterial diastólica (PAD e duplo produto (DP na carga m

  10. Inhaled Beta2-agonist increases power output and glycolysis during sprinting in men

    DEFF Research Database (Denmark)

    Kalsen, Anders; Hostrup, Morten; Söderlund, Karin

    2016-01-01

    . Moreover, net rate of glycogenolysis (6.5±0.8 vs. 3.1±0.7 mmol glucosyl units kg dw s) and glycolysis (2.4±0.2 vs. 1.6±0.2 mmol glucosyl units kg dw s) were higher (P... and glycolysis in skeletal muscles. Furthermore, as terbutaline counteracted a reduction in ATP in type II fibers, terbutaline may postpone fatigue development in these fibers....

  11. Peak versus mean propulsive power outputs: which is more closely related to jump squat performance?

    Science.gov (United States)

    Loturco, Irineu; Pereira, Lucas A; Kobal, Ronaldo; Kitamura, Katia; Cal Abad, Cesar C; Nakamura, Fábio Y; Pai, Chi N

    2017-11-01

    This study aimed to compare the predictive value of muscle power (peak power, mean power until the peak-velocity or mean propulsive power) in relation to the jump height achieved during the jump squat performed at different loads. One hundred and ninety-four elite athletes performed jump squats against loads corresponding to 40%, 60%, and 80% of their respective body mass. A linear regression analysis was performed to establish the relationship between muscle power expressions and jump squat height. The coefficient of determination (R2) in the different linear regression models between muscle power-related variables and jump squat height, for the different load ranges, varied from 0.50 to 0.57 (for absolute power values) and from 0.72 to 0.78 (for relative power values [W/kg]). The mean propulsive power presented similar capacity to predict the jump squat height as the peak power-related values. For all analyzed variables, this prediction power was increased when the absolute power values were normalized by the individuals' body mass. Selection of the values related to the mean propulsive phase to assess top-level athletes might be considered as an advantageous alternative, due to its adequacy to properly reflect the neuromuscular potential of the subjects in both ballistic and traditional exercises.

  12. The relationship between passive stiffness and muscle power output: influence of muscle cross-sectional area normalization.

    Science.gov (United States)

    Palmer, Ty B; Jenkins, Nathaniel D M; Thompson, Brennan J; Smith, Douglas B; Cramer, Joel T

    2014-01-01

    We examined the relationship between passive stiffness of posterior hip and thigh muscles and muscle power output before and after normalization of passive stiffness to muscle cross-sectional area (CSA). Pearson correlation coefficients (r) were used to assess the relationships between the normalized and non-normalized slopes of the initial (phase 1) and final (phase 2) portions of the angle-torque curve and peak power output (Pmax). A significant positive relationship was observed between the non-normalized slope of phase 1 and Pmax (r = 0.723; P ≤ 0.001); however, no correlations were observed between the normalized slope of phase 1 and Pmax (r = 0.244; P = 0.299) nor between Pmax and the normalized and non-normalized slopes of phase 2 (r = -0.159-0.418; P = 0.067-0.504). The findings suggest that muscle size, rather than stiffness, accounted for a significant portion of the variance in muscle power output. Copyright © 2013 Wiley Periodicals, Inc.

  13. CFD Study on Aerodynamic Power Output Changes with Inter-Turbine Spacing Variation for a 6 MW Offshore Wind Farm

    Directory of Open Access Journals (Sweden)

    Nak Joon Choi

    2014-11-01

    Full Text Available This study examined the aerodynamic power output change of wind turbines with inter-turbine spacing variation for a 6 MW wind farm composed of three sets of 2 MW wind turbines using computational fluid dynamics (CFD. The wind farm layout design is becoming increasingly important as the use of wind energy is steadily increasing. Among the many wind farm layout design parameters, the inter-turbine spacing is a key factor in the initial investment cost, annual energy production and maintenance cost. The inter-turbine spacing should be determined to maximize the annual energy production and minimize the wake effect, turbulence effect and fatigue load during the service lifetime of wind turbines. Therefore, some compromise between the aerodynamic power output of wind turbines and the inter-turbine spacing is needed. An actuator disc model with the addition of a momentum source was not used, and instead, a full 3-dimensional model with a tower and nacelle was used for CFD analysis because of its great technical significance. The CFD analysis results, such as the aerodynamic power output, axial direction wind speed change, pressure drop across the rotor of wind turbine, and wind speed deficit due to the wake effect with inter-turbine spacing variation, were studied. The results of this study can be applied effectively to wind farm layout design and evaluation.

  14. The relative power output and relative lean body mass of World and Olympic male and female champions with implications for gender equity.

    Science.gov (United States)

    Stefani, Raymond T

    2006-12-01

    A uniform measure of the gender-related differential performance of female and male Olympic and World champions is proposed: relative power output applied to the environment. Laws of physics are employed to derive equations for estimating relative power output. In previous controlled laboratory studies, equally trained male and female athletes were shown to have a relative power output not significantly different from relative lean body mass. As to the estimated power output for 32 Olympic and World championship events contested between 1976 and 2004, eight in running, four in speed skating, three in jumping, twelve in swimming and five in rowing: 100% of the 32 event mean percentage differences in power output and 96% of the 411 event percentage differences in power output are within one standard deviation of the appropriate lean body mass percentage difference, consistent with equality of training. For 1952-1972, significantly higher percentage differences in power output are estimated in running and swimming compared with 1976-2004, consistent with women being less well trained than men during that earlier period. It is noted that efforts in recent years to provide equality of opportunity for female athletes coincide with equalization of estimated relative power output in competition with the relative lean body mass.

  15. Electrical output of bryophyte microbial fuel cell systems is sufficient to power a radio or an environmental sensor

    Science.gov (United States)

    Dennis, Ross J.; Felder, Fabienne; Cooper, Matt B.; Royles, Jessica; Harrison, Susan T. L.; Smith, Alison G.; Howe, Christopher J.

    2016-01-01

    Plant microbial fuel cells are a recently developed technology that exploits photosynthesis in vascular plants by harnessing solar energy and generating electrical power. In this study, the model moss species Physcomitrella patens, and other environmental samples of mosses, have been used to develop a non-vascular bryophyte microbial fuel cell (bryoMFC). A novel three-dimensional anodic matrix was successfully created and characterized and was further tested in a bryoMFC to determine the capacity of mosses to generate electrical power. The importance of anodophilic microorganisms in the bryoMFC was also determined. It was found that the non-sterile bryoMFCs operated with P. patens delivered over an order of magnitude higher peak power output (2.6 ± 0.6 µW m−2) than bryoMFCs kept in near-sterile conditions (0.2 ± 0.1 µW m−2). These results confirm the importance of the microbial populations for delivering electrons to the anode in a bryoMFC. When the bryoMFCs were operated with environmental samples of moss (non-sterile) the peak power output reached 6.7 ± 0.6 mW m−2. The bryoMFCs operated with environmental samples of moss were able to power a commercial radio receiver or an environmental sensor (LCD desktop weather station). PMID:27853542

  16. Timing of the compensation of winter respiratory carbon losses provides explanatory power for net ecosystem productivity of forests

    DEFF Research Database (Denmark)

    Haeni, M.; Zweifel, R.; Eugster, W.

    2017-01-01

    , and Australia, using different NEPc integration methods. We found cDOY to be a particularly powerful predictor for NEPc of temperate evergreen needle-leaf forests (R2 = 0.58) and deciduous broadleaf forests (R2 = 0.68). In general, the latest cDOY correlated with the lowest NEPc. The explanatory power of c......Accurate predictions of net ecosystem productivity (NEPc) of forest ecosystems are essential for climate change decisions and requirements in the context of national forest growth and greenhouse gas inventories. However, drivers and underlying mechanisms determining NEPc (e.g. climate, nutrients......) are not entirely understood yet, particularly when considering the influence of past periods. Here we explored the explanatory power of the compensation day (cDOY) —defined as the day of year when winter net carbon losses are compensated by spring assimilation— for NEPc in 26 forests in Europe, North America...

  17. Downscaling Solar Power Output to 4-Seconds for Use in Integration Studies (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Hummon, M.; Weekley, A.; Searight, K.; Clark, K.

    2013-10-01

    High penetration renewable integration studies require solar power data with high spatial and temporal accuracy to quantify the impact of high frequency solar power ramps on the operation of the system. Our previous work concentrated on downscaling solar power from one hour to one minute by simulation. This method used clearness classifications to categorize temporal and spatial variability, and iterative methods to simulate intra-hour clearness variability. We determined that solar power ramp correlations between sites decrease with distance and the duration of the ramp, starting at around 0.6 for 30-minute ramps between sites that are less than 20 km apart. The sub-hour irradiance algorithm we developed has a noise floor that causes the correlations to approach ~0.005. Below one minute, the majority of the correlations of solar power ramps between sites less than 20 km apart are zero, and thus a new method to simulate intra-minute variability is needed. These intra-minute solar power ramps can be simulated using several methods, three of which we evaluate: a cubic spline fit to the one-minute solar power data; projection of the power spectral density toward the higher frequency domain; and average high frequency power spectral density from measured data. Each of these methods either under- or over-estimates the variability of intra-minute solar power ramps. We show that an optimized weighted linear sum of methods, dependent on the classification of temporal variability of the segment of one-minute solar power data, yields time series and ramp distributions similar to measured high-resolution solar irradiance data.

  18. Intra-Minute Cloud Passing Forecasting Based on a Low Cost IoT Sensor-A Solution for Smoothing the Output Power of PV Power Plants.

    Science.gov (United States)

    Sukič, Primož; Štumberger, Gorazd

    2017-05-13

    Clouds moving at a high speed in front of the Sun can cause step changes in the output power of photovoltaic (PV) power plants, which can lead to voltage fluctuations and stability problems in the connected electricity networks. These effects can be reduced effectively by proper short-term cloud passing forecasting and suitable PV power plant output power control. This paper proposes a low-cost Internet of Things (IoT)-based solution for intra-minute cloud passing forecasting. The hardware consists of a Raspberry PI Model B 3 with a WiFi connection and an OmniVision OV5647 sensor with a mounted wide-angle lens, a circular polarizing (CPL) filter and a natural density (ND) filter. The completely new algorithm for cloud passing forecasting uses the green and blue colors in the photo to determine the position of the Sun, to recognize the clouds, and to predict their movement. The image processing is performed in several stages, considering selectively only a small part of the photo relevant to the movement of the clouds in the vicinity of the Sun in the next minute. The proposed algorithm is compact, fast and suitable for implementation on low cost processors with low computation power. The speed of the cloud parts closest to the Sun is used to predict when the clouds will cover the Sun. WiFi communication is used to transmit this data to the PV power plant control system in order to decrease the output power slowly and smoothly.

  19. Human Muscle Power Output during Upper- and Lower-Body Exercises.

    Science.gov (United States)

    Siegel, Judith A.; Gilders, Roger M.; Staron, Robert S.; Hagerman, Fredrick C.

    2002-01-01

    Evaluated the use of traditional resistance training equipment in measuring muscular power, measuring the velocity of movement through a measured distance during maximal effort lifts using a Smith rack. Data collected on male volunteers indicated that this method of evaluating muscle power was reliable, although it was not predictive of muscle…

  20. Myosin light chain phosphorylation is required for peak power output of mouse fast skeletal muscle in vitro.

    Science.gov (United States)

    Bowslaugh, Joshua; Gittings, William; Vandenboom, Rene

    2016-11-01

    The skeletal myosin light chain kinase (skMLCK) catalyzed phosphorylation of the myosin regulatory light chain (RLC) is associated with potentiation of force, work, and power in rodent fast twitch muscle. The purpose of this study was to compare concentric responses of EDL from wild-type (WT) and skMLCK devoid (skMLCK(-/-)) muscles at a range of shortening speeds (0.05 to 0.70 V max) around that expected to produce maximal power (in vitro, 25 °C) both before (unpotentiated) and after (potentiated) a potentiating stimulus (PS). When collapsed across all speeds tested, neither unpotentiated force, work, or power differed between genotypes (all data n = 10, P muscles. For example, when collapsed across the six fastest speeds we tested, both concentric force and power were increased 30-34 % in WT but only 15-17 % in skMLCK(-/-) muscles. In contrast, at the two slowest speeds, these parameters were increased in WT but decreased in skMLCK(-/-) muscles (8-10 and 7-9 %, respectively). Intriguingly, potentiation of concentric force and power was optimal near speeds producing maximal power in both genotypes. Because the PS elevated RLC phosphorylation above resting levels in WT but not in skMLCK(-/-) muscles, our data suggest that skMLCK-catalyzed phosphorylation of the RLC is required for maximal concentric power output of mouse EDL muscle stimulated at high frequency in vitro.

  1. High power Er:YAG laser with radially-polarized Laguerre-Gaussian (LG01) mode output

    Science.gov (United States)

    Kim, J. W.; MacKenzie, J. I.; Hayes, J. R.; Clarkson, W. A.

    2011-07-01

    A simple method for conditioning the pump beam in an end-pumped solid-state laser to allow direct excitation of the first order Laguerre-Gaussian doughnut (LG01) mode is reported. This approach has been applied to a hybrid (fiber-laser-pumped) Er:YAG laser yielding 13.1 W of continuous-wave output at 1645 nm in a radially-polarized LG01 doughnut beam with beam propagation factor (M2) < 2.4 for 34 W of incident pump power at 1532 nm. The corresponding slope efficiency with respect to incident pump power was 48%. The prospects of further power scaling and improved laser performance are discussed.

  2. Low power low temperature poly-Si thin-film transistor shift register with DC-type output driver

    Science.gov (United States)

    Song, Seok-Jeong; Kim, Byung Hoon; Jang, Jin; Nam, Hyoungsik

    2015-09-01

    This paper demonstrates a low power DC-type low temperature poly-Si (LTPS) thin-film transistor (TFT) shift register that consists of nine TFTs and one bootstrapping capacitor. The proposed circuit connects large size pull-up TFTs of output drivers to positive supply instead of alternating clock signals in order to reduce substantially the power consumption of clock drivers. The SPICE simulation ensures that the variable overlap intervals can be programmed by the delay between clock signals and the overall power consumption of a DC-type circuit can be reduced to 45% of an AC-type one for a full-HD display. The operation of a proposed structure is also verified with a fabricated 16-stage gate driver.

  3. Single-frequency 1178nm SDL/Yb-PBGF MOPA with an output power of 31 W

    Science.gov (United States)

    Leinonen, Tomi; Chen, Mingchen; Fan, Xinyan; Kantola, Emmi; Shirakawa, Akira; Guina, Mircea

    2014-03-01

    We report on the use of a Semiconductor Disk Laser (SDL) as a seed laser for an Ytterbium-Doped Photonic Bandgap Fiber (Yb-PBGF) amplifier in a Master-Oscillator Power-Amplifier (MOPA) configuration. The SDL comprised a GaInAs/GaAs/GaAsP gain chip, a 1-mm-thick etalon for mode selection, and a 3-mm-thick birefringent filter for wavelength tuning. The fiber amplifier consisted of an Yb-doped core surrounded by a structure of periodically arranged germanium rods with a pitch of 10.2 μm, and to maintain the polarization, the fiber comprised two boron rods. The output of the MOPA-configuration was 31 W and the linewidth of the amplifier output was 149±31 kHz.

  4. Technical Design of Flexible Thin-Film Solar Heating Clothes with Switchable Output Power

    Directory of Open Access Journals (Sweden)

    Zhao Yu Xiao

    2016-01-01

    Full Text Available This research focuses on the research and development of thermal clothes through technical design, by adopting unique removable electronic equipment and applying carbon fiber material to thermal clothes against cold, so as to meet the requirements of active heating and passive warmth retention. Firstly, the specification of power supply system was determined in accordance with the requirements of power system, and the specification of charging system was determined according to the specification of power system. Then circuit system was designed and tested. Fianlly, the electronic device was configured on the clothes appropriately, so that it should be conforms to ergonomic principles, convenient and fast.

  5. The acute effect of lower-body training on average power output measured by loaded half-squat jump exercise

    Directory of Open Access Journals (Sweden)

    Matúš Krčmár

    2015-09-01

    Full Text Available Background: High muscular power output is required in many athletic endeavors in order for success to be achieved. In the scientific community postactivation potentiation and its effect on performance are often discussed. There are many studies where the effect of resistance exercise on motor performance (such as vertical jump performance and running speed has been investigated but only a few of them studied power output. Objective: The purpose of this study was to determine the acute responses to a 2 set loaded half-squat jumps and 2 set loaded back half-squat protocols designed to induce the acute maximum average power output during loaded half-squat jumps. Methods: A randomized cross-over design was used. 11 participants of this study performed 3 trials in randomized order separated by at least 48 hours where maximum average power output was measured. The specific conditioning activities were comprised of 2 sets and 4 repetitions of half-squat jumps, 2 sets and 4 repetitions of back half-squat exercises and a control protocol without an intervention by specific a conditioning activity. Participants were strength trained athletes with different sport specializations (e.g. ice-hockey, volleyball. Mean age of the athletes was 22 ± 1.8 years, body mass 80 ± 7.1 kg and body height 185 ± 6.5 cm. Analysis of variance with repeated measures was used to determine differences between pre- and post-condition in each protocol, as well as between conditioning protocols, and also effect size was used to evaluate practical significance. Results: Maximum average power was significantly enhanced after application of the half-squat jump condition protocol (1496.2 ± 194.5 to 1552 ± 196.1 W, Δ ~ 3.72%, p < .001 and after application of the back half-squat protocol (1500.7 ± 193.2 to 1556 ± 191.2 W, Δ ~ 3.68%, p < .001 after 10 min of rest. Power output after control protocol was

  6. Brief communication: On the influence of vertical wind shear on the combined power output of two model wind turbines in yaw

    Directory of Open Access Journals (Sweden)

    J. Schottler

    2017-08-01

    Full Text Available The effect of vertical wind shear on the total power output of two aligned model wind turbines as a function of yaw misalignment of the upstream turbine is studied experimentally. It is shown that asymmetries of the power output of the downstream turbine and the combined power of both with respect to the upstream turbine's yaw misalignment angle can be linked to the vertical wind shear of the inflow.

  7. Local and regional effects of large scale atmospheric circulation patterns on winter wind power output in Western Europe

    Science.gov (United States)

    Zubiate, Laura; McDermott, Frank; Sweeney, Conor; O'Malley, Mark

    2014-05-01

    Recent studies (Brayshaw, 2009, Garcia-Bustamante, 2010, Garcia-Bustamante, 2013) have drawn attention to the sensitivity of wind speed distributions and likely wind energy power output in Western Europe to changes in low-frequency, large scale atmospheric circulation patterns such as the North Atlantic Oscillation (NAO). Wind speed variations and directional shifts as a function of the NAO state can be larger or smaller depending on the North Atlantic region that is considered. Wind speeds in Ireland and the UK for example are approximately 20 % higher during NAO + phases, and up to 30 % lower during NAO - phases relative to the long-term (30 year) climatological means. By contrast, in southern Europe, wind speeds are 15 % lower than average during NAO + phases and 15 % higher than average during NAO - phases. Crucially however, some regions such as Brittany in N.W. France have been identified in which there is negligible variability in wind speeds as a function of the NAO phase, as observed in the ERA-Interim 0.5 degree gridded reanalysis database. However, the magnitude of these effects on wind conditions is temporally and spatially non-stationary. As described by Comas-Bru and McDermott (2013) for temperature and precipitation, such non-stationarity is caused by the influence of two other patterns, the East Atlantic pattern, (EA), and the Scandinavian pattern, (SCA), which modulate the position of the NAO dipole. This phenomenon has also implications for wind speeds and directions, which has been assessed using the ERA-Interim reanalysis dataset and the indices obtained from the PC analysis of sea level pressure over the Atlantic region. In order to study the implications for power production, the interaction of the NAO and the other teleconnection patterns with local topography was also analysed, as well as how these interactions ultimately translate into wind power output. The objective is to have a better defined relationship between wind speed and power

  8. SIMULATING MODEL OF SYSTEM FOR MAXIMUM OUTPUT POWER OF SOLAR BATTERY

    Directory of Open Access Journals (Sweden)

    Abdul Majid Al-Khatib

    2005-01-01

    Full Text Available Simulating model and algorithm for control of electric power converter of a solar battery are proposed in the paper. Control device of D.C. step-down converter with pulse-width modulation is designed on microprocessor basis. Simulating model permits to investigate various operational modes of a solar battery, demonstrates a process with maximum power mode and is characterized by convenient user’s interface.

  9. Limits and Optimization of Power Input or Output of Actual Thermal Cycles

    OpenAIRE

    Emin Açıkkalp; Hasan Yamık

    2013-01-01

    In classical thermodynamic, maximum power obtained from system (or minimum power supplied to system) defined as availability (exergy), but availability term is only used for reversible systems. In reality, there is no reversible system, all systems are irreversible, because reversible cycles doesn’t include constrains like time or size and they operates in quasi-equilibrium state. Purpose of this study is to define limits of the all basic thermodynamic cycles and to provide finite-time exergy...

  10. Strong doping of the n-optical confinement layer for increasing output power of high- power pulsed laser diodes in the eye safe wavelength range

    Science.gov (United States)

    Ryvkin, Boris S.; Avrutin, Eugene A.; Kostamovaara, Juha T.

    2017-12-01

    An analytical model for internal optical losses at high power in a 1.5 μm laser diode with strong n-doping in the n-side of the optical confinement layer is created. The model includes intervalence band absorption by holes supplied by both current flow and two-photon absorption (TPA), as well as the direct TPA effect. The resulting losses are compared with those in an identical structure with a weakly doped waveguide, and shown to be substantially lower, resulting in a significant improvement in the output power and efficiency in the structure with a strongly doped waveguide.

  11. An Artificial Neural Network Compensated Output Feedback Power-Level Control for Modular High Temperature Gas-Cooled Reactors

    Directory of Open Access Journals (Sweden)

    Zhe Dong

    2014-02-01

    Full Text Available Small modular reactors (SMRs could be beneficial in providing electricity power safely and also be viable for applications such as seawater desalination and heat production. Due to its inherent safety features, the modular high temperature gas-cooled reactor (MHTGR has been seen as one of the best candidates for building SMR-based nuclear power plants. Since the MHTGR dynamics display high nonlinearity and parameter uncertainty, it is necessary to develop a nonlinear adaptive power-level control law which is not only beneficial to the safe, stable, efficient and autonomous operation of the MHTGR, but also easy to implement practically. In this paper, based on the concept of shifted-ectropy and the physically-based control design approach, it is proved theoretically that the simple proportional-differential (PD output-feedback power-level control can provide asymptotic closed-loop stability. Then, based on the strong approximation capability of the multi-layer perceptron (MLP artificial neural network (ANN, a compensator is established to suppress the negative influence caused by system parameter uncertainty. It is also proved that the MLP-compensated PD power-level control law constituted by an experientially-tuned PD regulator and this MLP-based compensator can guarantee bounded closed-loop stability. Numerical simulation results not only verify the theoretical results, but also illustrate the high performance of this MLP-compensated PD power-level controller in suppressing the oscillation of process variables caused by system parameter uncertainty.

  12. Muscle contractile properties as an explanation of the higher mean power output in marmosets than humans during jumping.

    Science.gov (United States)

    Plas, Rogier L C; Degens, Hans; Meijer, J Peter; de Wit, Gerard M J; Philippens, Ingrid H C H M; Bobbert, Maarten F; Jaspers, Richard T

    2015-07-01

    The muscle mass-specific mean power output (PMMS,mean) during push-off in jumping in marmosets (Callithrix jacchus) is more than twice that in humans. In the present study it was tested whether this is attributable to differences in muscle contractile properties. In biopsies of marmoset m. vastus lateralis (VL) and m. gastrocnemius medialis (GM) (N=4), fibre-type distribution was assessed using fluorescent immunohistochemistry. In single fibres from four marmoset and nine human VL biopsies, the force-velocity characteristics were determined. Marmoset VL contained almost exclusively fast muscle fibres (>99.0%), of which 63% were type IIB and 37% were hybrid fibres, fibres containing multiple myosin heavy chains. GM contained 9% type I fibres, 44% type IIB and 47% hybrid muscle fibres. The proportions of fast muscle fibres in marmoset VL and GM were substantially larger than those reported in the corresponding human muscles. The curvature of the force-velocity relationships of marmoset type IIB and hybrid fibres was substantially flatter than that of human type I, IIA, IIX and hybrid fibres, resulting in substantially higher muscle fibre mass-specific peak power (PFMS,peak). Muscle mass-specific peak power output (PMMS,peak) values of marmoset whole VL and GM, estimated from their fibre-type distributions and force-velocity characteristics, were more than twice the estimates for the corresponding human muscles. As the relative difference in estimated PMMS,peak between marmosets and humans is similar to that of PMMS,mean during push-off in jumping, it is likely that the difference in in vivo mechanical output between humans and marmosets is attributable to differences in muscle contractile properties. © 2015. Published by The Company of Biologists Ltd.

  13. Multicanonical evaluation of the tails of the probability density function of semiconductor optical amplifier output power fluctuations

    DEFF Research Database (Denmark)

    Tromborg, Bjarne; Reimer, Michael; Yevick, David

    2010-01-01

    This paper presents a multicanonical Monte Carlo method for simulating the tails of a pdf distribution of the filtered output power from a semiconductor optical amplifier down to values of the order of 10−40. The influence of memory effects on the pdf is examined in order to demonstrate the manner...... in which the calculated pdf approaches the true pdf with increasing integration time. The simulated pdf is shown to be in good agreement with a second order analytic expression for the pdf....

  14. High-current pulsed electron accelerator “Gamma-1” with output power up to 1.5 TW

    Science.gov (United States)

    Zavyalov, N. V.; Gordeev, V. S.; Punin, V. T.; Grishin, A. V.; Myskov, G. A.; Nazarenko, S. T.; Mikhailov, E. S.; Kalashnikov, D. A.; Kozachek, A. V.; Pavlov, V. S.; Strabykin, K. V.; Glushkov, S. L.; Puchagin, S. Yu.; Mayornikova, V. L.; Mayorov, R. A.; Moiseevskikh, M. A.

    2014-08-01

    A multi-module multi-terawatt electrophysical facility “Gamma” is being developed at RFNCVNIIEF, Sarov, Russia. The facility will be used for conducting experiments in different fields of radiation physics. The first module of the facility - a high-current electron accelerator “Gamma-1” has been created. The output electric parameters of the module are as follows: electron energy ≤2.0 MeV, diode current 0.75 MA, maximal electric power 1.5 TW. Description of accelerator design and principles of its operation are presented. Results of experiments as well as further prospects on building a full-scale facility are given.

  15. Saturated Adaptive Output-Feedback Power-Level Control for Modular High Temperature Gas-Cooled Reactors

    Directory of Open Access Journals (Sweden)

    Zhe Dong

    2014-11-01

    Full Text Available Small modular reactors (SMRs are those nuclear fission reactors with electrical output powers of less than 300 MWe. Due to its inherent safety features, the modular high temperature gas-cooled reactor (MHTGR has been seen as one of the best candidates for building SMR-based nuclear plants with high safety-level and economical competitive power. Power-level control is crucial in providing grid-appropriation for all types of SMRs. Usually, there exists nonlinearity, parameter uncertainty and control input saturation in the SMR-based plant dynamics. Motivated by this, a novel saturated adaptive output-feedback power-level control of the MHTGR is proposed in this paper. This newly-built control law has the virtues of having relatively neat form, of being strong adaptive to parameter uncertainty and of being able to compensate control input saturation, which are given by constructing Lyapunov functions based upon the shifted-ectropies of neutron kinetics and reactor thermal-hydraulics, giving an online tuning algorithm for the controller parameters and proposing a control input saturation compensator respectively. It is proved theoretically that input-to-state stability (ISS can be guaranteed for the corresponding closed-loop system. In order to verify the theoretical results, this new control strategy is then applied to the large-range power maneuvering control for the MHTGR of the HTR-PM plant. Numerical simulation results show not only the relationship between regulating performance and control input saturation bound but also the feasibility of applying this saturated adaptive control law practically.

  16. A Novel Device for Total Acoustic Output Measurement of High Power Transducers

    Science.gov (United States)

    Howard, S.; Twomey, R.; Morris, H.; Zanelli, C. I.

    2010-03-01

    The objective of this work was to develop a device for ultrasound power measurement applicable over a broad range of medical transducer types, orientations and powers, and which supports automatic measurements to simplify use and minimize errors. Considering all the recommendations from standards such as IEC 61161, an accurate electromagnetic null-balance has been designed for ultrasound power measurements. The sensing element is placed in the water to eliminate errors due to surface tension and water evaporation, and the motion and detection of force is constrained to one axis, to increase immunity to vibration from the floor, water sloshing and water surface waves. A transparent tank was designed so it could easily be submerged in a larger tank to accommodate large transducers or side-firing geometries, and can also be turned upside-down for upward-firing transducers. A vacuum lid allows degassing the water and target in situ. An external control module was designed to operate the sensing/driving loop and to communicate to a local computer for data logging. The sensing algorithm, which incorporates temperature compensation, compares the feedback force needed to cancel the motion for sources in the "on" and "off" states. These two states can be controlled by the control unit or manually by the user, under guidance by a graphical user interface (the system presents measured power live during collection). Software allows calibration to standard weights, or to independently calibrated acoustic sources. The design accommodates a variety of targets, including cone, rubber, brush targets and an oil-filled target for power measurement via buoyancy changes. Measurement examples are presented, including HIFU sources operating at powers from 1 to 100.

  17. Gait Variability Related to Muscle Quality and Muscle Power Output in Frail Nonagenarian Older Adults.

    Science.gov (United States)

    Martinikorena, Ion; Martínez-Ramírez, Alicia; Gómez, Marisol; Lecumberri, Pablo; Casas-Herrero, Alvaro; Cadore, Eduardo L; Millor, Nora; Zambom-Ferraresi, Fabricio; Idoate, Fernando; Izquierdo, Mikel

    2016-02-01

    Frailty has become the center of attention of basic, clinical, and demographic research because of its incidence level and the gravity of adverse outcomes with age. Moreover, with advanced age, motor variability increases, particularly in gait. Muscle quality and muscle power seem to be closely associated with performance on functional tests in frail populations. Insight into the relationships among muscle power, muscle quality, and functional capacity could improve the quality of life in this population. In this study, the relationship between the quality of the muscle mass and muscle strength with gait performance in a frail population was examined. Twenty-two institutionalized frail elderly individuals (93.1 ± 3.6) participated in this study. Muscle quality was measured by segmenting areas of high- and low-density fibers as observed in computed tomography images. The assessed functional outcomes were leg strength and power, velocity of gait, and kinematic gait parameters obtained from a tri-axial inertial sensor. Our results showed that a greater number of high-density fibers, specifically those of the quadriceps femoris muscle, were associated with better gait performance in terms of step time variability, regularity, and symmetry. Additionally, gait variability was associated with muscle power. In contrast, no significant relationship was observed between gait velocity and either muscle quality or muscle power. Gait pattern disorders could be explained by a deterioration of the lower limb muscles. It is known that an impaired gait is an important predictor of falls in older populations; thus, the loss of muscle quality and power could underlie the impairments in motor control and balance that lead to falls and adverse outcomes. Copyright © 2016 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

  18. High-efficiency, high-output-power antiguide laser diode arrays

    Science.gov (United States)

    Mehuys, D.; Major, J. S., Jr.; Welch, D.; Scifres, D. R.

