WorldWideScience

Sample records for high efficiency traction

  1. Wheel Slip Control for Improving Traction-Ability and Energy Efficiency of a Personal Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Kanghyun Nam

    2015-07-01

    Full Text Available In this paper, a robust wheel slip control system based on a sliding mode controller is proposed for improving traction-ability and reducing energy consumption during sudden acceleration for a personal electric vehicle. Sliding mode control techniques have been employed widely in the development of a robust wheel slip controller of conventional internal combustion engine vehicles due to their application effectiveness in nonlinear systems and robustness against model uncertainties and disturbances. A practical slip control system which takes advantage of the features of electric motors is proposed and an algorithm for vehicle velocity estimation is also introduced. The vehicle velocity estimator was designed based on rotational wheel dynamics, measurable motor torque, and wheel velocity as well as rule-based logic. The simulations and experiments were carried out using both CarSim software and an experimental electric vehicle equipped with in-wheel-motors. Through field tests, traction performance and effectiveness in terms of energy saving were all verified. Comparative experiments with variations of control variables proved the effectiveness and practicality of the proposed control design.

  2. Loss minimization control and efficiency determination of electric drives in traction applications

    Energy Technology Data Exchange (ETDEWEB)

    Windisch, Thomas; Hofmann, Wilfried [Technische Univ. Dresden (Germany). Lehrstuhl fuer Elektrische Maschinen und Antriebe

    2012-11-01

    High-power electric drives in automotive traction applications consume a large part of the disposable electric energy. For this reason the energy efficiency of the drives is of great importance for range and fuel consumption of the hybrid electric vehicle. The paper describes two possible drives with different electric motors from a control point of view. The electric power losses in the drive system are determined depending on the operating point of the machine. With these loss characteristics the control of the drives is optimized to produce minimal losses. Finally the energy efficiency for a realistic urban bus drive cycle is calculated to compare the two types. (orig.)

  3. High resolution, large deformation 3D traction force microscopy.

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    Jennet Toyjanova

    Full Text Available Traction Force Microscopy (TFM is a powerful approach for quantifying cell-material interactions that over the last two decades has contributed significantly to our understanding of cellular mechanosensing and mechanotransduction. In addition, recent advances in three-dimensional (3D imaging and traction force analysis (3D TFM have highlighted the significance of the third dimension in influencing various cellular processes. Yet irrespective of dimensionality, almost all TFM approaches have relied on a linear elastic theory framework to calculate cell surface tractions. Here we present a new high resolution 3D TFM algorithm which utilizes a large deformation formulation to quantify cellular displacement fields with unprecedented resolution. The results feature some of the first experimental evidence that cells are indeed capable of exerting large material deformations, which require the formulation of a new theoretical TFM framework to accurately calculate the traction forces. Based on our previous 3D TFM technique, we reformulate our approach to accurately account for large material deformation and quantitatively contrast and compare both linear and large deformation frameworks as a function of the applied cell deformation. Particular attention is paid in estimating the accuracy penalty associated with utilizing a traditional linear elastic approach in the presence of large deformation gradients.

  4. ENERGY EFFICIENCY DETERMINATION OF LOADING-BACK SYSTEM OF ELECTRIC TRACTION MACHINES

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    A. M. Afanasov

    2014-03-01

    Full Text Available Purpose.Acceptance post-repair testsof electric traction machinesare conducted onloading-backstandsthat reducethe overall power costsfor the tests.Currentlya numberof possiblecircuit designs of loading-backsystems of electric machines are known, but there is nomethod of determiningtheir energy efficiency. This in turn makes difficult the choiceof rationaloptions. The purpose of the article is the development of the corresponding methodo-logy to make easier this process. Methodology. Expressions for determining theenergy efficiency ofa stand for testingof electric traction machineswere obtained using the generalizedscheme analysisof energy transformationsin the loading-backsystems of universal structure. Findings.Thetechnique wasoffered and the analytical expressions for determining the energy efficiency of loading-backsystemsof electric traction machines wereobtained. Energy efficiency coefficientofloading-backsystemisproposed to consider as the ratio of the total actionenergy of the mechanical and electromotive forces, providing anchors rotation and flowof currents in electric machines, which are being tested,to the total energy, consumed during the test from the external network. Originality. The concept was introduced and the analytical determination method of the energy efficiency of loading-backsystem in electric traction machines was offered. It differs by efficiency availability of power sources and converters, as well as energy efficiency factors of indirect methods of loss compensation. Practical value. The proposed technique of energy efficiency estimation of a loading-backsystemcan be used in solving the problem of rational options choice of schematics stands decisions for electric traction machines acceptance tests of main line and industrial transport.

  5. Model-based efficiency evaluation of combine harvester traction drives

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    Steffen Häberle

    2015-08-01

    Full Text Available As part of the research the drive train of the combine harvesters is investigated in detail. The focus on load and power distribution, energy consumption and usage distribution are explicitly explored on two test machines. Based on the lessons learned during field operations, model-based studies of energy saving potential in the traction train of combine harvesters can now be quantified. Beyond that the virtual machine trial provides an opportunity to compare innovative drivetrain architectures and control solutions under reproducible conditions. As a result, an evaluation method is presented and generically used to draw comparisons under local representative operating conditions.

  6. Wavelet Entropy-Based Traction Inverter Open Switch Fault Diagnosis in High-Speed Railways

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    Keting Hu

    2016-03-01

    Full Text Available In this paper, a diagnosis plan is proposed to settle the detection and isolation problem of open switch faults in high-speed railway traction system traction inverters. Five entropy forms are discussed and compared with the traditional fault detection methods, namely, discrete wavelet transform and discrete wavelet packet transform. The traditional fault detection methods cannot efficiently detect the open switch faults in traction inverters because of the low resolution or the sudden change of the current. The performances of Wavelet Packet Energy Shannon Entropy (WPESE, Wavelet Packet Energy Tsallis Entropy (WPETE with different non-extensive parameters, Wavelet Packet Energy Shannon Entropy with a specific sub-band (WPESE3,6, Empirical Mode Decomposition Shannon Entropy (EMDESE, and Empirical Mode Decomposition Tsallis Entropy (EMDETE with non-extensive parameters in detecting the open switch fault are evaluated by the evaluation parameter. Comparison experiments are carried out to select the best entropy form for the traction inverter open switch fault detection. In addition, the DC component is adopted to isolate the failure Isolated Gate Bipolar Transistor (IGBT. The simulation experiments show that the proposed plan can diagnose single and simultaneous open switch faults correctly and timely.

  7. Permanent Magnet Synchronous Motor with Different Rotor Structures for Traction Motor in High Speed Trains

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    Marcel Torrent

    2018-06-01

    Full Text Available In this work we proposed to study the use of permanent magnet synchronous motors (PMSM for railway traction in the high-speed trains (HST of Renfe Operadora (the Spanish national railway operator. Currently, induction motors (IM are used in AVE classes 102–112 trains, so, the IM used as a traction motor in these trains has been studied and characterized by comparing the results with data provided by Renfe. A PMSM of equivalent power to the IM has been dimensioned, and different electromagnetic structures of the PMSM rotor have been evaluated. The simulation by the finite element method and analysis of the equivalent electrical circuit used in all the motors have been studied to evaluate the performance of the motors in this application. Efficiency is calculated at different operating points due to its impact on the energy consumption of railway traction. The implementation of the PMSM evaluated is recommended, mainly due to the improvements achieved in efficiency as compared with the IM currently used.

  8. A Traction Control Strategy with an Efficiency Model in a Distributed Driving Electric Vehicle

    OpenAIRE

    Lin, Cheng; Cheng, Xingqun

    2014-01-01

    Both active safety and fuel economy are important issues for vehicles. This paper focuses on a traction control strategy with an efficiency model in a distributed driving electric vehicle. In emergency situation, a sliding mode control algorithm was employed to achieve antislip control through keeping the wheels' slip ratios below 20%. For general longitudinal driving cases, an efficiency model aiming at improving the fuel economy was built through an offline optimization stream within the tw...

  9. Efficient start–up energy management via nonlinear control for eco–traction systems

    International Nuclear Information System (INIS)

    Becherif, M.; Ramadan, H.S.; Ayad, M.Y.; Hissel, D.; Desideri, U.; Antonelli, M.

    2017-01-01

    Highlights: • Renewable HPS for the train start-up within feeding durations. • Dynamic modelling of the modern HPS applied to traction systems. • Port-Controlled Hamiltonian (PCH) design for supercapacitors’ charge/discharge operation. • Experimental validation and applicability of HPSs for energy management in eco-tractions. - Abstract: Electrochemical capacitors, called supercapacitors (SCs) or ultracapacitors, are devices conveniently used for embedded electrical energy management owing to their huge capacitance, low internal resistance and flexible control through power electronic conversion. This paper proposes a main power supply of hybrid Wind Generator (WG)–SC within the train station for feeding the traction onboard SC through specified limited feeding transit durations. Onboard SCs provide the train with the requested start–up self–energy. The hybrid WG–SCs system is an environmental–friendly source that enables the independency on national grid and guarantees an efficient bidirectional power transfer for energy management with enhanced dynamic performance. Therefore, the dynamic modelling and the experimental analysis of the modern hybrid WG–SCs used for managing the charge/discharge operation of SCs at Unity Power Factor (UPF) mode are presented. For this purpose, the Port–Controlled Hamiltonian (PCH) methodology is deduced and explicitly presented. Simulation results, via MATLAB™, reveal that the proposed PCH control methodology can be successfully implemented to ensure acceptable system dynamic behavior. Numerical results are validated with experimental measurements to investigate the significance of the PCH approach for the energy management operation in eco-tractions.

  10. ANALYSIS OF ENERGY EFFICIENCY OF OPERATING MODES OF ELECTRICAL SYSTEMS WITH THE TRACTION LOADS

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    V. E. Bondarenko

    2017-03-01

    Full Text Available Innovative scenarios of reliable energy supply of transportation process aimed at reducing the specific energy consumption and increase energy efficiency of the systems of electric traction. The paper suggests innovative energy saving directions in traction networks of railways and new circuit solutions accessing traction substations in energy systems networks, ensure energy security of the transportation process. To ensure the energy security of rail transport special schemes were developed to propose the concept of external power traction substations, which would increase the number of connections to the networks of 220 – 330 kV, as well as the creation of transport and energy corridors, development of its own supply of electric networks of 110 kV substations and mobile RP-110 kV of next generation. Therefore, the investment program of the structures owned by the Ukrainian Railways (Ukrzaliznytsia need to be synchronized in their technological characteristics, as well as the criteria of reliability and quality of power supply with the same external energy investment programs. It is found that without any load on left or right supplying arm one of two less loaded phases of traction transformer begins generating specific modes in the supplying three-phase line. Thus, modes of mobile substation cause leakage in one of the phases of the supply line of traction transformers of active-capacitive current, and as a result generating energy in the main power line of 154 kV, which is fixed and calculated by electricity meters. For these three phase mode supply network is necessary to use 1st algorithm, i.e. taking into account the amount of electricity as the energy in all phases. For effective application of reactive power compensation devices in the AC traction power supply systems it is proposed to develop regulatory documentation on necessity of application and the order of choice of parameters and placement of compensation systems taking into

  11. Observer Based Traction/Braking Control Design for High Speed Trains Considering Adhesion Nonlinearity

    OpenAIRE

    Cai, Wenchuan; Liao, Wenhao; Li, Danyong; Song, Yongduan

    2014-01-01

    Train traction/braking control, one of the key enabling technologies for automatic train operation, literally takes its action through adhesion force. However, adhesion coefficient of high speed train (HST) is uncertain in general because it varies with wheel-rail surface condition and running speed; thus, it is extremely difficult to be measured, which makes traction/braking control design and implementation of HSTs greatly challenging. In this work, force observers are applied to estimate t...

  12. A traction control strategy with an efficiency model in a distributed driving electric vehicle.

    Science.gov (United States)

    Lin, Cheng; Cheng, Xingqun

    2014-01-01

    Both active safety and fuel economy are important issues for vehicles. This paper focuses on a traction control strategy with an efficiency model in a distributed driving electric vehicle. In emergency situation, a sliding mode control algorithm was employed to achieve antislip control through keeping the wheels' slip ratios below 20%. For general longitudinal driving cases, an efficiency model aiming at improving the fuel economy was built through an offline optimization stream within the two-dimensional design space composed of the acceleration pedal signal and the vehicle speed. The sliding mode control strategy for the joint roads and the efficiency model for the typical drive cycles were simulated. Simulation results show that the proposed driving control approach has the potential to apply to different road surfaces. It keeps the wheels' slip ratios within the stable zone and improves the fuel economy on the premise of tracking the driver's intention.

  13. A Traction Control Strategy with an Efficiency Model in a Distributed Driving Electric Vehicle

    Science.gov (United States)

    Lin, Cheng

    2014-01-01

    Both active safety and fuel economy are important issues for vehicles. This paper focuses on a traction control strategy with an efficiency model in a distributed driving electric vehicle. In emergency situation, a sliding mode control algorithm was employed to achieve antislip control through keeping the wheels' slip ratios below 20%. For general longitudinal driving cases, an efficiency model aiming at improving the fuel economy was built through an offline optimization stream within the two-dimensional design space composed of the acceleration pedal signal and the vehicle speed. The sliding mode control strategy for the joint roads and the efficiency model for the typical drive cycles were simulated. Simulation results show that the proposed driving control approach has the potential to apply to different road surfaces. It keeps the wheels' slip ratios within the stable zone and improves the fuel economy on the premise of tracking the driver's intention. PMID:25197697

  14. Performance Comparison between a Permanent Magnet Synchronous Motor and an Induction Motor as a Traction Motor for High Speed Train

    Science.gov (United States)

    Kondo, Minoru; Kawamura, Junya; Terauchi, Nobuo

    Performance tests are carried out to demonstrate the superiority of a permanent magnet synchronous motor to an induction motor as a traction motor for high-speed train. A prototype motor was manufactured by replacing the rotor of a conventional induction motor. The test results show that the permanent magnet motor is lighter, efficient and more silent than the induction motor because of the different rotor structure.

  15. Investigation of efficiency of electric drive control system of excavator traction mechanism based on feedback on load

    Science.gov (United States)

    Kuznetsov, N. K.; Iov, I. A.; Iov, A. A.

    2018-05-01

    The article presents the results of a study of the efficiency of the electric drive control system of the traction mechanism of a dragline based on the use of feedback on load in the traction cable. The investigations were carried out using a refined electromechanical model of the traction mechanism, which took into account not only the elastic elements of the gearbox, the backlashes in it and the changes in the kinematic parameters of the mechanism during operation, but also the mechanical characteristics of the electric drive and the features of its control system. By mathematical modeling of the transient processes of the electromechanical system, it is shown that the introduction of feedback on the load in the elastic element allows one to reduce the dynamic loads in the traction mechanism and to limit the elastic oscillations of the actuating mechanism in comparison with the standard control system. Fixed as a general decrease in the dynamic load of the nodes of traction mechanism in the modes of loading and latching of the bucket, and a decrease the operating time of the mechanism at maximum load. At the same time, undesirable phenomena in the operation of the electric drive were also associated with the increase in the recovery time of the steady-state value of the speed of the actuating mechanism under certain operating conditions, which can lead to a decrease in the reliability of the mechanical part and the productivity of the traction mechanism.

  16. Observer Based Traction/Braking Control Design for High Speed Trains Considering Adhesion Nonlinearity

    Directory of Open Access Journals (Sweden)

    Wenchuan Cai

    2014-01-01

    Full Text Available Train traction/braking control, one of the key enabling technologies for automatic train operation, literally takes its action through adhesion force. However, adhesion coefficient of high speed train (HST is uncertain in general because it varies with wheel-rail surface condition and running speed; thus, it is extremely difficult to be measured, which makes traction/braking control design and implementation of HSTs greatly challenging. In this work, force observers are applied to estimate the adhesion force or/and the resistance, based on which simple traction/braking control schemes are established under the consideration of actual wheel-rail adhesion condition. It is shown that the proposed controllers have simple structure and can be easily implemented from real applications. Numerical simulation also validates the effectiveness of the proposed control scheme.

  17. Rational Formations of a Metro Train Improve Its Efficiencies of Both Traction Energy Utilization and Passenger Transport

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    Xuesong Feng

    2013-01-01

    Full Text Available Based on simulations of passenger transports of two representative types of metro trains in China, this study analyzes efficiencies of energy consumption and passenger transport of a metro train in the effect of its target speed, formation scale (FS (i.e., length and mass of the formation, relative traction capacity (RTC (i.e., ratio of the motoring cars to all its cars, and so forth. It is found that increasing energy cost efficiency of a metro train with decreasing its target speed is evidently accelerated with reducing its RTC below 0.50 at the expense of obviously lowering its passenger transport efficiency. Moreover, if the passenger capacity of the train is sufficiently utilized, increasing its FS for the same RTC is easy to have its passenger transport efficiency improved significantly even for a meanwhile much decreased target speed with consuming energy less intensively. Therefore, metro trains in peak hours may take comparatively big FSs, relatively high target speeds, and RTCs over 0.50 to meet usually urgent and large-scale travel demands in such time. In contrast, trains in nonpeak hours ought to have small FSs, relatively low target speeds, and RTCs smaller than 0.50 for mainly avoiding energy waste.

  18. Group traction drive as means to increase energy efficiency of lokomotives of open-pit transport

    Science.gov (United States)

    Antipin, D. Ya; Izmerov, O. V.; Bishutin, S. G.; Kobishchanov, V. V.

    2017-10-01

    Questions of possible use of a group drive for locomotives of an open-pit transport are considered. The possibility of a significant reduction of traction costs in the case of a combination of a group traction drive with devices for the non-inertial regulation of the coefficient of friction between the wheel and the rail has been shown, and new patentable solutions have been proposed.

  19. Application of a High-Power Reversible Converter in a Hybrid Traction Power Supply System

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    Gang Zhang

    2017-03-01

    Full Text Available A high-power reversible converter can achieve a variety of functions, such as recovering regenerative braking energy, expanding traction power capacity, and improving an alternating current (AC grid power factor. A new hybrid traction power supply scheme, which consists of a high-power reversible converter and two 12-pulse diode rectifiers, is proposed. A droop control method based on load current feed-forward is adopted to realize the load distribution between the reversible converter and the existing 12-pulse diode rectifiers. The direct current (DC short-circuit characteristics of the reversible converter is studied, then the relationship between the peak fault current and the circuit parameters is obtained from theoretical calculations and validated by computer simulation. The first two sets of 2 MW reversible converters have been successfully applied in Beijing Metro Line 10, the proposed hybrid application scheme and coordinated control strategy are verified, and 11.15% of average energy-savings is reached.

  20. Increase of energy efficiency of testing of traction electric machines of direct and pulsating current

    Directory of Open Access Journals (Sweden)

    A.M. Afanasov

    2015-03-01

    Full Text Available The results of the analysis of the effect of the load current of traction electric machines when tested for heating on the total electricity consumption for the test are presented. It is shown that increase of load current at the heating test permits to significantly reduce the consumption of electrical energy, and reduce the testing time without reducing its quality.

  1. System design of the traction power supply for the high-speed line Beijing - Tianjin

    Energy Technology Data Exchange (ETDEWEB)

    Altmann, Martin; Fischer, Andreas; Tornow, Torsten [Siemens AG, Erlangen (Germany)

    2011-11-15

    The high-speed line Beijing - Tianjin connecting the Capital Beijing with the harbour city Tianjin is the first high-speed line in China dedicated only to passenger traffic and is operated at 300 km/h. The commercial service started in due time for the Olympic games in 2008. For the system design and a reliable traction power supply the simulation software Sitras {sup registered} Sidytrac was used. The program incorporates all modules necessary for the overall system design and relating detailed investigations. Measurements during system integration test validated the simulation results. (orig.)

  2. Sustainability Aspects of Energy Conversion in Modern High-Speed Trains with Traction Induction Motors

    Directory of Open Access Journals (Sweden)

    Marc A. Rosen

    2015-03-01

    Full Text Available Some aspects are illustrated of energy conversion processes during the operation of electric railway vehicles with traction induction motors, in order to support transport systems’ sustainability. Increasing efforts are being expended to enhance the sustainability of transportation technologies and systems. Since electric drive systems are used with variable voltage variable frequency (VVVF inverters and traction induction motors, these machines with appropriate controls can realize both traction and electric braking regimes for electric traction vehicles. In line with this idea, this paper addresses the operation sustainability of electric railway vehicles highlighting the chain of interactions among the main electric equipment on an electrically driven railway system supplied from an a.c. contact line: The contact line-side converter, the machine-side converter and the traction induction motor. The paper supports the findings that electric traction drive systems using induction motors fed by network-side converters and VVVF inverters enhance the sustainable operation of railway trains.

  3. Performance and economic analysis of a plug and play regenerative brake for improving energy efficiency for traction elevators

    Science.gov (United States)

    Jeraputra, Chuttchaval; Tiptipakorn, Supun

    2017-05-01

    This paper presents performance and economic analysis of a plug and play regenerative brake for improving energy efficiency for traction elevators. The proposed regenerative brake recycles the energy loss of a dynamic brake and feeds into the grid while an elevator inverter is operating in the braking mode. According to field measurement of energy consumption, it reveals that the efficiency can be improved as much as 18%. The prototype of a regenerative brake 12 kW, 400V, 3ϕ is developed and tested on an elevator simulator. It is shown that it can transfer energy out of a DC capacitor before the dynamic brake kicks in. Further, an economic analysis is provided to carry out the payback period and the present worth equivalent to confirm economic feasibility.

  4. Footwear traction and lower extremity noncontact injury.

    Science.gov (United States)

    Wannop, John W; Luo, Geng; Stefanyshyn, Darren J

    2013-11-01

    Football is the most popular high school sport; however, it has the highest rate of injury. Speculation has been prevalent that foot fixation due to high footwear traction contributes to injury risk. Therefore, the purpose of the study was to determine whether a relationship exists between the athlete's specific footwear traction (measured with their own shoes on the field of play) and lower extremity noncontact injury in high school football. For 3 yr, 555 high school football athletes had their footwear traction measured on the actual field of play at the start of the season, and any injury the athletes suffered during a game was recorded. Lower extremity noncontact injury rates, grouped based on the athlete's specific footwear traction (both translational and rotational), were compared. For translational traction, injury rate reached a peak of 23.3 injuries/1000 game exposures within the midrange of translational traction, before decreasing to 5.0 injuries/1000 game exposures in the high range of traction. For rotational traction, there was a steady increase in injury rate as footwear traction increased, starting at 4.2 injuries/1000 game exposures at low traction and reaching 19.2 injuries/1000 game exposures at high traction. A relationship exists between footwear traction and noncontact lower extremity injury, with increases in rotational traction leading to a greater injury rate and increases in translational traction leading to a decrease in injury. It is recommended that athletes consider selecting footwear with the lowest rotational traction values for which no detriment in performance results.

  5. Visualizing the interior architecture of focal adhesions with high-resolution traction maps.

    Science.gov (United States)

    Morimatsu, Masatoshi; Mekhdjian, Armen H; Chang, Alice C; Tan, Steven J; Dunn, Alexander R

    2015-04-08

    Focal adhesions (FAs) are micron-sized protein assemblies that coordinate cell adhesion, migration, and mechanotransduction. How the many proteins within FAs are organized into force sensing and transmitting structures is poorly understood. We combined fluorescent molecular tension sensors with super-resolution light microscopy to visualize traction forces within FAs with <100 nm spatial resolution. We find that αvβ3 integrin selectively localizes to high force regions. Paxillin, which is not generally considered to play a direct role in force transmission, shows a higher degree of spatial correlation with force than vinculin, talin, or α-actinin, proteins with hypothesized roles as force transducers. These observations suggest that αvβ3 integrin and paxillin may play important roles in mechanotransduction.

  6. Advanced Integrated Traction System

    Energy Technology Data Exchange (ETDEWEB)

    Greg Smith; Charles Gough

    2011-08-31

    The United States Department of Energy elaborates the compelling need for a commercialized competitively priced electric traction drive system to proliferate the acceptance of HEVs, PHEVs, and FCVs in the market. The desired end result is a technically and commercially verified integrated ETS (Electric Traction System) product design that can be manufactured and distributed through a broad network of competitive suppliers to all auto manufacturers. The objectives of this FCVT program are to develop advanced technologies for an integrated ETS capable of 55kW peak power for 18 seconds and 30kW of continuous power. Additionally, to accommodate a variety of automotive platforms the ETS design should be scalable to 120kW peak power for 18 seconds and 65kW of continuous power. The ETS (exclusive of the DC/DC Converter) is to cost no more than $660 (55kW at $12/kW) to produce in quantities of 100,000 units per year, should have a total weight less than 46kg, and have a volume less than 16 liters. The cost target for the optional Bi-Directional DC/DC Converter is $375. The goal is to achieve these targets with the use of engine coolant at a nominal temperature of 105C. The system efficiency should exceed 90% at 20% of rated torque over 10% to 100% of maximum speed. The nominal operating system voltage is to be 325V, with consideration for higher voltages. This project investigated a wide range of technologies, including ETS topologies, components, and interconnects. Each technology and its validity for automotive use were verified and then these technologies were integrated into a high temperature ETS design that would support a wide variety of applications (fuel cell, hybrids, electrics, and plug-ins). This ETS met all the DOE 2010 objectives of cost, weight, volume and efficiency, and the specific power and power density 2015 objectives. Additionally a bi-directional converter was developed that provides charging and electric power take-off which is the first step

  7. Verification of electricity savings through energy-efficient train management - Energy data base for traction units - Annex 5; Verifizierung der Stromeinsparung durch energieeffizientes Zugsmanagement - Anhang 5: Energiedatenbank Traktion

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, M.; Lerjen, M.; Menth, S. [emkamatik GmbH, Wettingen (Switzerland); Luethi, M. [Swiss Federal Insitute of Technology (ETHZ), Institute for Transport Planning and Systems (IVT), Zuerich (Switzerland); Tuchschmid, M. [SBB AG, BahnUmwelt-Center, 3000 Bern (Switzerland)

    2009-11-15

    This appendix to a final report for the Swiss Federal Office of Energy (SFOE) takes a look at how various data sources on the energy consumption of the SBB's traction units can be combined into an energy-data basis. In this way, the considerable amount of work previously involved in combining and correlating data can be avoided. The aims being followed in the realisation of the traction data base are examined and discussed. The data base will provide the basis for the manual detail analysis of energy consumption within the framework of the overall efforts to save electricity using efficient train management.

  8. Sustainability Aspects of Energy Conversion in Modern High-Speed Trains with Traction Induction Motors

    OpenAIRE

    Marc A. Rosen; Doru A. Nicola; Cornelia A. Bulucea; Daniel C. Cismaru

    2015-01-01

    Some aspects are illustrated of energy conversion processes during the operation of electric railway vehicles with traction induction motors, in order to support transport systems’ sustainability. Increasing efforts are being expended to enhance the sustainability of transportation technologies and systems. Since electric drive systems are used with variable voltage variable frequency (VVVF) inverters and traction induction motors, these machines with appropriate controls can realize both tra...

  9. Multiple incipient sensor faults diagnosis with application to high-speed railway traction devices.

    Science.gov (United States)

    Wu, Yunkai; Jiang, Bin; Lu, Ningyun; Yang, Hao; Zhou, Yang

    2017-03-01

    This paper deals with the problem of incipient fault diagnosis for a class of Lipschitz nonlinear systems with sensor biases and explores further results of total measurable fault information residual (ToMFIR). Firstly, state and output transformations are introduced to transform the original system into two subsystems. The first subsystem is subject to system disturbances and free from sensor faults, while the second subsystem contains sensor faults but without any system disturbances. Sensor faults in the second subsystem are then formed as actuator faults by using a pseudo-actuator based approach. Since the effects of system disturbances on the residual are completely decoupled, multiple incipient sensor faults can be detected by constructing ToMFIR, and the fault detectability condition is then derived for discriminating the detectable incipient sensor faults. Further, a sliding-mode observers (SMOs) based fault isolation scheme is designed to guarantee accurate isolation of multiple sensor faults. Finally, simulation results conducted on a CRH2 high-speed railway traction device are given to demonstrate the effectiveness of the proposed approach. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  10. Counter traction makes endoscopic submucosal dissection easier.

    Science.gov (United States)

    Oyama, Tsuneo

    2012-11-01

    Poor counter traction and poor field of vision make endoscopic submucosal dissection (ESD) difficult. Good counter traction allows dissections to be performed more quickly and safely. Position change, which utilizes gravity, is the simplest method to create a clear field of vision. It is useful especially for esophageal and colon ESD. The second easiest method is clip with line method. Counter traction made by clip with line accomplishes the creation of a clear field of vision and suitable counter traction thereby making ESD more efficient and safe. The author published this method in 2002. The name ESD was not established in those days; the name cutting endoscopic mucosal resection (EMR) or EMR with hook knife was used. The other traction methods such as external grasping forceps, internal traction, double channel scope, and double scopes method are introduced in this paper. A good strategy for creating counter traction makes ESD easier.

  11. High-Force Versus Low-Force Lumbar Traction in Acute Lumbar Sciatica Due to Disc Herniation: A Preliminary Randomized Trial.

    Science.gov (United States)

    Isner-Horobeti, Marie-Eve; Dufour, Stéphane Pascal; Schaeffer, Michael; Sauleau, Erik; Vautravers, Philippe; Lecocq, Jehan; Dupeyron, Arnaud

    This study compared the effects of high-force versus low-force lumbar traction in the treatment of acute lumbar sciatica secondary to disc herniation. A randomized double blind trial was performed, and 17 subjects with acute lumbar sciatica secondary to disc herniation were assigned to high-force traction at 50% body weight (BW; LT50, n = 8) or low force traction at 10% BW (LT10, n = 9) for 10 sessions in 2 weeks. Radicular pain (visual analogue scale [VAS]), lumbo-pelvic-hip complex motion (finger-to-toe test), lumbar-spine mobility (Schöber-Macrae test), nerve root compression (straight-leg-raising test), disability (EIFEL score), drug consumption, and overall evaluation of each patient were measured at days 0, 7, 1, 4, and 28. Significant (P sciatica secondary to disc herniation who received 2 weeks of lumbar traction reported reduced radicular pain and functional impairment and improved well-being regardless of the traction force group to which they were assigned. The effects of the traction treatment were independent of the initial level of medication and appeared to be maintained at the 2-week follow-up. Copyright © 2016. Published by Elsevier Inc.

  12. Open coil traction system.

    Science.gov (United States)

    Vibhute, Pavankumar Janardan

    2012-01-01

    Sliding mechanics have become a popular method for space closure, with the development of preadjusted edgewise appliances. Furthermore, various space closing auxiliaries have been developed and extensively evaluated for their clinical efficiency. Their effectiveness is enhanced with optimum force magnitude and low load deflection rate/force decay. With the advent of nickel-titanium (Ni-Ti) springs in orthodontics, load deflection rates have been markedly reduced. To use Ni-Ti springs, clinicians have to depend upon prefabricated closed coil springs. The open coil traction system, or open coil retraction spring, is developed utilizing Ni-Ti open coil springs for orthodontic space closure. This article describes the fabrication and clinical application of the open coil traction system, which has a number of advantages. It sustains a low load deflection rate with optimum force magnitude, and its design is adjustable for a desired length and force level. It is fail-safe for both activation and deactivation (ie, it cannot be overactivated, and the decompression limit of the open coil is controlled by the operator). The open coil traction system can be offset from the mucosa to help reduce soft tissue impingement.

  13. A Soft-Switching Inverter for High-Temperature Advanced Hybrid Electric Vehicle Traction Motor Drives

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Jason [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Yu, Wensong [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Sun, Pengwei [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Leslie, Scott [Powerex, Inc., Harrison, OH (United States); Prusia, Duane [Powerex, Inc., Harrison, OH (United States); Arnet, Beat [Azure Dynamics, Oak Park, MI (United States); Smith, Chris [Azure Dynamics, Oak Park, MI (United States); Cogan, Art [Azure Dynamics, Oak Park, MI (United States)

    2012-03-31

    The state-of-the-art hybrid electric vehicles (HEVs) require the inverter cooling system to have a separate loop to avoid power semiconductor junction over temperatures because the engine coolant temperature of 105°C does not allow for much temperature rise in silicon devices. The proposed work is to develop an advanced soft-switching inverter that will eliminate the device switching loss and cut down the power loss so that the inverter can operate at high-temperature conditions while operating at high switching frequencies with small current ripple in low inductance based permanent magnet motors. The proposed tasks also include high-temperature packaging and thermal modeling and simulation to ensure the packaged module can operate at the desired temperature. The developed module will be integrated with the motor and vehicle controller for dynamometer and in-vehicle testing to prove its superiority. This report will describe the detailed technical design of the soft-switching inverters and their test results. The experiments were conducted both in module level for the module conduction and switching characteristics and in inverter level for its efficiency under inductive and dynamometer load conditions. The performance will be compared with the DOE original specification.

  14. Measurement of the traction force of biological cells by digital holography

    Science.gov (United States)

    Yu, Xiao; Cross, Michael; Liu, Changgeng; Clark, David C.; Haynie, Donald T.; Kim, Myung K.

    2011-01-01

    The traction force produced by biological cells has been visualized as distortions in flexible substrata. We have utilized quantitative phase microscopy by digital holography (DH-QPM) to study the wrinkling of a silicone rubber film by motile fibroblasts. Surface deformation and the cellular traction force have been measured from phase profiles in a direct and straightforward manner. DH-QPM is shown to provide highly efficient and versatile means for quantitatively analyzing cellular motility. PMID:22254175

  15. Analysis methods of stochastic transient electro–magnetic processes in electric traction system

    Directory of Open Access Journals (Sweden)

    T. M. Mishchenko

    2013-04-01

    Full Text Available Purpose. The essence and basic characteristics of calculation methods of transient electromagnetic processes in the elements and devices of non–linear dynamic electric traction systems taking into account the stochastic changes of voltages and currents in traction networks of power supply subsystem and power circuits of electric rolling stock are developed. Methodology. Classical methods and the methods of non–linear electric engineering, as well as probability theory method, especially the methods of stationary ergodic and non–stationary stochastic processes application are used in the research. Findings. Using the above-mentioned methods an equivalent circuit and the system of nonlinear integra–differential equations for electromagnetic condition of the double–track inter-substation zone of alternating current electric traction system are drawn up. Calculations allow obtaining electric traction current distribution in the areas of feeder zones. Originality. First of all the paper is interesting and important from scientific point of view due to the methods, which allow taking into account probabilistic character of change for traction voltages and electric traction system currents. On the second hand the researches develop the most efficient methods of nonlinear circuits’ analysis. Practical value. The practical value of the research is presented in application of the methods to the analysis of electromagnetic and electric energy processes in the traction power supply system in the case of high-speed train traffic.

  16. Development of low AC loss windings for superconducting traction transformer

    International Nuclear Information System (INIS)

    Kamijo, H; Hata, H; Fukumoto, Y; Tomioka, A; Bohno, T; Yamada, H; Ayai, N; Yamasaki, K; Kato, T; Iwakuma, M; Funaki, K

    2010-01-01

    We have been developing a light weight and high efficiency superconducting traction transformer for railway rolling stock. We designed and fabricated a prototype superconducting traction transformer of a floor-mount type for Shinkansen rolling stock in 2004. We performed the type-test, the system-test, and the vibration-test. Consequently, we could verify that the transformer satisfied the requirement almost exactly as initially planned. However, there have been raised some problems to be solved to put superconducting traction transformer into practical use such that AC loss of the superconducting tape must be lower and the capacity of the refrigerator must be larger. Especially it is the most important to reduce the AC loss of superconducting windings for lightweight and high efficiency. The AC loss must be reduced near the theoretical value of superconducting tape with multifilament. In this study, we fabricated and evaluated the Bi2223 tapes as introduced various measures to reduce the AC loss. We confirmed that the AC loss of the narrow type of Bi2223 tapes with twist of filaments is lower, and we fabricated windings of this tape for use in superconducting traction transformer.

  17. Analysis and Comparison of Modular Railway Power Conditioner for High-Speed Railway Traction System

    DEFF Research Database (Denmark)

    Xu, Qianming; Ma, Fujun; He, Zhixing

    2017-01-01

    , IPOSIM calculation as well as PSIM simulation. These calculations are validated via simulations results in PSIM. The main conclusion is that presented modular RPCs can be divided into general purpose RPC and special purpose RPC in terms of the behavior and efficiency. It is helpful to choose......, voltage stress and current stress of power switch, numbers of the power switches and capacitor are derived by analytical methods. Moreover, the numerical comparison of operating controllers is completed for modular RPCs. In addition, power losses of five modular RPCs are obtained by theoretical analysis...

  18. High voltage traction power supply; Ein- und Mehrspannungssysteme in der Bahnenergieversorgung mit hohen Spannungen

    Energy Technology Data Exchange (ETDEWEB)

    Borchard, Ludwig O. [Transnet freight rail, (Technology Management), Braamfontein (South Africa); Lehmann, Michael [Technische Univ. Dresden (Germany). Professur Elektrische Bahnen

    2009-04-15

    Raising the nominal voltage of electric railway systems implies many advantages, therefore several concepts can be presented and compared. Detailed studies on two systems with high contact line voltages were performed for the upgrade of the 1 AC 50 kV railway line in South Africa. Finally requirements for high voltage locomotives are derived and illustrated by examples. (orig.)

  19. High performance control strategy for single-phase three-level neutral-point-clamped traction four-quadrant converters

    DEFF Research Database (Denmark)

    Kejian, Song; Konstantinou, Georgios; Jing, Li

    2017-01-01

    Operational data from Chinese railways indicate a number of challenges for traction four-quadrant converter (4QC) control including low-order voltage and current harmonics and reference tracking. A control strategy for a single-phase three-level neutral-point-clamped 4QC employed in the electric...

  20. Highly efficient high temperature electrolysis

    DEFF Research Database (Denmark)

    Hauch, Anne; Ebbesen, Sune; Jensen, Søren Højgaard

    2008-01-01

    High temperature electrolysis of water and steam may provide an efficient, cost effective and environmentally friendly production of H-2 Using electricity produced from sustainable, non-fossil energy sources. To achieve cost competitive electrolysis cells that are both high performing i.e. minimum...... internal resistance of the cell, and long-term stable, it is critical to develop electrode materials that are optimal for steam electrolysis. In this article electrolysis cells for electrolysis of water or steam at temperatures above 200 degrees C for production of H-2 are reviewed. High temperature...... electrolysis is favourable from a thermodynamic point of view, because a part of the required energy can be supplied as thermal heat, and the activation barrier is lowered increasing the H-2 production rate. Only two types of cells operating at high temperature (above 200 degrees C) have been described...

  1. HIGH EFFICIENCY TURBINE

    OpenAIRE

    VARMA, VIJAYA KRUSHNA

    2012-01-01

    Varma designed ultra modern and high efficiency turbines which can use gas, steam or fuels as feed to produce electricity or mechanical work for wide range of usages and applications in industries or at work sites. Varma turbine engines can be used in all types of vehicles. These turbines can also be used in aircraft, ships, battle tanks, dredgers, mining equipment, earth moving machines etc, Salient features of Varma Turbines. 1. Varma turbines are simple in design, easy to manufac...

  2. Solid-state transformer-based new traction drive system and control

    Science.gov (United States)

    Feng, Jianghua; Shang, Jing; Zhang, Zhixue; Liu, Huadong; Huang, Zihao

    2017-11-01

    A new type of traction drive system consisting of solid-state traction transformer (SSTT), inverter unit, auxiliary inverter, traction motor and other key components is built in order to suit the demand of developing the next-generation electric traction system which will be efficient and lightweight, with high power density. For the purpose of reducing system volume and weight and improving efficiency and grid-side power quality, an efficient SSTT optimized topology combining high-voltage cascaded rectifiers with high-power high-frequency LLC resonant converter is proposed. On this basis, an integrated control strategy built upon synchronous rotating reference frame is presented to achieve unified control over fundamental active, reactive and harmonic components. The carrier-interleaving phase shift modulation strategy is proposed to improve the harmonic performance of cascaded rectifiers. In view of the secondary pulsating existing in a single-phase system, the mathematical model of secondary power transfer is built, and the mechanism of pulsating voltage resulting in beat frequency of LLC resonant converter is revealed, so as to design optimum matching of system parameters. Simulation and experimental results have verified that the traction system and control scheme mentioned in this paper are reasonable and superior and that they meet the future application requirements for rail transit.

  3. Regression analysis of traction characteristics of traction fluids

    Science.gov (United States)

    Loewenthal, S. H.; Rohn, D. A.

    1983-01-01

    Traction data for Santotrac 50 and TDF-88 over a wide range of operating conditions were analyzed. An eight term correlation equation to predict the maximum traction coefficient and a six term correlation equation to predict the initial slope of the traction curve were developed. The slope correlation was corrected for size effect considering the compliance of the disks. The effects of different operating conditions on the traction performance of each traction fluid were studied. Both fluids exhibited a loss in traction with increases in spin, but the losses with the TDF-88 fluid were not as severe as those with Santotrac 50. Overall, both fluids exhibited similar performance, showing an increase in traction with contact pressure up to about 2.0 GPa, and a reduction in traction with higher surface speeds up to about 100 m/sec. The apparent stiffness of the traction contact, that is, film disk combination, increases with contact pressure and decreases with speed.

  4. The dual-system traction equipment of the high speed train Velaro for Russia; Die Mehrsystemtraktionsausruestung des Hochgeschwindigkeitszuges Velaro fuer Russland

    Energy Technology Data Exchange (ETDEWEB)

    Horstmann, D.; Budzinski, F.; Pirwitz, J. [Siemens AG, Erlangen (Germany)

    2007-07-01

    As from 2009 eight high speed trainsets of the Velaro-family will be delivered to Russia. The ten-car trainsets with distributed traction equipment are intended for service on all high speed lines in Russia, starting with the Moscow - St. Petersburg line. They will be supplied in two variants, single- and dual-system trainsets, so that they are deployable in a broad area. Furthermore the Russian standards and specifics have to be considered. The track gauge in Russia is 1520 mm instead of 1435 mm as common in Europe and the cold and snowy winters require a special ventilation- or cooling system. (orig.)

  5. High-efficiency CARM

    Energy Technology Data Exchange (ETDEWEB)

    Bratman, V.L.; Kol`chugin, B.D.; Samsonov, S.V.; Volkov, A.B. [Institute of Applied Physics, Nizhny Novgorod (Russian Federation)

    1995-12-31

    The Cyclotron Autoresonance Maser (CARM) is a well-known variety of FEMs. Unlike the ubitron in which electrons move in a periodical undulator field, in the CARM the particles move along helical trajectories in a uniform magnetic field. Since it is much simpler to generate strong homogeneous magnetic fields than periodical ones for a relatively low electron energy ({Brit_pounds}{le}1-3 MeV) the period of particles` trajectories in the CARM can be sufficiently smaller than in the undulator in which, moreover, the field decreases rapidly in the transverse direction. In spite of this evident advantage, the number of papers on CARM is an order less than on ubitron, which is apparently caused by the low (not more than 10 %) CARM efficiency in experiments. At the same time, ubitrons operating in two rather complicated regimes-trapping and adiabatic deceleration of particles and combined undulator and reversed guiding fields - yielded efficiencies of 34 % and 27 %, respectively. The aim of this work is to demonstrate that high efficiency can be reached even for a simplest version of the CARM. In order to reduce sensitivity to an axial velocity spread of particles, a short interaction length where electrons underwent only 4-5 cyclotron oscillations was used in this work. Like experiments, a narrow anode outlet of a field-emission electron gun cut out the {open_quotes}most rectilinear{close_quotes} near-axis part of the electron beam. Additionally, magnetic field of a small correcting coil compensated spurious electron oscillations pumped by the anode aperture. A kicker in the form of a sloping to the axis frame with current provided a control value of rotary velocity at a small additional velocity spread. A simple cavity consisting of a cylindrical waveguide section restricted by a cut-off waveguide on the cathode side and by a Bragg reflector on the collector side was used as the CARM-oscillator microwave system.

  6. Traction-related problems after hip arthroscopy

    Science.gov (United States)

    Lund, Bent; Grønbech Nielsen, Torsten; Lind, Martin

    2017-01-01

    Abstract Traction-related problems are poorly described in the existing literature. The purpose of this prospective study was to describe traction-related problems and how patients perceive these problems. The study was a descriptive cohort study and data were collected from questionnaires and patient files. The questionnaire included questions on patients’ perceptions of traction-related problems in the groin area, at the knee and ankle and how patients had coped with these problems. A total of 100 consecutive patients undergoing hip arthroscopy filled out the questionnaire. Primary findings of this study were that 74% of patients reported some sort of traction-related problems after hip arthroscopy. About 32% of the patients had problems in the groin area and 49% of the patients complained of symptoms in the knee joint. A total of 37% of the patients had experienced problems from the traction boot in the ankle area. The complications were found to be temporary and disappeared after 2–4 weeks. Five patients still had complaints after 3 months. All five patients had a pre-existing knee injury prior to undergoing hip arthroscopy. Traction-related problems after hip arthroscopy are a challenge and our study showed that 74% of the patients reported traction-related problems. This is significantly higher than previously reported. The present study found a high rate of complaints from the knee and ankle joints that have not previously been reported. The presented data suggest the need for more pre-surgery patient information about possible traction-related problems. PMID:28630721

  7. Home Cervical Traction to Reduce Neck Pain in Fighter Pilots.

    Science.gov (United States)

    Chumbley, Eric M; O'Hair, Nicole; Stolfi, Adrienne; Lienesch, Christopher; McEachen, James C; Wright, Bruce A

    2016-12-01

    Most fighter pilots report cervical pain during their careers. Recommendations for remediation lack evidence. We sought to determine whether regular use of a home cervical traction device could decrease reported cervical pain in F-15C pilots. An institutional review board-approved, Health Insurance Portability and Accountability Act-compliant, controlled crossover study was undertaken with 21 male F-15C fighter pilots between February and June 2015. Of the 21 subjects, 12 completed 6 wk each of traction and control, while logging morning, postflying, and post-traction pain. Pain was compared with paired t-tests between the periods, from initial pain scores to postflying, and postflying to post-traction. In the traction phase, initial pain levels increased postflight, from 1.2 (0.7) to 1.6 (1.0) Subsequent post-traction pain levels decreased to 1.3 (0.9), with a corresponding linear decrease in pain relative to pain reported postflight. The difference in pain levels after traction compared to initial levels was not significant, indicating that cervical traction was effective in alleviating flying-related pain. Control pain increased postflight from 1.4 (0.9) to 1.9 (1.3). Daily traction phase pain was lower than the control, but insignificant. To our knowledge, this is the first study of home cervical traction to address fighter pilots' cervical pain. We found a small but meaningful improvement in daily pain rating when using cervical traction after flying. These results help inform countermeasure development for pilots flying high-performance aircraft. Further study should clarify the optimal traction dose and timing in relation to flying.Chumbley EM, O'Hair N, Stolfi A, Lienesch C, McEachen JC, Wright BA. Home cervical traction to reduce neck pain in fighter pilots. Aerosp Med Hum Perform. 2016; 87(12):1010-1015.

  8. Mechanical Hybrid KERS Based on Toroidal Traction Drives: An Example of Smart Tribological Design to Improve Terrestrial Vehicle Performance

    Directory of Open Access Journals (Sweden)

    Francesco Bottiglione

    2013-01-01

    Full Text Available We analyse in terms of efficiency and traction capabilities a recently patented traction drive, referred to as the double roller full-toroidal variator (DFTV. We compare its performance with the single roller full-toroidal variator (SFTV and the single roller half-toroidal variator (SHTV. Modeling of these variators involves challenging tribological issues; the traction and efficiency performances depend on tribological phenomena occurring at the interface between rollers and disks, where the lubricant undergoes very severe elastohydrodynamic lubrication regimes. Interestingly, the DFTV shows an improvement of the mechanical efficiency over a wide range of transmission ratios and in particular at the unit speed ratio as in such conditions in which the DFTV allows for zero-spin, thus strongly enhancing its traction capabilities. The very high mechanical efficiency and traction performances of the DFTV are exploited to investigate the performance of a flywheel-based Kinetic Energy Recovery System (KERS, where the efficiency of the variator plays an important role in determining the overall energy recovery performance. The energy boost capabilities and the round-trip efficiency are calculated for the three different variators considered in this study. The results suggest that the energy recovery potential of the mechanical KERS can be improved with a proper choice of the variator.

  9. Assessment of potential energy efficiency improvements in the traction sector of the Swiss Federal Railways; Potentialermittlung Energieeffizienz Traktion bei den SBB - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, M.; Menth, S.; Lerjen, M.

    2007-07-01

    Possibilities to reduce the consumption of 16.7-Hz traction energy of Swiss Federal Railways (SBB) have been investigated. Various proposals have been discussed together with experts of SBB's Passenger, Cargo and Infrastructure divisions. Based on numerical simulations for representative train runs, the total consumption of the SBB network could be calculated and compared with real values. The possible reduction e.g. by energy optimised driving could be derived from this comparison; it is between 3 and 5 % of the specific consumption both for the influence by train driver and by traffic control. Technical measures in traction units and passenger coaches lead to reductions of up to about 3%, depending on the vehicle type. It is important that all measures take into account the extremely dense traffic on SBB's network and do not reduce the attractiveness for the customers. (author)

  10. Elastic model of the traction behavior of two traction lubricants

    Science.gov (United States)

    Loewenthal, S. H.; Rohn, D. A.

    1984-01-01

    In the analysis of rolling-sliding concentrated contacts, such as gears, bearings and traction drives, the traction characteristics of the lubricant are of prime importance. The elastic shear modulus and limiting shear stress properties of the lubricant dictate the traction/slip characteristics and power loss associated with an EHD contact undergoing slip and/or spin. These properties can be deducted directly from the initial slope m and maximum traction coefficient micron of an experimental traction curve. In this investigation, correlation equations are presented to predict m and micron for two modern traction fluids based on the regression analysis of 334 separate traction disk machine experiments. The effects of contact pressure, temperature, surface velocity, ellipticity ratio are examined. Problems in deducing lubricant shear moduli from disk machine tests are discussed. Previously announced in STAR as N83-20116

  11. Operation analysis of AC traction motors in terms of electromagnetic torque capability on sustainable railway vehicles

    OpenAIRE

    Bulucea Cornelia A.; Nicola Doru A.; Rosen Marc A.; Mastorakis Nikos E.; Bulucea Carmen A.

    2016-01-01

    Sustainable operation of electric railway systems represents a significant purpose nowadays in the development of high power and high speed locomotives and trains. At present, high speed electric vehicles mostly work with three-phase induction motors or three-phase synchronous motors as traction motors. The two electric machine types have different efficiencies at different operation points, and experience differences with respect to safety, speed and power, energy use and exergy efficiency. ...

  12. High efficiency positron moderation

    International Nuclear Information System (INIS)

    Taqqu, D.

    1990-01-01

    A new positron moderation scheme is proposed. It makes use of electric and magnetic fields to confine the β + emitted by a radioactive source forcing them to slow down within a thin foil. A specific arrangement is described where an intermediary slowed-down beam of energy below 10 keV is produced. By directing it towards a standard moderator optimal conversion into slow positrons is achieved. This scheme is best applied to short lived β + emitters for which a 25% moderation efficiency can be reached. Within the state of the art technology a slow positron source intensity exceeding 2 x 10 10 e + /sec is achievable. (orig.)

  13. The Simulation of the Traction Drive with Middle-Frequency Transformer

    Directory of Open Access Journals (Sweden)

    Pavel Drabek

    2008-01-01

    Full Text Available This paper presents research motivated by industrial demand for special traction drive topology devoted to minimization of traction transformer weight against topology with classical 50Hz traction transformer. The special traction drive topology for AC power systems consists of input high voltage trolley converter (single phase matrix converter –middle frequency transformer - output converter - traction motor has been described. The main attention has been given tothe control algorithm of the traction topology (inserting of NULL vector of matrix converter and Two-value control ofsecondary active rectifier.

  14. Operation analysis of AC traction motors in terms of electromagnetic torque capability on sustainable railway vehicles

    Directory of Open Access Journals (Sweden)

    Bulucea Cornelia A.

    2016-01-01

    Full Text Available Sustainable operation of electric railway systems represents a significant purpose nowadays in the development of high power and high speed locomotives and trains. At present, high speed electric vehicles mostly work with three-phase induction motors or three-phase synchronous motors as traction motors. The two electric machine types have different efficiencies at different operation points, and experience differences with respect to safety, speed and power, energy use and exergy efficiency. An important issue that correlates these aspects is the electromagnetic torque developed by an electric traction motor. In order to provide an overview of the technical performance of the operation of sustainable railway systems, a detailed analysis is carried out of the electromagnetic torque capability of AC electric motors utilized as traction motors in modern locomotives of high power and/or high speed. The results of this work may help in enhancing the main criteria for optimising the safe and sustainable operation of electric railway traction systems.

  15. INTELLIGENT DIAGNOSTIC SYSTEM OF EMERGENCY SITUATIONS IN TRACTION SUBSTATIONS DC

    Directory of Open Access Journals (Sweden)

    Sh. N. Nasyrov

    2009-09-01

    Full Text Available In the article the architecture and algorithm of operating an expert system providing the efficiency of functioning the electric equipment for traction substation as well as the four-parameter belonging function are determined.

  16. Development of Traction Drive Motors for the Toyota Hybrid System

    Science.gov (United States)

    Kamiya, Munehiro

    Toyota Motor Corporation developed in 2005 a new hybrid system for a large SUV. This system included the new development of a high-speed traction drive motor achieving a significant increase in power weight ratio. This paper provides an overview of the hybrid system, discusses the characteristics required of a traction drive motor, and presents the technologies employed in the developed motor.

  17. New highly efficient piezoceramic materials

    International Nuclear Information System (INIS)

    Dantsiger, A.Ya.; Razumovskaya, O.N.; Reznichenko, L.A.; Grineva, L.D.; Devlikanova, R.U.; Dudkina, S.I.; Gavrilyachenko, S.V.; Dergunova, N.V.

    1993-01-01

    New high efficient piezoceramic materials with various combination of parameters inclusing high Curie point for high-temperature transducers using in atomic power engineering are worked. They can be used in systems for heated matters nondestructive testing, controllers for varied industrial power plants and other high-temperature equipment

  18. A Harmonic Resonance Suppression Strategy for a High-Speed Railway Traction Power Supply System with a SHE-PWM Four-Quadrant Converter Based on Active-Set Secondary Optimization

    Directory of Open Access Journals (Sweden)

    Runze Zhang

    2017-10-01

    Full Text Available Pulse width modulation (PWM technology is widely used in traction converters for high-speed railways. The harmonic distribution caused by PWM is quite extensive, and increases the possibility of grid–train coupling resonance in the traction power supply system (TPSS. This paper first analyzes the mechanism of resonance, when the characteristic harmonic frequency of a four-quadrant converter (4QC current that injects into the traction grid matches the resonant frequency of the traction grid, which may result in resonance in the system. To suppress resonance, this paper adopts specific harmonic elimination–pulse width modulation (SHE-PWM technology combined with a transient direct current control strategy to eliminate the harmonics in the resonant frequency, which may suppress the grid–train coupling resonance. Due to the fact that the SHE-PWM process with multiple switching angles contains complex transcendental equations, the initial value is difficult to provide, and is difficult to solve using ordinary iterative algorithms. In this paper, an active-set secondary optimization method is used to solve the equation. The algorithm has the benefits of low dependence on initial values, fast convergence and high solution accuracy. Finally, the feasibility of the resonant suppression algorithm is verified by means of Matlab simulation.

  19. An advanced pitch change mechanism incorporating a hybrid traction drive

    Science.gov (United States)

    Steinetz, B. M.; Loewenthal, S. H.; Sargisson, D. F.; White, G.

    1984-01-01

    A design of a propeller pitch control mechanism is described that meets the demanding requirements of a high-power, advanced turboprop. In this application, blade twisting moment torque can be comparable to that of the main reduction gearbox output: precise pitch control, reliability and compactness are all at a premium. A key element in the design is a compact, high-ratio hybrid traction drive which offers low torque ripple and high torsional stiffness. The traction drive couples a high speed electric motor/alternator unit to a ball screw that actuates the blade control links. The technical merits of this arrangement and the performance characteristics of the traction drive are discussed.

  20. Traction alopecia: the root of the problem

    Directory of Open Access Journals (Sweden)

    Billero V

    2018-04-01

    Full Text Available Victoria Billero, Mariya MitevaDepartment of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, FL, USAAbstract: Traction alopecia (TA affects one-third of women of African descent who wear various forms of traumatic hairstyling for a prolonged period of time. The risk of TA is increased by the extent of pulling and duration of traction, as well as the use of chemical relaxation. The frequent use of tight buns or ponytails, the attachment of weaves or hair extensions, and tight braids (such as cornrows and dreadlocks are believed to be the highest risk hairstyles. TA can also occur in the setting of religious and occupational traumatic hairstyling. In its later stages, the disease may progress into an irreversible scarring alopecia if traumatic hairstyling continues without appropriate intervention. The most common clinical presentation includes marginal alopecia and non-marginal patchy alopecia. A clue to the clinical diagnosis is the preservation of the fringe sign as opposed to its loss in frontal fibrosing alopecia (FFA. Dermoscopy can be helpful in the diagnosis and can detect the ongoing traction by the presence of hair casts. Histopathology can distinguish TA from alopecia areata, FFA, and patchy central centrifugal cicatricial alopecia. Currently, there is no cure. Therefore, it is imperative that clinicians educate high-risk populations about TA and those practices that may convey the risk of hair loss. Keywords: hair loss, alopecia, dermoscopy, trichoscopy, traction alopecia, African-American 

  1. FreedomCAR Advanced Traction Drive Motor Development Phase I

    Energy Technology Data Exchange (ETDEWEB)

    Ley, Josh (UQM Technologies, Inc.); Lutz, Jon (UQM Technologies, Inc.)

    2006-09-01

    The overall objective of this program is to design and develop an advanced traction motor that will meet the FreedomCAR and Vehicle Technologies (FCVT) 2010 goals and the traction motor technical targets. The motor specifications are given in Section 1.3. Other goals of the program include providing a cost study to ensure the motor can be developed within the cost targets needed for the automotive industry. The program has focused on using materials that are both high performance and low costs such that the performance can be met and cost targets are achieved. In addition, the motor technologies and machine design features must be compatible with high volume manufacturing and able to provide high reliability, efficiency, and ruggedness while simultaneously reducing weight and volume. Weight and volume reduction will become a major factor in reducing cost, material cost being the most significant part of manufacturing cost at high volume. Many motor technology categories have been considered in the past and present for traction drive applications, including: brushed direct current (DC), PM (PM) brushless dc (BLDC), alternating current (AC) induction, switched reluctance and synchronous reluctance machines. Of these machine technologies, PM BLDC has consistently demonstrated an advantage in terms of power density and efficiency. As rare earth magnet cost has declined, total cost may also be reduced over the other technologies. Of the many different configurations of PM BLDC machines, those which incorporate power production utilizing both magnetic torque as well as reluctance torque appear to have the most promise for traction applications. There are many different PM BLDC machine configurations which employ both of these torque producing mechanisms; however, most would fall into one of two categories--some use weaker magnets and rely more heavily on reluctance torque (reluctance-dominant PM machines), others use strong PMs and supplement with reluctance torque

  2. The selection of the traction system based on the energy efficiency for vehicles of heavy service; La seleccion del tren motriz basada en la eficiencia energetica para vehiculos de servicio pesado

    Energy Technology Data Exchange (ETDEWEB)

    Rafael Morales, M.Y [Instituto Mexicano del Transporte, (Mexico); Cervantes de Gortari, J [Departamento de termoenergia, Facultad de ingenieria, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2004-01-15

    Transportation activities in Mexico, especially in heavy-duty vehicles, are affected by the low efficiency in fuel consumption. In spite of the advanced technology in energy efficiency that generally is being adopted and used in the Mexican cargo fleet, there is not a significant reduction in the operation costs of this very important economic activity. In this paper, an account about the influence that the selection of the traction system components has on the fuel consumption and the ascending capacity of the vehicle, is presented. As a result of the study, an algorithm based on real performance tests with optimal fuel economy, was developed. The program is useful for the selection of the most appropriate traction system of a given vehicle, taking into account the condition that has to fulfill for a give task. [Spanish] Entre los problemas que afectan a la economia del sector de autotransporte en Mexico, especialmente en el transporte destinado al servicio pesado, se encuentra el de baja eficiencia en el consumo de combustible. A pesar de la avanzada tecnologia que generalmente se va disponiendo y adoptando en el parque vehicular con relacion a la eficiencia energetica, el costo por toneladas transportada no ha disminuido de manera importante. En este trabajo, se presenta un estudio acerca de la influencia que tiene dentro de esta problematica la seleccion de los componentes del tren motriz en el consumo de combustible y en la capacidad de ascenso del vehiculo, en relacion con el peso de la carga transportada. Como resultado del estudio se desarrollo un algoritmo basado en las pruebas reales de desempeno a que puede someterse un vehiculo, buscando el regimen optimo de economia del combustible. El programa permite a las empresas de transporte, seleccionar el tren motriz mas adecuado para cada vehiculo teniendo en cuenta las operaciones a que debera sujetarse en un determinado servicio.

  3. Selection of the traction based on the power efficiency for vehicles of heavy service; La seleccion del tren motriz basada en la eficiencia energetica para vehiculos de servicio pesado

    Energy Technology Data Exchange (ETDEWEB)

    Morales, Rafael [Instituto Mexicano del Transporte, (Mexico); Cervantes de Gortari, J. [Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico (UNAM), Mexico, D.F. (Mexico)

    2004-03-01

    Transportation activities in Mexico, especially in heavy-duty vehicles, are affected by the low efficiency in fuel consumption, in spite of the advanced technology in energy efficiency that generally is being adopted and used in the Mexican cargo fleet, there is not a significant reduction in the operation costs of this very important economic activity. In this paper, an account about the influence that the selection of the traction system components has on the fuel consumption and the ascending capacity of the vehicle, is presented. As a result of the study, an algorithm based on real performance tests with optimal fuel economy, was developed. The program is useful for the selection of the most appropriate traction system of a given vehicle, taking into account the condition that has to fulfill for a given task. [Spanish] Entre los problemas que afectan a la economia del sector de autotransporte en Mexico, especialmente en el transporte destinado al servicio pesado, se encuentra el de baja eficiencia en el consumo de combustible. A pesar de la avanzada tecnologia que generalmente se va disponiendo y adoptando en el parque vehicular con relacion a la eficiencia energetica, el costo por tonelada transportada no ha disminuido de manera importante. En este trabajo, se presenta un estudio acerca de la influencia que tiene dentro de esta problematica la seleccion de los componentes del tren motriz en el consumo de combustible y en la capacidad de ascenso del vehiculo, en relacion con el peso de la carga transportada. Como resultado del estudio se desarrollo un algoritmo basado en las pruebas reales de desempeno a que puede someterse un vehiculo, buscando el regimen optimo de economia del combustible. El programa permite a las empresas de transporte, seleccionar el tren motriz mas adecuado para cada vehiculo teniendo en cuenta las operaciones a que debera sujetarse en un determinado servicio.

  4. Unconventional, High-Efficiency Propulsors

    DEFF Research Database (Denmark)

    Andersen, Poul

    1996-01-01

    The development of ship propellers has generally been characterized by search for propellers with as high efficiency as possible and at the same time low noise and vibration levels and little or no cavitation. This search has lead to unconventional propulsors, like vane-wheel propulsors, contra-r...