    1992-01-01

    Antiguide laser arrays have been fabricated and operated up to peak pulsed powers of 7.7 W in a beam with a full-width at half-maximum in the main lobe of 0.7 deg. Up to 0.7 W of continuous wave power is emitted into a radiation pattern 2.5 times the diffraction limit. By varying the temperature of the array to vary the operating wavelength of the device, the threshold gain condition of the array modes is altered, allowing thermal tuning of the far field of the device.

  19. Electrical power converter method and system employing multiple-output converters

    Science.gov (United States)

    Beihoff, Bruce C.; Radosevich, Lawrence D.; Meyer, Andreas A.; Gollhardt, Neil; Kannenberg, Daniel G.

    2006-03-21

    A support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. The support, in conjunction with other packaging features may form a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

  20. Model Predictive Current Control for High-Power Grid-Connected Converters with Output LCL Filter

    DEFF Research Database (Denmark)

    Delpino, Hernan Anres Miranda; Teodorescu, Remus; Rodriguez, Pedro

    2009-01-01

    A model predictive control strategy for a highpower, grid connected 3-level neutral clamped point converter is presented. Power losses constraints set a limit on commutation losses so reduced switching frequency is required, thus producing low frequency current harmonics. To reduce these harmonics...... an LCL filter is used. The proposed control strategy allows control of the active and reactive power fed into the grid, reduce the switching frequency within acceptable operational margins and keep balance of the DC-link capacitor voltages while avoiding excitation of the filter resonance frequencies....

  1. Optimization of the output and efficiency of a high power cascaded arc hydrogen plasma source

    NARCIS (Netherlands)

    Vijvers, W. A. J.; van Gils, C. A. J.; W. J. Goedheer,; van der Meiden, H. J.; D.C. Schram,; Veremiyenko, V. P.; Westerhout, J.; Cardozo, N. J. L.; van Rooij, G. J.

    2008-01-01

    The operation of a cascaded arc hydrogen plasma source was experimentally investigated to provide an empirical basis for the scaling of this source to higher plasma fluxes and efficiencies. The flux and efficiency were determined as a function of the input power, discharge channel diameter, and

  2. Controlling the Power Output of a Nuclear Reactor with Fuzzy Logic

    NARCIS (Netherlands)

    Ruan, D.; Wal, A.J. van der

    1997-01-01

    The application of fuzzy logic control (FLC) in the domain of nuclear industry presents a tremendous challenge. The main reason for this is the public awareness of the risks of nuclear reactors and the very strict safety regulations in force for nuclear power plants. The very same regulations

  3. Controlling the power output of a nuclear reactor with fuzzy logic

    NARCIS (Netherlands)

    Ruan, D.; Wal, A.J. van der

    1998-01-01

    The application of fuzzy logic control (FLC) in the domain of nuclear industry presents a tremendous challenge. The main reason for this is the public awareness of the risks of nuclear reactors and the very strict safety regulations in force for nuclear power plants. The very same regulations

  4. Predictability of the Power Output of Three Wave Energy Technologies in the Danish North Sea

    DEFF Research Database (Denmark)

    Chozas, Julia Fernandez; Jensen, N. E. Helstrup; Sørensen, H. C.

    2011-01-01

    , during a very energetic time period. Results show that for the 12 to 36 hours time horizon forecast, the accuracy in the predictions (in terms of scatter index) of the significant wave height, zero crossing period and wave power are 22%, 11% and 68%, respectively; and the accuracy in the predictions...

  5. Two-Stage Robust Security-Constrained Unit Commitment with Optimizable Interval of Uncertain Wind Power Output

    Directory of Open Access Journals (Sweden)

    Dayan Sun

    2017-01-01

    Full Text Available Because wind power spillage is barely considered, the existing robust unit commitment cannot accurately analyze the impacts of wind power accommodation on on/off schedules and spinning reserve requirements of conventional generators and cannot consider the network security limits. In this regard, a novel double-level robust security-constrained unit commitment formulation with optimizable interval of uncertain wind power output is firstly proposed in this paper to obtain allowable interval solutions for wind power generation and provide the optimal schedules for conventional generators to cope with the uncertainty in wind power generation. The proposed double-level model is difficult to be solved because of the invalid dual transform in solution process caused by the coupling relation between the discrete and continuous variables. Therefore, a two-stage iterative solution method based on Benders Decomposition is also presented. The proposed double-level model is transformed into a single-level and two-stage robust interval unit commitment model by eliminating the coupling relation, and then this two-stage model can be solved by Benders Decomposition iteratively. Simulation studies on a modified IEEE 26-generator reliability test system connected to a wind farm are conducted to verify the effectiveness and advantages of the proposed model and solution method.

  6. Analysis of Upper Bound Power Output for a Wrist-Worn Rotational Energy Harvester from Real-World Measured Inputs

    Science.gov (United States)

    Xue, T.; Ma, X.; Rahn, C.; Roundy, S.

    2014-11-01

    Energy harvesting from human motion addresses the growing need for battery-free health and wellness sensors in wearable applications. The major obstacles to harvesting energy in such applications are low and random frequencies due to the nature of human motion. This paper presents a generalized rotational harvester model in 3 dimensions to determine the upper bound of power output from real world measured data. Simulation results indicate much space for improvement on power generation comparing to existing devices. We have developed a rotational energy harvester for human motion that attempts to close the gap between theoretical possibility and demonstrated devices. Like previous work, it makes use of magnetically plucked piezoelectric beams. However, it more fully utilizes the space available and has many degrees of freedom available for optimization. Finally we present a prototype harvester based on the coupled harvester model with preliminary experimental validation.

  7. Wind Farm Active Power Dispatch for Output Power Maximizing Based on a Wind Turbine Control Strategy for Load Minimizing

    DEFF Research Database (Denmark)

    Zhang, Baohua; Hu, Weihao; Hou, Peng

    2015-01-01

    Inclusion of the wake effect in the wind farm control design (WF) can increase the total captured power by wind turbines (WTs), which is usually implemented by derating upwind WTs. However, derating the WT without a proper control strategy will increase the structural loads, caused by operation...... algorithm is used for solving the problem. Simulation results show the effectiveness of the proposed strategy....

  8. Measurement Of Trailing Edge Noise using Directional Array and Coherent Output Power Methods

    Science.gov (United States)

    Hutcheson, Florence V.; Brooks, Thomas F.

    2002-01-01

    The use of a directional array of microphones for the measurement of trailing edge (TE) noise is described. The capabilities of this method are evaluated via measurements of TE noise from a NACA 63-215 airfoil model and from a cylindrical rod. This TE noise measurement approach is compared to one that is based on the cross spectral analysis of output signals from a pair of microphones (COP method). Advantages and limitations of both methods are examined. It is shown that the microphone array can accurately measures TE noise and captures its two-dimensional characteristic over a large frequency range for any TE configuration as long as noise contamination from extraneous sources is within bounds. The COP method is shown to also accurately measure TE noise but over a more limited frequency range that narrows for increased TE thickness. Finally, the applicability and generality of an airfoil self-noise prediction method was evaluated via comparison to the experimental data obtained using the COP and array measurement methods. The predicted and experimental results are shown to agree over large frequency ranges.

  9. Low Power Digital Clock Design Using LVCMOS Input/Output Standards on 45nm FPGA

    DEFF Research Database (Denmark)

    Pandey, Sujeet; Mehta, Rishabh; Kalia, Kartik

    2016-01-01

    metal oxide semiconductor i.e. LVCMOS and 45nm Spartan-6 FPGA family is used for simulation and amount of total power consumed is noted down. There is 90.02%, 98.88%, 99.86% and 100% reduction in the clock when we scale down frequency from 100GHz to 10GHz, 1GHz, 0.1GHz, and 0.01GHz respectively....

  10. Nonlinear Adaptive Dynamic Output-Feedback Power-Level Control of Nuclear Heating Reactors

    Directory of Open Access Journals (Sweden)

    Zhe Dong

    2013-01-01

    Full Text Available Due to the high safety performance of small nuclear reactors, there is a promising future for small reactors. Nuclear heating reactor (NHR is a small reactor that has many advanced safety features such as the integrated arrangement, natural circulation at any power levels, self-pressurization, hydraulic control rod driving, and passive residual heating removing and can be applied to the fields of district heating, seawater desalination, and electricity production. Since the NHR dynamics has strong nonlinearity and uncertainty, it is meaningful to develop the nonlinear adaptive power-level control technique. From the idea of physically based control design method, a novel nonlinear adaptive power-level control is given for the NHR in this paper. It is theoretically proved that this newly built controller does not only provide globally asymptotic closed-loop stability but is also adaptive to the system uncertainty. Numerical simulation results show the feasibility of this controller and the relationship between the performance and controller parameters.

  11. Real-Time Wavelet-Based Coordinated Control of Hybrid Energy Storage Systems for Denoising and Flattening Wind Power Output

    Directory of Open Access Journals (Sweden)

    Tran Thai Trung

    2014-10-01

    Full Text Available Since the penetration level of wind energy is continuously increasing, the negative impact caused by the fluctuation of wind power output needs to be carefully managed. This paper proposes a novel real-time coordinated control algorithm based on a wavelet transform to mitigate both short-term and long-term fluctuations by using a hybrid energy storage system (HESS. The short-term fluctuation is eliminated by using an electric double-layer capacitor (EDLC, while the wind-HESS system output is kept constant during each 10-min period by a Ni-MH battery (NB. State-of-charge (SOC control strategies for both EDLC and NB are proposed to maintain the SOC level of storage within safe operating limits. A ramp rate limitation (RRL requirement is also considered in the proposed algorithm. The effectiveness of the proposed algorithm has been tested by using real time simulation. The simulation model of the wind-HESS system is developed in the real-time digital simulator (RTDS/RSCAD environment. The proposed algorithm is also implemented as a user defined model of the RSCAD. The simulation results demonstrate that the HESS with the proposed control algorithm can indeed assist in dealing with the variation of wind power generation. Moreover, the proposed method shows better performance in smoothing out the fluctuation and managing the SOC of battery and EDLC than the simple moving average (SMA based method.

  12. Measurement of unsteady loading and power output variability in a micro wind farm model in a wind tunnel

    Science.gov (United States)

    Bossuyt, Juliaan; Howland, Michael F.; Meneveau, Charles; Meyers, Johan

    2017-01-01

    Unsteady loading and spatiotemporal characteristics of power output are measured in a wind tunnel experiment of a microscale wind farm model with 100 porous disk models. The model wind farm is placed in a scaled turbulent boundary layer, and six different layouts, varied from aligned to staggered, are considered. The measurements are done by making use of a specially designed small-scale porous disk model, instrumented with strain gages. The frequency response of the measurements goes up to the natural frequency of the model, which corresponds to a reduced frequency of 0.6 when normalized by the diameter and the mean hub height velocity. The equivalent range of timescales, scaled to field-scale values, is 15 s and longer. The accuracy and limitations of the acquisition technique are documented and verified with hot-wire measurements. The spatiotemporal measurement capabilities of the experimental setup are used to study the cross-correlation in the power output of various porous disk models of wind turbines. A significant correlation is confirmed between streamwise aligned models, while staggered models show an anti-correlation.

  13. High-output-power, single-wavelength silicon hybrid laser using precise flip-chip bonding technology.

    Science.gov (United States)

    Tanaka, Shinsuke; Jeong, Seok-Hwan; Sekiguchi, Shigeaki; Kurahashi, Teruo; Tanaka, Yu; Morito, Ken

    2012-12-17

    An Si/III-V hybrid laser oscillating at a single wavelength was developed for use in a large-scale Si optical I/O chip. The laser had an InP-based reflective semiconductor optical amplifier (SOA) chip integrated with an Si wavelength-selection-mirror chip in a flip-chip configuration. A low coupling loss of 1.55 dB at the Si-SOA interface was accomplished by both mode-field-matching between Si-SOA waveguides and accurately controlling the bonding position. The fabricated Si hybrid laser exhibited a very low threshold current of 9.4 mA, a high output power of 15.0 mW, and a high wall-plug efficiency of 7.6% at 20 °C. Moreover, the device maintained a high output power of >10 mW up to 60°C due to the high thermal conductance between the SOA chip and Si substrate. The short cavity length of the flip-chip bonded laser expanded the longitudinal mode spacing. This resulted in temperature-stable single longitudinal mode lasing and a low RIN level of <-130 dB/Hz.

  14. Modeling of Combined Heat and Power Plant Based on a Multi-Stage Gasifier and Internal Combustion Engines of Various Power Outputs

    Science.gov (United States)

    Khudyakova, G. I.; Kozlov, A. N.; Svishchev, D. A.

    2017-11-01

    The paper is concerned with an integrated system of internal combustion engine and mini combined heat and power plant (ICE-CHP). The system is based on multi-stage wood biomass gasification. The use of producer gas in the system affects negatively the internal combustion engine performance and, therefore, reduces the efficiency of the ICE-CHP plant. A mathematical model of an internal combustion engine running on low-calorie producer gas was developed using an overview of Russian and foreign manufacturers of reciprocating units, that was made in the research. A thermal calculation was done for four-stroke gas engines of different rated power outputs (30, 100 and 250 kW), running on producer gas (CO2 – 10.2, CO – 45.8, N2 – 38.8%). Thermal calculation demonstrates that the engine exhaust gas temperature reaches 500 – 600°C at the rated power level and with the lower engine power, the temperature gets higher. For example, for an internal combustion engine power of 1000 kW the temperature of exhaust gases equals 400°C. A comparison of the efficiency of engine operation on natural gas and producer gas shows that with the use of producer gas the power output declines from 300 to 250 kWe. The reduction in the effective efficiency in this case makes up 2%. The measures are proposed to upgrade the internal combustion engine to enable it to run on low-calorie producer gas.

  15. Using an elastic magnifier to increase power output and performance of heart-beat harvesters

    Science.gov (United States)

    Galbier, Antonio C.; Karami, M. Amin

    2017-09-01

    Embedded piezoelectric energy harvesting (PEH) systems in medical pacemakers have been a growing and innovative research area. The goal of these systems, at present, is to remove the pacemaker battery, which makes up 60%-80% of the unit, and replace it with a sustainable power source. This requires that energy harvesting systems provide sufficient power, 1-3 μW, for operating a pacemaker. The goal of this work is to develop, test, and simulate cantilevered energy harvesters with a linear elastic magnifier (LEM). This research hopes to provide insight into the interaction between pacemaker energy harvesters and the heart. By introducing the elastic magnifier into linear and nonlinear systems oscillations of the tip are encouraged into high energy orbits and large tip deflections. A continuous nonlinear model is presented for the bistable piezoelectric energy harvesting (BPEH) system and a one-degree-of-freedom linear mass-spring-damper model is presented for the elastic magnifier. The elastic magnifier will not consider the damping negligible, unlike most models. A physical model was created for the bistable structure and formed to an elastic magnifier. A hydrogel was designed for the experimental model for the LEM. Experimental results show that the BPEH coupled with a LEM (BPEH + LEM) produces more power at certain input frequencies and operates a larger bandwidth than a PEH, BPEH, and a standard piezoelectric energy harvester with the elastic magnifier (PEH + LEM). Numerical simulations are consistent with these results. It was observed that the system enters high-energy and high orbit oscillations and that, ultimately, BPEH systems implemented in medical pacemakers can, if designed properly, have enhanced performance if positioned over the heart.

  16. HRR TEA CO2 laser with 220W average output power

    Directory of Open Access Journals (Sweden)

    M. Zand

    2008-03-01

    Full Text Available In this study, the design and construction of a pulse high repetition rate (HRR, transverse atmospheric pressure (TEA CO2 laser with ultra violet preionization is presented. In this laser, normal pure, industrial gases and also a combination of spark and corona preionization are used. In semi-sealed off condition, we obtained 220 watts at 300 Hz, %7.7 efficiency, 735 mJ/pulse. The best records that we reached separately were 1.1 J/pulse, 320 Hz PRR, 11 MW peak power and 10.6% efficiency .

  17. A Shrouded Wind Turbine Generating High Output Power with Wind-lens Technology

    OpenAIRE

    Yuji Ohya; Takashi Karasudani

    2010-01-01

    We have developed a new wind turbine system that consists of a diffuser shroud with a broad-ring brim at the exit periphery and a wind turbine inside it. The shrouded wind turbine with a brimmed diffuser has demonstrated power augmentation by a factor of about 2–5 compared with a bare wind turbine, for a given turbine diameter and wind speed. This is because a low-pressure region, due to a strong vortex formation behind the broad brim, draws more mass flow to the wind turbine inside the diffu...

  18. Evaluation of piezoelectric material properties for a higher power output from energy harvesters with insight into material selection using a coupled piezoelectric-circuit-finite element method.

    Science.gov (United States)

    Daniels, Alice; Zhu, Meiling; Tiwari, Ashutosh

    2013-12-01

    Piezoelectric material properties have substantial influence on electrical power output from piezoelectric energy harvesters (PEHs). Understanding their influences is the first step in designing effective PEHs to generate higher power outputs. This paper uses a coupled piezoelectric-circuit-finite element method to study the power outputs of different types of piezoelectric materials, including single crystal, polyvinylidene fluoride (PVDF), and soft and hard lead zirconate titanate (PZT) materials. The purpose of this study is to try to gain an understanding of which piezoelectric material property--the elastic compliance s11, the piezoelectric strain constant d31, the piezoelectric stress constant g31, and the relative dielectric constant ϵ(T)r33, and the associated material properties of the d31 × g31, called the figure of merit (FOM), and the coupling coefficient k31--dominates the power output. A rectangular piezoelectric plate under a low-frequency excitation is used to evaluate piezoelectric material properties for a higher power output. It was found that 1) d31 is a more dominant material property over other material properties for higher power output; 2) FOM was more linearly related to the power output than either the k31 or the d31; and 3) ϵ(T)r33 had some role; when the materials have an identical d31; a lower ϵ(T)r33 was preferred. Because of unexplained outliers, no single material parameter was able to be recommended as selection criteria, but combined FOM with d31 parameters is recommended for selection of piezoelectric material for a higher power output from PEHs.

  19. Doubling Power Output of Starch Biobattery Treated by the Most Thermostable Isoamylase from an Archaeon Sulfolobus tokodaii.

    Science.gov (United States)

    Cheng, Kun; Zhang, Fei; Sun, Fangfang; Chen, Hongge; Percival Zhang, Y-H

    2015-08-20

    Biobattery, a kind of enzymatic fuel cells, can convert organic compounds (e.g., glucose, starch) to electricity in a closed system without moving parts. Inspired by natural starch metabolism catalyzed by starch phosphorylase, isoamylase is essential to debranch alpha-1,6-glycosidic bonds of starch, yielding linear amylodextrin - the best fuel for sugar-powered biobattery. However, there is no thermostable isoamylase stable enough for simultaneous starch gelatinization and enzymatic hydrolysis, different from the case of thermostable alpha-amylase. A putative isoamylase gene was mined from megagenomic database. The open reading frame ST0928 from a hyperthermophilic archaeron Sulfolobus tokodaii was cloned and expressed in E. coli. The recombinant protein was easily purified by heat precipitation at 80 (o)C for 30 min. This enzyme was characterized and required Mg(2+) as an activator. This enzyme was the most stable isoamylase reported with a half lifetime of 200 min at 90 (o)C in the presence of 0.5 mM MgCl2, suitable for simultaneous starch gelatinization and isoamylase hydrolysis. The cuvett-based air-breathing biobattery powered by isoamylase-treated starch exhibited nearly doubled power outputs than that powered by the same concentration starch solution, suggesting more glucose 1-phosphate generated.

  20. Relationships between vertical jump and full squat power outputs with sprint times in u21 soccer players.

    Science.gov (United States)

    López-Segovia, Manuel; Marques, Mário C; van den Tillaar, Roland; González-Badillo, Juan J

    2011-12-01

    The aim of this study was to assess the relationship between power variables in the vertical jump and full squat with the sprint performance in soccer players. Fourteen under-21 soccer players were evaluated in two testing sessions separated by 7 days. In the first testing session, vertical jump height in countermovement was assessed, and power output for both loaded countermovement jump (CMJL) and full squat (FS) exercises in two progressive load tests. The second testing session included sprinting at 10, 20, and 30m (T10, T20, T30, T10-20, T10-30, T20-30). Power variables obtained in the loaded vertical jump with 20kg and full squat exercise with 70kg showed significant relationships with all split times (r=-0.56/-0.79; p≤ 0.01/0.01). The results suggest that power produced either with vertical jump or full squat exercises is an important factor to explain short sprint performance in soccer players. These findings might suggest that certain levels of neuromuscular activation are more related with sprint performance reflecting the greater suitability of loads against others for the improvement of short sprint ability in under-21 soccer players.

  1. ANN Sizing Procedure for the Day-Ahead Output Power Forecast of a PV Plant

    Directory of Open Access Journals (Sweden)

    Francesco Grimaccia

    2017-06-01

    Full Text Available Since the beginning of this century, the share of renewables in Europe’s total power capacity has almost doubled, becoming the largest source of its electricity production. In 2015 alone, photovoltaic (PV energy generation rose with a rate of more than 5%; nowadays, Germany, Italy, and Spain account together for almost 70% of total European PV generation. In this context, the so-called day-ahead electricity market represents a key trading platform, where prices and exchanged hourly quantities of energy are defined 24 h in advance. Thus, PV power forecasting in an open energy market can greatly benefit from machine learning techniques. In this study, the authors propose a general procedure to set up the main parameters of hybrid artificial neural networks (ANNs in terms of the number of neurons, layout, and multiple trials. Numerical simulations on real PV plant data are performed, to assess the effectiveness of the proposed methodology on the basis of statistical indexes, and to optimize the forecasting network performance.

  2. Winter respiratory C losses provide explanatory power for net ecosystem productivity

    NARCIS (Netherlands)

    Haeni, M.; Zweifel, R.; Eugster, W.; Gessler, A.; Zielis, S.; Bernhofer, C.; Carrara, A.; Grünwald, T.; Havránková, K.; Heinesch, B.; Marek, M.; Moors, E.; Schelhaas, M.J.; Buchmann, N.

    2017-01-01

    Accurate predictions of net ecosystem productivity (NEPc) of forest ecosystems are essential for climate change decisions and requirements in the context of national forest growth and greenhouse gas inventories. However, drivers and underlying mechanisms determining NEPc

  3. The necessity of distinguishing weak and strong disposability among undesirable outputs in DEA: Environmental performance of Chinese coal-fired power plants

    Energy Technology Data Exchange (ETDEWEB)

    Yang Hongliang, E-mail: h.yang.03@cantab.ne [Asia Development Bank, 6 ADB Avenue, Metro Manila 1550 (Philippines); Pollitt, Michael, E-mail: m.pollitt@jbs.cam.ac.u [Judge Business School, University of Cambridge, Cambridge CB2 1AG (United Kingdom)

    2010-08-15

    Different from previous efficiency researches, which normally assume a uniform disposability for all undesirable outputs in a production process, this paper proposes a model that distinguishes weak and strong disposability assumptions among various undesirable outputs based on their respective technical features. The paper illustrates the approach using a research sample covering 582 base-load Chinese coal-fired power plants in 2002. The final results show that imposing the technically correct disposability features on undesirable outputs makes a significant difference to the final efficiency evaluation. This suggests the necessity of properly distinguishing disposability features among undesirable outputs in a production process in efficiency models.

  4. The necessity of distinguishing weak and strong disposability among undesirable outputs in DEA. Environmental performance of Chinese coal-fired power plants

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Hongliang [Asia Development Bank, 6 ADB Avenue, Metro Manila 1550 (Philippines); Pollitt, Michael [Judge Business School, University of Cambridge, Cambridge CB2 1AG (United Kingdom)

    2010-08-15

    Different from previous efficiency researches, which normally assume a uniform disposability for all undesirable outputs in a production process, this paper proposes a model that distinguishes weak and strong disposability assumptions among various undesirable outputs based on their respective technical features. The paper illustrates the approach using a research sample covering 582 base-load Chinese coal-fired power plants in 2002. The final results show that imposing the technically correct disposability features on undesirable outputs makes a significant difference to the final efficiency evaluation. This suggests the necessity of properly distinguishing disposability features among undesirable outputs in a production process in efficiency models. (author)

  5. The necessity of distinguishing weak and strong disposability among undesirable outputs in DEA: environmental performance of Chinese coal-fired power plants

    Energy Technology Data Exchange (ETDEWEB)

    Hongliang Yang; Michael Pollitt [Asia Development Bank, Manila (Philippines)

    2010-08-15

    Different from previous efficiency researches, which normally assume a uniform disposability for all undesirable outputs in a production process, this paper proposes a model that distinguishes weak and strong disposability assumptions among various undesirable outputs based on their respective technical features. The paper illustrates the approach using a research sample covering 582 base-load Chinese coal-fired power plants in 2002. The final results show that imposing the technically correct disposability features on undesirable outputs makes a significant difference to the evaluation of final efficiency. This suggests the necessity of properly distinguishing disposability features among undesirable outputs in a production process in efficiency models. 16 refs., 1 fig., 4 tabs.

  6. Uncalibrated pulse power analysis fails to reliably measure cardiac output in patients undergoing coronary artery bypass surgery.

    Science.gov (United States)

    Broch, Ole; Renner, Jochen; Höcker, Jan; Gruenewald, Matthias; Meybohm, Patrick; Schöttler, Jan; Steinfath, Markus; Bein, Berthold

    2011-01-01

    Uncalibrated arterial pulse power analysis has been recently introduced for continuous monitoring of cardiac index (CI). The aim of the present study was to compare the accuracy of arterial pulse power analysis with intermittent transpulmonary thermodilution (TPTD) before and after cardiopulmonary bypass (CPB). Forty-two patients scheduled for elective coronary surgery were studied after induction of anaesthesia, before and after CPB respectively. Each patient was monitored with the pulse contour cardiac output (PiCCO) system, a central venous line and the recently introduced LiDCO monitoring system. Haemodynamic variables included measurement of CI derived by transpulmonary thermodilution (CITPTD) or CI derived by pulse power analysis (CIPP), before and after calibration (CIPPnon-cal., CIPPcal.). Percentage changes of CI (ΔCITPTD, ΔCIPPnon-cal./PPcal.) were calculated to analyse directional changes. Before CPB there was no significant correlation between CIPPnon-cal. and CITPTD (r2 = 0.04, P = 0.08) with a percentage error (PE) of 86%. Higher mean arterial pressure (MAP) values were significantly correlated with higher CIPPnon-cal. (r2 = 0.26, P < 0.0001). After CPB, CIPPcal. revealed a significant correlation compared with CITPTD (r2 = 0.77, P < 0.0001) with PE of 28%. Changes in CIPPcal. (ΔCIPPcal.) showed a correlation with changes in CITPTD (ΔCITPTD) only after CPB (r2 = 0.52, P = 0.005). Uncalibrated pulse power analysis was significantly influenced by MAP and was not able to reliably measure CI compared with TPTD. Calibration improved accuracy, but pulse power analysis was still not consistently interchangeable with TPTD. Only calibrated pulse power analysis was able to reliably track haemodynamic changes and trends.

  7. The effect of twine thickness on the size selectivity and fishing power of Baltic cod gill nets

    DEFF Research Database (Denmark)

    Holst, René; Wileman, D.; Madsen, Niels

    2002-01-01

    . Subsequently a model was fitted for the mean selectivity taking between-set variation into account. The selectivity Curve that fitted the data best was given by the sum of two normal distributions. It was found that twine thickness and trials period had relatively little effect upon the shape......Sea trials were carried out on a Danish commercial vessel measuring the size selectivity and fishing power of gill nets used to catch Baltic cod (Gadus morhua). A comparison was made of two different twine thicknesses at two different times of the year. Nominal mesh sizes of 70-130 mm were used....... Method of capture, condition factor and girths were measured for sub- samples of the cod caught. A model of the size selectivity of the gill nets was adapted to the experimental conditions where two gears were fished on the same population. This model was fitted to the catch data for each set...

  8. Timing of the compensation of winter respiratory carbon losses provides explanatory power for net ecosystem productivity of forests

    DEFF Research Database (Denmark)

    Haeni, M.; Zweifel, R.; Eugster, W.

    2017-01-01

    Accurate predictions of net ecosystem productivity (NEPc) of forest ecosystems are essential for climate change decisions and requirements in the context of national forest growth and greenhouse gas inventories. However, drivers and underlying mechanisms determining NEPc (e.g. climate, nutrients......DOY depended on the integration method for NEPc, forest type, and whether the site had a distinct winter net respiratory carbon loss or not. The integration methods starting in autumn led to better predictions of NEPc from cDOY then the classical calendar method starting at January 1. Limited explanatory power...... of cDOY for NEPc was found for warmer sites with no distinct winter respiratory loss period. Our findings highlight the importance of the influence of winter processes and the delayed responses of previous seasons’ climatic conditions on current year's NEPc. Such carry-over effects may contain...

  9. Local-stability analysis of a low-dissipation heat engine working at maximum power output

    Science.gov (United States)

    Reyes-Ramírez, I.; Gonzalez-Ayala, J.; Calvo Hernández, A.; Santillán, M.

    2017-10-01

    In this paper we address the stability of a low-dissipation (LD) heat engine (HE) under maximum power conditions. The LD system dynamics are analyzed in terms of the contact times between the engine and the external heat reservoirs, which determine the amount of heat exchanged by the system. We study two different scenarios that secure the existence of a single stable steady state. In these scenarios, contact times dynamics are governed by restitutive forces that are linear functions of either the heat amounts exchanged per cycle, or the corresponding heat fluxes. In the first case, according to our results, preferably locating the system irreversibility sources at the hot-reservoir coupling improves the system stability and increases its efficiency. On the other hand, reducing the thermal gradient increases the system efficiency but deteriorates its stability properties, because the restitutive forces are smaller. Additionally, it is possible to compare the relaxation times with the total cycle time and obtain some constraints upon the system dynamics. In the second case, where the restitutive forces are assumed to be linear functions of the heat fluxes, we find that although the partial contact time presents a locally stable stationary value, the total cycle time does not; instead, there exists an infinite collection of steady values located in the neighborhood of the fixed point, along a one-dimensional manifold. Finally, the role of dissipation asymmetries on the efficiency, the stability, and the ratio of the total cycle time to the relaxation time is emphasized.

  10. Effect of stroke rate on the distribution of net mechanical power in rowing

    NARCIS (Netherlands)

    Hofmijster, M.J.; Landman, E.H.; Smith, R.M.; van Soest, A.J.

    2007-01-01

    The aim of this study was to assess the effect of manipulating stroke rate on the distribution of mechanical power in rowing. Two causes of inefficient mechanical energy expenditure were identified in rowing. The ratio between power not lost at the blades and generated mechanical power (P̄

  11. About the selection of transverse modes in the X-band oversized oscillator with 2.5 GW output power

    Science.gov (United States)

    Tsygankov, R. V.; Rostov, V. V.; Gunin, A. V.; Elchaninov, A. A.; Markov, A. B.; Ozur, G. E.

    2017-05-01

    The paper describes the numerical and experimental results of the microwave O-type oscillator based on an oversized slow wave structure (SWS). The feedback is applied to the design scheme, which provides intense modulation of the electron beam in the cathode-anode region and two special cavities before SWS. The selectivity of TM02 operating mode occurs due to increased diffraction loss of parasitic modes in the cathode part. The slow wave structure consists of two identical sections with the phase-shifting region in between. The use of this configuration leads to the formation of a locked TM01 wave, having good conditions for the transformation into the working mode TM02. In the experiments, a stable generation regime with pure TM02 mode at a frequency of 10 GHz with an efficiency of about 30% and the output power of 2.5 GW in the magnetic field below the cyclotron resonance was obtained.

  12. Air-Hybrid Distributed Bragg Reflector Structure for Improving the Light Output Power in AlGalnP-Based LEDs.

    Science.gov (United States)

    Oh, Hwa Sub; Ryu, Ho-Soung; Park, Sueng Ho; Jeong, Tak; Kim, Young Jin; Lee, Hyung Joo; Cho, Young Dae; Kwak, Joon-Seop; Baek, Jong Hyeob

    2015-07-01

    We investigated air gap-induced hybrid distributed Bragg reflectors (AH-DBRs) for use in high brightness and reliable AlGalnP-based light emitting diodes (LEDs). An air gap was inserted into the side of DBRs by selectively etching the Al(x),Ga1-xAs DBR structures. With the AH-DBR structures, the optical output power of LEDs was enhanced by 15% compared to LEDs having conventional DBRs, due to the effective reflection of obliquely incident light by the air gap structures. In addition, the electrical characteristics showed that the AH-DBR LED is a desirable structure for reducing the leakage current, as it suppresses unwanted surface recombinations.

  13. A High-Gain Three-Port Power Converter with Fuel Cell, Battery Sources and Stacked Output for Hybrid Electric Vehicles and DC-Microgrids

    Directory of Open Access Journals (Sweden)

    Ching-Ming Lai

    2016-03-01

    Full Text Available This paper proposes a novel high-gain three-port power converter with fuel cell (FC, battery sources and stacked output for a hybrid electric vehicle (HEV connected to a dc-microgrid. In the proposed power converter, the load power can be flexibly distributed between the input sources. Moreover, the charging or discharging of the battery storage device can be controlled effectively using the FC source. The proposed converter has several outputs in series to achieve a high-voltage output, which makes it suitable for interfacing with the HEV and dc-microgrid. On the basis of the charging and discharging states of the battery storage device, two power operation modes are defined. The proposed power converter comprises only one boost inductor integrated with a flyback transformer; the boost and flyback circuit output terminals are stacked to increase the output voltage gain and reduce the voltage stress on the power devices. This paper presents the circuit configuration, operating principle, and steady-state analysis of the proposed converter, and experiments conducted on a laboratory prototype are presented to verify its effectiveness.

  14. REGULATION OF INSTANTANEOUS POWER OUTPUT VALUE IN MAGNETRON WITH CONTINUOUS GENERATION MODE (M-105-, M-112-TYPES BEING PART OF PLASMA TECHNOLOGICAL UNIT

    Directory of Open Access Journals (Sweden)

    S. V. Bordusov

    2010-01-01

    Full Text Available The paper presents results of investigations pertaining to the possibility of regulating instantaneous power output  in a magnetron of M-105 (M-112-type by changing the capacity value of a capacitor in structure diagram for doubling voltage of high-voltage power supply on the basis of a step-up transformer operating in the saturation regime.

  15. Resonantly pumped monolithic nonplanar Ho:YAG ring laser with high-power single-frequency laser output at 2122 nm.

    Science.gov (United States)

    Wang, Lei; Gao, Chunqing; Gao, Mingwei; Li, Yan

    2013-04-22

    We demonstrated a stable single-frequency laser operating at 2122 nm from a monolithic nonplanar Ho:YAG ring oscillator (NPRO). The Ho:YAG NPRO was resonantly pumped by a 1907 nm Tm:YLF laser built up by ourselves. The maximum multimode output power from the Ho:YAG NPRO was 9.66 W and the slope efficiency was 71.7%. With accurate adjustment of the pump position to make the laser oscillate in single frequency condition, an output power of 8.0 W was obtained with a slope efficiency of 61.4% and an optical-optical efficiency of 50.0%. The power stability of the Ho:YAG NPRO laser was 0.29% at maximum single frequency output power. The beam quality M(2) factors were measured to be less than 1.1 in x- and y- directions.

  16. Graphite anode surface modification with controlled reduction of specific aryl diazonium salts for improved microbial fuel cells power output.

    Science.gov (United States)

    Picot, Matthieu; Lapinsonnière, Laure; Rothballer, Michael; Barrière, Frédéric

    2011-10-15

    Graphite electrodes were modified with reduction of aryl diazonium salts and implemented as anodes in microbial fuel cells. First, reduction of 4-aminophenyl diazonium is considered using increased coulombic charge density from 16.5 to 200 mC/cm(2). This procedure introduced aryl amine functionalities at the surface which are neutral at neutral pH. These electrodes were implemented as anodes in "H" type microbial fuel cells inoculated with waste water, acetate as the substrate and using ferricyanide reduction at the cathode and a 1000 Ω external resistance. When the microbial anode had developed, the performances of the microbial fuel cells were measured under acetate saturation conditions and compared with those of control microbial fuel cells having an unmodified graphite anode. We found that the maximum power density of microbial fuel cell first increased as a function of the extent of modification, reaching an optimum after which it decreased for higher degree of surface modification, becoming even less performing than the control microbial fuel cell. Then, the effect of the introduction of charged groups at the surface was investigated at a low degree of surface modification. It was found that negatively charged groups at the surface (carboxylate) decreased microbial fuel cell power output while the introduction of positively charged groups doubled the power output. Scanning electron microscopy revealed that the microbial anode modified with positively charged groups was covered by a dense and homogeneous biofilm. Fluorescence in situ hybridization analyses showed that this biofilm consisted to a large extent of bacteria from the known electroactive Geobacter genus. In summary, the extent of modification of the anode was found to be critical for the microbial fuel cell performance. The nature of the chemical group introduced at the electrode surface was also found to significantly affect the performance of the microbial fuel cells. The method used for

  17. Hybrid Cooling Systems for Low-Temperature Geothermal Power Production

    Energy Technology Data Exchange (ETDEWEB)

    Ashwood, A.; Bharathan, D.

    2011-03-01

    This paper describes the identification and evaluation of methods by which the net power output of an air-cooled geothermal power plant can be enhanced during hot ambient conditions with a minimal amount of water use.

  18. Design of a high voltage input - output ratio dc-dc converter dedicated to small power fuel cell systems

    Science.gov (United States)

    Béthoux, O.; Cathelin, J.

    2010-12-01

    Consuming chemical energy, fuel cells produce simultaneously heat, water and useful electrical power [J.M. Andújar, F. Segura, Renew. Sust. Energy Rev. 13, 2309 (2009)], [J. Larminie, A. Dicks, Fuel Cell Systems Explained, 2nd edn. (John Wiley & Sons, 2003)]. As a matter of fact, the voltage generated by a fuel cell strongly depends on both the load power demand and the operating conditions. Besides, as a result of many design aspects, fuel cells are low voltage and high current electric generators. On the contrary, electric loads are commonly designed for small voltage swing and a high V/I ratio in order to minimize Joule losses. Therefore, electric loads supplied by fuel cells are typically fed by means of an intermediate power voltage regulator. The specifications of such a power converter are to be able to step up the input voltage with a high ratio (a ratio of 10 is a classic situation) and also to work with an excellent efficiency (in order to minimize its size, its weight and its losses) [A. Shahin, B. Huang, J.P. Martin, S. Pierfederici, B. Davat, Energy Conv. Manag. 51, 56 (2010)]. This paper deals with the design of this essential ancillary device. It intends to bring out the best structure for fulfilling this function. Several dc-dc converters with large voltage step-up ratios are introduced. A topology based on a coupled inductor or tapped inductor is closely studied. A detailed modelling is performed with the purpose of providing designing rules. This model is validated with both simulation and implementation. The experimental prototype is based on the following specifications: the fuel cell output voltage ranges from a 50 V open-voltage to a 25 V rated voltage while the load requires a constant 250 V voltage. The studied coupled inductor converter is compared with a classic boost converter commonly used in this voltage elevating application. Even though the voltage regulator faces severe FC specifications, the measured efficiency reaches 96% at the

  19. Picosecond laser with 11 W output power at 1342 nm based on composite multiple doping level Nd:YVO4 crystal

    Science.gov (United States)

    Rodin, Aleksej M.; Grishin, Mikhail; Michailovas, Andrejus

    2016-01-01

    We report results of design and optimization of high average output power picosecond and nanosecond laser operating at 1342 nm wavelength. Developed for selective micromachining, this DPSS laser is comprised of master oscillator, regenerative amplifier and output pulse control module. Passively mode-locked by means of semiconductor saturable absorber mirror and pumped with 808 nm wavelength Nd:YVO4 master oscillator emits 12.5 ps pulses at repetition rate of 55 MHz with average output power of ∼100 mW. The four-pass confocal delay line forms a longest part of the oscillator cavity in order to suppress thermo-mechanical misalignment. Picked from the train seed pulses were injected to the cavity of regenerative amplifier based on composite Nd:YVO4 crystal with diffusion-bonded segments of multiple Nd doping concentration end-pumped at 880 nm wavelength. Laser produces pulses of ∼13 ps duration at 300 kHz repetition rate with average output power of 11 W and nearly diffraction limited beam quality of M2∼1.03. Attained high peak power ∼2.8 MW facilitates conversion to the 2nd, 3rd and 6th harmonics at 671 nm, 447 nm and 224 nm wavelengths with 80%, 50% and 15% efficiency respectively. Without seeding the regenerative amplifier transforms to electro-optically cavity-dumped Q-switched laser providing 10 ns output pulses at high repetition rates with beam propagation factor of M2∼1.06.

  20. Improvement of light output power of InGaN/GaN light-emitting diode by lateral epitaxial overgrowth using pyramidal-shaped SiO(2).

    Science.gov (United States)

    Cho, Chu-Young; Lee, Jin-Bock; Lee, Sang-Jun; Han, Sang-Heon; Park, Tae-Young; Kim, Je Won; Kim, Yong Chun; Park, Seong-Ju

    2010-01-18

    We report on the improvement of light output power of InGaN/GaN blue light-emitting diodes (LEDs) by lateral epitaxial overgrowth (LEO) of GaN using a pyramidal-shaped SiO(2) mask. The light output power was increased by 80% at 20 mA of injection current compared with that of conventional LEDs without LEO structures. This improvement is attributed to an increased internal quantum efficiency by a significant reduction in threading dislocation and by an enhancement of light extraction efficiency by pyramidal-shaped SiO(2) LEO mask.

  1. Less is more: standard warm-up causes fatigue and less warm-up permits greater cycling power output.

    Science.gov (United States)

    Tomaras, Elias K; MacIntosh, Brian R

    2011-07-01

    The traditional warm-up (WU) used by athletes to prepare for a sprint track cycling event involves a general WU followed by a series of brief sprints lasting ≥ 50 min in total. A WU of this duration and intensity could cause significant fatigue and impair subsequent performance. The purpose of this research was to compare a traditional WU with an experimental WU and examine the consequences of traditional and experimental WU on the 30-s Wingate test and electrically elicited twitch contractions. The traditional WU began with 20 min of cycling with a gradual intensity increase from 60% to 95% of maximal heart rate; then four sprints were performed at 8-min intervals. The experimental WU was shorter with less high-intensity exercise: intensity increased from 60% to 70% of maximal heart rate over 15 min; then just one sprint was performed. The Wingate test was conducted with a 1-min lead-in at 80% of optimal cadence followed by a Wingate test at optimal cadence. Peak active twitch torque was significantly lower after the traditional than experimental WU (86.5 ± 3.3% vs. 94.6 ± 2.4%, P track cyclist's WU results in significant fatigue, which corresponds with impaired peak power output. A shorter and lower-intensity WU permits a better performance.

  2. Effects of isokinetic training of the knee extensors on isometric strength and peak power output during cycling.

    Science.gov (United States)

    Mannion, A F; Jakeman, P M; Willan, P L

    1992-01-01

    Isokinetic training of right and left quadriceps femoris was undertaken three times per week for 16 weeks. One group of subjects (n = 13) trained at an angular velocity of 4.19 rad.s-1 and a second group (n = 10) at 1.05 rad.s-1. A control group (n = 10) performed no training. Maximal voluntary contraction (MVC) of the quadriceps, and peak pedal velocity nu p,peak) and peak power output (Wpeak) during all-out cycling (against loads equivalent to 9, 10, 11, 12, 13 and 14% MVC) were assessed before and after training. The two training groups did not differ significantly from each other in their training response to any of the performance variables (P > 0.05). No significant difference in MVC was observed for any group after the 16-week period (P = 0.167). The post-training increases in average Wpeak (7%) and nu p,peak (6%) during the cycle tests were each significantly different from the control group response (P = 0.018 and P = 0.008, respectively). It is concluded that 16 weeks of isokinetic strength training of the knee extensors is able to significantly improve nu p, peak and Wpeak during spring cycling, an activity which demands considerable involvement of the trained muscle group but with its own distinct pattern of coordination.

  3. Hybrid Solid Oxide Fuel Cell and Thermoelectric Generator for Maximum Power Output in Micro-CHP Systems

    DEFF Research Database (Denmark)

    Rosendahl, Lasse; Mortensen, Paw Vestergård; Enkeshafi, Ali A.

    2011-01-01

    and market segments which are not yet quantified. This paper quantifies a micro-CHP system based on a solid oxide fuel cell (SOFC) and a high-performance TE generator. Based on a 3 kW fuel input, the hybrid SOFC implementation boosts electrical output from 945 W to 1085 W, with 1794 W available for heating......One of the most obvious early market applications for thermoelectric generators (TEG) is decentralized micro combined heat and power (CHP) installations of 0.5 kWe to 5 kWe based on fuel cell technology. Through the use of TEG technology for waste heat recovery it is possible to increase...... the electricity production in micro-CHP systems by more than 15%, corresponding to system electrical efficiency increases of some 4 to 5 percentage points. This will make fuel cell-based micro-CHP systems very competitive and profitable and will also open opportunities in a number of other potential business...

  4. Comparative metabolomic studies of Alkanivorax xenomutans showing differential power output in a three chambered microbial fuel cell.

    Science.gov (United States)

    Mahidhara, Ganesh; Ch, Sasikala; Ch, Venkata Ramana

    2017-06-01

    Metabolomic study of electrogenic bacteria is a necessity to understand the extent of complex organic matter degradation and to invent new co-culture techniques to achieve complete degradation. In this study, we have subjected Alkanivorax xenomutans (KCTC 23751T; NBRC 108843T), a bacterium capable for biodegradation of complex hydrocarbons, to oxic and anoxic conditions in a three chambered microbial fuel cell. In an attempt to understand the molecular mechanisms during the electrogenic processes of A. xenomutans, intra cellular (endo metabolome or the fingerprint) and exo metabolome (extracellular metabolome or the foot print) were analyzed under oxic and anoxic conditions, using FTIR and GC-MS. Interpretation of the data revealed higher number of metabolites in the anoxic fraction as compared to oxic fraction. In addition, expression of putative metabolites that influence electron transfer like flavins, fumarate and quinones were found to be predominant in the organisms when grown in anoxic conditions. Hence, the presence of anoxic conditions governed the electrogenic bacteria to produce enhanced power output by modulating differential metabolomic profiling, compared to the culture grown in oxic conditions.

  5. Hybrid Solid Oxide Fuel Cell and Thermoelectric Generator for Maximum Power Output in Micro-CHP Systems

    Science.gov (United States)

    Rosendahl, L. A.; Mortensen, Paw V.; Enkeshafi, Ali A.

    2011-05-01

    One of the most obvious early market applications for thermoelectric generators (TEG) is decentralized micro combined heat and power (CHP) installations of 0.5 kWe to 5 kWe based on fuel cell technology. Through the use of TEG technology for waste heat recovery it is possible to increase the electricity production in micro-CHP systems by more than 15%, corresponding to system electrical efficiency increases of some 4 to 5 percentage points. This will make fuel cell-based micro-CHP systems very competitive and profitable and will also open opportunities in a number of other potential business and market segments which are not yet quantified. This paper quantifies a micro-CHP system based on a solid oxide fuel cell (SOFC) and a high-performance TE generator. Based on a 3 kW fuel input, the hybrid SOFC implementation boosts electrical output from 945 W to 1085 W, with 1794 W available for heating purposes.

  6. Analysis of power output time series in response to supramaximal exercise: an approach through dynamic factor analysis.

    Science.gov (United States)

    Bruno, Paula Marta; Pereira, Fernando Duarte; Fernandes, Renato; de Mendonça, Goncalo Vilhena

    2011-02-01

    The responses to supramaximal exercise testing have been traditionally analyzed by means of standard parametric and nonparametric statistics. Unfortunately, these statistical approaches do not allow insight into the pattern of variation of a given parameter over time. The purpose of this study was to determine if the application of dynamic factor analysis (DFA) allowed discriminating different patterns of power output (PO), during supramaximal exercise, in two groups of children engaged in competitive sports: swimmers and soccer players. Data derived from Wingate testing were used in this study. Analyses were performed on epochs (30 s) of upper and lower body PO obtained from twenty two healthy boys (11 swimmers and 11 soccer players) age 11-12 years old. DFA revealed two distinct patterns of PO during Wingate. Swimmers tended to attain their peak PO (upper and lower body) earlier than soccer players. As importantly, DFA showed that children with a given pattern of upper body PO tend to perform similarly during lower body exercise.

  7. FORECASTING OF PRODUCTION OUTPUT FOR LIGHT INDUSTRY ENTERPRISES WITH PURPOSE TO DETERMINE THEIR POWER RESOURCES REQUIREMENTS. Part 1

    Directory of Open Access Journals (Sweden)

    V. N. Romaniuk

    2015-01-01

    Full Text Available The paper presents an interest for those specialists who are involved in solution of efficiency problems in light industry of Belarus as one of the significant industries that forms an economic situation in the Republic, its export potential and social climate. It is extremely relevant for the Belarusian enterprises to reduce production costs in order to preserve and strengthen positions in the light industry market. Operating capacities for production of natural, synthetic textile and knit-wear materials and their subsequent treatment are in many respects unjustifiably energy intensive. Nowadays the only acceptable solution of the problem for reduction of production costs is to decrease its energy component. Such approach requires transition to creation of modern heat and power supply systems at heat technology enterprises.The most important sub-system of the enterprises is own combined production of energy flows of secondary electrical and heat energy, freeze. There is a complex of problems that arise during designing process of tri-generation unit. One of the most important problems presupposes determination of a base load demand and capacity of every energy flow generated by an energy source. The solution is directly related to production output, which in its turn is determined by the requirements of sales markets. Due to various reasons the markets have their own specificity for the enterprises under consideration. It is proposed to use statistical methods for searching requirements. In this connection it is necessary to take into account industry development rate (pre-determined by State Programs, Plans, Governmental solutions, including directive instructions, production volumes of competitive goods and actual goods situation on the sales market.The paper presents the first part of the executed complex investigations which are directed on the development of scientifically-substantiated proposals for higher energy efficiency of the

  8. Effect of PV module output power on module temperature; Taiyo denchi no shutsuryoku henka ga module hyomen ondo ni oyobosu eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Hongo, T.; Kitamura, A. [Kansai Electric Power Co. Inc., Osaka (Japan); Igaki, K.; Mizumoto, T. [Kanden Kako Co. Inc., Osaka (Japan)

    1996-10-27

    Effect of the photovoltaic (PV) module output power variation on the module surface temperature has been investigated by field measurements. PV modules with capacity of 54 W were used for the temperature measurements. Three 2 kW-class PV systems were operated. T-type thermocouples were used for measuring temperatures. Measurement time intervals were 15 minutes, 30 minutes, 60 minutes, and 24 hours. Measurement period was between May 25, 1995 and June 25, 1996. The surface temperature increased during non-loaded PV output, and decreased during load-carrying PV output. Difference of the surface temperature between non-loaded PV output and load-carrying PV output was 3.5{degree}C at maximum through a year. The surface temperature was saturated within 30 minutes. When PV output was changed in 30 or 60 minutes interval, the variation of surface temperature was distinctly observed. When PV output was changed in 15 minutes interval, it was not observed distinctly. There was no difference of the surface temperatures during the time zones with less solar radiation, such as in the morning and evening, and at night. Except these time zones, difference of the surface temperatures was 3.5{degree}C at maximum. 4 figs.

  9. The acute effect of upper-body complex training on power output of martial art athletes as measured by the bench press throw exercise.

    Science.gov (United States)

    Liossis, Loudovikos Dimitrios; Forsyth, Jacky; Liossis, Ceorge; Tsolakis, Charilaos

    2013-12-18

    The purpose of this study was to examine the acute effect of upper body complex training on power output, as well as to determine the requisite preload intensity and intra-complex recovery interval needed to induce power output increases. Nine amateur-level combat/martial art athletes completed four distinct experimental protocols, which consisted of 5 bench press repetitions at either: 65% of one-repetition maximum (1RM) with a 4 min rest interval; 65% of 1RM with an 8 min rest; 85% of 1RM with a 4 min rest; or 85% of 1RM with an 8 min rest interval, performed on different days. Before (pre-conditioning) and after (post-conditioning) each experimental protocol, three bench press throws at 30% of 1RM were performed. Significant differences in power output pre-post conditioning were observed across all experimental protocols (F=26.489, partial eta2=0.768, p=0.001). Mean power output significantly increased when the preload stimulus of 65% 1RM was matched with 4 min of rest (p=0.001), and when the 85% 1RM preload stimulus was matched with 8 min of rest (p=0.001). Moreover, a statistically significant difference in power output was observed between the four conditioning protocols (F= 21.101, partial eta(2)=0.913, p=0.001). It was concluded that, in complex training, matching a heavy preload stimulus with a longer rest interval, and a lighter preload stimulus with a shorter rest interval is important for athletes wishing to increase their power production before training or competition.

  10. Automation of CO 2 laser output power measurement as a function of the absorber gas pressure in a cell located inside or outside the laser cavity

    Science.gov (United States)

    Weiss, C.; Aghabi, S.

    2011-04-01

    The automation of CO 2 laser output power measurement is discussed in this paper as a function of the absorber gas pressure in a cell located inside or outside the laser cavity. A manually tunable laser was used which can be operated in one of about 44 different laser lines aligned by the user and registered respectively by the acquisition program for further analysis. The voltages representing the absorber gas pressure and the output power were very small (a few hundred μV), therefore a proper voltage amplification circuit was designed to amplify the analog outputs of both the pressure meter and the laser output power meter. These amplified signals were then applied directly to a PCI-9112 ADLINK data acquisition card using a personal computer (PC). A suitable controlling program using LabVIEW graphical programming language was written to measure the pressure and laser power signals, draw the relationship between them and save the results for later processing and analysis; such as, gas absorbance coefficient α, mean absorption cross section σ calculations that can be applied in many areas such as molecular spectroscopy and environmental pollution studies.

  11. A nitrogen-doped graphene/gold nanoparticle/formate dehydrogenase bioanode for high power output membrane-less formic acid/O2 biofuel cells.

    Science.gov (United States)

    Gai, Panpan; Ji, Yusheng; Chen, Yun; Zhu, Cheng; Zhang, Jianrong; Zhu, Jun-Jie

    2015-03-21

    A high power output, membrane-less formic acid/O2 enzymatic biofuel cell was fabricated, in which nitrogen-doped graphene was proven to be effective for recycling the NAD(+)/NADH cofactor at a nitrogen-doped graphene/gold nanoparticle/formate dehydrogenase bioanode in the catalytic oxidation of formic acid.

  12. Effect of the recovery duration of a repeated sprint exercise on the power output, jumping performance and lactate concentration in pre-pubescent soccer players

    Directory of Open Access Journals (Sweden)

    Nikolaidis Pantelis T.

    2016-05-01

    Full Text Available Study aim: The aim of the present study was to examine the effect of two different recovery durations (2 min versus 5 min on the physiological responses (power output, stretch-shortening cycle and lactate concentration to a 5×6 s repeated cycling sprint exercise protocol in pre-pubescent soccer players.

  13. Microbiofuel cell powered by glucose/O-2 based on electrodeposition of enzyme, conducting polymer and redox mediators. Part II : Influence of the electropolymerized monomer on the output power density and stability

    NARCIS (Netherlands)

    Ammam, Malika; Fransaer, Jan

    2014-01-01

    In this study, we investigated the influence of nature of the electropolymerized monomer on the resulting power output and stability of a glucose/O-2 powered biofuel cells (BFCs). The bioanode was prepared from a mixture of glucose oxidase-polymeric monomer-ferrocenium

  14. Switching power supplies with multiple isolated output and unitary power factor with an only switch; Fonte chaveada com multiplas saidas isoladas e fator de potencia unitario com um unico interruptor

    Energy Technology Data Exchange (ETDEWEB)

    Canesin, Carlos Alberto

    1990-09-01

    The analysis and implementation of switching power supplies with multiple output, through the use of the D C/D C Single Ended Primary Inductance Converter - SEPIC is presented. The structure has a single switch mode processing stage, improved input power factor, with the use of the variable current hysteresis control, or, constant on time control. The analysis of the D C/D C SEPIC, output characteristics and computer simulation is presented. A switching power supply practical design and experimental results are presented to demonstrate the validity of the theoretical analysis. (author)

  15. Comparison of power output by rice (Oryza sativa) and an associated weed (Echinochloa glabrescens) in vascular plant bio-photovoltaic (VP-BPV) systems.

    Science.gov (United States)

    Bombelli, Paolo; Iyer, Durgaprasad Madras Rajaraman; Covshoff, Sarah; McCormick, Alistair J; Yunus, Kamran; Hibberd, Julian M; Fisher, Adrian C; Howe, Christopher J

    2013-01-01

    Vascular plant bio-photovoltaics (VP-BPV) is a recently developed technology that uses higher plants to harvest solar energy and the metabolic activity of heterotrophic microorganisms in the plant rhizosphere to generate electrical power. In the present study, electrical output and maximum power output variations were investigated in a novel VP-BPV configuration using the crop plant rice (Oryza sativa L.) or an associated weed, Echinochloa glabrescens (Munro ex Hook. f.). In order to compare directly the physiological performances of these two species in VP-BPV systems, plants were grown in the same soil and glasshouse conditions, while the bio-electrochemical systems were operated in the absence of additional energy inputs (e.g. bias potential, injection of organic substrate and/or bacterial pre-inoculum). Diurnal oscillations were clearly observed in the electrical outputs of VP-BPV systems containing the two species over an 8-day growth period. During this 8-day period, O. sativa generated charge ∼6 times faster than E. glabrescens. This greater electrogenic activity generated a total charge accumulation of 6.75 ± 0.87 Coulombs for O. sativa compared to 1.12 ± 0.16 for E. glabrescens. The average power output observed over a period of about 30 days for O. sativa was significantly higher (0.980 ± 0.059 GJ ha(-1) year(-1)) than for E. glabrescens (0.088 ± 0.008 GJ ha(-1) year(-1)). This work indicates that electrical power can be generated in both VP-BPV systems (O. sativa and E. glabrescens) when bacterial populations are self-forming. Possible reasons for the differences in power outputs between the two plant species are discussed.

  16. 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

    Science.gov (United States)

    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…

  17. A 25 W 70% Efficiency Doherty Power Amplifier at 6 dB Output Back-Off for 2.4 GHz Applications with VGS, PEAK

    Directory of Open Access Journals (Sweden)

    Jorge Moreno Rubio

    2015-01-01

    Full Text Available This paper shows the design and simulation results of a hybrid Doherty power amplifier. The amplifier has been designed at 2,4 GHz, obtaining power-added efficiency above 70 % for 6 dB output power back-off, together with a small signal gain of 17 dB. Design and analysis equations are presented considering class AB bias conditions for the main amplifier and class C for the peak one in back-off larger than 6 dB, and FET device assumption. An additional control on the bias point of the peak device has been carried out, in order to increase the gain on the Doherty region and ease the design of the peak branch. A Cree’s GaN-HEMT CGH40010F device has been used with a nonlinear model guarantied up to 6 GHz and with an expected output power of 10 W. The obtained output power is higher than 25-W. The simulation has been carried out using Agilent ADS CAD tools. The present design could present the state of the art in terms of continuous-wave (CW characterization

  18. Studies on the power output of a MADE AE-30 operating on complex terrain. Annual Energy Production estimation and Multivariable analysis. A case of multi-stall effect

    Energy Technology Data Exchange (ETDEWEB)

    Cuerva, A.

    1996-12-01

    The main need of the EWTS-II Sub-project IV group is to have a suitable data-base which allows it to reach proper conclusions on the characteristics of power performance of wind turbines in complex terrain. With this aim, this document presents an analysis on the power output of the MADE AE-30 Wind turbine operating at Tarifa (also data from flat terrain are enclosed as a reference). An application of the bin method and AEP estimation for energy production method, in the two last issues a directional analysis and an study for two different turbulence intensity ranges are enclosed. Finally the Stepwise multirregression method is applied on the measurements to identify the stored parameters that have influence on the power output. A brief description of multi stall effect is enclosed. (Author)

  19. Muscle contraction velocity, strength and power output changes following different degrees of hypohydration in competitive olympic combat sports.