  5. Integrated Cooling System for Induction Motor Traction Drives, CARAT Program Phase Two Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Konrad, Charles E. [VPT, Inc., Blacksburg, VA (United States)

    2002-12-03

    This Program is directed toward improvements in electric vehicle/hybrid electric vehicle traction systems, and in particular, the development of a low cost, highly efficient, compact traction motor-controller system targeted for high volume automotive use. Because of the complex inter-relationships between the motor and the controller, the combination of motor and controller must be considered as a system in the design and evaluation of overall cost and performance. The induction motor is ideally suited for use as a traction motor because of its basic ruggedness, low cost, and high efficiency. As one can see in Figure 1.1, the induction motor traction drive has been continually evolving through a succession of programs spanning the past fifteen years. VPT marketed an induction motor-based traction drive system, the EV2000, which proved to be a reliable, high performance system that was used in a wide range of vehicles. The EV2000 drives evolved from the Modular Electric Vehicle Program (MEVP) and has been used in vehicles ranging in size from 3,000 lb. autos and utility vans, to 32,000 lb. city transit buses. Vehicles powered by the EV2000 induction motor powertrain have accumulated over 2 million miles of service. The EV2000 induction motor system represents 1993 state-of-the-art technology, and evolved from earlier induction motor programs that drove induction motor speeds up to 15,000 rpm to reduce the motor size and cost. It was recognized that the improvements in power density and motor cost sought in the PNGV program could only be achieved through increases in motor speed. Esson’s Rule for motor power clearly states that the power obtainable from a given motor design is the product of motor speed and volume. In order to meet the CARAT Program objectives, the maximum speed goal of the induction motor designed in this Program was increased from 15,000 rpm to 20,000 rpm while maintaining the efficiency and durability demonstrated by lower speed designs done in

  6. Integrated Traction Control Strategy for Distributed Drive Electric Vehicles with Improvement of Economy and Longitudinal Driving Stability

    Directory of Open Access Journals (Sweden)

    Xudong Zhang

    2017-01-01

    Full Text Available This paper presents an integrated traction control strategy (ITCS for distributed drive electric vehicles. The purpose of the proposed strategy is to improve vehicle economy and longitudinal driving stability. On high adhesion roads, economy optimization algorithm is applied to maximize motors efficiency by means of the optimized torque distribution. On low adhesion roads, a sliding mode control (SMC algorithm is implemented to guarantee the wheel slip ratio around the optimal slip ratio point to make full use of road adhesion capacity. In order to avoid the disturbance on slip ratio calculation due to the low vehicle speed, wheel rotational speed is taken as the control variable. Since the optimal slip ratio varies according to different road conditions, Bayesian hypothesis selection is utilized to estimate the road friction coefficient. Additionally, the ITCS is designed for combining the vehicle economy and stability control through three traction allocation cases: economy-based traction allocation, pedal self-correcting traction allocation and inter-axles traction allocation. Finally, simulations are conducted in CarSim and Matlab/Simulink environment. The results show that the proposed strategy effectively reduces vehicle energy consumption, suppresses wheels-skid and enhances the vehicle longitudinal stability and dynamic performance.

  7. Overview of Ecological Agriculture with High Efficiency

    OpenAIRE

    Huang, Guo-qin; Zhao, Qi-guo; Gong, Shao-lin; Shi, Qing-hua

    2012-01-01

    From the presentation, connotation, characteristics, principles, pattern, and technologies of ecological agriculture with high efficiency, we conduct comprehensive and systematic analysis and discussion of the theoretical and practical progress of ecological agriculture with high efficiency. (i) Ecological agriculture with high efficiency was first advanced in China in 1991. (ii) Ecological agriculture with high efficiency highlights "high efficiency", "ecology", and "combination". (iii) Ecol...

  8. Orthodontic Traction of Impacted Canine Using Cantilever

    Directory of Open Access Journals (Sweden)

    Cláudia Nakandakari

    2016-01-01

    Full Text Available The impaction of the maxillary canines causes relevant aesthetic and functional problems. The multidisciplinary approach to the proper planning and execution of orthodontic traction of the element in question is essential. Many strategies are cited in the literature; among them is the good biomechanical control in order to avoid possible side effects. The aim of this paper is to present a case report in which a superior canine impacted by palatine was pulled out with the aid of the cantilever on the Segmented Arch Technique (SAT concept. A 14.7-year-old female patient appeared at clinic complaining about the absence of the upper right permanent canine. The proposed treatment prioritized the traction of the upper right canine without changing the occlusion and aesthetics. For this, it only installed the upper fixed appliance (Roth with slot 0.018, opting for SAT in order to minimize unwanted side effects. The use of cantilever to the traction of the upper right canine has enabled an efficient and predictable outcome, because it is of statically determined mechanics.

  9. High-power, high-efficiency FELs

    International Nuclear Information System (INIS)

    Sessler, A.M.

    1989-04-01

    High power, high efficiency FELs require tapering, as the particles loose energy, so as to maintain resonance between the electromagnetic wave and the particles. They also require focusing of the particles (usually done with curved pole faces) and focusing of the electromagnetic wave (i.e. optical guiding). In addition, one must avoid transverse beam instabilities (primarily resistive wall) and longitudinal instabilities (i.e sidebands). 18 refs., 7 figs., 3 tabs

  10. Advanced state prediction of lithium-ion traction batteries in hybrid and battery electric vehicle applications

    Energy Technology Data Exchange (ETDEWEB)

    Jadidi, Yasser

    2011-07-01

    Automotive power trains with high energy efficiencies - particularly to be found in battery and hybrid electric vehicles - find increasing attention in the focus of reduction of exhaust emissions and increase of mileage. The underlying concept, the electrification of the power train, is subject to the traction battery and its battery management system since the capability of the battery permits and restricts electric propulsion. Consequently, the overall vehicle efficiency and in particular the operation strategy performance strongly depends on the quality of information about the battery. Besides battery technology, the key challenges are given by both the accurate prediction of battery behaviour and the electrochemical battery degradation that leads to power and capacity fade of the traction battery. This book provides the methodology for development of a battery state monitoring and prediction algorithm for application in a battery management system that accounts for the effects of electrochemical degradation. (orig.)

  11. High Efficiency Room Air Conditioner

    Energy Technology Data Exchange (ETDEWEB)

    Bansal, Pradeep [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-01-01

    This project was undertaken as a CRADA project between UT-Battelle and Geberal Electric Company and was funded by Department of Energy to design and develop of a high efficiency room air conditioner. A number of novel elements were investigated to improve the energy efficiency of a state-of-the-art WAC with base capacity of 10,000 BTU/h. One of the major modifications was made by downgrading its capacity from 10,000 BTU/hr to 8,000 BTU/hr by replacing the original compressor with a lower capacity (8,000 BTU/hr) but high efficiency compressor having an EER of 9.7 as compared with 9.3 of the original compressor. However, all heat exchangers from the original unit were retained to provide higher EER. The other subsequent major modifications included- (i) the AC fan motor was replaced by a brushless high efficiency ECM motor along with its fan housing, (ii) the capillary tube was replaced with a needle valve to better control the refrigerant flow and refrigerant set points, and (iii) the unit was tested with a drop-in environmentally friendly binary mixture of R32 (90% molar concentration)/R125 (10% molar concentration). The WAC was tested in the environmental chambers at ORNL as per the design rating conditions of AHAM/ASHRAE (Outdoor- 95F and 40%RH, Indoor- 80F, 51.5%RH). All these modifications resulted in enhancing the EER of the WAC by up to 25%.

  12. High-efficient electron linacs

    International Nuclear Information System (INIS)

    Glavatskikh, K.V.; Zverev, B.V.; Kalyuzhnyj, V.E.; Morozov, V.L.; Nikolaev, S.V.; Plotnikov, S.N.; Sobenin, N.P.; Vovna, V.A.; Gryzlov, A.V.

    1993-01-01

    Comparison analysis of ELA on running and still waves designed for 10 MeV energy and with high efficiency is carried out. It is shown, that from the point of view of dimensions ELA with a still wave or that of a combined type is more preferable. From the point of view of impedance characteristics in any variant with application of magnetron as HF-generator it is necessary to implement special requirements to the accelerating structure if no ferrite isolation is provided in HF-channel. 3 refs., 4 figs., 1 tab

  13. Traction alopecia: the root of the problem.

    Science.gov (United States)

    Billero, Victoria; Miteva, Mariya

    2018-01-01

    Traction alopecia (TA) affects one-third of women of African descent who wear various forms of traumatic hairstyling for a prolonged period of time. The risk of TA is increased by the extent of pulling and duration of traction, as well as the use of chemical relaxation. The frequent use of tight buns or ponytails, the attachment of weaves or hair extensions, and tight braids (such as cornrows and dreadlocks) are believed to be the highest risk hairstyles. TA can also occur in the setting of religious and occupational traumatic hairstyling. In its later stages, the disease may progress into an irreversible scarring alopecia if traumatic hairstyling continues without appropriate intervention. The most common clinical presentation includes marginal alopecia and non-marginal patchy alopecia. A clue to the clinical diagnosis is the preservation of the fringe sign as opposed to its loss in frontal fibrosing alopecia (FFA). Dermoscopy can be helpful in the diagnosis and can detect the ongoing traction by the presence of hair casts. Histopathology can distinguish TA from alopecia areata, FFA, and patchy central centrifugal cicatricial alopecia. Currently, there is no cure. Therefore, it is imperative that clinicians educate high-risk populations about TA and those practices that may convey the risk of hair loss.

  14. High-efficiency photovoltaic cells

    Science.gov (United States)

    Yang, H.T.; Zehr, S.W.

    1982-06-21

    High efficiency solar converters comprised of a two cell, non-lattice matched, monolithic stacked semiconductor configuration using optimum pairs of cells having bandgaps in the range 1.6 to 1.7 eV and 0.95 to 1.1 eV, and a method of fabrication thereof, are disclosed. The high band gap subcells are fabricated using metal organic chemical vapor deposition (MOCVD), liquid phase epitaxy (LPE) or molecular beam epitaxy (MBE) to produce the required AlGaAs layers of optimized composition, thickness and doping to produce high performance, heteroface homojunction devices. The low bandgap subcells are similarly fabricated from AlGa(As)Sb compositions by LPE, MBE or MOCVD. These subcells are then coupled to form a monolithic structure by an appropriate bonding technique which also forms the required transparent intercell ohmic contact (IOC) between the two subcells. Improved ohmic contacts to the high bandgap semiconductor structure can be formed by vacuum evaporating to suitable metal or semiconductor materials which react during laser annealing to form a low bandgap semiconductor which provides a low contact resistance structure.

  15. DEFINITION OF LOCOMOTIVE TRACTION FORCE WITH REGARD TO UNEVEN LOADING OF WHEEL-MOTOR BLOCK

    Directory of Open Access Journals (Sweden)

    B. Ye. Bodnar

    2013-11-01

    Full Text Available Purpose. The article describes the most common methods for determining the locomotive traction force. Solving the tasks of traction calculations involves determination of the forces influencing the train at every point of the way. When choosing a rational trajectory of the train motion and the development of operational regulations of train driving it is necessary to determine the actual value of the locomotive traction force. Considering various factors, power value of traction electric motor of locomotive may have significant differences. Advancement of the operational definition system of the locomotive traction force during the calculations by electrical parameters of traction electric motor with regard to uneven load of wheel-motor block is the purpose of the article. Methodology. The method of determining the traction force of locomotives and diesel locomotives with electric transmission, which is based on primary data acquisition of traction electric engines of direct current behavior, was proposed. Sensors and their integration into the electrical circuitry of the locomotive in order to get the data in digital form and for operational calculation of the each traction motor mode and the definition of locomotive traction force are presented. Findings. The experimental investigation of the system of locomotive traction force determination with the electric traction motor ED-105 was offered. A comparison of electrical and mechanical power of the electric motor was conducted. Originality. The system of locomotives power operational definition, which takes into account the variable electro-mechanical factors of wheel and motor blocks and increases the accuracy of the calculations, was proposed. Practical value. The system is a part of an onboard complex in definition of energy-efficient regimes for trains movement and provides the definition of accelerating and decelerating forces.

  16. Syntegra: complete integration of traction, bogie and brake systems

    Energy Technology Data Exchange (ETDEWEB)

    Loewenstein, L.; Wangelin, F. von [Siemens AG, Transportation Systems, Erlangen (Germany). Group Technology TS GT; Teichmann, M.; Hoffmann, T. [Siemens TS, Graz (Austria); Joeckel, A. [Siemens Automation and Drives, Nuernberg (Germany)

    2007-07-01

    With Syntegra {sup registered} technology, Siemens has developed an approach to the complete integration of traction, bogie and brake systems, and this has initially been put into practice for metro, underground and S-Bahn (urban regional express) trains. Syntegra constitutes a fundamentally new approach, achieving a greater intensity of integration compared with the types of drive system that have been in use up until now. With Syntegra, the bogie, transmission and brake components are all brought together as part of one and the same system. The integration and, more especially, the technological advances within the three named areas bring about numerous synergies. The new generation of powered bogie features a combination of high efficiency, low dead weight and reduced emissions. A Syntegra drive system achieves a performance which is markedly better than that of conventional systems. (orig.)

  17. Traction force dynamics predict gap formation in activated endothelium

    Energy Technology Data Exchange (ETDEWEB)

    Valent, Erik T.; Nieuw Amerongen, Geerten P. van; Hinsbergh, Victor W.M. van; Hordijk, Peter L., E-mail: p.hordijk@vumc.nl

    2016-09-10

    In many pathological conditions the endothelium becomes activated and dysfunctional, resulting in hyperpermeability and plasma leakage. No specific therapies are available yet to control endothelial barrier function, which is regulated by inter-endothelial junctions and the generation of acto-myosin-based contractile forces in the context of cell-cell and cell-matrix interactions. However, the spatiotemporal distribution and stimulus-induced reorganization of these integral forces remain largely unknown. Traction force microscopy of human endothelial monolayers was used to visualize contractile forces in resting cells and during thrombin-induced hyperpermeability. Simultaneously, information about endothelial monolayer integrity, adherens junctions and cytoskeletal proteins (F-actin) were captured. This revealed a heterogeneous distribution of traction forces, with nuclear areas showing lower and cell-cell junctions higher traction forces than the whole-monolayer average. Moreover, junctional forces were asymmetrically distributed among neighboring cells. Force vector orientation analysis showed a good correlation with the alignment of F-actin and revealed contractile forces in newly formed filopodia and lamellipodia-like protrusions within the monolayer. Finally, unstable areas, showing high force fluctuations within the monolayer were prone to form inter-endothelial gaps upon stimulation with thrombin. To conclude, contractile traction forces are heterogeneously distributed within endothelial monolayers and force instability, rather than force magnitude, predicts the stimulus-induced formation of intercellular gaps. - Highlights: • Endothelial monolayers exert dynamic- and heterogeneous traction forces. • High traction forces correlate with junctional areas and the F-actin cytoskeleton. • Newly formed inter-endothelial gaps are characterized by opposing traction forces. • Force stability is a key feature controlling endothelial permeability.

  18. Traction force dynamics predict gap formation in activated endothelium

    International Nuclear Information System (INIS)

    Valent, Erik T.; Nieuw Amerongen, Geerten P. van; Hinsbergh, Victor W.M. van; Hordijk, Peter L.

    2016-01-01

    In many pathological conditions the endothelium becomes activated and dysfunctional, resulting in hyperpermeability and plasma leakage. No specific therapies are available yet to control endothelial barrier function, which is regulated by inter-endothelial junctions and the generation of acto-myosin-based contractile forces in the context of cell-cell and cell-matrix interactions. However, the spatiotemporal distribution and stimulus-induced reorganization of these integral forces remain largely unknown. Traction force microscopy of human endothelial monolayers was used to visualize contractile forces in resting cells and during thrombin-induced hyperpermeability. Simultaneously, information about endothelial monolayer integrity, adherens junctions and cytoskeletal proteins (F-actin) were captured. This revealed a heterogeneous distribution of traction forces, with nuclear areas showing lower and cell-cell junctions higher traction forces than the whole-monolayer average. Moreover, junctional forces were asymmetrically distributed among neighboring cells. Force vector orientation analysis showed a good correlation with the alignment of F-actin and revealed contractile forces in newly formed filopodia and lamellipodia-like protrusions within the monolayer. Finally, unstable areas, showing high force fluctuations within the monolayer were prone to form inter-endothelial gaps upon stimulation with thrombin. To conclude, contractile traction forces are heterogeneously distributed within endothelial monolayers and force instability, rather than force magnitude, predicts the stimulus-induced formation of intercellular gaps. - Highlights: • Endothelial monolayers exert dynamic- and heterogeneous traction forces. • High traction forces correlate with junctional areas and the F-actin cytoskeleton. • Newly formed inter-endothelial gaps are characterized by opposing traction forces. • Force stability is a key feature controlling endothelial permeability.

  19. Energy and wear optimisation of train longitudinal dynamics and of traction and braking systems

    Science.gov (United States)

    Conti, R.; Galardi, E.; Meli, E.; Nocciolini, D.; Pugi, L.; Rindi, A.

    2015-05-01

    Traction and braking systems deeply affect longitudinal train dynamics, especially when an extensive blending phase among different pneumatic, electric and magnetic devices is required. The energy and wear optimisation of longitudinal vehicle dynamics has a crucial economic impact and involves several engineering problems such as wear of braking friction components, energy efficiency, thermal load on components, level of safety under degraded or adhesion conditions (often constrained by the current regulation in force on signalling or other safety-related subsystem). In fact, the application of energy storage systems can lead to an efficiency improvement of at least 10% while, as regards the wear reduction, the improvement due to distributed traction systems and to optimised traction devices can be quantified in about 50%. In this work, an innovative integrated procedure is proposed by the authors to optimise longitudinal train dynamics and traction and braking manoeuvres in terms of both energy and wear. The new approach has been applied to existing test cases and validated with experimental data provided by Breda and, for some components and their homologation process, the results of experimental activities derive from cooperation performed with relevant industrial partners such as Trenitalia and Italcertifer. In particular, simulation results are referred to the simulation tests performed on a high-speed train (Ansaldo Breda Emu V250) and on a tram (Ansaldo Breda Sirio Tram). The proposed approach is based on a modular simulation platform in which the sub-models corresponding to different subsystems can be easily customised, depending on the considered application, on the availability of technical data and on the homologation process of different components.

  20. Towards highly efficient water photoelectrolysis

    Science.gov (United States)

    Elavambedu Prakasam, Haripriya

    ethylene glycol resulted in remarkable growth characteristics of titania nanotube arrays, hexagonal closed packed up to 1 mm in length, with tube aspect ratios of approximately 10,000. For the first time, complete anodization of the starting titanium foil has been demonstrated resulting in back to back nanotube array membranes ranging from 360 mum--1 mm in length. The nanotubes exhibited growth rates of up to 15 mum/hr. A detailed study on the factors affecting the growth rate and nanotube dimensions is presented. It is suggested that faster high field ionic conduction through a thinner barrier layer is responsible for the higher growth rates observed in electrolytes containing ethylene glycol. Methods to fabricate free standing, titania nanotube array membranes ranging in thickness from 50 microm--1000 mum has also been an outcome of this dissertation. In an effort to combine the charge transport properties of titania with the light absorption properties of iron (III) oxide, films comprised of vertically oriented Ti-Fe-O nanotube arrays on FTO coated glass substrates have been successfully synthesized in ethylene glycol electrolytes. Depending upon the Fe content the bandgap of the resulting films varied from about 3.26 to 2.17 eV. The Ti-Fe oxide nanotube array films demonstrated a photocurrent of 2 mA/cm2 under global AM 1.5 illumination with a 1.2% (two-electrode) photoconversion efficiency, demonstrating a sustained, time-energy normalized hydrogen evolution rate by water splitting of 7.1 mL/W·hr in a 1 M KOH solution with a platinum counter electrode under an applied bias of 0.7 V. The Ti-Fe-O material architecture demonstrates properties useful for hydrogen generation by water photoelectrolysis and, more importantly, this dissertation demonstrates that the general nanotube-array synthesis technique can be extended to other ternary oxide compositions of interest for water photoelectrolysis.

  1. HIGH-EFFICIENCY INFRARED RECEIVER

    Directory of Open Access Journals (Sweden)

    A. K. Esman

    2016-01-01

    Full Text Available Recent research and development show promising use of high-performance solid-state receivers of the electromagnetic radiation. These receivers are based on the low-barrier Schottky diodes. The approach to the design of the receivers on the basis of delta-doped low-barrier Schottky diodes with beam leads without bias is especially actively developing because for uncooled receivers of the microwave radiation these diodes have virtually no competition. The purpose of this work is to improve the main parameters and characteristics that determine the practical relevance of the receivers of mid-infrared electromagnetic radiation at the operating room temperature by modifying the electrodes configuration of the diode and optimizing the distance between them. Proposed original design solution of the integrated receiver of mid-infrared radiation on the basis of the low-barrier Schottky diodes with beam leads allows to effectively adjust its main parameters and characteristics. Simulation of the electromagnetic characteristics of the proposed receiver by using the software package HFSS with the basic algorithm of a finite element method which implemented to calculate the behavior of electromagnetic fields on an arbitrary geometry with a predetermined material properties have shown that when the inner parts of the electrodes of the low-barrier Schottky diode is performed in the concentric elliptical convex-concave shape, it can be reduce the reflection losses to -57.75 dB and the standing wave ratio to 1.003 while increasing the directivity up to 23 at a wavelength of 6.09 μm. At this time, the rounded radii of the inner parts of the anode and cathode electrodes are equal 212 nm and 318 nm respectively and the gap setting between them is 106 nm. These parameters will improve the efficiency of the developed infrared optical-promising and electronic equipment for various purposes intended for work in the mid-infrared wavelength range. 

  2. High-efficiency wind turbine

    Science.gov (United States)

    Hein, L. A.; Myers, W. N.

    1980-01-01

    Vertical axis wind turbine incorporates several unique features to extract more energy from wind increasing efficiency 20% over conventional propeller driven units. System also features devices that utilize solar energy or chimney effluents during periods of no wind.

  3. High efficiency, long life terrestrial solar panel

    Science.gov (United States)

    Chao, T.; Khemthong, S.; Ling, R.; Olah, S.

    1977-01-01

    The design of a high efficiency, long life terrestrial module was completed. It utilized 256 rectangular, high efficiency solar cells to achieve high packing density and electrical output. Tooling for the fabrication of solar cells was in house and evaluation of the cell performance was begun. Based on the power output analysis, the goal of a 13% efficiency module was achievable.

  4. High efficiency turbine blade coatings

    Energy Technology Data Exchange (ETDEWEB)

    Youchison, Dennis L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gallis, Michail A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-06-01

    The development of advanced thermal barrier coatings (TBCs) of yttria stabilized zirconia (YSZ) that exhibit lower thermal conductivity through better control of electron beam - physical vapor deposition (EB-PVD) processing is of prime interest to both the aerospace and power industries. This report summarizes the work performed under a two-year Lab-Directed Research and Development (LDRD) project (38664) to produce lower thermal conductivity, graded-layer thermal barrier coatings for turbine blades in an effort to increase the efficiency of high temperature gas turbines. This project was sponsored by the Nuclear Fuel Cycle Investment Area. Therefore, particular importance was given to the processing of the large blades required for industrial gas turbines proposed for use in the Brayton cycle of nuclear plants powered by high temperature gas-cooled reactors (HTGRs). During this modest (~1 full-time equivalent (FTE)) project, the processing technology was developed to create graded TBCs by coupling ion beam-assisted deposition (IBAD) with substrate pivoting in the alumina-YSZ system. The Electron Beam - 1200 kW (EB-1200) PVD system was used to deposit a variety of TBC coatings with micron layered microstructures and reduced thermal conductivity below 1.5 W/m.K. The use of IBAD produced fully stoichiometric coatings at a reduced substrate temperature of 600°C and a reduced oxygen background pressure of 0.1 Pa. IBAD was also used to successfully demonstrate the transitioning of amorphous PVD-deposited alumina to the -phase alumina required as an oxygen diffusion barrier and for good adhesion to the substrate Ni2Al3 bondcoat. This process replaces the time consuming thermally grown oxide formation required before the YSZ deposition. In addition to the process technology, Direct Simulation Monte Carlo plume modeling and spectroscopic characterization of the PVD plumes were performed. The project consisted of five tasks. These included the

  5. Traction for low-back pain with or without sciatica.

    Science.gov (United States)

    Wegner, Inge; Widyahening, Indah S; van Tulder, Maurits W; Blomberg, Stefan E I; de Vet, Henrica Cw; Brønfort, Gert; Bouter, Lex M; van der Heijden, Geert J

    2013-08-19

    physiotherapy alone or when comparing traction with other treatments, there was very-low- to moderate-quality evidence that traction may make little or no difference in pain intensity, functional status or global improvement.For people with LBP with sciatica and acute, subacute or chronic pain, there was low- to moderate-quality evidence that traction probably has no impact on pain intensity, functional status or global improvement. This was true when traction was compared with controls and other treatments, as well as when the combination of traction plus physiotherapy was compared with physiotherapy alone. No studies reported the effect of traction on return to work.For chronic LBP without sciatica, there was moderate-quality evidence that traction probably makes little or no difference in pain intensity when compared with sham treatment. No studies reported on the effect of traction on functional status, global improvement or return to work.Adverse effects were reported in seven of the 32 studies. These included increased pain, aggravation of neurological signs and subsequent surgery. Four studies reported that there were no adverse effects. The remaining studies did not mention adverse effects. These findings indicate that traction, either alone or in combination with other treatments, has little or no impact on pain intensity, functional status, global improvement and return to work among people with LBP. There is only limited-quality evidence from studies with small sample sizes and moderate to high risk of bias. The effects shown by these studies are small and are not clinically relevant. Implications for practice To date, the use of traction as treatment for non-specific LBP cannot be motivated by the best available evidence. These conclusions are applicable to both manual and mechanical traction. Implications for research Only new, large, high-quality studies may change the point estimate and its accuracy, but it should be noted that such change may not necessarily

  6. Plica neuropathica causing traction alopecia

    Directory of Open Access Journals (Sweden)

    K Pavithran

    1990-01-01

    Full Text Available A middle aged woman developed matting of the hairs of the scalp following use of a home made shampoo that contained leaves of Hibiscus rosasiensis. The entangled and matted hair mass in the occipital region pulled hairs of the vertex region of the scalp, resulting in a patch of traction alopecia. Release of tension on the hairs by cutting them with scissors prevented further extension of alopecia.

  7. Integrated traction control strategy for distributed drive electric vehicles with improvement of economy and longitudinal driving stability

    OpenAIRE

    Zhang, Xudong; Göhlich, Dietmar

    2017-01-01

    This paper presents an integrated traction control strategy (ITCS) for distributed drive electric vehicles. The purpose of the proposed strategy is to improve vehicle economy and longitudinal driving stability. On high adhesion roads, economy optimization algorithm is applied to maximize motors efficiency by means of the optimized torque distribution. On low adhesion roads, a sliding mode control (SMC) algorithm is implemented to guarantee the wheel slip ratio around the optimal slip ratio po...

  8. Maximum Safety Regenerative Power Tracking for DC Traction Power Systems

    Directory of Open Access Journals (Sweden)

    Guifu Du

    2017-02-01

    Full Text Available Direct current (DC traction power systems are widely used in metro transport systems, with running rails usually being used as return conductors. When traction current flows through the running rails, a potential voltage known as “rail potential” is generated between the rails and ground. Currently, abnormal rises of rail potential exist in many railway lines during the operation of railway systems. Excessively high rail potentials pose a threat to human life and to devices connected to the rails. In this paper, the effect of regenerative power distribution on rail potential is analyzed. Maximum safety regenerative power tracking is proposed for the control of maximum absolute rail potential and energy consumption during the operation of DC traction power systems. The dwell time of multiple trains at each station and the trigger voltage of the regenerative energy absorbing device (READ are optimized based on an improved particle swarm optimization (PSO algorithm to manage the distribution of regenerative power. In this way, the maximum absolute rail potential and energy consumption of DC traction power systems can be reduced. The operation data of Guangzhou Metro Line 2 are used in the simulations, and the results show that the scheme can reduce the maximum absolute rail potential and energy consumption effectively and guarantee the safety in energy saving of DC traction power systems.

  9. High efficiency motor selection handbook

    Science.gov (United States)

    McCoy, Gilbert A.; Litman, Todd; Douglass, John G.

    1990-10-01

    Substantial reductions in energy and operational costs can be achieved through the use of energy-efficient electric motors. A handbook was compiled to help industry identify opportunities for cost-effective application of these motors. It covers the economic and operational factors to be considered when motor purchase decisions are being made. Its audience includes plant managers, plant engineers, and others interested in energy management or preventative maintenance programs.

  10. The Harmonoise/IMAGINE model for traction noise of powered railway vehicles

    NARCIS (Netherlands)

    Dittrich, M.G.; Zhang, X.

    2006-01-01

    Traction noise is one of the noise sources of powered railway vehicles such as locomotives, electric- and diesel-powered multiple unit trains and high-speed trains. Especially at speeds below 60 km/h and at idling, but also at acceleration conditions for a wide range of speeds, traction noise can be

  11. [Assessment of rehabilitation progress in patients with cervical radicular pain syndrome after application of high intensity laser therapy - HILT and Saunders traction device].

    Science.gov (United States)

    Haładaj, Robert; Pingot, Julia; Pingot, Mariusz

    2015-07-01

    Osteoarthritis of the spine is a major global health problem, it is an epidemic of our times. It affects all parts of the spine, but the hardest to treat is its cervical region. The cervical spine is most mobile, delicate and sensitive to any load. It requires special care in conservative treatment. To date the selection of effective therapeutic approaches has been controversial. The aim of the study was to assess the progress of rehabilitation in patients with cervical radicular pain syndrome after using two different methods of treatment: HILT and spinal axial traction with the use of Saunders device. The randomized study included 150 patients (81 women and 69 men, aged 24-67 years, mean age 45.5) divided into two groups of 75 patients each with characteristic symptoms of radicular pain. The measurement of the range of cervical spine movement of the cervical spine, visual analog scale for pain - VAS and a NDI questionnaire (Neck Disability Index - Polish version) - an indicator of functional disorders - were used to evaluate the effectiveness of the two different therapies. The results obtained by Saunders method remained significantly higher than those obtained when HILT laser therapy was used for most of the examined parameters. A thorough analysis of the results showed greater analgesic efficacy, improved global mobility and reduced functional impairment in patients treated with Saunders method. Both therapeutic methods manifest analgesic effect and a positive impact on the improvement of range of cervical spine movement in patients with radicular pain in this spine region. HILT laser therapy and Saunders traction device reduce neck disability index in the treated patients. © 2015 MEDPRESS.

  12. Highly efficient and compact bidirectional charger for E-mobility; Hoch effizientes und kompaktes bidirektionales Ladegeraet fuer die Elektromobilitaet

    Energy Technology Data Exchange (ETDEWEB)

    Burger, Bruno; Goeldi, Benriah; Reichert, Stefan; Schoenberger, Stefan [Fraunhofer Institut fuer Solare Energiesysteme ISE, Freiburg (Germany)

    2011-07-01

    The increasing number of battery driven electric vehicles requires a wide range of charging possibilities. The key component for charging the battery is a charger in the car (on-board) or stationary - integrated in a charging station. The charging device connects the high voltage traction battery with the low voltage grid. Different technical approaches and different aspects have to be considered. A basic choice has to be made between an on-board or a stationary charging device and also whether to use a galvanic isolation or not. Within the Fraunhofer joint research project FSEM a transformerless, three-phase charger with highest efficiency and high power density was developed. (orig.)

  13. Counter Traction Makes Endoscopic Submucosal Dissection Easier

    OpenAIRE

    Oyama, Tsuneo

    2012-01-01

    Poor counter traction and poor field of vision make endoscopic submucosal dissection (ESD) difficult. Good counter traction allows dissections to be performed more quickly and safely. Position change, which utilizes gravity, is the simplest method to create a clear field of vision. It is useful especially for esophageal and colon ESD. The second easiest method is clip with line method. Counter traction made by clip with line accomplishes the creation of a clear field of vision and suitable co...

  14. Traction Control System for Motorcycles

    Directory of Open Access Journals (Sweden)

    Cardinale Pascal

    2009-01-01

    Full Text Available Traction control is a widely used control system to increase stability and safety of four wheel vehicles. Automatic stability control is used in the BMW K1200R motorcycle and in motoGP competition, but not in other motorcycles. This paper presents an algorithm and a low-cost real-time hardware implementation for motorcycles. A prototype has been developed, applied on a commercial motorcycle, and tested in a real track. The control system that can be tuned by the driver during the race has been appreciated by the test driver.

  15. High efficiency focus neutron generator

    Science.gov (United States)

    Sadeghi, H.; Amrollahi, R.; Zare, M.; Fazelpour, S.

    2017-12-01

    In the present paper, the new idea to increase the neutron yield of plasma focus devices is investigated and the results are presented. Based on many studies, more than 90% of neutrons in plasma focus devices were produced by beam target interactions and only 10% of them were due to thermonuclear reactions. While propounding the new idea, the number of collisions between deuteron ions and deuterium gas atoms were increased remarkably well. The COMSOL Multiphysics 5.2 was used to study the given idea in the known 28 plasma focus devices. In this circumstance, the neutron yield of this system was also obtained and reported. Finally, it was found that in the ENEA device with 1 Hz working frequency, 1.1 × 109 and 1.1 × 1011 neutrons per second were produced by D-D and D-T reactions, respectively. In addition, in the NX2 device with 16 Hz working frequency, 1.34 × 1010 and 1.34 × 1012 neutrons per second were produced by D-D and D-T reactions, respectively. The results show that with regards to the sizes and energy of these devices, they can be used as the efficient neutron generators.

  16. Influences of Traction Load Shock on Artificial Partial Discharge Faults within Traction Transformer—Experimental Test for Pattern Recognition

    Directory of Open Access Journals (Sweden)

    Shuaibing Li

    2017-10-01

    Full Text Available Partial discharge (PD measurement and its pattern recognition are vital to fault diagnosis of transformers, especially to those traction substation transformers undergoing repetitive traction load shocks. This paper presents the primary factors induced by traction load shocks including high total harmonics distortion (THD, transient voltage impulse and high-temperature rise, and their effects on the feature parameters of PD. Experimental tests are conducted on six artificial PD models with these factors introduced one by one. Results reveal that the maximum PD quantity and the PD repetitive rate are favorable to be enlarged when the oil temperature exceeds 80 °C or the THD is higher than 16% with certain orders of harmonic. The decline in PD inception voltage can mainly be attributed to the transient voltage impulse. The variation in central frequency of the fast Fourier transformation (FFT spectra transformed from ultra-high frequency signals can mainly be attributed to high THD, especially when it exceeds 20%. The temperature rise has no significant influence on the FFT spectra; the transient voltage impulse, however, can result in a central frequency shift of the floating particle discharge. With the rapid development of high-speed railways, the study presented in this paper will be helpful for field PD detection and recognition of traction substation transformers in the future.

  17. Advanced dc-Traction-Motor Control System

    Science.gov (United States)

    Vittone, O.

    1985-01-01

    Motor-control concept for battery-powered vehicles includes stateof-the-art power-transistor switching and separate excitation of motor windings in traction and regenerative braking. Switching transistors and other components of power-conditioning subsystem operate under control of computer that coordinates traction, braking, and protective functions.

  18. Elastohydrodynamic Traction Properties of Seed Oils

    Science.gov (United States)

    The elastohydrodynamic traction coefficient (tc) properties of nine seed oils of varying chemical structures, PAO and hexadecane, were investigated using a ball-on disk traction apparatus. The seed oils were: castor oil, a triglyceride with hydroxyl functional group; jojoba, a monoglyceride; and s...

  19. Elastohydrodynamic (EHD) traction properties of seed oils

    Science.gov (United States)

    The elastohydrodynamic traction coefficient (tc) properties of nine seed oils of varying chemical structures, PAO and hexadecane, were investigated using a ball-on disk traction apparatus. The seed oils were: castor oil, a triglyceride with hydroxyl functional group; jojoba, a monoglyceride; and sev...

  20. Relação cinemática em um trator 4x2 com tração dianteira auxiliar equipado com pneus radiais na eficiência de tração Kinematic relation on radial tires in a front wheel assist tractor on traction efficience

    Directory of Open Access Journals (Sweden)

    Mauro Fernando Ferreira

    2000-12-01

    Full Text Available Diferentes combinações de pressões internas dos pneus do trator pode afetar a interferência entre eixos motrizes dos tratores agrícolas, principalmente com pneus do tipo radial. Um trator 4x2 com tração dianteira auxiliar foi analisado quanto a seu desempenho em tração. Pneus de carcaça radial com diferentes pressões internas foram utilizados, com o objetivo de variar as relações cinemá ticas entre os eixos. Mediram-se o patinamento das rodas dianteiras e traseiras, a resistência ao rolamento e a força de tração, em duas condições de solo (firme e solto. Os resultados obtidos permitiram verificar que a eficiência de tração não foi significativamente influenciada pela variação das relações cinemáticas de 0,962 a 1,102. As máximas eficiências de tração ocorreram com relaçõ es cinemáticas variáveis dentro da faixa estudada e de acordo com as cargas impostas à barra de tração.Different combinations of tractor tire inflating pressure may affect interference between tractor axles, mainly with radial tires type. A front wheel assist tractor was studied in its traction performance. Radial tires with different inflation pressure were used, changing kinematic relations between axles. The measured parameters were: front and rear slip, rolling resistence and drawbar pull in two soil conditions (firm and loose. The results indicate that traction efficience was not significantly influenced by kinematic relations variation between 0.962 to 1.102. The maximum traction efficiency ocurred within the range studied and according to drawbar pull.

  1. Critical study of high efficiency deep grinding

    OpenAIRE

    Johnstone, lain

    2002-01-01

    The recent years, the aerospace industry in particular has embraced and actively pursued the development of stronger high performance materials, namely nickel based superalloys and hardwearing steels. This has resulted in a need for a more efficient method of machining, and this need was answered with the advent of High Efficiency Deep Grinding (HEDG). This relatively new process using Cubic Boron Nitride (CBN) electroplated grinding wheels has been investigated through experim...

  2. An assessment of available measures to reduce traction energy use in railway networks

    International Nuclear Information System (INIS)

    Douglas, Heather; Roberts, Clive; Hillmansen, Stuart; Schmid, Felix

    2015-01-01

    Highlights: • Railway networks are defined in terms of their distinguishing features. • Current energy saving measures are reviewed and categorised by the energy use they target. • The achievable energy savings of different measures are compared dependent on the network type. • The success of a measure depends on the characteristics of the network, vehicle and service. • Measures should be evaluated at system level due to interdependencies. - Abstract: Rail is becoming an increasingly popular choice to satisfy transportation demands locally, nationally and internationally, due to its inherent efficiency and high capacity. Despite this, operators are facing pressure to reduce rail energy consumption to meet efficiency targets, whilst still maintaining service quality and managing increased demand. A number of individual measures have been proposed to reduce energy in the rail sector, often showing good results on specific case studies. It is generally agreed that the attainable savings of a given measure change dependant on the route, vehicle and service characteristics. However, there is little information in the literature specifically regarding which measures are most suitable for given network types, or how they interact. This paper therefore aims to begin evaluating the available measures in terms of their suitability for different systems. Firstly, networks are defined in terms of their distinguishing features. As traction accounts for the majority of all energy use in the rail sector, the traction flow through a vehicle is considered as the starting point for an evaluation of measures. Current technologies and procedures are reviewed and categorised based on which area of traction use they target. Thought is given to the factors that affect implementation and the networks where they are applied. A key output of this paper is a comparison of the achievable energy savings of different measures dependent on the network type. It is hoped that this will

  3. Posture manipulation for rescue activity via small traction robots

    International Nuclear Information System (INIS)

    Iwano, Yuki; Osuka, Koichi; Amano, Hisanori

    2006-01-01

    We discuss a conceptual design of rescue robots against nuclear-power plant accidents. We claim that the rescue robots in nuclear-power plants should have the following properties. (1) The size is small. (2) The structure is simple. (3) The number of the robots is large. This paper studies the rescue robots to rescue people in an area polluted with radioactive leakage in nuclear power institutions. In particular, we propose a rescue system which consists of a group of small mobile robots. First, small traction robots set the posture of the fainted victims to carry easily, and carry them to the safety space with the mobile robots for the stretcher composition. In this paper, we describe the produced small traction robots. And, we confirm that the robots can manipulate a 40 kg dummy doll's posture. We also examine the optimal number of robots from a perspective of working efficiency in the assumption spot. (author)

  4. Traction-related problems after hip arthroscopy

    DEFF Research Database (Denmark)

    Frandsen, Lone; Lund, Bent; Grønbech Nielsen, Torsten

    2017-01-01

    . The questionnaire included questions on patients' perceptions of traction-related problems in the groin area, at the knee and ankle and how patients had coped with these problems. A total of 100 consecutive patients undergoing hip arthroscopy filled out the questionnaire. Primary findings of this study were that 74......% of patients reported some sort of traction-related problems after hip arthroscopy. About 32% of the patients had problems in the groin area and 49% of the patients complained of symptoms in the knee joint. A total of 37% of the patients had experienced problems from the traction boot in the ankle area....... The complications were found to be temporary and disappeared after 2-4 weeks. Five patients still had complaints after 3 months. All five patients had a pre-existing knee injury prior to undergoing hip arthroscopy. Traction-related problems after hip arthroscopy are a challenge and our study showed that 74...

  5. Progress of OLED devices with high efficiency at high luminance

    Science.gov (United States)

    Nguyen, Carmen; Ingram, Grayson; Lu, Zhenghong

    2014-03-01

    Organic light emitting diodes (OLEDs) have progressed significantly over the last two decades. For years, OLEDs have been promoted as the next generation technology for flat panel displays and solid-state lighting due to their potential for high energy efficiency and dynamic range of colors. Although high efficiency can readily be obtained at low brightness levels, a significant decline at high brightness is commonly observed. In this report, we will review various strategies for achieving highly efficient phosphorescent OLED devices at high luminance. Specifically, we will provide details regarding the performance and general working principles behind each strategy. We will conclude by looking at how some of these strategies can be combined to produce high efficiency white OLEDs at high brightness.

  6. Research of the multipolar induction traction frequency regulated motor

    Directory of Open Access Journals (Sweden)

    V. Ia. Bespalov

    2014-01-01

    Full Text Available The paper considers the application features of traction induction electric motors in transmissions of vehicles. It shows that one of important stages in their designing is to choose the number of poles. In traction electric drives engines with the raised number of poles without comprehensive assessment of such solution are often applied. The paper investigates dynamic and power characteristics of the multi-polar traction asynchronous engine (TAE designed and made for using in the individual electric drive of heavy-load wheeled cars. The basic functional elements of the model to simulate the electric drive in Matlab environment with the Simulink and SimPower Systems applications in the structure with vector control are described, and the simulation modeling results of its dynamic mechanical characteristics are provided. It is established that because of increased alternating frequency of currents of the multi-polar engine in the range of high speeds there is an excessive decrease in the torque and the requirement for constancy of the target capacity, corresponding to the specified traction characteristic is not fulfilled. It is a consequence of the waveform distortion of engine phase current in the range of high speeds because of incapability of the power source to compensate an increasing EMF of movement as the speed continues to grow.The paper studies the influence of increased current frequencies on the additional losses in the engine. The analysis of electromagnetic field penetration depth in the copper conductor of stator winding at high frequency allowed us to establish a significant skin – effect. The quantitative assessment is given to this phenomenon by results of numerical calculation of electromagnetic field distribution in a stator groove. Significant increase in additional losses in the engine is established, and estimates of flow loss extent because of damping actions of eddy currents in the laminated steel of stator at

  7. 3D Viscoelastic Traction Force Microscopy

    Science.gov (United States)

    Toyjanova, Jennet; Hannen, Erin; Bar-Kochba, Eyal; Darling, Eric M.; Henann, David L.; Franck, Christian

    2014-01-01

    Native cell-material interactions occur on materials differing in their structural composition, chemistry, and physical compliance. While the last two decades have shown the importance of traction forces during cell-material interactions, they have been almost exclusively presented on purely elastic in-vitro materials. Yet, most bodily tissue materials exhibit some level of viscoelasticity, which could play an important role in how cells sense and transduce tractions. To expand the realm of cell traction measurements and to encompass all materials from elastic to viscoelastic, this paper presents a general, and comprehensive approach for quantifying 3D cell tractions in viscoelastic materials. This methodology includes the experimental characterization of the time-dependent material properties for any viscoelastic material with the subsequent mathematical implementation of the determined material model into a 3D traction force microscopy (3D TFM) framework. Utilizing this new 3D viscoelastic TFM (3D VTFM) approach, we quantify the influence of viscosity on the overall material traction calculations and quantify the error associated with omitting time-dependent material effects, as is the case for all other TFM formulations. We anticipate that the 3D VTFM technique will open up new avenues of cell-material investigations on even more physiologically relevant time-dependent materials including collagen and fibrin gels. PMID:25170569

  8. Measure Guideline. High Efficiency Natural Gas Furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Brand, L. [Partnership for Advanced Residential Retrofit (PARR), Des Plaines, IL (United States); Rose, W. [Partnership for Advanced Residential Retrofit (PARR), Des Plaines, IL (United States)

    2012-10-01

    This measure guideline covers installation of high-efficiency gas furnaces, including: when to install a high-efficiency gas furnace as a retrofit measure; how to identify and address risks; and the steps to be used in the selection and installation process. The guideline is written for Building America practitioners and HVAC contractors and installers. It includes a compilation of information provided by manufacturers, researchers, and the Department of Energy as well as recent research results from the Partnership for Advanced Residential Retrofit (PARR) Building America team.

  9. Measure Guideline: High Efficiency Natural Gas Furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Brand, L.; Rose, W.

    2012-10-01

    This Measure Guideline covers installation of high-efficiency gas furnaces. Topics covered include when to install a high-efficiency gas furnace as a retrofit measure, how to identify and address risks, and the steps to be used in the selection and installation process. The guideline is written for Building America practitioners and HVAC contractors and installers. It includes a compilation of information provided by manufacturers, researchers, and the Department of Energy as well as recent research results from the Partnership for Advanced Residential Retrofit (PARR) Building America team.

  10. Experiments on high efficiency aerosol filtration

    International Nuclear Information System (INIS)

    Mazzini, M.; Cuccuru, A.; Kunz, P.

    1977-01-01

    Research on high efficiency aerosol filtration by the Nuclear Engineering Institute of Pisa University and by CAMEN in collaboration with CNEN is outlined. HEPA filter efficiency was studied as a function of the type and size of the test aerosol, and as a function of flowrate (+-50% of the nominal value), air temperature (up to 70 0 C), relative humidity (up to 100%), and durability in a corrosive atmosphere (up to 140 hours in NaCl mist). In the selected experimental conditions these influences were appreciable but are not sufficient to be significant in industrial HEPA filter applications. Planned future research is outlined: measurement of the efficiency of two HEPA filters in series using a fixed particle size; dependence of the efficiency on air, temperatures up to 300-500 0 C; performance when subject to smoke from burning organic materials (natural rubber, neoprene, miscellaneous plastics). Such studies are relevant to possible accidental fires in a plutonium laboratory

  11. High efficiency, variable geometry, centrifugal cryogenic pump

    International Nuclear Information System (INIS)

    Forsha, M.D.; Nichols, K.E.; Beale, C.A.

    1994-01-01

    A centrifugal cryogenic pump has been developed which has a basic design that is rugged and reliable with variable speed and variable geometry features that achieve high pump efficiency over a wide range of head-flow conditions. The pump uses a sealless design and rolling element bearings to achieve high reliability and the ruggedness to withstand liquid-vapor slugging. The pump can meet a wide range of variable head, off-design flow requirements and maintain design point efficiency by adjusting the pump speed. The pump also has features that allow the impeller and diffuser blade heights to be adjusted. The adjustable height blades were intended to enhance the pump efficiency when it is operating at constant head, off-design flow rates. For small pumps, the adjustable height blades are not recommended. For larger pumps, they could provide off-design efficiency improvements. This pump was developed for supercritical helium service, but the design is well suited to any cryogenic application where high efficiency is required over a wide range of head-flow conditions

  12. Saving energy via high-efficiency fans.

    Science.gov (United States)

    Heine, Thomas

    2016-08-01

    Thomas Heine, sales and market manager for EC Upgrades, the retrofit arm of global provider of air movement solutions, ebm-papst A&NZ, discusses the retrofitting of high-efficiency fans to existing HVAC equipment to 'drastically reduce energy consumption'.

  13. High Efficiency Reversible Fuel Cell Power Converter

    DEFF Research Database (Denmark)

    Pittini, Riccardo

    as well as different dc-ac and dc-dc converter topologies are presented and analyzed. A new ac-dc topology for high efficiency data center applications is proposed and an efficiency characterization based on the fuel cell stack I-V characteristic curve is presented. The second part discusses the main...... converter components. Wide bandgap power semiconductors are introduced due to their superior performance in comparison to traditional silicon power devices. The analysis presents a study based on switching loss measurements performed on Si IGBTs, SiC JFETs, SiC MOSFETs and their respective gate drivers...

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

    DEFF Research Database (Denmark)

    Nymand, Morten

    The topic of this thesis is the design of high efficiency power electronic dc-to-dc converters for high-power, low-input-voltage to high-output-voltage applications. These converters are increasingly required for emerging sustainable energy systems such as fuel cell, battery or photo voltaic based......, and remote power generation for light towers, camper vans, boats, beacons, and buoys etc. A review of current state-of-the-art is presented. The best performing converters achieve moderately high peak efficiencies at high input voltage and medium power level. However, system dimensioning and cost are often...

  15. High Efficiency Centrifugal Compressor for Rotorcraft Applications

    Science.gov (United States)

    Medic, Gorazd; Sharma, Om P.; Jongwook, Joo; Hardin, Larry W.; McCormick, Duane C.; Cousins, William T.; Lurie, Elizabeth A.; Shabbir, Aamir; Holley, Brian M.; Van Slooten, Paul R.

    2017-01-01

    A centrifugal compressor research effort conducted by United Technologies Research Center under NASA Research Announcement NNC08CB03C is documented. The objectives were to identify key technical barriers to advancing the aerodynamic performance of high-efficiency, high work factor, compact centrifugal compressor aft-stages for turboshaft engines; to acquire measurements needed to overcome the technical barriers and inform future designs; to design, fabricate, and test a new research compressor in which to acquire the requisite flow field data. A new High-Efficiency Centrifugal Compressor stage -- splittered impeller, splittered diffuser, 90 degree bend, and exit guide vanes -- with aerodynamically aggressive performance and configuration (compactness) goals were designed, fabricated, and subquently tested at the NASA Glenn Research Center.

  16. High-Temperature High-Efficiency Solar Thermoelectric Generators

    Energy Technology Data Exchange (ETDEWEB)

    Baranowski, LL; Warren, EL; Toberer, ES

    2014-03-01

    Inspired by recent high-efficiency thermoelectric modules, we consider thermoelectrics for terrestrial applications in concentrated solar thermoelectric generators (STEGs). The STEG is modeled as two subsystems: a TEG, and a solar absorber that efficiently captures the concentrated sunlight and limits radiative losses from the system. The TEG subsystem is modeled using thermoelectric compatibility theory; this model does not constrain the material properties to be constant with temperature. Considering a three-stage TEG based on current record modules, this model suggests that 18% efficiency could be experimentally expected with a temperature gradient of 1000A degrees C to 100A degrees C. Achieving 15% overall STEG efficiency thus requires an absorber efficiency above 85%, and we consider two methods to achieve this: solar-selective absorbers and thermally insulating cavities. When the TEG and absorber subsystem models are combined, we expect that the STEG modeled here could achieve 15% efficiency with optical concentration between 250 and 300 suns.

  17. High efficiency and broadband acoustic diodes

    Science.gov (United States)

    Fu, Congyi; Wang, Bohan; Zhao, Tianfei; Chen, C. Q.

    2018-01-01

    Energy transmission efficiency and working bandwidth are the two major factors limiting the application of current acoustic diodes (ADs). This letter presents a design of high efficiency and broadband acoustic diodes composed of a nonlinear frequency converter and a linear wave filter. The converter consists of two masses connected by a bilinear spring with asymmetric tension and compression stiffness. The wave filter is a linear mass-spring lattice (sonic crystal). Both numerical simulation and experiment show that the energy transmission efficiency of the acoustic diode can be improved by as much as two orders of magnitude, reaching about 61%. Moreover, the primary working band width of the AD is about two times of the cut-off frequency of the sonic crystal filter. The cut-off frequency dependent working band of the AD implies that the developed AD can be scaled up or down from macro-scale to micro- and nano-scale.

  18. Complexity-aware high efficiency video coding

    CERN Document Server

    Correa, Guilherme; Agostini, Luciano; Cruz, Luis A da Silva

    2016-01-01

    This book discusses computational complexity of High Efficiency Video Coding (HEVC) encoders with coverage extending from the analysis of HEVC compression efficiency and computational complexity to the reduction and scaling of its encoding complexity. After an introduction to the topic and a review of the state-of-the-art research in the field, the authors provide a detailed analysis of the HEVC encoding tools compression efficiency and computational complexity.  Readers will benefit from a set of algorithms for scaling the computational complexity of HEVC encoders, all of which take advantage from the flexibility of the frame partitioning structures allowed by the standard.  The authors also provide a set of early termination methods based on data mining and machine learning techniques, which are able to reduce the computational complexity required to find the best frame partitioning structures. The applicability of the proposed methods is finally exemplified with an encoding time control system that emplo...

  19. High Efficiency, Low Emission Refrigeration System

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, Brian A [ORNL; Sharma, Vishaldeep [ORNL

    2016-08-01

    Supermarket refrigeration systems account for approximately 50% of supermarket energy use, placing this class of equipment among the highest energy consumers in the commercial building domain. In addition, the commonly used refrigeration system in supermarket applications is the multiplex direct expansion (DX) system, which is prone to refrigerant leaks due to its long lengths of refrigerant piping. This leakage reduces the efficiency of the system and increases the impact of the system on the environment. The high Global Warming Potential (GWP) of the hydrofluorocarbon (HFC) refrigerants commonly used in these systems, coupled with the large refrigerant charge and the high refrigerant leakage rates leads to significant direct emissions of greenhouse gases into the atmosphere. Methods for reducing refrigerant leakage and energy consumption are available, but underutilized. Further work needs to be done to reduce costs of advanced system designs to improve market utilization. In addition, refrigeration system retrofits that result in reduced energy consumption are needed since the majority of applications address retrofits rather than new stores. The retrofit market is also of most concern since it involves large-volume refrigerant systems with high leak rates. Finally, alternative refrigerants for new and retrofit applications are needed to reduce emissions and reduce the impact on the environment. The objective of this Collaborative Research and Development Agreement (CRADA) between the Oak Ridge National Laboratory and Hill Phoenix is to develop a supermarket refrigeration system that reduces greenhouse gas emissions and has 25 to 30 percent lower energy consumption than existing systems. The outcomes of this project will include the design of a low emission, high efficiency commercial refrigeration system suitable for use in current U.S. supermarkets. In addition, a prototype low emission, high efficiency supermarket refrigeration system will be produced for

  20. Smart Battery Thermal Management for PHEV Efficiency Une gestion avancée de la thermique de la batterie basse tension de traction pour optimiser l’efficacité d’un véhicule hybride électrique rechargeable

    Directory of Open Access Journals (Sweden)

    Lefebvre L.

    2013-03-01

    Full Text Available A smart battery thermal management is crucial for vehicle performances and battery lifetime targets achievements when electric and plug-in hybrid electric vehicles are concerned. The thermal system needs to be designed and tuned in accordance and compromises with powertrain and vehicle requirements, battery pack architecture, environmental constraints, costs, weight, etc., in a process that will be described in the first part of this paper. Among the portfolio of battery thermal management technologies, these items will be illustrated by two examples: thermal management by cabin air and by refrigerant in a direct cooling, enlightening a decision process. A simplified battery thermo-electric simulation model, which the second part of our work focuses on, has been built, first for both thermal and energetic balance dimensioning of the battery thermal management system. Examples are given on these two perspectives. That simplified simulation model has also identified some promising thermal management strategies for improving vehicle efficiency and performances and battery lifetime. That is the task of the last part of this paper. Battery heating has shown opportunities for improving energy and power availability at cold conditions and, thus, electric drive availability and autonomy. Post-cooling the battery at the end of a journey and its pre-conditioning before the following journey, not only improve vehicle efficiency, electric drive availability and autonomy, but also enhance battery lifetime and compromises with cabin thermal comfort. Others promising strategies optimizing the relation between vehicle performances and battery lifetime are still under investigations. L’atteinte des performances et des prestations requises d’un véhicule électrique ou hybride électrique rechargeable nécessite un thermomanagement intelligent de la batterie basse tension de traction. Ce thermomanagement est incontournable pour respecter dans le même temps

  1. High efficiency novel window air conditioner

    International Nuclear Information System (INIS)

    Bansal, Pradeep

    2015-01-01

    Highlights: • Use of novel refrigerant mixture of R32/R125 (85/15% molar conc.) to reduce global warming and improve energy efficiency. • Use of novel features such as electronically commuted motor (ECM) fan motor, slinger and sub-merged sub-cooler. • Energy savings of up to 0.1 Quads per year in USA and much more in Asia/Middle East where WACs are used in large numbers. • Payback period of only 1.4 years of the novel efficient WAC. - Abstract: This paper presents the results of an experimental and analytical evaluation of measures to raise the efficiency of window air conditioners (WAC). In order to achieve a higher energy efficiency ratio (EER), the original capacity of a baseline R410A unit was reduced by replacing the original compressor with a lower capacity but higher EER compressor, while all heat exchangers and the chassis from the original unit were retained. Subsequent major modifications included – replacing the alternating current fan motor with a brushless high efficiency electronically commutated motor (ECM) motor, replacing the capillary tube with a needle valve to better control the refrigerant flow and refrigerant set points, and replacing R410A with a ‘drop-in’ lower global warming potential (GWP) binary mixture of R32/R125 (85/15% molar concentration). All these modifications resulted in significant enhancement in the EER of the baseline WAC. Further, an economic analysis of the new WAC revealed an encouraging payback period

  2. High efficiency carbon nanotube thread antennas

    Science.gov (United States)

    Amram Bengio, E.; Senic, Damir; Taylor, Lauren W.; Tsentalovich, Dmitri E.; Chen, Peiyu; Holloway, Christopher L.; Babakhani, Aydin; Long, Christian J.; Novotny, David R.; Booth, James C.; Orloff, Nathan D.; Pasquali, Matteo

    2017-10-01

    Although previous research has explored the underlying theory of high-frequency behavior of carbon nanotubes (CNTs) and CNT bundles for antennas, there is a gap in the literature for direct experimental measurements of radiation efficiency. These measurements are crucial for any practical application of CNT materials in wireless communication. In this letter, we report a measurement technique to accurately characterize the radiation efficiency of λ/4 monopole antennas made from the CNT thread. We measure the highest absolute values of radiation efficiency for CNT antennas of any type, matching that of copper wire. To capture the weight savings, we propose a specific radiation efficiency metric and show that these CNT antennas exceed copper's performance by over an order of magnitude at 1 GHz and 2.4 GHz. We also report direct experimental observation that, contrary to metals, the radiation efficiency of the CNT thread improves significantly at higher frequencies. These results pave the way for practical applications of CNT thread antennas, particularly in the aerospace and wearable electronics industries where weight saving is a priority.

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

    DEFF Research Database (Denmark)

    Nymand, Morten

    The topic of this thesis is the design of high efficiency power electronic dc-to-dc converters for high-power, low-input-voltage to high-output-voltage applications. These converters are increasingly required for emerging sustainable energy systems such as fuel cell, battery or photo voltaic based...

  4. Rigid two-axis MEMS force plate for measuring cellular traction force

    International Nuclear Information System (INIS)

    Takahashi, Hidetoshi; Jung, Uijin G; Shimoyama, Isao; Kan, Tetsuo; Tsukagoshi, Takuya; Matsumoto, Kiyoshi

    2016-01-01

    Cellular traction force is one of the important factors for understanding cell behaviors, such as spreading, migration and differentiation. Cells are known to change their behavior according to the mechanical stiffness of the environment. However, the measurement of cell traction forces on a rigid environment has remained difficult. This paper reports a micro-electromechanical systems (MEMS) force plate that provides a cellular traction force measurement on a rigid substrate. Both the high force sensitivity and high stiffness of the substrate were obtained using piezoresistive sensing elements. The proposed force plate consists of a 70 µ m  ×  15 µ m  ×  5 µ m base as the substrate for cultivating a bovine aortic smooth muscle cell, and the supporting beams with piezoresistors on the sidewall and the surface were used to measure the forces in both the horizontal and vertical directions. The spring constant and force resolution of the fabricated force plate in the horizontal direction were 0.2 N m −1 and less than 0.05 µ N, respectively. The cell traction force was measured, and the traction force increased by approximately 1 µ N over 30 min. These results demonstrate that the proposed force plate is applicable as an effective traction force measurement. (paper)

  5. A Study of Torque Vectoring and Traction Control for an All-Wheel Drive Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Maharun Mui’nuddin

    2014-07-01

    Full Text Available Common vehicle always experience energy loss during cornering manoeuver. Thus, to ensure it did not happened especially at high speed, a study of torque vectoring and traction control need to be made since it can increase the traction control of tyres during cornering at high speed. The study of torque vectoring and traction control for an all-wheel drive electric vehicle was conducted by modelling an all-wheel drive electric vehicle (EV in ADAMS/Car software. In addition, an optimal control algorithm will be developed for best performance to minimize energy losses using MATLAB/Simulink software. Furthermore, to prove the effectiveness of the all-wheel drive electric, the torque and traction control simulation of the all-wheel drive electric vehicle will be compared with uncontrolled electric vehicle model. According to the result, torque vectoring and traction control of in-wheel motor in all wheel drive EV can help to increase the performance of the electric vehicle during cornering manoeuver. In conclusion, this study of torque vectoring and traction control for an all-wheel drive electric vehicle will help researchers to improve the design of the future electric vehicle in term of the vehicle performance during cornering manoeuvre.

  6. Asymmetry of activation of lateral abdominal muscles during the neurodevelopmental traction technique.

    Science.gov (United States)

    Gogola, Anna; Gnat, Rafał; Zaborowska, Małgorzata; Dziub, Dorota; Gwóźdź, Michalina

    2018-01-01

    The aim of the study was to evaluate the symmetry and pattern of activation of lateral abdominal muscles (LAM) in response to neurodevelopmental traction technique. Measurements of LAM thickness were performed in four experimental conditions: during traction with the force of 5% body weight (5% traction): 1) in neutral position, 2) in 20° posterior trunk inclination; during traction with the force of 15% body weight (15% traction): 3) in neutral position, 4) in 20° posterior trunk inclination. Thirty-seven healthy children participated in the study. Not applicable. To evaluate LAM activation level ultrasound technology was employed (two Mindray DP660 devices (Mindray, Shenzhen, China) with 75L38EA linear probes). An experiment with repeated measurements of the dependent variables was conducted. Side-to-side LAM activation asymmetry showed relatively high magnitude, however, significant difference was found only in case of the obliquus externus (OE) during stronger traction (P muscle differences were most pronounced between the OE and TrA (P muscles showing less intense activation. In statistical terms, the only signs of side-to-side asymmetry of LAM activation are visible in case of the OE, however, the magnitude of asymmetry is relatively high. The results allow to identify patterns of activation of LAM in children showing typical development that will serve as a reference in future studies in children with neurological disorder. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. High efficiency lithium-thionyl chloride cell

    Science.gov (United States)

    Doddapaneni, N.

    1982-08-01

    The polarization characteristics and the specific cathode capacity of Teflon bonded carbon electrodes in the Li/SOCl2 system have been evaluated. Doping of electrocatalysts such as cobalt and iron phthalocyanine complexes improved both cell voltage and cell rate capability. High efficiency Li/SOCl2 cells were thus achieved with catalyzed cathodes. The electrochemical reduction of SOCl2 seems to undergo modification at catalyzed cathode. For example, the reduction of SOCl2 at FePc catalyzed cathode involves 2-1/2 e-/mole of SOCl2. Furthermore, the reduction mechanism is simplified and unwanted chemical species are eliminated by the catalyst. Thus a potentially safer high efficiency Li/SOCl2 can be anticipated.

  8. TRACTION RESISTANCE IN CHITOSAN TREATED COTTON

    Directory of Open Access Journals (Sweden)

    LOX Wouter

    2015-05-01

    Full Text Available Nowadays natural products interest has increased. However, when some products are included on textile fibers, they have no affinity and need some binders or other kind of auxiliaries to improve the yeld of the process, and some of them are not so natural as the product which are binding and consequently the “bio” definition is missed as some of them can be considered as highly pollutant. Chitosan is a common used bonding agent for cotton. It improves the antimicrobial and antifungal activity, improves wound healing and is a non-toxic bonding agent. The biopolymer used in this work is chitosan, which is a deacetylated derivative of chitin. These properties depend on the amount of deacetylation (DD and the Molecular weight (MW. Along with these improving properties, as it requires some acid pH to ve solved the treatment with chitosan can have some decreasing mechanical properties. The aim of that paper is to evaluate the change in breaking force of the treated samples and a change in elongation of those samples. It compared different amounts of concentration of chitosan with non treated cotton. The traction resistance test were performed on a dynamometer. The test was conducted according to the UNE EN ISO 13934-1 standard.