    Science.gov (United States)

    Pallarés, J G; Martínez-Abellán, A; López-Gullón, J M; Morán-Navarro, R; De la Cruz-Sánchez, E; Mora-Rodríguez, R

    2016-01-01

    It is habitual for combat sports athletes to lose weight rapidly to get into a lower weight class. Fluid restriction, dehydration by sweating (sauna or exercise) and the use of diuretics are among the most recurrent means of weight cutting. Although it is difficult to dissuade athletes from this practice due to the possible negative effect of severe dehydration on their health, athletes may be receptive to avoid weight cutting if there is evidence that it could affect their muscle performance. Therefore, the purpose of the present study was to investigate if hypohydration, to reach a weight category, affects neuromuscular performance and combat sports competition results. We tested 163 (124 men and 39 woman) combat sports athletes during the 2013 senior Spanish National Championships. Body mass and urine osmolality (UOSM) were measured at the official weigh-in (PRE) and 13-18 h later, right before competing (POST). Athletes were divided according to their USOM at PRE in euhydrated (EUH; UOSM 250-700 mOsm · kgH2O(-1)), hypohydrated (HYP; UOSM 701-1080 mOsm · kgH2O(-1)) and severely hypohydrated (S-HYP; UOSM 1081-1500 mOsm · kgH2O(-1)). Athletes' muscle strength, power output and contraction velocity were measured in upper (bench press and grip) and lower body (countermovement jump - CMJ) muscle actions at PRE and POST time-points. At weigh-in 84 % of the participants were hypohydrated. Before competition (POST) UOSM in S-HYP and HYP decreased but did not reach euhydration levels. However, this partial rehydration increased bench press contraction velocity (2.8-7.3 %; p sports athletes at weigh-in and not fully reversed in the 13-18 h from weigh-in to competition. Nonetheless, partial rehydration recovers upper and lower body neuromuscular performance in the severely hypohydrated participants. Our data suggest that the advantage of competing in a lower weight category could compensate the declines in neuromuscular performance at the onset of competition, since 69

  20. Single mode low-NA step index Yb-doped fiber design for output powers beyond 4kW (Conference Presentation)

    Science.gov (United States)

    Beier, Franz; Proske, Fritz; Hupel, Christian; Kuhn, Stefan; Hein, Sigrun; Sattler, Bettina; Nold, Johannes; Haarlammert, Nicoletta; Schreiber, Thomas; Eberhardt, Ramona; Tünnermann, Andreas

    2017-03-01

    Fiber amplifiers are representing one of the most promising solid state laser concepts, due to the compact setup size, a simple thermal management and furthermore excellent beam quality. In this contribution, we report on the latest results from a low-NA, large mode area single mode fiber with a single mode output power beyond 4 kW without any indication of mode instabilities or nonlinear effects and high slope efficiency. Furthermore, we quantify the influence of the bending diameter of our manufactured low NA fiber on the average core loss by an OFDR measurement and determine the optimal bending diameter in comparison to a second fiber with a slightly changed NA. The fibers used in the experiments were fabricated by MCVD technology combined with the solution doping technique. The investigation indicates the limitation of the step index fiber design and its influence on the use in high power fiber amplifiers. We demonstrate, that even a slightly change in the core NA crucially influences the minimum bending diameter of the fiber and has to be taken into account in applications. The measured output power represents to the best of our knowledge the highest single mode output power of an amplifier fiber ever reported on.

  1. Input and output budgets of radiocesium concerning the forest floor in the mountain forest of Fukushima released from the TEPCO's Fukushima Dai-ichi nuclear power plant accident.

    Science.gov (United States)

    Niizato, Tadafumi; Abe, Hironobu; Mitachi, Katsuaki; Sasaki, Yoshito; Ishii, Yasuo; Watanabe, Takayoshi

    2016-09-01

    Estimations of radiocesium input and output concerning the forest floor within a mountain forest region have been conducted in the north and central part of the Abukuma Mountains of Fukushima, northeast Japan, after a 2-3 year period following the TEPCO Fukushima Dai-ichi nuclear power plant accident. The radiocesium input and output associated with surface washoff, throughfall, stemflow, and litterfall processes at experimental plots installed on the forest floor of evergreen Japanese cedars and deciduous Konara oaks have been monitored. Despite the high output potential in the mountainous forest of Fukushima, the results at both monitoring locations show the radiocesium input to be 4-50 times higher than the output during the summer monsoon in Fukushima. These results indicate that the radiocesium tends to be preserved in the forest ecosystem due to extremely low output ratios (0.05%-0.19%). Thus, the associated fluxes throughout the circulation process are key issues for the projecting the environmental fate of the radiocesium levels, along with the subsequent reconstruction of life emphasized within the setting. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Improving the light output power of DUV-LED by introducing an intrinsic last quantum barrier interlayer on the high-quality AlN template

    Science.gov (United States)

    Tsai, Chia-Lung; Liu, Hsueh-Hsing; Chen, Jun-Wei; Lu, Chien-Pin; Ikenaga, Kazutada; Tabuchi, Toshiya; Matsumoto, Koh; Fu, Yi-Keng

    2017-12-01

    We demonstrate that the light output power of deep ultraviolet light-emitting diodes (DUV-LEDs) can be improved by introducing an intrinsic last quantum barrier interlayer to a high quality AlN template. The light output power of the DUV-LEDs can be doubled by substituting the last quantum barrier with an intrinsic last quantum barrier (u-LQB)/Mg-doped LQB for only pure u-LQB in the same thickness with a 35 A/cm2 injection current. It is believed that the improved performance of the DUV LED could be attributed to the decreased diffusion of Mg tunneling into MQW and the reduction of sub-band parasitic emissions.

  3. Mechanisms underlying enhancements in muscle force and power output during maximal cycle ergometer exercise induced by chronic β2-adrenergic stimulation in men

    DEFF Research Database (Denmark)

    Hostrup, Morten; Kalsen, Anders; Onslev, Johan

    2015-01-01

    The study was a randomized placebo-controlled trial investigating mechanisms by which chronic β2-adrenergic stimulation enhances muscle force and power output during maximal cycle ergometer exercise in young men. Eighteen trained men were assigned to an experimental group (oral terbutaline 5 mg∙30...... output during 30-s of maximal cycling increased (P≤0.01) by 32±8 and 25±9 W, respectively, with the intervention in TER compared to PLA. Maximal oxygen consumption (V̇o2 max) and time to fatigue during incremental cycling did not change with the intervention. Lean body mass increased by 1.95±0.8 kg (P≤0...... and peak power during maximal cycling induced by chronic β2-adrenergic stimulation in humans....

  4. Influence of gender, age and BMI on lower limb muscular power output in a large population of obese men and women.

    Science.gov (United States)

    Sartorio, A; Proietti, M; Marinone, P G; Agosti, F; Adorni, F; Lafortuna, C L

    2004-01-01

    To depict the general trends of muscle anaerobic performance in obese subjects within a wide range of age and body weight. Cross-sectional study for the measurement of lower limb maximal anaerobic power output with a modification of the Margaria stair climbing test in a large population of obese subjects of both genders within a wide span of age (18-80 y) and body mass index (BMI, 30-68 kg m(-2)). Furthermore, body composition was also determined by bioimpedance analysis in a representative subgroup, in order to evaluate the relationships between fat-free mass (FFM) and power output. A total of 1298 obese subjects (486 males, 812 females) from an Italian population seeking medical support for body weight reduction. Within this sample, a consistent subgroup of 193 subjects (59 males, 134 females) was also selected for accessory study of body composition. In general, male subjects developed significantly higher lower limb power output (W) than female subjects (Pfashion comparable with that displayed by W. The gender-related differences in W disappeared when expressed per unit FFM and a significant linear correlation was found between FFM and W, both in male and female subjects (R2=0.32-0.51, P<0.001). The lower limb maximal power output is significantly higher in obese male subjects than in female subjects, being negatively influenced by age but positively related to BMI. Female subjects appear to be at a greater disadvantage for effect of obesity, the major motor limitations being suffered by older women with higher BMI. These gender differences in age- and BMI-dependent W changes seem to be related to changes in FFM in the subgroup in whom body composition was studied.

  5. Effect of formoterol, a long-acting β2-adrenergic agonist, on muscle strength and power output, metabolism and fatigue during maximal sprinting in men

    DEFF Research Database (Denmark)

    Kalsen, Anders; Hostrup, Morten; Backer, Vibeke

    2016-01-01

    The aim was to investigate the effect of the long-acting β2-adrenergic agonist formoterol on muscle strength and power output, muscle metabolism and phosphorylation of CaMKII Thr(287) and FXYD1 during maximal sprinting. In a double-blind crossover study, thirteen males (VO2max: 45.0±0.2 (mean±SE)...... is associated with increased rates of glycogenolysis and glycolysis that may counteract development of fatigue....

  6. Phosphate ytterbium-doped single-mode all-solid photonic crystal fiber with output power of 13.8 W

    Science.gov (United States)

    Wang, Longfei; He, Dongbing; Feng, Suya; Yu, Chunlei; Hu, Lili; Qiu, Jianrong; Chen, Danping

    2015-01-01

    Single-mode ytterbium-doped phosphate all-solid photonic crystal fiber (AS-PCF) with 13.8 W output power and 32% slope efficiency was reported. By altering the diameter of the rods around the doped core and thus breaking the symmetry of the fiber, a polarization-maintaining AS-PCF with degree of polarization of >85% was also achieved, for the first time to knowledge, in a phosphate PCF. PMID:25684731

  7. Intracavity frequency converted Raman laser producing 10 deep blue to cyan emission lines with up to 0.94  W output power.

    Science.gov (United States)

    Geskus, Dimitri; Jakutis-Neto, Jonas; Pask, Helen M; Wetter, Niklaus U

    2014-12-15

    Here we report 10 laser emission lines in the attractive deep blue to cyan spectral region from an intracavity frequency doubled Raman laser. The fundamental laser field that drives the Raman laser is based on the three-level transition of Nd:YLF. A maximum extracted quasi-continuous wave (qcw) output power of 0.94 W is achieved in the deep blue to cyan spectral regime.

  8. Effects of time of day on power output and thermoregulation responses during cycling over a simulated hilly course in the heat (35ºc)

    OpenAIRE

    KONSTANTINOS BARDIS; CREG ATKINSON

    2008-01-01

    The aim of the present investigation was to compare responses to sustained exercise in the morning and evening in the heat (35ºC) over a hilly prolonged simulated course. The thermoregulatory response examined was core temperature (Tc). In addition power output, and time were examined. Eight active males (25-40years) were instructed to work as hard as possible over the entire exercise period, with variation of pedal frequency permitted at any time. Two prolonged sessions were performed at 08:...

  9. Effect of hot versus cold climates on power output, muscle activation, and perceived fatigue during a dynamic 100-km cycling trial.

    Science.gov (United States)

    Abbiss, Chris R; Burnett, Angus; Nosaka, Ken; Green, Jonathon P; Foster, Jonathan K; Laursen, Paul B

    2010-01-01

    The purpose of this study was to examine the influence of environmental temperature on power output, muscle activation, body temperature, and perceived physical strain during a dynamic self-paced 100-km cycling trial. Nine endurance-trained male cyclists (mean + or - s: age 31 + or - 6 years; VO(2max) 62.1 + or - 8.5 ml x kg(-1) x min(-1)) completed two 100-km experimental trials, interspersed with five 1-km and four 4-km high-intensity epochs, in hot (34 degrees C) and cold (10 degrees C) environments. Measurements consisted of power output, rectal and skin temperature, muscle activation of vastus lateralis, biceps femoris and soleus, ratings of perceived exertion, thermal sensation and pain intensity in the quadriceps. Power output and muscle activation of the biceps femoris and soleus were lower in the hot trial (22 km; P cold) vs. 39.1 degrees C (hot)] at 42 km. Muscle activation of the vastus lateralis, biceps femoris, and soleus was significantly (P 0.68) but not with perceived pain or exertion. Thus, a hyperthermic-induced anticipatory reduction of muscle activation may have occurred during the hot exercise trials only. Fatigue and pacing during prolonged dynamic exercise in the cold appears to be influenced by factors dissociated from hyperthermic-induced stress.

  10. Metabolic and cardiorespiratory responses in young oarsmen during prolonged exercise tests on a rowing ergometer at power outputs corresponding to two concepts of anaerobic threshold.

    Science.gov (United States)

    Bourgois, J; Vrijens, J

    1998-01-01

    A group of ten young experienced oarsmen [mean age 17.5 (SD 1.7) years, height 182.5 (SD 5.9) cm, body mass 77.0 (SEM 10.6) kg] exercised in a progressive incremental test (PIE: 50W x 3 min[-1]) on a rowing ergometer to determine the power output corresponding to the 4 mmol lactate x l(-1) anaerobic threshold (AT4) and the individual anaerobic threshold (IAT). Within 10 days they performed at random two 30-min prolonged exercise tests (PET) at power outputs corresponding to AT4 and IAT to demonstrate whether or not a steady-state blood lactate concentration [La-]b could be maintained. Oxygen uptake (VO2), heart rate (HR) and [La-]b were measured. The PIE revealed significant lower values at IAT compared to AT4 for power output (P concepts of anaerobic threshold gave different information about submaximal endurance capacity. Only IAT represented on average [La-]ss. It is suggested that more research is needed to elicit optimal guidelines for the intensity of endurance training.

  11. Effect of formoterol, a long-acting β2-adrenergic agonist, on muscle strength and power output, metabolism, and fatigue during maximal sprinting in men.

    Science.gov (United States)

    Kalsen, Anders; Hostrup, Morten; Backer, Vibeke; Bangsbo, Jens

    2016-06-01

    The aim was to investigate the effect of the long-acting β2-adrenergic agonist formoterol on muscle strength and power output, muscle metabolism, and phosphorylation of CaMKII Thr(287) and FXYD1 during maximal sprinting. In a double-blind crossover study, 13 males [V̇o2 max: 45.0 ± 0.2 (means ± SE) ml·min(-1)·kg(-1)] performed a 30-s cycle ergometer sprint after inhalation of either 54 μg of formoterol (FOR) or placebo (PLA). Before and after the sprint, muscle biopsies were collected from vastus lateralis and maximal voluntary contraction (MVC), and contractile properties of quadriceps were measured. Oxygen uptake was measured during the sprint. During the sprint, peak power, mean power, and end power were 4.6 ± 0.8, 3.9 ± 1.1, and 9.5 ± 3.2% higher (P power output during maximal sprinting is associated with increased rates of glycogenolysis and glycolysis that may counteract development of fatigue. Copyright © 2016 the American Physiological Society.

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

    Directory of Open Access Journals (Sweden)

    Kyle Holzer

    2015-05-01

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

  13. Effects of Creatine and Sodium Bicarbonate Coingestion on Multiple Indices of Mechanical Power Output During Repeated Wingate Tests in Trained Men.

    Science.gov (United States)

    Griffen, Corbin; Rogerson, David; Ranchordas, Mayur; Ruddock, Alan

    2015-06-01

    This study investigated the effects of creatine and sodium bicarbonate coingestion on mechanical power during repeated sprints. Nine well-trained men (age = 21.6 ± 0.9 yr, stature = 1.82 ± 0.05 m, body mass = 80.1 ±12.8 kg) participated in a double-blind, placebo-controlled, counterbalanced, crossover study using six 10-s repeated Wingate tests. Participants ingested either a placebo (0.5 g·kg(-1) of maltodextrin), 20 g·d(-1) of creatine monohydrate + placebo, 0.3 g·kg(-1) of sodium bicarbonate + placebo, or coingestion + placebo for 7 days, with a 7-day washout between conditions. Participants were randomized into two groups with a differential counterbalanced order. Creatine conditions were ordered first and last. Indices of mechanical power output (W), total work (J) and fatigue index (W·s(-1)) were measured during each test and analyzed using the magnitude of differences between groups in relation to the smallest worthwhile change in performance. Compared with placebo, both creatine (effect size (ES) = 0.37-0.83) and sodium bicarbonate (ES = 0.22-0.46) reported meaningful improvements on indices of mechanical power output. Coingestion provided small meaningful improvements on indices of mechanical power output (W) compared with sodium bicarbonate (ES = 0.28-0.41), but not when compared with creatine (ES = -0.21-0.14). Coingestion provided a small meaningful improvement in total work (J; ES = 0.24) compared with creatine. Fatigue index (W·s(-1)) was impaired in all conditions compared with placebo. In conclusion, there was no meaningful additive effect of creatine and sodium bicarbonate coingestion on mechanical power during repeated sprints.

  14. Effects of 4-Week Training Intervention with Unknown Loads on Power Output Performance and Throwing Velocity in Junior Team Handball Players.

    Science.gov (United States)

    Sabido, Rafael; Hernández-Davó, Jose Luis; Botella, Javier; Moya, Manuel

    2016-01-01

    To compare the effect of 4-week unknown vs known loads strength training intervention on power output performance and throwing velocity in junior team handball players. Twenty-eight junior team-handball players (17.2 ± 0.6 years, 1.79 ± 0.07 m, 75.6 ± 9.4 kg)were divided into two groups (unknown loads: UL; known loads: KL). Both groups performed two sessions weekly consisting of four sets of six repetitions of the bench press throw exercise, using the 30%, 50% and 70% of subjects' individual 1 repetition maximum (1RM). In each set, two repetitions with each load were performed, but the order of the loads was randomised. In the KL group, researchers told the subjects the load to mobilise prior each repetition, while in the UL group, researchers did not provide any information. Maximal dynamic strength (1RM bench press), power output (with 30, 50 and 70% of 1RM) and throwing velocity (7 m standing throw and 9 m jumping throw) were assessed pre- and post-training intervention. Both UL and KL group improved similarly their 1RM bench press as well as mean and peak power with all loads. There were significant improvements in power developed in all the early time intervals measured (150 ms) with the three loads (30, 50, 70% 1RM) in the UL group, while KL only improved with 30% 1RM (all the time intervals) and with 70% 1RM (at certain time intervals). Only the UL group improved throwing velocity in both standing (4.7%) and jumping (5.3%) throw (p > 0.05). The use of unknown loads has led to greater gains in power output in the early time intervals as well as to increases in throwing velocity compared with known loads. Therefore unknown loads are of significant practical use to increase both strength and in-field performance in a short period of training.

  15. Effects of 4-Week Training Intervention with Unknown Loads on Power Output Performance and Throwing Velocity in Junior Team Handball Players.

    Directory of Open Access Journals (Sweden)

    Rafael Sabido

    Full Text Available To compare the effect of 4-week unknown vs known loads strength training intervention on power output performance and throwing velocity in junior team handball players.Twenty-eight junior team-handball players (17.2 ± 0.6 years, 1.79 ± 0.07 m, 75.6 ± 9.4 kgwere divided into two groups (unknown loads: UL; known loads: KL. Both groups performed two sessions weekly consisting of four sets of six repetitions of the bench press throw exercise, using the 30%, 50% and 70% of subjects' individual 1 repetition maximum (1RM. In each set, two repetitions with each load were performed, but the order of the loads was randomised. In the KL group, researchers told the subjects the load to mobilise prior each repetition, while in the UL group, researchers did not provide any information. Maximal dynamic strength (1RM bench press, power output (with 30, 50 and 70% of 1RM and throwing velocity (7 m standing throw and 9 m jumping throw were assessed pre- and post-training intervention.Both UL and KL group improved similarly their 1RM bench press as well as mean and peak power with all loads. There were significant improvements in power developed in all the early time intervals measured (150 ms with the three loads (30, 50, 70% 1RM in the UL group, while KL only improved with 30% 1RM (all the time intervals and with 70% 1RM (at certain time intervals. Only the UL group improved throwing velocity in both standing (4.7% and jumping (5.3% throw (p > 0.05.The use of unknown loads has led to greater gains in power output in the early time intervals as well as to increases in throwing velocity compared with known loads. Therefore unknown loads are of significant practical use to increase both strength and in-field performance in a short period of training.

  16. A Game Theoretic Framework for Green HetNets Using D2D Traffic Offload and Renewable Energy Powered Base Stations

    KAUST Repository

    Yaacoub, Elias

    2015-08-26

    This chapter investigates the interplay between cooperative device-to-device (D2D) communications and green communications in LTE heterogeneous networks (HetNets). Two game theoretic concepts are studied and analyzed in order to perform dynamic HetNet base station (BS) on/off switching. The first approach is a coalition-based method whereas the second is based on the Nash bargaining solution. Afterwards, a method for coupling the BS on/off switching approach with D2D collaborative communications is presented and shown to lead to increased energy efficiency. The savings are additionally increased when a portion of the small cell BSs in a HetNet are powered by renewable energy sources. Different utility functions, modeling the game theoretic framework governing the energy consumption balance between the cellular network and the mobile terminals (MTs), are proposed and compared, and their impact on MT quality of service (QoS) is analyzed.

  17. Socio-economic and environmental effects of concentrated solar power in spain: A multiregional input output analysis

    NARCIS (Netherlands)

    Corona, B.; de la Rúa, C.; San Miguel, G.

    2016-01-01

    Concentrated Solar Power (CSP) is receiving increasing attention as a technology with the potential to provide clean electricity in a cost effective and dispatchable manner. Despite its renewable nature, solar power generation generates impacts that need to be adequately evaluated and managed. The

  18. Output characteristics of floating type wave power generator system using a ball screw; Fuyugata nejishiki haryoku hatsuden sochi no shutsuryoku tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Abe, T.; Omata, K. [Meiji University, Tokyo (Japan)

    1996-10-27

    A floating type wave power generator system using a ball screw is proposed. Output characteristics are simulated on the supposition of its employment aboard a navigational aid buoy. The relative linear movement produced by waves between the main body and float is transmitted via a load column to a ball nut and is converted into a rotary movement of a threaded shaft engaging the ball nut. Attached to the bottom end of the threaded shaft is a one-way clutch which connects to the generator axle when the relative velocity between the float and main body is positive. The simulation was conducted for a wave activated power generation buoy, 2.6m in outer diameter, 4.5m in length, and 6000kg in total mass. The buoy generated a mechanical output of 340kW when exposed to a sinusoidal wave 2.5 seconds in period and 40cm in wave height. A tank test was performed using a reduced scale model consisting of a ball screw, bicycle dynamo, and float, with the main body being 318mm in diameter and 833mm in length, when an average output of 4.51W was obtained at 60% efficiency. The results of the experiment agreed in some degree with the results of calculation, verifying the righteousness of the theoretical formula. 3 refs., 7 figs., 4 tabs.

  19. Output feedback dissipation control for the power-level of modular high-temperature gas-cooled reactors

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Z. [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing (China)

    2011-07-01

    Because of its strong inherent safety features and the high outlet temperature, the modular high temperature gas-cooled nuclear reactor (MHTGR) is the chosen technology for a new generation of nuclear power plants. Such power plants are being considered for industrial applications with a wide range of power levels, thus power-level regulation is very important for their efficient and stable operation. Exploiting the large scale asymptotic closed-loop stability provided by nonlinear controllers, a nonlinear power-level regulator is presented in this paper that is based upon both the techniques of feedback dissipation and well-established backstepping. The virtue of this control strategy, i.e., the ability of globally asymptotic stabilization, is that it takes advantage of the inherent zero-state detectability property of the MHTGR dynamics. Moreover, this newly built power-level regulator is also robust towards modeling uncertainty in the control rod dynamics. If modeling uncertainty of the control rod dynamics is small enough to be omitted, then this control law can be simplified to a classical proportional feedback controller. The comparison of the control performance between the newly-built power controller and the simplified controller is also given through numerical study and theoretical analysis. (author)

  20. Output Feedback Dissipation Control for the Power-Level of Modular High-Temperature Gas-Cooled Reactors

    Directory of Open Access Journals (Sweden)

    Zhe Dong

    2011-11-01

    Full Text Available Because of its strong inherent safety features and the high outlet temperature, the modular high temperature gas-cooled nuclear reactor (MHTGR is the chosen technology for a new generation of nuclear power plants. Such power plants are being considered for industrial applications with a wide range of power levels, thus power-level regulation is very important for their efficient and stable operation. Exploiting the large scale asymptotic closed-loop stability provided by nonlinear controllers, a nonlinear power-level regulator is presented in this paper that is based upon both the techniques of feedback dissipation and well-established backstepping. The virtue of this control strategy, i.e., the ability of globally asymptotic stabilization, is that it takes advantage of the inherent zero-state detectability property of the MHTGR dynamics. Moreover, this newly built power-level regulator is also robust towards modeling uncertainty in the control rod dynamics. If modeling uncertainty of the control rod dynamics is small enough to be omitted, then this control law can be simplified to a classical proportional feedback controller. The comparison of the control performance between the newly-built power controller and the simplified controller is also given through numerical study and theoretical analysis.

  1. A comprehensive analysis and hardware implementation of control strategies for high output voltage DC-DC boost power converter

    DEFF Research Database (Denmark)

    Padmanaban, Sanjeevikumar; Grandi, Gabriele; Blaabjerg, Frede

    2017-01-01

    -loop controller to get high and stable output voltage. Complete hardware prototype of EHV is implemented and experimental tasks are carried out with digital signal processor (DSP) TMS320F2812. The control algorithms P-I, fuzzy logic and the pulse-width modulation (PWM) signals for N-channel MOSFET device...... are performed by the DSP. The experimental results provided show good conformity with developed hypothetical predictions. Additionally, the presented study confirms that the fuzzy logic controller provides better performance than classical P-I controller under different perturbation conditions....

  2. Design of a high voltage input - output ratio dc-dc converter dedicated to small power fuel cell systems

    OpenAIRE

    Béthoux, O.; Cathelin, J.

    2010-01-01

    Abstract Consuming chemical energy, fuel cells produce simultaneously heat, water and useful electrical power [J.M. Andujar, F. Segura, Renew. Sust. Energy Rev. 13, 2309 (2009)], [J. Larminie, A. Dicks, Fuel Cell Systems Explained, 2nd edn. (John Wiley & Sons, 2003)]. As a matter of fact, the voltage generated by a fuel cell strongly depends on both the load power demand and the operating conditions. Besides, as a result of many design aspects, fuel cells ar...

  3. The Economic Value of Korean Nuclear Power Industry in the National Economy: An Input-Output Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, M. K.; Kim, S. S.; Lee, J. H.; Kim, S. H. [Nuclear Policy Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    In 1978, Korea introduced the first nuclear power plant, Kori-1 unit, in parallel with the nation's industrialization policy. Thereafter, Korea has carried out a very ambitious nuclear power program and sustained a strong commitment to nuclear power development. Thus, nuclear is a prime energy source which presently meets about 30 percent of Korea's power demands. Also, Korea won a contract for APR-1400 NPPs to the UAE in 2009 which led to Korea as a significant exporter in the world nuclear market. Recently, the new government of Korea has been launching 'Creative Economy', from this perspective, the quantitative contributions of nuclear sector to the national economic growth are required to be estimated. This paper is to estimate quantitatively the economic values created by nuclear power industry in the framework of national economy. The total economic values created by nuclear power industry are estimated to be 63.6 trillion won for the study period.

  4. Inverter communications using output signal

    Science.gov (United States)

    Chapman, Patrick L.

    2017-02-07

    Technologies for communicating information from an inverter configured for the conversion of direct current (DC) power generated from an alternative source to alternating current (AC) power are disclosed. The technologies include determining information to be transmitted from the inverter over a power line cable connected to the inverter and controlling the operation of an output converter of the inverter as a function of the information to be transmitted to cause the output converter to generate an output waveform having the information modulated thereon.

  5. Environmental summary document for the Republic Geothermal, Inc. application for a geothermal loan guaranty project: 64 MW well field and 48 MW (net) geothermal power plant

    Energy Technology Data Exchange (ETDEWEB)

    Layton, D.W.; Powers, D.J.; Leitner, P.; Crow, N.B.; Gudiksen, P.H.; Ricker, Y.E.

    1979-07-01

    A comprehensive review and analysis is provided of the environmental consequences of (1) guaranteeing a load for the completion of the 64 MW well field and the 48 MW (net) power plant or (2) denying a guaranteed load that is needed to finish the project. Mitigation measures are discussed. Alternatives and their impacts are compared and some discussion is included on unavoidable adverse impacts. (MHR)

  6. A comprehensive analysis and hardware implementation of control strategies for high output voltage DC-DC boost power converter

    DEFF Research Database (Denmark)

    Padmanaban, Sanjeevikumar; Grandi, Gabriele; Blaabjerg, Frede

    2017-01-01

    voltage and efficiency of classical HV converters. This paper deals with extra high-voltage (EHV) dc-dc boost converter by the application of voltage-lift technique to overcome the aforementioned deficiencies. The control strategy is based on classical proportional-integral (P-I) and fuzzy logic closed......-loop controller to get high and stable output voltage. Complete hardware prototype of EHV is implemented and experimental tasks are carried out with digital signal processor (DSP) TMS320F2812. The control algorithms P-I, fuzzy logic and the pulse-width modulation (PWM) signals for N-channel MOSFET device...... are performed by the DSP. The experimental results provided show good conformity with developed hypothetical predictions. Additionally, the presented study confirms that the fuzzy logic controller provides better performance than classical P-I controller under different perturbation conditions....

  7. Miniaturized laser amplifier modules for wavelengths of 1180 nm with PM-fiber input and more than 1 W optical output power

    Science.gov (United States)

    Hofmann, Julian; Jedrzejczyk, Daniel; Sahm, Alexander; Werner, Nils; Blume, Gunnar; Eppich, Bernd; Feise, David; Bugge, Frank; Paschke, Katrin

    2017-02-01

    In this paper a micro-integrated laser-amplifier for a wavelength of 1180nm is presented. The modules can amplify laser emission from any source, which is coupled into the polarization-maintaining input fiber of the module, to an optical power > 1W. Thereby, the spectral properties of the seed source are maintained. The output of the module is free space allowing easy access to the emitted beam. The footprint of the module is only 47mm • 34 mm. The article discusses the utilized amplifiers, preceding bench top experiments and gives a detailed experimental characterization of the amplifier module.

  8. Study on fault diagnosis method for nuclear power plant based on hadamard error-correcting output code

    Science.gov (United States)

    Mu, Y.; Sheng, G. M.; Sun, P. N.

    2017-05-01

    The technology of real-time fault diagnosis for nuclear power plants(NPP) has great significance to improve the safety and economy of reactor. The failure samples of nuclear power plants are difficult to obtain, and support vector machine is an effective algorithm for small sample problem. NPP is a very complex system, so in fact the type of NPP failure may occur very much. ECOC is constructed by the Hadamard error correction code, and the decoding method is Hamming distance method. The base models are established by lib-SVM algorithm. The result shows that this method can diagnose the faults of the NPP effectively.

  9. Programming NET Web Services

    CERN Document Server

    Ferrara, Alex

    2007-01-01

    Web services are poised to become a key technology for a wide range of Internet-enabled applications, spanning everything from straight B2B systems to mobile devices and proprietary in-house software. While there are several tools and platforms that can be used for building web services, developers are finding a powerful tool in Microsoft's .NET Framework and Visual Studio .NET. Designed from scratch to support the development of web services, the .NET Framework simplifies the process--programmers find that tasks that took an hour using the SOAP Toolkit take just minutes. Programming .NET

  10. Yellow laser light generation by frequency doubling of the output from a master oscillator fiber power amplifier system

    Science.gov (United States)

    Ryser, Manuel; Marques, Carlos; Nogueira, Rogério; Romano, Valerio

    2015-03-01

    We present a power-scalable approach for yellow laser-light generation based on standard Ytterbium (Yb) doped fibers. To force the cavity to lase at 1154 nm, far above the gain-maximum, measures must be taken to fulfill lasing condition and to suppress competing amplified spontaneous emission (ASE) in the high-gain region. To prove the principle we built a fiber-laser cavity and a fiber-amplifier both at 1154 nm. In between cavity and amplifier we suppressed the ASE by 70 dB using a fiber Bragg grating (FBG) based filter. Finally we demonstrated efficient single pass frequency doubling to 577 nm with a periodically poled lithium niobate crystal (PPLN). With our linearly polarized 1154 nm master oscillator power fiber amplifier (MOFA) system we achieved slope efficiencies of more than 15 % inside the cavity and 24 % with the fiber-amplifier. The frequency doubling followed the predicted optimal efficiency achievable with a PPLN crystal. So far we generated 1.5 W at 1154nm and 90 mW at 577 nm. Our MOFA approach for generation of 1154 nm laser radiation is power-scalable by using multi-stage amplifiers and large mode-area fibers and is therefore very promising for building a high power yellow laser-light source of several tens of Watt.

  11. A simple algorithm to compute the peak power output of GaAs/Ge solar cells on the Martian surface

    Energy Technology Data Exchange (ETDEWEB)

    Glueck, P.R.; Bahrami, K.A. [California Inst. of Technology, Pasadena, CA (United States). Jet Propulsion Lab.

    1995-12-31

    The Jet Propulsion Laboratory`s (JPL`s) Mars Pathfinder Project will deploy a robotic ``microrover`` on the surface of Mars in the summer of 1997. This vehicle will derive primary power from a GaAs/Ge solar array during the day and will ``sleep`` at night. This strategy requires that the rover be able to (1) determine when it is necessary to save the contents of volatile memory late in the afternoon and (2) determine when sufficient power is available to resume operations in the morning. An algorithm was developed that estimates the peak power point of the solar array from the solar array short-circuit current and temperature telemetry, and provides functional redundancy for both measurements using the open-circuit voltage telemetry. The algorithm minimizes vehicle processing and memory utilization by using linear equations instead of look-up tables to estimate peak power with very little loss in accuracy. This paper describes the method used to obtain the algorithm and presents the detailed algorithm design.

  12. 11.9 W Output Power at S-band from 1 mm AlGaN/GaN HEMTs

    NARCIS (Netherlands)

    Krämer, M.C.J.C.M.; Karouta, F.; Kwaspen, J.J.M.; Rudzinski, M.; Larsen, P.K.; Suijker, E.M.; Hek, P.A. de; Rödle, T.; Volokhine, I.; Kaufmann, L.M.F.

    2008-01-01

    We present radio-frequency (RF) power results of GaN-based high electron mobility transistors (HEMTs) with total gate widths (Wg) up to 1 mm. The AlGaN/GaN epi-structures are MOVPE-grown on 2-inches semi-insulating (s.i.) 4H-silicon carbide substrates. The HEMTs have been fabricated using an

  13. 11.9 W output power at 4 GHz from 1 mm AlGaN/GaN HEMT

    NARCIS (Netherlands)

    Krämer, M.C.J.C.M.; Karouta, F.; Kwaspen, J.J.M.; Rudzinski, M.; Larsen, P.K.; Suijker, E.M.; Hek, P.A. de; Rödle, T.; Volokhine, I.; Kaufmann, L.M.F.

    2008-01-01

    A high electrical breakdown field combined with a high electron saturation velocity make GaN very attractive for high power high frequency electronics. The maximum drain current densities of AlGaN/GaN HFETs range from 1.0 A/mm to 1.5 A/mm [1-3]. Hence, it is obvious that breakdown voltages over 160

  14. DisGeNET-RDF: harnessing the innovative power of the Semantic Web to explore the genetic basis of diseases.

    Science.gov (United States)

    Queralt-Rosinach, Núria; Piñero, Janet; Bravo, Àlex; Sanz, Ferran; Furlong, Laura I

    2016-07-15

    DisGeNET-RDF makes available knowledge on the genetic basis of human diseases in the Semantic Web. Gene-disease associations (GDAs) and their provenance metadata are published as human-readable and machine-processable web resources. The information on GDAs included in DisGeNET-RDF is interlinked to other biomedical databases to support the development of bioinformatics approaches for translational research through evidence-based exploitation of a rich and fully interconnected linked open data. http://rdf.disgenet.org/ support@disgenet.org. © The Author 2016. Published by Oxford University Press.

  15. The Diamond Window with Boron-Doped Layers for the Output of Microwave Radiation at High Peak and Average Power Levels

    Science.gov (United States)

    Ivanov, O. A.; Kuzikov, S. V.; Vikharev, A. A.; Vikharev, A. L.; Lobaev, M. A.

    2017-10-01

    We propose a novel design of the barrier window for the output of microwave radiation at high peak and average power levels. A window based on a plate of polycrystalline CVD diamond with thin (nanometer-thick) boron-doped layers with increased conductivity is considered. Such a window, which retains the low radiation loss due to the small total thickness of the conductive layers and the high thermal conductivity inherent in diamond, prevents accumulation of a static charge on its surface, on the one hand, and allows one to produce a static electric field on the surface of the doped layer, which impedes the development of a multipactor discharge, on the other hand. In this case, a high level of the power of the transmitted radiation and a large passband width are ensured by choosing the configuration of the field in the form of a traveling wave inside the window.

  16. A low power and low distortion rail-to-rail input/output amplifier using constant current technique

    Energy Technology Data Exchange (ETDEWEB)

    Liu Yan; Zhao Yiqiang; Zhang Shilin [School of Electronic Information Engineering, Tianjin University, Tianjin 300072 (China); Zhao Hongliang, E-mail: zhaoyq@tju.edu.cn [School of Physics, Liaoning University, Shenyang 110036 (China)

    2011-04-15

    A rail-to-rail amplifier with constant transconductance, intended for audio processing, is presented. The constant transconductance is obtained by a constant current technique based on the input differential pairs operating in the weak inversion region. MOSFETs working in the weak inversion region have the advantages of low power and low distortion. The proposed rail-to-rail amplifier, fabricated in a standard 0.35 {mu}m CMOS process, occupies a core die area of 75 x 183 {mu}m{sup 2}. Measured results show that the maximum power consumption is 85.37 {mu}W with a supply voltage of 3.3 V and the total harmonic distortion level is 1.2% at 2 kHz. (semiconductor integrated circuits)

  17. Testing for Market Power in Multiple-Input, Multiple-Output Industries: The Australian Grains and Oilseeds Industries

    OpenAIRE

    O?Donnell, Christopher J.; Griffith, Garry R.; Nightingale, John J.; Piggott, Roley R.

    2004-01-01

    Recent empirical studies have found significant evidence of departures from competition in the input side of the Australian bread, breakfast cereal and margarine end-product markets. For example, Griffith (2000) found that firms in some parts of the processing and marketing sector exerted market power when purchasing grains and oilseeds from farmers. As noted at the time, this result accorded well with the views of previous regulatory authorities (p.358). In the mid-1990s, the Prices Surveill...

  18. Excitation Method of Linear-Motor-Type Rail Brake without Using Power Sources by Dynamic Braking with Zero Electrical Output

    Science.gov (United States)

    Sakamoto, Yasuaki; Kashiwagi, Takayuki; Hasegawa, Hitoshi; Sasakawa, Takashi; Fujii, Nobuo

    The eddy current rail brake is a type of braking system used in railway vehicles. Because of problems such as rail heating and problems associated with ensuring that power is supplied when the feeder malfunctions, this braking system has not been used for practical applications in Japan. Therefore, we proposed the use of linear induction motor (LIM) technology in eddy current rail brake systems. The LIM rail brake driven by dynamic braking can reduce rail heating and generate the energy required for self-excitation. In this paper, we present an excitation system and control method for the LIM rail brake driven by “dynamic braking with zero electrical output”. The proposed system is based on the concept that the LIM rail brake can be energized without using excitation power sources such as a feeder circuit and that high reliability can be realized by providing an independent excitation system. We have studied this system and conducted verification tests using a prototype LIM rail brake on a roller rig. The results show that the system performance is adequate for commercializing the proposed system, in which the LIM rail brake is driven without using any excitation power source.

  19. The effects of elevated levels of sodium bicarbonate (NaHCO₃) on the acute power output and time to fatigue of maximally stimulated mouse soleus and EDL muscles.

    Science.gov (United States)

    Higgins, M F; Tallis, J; Price, M J; James, R S

    2013-05-01

    This study examined the effects of elevated buffer capacity [~32 mM HCO₃(-)] through administration of sodium bicarbonate (NaHCO₃) on maximally stimulated isolated mouse soleus (SOL) and extensor digitorum longus (EDL) muscles undergoing cyclical length changes at 37 °C. The elevated buffering capacity was of an equivalent level to that achieved in humans with acute oral supplementation. We evaluated the acute effects of elevated [HCO₃(-)] on (1) maximal acute power output (PO) and (2) time to fatigue to 60 % of maximum control PO (TLIM60), the level of decline in muscle PO observed in humans undertaking similar exercise, using the work loop technique. Acute PO was on average 7.0 ± 4.8 % greater for NaHCO₃-treated EDL muscles (P muscles (P muscle performance was variable, suggesting that there might be inter-individual differences in response to NaHCO₃ supplementation. These results present the best indication to date that NaHCO₃ has direct peripheral effects on mammalian skeletal muscle resulting in increased acute power output.

  20. Enhancement of light output power in GaN-based light-emitting diodes using hydrothermally grown ZnO micro-walls.

    Science.gov (United States)

    Jeong, Hyun; Kim, Yong Hwan; Seo, Tae Hoon; Lee, Hong Seok; Kim, Jun Sung; Suh, Eun-Kyung; Jeong, Mun Seok

    2012-05-07

    We report on the efficiency enhancement in GaN-based light-emitting diodes (LEDs) using ZnO micro-walls grown by a hydrothermal method. The formation of ZnO micro-walls at the indium tin oxide (ITO) border on the LED structure is explained by the heterogeneous nucleation effect. The light output power of LEDs with ZnO micro-walls operated at 20 mA was found to increase by approximately 30% compared to conventional LEDs. Moreover, the finding of nearly the same current-voltage characteristics of GaN-based LEDs with and without a ZnO micro-wall shows that the ZnO micro-wall does not influence the electrical properties of the device but only leads to an increase in the light extraction efficiency. From the confocal scanning electroluminescence results, we confirm that ZnO micro-walls enhance the light output power via the photon wave-guiding effect.

  1. Regional thermal specialisation in a mammal: temperature affects power output of core muscle more than that of peripheral muscle in adult mice (Mus musculus).

    Science.gov (United States)

    James, Rob S; Tallis, Jason; Angilletta, Michael J

    2015-01-01

    In endotherms, such as mammals and birds, internal organs can specialise to function within a narrow thermal range. Consequently, these organs should become more sensitive to changes in body temperature. Yet, organs at the periphery of the body still experience considerable fluctuations in temperature, which could select for lower thermal sensitivity. We hypothesised that the performance of soleus muscle taken from the leg would depend less on temperature than would the performance of diaphragm muscle taken from the body core. Soleus and diaphragm muscles were isolated from mice and subjected to isometric and work-loop studies to analyse mechanical performance at temperatures between 15 and 40 °C. Across this thermal range, soleus muscle took longer to generate isometric force and longer to relax, and tended to produce greater normalised maximal force (stress) than did diaphragm muscle. The time required to produce half of maximal force during isometric tetanus and the time required to relax half of maximal force were both more sensitive to temperature in soleus than they were in diaphragm. However, thermal sensitivities of maximal force during isometric tetani were similar for both muscles. Consistent with our hypothesis, power output (the product of speed and force) was greater in magnitude and more thermally sensitive in diaphragm than it was in soleus. Our findings, when combined with previous observations of muscles from regionally endothermic fish, suggest that endothermy influences the thermal sensitivities of power output in core and peripheral muscles.

  2. Willingness to pay for small solar powered bed net fans: results of a Becker-DeGroot-Marschak auction in Ghana.

    Science.gov (United States)

    Yukich, Joshua O; Briët, Olivier J T; Ahorlu, Collins K; Nardini, Peter; Keating, Joseph

    2017-08-07

    Long-lasting insecticidal nets (LLINs) are one of the main interventions recommended by the World Health Organization for malaria vector control. LLINs are ineffective if they are not being used. Subsequent to the completion of a cluster randomized cross over trial conducted in rural Greater Accra where participants were provided with the 'Bɔkɔɔ System'-a set of solar powered net fan and light consoles with a solar panel and battery-or alternative household water filters, all trial participants were invited to participate in a Becker-DeGroot-Marschak auction to determine the mean willingness to pay (WTP) for the fan and light consoles and to estimate the demand curve for the units. Results demonstraed a mean WTP of approximately 55 Cedis (~13 USD). Demand results suggested that at a price which would support full manufacturing cost recovery, a majority of households in the area would be willing to purchase at least one such unit.

  3. Influence of temperature on power output of a panel of polycrystalline silicon in the west region of Parana, Brazil; Influencia da temperatura sobre a potencia de saida de um painel de silicio policristalino na regiao oeste paranaense

    Energy Technology Data Exchange (ETDEWEB)

    Michels, Roger Nabeyama; Santos, Jose Airton Azevedo dos; Gnoatto, Estor; Kawanagh, Edward; Fischborn, Marcos [Universidade Tecnologica Federal do Parana (UTFPR), Medianeira, PR (Brazil); Halmeman, Maria Cristina Rodrigues [Universidade Estadual Paulista (UNESP), Botucatu, SP (Brazil)

    2008-07-01

    Photovoltaic panels have been confirmed as an alternative source of electric energy. However, the output power of a photovoltaic panel is strongly dependent on solar intensity modifications and ambient temperature too. Then, it is necessary to know like the panels work under these alterations. This work intend to analyze the influence of the temperature on the output power of a polycrystalline silicon photovoltaic panel in Medianeira City located in West Region of Parana State by one year observation period. (author)

  4. Development of work, time and output utilisation of nuclear power plants with light water reactors in the world for the period 1968 to 1987 i. e. from the 1. to the 17. year of operation

    Energy Technology Data Exchange (ETDEWEB)

    Held, C.

    The cumulated work utilisation of light water reactors in the world rose as function of the calendar years from 56% in 1968 to 65% in 1986. Even more remarkable is the almost consistent value of 65% throughout 17 years of operation. In some countries values of over 80% are attained. Nuclear power plants with light water reactors could, as planned, be operated as basic output power plants with an output utilisation rising to over 90%. The cumulated work, time and output utilisation followed as function of the calendar year as well as operating year the law of the equation y = a + b . ln x.

  5. Relationship between vertical jump and maximal power output of legs and arms: effects of ethnicity and sport.

    Science.gov (United States)

    Rouis, M; Attiogbé, E; Vandewalle, H; Jaafar, H; Noakes, T D; Driss, T

    2015-04-01

    The hypothesis that ethnicity and sport practice influence the relationship between maximal power in cycling (P(max)) and countermovement jump (CMJ) has been studied by relating CMJ and P(max) in two groups (volleyball players, VB, and physical education students, PES) including subjects with Caucasian (67 C) or West African (39 WA) origins. Maximal power of the arms (P(max) Arms) was also measured. A two-way analysis of variance (groups × ethnicity) showed significant effects of both factors upon CMJ, which was higher in WA and VB, P = 0.002 and P < 0.001, respectively. Within WA, CMJ was significantly higher in VB (0.732 ± 0.057 m) than in PES (0.661 ± 0.082 m), although there was no difference in P(max) (14.7 ± 1.7 vs 14.7 ± 1.9 W/kg). CMJ was significantly higher in WA (0.69 ± 0.08 vs 0.65 ± 0.09 m in C, P = 0.002) without significant interethnic difference in P(max) (14.7 ± 1.8 in WA, and 14.8 ± 1.9 W/kg in C). The CMJ-P(max) relationships were different in C and WA (P = 0.003). Therefore, CMJ predicted from P(max) would be underestimated in WA. The same difference was observed for the relationship between CMJ and P(max) Arms. These results were confirmed by the comparison with previous P(max) -CMJ relationship in the literature, collected in Caucasian and African subjects with the same protocols. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Niland development project geothermal loan guaranty: 49-MW (net) power plant and geothermal well field development, Imperial County, California: Environmental assessment

    Energy Technology Data Exchange (ETDEWEB)

    1984-10-01

    The proposed federal action addressed by this environmental assessment is the authorization of disbursements under a loan guaranteed by the US Department of Energy for the Niland Geothermal Energy Program. The disbursements will partially finance the development of a geothermal well field in the Imperial Valley of California to supply a 25-MW(e) (net) power plant. Phase I of the project is the production of 25 MW(e) (net) of power; the full rate of 49 MW (net) would be achieved during Phase II. The project is located on approximately 1600 acres (648 ha) near the city of Niland in Imperial County, California. Well field development includes the initial drilling of 8 production wells for Phase I, 8 production wells for Phase II, and the possible need for as many as 16 replacement wells over the anticipated 30-year life of the facility. Activities associated with the power plant in addition to operation are excavation and construction of the facility and associated systems (such as cooling towers). Significant environmental impacts, as defined in Council on Environmental Quality regulation 40 CFR Part 1508.27, are not expected to occur as a result of this project. Minor impacts could include the following: local degradation of ambient air quality due to particulate and/or hydrogen sulfide emissions, temporarily increased ambient noise levels due to drilling and construction activities, and increased traffic. Impacts could be significant in the event of a major spill of geothermal fluid, which could contaminate groundwater and surface waters and alter or eliminate nearby habitat. Careful land use planning and engineering design, implementation of mitigation measures for pollution control, and design and implementation of an environmental monitoring program that can provide an early indication of potential problems should ensure that impacts, except for certain accidents, will be minimized.

  7. Optimization of power output and study of electron beam energy spread in a Free Electron Laser oscillator

    CERN Document Server

    Abramovich, A; Efimov, S; Gover, A; Pinhasi, Y; Yahalom, A

    2001-01-01

    Design of a multi-stage depressed collector for efficient operation of a Free Electron Laser (FEL) oscillator requires knowledge of the electron beam energy distribution. This knowledge is necessary to determine the voltages of the depressed collector electrodes that optimize the collection efficiency and overall energy conversion efficiency of the FEL. The energy spread in the electron beam is due to interaction in the wiggler region, as electrons enter the interaction region at different phases relative to the EM wave. This interaction can be simulated well by a three-dimensional simulation code such as FEL3D. The main adjustable parameters that determine the electron beam energy spread after interaction are the e-beam current, the initial beam energy, and the quality factor of the resonator out-coupling coefficient. Using FEL3D, we study the influence of these parameters on the available radiation power and on the electron beam energy distribution at the undulator exit. Simulations performed for I=1.5 A, E...

  8. Photoluminescence close to V-shaped pits in the quantum wells and enhanced output power for InGaN light emitting diode

    Science.gov (United States)

    Han, Dan; Ma, Shufang; Jia, Zhigang; Jia, Wei; Liu, Peizhi; Dong, Hailiang; Shang, Lin; Zhang, Aiqin; Zhai, Guangmei; Li, Xuemin; Liu, Xuguang; Xu, Bingshe

    2017-11-01

    Unlike the typical ‘S-shaped’ temperature dependent behavior for InGaN/GaN light emitting diodes (LEDs), the emission of the c-plane MQWs (C-QWs) close to V-shaped pits (V-pits) broadens across the short-wavelength band and exhibits a blue-shift as temperature increases by temperature-dependent micro photoluminescence (µ-TDPL). The phenomenon can be mainly attributed to a higher proportion carriers generate high-energy radiative transition in C-QWs close to V-pits because of augmented carrier mobility, in which the mechanism of carriers absorbed in sidewall MQWs (S-QWs) move to the C-QWs close to V-pits acts as a significant process. The sizes of V-pits can be enlarged as increasing the thickness of low temperature GaN interlayer (LT-GaN interlayer), leading to improved output power for LEDs.

  9. Mechanosensing in myosin filament solves a 60 years old conflict in skeletal muscle modeling between high power output and slow rise in tension

    CERN Document Server

    Marcucci, Lorenzo

    2016-01-01

    Almost 60 years ago Andrew Huxley with his seminal paper \\cite{Huxley1957} laid the foundation of modern muscle modeling, linking chemical events to mechanical performance. He described mechanics and energetics of muscle contraction through the cyclical attachment and detachment of myosin motors to the actin filament with ad hoc assumptions on the dependence of the rate constants on the strain of the myosin motors. That relatively simple hypothesis is still present in recent models, even though with several modifications to adapt the model to the different experimental constraints which became subsequently available. However, already in that paper, one controversial aspect of the model became clear. Relatively high attachment and detachment rates of myosin to the actin filament were needed to simulate the high power output at intermediate velocity of contraction. However, these rates were incompatible with the relatively slow rise in tension after activation, despite the rise should be generated by the same r...

  10. Enhanced light output power of InGaN-based amber LEDs by strain-compensating AlN/AlGaN barriers

    Science.gov (United States)

    Iida, Daisuke; Lu, Shen; Hirahara, Sota; Niwa, Kazumasa; Kamiyama, Satoshi; Ohkawa, Kazuhiro

    2016-08-01

    We investigated the effect of a combined AlN/Al0.03Ga0.97N barrier on InGaN-based amber light-emitting diodes (LEDs) grown by metalorganic vapor-phase epitaxy. InGaN-based multiple quantum wells with a combined AlN/Al0.03Ga0.97N barrier showed intense photoluminescence with a narrow full-width at half-maximum. The amber LEDs with a combined AlN/Al0.03Ga0.97N barrier achieved a light output power enhanced approximately 2.5-fold at 20 mA compared to that of the LED with a combined AlN/GaN barrier, owing to the reduction of defects in InGaN active layers. Thus, the efficiency of high-In-content InGaN-based LEDs can be improved in the spectrum range of amber.

  11. Evolutionary adaptation of muscle power output to environmental temperature: force-velocity characteristics of skinned fibres isolated from antarctic, temperate and tropical marine fish.

    Science.gov (United States)

    Johnston, I A; Altringham, J D

    1985-09-01

    Single fast fibres were isolated from the myotomal muscles of icefish (Chaenocephalus aceratus Lönnberg, Antarctica), North Sea Cod (Gadus morhua L.) and Pacific Blue Marlin (Makaira nigricans Wakiya, Hawaii). Fibres were chemically skinned with the non-ionic detergent Brij-58. Maximum tensions (Po, kN m-2) developed at the characteristic body temperature of each species are 231 for icefish (-1 degree C), 187 for cod (8 degrees C) and 156 for marlin (20 degrees C). At 0 degree C Po is 7 times higher for fibres from the icefish than from the marlin. Fibres from icefish and cod failed to relax completely following activations at temperatures above approximately 12 degrees C. The resultant post-contraction force is associated with a proportional increase in stiffness, suggesting the formation of a population of Ca-insensitive cross bridges. At 10 degrees C there is little interspecific variation in unloaded contraction velocity (Vmax) among the three species. Vmax (muscle lengths s-1) at normal body temperatures are 0.9 for icefish (-1 degree C), 1.0 for cod (8 degrees C) and 3.4 for marlin (20 degrees C). The force-velocity (P-V) relationship becomes progressively more curved with increasing temperature for all three species. Maximum power output for the fast muscle fibres from the Antarctic species at -1 degree C is around 60% of that of the tropical fish at 20 degrees C. Evolutionary temperature compensation of muscle power output appears largely to involve differences in the ability of cross bridges to generate force.

  12. The impact of the driving frequency on the output flux of high-power InGaAlP-LEDs during high-current pulsed operation

    Science.gov (United States)

    Schulz, Benjamin; Morgott, Stefan

    2017-09-01

    Direct red light-emitting diodes based on InGaAlP comprise a strong temperature sensitivity regarding their output flux. In étendue-limited applications, like digital projectors, these LEDs are usually driven at current densities exceeding 3 A/mm2 in pulsed mode. The losses inside the semiconductor lead to a large amount of heat, which has to be removed most efficiently by a heatsink to keep the junction temperature as low as possible and therefore to obtain the maximum output flux. One important performance parameter is the thermal resistance Rth of the LED, which has been improved during the last few years, e.g. by the development of new high-power chips and packages. In our present approach, we investigated the influence of the driving frequency - which is closely related to the thermal impedance Zth - on the luminous and the radiant flux of red LEDs. A simulation model based on the electro-thermal analogies was implemented in SPICE and the optical and electrical characteristics of one LED type (OSRAM OSTAR Projection Power LE A P1W) were measured under application-related driving conditions while varying the parameters frequency, duty cycle, forward current, and heatsink temperature. The experimental results show clearly that the luminous and the radiant flux go up when the driving frequency is increased while the other parameters are maintained. Moreover, it can be noticed that the degree of this effect depends on the other parameters. The largest impact can be observed at the lowest tested duty cycle (30 %) and the highest tested current density (4 A/mm2) and heatsink temperature (80 °C). At this operating point, the luminous and the radiant flux increase by 20 % and 14 % respectively when raising the frequency from 240 Hz to 1920 Hz.

  13. A two-step approach to estimating selectivity and fishing power of research gill nets used in Greenland waters

    DEFF Research Database (Denmark)

    Hovgård, Holger

    1996-01-01

    Catches of Atlantic cod (Gadus morhua) from Greenland gill-net surveys were analyzed by a two-step approach. In the initial step the form of the selection curve was identified as binormal, which was caused by fish being gilled or caught by the maxillae. Both capture processes could be described...... by normal distributions and could be related to mesh size in accordance with the principle of geometrical similarity. In the second step the selection parameters were estimated by a nonlinear least squares fit. The model also estimated the relative efficiency of the two capture processes and the fishing...

  14. Effect of Er,Cr:YSGG Laser at Different Output Powers on the Micromorphology and the Bond Property of Non-Carious Sclerotic Dentin to Resin Composites.

    Directory of Open Access Journals (Sweden)

    Xiang Sun

    Full Text Available The objective of this study was to investigate the influence of Er,Cr:YSGG laser irradiated at different powers on the micromorphology and the bonding property of non-carious sclerotic dentin to resin composites.Two hundred bovine incisors characterized by non-carious sclerotic dentin were selected, and the seventy-two teeth of which for surface morphological analysis were divided into nine groups according to various treatments (A: the control group, B: only treated with the adhesive Adper Easy One, C: diamond bur polishing followed by Adper Easy One, D-I: Er,Cr:YSGG laser irradiating at 1W, 2W, 3W, 4W, 5W, 6W output power, respectively, followed by Adper Easy One. The surface roughness values were measured by the non-contact three-dimensional morphology scanner, then the surface micromorphologies of surfaces in all groups were assessed by scanning electron microscopy (SEM; meanwhile, Image Pro-Plus 6.0 software was used to measure the relative percentage of open tubules on SEM images. The rest, one hundred twenty-eight teeth for bond strength test, were divided into eight groups according to the different treatments (A: only treated with the adhesive Adper Easy One, B: diamond bur polishing followed by the above adhesive, C-H: Er,Cr:YSGG laser irradiating at 1 W, 2 W, 3 W, 4 W, 5 W, 6 W output power, respectively, followed by the above adhesive, and each group was subsequently divided into two subgroups according to whether aging is performed (immediately tested and after thermocycling. Micro-shear bond strength test was used to evaluate the bond strength.The 4W laser group showed the highest roughness value (30.84±1.93μm, which was statistically higher than the control group and the diamond bur groups (p<0.05. The mean percentages ((27.8±1.8%, (28.0±2.2%, (30.0±1.9% of open tubules area in the 4W, 5W, 6W group were higher than other groups (p<0.05. The 4W laser group showed the highest micro-shear bond strength not only in immediately

  15. Stochastic Petri Net Models for the Analysis of Trade-Offs in Data Centres with Power Management

    NARCIS (Netherlands)

    Postema, Björn Frits; Haverkort, Boudewijn R.H.M.; Klingert, Sonja; Chinnici, Marta; Rey Porto, Milagros

    2014-01-01

    Due to the growth in energy consumption of data centres, the demand for optimal usage of servers has become a relevant topic. This paper contributes to the early design phases of data centres by providing insight into the power-performance trade-off that arises from power management. This paper

  16. A homogeneous group of persons with multiple sclerosis seem to use different net joint power strategies to increase gait speed - a pilot study

    DEFF Research Database (Denmark)

    Brincks, John

    PwMS with an EDSS score median at 2.5 (Inter quartile range=1) participated. The gait patterns were analysed using 3D motion analysis at self-selected and maximum gait speed. The net joint power peaks were measured for H1-S, H2-S, H3-S, H1-F, H2-F, H3-F, K1-S, K2-S, K3-S, A1-S and A2-S......Background: Major symptoms associated with multiple sclerosis are muscle weakness, fatique and loss of limb coordination, all of which contribute to an unsafe gait. To improve gait function in persons with multiple sclerosis (PwMS) it is essential to determine which problems underlie gait...... dysfunction. Aims: This pilot study examined changes in net joint power generated or absorbed by hip flexors (H2-S, H3-S), hip extensors (H1-S), hip abductors (H1-F, H2-F, H3-F) knee extensors (K1-S, K2-S, K3-S) and ankle plantar flexors (A1-S, A2-S) bilaterally, when gait speed increased. Methods: Fourteen...

  17. A homogeneous group of persons with multiple sclerosis seem to use different net joint power strategies to increase gait speed - a pilot study

    DEFF Research Database (Denmark)

    Brincks, John

    2014-01-01

    PwMS with an EDSS score median at 2.5 (Inter quartile range=1) participated. The gait patterns were analysed using 3D motion analysis at self-selected and maximum gait speed. The net joint power peaks were measured for H1-S, H2-S, H3-S, H1-F, H2-F, H3-F, K1-S, K2-S, K3-S, A1-S and A2-S......Background: Major symptoms associated with multiple sclerosis are muscle weakness, fatique and loss of limb coordination, all of which contribute to an unsafe gait. To improve gait function in persons with multiple sclerosis (PwMS) it is essential to determine which problems underlie gait...... dysfunction. Aims: This pilot study examined changes in net joint power generated or absorbed by hip flexors (H2-S, H3-S), hip extensors (H1-S), hip abductors (H1-F, H2-F, H3-F) knee extensors (K1-S, K2-S, K3-S) and ankle plantar flexors (A1-S, A2-S) bilaterally, when gait speed increased. Methods: Fourteen...

  18. Bio-cathode materials evaluation and configuration optimization for power output of vertical subsurface flow constructed wetland - microbial fuel cell systems.

    Science.gov (United States)

    Liu, Shentan; Song, Hailiang; Wei, Size; Yang, Fei; Li, Xianning

    2014-08-01

    To optimize the performance of a vertical subsurface flow constructed wetland-microbial fuel cell (CW-MFC), studies of bio-cathode materials and reactor configurations were carried out. Three commonly used bio-cathode materials including stainless steel mesh (SSM), carbon cloth (CC) and granular activated carbon (GAC) were compared and evaluated. GAC-SSM bio-cathode achieved the highest maximum power density of 55.05 mWm(-2), and it was most suitable for CW-MFCs application because of its large surface area and helpful capillary water absorption. Two types of CW-MFCs with roots were constructed, one was placed in the anode and the other was placed in the cathode. Both planted CW-MFCs obtained higher power output than non-planted CW-MFC. Periodic voltage fluctuations of planted CW-MFCs were caused by light/dark cycles, and the influent substrate concentration significantly affected the amplitude of oscillation. The coulombic efficiencies of CW-MFCs decreased greatly with the increase of the influent substrate concentration. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Net Locality

    DEFF Research Database (Denmark)

    de Souza e Silva, Adriana Araujo; Gordon, Eric

    Provides an introduction to the new theory of Net Locality and the profound effect on individuals and societies when everything is located or locatable. Describes net locality as an emerging form of location awareness central to all aspects of digital media, from mobile phones, to Google Maps...... of emerging technologies, from GeoCities to GPS, Wi-Fi, Wiki Me, and Google Android....