  9. Traction force microscopy of engineered cardiac tissues.

    Science.gov (United States)

    Pasqualini, Francesco Silvio; Agarwal, Ashutosh; O'Connor, Blakely Bussie; Liu, Qihan; Sheehy, Sean P; Parker, Kevin Kit

    2018-01-01

    Cardiac tissue development and pathology have been shown to depend sensitively on microenvironmental mechanical factors, such as extracellular matrix stiffness, in both in vivo and in vitro systems. We present a novel quantitative approach to assess cardiac structure and function by extending the classical traction force microscopy technique to tissue-level preparations. Using this system, we investigated the relationship between contractile proficiency and metabolism in neonate rat ventricular myocytes (NRVM) cultured on gels with stiffness mimicking soft immature (1 kPa), normal healthy (13 kPa), and stiff diseased (90 kPa) cardiac microenvironments. We found that tissues engineered on the softest gels generated the least amount of stress and had the smallest work output. Conversely, cardiomyocytes in tissues engineered on healthy- and disease-mimicking gels generated significantly higher stresses, with the maximal contractile work measured in NRVM engineered on gels of normal stiffness. Interestingly, although tissues on soft gels exhibited poor stress generation and work production, their basal metabolic respiration rate was significantly more elevated than in other groups, suggesting a highly ineffective coupling between energy production and contractile work output. Our novel platform can thus be utilized to quantitatively assess the mechanotransduction pathways that initiate tissue-level structural and functional remodeling in response to substrate stiffness.

  10. Bioblendstocks that Enable High Efficiency Engine Designs

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, Robert L.; Fioroni, Gina M.; Ratcliff, Matthew A.; Zigler, Bradley T.; Farrell, John

    2016-11-03

    The past decade has seen a high level of innovation in production of biofuels from sugar, lipid, and lignocellulose feedstocks. As discussed in several talks at this workshop, ethanol blends in the E25 to E50 range could enable more highly efficient spark-ignited (SI) engines. This is because of their knock resistance properties that include not only high research octane number (RON), but also charge cooling from high heat of vaporization, and high flame speed. Emerging alcohol fuels such as isobutanol or mixed alcohols have desirable properties such as reduced gasoline blend vapor pressure, but also have lower RON than ethanol. These fuels may be able to achieve the same knock resistance benefits, but likely will require higher blend levels or higher RON hydrocarbon blendstocks. A group of very high RON (>150) oxygenates such as dimethyl furan, methyl anisole, and related compounds are also produced from biomass. While providing no increase in charge cooling, their very high octane numbers may provide adequate knock resistance for future highly efficient SI engines. Given this range of options for highly knock resistant fuels there appears to be a critical need for a fuel knock resistance metric that includes effects of octane number, heat of vaporization, and potentially flame speed. Emerging diesel fuels include highly branched long-chain alkanes from hydroprocessing of fats and oils, as well as sugar-derived terpenoids. These have relatively high cetane number (CN), which may have some benefits in designing more efficient CI engines. Fast pyrolysis of biomass can produce diesel boiling range streams that are high in aromatic, oxygen and acid contents. Hydroprocessing can be applied to remove oxygen and consequently reduce acidity, however there are strong economic incentives to leave up to 2 wt% oxygen in the product. This oxygen will primarily be present as low CN alkyl phenols and aryl ethers. While these have high heating value, their presence in diesel fuel

  11. Evaluating performance of high efficiency mist eliminators

    Energy Technology Data Exchange (ETDEWEB)

    Waggoner, Charles A.; Parsons, Michael S.; Giffin, Paxton K. [Mississippi State University, Institute for Clean Energy Technology, 205 Research Blvd, Starkville, MS (United States)

    2013-07-01

    Processing liquid wastes frequently generates off gas streams with high humidity and liquid aerosols. Droplet laden air streams can be produced from tank mixing or sparging and processes such as reforming or evaporative volume reduction. Unfortunately these wet air streams represent a genuine threat to HEPA filters. High efficiency mist eliminators (HEME) are one option for removal of liquid aerosols with high dissolved or suspended solids content. HEMEs have been used extensively in industrial applications, however they have not seen widespread use in the nuclear industry. Filtering efficiency data along with loading curves are not readily available for these units and data that exist are not easily translated to operational parameters in liquid waste treatment plants. A specialized test stand has been developed to evaluate the performance of HEME elements under use conditions of a US DOE facility. HEME elements were tested at three volumetric flow rates using aerosols produced from an iron-rich waste surrogate. The challenge aerosol included submicron particles produced from Laskin nozzles and super micron particles produced from a hollow cone spray nozzle. Test conditions included ambient temperature and relative humidities greater than 95%. Data collected during testing HEME elements from three different manufacturers included volumetric flow rate, differential temperature across the filter housing, downstream relative humidity, and differential pressure (dP) across the filter element. Filter challenge was discontinued at three intermediate dPs and the filter to allow determining filter efficiency using dioctyl phthalate and then with dry surrogate aerosols. Filtering efficiencies of the clean HEME, the clean HEME loaded with water, and the HEME at maximum dP were also collected using the two test aerosols. Results of the testing included differential pressure vs. time loading curves for the nine elements tested along with the mass of moisture and solid

  12. High efficiency inverter and ballast circuits

    International Nuclear Information System (INIS)

    Nilssen, O.K.

    1984-01-01

    A high efficiency push-pull inverter circuit employing a pair of relatively high power switching transistors is described. The switching on and off of the transistors is precisely controlled to minimize power losses due to common-mode conduction or due to transient conditions that occur in the process of turning a transistor on or off. Two current feed-back transformers are employed in the transistor base drives; one being saturable for providing a positive feedback, and the other being non-saturable for providing a subtractive feedback

  13. Optimization of a high efficiency FEL amplifier

    International Nuclear Information System (INIS)

    Schneidmiller, E.A.; Yurkov, M.V.

    2014-10-01

    The problem of an efficiency increase of an FEL amplifier is now of great practical importance. Technique of undulator tapering in the post-saturation regime is used at the existing X-ray FELs LCLS and SACLA, and is planned for use at the European XFEL, Swiss FEL, and PAL XFEL. There are also discussions on the future of high peak and average power FELs for scientific and industrial applications. In this paper we perform detailed analysis of the tapering strategies for high power seeded FEL amplifiers. Application of similarity techniques allows us to derive universal law of the undulator tapering.

  14. Highly efficient fully transparent inverted OLEDs

    Science.gov (United States)

    Meyer, J.; Winkler, T.; Hamwi, S.; Schmale, S.; Kröger, M.; Görrn, P.; Johannes, H.-H.; Riedl, T.; Lang, E.; Becker, D.; Dobbertin, T.; Kowalsky, W.

    2007-09-01

    One of the unique selling propositions of OLEDs is their potential to realize highly transparent devices over the visible spectrum. This is because organic semiconductors provide a large Stokes-Shift and low intrinsic absorption losses. Hence, new areas of applications for displays and ambient lighting become accessible, for instance, the integration of OLEDs into the windshield or the ceiling of automobiles. The main challenge in the realization of fully transparent devices is the deposition of the top electrode. ITO is commonly used as transparent bottom anode in a conventional OLED. To obtain uniform light emission over the entire viewing angle and a low series resistance, a TCO such as ITO is desirable as top contact as well. However, sputter deposition of ITO on top of organic layers causes damage induced by high energetic particles and UV radiation. We have found an efficient process to protect the organic layers against the ITO rf magnetron deposition process of ITO for an inverted OLED (IOLED). The inverted structure allows the integration of OLEDs in more powerful n-channel transistors used in active matrix backplanes. Employing the green electrophosphorescent material Ir(ppy) 3 lead to IOLED with a current efficiency of 50 cd/A and power efficiency of 24 lm/W at 100 cd/m2. The average transmittance exceeds 80 % in the visible region. The on-set voltage for light emission is lower than 3 V. In addition, by vertical stacking we achieved a very high current efficiency of more than 70 cd/A for transparent IOLED.

  15. High Efficiency Colloidal Quantum Dot Phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Kahen, Keith

    2013-12-31

    The project showed that non-Cd containing, InP-based nanocrystals (semiconductor materials with dimensions of ~6 nm) have high potential for enabling next-generation, nanocrystal-based, on chip phosphors for solid state lighting. Typical nanocrystals fall short of the requirements for on chip phosphors due to their loss of quantum efficiency under the operating conditions of LEDs, such as, high temperature (up to 150 °C) and high optical flux (up to 200 W/cm2). The InP-based nanocrystals invented during this project maintain high quantum efficiency (>80%) in polymer-based films under these operating conditions for emission wavelengths ranging from ~530 to 620 nm. These nanocrystals also show other desirable attributes, such as, lack of blinking (a common problem with nanocrystals which limits their performance) and no increase in the emission spectral width from room to 150 °C (emitters with narrower spectral widths enable higher efficiency LEDs). Prior to these nanocrystals, no nanocrystal system (regardless of nanocrystal type) showed this collection of properties; in fact, other nanocrystal systems are typically limited to showing only one desirable trait (such as high temperature stability) but being deficient in other properties (such as high flux stability). The project showed that one can reproducibly obtain these properties by generating a novel compositional structure inside of the nanomaterials; in addition, the project formulated an initial theoretical framework linking the compositional structure to the list of high performance optical properties. Over the course of the project, the synthetic methodology for producing the novel composition was evolved to enable the synthesis of these nanomaterials at a cost approximately equal to that required for forming typical conventional nanocrystals. Given the above results, the last major remaining step prior to scale up of the nanomaterials is to limit the oxidation of these materials during the tens of

  16. Highly Efficient Estimators of Multivariate Location with High Breakdown Point

    NARCIS (Netherlands)

    Lopuhaa, H.P.

    1991-01-01

    We propose an affine equivariant estimator of multivariate location that combines a high breakdown point and a bounded influence function with high asymptotic efficiency. This proposal is basically a location $M$-estimator based on the observations obtained after scaling with an affine equivariant

  17. Road dust from pavement wear and traction sanding

    Energy Technology Data Exchange (ETDEWEB)

    Kupiainen, K.

    2007-07-01

    Vehicles affect the concentrations of ambient airborne particles through exhaust emissions, but particles are also formed in the mechanical processes in the tire-road interface, brakes, and engine. Particles deposited on or in the vicinity of the road may be re-entrained, or resuspended, into air through vehicle-induced turbulence and shearing stress of the tires. A commonly used term for these particles is 'road dust'. The processes affecting road dust emissions are complex and currently not well known. Road dust has been acknowledged as a dominant source of PM10 especially during spring in the sub-arctic urban areas, e.g. in Scandinavia, Finland, North America and Japan. The high proportion of road dust in sub-arctic regions of the world has been linked to the snowy winter conditions that make it necessary to use traction control methods. Traction control methods include dispersion of traction sand, melting of ice with brine solutions, and equipping the tires with either metal studs (studded winter tires), snow chains, or special tire design (friction tires). Several of these methods enhance the formation of mineral particles from pavement wear and/or from traction sand that accumulate in the road environment during winter. When snow and ice melt and surfaces dry out, traffic-induced turbulence makes some of the particles airborne. A general aim of this study was to study processes and factors underlying and affecting the formation and emissions of road dust from paved road surfaces. Special emphasis was placed on studying particle formation and sources during tire road interaction, especially when different applications of traction control, namely traction sanding and/or winter tires were in use. Respirable particles with aerodynamic diameter below 10 micrometers (PM10) have been the main concern, but other size ranges and particle size distributions were also studied. The following specific research questions were addressed: (i) How do traction

  18. High efficiency motors; Motores de alta eficiencia

    Energy Technology Data Exchange (ETDEWEB)

    Uranga Favela, Ivan Jaime [Energia Controlada de Mexico, S. A. de C. V., Mexico, D. F. (Mexico)

    1993-12-31

    This paper is a technical-financial study of the high efficiency and super-premium motors. As it is widely known, more than 60% of the electrical energy generated in the country is used for the operation of motors, in industry as well as in commerce. Therefore the importance that the motors have in the efficient energy use. [Espanol] El presente trabajo es un estudio tecnico-financiero de los motores de alta eficiencia y los motores super premium. Como es ampliamente conocido, mas del 60% de la energia electrica generada en el pais, es utilizada para accionar motores, dentro de la industria y el comercio. De alli la importancia que los motores tienen en el uso eficiente de la energia.

  19. High-efficiency organic glass scintillators

    Science.gov (United States)

    Feng, Patrick L.; Carlson, Joseph S.

    2017-12-19

    A new family of neutron/gamma discriminating scintillators is disclosed that comprises stable organic glasses that may be melt-cast into transparent monoliths. These materials have been shown to provide light yields greater than solution-grown trans-stilbene crystals and efficient PSD capabilities when combined with 0.01 to 0.05% by weight of the total composition of a wavelength-shifting fluorophore. Photoluminescence measurements reveal fluorescence quantum yields that are 2 to 5 times greater than conventional plastic or liquid scintillator matrices, which accounts for the superior light yield of these glasses. The unique combination of high scintillation light-yields, efficient neutron/gamma PSD, and straightforward scale-up via melt-casting distinguishes the developed organic glasses from existing scintillators.

  20. High efficiency motors; Motores de alta eficiencia

    Energy Technology Data Exchange (ETDEWEB)

    Uranga Favela, Ivan Jaime [Energia Controlada de Mexico, S. A. de C. V., Mexico, D. F. (Mexico)

    1992-12-31

    This paper is a technical-financial study of the high efficiency and super-premium motors. As it is widely known, more than 60% of the electrical energy generated in the country is used for the operation of motors, in industry as well as in commerce. Therefore the importance that the motors have in the efficient energy use. [Espanol] El presente trabajo es un estudio tecnico-financiero de los motores de alta eficiencia y los motores super premium. Como es ampliamente conocido, mas del 60% de la energia electrica generada en el pais, es utilizada para accionar motores, dentro de la industria y el comercio. De alli la importancia que los motores tienen en el uso eficiente de la energia.

  1. High efficiency beam splitting for H- accelerators

    International Nuclear Information System (INIS)

    Kramer, S.L.; Stipp, V.; Krieger, C.; Madsen, J.

    1985-01-01

    Beam splitting for high energy accelerators has typically involved a significant loss of beam and radiation. This paper reports on a new method of splitting beams for H - accelerators. This technique uses a high intensity flash of light to strip a fraction of the H - beam to H 0 which are then easily separated by a small bending magnet. A system using a 900-watt (average electrical power) flashlamp and a highly efficient collector will provide 10 -3 to 10 -2 splitting of a 50 MeV H - beam. Results on the operation and comparisons with stripping cross sections are presented. Also discussed is the possibility for developing this system to yield a higher stripping fraction

  2. High Quantum Efficiency OLED Lighting Systems

    Energy Technology Data Exchange (ETDEWEB)

    Shiang, Joseph [General Electric (GE) Global Research, Fairfield, CT (United States)

    2011-09-30

    The overall goal of the program was to apply improvements in light outcoupling technology to a practical large area plastic luminaire, and thus enable the product vision of an extremely thin form factor high efficiency large area light source. The target substrate was plastic and the baseline device was operating at 35 LPW at the start of the program. The target LPW of the program was a >2x improvement in the LPW efficacy and the overall amount of light to be delivered was relatively high 900 lumens. Despite the extremely difficult challenges associated with scaling up a wet solution process on plastic substrates, the program was able to make substantial progress. A small molecule wet solution process was successfully implemented on plastic substrates with almost no loss in efficiency in transitioning from the laboratory scale glass to large area plastic substrates. By transitioning to a small molecule based process, the LPW entitlement increased from 35 LPW to 60 LPW. A further 10% improvement in outcoupling efficiency was demonstrated via the use of a highly reflecting cathode, which reduced absorptive loss in the OLED device. The calculated potential improvement in some cases is even larger, ~30%, and thus there is considerable room for optimism in improving the net light coupling efficacy, provided absorptive loss mechanisms are eliminated. Further improvements are possible if scattering schemes such as the silver nanowire based hard coat structure are fully developed. The wet coating processes were successfully scaled to large area plastic substrate and resulted in the construction of a 900 lumens luminaire device.

  3. High-efficiency concentrator silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sinton, R.A.; Cuevas, A.; King, R.R.; Swanson, R.M. (Stanford Univ., CA (USA). Solid-State Electronics Lab.)

    1990-11-01

    This report presents results from extensive process development in high-efficiency Si solar cells. An advanced design for a 1.56-cm{sup 2} cell with front grids achieved 26% efficiency at 90 suns. This is especially significant since this cell does not require a prismatic cover glass. New designs for simplified backside-contact solar cells were advanced from a status of near-nonfunctionality to demonstrated 21--22% for one-sun cells in sizes up to 37.5 cm{sup 2}. An efficiency of 26% was achieved for similar 0.64-cm{sup 2} concentrator cells at 150 suns. More fundamental work on dopant-diffused regions is also presented here. The recombination vs. various process and physical parameters was studied in detail for boron and phosphorous diffusions. Emitter-design studies based solidly upon these new data indicate the performance vs design parameters for a variety of the cases of most interest to solar cell designers. Extractions of p-type bandgap narrowing and the surface recombination for p- and n-type regions from these studies have a generality that extends beyond solar cells into basic device modeling. 68 refs., 50 figs.

  4. Nanooptics for high efficient photon managment

    Science.gov (United States)

    Wyrowski, Frank; Schimmel, Hagen

    2005-09-01

    Optical systems for photon management, that is the generation of tailored electromagnetic fields, constitute one of the keys for innovation through photonics. An important subfield of photon management deals with the transformation of an incident light field into a field of specified intensity distribution. In this paper we consider some basic aspects of the nature of systems for those light transformations. It turns out, that the transversal redistribution of energy (TRE) is of central concern to achieve systems with high transformation efficiency. Besides established techniques nanostructured optical elements (NOE) are demanded to implement transversal energy redistribution. That builds a bridge between the needs of photon management, optical engineering, and nanooptics.

  5. Traction alopecia: A neglected entity in 2017

    Directory of Open Access Journals (Sweden)

    Christiana Oyinlola Akingbola

    2017-01-01

    Full Text Available Traction alopecia was first described in 1904 but is still a cause of scarring hair loss in young women worldwide. It is unique in being initially a reversible then an irreversible (scarring form of alopecia. Linked to tightly-pulled hairstyles, it is seen across all races. The pattern of hair loss depends on the style creating it but most commonly affects the frontotemporal hairline. There are some new examination findings associated with traction alopecia, which are traction folliculitis, the fringe sign and hair casts (pseudonits on dermatoscopy. These may prove key in prompting early specialist referral. The mainstay of current treatment is cessation of the contributing hairstyles. Camouflage, anti-inflammatory or growth-stimulating topical preparations are second line treatments. In later stages of severe traction alopecia hair transplantation may be the only effective treatment. The evidence basis for medical intervention with topical agents is anecdotal at best. Furthermore, additional research is required to clarify the pathogenesis of this biphasic alopecia. Until then, prompt diagnosis and identification of causative hairstyles are focus of current dermatological practice.

  6. Prediction of traction forces of motile cells.

    Science.gov (United States)

    Roux, Clément; Duperray, Alain; Laurent, Valérie M; Michel, Richard; Peschetola, Valentina; Verdier, Claude; Étienne, Jocelyn

    2016-10-06

    When crawling on a flat substrate, living cells exert forces on it via adhesive contacts, enabling them to build up tension within their cytoskeleton and to change shape. The measurement of these forces has been made possible by traction force microscopy (TFM), a technique which has allowed us to obtain time-resolved traction force maps during cell migration. This cell 'footprint' is, however, not sufficient to understand the details of the mechanics of migration, that is how cytoskeletal elements (respectively, adhesion complexes) are put under tension and reinforce or deform (respectively, mature and/or unbind) as a result. In a recent paper, we have validated a rheological model of actomyosin linking tension, deformation and myosin activity. Here, we complement this model with tentative models of the mechanics of adhesion and explore how closely these models can predict the traction forces that we recover from experimental measurements during cell migration. The resulting mathematical problem is a PDE set on the experimentally observed domain, which we solve using a finite-element approach. The four parameters of the model can then be adjusted by comparison with experimental results on a single frame of an experiment, and then used to test the predictive power of the model for following frames and other experiments. It is found that the basic pattern of traction forces is robustly predicted by the model and fixed parameters as a function of current geometry only.

  7. Highly Efficient Compression Algorithms for Multichannel EEG.

    Science.gov (United States)

    Shaw, Laxmi; Rahman, Daleef; Routray, Aurobinda

    2018-05-01

    The difficulty associated with processing and understanding the high dimensionality of electroencephalogram (EEG) data requires developing efficient and robust compression algorithms. In this paper, different lossless compression techniques of single and multichannel EEG data, including Huffman coding, arithmetic coding, Markov predictor, linear predictor, context-based error modeling, multivariate autoregression (MVAR), and a low complexity bivariate model have been examined and their performances have been compared. Furthermore, a high compression algorithm named general MVAR and a modified context-based error modeling for multichannel EEG have been proposed. The resulting compression algorithm produces a higher relative compression ratio of 70.64% on average compared with the existing methods, and in some cases, it goes up to 83.06%. The proposed methods are designed to compress a large amount of multichannel EEG data efficiently so that the data storage and transmission bandwidth can be effectively used. These methods have been validated using several experimental multichannel EEG recordings of different subjects and publicly available standard databases. The satisfactory parametric measures of these methods, namely percent-root-mean square distortion, peak signal-to-noise ratio, root-mean-square error, and cross correlation, show their superiority over the state-of-the-art compression methods.

  8. Traction for low-back pain with or without sciatica.

    NARCIS (Netherlands)

    Clarke, J.A.; van Tulder, M.W.; Blomberg, S.E.; de Vet, H.C.W.; van der Heijden, G.J.; Bronfort, G.; Bouter, L.M.

    2007-01-01

    Background: Traction is used to treat low-back pain (LBP), often with other treatments. Objectives: To determine traction's effectiveness, compared to reference treatments, placebo, sham traction or no treatment for LBP. Search strategy: We searched CENTRAL (The Cochrane Library 2006, issue 4),

  9. The Determination of the Asynchronous Traction Motor Characteristics of Locomotive

    Directory of Open Access Journals (Sweden)

    Pavel Grigorievich Kolpakhchyan

    2017-01-01

    Full Text Available The article deals with the problem of the locomotive asynchronous traction motor control with the AC diesel-electric transmission. The limitations of the torque of the traction motor when powered by the inverter are determined. The recommendations to improve the use of asynchronous traction motor of locomotives with the AC diesel-electric transmission are given.

  10. 21 CFR 882.5960 - Skull tongs for traction.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Skull tongs for traction. 882.5960 Section 882...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5960 Skull tongs for traction. (a) Identification. Skull tongs for traction is an instrument used to immobilize a patient with a...

  11. COMPARATIVE ANALYSIS OF CONVERTER STRUCTURES OF THE TRACTION DRIVE PROSPECTIVE MULTI-SYSTEM ELECTRIC LOCOMOTIVES WITH DC TRACTION MOTORS

    Directory of Open Access Journals (Sweden)

    A. M. Muha

    2009-03-01

    Full Text Available In the article the structured schemes of steady-state converter are offered for traction drive of promising multisystem electric locomotives with traction engines of direct current and their comparative analysis is conducted.

  12. High efficiency double sided solar cells

    International Nuclear Information System (INIS)

    Seddik, M.M.

    1990-06-01

    Silicon technology state of the art for single crystalline was given to be limited to less than 20% efficiency. A proposed new form of photovoltaic solar cell of high current high efficiency with double sided structures has been given. The new forms could be n ++ pn ++ or p ++ np ++ double side junctions. The idea of double sided devices could be understood as two solar cells connected back-to-back in parallel electrical connection, in which the current is doubled if the cell is illuminated from both sides by a V-shaped reflector. The cell is mounted to the reflector such that each face is inclined at an angle of 45 deg. C to each side of the reflector. The advantages of the new structure are: a) High power devices. b) Easy to fabricate. c) The cells are used vertically instead of horizontal use of regular solar cell which require large area to install. This is very important in power stations and especially for satellite installation. If the proposal is made real and proved to be experimentally feasible, it would be a new era for photovoltaic solar cells since the proposal has already been extended to even higher currents. The suggested structures could be stated as: n ++ pn ++ Vp ++ np ++ ;n ++ pn ++ Vn ++ pn ++ ORp ++ np ++ Vp ++ np ++ . These types of structures are formed in wedged shape to employ indirect illumination by either parabolic; conic or V-shaped reflectors. The advantages of these new forms are low cost; high power; less in size and space; self concentrating; ... etc. These proposals if it happens to find their ways to be achieved experimentally, I think they will offer a short path to commercial market and would have an incredible impact on solar cell technology and applications. (author). 12 refs, 5 figs

  13. Simple Motor Control Concept Results High Efficiency at High Velocities

    Science.gov (United States)

    Starin, Scott; Engel, Chris

    2013-09-01

    The need for high velocity motors in space applications for reaction wheels and detectors has stressed the limits of Brushless Permanent Magnet Motors (BPMM). Due to inherent hysteresis core losses, conventional BPMMs try to balance the need for torque verses hysteresis losses. Cong-less motors have significantly less hysteresis losses but suffer from lower efficiencies. Additionally, the inherent low inductance in cog-less motors result in high ripple currents or high switching frequencies, which lowers overall efficiency and increases performance demands on the control electronics.However, using a somewhat forgotten but fully qualified technology of Isotropic Magnet Motors (IMM), extremely high velocities may be achieved at low power input using conventional drive electronics. This paper will discuss the trade study efforts and empirical test data on a 34,000 RPM IMM.

  14. Traction forces exerted by epithelial cell sheets

    International Nuclear Information System (INIS)

    Saez, A; Anon, E; Ghibaudo, M; Di Meglio, J-M; Hersen, P; Ladoux, B; Du Roure, O; Silberzan, P; Buguin, A

    2010-01-01

    Whereas the adhesion and migration of individual cells have been well described in terms of physical forces, the mechanics of multicellular assemblies is still poorly understood. Here, we study the behavior of epithelial cells cultured on microfabricated substrates designed to measure cell-to-substrate interactions. These substrates are covered by a dense array of flexible micropillars whose deflection enables us to measure traction forces. They are obtained by lithography and soft replica molding. The pillar deflection is measured by video microscopy and images are analyzed with home-made multiple particle tracking software. First, we have characterized the temporal and spatial distributions of traction forces of cellular assemblies of various sizes. The mechanical force balance within epithelial cell sheets shows that the forces exerted by neighboring cells strongly depend on their relative position in the monolayer: the largest deformations are always localized at the edge of the islands of cells in the active areas of cell protrusions. The average traction stress rapidly decreases from its maximum value at the edge but remains much larger than the inherent noise due to the force resolution of our pillar tracking software, indicating an important mechanical activity inside epithelial cell islands. Moreover, these traction forces vary linearly with the rigidity of the substrate over about two decades, suggesting that cells exert a given amount of deformation rather than a force. Finally, we engineer micropatterned substrates supporting pillars with anisotropic stiffness. On such substrates cellular growth is aligned with respect to the stiffest direction in correlation with the magnitude of the applied traction forces.

  15. High Efficiency, Illumination Quality OLEDs for Lighting

    Energy Technology Data Exchange (ETDEWEB)

    Joseph Shiang; James Cella; Kelly Chichak; Anil Duggal; Kevin Janora; Chris Heller; Gautam Parthasarathy; Jeffery Youmans; Joseph Shiang

    2008-03-31

    The goal of the program was to demonstrate a 45 lumen per watt white light device based upon the use of multiple emission colors through the use of solution processing. This performance level is a dramatic extension of the team's previous 15 LPW large area illumination device. The fundamental material system was based upon commercial polymer materials. The team was largely able to achieve these goals, and was able to deliver to DOE a 90 lumen illumination source that had an average performance of 34 LPW a 1000 cd/m{sup 2} with peak performances near 40LPW. The average color temperature is 3200K and the calculated CRI 85. The device operated at a brightness of approximately 1000cd/m{sup 2}. The use of multiple emission colors particularly red and blue, provided additional degrees of design flexibility in achieving white light, but also required the use of a multilayered structure to separate the different recombination zones and prevent interconversion of blue emission to red emission. The use of commercial materials had the advantage that improvements by the chemical manufacturers in charge transport efficiency, operating life and material purity could be rapidly incorporated without the expenditure of additional effort. The program was designed to take maximum advantage of the known characteristics of these material and proceeded in seven steps. (1) Identify the most promising materials, (2) assemble them into multi-layer structures to control excitation and transport within the OLED, (3) identify materials development needs that would optimize performance within multilayer structures, (4) build a prototype that demonstrates the potential entitlement of the novel multilayer OLED architecture (5) integrate all of the developments to find the single best materials set to implement the novel multilayer architecture, (6) further optimize the best materials set, (7) make a large area high illumination quality white OLED. A photo of the final deliverable is shown

  16. The aspect of vector control using the asynchronous traction motor in locomotives

    Directory of Open Access Journals (Sweden)

    L. Liudvinavičius

    2009-12-01

    Full Text Available The article examines curves controlling asynchronous traction motors increasingly used in locomotive electric drives the main task of which is to create a tractive effort-speed curve of an ideal locomotive Fk = f(v, including a hyperbolic area the curve of which will create conditions showing that energy created by the diesel engine of diesel locomotives (electric locomotives and in case of electric trains, electricity taken from the contact network over the entire range of locomotive speed is turned into efficient work. Mechanical power on wheel sets is constant Pk = Fkv = const, the power of the diesel engine is fully used over the entire range of locomotive speed. Tractive effort-speed curve Fk(v shows the dependency of locomotive traction power Fk on movement speed v. The article presents theoretical and practical aspects relevant to creating the structure of locomotive electric drive and selecting optimal control that is especially relevant to creating the structure of locomotive electric drive using ATM (asynchronous traction motor that gains special popularity in traction rolling stock replacing DC traction motors having low reliability. The frequency modes of asynchronous motor speed regulation are examined. To control ATM, the authors suggest the method of vector control presenting the structural schemes of a locomotive with ATM and control algorithm.

  17. Comparison of the environmental performance of light mechanization and animal traction using a modular LCA approach

    DEFF Research Database (Denmark)

    Cerutti, Alessandro K.; Calvo, Angela; Bruun, Sander

    2014-01-01

    Animal traction has supported humans in most field operations since the origin of agriculture. With the introduction of mechanization, humans gained access to much more work power at similar management costs and were able to significantly increase the productivity and time efficiency of field...... Italy, while use of machine traction was evaluated using field data on two-wheel tractors performing the operations in similar production systems, converted to the specific functional unit. Owing to the differing properties of mechanical and living systems, it was difficult to establish a reliable...

  18. Multiroller traction drive speed reducer: Evaluation for automotive gas turbine engine

    Science.gov (United States)

    Rohn, D. A.; Anderson, N. E.; Loewenthal, S. H.

    1982-01-01

    Tests were conducted on a nominal 14:1 fixed-ratio Nasvytis multiroller traction drive retrofitted as the speed reducer in an automotive gas turbine engine. Power turbine speeds of 45,000 rpm and a drive output power of 102 kW (137 hp) were reached. The drive operated under both variable roller loading (proportional to torque) and fixed roller loading (automatic loading mechanism locked). The drive operated smoothly and efficiently as the engine speed reducer. Engine specific fuel consumption with the traction speed reducer was comparable to that with the original helical gearset.

  19. Multiscale approaches to high efficiency photovoltaics

    Directory of Open Access Journals (Sweden)

    Connolly James Patrick

    2016-01-01

    Full Text Available While renewable energies are achieving parity around the globe, efforts to reach higher solar cell efficiencies becomes ever more difficult as they approach the limiting efficiency. The so-called third generation concepts attempt to break this limit through a combination of novel physical processes and new materials and concepts in organic and inorganic systems. Some examples of semi-empirical modelling in the field are reviewed, in particular for multispectral solar cells on silicon (French ANR project MultiSolSi. Their achievements are outlined, and the limits of these approaches shown. This introduces the main topic of this contribution, which is the use of multiscale experimental and theoretical techniques to go beyond the semi-empirical understanding of these systems. This approach has already led to great advances at modelling which have led to modelling software, which is widely known. Yet, a survey of the topic reveals a fragmentation of efforts across disciplines, firstly, such as organic and inorganic fields, but also between the high efficiency concepts such as hot carrier cells and intermediate band concepts. We show how this obstacle to the resolution of practical research obstacles may be lifted by inter-disciplinary cooperation across length scales, and across experimental and theoretical fields, and finally across materials systems. We present a European COST Action “MultiscaleSolar” kicking off in early 2015, which brings together experimental and theoretical partners in order to develop multiscale research in organic and inorganic materials. The goal of this defragmentation and interdisciplinary collaboration is to develop understanding across length scales, which will enable the full potential of third generation concepts to be evaluated in practise, for societal and industrial applications.

  20. High efficiency thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Schock, Hans-Werner [Helmholtz Zentrum Berlin (Germany). Solar Energy

    2012-11-01

    Production of photovoltaics is growing worldwide on a gigawatt scale. Among the thin film technologies, Cu(In,Ga)S,Se{sub 2} (CIS or CIGS) based solar cells have been the focus of more and more attention. This paper aims to analyze the success of CIGS based solar cells and the potential of this technology for future photovoltaics large-scale production. Specific material properties make CIS unique and allow the preparation of the material with a wide range of processing options. The huge potential lies in the possibility to take advantage of modern thin film processing equipment and combine it with very high efficiencies beyond 20% already achieved on the laboratory scale. A sustainable development of this technology could be realized by modifying the materials and replacing indium by abundant elements. (orig.)

  1. Design of High Efficient MPPT Solar Inverter

    Directory of Open Access Journals (Sweden)

    Sunitha K. A.

    2017-01-01

    Full Text Available This work aims to design a High Efficient Maximum Power Point Tracking (MPPT Solar Inverter. A boost converter is designed in the system to boost the power from the photovoltaic panel. By this experimental setup a room consisting of 500 Watts load (eight fluorescent tubes is completely controlled. It is aimed to decrease the maintenance cost. A microcontroller is introduced for tracking the P&O (Perturb and Observe algorithm used for tracking the maximum power point. The duty cycle for the operation of the boost convertor is optimally adjusted by using MPPT controller. There is a MPPT charge controller to charge the battery as well as fed to inverter which runs the load. Both the P&O scheme with the fixed variation for the reference current and the intelligent MPPT algorithm were able to identify the global Maximum power point, however the performance of the MPPT algorithm was better.

  2. High Efficiency Ka-Band Spatial Combiner

    Directory of Open Access Journals (Sweden)

    D. Passi

    2014-12-01

    Full Text Available A Ka-Band, High Efficiency, Small Size Spatial Combiner (SPC is proposed in this paper, which uses an innovatively matched quadruple Fin Lines to microstrip (FLuS transitions. At the date of this paper and at the Author's best knowledge no such FLuS innovative transitions have been reported in literature before. These transitions are inserted into a WR28 waveguide T-junction, in order to allow the integration of 16 Monolithic Microwave Integrated Circuit (MMIC Solid State Power Amplifiers (SSPA's. A computational electromagnetic model using the finite elements method has been implemented. A mean insertion loss of 2 dB is achieved with a return loss better the 10 dB in the 31-37 GHz bandwidth.

  3. Multi-petascale highly efficient parallel supercomputer

    Science.gov (United States)

    Asaad, Sameh; Bellofatto, Ralph E.; Blocksome, Michael A.; Blumrich, Matthias A.; Boyle, Peter; Brunheroto, Jose R.; Chen, Dong; Cher, Chen-Yong; Chiu, George L.; Christ, Norman; Coteus, Paul W.; Davis, Kristan D.; Dozsa, Gabor J.; Eichenberger, Alexandre E.; Eisley, Noel A.; Ellavsky, Matthew R.; Evans, Kahn C.; Fleischer, Bruce M.; Fox, Thomas W.; Gara, Alan; Giampapa, Mark E.; Gooding, Thomas M.; Gschwind, Michael K.; Gunnels, John A.; Hall, Shawn A.; Haring, Rudolf A.; Heidelberger, Philip; Inglett, Todd A.; Knudson, Brant L.; Kopcsay, Gerard V.; Kumar, Sameer; Mamidala, Amith R.; Marcella, James A.; Megerian, Mark G.; Miller, Douglas R.; Miller, Samuel J.; Muff, Adam J.; Mundy, Michael B.; O'Brien, John K.; O'Brien, Kathryn M.; Ohmacht, Martin; Parker, Jeffrey J.; Poole, Ruth J.; Ratterman, Joseph D.; Salapura, Valentina; Satterfield, David L.; Senger, Robert M.; Steinmacher-Burow, Burkhard; Stockdell, William M.; Stunkel, Craig B.; Sugavanam, Krishnan; Sugawara, Yutaka; Takken, Todd E.; Trager, Barry M.; Van Oosten, James L.; Wait, Charles D.; Walkup, Robert E.; Watson, Alfred T.; Wisniewski, Robert W.; Wu, Peng

    2018-05-15

    A Multi-Petascale Highly Efficient Parallel Supercomputer of 100 petaflop-scale includes node architectures based upon System-On-a-Chip technology, where each processing node comprises a single Application Specific Integrated Circuit (ASIC). The ASIC nodes are interconnected by a five dimensional torus network that optimally maximize the throughput of packet communications between nodes and minimize latency. The network implements collective network and a global asynchronous network that provides global barrier and notification functions. Integrated in the node design include a list-based prefetcher. The memory system implements transaction memory, thread level speculation, and multiversioning cache that improves soft error rate at the same time and supports DMA functionality allowing for parallel processing message-passing.

  4. The CRRES high efficiency solar panel

    International Nuclear Information System (INIS)

    Trumble, T.M.

    1991-01-01

    This paper reports on the High Efficiency Solar Panel (HESP) experiments which is to provide both engineering and scientific information concerning the effects of space radiation on advanced gallium arsenide (GaAs) solar cells. The HESP experiment consists of an ambient panel, and annealing panel and a programmable load. This experiment, in conjunction with the radiation measurement experiments abroad the CREES, provides the first opportunity to simultaneously measure the trapped radiation belts and the results of radiation damage to solar cells. The engineering information will result in a design guide for selecting the optimum solar array characteristics for different orbits and different lifetimes. The scientific information will provide both correlation of laboratory damage effects to space damage effects and a better model for predicting effective solar cell panel lifetimes

  5. Zerodur polishing process for high surface quality and high efficiency

    International Nuclear Information System (INIS)

    Tesar, A.; Fuchs, B.

    1992-08-01

    Zerodur is a glass-ceramic composite importance in applications where temperature instabilities influence optical and mechanical performance, such as in earthbound and spaceborne telescope mirror substrates. Polished Zerodur surfaces of high quality have been required for laser gyro mirrors. Polished surface quality of substrates affects performance of high reflection coatings. Thus, the interest in improving Zerodur polished surface quality has become more general. Beyond eliminating subsurface damage, high quality surfaces are produced by reducing the amount of hydrated material redeposited on the surface during polishing. With the proper control of polishing parameters, such surfaces exhibit roughnesses of < l Angstrom rms. Zerodur polishing was studied to recommend a high surface quality polishing process which could be easily adapted to standard planetary continuous polishing machines and spindles. This summary contains information on a polishing process developed at LLNL which reproducibly provides high quality polished Zerodur surfaces at very high polishing efficiencies

  6. The improvement of maintenance service for traction networks equipment on the base of process approach

    Directory of Open Access Journals (Sweden)

    D. V. Mironov

    2014-12-01

    Full Text Available Purpose. The new methods development for improving the maintenance service for equipment of traction networks in order to increase its efficiency and quality. Methodology. In world practice of solving problems related to the quality of products and services is usually achieved by introducing quality management system in to the enterprises. The provisions of quality management system were used for solving the problem. The technologies of process engineering were used for describing the main stages of maintenance service. Findings. The development of high-speed movement and growth of its intensity, the use of electric rolling stock of a new generation require the introduction of new methods diagnostics of equipment technical state and improvement of the existing maintenance system and repair of power supply. Developing a model of business-processes, their optimization with using techniques of process engineering and system management is needed for the transition to the management system based on the process approach. From the standpoint of the process approach and in accordance with the requirements of the quality management system (ISO 9001-2009, the operation of the E (Department of electrification and power supply infrastructure sector is represented as a scheme of business-processes in which the guaranteed supply with electricity of railway and third-party consumers is defined as the main business-process of management. Each of the sub-process of power supply for consumers is described in details. The use methods and main stages of process approach for sample management system reorganization were investigated. The methodology and the application method of PDCA (Plan-Do-Check-Act closed loop to the equipment maintenance system were described. The monitoring process of traction networks maintenance using the process approach was divided into components after investigations. The technical documentation of maintenance service was investigated in

  7. Highly efficient red electrophosphorescent devices at high current densities

    International Nuclear Information System (INIS)

    Wu Youzhi; Zhu Wenqing; Zheng Xinyou; Sun, Runguang; Jiang Xueyin; Zhang Zhilin; Xu Shaohong

    2007-01-01

    Efficiency decrease at high current densities in red electrophosphorescent devices is drastically restrained compared with that from conventional electrophosphorescent devices by using bis(2-methyl-8-quinolinato)4-phenylphenolate aluminum (BAlq) as a hole and exciton blocker. Ir complex, bis(2-(2'-benzo[4,5-α]thienyl) pyridinato-N,C 3' ) iridium (acetyl-acetonate) is used as an emitter, maximum external quantum efficiency (QE) of 7.0% and luminance of 10000cd/m 2 are obtained. The QE is still as high as 4.1% at higher current density J=100mA/cm 2 . CIE-1931 co-ordinates are 0.672, 0.321. A carrier trapping mechanism is revealed to dominate in the process of electroluminescence

  8. White LED with High Package Extraction Efficiency

    International Nuclear Information System (INIS)

    Yi Zheng; Stough, Matthew

    2008-01-01

    The goal of this project is to develop a high efficiency phosphor converting (white) Light Emitting Diode (pcLED) 1-Watt package through an increase in package extraction efficiency. A transparent/translucent monolithic phosphor is proposed to replace the powdered phosphor to reduce the scattering caused by phosphor particles. Additionally, a multi-layer thin film selectively reflecting filter is proposed between blue LED die and phosphor layer to recover inward yellow emission. At the end of the project we expect to recycle approximately 50% of the unrecovered backward light in current package construction, and develop a pcLED device with 80 lm/W e using our technology improvements and commercially available chip/package source. The success of the project will benefit luminous efficacy of white LEDs by increasing package extraction efficiency. In most phosphor-converting white LEDs, the white color is obtained by combining a blue LED die (or chip) with a powdered phosphor layer. The phosphor partially absorbs the blue light from the LED die and converts it into a broad green-yellow emission. The mixture of the transmitted blue light and green-yellow light emerging gives white light. There are two major drawbacks for current pcLEDs in terms of package extraction efficiency. The first is light scattering caused by phosphor particles. When the blue photons from the chip strike the phosphor particles, some blue light will be scattered by phosphor particles. Converted yellow emission photons are also scattered. A portion of scattered light is in the backward direction toward the die. The amount of this backward light varies and depends in part on the particle size of phosphors. The other drawback is that yellow emission from phosphor powders is isotropic. Although some backward light can be recovered by the reflector in current LED packages, there is still a portion of backward light that will be absorbed inside the package and further converted to heat. Heat generated

  9. Tailored Materials for High Efficiency CIDI Engines

    Energy Technology Data Exchange (ETDEWEB)

    Grant, G.J.; Jana, S.

    2012-03-30

    The overall goal of the project, Tailored Materials for High Efficiency Compression Ignition Direct Injection (CIDI) Engines, is to enable the implementation of new combustion strategies, such as homogeneous charge compression ignition (HCCI), that have the potential to significantly increase the energy efficiency of current diesel engines and decrease fuel consumption and environmental emissions. These strategies, however, are increasing the demands on conventional engine materials, either from increases in peak cylinder pressure (PCP) or from increases in the temperature of operation. The specific objective of this project is to investigate the application of a new material processing technology, friction stir processing (FSP), to improve the thermal and mechanical properties of engine components. The concept is to modify the surfaces of conventional, low-cost engine materials. The project focused primarily on FSP in aluminum materials that are compositional analogs to the typical piston and head alloys seen in small- to mid-sized CIDI engines. Investigations have been primarily of two types over the duration of this project: (1) FSP of a cast hypoeutectic Al-Si-Mg (A356/357) alloy with no introduction of any new components, and (2) FSP of Al-Cu-Ni alloys (Alloy 339) by physically stirring-in various quantities of carbon nanotubes/nanofibers or carbon fibers. Experimental work to date on aluminum systems has shown significant increases in fatigue lifetime and stress-level performance in aluminum-silicon alloys using friction processing alone, but work to demonstrate the addition of carbon nanotubes and fibers into aluminum substrates has shown mixed results due primarily to the difficulty in achieving porosity-free, homogeneous distributions of the particulate. A limited effort to understand the effects of FSP on steel materials was also undertaken during the course of this project. Processed regions were created in high-strength, low-alloyed steels up to 0.5 in

  10. High efficiency diffusion molecular retention tumor targeting.

    Directory of Open Access Journals (Sweden)

    Yanyan Guo

    Full Text Available Here we introduce diffusion molecular retention (DMR tumor targeting, a technique that employs PEG-fluorochrome shielded probes that, after a peritumoral (PT injection, undergo slow vascular uptake and extensive interstitial diffusion, with tumor retention only through integrin molecular recognition. To demonstrate DMR, RGD (integrin binding and RAD (control probes were synthesized bearing DOTA (for (111 In(3+, a NIR fluorochrome, and 5 kDa PEG that endows probes with a protein-like volume of 25 kDa and decreases non-specific interactions. With a GFP-BT-20 breast carcinoma model, tumor targeting by the DMR or i.v. methods was assessed by surface fluorescence, biodistribution of [(111In] RGD and [(111In] RAD probes, and whole animal SPECT. After a PT injection, both probes rapidly diffused through the normal and tumor interstitium, with retention of the RGD probe due to integrin interactions. With PT injection and the [(111In] RGD probe, SPECT indicated a highly tumor specific uptake at 24 h post injection, with 352%ID/g tumor obtained by DMR (vs 4.14%ID/g by i.v.. The high efficiency molecular targeting of DMR employed low probe doses (e.g. 25 ng as RGD peptide, which minimizes toxicity risks and facilitates clinical translation. DMR applications include the delivery of fluorochromes for intraoperative tumor margin delineation, the delivery of radioisotopes (e.g. toxic, short range alpha emitters for radiotherapy, or the delivery of photosensitizers to tumors accessible to light.

  11. High collection efficiency CVD diamond alpha detectors

    International Nuclear Information System (INIS)

    Bergonzo, P.; Foulon, F.; Marshall, R.D.; Jany, C.; Brambilla, A.; McKeag, R.D.; Jackman, R.B.

    1998-01-01

    Advances in Chemical Vapor Deposited (CVD) diamond have enabled the routine use of this material for sensor device fabrication, allowing exploitation of its unique combination of physical properties (low temperature susceptibility (> 500 C), high resistance to radiation damage (> 100 Mrad) and to corrosive media). A consequence of CVD diamond growth on silicon is the formation of polycrystalline films which has a profound influence on the physical and electronic properties with respect to those measured on monocrystalline diamond. The authors report the optimization of physical and geometrical device parameters for radiation detection in the counting mode. Sandwich and co-planar electrode geometries are tested and their performances evaluated with regard to the nature of the field profile and drift distances inherent in such devices. The carrier drift length before trapping was measured under alpha particles and values as high as 40% of the overall film thickness are reported. Further, by optimizing the device geometry, they show that a gain in collection efficiency, defined as the induced charge divided by the deposited charge within the material, can be achieved even though lower bias values are used

  12. High bandgap III-V alloys for high efficiency optoelectronics

    Energy Technology Data Exchange (ETDEWEB)

    Alberi, Kirstin; Mascarenhas, Angelo; Wanlass, Mark

    2017-01-10

    High bandgap alloys for high efficiency optoelectronics are disclosed. An exemplary optoelectronic device may include a substrate, at least one Al.sub.1-xIn.sub.xP layer, and a step-grade buffer between the substrate and at least one Al.sub.1-xIn.sub.xP layer. The buffer may begin with a layer that is substantially lattice matched to GaAs, and may then incrementally increase the lattice constant in each sequential layer until a predetermined lattice constant of Al.sub.1-xIn.sub.xP is reached.

  13. Performance of a high efficiency high power UHF klystron

    International Nuclear Information System (INIS)

    Konrad, G.T.

    1977-03-01

    A 500 kW c-w klystron was designed for the PEP storage ring at SLAC. The tube operates at 353.2 MHz, 62 kV, a microperveance of 0.75, and a gain of approximately 50 dB. Stable operation is required for a VSWR as high as 2 : 1 at any phase angle. The design efficiency is 70%. To obtain this value of efficiency, a second harmonic cavity is used in order to produce a very tightly bunched beam in the output gap. At the present time it is planned to install 12 such klystrons in PEP. A tube with a reduced size collector was operated at 4% duty at 500 kW. An efficiency of 63% was observed. The same tube was operated up to 200 kW c-w for PEP accelerator cavity tests. A full-scale c-w tube reached 500 kW at 65 kV with an efficiency of 55%. In addition to power and phase measurements into a matched load, some data at various load mismatches are presented

  14. ONCE AGAIN ABOUT DETERMINATION OF SAVING OF ENERGY FOR TRACTION DUE TO PARTIAL CUT–OFF OF TRACTION ENGINES OF ELECTRIC ROLLING STOCK

    Directory of Open Access Journals (Sweden)

    G. K. Getman

    2013-09-01

    Full Text Available Purpose. In general the well known methods for determination of energy saving due to the partial traction engines cut-off based on their comparison to efficiency coefficient or to the power of energy losses do not allow objective estimation of efficiency of these measures and in a number of cases result in erroneous results and errors. The search for new more advanced methods for determination of energy saving at the partial cut-off of the traction engines is needed. Methodology. The method of calculation determination of energy saving when partial cutting-off of the traction engines is offered. It is based on the use of rationality coefficient as the loading mode of the electric power consumption for the measuring instrument of transportation activity. Findings. Using the given mathematical expressions it is possible to determine the energy saving in both the relative and absolute values and set the terms (motion speed and route gradient, under which the energy saving will take place. Originality. The method of the task solving, which is based on the evaluation of energy consumption differences for the compared variants (not on the comparison of efficiency coefficient or differences of power of energy losses is offered. Practical value. The given methodology allows obtaining more exact conclusions in relation to the electric power consumption, as the comparison of energy losses power or the efficiency coefficient does not determine precisely the electric power consumption for traction. Therefore the conclusions based on the comparison of power of energy losses or efficiency coefficient can appear inexact.

  15. Orthodontic Traction of Impacted Canine Using Cantilever

    OpenAIRE

    Nakandakari, Cláudia; Gonçalves, João Roberto; Cassano, Daniel Serra; Raveli, Taísa Boamorte; Bianchi, Jonas; Raveli, Dirceu Barnabé

    2016-01-01

    The impaction of the maxillary canines causes relevant aesthetic and functional problems. The multidisciplinary approach to the proper planning and execution of orthodontic traction of the element in question is essential. Many strategies are cited in the literature; among them is the good biomechanical control in order to avoid possible side effects. The aim of this paper is to present a case report in which a superior canine impacted by palatine was pulled out with the aid of the cantilever...

  16. Digital Model of Railway Electric Traction Lines

    Science.gov (United States)

    Garg, Rachana; Mahajan, Priya; Kumar, Parmod

    2017-08-01

    The characteristic impedance and propagation constant define the behavior of signal propagation over the transmission lines. The digital model for railway traction lines which includes railway tracks is developed, using curve fitting technique in MATLAB. The sensitivity of this model has been computed with respect to frequency. The digital sensitivity values are compared with the values of analog sensitivity. The developed model is useful for digital protection, integrated operation, control and planning of the system.

  17. Understanding the traction of tennis surfaces

    OpenAIRE

    Clarke, James; Carré, Matt; Richardson, Andrea; Yang, Zhijun; Damm, Loic; Dixon, Sharon

    2011-01-01

    The traction provided by a footwear-surface interaction can have an impact on player safety, performance and overall enjoyment of sport. Mechanical test methods used for the testing and categorisation of safe playing surfaces do not tend to simulate loads occurring during participation on the surface, and thus are unlikely to predict human response to the surface. For example, the pendulum system routinely employed by the International Tennis Federation (I.T.F.) utilises a standard rubber ‘fo...

  18. Series-Tuned High Efficiency RF-Power Amplifiers

    DEFF Research Database (Denmark)

    Vidkjær, Jens

    2008-01-01

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

  19. Multi-petascale highly efficient parallel supercomputer

    Science.gov (United States)

    Asaad, Sameh; Bellofatto, Ralph E.; Blocksome, Michael A.; Blumrich, Matthias A.; Boyle, Peter; Brunheroto, Jose R.; Chen, Dong; Cher, Chen -Yong; Chiu, George L.; Christ, Norman; Coteus, Paul W.; Davis, Kristan D.; Dozsa, Gabor J.; Eichenberger, Alexandre E.; Eisley, Noel A.; Ellavsky, Matthew R.; Evans, Kahn C.; Fleischer, Bruce M.; Fox, Thomas W.; Gara, Alan; Giampapa, Mark E.; Gooding, Thomas M.; Gschwind, Michael K.; Gunnels, John A.; Hall, Shawn A.; Haring, Rudolf A.; Heidelberger, Philip; Inglett, Todd A.; Knudson, Brant L.; Kopcsay, Gerard V.; Kumar, Sameer; Mamidala, Amith R.; Marcella, James A.; Megerian, Mark G.; Miller, Douglas R.; Miller, Samuel J.; Muff, Adam J.; Mundy, Michael B.; O'Brien, John K.; O'Brien, Kathryn M.; Ohmacht, Martin; Parker, Jeffrey J.; Poole, Ruth J.; Ratterman, Joseph D.; Salapura, Valentina; Satterfield, David L.; Senger, Robert M.; Smith, Brian; Steinmacher-Burow, Burkhard; Stockdell, William M.; Stunkel, Craig B.; Sugavanam, Krishnan; Sugawara, Yutaka; Takken, Todd E.; Trager, Barry M.; Van Oosten, James L.; Wait, Charles D.; Walkup, Robert E.; Watson, Alfred T.; Wisniewski, Robert W.; Wu, Peng

    2015-07-14

    A Multi-Petascale Highly Efficient Parallel Supercomputer of 100 petaOPS-scale computing, at decreased cost, power and footprint, and that allows for a maximum packaging density of processing nodes from an interconnect point of view. The Supercomputer exploits technological advances in VLSI that enables a computing model where many processors can be integrated into a single Application Specific Integrated Circuit (ASIC). Each ASIC computing node comprises a system-on-chip ASIC utilizing four or more processors integrated into one die, with each having full access to all system resources and enabling adaptive partitioning of the processors to functions such as compute or messaging I/O on an application by application basis, and preferably, enable adaptive partitioning of functions in accordance with various algorithmic phases within an application, or if I/O or other processors are underutilized, then can participate in computation or communication nodes are interconnected by a five dimensional torus network with DMA that optimally maximize the throughput of packet communications between nodes and minimize latency.

  20. Energy Efficient Graphene Based High Performance Capacitors.

    Science.gov (United States)

    Bae, Joonwon; Kwon, Oh Seok; Lee, Chang-Soo

    2017-07-10

    Graphene (GRP) is an interesting class of nano-structured electronic materials for various cutting-edge applications. To date, extensive research activities have been performed on the investigation of diverse properties of GRP. The incorporation of this elegant material can be very lucrative in terms of practical applications in energy storage/conversion systems. Among various those systems, high performance electrochemical capacitors (ECs) have become popular due to the recent need for energy efficient and portable devices. Therefore, in this article, the application of GRP for capacitors is described succinctly. In particular, a concise summary on the previous research activities regarding GRP based capacitors is also covered extensively. It was revealed that a lot of secondary materials such as polymers and metal oxides have been introduced to improve the performance. Also, diverse devices have been combined with capacitors for better use. More importantly, recent patents related to the preparation and application of GRP based capacitors are also introduced briefly. This article can provide essential information for future study. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  1. Highly efficient silicon light emitting diode

    NARCIS (Netherlands)

    Le Minh, P.; Holleman, J.; Wallinga, Hans

    2002-01-01

    In this paper, we describe the fabrication, using standard silicon processing techniques, of silicon light-emitting diodes (LED) that efficiently emit photons with energy around the silicon bandgap. The improved efficiency had been explained by the spatial confinement of charge carriers due to a

  2. A novel high efficiency solar photovoltalic pump

    NARCIS (Netherlands)

    Diepens, J.F.L.; Smulders, P.T.; Vries, de D.A.

    1993-01-01

    The daily average overall efficiency of a solar pump system is not only influenced by the maximum efficiency of the components of the system, but just as much by the correct matching of the components to the local irradiation pattern. Normally centrifugal pumps are used in solar pump systems. The

  3. High efficiency targets for high gain inertial confinement fusion

    International Nuclear Information System (INIS)

    Gardner, J.H.; Bodner, S.E.

    1986-01-01

    Rocket efficiencies as high as 15% are possible using short wavelength lasers and moderately high aspect ratio pellet designs. These designs are made possible by two recent breakthroughs in physics constraints. First is the development of the Induced Spatial Incoherence (ISI) technique which allows uniform illumination of the pellet and relaxes the constraint of thermal smoothing, permitting the use of short wavelength laser light. Second is the discovery that the Rayleigh-Taylor growth rate is considerably reduced at the short laser wavelengths. By taking advantage of the reduced constraints imposed by nonuniform laser illumination and Rayleigh-Taylor instability, pellets using 1/4 micron laser light and initial aspect ratios of about 10 (with in flight aspect ratios of about 150 to 200) may produce energy gains as high as 200 to 250

  4. High power klystrons for efficient reliable high power amplifiers

    Science.gov (United States)

    Levin, M.

    1980-11-01

    This report covers the design of reliable high efficiency, high power klystrons which may be used in both existing and proposed troposcatter radio systems. High Power (10 kW) klystron designs were generated in C-band (4.4 GHz to 5.0 GHz), S-band (2.5 GHz to 2.7 GHz), and L-band or UHF frequencies (755 MHz to 985 MHz). The tubes were designed for power supply compatibility and use with a vapor/liquid phase heat exchanger. Four (4) S-band tubes were developed in the course of this program along with two (2) matching focusing solenoids and two (2) heat exchangers. These tubes use five (5) tuners with counters which are attached to the focusing solenoids. A reliability mathematical model of the tube and heat exchanger system was also generated.

  5. High efficiency quasi-monochromatic infrared emitter

    Energy Technology Data Exchange (ETDEWEB)

    Brucoli, Giovanni; Besbes, Mondher; Benisty, Henri, E-mail: henri.benisty@institutoptique.fr; Greffet, Jean-Jacques [Laboratoire Charles Fabry, UMR 8501, Institut d’Optique, CNRS, Université Paris-Sud 11, 2, Avenue Augustin Fresnel, 91127 Palaiseau Cedex (France); Bouchon, Patrick; Haïdar, Riad [Office National d’Études et de Recherches Aérospatiales, Chemin de la Hunière, 91761 Palaiseau (France)

    2014-02-24

    Incandescent radiation sources are widely used as mid-infrared emitters owing to the lack of alternative for compact and low cost sources. A drawback of miniature hot systems such as membranes is their low efficiency, e.g., for battery powered systems. For targeted narrow-band applications such as gas spectroscopy, the efficiency is even lower. In this paper, we introduce design rules valid for very generic membranes demonstrating that their energy efficiency for use as incandescent infrared sources can be increased by two orders of magnitude.

  6. Energy efficiency of high-rise buildings

    Science.gov (United States)

    Zhigulina, Anna Yu.; Ponomarenko, Alla M.

    2018-03-01

    The article is devoted to analysis of tendencies and advanced technologies in the field of energy supply and energy efficiency of tall buildings, to the history of the emergence of the concept of "efficiency" and its current interpretation. Also the article show the difference of evaluation criteria of the leading rating systems LEED and BREEAM. Authors reviewed the latest technologies applied in the construction of energy efficient buildings. Methodological approach to the design of tall buildings taking into account energy efficiency needs to include the primary energy saving; to seek the possibility of production and accumulation of alternative electric energy by converting energy from the sun and wind with the help of special technical devices; the application of regenerative technologies.

  7. High Efficiency Refrigeration Process, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — It has been proposed by NASA JSC studies, that the most mass efficient (non-nuclear) method of Lunar habitat cooling is via photovoltaic (PV) direct vapor...

  8. An overview of the development of lead/acid traction batteries for electric vehicles in India

    Science.gov (United States)

    Sivaramaiah, G.; Subramanian, V. R.

    Electric vehicles (EVs) made an entry into the Indian scene quite recently in the area of passenger transportation, milk floats and other similar applications. The industrial EV market, with various models of fork-lift trucks and platform trucks already in wide use all over India, is a better understood application of EV batteries. The lead/acid traction batteries available in India are not of high-energy density. The best available indigenous lead/acid traction battery has an energy density ( C/5 rate) of 30 W h kg -1 as against 39 W h kg -1 available abroad. This paper reviews the developmental efforts relating to lead/acid traction batteries for electric vehicle applications in India, such as prototype road vehicles, commercial vehicles, rail cars, and locomotives. Due to the need for environmental protection and recognition of exhaustible, finite supplies of petroleum fuel, the Indian government is presently taking active interest in EV projects.

  9. High Power High Efficiency Diode Laser Stack for Processing

    Science.gov (United States)

    Gu, Yuanyuan; Lu, Hui; Fu, Yueming; Cui, Yan

    2018-03-01

    High-power diode lasers based on GaAs semiconductor bars are well established as reliable and highly efficient laser sources. As diode laser is simple in structure, small size, longer life expectancy with the advantages of low prices, it is widely used in the industry processing, such as heat treating, welding, hardening, cladding and so on. Respectively, diode laser could make it possible to establish the practical application because of rectangular beam patterns which are suitable to make fine bead with less power. At this power level, it can have many important applications, such as surgery, welding of polymers, soldering, coatings and surface treatment of metals. But there are some applications, which require much higher power and brightness, e.g. hardening, key hole welding, cutting and metal welding. In addition, High power diode lasers in the military field also have important applications. So all developed countries have attached great importance to high-power diode laser system and its applications. This is mainly due their low performance. In this paper we will introduce the structure and the principle of the high power diode stack.

  10. Parametric tests of a traction drive retrofitted to an automotive gas turbine

    Science.gov (United States)

    Rohn, D. A.; Lowenthal, S. H.; Anderson, N. E.

    1980-01-01

    The results of a test program to retrofit a high performance fixed ratio Nasvytis Multiroller Traction Drive in place of a helical gear set to a gas turbine engine are presented. Parametric tests up to a maximum engine power turbine speed of 45,500 rpm and to a power level of 11 kW were conducted. Comparisons were made to similar drives that were parametrically tested on a back-to-back test stand. The drive showed good compatibility with the gas turbine engine. Specific fuel consumption of the engine with the traction drive speed reducer installed was comparable to the original helical gearset equipped engine.

  11. Designing high efficient solar powered lighting systems

    DEFF Research Database (Denmark)

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

    2016-01-01

    Some major challenges in the development of L2L products is the lack of efficient converter electronics, modelling tools for dimensioning and furthermore, characterization facilities to support the successful development of the products. We report the development of 2 Three-Port-Converters respec...

  12. Energy efficiency indicators for high electric-load buildings

    Energy Technology Data Exchange (ETDEWEB)

    Aebischer, Bernard; Balmer, Markus A.; Kinney, Satkartar; Le Strat, Pascale; Shibata, Yoshiaki; Varone, Frederic

    2003-06-01

    Energy per unit of floor area is not an adequate indicator for energy efficiency in high electric-load buildings. For two activities, restaurants and computer centres, alternative indicators for energy efficiency are discussed.

  13. Efficient and Highly Aldehyde Selective Wacker Oxidation

    KAUST Repository

    Teo, Peili; Wickens, Zachary K.; Dong, Guangbin; Grubbs, Robert H.

    2012-01-01

    A method for efficient and aldehyde-selective Wacker oxidation of aryl-substituted olefins using PdCl 2(MeCN) 2, 1,4-benzoquinone, and t-BuOH in air is described. Up to a 96% yield of aldehyde can be obtained, and up to 99% selectivity can be achieved with styrene-related substrates. © 2012 American Chemical Society.

  14. Efficient and Highly Aldehyde Selective Wacker Oxidation

    KAUST Repository

    Teo, Peili

    2012-07-06

    A method for efficient and aldehyde-selective Wacker oxidation of aryl-substituted olefins using PdCl 2(MeCN) 2, 1,4-benzoquinone, and t-BuOH in air is described. Up to a 96% yield of aldehyde can be obtained, and up to 99% selectivity can be achieved with styrene-related substrates. © 2012 American Chemical Society.

  15. Spatial discretization methods for air gap permeance calculations in double salient traction motors

    NARCIS (Netherlands)

    Ilhan, E.; Kremers, M.F.J.; Motoasca, T.E.; Paulides, J.J.H.; Lomonova, E.

    2012-01-01

    Weight limitations in electric/hybrid cars demand the highest possible power-to-weight ratio from the traction motor, as in double salient permanent magnet (PM) machines. Their high flux densities in the air gap result in nonlinear analytical models, which need to be time optimized. The incorporated

  16. Regulation of unbalanced electromagnetic moment in mutual loading systems of electric machines of traction rolling stock and multiple unit of mainline and industrial transport

    Directory of Open Access Journals (Sweden)

    A. M. Afanasov

    2014-12-01

    Full Text Available Purpose. The research data are aimed to identify the regulatory principles of unbalanced electromagnetic moment of mutually loaded electric machines of traction rolling stock and multiple unit of main and industrial transport. The purpose of this study is energy efficiency increase of the testing of traction electric machines of direct and pulse current using the improvement methods of their mutual loading, including the principles of automatic regulation of mutual loading system. Methodology. The general theoretical provisions and principles of system approach to the theoretical electric engineering, the theory of electric machines and theoretical mechanics are the methodological basis of this research. The known methods of analysis of electromagnetic and electromechanical processes in electrical machines of direct and pulse current are used in the study. Methods analysis of loading modes regulation of traction electric machines was conducted using the generalized scheme of mutual loading. It is universal for all known methods to cover the losses of idling using the electric power. Findings. The general management principles of mutual loading modes of the traction electric machines of direct and pulse current by regulating their unbalanced electric magnetic moment were developed. Regulatory options of unbalanced electromagnetic moment are examined by changing the difference of the magnetic fluxes of mutually loaded electric machines, the current difference of electric machines anchors, the difference of the angular velocities of electric machines shafts. Originality. It was obtained the scientific basis development to improve the energy efficiency test methods of traction electric machines of direct and pulse current. The management principles of mutual loading modes of traction electric machines were formulated. For the first time it is introduced the concept and developed the principles of regulation of unbalanced electromagnetic moment in

  17. High efficiency nebulization for helium inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Jorabchi, Kaveh; McCormick, Ryan; Levine, Jonathan A.; Liu Huiying; Nam, S.-H.; Montaser, Akbar

    2006-01-01

    A pneumatically-driven, high efficiency nebulizer is explored for helium inductively coupled plasma mass spectrometry. The aerosol characteristics and analyte transport efficiencies of the high efficiency nebulizer for nebulization with helium are measured and compared to the results obtained with argon. Analytical performance indices of the helium inductively coupled plasma mass spectrometry are evaluated in terms of detection limits and precision. The helium inductively coupled plasma mass spectrometry detection limits obtained with the high efficiency nebulizer at 200 μL/min are higher than those achieved with the ultrasonic nebulizer consuming 2 mL/min solution, however, precision is generally better with high efficiency nebulizer (1-4% vs. 3-8% with ultrasonic nebulizer). Detection limits with the high efficiency nebulizer at 200 μL/min solution uptake rate approach those using ultrasonic nebulizer upon efficient desolvation with a heated spray chamber followed by a Peltier-cooled multipass condenser

  18. Recent Advances in High Efficiency Solar Cells

    Institute of Scientific and Technical Information of China (English)

    Yoshio; Ohshita; Hidetoshi; Suzuki; Kenichi; Nishimura; Masafumi; Yamaguchi

    2007-01-01

    1 Results The conversion efficiency of sunlight to electricity is limited around 25%,when we use single junction solar cells. In the single junction cells,the major energy losses arise from the spectrum mismatching. When the photons excite carriers with energy well in excess of the bandgap,these excess energies were converted to heat by the rapid thermalization. On the other hand,the light with lower energy than that of the bandgap cannot be absorbed by the semiconductor,resulting in the losses. One way...

  19. High efficiency cyclotron trap assisted positron moderator

    OpenAIRE

    Gerchow, L.; Cooke, D. A.; Braccini, S.; Döbeli, M.; Kirch, K.; Köster, U.; Müller, A.; Van Der Meulen, N. P.; Vermeulen, C.; Rubbia, A.; Crivelli, P.

    2017-01-01

    We report the realisation of a cyclotron trap assisted positron tungsten moderator for the conversion of positrons with a broad keV- few MeV energy spectrum to a mono-energetic eV beam with an efficiency of 1.8(2)% defined as the ratio of the slow positrons divided by the $\\beta^+$ activity of the radioactive source. This is an improvement of almost two orders of magnitude compared to the state of the art of tungsten moderators. The simulation validated with this measurement suggests that usi...

  20. A high-efficiency electromechanical battery

    Science.gov (United States)

    Post, Richard F.; Fowler, T. K.; Post, Stephen F.

    1993-03-01

    In our society there is a growing need for efficient cost-effective means for storing electrical energy. The electric auto is a prime example. Storage systems for the electric utilities, and for wind or solar power, are other examples. While electrochemical cells could in principle supply these needs, the existing E-C batteries have well-known limitations. This article addresses an alternative, the electromechanical battery (EMB). An EMB is a modular unit consisting of an evacuated housing containing a fiber-composite rotor. The rotor is supported by magnetic bearings and contains an integrally mounted permanent magnet array. This article addresses design issues for EMBs with rotors made up of nested cylinders. Issues addressed include rotational stability, stress distributions, generator/motor power and efficiency, power conversion, and cost. It is concluded that the use of EMBs in electric autos could result in a fivefold reduction (relative to the IC engine) in the primary energy input required for urban driving, with a concomitant major positive impact on our economy and on air pollution.

  1. Vehicle non-exhaust emissions from the tyre-road interface - effect of stud properties, traction sanding and resuspension

    Science.gov (United States)

    Kupiainen, Kaarle J.; Pirjola, Liisa

    2011-08-01

    In Northern cities respirable street dust emission levels (PM 10) are especially high during spring. The spring time dust has been observed to cause health effects as well as discomfort among citizens. Major sources of the dust are the abrasion products from the pavement and traction sand aggregates that are formed due to the motion of the tyre. We studied the formation of respirable abrasion particles in the tyre-road interface due to tyre studs and traction sanding by a mobile laboratory vehicle Sniffer. The measurements were preformed on a test track, where the influence of varying stud weight and stud number per tyre on PM 10 emissions was studied. Studded tyres resulted in higher emission levels than studless tyres especially with speeds 50 km h -1 and higher; however, by using light weight studs, which approximately halves the weight of studs, or by reducing the number of studs per tyre to half, the emission levels decreased by approximately half. Additionally measurements were done with and without traction sand coverage on the pavement of a public road. After traction sanding the emission levels were not affected by tyre type but by formation and suspension of traction sand related dust from the road surface. The emissions after traction sanding decreased as a function of time as passing vehicles' motion shifted the sand grains away from the areas with most tyre-road contact.

  2. Long-Life, Lightweight, Multi-Roller Traction Drives for Planetary Vehicle Surface Exploration

    Science.gov (United States)

    Klein, Richard C.; Fusaro, Robert L.; Dimofte, Florin

    2012-01-01

    NASA s initiative for Lunar and Martian exploration will require long lived, robust drive systems for manned vehicles that must operate in hostile environments. The operation of these mechanical drives will pose a problem because of the existing extreme operating conditions. Some of these extreme conditions include operating at a very high or very cold temperature, operating over a wide range of temperatures, operating in very dusty environments, operating in a very high radiation environment, and operating in possibly corrosive environments. Current drive systems use gears with various configurations of teeth. These gears must be lubricated with oil (or grease) and must have some sort of a lubricant resupply system. For drive systems, oil poses problems such as evaporation, becoming too viscous and eventually freezing at cold temperatures, being too thin to lubricate at high temperatures, being degraded by the radiation environment, being contaminated by the regolith (soil), and if vaporized (and not sealed), it will contaminate the regolith. Thus, it may not be advisable or even possible to use oil because of these limitations. An oil-less, compact traction vehicle drive is a drive designed for use in hostile environments like those that will be encountered on planetary surfaces. Initially, traction roller tests in vacuum were conducted to obtain traction and endurance data needed for designing the drives. From that data, a traction drive was designed that would fit into a prototype lunar rover vehicle, and this design data was used to construct several traction drives. These drives were then tested in air to determine their performance characteristics, and if any final corrections to the designs were necessary. A limitation with current speed reducer systems such as planetary gears and harmonic drives is the high-contact stresses that occur at tooth engagement and in the harmonic drive wave generator interface. These high stresses induce high wear of solid

  3. Evaluation of Strategies to Reducing Traction Energy Consumption of Metro Systems Using an Optimal Train Control Simulation Model

    Directory of Open Access Journals (Sweden)

    Shuai Su

    2016-02-01

    Full Text Available Increasing attention is being paid to the energy efficiency in metro systems to reduce the operational cost and to advocate the sustainability of railway systems. Classical research has studied the energy-efficient operational strategy and the energy-efficient system design separately to reduce the traction energy consumption. This paper aims to combine the operational strategies and the system design by analyzing how the infrastructure and vehicle parameters of metro systems influence the operational traction energy consumption. Firstly, a solution approach to the optimal train control model is introduced, which is used to design the Optimal Train Control Simulator(OTCS. Then, based on the OTCS, the performance of some important energy-efficient system design strategies is investigated to reduce the trains’ traction energy consumption, including reduction of the train mass, improvement of the kinematic resistance, the design of the energy-saving gradient, increasing the maximum traction and braking forces, introducing regenerative braking and timetable optimization. As for these energy-efficient strategies, the performances are finally evaluated using the OTCS with the practical operational data of the Beijing Yizhuang metro line. The proposed approach gives an example to quantitatively analyze the energy reduction of different strategies in the system design procedure, which may help the decision makers to have an overview of the energy-efficient performances and then to make decisions by balancing the costs and the benefits.

  4. Development of high efficiency neutron detectors

    International Nuclear Information System (INIS)

    Pickrell, M.M.; Menlove, H.O.

    1993-01-01

    The authors have designed a novel neutron detector system using conventional 3 He detector tubes and composites of polyethylene and graphite. At this time the design consists entirely of MCNP simulations of different detector configurations and materials. These detectors are applicable to low-level passive and active neutron assay systems such as the passive add-a-source and the 252 Cf shuffler. Monte Carlo simulations of these neutron detector designs achieved efficiencies of over 35% for assay chambers that can accommodate 55-gal. drums. Only slight increases in the number of detector tubes and helium pressure are required. The detectors also have reduced die-away times. Potential applications are coincident and multiplicity neutron counting for waste disposal and safeguards. The authors will present the general design philosophy, underlying physics, calculation mechanics, and results

  5. High efficient white organic light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, Stefan; Krause, Ralf [Department of Materials Science VI, University of Erlangen-Nuremberg (Germany); Siemens AG, CT MM 1, Erlangen (Germany); Kozlowski, Fryderyk; Schmid, Guenter; Hunze, Arvid [Siemens AG, CT MM 1, Erlangen (Germany); Winnacker, Albrecht [Department of Materials Science VI, University of Erlangen-Nuremberg (Germany)

    2007-07-01

    Due to the rapid progress in the last years the performance of organic light emitting diodes (OLEDs) has reached a level where general lighting presents a most interesting application target. We demonstrate, how the color coordinates of the emission spectrum can be adjusted using a combinatorial evaporation tool to lie on the desired black body curve representing cold and warm white, respectively. The evaluation includes phosphorescent and fluorescent dye approaches to optimize lifetime and efficiency, simultaneously. Detailed results are presented with respect to variation of layer thicknesses and dopant concentrations of each layer within the OLED stack. The most promising approach contains phosphorescent red and green dyes combined with a fluorescent blue one as blue phosphorescent dopants are not yet stable enough to achieve long lifetimes.

  6. High-Efficient Circuits for Ternary Addition

    Directory of Open Access Journals (Sweden)

    Reza Faghih Mirzaee

    2014-01-01

    Full Text Available New ternary adders, which are fundamental components of ternary addition, are presented in this paper. They are on the basis of a logic style which mostly generates binary signals. Therefore, static power dissipation reaches its minimum extent. Extensive different analyses are carried out to examine how efficient the new designs are. For instance, the ternary ripple adder constructed by the proposed ternary half and full adders consumes 2.33 μW less power than the one implemented by the previous adder cells. It is almost twice faster as well. Due to their unique superior characteristics for ternary circuitry, carbon nanotube field-effect transistors are used to form the novel circuits, which are entirely suitable for practical applications.

  7. A high-efficiency superconductor distributed amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Herr, Q P, E-mail: quentin.herr@ngc.co [Northrop Grumman Corporation, 7323 Aviation Boulevard, Baltimore, MD 21240 (United States)

    2010-02-15

    A superconductor output amplifier that converts single-flux-quantum signals to a non-return-to-zero pattern is reported using a twelve-stage distributed amplifier configuration. The output amplitude is measured to be 1.75 mV over a wide bias current range of {+-} 12%. The bit error rate is measured using a Delta-Sigma data pattern to be less than 1 x 10{sup -9} at 10 Gb s{sup -1} per channel. Analysis of the eye diagram suggests that the actual bit error rate may be much lower. The amplifier has power efficiency of 12% neglecting the termination resistor, which may be eliminated from the circuit with a small modification. (rapid communication)

  8. Skeletal traction and intramedullary nailing cost-effectiveness

    African Journals Online (AJOL)

    In the operative group 24 patients had union with one delayed union while in the traction group 12 patients had union, 9 with mal union and 4 delayed union. Conclusion: Intramedullary nailing is more cost-effective than skeletal traction. It met the dominant strategy, because it was significantly less costly than skeletal ...

  9. Traction for low-back pain with or without sciatica

    NARCIS (Netherlands)

    Wegner, I.; Widyahehening, I.S.; van Tulder, M.W.; Blomberg, S.E.I.; de Vet, H.C.W.; Brønfort, G.; Bouter, L.M.; van der Heijden, G.J.

    2013-01-01

    Background Traction has been used to treat low-back pain (LBP), often in combination with other treatments. We included both manual and machine-delivered traction in this review. This is an update of a Cochrane review first published in 1995, and previously updated in 2006. Objectives To assess the

  10. Orthodontic traction of impacted canine using magnet: a case report

    OpenAIRE

    Li, Larry CF; Wong, Ricky WK; King, Nigel M

    2008-01-01

    ABSTRACT: A 15 year and 1 month old Chinese female with palatally impacted upper left canine was successfully treated with an upper removable appliance with a magnet incorporated to provide orthodontic traction force. This case report indicates the possibility of using magnetic force as a safe, effective and comfortable way for orthodontic traction.

  11. Cost effectiveness of using surgery versus skeletal traction in ...

    African Journals Online (AJOL)

    The financial cost benefit of surgery was further complimented by better functional outcomes. Conclusion: The data indicates a cost advantage of managing femoral shaft fracture by surgery compared to traction. Furthermore the longer hospital stay in the traction group is associated with more malunion, limb deformity and ...

  12. THE TRACTION ELECTRIC OPERATION AND ITS EXPLOITATION ABILITIES

    Directory of Open Access Journals (Sweden)

    V. M. Bezruchenko

    2011-04-01

    Full Text Available The possibilities of asynchronous traction electric motor drive are considered at the certain coupling mass taking into account the coupling restrictions. A variant of using the regulation law for electric motor drive allowing realizing traction force more rationally is offered. The possibility of reaching the speeds to 220 km/h for electric locomotive DS3 is shown

  13. High Efficiency Regenerative Helium Compressor, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Helium plays several critical rolls in spacecraft propulsion. High pressure helium is commonly used to pressurize propellant fuel tanks. Helium cryocoolers can be...

  14. Highly Efficient, Durable Regenerative Solid Oxide Stack, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Precision Combustion, Inc. (PCI) proposes to develop a highly efficient regenerative solid oxide stack design. Novel structural elements allow direct internal...

  15. Electric vehicle regenerative antiskid braking and traction control system

    Science.gov (United States)

    Cikanek, Susan R.

    1995-01-01

    An antiskid braking and traction control system for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes one or more sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensors and determining if regenerative antiskid braking control, requiring hydrualic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control.

  16. Alignment of displaced or impacted teeth with the traction chain.

    Science.gov (United States)

    Sander, Franz Martin; Sander, Christian; Sander, Franz Günter

    2006-07-01

    To align those teeth in the dental arch that cannot erupt or are displaced, they must be surgically exposed. After the traction device is attached, the tooth is again covered with the mucoperiosteal flap to protect the tissues involved. For this reason, the loss of this traction device must be absolutely avoided in order to prevent another surgical intervention. Here at the University of Ulm, we have developed and tested an optimized traction chain for that purpose. The chain is attached to the tooth with a laser-roughened pad applying the acid-etching technique. The chain links serve as fixation elements for traction devices such as elastic ligatures or piggyback archwires. At the same time, one can determine the distance covered by the tooth by the number of the erupting chain links. We demonstrate the clinical application of this traction device in two cases.

  17. Electric vehicle regenerative antiskid braking and traction control system

    Science.gov (United States)

    Cikanek, S.R.

    1995-09-12

    An antiskid braking and traction control system for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes one or more sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensors and determining if regenerative antiskid braking control, requiring hydraulic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control. 10 figs.

  18. High-efficiency airfoil rudders applied to submarines

    Directory of Open Access Journals (Sweden)

    ZHOU Yimei

    2017-03-01

    Full Text Available Modern submarine design puts forward higher and higher requirements for control surfaces, and this creates a requirement for designers to constantly innovate new types of rudder so as to improve the efficiency of control surfaces. Adopting the high-efficiency airfoil rudder is one of the most effective measures for improving the efficiency of control surfaces. In this paper, we put forward an optimization method for a high-efficiency airfoil rudder on the basis of a comparative analysis of the various strengths and weaknesses of the airfoil, and the numerical calculation method is adopted to analyze the influence rule of the hydrodynamic characteristics and wake field by using the high-efficiency airfoil rudder and the conventional NACA rudder comparatively; at the same time, a model load test in a towing tank was carried out, and the test results and simulation calculation obtained good consistency:the error between them was less than 10%. The experimental results show that the steerage of a high-efficiency airfoil rudder is increased by more than 40% when compared with the conventional rudder, but the total resistance is close:the error is no more than 4%. Adopting a high-efficiency airfoil rudder brings much greater lifting efficiency than the total resistance of the boat. The results show that high-efficiency airfoil rudder has obvious advantages for improving the efficiency of control, giving it good application prospects.

  19. Novel Transverse Flux Machine for Vehicle Traction Applications: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Z.; Ahmed, A.; Husain, I.; Muljadi, E.

    2015-04-02

    A novel transverse flux machine topology for electric vehicle traction applications using ferrite magnets is presented in this paper. The proposed transverse flux topology utilizes novel magnet arrangements in the rotor that are similar to the Halbach array to boost flux linkage; on the stator side, cores are alternately arranged around a pair of ring windings in each phase to make use of the entire rotor flux that eliminates end windings. Analytical design considerations and finite-element methods are used for an optimized design of a scooter in-wheel motor. Simulation results from finite element analysis (FEA) show that the motor achieved comparable torque density to conventional rare-earth permanent magnet (PM) machines. This machine is a viable candidate for direct-drive applications with low cost and high torque density.

  20. High Efficiency, High Density Terrestrial Panel. [for solar cell modules

    Science.gov (United States)

    Wohlgemuth, J.; Wihl, M.; Rosenfield, T.

    1979-01-01

    Terrestrial panels were fabricated using rectangular cells. Packing densities in excess of 90% with panel conversion efficiencies greater than 13% were obtained. Higher density panels can be produced on a cost competitive basis with the standard salami panels.

  1. Design of salient pole PM synchronous machines for a vehicle traction application. Analysis and implementation

    Energy Technology Data Exchange (ETDEWEB)

    Rilla, M.

    2012-07-01

    This doctoral thesis presents a study on the development of a liquid-cooled frame salient pole permanent-magnet-exited traction machine for a four-wheel-driven electric car. The emphasis of the thesis is put on a radial flux machine design in order to achieve a light-weight machine structure for traction applications. The design features combine electromagnetic and thermal design methods, because traction machine operation does not have a strict operating point. Arbitrary load cycles and the flexible supply require special attention in the design process. It is shown that accurate modelling of the machine magnetic state is essential for high-performance operation. The saturation effect related to the cross-saturation has to be taken carefully into account in order to achieve the desired operation. Two prototype machines have been designed and built for testing: one totally enclosed machine with a special magnet module pole arrangement and another through-ventilated machine with a more traditional embedded magnet structure. Both structures are built with magnetically salient structures in order to increase the torque production capability with the reluctance torque component. Both machine structures show potential for traction usage. However, the traditional embedded magnet design turns out to be mechanically the more secure one of these two machine options. (orig.)

  2. Distributed Active Traction Control System Applied to the RoboCup Middle Size League

    Directory of Open Access Journals (Sweden)

    José Almeida

    2013-10-01

    Full Text Available This work addresses the problem of traction control in mobile wheeled robots in the particular case of the RoboCup Middle Size League (MSL. The slip control problem is formulated using simple friction models for ISePorto Team Robots with a differential wheel configuration. Traction was also characterized experimentally in the MSL scenario for relevant game events. This work proposes a hierarchical traction control architecture which relies on local slip detection and control at each wheel, with relevant information being relayed to a higher level responsible for global robot motion control. A dedicated one axis control embedded hardware subsystem allowing complex local control, high frequency current sensing and odometric information procession was developed. This local axis control board is integrated in a distributed system using CAN bus communications. The slipping observer was implemented in the axis control hardware nodes integrated in the ISePorto Robots and was used to control and detect loss of traction. An external vision system was used to perform a qualitative analysis of the slip detection and observer performance results are presented.

  3. 40 CFR 761.71 - High efficiency boilers.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false High efficiency boilers. 761.71... PROHIBITIONS Storage and Disposal § 761.71 High efficiency boilers. (a) To burn mineral oil dielectric fluid containing a PCB concentration of ≥50 ppm, but boiler shall comply with the following...

  4. HIGH EFFICIENCY DESULFURIZATION OF SYNTHESIS GAS

    Energy Technology Data Exchange (ETDEWEB)

    Anirban Mukherjee; Kwang-Bok Yi; Elizabeth J. Podlaha; Douglas P. Harrison

    2001-11-01

    Mixed metal oxides containing CeO{sub 2} and ZrO{sub 2} are being studied as high temperature desulfurization sorbents capable of achieving the DOE Vision 21 target of 1 ppmv of less H{sub 2}S. The research is justified by recent results in this laboratory that showed that reduced CeO{sub 2}, designated CeO{sub n} (1.5 < n < 2.0), is capable of achieving the 1 ppmv target in highly reducing gas atmospheres. The addition of ZrO{sub 2} has improved the performance of oxidation catalysts and three-way automotive catalysts containing CeO{sub 2}, and should have similar beneficial effects on CeO{sub 2} desulfurization sorbents. An electrochemical method for synthesizing CeO{sub 2}-ZrO{sub 2} has been developed and the products have been characterized by XRD and TEM during year 01. Nanocrystalline particles having a diameter of about 5 nm and containing from approximately 10 mol% to 80 mol% ZrO{sub 2} have been prepared. XRD showed the product to be a solid solution at low ZrO{sub 2} contents with a separate ZrO{sub 2} phase emerging at higher ZrO{sub 2} levels. Phase separation did not occur when the solid solutions were heat treated at 700 C. A flow reactor system constructed of quartz and teflon has been constructed, and a gas chromatograph equipped with a pulsed flame photometric detector (PFPD) suitable for measuring sub-ppmv levels of H{sub 2}S has been purchased with LSU matching funds. Preliminary desulfurization tests using commercial CeO{sub 2} and CeO{sub 2}-ZrO{sub 2} in highly reducing gas compositions has confirmed that CeO{sub 2}-ZrO{sub 2} is more effective than CeO{sub 2} in removing H{sub 2}S. At 700 C the product H{sub 2}S concentration using CeO{sub 2}-ZrO{sub 2} sorbent was near the 0.1 ppmv PFPD detection limit during the prebreakthrough period.

  5. Highly efficient induction of chirality in intramolecular

    Science.gov (United States)

    Cossio; Arrieta; Lecea; Alajarin; Vidal; Tovar

    2000-06-16

    Highly stereocontrolled, intramolecular [2 + 2] cycloadditions between ketenimines and imines leading to 1,2-dihydroazeto[2, 1-b]quinazolines have been achieved. The source of stereocontrol is a chiral carbon atom adjacent either to the iminic carbon or nitrogen atom. In the first case, the stereocontrol stems from the preference for the axial conformer in the first transition structure. In the second case, the origin of the stereocontrol lies on the two-electron stabilizing interaction between the C-C bond being formed and the sigma orbital corresponding to the polar C-X bond, X being an electronegative atom. These models can be extended to other related systems for predicting the stereochemical outcome in this intramolecular reaction.

  6. High Efficiency, Low Cost Scintillators for PET

    International Nuclear Information System (INIS)

    Kanai Shah

    2007-01-01

    Inorganic scintillation detectors coupled to PMTs are an important element of medical imaging applications such as positron emission tomography (PET). Performance as well as cost of these systems is limited by the properties of the scintillation detectors available at present. The Phase I project was aimed at demonstrating the feasibility of producing high performance scintillators using a low cost fabrication approach. Samples of these scintillators were produced and their performance was evaluated. Overall, the Phase I effort was very successful. The Phase II project will be aimed at advancing the new scintillation technology for PET. Large samples of the new scintillators will be produced and their performance will be evaluated. PET modules based on the new scintillators will also be built and characterized

  7. Compact and highly efficient laser pump cavity

    Science.gov (United States)

    Chang, Jim J.; Bass, Isaac L.; Zapata, Luis E.

    1999-01-01

    A new, compact, side-pumped laser pump cavity design which uses non-conventional optics for injection of laser-diode light into a laser pump chamber includes a plurality of elongated light concentration channels. In one embodiment, the light concentration channels are compound parabolic concentrators (CPC) which have very small exit apertures so that light will not escape from the pumping chamber and will be multiply reflected through the laser rod. This new design effectively traps the pump radiation inside the pump chamber that encloses the laser rod. It enables more uniform laser pumping and highly effective recycle of pump radiation, leading to significantly improved laser performance. This new design also effectively widens the acceptable radiation wavelength of the diodes, resulting in a more reliable laser performance with lower cost.

  8. HIGH EFFICIENCY DESULFURIZATION OF SYNTHESIS GAS

    Energy Technology Data Exchange (ETDEWEB)

    Kwang-Bok Yi; Anirban Mukherjee; Elizabeth J. Podlaha; Douglas P. Harrison

    2004-03-01

    Mixed metal oxides containing ceria and zirconia have been studied as high temperature desulfurization sorbents with the objective of achieving the DOE Vision 21 target of 1 ppmv or less H{sub 2}S in the product gas. The research was justified by recent results in this laboratory that showed that reduced CeO{sub 2}, designated CeOn (1.5 < n < 2.0), is capable of achieving the 1 ppmv target in highly reducing gas atmospheres. The addition of ZrO{sub 2} has improved the performance of oxidation catalysts and three-way automotive catalysts containing CeO{sub 2}, and was postulated to have similar beneficial effects on CeO{sub 2} desulfurization sorbents. An electrochemical method for synthesizing CeO{sub 2}-ZrO{sub 2} mixtures was developed and the products were characterized by XRD and TEM during year 01. Nanocrystalline particles having a diameter of about 5 nm and containing from approximately 10 mol% to 80 mol% ZrO{sub 2} were prepared. XRD analysis showed the product to be a solid solution at low ZrO{sub 2} contents with a separate ZrO{sub 2} phase emerging at higher ZrO{sub 2} levels. Unfortunately, the quantity of CeO{sub 2}-ZrO{sub 2} that could be prepared electrochemically was too small to permit desulfurization testing. Also during year 01 a laboratory-scale fixed-bed reactor was constructed for desulfurization testing. All components of the reactor and analytical systems that were exposed to low concentrations of H{sub 2}S were constructed of quartz, Teflon, or silcosteel. Reactor product gas composition as a function of time was determined using a Varian 3800 gas chromatograph equipped with a pulsed flame photometric detector (PFPD) for measuring low H{sub 2}S concentrations from approximately 0.1 to 10 ppmv, and a thermal conductivity detector (TCD) for higher concentrations of H{sub 2}S. Larger quantities of CeO{sub 2}-ZrO{sub 2} mixtures from other sources, including mixtures prepared in this laboratory using a coprecipitation procedure, were obtained

  9. Toward single cell traction microscopy within 3D collagen matrices

    International Nuclear Information System (INIS)

    Hall, Matthew S.; Long, Rong; Feng, Xinzeng; Huang, YuLing; Hui, Chung-Yuen; Wu, Mingming

    2013-01-01

    Mechanical interaction between the cell and its extracellular matrix (ECM) regulates cellular behaviors, including proliferation, differentiation, adhesion, and migration. Cells require the three-dimensional (3D) architectural support of the ECM to perform physiologically realistic functions. However, current understanding of cell–ECM and cell–cell mechanical interactions is largely derived from 2D cell traction force microscopy, in which cells are cultured on a flat substrate. 3D cell traction microscopy is emerging for mapping traction fields of single animal cells embedded in either synthetic or natively derived fibrous gels. We discuss here the development of 3D cell traction microscopy, its current limitations, and perspectives on the future of this technology. Emphasis is placed on strategies for applying 3D cell traction microscopy to individual tumor cell migration within collagen gels. - Highlights: • Review of the current state of the art in 3D cell traction force microscopy. • Bulk and micro-characterization of remodelable fibrous collagen gels. • Strategies for performing 3D cell traction microscopy within collagen gels

  10. Toward single cell traction microscopy within 3D collagen matrices

    Energy Technology Data Exchange (ETDEWEB)

    Hall, Matthew S. [Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853 (United States); Long, Rong [Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada T6G 2G8 (Canada); Feng, Xinzeng [Department of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14853 (United States); Huang, YuLing [Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853 (United States); Hui, Chung-Yuen [Department of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14853 (United States); Wu, Mingming, E-mail: mw272@cornell.edu [Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853 (United States)

    2013-10-01

    Mechanical interaction between the cell and its extracellular matrix (ECM) regulates cellular behaviors, including proliferation, differentiation, adhesion, and migration. Cells require the three-dimensional (3D) architectural support of the ECM to perform physiologically realistic functions. However, current understanding of cell–ECM and cell–cell mechanical interactions is largely derived from 2D cell traction force microscopy, in which cells are cultured on a flat substrate. 3D cell traction microscopy is emerging for mapping traction fields of single animal cells embedded in either synthetic or natively derived fibrous gels. We discuss here the development of 3D cell traction microscopy, its current limitations, and perspectives on the future of this technology. Emphasis is placed on strategies for applying 3D cell traction microscopy to individual tumor cell migration within collagen gels. - Highlights: • Review of the current state of the art in 3D cell traction force microscopy. • Bulk and micro-characterization of remodelable fibrous collagen gels. • Strategies for performing 3D cell traction microscopy within collagen gels.

  11. All passive architecture for high efficiency cascaded Raman conversion

    Science.gov (United States)

    Balaswamy, V.; Arun, S.; Chayran, G.; Supradeepa, V. R.

    2018-02-01

    Cascaded Raman fiber lasers have offered a convenient method to obtain scalable, high-power sources at various wavelength regions inaccessible with rare-earth doped fiber lasers. A limitation previously was the reduced efficiency of these lasers. Recently, new architectures have been proposed to enhance efficiency, but this came at the cost of enhanced complexity, requiring an additional low-power, cascaded Raman laser. In this work, we overcome this with a new, all-passive architecture for high-efficiency cascaded Raman conversion. We demonstrate our architecture with a fifth-order cascaded Raman converter from 1117nm to 1480nm with output power of ~64W and efficiency of 60%.

  12. Effects of Different Angles of the Traction Table on Lumbar Spine Ligaments: A Finite Element Study.

    Science.gov (United States)

    Farajpour, Hekmat; Jamshidi, Nima

    2017-12-01

    The traction bed is a noninvasive device for treating lower back pain caused by herniated intervertebral discs. In this study, we investigated the impact of the traction bed on the lower back as a means of increasing the disc height and creating a gap between facet joints. Computed tomography (CT) images were obtained from a female volunteer and a three-dimensional (3D) model was created using software package MIMICs 17.0. Afterwards, the 3D model was analyzed in an analytical software (Abaqus 6.14). The study was conducted under the following traction loads: 25%, 45%, 55%, and 85% of the whole body weight in different angles. Results indicated that the loading angle in the L3-4 area had 36.8%, 57.4%, 55.32%, 49.8%, and 52.15% effect on the anterior longitudinal ligament, posterior longitudinal ligament, intertransverse ligament, interspinous ligament, and supraspinous ligament, respectively. The respective values for the L4-5 area were 32.3%, 10.6%, 53.4%, 56.58%, and 57.35%. Also, the body weight had 63.2%, 42.6%, 44.68%, 50.2%, and 47.85% effect on the anterior longitudinal ligament, posterior longitudinal ligament, intertransverse ligament, interspinous ligament, and supraspinous ligament, respectively. The respective values for the L4-5 area were 67.7%, 89.4%, 46.6%, 43.42% and 42.65%. The authenticity of results was checked by comparing with the experimental data. The results show that traction beds are highly effective for disc movement and lower back pain relief. Also, an optimal angle for traction can be obtained in a 3D model analysis using CT or magnetic resonance imaging images. The optimal angle would be different for different patients and thus should be determined based on the decreased height of the intervertebral disc, weight and height of patients.

  13. Targeted traction of impacted teeth with C-tube miniplates.

    Science.gov (United States)

    Chung, Kyu-Rhim; Kim, Yong; Ahn, Hyo-Won; Lee, Dongjoo; Yang, Dong-Min; Kim, Seong-Hun; Nelson, Gerald

    2014-09-01

    Orthodontic traction of impacted teeth has typically been performed using full fixed appliance as anchorage against the traction force. This conventional approach can be difficult to apply in the mixed dentition if the partial fixed appliance offers an insufficient anchor unit. In addition, full fixed appliance can induce unwanted movement of adjacent teeth. This clinical report presents 3 cases where impacted teeth were recovered in the mixed or transitional dentition with skeletal anchorage on the opposite arch without full fixed appliance. Instead, intermaxillary traction was used to bring the impacted teeth into position. With this approach, side effects on teeth and periodontal tissues adjacent to the impaction were minimized.

  14. Stabilization void-fill encapsulation high-efficiency particulate filters

    International Nuclear Information System (INIS)

    Alexander, R.G.; Stewart, W.E.; Phillips, S.J.; Serkowski, M.M.; England, J.L.; Boynton, H.C.

    1994-05-01

    This report discusses high-efficiency particulate air (HEPA) filter systems that which are contaminated with radionuclides are part of the nuclear fuel processing systems conducted by the US Department of Energy (DOE) and require replacement and safe and efficient disposal for plant safety. Two K-3 HEPA filters were removed from service, placed burial boxes, buried, and safely and efficiently stabilized remotely which reduced radiation exposure to personnel and the environment

  15. Design of High Efficiency Illumination for LED Lighting

    OpenAIRE

    Chang, Yong-Nong; Cheng, Hung-Liang; Kuo, Chih-Ming

    2013-01-01

    A high efficiency illumination for LED street lighting is proposed. For energy saving, this paper uses Class-E resonant inverter as main electric circuit to improve efficiency. In addition, single dimming control has the best efficiency, simplest control scheme and lowest circuit cost among other types of dimming techniques. Multiple serial-connected transformers used to drive the LED strings as they can provide galvanic isolation and have the advantage of good current distribution against de...

  16. The Energy Efficiency of High Intensity Proton Driver Concepts

    Energy Technology Data Exchange (ETDEWEB)

    Yakovlev, Vyacheslav [Fermilab; Grillenberger, Joachim [PSI, Villigen; Kim, Sang-Ho [ORNL, Oak Ridge (main); Seidel, Mike [PSI, Villigen; Yoshii, Masahito [JAEA, Ibaraki

    2017-05-01

    For MW class proton driver accelerators the energy efficiency is an important aspect; the talk reviews the efficiency of different accelerator concepts including s.c./n.c. linac, rapid cycling synchrotron, cyclotron; the potential of these concepts for very high beam power is discussed.

  17. High Efficiency Lighting with Integrated Adaptive Control (HELIAC), Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed project is the continued development of the High Efficiency Lighting with Integrated Adaptive Control (HELIAC) system. Solar radiation is not a viable...

  18. High Efficiency Lighting with Integrated Adaptive Control (HELIAC), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation of the proposed project is the development of High Efficiency Lighting with Integrated Adaptive Control (HELIAC) systems to drive plant growth. Solar...

  19. Efficiency of poly-generating high temperature fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Margalef, Pere; Brown, Tim; Brouwer, Jacob; Samuelsen, Scott [National Fuel Cell Research Center (NFCRC), University of California, Irvine, CA 92697-3550 (United States)

    2011-02-15

    High temperature fuel cells can be designed and operated to poly-generate electricity, heat, and useful chemicals (e.g., hydrogen) in a variety of configurations. The highly integrated and synergistic nature of poly-generating high temperature fuel cells, however, precludes a simple definition of efficiency for analysis and comparison of performance to traditional methods. There is a need to develop and define a methodology to calculate each of the co-product efficiencies that is useful for comparative analyses. Methodologies for calculating poly-generation efficiencies are defined and discussed. The methodologies are applied to analysis of a Hydrogen Energy Station (H{sub 2}ES) showing that high conversion efficiency can be achieved for poly-generation of electricity and hydrogen. (author)

  20. An Improved, Highly Efficient Method for the Synthesis of Bisphenols

    Directory of Open Access Journals (Sweden)

    L. S. Patil

    2011-01-01

    Full Text Available An efficient synthesis of bisphenols is described by condensation of substituted phenols with corresponding cyclic ketones in presence of cetyltrimethylammonium chloride and 3-mercaptopropionic acid as a catalyst in extremely high purity and yields.

  1. High Efficiency S-Band 20 Watt Amplifier

    Data.gov (United States)

    National Aeronautics and Space Administration — This project includes the design and build of a prototype 20 W, high efficiency, S-Band amplifier.   The design will incorporate the latest semiconductor technology,...

  2. Adaptive control system of dump truck traction electric drive

    Science.gov (United States)

    Bolshunova, O. M.; Korzhev, A. A.; Kamyshyan, A. M.

    2018-03-01

    The paper describes the operational factors that determine the accident rate of a quarry motor vehicle and assessment of their impact on the choice of the operation mode of the traction drive control system.

  3. Intravitreal injection of perfluoropropane for the treatment of vitreomacular traction

    Directory of Open Access Journals (Sweden)

    Xiao-Ping Wan

    2013-07-01

    Full Text Available AIM: To study the efficacy of a single intravitreal injection of perfluoropropane(C3F8in releasing vitreomacular traction. METHODS: Twelve eyes of 12 consecutive patients with vitreomacular traction received a single intravitreal injection of 0.3mL 100%(C3F8were retrospectively analyzed. The best corrected vision acuity and the neural epithelium thickness of central macular were observed. RESULTS: One month following treatment, vitreomacular traction was released in 5 eyes(42%, mean final visual acuity(VAimproved 0.04 and mean central foveal thickness decreased by 69μm. The vision acuity before and after treatment were 0.20±0.07, 0.25±0.04 respectively.CONCLUSION: Intravitreal C3F8 injection could offer a minimally invasive alternative to pars plana vitrectomy in patients with vitreomacular traction.

  4. THE FLOW ANALYSIS ABOUT TRACTION OF QUARRY TRAINS

    Directory of Open Access Journals (Sweden)

    G. K. Getman

    2010-04-01

    Full Text Available The method of determination of constituents of expense of electric power on traction of quarry trains is resulted in the article, and also the degree of their intercommunication with the mode of train motion is analysed.

  5. Process development for high-efficiency silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Gee, J.M.; Basore, P.A.; Buck, M.E.; Ruby, D.S.; Schubert, W.K.; Silva, B.L.; Tingley, J.W.

    1991-12-31

    Fabrication of high-efficiency silicon solar cells in an industrial environment requires a different optimization than in a laboratory environment. Strategies are presented for process development of high-efficiency silicon solar cells, with a goal of simplifying technology transfer into an industrial setting. The strategies emphasize the use of statistical experimental design for process optimization, and the use of baseline processes and cells for process monitoring and quality control. 8 refs.

  6. Highly efficient procedure for the transesterification of vegetable oil

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Xuezheng; Gao, Shan; He, Mingyuan [Shanghai Key Laboratory of Green Chemistry and Chemical Process, Department of Chemistry, East China Normal University, Shanghai 200062 (China); Yang, Jianguo [Shanghai Key Laboratory of Green Chemistry and Chemical Process, Department of Chemistry, East China Normal University, Shanghai 200062 (China); Energy Institute, Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States)

    2009-10-15

    The highly efficient procedure has been developed for the synthesis of biodiesel from vegetable oil and methanol. The KF/MgO has been selected as the most efficient catalyst for the reactions with the yield of 99.3%. Operational simplicity, without need of the purification of raw vegetable oil, low cost of the catalyst used, high activities, no saponification and reusability are the key features of this methodology. (author)

  7. The photonic nanowire: A highly efficient single-photon source

    DEFF Research Database (Denmark)

    Gregersen, Niels

    2014-01-01

    The photonic nanowire represents an attractive platform for a quantum light emitter. However, careful optical engineering using the modal method, which elegantly allows access to all relevant physical parameters, is crucial to ensure high efficiency.......The photonic nanowire represents an attractive platform for a quantum light emitter. However, careful optical engineering using the modal method, which elegantly allows access to all relevant physical parameters, is crucial to ensure high efficiency....

  8. Highly Efficient Spontaneous Emission from Self-Assembled Quantum Dots

    DEFF Research Database (Denmark)

    Johansen, Jeppe; Lund-Hansen, Toke; Hvam, Jørn Märcher

    2006-01-01

    We present time resolved measurements of spontaneous emission (SE) from InAs/GaAs quantum dots (QDs). The measurements are interpreted using Fermi's Golden Rule and from this analysis we establish the parameters for high quantum efficiency.......We present time resolved measurements of spontaneous emission (SE) from InAs/GaAs quantum dots (QDs). The measurements are interpreted using Fermi's Golden Rule and from this analysis we establish the parameters for high quantum efficiency....

  9. Global climate change: Mitigation opportunities high efficiency large chiller technology

    Energy Technology Data Exchange (ETDEWEB)

    Stanga, M.V.

    1997-12-31

    This paper, comprised of presentation viewgraphs, examines the impact of high efficiency large chiller technology on world electricity consumption and carbon dioxide emissions. Background data are summarized, and sample calculations are presented. Calculations show that presently available high energy efficiency chiller technology has the ability to substantially reduce energy consumption from large chillers. If this technology is widely implemented on a global basis, it could reduce carbon dioxide emissions by 65 million tons by 2010.

  10. Tractional retinal detachment in Usher syndrome type II.

    Science.gov (United States)

    Rani, Alka; Pal, Nikhil; Azad, Raj Vardhan; Sharma, Yog Raj; Chandra, Parijat; Vikram Singh, Deependra

    2005-08-01

    Retinal detachment is a rare complication in patients with retinitis pigmentosa. A case is reported of tractional retinal detachment in a patient with retinitis pigmentosa and sensorineural hearing loss, which was diagnosed as Usher syndrome type II. Because of the poor visual prognosis, the patient refused surgery in that eye. Tractional retinal detachment should be added to the differential diagnoses of visual loss in patients with retinitis pigmentosa.

  11. Traction Stresses Exerted by Adherent Cells: From Angiogenesis to Metastasis

    Science.gov (United States)

    Reinhart-King, Cynthia

    2010-03-01

    Cells exert traction stresses against their substrate that mediate their ability to sense the mechanical properties of their microenvironment. These same forces mediate cell adhesion, migration and the formation of stable cell-cell contacts during tissue formation. In this talk, I will present our data on the traction stresses generated by endothelial cells and metastatic breast cancer cells focused on understanding the processes of angiogenesis and metastasis, respectively. In the context of capillary formation, our data indicate that the mechanics of the substrate play a critical role in establishing endothelial cell-cell contacts. On more compliant substrates, endothelial cell shape and traction stresses polarize and promote the formation of stable cell-cell contacts. On stiffer substrates, traction stresses are less polarized and cell connectivity is disrupted. These data indicate that the mechanical properties of the microenvironment may drive cell connectivity and the formation of stable cell-cell contacts through the reorientation of traction stresses. In our studies of metastatic cell migration, we have found that traction stresses increase with increasing metastatic potential. We investigated three lines of varying metastatic potential (MCF10A, MCF7 and MDAMB231). MDAMB231, which are the most invasive, exert the most significant forces as measured by Traction Force Microscopy. These data present the possibility that cellular traction stress generation aids in the ability of metastatic cells to migrate through the matrix-dense tumor microenvironment. Such measurements are integral to link the mechanical and chemical microenvironment with the resulting response of the cell in health and disease.

  12. High efficiency USC power plant - present status and future potential

    Energy Technology Data Exchange (ETDEWEB)

    Blum, R. [Faelleskemikerne I/S Fynsvaerket (Denmark); Hald, J. [Elsam/Elkraft/TU Denmark (Denmark)

    1998-12-31

    Increasing demand for energy production with low impact on the environment and minimised fuel consumption can be met with high efficient coal fired power plants with advanced steam parameters. An important key to this improvement is the development of high temperature materials with optimised mechanical strength. Based on the results of more than ten years of development a coal fired power plant with an efficiency above 50 % can now be realised. Future developments focus on materials which enable an efficiency of 52-55 %. (orig.) 25 refs.

  13. High efficiency USC power plant - present status and future potential

    Energy Technology Data Exchange (ETDEWEB)

    Blum, R [Faelleskemikerne I/S Fynsvaerket (Denmark); Hald, J [Elsam/Elkraft/TU Denmark (Denmark)

    1999-12-31

    Increasing demand for energy production with low impact on the environment and minimised fuel consumption can be met with high efficient coal fired power plants with advanced steam parameters. An important key to this improvement is the development of high temperature materials with optimised mechanical strength. Based on the results of more than ten years of development a coal fired power plant with an efficiency above 50 % can now be realised. Future developments focus on materials which enable an efficiency of 52-55 %. (orig.) 25 refs.

  14. Integral Sensor Fault Detection and Isolation for Railway Traction Drive.

    Science.gov (United States)

    Garramiola, Fernando; Del Olmo, Jon; Poza, Javier; Madina, Patxi; Almandoz, Gaizka

    2018-05-13

    Due to the increasing importance of reliability and availability of electric traction drives in Railway applications, early detection of faults has become an important key for Railway traction drive manufacturers. Sensor faults are important sources of failures. Among the different fault diagnosis approaches, in this article an integral diagnosis strategy for sensors in traction drives is presented. Such strategy is composed of an observer-based approach for direct current (DC)-link voltage and catenary current sensors, a frequency analysis approach for motor current phase sensors and a hardware redundancy solution for speed sensors. None of them requires any hardware change requirement in the actual traction drive. All the fault detection and isolation approaches have been validated in a Hardware-in-the-loop platform comprising a Real Time Simulator and a commercial Traction Control Unit for a tram. In comparison to safety-critical systems in Aerospace applications, Railway applications do not need instantaneous detection, and the diagnosis is validated in a short time period for reliable decision. Combining the different approaches and existing hardware redundancy, an integral fault diagnosis solution is provided, to detect and isolate faults in all the sensors installed in the traction drive.

  15. Charge transport in highly efficient iridium cored electrophosphorescent dendrimers

    Science.gov (United States)

    Markham, Jonathan P. J.; Samuel, Ifor D. W.; Lo, Shih-Chun; Burn, Paul L.; Weiter, Martin; Bässler, Heinz

    2004-01-01

    Electrophosphorescent dendrimers are promising materials for highly efficient light-emitting diodes. They consist of a phosphorescent core onto which dendritic groups are attached. Here, we present an investigation into the optical and electronic properties of highly efficient phosphorescent dendrimers. The effect of dendrimer structure on charge transport and optical properties is studied using temperature-dependent charge-generation-layer time-of-flight measurements and current voltage (I-V) analysis. A model is used to explain trends seen in the I-V characteristics. We demonstrate that fine tuning the mobility by chemical structure is possible in these dendrimers and show that this can lead to highly efficient bilayer dendrimer light-emitting diodes with neat emissive layers. Power efficiencies of 20 lm/W were measured for devices containing a second-generation (G2) Ir(ppy)3 dendrimer with a 1,3,5-tris(2-N-phenylbenzimidazolyl)benzene electron transport layer.

  16. Very-High Efficiency, High Power Laser Diodes, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — AdTech Photonics, in collaboration with the Center for Advanced Studies in Photonics Research (CASPR) at UMBC, is pleased to submit this proposal entitled ?Very-High...

  17. [Characteristics of phosphorus uptake and use efficiency of rice with high yield and high phosphorus use efficiency].

    Science.gov (United States)

    Li, Li; Zhang, Xi-Zhou; Li, Tinx-Xuan; Yu, Hai-Ying; Ji, Lin; Chen, Guang-Deng

    2014-07-01

    A total of twenty seven middle maturing rice varieties as parent materials were divided into four types based on P use efficiency for grain yield in 2011 by field experiment with normal phosphorus (P) application. The rice variety with high yield and high P efficiency was identified by pot experiment with normal and low P applications, and the contribution rates of various P efficiencies to yield were investigated in 2012. There were significant genotype differences in yield and P efficiency of the test materials. GRLu17/AiTTP//Lu17_2 (QR20) was identified as a variety with high yield and high P efficiency, and its yields at the low and normal rates of P application were 1.96 and 1.92 times of that of Yuxiang B, respectively. The contribution rate of P accumulation to yield was greater than that of P grain production efficiency and P harvest index across field and pot experiments. The contribution rates of P accumulation and P grain production efficiency to yield were not significantly different under the normal P condition, whereas obvious differences were observed under the low P condition (66.5% and 26.6%). The minimal contribution to yield was P harvest index (11.8%). Under the normal P condition, the contribution rates of P accumulation to yield and P harvest index were the highest at the jointing-heading stage, which were 93.4% and 85.7%, respectively. In addition, the contribution rate of P accumulation to grain production efficiency was 41.8%. Under the low P condition, the maximal contribution rates of P accumulation to yield and grain production efficiency were observed at the tillering-jointing stage, which were 56.9% and 20.1% respectively. Furthermore, the contribution rate of P accumulation to P harvest index was 16.0%. The yield, P accumulation, and P harvest index of QR20 significantly increased under the normal P condition by 20.6%, 18.1% and 18.2% respectively compared with that in the low P condition. The rank of the contribution rates of P

  18. High Efficiency of Two Efficient QSDC with Authentication Is at the Cost of Their Security

    International Nuclear Information System (INIS)

    Su-Juan, Qin; Qiao-Yan, Wen; Luo-Ming, Meng; Fu-Chen, Zhu

    2009-01-01

    Two efficient protocols of quantum secure direct communication with authentication [Chin. Phys. Lett. 25 (2008) 2354] were recently proposed by Liu et al. to improve the efficiency of two protocols presented in [Phys. Rev. A 75 (2007) 026301] by four Pauli operations. We show that the high efficiency of the two protocols is at the expense of their security. The authenticator Trent can reach half the secret by a particular attack strategy in the first protocol. In the second protocol, not only Trent but also an eavesdropper outside can elicit half-information about the secret from the public declaration

  19. The emerging High Efficiency Video Coding standard (HEVC)

    International Nuclear Information System (INIS)

    Raja, Gulistan; Khan, Awais

    2013-01-01

    High definition video (HDV) is becoming popular day by day. This paper describes the performance analysis of latest upcoming video standard known as High Efficiency Video Coding (HEVC). HEVC is designed to fulfil all the requirements for future high definition videos. In this paper, three configurations (intra only, low delay and random access) of HEVC are analyzed using various 480p, 720p and 1080p high definition test video sequences. Simulation results show the superior objective and subjective quality of HEVC

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

    International Nuclear Information System (INIS)

    Aoki, Shigeyuki; Nagura, Yasumi

    1996-01-01

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

  1. High-concentration planar microtracking photovoltaic system exceeding 30% efficiency

    Science.gov (United States)

    Price, Jared S.; Grede, Alex J.; Wang, Baomin; Lipski, Michael V.; Fisher, Brent; Lee, Kyu-Tae; He, Junwen; Brulo, Gregory S.; Ma, Xiaokun; Burroughs, Scott; Rahn, Christopher D.; Nuzzo, Ralph G.; Rogers, John A.; Giebink, Noel C.

    2017-08-01

    Prospects for concentrating photovoltaic (CPV) power are growing as the market increasingly values high power conversion efficiency to leverage now-dominant balance of system and soft costs. This trend is particularly acute for rooftop photovoltaic power, where delivering the high efficiency of traditional CPV in the form factor of a standard rooftop photovoltaic panel could be transformative. Here, we demonstrate a fully automated planar microtracking CPV system 660× concentration ratio over a 140∘ full field of view. In outdoor testing over the course of two sunny days, the system operates automatically from sunrise to sunset, outperforming a 17%-efficient commercial silicon solar cell by generating >50% more energy per unit area per day in a direct head-to-head competition. These results support the technical feasibility of planar microtracking CPV to deliver a step change in the efficiency of rooftop solar panels at a commercially relevant concentration ratio.

  2. Development of high-efficiency solar cells on silicon web

    Science.gov (United States)

    Meier, D. L.; Greggi, J.; Okeeffe, T. W.; Rai-Choudhury, P.

    1986-01-01

    Work was performed to improve web base material with a goal of obtaining solar cell efficiencies in excess of 18% (AM1). Efforts in this program are directed toward identifying carrier loss mechanisms in web silicon, eliminating or reducing these mechanisms, designing a high efficiency cell structure with the aid of numerical models, and fabricating high efficiency web solar cells. Fabrication techniques must preserve or enhance carrier lifetime in the bulk of the cell and minimize recombination of carriers at the external surfaces. Three completed cells were viewed by cross-sectional transmission electron microscopy (TEM) in order to investigate further the relation between structural defects and electrical performance of web cells. Consistent with past TEM examinations, the cell with the highest efficiency (15.0%) had no dislocations but did have 11 twin planes.

  3. Efficient Unsteady Flow Visualization with High-Order Access Dependencies

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jiang; Guo, Hanqi; Yuan, Xiaoru

    2016-04-19

    We present a novel high-order access dependencies based model for efficient pathline computation in unsteady flow visualization. By taking longer access sequences into account to model more sophisticated data access patterns in particle tracing, our method greatly improves the accuracy and reliability in data access prediction. In our work, high-order access dependencies are calculated by tracing uniformly-seeded pathlines in both forward and backward directions in a preprocessing stage. The effectiveness of our proposed approach is demonstrated through a parallel particle tracing framework with high-order data prefetching. Results show that our method achieves higher data locality and hence improves the efficiency of pathline computation.

  4. Efficient estimation for ergodic diffusions sampled at high frequency

    DEFF Research Database (Denmark)

    Sørensen, Michael

    A general theory of efficient estimation for ergodic diffusions sampled at high fre- quency is presented. High frequency sampling is now possible in many applications, in particular in finance. The theory is formulated in term of approximate martingale estimating functions and covers a large class...

  5. High-Efficiency Klystron Design for the CLIC Project

    CERN Document Server

    Mollard, Antoine; Peauger, Franck; Plouin, Juliette; Beunas, Armel; Marchesin, Rodolphe

    2017-01-01

    The CLIC project requests new type of RF sources for the high power conditioning of the accelerating cavities. We are working on the development of a new kind of high-efficiency klystron to fulfill this need. This work is performed under the EuCARD-2 European program and involves theoretical and experimental study of a brand new klystron concept.

  6. Efficient estimation for high similarities using odd sketches

    DEFF Research Database (Denmark)

    Mitzenmacher, Michael; Pagh, Rasmus; Pham, Ninh Dang

    2014-01-01

    . This means that Odd Sketches provide a highly space-efficient estimator for sets of high similarity, which is relevant in applications such as web duplicate detection, collaborative filtering, and association rule learning. The method extends to weighted Jaccard similarity, relevant e.g. for TF-IDF vector...... and web duplicate detection tasks....

  7. Design of High Efficiency Illumination for LED Lighting

    Directory of Open Access Journals (Sweden)

    Yong-Nong Chang

    2013-01-01

    Full Text Available A high efficiency illumination for LED street lighting is proposed. For energy saving, this paper uses Class-E resonant inverter as main electric circuit to improve efficiency. In addition, single dimming control has the best efficiency, simplest control scheme and lowest circuit cost among other types of dimming techniques. Multiple serial-connected transformers used to drive the LED strings as they can provide galvanic isolation and have the advantage of good current distribution against device difference. Finally, a prototype circuit for driving 112 W LEDs in total was built and tested to verify the theoretical analysis.

  8. High-Efficient Low-Cost Photovoltaics Recent Developments

    CERN Document Server

    Petrova-Koch, Vesselinka; Goetzberger, Adolf

    2009-01-01

    A bird's-eye view of the development and problems of recent photovoltaic cells and systems and prospects for Si feedstock is presented. High-efficient low-cost PV modules, making use of novel efficient solar cells (based on c-Si or III-V materials), and low cost solar concentrators are in the focus of this book. Recent developments of organic photovoltaics, which is expected to overcome its difficulties and to enter the market soon, are also included.

  9. METHODOLOGY OF DETERMINATION OF QUALITY INDEX OF MAINTENANCE SERVICE SYSTEM OF POWER EQUIPMENT OF TRACTION SUBSTATIONS

    Directory of Open Access Journals (Sweden)

    O.O. Matusevych

    2016-03-01

    information was further developed. The author offers a number of options at first time. There are version of the document formalized quality evaluation of power equipment of traction substations by experts; expression to define the integral Quality systems maintenance and electrical power P TS, which is absent in the standard system maintenance and P; matrix of quality system with regard to steps (methods and ways of increasing service quality electrical power control systems. This method makes it possible to conduct an expert assessment of the maintenance system and to predict and select the option rational system of quality improvement and maintenance of power equipment of traction substations considering not only technical but also organizational, legal, financial and economic measures. Practical value. Improvement on electrified railways of Ukraine quality management system maintenance and P TS will improve the efficiency and quality of maintenance of power equipment and provide TA prevent or reduce the severity of possible equipment failures. Based on the relationships matrix components as systems maintenance and electrical power P TP were formed expressions calculating quality indices of integrated systems with directions and stages for specific equipment and systems in general. It was determined that an increase in the quality and maintenance of electrical PR, the rate of change of the measured value at step k during operation is reduced while the standard deviation parameter is also reduced, and the probability of electrical TA increases.

  10. High efficiency heat transport and power conversion system for cascade

    International Nuclear Information System (INIS)

    Maya, I.; Bourque, R.F.; Creedon, R.L.; Schultz, K.R.

    1985-02-01

    The Cascade ICF reactor features a flowing blanket of solid BeO and LiAlO 2 granules with very high temperature capability (up to approx. 2300 K). The authors present here the design of a high temperature granule transport and heat exchange system, and two options for high efficiency power conversion. The centrifugal-throw transport system uses the peripheral speed imparted to the granules by the rotating chamber to effect granule transport and requires no additional equipment. The heat exchanger design is a vacuum heat transfer concept utilizing gravity-induced flow of the granules over ceramic heat exchange surfaces. A reference Brayton power cycle is presented which achieves 55% net efficiency with 1300 K peak helium temperature. A modified Field steam cycle (a hybrid Rankine/Brayton cycle) is presented as an alternate which achieves 56% net efficiency

  11. Highly Efficient Coherent Optical Memory Based on Electromagnetically Induced Transparency

    Science.gov (United States)

    Hsiao, Ya-Fen; Tsai, Pin-Ju; Chen, Hung-Shiue; Lin, Sheng-Xiang; Hung, Chih-Chiao; Lee, Chih-Hsi; Chen, Yi-Hsin; Chen, Yong-Fan; Yu, Ite A.; Chen, Ying-Cheng

    2018-05-01

    Quantum memory is an important component in the long-distance quantum communication based on the quantum repeater protocol. To outperform the direct transmission of photons with quantum repeaters, it is crucial to develop quantum memories with high fidelity, high efficiency and a long storage time. Here, we achieve a storage efficiency of 92.0 (1.5)% for a coherent optical memory based on the electromagnetically induced transparency scheme in optically dense cold atomic media. We also obtain a useful time-bandwidth product of 1200, considering only storage where the retrieval efficiency remains above 50%. Both are the best record to date in all kinds of schemes for the realization of optical memory. Our work significantly advances the pursuit of a high-performance optical memory and should have important applications in quantum information science.

  12. High-efficiency white OLEDs based on small molecules

    Science.gov (United States)

    Hatwar, Tukaram K.; Spindler, Jeffrey P.; Ricks, M. L.; Young, Ralph H.; Hamada, Yuuhiko; Saito, N.; Mameno, Kazunobu; Nishikawa, Ryuji; Takahashi, Hisakazu; Rajeswaran, G.

    2004-02-01

    Eastman Kodak Company and SANYO Electric Co., Ltd. recently demonstrated a 15" full-color, organic light-emitting diode display (OLED) using a high-efficiency white emitter combined with a color-filter array. Although useful for display applications, white emission from organic structures is also under consideration for other applications, such as solid-state lighting, where high efficiency and good color rendition are important. By incorporating adjacent blue and orange emitting layers in a multi-layer structure, highly efficient, stable white emission has been attained. With suitable host and dopant combinations, a luminance yield of 20 cd/A and efficiency of 8 lm/W have been achieved at a drive voltage of less than 8 volts and luminance level of 1000 cd/m2. The estimated external efficiency of this device is 6.3% and a high level of operational stability is observed. To our knowledge, this is the highest performance reported so far for white organic electroluminescent devices. We will review white OLED technology and discuss the fabrication and operating characteristics of these devices.

  13. Low Cost, High Efficiency, High Pressure Hydrogen Storage

    Energy Technology Data Exchange (ETDEWEB)

    Mark Leavitt

    2010-03-31

    A technical and design evaluation was carried out to meet DOE hydrogen fuel targets for 2010. These targets consisted of a system gravimetric capacity of 2.0 kWh/kg, a system volumetric capacity of 1.5 kWh/L and a system cost of $4/kWh. In compressed hydrogen storage systems, the vast majority of the weight and volume is associated with the hydrogen storage tank. In order to meet gravimetric targets for compressed hydrogen tanks, 10,000 psi carbon resin composites were used to provide the high strength required as well as low weight. For the 10,000 psi tanks, carbon fiber is the largest portion of their cost. Quantum Technologies is a tier one hydrogen system supplier for automotive companies around the world. Over the course of the program Quantum focused on development of technology to allow the compressed hydrogen storage tank to meet DOE goals. At the start of the program in 2004 Quantum was supplying systems with a specific energy of 1.1-1.6 kWh/kg, a volumetric capacity of 1.3 kWh/L and a cost of $73/kWh. Based on the inequities between DOE targets and Quantum’s then current capabilities, focus was placed first on cost reduction and second on weight reduction. Both of these were to be accomplished without reduction of the fuel system’s performance or reliability. Three distinct areas were investigated; optimization of composite structures, development of “smart tanks” that could monitor health of tank thus allowing for lower design safety factor, and the development of “Cool Fuel” technology to allow higher density gas to be stored, thus allowing smaller/lower pressure tanks that would hold the required fuel supply. The second phase of the project deals with three additional distinct tasks focusing on composite structure optimization, liner optimization, and metal.

  14. Degradation-mediated cellular traction directs stem cell fate in covalently crosslinked three-dimensional hydrogels

    Science.gov (United States)

    Khetan, Sudhir; Guvendiren, Murat; Legant, Wesley R.; Cohen, Daniel M.; Chen, Christopher S.; Burdick, Jason A.