  20. Net Neutrality

    DEFF Research Database (Denmark)

    Savin, Andrej

    2017-01-01

    Repealing “net neutrality” in the US will have no bearing on Internet freedom or security there or anywhere else.......Repealing “net neutrality” in the US will have no bearing on Internet freedom or security there or anywhere else....

  1. High-peak-power single-oscillator actively Q-switched mode-locked Tm3+-doped fiber laser and its application for high-average output power mid-IR supercontinuum generation in a ZBLAN fiber.

    Science.gov (United States)

    Kneis, Christian; Donelan, Brenda; Manek-Hönninger, Inka; Robin, Thierry; Cadier, Benoît; Eichhorn, Marc; Kieleck, Christelle

    2016-06-01

    A single-oscillator actively Q-switched mode-locked (QML) thulium-doped silica fiber laser is presented and used to pump a ZrF4-BaF2-LaF3-AlF3-NaF (ZBLAN) fiber for mid-infrared (mid-IR) supercontinuum (SC) generation. The fiber laser provided high-peak-power levels directly from the oscillator delivering single mode-locked pulse energies up to 48 μJ, being 2-4 orders of magnitude higher than conventional continuous wave mode-locked lasers. By pumping a ZBLAN fiber specially designed for high-output-power SC generation, 7.8 W have been achieved in all spectral bands with a spectrum extending to 4.2 μm.

  2. The Effect of Water Injection on the Control of In-Cylinder Pressure and Enhanced Power Output in a Four-Stroke Spark-Ignition Engine

    Directory of Open Access Journals (Sweden)

    Mingrui Wei

    2016-09-01

    Full Text Available This paper presents the results for liquid water injection (WI into a cylinder during the compression and expansion strokes of an internal combustion engine (ICE, with the aim of achieving an optimal in-cylinder pressure and improving power output using CFD simulation. Employing WI during the compression stroke at 80° of crank angle (CA before top dead centre (bTDC resulted in the reduction of compression work due to a reduction in peak compression pressure by a margin of about 2%. The decreased peak compression pressure also yielded the benefit of a decrease in NOx emission by a margin of 34% as well as the prevention of detonation. Using WI during the expansion stroke (after top dead centre–aTDC revealed two stages of the in-cylinder pressure: the first stage involved a decrease in pressure by heat absorption, and the second stage involved an increase in the pressure as a result of an increase in the steam volume via expansion. For the case of water addition (WA 3.0% and a water temperature of 100 °C, the percentage decrease of in-cylinder pressure was 2.7% during the first stage and a 2.5% pressure increase during the second stage. Water injection helped in reducing the energy losses resulting from the transfer of heat to the walls and exhaust gases. At 180° CA aTDC, the exhaust gas temperature decreased by 42 K, 89 K, and 136 K for WA 1.0, WA 2.0, and WA 3.0, respectively. Increasing the WI temperature to 200 °C resulted in a decrease of the in-cylinder pressure by 1.0% during the first stage, with an increase of approximately 4.0% in the second stage. The use of WI in both compression and expansion strokes resulted in a maximum increase of in-cylinder pressure of about 7%, demonstrating the potential of higher power output.

  3. The effects of modified exponential tapering technique on perceived exertion, heart rate, time trial performance, VO2max and power output among highly trained junior cyclists.

    Science.gov (United States)

    Ishak, Asmadi; Hashim, Hairul A; Krasilshchikov, Oleksandr

    2016-09-01

    The present study investigated the effects of a 2-week modified exponential taper on physiological adaptation and time trial performance among junior cyclists. Participants (N.=27) with the mean age of 16.95±0.8 years, height of 165.6±6.1 cm and weight of 54.19±8.1 kg were matched into either modified exponential taper (N.=7), normal exponential taper (N.=7), or control (N.=7) groups using their initial VO2max values. Both experimental groups followed a 12-week progressive endurance training program and subsequently, a 2-week tapering phase. A simulated 20-km time trial performance along with VO2max, power output, heart rate and rating of perceived exertion were measured at baseline, pre and post-taper. One way ANOVA was used to analyze the difference between groups before the start of the intervention while mixed factorial ANOVA was used to analyze the difference between groups across measurement sessions. When homogeneity assumption was violated, the Greenhouse-Geisser Value was used for the corrected values of the degrees of freedom for the within subject factor the analysis. Significant interactions between experimental groups and testing sessions were found in VO2max (F=6.67, df=4, P<0.05), power output (F=5.02, df=4, P<0.05), heart rate (F=10.87, df=2.51, P<0.05) rating of perceived exertion (F=13.04, df=4, P<0.05) and 20KM time trial (F=4.64, df=2.63, P<0.05). Post-hoc analysis revealed that both types of taper exhibited positive effects compared to the non-taper condition in the measured performance markers at post-taper while no different were found between the two taper groups. It was concluded that both taper protocols successfully inducing physiological adaptations among the junior cyclists by reducing the volume and maintaining the intensity of training.

  4. Prescriptive amplification recommendations for hearing losses with a conductive component and their impact on the required maximum power output: an update with accompanying clinical explanation.

    Science.gov (United States)

    Johnson, Earl E

    2013-06-01

    Hearing aid prescriptive recommendations for hearing losses having a conductive component have received less clinical and research interest than for losses of a sensorineural nature; as a result, much variation remains among current prescriptive methods in their recommendations for conductive and mixed hearing losses (Johnson and Dillon, 2011). The primary intent of this brief clinical note is to demonstrate differences between two algebraically equivalent expressions of hearing loss, which have been approaches used historically to generate a prescription for hearing losses with a conductive component. When air and bone conduction thresholds are entered into hearing aid prescriptions designed for nonlinear hearing aids, it was hypothesized that that two expressions would not yield equivalent amounts of prescribed insertion gain and output. These differences are examined for their impact on the maximum power output (MPO) requirements of the hearing aid. Subsequently, the MPO capabilities of two common behind-the-ear (BTE) receiver placement alternatives, receiver-in-aid (RIA) and receiver-in-canal (RIC), are examined. The two expressions of hearing losses examined were the 25% ABG + AC approach and the 75% ABG + BC approach, where ABG refers to air-bone gap, AC refers to air-conduction threshold, and BC refers to bone-conduction threshold. Example hearing loss cases with a conductive component are sampled for calculations. The MPO capabilities of the BTE receiver placements in commercially-available products were obtained from hearing aids on the U.S. federal purchasing contract. Prescribed gain and the required MPO differs markedly between the two approaches. The 75% ABG + BC approach prescribes a compression ratio that is reflective of the amount of sensorineural hearing loss. Not all hearing aids will have the MPO capabilities to support the output requirements for fitting hearing losses with a large conductive component particularly when combined with

  5. Industrial mJ-class all-fiber front end with spatially coherent top-hat beam output used as seeder for high power laser

    Science.gov (United States)

    Gleyze, Jean-François; Perrin, A.; Calvet, Pierre; Gouriou, Pierre; Scol, Florent; Valentin, Constance; Bouwmans, Géraud; Lecren, E.; Hugonnot, Emmanuel

    2015-05-01

    In large scale laser facility dedicated to laser-matter interaction including inertial confinement fusion, such as LMJ or NIF, high-energy main amplifier is injected by a laser source in which the beam parameters must be controlled. For many years, the CEA has developed nano-joule pulses all-fiber front end sources, based on the telecommunications fiber optics technologies. Thanks to these technologies, we have been able to precisely control temporal shaping and phase-modulated pulse. Nowadays, fiber lasers are able to deliver very high power beams and high energy pulses for industrial needs (laser marking, welding,…). Therefore, we have currently developed new nanosecond pulses fibered amplifiers able to increase output pulse energy up to the mJ level. These amplifiers are based on flexible fibers and not on rod type. This allows us to achieve a compact source. Nevertheless the intensity profile of theses fibers usually has a Gaussian shape. To be compatible with main amplifier section injection, the Gaussian intensity profile must then be transformed into `top-hat' profile. To reach the goal, we have recently developed an elegant and efficient solution based on a single-mode fiber which directly delivers a spatially coherent `top-hat' beam. In the conference, we will present this mJ-class top-hat all-fiber laser system, the results and the industrial prototype which can be used as a front-end of high-power lasers or as a seeder for other types of lasers.

  6. Mechanosensing in myosin filament solves a 60 years old conflict in skeletal muscle modeling between high power output and slow rise in tension

    Directory of Open Access Journals (Sweden)

    Lorenzo Marcucci

    2016-09-01

    Full Text Available Almost 60 years ago Andrew Huxley with his seminal paper [Huxley1957] laid the foundation of modern muscle modeling, linking chemical events to mechanical performance. He described mechanics and energetics of muscle contraction through the cyclical attachment and detachment of myosin motors to the actin filament with ad hoc assumptions on the dependence of the rate constants on the strain of the myosin motors. That relatively simple hypothesis is still present in recent models, even though with several modifications to adapt the model to the different experimental constraints which became subsequently available. However, already in that paper, one controversial aspect of the model became clear. Relatively high attachment and detachment rates of myosin to the actin filament were needed to simulate the high power output at intermediate velocity of contraction. However, these rates were incompatible with the relatively slow rise in tension after activation, despite the rise should be generated by the same rate functions. This discrepancy has not been fully solved till today, despite several hypotheses have been forwarded to reconcile the two aspects.Here, using a conventional muscle model, we show that the recently revealed mechanosensing mechanism of recruitment of myosin motors [Linarietal2015] can solve this long standing problem without any further ad-hoc hypotheses.

  7. Variations of ankle-foot orthosis-constrained movements increase ankle range of movement while maintaining power output of recumbent cycling.

    Science.gov (United States)

    Hamdan, Puteri N F; Hamzaid, Nur Azah; Usman, Juliana; Islam, Md Anamul; Kean, Victor S P; Wahab, Ahmad K Abdul; Hasnan, Nazirah; Davis, Glen M

    2017-09-15

    Previous research investigated recumbent cycle power output (PO) from the perspective of knee and hip joint biomechanics. However, ankle-foot biomechanics and, in particular, the effect of ankle-foot orthosis (AFO)-constrained movements on cycle PO has not been widely explored. Therefore, the purpose of this study was to determine whether AFOs of a fixed position (FP) and in dorsi-plantarflexion (DPF)-, dorsiflexion (DF)- and plantarflexion (PF)-constrained movements might influence PO during voluntary recumbent cycling exercises. Twenty-five healthy individuals participated in this study. All underwent 1-min cycling at a fixed cadence for each of the AFOs. The peak and average PO of each condition were analyzed. The peak and average PO were 27.2±12.0 W (range 6-60) and 17.2±9.0 W (range 2-36), respectively, during voluntary cycling. There were no significant differences in the peak PO generated by the AFOs (p=0.083). There were also no significant differences in the average PO generated using different AFOs (p=0.063). There were no significant differences in the changes of the hip and knee joint angles with different AFOs (p=0.974 and p=1.00, respectively). However, there was a significant difference in the changes of the ankle joint angle (pcycling in healthy individuals. This finding might serve as a reference for future rehabilitative cycling protocols.

  8. Effect of a prior force-velocity test performed with legs on subsequent peak power output measured with arms or vice versa.

    Science.gov (United States)

    Bouhlel, Ezzedine; Chelly, Mohamed Souhaiel; Gmada, Nebil; Tabka, Zouhair; Shephard, Roy

    2010-04-01

    The aim of this study was to examine whether measurement of peak anaerobic power (Wpeak) by force-velocity test using the arms or the legs influenced the performance obtained when the opposite muscle group was tested. Ten trained male throwers (age: 20.6 +/- 2; stature: 1.82 +/- 0.06 m; and body mass: 85.5 +/- 17.2 kg) performed, on separate days, 2 Monark cycle-ergometer protocols comprising (a) arm cranking (A1) followed by a leg cycling (L2) force-velocity test (series A-L) and (b) a leg cycling (L1) followed by an arm cranking (A2) force-velocity test (series L-A). On each day, 8 minutes of seated rest separated the 2 force-velocity tests. Arterialized capillary blood was collected from the finger tips for blood lactate analysis at rest and at the end of each force-velocity test. Wpeak-A1 and Wpeak-A2 were similar (8.1 +/- 1.7 and 8.6 +/- 1.5 W.kg, respectively). Wpeak-L1 and Wpeak-L2 were 14.0 +/- 3 and 13.4 +/- 2.8 W.kg (NS). Blood [La] increased significantly after each force-velocity test (p < 0.001), but peak blood [La] did not differ significantly between L1 (6.6 +/- 1.2) and L2 (6.2 +/- 1.4 mmol.L) or between A1 (7.2 +/- 1.0) and A2 (7.4 +/- 1.6 mmol.L). In this population, force-velocity tests performed using the legs or the arms did not induce a significant decrease in force-velocity determinations of peak anaerobic power performed subsequently with the opposite muscle group. In strength-trained athletes, the force-velocity approach can thus be used to measure the peak power output of both the legs and the arms in a single laboratory session, without adversely affecting estimates of an athlete's performance.

  9. Determination of optimal whole body vibration amplitude and frequency parameters with plyometric exercise and its influence on closed-chain lower extremity acute power output and EMG activity in resistance trained males

    Science.gov (United States)

    Hughes, Nikki J.

    The optimal combination of Whole body vibration (WBV) amplitude and frequency has not been established. Purpose. To determine optimal combination of WBV amplitude and frequency that will enhance acute mean and peak power (MP and PP) output EMG activity in the lower extremity muscles. Methods. Resistance trained males (n = 13) completed the following testing sessions: On day 1, power spectrum testing of bilateral leg press (BLP) movement was performed on the OMNI. Days 2 and 3 consisted of WBV testing with either average (5.8 mm) or high (9.8 mm) amplitude combined with either 0 (sham control), 10, 20, 30, 40 and 50 Hz frequency. Bipolar surface electrodes were placed on the rectus femoris (RF), vastus lateralis (VL), bicep femoris (BF) and gastrocnemius (GA) muscles for EMG analysis. MP and PP output and EMG activity of the lower extremity were assessed pre-, post-WBV treatments and after sham-controls on the OMNI while participants performed one set of five repetitions of BLP at the optimal resistance determined on Day 1. Results. No significant differences were found between pre- and sham-control on MP and PP output and on EMG activity in RF, VL, BF and GA. Completely randomized one-way ANOVA with repeated measures demonstrated no significant interaction of WBV amplitude and frequency on MP and PP output and peak and mean EMGrms amplitude and EMG rms area under the curve. RF and VL EMGrms area under the curve significantly decreased (p power output.

  10. RESTful NET

    CERN Document Server

    Flanders, Jon

    2008-01-01

    RESTful .NET is the first book that teaches Windows developers to build RESTful web services using the latest Microsoft tools. Written by Windows Communication Foundation (WFC) expert Jon Flanders, this hands-on tutorial demonstrates how you can use WCF and other components of the .NET 3.5 Framework to build, deploy and use REST-based web services in a variety of application scenarios. RESTful architecture offers a simpler approach to building web services than SOAP, SOA, and the cumbersome WS- stack. And WCF has proven to be a flexible technology for building distributed systems not necessa

  11. Redes e icebergs: diagramas de poder em disputa/Nets and icebergs: diagrams of power in dispute

    Directory of Open Access Journals (Sweden)

    Henrique Z.M. Parra

    2008-10-01

    Full Text Available O artigo tem dois objetivos. Primeiramente, busca exercitar uma forma de conhecimento poético-científico na medida em que se deixa guiar pela apreensão imaginativa dos problemas empíricos analisados através de uma pesquisa visual e da produção de expressões imagéticas que abram outras vias de reflexão sobre os casos investigados. Em segundo lugar, o artigo analisará dois eventos relativos à internet que tiveram grande repercussão na imprensa brasileira em julho de 2008, procurando evidenciar uma disputa entre configurações distintas do poder que se desenvolvem sob a superfície da internet. This paper has two objectives. First, it aims to put into practice a form of poetic-scientific knowledge to the extent that we are guided by an imaginative comprehension of the empirical problems analyzed; the paper promotes this practice through visual research and through the production of image-based expression, which provide alternative means to reflect on the cases analyzed. Second, the paper analyzes two events related to the internet that strongly impacted Brazilian media in July 2008; the analysis of these two cases focuses on distinct power dynamics that developed underneath the front end of the internet.

  12. Compressive power spectrum sensing for vibration-based output-only system identification of structural systems in the presence of noise

    Science.gov (United States)

    Tau Siesakul, Bamrung; Gkoktsi, Kyriaki; Giaralis, Agathoklis

    2015-05-01

    Motivated by the need to reduce monetary and energy consumption costs of wireless sensor networks in undertaking output-only/operational modal analysis of engineering structures, this paper considers a multi-coset analog-toinformation converter for structural system identification from acceleration response signals of white noise excited linear damped structures sampled at sub-Nyquist rates. The underlying natural frequencies, peak gains in the frequency domain, and critical damping ratios of the vibrating structures are estimated directly from the sub-Nyquist measurements and, therefore, the computationally demanding signal reconstruction step is by-passed. This is accomplished by first employing a power spectrum blind sampling (PSBS) technique for multi-band wide sense stationary stochastic processes in conjunction with deterministic non-uniform multi-coset sampling patterns derived from solving a weighted least square optimization problem. Next, modal properties are derived by the standard frequency domain peak picking algorithm. Special attention is focused on assessing the potential of the adopted PSBS technique, which poses no sparsity requirements to the sensed signals, to derive accurate estimates of modal structural system properties from noisy sub- Nyquist measurements. To this aim, sub-Nyquist sampled acceleration response signals corrupted by various levels of additive white noise pertaining to a benchmark space truss structure with closely spaced natural frequencies are obtained within an efficient Monte Carlo simulation-based framework. Accurate estimates of natural frequencies and reasonable estimates of local peak spectral ordinates and critical damping ratios are derived from measurements sampled at about 70% below the Nyquist rate and for SNR as low as 0db demonstrating that the adopted approach enjoys noise immunity.

  13. Effects of a 6-Week Upper Extremity Low-Volume, High Intensity Interval Training on Oxygen Uptake, Peak Power Output and Total Exercise Time.

    Science.gov (United States)

    Pinto, Nicole; Salassi, James W; Donlin, Ayla; Schroeder, Jan; Rozenek, Ralph

    2017-05-30

    The purpose of this study was to compare the effects of upper extremity (UE) high intensity interval training (HIIT) to UE continuous training (CT) when training at a similar intensity. 20 participants (mean age = 23 ± 3 yrs) were randomly assigned to either a HIIT (n = 10) or CT (n = 10) group. Participants completed a graded exercise test utilizing arm cranking prior to and following 6 wks (2 sessions · wk-1) of UE training. During sessions, HIIT performed 10 repetitions of 60 s of work at 92.3 ± 1.0% of the arm HRpeak (%aHRpeak) and 60 s of passive recovery (%aHRpeak = 73.0 ± 4.0%) yielding an average training intensity of 82.6 ± 1.5 %aHRpeak. CT exercised for 20 min. at an average intensity of 81.9 ± 2.2 %aHRpeak. Following training HIIT showed greater improvement in V[Combining Dot Above]O2peak compared to CT (Δ = 4.1 ml · min-¹ · kg-¹, 95%CI: 1.3 - 6.9 ml · min-¹ · kg-¹, p = .007). Total exercise time during the post-test GXT was also improved as a result of HIIT (Δ = 1.4 min, 95%CI: 0.4 - 2.3 min, p = .008). Both groups improved peak power output, but no difference was observed between them (Δ = 3.3 W, 95%CI: -3.3 - 9.9 W, p = .305). For a similar time investment, HIIT appeared to improve cardiopulmonary capacity and exercise time to a greater extent than CT and may be a time-efficient alternative for those who incorporate UE aerobic activity into a training program.

  14. Petri Nets

    Indian Academy of Sciences (India)

    Associate Professor of. Computer Science and. Automation at the Indian. Institute of Science,. Bangalore. His research interests are broadly in the areas of stochastic modeling and scheduling methodologies for future factories; and object oriented modeling. GENERAL I ARTICLE. Petri Nets. 1. Overview and Foundations.

  15. Petri Nets

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 8. Petri Nets - Overview and Foundations. Y Narahari. General Article Volume 4 Issue 8 August 1999 pp ... Author Affiliations. Y Narahari1. Department ot Computer Science and Automation, Indian Institute of Science, Bangalore 560 012, India.

  16. Mars MetNet Mission Status

    Science.gov (United States)

    Harri, Ari-Matti; Aleksashkin, Sergei; Arruego, Ignacio; Schmidt, Walter; Genzer, Maria; Vazquez, Luis; Haukka, Harri

    2015-04-01

    descent phase starting shortly after separation from the spacecraft. MetNet Mission payload instruments are specially designed to operate in very low power conditions. MNL flexible solar panels provides a total of approximately 0.7-0.8 W of electric power during the daylight time. As the provided power output is insufficient to operate all instruments simultaneously they are activated sequentially according to a specially designed cyclogram table which adapts itself to the different environmental constraints. 3. Mission Status Full Qualification Model (QM) of the MetNet landing unit with the Precursor Mission payload is currently under functional tests. In near future the QM unit will be exposed to environmental tests with qualification levels including vibrations, thermal balance, thermal cycling and mechanical impact shock. One complete flight unit of the entry, descent and landing systems (EDLS) has been manufactured and tested with acceptance levels. Another flight-like EDLS has been exposed to most of the qualification tests, and hence it may be used for flight after refurbishments. Accordingly two flight-capable EDLS systems exist. The eventual goal is to create a network of atmospheric observational posts around the Martian surface. Even if the MetNet mission is focused on the atmospheric science, the mission payload will also include additional kinds of geophysical instrumentation. The next step in the MetNet Precursor Mission to demonstrate the technical robustness and scientific capabilities of the MetNet type of landing vehicle. Definition of the Precursor Mission and discussions on launch opportunities are currently under way. The baseline program development funding exists for the next five years. Flight unit manufacture of the payload bay takes about 18 months, and it will be commenced after the Precursor Mission has been defined. References [1] http://metnet.fmi.fi

  17. High output piezo/triboelectric hybrid generator

    National Research Council Canada - National Science Library

    Jung, Woo-Suk; Kang, Min-Gyu; Moon, Hi Gyu; Baek, Seung-Hyub; Yoon, Seok-Jin; Wang, Zhong-Lin; Kim, Sang-Woo; Kang, Chong-Yun

    2015-01-01

    .... Here, we demonstrate a hybrid generator which does not use nanostructure but generates much higher output power by a small mechanical force and integrates piezoelectric generator into triboelectric...

  18. Net technical assessment

    OpenAIRE

    Wegmann, David G.

    1989-01-01

    Approved for public release; distribution is unlimited. The present and near term military balance of power between the U.S. and the Soviet Union can be expressed in a variety of net assessments. One can examine the strategic nuclear balance, the conventional balance in Europe, the maritime balance, and many others. Such assessments are essential not only for policy making but for arms control purposes and future force structure planning. However, to project the future military balance, on...

  19. Is the Ergogenicity of Caffeine Affected by Increasing Age? The Direct Effect of a Physiological Concentration of Caffeine on the Power Output of Maximally Stimulated EDL and Diaphragm Muscle Isolated from the Mouse.

    Science.gov (United States)

    Tallis, J; James, R S; Cox, V M; Duncan, M J

    2017-01-01

    Caffeine is a well-established performance enhancing nutritional supplement in a young healthy population, however far less is known about how its ergogenicity is affected by increasing age. A recent review has highlighted the value of studies examining the direct effect of caffeine on isolated skeletal muscle contractility, but the present work is the first to assess the direct effect of 70µM caffeine (physiological maximum) on the maximal power output of isolated mammalian muscle from an age range representing developmental to early ageing. Female CD1 mice were aged to 3, 10, 30 and 50 weeks (n = 20 in each case) and either whole EDL or a section of the diaphragm was isolated and maximal power output determined using the work loop technique. Once contractile performance was maximised, each muscle preparation was treated with 70µM caffeine and its contractile performance was measured for a further 60 minutes. In both mouse EDL and diaphragm 70µM caffeine treatment resulted in a significant increase in maximal muscle power output that was greatest at 10 or 30 weeks (up to 5% and 6% improvement respectively). This potentiation of maximal muscle power output was significantly lower at the early ageing time point, 50 weeks (up to 3% and 2% improvement respectively), and in mice in the developmental stage, at 3 weeks of age (up to 1% and 2% improvement respectively). Uniquely, the present findings indicate a reduced age specific sensitivity to the performance enhancing effect of caffeine in developmental and aged mice which is likely to be attributed to age related muscle growth and degradation, respectively. Importantly, the findings indicate that caffeine may still provide a substantial ergogenic aid in older populations which could prove important for improving functional capacity in tasks of daily living.

  20. Enhancement of light output power of GaN-based light-emitting diodes with photonic quasi-crystal patterned on p-GaN surface and n-side sidewall roughing.

    Science.gov (United States)

    Lai, Fang-I; Yang, Jui-Fu

    2013-05-17

    In this paper, GaN-based light-emitting diodes (LEDs) with photonic quasi-crystal (PQC) structure on p-GaN surface and n-side roughing by nano-imprint lithography are fabricated and investigated. At an injection current of 20 mA, the LED with PQC structure on p-GaN surface and n-side roughing increased the light output power of the InGaN/GaN multiple quantum well LEDs by a factor of 1.42, and the wall-plug efficiency is 26% higher than the conventional GaN-based LED type. After 500-h life test (55°C/50 mA), it was found that the normalized output power of GaN-based LED with PQC structure on p-GaN surface and n-side roughing only decreased by 6%. These results offer promising potential to enhance the light output powers of commercial light-emitting devices using the technique of nano-imprint lithography.

  1. Modeling safety requirements of an FMS using Petri-nets

    Science.gov (United States)

    Hanna, Moheb M.; Buck, A. A.; Smith, R.

    1993-08-01

    This paper is concerned with the modelling of safety requirements using Petri nets as a tool to model and simulate a Flexible Manufacturing System (FMS). The FMS cell described comprises a pick and place robot, a multi-head drilling machine together with a vision system and illustrates how the hierarchical structure of Petri nets can be used to ensure that all fail- safe requirements are satisfied; block diagrams together with fully detailed example Petri nets are given. The work demonstrates the use of cell and robot control Petro nets together with robot subnets for the x, y and z axes and associated output nets; the control and output nets are linked together with a safety net. Individual machines are linked with the control and safety nets of an FMS at cell level. The paper also illustrates how a Petri net can act as a decision maker during image inspection and identifies the unsafe conditions that can arise within an FMS.

  2. The Economics of Net Neutrality

    OpenAIRE

    Hahn, Robert W.; Wallsten, Scott

    2006-01-01

    This essay examines the economics of "net neutrality" and broadband Internet access. We argue that mandating net neutrality would be likely to reduce economic welfare. Instead, the government should focus on creating competition in the broadband market by liberalizing more spectrum and reducing entry barriers created by certain local regulations. In cases where a broadband provider can exercise market power the government should use its antitrust enforcement authority to police anticompetitiv...

  3. Compact Circuit Preprocesses Accelerometer Output

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1993-01-01

    Compact electronic circuit transfers dc power to, and preprocesses ac output of, accelerometer and associated preamplifier. Incorporated into accelerometer case during initial fabrication or retrofit onto commercial accelerometer. Made of commercial integrated circuits and other conventional components; made smaller by use of micrologic and surface-mount technology.

  4. Balancing Power Absorption and Structural Loading for a Novel Fixed-Bottom Wave Energy Converter with Nonideal Power Take-Off in Regular Waves: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Tom, Nathan M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Yu, Yi-Hsiang [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wright, Alan D [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-06-08

    In this work, the net power delivered to the grid from a nonideal power take-off (PTO) is introduced followed by a review of the pseudo-spectral control theory. A power-to-load ratio, used to evaluate the pseudo-spectral controller performance, is discussed, and the results obtained from optimizing a multiterm objective function are compared against results obtained from maximizing the net output power to the grid. Simulation results are then presented for four different oscillating wave energy converter geometries to highlight the potential of combing both geometry and PTO control to maximize power while minimizing loads.

  5. Design and implementation of high performance direct power control of three-phase PWM rectifier, via fuzzy and PI controller for output voltage regulation

    Energy Technology Data Exchange (ETDEWEB)

    Bouafia, Abdelouahab; Krim, Fateh [Laboratoire d' Electronique de Puissance et Commande Industrielle (LEPCI), Universite de Setif, Departement d' electronique, Route de Bejaia, Setif (Algeria); Gaubert, Jean-Paul [Laboratoire d' Automatique et d' Informatique Industrielle (LAII), ESIP, Universite de Poitiers (France)

    2009-01-15

    This paper proposes direct power control (DPC) for three-phase PWM rectifiers using a new switching table, without line voltage sensors. The instantaneous active and reactive powers, directly controlled by selecting the optimum state of the converter, are used as the PWM control variables instead of the phase line currents being used. The main goal of the control system is to maintain the dc-bus voltage at the required level, while input currents drawn from the power supply should be sinusoidal and in phase with respective phase voltages to satisfy the unity power factor (UPF) operation. Conventional PI and a designed fuzzy logic-based controller, in the dc-bus voltage control loop, have been used to provide active power command. A dSPACE based experimental system was developed to verify the validity of the proposed DPC. The steady-state, and dynamic results illustrating the operation and performance of the proposed control scheme are presented. As a result, it was confirmed that the novel DPC is much better than the classical one. Line currents very close to sinusoidal waveforms (THD < 2%) and good regulation of dc-bus voltage are achieved using PI or fuzzy controller. Moreover, fuzzy logic controller gives excellent performance in transient state, a good rejection of impact load disturbance, and a good robustness. (author)

  6. Influence of pumping power density on output intensities and stabilities of competitive multi-line frequency up-conversions in cesium vapor

    Science.gov (United States)

    Gai, Baodong; Hu, Shu; Li, Xueyang; Yuan, Hong; Cai, Xianglong; Liu, Jinbo; Guo, Jingwei; Jin, Yuqi; Sang, Fengting

    2017-10-01

    Multi-line frequency up-conversions are realized in Cs vapor using 718.8 nm pumping laser resonating with the two-photon transition 62S1/2 → 82D5/2 of Cs atom. The pumping beam is converted into a beam including wavelengths of 361.2, 387.7, 455.7 and 621.5 nm. Experiments with collimated and focused pumping configurations are carried out and compared. Spectrum peak at 361.2 nm is strongest under collimated pumping condition, while 387.7 nm is strongest under focused pumping beam. The output beam under focused pumping is more stable than that under collimated pumping. Results in this work may be useful in laser frequency standard, beacon light, laser measuring and optics communications, etc.

  7. Repetitively pulsed Fe: ZnSe laser with an average output power of 20 W at room temperature of the polycrystalline active element

    Science.gov (United States)

    Velikanov, S. D.; Gavrishchuk, E. M.; Zaretsky, N. A.; Zakhryapa, A. V.; Ikonnikov, V. B.; Kazantsev, S. Yu.; Kononov, I. G.; Maneshkin, A. A.; Mashkovskii, D. A.; Saltykov, E. V.; Firsov, K. N.; Chuvatkin, R. S.; Yutkin, I. M.

    2017-05-01

    The energy and spectral-temporal characteristics of a Fe : ZnSe laser operating in pulsed and repetitively pulsed regimes are studied at room temperature of the polycrystalline active element. The crystal was pumped by a nonchain electric-discharge HF laser. The energy of the Fe : ZnSe laser in a single-pulse regime was 1.67 J at the slope efficiency with respect to the absorbed and incident energy of ∼43% and ∼27%, respectively. In a repetitively pulsed regime with a pulse repetition rate of 20 Hz and an efficiency with respect to the absorbed power of ∼40%, the average laser power was ∼20 W with an individual pulse energy of ∼1 J. The possibility of increasing the average power of the repetitively pulsed Fe : ZnSe laser at room temperature is discussed.

  8. Theoretical Design of a Single Phase 2kW Power Supply with 1.5kV DC Output

    OpenAIRE

    Mossadeghi Björklund, Per

    2014-01-01

    This 15hp degree project in electrical engineering is carried out at ScandiNova Systems AB in Uppsala, Sweden. The company constructs pulse generators used in areas such as sterilization or radiation therapy. As a step in development they want to design their own power supply for one of their generators instead of purchasing it from an external supplier. This paper is about how to make a theoretical design of a power supply that can use worldwide single-phase AC line input and deliver ~1500V...

  9. Evaluation of Advanced Stirling Convertor Net Heat Input Correlation Methods Using a Thermal Standard

    Science.gov (United States)

    Briggs, Maxwell H.; Schifer, Nicholas A.

    2012-01-01

    The U.S. Department of Energy (DOE) and Lockheed Martin Space Systems Company (LMSSC) have been developing the Advanced Stirling Radioisotope Generator (ASRG) for use as a power system for space science missions. This generator would use two high-efficiency Advanced Stirling Convertors (ASCs), developed by Sunpower Inc. and NASA Glenn Research Center (GRC). The ASCs convert thermal energy from a radioisotope heat source into electricity. As part of ground testing of these ASCs, different operating conditions are used to simulate expected mission conditions. These conditions require achieving a particular operating frequency, hot end and cold end temperatures, and specified electrical power output for a given net heat input. In an effort to improve net heat input predictions, numerous tasks have been performed which provided a more accurate value for net heat input into the ASCs, including testing validation hardware, known as the Thermal Standard, to provide a direct comparison to numerical and empirical models used to predict convertor net heat input. This validation hardware provided a comparison for scrutinizing and improving empirical correlations and numerical models of ASC-E2 net heat input. This hardware simulated the characteristics of an ASC-E2 convertor in both an operating and non-operating mode. This paper describes the Thermal Standard testing and the conclusions of the validation effort applied to the empirical correlation methods used by the Radioisotope Power System (RPS) team at NASA Glenn.

  10. Effects of temperature on power output and contraction kinetics in the locomotor muscle of the regionally endothermic common thresher shark (Alopias vulpinus).

    Science.gov (United States)

    Donley, Jeanine M; Sepulveda, Chugey A; Aalbers, Scott A; McGillivray, David G; Syme, Douglas A; Bernal, Diego

    2012-10-01

    The common thresher shark (Alopias vulpinus) is a pelagic species with medially positioned red aerobic swimming musculature (RM) and regional RM endothermy. This study tested whether the contractile characteristics of the RM are functionally similar along the length of the body and assessed how the contractile properties of the common thresher shark compare with those of other sharks. Contractile properties of the RM were examined at 8, 16 and 24 °C from anterior and posterior axial positions (0.4 and 0.6 fork length, respectively) using the work loop technique. Experiments were performed to determine whether the contractile properties of the RM are similar along the body of the common thresher shark and to document the effects of temperature on muscle power. Axial differences in contractile properties of RM were found to be small or absent. Isometric twitch kinetics of RM were ~fivefold slower than those of white muscle, with RM twitch durations of about 1 s at 24 °C and exceeding 5 s at 8 °C, a Q(10) of nearly 2.5. Power increased approximately tenfold with the 16 °C increase in temperature, while the cycle frequency for maximal power only increased from about 0.5-1.0 Hz over this temperature range. These data support the hypothesis that the RM is functionally similar along the body of the common thresher shark and corroborate previous findings from shark species both with and without medial RM. While twitch kinetics suggest the endothermic RM is not unusually temperature sensitive, measures of power suggest that the RM is not well suited to function at cool temperatures. The cycle frequency at which power is maximized appeared relatively insensitive to temperature in RM, which may reflect the relatively cooler temperature of the thresher RM compared to that observed in lamnid sharks as well as the relatively slow RM phenotype in these large fish.

  11. Applying the Power of Reticular Chemistry to Finding the Missing alb-MOF Platform Based on the (6,12)-Coordinated Edge-Transitive Net

    KAUST Repository

    Chen, Zhijie

    2017-02-05

    Highly connected and edge-transitive nets are of prime importance in crystal chemistry and are regarded as ideal blueprints for the rational design and construction of metal-organic frameworks (MOFs). We report the design and synthesis of highly connected MOFs based on reticulation of the sole two edge-transitive nets with a vertex figure as double six-membered-ring (d6R) building unit, namely the (4,12)-coordinated shp net (square and hexagonal-prism) and the (6,12)-coordinated alb net (aluminum diboride, hexagonal-prism and trigonal-prism). Decidedly, the combination of our recently isolated 12-connected (12-c) rare-earth (RE) nonanuclear [RE(μ-OH)(μ-O)(OC-)] carboxylate-based cluster, points of extension matching the 12 vertices of hexagonal-prism d6R, with 4-connected (4-c) square porphyrinic tetracarboxylate ligand led to the formation of the targeted RE-shp-MOF. This is the first time that RE-MOFs based on 12-c molecular building blocks (MBBs), d6R building units, have been deliberately targeted and successfully isolated, paving the way for the long-awaited (6,12)-c MOF with alb topology. Indeed, combination of a custom-designed hexacarboxylate ligand with RE salts led to the formation of the first related alb-MOF, RE-alb-MOF. Intuitively, we successfully transplanted the alb topology to another chemical system and constructed the first indium-based alb-MOF, In-alb-MOF, by employing trinuclear [In(μ-O)(OC-)] as the requisite 6-connected trigonal-prism and purposely made a dodecacarboxylate ligand as a compatible 12-c MBB. Prominently, the dodecacarboxylate ligand was employed to transplant shp topology into copper-based MOFs by employing the copper paddlewheel [Cu(OC-)] as the complementary square building unit, affording the first Cu-shp-MOF. We revealed that highly connected edge-transitive nets such shp and alb are ideal for topological transplantation and deliberate construction of related MOFs based on minimal edge-transitive nets.

  12. Applying the Power of Reticular Chemistry to Finding the Missing alb-MOF Platform Based on the (6,12)-Coordinated Edge-Transitive Net.

    Science.gov (United States)

    Chen, Zhijie; Weseliński, Łukasz J; Adil, Karim; Belmabkhout, Youssef; Shkurenko, Aleksander; Jiang, Hao; Bhatt, Prashant M; Guillerm, Vincent; Dauzon, Emilie; Xue, Dong-Xu; O'Keeffe, Michael; Eddaoudi, Mohamed

    2017-03-01

    Highly connected and edge-transitive nets are of prime importance in crystal chemistry and are regarded as ideal blueprints for the rational design and construction of metal-organic frameworks (MOFs). We report the design and synthesis of highly connected MOFs based on reticulation of the sole two edge-transitive nets with a vertex figure as double six-membered-ring (d6R) building unit, namely the (4,12)-coordinated shp net (square and hexagonal-prism) and the (6,12)-coordinated alb net (aluminum diboride, hexagonal-prism and trigonal-prism). Decidedly, the combination of our recently isolated 12-connected (12-c) rare-earth (RE) nonanuclear [RE 9 (μ 3 -OH) 12 (μ 3 -O) 2 (O 2 C-) 12 ] carboxylate-based cluster, points of extension matching the 12 vertices of hexagonal-prism d6R, with 4-connected (4-c) square porphyrinic tetracarboxylate ligand led to the formation of the targeted RE-shp-MOF. This is the first time that RE-MOFs based on 12-c molecular building blocks (MBBs), d6R building units, have been deliberately targeted and successfully isolated, paving the way for the long-awaited (6,12)-c MOF with alb topology. Indeed, combination of a custom-designed hexacarboxylate ligand with RE salts led to the formation of the first related alb-MOF, RE-alb-MOF. Intuitively, we successfully transplanted the alb topology to another chemical system and constructed the first indium-based alb-MOF, In-alb-MOF, by employing trinuclear [In 3 (μ 3 -O)(O 2 C-) 6 ] as the requisite 6-connected trigonal-prism and purposely made a dodecacarboxylate ligand as a compatible 12-c MBB. Prominently, the dodecacarboxylate ligand was employed to transplant shp topology into copper-based MOFs by employing the copper paddlewheel [Cu 2 (O 2 C-) 4 ] as the complementary square building unit, affording the first Cu-shp-MOF. We revealed that highly connected edge-transitive nets such shp and alb are ideal for topological transplantation and deliberate construction of related MOFs based on

  13. Input-output rearrangement of isolated converters

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre; Kovacevic, Milovan; Mønster, Jakob Døllner

    2015-01-01

    This paper presents a new way of rearranging the input and output of isolated converters. The new arrangement posses several advantages, as increased voltage range, higher power handling capabilities, reduced voltage stress and improved efficiency, for applications where galvanic isolation...

  14. High Output Piezo/Triboelectric Hybrid Generator

    Science.gov (United States)

    Jung, Woo-Suk; Kang, Min-Gyu; Moon, Hi Gyu; Baek, Seung-Hyub; Yoon, Seok-Jin; Wang, Zhong-Lin; Kim, Sang-Woo; Kang, Chong-Yun

    2015-03-01

    Recently, piezoelectric and triboelectric energy harvesting devices have been developed to convert mechanical energy into electrical energy. Especially, it is well known that triboelectric nanogenerators have a simple structure and a high output voltage. However, whereas nanostructures improve the output of triboelectric generators, its fabrication process is still complicated and unfavorable in term of the large scale and long-time durability of the device. Here, we demonstrate a hybrid generator which does not use nanostructure but generates much higher output power by a small mechanical force and integrates piezoelectric generator into triboelectric generator, derived from the simultaneous use of piezoelectric and triboelectric mechanisms in one press-and-release cycle. This hybrid generator combines high piezoelectric output current and triboelectric output voltage, which produces peak output voltage of ~370 V, current density of ~12 μA.cm-2, and average power density of ~4.44 mW.cm-2. The output power successfully lit up 600 LED bulbs by the application of a 0.2 N mechanical force and it charged a 10 μF capacitor to 10 V in 25 s. Beyond energy harvesting, this work will provide new opportunities for developing a small, built-in power source in self-powered electronics such as mobile electronics.

  15. Pulsed low-level infrared laser alters mRNA levels from muscle repair genes dependent on power output in Wistar rats

    Science.gov (United States)

    Trajano, L. A. S. N.; Trajano, E. T. L.; Thomé, A. M. C.; Sergio, L. P. S.; Mencalha, A. L.; Stumbo, A. C.; Fonseca, A. S.

    2017-10-01

    Satellite cells are present in skeletal muscle functioning in the repair and regeneration of muscle injury. Activation of these cells depends on the expression of myogenic factor 5 (Myf5), myogenic determination factor 1(MyoD), myogenic regulatory factor 4 (MRF4), myogenin (MyoG), paired box transcription factors 3 (Pax3), and 7 (Pax7). Low-level laser irradiation accelerates the repair of muscle injuries. However, data from the expression of myogenic factors have been controversial. Furthermore, the effects of different laser beam powers on the repair of muscle injuries have been not evaluated. The aim of this study was to evaluate the effects of low-level infrared laser at different powers and in pulsed emission mode on the expression of myogenic regulatory factors and on Pax3 and Pax7 in injured skeletal muscle from Wistar rats. Animals that underwent cryoinjury were divided into three groups: injury, injury laser 25 Mw, and injury laser 75 mW. Low-level infrared laser irradiation (904 nm, 3 J cm-2, 5 kHz) was carried out at 25 and 75 mW. After euthanasia, skeletal muscle samples were withdrawn and the total RNA was extracted for the evaluation of mRNA levels from the MyoD, MyoG, MRF4, Myf5, Pax3, and Pax7 gene. Pax 7 mRNA levels did not alter, but Pax3 mRNA levels increased in the injured and laser-irradiated group at 25 mW. MyoD, MyoG, and MYf5 mRNA levels increased in the injured and laser-irradiated animals at both powers, and MRF4 mRNA levels decreased in the injured and laser-irradiated group at 75 mW. In conclusion, exposure to pulsed low-level infrared laser, by power-dependent effect, could accelerate the muscle repair process altering mRNA levels from paired box transcription factors and myogenic regulatory factors.

  16. Mars MetNet Mission - Martian Atmospheric Observational Post Network

    Science.gov (United States)

    Hari, Ari-Matti; Haukka, Harri; Aleksashkin, Sergey; Arruego, Ignacio; Schmidt, Walter; Genzer, Maria; Vazquez, Luis; Siikonen, Timo; Palin, Matti

    2017-04-01

    accelerometer combined with a 3-axis gyrometer. The data will be sent via auxiliary beacon antenna throughout the descent phase starting shortly after separation from the spacecraft. MetNet Mission payload instruments are specially designed to operate under very low power conditions. MNL flexible solar panels provides a total of approximately 0.7-0.8 W of electric power during the daylight time. As the provided power output is insufficient to operate all instruments simultaneously they are activated sequentially according to a specially designed cyclogram table which adapts itself to the different environmental constraints. 3. Mission Status he eventual goal is to create a network of atmospheric observational posts around the Martian surface. Even if the MetNet mission is focused on the atmospheric science, the mission payload will also include additional kinds of geophysical instrumentation. The next step is the MetNet Precursor Mission that will demonstrate the technical robustness and scientific capabilities of the MetNet type of landing vehicle. Definition of the Precursor Mission and discussions on launch opportunities are currently under way. The first MetNet Science Payload Precursors have already been successfully completed, e,g, the REMS/MSL and DREAMS/Exomars-2016. The next MetNet Payload Precursors will be METEO/Exomars-2018 and MEDA/Mars-2020. The baseline program development funding exists for the next seven years. Flight unit manufacture of the payload bay takes about 18 months, and it will be commenced after the Precursor Mission has been defined. References [1] http://metnet.fmi.fi

  17. Cardiac output monitoring

    Directory of Open Access Journals (Sweden)

    Mathews Lailu

    2008-01-01

    Full Text Available Minimally invasive and non-invasive methods of estimation of cardiac output (CO were developed to overcome the limitations of invasive nature of pulmonary artery catheterization (PAC and direct Fick method used for the measurement of stroke volume (SV. The important minimally invasive techniques available are: oesophageal Doppler monitoring (ODM, the derivative Fick method (using partial carbon dioxide (CO 2 breathing, transpulmonary thermodilution, lithium indicator dilution, pulse contour and pulse power analysis. Impedance cardiography is probably the only non-invasive technique in true sense. It provides information about haemodynamic status without the risk, cost and skill associated with the other invasive or minimally invasive techniques. It is important to understand what is really being measured and what assumptions and calculations have been incorporated with respect to a monitoring device. Understanding the basic principles of the above techniques as well as their advantages and limitations may be useful. In addition, the clinical validation of new techniques is necessary to convince that these new tools provide reliable measurements. In this review the physics behind the working of ODM, partial CO 2 breathing, transpulmonary thermodilution and lithium dilution techniques are dealt with. The physical and the physiological aspects underlying the pulse contour and pulse power analyses, various pulse contour techniques, their development, advantages and limitations are also covered. The principle of thoracic bioimpedance along with computation of CO from changes in thoracic impedance is explained. The purpose of the review is to help us minimize the dogmatic nature of practice favouring one technique or the other.

  18. Very low power, high voltage base for a Photo Multiplier Tube for the KM3NeT deep sea neutrino telescope

    CERN Document Server

    Timmer, P; Peek, H

    2010-01-01

    The described system is developed in the framework of a deep-sea submerged Very Large Volume neutrino Telescope where photons are detected by a large number of Photo Multiplier Tubes. These PMTs are placed in optical modules (OM). A basic Cockcroft-Walton (CW) voltage multiplier circuit design is used to generate multiple voltages to drive the dynodes of the photomultiplier tube. To achieve a long lifetime and a high reliability the dissipation in the OM must be kept to the minimum. The design is also constrained by size restrictions, load current, voltage range, and the maximum allowable ripple in the output voltage. A surface mount PMT-base PCB prototype is designed and successfully tested. The system draws less than 1.5 mA of supply current at a voltage of 3.3 V with outputs up to -1400 Vdc cathode voltage, a factor 10 less than the commercially available state of the art

  19. Power

    OpenAIRE

    Bowles, Samuel; Gintis, Herbert

    2007-01-01

    We consider the exercise of power in competitive markets for goods, labour and credit. We offer a definition of power and show that if contracts are incomplete it may be exercised either in Pareto-improving ways or to the disadvantage of those without power. Contrasting conceptions of power including bargaining power, market power, and consumer sovereignty are considered. Because the exercise of power may alter prices and other aspects of exchanges, abstracting from power may miss essential a...

  20. The Investigation of Properties of Copper Vapor Pulsed Power Active Medium in Time and Development of Operational Control Methods of Output Radiation Parameters on Their Basis

    Directory of Open Access Journals (Sweden)

    N. A. Lyabin

    2014-01-01

    Full Text Available The given paper focuses on the investigation in time of the properties of a pulsed CVL AM using CVLS of the type DO – SFC –PA and mistiming method in wide limits (± 1000 ns of a DO light radiation pulse relatively to PA light pulse from the moment of maximal amplification.It was stated that CVL AM in relation to its own radiation has got four characteristic time zones following each other and repeating from pulse to pulse: weak absorption 30-50 ns in length (appears at the initial stage of pulse pump current development, amplification 20-40 ns in length (appears at the sharp leading edge of the current pulse, complete absorption over 1000 ns in length (appears at the pulse current cut and follows the pulse and maximal transparency over 1000 ns in length (before the new current pulse.These AM properties have become the basis for developing methods and electron devices of operational control of power and radiation pulse repetition frequency (PRF, including packet and pulse-to-pulse modulation according to preset algorithm in industrial CVLs and CVLSs of new generation. Based on such class of CVLs and CVLSs a set of up-to-date automated laser technological installations (ALTI “Karavella” with computerized control: “Karavella-1”, “Karavella-1M”, “Karavella-2”, “Karavella-2M” were created for precision microprocessing of materials for electron engineering products (EEP 0.02 – 2 mm thick.The capability of ALTI “Karavella” to operate in the modes of high speed control over the laser radiation parameters allows to increase significantly the operational control over technological processes of manufacturing precision parts, to increase the productivity of material microprocessing, to make cuts and holes with minimal roughness and zone of thermal influence.The main conclusions made in the given paper on the results of experimental investigations of CVL AM time properties are also true for lasers on self-contained transitions

  1. A Lightweight TwiddleNet Portal

    National Research Council Canada - National Science Library

    Rimikis, Antonios M

    2008-01-01

    TwiddleNet is a distributed architecture of personal servers that harnesses the power of the mobile devices, enabling real time information and file sharing of multiple data types from commercial-off-the-shelf platforms...

  2. Pro ASP.NET MVC 4

    CERN Document Server

    Freeman, Adam

    2012-01-01

    The ASP.NET MVC 4 Framework is the latest evolution of Microsoft's ASP.NET web platform. It provides a high-productivity programming model that promotes cleaner code architecture, test-driven development, and powerful extensibility, combined with all the benefits of ASP.NET. ASP.NET MVC 4 contains a number of significant advances over previous versions. New mobile and desktop templates (employing adaptive rendering) are included together with support for jQuery Mobile for the first time. New display modes allow your application to select views based on the browser that's making the request whi

  3. NA-NET numerical analysis net

    Energy Technology Data Exchange (ETDEWEB)

    Dongarra, J. [Tennessee Univ., Knoxville, TN (United States). Dept. of Computer Science]|[Oak Ridge National Lab., TN (United States); Rosener, B. [Tennessee Univ., Knoxville, TN (United States). Dept. of Computer Science

    1991-12-01

    This report describes a facility called NA-NET created to allow numerical analysts (na) an easy method of communicating with one another. The main advantage of the NA-NET is uniformity of addressing. All mail is addressed to the Internet host ``na-net.ornl.gov`` at Oak Ridge National Laboratory. Hence, members of the NA-NET do not need to remember complicated addresses or even where a member is currently located. As long as moving members change their e-mail address in the NA-NET everything works smoothly. The NA-NET system is currently located at Oak Ridge National Laboratory. It is running on the same machine that serves netlib. Netlib is a separate facility that distributes mathematical software via electronic mail. For more information on netlib consult, or send the one-line message ``send index`` to netlib{at}ornl.gov. The following report describes the current NA-NET system from both a user`s perspective and from an implementation perspective. Currently, there are over 2100 members in the NA-NET. An average of 110 mail messages pass through this facility daily.

  4. NA-NET numerical analysis net

    Energy Technology Data Exchange (ETDEWEB)

    Dongarra, J. (Tennessee Univ., Knoxville, TN (United States). Dept. of Computer Science Oak Ridge National Lab., TN (United States)); Rosener, B. (Tennessee Univ., Knoxville, TN (United States). Dept. of Computer Science)

    1991-12-01

    This report describes a facility called NA-NET created to allow numerical analysts (na) an easy method of communicating with one another. The main advantage of the NA-NET is uniformity of addressing. All mail is addressed to the Internet host na-net.ornl.gov'' at Oak Ridge National Laboratory. Hence, members of the NA-NET do not need to remember complicated addresses or even where a member is currently located. As long as moving members change their e-mail address in the NA-NET everything works smoothly. The NA-NET system is currently located at Oak Ridge National Laboratory. It is running on the same machine that serves netlib. Netlib is a separate facility that distributes mathematical software via electronic mail. For more information on netlib consult, or send the one-line message send index'' to netlib{at}ornl.gov. The following report describes the current NA-NET system from both a user's perspective and from an implementation perspective. Currently, there are over 2100 members in the NA-NET. An average of 110 mail messages pass through this facility daily.

  5. Output hardcopy devices

    CERN Document Server

    Durbeck, Robert

    1988-01-01

    Output Hardcopy Devices provides a technical summary of computer output hardcopy devices such as plotters, computer output printers, and CRT generated hardcopy. Important related technical areas such as papers, ribbons and inks, color techniques, controllers, and character fonts are also covered. Emphasis is on techniques primarily associated with printing, as well as the plotting capabilities of printing devices that can be effectively used for computer graphics in addition to their various printing functions. Comprised of 19 chapters, this volume begins with an introduction to vector and ras

  6. Arrayed liquid rotor electret power generator systems

    OpenAIRE

    Boland, J. S.; Messenger, J. D. M.; Lo, H. W.; Tai, Y.C.

    2005-01-01

    We report our work on liquid rotor electret power generators (LEPG), LEPG devices are essentially fixed-charged, Teflon-electret capacitors with air-filled gaps and liquid droplets that move by vibration. As the liquid moves into and out of the gaps, a net voltage is generated across the capacitor as image charges on the electrodes redistribute according to the position of the droplets. In this work, we also study serial and parallel arrays of LEPG power generators to increase power output. P...

  7. Net Ecosystem Carbon Flux

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Net Ecosystem Carbon Flux is defined as the year-over-year change in Total Ecosystem Carbon Stock, or the net rate of carbon exchange between an ecosystem and the...

  8. Generation of 6.8 W of CW output power at 1550 nm using small mode field diameter Er:Yb co-doped double clad fiber in laser oscillator configuration

    Science.gov (United States)

    Gurram, Srikanth; Kuruvilla, A.; Singh, Rajpal; Bindra, K. S.

    2017-06-01

    We report studies on erbium:ytterbium doped fiber laser, that uses a commercially available off-the-shelf Er:Yb co-doped single mode fiber with small mode field diameter of 7 µm, which is compatible with single mode fibers used in most of the communication systems. In a FBG based laser oscillator configuration pumped at 976 nm, the single transverse mode fiber laser emitted more than 6.87 Watts of output power at 1550 nm with a conversion efficiency of ~32% over a narrow line width. The pump radiation is coupled into active fiber using free-space optics. To the best of our knowledge, this is the highest power reported in the 1.55 µm region by using commercially available off-the-shelf active fiber of small mode field diameter (~7 µm) in a simple laser oscillator configuration with 9×× nm pumping. We also observed the effect of weak secondary grating structure in FBGs on the spectral characteristics of EYDFLs and explained its significance for co-doped fiber lasers such as erbium-ytterbium fiber lasers.

  9. WRF Model Output

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset contains WRF model output. There are three months of data: July 2012, July 2013, and January 2013. For each month, several simulations were made: A...

  10. CMAQ Model Output

    Data.gov (United States)

    U.S. Environmental Protection Agency — CMAQ and CMAQ-VBS model output. This dataset is not publicly accessible because: Files too large. It can be accessed through the following means: via EPA's NCC tape...

  11. VMS forms Output Tables

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These output tables contain parsed and format validated data from the various VMS forms that are sent from any given vessel, while at sea, from the VMS devices on...

  12. Integration of a high-pressure piperazine capture plant with a power plant: an energetic evaluation

    NARCIS (Netherlands)

    Ham, L.V. van der; Kler, R.C.F. de; Goetheer, E.L.V.

    2013-01-01

    Post-combustion CO2 capture can have a significant contribution to the reduction of CO2 emissions. However, it also requires a considerable amount of energy, causing a significant decrease in the net electricity output of the power plant it is associated with. A vast array of research initiatives is

  13. Modeling and analysis of a transcritical rankine power cycle with a low grade heat source

    DEFF Research Database (Denmark)

    Nguyen, Chan; Veje, Christian

    efficiency, exergetic efficiency and specific net power output. A generic cycle configuration has been used for analysis of a geothermal energy heat source. This model has been validated against similar calculations using industrial waste heat as the energy source. Calculations are done with fixed...

  14. Power output for a nonlinear Brownian machine

    Science.gov (United States)

    Defaveri, Lucianno A. C. A.; Morgado, Welles A. M.; Queirós, Sílvio M. Duarte

    2017-11-01

    We propose a method that makes use of the nonlinear properties of some hypothetical microscopic solid material as the working substance for a microscopic machine. The protocols used are simple (step and elliptic) and allow us to obtain the work and heat exchanged between machine and reservoirs. We calculate the work for a nonlinear single-particle machine that can be treated perturbingly. We obtain the instantaneous work and heat for the machine undergoing cycles that mimic the Carnot and multireservoir protocols. The work calculations are then extended to high values of the nonlinear parameter yielding the quasistatic limit, which is verified numerically. The model we propose is fluctuation driven and we can study in detail its thermostatistics, namely, the work distribution both per cycle and instantaneous and the corresponding fluctuation relations.

  15. Hydrogen-based power generation from bioethanol steam reforming

    Science.gov (United States)

    Tasnadi-Asztalos, Zs.; Cormos, C. C.; Agachi, P. S.

    2015-12-01

    This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO2 emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint.

  16. Hydrogen-based power generation from bioethanol steam reforming

    Energy Technology Data Exchange (ETDEWEB)

    Tasnadi-Asztalos, Zs., E-mail: tazsolt@chem.ubbcluj.ro; Cormos, C. C., E-mail: cormos@chem.ubbcluj.ro; Agachi, P. S. [Babes-Bolyai University, Faculty of Chemistry and Chemical Engineering, 11 Arany Janos, Postal code: 400028, Cluj-Napoca (Romania)

    2015-12-23

    This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO{sub 2} emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint.

  17. Professional Enterprise NET

    CERN Document Server

    Arking, Jon

    2010-01-01

    Comprehensive coverage to help experienced .NET developers create flexible, extensible enterprise application code If you're an experienced Microsoft .NET developer, you'll find in this book a road map to the latest enterprise development methodologies. It covers the tools you will use in addition to Visual Studio, including Spring.NET and nUnit, and applies to development with ASP.NET, C#, VB, Office (VBA), and database. You will find comprehensive coverage of the tools and practices that professional .NET developers need to master in order to build enterprise more flexible, testable, and ext

  18. Development of net energy ratio for quad-generation pathways

    DEFF Research Database (Denmark)

    Rudra, Souman; Rosendahl, Lasse; Kumar, Amit

    2012-01-01

    The conversion of biomass to four different outputs via gasification and catalytic methanation is a renewable technology that could reduce the use of fossil fuels and GHG emissions. This study investigates the energy aspects of producing electricity, heat, methanol and methane. The Gas Technology......-based power, heat, methanol and methane production pathway using GTI technology. Since more efficient alternatives exist for the generation of heat and electricity from biomass, it is argued that syngas is best used for methanol production. The aim of this study was to evaluate the energy performance...... Institute (GTI) gasifier and Circulating Fluidized Bed (CFB) technologies are used for this quad generation process. Three different biomass feedstocks are considered in this study. The net energy ratio for six different pathways having the range of between 1.3–9.3. The lowest limit corresponds to the straw...

  19. Desempenho da potência anaeróbia em atletas de elite do mountain bike submetidos à suplementação aguda com creatina Anaerobic power output of elite off-road cyclists with acute oral creatine supplementation

    Directory of Open Access Journals (Sweden)

    Guilherme Eckhardt Molina

    2009-10-01

    (PRE and after (POS seven days of supplementation. The oral supplements (creatine and maltodextrine were taken in sweetened vehicle with three equal doses per day (0. 3 g/kg body mass/dose. After a seven-day period, no significant differences were found on morphological variables (PRE x POS and there was no difference between the groups in spite of the opposite percent variation (Δ% (positive for CRE and negative for PLA group. The anaerobic power output (PP and the moment of pick power (IPP increased and the fatigue index decreased from PRE to POST tests in CRE group; however, the PLA group did not show significant differences. The PP showed strong tendency to increased values and IPP was greater in the CRE compared with the PLA group. The results of the present study indicated that short-term creatine supplementation (0.3g/kg can postpone the anaerobic IPP (CRE 3.0 ± 0.5/3.6 ± 0.8 Δ%= 20% leading to significant improvement on the performance of power output and peak power moment in off-road cyclists.

  20. Cardiac output measurement

    Directory of Open Access Journals (Sweden)

    Andreja Möller Petrun

    2014-02-01

    Full Text Available In recent years, developments in the measuring of cardiac output and other haemodynamic variables are focused on the so-called minimally invasive methods. The aim of these methods is to simplify the management of high-risk and haemodynamically unstable patients. Due to the need of invasive approach and the possibility of serious complications the use of pulmonary artery catheter has decreased. This article describes the methods for measuring cardiac output, which are based on volume measurement (Fick method, indicator dilution method, pulse wave analysis, Doppler effect, and electrical bioimpedance.