    2013-05-01

    Although cell-matrix adhesive interactions are known to regulate stem cell differentiation, the underlying mechanisms, in particular for direct three-dimensional encapsulation within hydrogels, are poorly understood. Here, we demonstrate that in covalently crosslinked hyaluronic acid (HA) hydrogels, the differentiation of human mesenchymal stem cells (hMSCs) is directed by the generation of degradation-mediated cellular traction, independently of cell morphology or matrix mechanics. hMSCs within HA hydrogels of equivalent elastic moduli that permit (restrict) cell-mediated degradation exhibited high (low) degrees of cell spreading and high (low) tractions, and favoured osteogenesis (adipogenesis). Moreover, switching the permissive hydrogel to a restrictive state through delayed secondary crosslinking reduced further hydrogel degradation, suppressed traction, and caused a switch from osteogenesis to adipogenesis in the absence of changes to the extended cellular morphology. Furthermore, inhibiting tension-mediated signalling in the permissive environment mirrored the effects of delayed secondary crosslinking, whereas upregulating tension induced osteogenesis even in the restrictive environment.

  15. High Efficient Bidirectional Battery Converter for residential PV Systems

    DEFF Research Database (Denmark)

    Pham, Cam; Kerekes, Tamas; Teodorescu, Remus

    2012-01-01

    Photovoltaic (PV) installation is suited for the residential environment and the generation pattern follows the distribution of residential power consumption in daylight hours. In the cases of unbalance between generation and demand, the Smart PV with its battery storage can absorb or inject...... the power to balance it. High efficient bidirectional converter for the battery storage is required due high system cost and because the power is processed twice. A 1.5kW prototype is designed and built with CoolMOS and SiC diodes, >;95% efficiency has been obtained with 200 kHz hard switching....

  16. Innovative-Simplified Nuclear Power Plant Efficiency Evaluation with High-Efficiency Steam Injector System

    International Nuclear Information System (INIS)

    Shoji, Goto; Shuichi, Ohmori; Michitsugu, Mori

    2006-01-01

    It is possible to establish simplified system with reduced space and total equipment weight using high-efficiency Steam Injectors (SI) instead of low-pressure feedwater heaters in Nuclear Power Plant (NPP). The SI works as a heat exchanger through direct contact between feedwater from condensers and extracted steam from turbines. It can get higher pressure than supplied steam pressure. The maintenance and reliability are still higher than the feedwater ones because SI has no movable parts. This paper describes the analysis of the heat balance, plant efficiency and the operation of this Innovative-Simplified NPP with high-efficiency SI. The plant efficiency and operation are compared with the electric power of 1100 MWe-class BWR system and the Innovative-Simplified BWR system with SI. The SI model is adapted into the heat balance simulator with a simplified model. The results show that plant efficiencies of the Innovated-Simplified BWR system are almost equal to original BWR ones. The present research is one of the projects that are carried out by Tokyo Electric Power Company, Toshiba Corporation, and six Universities in Japan, funded from the Institute of Applied Energy (IAE) of Japan as the national public research-funded program. (authors)

  17. A metamaterial electromagnetic energy rectifying surface with high harvesting efficiency

    Directory of Open Access Journals (Sweden)

    Xin Duan

    2016-12-01

    Full Text Available A novel metamaterial rectifying surface (MRS for electromagnetic energy capture and rectification with high harvesting efficiency is presented. It is fabricated on a three-layer printed circuit board, which comprises an array of periodic metamaterial particles in the shape of mirrored split rings, a metal ground, and integrated rectifiers employing Schottky diodes. Perfect impedance matching is engineered at two interfaces, i.e. one between free space and the surface, and the other between the metamaterial particles and the rectifiers, which are connected through optimally positioned vias. Therefore, the incident electromagnetic power is captured with almost no reflection by the metamaterial particles, then channeled maximally to the rectifiers, and finally converted to direct current efficiently. Moreover, the rectifiers are behind the metal ground, avoiding the disturbance of high power incident electromagnetic waves. Such a MRS working at 2.45 GHz is designed, manufactured and measured, achieving a harvesting efficiency up to 66.9% under an incident power density of 5 mW/cm2, compared with a simulated efficiency of 72.9%. This high harvesting efficiency makes the proposed MRS an effective receiving device in practical microwave power transmission applications.

  18. A metamaterial electromagnetic energy rectifying surface with high harvesting efficiency

    Science.gov (United States)

    Duan, Xin; Chen, Xing; Zhou, Lin

    2016-12-01

    A novel metamaterial rectifying surface (MRS) for electromagnetic energy capture and rectification with high harvesting efficiency is presented. It is fabricated on a three-layer printed circuit board, which comprises an array of periodic metamaterial particles in the shape of mirrored split rings, a metal ground, and integrated rectifiers employing Schottky diodes. Perfect impedance matching is engineered at two interfaces, i.e. one between free space and the surface, and the other between the metamaterial particles and the rectifiers, which are connected through optimally positioned vias. Therefore, the incident electromagnetic power is captured with almost no reflection by the metamaterial particles, then channeled maximally to the rectifiers, and finally converted to direct current efficiently. Moreover, the rectifiers are behind the metal ground, avoiding the disturbance of high power incident electromagnetic waves. Such a MRS working at 2.45 GHz is designed, manufactured and measured, achieving a harvesting efficiency up to 66.9% under an incident power density of 5 mW/cm2, compared with a simulated efficiency of 72.9%. This high harvesting efficiency makes the proposed MRS an effective receiving device in practical microwave power transmission applications.

  19. Highly efficient light management for perovskite solar cells.

    Science.gov (United States)

    Wang, Dong-Lin; Cui, Hui-Juan; Hou, Guo-Jiao; Zhu, Zhen-Gang; Yan, Qing-Bo; Su, Gang

    2016-01-06

    Organic-inorganic halide perovskite solar cells have enormous potential to impact the existing photovoltaic industry. As realizing a higher conversion efficiency of the solar cell is still the most crucial task, a great number of schemes were proposed to minimize the carrier loss by optimizing the electrical properties of the perovskite solar cells. Here, we focus on another significant aspect that is to minimize the light loss by optimizing the light management to gain a high efficiency for perovskite solar cells. In our scheme, the slotted and inverted prism structured SiO2 layers are adopted to trap more light into the solar cells, and a better transparent conducting oxide layer is employed to reduce the parasitic absorption. For such an implementation, the efficiency and the serviceable angle of the perovskite solar cell can be promoted impressively. This proposal would shed new light on developing the high-performance perovskite solar cells.

  20. A Low VSWR and High Efficiency Waveguide Feed Antenna Array

    Directory of Open Access Journals (Sweden)

    Zhao Xiao-Fang

    2018-01-01

    Full Text Available A low VSWR and high efficiency antenna array operating in the Ku band for satellite communications is presented in this paper. To achieve high radiation efficiency and broad enough bandwidth, all-metal radiation elements and full-corporate waveguide feeding network are employed. As the general milling method is used in the multilayer antenna array fabrication, the E-plane waveguide feeding network is adopted here to suppress the wave leakage caused by the imperfect connectivity between adjacent layers. A 4 × 8 elements array prototype was fabricated and tested for verification. The measured results of proposed antenna array show bandwidth of 6.9% (13.9–14.8 GHz for VSWR < 1.5. Furthermore, antenna gain and efficiency of higher than 22.2 dBi and 80% are also exhibited, respectively.

  1. Potential high efficiency solar cells: Applications from space photovoltaic research

    Science.gov (United States)

    Flood, D. J.

    1986-01-01

    NASA involvement in photovoltaic energy conversion research development and applications spans over two decades of continuous progress. Solar cell research and development programs conducted by the Lewis Research Center's Photovoltaic Branch have produced a sound technology base not only for the space program, but for terrestrial applications as well. The fundamental goals which have guided the NASA photovoltaic program are to improve the efficiency and lifetime, and to reduce the mass and cost of photovoltaic energy conversion devices and arrays for use in space. The major efforts in the current Lewis program are on high efficiency, single crystal GaAs planar and concentrator cells, radiation hard InP cells, and superlattice solar cells. A brief historical perspective of accomplishments in high efficiency space solar cells will be given, and current work in all of the above categories will be described. The applicability of space cell research and technology to terrestrial photovoltaics will be discussed.

  2. The thermodynamic characteristics of high efficiency, internal-combustion engines

    International Nuclear Information System (INIS)

    Caton, Jerald A.

    2012-01-01

    Highlights: ► The thermodynamics of an automotive engine are determined using a cycle simulation. ► The net indicated thermal efficiency increased from 37.0% to 53.9%. ► High compression ratio, lean mixtures and high EGR were the important features. ► Efficiency increased due to lower heat losses, and increased work conversion. ► The nitric oxides were essentially zero due to the low combustion temperatures. - Abstract: Recent advancements have demonstrated new combustion modes for internal combustion engines that exhibit low nitric oxide emissions and high thermal efficiencies. These new combustion modes involve various combinations of stratification, lean mixtures, high levels of EGR, multiple injections, variable valve timings, two fuels, and other such features. Although the exact combination of these features that provides the best design is not yet clear, the results (low emissions with high efficiencies) are of major interest. The current work is directed at determining some of the fundamental thermodynamic reasons for the relatively high efficiencies and to quantify these factors. Both the first and second laws are used in this assessment. An automotive engine (5.7 l) which included some of the features mentioned above (e.g., high compression ratios, lean mixtures, and high EGR) was evaluated using a thermodynamic cycle simulation. These features were examined for a moderate load (bmep = 900 kPa), moderate speed (2000 rpm) condition. By the use of lean operation, high EGR levels, high compression ratio and other features, the net indicated thermal efficiency increased from 37.0% to 53.9%. These increases are explained in a step-by-step fashion. The major reasons for these improvements include the higher compression ratio and the dilute charge (lean mixture, high EGR). The dilute charge resulted in lower temperatures which in turn resulted in lower heat loss. In addition, the lower temperatures resulted in higher ratios of the specific heats which

  3. Creep force modelling for rail traction vehicles based on the Fastsim algorithm

    Science.gov (United States)

    Spiryagin, Maksym; Polach, Oldrich; Cole, Colin

    2013-11-01

    The evaluation of creep forces is a complex task and their calculation is a time-consuming process for multibody simulation (MBS). A methodology of creep forces modelling at large traction creepages has been proposed by Polach [Creep forces in simulations of traction vehicles running on adhesion limit. Wear. 2005;258:992-1000; Influence of locomotive tractive effort on the forces between wheel and rail. Veh Syst Dyn. 2001(Suppl);35:7-22] adapting his previously published algorithm [Polach O. A fast wheel-rail forces calculation computer code. Veh Syst Dyn. 1999(Suppl);33:728-739]. The most common method for creep force modelling used by software packages for MBS of running dynamics is the Fastsim algorithm by Kalker [A fast algorithm for the simplified theory of rolling contact. Veh Syst Dyn. 1982;11:1-13]. However, the Fastsim code has some limitations which do not allow modelling the creep force - creep characteristic in agreement with measurements for locomotives and other high-power traction vehicles, mainly for large traction creep at low-adhesion conditions. This paper describes a newly developed methodology based on a variable contact flexibility increasing with the ratio of the slip area to the area of adhesion. This variable contact flexibility is introduced in a modification of Kalker's code Fastsim by replacing the constant Kalker's reduction factor, widely used in MBS, by a variable reduction factor together with a slip-velocity-dependent friction coefficient decreasing with increasing global creepage. The proposed methodology is presented in this work and compared with measurements for different locomotives. The modification allows use of the well recognised Fastsim code for simulation of creep forces at large creepages in agreement with measurements without modifying the proven modelling methodology at small creepages.

  4. Morphostructural characterization of soil conventionally tilled with mechanized and animal traction with and without cover crop

    Directory of Open Access Journals (Sweden)

    Ricardo Ralisch

    2010-12-01

    Full Text Available The structural stability and restructuring ability of a soil are related to the methods of crop management and soil preparation. A recommended strategy to reduce the effects of soil preparation is to use crop rotation and cover crops that help conserve and restore the soil structure. The aim of this study was to evaluate and quantify the homogeneous morphological units in soil under conventional mechanized tillage and animal traction, as well as to assess the effect on the soil structure of intercropping with jack bean (Canavalia ensiformis L.. Profiles were analyzed in April of 2006, in five counties in the Southern-Central region of Paraná State (Brazil, on family farms producing maize (Zea mays L., sometimes intercropped with jack bean. The current structures in the crop profile were analyzed using Geographic Information Systems (GIS and subsequently principal component analysis (PCA to generate statistics. Morphostructural soil analysis showed a predominance of compact units in areas of high-intensity cultivation under mechanized traction. The cover crop did not improve the structure of the soil with low porosity and compact units that hamper the root system growth. In areas exposed to animal traction, a predominance of cracked units was observed, where roots grew around the clods and along the gaps between them.

  5. A nuclear standard high-efficiency adsorber for iodine

    International Nuclear Information System (INIS)

    Wang Jianmin; Qian Yinge

    1988-08-01

    The structure of a nuclear standard high-efficiency adsorber, adsorbent and its performance are introduced. The performance and structure were compared with the same kind product of other firms. The results show that the leakage rate is less than 0.005%

  6. Efficiency criteria for high reliability measured system structures

    International Nuclear Information System (INIS)

    Sal'nikov, N.L.

    2012-01-01

    The procedures of structural redundancy are usually used to develop high reliability measured systems. To estimate efficiency of such structures the criteria to compare different systems has been developed. So it is possible to develop more exact system by inspection of redundant system data unit stochastic characteristics in accordance with the developed criteria [ru

  7. Optimization of high-efficiency components; Optimieren auf hohem Niveau

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, Eva

    2009-07-01

    High efficiency is a common feature of modern current inverters and is not a unique selling proposition. Other factors that influence the buyer's decision are cost reduction, reliability and service, optimum grid integration, and the challenges of the competitive thin film technology. (orig.)

  8. Orion, a high efficiency 4π neutron detector

    International Nuclear Information System (INIS)

    Crema, E.; Piasecki, E.; Wang, X.M.; Doubre, H.; Galin, J.; Guerreau, D.; Pouthas, J.; Saint-Laurent, F.

    1990-01-01

    In intermediate energy heavy ion collisions the multiplicity of emitted neutrons is strongly connected to energy dissipation and to impact parameter. We present the 4π detector ORION, a high efficiency liquid scintillator detector which permits to get information on the multiplicity of neutrons measured event-wise and on the spatial distribution of these neutrons [fr

  9. High efficiency hydrodynamic DNA fragmentation in a bubbling system

    NARCIS (Netherlands)

    Li, Lanhui; Jin, Mingliang; Sun, Chenglong; Wang, Xiaoxue; Xie, Shuting; Zhou, Guofu; Van Den Berg, Albert; Eijkel, Jan C.T.; Shui, Lingling

    2017-01-01

    DNA fragmentation down to a precise fragment size is important for biomedical applications, disease determination, gene therapy and shotgun sequencing. In this work, a cheap, easy to operate and high efficiency DNA fragmentation method is demonstrated based on hydrodynamic shearing in a bubbling

  10. High efficiency confinement mode by electron cyclotron heating

    International Nuclear Information System (INIS)

    Funahashi, Akimasa

    1987-01-01

    In the medium size nuclear fusion experiment facility JFT-2M in the Japan Atomic Energy Research Institute, the research on the high efficiency plasma confinement mode has been advanced, and in the experiment in June, 1987, the formation of a high efficiency confinement mode was successfully controlled by electron cyclotron heating, for the first time in the world. This result further advanced the control of the formation of a high efficiency plasma confinement mode and the elucidation of the physical mechanism of that mode, and promoted the research and development of the plasma heating by electron cyclotron heating. In this paper, the recent results of the research on a high efficiency confinement mode at the JFT-2M are reported, and the role of the JFT-2M and the experiment on the improvement of core plasma performance are outlined. Now the plasma temperature exceeding 100 million deg C has been attained in large tokamaks, and in medium size facilities, the various measures for improving confinement performance are to be brought forth and their scientific basis is elucidated to assist large facilities. The JFT-2M started the operation in April, 1983, and has accumulated the results smoothly since then. (Kako, I.)

  11. Super Boiler: First Generation, Ultra-High Efficiency Firetube Boiler

    Energy Technology Data Exchange (ETDEWEB)

    None

    2006-06-01

    This factsheet describes a research project whose goal is to develop and demonstrate a first-generation ultra-high-efficiency, ultra-low emissions, compact gas-fired package boiler (Super Boiler), and formulate a long-range RD&D plan for advanced boiler technology out to the year 2020.

  12. High-efficient solar cells with porous silicon

    International Nuclear Information System (INIS)

    Migunova, A.A.

    2002-01-01

    It has been shown that the porous silicon is multifunctional high-efficient coating on silicon solar cells, modifies its surface and combines in it self antireflection and passivation properties., The different optoelectronic effects in solar cells with porous silicon were considered. The comparative parameters of uncovered photodetectors also solar cells with porous silicon and other coatings were resulted. (author)

  13. Benefits of high aerodynamic efficiency to orbital transfer vehicles

    Science.gov (United States)

    Andrews, D. G.; Norris, R. B.; Paris, S. W.

    1984-01-01

    The benefits and costs of high aerodynamic efficiency on aeroassisted orbital transfer vehicles (AOTV) are analyzed. Results show that a high lift to drag (L/D) AOTV can achieve significant velocity savings relative to low L/D aerobraked OTV's when traveling round trip between low Earth orbits (LEO) and alternate orbits as high as geosynchronous Earth orbit (GEO). Trajectory analysis is used to show the impact of thermal protection system technology and the importance of lift loading coefficient on vehicle performance. The possible improvements in AOTV subsystem technologies are assessed and their impact on vehicle inert weight and performance noted. Finally, the performance of high L/D AOTV concepts is compared with the performances of low L/D aeroassisted and all propulsive OTV concepts to assess the benefits of aerodynamic efficiency on this class of vehicle.

  14. Windowed SHE-PWM of Interleaved Four-Quadrant Converters for Resonance Suppression in Traction Power Supply Systems

    DEFF Research Database (Denmark)

    Song, Kejian; Konstantinou, Georgios; Mingli, Wu

    2017-01-01

    AC electric locomotives that use a number of interleaved four-quadrant converters generate high-frequency switching harmonics which may stimulate certain resonances in traction power supply systems (TPSSs). A windowed selective harmonic elimination pulse-width modulation (SHE-PWM) method...

  15. High efficiency inductive output tubes with intense annular electron beams

    Science.gov (United States)

    Appanam Karakkad, J.; Matthew, D.; Ray, R.; Beaudoin, B. L.; Narayan, A.; Nusinovich, G. S.; Ting, A.; Antonsen, T. M.

    2017-10-01

    For mobile ionospheric heaters, it is necessary to develop highly efficient RF sources capable of delivering radiation in the frequency range from 3 to 10 MHz with an average power at a megawatt level. A promising source, which is capable of offering these parameters, is a grid-less version of the inductive output tube (IOT), also known as a klystrode. In this paper, studies analyzing the efficiency of grid-less IOTs are described. The basic trade-offs needed to reach high efficiency are investigated. In particular, the trade-off between the peak current and the duration of the current micro-pulse is analyzed. A particle in the cell code is used to self-consistently calculate the distribution in axial and transverse momentum and in total electron energy from the cathode to the collector. The efficiency of IOTs with collectors of various configurations is examined. It is shown that the efficiency of IOTs can be in the 90% range even without using depressed collectors.

  16. How high are option values in energy-efficiency investments?

    International Nuclear Information System (INIS)

    Sanstad, A.H.; Blumstein, C.; Stoft, S.E.; California Univ., Berkeley, CA,

    1995-01-01

    High implicit discount rates in consumers' energy-efficiency investments have long been a source of controversy. In several recent papers, Hassett and Metcalf argue that the uncertainty and irreversibility attendant to such investments, and the resulting option value, account for this anomalously high implicit discounting. Using their model and data, we show that, to the contrary, their analysis falls well short of providing an explanation of this pattern. (author)

  17. Contact traction analysis for profile change during coining process

    International Nuclear Information System (INIS)

    Kim, Hyung Kyu; Yoon, Kyung Ho; Kang, Heung Seok; Song, Kee Nam

    2002-01-01

    Contact tractions are analysed in the case of the change in contact profile occurring during the coining process of a thin strip material. The changed profile is assumed as a concave circular arc in the central part of the contact region which is smoothly connected with convex circular arcs at both sides, referring to the actual measurement of the coined material. The profile is discretized and the known solutions of singular integral equations are used. Since the contact profile affects the contact traction and relevant tribological behaviour (e.g. wear) as well, an accurate definition of the profile is necessary in the analysis of material failure. Parametric study is conducted with the variation of the radii and distance of the arcs, which defines the height difference between the summits of the arcs. Considered is the contact profile, which can give the negligible variation of the traction in comparison with that before the coining process

  18. A modification of the maitland roll top traction table.

    Science.gov (United States)

    Kneipp, K

    1975-03-01

    This modification of the Maitland Roll Top Traction Table (Maitland, 1973) differs from the original as follows: 1. The two weight-bearing leaves are enclosed by a "guide frame" and the "U-piece" of the original is replaced by a hinged "gate" at the foot, which can be opened downwards for lumbar traction, or can be locked to restrain the leaves when the table is required for other purposes. 2. Four rollers of light steel replace the wooden dowels. 3. The modified table in use by the author is held by a floor peg, and is set up be-between two walls 10' 6″ apart which provide purchase points for traction. Alternatively, purchase at the head end can be taken by hooks attached to the table itself. 4. The design permits a six-foot plinth to be used. Copyright © 1975 Australian Physiotherapy Association. Published by . All rights reserved.

  19. Traction sheave elevator, hoisting unit and machine space

    Science.gov (United States)

    Hakala, Harri; Mustalahti, Jorma; Aulanko, Esko

    2000-01-01

    Traction sheave elevator consisting of an elevator car moving along elevator guide rails, a counterweight moving along counterweight guide rails, a set of hoisting ropes (3) on which the elevator car and counterweight are suspended, and a drive machine unit (6) driving a traction sheave (7) acting on the hoisting ropes (3) and placed in the elevator shaft. The drive machine unit (6) is of a flat construction. A wall of the elevator shaft is provided with a machine space with its open side facing towards the shaft, the essential parts of the drive machine unit (6) being placed in the space. The hoisting unit (9) of the traction sheave elevator consists of a substantially discoidal drive machine unit (6) and an instrument panel (8) mounted on the frame (20) of the hoisting unit.

  20. Efficiency and Loading Evaluation of High Efficiency Mist Eliminators (HEME) - 12003

    Energy Technology Data Exchange (ETDEWEB)

    Giffin, Paxton K.; Parsons, Michael S.; Waggoner, Charles A. [Institute for Clean Energy Technology, Mississippi State University, 205 Research Blvd Starkville, MS 39759 (United States)

    2012-07-01

    High efficiency mist eliminators (HEME) are filters primarily used to remove moisture and/or liquid aerosols from an air stream. HEME elements are designed to reduce aerosol and particulate load on primary High Efficiency Particulate Air (HEPA) filters and to have a liquid particle removal efficiency of approximately 99.5% for aerosols down to sub-micron size particulates. The investigation presented here evaluates the loading capacity of the element in the absence of a water spray cleaning system. The theory is that without the cleaning system, the HEME element will suffer rapid buildup of solid aerosols, greatly reducing the particle loading capacity. Evaluation consists of challenging the element with a waste surrogate dry aerosol and di-octyl phthalate (DOP) at varying intervals of differential pressure to examine the filtering efficiency of three different element designs at three different media velocities. Also, the elements are challenged with a liquid waste surrogate using Laskin nozzles and large dispersion nozzles. These tests allow the loading capacity of the unit to be determined and the effectiveness of washing down the interior of the elements to be evaluated. (authors)

  1. Heat pumps; Synergy of high efficiency and low carbon electricity

    Energy Technology Data Exchange (ETDEWEB)

    Koike, Akio

    2010-09-15

    Heat pump is attracting wide attention for its high efficiency to utilize inexhaustible and renewable ambient heat in the environment. With its rapid innovation and efficiency improvement, this technology has a huge potential to reduce CO2 emissions by replacing currently widespread fossil fuel combustion systems to meet various heat demands from the residential, commercial and industrial sectors. Barriers to deployment such as low public awareness and a relatively long pay-back period do exist, so it is strongly recommended that each country implement policies to promote heat pumps as a renewable energy option and an effective method to combat global warming.

  2. Development of large area, high efficiency amorphous silicon solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, K.S.; Kim, S.; Kim, D.W. [Yu Kong Taedok Institute of Technology (Korea, Republic of)

    1996-02-01

    The objective of the research is to develop the mass-production technologies of high efficiency amorphous silicon solar cells in order to reduce the costs of solar cells and dissemination of solar cells. Amorphous silicon solar cell is the most promising option of thin film solar cells which are relatively easy to reduce the costs. The final goal of the research is to develop amorphous silicon solar cells having the efficiency of 10%, the ratio of light-induced degradation 15% in the area of 1200 cm{sup 2} and test the cells in the form of 2 Kw grid-connected photovoltaic system. (author) 35 refs., 8 tabs., 67 figs.

  3. Iodine laser of high efficiency and fast repetition rate

    Energy Technology Data Exchange (ETDEWEB)

    Hohla, K; Witte, K J

    1976-07-01

    The scaling laws of an iodine laser of high efficiency and fast repetition rate are reported. The laser is pumped with a new kind of low pressure Hg-UV-lamps which convert 32% of the electrical input in UV-light in the absorption band of the iodine laser and which can be fired up to 100 Hz. Details of a 10 kJ/1 nsec system as dimensions, energy density, repetition rate, flow velocity, gas composition and gas pressure and the overall efficiency are given which is expected to be about 2%.

  4. The problems of high efficient extraction from the isochronous cyclotron

    International Nuclear Information System (INIS)

    Schwabe, J.

    1994-06-01

    The problem of high efficient extraction (η ≥ 50%) from isochronous cyclotrons (with the exception of the stripping method) is not completely solved up to this day. This problem is specifically important, because these cyclotrons are being also applied in the production of medical radioisotopes, labeled pharmaceuticals as well as in neutron therapy (oncology), machine industry, agriculture (plant mutagenesis), etc. The aim of the proposed topic is to solve this problem on the AIC-144 isochronous cyclotron in the INP (Institute of Nuclear Physics). Lately, a beam of 20 MeV deuterons with an efficiency of ca. 15% was extracted from this cyclotron. (author). 25 refs, 14 figs

  5. IMPLEMENTATION MODEL OF MOTOR TRACTION FORCE OF MAGLEV TRAIN

    Directory of Open Access Journals (Sweden)

    V. O. Polyakov

    2016-08-01

    Full Text Available Purpose. Traction force implementation (TFI by the motor of magnetic levitation train (MLT occurs in the process of electric-to-kinetic energy transformation at interaction of inductor and armature magnetic fields. Ac-cordingly, the aim of this study is to obtain a correct description of such energy transformation. Methodology. At the present stage, a mathematical and, in particular, computer simulation is the main and most universal tool for analysis and synthesis of processes and systems. At the same time, radical advantages of this tool make the precision of selection of a particular research methodology even more important. It is especially important for such a large and complex system as MLT. Therefore the special attention in the work is given to the rationale for choosing the research paradigm selective features. Findings. The analysis results of existing TFI process model versions indicate that each of them has both advantages and disadvantages. Therefore, one of the main results of this study was the creation of a mathematical model for such process that would preserve the advantages of previous versions, but would be free from their disadvantages. The work provides rationale for application (for the purposes of research of train motor TFI of the integrative holistic paradigm, which assimilates the advantages of the theory of electric circuit and magnetic field. Originality. The priority of creation of such paradigm and corresponding version of FI model constitute the originality of the research. Practical value. The main manifestation of practical value of this research in the opportunity, in case of use of its results, for significant increase in efficiency of MLT dynamic studies, on the condition that their generalized costs will not rise.

  6. Highly Flexible and Efficient Solar Steam Generation Device.

    Science.gov (United States)

    Chen, Chaoji; Li, Yiju; Song, Jianwei; Yang, Zhi; Kuang, Yudi; Hitz, Emily; Jia, Chao; Gong, Amy; Jiang, Feng; Zhu, J Y; Yang, Bao; Xie, Jia; Hu, Liangbing

    2017-08-01

    Solar steam generation with subsequent steam recondensation has been regarded as one of the most promising techniques to utilize the abundant solar energy and sea water or other unpurified water through water purification, desalination, and distillation. Although tremendous efforts have been dedicated to developing high-efficiency solar steam generation devices, challenges remain in terms of the relatively low efficiency, complicated fabrications, high cost, and inability to scale up. Here, inspired by the water transpiration behavior of trees, the use of carbon nanotube (CNT)-modified flexible wood membrane (F-Wood/CNTs) is demonstrated as a flexible, portable, recyclable, and efficient solar steam generation device for low-cost and scalable solar steam generation applications. Benefitting from the unique structural merits of the F-Wood/CNTs membrane-a black CNT-coated hair-like surface with excellent light absorbability, wood matrix with low thermal conductivity, hierarchical micro- and nanochannels for water pumping and escaping, solar steam generation device based on the F-Wood/CNTs membrane demonstrates a high efficiency of 81% at 10 kW cm -2 , representing one of the highest values ever-reported. The nature-inspired design concept in this study is straightforward and easily scalable, representing one of the most promising solutions for renewable and portable solar energy generation and other related phase-change applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. THE MEASUREMENT ELECTROMAGNETIC INTERFERENCE IN THE REVERSE TRACTION NETWORK

    Directory of Open Access Journals (Sweden)

    T. M. Serdiuk

    2009-09-01

    Full Text Available The original automated method of measurement of electrical noise in the return electric-traction network is proposed. It is realized on the base of car-laboratory “Automatics, telemechanics and communication”. The mathematic model of return electric-traction network is developed to scientific bases of automated measurement. It allows us obtaining the mathematic expressions for change of voltage and current harmonics in the rail net and taking into account the inhomogeneity of lines for the following analytic determination of a source of electric noise.

  8. Simple traction-immobilization device for CT scanners

    International Nuclear Information System (INIS)

    Robertson, J.; Federle, M.P.

    1983-01-01

    Successful computed tomographic (CT) scanning of acutely ill or traumatized patients often requires immobilization or traction of the extremities. Existing medical appliances and external fixation devices often are cumbersome, produce technical artifacts, or are uncomfortable for patients. This paper describes a traction-immobilization device that overcomes many of these difficulties. The authors have used this device successfully in several hundred cases and found that it markedly facilitated patient comfort and throughput. Construction is simple and inexpensive, using materials available in most hardware stores

  9. Temperature control of power semiconductor devices in traction applications

    Science.gov (United States)

    Pugachev, A. A.; Strekalov, N. N.

    2017-02-01

    The peculiarity of thermal management of traction frequency converters of a railway rolling stock is highlighted. The topology and the operation principle of the automatic temperature control system of power semiconductor modules of the traction frequency converter are designed and discussed. The features of semiconductors as an object of temperature control are considered; the equivalent circuit of thermal processes in the semiconductors is suggested, the power losses in the two-level voltage source inverters are evaluated and analyzed. The dynamic properties and characteristics of the cooling fan induction motor electric drive with the scalar control are presented. The results of simulation in Matlab are shown for the steady state of thermal processes.

  10. THE CALCULATION OF THE ENERGY RECOVERY ELECTRIFIED URBAN TRANSPORT DURING THE INSTALLATION DRIVE FOR TRACTION SUBSTATION

    Directory of Open Access Journals (Sweden)

    A. A. Sulim

    2014-01-01

    Full Text Available At present a great attention is paid to increasing of energy efficiency at operated electrified urban transport. Perspective direction for increasing energy efficiency at that type of transport is the application of regenerative braking. For additional increasing of energy efficiency there were suggested the use of capacitive drive on tires of traction substation. One of the main task is the analysis of energy recovery application  with drive and without it.These analysis demonstrated that the calculation algorithms don’t allow in the full volume to carry out calculations of amount and cost of energy recovery without drive and with it. That is why we see the current interest to this topic. The purpose of work is to create methods of algorithms calculation for definite amount and cost of consumed, redundant and recovery energy of electrified urban transport due to definite regime of motion on wayside. There is algorithm developed, which allow to calculate amount and cost of consumed, redundant and recovery energy of electrified urban transport on wayside during the installation capacitive drive at traction substation. On the basis of developed algorithm for the definite regime of wagon motion of subway there were fulfilled the example of energy recovery amount and its cost calculation, among them with limited energy intensity drive, when there are 4 trains on wayside simultaneously.

  11. Simple processing of high efficiency silicon solar cells

    International Nuclear Information System (INIS)

    Hamammu, I.M.; Ibrahim, K.

    2006-01-01

    Cost effective photovoltaic devices have been an area research since the development of the first solar cells, as cost is the major factor in their usage. Silicon solar cells have the biggest share in the photovoltaic market, though silicon os not the optimal material for solar cells. This work introduces a simplified approach for high efficiency silicon solar cell processing, by minimizing the processing steps and thereby reducing cost. The suggested procedure might also allow for the usage of lower quality materials compared to the one used today. The main features of the present work fall into: simplifying the diffusion process, edge shunt isolation and using acidic texturing instead of the standard alkaline processing. Solar cells of 17% efficiency have been produced using this procedure. Investigations on the possibility of improving the efficiency and using less quality material are still underway

  12. High efficiency graphene coated copper based thermocells connected in series

    Science.gov (United States)

    Sindhuja, Mani; Indubala, Emayavaramban; Sudha, Venkatachalam; Harinipriya, Seshadri

    2018-04-01

    Conversion of low-grade waste heat into electricity had been studied employing single thermocell or flowcells so far. Graphene coated copper electrodes based thermocells connected in series displayed relatively high efficiency of thermal energy harvesting. The maximum power output of 49.2W/m2 for normalized cross sectional electrode area is obtained at 60ºC of inter electrode temperature difference. The relative carnot efficiency of 20.2% is obtained from the device. The importance of reducing the mass transfer and ion transfer resistance to improve the efficiency of the device is demonstrated. Degradation studies confirmed mild oxidation of copper foil due to corrosion caused by the electrolyte.

  13. High Efficiency Graphene Coated Copper Based Thermocells Connected in Series

    Directory of Open Access Journals (Sweden)

    Mani Sindhuja

    2018-04-01

    Full Text Available Conversion of low-grade waste heat into electricity had been studied employing single thermocell or flowcells so far. Graphene coated copper electrodes based thermocells connected in series displayed relatively high efficiency of thermal energy harvesting. The maximum power output of 49.2 W/m2 for normalized cross sectional electrode area is obtained at 60°C of inter electrode temperature difference. The relative carnot efficiency of 20.2% is obtained from the device. The importance of reducing the mass transfer and ion transfer resistance to improve the efficiency of the device is demonstrated. Degradation studies confirmed mild oxidation of copper foil due to corrosion caused by the electrolyte.

  14. Rigid-beam model of a high-efficiency magnicon

    International Nuclear Information System (INIS)

    Rees, D.E.; Tallerico, P.J.; Humphries, S.J. Jr.

    1993-01-01

    The magnicon is a new type of high-efficiency deflection-modulated amplifier developed at the Institute of Nuclear Physics in Novosibirsk, Russia. The prototype pulsed magnicon achieved an output power of 2.4 MW and an efficiency of 73% at 915 MHz. This paper presents the results of a rigid-beam model for a 700-MHz, 2.5-MW 82%-efficient magnicon. The rigid-beam model allows for characterization of the beam dynamics by tracking only a single electron. The magnicon design presented consists of a drive cavity; passive cavities; a pi-mode, coupled-deflection cavity; and an output cavity. It represents an optimized design. The model is fully self-consistent, and this paper presents the details of the model and calculated performance of a 2.5-MW magnicon

  15. HIGH JET EFFICIENCY AND SIMULATIONS OF BLACK HOLE MAGNETOSPHERES

    International Nuclear Information System (INIS)

    Punsly, Brian

    2011-01-01

    This Letter reports on a growing body of observational evidence that many powerful lobe-dominated (FR II) radio sources likely have jets with high efficiency. This study extends the maximum efficiency line (jet power ∼25 times the thermal luminosity) defined in Fernandes et al. so as to span four decades of jet power. The fact that this line extends over the full span of FR II radio power is a strong indication that this is a fundamental property of jet production that is independent of accretion power. This is a valuable constraint for theorists. For example, the currently popular 'no-net-flux' numerical models of black hole accretion produce jets that are two to three orders of magnitude too weak to be consistent with sources near maximum efficiency.

  16. High efficiency particulate removal with sintered metal filters

    International Nuclear Information System (INIS)

    Kirstein, B.E.; Paplawsky, W.J.; Pence, D.T.; Hedahl, T.G.

    1981-01-01

    Because of their particle removal efficiencies and durability, sintered metal filters have been chosen for high efficiency particulate air (HEPA) filter protection in the off-gas treatment system for the proposed Idaho National Engineering Laboratory Transuranic Waste Treatment Facility. Process evaluation of sintered metal filters indicated a lack of sufficient process design data to ensure trouble-free operation. Subsequence pilot scale testing was performed with flyash as the test particulate. The test results showed that the sintered metal filters can have an efficiency greater than 0.9999999 for the specific test conditions used. Stable pressure drop characteristics were observed in pulsed and reversed flow blowback modes of operation. Over 4900 hours of operation were obtained with operating conditions ranging up to approximately 90 0 C and 24 vol % water vapor in the gas stream

  17. 3rd symposium on high-efficiency boiler technology: potential, performance, shortcomings of natural gas fuelled high-efficiency boilers

    International Nuclear Information System (INIS)

    1993-01-01

    The brochure contains abstracts of the papers presented at the symposium. The potential, performance and marketing problems of natural gas high-efficiency boiler systems are outlined, and new ideas are presented for gas utilities, producers of appliances, fitters, and chimneysweeps. 13 papers are available as separate regards in this database. (HW) [de

  18. Lightweight High Efficiency Electric Motors for Space Applications

    Science.gov (United States)

    Robertson, Glen A.; Tyler, Tony R.; Piper, P. J.

    2011-01-01

    Lightweight high efficiency electric motors are needed across a wide range of space applications from - thrust vector actuator control for launch and flight applications to - general vehicle, base camp habitat and experiment control for various mechanisms to - robotics for various stationary and mobile space exploration missions. QM Power?s Parallel Path Magnetic Technology Motors have slowly proven themselves to be a leading motor technology in this area; winning a NASA Phase II for "Lightweight High Efficiency Electric Motors and Actuators for Low Temperature Mobility and Robotics Applications" a US Army Phase II SBIR for "Improved Robot Actuator Motors for Medical Applications", an NSF Phase II SBIR for "Novel Low-Cost Electric Motors for Variable Speed Applications" and a DOE SBIR Phase I for "High Efficiency Commercial Refrigeration Motors" Parallel Path Magnetic Technology obtains the benefits of using permanent magnets while minimizing the historical trade-offs/limitations found in conventional permanent magnet designs. The resulting devices are smaller, lower weight, lower cost and have higher efficiency than competitive permanent magnet and non-permanent magnet designs. QM Power?s motors have been extensively tested and successfully validated by multiple commercial and aerospace customers and partners as Boeing Research and Technology. Prototypes have been made between 0.1 and 10 HP. They are also in the process of scaling motors to over 100kW with their development partners. In this paper, Parallel Path Magnetic Technology Motors will be discussed; specifically addressing their higher efficiency, higher power density, lighter weight, smaller physical size, higher low end torque, wider power zone, cooler temperatures, and greater reliability with lower cost and significant environment benefit for the same peak output power compared to typically motors. A further discussion on the inherent redundancy of these motors for space applications will be provided.

  19. Test Program for High Efficiency Gas Turbine Exhaust Diffuser

    Energy Technology Data Exchange (ETDEWEB)

    Norris, Thomas R.

    2009-12-31

    This research relates to improving the efficiency of flow in a turbine exhaust, and thus, that of the turbine and power plant. The Phase I SBIR project demonstrated the technical viability of “strutlets” to control stalls on a model diffuser strut. Strutlets are a novel flow-improving vane concept intended to improve the efficiency of flow in turbine exhausts. Strutlets can help reduce turbine back pressure, and incrementally improve turbine efficiency, increase power, and reduce greenhouse gas emmission. The long-term goal is a 0.5 percent improvement of each item, averaged over the US gas turbine fleet. The strutlets were tested in a physical scale model of a gas turbine exhaust diffuser. The test flow passage is a straight, annular diffuser with three sets of struts. At the end of Phase 1, the ability of strutlets to keep flow attached to struts was demonstrated, but the strutlet drag was too high for a net efficiency advantage. An independently sponsored followup project did develop a highly-modified low-drag strutlet. In combination with other flow improving vanes, complicance to the stated goals was demonstrated for for simple cycle power plants, and to most of the goals for combined cycle power plants using this particular exhaust geometry. Importantly, low frequency diffuser noise was reduced by 5 dB or more, compared to the baseline. Appolicability to other diffuser geometries is yet to be demonstrated.

  20. Efficient Smoothed Concomitant Lasso Estimation for High Dimensional Regression

    Science.gov (United States)

    Ndiaye, Eugene; Fercoq, Olivier; Gramfort, Alexandre; Leclère, Vincent; Salmon, Joseph

    2017-10-01

    In high dimensional settings, sparse structures are crucial for efficiency, both in term of memory, computation and performance. It is customary to consider ℓ 1 penalty to enforce sparsity in such scenarios. Sparsity enforcing methods, the Lasso being a canonical example, are popular candidates to address high dimension. For efficiency, they rely on tuning a parameter trading data fitting versus sparsity. For the Lasso theory to hold this tuning parameter should be proportional to the noise level, yet the latter is often unknown in practice. A possible remedy is to jointly optimize over the regression parameter as well as over the noise level. This has been considered under several names in the literature: Scaled-Lasso, Square-root Lasso, Concomitant Lasso estimation for instance, and could be of interest for uncertainty quantification. In this work, after illustrating numerical difficulties for the Concomitant Lasso formulation, we propose a modification we coined Smoothed Concomitant Lasso, aimed at increasing numerical stability. We propose an efficient and accurate solver leading to a computational cost no more expensive than the one for the Lasso. We leverage on standard ingredients behind the success of fast Lasso solvers: a coordinate descent algorithm, combined with safe screening rules to achieve speed efficiency, by eliminating early irrelevant features.

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

    Data.gov (United States)

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

  2. Combustion phasing for maximum efficiency for conventional and high efficiency engines

    International Nuclear Information System (INIS)

    Caton, Jerald A.

    2014-01-01

    Highlights: • Combustion phasing for max efficiency is a function of engine parameters. • Combustion phasing is most affected by heat transfer, compression ratio, burn duration. • Combustion phasing is less affected by speed, load, equivalence ratio and EGR. • Combustion phasing for a high efficiency engine was more advanced. • Exergy destruction during combustion as functions of combustion phasing is reported. - Abstract: The importance of the phasing of the combustion event for internal-combustion engines is well appreciated, but quantitative details are sparse. The objective of the current work was to examine the optimum combustion phasing (based on maximum bmep) as functions of engine design and operating variables. A thermodynamic, engine cycle simulation was used to complete this assessment. As metrics for the combustion phasing, both the crank angle for 50% fuel mass burned (CA 50 ) and the crank angle for peak pressure (CA pp ) are reported as functions of the engine variables. In contrast to common statements in the literature, the optimum CA 50 and CA pp vary depending on the design and operating variables. Optimum, as used in this paper, refers to the combustion timing that provides the maximum bmep and brake thermal efficiency (MBT timing). For this work, the variables with the greatest influence on the optimum CA 50 and CA pp were the heat transfer level, the burn duration and the compression ratio. Other variables such as equivalence ratio, EGR level, engine speed and engine load had a much smaller impact on the optimum CA 50 and CA pp . For the conventional engine, for the conditions examined, the optimum CA 50 varied between about 5 and 11°aTDC, and the optimum CA pp varied between about 9 and 16°aTDC. For a high efficiency engine (high dilution, high compression ratio), the optimum CA 50 was 2.5°aTDC, and the optimum CA pp was 7.8°aTDC. These more advanced values for the optimum CA 50 and CA pp for the high efficiency engine were

  3. High resolution PET breast imager with improved detection efficiency

    Science.gov (United States)

    Majewski, Stanislaw

    2010-06-08

    A highly efficient PET breast imager for detecting lesions in the entire breast including those located close to the patient's chest wall. The breast imager includes a ring of imaging modules surrounding the imaged breast. Each imaging module includes a slant imaging light guide inserted between a gamma radiation sensor and a photodetector. The slant light guide permits the gamma radiation sensors to be placed in close proximity to the skin of the chest wall thereby extending the sensitive region of the imager to the base of the breast. Several types of photodetectors are proposed for use in the detector modules, with compact silicon photomultipliers as the preferred choice, due to its high compactness. The geometry of the detector heads and the arrangement of the detector ring significantly reduce dead regions thereby improving detection efficiency for lesions located close to the chest wall.

  4. The high efficiency steel filters for nuclear air cleaning

    International Nuclear Information System (INIS)

    Bergman, W.; Larsen, G.; Lopez, R.; Williams, K.; Violet, C.

    1990-08-01

    We have, in cooperation with industry, developed high-efficiency filters made from sintered stainless-steel fibers for use in several air-cleaning applications in the nuclear industry. These filters were developed to overcome the failure modes in present high-efficiency particulate air (HEPA) filters. HEPA filters are made from glass paper and glue, and they may fail when they get hot or wet and when they are overpressured. In developing our steel filters, we first evaluated the commercially available stainless-steel filter media made from sintered powder and sintered fiber. The sintered-fiber media performed much better than sintered-powder media, and the best media had the smallest fiber diameter. Using the best media, we then built prototype filters for venting compressed gases and evaluated them in our automated filter tester. 12 refs., 20 figs

  5. High efficiency steel filters for nuclear air cleaning

    International Nuclear Information System (INIS)

    Bergman, W.; Conner, J.; Larsen, G.; Lopez, R.; Turner, C.; Vahla, G.; Violet, C.; Williams, K.

    1991-01-01

    The authors have, in cooperation with industry, developed high-efficiency filters made from sintered stainless-steel fibers for use in several air-cleaning applications in the nuclear industry. These filters were developed to overcome the failure modes in present high-efficiently particulate air (HEPA) filters. HEPA filters are made from glass paper and glue, and they may fail when they get hot or wet and when they are overpressured. In developing steel filters, they first evaluated the commercially available stainless-steel filter media made from sintered powder and sintered fiber. The sintered-fiber media performed much better than sintered-powder media, and the best media had the smallest fiber diameter. Using the best media, prototype filters were then built for venting compressed gases and evaluated in their automated filter tester

  6. Blanket options for high-efficiency fusion power

    International Nuclear Information System (INIS)

    Usher, J.L.; Lazareth, O.W.; Fillo, J.A.; Horn, F.L.; Powell, J.R.

    1980-01-01

    The efficiencies of blankets for fusion reactors are usually in the range of 30 to 40%, limited by the operating temperatures (500 0 C) of conventional structural materials such as stainless steels. In this project two-zone blankets are proposed; these blankets consist of a low-temperature shell surrounding a high-temperature interior zone. A survey of nucleonics and thermal hydraulic parameters has led to a reference blanket design consisting of a water-cooled stainless steel shell around a BeO, ZrO 2 interior (cooled by argon) utilizing Li 2 O for tritium breeding. In this design, approximately 60% of the fusion energy is deposited in the high-temperature interior. The maximum argon temperature is 2230 0 C leading to an overall efficiency estimate of 55 to 60% for this reference case

  7. Fusion blankets for high-efficiency power cycles

    International Nuclear Information System (INIS)

    Usher, J.L.; Lazareth, O.W.; Fillo, J.A.; Horn, F.L.; Powell, J.R.

    1980-01-01

    The efficiencies of blankets for fusion reactors are usually in the range of 30 to 40%, limited by the operating temperatures (500 0 C) of conventional structural materials such as stainless steels. In this project two-zone blankets are proposed; these blankets consist of a low-temperature shell surrounding a high-temperature interior zone. A survey of nucleonics and thermal hydraulic parameters has led to a reference blanket design consisting of a water-cooled stainless steel shell around a BeO, ZrO 2 interior (cooled by argon) utilizing Li 2 O for tritium breeding. In this design, approximately 60% of the fusion energy is deposited in the high-temperature interior. The maximum argon temperature is 2230 0 C leading to an overall efficiency estimate of 55 to 60% for this reference case

  8. Fusion blanket for high-efficiency power cycles

    International Nuclear Information System (INIS)

    Usher, J.L.; Powell, J.R.; Fillo, J.A.; Horn, F.L.; Lazareth, O.W.; Taussig, R.

    1980-01-01

    The efficiencies of blankets for fusion reactors are usually in the range of 30 to 40%, limited by the operating temperature (500 0 C) of conventional structural materials such as stainless steels. In this project two-zone blankets are proposed; these blankets consist of a low-temperature shell surrounding a high-temperature interior zone. A survey of nucleonics and thermal hydraulic parameters has led to a reference blanket design consisting of a water-cooled stainless steel shell around a BeO, ZrO 2 interior (cooled by Ar) utilizing Li 2 O for tritium breeding. In this design, approx. 60% of the fusion energy is deposited in the high-temperature interior. The maximum Ar temperature is 2230 0 C leading to an overall efficiency estimate of 55 to 60% for this reference case

  9. Fusion blankets for high-efficiency power cycles

    International Nuclear Information System (INIS)

    Usher, J.L.; Lazareth, O.W.; Fillo, J.A.; Horn, F.L.; Powell, J.R.

    1981-01-01

    The efficiencies of blankets for fusion reactors are usually in the range of 30 to 40%, limited by the operating temperatures (500 deg C) of conventional structural materials such as stainless steels. In this project 'two-zone' blankets are proposed; these blankets consist of a low-temperature shell surrounding a high-temperature interior zone. A survey of nucleonics and thermal hydraulic parameters has led to a reference blanket design consisting of a water-cooled stainless steel shell around a BeO, ZrO 2 interior (cooled by argon) utilizing Li 2 O for tritium breeding. In this design, approximately 60% of the fusion energy is deposited in the high-temperature interior. The maximum argon temperature is 2230 deg C leading to an overall efficiency estimate of 55 to 60% for this reference case. (author)

  10. Irradiation effects on high efficiency Si solar cells

    International Nuclear Information System (INIS)

    Nguyen Duy, T.; Amingual, D.; Colardelle, P.; Bernard, J.

    1974-01-01

    By optimizing the diffusion parameters, high efficiency cells are obtained with 2ohmsxcm (13.5% AMO) and 10ohmsxcm (12.5% AMO) silicon material. These new cells have been submitted to radiation tests under 1MeV, 2MeV electrons and 2.5MeV protons. Their behavior under irradiation is found to be dependent only on the bulk material. By using the same resistivity silicon, the rate of degradation is exactly the same than those of conventional cells. The power increase, due to a better superficial response of the cell, is maintained after irradiation. These results show that new high efficiency cells offer an E.O.L. power higher than conventional cells [fr

  11. Highly efficient electron vortex beams generated by nanofabricated phase holograms

    Energy Technology Data Exchange (ETDEWEB)

    Grillo, Vincenzo, E-mail: vincenzo.grillo@nano.cnr.it [CNR-Istituto Nanoscienze, Centro S3, Via G Campi 213/a, I-41125 Modena (Italy); CNR-IMEM Parco Area delle Scienze 37/A, I-43124 Parma (Italy); Carlo Gazzadi, Gian [CNR-Istituto Nanoscienze, Centro S3, Via G Campi 213/a, I-41125 Modena (Italy); Karimi, Ebrahim [CNR-Istituto Nanoscienze, Centro S3, Via G Campi 213/a, I-41125 Modena (Italy); Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario K1N 6N5 (Canada); Mafakheri, Erfan [Dipartimento di Fisica Informatica e Matematica, Università di Modena e Reggio Emilia, via G Campi 213/a, I-41125 Modena (Italy); Boyd, Robert W. [Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario K1N 6N5 (Canada); Frabboni, Stefano [CNR-Istituto Nanoscienze, Centro S3, Via G Campi 213/a, I-41125 Modena (Italy); Dipartimento di Fisica Informatica e Matematica, Università di Modena e Reggio Emilia, via G Campi 213/a, I-41125 Modena (Italy)

    2014-01-27

    We propose an improved type of holographic-plate suitable for the shaping of electron beams. The plate is fabricated by a focused ion beam on a silicon nitride membrane and introduces a controllable phase shift to the electron wavefunction. We adopted the optimal blazed-profile design for the phase hologram, which results in the generation of highly efficient (25%) electron vortex beams. This approach paves the route towards applications in nano-scale imaging and materials science.

  12. Holography as a highly efficient RG flow I: Rephrasing gravity

    OpenAIRE

    Behr, Nicolas; Kuperstein, Stanislav; Mukhopadhyay, Ayan

    2015-01-01

    We investigate how the holographic correspondence can be reformulated as a generalisation of Wilsonian RG flow in a strongly interacting large $N$ quantum field theory. We firstly define a \\textit{highly efficient RG flow} as one in which the Ward identities related to local conservation of energy, momentum and charges preserve the same form at each scale -- to achieve this it is necessary to redefine the background metric and external sources at each scale as functionals of the effective sin...

  13. Sm , Bi phosphors with high efficiency white-light-emittin

    Indian Academy of Sciences (India)

    2017-08-29

    Aug 29, 2017 ... Therefore, researches on high efficiency red phos- phors are very important. So far ..... ing concentration and reached a maximum at y = 8 mol%. A .... [10] Xue L P, Wang Y J, Lv P W, Chen D G, Lin Z, Liang J K et al. 2009 Crystal ... [28] Liu J, Xu B, Song C, Luo H, Zou X, Han L et al 2012 Cryst-. EngComm.

  14. High-efficiency pumps drastically reduce energy consumption

    Energy Technology Data Exchange (ETDEWEB)

    Anon

    2002-05-01

    Wilo's Stratos pumps for air conditioning and other domestic heating applications combine the advantages of wet runner technology with an innovative electronic commutator motor. The energy consumption of these high-efficiency pumps is halved compared with similar wet runner designs. With vast numbers of pumps used in buildings across Europe alone, the adoption of this technology potentially offers significant energy sayings. (Author)

  15. Wavy channel transistor for area efficient high performance operation

    KAUST Repository

    Fahad, Hossain M.

    2013-04-05

    We report a wavy channel FinFET like transistor where the channel is wavy to increase its width without any area penalty and thereby increasing its drive current. Through simulation and experiments, we show the effectiveness of such device architecture is capable of high performance operation compared to conventional FinFETs with comparatively higher area efficiency and lower chip latency as well as lower power consumption.

  16. Highly efficient electron vortex beams generated by nanofabricated phase holograms

    International Nuclear Information System (INIS)

    Grillo, Vincenzo; Carlo Gazzadi, Gian; Karimi, Ebrahim; Mafakheri, Erfan; Boyd, Robert W.; Frabboni, Stefano

    2014-01-01

    We propose an improved type of holographic-plate suitable for the shaping of electron beams. The plate is fabricated by a focused ion beam on a silicon nitride membrane and introduces a controllable phase shift to the electron wavefunction. We adopted the optimal blazed-profile design for the phase hologram, which results in the generation of highly efficient (25%) electron vortex beams. This approach paves the route towards applications in nano-scale imaging and materials science

  17. High voltage generator circuit with low power and high efficiency applied in EEPROM

    International Nuclear Information System (INIS)

    Liu Yan; Zhang Shilin; Zhao Yiqiang

    2012-01-01

    This paper presents a low power and high efficiency high voltage generator circuit embedded in electrically erasable programmable read-only memory (EEPROM). The low power is minimized by a capacitance divider circuit and a regulator circuit using the controlling clock switch technique. The high efficiency is dependent on the zero threshold voltage (V th ) MOSFET and the charge transfer switch (CTS) charge pump. The proposed high voltage generator circuit has been implemented in a 0.35 μm EEPROM CMOS process. Measured results show that the proposed high voltage generator circuit has a low power consumption of about 150.48 μW and a higher pumping efficiency (83.3%) than previously reported circuits. This high voltage generator circuit can also be widely used in low-power flash devices due to its high efficiency and low power dissipation. (semiconductor integrated circuits)

  18. Development and evaluation of a cleanable high efficiency steel filter

    International Nuclear Information System (INIS)

    Bergman, W.; Larsen, G.; Weber, F.; Wilson, P.; Lopez, R.; Valha, G.; Conner, J.; Garr, J.; Williams, K.; Biermann, A.; Wilson, K.; Moore, P.; Gellner, C.; Rapchun, D.; Simon, K.; Turley, J.; Frye, L.; Monroe, D.

    1993-01-01

    We have developed a high efficiency steel filter that can be cleaned in-situ by reverse air pulses. The filter consists of 64 pleated cylindrical filter elements packaged into a 6l0 x 6l0 x 292 mm aluminum frame and has 13.5 m 2 of filter area. The filter media consists of a sintered steel fiber mat using 2 μm diameter fibers. We conducted an optimization study for filter efficiency and pressure drop to determine the filter design parameters of pleat width, pleat depth, outside diameter of the cylinder, and the total number of cylinders. Several prototype cylinders were then built and evaluated in terms of filter cleaning by reverse air pulses. The results of these studies were used to build the high efficiency steel filter. We evaluated the prototype filter for efficiency and cleanability. The DOP filter certification test showed the filter has a passing efficiency of 99.99% but a failing pressure drop of 0.80 kPa at 1,700 m 3 /hr. Since we were not able to achieve a pressure drop less than 0.25 kPa, the steel filter does not meet all the criteria for a HEPA filter. Filter loading and cleaning tests using AC Fine dust showed the filter could be repeatedly cleaned by reverse air pulses. The next phase of the prototype evaluation consisted of installing the unit and support housing in the exhaust duct work of a uranium grit blaster for a field evaluation at the Y-12 Plant in Oak Ridge, TN. The grit blaster is used to clean the surface of uranium parts and generates a cloud of UO 2 aerosols. We used a 1,700 m 3 /hr slip stream from the 10,200 m 3 /hr exhaust system

  19. Telescoping Solar Array Concept for Achieving High Packaging Efficiency

    Science.gov (United States)

    Mikulas, Martin; Pappa, Richard; Warren, Jay; Rose, Geoff

    2015-01-01

    Lightweight, high-efficiency solar arrays are required for future deep space missions using high-power Solar Electric Propulsion (SEP). Structural performance metrics for state-of-the art 30-50 kW flexible blanket arrays recently demonstrated in ground tests are approximately 40 kW/cu m packaging efficiency, 150 W/kg specific power, 0.1 Hz deployed stiffness, and 0.2 g deployed strength. Much larger arrays with up to a megawatt or more of power and improved packaging and specific power are of interest to mission planners for minimizing launch and life cycle costs of Mars exploration. A new concept referred to as the Compact Telescoping Array (CTA) with 60 kW/cu m packaging efficiency at 1 MW of power is described herein. Performance metrics as a function of array size and corresponding power level are derived analytically and validated by finite element analysis. Feasible CTA packaging and deployment approaches are also described. The CTA was developed, in part, to serve as a NASA reference solar array concept against which other proposed designs of 50-1000 kW arrays for future high-power SEP missions could be compared.

  20. MODELING OF TRACTION SYNCHRONOUS PERMANENT MAGNET MOTOR MODES

    Directory of Open Access Journals (Sweden)

    Y.N. Vas’kovsky

    2013-10-01

    Full Text Available A mathematical model of electromagnetic field for simulating operational modes of traction synchronous motors with permanent magnets intended for electric vehicles is developed. The mathematical model takes into account real-time rotor rotation and allows calculating and analyzing the motor basic running characteristics as time functions.

  1. Physical and electrocardiographic evaluation of horses used for wagon traction

    Directory of Open Access Journals (Sweden)

    M.M. Bomfim

    Full Text Available ABSTRACT The objective of this research was to evaluate the electrocardiogram (ECG of horses used for wagon traction and to compare the results with the parameters obtained from inactive horses or horses submitted to a training routine. Fifty-six 3-15-year-old healthy horses (22 females and 34 males were divided into three groups: control (without a work routine; N=21, wagon traction (N=25 and athlete (N=10 and submitted to physical examination and ECG (at rest. The rhythm, heart rate (HR, amplitude and duration of ECG waveforms and intervals were obtained from the frontal plane and base-apex leads. Heart score (HS was calculated using the arithmetic mean of QRS duration in LI, LII and LIII. Measurements of ECG waves were smaller in control group, in comparison with wagon traction and athlete groups, suggesting that exercise can change ECG. Similar results were observed in the wagon traction and athlete groups, but the electrophysiological adjustments to exercise were not the same for these groups.

  2. LOADING OF MECHANICAL TRANSMISSION OF TROLLEYBUS TRACTION DRIVING GEAR

    Directory of Open Access Journals (Sweden)

    A. I. Safonov

    2009-01-01

    Full Text Available The paper analyzes factors that determine dynamic loads of mechanical transmission of trolleybus traction driving gear. The paper proposes a methodology for determination of calculative moments of loading transmission elements. Results of the research are analyzed and recommendations on  dynamic reduction of trolleybus transmission are given in the paper. 

  3. Traction control of an electric formula student racing car

    NARCIS (Netherlands)

    Loof, J.W.; Besselink, I.J.M.; Nijmeijer, H.

    2014-01-01

    This article describes the design of a traction control system in an electric Formula Student vehicle. In many race applications the accelerator pedal is difficult to control for an in-experienced driver, especially in the case of electric vehicles, where a large torque is available from standstill.

  4. COMPROMISE, OPTIMAL AND TRACTIONAL ACCOUNTS ON PARETO SET

    Directory of Open Access Journals (Sweden)

    V. V. Lahuta

    2010-11-01

    Full Text Available The problem of optimum traction calculations is considered as a problem about optimum distribution of a resource. The dynamic programming solution is based on a step-by-step calculation of set of points of Pareto-optimum values of a criterion function (energy expenses and a resource (time.

  5. Quality electricity lines of external power systems electric traction DC

    Directory of Open Access Journals (Sweden)

    A.V. Petrov

    2012-08-01

    Full Text Available The results of studies that compare and analyze the numerical values of some key indicators quality electricity in the lines of the external power supply system the electric traction DC. As a supplement are additional and fundamental values of energy losses in them.

  6. THE DYNAMICS AND TRACTION ENERGY METRICS LOCOMOTIVE VL40

    Directory of Open Access Journals (Sweden)

    S. V. Pylypenko

    2008-03-01

    Full Text Available In the article the results of dynamic running and traction-energy tests of the electric locomotive VL40U are presented. In accordance with the test results a conclusion about the suitability of electric locomotive of such a type for operation with trains containing up to 15 passenger coaches inclusive is made.

  7. Apicotomy as Treatment for Failure of Orthodontic Traction

    Directory of Open Access Journals (Sweden)

    Leandro Berni Osório

    2013-01-01

    Full Text Available Objective. The purpose of this study was to present a case report that demonstrated primary failure in a tooth traction that was subsequently treated with apicotomy technique. Case Report. A 10-year-old girl had an impacted upper right canine with increased pericoronal space, which was apparent on a radiographic image. The right maxillary sinus showed an opacity suggesting sinusitis. The presumptive diagnosis was dentigerous cyst associated with maxillary sinus infection. The plan for treatment included treatment of the sinus infection and cystic lesion and orthodontic traction of the canine after surgical exposure and bonding of an orthodontic appliance. The surgical procedure, canine position, root dilaceration, and probably apical ankylosis acted in the primary failure of the orthodontic traction. Surgical apical cut of the displaced teeth was performed, and tooth position in the dental arch was possible, with a positive response to the pulp vitality test. Conclusion. Apicotomy is an effective technique to treat severe canine displacement and primary orthodontic traction failure of palatally displaced canines.

  8. High precision efficiency calibration of a HPGe detector

    International Nuclear Information System (INIS)

    Nica, N.; Hardy, J.C.; Iacob, V.E.; Helmer, R.G.