  1. Performance Analysis Using Coloured Petri Nets

    DEFF Research Database (Denmark)

    Wells, Lisa Marie

    2002-01-01

    This paper provides an overview of improved facilities for performance analysis using coloured Petri nets. Coloured Petri nets is a formal method that is well suited for modeling and analyzing large and complex systems. The paper describes steps that have been taken to make a distinction between...... modeling the behavior of a system and observing the behavior of a model. Performance-related facilities are discussed, including facilities for collecting data, running multiple simulations, generating statistically reliable simulation output, and comparing alternative system configurations....

  2. Power

    DEFF Research Database (Denmark)

    Elmholdt, Claus Westergård; Fogsgaard, Morten

    2016-01-01

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

  3. A new variant of Petri net controlled grammars

    Science.gov (United States)

    Jan, Nurhidaya Mohamad; Turaev, Sherzod; Fong, Wan Heng; Sarmin, Nor Haniza

    2015-10-01

    A Petri net controlled grammar is a Petri net with respect to a context-free grammar where the successful derivations of the grammar can be simulated using the occurrence sequences of the net. In this paper, we introduce a new variant of Petri net controlled grammars, called a place-labeled Petri net controlled grammar, which is a context-free grammar equipped with a Petri net and a function which maps places of the net to productions of the grammar. The language consists of all terminal strings that can be obtained by parallelly applying multisets of the rules which are the images of the sets of the input places of transitions in a successful occurrence sequence of the Petri net. We study the effect of the different labeling strategies to the computational power and establish lower and upper bounds for the generative capacity of place-labeled Petri net controlled grammars.

  4. Variability in large-scale wind power generation: Variability in large-scale wind power generation

    Energy Technology Data Exchange (ETDEWEB)

    Kiviluoma, Juha [VTT Technical Research Centre of Finland, Espoo Finland; Holttinen, Hannele [VTT Technical Research Centre of Finland, Espoo Finland; Weir, David [Energy Department, Norwegian Water Resources and Energy Directorate, Oslo Norway; Scharff, Richard [KTH Royal Institute of Technology, Electric Power Systems, Stockholm Sweden; Söder, Lennart [Royal Institute of Technology, Electric Power Systems, Stockholm Sweden; Menemenlis, Nickie [Institut de recherche Hydro-Québec, Montreal Canada; Cutululis, Nicolaos A. [DTU, Wind Energy, Roskilde Denmark; Danti Lopez, Irene [Electricity Research Centre, University College Dublin, Dublin Ireland; Lannoye, Eamonn [Electric Power Research Institute, Palo Alto California USA; Estanqueiro, Ana [LNEG, Laboratorio Nacional de Energia e Geologia, UESEO, Lisbon Spain; Gomez-Lazaro, Emilio [Renewable Energy Research Institute and DIEEAC/EDII-AB, Castilla-La Mancha University, Albacete Spain; Zhang, Qin [State Grid Corporation of China, Beijing China; Bai, Jianhua [State Grid Energy Research Institute Beijing, Beijing China; Wan, Yih-Huei [National Renewable Energy Laboratory, Transmission and Grid Integration Group, Golden Colorado USA; Milligan, Michael [National Renewable Energy Laboratory, Transmission and Grid Integration Group, Golden Colorado USA

    2015-10-25

    The paper demonstrates the characteristics of wind power variability and net load variability in multiple power systems based on real data from multiple years. Demonstrated characteristics include probability distribution for different ramp durations, seasonal and diurnal variability and low net load events. The comparison shows regions with low variability (Sweden, Spain and Germany), medium variability (Portugal, Ireland, Finland and Denmark) and regions with higher variability (Quebec, Bonneville Power Administration and Electric Reliability Council of Texas in North America; Gansu, Jilin and Liaoning in China; and Norway and offshore wind power in Denmark). For regions with low variability, the maximum 1 h wind ramps are below 10% of nominal capacity, and for regions with high variability, they may be close to 30%. Wind power variability is mainly explained by the extent of geographical spread, but also higher capacity factor causes higher variability. It was also shown how wind power ramps are autocorrelated and dependent on the operating output level. When wind power was concentrated in smaller area, there were outliers with high changes in wind output, which were not present in large areas with well-dispersed wind power.

  5. A reappraisal of existing expressions for estimating radiation output ...

    African Journals Online (AJOL)

    The considerable differences in radiation output from different X-ray machine with given kVp and mAs has led a number of expressions being proposed for skin does in diagnostic radiography each having a power dependence of the output with the peak tube voltage. The values of the exponent in the power expression and ...

  6. WaveNet

    Science.gov (United States)

    2015-10-30

    Coastal Inlets Research Program WaveNet WaveNet is a web-based, Graphical-User-Interface ( GUI ) data management tool developed for Corps coastal...generates tabular and graphical information for project planning and design documents. The WaveNet is a web-based GUI designed to provide users with a...data from different sources, and employs a combination of Fortran, Python and Matlab codes to process and analyze data for USACE applications

  7. Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1991-01-01

    This paper describes how Coloured Petri Nets (CP-nets) have been developed — from being a promising theoretical model to being a full-fledged language for the design, specification, simulation, validation and implementation of large software systems (and other systems in which human beings and...... use of CP-nets — because it means that the function representation and the translations (which are a bit mathematically complex) no longer are parts of the basic definition of CP-nets. Instead they are parts of the invariant method (which anyway demands considerable mathematical skills...

  8. Game Coloured Petri Nets

    DEFF Research Database (Denmark)

    Westergaard, Michael

    2006-01-01

    This paper introduces the notion of game coloured Petri nets. This allows the modeler to explicitly model what parts of the model comprise the modeled system and what parts are the environment of the modeled system. We give the formal definition of game coloured Petri nets, a means of reachability...... analysis of this net class, and an application of game coloured Petri nets to automatically generate easy-to-understand visualizations of the model by exploiting the knowledge that some parts of the model are not interesting from a visualization perspective (i.e. they are part of the environment...

  9. Annotating Coloured Petri Nets

    DEFF Research Database (Denmark)

    Lindstrøm, Bo; Wells, Lisa Marie

    2002-01-01

    -net. An example of such auxiliary information is a counter which is associated with a token to be able to do performance analysis. Modifying colour sets and arc inscriptions in a CP-net to support a specific use may lead to creation of several slightly different CP-nets – only to support the different uses...... a method which makes it possible to associate auxiliary information, called annotations, with tokens without modifying the colour sets of the CP-net. Annotations are pieces of information that are not essential for determining the behaviour of the system being modelled, but are rather added to support...

  10. Power

    OpenAIRE

    Hafford-Letchfield, Trish

    2015-01-01

    This chapter looks at the concept of power in social work by focusing on what this means as a ‘professional’ and theorizes competing discourses of empowerment in social work and its key concepts, drawing in particular on the explanatory powers of critical theorist Michel Foucault (1991). The chapter problematizes the concept of power by explicitly drawing on both users’ and carers’ accounts from the literature to demonstrate different external and internal influences on the root causes of dis...

  11. .NET 4.5 parallel extensions

    CERN Document Server

    Freeman, Bryan

    2013-01-01

    This book contains practical recipes on everything you will need to create task-based parallel programs using C#, .NET 4.5, and Visual Studio. The book is packed with illustrated code examples to create scalable programs.This book is intended to help experienced C# developers write applications that leverage the power of modern multicore processors. It provides the necessary knowledge for an experienced C# developer to work with .NET parallelism APIs. Previous experience of writing multithreaded applications is not necessary.

  12. Adaption of the power distribution system to a sustainable energy system - Smart meters and intelligent nets; Anpassning av elnaeten, till ett uthaalligt energisystem - Smarta maetare och intelligenta naet

    Energy Technology Data Exchange (ETDEWEB)

    Bollen, Math

    2010-11-15

    The conversion of the energy system towards sustainability is a major challenge for society. The conversion includes a large-scale introduction of renewable electricity and the electrification of transport. Adaptations of the grid are needed in order to cope with this development: - Facilitate an increased introduction of renewable electricity; - Enabling power reduction at peak load; - Improve incentives for energy efficiency; - Creating conditions for more active purchasers of electricity. Security of supply must be high, although the new production affects the electricity grid in a different way than today. Therefore, new technical solutions, a so-called smart grid, is necessary in order to, inter alia, prevent congestion and over voltages, but also to enhance the operational safety in general. There is new technology that can help adjust the grid in an efficient and flexible way. Intelligent networks, or smart grids, is the collection of new technology, function and regulatory framework in the electricity market, etc. that cost-effectively facilitate introduction and utilization of renewable electricity generation, leading to reduced energy consumption, contributes to power reduction in peak load and creates conditions for active electricity customers. Sweden is one of the countries that score high in terms of active electricity customers and feedback of consumption for electricity customers. There is a direct consequence of introduction of the metering reform and installation of the AMR, in which Sweden was one of the first countries in Europe. As for modern technology to increase transmission capacity of transmission networks such as HVDC and FACTS technology, Sweden is a world leader. This technology will play an important role in enabling large-scale use of renewable electricity generation on European level. The investigation has resulted in the following proposals: - A knowledge platform created to be collect and disseminate relevant knowledge of research

  13. Workload of official contests, net cost of transport, and metabolic power of Mangalarga Marchador horses of marcha batida or picada gaits.

    Science.gov (United States)

    Lage, J; Fonseca, M G; de Barros, G G M; Feringer-Júnior, W H; Pereira, G T; Ferraz, G C

    2017-06-01

    This study aimed to characterize the maximum heart rate (HR) and the intensity of official marcha contests (OMC) and to compare the cost of transport (COT) and metabolic power (Pmet) of Mangalarga Marchador (MM) horses of marcha batida (MB) and marcha picada (MP) gaits. Twenty-two MM horses participated in this study. The experiment was conducted in 3 phases: 1) maximum effort test (MET), 2) OMC, and 3) standardized marcha test (SMT). To characterize the HR, 19 horses (14 MB and 5 MP) underwent a MET. Of those, 13 (9 MB and 4 MP) were monitored during the OMC, which consisted of 4 stages: marcha, walk, functional trial, and rest. The average heart rate (HR) in each stage of the OMC was related to the HR to determine their relative intensity. The SMT was performed with 14 horses (9 MB and 5 MP), of which 11 had already participated in the previous stages. The COT and Pmet were calculated from the HR values obtained during the SMT. Blood samples were collected to analyze plasma lactate concentration ([Lac]). One-way ANOVA or 1-way repeated-measures ANOVA followed by the Tukey's test ( 0.05). This indicated that horses of both groups had the same physical fitness levels. The OMC stages defined in our study differed ( < 0.05) regarding the relative intensity of the HR, except for the walk and standing stages, which were similar ( = 0.0875). The MP group presented greater COT ( = 0.0247) and Pmet ( = 0.0193). It can be concluded that the mean HR of MM horses (MB and MP) is 212 ± 11 bpm. The OMC of the MM breed can be characterized as an effort of intermittent and submaximal intensity. In addition, the locomotion of the MB horses is probably more energetically efficient than that of MP horses.

  14. Net zero water

    CSIR Research Space (South Africa)

    Lindeque, M

    2013-01-01

    Full Text Available Is it possible to develop a building that uses a net zero amount of water? In recent years it has become evident that it is possible to have buildings that use a net zero amount of electricity. This is possible when the building is taken off...

  15. SolNet

    DEFF Research Database (Denmark)

    Jordan, Ulrike; Vajen, Klaus; Bales, Chris

    2014-01-01

    SolNet, founded in 2006, is the first coordinated International PhD education program on Solar Thermal Engineering. The SolNet network is coordinated by the Institute of Thermal Engineering at Kassel University, Germany. The network offers PhD courses on solar heating and cooling, conference...

  16. Kunstige neurale net

    DEFF Research Database (Denmark)

    Hørning, Annette

    1994-01-01

    Artiklen beskæftiger sig med muligheden for at anvende kunstige neurale net i forbindelse med datamatisk procession af naturligt sprog, specielt automatisk talegenkendelse.......Artiklen beskæftiger sig med muligheden for at anvende kunstige neurale net i forbindelse med datamatisk procession af naturligt sprog, specielt automatisk talegenkendelse....

  17. Comparing World Economic and Net Energy Metrics, Part 2: Total Economy Expenditure Perspective

    Directory of Open Access Journals (Sweden)

    Carey W. King

    2015-11-01

    Full Text Available We translate between energetic and economic metrics that characterize the role of energy in the economy. Specifically, we estimate monetary expenditures for the primary energy and net external power ratio (NEPR direct ; NEPR, net external power ratio, a power return ratio of annual energy production divided by annual direct energy inputs within the energy industry. We estimate these on an annualized basis for forty-four countries from 1978 to 2010. Expressed as a fraction of gross domestic product (GDP, f e , GDP , the forty-four country aggregate (composing >90% world GDP worldwide expenditures on energy decreased from a maximum of 10.3% in 1979 to a minimum of 3.0% in 1998 before increasing to a second peak of 8.1% in 2008. While the global f e , GDP fluctuates significantly, global NEPR direct declined from a value of 34 in 1980 to 17 in 1986 before staying in a range between 14 and 16 from 1991 to 2010. In comparing both of these metrics as ratios of power output over power input, one economic ( f e , GDP - 1 and one biophysical (NEPR direct , we see that when the former divided by the latter is below unity, the world was in a low-growth or recessionary state.

  18. Electrical Power Converter

    NARCIS (Netherlands)

    Ferreira, J.A.

    2014-01-01

    Electrical power converter for converting electrical power of a power source connected or connectable at an input to electrical DC-power at an output, wherein between the input and the output a first circuit of submodules is provided, wherein said first circuit of submodules and the power source

  19. Approximation methods for stochastic petri nets

    Science.gov (United States)

    Jungnitz, Hauke Joerg

    1992-01-01

    Stochastic Marked Graphs are a concurrent decision free formalism provided with a powerful synchronization mechanism generalizing conventional Fork Join Queueing Networks. In some particular cases the analysis of the throughput can be done analytically. Otherwise the analysis suffers from the classical state explosion problem. Embedded in the divide and conquer paradigm, approximation techniques are introduced for the analysis of stochastic marked graphs and Macroplace/Macrotransition-nets (MPMT-nets), a new subclass introduced herein. MPMT-nets are a subclass of Petri nets that allow limited choice, concurrency and sharing of resources. The modeling power of MPMT is much larger than that of marked graphs, e.g., MPMT-nets can model manufacturing flow lines with unreliable machines and dataflow graphs where choice and synchronization occur. The basic idea leads to the notion of a cut to split the original net system into two subnets. The cuts lead to two aggregated net systems where one of the subnets is reduced to a single transition. A further reduction leads to a basic skeleton. The generalization of the idea leads to multiple cuts, where single cuts can be applied recursively leading to a hierarchical decomposition. Based on the decomposition, a response time approximation technique for the performance analysis is introduced. Also, delay equivalence, which has previously been introduced in the context of marked graphs by Woodside et al., Marie's method and flow equivalent aggregation are applied to the aggregated net systems. The experimental results show that response time approximation converges quickly and shows reasonable accuracy in most cases. The convergence of Marie's method and flow equivalent aggregation are applied to the aggregated net systems. The experimental results show that response time approximation converges quickly and shows reasonable accuracy in most cases. The convergence of Marie's is slower, but the accuracy is generally better. Delay

  20. MotifNet: a web-server for network motif analysis.

    Science.gov (United States)

    Smoly, Ilan Y; Lerman, Eugene; Ziv-Ukelson, Michal; Yeger-Lotem, Esti

    2017-06-15

    Network motifs are small topological patterns that recur in a network significantly more often than expected by chance. Their identification emerged as a powerful approach for uncovering the design principles underlying complex networks. However, available tools for network motif analysis typically require download and execution of computationally intensive software on a local computer. We present MotifNet, the first open-access web-server for network motif analysis. MotifNet allows researchers to analyze integrated networks, where nodes and edges may be labeled, and to search for motifs of up to eight nodes. The output motifs are presented graphically and the user can interactively filter them by their significance, number of instances, node and edge labels, and node identities, and view their instances. MotifNet also allows the user to distinguish between motifs that are centered on specific nodes and motifs that recur in distinct parts of the network. MotifNet is freely available at http://netbio.bgu.ac.il/motifnet . The website was implemented using ReactJs and supports all major browsers. The server interface was implemented in Python with data stored on a MySQL database. estiyl@bgu.ac.il or michaluz@cs.bgu.ac.il. Supplementary data are available at Bioinformatics online.

  1. Pro NET Best Practices

    CERN Document Server

    Ritchie, Stephen D

    2011-01-01

    Pro .NET Best Practices is a practical reference to the best practices that you can apply to your .NET projects today. You will learn standards, techniques, and conventions that are sharply focused, realistic and helpful for achieving results, steering clear of unproven, idealistic, and impractical recommendations. Pro .NET Best Practices covers a broad range of practices and principles that development experts agree are the right ways to develop software, which includes continuous integration, automated testing, automated deployment, and code analysis. Whether the solution is from a free and

  2. Getting to Net Zero

    Energy Technology Data Exchange (ETDEWEB)

    2016-09-01

    The technology necessary to build net zero energy buildings (NZEBs) is ready and available today, however, building to net zero energy performance levels can be challenging. Energy efficiency measures, onsite energy generation resources, load matching and grid interaction, climatic factors, and local policies vary from location to location and require unique methods of constructing NZEBs. It is recommended that Components start looking into how to construct and operate NZEBs now as there is a learning curve to net zero construction and FY 2020 is just around the corner.

  3. Instant Lucene.NET

    CERN Document Server

    Heydt, Michael

    2013-01-01

    Filled with practical, step-by-step instructions and clear explanations for the most important and useful tasks. A step-by-step guide that helps you to index, search, and retrieve unstructured data with the help of Lucene.NET.Instant Lucene.NET How-to is essential for developers new to Lucene and Lucene.NET who are looking to get an immediate foundational understanding of how to use the library in their application. It's assumed you have programming experience in C# already, but not that you have experience with search techniques such as information retrieval theory (although there will be a l

  4. Reachability Trees for High-level Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt; Jensen, Arne M.; Jepsen, Leif Obel

    1986-01-01

    High-level Petri nets have been introduced as a powerful net type by which it is possible to handle rather complex systems in a succinct and manageable way. The success of high-level Petri nets is undebatable when we speak about description, but there is still much work to be done to establish...... the necessary analysis methods. In other papers it is shown how to generalize the concept of place- and transition invariants from place/transition nets to high-level Petri nets. Our present paper contributes to this with a generalization of reachability trees, which is one of the other important analysis...

  5. Post-prandial carbohydrate ingestion during 1-h of moderate-intensity, intermittent cycling does not improve mood, perceived exertion, or subsequent power output in recreationally-active exercisers

    Directory of Open Access Journals (Sweden)

    O’Neal Eric K

    2013-01-01

    Full Text Available Abstract Background This study compared the effects of ingesting water (W, a flavored carbohydrate-electrolyte (CE or a flavored non-caloric electrolyte (NCE beverage on mood, ratings of perceived exertion (RPE, and sprint power during cycling in recreational exercisers. Methods Men (n = 23 and women (n = 13 consumed a 24–h standardized diet and reported 2–4 h post-prandial for all test sessions. After a familiarization session, participants completed 50 min of stationary cycling in a warm environment (wet bulb globe temperature = 25.0°C at ~ 60-65% of heart rate reserve (146 ± 4 bpm interspersed with 5 rest periods of 2 min each. During exercise, participants consumed W, CE, or NCE, served in a counterbalanced cross-over design. Beverage volume was served in 3 aliquots equaling each individual’s sweat losses (mean 847 ± 368 mL during the familiarization session. Profiles of Mood States questionnaires (POMS were administered and blood glucose levels were determined pre- and post- sub-maximal cycling. Following sub-maximal exercise, participants completed 3 30–s Wingate anaerobic tests (WAnT with 2.5 min rest between tests to assess performance. Results Blood glucose was higher (p AnT for CE (6.1 ± 1.7 mmol/L compared to W (4.9 ± 1.5 mmol/L and NCE (4.6 ± 1.2 mmol/L. Nonetheless, there were no differences among treatments in peak (642 ± 153, 635 ± 143, 650 ± 141 watts for W, NCE, and CE, respectively; p  =  0.44 or mean (455 ± 100, 458 ± 95, 454 ± 95 watts for W, NCE, and CE, respectively; p = 0.62 power for the first WAnT or mean (414 ± 92, 425 ± 85, 423 ± 82 watts, respectively; p = 0.13 power output averaged across all 3 WAnT. Likewise, RPE during submaximal exercise, session RPE, and fatigue and vigor assessed by POMS did not differ among beverage treatments (p > 0.05. Conclusions Carbohydrate ingestion consumed by recreational

  6. Design of laser diode stable output system

    Science.gov (United States)

    Liu, Bo; Cao, Rui-ming

    2008-03-01

    High-stability output's system of laser diode is introduced in this paper. The system which is based on the MCU of MSP430 has been designed light power feedback loop and coller of TEC. It includes stable current, protecting circuit, light power feedback loop, temperature controlling, power display and so on. It is also able to control and show the power at the real time. The power could be set by botton too. The software of slow start up, slow close and the protecting relay are adopted by MCU. DRV592 is introduced as PWM driver to control the current of TEC. The duty cycle is generate by MCU. In order to control temperature, it is changed to influence the current of TEC. The power that is sampled by photodiode which is integrated in the laser diode is controlled by the micro-processing. The laser is monitored by voltage control circuit and current control circuit at the real time.

  7. Net Zero Energy Buildings

    DEFF Research Database (Denmark)

    Marszal, Anna Joanna; Bourrelle, Julien S.; Musall, Eike

    2010-01-01

    and identify possible renewable energy supply options which may be considered in calculations. Finally, the gap between the methodology proposed by each organisation and their respective national building code is assessed; providing an overview of the possible changes building codes will need to undergo......The international cooperation project IEA SHC Task 40 / ECBCS Annex 52 “Towards Net Zero Energy Solar Buildings”, attempts to develop a common understanding and to set up the basis for an international definition framework of Net Zero Energy Buildings (Net ZEBs). The understanding of such buildings...... parameters used in the calculations are discussed and the various renewable supply options considered in the methodologies are summarised graphically. Thus, the paper helps to understand different existing approaches to calculate energy balance in Net ZEBs, highlights the importance of variables selection...

  8. PhysioNet

    Data.gov (United States)

    U.S. Department of Health & Human Services — The PhysioNet Resource is intended to stimulate current research and new investigations in the study of complex biomedical and physiologic signals. It offers free...

  9. NetSig

    DEFF Research Database (Denmark)

    Horn, Heiko; Lawrence, Michael S; Chouinard, Candace R

    2018-01-01

    Methods that integrate molecular network information and tumor genome data could complement gene-based statistical tests to identify likely new cancer genes; but such approaches are challenging to validate at scale, and their predictive value remains unclear. We developed a robust statistic (Net......Sig) that integrates protein interaction networks with data from 4,742 tumor exomes. NetSig can accurately classify known driver genes in 60% of tested tumor types and predicts 62 new driver candidates. Using a quantitative experimental framework to determine in vivo tumorigenic potential in mice, we found that Net......Sig candidates induce tumors at rates that are comparable to those of known oncogenes and are ten-fold higher than those of random genes. By reanalyzing nine tumor-inducing NetSig candidates in 242 patients with oncogene-negative lung adenocarcinomas, we find that two (AKT2 and TFDP2) are significantly amplified...

  10. TideNet

    Science.gov (United States)

    2015-10-30

    query tide data sources in a desired geographic region of USA and its territories (Figure 1). Users can select a tide data source through the Google Map ...select data sources according to the desired geographic region. It uses the Google Map interface to display data from different sources. Recent...Coastal Inlets Research Program TideNet The TideNet is a web-based Graphical User Interface (GUI) that provides users with GIS mapping tools to

  11. Building Neural Net Software

    OpenAIRE

    Neto, João Pedro; Costa, José Félix

    1999-01-01

    In a recent paper [Neto et al. 97] we showed that programming languages can be translated on recurrent (analog, rational weighted) neural nets. The goal was not efficiency but simplicity. Indeed we used a number-theoretic approach to machine programming, where (integer) numbers were coded in a unary fashion, introducing a exponential slow down in the computations, with respect to a two-symbol tape Turing machine. Implementation of programming languages in neural nets turns to be not only theo...

  12. Interaction Nets in Russian

    OpenAIRE

    Salikhmetov, Anton

    2013-01-01

    Draft translation to Russian of Chapter 7, Interaction-Based Models of Computation, from Models of Computation: An Introduction to Computability Theory by Maribel Fernandez. "In this chapter, we study interaction nets, a model of computation that can be seen as a representative of a class of models based on the notion of 'computation as interaction'. Interaction nets are a graphical model of computation devised by Yves Lafont in 1990 as a generalisation of the proof structures of linear logic...

  13. Programming NET 35

    CERN Document Server

    Liberty, Jesse

    2009-01-01

    Bestselling author Jesse Liberty and industry expert Alex Horovitz uncover the common threads that unite the .NET 3.5 technologies, so you can benefit from the best practices and architectural patterns baked into the new Microsoft frameworks. The book offers a Grand Tour" of .NET 3.5 that describes how the principal technologies can be used together, with Ajax, to build modern n-tier and service-oriented applications. "

  14. MyProteinNet: build up-to-date protein interaction networks for organisms, tissues and user-defined contexts.

    Science.gov (United States)

    Basha, Omer; Flom, Dvir; Barshir, Ruth; Smoly, Ilan; Tirman, Shoval; Yeger-Lotem, Esti

    2015-07-01

    The identification of the molecular pathways active in specific contexts, such as disease states or drug responses, often requires an extensive view of the potential interactions between a subset of proteins. This view is not easily obtained: it requires the integration of context-specific protein list or expression data with up-to-date data of protein interactions that are typically spread across multiple databases. The MyProteinNet web server allows users to easily create such context-sensitive protein interaction networks. Users can automatically gather and consolidate data from up to 11 different databases to create a generic protein interaction network (interactome). They can score the interactions based on reliability and filter them by user-defined contexts including molecular expression and protein annotation. The output of MyProteinNet includes the generic and filtered interactome files, together with a summary of their network attributes. MyProteinNet is particularly geared toward building human tissue interactomes, by maintaining tissue expression profiles from multiple resources. The ability of MyProteinNet to facilitate the construction of up-to-date, context-specific interactomes and its applicability to 11 different organisms and to tens of human tissues, make it a powerful tool in meaningful analysis of protein networks. MyProteinNet is available at http://netbio.bgu.ac.il/myproteinnet. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  15. Relationship between resultant force at the pushrim and the net shoulder joint moments during manual wheelchair propulsion in elderly persons.

    Science.gov (United States)

    Desroches, Guillaume; Aissaoui, Rachid; Bourbonnais, Daniel

    2008-06-01

    To determine the relationship between the resultant force at the pushrim and the net shoulder joint moments during manual wheelchair propulsion in elderly persons. Convenience sample. Motion analysis laboratory. Older manual wheelchair users (N=14; age, 68.2+/-5.2y) were tested. Kinematic and kinetic data were collected during manual wheelchair propulsion at a speed between 0.96 and 1.01m/s for 10 seconds and at a power output around 22.4W on a wheelchair ergometer. Net shoulder joint moments were computed with an inverse dynamic model. The mechanical use of the forces at the pushrim and the mechanical fraction of effective force were measured during propulsion. Mechanical use and mechanical fraction of effective force had a positive and significant correlation with the net internal (Pplane, and the net flexion (Pplane. The results suggest that because the resultant force at the pushrim has a greater tangential component and a greater proportion of the maximal voluntary force, most of the net moments around the shoulder are higher. Thus the optimal way of propelling, from a mechanical point of view (ie, tangential), may not be advantageous for manual wheelchair users.

  16. Method for estimation of the output electric power of PV module with considering environmental factors. Method for estimation of output using I-V curves; Kankyo inshi wo koryoshita taiyo denchi module no shutsuryoku keisanho. I-V tokusei curve ni yoru keisan

    Energy Technology Data Exchange (ETDEWEB)

    Yamagami, Y.; Tani, T. [Science University of Tokyo, Tokyo (Japan)

    1996-10-27

    Based on the basic quality equation of photovoltaic (PV) cell, a quality equation of PV module has been constructed by considering the spectral distribution of solar radiation and its intensity. A calculation method has been also proposed for determining the output from current-voltage (I-V) curves. Effectiveness of this method was examined by comparing calculated results and observed results. Amorphous Si (a-Si) and polycrystal Si PV modules were examined. By considering the environmental factors, differences of the annual output between the calculated and observed values were reduced from 2.50% to 0.95% for the a-Si PV module, and from 2.52% to 1.24% for the polycrystal Si PV module, which resulted in the reduction more than 50%. For the a-Si PV module, the environmental factor most greatly affecting the annual output was the spectral distribution of solar radiation, which was 3.86 times as large as the cell temperature, and 1.04 times as large as the intensity of solar radiation. For the polycrystal PV module, the environmental factor most greatly affecting the annual output was the cell temperature, which was 7.05 times as large as the spectral distribution of solar radiation, and 1.74 times as large as the intensity of solar radiation. 6 refs., 4 figs., 1 tab.

  17. A Fuzzy Petri Nets System for Heart Disease Diagnosis

    Directory of Open Access Journals (Sweden)

    Hussin Attya Lafta

    2017-02-01

    Full Text Available In this paper we have proposed a Fuzzy Petri Nets Expert System for heart disease diagnosis. The aim of the proposed system is simulating experience of experts in Diagnosis Heart Disease stage, based on Fuzzy Rule System and modeling reasoning operation by using Fuzzy Petri Nets. The database taken from Machine Learning Repository Center for machine learning and intelligent system. The system has 11 input fields and one output field. The accuracy of proposed system is 75%.

  18. Site compare scripts and output

    Data.gov (United States)

    U.S. Environmental Protection Agency — Monthly site compare scripts and output used to generate the model/ob plots and statistics in the manuscript. The AQS hourly site compare output files are not...

  19. Petri Nets as Models of Linear Logic

    DEFF Research Database (Denmark)

    Engberg, Uffe Henrik; Winskel, Glynn

    1990-01-01

    The chief purpose of this paper is to appraise the feasibility of Girad's linear logic as a specification language for parallel processes. To this end we propose an interpretation of linear logic in Petri nets, with respect to which we investigate the expressive power of the logic...

  20. Development of net energy ratio and emission factor for quad-generation pathways

    DEFF Research Database (Denmark)

    Rudra, Souman; Rosendahl, Lasse; Kumar, Amit

    2014-01-01

    The conversion of biomass to four different outputs via gasification is a renewable technology that could reduce the use of fossil fuels and greenhouse gas (GHG) emissions. This study investigates the energy aspects for a new concept of biomass based quad-generation plant producing power, heat......, methanol and methane. Circulating fluidized bed gasifier and the gas technology institute (GTI) gasifier technologies are used for this quad-generation process. Two different biomass feedstocks are considered in this study. The net energy ratio for six different pathways having the range of between 1.......3 and 7.2. The lowest limit corresponds to the wood chips-based power, heat, methanol and methane production pathway using GTI technology. Since more efficient alternatives exist for the generation of heat and electricity from biomass, it is argued that syngas is best used for methanol production. The aim...