    2003-01-01

    Many experiments involving measurements of γ rays require a very precise efficiency calibration. Since γ-ray detection and identification also requires good energy resolution, the most commonly used detectors are of the coaxial HPGe type. We have calibrated our 70% HPGe to ∼ 0.2% precision, motivated by the measurement of precise branching ratios (BR) in superallowed 0 + → 0 + β decays. These BRs are essential ingredients in extracting ft-values needed to test the Standard Model via the unitarity of the Cabibbo-Kobayashi-Maskawa matrix, a test that it currently fails by more than two standard deviations. To achieve the required high precision in our efficiency calibration, we measured 17 radioactive sources at a source-detector distance of 15 cm. Some of these were commercial 'standard' sources but we achieved the highest relative precision with 'home-made' sources selected because they have simple decay schemes with negligible side feeding, thus providing exactly matched γ-ray intensities. These latter sources were produced by us at Texas A and M by n-activation or by nuclear reactions. Another critical source among the 17 was a 60 Co source produced by Physikalisch-Technische Bundesanstalt, Braunschweig, Germany: its absolute activity was quoted to better than 0.06%. We used it to establish our absolute efficiency, while all the other sources were used to determine relative efficiencies, extending our calibration over a large energy range (40-3500 keV). Efficiencies were also determined with Monte Carlo calculations performed with the CYLTRAN code. The physical parameters of the Ge crystal were independently determined and only two (unmeasurable) dead-layers were adjusted, within physically reasonable limits, to achieve precise absolute agreement with our measured efficiencies. The combination of measured efficiencies at more than 60 individual energies and Monte Carlo calculations to interpolate between them allows us to quote the efficiency of our

  9. Novel characteristics of traction force in biliary self-expandable metallic stents.

    Science.gov (United States)

    Hori, Yasuki; Hayashi, Kazuki; Yoshida, Michihiro; Naitoh, Itaru; Ban, Tesshin; Miyabe, Katsuyuki; Kondo, Hiromu; Nishi, Yuji; Umemura, Shuichiro; Fujita, Yasuaki; Natsume, Makoto; Kato, Akihisa; Ohara, Hirotaka; Joh, Takashi

    2017-05-01

    In recent years, knowledge concerning the mechanical properties of self-expandable metallic stents (SEMS) has increased. In a previous study, we defined traction force and traction momentum and reported that these characteristics are important for optimal stent deployment. However, traction force and traction momentum were represented as relative values and were not evaluated in various conditions. The purpose of the present study was to measure traction force in various situations assumed during SEMS placement. Traction force and traction momentum were measured in non-stricture, stricture, and angled stricture models using in-house equipment. Stricture and angled stricture models had significantly higher traction force and traction momentum than those of the non-stricture model (stricture vs non-stricture: traction force, 7.2 N vs 1.4 N, P stent influenced the traction force. Clinicians should be aware of the transition of the traction force and should schedule X-ray imaging during SEMS placement. © 2017 Japan Gastroenterological Endoscopy Society.

  10. Cellular adhesome screen identifies critical modulators of focal adhesion dynamics, cellular traction forces and cell migration behaviour

    Science.gov (United States)

    Fokkelman, Michiel; Balcıoğlu, Hayri E.; Klip, Janna E.; Yan, Kuan; Verbeek, Fons J.; Danen, Erik H. J.; van de Water, Bob

    2016-01-01

    Cancer cells migrate from the primary tumour into surrounding tissue in order to form metastasis. Cell migration is a highly complex process, which requires continuous remodelling and re-organization of the cytoskeleton and cell-matrix adhesions. Here, we aimed to identify genes controlling aspects of tumour cell migration, including the dynamic organization of cell-matrix adhesions and cellular traction forces. In a siRNA screen targeting most cell adhesion-related genes we identified 200+ genes that regulate size and/or dynamics of cell-matrix adhesions in MCF7 breast cancer cells. In a subsequent secondary screen, the 64 most effective genes were evaluated for growth factor-induced cell migration and validated by tertiary RNAi pool deconvolution experiments. Four validated hits showed significantly enlarged adhesions accompanied by reduced cell migration upon siRNA-mediated knockdown. Furthermore, loss of PPP1R12B, HIPK3 or RAC2 caused cells to exert higher traction forces, as determined by traction force microscopy with elastomeric micropillar post arrays, and led to considerably reduced force turnover. Altogether, we identified genes that co-regulate cell-matrix adhesion dynamics and traction force turnover, thereby modulating overall motility behaviour. PMID:27531518

  11. CFD application to advanced design for high efficiency spacer grid

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, Kazuo, E-mail: kazuo3_ikeda@ndc.mhi.co.jp

    2014-11-15

    Highlights: • A new LDV was developed to investigate the local velocity in a rod bundle and inside a spacer grid. • The design information that utilizes for high efficiency spacer grid has been obtained. • CFD methodology that predicts flow field in a PWR fuel has been developed. • The high efficiency spacer grid was designed using the CFD methodology. - Abstract: Pressurized water reactor (PWR) fuels have been developed to meet the needs of the market. A spacer grid is a key component to improve thermal hydraulic performance of a PWR fuel assembly. Mixing structures (vanes) of a spacer grid promote coolant mixing and enhance heat removal from fuel rods. A larger mixing vane would improve mixing effect, which would increase the departure from nucleate boiling (DNB) benefit for fuel. However, the increased pressure loss at large mixing vanes would reduce the coolant flow at the mixed fuel core, which would reduce the DNB margin. The solution is to develop a spacer grid whose pressure loss is equal to or less than the current spacer grid and that has higher critical heat flux (CHF) performance. For this reason, a requirement of design tool for predicting the pressure loss and CHF performance of spacer grids has been increased. The author and co-workers have been worked for development of high efficiency spacer grid using Computational Fluid Dynamics (CFD) for nearly 20 years. A new laser Doppler velocimetry (LDV), which is miniaturized with fiber optics embedded in a fuel cladding, was developed to investigate the local velocity profile in a rod bundle and inside a spacer grid. The rod-embedded fiber LDV (rod LDV) can be inserted in an arbitrary grid cell instead of a fuel rod, and has the advantage of not disturbing the flow field since it is the same shape as a fuel rod. The probe volume of the rod LDV is small enough to measure spatial velocity profile in a rod gap and inside a spacer grid. According to benchmark experiments such as flow velocity

  12. CFD application to advanced design for high efficiency spacer grid

    International Nuclear Information System (INIS)

    Ikeda, Kazuo

    2014-01-01

    Highlights: • A new LDV was developed to investigate the local velocity in a rod bundle and inside a spacer grid. • The design information that utilizes for high efficiency spacer grid has been obtained. • CFD methodology that predicts flow field in a PWR fuel has been developed. • The high efficiency spacer grid was designed using the CFD methodology. - Abstract: Pressurized water reactor (PWR) fuels have been developed to meet the needs of the market. A spacer grid is a key component to improve thermal hydraulic performance of a PWR fuel assembly. Mixing structures (vanes) of a spacer grid promote coolant mixing and enhance heat removal from fuel rods. A larger mixing vane would improve mixing effect, which would increase the departure from nucleate boiling (DNB) benefit for fuel. However, the increased pressure loss at large mixing vanes would reduce the coolant flow at the mixed fuel core, which would reduce the DNB margin. The solution is to develop a spacer grid whose pressure loss is equal to or less than the current spacer grid and that has higher critical heat flux (CHF) performance. For this reason, a requirement of design tool for predicting the pressure loss and CHF performance of spacer grids has been increased. The author and co-workers have been worked for development of high efficiency spacer grid using Computational Fluid Dynamics (CFD) for nearly 20 years. A new laser Doppler velocimetry (LDV), which is miniaturized with fiber optics embedded in a fuel cladding, was developed to investigate the local velocity profile in a rod bundle and inside a spacer grid. The rod-embedded fiber LDV (rod LDV) can be inserted in an arbitrary grid cell instead of a fuel rod, and has the advantage of not disturbing the flow field since it is the same shape as a fuel rod. The probe volume of the rod LDV is small enough to measure spatial velocity profile in a rod gap and inside a spacer grid. According to benchmark experiments such as flow velocity

  13. Metamaterial Receivers for High Efficiency Concentrated Solar Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Yellowhair, Julius E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Concentrating Solar Technologies Dept.; Kwon, Hoyeong [Univ. of Texas, Austin, TX (United States). Dept. of Electrical and Computer Engineering; Alu, Andrea [Univ. of Texas, Austin, TX (United States). Dept. of Electrical and Computer Engineering; Jarecki, Robert L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Concentrating Solar Technologies Dept.; Shinde, Subhash L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Concentrating Solar Technologies Dept.

    2016-09-01

    Operation of concentrated solar power receivers at higher temperatures (>700°C) would enable supercritical carbon dioxide (sCO2) power cycles for improved power cycle efficiencies (>50%) and cost-effective solar thermal power. Unfortunately, radiative losses at higher temperatures in conventional receivers can negatively impact the system efficiency gains. One approach to improve receiver thermal efficiency is to utilize selective coatings that enhance absorption across the visible solar spectrum while minimizing emission in the infrared to reduce radiative losses. Existing coatings, however, tend to degrade rapidly at elevated temperatures. In this report, we report on the initial designs and fabrication of spectrally selective metamaterial-based absorbers for high-temperature, high-thermal flux environments important for solarized sCO2 power cycles. Metamaterials are structured media whose optical properties are determined by sub-wavelength structural features instead of bulk material properties, providing unique solutions by decoupling the optical absorption spectrum from thermal stability requirements. The key enabling innovative concept proposed is the use of structured surfaces with spectral responses that can be tailored to optimize the absorption and retention of solar energy for a given temperature range. In this initial study through the Academic Alliance partnership with University of Texas at Austin, we use Tungsten for its stability in expected harsh environments, compatibility with microfabrication techniques, and required optical performance. Our goal is to tailor the optical properties for high (near unity) absorptivity across the majority of the solar spectrum and over a broad range of incidence angles, and at the same time achieve negligible absorptivity in the near infrared to optimize the energy absorbed and retained. To this goal, we apply the recently developed concept of plasmonic Brewster angle to suitably designed

  14. Highly Efficient Thermoresponsive Nanocomposite for Controlled Release Applications

    KAUST Repository

    Yassine, Omar

    2016-06-23

    Highly efficient magnetic release from nanocomposite microparticles is shown, which are made of Poly (N-isopropylacrylamide) hydrogel with embedded iron nanowires. A simple microfluidic technique was adopted to fabricate the microparticles with a high control of the nanowire concentration and in a relatively short time compared to chemical synthesis methods. The thermoresponsive microparticles were used for the remotely triggered release of Rhodamine (B). With a magnetic field of only 1 mT and 20 kHz a drug release of 6.5% and 70% was achieved in the continuous and pulsatile modes, respectively. Those release values are similar to the ones commonly obtained using superparamagnetic beads but accomplished with a magnetic field of five orders of magnitude lower power. The high efficiency is a result of the high remanent magnetization of the nanowires, which produce a large torque when exposed to a magnetic field. This causes the nanowires to vibrate, resulting in friction losses and heating. For comparison, microparticles with superparamagnetic beads were also fabricated and tested; while those worked at 73 mT and 600 kHz, no release was observed at the low field conditions. Cytotoxicity assays showed similar and high cell viability for microparticles with nanowires and beads.

  15. Highly Efficient Thermoresponsive Nanocomposite for Controlled Release Applications

    KAUST Repository

    Yassine, Omar; Zaher, Amir; Li, Erqiang; Alfadhel, Ahmed; Perez, Jose E.; Kavaldzhiev, Mincho; Contreras, Maria F.; Thoroddsen, Sigurdur T; Khashab, Niveen M.; Kosel, Jü rgen

    2016-01-01

    Highly efficient magnetic release from nanocomposite microparticles is shown, which are made of Poly (N-isopropylacrylamide) hydrogel with embedded iron nanowires. A simple microfluidic technique was adopted to fabricate the microparticles with a high control of the nanowire concentration and in a relatively short time compared to chemical synthesis methods. The thermoresponsive microparticles were used for the remotely triggered release of Rhodamine (B). With a magnetic field of only 1 mT and 20 kHz a drug release of 6.5% and 70% was achieved in the continuous and pulsatile modes, respectively. Those release values are similar to the ones commonly obtained using superparamagnetic beads but accomplished with a magnetic field of five orders of magnitude lower power. The high efficiency is a result of the high remanent magnetization of the nanowires, which produce a large torque when exposed to a magnetic field. This causes the nanowires to vibrate, resulting in friction losses and heating. For comparison, microparticles with superparamagnetic beads were also fabricated and tested; while those worked at 73 mT and 600 kHz, no release was observed at the low field conditions. Cytotoxicity assays showed similar and high cell viability for microparticles with nanowires and beads.

  16. High Efficiency Heat Exchanger for High Temperature and High Pressure Applications

    Energy Technology Data Exchange (ETDEWEB)

    Sienicki, James J. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Lv, Qiuping [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Moisseytsev, Anton [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division

    2017-09-29

    CompRex, LLC (CompRex) specializes in the design and manufacture of compact heat exchangers and heat exchange reactors for high temperature and high pressure applications. CompRex’s proprietary compact technology not only increases heat exchange efficiency by at least 25 % but also reduces footprint by at least a factor of ten compared to traditional shell-and-tube solutions of the same capacity and by 15 to 20 % compared to other currently available Printed Circuit Heat Exchanger (PCHE) solutions. As a result, CompRex’s solution is especially suitable for Brayton cycle supercritical carbon dioxide (sCO2) systems given its high efficiency and significantly lower capital and operating expenses. CompRex has already successfully demonstrated its technology and ability to deliver with a pilot-scale compact heat exchanger that was under contract by the Naval Nuclear Laboratory for sCO2 power cycle development. The performance tested unit met or exceeded the thermal and hydraulic specifications with measured heat transfer between 95 to 98 % of maximum heat transfer and temperature and pressure drop values all consistent with the modeled values. CompRex’s vision is to commercialize its compact technology and become the leading provider for compact heat exchangers and heat exchange reactors for various applications including Brayton cycle sCO2 systems. One of the limitations of the sCO2 Brayton power cycle is the design and manufacturing of efficient heat exchangers at extreme operating conditions. Current diffusion-bonded heat exchangers have limitations on the channel size through which the fluid travels, resulting in excessive solid material per heat exchanger volume. CompRex’s design allows for more open area and shorter fluid proximity for increased heat transfer efficiency while sustaining the structural integrity needed for the application. CompRex is developing a novel improvement to its current heat exchanger design where fluids are directed to alternating

  17. A high efficiency hybrid stirling-pulse tube cryocooler

    Directory of Open Access Journals (Sweden)

    Xiaotao Wang

    2015-03-01

    Full Text Available This article presented a hybrid cryocooler which combines the room temperature displacers and the pulse tube in one system. Compared with a traditional pulse tube cryocooler, the system uses the rod-less ambient displacer to recover the expansion work from the pulse tube cold end to improve the efficiency while still keeps the advantage of the pulse tube cryocooler with no moving parts at the cold region. In the meantime, dual-opposed configurations for both the compression pistons and displacers reduce the cooler vibration to a very low level. In the experiments, a lowest no-load temperature of 38.5 K has been obtained and the cooling power at 80K was 26.4 W with an input electric power of 290 W. This leads to an efficiency of 24.2% of Carnot, marginally higher than that of an ordinary pulse tube cryocooler. The hybrid configuration herein provides a very competitive option when a high efficiency, high-reliability and robust cryocooler is desired.

  18. High-efficiency ballistic electrostatic generator using microdroplets

    Science.gov (United States)

    Xie, Yanbo; Bos, Diederik; de Vreede, Lennart J.; de Boer, Hans L.; van der Meulen, Mark-Jan; Versluis, Michel; Sprenkels, Ad J.; van den Berg, Albert; Eijkel, Jan C. T.

    2014-04-01

    The strong demand for renewable energy promotes research on novel methods and technologies for energy conversion. Microfluidic systems for energy conversion by streaming current are less known to the public, and the relatively low efficiencies previously obtained seemed to limit the further applications of such systems. Here we report a microdroplet-based electrostatic generator operating by an acceleration-deceleration cycle (‘ballistic’ conversion), and show that this principle enables both high efficiency and compact simple design. Water is accelerated by pumping it through a micropore to form a microjet breaking up into fast-moving charged droplets. Droplet kinetic energy is converted to electrical energy when the charged droplets decelerate in the electrical field that forms between membrane and target. We demonstrate conversion efficiencies of up to 48%, a power density of 160 kW m-2 and both high- (20 kV) and low- (500 V) voltage operation. Besides offering striking new insights, the device potentially opens up new perspectives for low-cost and robust renewable energy conversion.

  19. Radiation hardened high efficiency silicon space solar cell

    International Nuclear Information System (INIS)

    Garboushian, V.; Yoon, S.; Turner, J.

    1993-01-01

    A silicon solar cell with AMO 19% Beginning of Life (BOL) efficiency is reported. The cell has demonstrated equal or better radiation resistance when compared to conventional silicon space solar cells. Conventional silicon space solar cell performance is generally ∼ 14% at BOL. The Radiation Hardened High Efficiency Silicon (RHHES) cell is thinned for high specific power (watts/kilogram). The RHHES space cell provides compatibility with automatic surface mounting technology. The cells can be easily combined to provide desired power levels and voltages. The RHHES space cell is more resistant to mechanical damage due to micrometeorites. Micro-meteorites which impinge upon conventional cells can crack the cell which, in turn, may cause string failure. The RHHES, operating in the same environment, can continue to function with a similar crack. The RHHES cell allows for very efficient thermal management which is essential for space cells generating higher specific power levels. The cell eliminates the need for electrical insulation layers which would otherwise increase the thermal resistance for conventional space panels. The RHHES cell can be applied to a space concentrator panel system without abandoning any of the attributes discussed. The power handling capability of the RHHES cell is approximately five times more than conventional space concentrator solar cells

  20. Highly Efficient Spectrally Stable Red Perovskite Light-Emitting Diodes.

    Science.gov (United States)

    Tian, Yu; Zhou, Chenkun; Worku, Michael; Wang, Xi; Ling, Yichuan; Gao, Hanwei; Zhou, Yan; Miao, Yu; Guan, Jingjiao; Ma, Biwu

    2018-05-01

    Perovskite light-emitting diodes (LEDs) have recently attracted great research interest for their narrow emissions and solution processability. Remarkable progress has been achieved in green perovskite LEDs in recent years, but not blue or red ones. Here, highly efficient and spectrally stable red perovskite LEDs with quasi-2D perovskite/poly(ethylene oxide) (PEO) composite thin films as the light-emitting layer are reported. By controlling the molar ratios of organic salt (benzylammonium iodide) to inorganic salts (cesium iodide and lead iodide), luminescent quasi-2D perovskite thin films are obtained with tunable emission colors from red to deep red. The perovskite/polymer composite approach enables quasi-2D perovskite/PEO composite thin films to possess much higher photoluminescence quantum efficiencies and smoothness than their neat quasi-2D perovskite counterparts. Electrically driven LEDs with emissions peaked at 638, 664, 680, and 690 nm have been fabricated to exhibit high brightness and external quantum efficiencies (EQEs). For instance, the perovskite LED with an emission peaked at 680 nm exhibits a brightness of 1392 cd m -2 and an EQE of 6.23%. Moreover, exceptional electroluminescence spectral stability under continuous device operation has been achieved for these red perovskite LEDs. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Design Strategies for Ultra-high Efficiency Photovoltaics

    Science.gov (United States)

    Warmann, Emily Cathryn

    While concentrator photovoltaic cells have shown significant improvements in efficiency in the past ten years, once these cells are integrated into concentrating optics, connected to a power conditioning system and deployed in the field, the overall module efficiency drops to only 34 to 36%. This efficiency is impressive compared to conventional flat plate modules, but it is far short of the theoretical limits for solar energy conversion. Designing a system capable of achieving ultra high efficiency of 50% or greater cannot be achieved by refinement and iteration of current design approaches. This thesis takes a systems approach to designing a photovoltaic system capable of 50% efficient performance using conventional diode-based solar cells. The effort began with an exploration of the limiting efficiency of spectrum splitting ensembles with 2 to 20 sub cells in different electrical configurations. Incorporating realistic non-ideal performance with the computationally simple detailed balance approach resulted in practical limits that are useful to identify specific cell performance requirements. This effort quantified the relative benefit of additional cells and concentration for system efficiency, which will help in designing practical optical systems. Efforts to improve the quality of the solar cells themselves focused on the development of tunable lattice constant epitaxial templates. Initially intended to enable lattice matched multijunction solar cells, these templates would enable increased flexibility in band gap selection for spectrum splitting ensembles and enhanced radiative quality relative to metamorphic growth. The III-V material family is commonly used for multijunction solar cells both for its high radiative quality and for the ease of integrating multiple band gaps into one monolithic growth. The band gap flexibility is limited by the lattice constant of available growth templates. The virtual substrate consists of a thin III-V film with the desired

  2. Efficient Four-Parametric with-and-without-Memory Iterative Methods Possessing High Efficiency Indices

    Directory of Open Access Journals (Sweden)

    Alicia Cordero

    2018-01-01

    Full Text Available We construct a family of derivative-free optimal iterative methods without memory to approximate a simple zero of a nonlinear function. Error analysis demonstrates that the without-memory class has eighth-order convergence and is extendable to with-memory class. The extension of new family to the with-memory one is also presented which attains the convergence order 15.5156 and a very high efficiency index 15.51561/4≈1.9847. Some particular schemes of the with-memory family are also described. Numerical examples and some dynamical aspects of the new schemes are given to support theoretical results.

  3. Microbial electrolytic disinfection process for highly efficient Escherichia coli inactivation

    DEFF Research Database (Denmark)

    Zhou, Shaofeng; Huang, Shaobin; Li, Xiaohu

    2018-01-01

    extensively studied for recalcitrant organics removal, its application potential towards water disinfection (e.g., inactivation of pathogens) is still unknown. This study investigated the inactivation of Escherichia coli in a microbial electrolysis cell based bio-electro-Fenton system (renamed as microbial......Water quality deterioration caused by a wide variety of recalcitrant organics and pathogenic microorganisms has become a serious concern worldwide. Bio-electro-Fenton systems have been considered as cost-effective and highly efficient water treatment platform technology. While it has been......]OH was identified as one potential mechanism for disinfection. This study successfully demonstrated the feasibility of bio-electro-Fenton process for pathogens inactivation, which offers insight for the future development of sustainable, efficient, and cost-effective biological water treatment technology....

  4. Improved entropy encoding for high efficient video coding standard

    Directory of Open Access Journals (Sweden)

    B.S. Sunil Kumar

    2018-03-01

    Full Text Available The High Efficiency Video Coding (HEVC has better coding efficiency, but the encoding performance has to be improved to meet the growing multimedia applications. This paper improves the standard entropy encoding by introducing the optimized weighing parameters, so that higher rate of compression can be accomplished over the standard entropy encoding. The optimization is performed using the recently introduced firefly algorithm. The experimentation is carried out using eight benchmark video sequences and the PSNR for varying rate of data transmission is investigated. Comparative analysis based on the performance statistics is made with the standard entropy encoding. From the obtained results, it is clear that the originality of the decoded video sequence is preserved far better than the proposed method, though the compression rate is increased. Keywords: Entropy, Encoding, HEVC, PSNR, Compression

  5. Study on a Novel High-Efficiency Bridgeless PFC Converter

    Directory of Open Access Journals (Sweden)

    Cao Taiqiang

    2014-01-01

    Full Text Available In order to implement a high-efficiency bridgeless power factor correction converter, a new topology and operation principles of continuous conduction mode (CCM and DC steady-state character of the converter are analyzed, which show that the converter not only has bipolar-gain characteristic but also has the same characteristic as the traditional Boost converter, while the voltage transfer ratio is not related with the resonant branch parameters and switching frequency. Based on the above topology, a novel bridgeless Bipolar-Gain Pseudo-Boost PFC converter is proposed. With this converter, the diode rectifier bridge of traditional AC-DC converter is eliminated, and zero-current switching of fast recovery diode is achieved. Thus, the efficiency is improved. Next, we also propose the one-cycle control policy of this converter. Finally, experiments are provided to verify the accuracy and feasibility of the proposed converter.

  6. Highly Efficient and Reliable Transparent Electromagnetic Interference Shielding Film.

    Science.gov (United States)

    Jia, Li-Chuan; Yan, Ding-Xiang; Liu, Xiaofeng; Ma, Rujun; Wu, Hong-Yuan; Li, Zhong-Ming

    2018-04-11

    Electromagnetic protection in optoelectronic instruments such as optical windows and electronic displays is challenging because of the essential requirements of a high optical transmittance and an electromagnetic interference (EMI) shielding effectiveness (SE). Herein, we demonstrate the creation of an efficient transparent EMI shielding film that is composed of calcium alginate (CA), silver nanowires (AgNWs), and polyurethane (PU), via a facile and low-cost Mayer-rod coating method. The CA/AgNW/PU film with a high optical transmittance of 92% achieves an EMI SE of 20.7 dB, which meets the requirements for commercial shielding applications. A superior EMI SE of 31.3 dB could be achieved, whereas the transparent film still maintains a transmittance of 81%. The integrated efficient EMI SE and high transmittance are superior to those of most previously reported transparent EMI shielding materials. Moreover, our transparent films exhibit a highly reliable shielding ability in a complex service environment, with 98 and 96% EMI SE retentions even after 30 min of ultrasound treatment and 5000 bending cycles (1.5 mm radius), respectively. The comprehensive performance that is associated with the facile fabrication strategy imparts the CA/AgNW/PU film with great potential as an optimized EMI shielding material in emerging optoelectronic devices, such as flexible solar cells, displays, and touch panels.

  7. Research & Implementation of AC - DC Converter with High Power Factor & High Efficiency

    Directory of Open Access Journals (Sweden)

    Hsiou-Hsian Nien

    2014-05-01

    Full Text Available In this paper, we design and develop a high power factor, high efficiency two-stage AC - DC power converter. This paper proposes a two-stage AC - DC power converter. The first stage is boost active power factor correction circuit. The latter stage is near constant frequency LLC resonant converter. In addition to traditional LLC high efficiency advantages, light-load conversion efficiency of this power converter can be improved. And it possesses high power factor and near constant frequency operating characteristics, can significantly reduce the electromagnetic interference. This paper first discusses the main structure and control manner of power factor correction circuit. And then by the LLC resonant converter equivalent model proceed to circuit analysis to determine the important parameters of the converter circuit elements. Then design a variable frequency resonant tank. The resonant frequency can change automatically on the basis of the load to reach near constant frequency operation and a purpose of high efficiency. Finally, actually design and produce an AC – DC power converter with output of 190W to verify the characteristics and feasibility of this converter. The experimental results show that in a very light load (9.5 W the efficiency is as high as 81%, the highest efficiency of 88% (90 W. Full load efficiency is 87%. At 19 W ~ 190 W power changes, the operating frequency change is only 0.4 kHz (AC 110 V and 0.3 kHz (AC 220 V.

  8. Approaches to achieve high grain yield and high resource use efficiency in rice

    Directory of Open Access Journals (Sweden)

    Jianchang YANG

    2015-06-01

    Full Text Available This article discusses approaches to simultaneously increase grain yield and resource use efficiency in rice. Breeding nitrogen efficient cultivars without sacrificing rice yield potential, improving grain fill in later-flowering inferior spikelets and enhancing harvest index are three important approaches to achieving the dual goal of high grain yield and high resource use efficiency. Deeper root distribution and higher leaf photosynthetic N use efficiency at lower N rates could be used as selection criteria to develop N-efficient cultivars. Enhancing sink activity through increasing sugar-spikelet ratio at the heading time and enhancing the conversion efficiency from sucrose to starch though increasing the ratio of abscisic acid to ethylene in grains during grain fill could effectively improve grain fill in inferior spikelets. Several practices, such as post-anthesis controlled soil drying, an alternate wetting and moderate soil drying regime during the whole growing season, and non-flooded straw mulching cultivation, could substantially increase grain yield and water use efficiency, mainly via enhanced remobilization of stored carbon from vegetative tissues to grains and improved harvest index. Further research is needed to understand synergistic interaction between water and N on crop and soil and the mechanism underlying high resource use efficiency in high-yielding rice.

  9. High efficiency electrophosphorescence from bilayer organic light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Li Minghang; Lin, Ming-Te; Shepherd, Nigel D [Department of Material Science and Engineering, University of North Texas, Denton, TX (United States); Chen, Wei-Hsuan; Oswald, Iain; Omary, Mohammad [Department of Chemeistry, University of North Texas, Denton, TX (United States)

    2011-09-14

    An electron mobility of 2.7 x 10{sup -5} cm{sup 2} V{sup -1} s{sup -1} was measured for the phosphorescent emitter bis[3,5-bis(2-pyridyl)-1,2,4-triazolato]platinum(II)(Pt(ptp)2), which prompted its evaluation as both the emissive layer and electron transport layer in organic light emitting diodes with a simple bilayer structure. Power and external quantum efficiencies of 54.0 {+-} 0.2 lm W{sup -1} and 15.9% were obtained, which as far as we could ascertain are amongst the highest reported values for bilayer devices. We ascribe the high device efficiency to the combination of the high electron mobility, short excited-state lifetime (117 ns) and high luminescence quantum yield (60%) of the bis[3,5-bis(2-pyridyl)-1,2,4-triazolato]platinum(II). The colour temperature of the devices was 2855 K at 5 V, which places the emission in the 'warm' light spectral region.

  10. Detecting Android Malwares with High-Efficient Hybrid Analyzing Methods

    Directory of Open Access Journals (Sweden)

    Yu Liu

    2018-01-01

    Full Text Available In order to tackle the security issues caused by malwares of Android OS, we proposed a high-efficient hybrid-detecting scheme for Android malwares. Our scheme employed different analyzing methods (static and dynamic methods to construct a flexible detecting scheme. In this paper, we proposed some detecting techniques such as Com+ feature based on traditional Permission and API call features to improve the performance of static detection. The collapsing issue of traditional function call graph-based malware detection was also avoided, as we adopted feature selection and clustering method to unify function call graph features of various dimensions into same dimension. In order to verify the performance of our scheme, we built an open-access malware dataset in our experiments. The experimental results showed that the suggested scheme achieved high malware-detecting accuracy, and the scheme could be used to establish Android malware-detecting cloud services, which can automatically adopt high-efficiency analyzing methods according to the properties of the Android applications.

  11. High efficiency thermal energy storage system for utility applications

    International Nuclear Information System (INIS)

    Vrable, D.L.; Quade, R.N.

    1979-01-01

    A concept of coupling a high efficiency base loaded coal or nuclear power plant with a thermal energy storage scheme for efficient and low-cost intermediate and peaking power is presented. A portion of the power plant's thermal output is used directly to generate superheated steam for continuous operation of a conventional turbine-generator to product base-load power. The remaining thermal output is used on a continuous basis to heat a conventional heat transfer salt (such as the eutectic composition of KaNO 3 /NaNO 3 /NaNO 2 ), which is stored in a high-temperature reservoir [538 0 C (1000 0 F)]. During peak demand periods, the salt is circulated from the high-temperature reservoir to a low-temperature reservoir through steam generators in order to provide peaking power from a conventional steam cycle plant. The period of operation can vary, but may typically be the equivalent of about 4 to 8 full-power hours each day. The system can be tailored to meet the utilities' load demand by varying the base-load level and the period of operation of the peak-load system

  12. High-efficiency target-ion sources for RIB generation

    International Nuclear Information System (INIS)

    Alton, G.D.

    1993-01-01

    A brief review is given of high-efficiency ion sources which have been developed or are under development at ISOL facilities which show particular promise for use at existing, future, or radioactive ion beam (RIB) facilities now under construction. Emphasis will be placed on those sources which have demonstrated high ionization efficiency, species versatility, and operational reliability and which have been carefully designed for safe handling in the high level radioactivity radiation fields incumbent at such facilities. Brief discussions will also be made of the fundamental processes which affect the realizable beam intensities in target-ion sources. Among the sources which will be reviewed will be selected examples of state-of-the-art electron-beam plasma-type ion sources, thermal-ionization, surface-ionization, ECR, and selectively chosen ion source concepts which show promise for radioactive ion beam generation. A few advanced, chemically selective target-ion sources will be described, such as sources based on the use of laser-resonance ionization, which, in principle, offer a more satisfactory solution to isobaric contamination problems than conventional electromagnetic techniques. Particular attention will be given to the sources which have been selected for initial or future use at the Holifield Radioactive Ion Beam Facility now under construction at the Oak Ridge National Laboratory

  13. Highly Efficient and Reproducible Nonfullerene Solar Cells from Hydrocarbon Solvents

    KAUST Repository

    Wadsworth, Andrew; Ashraf, Raja; Abdelsamie, Maged; Pont, Sebastian; Little, Mark; Moser, Maximilian; Hamid, Zeinab; Neophytou, Marios; Zhang, Weimin; Amassian, Aram; Durrant, James R.; Baran, Derya; McCulloch, Iain

    2017-01-01

    With chlorinated solvents unlikely to be permitted for use in solution-processed organic solar cells in industry, there must be a focus on developing nonchlorinated solvent systems. Here we report high-efficiency devices utilizing a low-bandgap donor polymer (PffBT4T-2DT) and a nonfullerene acceptor (EH-IDTBR) from hydrocarbon solvents and without using additives. When mesitylene was used as the solvent, rather than chlorobenzene, an improved power conversion efficiency (11.1%) was achieved without the need for pre- or post-treatments. Despite altering the processing conditions to environmentally friendly solvents and room-temperature coating, grazing incident X-ray measurements confirmed that active layers processed from hydrocarbon solvents retained the robust nanomorphology obtained with hot-processed chlorinated solvents. The main advantages of hydrocarbon solvent-processed devices, besides the improved efficiencies, were the reproducibility and storage lifetime of devices. Mesitylene devices showed better reproducibility and shelf life up to 4000 h with PCE dropping by only 8% of its initial value.

  14. Highly efficient solar-pumped Nd:YAG laser.

    Science.gov (United States)

    Liang, Dawei; Almeida, Joana

    2011-12-19

    The recent progress in solar-pumped laser with Fresnel lens and Cr:Nd:YAG ceramic medium has revitalized solar laser researches, revealing a promising future for renewable reduction of magnesium from magnesium oxide. Here we show a big advance in solar laser collection efficiency by utilizing an economical Fresnel lens and a most widely used Nd:YAG single-crystal rod. The incoming solar radiation from the sun is focused by a 0.9 m diameter Fresnel lens. A dielectric totally internally reflecting secondary concentrator is employed to couple the concentrated solar radiation from the focal zone to a 4 mm diameter Nd:YAG rod within a conical pumping cavity. 12.3 W cw laser power is produced, corresponding to 19.3 W/m(2) collection efficiency, which is 2.9 times larger than the previous results with Nd:YAG single-crystal medium. Record-high slope efficiency of 3.9% is also registered. Laser beam quality is considerably improved by pumping a 3 mm diameter Nd:YAG rod.

  15. EUROGAM: A high efficiency escape suppressed spectrometer array

    Energy Technology Data Exchange (ETDEWEB)

    Nolan, P J [Liverpool Univ. (United Kingdom). Oliver Lodge Lab.

    1992-08-01

    EUROGAM is a UK-France collaboration to develop and build a high efficiency escape suppressed spectrometer array. The project has involved the development of both germanium (Ge) and bismuth germanate (BGO) detectors to produce crystals which are both bigger and have a more complex geometry. As a major investment for the future, the collaboration has developed a new electronics and data acquisition system based on the VXI and VME standards. The array will start its experimental programme in mid 1992 at the Nuclear Structure Facility at Daresbury, U.K. At this stage it will have a total photopeak efficiency (for 1.33 MeV gamma-rays) of {approx} 4.5%. This will give an improvement in sensitivity (relative to presently operating arrays) of a factor of about 10. When EUROGAM moves to France in mid 1993 its photopeak efficiency will have increased to about 8.5% which will result in an increase in sensitivity of a further factor of about 10. In this article I will concentrate on the array which will operate at Daresbury in 1992 and only briefly cover the developments which will take place for the full array before it is used in France in 1993. (author). 13 refs., 2 tabs., 10 figs.

  16. High-efficiency integrated piezoelectric energy harvesting systems

    Science.gov (United States)

    Hande, Abhiman; Shah, Pradeep

    2010-04-01

    This paper describes hierarchically architectured development of an energy harvesting (EH) system that consists of micro and/or macro-scale harvesters matched to multiple components of remote wireless sensor and communication nodes. The micro-scale harvesters consist of thin-film MEMS piezoelectric cantilever arrays and power generation modules in IC-like form to allow efficient EH from vibrations. The design uses new high conversion efficiency thin-film processes combined with novel cantilever structures tuned to multiple resonant frequencies as broadband arrays. The macro-scale harvesters are used to power the collector nodes that have higher power specifications. These bulk harvesters can be integrated with efficient adaptive power management circuits that match transducer impedance and maximize power harvested from multiple scavenging sources with very low intrinsic power consumption. Texas MicroPower, Inc. is developing process based on a composition that has the highest reported energy density as compared to other commercially available bulk PZT-based sensor/actuator ceramic materials and extending it to thin-film materials and miniature conversion transducer structures. The multiform factor harvesters can be deployed for several military and commercial applications such as underground unattended sensors, sensors in oil rigs, structural health monitoring, supply chain management, and battlefield applications such as sensors on soldier apparel, equipment, and wearable electronics.

  17. Highly Efficient and Reproducible Nonfullerene Solar Cells from Hydrocarbon Solvents

    KAUST Repository

    Wadsworth, Andrew

    2017-06-01

    With chlorinated solvents unlikely to be permitted for use in solution-processed organic solar cells in industry, there must be a focus on developing nonchlorinated solvent systems. Here we report high-efficiency devices utilizing a low-bandgap donor polymer (PffBT4T-2DT) and a nonfullerene acceptor (EH-IDTBR) from hydrocarbon solvents and without using additives. When mesitylene was used as the solvent, rather than chlorobenzene, an improved power conversion efficiency (11.1%) was achieved without the need for pre- or post-treatments. Despite altering the processing conditions to environmentally friendly solvents and room-temperature coating, grazing incident X-ray measurements confirmed that active layers processed from hydrocarbon solvents retained the robust nanomorphology obtained with hot-processed chlorinated solvents. The main advantages of hydrocarbon solvent-processed devices, besides the improved efficiencies, were the reproducibility and storage lifetime of devices. Mesitylene devices showed better reproducibility and shelf life up to 4000 h with PCE dropping by only 8% of its initial value.

  18. A High Efficiency PSOFC/ATS-Gas Turbine Power System

    Energy Technology Data Exchange (ETDEWEB)

    W.L. Lundberg; G.A. Israelson; M.D. Moeckel; S.E. Veyo; R.A. Holmes; P.R. Zafred; J.E. King; R.E. Kothmann

    2001-02-01

    A study is described in which the conceptual design of a hybrid power system integrating a pressurized Siemens Westinghouse solid oxide fuel cell generator and the Mercury{trademark} 50 gas turbine was developed. The Mercury{trademark} 50 was designed by Solar Turbines as part of the US. Department of Energy Advanced Turbine Systems program. The focus of the study was to develop the hybrid power system concept that principally would exhibit an attractively-low cost of electricity (COE). The inherently-high efficiency of the hybrid cycle contributes directly to achieving this objective, and by employing the efficient, power-intensive Mercury{trademark} 50, with its relatively-low installed cost, the higher-cost SOFC generator can be optimally sized such that the minimum-COE objective is achieved. The system cycle is described, major system components are specified, the system installed cost and COE are estimated, and the physical arrangement of the major system components is discussed. Estimates of system power output, efficiency, and emissions at the system design point are also presented. In addition, two bottoming cycle options are described, and estimates of their effects on overall-system performance, cost, and COE are provided.

  19. EUROGAM: A high efficiency escape suppressed spectrometer array

    International Nuclear Information System (INIS)

    Nolan, P.J.

    1992-01-01

    EUROGAM is a UK-France collaboration to develop and build a high efficiency escape suppressed spectrometer array. The project has involved the development of both germanium (Ge) and bismuth germanate (BGO) detectors to produce crystals which are both bigger and have a more complex geometry. As a major investment for the future, the collaboration has developed a new electronics and data acquisition system based on the VXI and VME standards. The array will start its experimental programme in mid 1992 at the Nuclear Structure Facility at Daresbury, U.K. At this stage it will have a total photopeak efficiency (for 1.33 MeV gamma-rays) of ∼ 4.5%. This will give an improvement in sensitivity (relative to presently operating arrays) of a factor of about 10. When EUROGAM moves to France in mid 1993 its photopeak efficiency will have increased to about 8.5% which will result in an increase in sensitivity of a further factor of about 10. In this article I will concentrate on the array which will operate at Daresbury in 1992 and only briefly cover the developments which will take place for the full array before it is used in France in 1993. (author). 13 refs., 2 tabs., 10 figs

  20. Cascade: a high-efficiency ICF power reactor

    International Nuclear Information System (INIS)

    Pitts, J.H.

    1985-01-01

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

  1. High-efficiency ventilated metamaterial absorber at low frequency

    Science.gov (United States)

    Wu, Xiaoxiao; Au-Yeung, Ka Yan; Li, Xin; Roberts, Robert Christopher; Tian, Jingxuan; Hu, Chuandeng; Huang, Yingzhou; Wang, Shuxia; Yang, Zhiyu; Wen, Weijia

    2018-03-01

    We demonstrate a ventilated metamaterial absorber operating at low frequency (90%) has been achieved in both simulations and experiments. This high-efficiency absorption under the ventilation condition originates from the weak coupling of two identical split tube resonators constituting the absorber, which leads to the hybridization of the degenerate eigenmodes and breaks the absorption upper limit of 50% for conventional transmissive symmetric acoustic absorbers. The absorber can also be extended to an array and work in free space. The absorber should have potential applications in acoustic engineering where both noise reduction and ventilation are required.

  2. Polarization holograms allow highly efficient generation of complex light beams.

    Science.gov (United States)

    Ruiz, U; Pagliusi, P; Provenzano, C; Volke-Sepúlveda, K; Cipparrone, Gabriella

    2013-03-25

    We report a viable method to generate complex beams, such as the non-diffracting Bessel and Weber beams, which relies on the encoding of amplitude information, in addition to phase and polarization, using polarization holography. The holograms are recorded in polarization sensitive films by the interference of a reference plane wave with a tailored complex beam, having orthogonal circular polarizations. The high efficiency, the intrinsic achromaticity and the simplicity of use of the polarization holograms make them competitive with respect to existing methods and attractive for several applications. Theoretical analysis, based on the Jones formalism, and experimental results are shown.

  3. High efficiency power production from biomass and waste

    Energy Technology Data Exchange (ETDEWEB)

    Rabou, L.P.L.M.; Van Leijenhorst, R.J.C.; Hazewinkel, J.H.O. [ECN Biomass, Coal and Environment, Petten (Netherlands)

    2008-11-15

    Two-stage gasification allows power production from biomass and waste with high efficiency. The process involves pyrolysis at about 550C followed by heating of the pyrolysis gas to about 1300C in order to crack hydrocarbons and obtain syngas, a mixture of H2, CO, H2O and CO2. The second stage produces soot as unwanted by-product. Experimental results are reported on the suppression of soot formation in the second stage for two different fuels: beech wood pellets and Rofire pellets, made from rejects of paper recycling. Syngas obtained from these two fuels and from an industrial waste fuel has been cleaned and fed to a commercial SOFC stack for 250 hours in total. The SOFC stack showed comparable performance on real and synthetic syngas and no signs of accelerated degradation in performance over these tests. The experimental results have been used for the design and analysis of a future 25 MWth demonstration plant. As an alternative, a 2.6 MWth system was considered which uses the Green MoDem approach to convert waste fuel into bio-oil and syngas. The 25 MWth system can reach high efficiency only if char produced in the pyrolysis step is converted into additional syngas by steam gasification, and if SOFC off-gas and system waste heat are used in a steam bottoming cycle for additional power production. A net electrical efficiency of 38% is predicted. In addition, heat can be delivered with 37% efficiency. The 2.6 MWth system with only a dual fuel engine to burn bio-oil and syngas promises nearly 40% electrical efficiency plus 41% efficiency for heat production. If syngas is fed to an SOFC system and off-gas and bio-oil to a dual fuel engine, the electrical efficiency can rise to 45%. However, the efficiency for heat production drops to 15%, as waste heat from the SOFC system cannot be used effectively. The economic analysis makes clear that at -20 euro/tonne fuel, 70 euro/MWh for electricity and 7 euro/GJ for heat the 25 MWth system is not economically viable at the

  4. Next generation of high-efficient waste incinerators. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Jappe Frandsen, F.

    2010-11-15

    Modern society produces increasing amounts of combustible waste which may be utilized for heat and power production, at a lower emission of CO{sub 2}, e.g. by substituting a certain fraction of energy from fossil fuel-fired power stations. In 2007, 20.4 % of the district heating and 4.5 % of the power produced in Denmark came from thermal conversion of waste, and waste is a very important part of a future sustainable, and independent, Danish energy supply [Frandsen et al., 2009; Groen Energi, 2010]. In Denmark, approx 3.3 Mtons of waste was produced in 2005, an amount predicted to increase to 4.4 Mtons by the year 2030. According to Affald Danmark, 25 % of the current WtE plant capacity in Denmark is older than 20 years, which is usually considered as the technical and economical lifetime of WtE plants. Thus, there is a need for installation of a significant fraction of new waste incineration capacity, preferentially with an increased electrical efficiency, within the next few years. Compared to fossil fuels, waste is difficult to handle in terms of pre-treatment, combustion, and generation of reusable solid residues. In particular, the content of inorganic species (S, Cl, K, Na, etc.) is problematic, due to enhanced deposition and corrosion - especially at higher temperatures. This puts severe constraints on the electrical efficiency of grate-fired units utilizing waste, which seldom exceeds 26-27%, campared to 46-48 % for coal combustion in suspension. The key parameters when targeting higher electrical efficiency are the pressure and temperature in the steam cycle, which are limited by high-temperature corrosion, boiler- and combustion-technology. This report reviews some of the means that can be applied in order to increase the electrical efficiency in plants firing waste on a grate. (Author)

  5. Advances in a high efficiency commercial pulse tube cooler

    Science.gov (United States)

    Zhang, Yibing; Li, Haibing; Wang, Xiaotao; Dai, Wei; Yang, Zhaohui; Luo, Ercang

    2017-12-01

    The pulse tube cryocooler has the advantage of no moving part at the cold end and offers a high reliability. To further extend its use in commercial applications, efforts are still needed to improve efficiency, reliability and cost effectiveness. This paper generalizes several key innovations in our newest cooler. The cooler consists of a moving magnet compressor with dual-opposed pistons, and a co-axial cold finger. Ambient displacers are employed to recover the expansion work to increase cooling efficiency. Inside the cold finger, the conventional flow straightener screens are replaced by a tapered throat between the cold heat exchanger and the pulse tube to strengthen its immunity to the working gas contamination as well as to simplify the manufacturing processes. The cold heat exchanger is made by copper forging process which further reduces the cost. Inside the compressor, a new gas bearing design has brought in assembling simplicity and running reliability. Besides the cooler itself, electronic controller is also important for actual application. A dual channel and dual driving mode control mechanism has been selected, which reduces the vibration to a minimum, meanwhile the cool-down speed becomes faster and run-time efficiency is higher. With these innovations, the cooler TC4189 reached a no-load temperature of 44 K and provided 15 W cooling power at 80K, with an input electric power of 244 W and a cooling water temperature of 23 ℃. The efficiency reached 16.9% of Carnot at 80 K. The whole system has a total mass of 4.3 kg.

  6. Hexagonal boron nitride neutron detectors with high detection efficiencies

    Science.gov (United States)

    Maity, A.; Grenadier, S. J.; Li, J.; Lin, J. Y.; Jiang, H. X.

    2018-01-01

    Neutron detectors fabricated from 10B enriched hexagonal boron nitride (h-10BN or h-BN) epilayers have demonstrated the highest thermal neutron detection efficiency among solid-state neutron detectors to date at about 53%. In this work, photoconductive-like vertical detectors with a detection area of 1 × 1 mm2 were fabricated from 50 μm thick free-standing h-BN epilayers using Ni/Au and Ti/Al bilayers as ohmic contacts. Leakage currents, mobility-lifetime (μτ) products under UV photoexcitation, and neutron detection efficiencies have been measured for a total of 16 different device configurations. The results have unambiguously identified that detectors incorporating the Ni/Au bilayer on both surfaces as ohmic contacts and using the negatively biased top surface for neutron irradiation are the most desired device configurations. It was noted that high growth temperatures of h-10BN epilayers on sapphire substrates tend to yield a higher concentration of oxygen impurities near the bottom surface, leading to a better device performance by the chosen top surface for irradiation than by the bottom. Preferential scattering of oxygen donors tends to reduce the mobility of holes more than that of electrons, making the biasing scheme with the ability of rapidly extracting holes at the irradiated surface while leaving the electrons to travel a large average distance inside the detector at a preferred choice. When measured against a calibrated 6LiF filled micro-structured semiconductor neutron detector, it was shown that the optimized configuration has pushed the detection efficiency of h-BN neutron detectors to 58%. These detailed studies also provided a better understanding of growth-mediated impurities in h-BN epilayers and their effects on the charge collection and neutron detection efficiencies.

  7. High efficiency, multiterawatt x-ray free electron lasers

    Directory of Open Access Journals (Sweden)

    C. Emma

    2016-02-01

    Full Text Available In this paper we present undulator magnet tapering methods for obtaining high efficiency and multiterawatt peak powers in x-ray free electron lasers (XFELs, a key requirement for enabling 3D atomic resolution single molecule imaging and nonlinear x-ray science. The peak power and efficiency of tapered XFELs is sensitive to time dependent effects, like synchrotron sideband growth. To analyze this dependence in detail we perform a comparative numerical optimization for the undulator magnetic field tapering profile including and intentionally disabling these effects. We show that the solution for the magnetic field taper profile obtained from time independent optimization does not yield the highest extraction efficiency when time dependent effects are included. Our comparative optimization is performed for a novel undulator designed specifically to obtain TW power x-ray pulses in the shortest distance: superconducting, helical, with short period and built-in strong focusing. This design reduces the length of the breaks between modules, decreasing diffraction effects, and allows using a stronger transverse electron focusing. Both effects reduce the gain length and the overall undulator length. We determine that after a fully time dependent optimization of a 100 m long Linac coherent light source-like XFEL we can obtain a maximum efficiency of 7%, corresponding to 3.7 TW peak radiation power. Possible methods to suppress the synchrotron sidebands, and further enhance the FEL peak power, up to about 6 TW by increasing the seed power and reducing the electron beam energy spread, are also discussed.

  8. HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-06-01

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

  9. The analysis of energy efficiency in water electrolysis under high temperature and high pressure

    Science.gov (United States)

    Hourng, L. W.; Tsai, T. T.; Lin, M. Y.

    2017-11-01

    This paper aims to analyze the energy efficiency of water electrolysis under high pressure and high temperature conditions. The effects of temperature and pressure on four different kinds of reaction mechanisms, namely, reversible voltage, activation polarization, ohmic polarization, and concentration polarization, are investigated in details. Results show that the ohmic and concentration over-potentials are increased as temperature is increased, however, the reversible and activation over-potentials are decreased as temperature is increased. Therefore, the net efficiency is enhanced as temperature is increased. The efficiency of water electrolysis at 350°C/100 bars is increased about 17%, compared with that at 80°C/1bar.

  10. High-Order Dielectric Metasurfaces for High-Efficiency Polarization Beam Splitters and Optical Vortex Generators

    Science.gov (United States)

    Guo, Zhongyi; Zhu, Lie; Guo, Kai; Shen, Fei; Yin, Zhiping

    2017-08-01

    In this paper, a high-order dielectric metasurface based on silicon nanobrick array is proposed and investigated. By controlling the length and width of the nanobricks, the metasurfaces could supply two different incremental transmission phases for the X-linear-polarized (XLP) and Y-linear-polarized (YLP) light with extremely high efficiency over 88%. Based on the designed metasurface, two polarization beam splitters working in high-order diffraction modes have been designed successfully, which demonstrated a high transmitted efficiency. In addition, we have also designed two vortex-beam generators working in high-order diffraction modes to create vortex beams with the topological charges of 2 and 3. The employment of dielectric metasurfaces operating in high-order diffraction modes could pave the way for a variety of new ultra-efficient optical devices.

  11. A critical study of high efficiency deep grinding

    International Nuclear Information System (INIS)

    Johnstone, Iain

    2002-01-01

    The recent years, the aerospace industry in particular has embraced and actively pursued the development of stronger high performance materials, namely nickel based superalloys and hardwearing steels. This has resulted in a need for a more efficient method of machining, and this need was answered with the advent of High Efficiency Deep Grinding (HEDG). This relatively new process using Cubic Boron Nitride (CBN) electroplated grinding wheels has been investigated through experimental and theoretical means applied to two widely used materials, M50 bearing steel and IN718 nickel based superalloy. It has been shown that this grinding method using a stiff grinding centre such as the Edgetek 5-axis machine is a viable process. Using a number of experimental designs, produced results which were analysed using a variety of methods including visual assessment, sub-surface microscopy and surface analysis using a Scanning Electron Microscope (SEM), residual stress measurement using X-Ray Diffraction (XRD) techniques, Barkhausen Noise Amplitude (BNA) measurements, surface roughness and Vickers micro-hardness appraisal. It has been shown that the fundamentals of the HEDG process have been understood through experimental as well as theoretical means and that through the various thermal models used, grinding temperatures can be predicted to give more control over this dynamic process. The main contributions to knowledge are made up of a number of elements within the grinding environment, the most important being the demonstration of the HEDG effect, explanation of the phenomenon and the ability to model the process. It has also been shown that grinding is a dynamic process and factors such as wheel wear will result in a continuous change in the optimum grinding conditions for a given material and wheel combination. With the significance of these factors recognised, they can be accounted for within an industrial adaptive control scenario with the process engineer confident of a

  12. MXene molecular sieving membranes for highly efficient gas separation.

    Science.gov (United States)

    Ding, Li; Wei, Yanying; Li, Libo; Zhang, Tao; Wang, Haihui; Xue, Jian; Ding, Liang-Xin; Wang, Suqing; Caro, Jürgen; Gogotsi, Yury

    2018-01-11

    Molecular sieving membranes with sufficient and uniform nanochannels that break the permeability-selectivity trade-off are desirable for energy-efficient gas separation, and the arising two-dimensional (2D) materials provide new routes for membrane development. However, for 2D lamellar membranes, disordered interlayer nanochannels for mass transport are usually formed between randomly stacked neighboring nanosheets, which is obstructive for highly efficient separation. Therefore, manufacturing lamellar membranes with highly ordered nanochannel structures for fast and precise molecular sieving is still challenging. Here, we report on lamellar stacked MXene membranes with aligned and regular subnanometer channels, taking advantage of the abundant surface-terminating groups on the MXene nanosheets, which exhibit excellent gas separation performance with H 2 permeability >2200 Barrer and H 2 /CO 2 selectivity >160, superior to the state-of-the-art membranes. The results of molecular dynamics simulations quantitatively support the experiments, confirming the subnanometer interlayer spacing between the neighboring MXene nanosheets as molecular sieving channels for gas separation.

  13. High efficiency video coding coding tools and specification

    CERN Document Server

    Wien, Mathias

    2015-01-01

    The video coding standard High Efficiency Video Coding (HEVC) targets at improved compression performance for video resolutions of HD and beyond, providing Ultra HD video at similar compressed bit rates as for HD video encoded with the well-established video coding standard H.264 | AVC. Based on known concepts, new coding structures and improved coding tools have been developed and specified in HEVC. The standard is expected to be taken up easily by established industry as well as new endeavors, answering the needs of todays connected and ever-evolving online world. This book presents the High Efficiency Video Coding standard and explains it in a clear and coherent language. It provides a comprehensive and consistently written description, all of a piece. The book targets at both, newbies to video coding as well as experts in the field. While providing sections with introductory text for the beginner, it suits as a well-arranged reference book for the expert. The book provides a comprehensive reference for th...

  14. Large-area high-efficiency flexible PHOLED lighting panels

    Science.gov (United States)

    Pang, Huiqing; Mandlik, Prashant; Levermore, Peter A.; Silvernail, Jeff; Ma, Ruiqing; Brown, Julie J.

    2012-09-01

    Organic Light Emitting Diodes (OLEDs) provide various attractive features for next generation illumination systems, including high efficiency, low power, thin and flexible form factor. In this work, we incorporated phosphorescent emitters and demonstrated highly efficient white phosphorescent OLED (PHOLED) devices on flexible plastic substrates. The 0.94 cm2 small-area device has total thickness of approximately 0.25 mm and achieved 63 lm/W at 1,000 cd/m2 with CRI = 85 and CCT = 2920 K. We further designed and fabricated a 15 cm x 15 cm large-area flexible white OLED lighting panels, finished with a hybrid single-layer ultra-low permeability single layer barrier (SLB) encapsulation film. The flexible panel has an active area of 116.4 cm2, and achieved a power efficacy of 47 lm/W at 1,000 cd/m2 with CRI = 83 and CCT = 3470 K. The efficacy of the panel at 3,000 cd/m2 is 43 lm/W. The large-area flexible PHOLED lighting panel is to bring out enormous possibilities to the future general lighting applications.

  15. Nanocoatings for High-Efficiency Industrial Hydraulic and Tooling Systems

    Energy Technology Data Exchange (ETDEWEB)

    Clifton B. Higdon III

    2011-01-07

    Industrial manufacturing in the U.S. accounts for roughly one third of the 98 quadrillion Btu total energy consumption. Motor system losses amount to 1.3 quadrillion Btu, which represents the largest proportional loss of any end-use category, while pumps alone represent over 574 trillion BTU (TBTU) of energy loss each year. The efficiency of machines with moving components is a function of the amount of energy lost to heat because of friction between contacting surfaces. The friction between these interfaces also contributes to downtime and the loss of productivity through component wear and subsequent repair. The production of new replacement parts requires additional energy. Among efforts to reduce energy losses, wear-resistant, low-friction coatings on rotating and sliding components offer a promising approach that is fully compatible with existing equipment and processes. In addition to lubrication, one of the most desirable solutions is to apply a protective coating or surface treatment to rotating or sliding components to reduce their friction coefficients, thereby leading to reduced wear. Historically, a number of materials such as diamond-like carbon (DLC), titanium nitride (TiN), titanium aluminum nitride (TiAlN), and tungsten carbide (WC) have been examined as tribological coatings. The primary objective of this project was the development of a variety of thin film nanocoatings, derived from the AlMgB14 system, with a focus on reducing wear and friction in both industrial hydraulics and cutting tool applications. Proof-of-concept studies leading up to this project had shown that the constituent phases, AlMgB14 and TiB2, were capable of producing low-friction coatings by pulsed laser deposition. These coatings combine high hardness with a low friction coefficient, and were shown to substantially reduce wear in laboratory tribology tests. Selection of the two applications was based largely on the concept of improved mechanical interface efficiencies for

  16. Investigation of control system of traction electric drive with feedbacks on load

    Science.gov (United States)

    Kuznetsov, N. K.; Iov, I. A.; Iov, A. A.

    2018-03-01

    In the article, by the example of a walking excavator, the results of a study of a control system of traction electric drive with a rigid and flexible feedback on the load are mentioned. Based on the analysis of known works, the calculation scheme has been chosen; the equations of motion of the electromechanical system have been obtained, taking into account the elasticity of the rope and feedbacks on the load in the elastic element. A simulation model of this system has been developed and mathematical modeling of the transient processes to evaluate the influence of feedback on the dynamic characteristics of the mechanism and its efficiency of work was carried out. It is shown that the use of rigid and flexible feedbacks makes it possible to reduce dynamic loads in the traction mechanism and to limit the elastic oscillation of the executive mechanism in transient operating modes in comparison with the standard control system; however, there is some decrease in productivity. It has been also established that the sign-variable of the loading of the electric drive, connected with the opening of the backlashes in the gearbox due to the action of feedbacks on the load in the elastic element, under certain conditions, can lead to undesirable phenomena in the operation of the drive and a decrease in the reliability of its operation.

  17. Development and characterization of high-efficiency, high-specific impulse xenon Hall thrusters

    Science.gov (United States)

    Hofer, Richard Robert

    This dissertation presents research aimed at extending the efficient operation of 1600 s specific impulse Hall thruster technology to the 2000--3000 s range. While recent studies of commercially developed Hall thrusters demonstrated greater than 4000 s specific impulse, maximum efficiency occurred at less than 3000 s. It was hypothesized that the efficiency maximum resulted as a consequence of modern magnetic field designs, optimized for 1600 s, which were unsuitable at high-specific impulse. Motivated by the industry efforts and mission studies, the aim of this research was to develop and characterize xenon Hall thrusters capable of both high-specific impulse and high-efficiency operation. The research divided into development and characterization phases. During the development phase, the laboratory-model NASA-173M Hall thrusters were designed with plasma lens magnetic field topographies and their performance and plasma characteristics were evaluated. Experiments with the NASA-173M version 1 (v1) validated the plasma lens design by showing how changing the magnetic field topography at high-specific impulse improved efficiency. Experiments with the NASA-173M version 2 (v2) showed there was a minimum current density and optimum magnetic field topography at which efficiency monotonically increased with voltage. Between 300--1000 V, total specific impulse and total efficiency of the NASA-173Mv2 operating at 10 mg/s ranged from 1600--3400 s and 51--61%, respectively. Comparison of the thrusters showed that efficiency can be optimized for specific impulse by varying the plasma lens design. During the characterization phase, additional plasma properties of the NASA-173Mv2 were measured and a performance model was derived accounting for a multiply-charged, partially-ionized plasma. Results from the model based on experimental data showed how efficient operation at high-specific impulse was enabled through regulation of the electron current with the magnetic field. The

  18. Highly Efficient TADF Polymer Electroluminescence with Reduced Efficiency Roll-off via Interfacial Exciplex Host Strategy.

    Science.gov (United States)

    Lin, Xingdong; Zhu, Yunhui; Zhang, Baohua; Zhao, Xiaofei; Yao, Bing; Cheng, Yanxiang; Li, Zhanguo; Qu, Yi; Xie, Zhiyuan

    2018-01-10

    Solution-processed organic light-emitting diodes (s-OLED) consisting of TAPC/TmPyPB interfacial exciplex host and polymer PAPTC TADF emitter are prepared, simultaneously displaying ultralow voltages (2.50/2.91/3.51/4.91 V at luminance of 1/100/1000/1000 cd m -2 ), high efficiencies (14.9%, 50.1 lm W -1 ), and extremely low roll-off rates (J 50 of 63.16 mA cm -2 , L 50 of ca. 15000 cd m -2 ). Such performance is distinctly higher than that of pure-PAPTC s-OLED. Compared to pure-PAPTC, the advanced emissive layer structure of TAPC:PAPTC/TmPyPB is unique in much higher PL quantum yield (79.5 vs 36.3%) and nearly 4-fold enhancement in k RISC of the PAPTC emitter to 1.48 × 10 7 s -1 .

  19. Fabrication of Superconducting Traction Transformer for Railway Rolling Stock

    International Nuclear Information System (INIS)

    Kamijo, H; Hata, H; Fujimoto, H; Inoue, A; Nagashima, K; Ikeda, K; Yamada, H; Sanuki, Y; Tomioka, A; Uwamori, K; Yoshida, S; Iwakuma, M; Funaki, K

    2006-01-01

    We designed a floor type single-phase 4 MVA superconducting traction transformer for Shinkansen rolling stock. In this study, we fabricated a prototype superconducting traction transformer based on this design. This transformer of the core-type design has a primary winding, four secondary windings and a tertiary winding. The windings are wound by Bi2223 superconducting tapes and cooled by subcooled liquid nitrogen. The core is kept at room temperature. The cryostat is made of GFRP with two holes to pass core legs through. The outer dimensions are about 1.2m x 0.7m x 1.9m excluding the compressor. Its weight is 1.71t excluding that of refrigerator and compressor. The transformer was tested according to Japanese Industrial Standards (JIS)-E5007. We confirmed that the performance of transformer has been achieved almost exactly as planned. The rated capacity is equivalent to 3.5MVA in the superconducting state

  20. Magnetic Refrigeration Technology for High Efficiency Air Conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Boeder, A; Zimm, C

    2006-09-30

    Magnetic refrigeration was investigated as an efficient, environmentally friendly, flexible alternative to conventional residential vapor compression central air conditioning systems. Finite element analysis (FEA) models of advanced geometry active magnetic regenerator (AMR) beds were developed to minimize bed size and thus magnet mass by optimizing geometry for fluid flow and heat transfer and other losses. Conventional and magnetocaloric material (MCM) regenerator fabrication and assembly techniques were developed and advanced geometry passive regenerators were built and tested. A subscale engineering prototype (SEP) magnetic air conditioner was designed, constructed and tested. A model of the AMR cycle, combined with knowledge from passive regenerator experiments and FEA results, was used to design the regenerator beds. A 1.5 Tesla permanent magnet assembly was designed using FEA and the bed structure and plenum design was extensively optimized using FEA. The SEP is a flexible magnetic refrigeration platform, with individually instrumented beds and high flow rate and high frequency capability, although the current advanced regenerator geometry beds do not meet performance expectations, probably due to manufacturing and assembly tolerances. A model of the AMR cycle was used to optimize the design of a 3 ton capacity magnetic air conditioner, and the system design was iterated to minimize external parasitic losses such as heat exchanger pressure drop and fan power. The manufacturing cost for the entire air conditioning system was estimated, and while the estimated SEER efficiency is high, the magnetic air conditioning system is not cost competitive as currently configured. The 3 ton study results indicate that there are other applications where magnetic refrigeration is anticipated to have cost advantages over conventional systems, especially applications where magnetic refrigeration, through the use of its aqueous heat transfer fluid, could eliminate intermediate

  1. High Efficiency and Low Cost Thermal Energy Storage System

    Energy Technology Data Exchange (ETDEWEB)

    Sienicki, James J. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Lv, Qiuping [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Moisseytsev, Anton [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Bucknor, Matthew [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division

    2017-09-29

    BgtL, LLC (BgtL) is focused on developing and commercializing its proprietary compact technology for processes in the energy sector. One such application is a compact high efficiency Thermal Energy Storage (TES) system that utilizes the heat of fusion through phase change between solid and liquid to store and release energy at high temperatures and incorporate state-of-the-art insulation to minimize heat dissipation. BgtL’s TES system would greatly improve the economics of existing nuclear and coal-fired power plants by allowing the power plant to store energy when power prices are low and sell power into the grid when prices are high. Compared to existing battery storage technology, BgtL’s novel thermal energy storage solution can be significantly less costly to acquire and maintain, does not have any waste or environmental emissions, and does not deteriorate over time; it can keep constant efficiency and operates cleanly and safely. BgtL’s engineers are experienced in this field and are able to design and engineer such a system to a specific power plant’s requirements. BgtL also has a strong manufacturing partner to fabricate the system such that it qualifies for an ASME code stamp. BgtL’s vision is to be the leading provider of compact systems for various applications including energy storage. BgtL requests that all technical information about the TES designs be protected as proprietary information. To honor that request, only non-proprietay summaries are included in this report.

  2. Preliminary field evaluation of high efficiency steel filters

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, W.; Larsen, G.; Lopez, R. [Lawrence Livermore National Laboratory, CA (United States)] [and others

    1995-02-01

    We have conducted an evaluation of two high efficiency steel filters in the exhaust of an uranium oxide grit blaster at the Y-12 Plant in Oak Ridge Tennessee. The filters were installed in a specially designed filter housing with a reverse air-pulse cleaning system for automatically cleaning the filters in-place. Previous tests conducted on the same filters and housing at LLNL under controlled conditions using Arizona road dust showed good cleanability with reverse air pulses. Two high efficiency steel filters, containing 64 pleated cartridge elements housed in the standard 2` x 2` x 1` HEPA frame, were evaluated in the filter test housing using a 1,000 cfm slip stream containing a high concentration of depleted uranium oxide dust. One filter had the pleated cartridges manufactured to our specifications by the Pall Corporation and the other by Memtec Corporation. Test results showed both filters had a rapid increase in pressure drop with time, and reverse air pulses could not decrease the pressure drop. We suspected moisture accumulation in the filters was the problem since there were heavy rains during the evaluations, and the pressure drop of the Memtec filter decreased dramatically after passing clean, dry air through the filter and after the filter sat idle for one week. Subsequent laboratory tests on a single filter cartridge confirmed that water accumulation in the filter was responsible for the increase in filter pressure drop and the inability to lower the pressure drop by reverse air pulses. No effort was made to identify the source of the water accumulation and correct the problem because the available funds were exhausted.

  3. A new approach to a high efficiency inductive store

    International Nuclear Information System (INIS)

    Zowarka, R.C. Jr.; Kajs, J.P.; Price, J.H.; Weldon, W.F.

    1991-01-01

    In the Spring of 1989, Parker Kinetic Design, Inc. (PKD) and the Center for Electromechanics at The University of Texas at Austin (CEM-UT) conducted a study to examine the basic technologies to be used in the construction and operation of a feasible and reliable electromagnetic (EM) gun system. This work was performed for Brown and Root Vickers, Ltd. (BRV) in response to a feasibility analysis requirement of the Royal Armament and Development Establishment (RARDE), Ministry of Defence (MD) of the United Kingdom. This paper summarizes that this study focused on the analysis and evaluation of the suitability and applicability of various pulsed power supply options for the performance goals of the RARDE EM gun program. The existing technologies considered included batteries, compulsators, capacitors, and homopolar generators (HPGs). Primary performance specifications for the electrical energy radius system were that it be capable of providing 12 MJ of muzzle energy; velocities between 2.0 and 3.5 km/s; and a repetitive shot rate of up to 10 shots per day, with no more than a 30-min interval between shots. In addition, the recommended system needed to be reliable, easily maintainable, and capable of routinely firing large numbers of shots. Strict adherence to the goal of designing a system based only on demonstrated technology results in power supplies that are prohibitively expensive and large. As a consequence, candidate system designs represent a modest extrapolation from demonstrated technology well within an acceptable design envelope. A new topology has been developed for a highly efficient inductive store suitable for pulsed-power applications. The new design features high L/R ratios without having to cryogenically cool the conductors. This allows for high efficiency charging of the inductor from low impedance dc sources such as batteries of HPGs

  4. Energy-Efficient Office Buildings at High Latitudes

    Energy Technology Data Exchange (ETDEWEB)

    Lerum, V.

    1996-12-31

    This doctoral thesis describes a method for energy efficient office building design at high latitudes and cold climates. The method combines daylighting, passive solar heating, solar protection, and ventilative cooling. The thesis focuses on optimal design of an equatorial-facing fenestration system. A spreadsheet framework linking existing simplified methods is used. The daylight analysis uses location specific data on frequency distribution of diffuse daylight on vertical surfaces to estimate energy savings from optimal window and room configurations in combination with a daylight-responsive electric lighting system. The passive solar heating analysis is a generalization of a solar load ratio method adapted to cold climates by combining it with the Norwegian standard NS3031 for winter months when the solar savings fraction is negative. The emphasis is on very high computational efficiency to permit rapid and comprehensive examination of a large number of options early in design. The procedure is illustrated for a location in Trondheim, Norway, testing the relative significance of various design improvement options relative to a base case. The method is also tested for two other locations in Norway, at latitudes 58 and 70 degrees North. The band of latitudes between these limits covers cities in Alaska, Canada, Greenland, Iceland, Scandinavia, Finland, Russia, and Northern Japan. A comprehensive study of the ``whole building approach`` shows the impact of integrated daylighting and low-energy design strategies. In general, consumption of lighting electricity may be reduced by 50-80%, even at extremely high latitudes. The reduced internal heat from electric lights is replaced by passive solar heating. 113 refs., 85 figs., 25 tabs.

  5. Creation of electromechanical device for electric vehicle traction

    Directory of Open Access Journals (Sweden)

    Денис Юрьевич Зубенко

    2016-10-01

    Full Text Available The problems of creation of electromechanical device for electric vehicle traction are considered in the article. The aim of creation this design are the replacement of the internal combustion engine on electromechanical device. For this electromechanical device are constructed model, which describe processes that occur in the electric drive of electromechanical device. Characteristics of the main modes of motion were recorded. The introduction of electromechanical device will reduce the level of emissions and reduce noise in the cities

  6. Modern Solutions for Automation of Electrical Traction Power Supply Systems

    Directory of Open Access Journals (Sweden)

    Ana Mihaela Andreica

    2011-09-01

    Full Text Available This paper presents modern solutions for the automation of the electrical traction power supply system used in urban public transport (trams, trolleybuses and subway trains. The monitoring and control of this process uses SCADA distributed architectures, grouped around a central point (dispatcher who controls all field sensors, transmitters and actuators using programmable logical controllers. The presented applications refer to the Bucharest electrical transport infrastructure.

  7. REACTIVE POWER DEVICES IN SYSTEMS OF ELECTRIC TRACTION

    Directory of Open Access Journals (Sweden)

    M. O. Kostin

    2010-04-01

    Full Text Available A comparative characteristic of different concepts and expressions for determination of reactive power in the circuits with non-sinusoidal electric values has been given. For the first Ukrainian electric locomotives of DE1 type with the system of DC electric traction, the values of reactive power after Budeany, Fryze, and also the differential, integral and generalized reactive powers have been determined. Some measures on reducing its consumption by the DC electric rolling stock have been suggested.

  8. Quality and efficiency in high dimensional Nearest neighbor search

    KAUST Repository

    Tao, Yufei; Yi, Ke; Sheng, Cheng; Kalnis, Panos

    2009-01-01

    Nearest neighbor (NN) search in high dimensional space is an important problem in many applications. Ideally, a practical solution (i) should be implementable in a relational database, and (ii) its query cost should grow sub-linearly with the dataset size, regardless of the data and query distributions. Despite the bulk of NN literature, no solution fulfills both requirements, except locality sensitive hashing (LSH). The existing LSH implementations are either rigorous or adhoc. Rigorous-LSH ensures good quality of query results, but requires expensive space and query cost. Although adhoc-LSH is more efficient, it abandons quality control, i.e., the neighbor it outputs can be arbitrarily bad. As a result, currently no method is able to ensure both quality and efficiency simultaneously in practice. Motivated by this, we propose a new access method called the locality sensitive B-tree (LSB-tree) that enables fast highdimensional NN search with excellent quality. The combination of several LSB-trees leads to a structure called the LSB-forest that ensures the same result quality as rigorous-LSH, but reduces its space and query cost dramatically. The LSB-forest also outperforms adhoc-LSH, even though the latter has no quality guarantee. Besides its appealing theoretical properties, the LSB-tree itself also serves as an effective index that consumes linear space, and supports efficient updates. Our extensive experiments confirm that the LSB-tree is faster than (i) the state of the art of exact NN search by two orders of magnitude, and (ii) the best (linear-space) method of approximate retrieval by an order of magnitude, and at the same time, returns neighbors with much better quality. © 2009 ACM.

  9. High Current Planar Transformer for Very High Efficiency Isolated Boost DC-DC Converters

    DEFF Research Database (Denmark)

    Pittini, Riccardo; Zhang, Zhe; Andersen, Michael A. E.

    2014-01-01

    This paper presents a design and optimization of a high current planar transformer for very high efficiency dc-dc isolated boost converters. The analysis considers different winding arrangements, including very high copper thickness windings. The analysis is focused on the winding ac-resistance a......This paper presents a design and optimization of a high current planar transformer for very high efficiency dc-dc isolated boost converters. The analysis considers different winding arrangements, including very high copper thickness windings. The analysis is focused on the winding ac......-resistance and transformer leakage inductance. Design and optimization procedures are validated based on an experimental prototype of a 6 kW dcdc isolated full bridge boost converter developed on fully planar magnetics. The prototype is rated at 30-80 V 0-80 A on the low voltage side and 700-800 V on the high voltage side...... with a peak efficiency of 97.8% at 80 V 3.5 kW. Results highlights that thick copper windings can provide good performance at low switching frequencies due to the high transformer filling factor. PCB windings can also provide very high efficiency if stacked in parallel utilizing the transformer winding window...

  10. In-situ high efficiency filter testing at AEE Winfrith

    International Nuclear Information System (INIS)

    Fraser, D.C.

    1977-01-01

    This paper discusses experience in the testing of high efficiency filters in a variety of reactor and plant installations at AEE Winfrith. There is rarely any concern about the effectiveness of the filter as supplied by any reputable manufacturer. Experience has shown there is a need to check for defects in the installation of filters which could lead to by-passing of aerosols and it is desirable to perform periodical re-tests to ensure that no subsequent deterioration occurs. It is important to use simple, portable apparatus for such tests; methods based on the use of sodium chloride aerosols, although suitable for the testing of filters prior to installation, involve apparatus which is too bulky for in-situ testing. At Winfrith a double automatic Pollak counter has been developed and used routinely since 1970. The aerosol involved has a particle size far smaller than the size most likely to penetrate intact filters, but this is irrelevant when one is primarily interested in particles which by-pass the filter. Comparisons with other methods of testing filters will be described. There is remarkably good agreement between the efficiency of the filter installation as measured by a Pollak counter compared with techniques involving aerosols of sodium chloride and Dioctyl Phthalate (DOP), presumably because the leakage around the filter is independent of particle size

  11. Prospects for development of powerful, highly efficient, relativistic gyrodevices

    International Nuclear Information System (INIS)

    Nusinovich, G.S.; Granatstein, V.L.

    1992-01-01

    For various applications the required parameters of sources of powerful microwave radiation lie far beyond the capabilities of existing tubes. This provokes an interest in reconsidering basic principles of relevant microwave sources in order to search for alternative concepts in their development. One of the most promising devices in the short-wavelength region of microwaves is the cyclotron resonance maser (CRM). During the last decade, two important varieties of CRMs have been distinguished, namely, gyrotrons, which operate at frequencies close to cut-off, and cyclotron autoresonance masers (CARMs), which operate at frequencies far from cut-off. When the axial phase velocity of the wave in properly adjusted to the beam voltage and electron pitch-ratio, the efficiency of relativistic CRMs may be high (≥50%). The method of optimizing efficiency based on a partial compensation of the shift in the relativistic electron cyclotron frequency by the change in the Doppler term can be, in principle, accompanied by a corresponding profiling of the external magnetic field and/or the wave phase velocity in a slightly irregular waveguide. These methods can be used in such relativistic CRMs as relativistic gyrotrons, gyroklystrons, gyro-traveling-wave-tubes and gyrotwistrons. The most important point is their sensitivity to a spread in electron parameters. As the beam voltage grows, the operation becomes more sensitive. However, at relatively low voltages such devices are quite tolerant to electron velocity spread

  12. Novel Intermode Prediction Algorithm for High Efficiency Video Coding Encoder

    Directory of Open Access Journals (Sweden)

    Chan-seob Park

    2014-01-01

    Full Text Available The joint collaborative team on video coding (JCT-VC is developing the next-generation video coding standard which is called high efficiency video coding (HEVC. In the HEVC, there are three units in block structure: coding unit (CU, prediction unit (PU, and transform unit (TU. The CU is the basic unit of region splitting like macroblock (MB. Each CU performs recursive splitting into four blocks with equal size, starting from the tree block. In this paper, we propose a fast CU depth decision algorithm for HEVC technology to reduce its computational complexity. In 2N×2N PU, the proposed method compares the rate-distortion (RD cost and determines the depth using the compared information. Moreover, in order to speed up the encoding time, the efficient merge SKIP detection method is developed additionally based on the contextual mode information of neighboring CUs. Experimental result shows that the proposed algorithm achieves the average time-saving factor of 44.84% in the random access (RA at Main profile configuration with the HEVC test model (HM 10.0 reference software. Compared to HM 10.0 encoder, a small BD-bitrate loss of 0.17% is also observed without significant loss of image quality.

  13. High Efficiency Driving Electronics for General Illumination LED Luminaires

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, Anand

    2012-10-31

    New generation of standalone LED driver platforms developed, which are more efficient These LED Drivers are more efficient (≥90%), smaller in size ( 0.15 in3/watt), lower in cost ( 12 cents/watt in high volumes in millions of units). And these products are very reliable having an operating life of over 50,000 hours. This technology will enable growth of LED light sources in the use. This will also help in energy saving and reducing total life cycle cost of LED units. Two topologies selected for next generation of LED drivers: 1) Value engineered single stage Flyback topology. This is suitable for low powered LED drivers up to 50W power. 2) Two stage boost power factor correction (PFC) plus LLC half bridge platform for higher powers. This topology is suitable for 40W to 300W LED drivers. Three new product platforms were developed to cover a wide range of LED drivers: 1) 120V 40W LED driver, 2) Intellivolt 75W LED driver, & 3) Intellivolt 150W LED driver. These are standalone LED drivers for rugged outdoor lighting applications. Based on these platforms number of products are developed and successfully introduced in the market place meeting key performance, size and cost goals.

  14. Characterization of three high efficiency and blue sensitive silicon photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Otte, Adam Nepomuk, E-mail: otte@gatech.edu; Garcia, Distefano; Nguyen, Thanh; Purushotham, Dhruv

    2017-02-21

    We report about the optical and electrical characterization of three high efficiency and blue sensitive Silicon photomultipliers from FBK, Hamamatsu, and SensL. Key features of the tested devices when operated at 90% breakdown probability are peak photon detection efficiencies between 40% and 55%, temperature dependencies of gain and PDE that are less than 1%/°C, dark rates of ∼50 kHz/mm{sup 2} at room temperature, afterpulsing of about 2%, and direct optical crosstalk between 6% and 20%. The characteristics of all three devices impressively demonstrate how the Silicon-photomultiplier technology has improved over the past ten years. It is further demonstrated how the voltage and temperature characteristics of a number of quantities can be parameterized on the basis of physical models. The models provide a deeper understanding of the device characteristics over a wide bias and temperature range. They also serve as examples how producers could provide the characteristics of their SiPMs to users. A standardized parameterization of SiPMs would enable users to find the optimal SiPM for their application and the operating point of SiPMs without having to perform measurements thus significantly reducing design and development cycles.

  15. Perfluorocarbon-perfused 23 gauge three-dimensional vitrectomy for complicated diabetic tractional retinal detachment

    Science.gov (United States)

    Velez-Montoya, Raul; Guerrero-Naranjo, Jose Luis; Garcia-Aguirre, Gerardo; Morales-Cantón, Virgilio; Fromow-Guerra, Jans; Quiroz-Mercado, Hugo

    2011-01-01

    Background Perfluorocarbon liquid (PCL)-perfused vitrectomy has been shown in previous studies to be feasible, safe, and to have advantages in managing complicated cases of tractional retinal detachment. The present study had the objectives of describing the anatomical results and measuring surgical time and PCL consumption when combining PCL-perfused techniques with modern vitrectomy equipment. Methods A prospective, interventional consecutive case series was investigated. We enrolled patients with diabetic tractional retinal detachment, complicated by proliferative vitreoretinopathy and poor vision. A 23 gauge PCL-perfused vitrectomy was done with three-dimensional settings. During the procedure, we assessed the degree of surgical bleeding, visualization quality, and difficulty of membrane dissections. Visual acuity, intraocular pressure, and anatomical success were assessed at one and 3 months of follow-up. Results Twelve patients were enrolled in this study. There were no statistical significant changes in intraocular pressure and visual acuity throughout the follow-up period. Surgery was performed in a hemorrhage-free environment in almost all cases, with good visualization and low technical difficulty. The mean complete surgical time was 94.92 ± 25.03 minutes. The mean effective vitrectomy time was 22.50 ± 19.04 minutes and the mean PCL consumption was 25.08 ± 9.76 mL, with a speed of 1.11 mL/minute. Anatomical success was 67% at 3 months. Conclusion Although the technique proved to have some advantages in managing complicated cases of diabetic tractional retinal detachment, there was a high consumption of PCL. A redesign of the entire system is needed in order to decrease the amount of PCL needed for the technique. PMID:22267907

  16. Gamma-ray spectrometer system with high efficiency and high resolution

    International Nuclear Information System (INIS)

    Moss, C.E.; Bernard, W.; Dowdy, E.J.; Garcia, C.; Lucas, M.C.; Pratt, J.C.

    1983-01-01

    Our gamma-ray spectrometer system, designed for field use, offers high efficiency and high resolution for safeguards applications. The system consists of three 40% high-purity germanium detectors and a LeCroy 3500 data acquisition system that calculates a composite spectrum for the three detectors. The LeCroy 3500 mainframe can be operated remotely from the detector array with control exercised through modems and the telephone system. System performance with a mixed source of 125 Sb, 154 Eu, and 155 Eu confirms the expected efficiency of 120% with the overall resolution showing little degradation over that of the worst detector

  17. 3.0T MR imaging of the ankle: Axial traction for morphological cartilage evaluation, quantitative T2 mapping and cartilage diffusion imaging-A preliminary study.

    Science.gov (United States)

    Jungmann, Pia M; Baum, Thomas; Schaeffeler, Christoph; Sauerschnig, Martin; Brucker, Peter U; Mann, Alexander; Ganter, Carl; Bieri, Oliver; Rummeny, Ernst J; Woertler, Klaus; Bauer, Jan S

    2015-08-01

    To determine the impact of axial traction during high resolution 3.0T MR imaging of the ankle on morphological assessment of articular cartilage and quantitative cartilage imaging parameters. MR images of n=25 asymptomatic ankles were acquired with and without axial traction (6kg). Coronal and sagittal T1-weighted (w) turbo spin echo (TSE) sequences with a driven equilibrium pulse and sagittal fat-saturated intermediate-w (IMfs) TSE sequences were acquired for morphological evaluation on a four-point scale (1=best, 4=worst). For quantitative assessment of cartilage degradation segmentation was performed on 2D multislice-multiecho (MSME) SE T2, steady-state free-precession (SSFP; n=8) T2 and SSFP diffusion-weighted imaging (DWI; n=8) images. Wilcoxon-tests and paired t-tests were used for statistical analysis. With axial traction, joint space width increased significantly and delineation of cartilage surfaces was rated superior (Pevaluation were smaller. Subchondral bone evaluation, motion artifacts and image quality were not significantly different between the acquisition methods (P>0.05). T2 values were lower at the tibia than at the talus (P<0.001). Reproducibility was better for images with axial traction. Axial traction increased the joint space width, allowed for better visualization of cartilage surfaces and improved compartment discrimination and reproducibility of quantitative cartilage parameters. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  18. Thin Film Packaging Solutions for High Efficiency OLED Lighting Products

    Energy Technology Data Exchange (ETDEWEB)

    None

    2008-06-30

    The objective of the 'Thin Film Packaging Solutions for High Efficiency OLED Lighting Products' project is to demonstrate thin film packaging solutions based on SiC hermetic coatings that, when applied to glass and plastic substrates, support OLED lighting devices by providing longer life with greater efficiency at lower cost than is currently available. Phase I Objective: Demonstrate thin film encapsulated working phosphorescent OLED devices on optical glass with lifetime of 1,000 hour life, CRI greater than 75, and 15 lm/W. Phase II Objective: Demonstrate thin film encapsulated working phosphorescent OLED devices on plastic or glass composite with 25 lm/W, 5,000 hours life, and CRI greater than 80. Phase III Objective: Demonstrate 2 x 2 ft{sup 2} thin film encapsulated working phosphorescent OLED with 40 lm/W, 10,000 hour life, and CRI greater than 85. This report details the efforts of Phase III (Budget Period Three), a fourteen month collaborative effort that focused on optimization of high-efficiency phosphorescent OLED devices and thin-film encapsulation of said devices. The report further details the conclusions and recommendations of the project team that have foundation in all three budget periods for the program. During the conduct of the Thin Film Packaging Solutions for High Efficiency OLED Lighting Products program, including budget period three, the project team completed and delivered the following achievements: (1) a three-year marketing effort that characterized the near-term and longer-term OLED market, identified customer and consumer lighting needs, and suggested prototype product concepts and niche OLED applications lighting that will give rise to broader market acceptance as a source for wide area illumination and energy conservation; (2) a thin film encapsulation technology with a lifetime of nearly 15,000 hours, tested by calcium coupons, while stored at 16 C and 40% relative humidity ('RH'). This encapsulation technology

  19. High efficiency solid-state sensitized heterojunction photovoltaic device

    KAUST Repository

    Wang, Mingkui

    2010-06-01

    The high molar extinction coefficient heteroleptic ruthenium dye, NaRu(4,4′-bis(5-(hexylthio)thiophen-2-yl)-2,2′-bipyridine) (4-carboxylic acid-4′-carboxylate-2,2′-bipyridine) (NCS) 2, exhibits certified 5% electric power conversion efficiency at AM 1.5 solar irradiation (100 mW cm-2) in a solid-state dye-sensitized solar cell using 2,2′,7,7′-tetrakis-(N,N-di-pmethoxyphenylamine)-9, 9′-spirobifluorene (spiro-MeOTAD) as the organic hole-transporting material. This demonstration elucidates a class of photovoltaic devices with potential for low-cost power generation. © 2010 Elsevier Ltd. All rights reserved.

  20. Dimensioning storage and computing clusters for efficient High Throughput Computing

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    Scientific experiments are producing huge amounts of data, and they continue increasing the size of their datasets and the total volume of data. These data are then processed by researchers belonging to large scientific collaborations, with the Large Hadron Collider being a good example. The focal point of Scientific Data Centres has shifted from coping efficiently with PetaByte scale storage to deliver quality data processing throughput. The dimensioning of the internal components in High Throughput Computing (HTC) data centers is of crucial importance to cope with all the activities demanded by the experiments, both the online (data acceptance) and the offline (data processing, simulation and user analysis). This requires a precise setup involving disk and tape storage services, a computing cluster and the internal networking to prevent bottlenecks, overloads and undesired slowness that lead to losses cpu cycles and batch jobs failures. In this paper we point out relevant features for running a successful s...

  1. Additive Manufacturing for Highly Efficient Window Inserts CRADA Report

    Energy Technology Data Exchange (ETDEWEB)

    Roschli, Alex C. [ORNL; Chesser, Phillip C. [ORNL; Love, Lonnie J. [ORNL

    2018-04-01

    ORNL partnered with the Mackinac Technology Company to demonstrate how additive manufacturing can be used to create highly energy efficient window inserts for retrofit in pre-existing buildings. Many early iterations of the window inserts were fabricated using carbon fiber reinforced thermoplastics and polycarbonate films as a stand in for the low-e coated films produced by the Mackinac Technology Company. After demonstration of the proof of concept, i.e. custom window inserts with tensioned film, the materials used for the manufacture of the frames was more closely examined. Hollow particle-filled syntactic foam and low-density polymer composites formed by expandable microspheres were explored as the materials used to additively manufacture the frames of the inserts. It was concluded that low-cost retrofit window inserts in custom sizes could be easily fabricated using large scale additive manufacturing. Furthermore, the syntactic and expanded foams developed and tested satisfy the mechanical performance requirements for the application.

  2. High Efficiency EBCOT with Parallel Coding Architecture for JPEG2000

    Directory of Open Access Journals (Sweden)

    Chiang Jen-Shiun

    2006-01-01

    Full Text Available This work presents a parallel context-modeling coding architecture and a matching arithmetic coder (MQ-coder for the embedded block coding (EBCOT unit of the JPEG2000 encoder. Tier-1 of the EBCOT consumes most of the computation time in a JPEG2000 encoding system. The proposed parallel architecture can increase the throughput rate of the context modeling. To match the high throughput rate of the parallel context-modeling architecture, an efficient pipelined architecture for context-based adaptive arithmetic encoder is proposed. This encoder of JPEG2000 can work at 180 MHz to encode one symbol each cycle. Compared with the previous context-modeling architectures, our parallel architectures can improve the throughput rate up to 25%.

  3. Disposal of aqueous condensate from high efficiency gas boilers

    Energy Technology Data Exchange (ETDEWEB)

    Hardwick, G J; Pattison, J R

    1984-01-01

    If highly efficient gas-fired condensing heating appliances are installed in Britain, the aqueous condensate produced can be conveniently run into existing sewage drains. The part of the drainage system that is most vulnerable to corrosion from the mildly acid condensate is that portion adjacent to the domestic premises. The tests described indicate that this is not at risk and the only precaution that might be considered necessary is to avoid running the condensate over galvanized drain covers in order to prevent unsightly staining. Water authorities in Britain and detailed studies in the US and Holland confirm that the condensate - after dilution by domestic waste, sewage, and rainwater - would be harmless to municipal sewage systems and would not, either in volume or chemical composition, affect the working of existing sewage treatment plants.

  4. High efficiency solid-state sensitized heterojunction photovoltaic device

    KAUST Repository

    Wang, Mingkui; Liu, Jingyuan; Cevey-Ha, Ngoc-Le; Moon, Soo-Jin; Liska, Paul; Humphry-Baker, Robin; Moser, Jacques-E.; Grä tzel, Carole; Wang, Peng; Zakeeruddin, Shaik M.

    2010-01-01

    The high molar extinction coefficient heteroleptic ruthenium dye, NaRu(4,4′-bis(5-(hexylthio)thiophen-2-yl)-2,2′-bipyridine) (4-carboxylic acid-4′-carboxylate-2,2′-bipyridine) (NCS) 2, exhibits certified 5% electric power conversion efficiency at AM 1.5 solar irradiation (100 mW cm-2) in a solid-state dye-sensitized solar cell using 2,2′,7,7′-tetrakis-(N,N-di-pmethoxyphenylamine)-9, 9′-spirobifluorene (spiro-MeOTAD) as the organic hole-transporting material. This demonstration elucidates a class of photovoltaic devices with potential for low-cost power generation. © 2010 Elsevier Ltd. All rights reserved.

  5. Highly Efficient Catalytic Cyclic Carbonate Formation by Pyridyl Salicylimines.

    Science.gov (United States)

    Subramanian, Saravanan; Park, Joonho; Byun, Jeehye; Jung, Yousung; Yavuz, Cafer T

    2018-03-21

    Cyclic carbonates as industrial commodities offer a viable nonredox carbon dioxide fixation, and suitable heterogeneous catalysts are vital for their widespread implementation. Here, we report a highly efficient heterogeneous catalyst for CO 2 addition to epoxides based on a newly identified active catalytic pocket consisting of pyridine, imine, and phenol moieties. The polymeric, metal-free catalyst derived from this active site converts less-reactive styrene oxide under atmospheric pressure in quantitative yield and selectivity to the corresponding carbonate. The catalyst does not need additives, solvents, metals, or co-catalysts, can be reused at least 10 cycles without the loss of activity, and scaled up easily to a kilogram scale. Density functional theory calculations reveal that the nucleophilicity of pyridine base gets stronger due to the conjugated imines and H-bonding from phenol accelerates the reaction forward by stabilizing the intermediate.

  6. Non-equilibrium Microwave Plasma for Efficient High Temperature Chemistry.

    Science.gov (United States)

    van den Bekerom, Dirk; den Harder, Niek; Minea, Teofil; Gatti, Nicola; Linares, Jose Palomares; Bongers, Waldo; van de Sanden, Richard; van Rooij, Gerard

    2017-08-01

    A flowing microwave plasma based methodology for converting electric energy into internal and/or translational modes of stable molecules with the purpose of efficiently driving non-equilibrium chemistry is discussed. The advantage of a flowing plasma reactor is that continuous chemical processes can be driven with the flexibility of startup times in the seconds timescale. The plasma approach is generically suitable for conversion/activation of stable molecules such as CO2, N2 and CH4. Here the reduction of CO2 to CO is used as a model system: the complementary diagnostics illustrate how a baseline thermodynamic equilibrium conversion can be exceeded by the intrinsic non-equilibrium from high vibrational excitation. Laser (Rayleigh) scattering is used to measure the reactor temperature and Fourier Transform Infrared Spectroscopy (FTIR) to characterize in situ internal (vibrational) excitation as well as the effluent composition to monitor conversion and selectivity.

  7. Comparison of high efficiency particulate filter testing methods

    International Nuclear Information System (INIS)

    1985-01-01

    High Efficiency Particulate Air (HEPA) filters are used for the removal of submicron size particulates from air streams. In nuclear industry they are used as an important engineering safeguard to prevent the release of air borne radioactive particulates to the environment. HEPA filters used in the nuclear industry should therefore be manufactured and operated under strict quality control. There are three levels of testing HEPA filters: i) testing of the filter media; ii) testing of the assembled filter including filter media and filter housing; and iii) on site testing of the complete filter installation before putting into operation and later for the purpose of periodic control. A co-ordinated research programme on particulate filter testing methods was taken up by the Agency and contracts were awarded to the Member Countries, Belgium, German Democratic Republic, India and Hungary. The investigations carried out by the participants of the present co-ordinated research programme include the results of the nowadays most frequently used HEPA filter testing methods both for filter medium test, rig test and in-situ test purposes. Most of the experiments were carried out at ambient temperature and humidity, but indications were given to extend the investigations to elevated temperature and humidity in the future for the purpose of testing the performance of HEPA filter under severe conditions. A major conclusion of the co-ordinated research programme was that it was not possible to recommend one method as a reference method for in situ testing of high efficiency particulate air filters. Most of the present conventional methods are adequate for current requirements. The reasons why no method is to be recommended were multiple, ranging from economical aspects, through incompatibility of materials to national regulations

  8. Efficient high-performance ultrasound beamforming using oversampling

    Science.gov (United States)

    Freeman, Steven R.; Quick, Marshall K.; Morin, Marc A.; Anderson, R. C.; Desilets, Charles S.; Linnenbrink, Thomas E.; O'Donnell, Matthew

    1998-05-01

    High-performance and efficient beamforming circuitry is very important in large channel count clinical ultrasound systems. Current state-of-the-art digital systems using multi-bit analog to digital converters (A/Ds) have matured to provide exquisite image quality with moderate levels of integration. A simplified oversampling beamforming architecture has been proposed that may a low integration of delta-sigma A/Ds onto the same chip as digital delay and processing circuitry to form a monolithic ultrasound beamformer. Such a beamformer may enable low-power handheld scanners for high-end systems with very large channel count arrays. This paper presents an oversampling beamformer architecture that generates high-quality images using very simple; digitization, delay, and summing circuits. Additional performance may be obtained with this oversampled system for narrow bandwidth excitations by mixing the RF signal down in frequency to a range where the electronic signal to nose ratio of the delta-sigma A/D is optimized. An oversampled transmit beamformer uses the same delay circuits as receive and eliminates the need for separate transmit function generators.

  9. Efficient binning for bitmap indices on high-cardinality attributes

    Energy Technology Data Exchange (ETDEWEB)

    Rotem, Doron; Stockinger, Kurt; Wu, Kesheng

    2004-11-17

    Bitmap indexing is a common technique for indexing high-dimensional data in data warehouses and scientific applications. Though efficient for low-cardinality attributes, query processing can be rather costly for high-cardinality attributes due to the large storage requirements for the bitmap indices. Binning is a common technique for reducing storage costs of bitmap indices. This technique partitions the attribute values into a number of ranges, called bins, and uses bitmap vectors to represent bins (attribute ranges) rather than distinct values. Although binning may reduce storage costs, it may increase the access costs of queries that do not fall on exact bin boundaries (edge bins). For this kind of queries the original data values associated with edge bins must be accessed, in order to check them against the query constraints.In this paper we study the problem of finding optimal locations for the bin boundaries in order to minimize these access costs subject to storage constraints. We propose a dynamic programming algorithm for optimal partitioning of attribute values into bins that takes into account query access patterns as well as data distribution statistics. Mathematical analysis and experiments on real life data sets show that the optimal partitioning achieved by this algorithm can lead to a significant improvement in the access costs of bitmap indexing systems for high-cardinality attributes.

  10. Highly Efficient Fiber Lasers for Wireless Power Transmission, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop ytterbium (Yb) fiber lasers with an electrical-to-optical efficiency of nominally 64% by directly coupling 80%-efficient diode lasers with Yb...

  11. A novel assessment of the traction forces upon settlement of two typical marine fouling invertebrates using PDMS micropost arrays

    Directory of Open Access Journals (Sweden)

    Kang Xiao

    2018-01-01

    Full Text Available Marine biofouling poses a severe threat to maritime and aquaculture industries. To prevent the attachment of marine biofouling organisms on man-made structures, countless cost and effort was spent annually. In particular, most attention has been paid on the development of efficient and environmentally friendly fouling-resistant coatings, as well as larval settlement mechanism of several major biofouling invertebrates. In this study, polydimethylsiloxane (PDMS micropost arrays were utilized as the settlement substrata and opposite tractions were identified during early settlement of the barnacle Amphibalanus amphitrite and the bryozoan Bugula neritina. The settling A. amphitrite pushed the periphery microposts with an average traction force of 376.2 nN, while settling B. neritina pulled the periphery microposts with an average traction force of 205.9 nN. These micropost displacements are consistent with the body expansion of A. amphitrite during early post-settlement metamorphosis stage and elevation of wall epithelium of B. neritina during early pre-ancestrula stage, respectively. As such, the usage of micropost array may supplement the traditional histological approach to indicate the early settlement stages or even the initiation of larval settlement of marine fouling organisms, and could finally aid in the development of automatic monitoring platform for the real-time analysis on this complex biological process.

  12. Traction cytometry: regularization in the Fourier approach and comparisons with finite element method.

    Science.gov (United States)

    Kulkarni, Ankur H; Ghosh, Prasenjit; Seetharaman, Ashwin; Kondaiah, Paturu; Gundiah, Namrata

    2018-05-09

    Traction forces exerted by adherent cells are quantified using displacements of embedded markers on polyacrylamide substrates due to cell contractility. Fourier Transform Traction Cytometry (FTTC) is widely used to calculate tractions but has inherent limitations due to errors in the displacement fields; these are mitigated through a regularization parameter (γ) in the Reg-FTTC method. An alternate finite element (FE) approach computes tractions on a domain using known boundary conditions. Robust verification and recovery studies are lacking but essential in assessing the accuracy and noise sensitivity of the traction solutions from the different methods. We implemented the L2 regularization method and defined a maximum curvature point in the traction with γ plot as the optimal regularization parameter (γ*) in the Reg-FTTC approach. Traction reconstructions using γ* yield accurate values of low and maximum tractions (Tmax) in the presence of up to 5% noise. Reg-FTTC is hence a clear improvement over the FTTC method but is inadequate to reconstruct low stresses such as those at nascent focal adhesions. FE, implemented using a node-by-node comparison, showed an intermediate reconstruction compared to Reg-FTTC. We performed experiments using mouse embryonic fibroblast (MEF) and compared results between these approaches. Tractions from FTTC and FE showed differences of ∼92% and 22% as compared to Reg-FTTC. Selection of an optimum value of γ for each cell reduced variability in the computed tractions as compared to using a single value of γ for all the MEF cells in this study.

  13. Improved throughput traction microscopy reveals pivotal role for matrix stiffness in fibroblast contractility and TGF-β responsiveness

    Science.gov (United States)

    Marinković, Aleksandar; Mih, Justin D.; Park, Jin-Ah; Liu, Fei

    2012-01-01

    Lung fibroblast functions such as matrix remodeling and activation of latent transforming growth factor-β1 (TGF-β1) are associated with expression of the myofibroblast phenotype and are directly linked to fibroblast capacity to generate force and deform the extracellular matrix. However, the study of fibroblast force-generating capacities through methods such as traction force microscopy is hindered by low throughput and time-consuming procedures. In this study, we improved at the detail level methods for higher-throughput traction measurements on polyacrylamide hydrogels using gel-surface-bound fluorescent beads to permit autofocusing and automated displacement mapping, and transduction of fibroblasts with a fluorescent label to streamline cell boundary identification. Together these advances substantially improve the throughput of traction microscopy and allow us to efficiently compute the forces exerted by lung fibroblasts on substrates spanning the stiffness range present in normal and fibrotic lung tissue. Our results reveal that lung fibroblasts dramatically alter the forces they transmit to the extracellular matrix as its stiffness changes, with very low forces generated on matrices as compliant as normal lung tissue. Moreover, exogenous TGF-β1 selectively accentuates tractions on stiff matrices, mimicking fibrotic lung, but not on physiological stiffness matrices, despite equivalent changes in Smad2/3 activation. Taken together, these results demonstrate a pivotal role for matrix mechanical properties in regulating baseline and TGF-β1-stimulated contraction of lung fibroblasts and suggest that stiff fibrotic lung tissue may promote myofibroblast activation through contractility-driven events, whereas normal lung tissue compliance may protect against such feedback amplification of fibroblast activation. PMID:22659883

  14. High quality ceramic coatings sprayed by high efficiency hypersonic plasma spraying gun

    International Nuclear Information System (INIS)

    Zhu Sheng; Xu Binshi; Yao JiuKun

    2005-01-01

    This paper introduced the structure of the high efficiency hypersonic plasma spraying gun and the effects of hypersonic plasma jet on the sprayed particles. The optimised spraying process parameters for several ceramic powders such as Al 2 O 3 , Cr 2 O 3 , ZrO 2 , Cr 3 C 2 and Co-WC were listed. The properties and microstructure of the sprayed ceramic coatings were investigated. Nano Al 2 O 3 -TiO 2 ceramic coating sprayed by using the high efficiency hypersonic plasma spraying was also studied. Compared with the conventional air plasma spraying, high efficiency hypersonic plasma spraying improves greatly the ceramic coatings quality but at low cost. (orig.)

  15. High efficiency, monolithic fiber chirped pulse amplification system for high energy femtosecond pulse generation.

    Science.gov (United States)

    Peng, Xiang; Kim, Kyungbum; Mielke, Michael; Jennings, Stephen; Masor, Gordon; Stohl, Dave; Chavez-Pirson, Arturo; Nguyen, Dan T; Rhonehouse, Dan; Zong, Jie; Churin, Dmitriy; Peyghambarian, N

    2013-10-21

    A novel monolithic fiber-optic chirped pulse amplification (CPA) system for high energy, femtosecond pulse generation is proposed and experimentally demonstrated. By employing a high gain amplifier comprising merely 20 cm of high efficiency media (HEM) gain fiber, an optimal balance of output pulse energy, optical efficiency, and B-integral is achieved. The HEM amplifier is fabricated from erbium-doped phosphate glass fiber and yields gain of 1.443 dB/cm with slope efficiency >45%. We experimentally demonstrate near diffraction-limited beam quality and near transform-limited femtosecond pulse quality at 1.55 µm wavelength. With pulse energy >100 µJ and pulse duration of 636 fs (FWHM), the peak power is estimated to be ~160 MW. NAVAIR Public Release Distribution Statement A-"Approved for Public release; distribution is unlimited".

  16. High-efficiency cavity-dumped micro-chip Yb:YAG laser

    Science.gov (United States)

    Nishio, M.; Maruko, A.; Inoue, M.; Takama, M.; Matsubara, S.; Okunishi, H.; Kato, K.; Kyomoto, K.; Yoshida, T.; Shimabayashi, K.; Morioka, M.; Inayoshi, S.; Yamagata, S.; Kawato, S.

    2014-09-01

    High-efficiency cavity-dumped ytterbium-doped yttrium aluminum garnet (Yb:YAG) laser was developed. Although the high quantum efficiency of ytterbium-doped laser materials is appropriate for high-efficiency laser oscillation, the efficiency is decreased by their quasi-three/four laser natures. High gain operation by high intensity pumping is suitable for high efficiency oscillation on the quasi-three/four lasers without extremely low temperature cooling. In our group, highest efficiency oscillations for continuous wave, nanosecond to picosecond pulse lasers were achieved at room temperature by the high gain operation in which pump intensities were beyond 100 kW/cm2.

  17. Perovskite Solar Cells for High-Efficiency Tandems

    Energy Technology Data Exchange (ETDEWEB)

    McGehee, Michael [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Buonassisi, Tonio [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2017-09-30

    The first monolithic perovskite/silicon tandem was made with a diffused silicon p-n junction, a tunnel junction made of n++ hydrogenated amorphous silicon, a titania electron transport layer, a methylammonium lead iodide absorber, and a Spiro-OMeTAD hole transport layer (HTL). The power conversion efficiency (PCE) was only 13.7% due to excessive parasitic absorption of light in the HTL, limiting the matched current density to 11.5 mA/cm2. Werner et al.15 raised the PCE to a record 21.2% by switching to a silicon heterojunction bottom cell and carefully tuning layer thicknesses to achieve lower optical loss and a higher current density of 15.9 mA/cm2. It is clear from these reports that minimizing parasitic absorption in the window layers is crucial to achieving higher current densities and efficiencies in monolithic tandems. To this end, the window layers through which light first passes before entering the perovskite and silicon absorber materials must be highly transparent. The front electrode must also be conductive to carry current laterally across the top of the device. Indium tin oxide (ITO) is widely utilized as a transparent electrode in optoelectronic devices such as flat-panel displays, smart windows, organic light-emitting diodes, and solar cells due to its high conductivity and broadband transparency. ITO is typically deposited through magnetron sputtering; however, the high kinetic energy of sputtered particles can damage underlying layers. In perovskite solar cells, a sputter buffer layer is required to protect the perovskite and organic carrier extraction layers from damage during sputter deposition. The ideal buffer layer should also be energetically well aligned so as to act as a carrier-selective contact, have a wide bandgap to enable high optical transmission, and have no reaction with the halides in the perovskite. Additionally, this buffer layer should act as a diffusion barrier layer to prevent both

  18. Efficiency of High Order Spectral Element Methods on Petascale Architectures

    KAUST Repository

    Hutchinson, Maxwell; Heinecke, Alexander; Pabst, Hans; Henry, Greg; Parsani, Matteo; Keyes, David E.

    2016-01-01

    High order methods for the solution of PDEs expose a tradeoff between computational cost and accuracy on a per degree of freedom basis. In many cases, the cost increases due to higher arithmetic intensity while affecting data movement minimally. As architectures tend towards wider vector instructions and expect higher arithmetic intensities, the best order for a particular simulation may change. This study highlights preferred orders by identifying the high order efficiency frontier of the spectral element method implemented in Nek5000 and NekBox: the set of orders and meshes that minimize computational cost at fixed accuracy. First, we extract Nek’s order-dependent computational kernels and demonstrate exceptional hardware utilization by hardware-aware implementations. Then, we perform productionscale calculations of the nonlinear single mode Rayleigh-Taylor instability on BlueGene/Q and Cray XC40-based supercomputers to highlight the influence of the architecture. Accuracy is defined with respect to physical observables, and computational costs are measured by the corehour charge of the entire application. The total number of grid points needed to achieve a given accuracy is reduced by increasing the polynomial order. On the XC40 and BlueGene/Q, polynomial orders as high as 31 and 15 come at no marginal cost per timestep, respectively. Taken together, these observations lead to a strong preference for high order discretizations that use fewer degrees of freedom. From a performance point of view, we demonstrate up to 60% full application bandwidth utilization at scale and achieve ≈1PFlop/s of compute performance in Nek’s most flop-intense methods.

  19. Efficiency of High Order Spectral Element Methods on Petascale Architectures

    KAUST Repository

    Hutchinson, Maxwell

    2016-06-14

    High order methods for the solution of PDEs expose a tradeoff between computational cost and accuracy on a per degree of freedom basis. In many cases, the cost increases due to higher arithmetic intensity while affecting data movement minimally. As architectures tend towards wider vector instructions and expect higher arithmetic intensities, the best order for a particular simulation may change. This study highlights preferred orders by identifying the high order efficiency frontier of the spectral element method implemented in Nek5000 and NekBox: the set of orders and meshes that minimize computational cost at fixed accuracy. First, we extract Nek’s order-dependent computational kernels and demonstrate exceptional hardware utilization by hardware-aware implementations. Then, we perform productionscale calculations of the nonlinear single mode Rayleigh-Taylor instability on BlueGene/Q and Cray XC40-based supercomputers to highlight the influence of the architecture. Accuracy is defined with respect to physical observables, and computational costs are measured by the corehour charge of the entire application. The total number of grid points needed to achieve a given accuracy is reduced by increasing the polynomial order. On the XC40 and BlueGene/Q, polynomial orders as high as 31 and 15 come at no marginal cost per timestep, respectively. Taken together, these observations lead to a strong preference for high order discretizations that use fewer degrees of freedom. From a performance point of view, we demonstrate up to 60% full application bandwidth utilization at scale and achieve ≈1PFlop/s of compute performance in Nek’s most flop-intense methods.

  20. [Tobacco--a highly efficient producer of vaccines].

    Science.gov (United States)

    Budzianowski, Jaromir

    2010-01-01

    Along with the depreciation of tobacco as a source of nicotine-containing commercial products, the increase of its appreciation as a potential producer of recombinant therapeutical proteins can be observed. Two species of tobacco--Nicotiana tabacum L. and N. benthamiana are easily grown by well established methods of field or green-house cultivation or cell culture, yield high biomass and soluble protein content, can be easily transformed by several methods and are not food for humans or feed for animals. Expression of foreign proteins, including vaccines, can be achieved in those plants either through stable transformation of nuclear or plastid (chloroplast) genomes or by transient transformation using infection with plant virus or bacteria--Agrobacterium tumefaciens (agroinfiltration). The most advanced mode of agrofiltration termed magnifection, which combines benefits of virus and Agrobacterium and depends on using Agrobacterium with viral pro-vectors, enables high-yield and rapid expression of therapeutical proteins, even in a few days, and can be employed on an industrial scale. Expression of many antigenic proteins, which may serve as antiviral, antibacterial, antiprotozoan and anticancer vaccines, and additionally a few autoantigens designed for the treatment of autoimunogenic diseases, like diabetes, have been achieved in tobacco. To date, a vaccine against Newcastle virus disease in poultry produced by tobacco cell culture has been approved for commercial application and several other vaccines are in advanced stage of development. The possibility of a high-level production of vaccines in tobacco against pandemic influenza or anthrax and plague due to a bioterroristic attack, as well as of individualised anticancer vaccines against non-Hodgkin's lymphoma (NHL) in a much shorter period of time than by traditional methods became realistic and hence caused increased interest in tobacco as a high-efficient producer of vaccines not only of specialistic

  1. Harmonic analysis of traction power supply system based on wavelet decomposition

    Science.gov (United States)

    Dun, Xiaohong

    2018-05-01

    With the rapid development of high-speed railway and heavy-haul transport, AC drive electric locomotive and EMU large-scale operation in the country on the ground, the electrified railway has become the main harmonic source of China's power grid. In response to this phenomenon, the need for timely monitoring of power quality problems of electrified railway, assessment and governance. Wavelet transform is developed on the basis of Fourier analysis, the basic idea comes from the harmonic analysis, with a rigorous theoretical model, which has inherited and developed the local thought of Garbor transformation, and has overcome the disadvantages such as window fixation and lack of discrete orthogonally, so as to become a more recently studied spectral analysis tool. The wavelet analysis takes the gradual and precise time domain step in the high frequency part so as to focus on any details of the signal being analyzed, thereby comprehensively analyzing the harmonics of the traction power supply system meanwhile use the pyramid algorithm to increase the speed of wavelet decomposition. The matlab simulation shows that the use of wavelet decomposition of the traction power supply system for harmonic spectrum analysis is effective.

  2. Using high-throughput barcode sequencing to efficiently map connectomes.

    Science.gov (United States)

    Peikon, Ian D; Kebschull, Justus M; Vagin, Vasily V; Ravens, Diana I; Sun, Yu-Chi; Brouzes, Eric; Corrêa, Ivan R; Bressan, Dario; Zador, Anthony M

    2017-07-07

    The function of a neural circuit is determined by the details of its synaptic connections. At present, the only available method for determining a neural wiring diagram with single synapse precision-a 'connectome'-is based on imaging methods that are slow, labor-intensive and expensive. Here, we present SYNseq, a method for converting the connectome into a form that can exploit the speed and low cost of modern high-throughput DNA sequencing. In SYNseq, each neuron is labeled with a unique random nucleotide sequence-an RNA 'barcode'-which is targeted to the synapse using engineered proteins. Barcodes in pre- and postsynaptic neurons are then associated through protein-protein crosslinking across the synapse, extracted from the tissue, and joined into a form suitable for sequencing. Although our failure to develop an efficient barcode joining scheme precludes the widespread application of this approach, we expect that with further development SYNseq will enable tracing of complex circuits at high speed and low cost. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  3. High efficiency video coding (HEVC) algorithms and architectures

    CERN Document Server

    Budagavi, Madhukar; Sullivan, Gary

    2014-01-01

    This book provides developers, engineers, researchers and students with detailed knowledge about the High Efficiency Video Coding (HEVC) standard. HEVC is the successor to the widely successful H.264/AVC video compression standard, and it provides around twice as much compression as H.264/AVC for the same level of quality. The applications for HEVC will not only cover the space of the well-known current uses and capabilities of digital video – they will also include the deployment of new services and the delivery of enhanced video quality, such as ultra-high-definition television (UHDTV) and video with higher dynamic range, wider range of representable color, and greater representation precision than what is typically found today. HEVC is the next major generation of video coding design – a flexible, reliable and robust solution that will support the next decade of video applications and ease the burden of video on world-wide network traffic. This book provides a detailed explanation of the various parts ...

  4. Hot nuclei studied with high efficiency neutron detectors

    International Nuclear Information System (INIS)

    Galin, J.

    1990-01-01

    We have shown the invaluable benefit that a high efficiency 4π neutron detector can bring to the study of reaction mechanisms following collisions of heavy nuclei at intermediate energy. Analysis requires Monte-Carlo simulations for comparison between experimental data and any emission model. In systematic measurements with projectiles of velocity corresponding to energies between 27 and 77 MeV/u, where both the influence of beam velocity and mass have been investigated separately, it has been shown that the projectile-target mass asymmetry, much more than velocity, has a decisive influence on energy dissipation. The closer the projectile mass to the target mass, the more energy is dissipated per unit mass of the considered projectile plus target system. The latter presents all the characteristics of a thermalized system, evaporating a copious number of light particles: up to about 40 neutrons (after efficiency correction) and 11 light charged particles in the most dissipative collisions between Kr+Au, and 90 neutrons for Pb+U with a yet unknown number of l.c.p. In the Kr experiment, these particles are isotropically emitted in the frame of a fused system, excited with 1.2 GeV. Moreover, l.c.p. exhibit Maxwellian energy distributions as in any standard evaporation process. We are now eager to better characterize the properties of the Pb+Au (U) systems for which about 1/3 of the neutrons are freed in a rather large fraction of all collisions. The thermalized energy should then approach very closely the total binding energy of the two interacting nuclei

  5. Progress of High Efficiency Centrifugal Compressor Simulations Using TURBO

    Science.gov (United States)

    Kulkarni, Sameer; Beach, Timothy A.

    2017-01-01

    Three-dimensional, time-accurate, and phase-lagged computational fluid dynamics (CFD) simulations of the High Efficiency Centrifugal Compressor (HECC) stage were generated using the TURBO solver. Changes to the TURBO Parallel Version 4 source code were made in order to properly model the no-slip boundary condition along the spinning hub region for centrifugal impellers. A startup procedure was developed to generate a converged flow field in TURBO. This procedure initialized computations on a coarsened mesh generated by the Turbomachinery Gridding System (TGS) and relied on a method of systematically increasing wheel speed and backpressure. Baseline design-speed TURBO results generally overpredicted total pressure ratio, adiabatic efficiency, and the choking flow rate of the HECC stage as compared with the design-intent CFD results of Code Leo. Including diffuser fillet geometry in the TURBO computation resulted in a 0.6 percent reduction in the choking flow rate and led to a better match with design-intent CFD. Diffuser fillets reduced annulus cross-sectional area but also reduced corner separation, and thus blockage, in the diffuser passage. It was found that the TURBO computations are somewhat insensitive to inlet total pressure changing from the TURBO default inlet pressure of 14.7 pounds per square inch (101.35 kilopascals) down to 11.0 pounds per square inch (75.83 kilopascals), the inlet pressure of the component test. Off-design tip clearance was modeled in TURBO in two computations: one in which the blade tip geometry was trimmed by 12 mils (0.3048 millimeters), and another in which the hub flow path was moved to reflect a 12-mil axial shift in the impeller hub, creating a step at the hub. The one-dimensional results of these two computations indicate non-negligible differences between the two modeling approaches.

  6. High-precision efficiency calibration of a high-purity co-axial germanium detector

    Energy Technology Data Exchange (ETDEWEB)

    Blank, B., E-mail: blank@cenbg.in2p3.fr [Centre d' Etudes Nucléaires de Bordeaux Gradignan, UMR 5797, CNRS/IN2P3, Université de Bordeaux, Chemin du Solarium, BP 120, 33175 Gradignan Cedex (France); Souin, J.; Ascher, P.; Audirac, L.; Canchel, G.; Gerbaux, M.; Grévy, S.; Giovinazzo, J.; Guérin, H.; Nieto, T. Kurtukian; Matea, I. [Centre d' Etudes Nucléaires de Bordeaux Gradignan, UMR 5797, CNRS/IN2P3, Université de Bordeaux, Chemin du Solarium, BP 120, 33175 Gradignan Cedex (France); Bouzomita, H.; Delahaye, P.; Grinyer, G.F.; Thomas, J.C. [Grand Accélérateur National d' Ions Lourds, CEA/DSM, CNRS/IN2P3, Bvd Henri Becquerel, BP 55027, F-14076 CAEN Cedex 5 (France)

    2015-03-11

    A high-purity co-axial germanium detector has been calibrated in efficiency to a precision of about 0.15% over a wide energy range. High-precision scans of the detector crystal and γ-ray source measurements have been compared to Monte-Carlo simulations to adjust the dimensions of a detector model. For this purpose, standard calibration sources and short-lived online sources have been used. The resulting efficiency calibration reaches the precision needed e.g. for branching ratio measurements of super-allowed β decays for tests of the weak-interaction standard model.

  7. Optical signal processing for enabling high-speed, highly spectrally efficient and high capacity optical systems

    Science.gov (United States)

    Fazal, Muhammad Irfan

    The unabated demand for more capacity due to the ever-increasing internet traffic dictates that the boundaries of the state of the art maybe pushed to send more data through the network. Traditionally, this need has been satisfied by multiple wavelengths (wavelength division multiplexing), higher order modulation formats and coherent communication (either individually or combined together). WDM has the ability to reduce cost by using multiple channels within the same physical fiber, and with EDFA amplifiers, the need for O-E-O regenerators is eliminated. Moreover the availability of multiple colors allows for wavelength-based routing and network planning. Higher order modulation formats increases the capacity of the link by their ability to encode data in both the phase and amplitude of light, thereby increasing the bits/sec/Hz as compared to simple on-off keyed format. Coherent communications has also emerged as a primary means of transmitting and receiving optical data due to its support of formats that utilize both phase and amplitude to further increase the spectral efficiency of the optical channel, including quadrature amplitude modulation (QAM) and quadrature phase shift keying (QPSK). Polarization multiplexing of channels can double capacity by allowing two channels to share the same wavelength by propagating on orthogonal polarization axis and is easily supported in coherent systems where the polarization tracking can be performed in the digital domain. Furthermore, the forthcoming IEEE 100 Gbit/s Ethernet Standard, 802.3ba, provides greater bandwidth, higher data rates, and supports a mixture of modulation formats. In particular, Pol-MUX QPSK is increasingly becoming the industry's format of choice as the high spectral efficiency allows for 100 Gbit/s transmission while still occupying the current 50 GHz/channel allocation of current 10 Gbit/s OOK fiber systems. In this manner, 100 Gbit/s transfer speeds using current fiber links, amplifiers, and filters

  8. High-Efficiency Nitride-Based Solid-State Lighting

    Energy Technology Data Exchange (ETDEWEB)

    Paul T. Fini; Shuji Nakamura

    2005-07-30

    In this final technical progress report we summarize research accomplished during Department of Energy contract DE-FC26-01NT41203, entitled ''High-Efficiency Nitride-Based Solid-State Lighting''. Two teams, from the University of California at Santa Barbara (Principle Investigator: Dr. Shuji Nakamura) and the Lighting Research Center at Rensselaer Polytechnic Institute (led by Dr. N. Narendran), pursued the goals of this contract from thin film growth, characterization, and packaging/luminaire design standpoints. The UCSB team initially pursued the development of blue gallium nitride (GaN)-based vertical-cavity surface-emitting lasers, as well as ultraviolet GaN-based light emitting diodes (LEDs). In Year 2, the emphasis shifted to resonant-cavity light emitting diodes, also known as micro-cavity LEDs when extremely thin device cavities are fabricated. These devices have very directional emission and higher light extraction efficiency than conventional LEDs. Via the optimization of thin-film growth and refinement of device processing, we decreased the total cavity thickness to less than 1 {micro}m, such that micro-cavity effects were clearly observed and a light extraction efficiency of over 10% was reached. We also began the development of photonic crystals for increased light extraction, in particular for so-called ''guided modes'' which would otherwise propagate laterally in the device and be re-absorbed. Finally, we pursued the growth of smooth, high-quality nonpolar a-plane and m-plane GaN films, as well as blue light emitting diodes on these novel films. Initial nonpolar LEDs showed the expected behavior of negligible peak wavelength shift with increasing drive current. M-plane LEDs in particular show promise, as unpackaged devices had unsaturated optical output power of {approx} 3 mW at 200 mA drive current. The LRC's tasks were aimed at developing the subcomponents necessary for packaging UCSB's light

  9. Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ojeda, William de

    2010-07-31

    The project which extended from November 2005 to May of 2010 demonstrated the application of Low Temperature Combustion (LTC) with engine out NOx levels of 0.2 g/bhp-hr throughout the program target load of 12.6bar BMEP. The project showed that the range of loads could be extended to 16.5bar BMEP, therefore matching the reference lug line of the base 2007 MY Navistar 6.4L V8 engine. Results showed that the application of LTC provided a dramatic improvement over engine out emissions when compared to the base engine. Furthermore LTC improved thermal efficiency by over 5% from the base production engine when using the steady state 13 mode composite test as a benchmark. The key enablers included improvements in the air, fuel injection, and cooling systems made in Phases I and II. The outcome was the product of a careful integration of each component under an intelligent control system. The engine hardware provided the conditions to support LTC and the controller provided the necessary robustness for a stable combustion. Phase III provided a detailed account on the injection strategy used to meet the high load requirements. During this phase, the control strategy was implemented in a production automotive grade ECU to perform cycle-by-cycle combustion feedback on each of the engine cylinders. The control interacted on a cycle base with the injection system and with the Turbo-EGR systems according to their respective time constants. The result was a unique system that could, first, help optimize the combustion system and maintain high efficiency, and secondly, extend the steady state results to the transient mode of operation. The engine was upgraded in Phase IV with a Variable Valve Actuation system and a hybrid EGR loop. The impact of the more versatile EGR loop did not provide significant advantages, however the application of VVA proved to be an enabler to further extend the operation of LTC and gain considerable benefits in fuel economy and soot reduction. Finally

  10. Second Generation Advanced Reburning for High Efficiency NOx Control

    International Nuclear Information System (INIS)

    Zamansky, Vladimir M.; Maly, Peter M.; Sheldon, Mark; Seeker, W. Randall; Folsom, Blair A.

    1997-01-01

    Energy and Environmental Research Corporation is developing a family of high efficiency and low cost NO x control technologies for coal fired utility boilers based on Advanced Reburning (AR), a synergistic integration of basic reburning with injection of an N-agent. In conventional AR, injection of the reburn fuel is followed by simultaneous N-agent and overfire air injection. The second generation AR systems incorporate several components which can be used in different combinations. These components include: (1) Reburning Injection of the reburn fuel and overfire air. (2) N-agent Injection The N-agent (ammonia or urea) can be injected at different locations: into the reburning zone, along with the overfire air, and downstream of the overfire air injection. (3) N-agent Promotion Several sodium compounds can considerably enhance the NO x control from N-agent injection. These ''promoters'' can be added to aqueous N-agents. (4) Two Stages of N-agent Injection and Promotion Two N-agents with or without promoters can be injected at different locations for deeper NO x control. AR systems are intended for post-RACT applications in ozone non-attainment areas where NO x control in excess of 80% is required. AR will provide flexible installations that allow NO x levels to be lowered when regulations become more stringent. The total cost of NO x control for AR systems is approximately half of that for SCR. Experimental and kinetic modeling results for development of these novel AR systems are presented. Tests have been conducted in a 1.0 MMBtu/hr Boiler Simulator Facility with coal as the main fuel and natural gas as the reburning fuel. The results show that high efficiency NO x control, in the range 84-95%, can be achieved with various elements of AR. A comparative byproduct emission study was performed to compare the emissions from different variants of AR with commercial technologies (reburning and SNCR). For each technology sampling included: CO, SO 2 , N 2 O, total

  11. Low-Cost, High Efficiency, Silicon Based Photovoltaic Devices

    Science.gov (United States)

    2015-08-27

    for photovoltaic applications. Figure 14: (a) Absorption and scattering efficiencies versus sizes of Au nanoparticle at 550 nm, (b) scattering...efficiency as a function of wavelength for different Au nanoparticles sizes . 32 Review of plasmonics light trapping for photovoltaic application...ensure that the irradiation variation was within 3%. The external quantum efficiency (EQE) system used a 300W Xenon light source with a spot size of 1mm

  12. Compact high efficiency, light weight 200-800 MHz high power RF source

    International Nuclear Information System (INIS)

    Shrader, M.B.; Preist, D.H.

    1985-01-01

    There has long been a need for a new more efficient less bulky high power RF power source to drive accelerators in the 200 to 800 MHz region. Results on a recent 5-year EIMAC sponsored R and D program which have lead to the introduction of the Klystrode for UHF television and troposcatter applications indicate that at power levels of 1MW or more efficiencies in excess of 75% can be obtained at 450 MHz. Efficiencies of this order coupled with potential size and weight parameters which are a fraction of those of existing high power UHF generators open up new applications which heretofore would have been impractical if not impossible. Measurements at 470 MHz on existing Klystrodes are given. Projected operating conditions for a 1MW 450 MHz Klystrode having an overall length of 60 inches and a total tube, circuit, and magnet weight of 250 pounds is presented

  13. Orthodontic traction of a transmigrated mandibular canine using mini-implant: a case report and review.

    Science.gov (United States)

    Plaza, Sonia Patricia

    2016-12-01

    The patient in this case is an 11-year-old girl, whose mandibular left canine was transmigrated. The traction to the arch was assisted by using a temporary skeletal anchorage device. After 5 months of poor response to traction, the biomechanics were re-adjusted, obtaining effective traction in to the arch in 12 months. After this period, the treatment was completed with fixed orthodontic appliances.

  14. Distributed active traction control system applied to the RoboCup middle size league

    OpenAIRE

    Almeida, José; Dias, André; Sequeira, João; Martins, Alfredo; Silva, Eduardo

    2013-01-01

    This work addresses the problem of traction control in mobile wheeled robots in the particular case of the RoboCup Middle Size League (MSL). The slip control problem is formulated using simple friction models for ISePorto Team robots with a differential wheel configuration. Traction was also characterized experimentally in the MSL scenario for relevant game events. This work proposes a hierarchical traction control architecture which relies in local slip detection and con...

  15. Harmonic analysis of electric locomotive and traction power system based on wavelet singular entropy

    Science.gov (United States)

    Dun, Xiaohong

    2018-05-01

    With the rapid development of high-speed railway and heavy-haul transport, the locomotive and traction power system has become the main harmonic source of China's power grid. In response to this phenomenon, the system's power quality issues need timely monitoring, assessment and governance. Wavelet singular entropy is an organic combination of wavelet transform, singular value decomposition and information entropy theory, which combines the unique advantages of the three in signal processing: the time-frequency local characteristics of wavelet transform, singular value decomposition explores the basic modal characteristics of data, and information entropy quantifies the feature data. Based on the theory of singular value decomposition, the wavelet coefficient matrix after wavelet transform is decomposed into a series of singular values that can reflect the basic characteristics of the original coefficient matrix. Then the statistical properties of information entropy are used to analyze the uncertainty of the singular value set, so as to give a definite measurement of the complexity of the original signal. It can be said that wavelet entropy has a good application prospect in fault detection, classification and protection. The mat lab simulation shows that the use of wavelet singular entropy on the locomotive and traction power system harmonic analysis is effective.

  16. Glutathione is a highly efficient thermostabilizer of poliovirus Sabin strains.

    Science.gov (United States)

    Abdelnabi, Rana; Delang, Leen; Neyts, Johan

    2017-03-07

    Glutathione (GSH) is the most abundant thiol peptide in animal cells and has a critical role in antioxidation. GSH was reported to be essential for stabilization of some enteroviruses, including poliovirus (PV), during viral morphogenesis. Here, we explored the potential use of GSH as a thermostabilizer of oral poliomyelitis vaccine (OPV) formulations. GSH significantly protected the three types of PV from heat-inactivation in a concentration-dependent manner. At a GSH concentration of 20mM, nearly complete protection was observed against heating temperatures up to 53°C for 2min.GSH also markedly protected PV1 from heat-inactivation and this up to 6 h at temperatures of 44°C and 46°C and 3 h at 48°C. The fact that GSH is naturally present at high concentration in the human body makes it an efficient candidate stabilizer for OPV formulations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Multiplexing a high-throughput liability assay to leverage efficiencies.

    Science.gov (United States)

    Herbst, John; Anthony, Monique; Stewart, Jeremy; Connors, David; Chen, Taosheng; Banks, Martyn; Petrillo, Edward W; Agler, Michele

    2009-06-01

    In order to identify potential cytochrome P-450 3A4 (drug-metabolizing enzyme) inducers at an early stage of the drug discovery process, a cell-based transactivation high-throughput luciferase reporter assay for the human pregnane X receptor (PXR) in HepG2 cells has been implemented and multiplexed with a viability end point for data interpretation, as part of a Lead Profiling portfolio of assays. As a routine part of Lead Profiling operations, assays are periodically evaluated for utility as well as for potential improvements in technology or process. We used a recent evaluation of our PXR-transactivation assay as a model for the application of Lean Thinking-based process analysis to lab-bench assay optimization and automation. This resulted in the development of a 384-well multiplexed homogeneous assay simultaneously detecting PXR transactivation and HepG2 cell cytotoxicity. In order to multiplex fluorescent and luminescent read-outs, modifications to each assay were necessary, which included optimization of multiple assay parameters such as cell density, plate type, and reagent concentrations. Subsequently, a set of compounds including known cytotoxic compounds and PXR inducers were used to validate the multiplexed assay. Results from the multiplexed assay correlate well with those from the singleplexed assay formats measuring PXR transactivation and viability separately. Implementation of the multiplexed assay for routine compound profiling provides improved data quality, sample conservation, cost savings, and resource efficiencies.

  18. High-Efficient Parallel CAVLC Encoders on Heterogeneous Multicore Architectures

    Directory of Open Access Journals (Sweden)

    H. Y. Su

    2012-04-01

    Full Text Available This article presents two high-efficient parallel realizations of the context-based adaptive variable length coding (CAVLC based on heterogeneous multicore processors. By optimizing the architecture of the CAVLC encoder, three kinds of dependences are eliminated or weaken, including the context-based data dependence, the memory accessing dependence and the control dependence. The CAVLC pipeline is divided into three stages: two scans, coding, and lag packing, and be implemented on two typical heterogeneous multicore architectures. One is a block-based SIMD parallel CAVLC encoder on multicore stream processor STORM. The other is a component-oriented SIMT parallel encoder on massively parallel architecture GPU. Both of them exploited rich data-level parallelism. Experiments results show that compared with the CPU version, more than 70 times of speedup can be obtained for STORM and over 50 times for GPU. The implementation of encoder on STORM can make a real-time processing for 1080p @30fps and GPU-based version can satisfy the requirements for 720p real-time encoding. The throughput of the presented CAVLC encoders is more than 10 times higher than that of published software encoders on DSP and multicore platforms.

  19. Improper ferroelectrics as high-efficiency energy conversion materials

    Energy Technology Data Exchange (ETDEWEB)

    Wakamatsu, Toru; Tanabe, Kenji; Terasaki, Ichiro; Taniguchi, Hiroki [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan)

    2017-05-15

    An improper ferroelectric is a certain type of ferroelectrics whose primary order parameter is not polarization but another physical quantity such as magnetization. In contrast to a conventional proper ferroelectrics as represented by Pb(Zr,Ti)O{sub 3} and BaTiO{sub 3}, the improper ferroelectrics has been inconceivable for practical applications thus far. Herein, we illustrate the great potential of improper ferroelectrics for efficient conversion of temperature fluctuation to electric energy, as demonstrated with (Ca{sub 0.84}Sr{sub 0.16}){sub 8}[AlO{sub 2}]{sub 12}(MoO{sub 4}){sub 2} (CSAM-16). The present study has experimentally proven that CSAM-16 achieves an excellent electrothermal coupling factor and high electric field sensitivity for pyroelectric energy conversion that approach a practical level for application to self-powered autonomous electronic devices for rapidly spreading wireless sensor networks. The present results provide a novel approach to developing innovative pyroelectric energy harvesting devices using improper ferroelectrics. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. High efficient ZnO nanowalnuts photocatalyst: A case study

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Feng [College of Chemistry and Chemical Engineering, Mudanjiang Normal University, Mudanjiang 157011 (China); College of Chemistry and Chemical Engineering, Harbin Normal University, Harbin 150025 (China); Zhang, Siwen; Liu, Yang [College of Chemistry and Chemical Engineering, Harbin Normal University, Harbin 150025 (China); Liu, Hongfeng [School of Basic Medical Sciences, Mudanjiang Medical University, Mudanjiang 157011 (China); Qu, Fengyu [College of Chemistry and Chemical Engineering, Harbin Normal University, Harbin 150025 (China); Cai, Xue, E-mail: xuecai@mail.sdu.edu.cn [College of Chemistry and Chemical Engineering, Mudanjiang Normal University, Mudanjiang 157011 (China); Wu, Xiang, E-mail: wuxiang@hrbnu.edu.cn [College of Chemistry and Chemical Engineering, Harbin Normal University, Harbin 150025 (China)

    2014-11-15

    Highlights: • Walnut-like ZnO nanostructures are synthesized through a facile hydrothermal method. • Morphologies and microstructures of the as-obtained ZnO products were investigated. • The photocatalytic results demonstrate that methyl orange (MO) aqueous solution can be degraded over 97% after 45 min under UV light irradiation. - Abstract: Walnut-like ZnO nanostructures are successfully synthesized through a facile hydrothermal method. The structure and morphology of the as-synthesized products were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The photocatalytic properties of ZnO nanowalnuts are investigated by photodegradating several organic dyes, such as Congo red (CR), methyl orange (MO) and eosin red aqueous solutions under UV irradiation, respectively. The results demonstrate that methyl orange (MO) aqueous solution can be degraded over 97% after 45 min under UV light irradiation. In addition, eosin red and Congo red (CR) aqueous solution degradation experiments are also conducted in the same condition, respectively. It showed that ZnO nanowalnuts represent high photocatalytic activities with a degradation efficiency of 87% for CR with 115 min of irradiation and 97% for eosin red with 55 min of irradiation. The reported ZnO products may be promising candidates as the photocatalysts in waste water treatment.

  1. High efficient ZnO nanowalnuts photocatalyst: A case study

    International Nuclear Information System (INIS)

    Yan, Feng; Zhang, Siwen; Liu, Yang; Liu, Hongfeng; Qu, Fengyu; Cai, Xue; Wu, Xiang

    2014-01-01

    Highlights: • Walnut-like ZnO nanostructures are synthesized through a facile hydrothermal method. • Morphologies and microstructures of the as-obtained ZnO products were investigated. • The photocatalytic results demonstrate that methyl orange (MO) aqueous solution can be degraded over 97% after 45 min under UV light irradiation. - Abstract: Walnut-like ZnO nanostructures are successfully synthesized through a facile hydrothermal method. The structure and morphology of the as-synthesized products were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The photocatalytic properties of ZnO nanowalnuts are investigated by photodegradating several organic dyes, such as Congo red (CR), methyl orange (MO) and eosin red aqueous solutions under UV irradiation, respectively. The results demonstrate that methyl orange (MO) aqueous solution can be degraded over 97% after 45 min under UV light irradiation. In addition, eosin red and Congo red (CR) aqueous solution degradation experiments are also conducted in the same condition, respectively. It showed that ZnO nanowalnuts represent high photocatalytic activities with a degradation efficiency of 87% for CR with 115 min of irradiation and 97% for eosin red with 55 min of irradiation. The reported ZnO products may be promising candidates as the photocatalysts in waste water treatment

  2. Dimensioning storage and computing clusters for efficient high throughput computing

    International Nuclear Information System (INIS)

    Accion, E; Bria, A; Bernabeu, G; Caubet, M; Delfino, M; Espinal, X; Merino, G; Lopez, F; Martinez, F; Planas, E

    2012-01-01

    Scientific experiments are producing huge amounts of data, and the size of their datasets and total volume of data continues increasing. These data are then processed by researchers belonging to large scientific collaborations, with the Large Hadron Collider being a good example. The focal point of scientific data centers has shifted from efficiently coping with PetaByte scale storage to deliver quality data processing throughput. The dimensioning of the internal components in High Throughput Computing (HTC) data centers is of crucial importance to cope with all the activities demanded by the experiments, both the online (data acceptance) and the offline (data processing, simulation and user analysis). This requires a precise setup involving disk and tape storage services, a computing cluster and the internal networking to prevent bottlenecks, overloads and undesired slowness that lead to losses cpu cycles and batch jobs failures. In this paper we point out relevant features for running a successful data storage and processing service in an intensive HTC environment.

  3. Development of high efficiency ventilation bag actuated dry powder inhalers.

    Science.gov (United States)

    Behara, Srinivas R B; Longest, P Worth; Farkas, Dale R; Hindle, Michael

    2014-04-25

    New active dry powder inhaler systems were developed and tested to efficiently aerosolize a carrier-free formulation. To assess inhaler performance, a challenging case study of aerosol lung delivery during high-flow nasal cannula (HFNC) therapy was selected. The active delivery system consisted of a ventilation bag for actuating the device, the DPI containing a flow control orifice and 3D rod array, and streamlined nasal cannula with separate inlets for the aerosol and HFNC therapy gas. In vitro experiments were conducted to assess deposition in the device, emitted dose (ED) from the nasal cannula, and powder deaggregation. The best performing systems achieved EDs of 70-80% with fine particle fractions <5 μm of 65-85% and mass median aerodynamic diameters of 1.5 μm, which were target conditions for controlled condensational growth aerosol delivery. Decreasing the size of the flow control orifice from 3.6 to 2.3mm reduced the flow rate through the system with manual bag actuations from an average of 35 to 15LPM, while improving ED and aerosolization performance. The new devices can be applied to improve aerosol delivery during mechanical ventilation, nose-to-lung aerosol administration, and to assist patients that cannot reproducibly use passive DPIs. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Improper ferroelectrics as high-efficiency energy conversion materials

    International Nuclear Information System (INIS)

    Wakamatsu, Toru; Tanabe, Kenji; Terasaki, Ichiro; Taniguchi, Hiroki

    2017-01-01

    An improper ferroelectric is a certain type of ferroelectrics whose primary order parameter is not polarization but another physical quantity such as magnetization. In contrast to a conventional proper ferroelectrics as represented by Pb(Zr,Ti)O_3 and BaTiO_3, the improper ferroelectrics has been inconceivable for practical applications thus far. Herein, we illustrate the great potential of improper ferroelectrics for efficient conversion of temperature fluctuation to electric energy, as demonstrated with (Ca_0_._8_4Sr_0_._1_6)_8[AlO_2]_1_2(MoO_4)_2 (CSAM-16). The present study has experimentally proven that CSAM-16 achieves an excellent electrothermal coupling factor and high electric field sensitivity for pyroelectric energy conversion that approach a practical level for application to self-powered autonomous electronic devices for rapidly spreading wireless sensor networks. The present results provide a novel approach to developing innovative pyroelectric energy harvesting devices using improper ferroelectrics. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. High Efficiency Hydrodynamic DNA Fragmentation in a Bubbling System.

    Science.gov (United States)

    Li, Lanhui; Jin, Mingliang; Sun, Chenglong; Wang, Xiaoxue; Xie, Shuting; Zhou, Guofu; van den Berg, Albert; Eijkel, Jan C T; Shui, Lingling

    2017-01-18

    DNA fragmentation down to a precise fragment size is important for biomedical applications, disease determination, gene therapy and shotgun sequencing. In this work, a cheap, easy to operate and high efficiency DNA fragmentation method is demonstrated based on hydrodynamic shearing in a bubbling system. We expect that hydrodynamic forces generated during the bubbling process shear the DNA molecules, extending and breaking them at the points where shearing forces are larger than the strength of the phosphate backbone. Factors of applied pressure, bubbling time and temperature have been investigated. Genomic DNA could be fragmented down to controllable 1-10 Kbp fragment lengths with a yield of 75.30-91.60%. We demonstrate that the ends of the genomic DNAs generated from hydrodynamic shearing can be ligated by T4 ligase and the fragmented DNAs can be used as templates for polymerase chain reaction. Therefore, in the bubbling system, DNAs could be hydrodynamically sheared to achieve smaller pieces in dsDNAs available for further processes. It could potentially serve as a DNA sample pretreatment technique in the future.

  6. High-order harmonic conversion efficiency in helium

    International Nuclear Information System (INIS)

    Crane, J.K.

    1992-01-01

    Calculated results are presented for the energy, number of photons, and conversion efficiency for high-order harmonic generation in helium. The results show the maximum values that we should expect to achieve experimentally with our current apparatus and the important parameters for scaling this source to higher output. In the desired operating regime where the coherence length, given by L coh =πb/(q-1), is greater than the gas column length, l, the harmonic output can be summarized by a single equation: N q =[(π z n z b 3 τ q |d q | z )/4h]{(p/q)(2l/b) z }. N q - numbers of photons of q-th harmonic; n - atom density; b - laser confocal parameter; τ q - pulse width of harmonic radiation; q - harmonic order; p - effective order of nonlinearity. (Note the term in brackets, the phase-matching function, has been separated from the rest of the expression in order to be consistent with the relevant literature)

  7. Efficient visualization of high-throughput targeted proteomics experiments: TAPIR.

    Science.gov (United States)

    Röst, Hannes L; Rosenberger, George; Aebersold, Ruedi; Malmström, Lars

    2015-07-15

    Targeted mass spectrometry comprises a set of powerful methods to obtain accurate and consistent protein quantification in complex samples. To fully exploit these techniques, a cross-platform and open-source software stack based on standardized data exchange formats is required. We present TAPIR, a fast and efficient Python visualization software for chromatograms and peaks identified in targeted proteomics experiments. The input formats are open, community-driven standardized data formats (mzML for raw data storage and TraML encoding the hierarchical relationships between transitions, peptides and proteins). TAPIR is scalable to proteome-wide targeted proteomics studies (as enabled by SWATH-MS), allowing researchers to visualize high-throughput datasets. The framework integrates well with existing automated analysis pipelines and can be extended beyond targeted proteomics to other types of analyses. TAPIR is available for all computing platforms under the 3-clause BSD license at https://github.com/msproteomicstools/msproteomicstools. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  8. A Novel High Efficiency Fractal Multiview Video Codec

    Directory of Open Access Journals (Sweden)

    Shiping Zhu

    2015-01-01

    Full Text Available Multiview video which is one of the main types of three-dimensional (3D video signals, captured by a set of video cameras from various viewpoints, has attracted much interest recently. Data compression for multiview video has become a major issue. In this paper, a novel high efficiency fractal multiview video codec is proposed. Firstly, intraframe algorithm based on the H.264/AVC intraprediction modes and combining fractal and motion compensation (CFMC algorithm in which range blocks are predicted by domain blocks in the previously decoded frame using translational motion with gray value transformation is proposed for compressing the anchor viewpoint video. Then temporal-spatial prediction structure and fast disparity estimation algorithm exploiting parallax distribution constraints are designed to compress the multiview video data. The proposed fractal multiview video codec can exploit temporal and spatial correlations adequately. Experimental results show that it can obtain about 0.36 dB increase in the decoding quality and 36.21% decrease in encoding bitrate compared with JMVC8.5, and the encoding time is saved by 95.71%. The rate-distortion comparisons with other multiview video coding methods also demonstrate the superiority of the proposed scheme.

  9. Dissolution-recrystallization method for high efficiency perovskite solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Han, Fei; Luo, Junsheng; Wan, Zhongquan; Liu, Xingzhao; Jia, Chunyang, E-mail: cyjia@uestc.edu.cn

    2017-06-30

    Highlights: • Dissolution-recrystallization method can improve perovskite crystallization. • Dissolution-recrystallization method can improve TiO{sub 2}/perovskite interface. • The optimal perovskite solar cell obtains the champion PCE of 16.76%. • The optimal devices are of high reproducibility. - Abstract: In this work, a dissolution-recrystallization method (DRM) with chlorobenzene and dimethylsulfoxide treating the perovskite films during the spin-coating process is reported. This is the first time that DRM is used to control perovskite crystallization and improve the device performance. Furthermore, the DRM is good for reducing defects and grain boundaries, improving perovskite crystallization and even improving TiO{sub 2}/perovskite interface. By optimizing, the DRM2-treated perovskite solar cell (PSC) obtains the best photoelectric conversion efficiency (PCE) of 16.76% under AM 1.5 G illumination (100 mW cm{sup −2}) with enhanced J{sub sc} and V{sub oc} compared to CB-treated PSC.

  10. Production of a high-efficiency TILLING population through polyploidization.

    Science.gov (United States)

    Tsai, Helen; Missirian, Victor; Ngo, Kathie J; Tran, Robert K; Chan, Simon R; Sundaresan, Venkatesan; Comai, Luca

    2013-04-01

    Targeting Induced Local Lesions in Genomes (TILLING) provides a nontransgenic method for reverse genetics that is widely applicable, even in species where other functional resources are missing or expensive to build. The efficiency of TILLING, however, is greatly facilitated by high mutation density. Species vary in the number of mutations induced by comparable mutagenic treatments, suggesting that genetic background may affect the response. Allopolyploid species have often yielded higher mutation density than diploids. To examine the effect of ploidy, we autotetraploidized the Arabidopsis (Arabidopsis thaliana) ecotype Columbia, whose diploid has been used for TILLING extensively, and mutagenized it with 50 mm ethylmethane sulfonate. While the same treatment sterilized diploid Columbia, the tetraploid M1 plants produced good seed. To determine the mutation density, we searched 528 individuals for induced mutations in 15 genes for which few or no knockout alleles were previously available. We constructed tridimensional pools from the genomic DNA of M2 plants, amplified target DNA, and subjected them to Illumina sequencing. The results were analyzed with an improved version of the mutation detection software CAMBa that accepts any pooling scheme. This small population provided a rich resource with approximately 25 mutations per queried 1.5-kb fragment, including on average four severe missense and 1.3 truncation mutations. The overall mutation density of 19.4 mutations Mb(-1) is 4 times that achieved in the corresponding diploid accession, indicating that genomic redundancy engenders tolerance to high mutation density. Polyploidization of diploids will allow the production of small populations, such as less than 2,000, that provide allelic series from knockout to mild loss of function for virtually all genes.

  11. High efficiency Dual-Cycle Conversion System using Kr-85.

    Science.gov (United States)

    Prelas, Mark A; Tchouaso, Modeste Tchakoua

    2018-04-26

    This paper discusses the use of one of the safest isotopes known isotopes, Kr-85, as a candidate fuel source for deep space missions. This isotope comes from 0.286% of fission events. There is a vast quantity of Kr-85 stored in spent fuel and it is continually being produced by nuclear reactors. In using Kr-85 with a novel Dual Cycle Conversion System (DCCS) it is feasible to boost the system efficiency from 26% to 45% over a single cycle device while only increasing the system mass by less than 1%. The Kr-85 isotope is the ideal fuel for a Photon Intermediate Direct Energy Conversion (PIDEC) system. PIDEC is an excellent choice for the top cycle in a DCCS. In the top cycle, ionization and excitation of the Kr-85:Cl gas mixture (99% Kr and 1% Cl) from beta particles creates KrCl* excimer photons which are efficiently absorbed by diamond photovoltaic cells on the walls of the pressure vessels. The benefit of using the DCCS is that Kr-85 is capable of operating at high temperatures in the primary cycle and the residual heat can then be converted into electrical power in the bottom cycle which uses a Stirling Engine. The design of the DCCS begins with a spherical pressure vessel of radius 13.7 cm with 3.7 cm thick walls and is filled with a Kr-85:Cl gas mixture. The inner wall has diamond photovoltaic cells attached to it and there is a sapphire window between the diamond photovoltaic cells and the Kr-85:Cl gas mixture which shields the photovoltaic cells from beta particles. The DCCS without a gamma ray shield has specific power of 6.49 W/kg. A removable 6 cm thick tungsten shield is used to safely limit the radiation exposure levels of personnel. A shadow shield remains in the payload to protect the radiation sensitive components in the flight package. The estimated specific power of the unoptimized system design in this paper is about 2.33 W/kg. The specific power of an optimized system should be higher. The Kr-85 isotope is relatively safe because it

  12. Advanced Nanomaterials for High-Efficiency Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Junhong [University of Wisconsin-Milwaukee

    2013-11-29

    Energy supply has arguably become one of the most important problems facing humankind. The exponential demand for energy is evidenced by dwindling fossil fuel supplies and record-high oil and gas prices due to global population growth and economic development. This energy shortage has significant implications to the future of our society, in addition to the greenhouse gas emission burden due to consumption of fossil fuels. Solar energy seems to be the most viable choice to meet our clean energy demand given its large scale and clean/renewable nature. However, existing methods to convert sun light into electricity are not efficient enough to become a practical alternative to fossil fuels. This DOE project aims to develop advanced hybrid nanomaterials consisting of semiconductor nanoparticles (quantum dots or QDs) supported on graphene for cost-effective solar cells with improved conversion efficiency for harvesting abundant, renewable, clean solar energy to relieve our global energy challenge. Expected outcomes of the project include new methods for low-cost manufacturing of hybrid nanostructures, systematic understanding of their properties that can be tailored for desired applications, and novel photovoltaic cells. Through this project, we have successfully synthesized a number of novel nanomaterials, including vertically-oriented graphene (VG) sheets, three-dimensional (3D) carbon nanostructures comprising few-layer graphene (FLG) sheets inherently connected with CNTs through sp{sup 2} carbons, crumpled graphene (CG)-nanocrystal hybrids, CdSe nanoparticles (NPs), CdS NPs, nanohybrids of metal nitride decorated on nitrogen-doped graphene (NG), QD-carbon nanotube (CNT) and QD-VG-CNT structures, TiO{sub 2}-CdS NPs, and reduced graphene oxide (RGO)-SnO{sub 2} NPs. We further assembled CdSe NPs onto graphene sheets and investigated physical and electronic interactions between CdSe NPs and the graphene. Finally we have demonstrated various applications of these

  13. Physical Basis for Interfacial Traction-Separation Models

    International Nuclear Information System (INIS)

    Neville R. Moody

    2002-01-01

    Many weapon components contain interfaces between dissimilar materials where cracks can initiate and cause failure. In recent years many researchers in the fracture community have adopted a cohesive zone model for simulating crack propagation (based upon traction-separation relations) Sandia is implementing this model in its ASCI codes. There is, however, one important obstacle to using a cohesive zone modeling approach. At the present time traction-separation relations are chosen in an ad hoc manner. The goal of the present work is to determine a physical basis for Traction-Separation (T-U) relations. This report presents results of a program aimed at determining the dependence of such relations on adhesive and bulk properties. The work focused on epoxy/solid interfaces, although the approach is applicable to a broad range of materials. Asymmetric double cantilevered beam and free surface film nanoindentation fracture toughness tests were used to generate a unique set of data spanning length scales, applied mode mixities, and yield (plastic) zone constraint. The crucial roles of crack tip plastic zone size and interfacial adhesion were defined by varying epoxy layer thickness and using coupling agents or special self-assembled monolayers in preparing the samples. The nature of the yield zone was probed in collaborative experiments run at the Advanced Photon Source. This work provides an understanding of the major phenomena governing polymer/solid interfacial fracture and identifies the essential features that must be incorporated in a T-U based cohesive zone failure model. We believe that models using physically based T-U relations provide a more accurate and widely applicable description of interface cracking than models using ad hoc relations. Furthermore, these T-U relations provide an essential tool for using models to tailor interface properties to meet design needs

  14. EVALUATION OF A LOW FRICTION - HIGH EFFICIENCY ROLLER BEARING ENGINE

    Energy Technology Data Exchange (ETDEWEB)

    Kolarik, Robert V. II; Shattuck, Charles W.; Copper, Anthony P.

    2009-06-30

    This Low Friction (High Efficiency Roller Bearing) Engine (LFE) report presents the work done by The Timken Company to conduct a technology demonstration of the benefits of replacing hydrodynamic bearings with roller bearings in the crankshaft and camshaft assemblies of an internal combustion engine for the purpose of collecting data sufficient to prove merit. The engines in the present study have been more extensively converted to roller bearings than any previous studies (40 needle roller bearings per engine) to gain understanding of the full potential of application of bearing technology. The project plan called for comparative testing of a production vehicle which was already respected for having demonstrated low engine friction levels with a rollerized version of that engine. Testing was to include industry standard tests for friction, emissions and fuel efficiency conducted on instrumented dynamometers. Additional tests for fuel efficiency, cold start resistance and other measures of performance were to be made in the actual vehicle. Comparative measurements of noise, vibration and harshness (NVH), were planned, although any work to mitigate the suspected higher NVH level in the rollerized engine was beyond the scope of this project. Timken selected the Toyota Avalon with a 3.5L V-6 engine as the test vehicle. In an attempt to minimize cost and fabrication time, a ‘made-from’ approach was proposed in which as many parts as possible would be used or modified from production parts to create the rollerized engine. Timken commissioned its test partner, FEV Engine Technology, to do a feasibility study in which they confirmed that using such an approach was possible to meet the required dimensional restrictions and tolerances. In designing the roller bearing systems for the crank and cam trains, Timken utilized as many production engine parts as possible. The crankshafts were produced from production line forgings, which use Timken steel, modified with special

  15. Effective Maxillary Protraction with Tandem Traction Bow Appliance

    Directory of Open Access Journals (Sweden)

    Pravin Kumar S Marure

    2014-01-01

    Full Text Available Tandem traction bow appliance (TTBA promotes patient compliance, because it is more esthetic and comfortable than extraoral appliances. TTBA should be used only in case where maxillary deficiency and normal mandible is present. Advantages of it includes good oral hygiene, early treatment of any Class III malocclusion, optimal retention, distribution of the forces for protraction to all maxillary teeth, free mandibular movement. It can be used in conjunction with fixed appliances if necessary. This paper includes two case reports. The treatment results in both the cases demonstrated significant skeletal and dental response to TTBA therapy. Skeletal change was primarily a result of anterior movement of the maxilla.

  16. Traction Control Study for a Scaled Automated Robotic Car

    OpenAIRE

    Morton, Mark A.

    2004-01-01

    This thesis presents the use of sliding mode control applied to a 1/10th scale robotic car to operate at a desired slip. Controlling the robot car at any desired slip has a direct relation to the amount of force that is applied to the driving wheels based on road surface conditions. For this model, the desired traction/slip is maintained for a specific surface which happens to be a Lego treadmill platform. How the platform evolved and the robot car was designed are also covered. To parame...

  17. A New Very-High-Efficiency R4 Converter for High-Power Fuel Cell Applications

    DEFF Research Database (Denmark)

    Nymand, Morten; Andersen, Michael Andreas E.

    2009-01-01

    of fullbridge switching stages and power transformers, operate in parallel on primary side and in series on secondary side. Current sharing is guaranteed by series connection of transformer secondary windings and three small cascaded current balancing transformers on primary side. The detailed design of a 10 k......W prototype converter is presented. Input voltage range is 30-60 V and output voltage is 800 V. Test results, including voltage- and current waveforms and efficiency measurements, are presented. A record high converter efficiency of 98.2 % is achieved. The proposed R4 boost converter thus constitutes a low...

  18. 3.0 T MR imaging of the ankle: Axial traction for morphological cartilage evaluation, quantitative T2 mapping and cartilage diffusion imaging—A preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Jungmann, Pia M., E-mail: pia.jungmann@tum.de [Department of Radiology, Klinikum rechts der Isar, Technische Universitaet Muenchen, Ismaninger Strasse 22, 81675 Munich (Germany); Baum, Thomas, E-mail: thomas.baum@tum.de [Department of Radiology, Klinikum rechts der Isar, Technische Universitaet Muenchen, Ismaninger Strasse 22, 81675 Munich (Germany); Schaeffeler, Christoph, E-mail: schaeffeler@me.com [Department of Radiology, Klinikum rechts der Isar, Technische Universitaet Muenchen, Ismaninger Strasse 22, 81675 Munich (Germany); Musculoskeletal Imaging, Kantonsspital Graubuenden, Loestrasse 170, CH-7000 Chur (Switzerland); Sauerschnig, Martin, E-mail: martin.sauerschnig@mri.tum.de [Department of Trauma Surgery, Klinikum rechts der Isar, Technische Universitaet Muenchen, Ismaninger Strasse 22, 81675 Munich (Germany); Department of Orthopaedic Sports Medicine, Klinikum rechts der Isar, Technische Universitaet Muenchen, Ismaninger Strasse 22, 81675 Munich (Germany); Brucker, Peter U., E-mail: peter.brucker@lrz.tu-muenchen.de [Department of Orthopaedic Sports Medicine, Klinikum rechts der Isar, Technische Universitaet Muenchen, Ismaninger Strasse 22, 81675 Munich (Germany); Mann, Alexander, E-mail: abmann@onlinemed.de [Department of Radiology, Klinikum rechts der Isar, Technische Universitaet Muenchen, Ismaninger Strasse 22, 81675 Munich (Germany); Department of Orthopaedic Sports Medicine, Klinikum rechts der Isar, Technische Universitaet Muenchen, Ismaninger Strasse 22, 81675 Munich (Germany); Ganter, Carl, E-mail: cganter@tum.de [Department of Radiology, Klinikum rechts der Isar, Technische Universitaet Muenchen, Ismaninger Strasse 22, 81675 Munich (Germany); Bieri, Oliver, E-mail: oliver.bieri@unibas.ch [Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Petersgraben 4, 4031 Basel (Switzerland); and others

    2015-08-15

    Highlights: • Axial traction is applicable during high resolution MR imaging of the ankle. • Axial traction during MR imaging oft the ankle improves cartilage surface delineation of the individual tibial and talar cartilage layer for better morphological evaluation without the need of intraarticular contrast agent application. • Coronal T1-weighted MR images with a driven equilibrium pulse performed best. • Axial traction during MR imaging of the ankle facilitates compartment discrimination for segmentation purposes resulting in better reproducibility. - Abstract: Purpose: To determine the impact of axial traction during high resolution 3.0 T MR imaging of the ankle on morphological assessment of articular cartilage and quantitative cartilage imaging parameters. Materials and Methods: MR images of n = 25 asymptomatic ankles were acquired with and without axial traction (6 kg). Coronal and sagittal T1-weighted (w) turbo spin echo (TSE) sequences with a driven equilibrium pulse and sagittal fat-saturated intermediate-w (IMfs) TSE sequences were acquired for morphological evaluation on a four-point scale (1 = best, 4 = worst). For quantitative assessment of cartilage degradation segmentation was performed on 2D multislice-multiecho (MSME) SE T2, steady-state free-precession (SSFP; n = 8) T2 and SSFP diffusion-weighted imaging (DWI; n = 8) images. Wilcoxon-tests and paired t-tests were used for statistical analysis. Results: With axial traction, joint space width increased significantly and delineation of cartilage surfaces was rated superior (P < 0.05). Cartilage surfaces were best visualized on coronal T1-w images (P < 0.05). Differences for cartilage matrix evaluation were smaller. Subchondral bone evaluation, motion artifacts and image quality were not significantly different between the acquisition methods (P > 0.05). T2 values were lower at the tibia than at the talus (P < 0.001). Reproducibility was better for images with axial traction. Conclusion

  19. 3.0 T MR imaging of the ankle: Axial traction for morphological cartilage evaluation, quantitative T2 mapping and cartilage diffusion imaging—A preliminary study

    International Nuclear Information System (INIS)

    Jungmann, Pia M.; Baum, Thomas; Schaeffeler, Christoph; Sauerschnig, Martin; Brucker, Peter U.; Mann, Alexander; Ganter, Carl; Bieri, Oliver

    2015-01-01

    Highlights: • Axial traction is applicable during high resolution MR imaging of the ankle. • Axial traction during MR imaging oft the ankle improves cartilage surface delineation of the individual tibial and talar cartilage layer for better morphological evaluation without the need of intraarticular contrast agent application. • Coronal T1-weighted MR images with a driven equilibrium pulse performed best. • Axial traction during MR imaging of the ankle facilitates compartment discrimination for segmentation purposes resulting in better reproducibility. - Abstract: Purpose: To determine the impact of axial traction during high resolution 3.0 T MR imaging of the ankle on morphological assessment of articular cartilage and quantitative cartilage imaging parameters. Materials and Methods: MR images of n = 25 asymptomatic ankles were acquired with and without axial traction (6 kg). Coronal and sagittal T1-weighted (w) turbo spin echo (TSE) sequences with a driven equilibrium pulse and sagittal fat-saturated intermediate-w (IMfs) TSE sequences were acquired for morphological evaluation on a four-point scale (1 = best, 4 = worst). For quantitative assessment of cartilage degradation segmentation was performed on 2D multislice-multiecho (MSME) SE T2, steady-state free-precession (SSFP; n = 8) T2 and SSFP diffusion-weighted imaging (DWI; n = 8) images. Wilcoxon-tests and paired t-tests were used for statistical analysis. Results: With axial traction, joint space width increased significantly and delineation of cartilage surfaces was rated superior (P < 0.05). Cartilage surfaces were best visualized on coronal T1-w images (P < 0.05). Differences for cartilage matrix evaluation were smaller. Subchondral bone evaluation, motion artifacts and image quality were not significantly different between the acquisition methods (P > 0.05). T2 values were lower at the tibia than at the talus (P < 0.001). Reproducibility was better for images with axial traction. Conclusion

  20. Safety and efficacy of endoscopic submucosal dissection using IT knife nano with clip traction method for early esophageal squamous cell carcinoma.

    Science.gov (United States)

    Kitagawa, Yoshiyasu; Suzuki, Takuto; Hara, Taro; Yamaguchi, Taketo

    2018-01-01

    Although endoscopic submucosal dissection (ESD) is an accepted and established treatment for early esophageal squamous cell carcinoma (EESCC), it is technically difficult, time consuming, and less safe than endoscopic mucosal resection. To perform ESD safely and more efficiently, we proposed a new technique of esophageal ESD using an IT knife nano with the clip traction method. This study aimed to evaluate the efficacy and safety of ESD using this new technique. We retrospectively reviewed all consecutive cases of esophageal ESD performed using an IT knife nano with the clip traction method at our hospital between March 2013 and January 2017. Therapeutic efficacy and safety were also assessed. A total of 103 patients underwent esophageal ESD using the IT knife nano with the clip traction method. In all cases, we performed en bloc resection. Complete resection was achieved in 100 cases (97.1%). The median operating time was 40 (range 13-230) min. No cases of perforation or delayed bleeding occurred. Although two cases (2.0%) of mediastinal emphysema occurred without visible perforation at endoscopy, all were successfully managed conservatively. The new technique of esophageal ESD using the IT knife nano with the clip traction method appears to be feasible, effective, and safe for EESCC treatment.

  1. Usefulness of MR arthrography of the hip with leg traction in the evaluation of ligamentum teres injuries

    Energy Technology Data Exchange (ETDEWEB)

    Cerezal, Luis; Fernandez-Hernando, Moises [Department of Radiology, Diagnostico Medico Cantabria, Santander, Cantabria (Spain); Perez Carro, Luis [Learnig Trauma Med. Centro de Consultas Medicas CCM, Orthopedic Surgery department, Santander (Spain); Llorca, Javier [University of Cantabria - IDIVAL, Santander (Spain); CIBER Epidemiology and Public Health, Santander (Spain); Llopis, Eva [Alzira Hospital, Department of Radiology, Valencia (Spain); Montero, Juan Antonio [Cantabria University, Anatomy and Cell Biology, Santander (Spain); Canga, Ana [Cantabria University, Anatomy and Cell Biology, Santander (Spain); Department of Radiology Marques de Valdecilla University Hospital, Santander, Cantabria (Spain)

    2015-11-15

    To retrospectively evaluate the diagnostic accuracy of magnetic resonance (MR) arthrography of the hip with leg traction in the evaluation of ligamentum teres lesions and to evaluate whether there is increased articular distraction, possibly indicating secondary instability, in hips with ligamentum teres injuries. Institutional review board approval and informed consent were obtained for this retrospective study. MR arthrograms of the hip with leg traction of 184 consecutive patients, including 108 men (mean age, 32.6 years; range, 19-53 years) and 76 women (mean age, 38.5 years; range, 18-56 years), who underwent hip arthroscopy were assessed for the presence of ligamentum teres lesions. The MR arthrographic findings were independently assessed by two radiologists who were blinded to the arthroscopic results. The inclusion criteria stipulated no previous surgery, arthroscopy within 1 month after MR arthrography, and availability of a detailed surgical report with ligamentum teres findings. The arthroscopy findings served as the reference standard. Sensitivity, specificity, accuracy, and K statistics for interobserver and intraobserver agreement were calculated. At arthroscopy, 32 ligamentum teres injuries were found. The ligamentum teres was normal in 152 (82.6 %) patients and had suffered low-grade partial tears in 15 (8.1 %) patients, high-grade partial tears in 10 (5.4 %) patients, and complete ruptures in 7 (3.8 %) patients. MR arthrography with axial traction demonstrated moderate sensitivity and high specificity for both low-grade (62/93 %) and high-grade (66/96 %) partial tears. Grouping low- and high-grade partial tears increased the diagnostic performance of MR arthrography, yielding a sensitivity of 87 % and a specificity of 95 %. For complete ligamentum teres tears, MR arthrography with leg traction demonstrated high sensitivity (92 %) and specificity (98 %). Articular distraction was significantly increased in patients with complete ruptures of the

  2. Usefulness of MR arthrography of the hip with leg traction in the evaluation of ligamentum teres injuries

    International Nuclear Information System (INIS)

    Cerezal, Luis; Fernandez-Hernando, Moises; Perez Carro, Luis; Llorca, Javier; Llopis, Eva; Montero, Juan Antonio; Canga, Ana

    2015-01-01

    To retrospectively evaluate the diagnostic accuracy of magnetic resonance (MR) arthrography of the hip with leg traction in the evaluation of ligamentum teres lesions and to evaluate whether there is increased articular distraction, possibly indicating secondary instability, in hips with ligamentum teres injuries. Institutional review board approval and informed consent were obtained for this retrospective study. MR arthrograms of the hip with leg traction of 184 consecutive patients, including 108 men (mean age, 32.6 years; range, 19-53 years) and 76 women (mean age, 38.5 years; range, 18-56 years), who underwent hip arthroscopy were assessed for the presence of ligamentum teres lesions. The MR arthrographic findings were independently assessed by two radiologists who were blinded to the arthroscopic results. The inclusion criteria stipulated no previous surgery, arthroscopy within 1 month after MR arthrography, and availability of a detailed surgical report with ligamentum teres findings. The arthroscopy findings served as the reference standard. Sensitivity, specificity, accuracy, and K statistics for interobserver and intraobserver agreement were calculated. At arthroscopy, 32 ligamentum teres injuries were found. The ligamentum teres was normal in 152 (82.6 %) patients and had suffered low-grade partial tears in 15 (8.1 %) patients, high-grade partial tears in 10 (5.4 %) patients, and complete ruptures in 7 (3.8 %) patients. MR arthrography with axial traction demonstrated moderate sensitivity and high specificity for both low-grade (62/93 %) and high-grade (66/96 %) partial tears. Grouping low- and high-grade partial tears increased the diagnostic performance of MR arthrography, yielding a sensitivity of 87 % and a specificity of 95 %. For complete ligamentum teres tears, MR arthrography with leg traction demonstrated high sensitivity (92 %) and specificity (98 %). Articular distraction was significantly increased in patients with complete ruptures of the

  3. Properties and toxicological effects of particles from the interaction between tyres, road pavement and winter traction material

    Energy Technology Data Exchange (ETDEWEB)

    Gustafsson, Mats [Swedish National Road and Transport Research Institute (VTI), SE-581 95 Linkoeping (Sweden)], E-mail: mats.gustafsson@vti.se; Blomqvist, Goeran [Swedish National Road and Transport Research Institute (VTI), SE-581 95 Linkoeping (Sweden); Gudmundsson, Anders; Dahl, Andreas [Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, P.O. Box 118, SE-221 00 Lund (Sweden); Swietlicki, Erik [Division of Nuclear Physics, Department of Physics, Lund University, P.O. Box 118, SE-221 00 Lund (Sweden); Bohgard, Mats [Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, P.O. Box 118, SE-221 00 Lund (Sweden); Lindbom, John; Ljungman, Anders [Faculty of Health Sciences, Department of Molecular and Clinical Medicine, Division of Occupational and Environmental Medicine, SE-581 85 Linkoeping (Sweden)

    2008-04-15

    In regions where studded tyres and traction material are used during winter, e.g. the Nordic countries, northern part of USA, Canada, and Japan, mechanically generated particles from traffic are the main reason for high particle mass concentrations in busy street and road environments. In many Nordic municipalities the European environmental quality standard for inhalable particles (PM{sub 10}) is exceeded due to these particles. In this study, particles from the wear of studded and studless friction tyres on two pavements and traction sanding were generated using a road simulator. The particles were characterized using particle sizers, Particle Induced X-Ray Emission Analysis and electron microscopy. Cell studies were conducted on particles sampled from the tests with studded tyres and compared with street environment, diesel exhaust and subway PM{sub 10}, respectively. The results show that in the road simulator, where resuspension is minimized, studded tyres produce tens of times more particles than friction tyres. Chemical analysis of the sampled particles shows that the generated wear particles consist almost entirely of minerals from the pavement stone material, but also that Sulfur is enriched for the submicron particles and that Zink is enriched for friction tyres for all particles sizes. The chemical data can be used for source identification and apportionment in urban aerosol studies. A mode of ultra-fine particles was also present and is hypothesised to originate in the tyres. Further, traction material properties affect PM{sub 10} emission. The inflammatory potential of the particles from wear of pavements seems to depend on type of pavement and can be at least as potent as diesel exhaust particles. The results imply that there is a need and a good potential to reduce particle emission from pavement wear and winter time road and street operation by adjusting both studded tyre use as well as pavement and traction material properties.

  4. Properties and toxicological effects of particles from the interaction between tyres, road pavement and winter traction material

    International Nuclear Information System (INIS)

    Gustafsson, Mats; Blomqvist, Goeran; Gudmundsson, Anders; Dahl, Andreas; Swietlicki, Erik; Bohgard, Mats; Lindbom, John; Ljungman, Anders

    2008-01-01

    In regions where studded tyres and traction material are used during winter, e.g. the Nordic countries, northern part of USA, Canada, and Japan, mechanically generated particles from traffic are the main reason for high particle mass concentrations in busy street and road environments. In many Nordic municipalities the European environmental quality standard for inhalable particles (PM 10 ) is exceeded due to these particles. In this study, particles from the wear of studded and studless friction tyres on two pavements and traction sanding were generated using a road simulator. The particles were characterized using particle sizers, Particle Induced X-Ray Emission Analysis and electron microscopy. Cell studies were conducted on particles sampled from the tests with studded tyres and compared with street environment, diesel exhaust and subway PM 10 , respectively. The results show that in the road simulator, where resuspension is minimized, studded tyres produce tens of times more particles than friction tyres. Chemical analysis of the sampled particles shows that the generated wear particles consist almost entirely of minerals from the pavement stone material, but also that Sulfur is enriched for the submicron particles and that Zink is enriched for friction tyres for all particles sizes. The chemical data can be used for source identification and apportionment in urban aerosol studies. A mode of ultra-fine particles was also present and is hypothesised to originate in the tyres. Further, traction material properties affect PM 10 emission. The inflammatory potential of the particles from wear of pavements seems to depend on type of pavement and can be at least as potent as diesel exhaust particles. The results imply that there is a need and a good potential to reduce particle emission from pavement wear and winter time road and street operation by adjusting both studded tyre use as well as pavement and traction material properties

  5. Highly efficient DNA extraction method from skeletal remains

    Directory of Open Access Journals (Sweden)

    Irena Zupanič Pajnič

    2011-03-01

    Full Text Available Background: This paper precisely describes the method of DNA extraction developed to acquire high quality DNA from the Second World War skeletal remains. The same method is also used for molecular genetic identification of unknown decomposed bodies in routine forensic casework where only bones and teeth are suitable for DNA typing. We analysed 109 bones and two teeth from WWII mass graves in Slovenia. Methods: We cleaned the bones and teeth, removed surface contaminants and ground the bones into powder, using liquid nitrogen . Prior to isolating the DNA in parallel using the BioRobot EZ1 (Qiagen, the powder was decalcified for three days. The nuclear DNA of the samples were quantified by real-time PCR method. We acquired autosomal genetic profiles and Y-chromosome haplotypes of the bones and teeth with PCR amplification of microsatellites, and mtDNA haplotypes 99. For the purpose of traceability in the event of contamination, we prepared elimination data bases including genetic profiles of the nuclear and mtDNA of all persons who have been in touch with the skeletal remains in any way. Results: We extracted up to 55 ng DNA/g of the teeth, up to 100 ng DNA/g of the femurs, up to 30 ng DNA/g of the tibias and up to 0.5 ng DNA/g of the humerus. The typing of autosomal and YSTR loci was successful in all of the teeth, in 98 % dekalof the femurs, and in 75 % to 81 % of the tibias and humerus. The typing of mtDNA was successful in all of the teeth, and in 96 % to 98 % of the bones. Conclusions: We managed to obtain nuclear DNA for successful STR typing from skeletal remains that were over 60 years old . The method of DNA extraction described here has proved to be highly efficient. We obtained 0.8 to 100 ng DNA/g of teeth or bones and complete genetic profiles of autosomal DNA, Y-STR haplotypes, and mtDNA haplotypes from only 0.5g bone and teeth samples.

  6. Exciplex-Forming Cohost for High Efficiency and High Stability Phosphorescent Organic Light-Emitting Diodes.

    Science.gov (United States)

    Shih, Chun-Jen; Lee, Chih-Chien; Chen, Ying-Hao; Biring, Sajal; Kumar, Gautham; Yeh, Tzu-Hung; Sen, Somaditya; Liu, Shun-Wei; Wong, Ken-Tsung

    2018-01-17

    An exciplex forming cohost system is employed to achieve a highly efficient organic light-emitting diode (OLED) with good electroluminescent lifetime. The exciplex is formed at the interfacial contact of a conventional star-shaped carbazole hole-transporting material, 4,4',4″-tris(N-carbazolyl)-triphenylamine (TCTA), and a triazine electron-transporting material, 2,4,6-tris[3-(1H-pyrazol-1-yl)phenyl]-1,3,5-triazine (3P-T2T). The excellent combination of TCTA and 3P-T2T is applied as the cohost of a common green phosphorescent emitter with almost zero energy loss. When Ir(ppy) 2 (acac) is dispersed in such exciplex cohost system, OLED device with maximum external quantum efficiency of 29.6%, the ultrahigh power efficiency of 147.3 lm/W, and current efficiency of 107 cd/A were successfully achieved. More importantly, the OLED device showed a low-efficiency roll-off and an operational lifetime (τ 80 ) of ∼1020 min with the initial brightness of 2000 cd/m 2 , which is 56 times longer than the reference device. The significant difference of device stability was attributed to the degradation of exciplex system for energy transfer process, which was investigated by the photoluminescence aging measurement at room temperature and 100 K, respectively.

  7. Traction calculation of band conveyors using the ''Nairi-2'' computer

    Energy Technology Data Exchange (ETDEWEB)

    Kutlunin, V A; Livshis, A V; Pod' yemshchikov, A N

    1982-01-01

    An algorithm is described and a program is introduced for traction calculation of band conveyors using the ''Nairi-2'' computer. The calculation system of the conveyor is derived by means of dividing the closed loop of the band into straight sections, which are separated by drums. The number of sections depends on the number of drums, the bypass system of them by the band, the shape of the conveyor route and in each specific case, a specific number is chosen. The initial information for the computer is assigned by a matrix, each row of which consists of parameters of the corresponding section. As a result, the forces of the beginning and end of the sections are found, and the required output of the drive motors with observance of the conditions of non-slippage of the drive drums and limiting of the maximum slack of the band between rollers are also found. The program allows one to make traction calculations of band conveyors with any routing shape for any number and position of the drive drums.

  8. MONITORING OF ELECTRICAL ENERGY QUALITY ON THE TRACTION SUBSTATION INPUT

    Directory of Open Access Journals (Sweden)

    O.G. Gryb

    2015-12-01

    Full Text Available For the implementation of measures to maintain the quality of the energy industrial enterprises have to spend a significant material and monetary assets. In this regard, significant is the feasibility study of the allocation of such funds and, primarily, the determination of the economic damage arising from low quality of electricity. The reliability of the electricity metering system, relay protection and automation of modern digital substations depends on the quality of electrical energy. At the present time to improve the reliability of the substation operation it is necessary to monitor indicators of quality of electric energy, allowing you to take organizational and technical solutions for their improvement. Monitoring the power quality at the input traction substation has shown that indicators such as the coefficient of the n-th harmonic component of the voltage does not meet the standards GOST 13109-97. The source of higher harmonics is a voltage Converter used on the locomotive. To eliminate higher harmonics in the supply network for traction substations will need to install power filters. Today, the USB-analyzer of power quality «Digital measurement system of power quality» type of CSICE of accuracy class 0.2. Work energy requires reliable and quality electricity supply to consumers. The new model of balancing energy market are bilateral contracts. The main task of this market, it ensure the stable and reliable operation of the unified energy system of Ukraine, that is, transmission and supply of electricity of appropriate quality.

  9. Development of Modified Pag (Polyalkylene Glycol) High VI High Fuel Efficient Lubricant for LDV Applications

    Energy Technology Data Exchange (ETDEWEB)

    Gangopadhyay, Arup [Ford Motor Company, Dearborn, MI (United States); McWatt, D. G. [Ford Motor Company, Dearborn, MI (United States); Zdrodowski, R. J. [Ford Motor Company, Dearborn, MI (United States); Liu, Zak [Ford Motor Company, Dearborn, MI (United States); Elie, Larry [Ford Motor Company, Dearborn, MI (United States); Simko, S. J. [Ford Motor Company, Dearborn, MI (United States); Erdemir, Ali [Argonne National Lab. (ANL), Argonne, IL (United States); Ramirez, Giovanni [Argonne National Lab. (ANL), Argonne, IL (United States); Cuthbert, J. [Dow Chemical Company, Midland, MI (United States); Hock, E. D. [Dow Chemical Company, Midland, MI (United States)

    2015-09-30

    Test Procedure) metro/highway cycles. Five different PAG chemistries were selected by varying the starting alcohol, the oxide monomers (ethylene oxide, propylene oxide, or butylene oxide), capped or uncapped, homopolymer or random copolymer. All formulations contained a proprietary additive package and one which contained additional antiwear and friction modifier additives. Laboratory bench tests (Pin-on-Disk, High Frequency Reciprocating Rig (HFRR), Block-on-Ring, Mini-Traction Machine (MTM) identified formulations having friction, wear, and load carrying characteristics similar to or better than baseline GF-5 SAE 5W-20 oil. Motored valvetrain and motored piston ring friction tests showed nearly 50% friction reduction for some of the PAG formulations compared to GF-5 SAE 5W-20 oil. Motored engine tests showed up to 15% friction benefit over GF-5 SAE 5W-20 oil. It was observed that friction benefits are more related to PAG base oil chemistry than their lower viscosity compared to GF-5 SAE 5W-20 oil. Analysis of wear surfaces from laboratory bench tests and bucket tappets from motored valvetrain tests confirmed the presence of PAG molecules. The adsorption of these polar molecules is believed to be reason for friction reduction. However, the wear surfaces also had thin tribo-film derived from additive components. The tribo-film consisting of phosphates, sulfides, and molybdenum disulfide (when molybdenum additive was present) were observed for both GF-5 SAE 5W-20 and PAG fluids. However, when using PAG fluids, motored valvetrain tests showed high initial wear, which is believed to be due to delay in protective tribo-film formation. After the initial wear, the wear rate of PAG fluids was comparable to GF-5 SAE 5W-20 oil. The PAG oil containing additional antiwear and friction reducing additives showed low initial wear as expected. However, when this oil was evaluated in Sequence IVA test, it showed initially low wear comparable to GF-5 oil but wear accelerated with oil

  10. Functionalized Graphene Enables Highly Efficient Solar Thermal Steam Generation.

    Science.gov (United States)

    Yang, Junlong; Pang, Yunsong; Huang, Weixin; Shaw, Scott K; Schiffbauer, Jarrod; Pillers, Michelle Anne; Mu, Xin; Luo, Shirui; Zhang, Teng; Huang, Yajiang; Li, Guangxian; Ptasinska, Sylwia; Lieberman, Marya; Luo, Tengfei

    2017-06-27

    The ability to efficiently utilize solar thermal energy to enable liquid-to-vapor phase transition has great technological implications for a wide variety of applications, such as water treatment and chemical fractionation. Here, we demonstrate that functionalizing graphene using hydrophilic groups can greatly enhance the solar thermal steam generation efficiency. Our results show that specially functionalized graphene can improve the overall solar-to-vapor efficiency from 38% to 48% at one sun conditions compared to chemically reduced graphene oxide. Our experiments show that such an improvement is a surface effect mainly attributed to the more hydrophilic feature of functionalized graphene, which influences the water meniscus profile at the vapor-liquid interface due to capillary effect. This will lead to thinner water films close to the three-phase contact line, where the water surface temperature is higher since the resistance of thinner water film is smaller, leading to more efficient evaporation. This strategy of functionalizing graphene to make it more hydrophilic can be potentially integrated with the existing macroscopic heat isolation strategies to further improve the overall solar-to-vapor conversion efficiency.

  11. Volume Bragg grating narrowed high-power and highly efficient cladding-pumped Raman fiber laser.

    Science.gov (United States)

    Liu, Jun; Yao, Weichao; Zhao, Chujun; Shen, Deyuan; Fan, Dianyuan

    2014-12-10

    High-power and highly efficient operation of a single-mode cladding-pumped Raman fiber laser with narrow lasing bandwidth is demonstrated. The spectral narrowing was realized by an external cavity containing a volume Bragg grating with a center wavelength of 1658 nm. A maximum output power of 10.4 W at 1658.3 nm with a spectral linewidth (FWHM) of ∼0.1  nm was obtained for the launched pump power of 18.4 W, corresponding to a slope efficiency of 109% with respect to the launched pump power. Lasing characteristics of free-running operation are also evaluated and discussed.

  12. Trial of accelerator cells machining with high precision and high efficiency at Okayama region

    International Nuclear Information System (INIS)

    Yoshikawa, Mitsuo; Yoden, Hiroyuki; Yokomizo, Seiichi; Sumida, Tsuneto; Kunishida, Jun; Oshita, Isao

    2005-01-01

    In the framework of the project 'Promotion of Science and Technology in Regional Areas' by the Ministry of Education, Culture, Sports, Science and Technology, we have prepared a special apparatus for machining accelerator cells with a high precision and a high efficiency for the future linear collider. A machining with as small an error as 2 micrometers has been realized. Necessary time to finish one accelerator cell is reduced from 128 minutes to 34 minutes due to the suppression of the heating of the object at the machining. If newly developed one chuck method was employed, the precision and efficiency would be further improved. By cutting at both sides of the spindle, the necessary time for machining would be reduced by half. (author)

  13. High efficiency and stable white OLED using a single emitter

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jian [Arizona State Univ., Tempe, AZ (United States). School of Mechanical, Aerospace, Chemical and Materials Engineering

    2016-01-18

    The ultimate objective of this project was to demonstrate an efficient and stable white OLED using a single emitter on a planar glass substrate. The focus of the project is on the development of efficient and stable square planar phosphorescent emitters and evaluation of such class of materials in the device settings. Key challenges included improving the emission efficiency of molecular dopants and excimers, controlling emission color of emitters and their excimers, and improving optical and electrical stability of emissive dopants. At the end of this research program, the PI has made enough progress to demonstrate the potential of excimer-based white OLED as a cost-effective solution for WOLED panel in the solid state lighting applications.

  14. Impurity effects in silicon for high efficiency solar cells

    Science.gov (United States)

    Hopkins, R. H.; Rohatgi, A.

    1986-01-01

    Model analyses indicate that sophisticated solar cell designs including, e.g., back surface fields, optical reflectors, surface passivation, and double layer antireflective coatings can produce devices with conversion efficiencies above 20 percent (AM1). To realize this potential, the quality of the silicon from which the cells are made must be improved; and these excellent electrical properties must be maintained during device processing. As the cell efficiency rises, the sensitivity to trace contaminants also increases. For example, the threshold Ti impurity concentration at which cell performance degrades is more than an order of magnitude lower for an 18-percent cell. Similar behavior occurs for numerous other metal species which introduce deep level traps that stimulate the recombination of photogenerated carriers in silicon. Purification via crystal growth in conjunction with gettering steps to preserve the large diffusion length of the as-grown material can lead to the production of devices with efficiencies aboved 18 percent, as has been verified experimentally.

  15. High-efficiency photovoltaic technology including thermoelectric generation

    Science.gov (United States)

    Fisac, Miguel; Villasevil, Francesc X.; López, Antonio M.

    2014-04-01

    Nowadays, photovoltaic solar energy is a clean and reliable source for producing electric power. Most photovoltaic systems have been designed and built up for use in applications with low power requirements. The efficiency of solar cells is quite low, obtaining best results in monocrystalline silicon structures, with an efficiency of about 18%. When temperature rises, photovoltaic cell efficiency decreases, given that the short-circuit current is slightly increased, and the open-circuit voltage, fill factor and power output are reduced. To ensure that this does not affect performance, this paper describes how to interconnect photovoltaic and thermoelectric technology into a single structure. The temperature gradient in the solar panel is used to supply thermoelectric cells, which generate electricity, achieving a positive contribution to the total balance of the complete system.

  16. High-efficiency transmision neutron polarizer for high-resolution double crystal diffractometer

    International Nuclear Information System (INIS)

    Ioffe, A.; Krist, T.; Mezei, F.; Gordeev, G.; Ibrayev, B.

    1997-01-01

    An efficient transmission geometry neutron polarizer for the high-resolution double crystal diffractometer at HMI (λ=4.8 A) is described. A polarization of about 94% was achieved and the polarized neutron beam intensity amounts to 40% of the nonpolarized beam intensity. This opens up wide possibilities for the study of magnetic small-angle scattering for extremely small momentum transfer (Q∝10 -5 A -1 ). (orig.)

  17. A versatile, highly-efficient, high-resolution von Hamos Bragg crystal x-ray spectrometer

    International Nuclear Information System (INIS)

    Vane, C.R.; Smith, M.S.; Raman, S.

    1988-01-01

    An efficient, high-resolution, vertical-focusing, Bragg crystal x-ray spectrometer has been specifically designed and constructed for use in measurements of x rays produced in collisions of energetic heavy ions. In this report the design and resulting operational characteristics of the final instrument are fully described. A wide variety of sample data is also included to illustrate the utility of this device in several areas of research. 14 refs., 38 figs

  18. High-Efficiency, Commercial Ready CdTe Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Sites, James R. [Colorado State Univ., Fort Collins, CO (United States)

    2015-11-19

    Colorado State’s F-PACE project explored several ways to increase the efficiency of CdTe solar cells and to better understand the device physics of those cells under study. Increases in voltage, current, and fill factor resulted in efficiencies above 17%. The three project tasks and additional studies are described in detail in the final report. Most cells studied were fabricated at Colorado State using an industry-compatible single-vacuum closed-space-sublimation (CSS) chamber for deposition of the key semiconductor layers. Additionally, some cells were supplied by First Solar for comparison purposes, and a small number of modules were supplied by Abound Solar.

  19. High-efficiency water-loaded microwave antenna in ultra-high-frequency band

    Science.gov (United States)

    Gong, Zilun; Bartone, Chris; Yang, Fuyi; Yao, Jie

    2018-03-01

    High-index dielectrics are widely used in microwave antennas to control the radiation characteristics. Liquid water, with a high dielectric index at microwave frequency, is an interesting material to achieving tunable functionalities. Here, we demonstrate a water-loaded microwave antenna system that has high loss-tolerance and wideband tunability enabled by fluidity. Our simulation and experimental results show that the resonance frequency can be effectively tuned by the size of loading water. Furthermore, the antenna systems with water loading can achieve high radiation efficiency (>90%) in the ultra-high-frequency (0.3-3 GHz) band. This work brings about opportunities in realistic tunable microwave antenna designs enabled by liquid.

  20. Deep-blue efficient OLED based on NPB with little efficiency roll-off under high current density

    Science.gov (United States)

    Liu, Jian

    2017-03-01

    NPB usually is used as a hole-transport layer in OLED. In fact, it is a standard pure blue-emission material. However, its light-emitting efficiency in OLED is low due to emissive nature of organic material. Herein, a deep-blue OLDE based on NPB was fabricated. The light-emitting efficiency of the device demonstrates a moderate value, and efficiency roll-off is little under high current density. The device demonstrates that the electroplex's emission decreases with increasing electric field intensity.